Ahmad S

References (71)

Title : Chemical Profiling, in-vitro biological evaluation and molecular docking studies of Ruellia tweediana: An unexplored plant - Kanwal_2024_Saudi.Pharm.J_32_101939
Author(s) : Kanwal S , Ahmad S , Yasmin Begum M , Siddiqua A , Rao H , Ghalloo BA , Shahzad MN , Ahmad I , Khan KU
Ref : Saudi Pharm J , 32 :101939 , 2024
Abstract : Many Ruellia species have been utilized in traditional medicine and despite the prevalent use of Ruellia tweediana in folk medicine, its antioxidant potential and polyphenol content have not been investigated. Therefore, the present study aimed to explore the medicinal value of R. tweediana by evaluating its total phenolic (TPC) and flavonoid contents (TFC), GC-MS analysis, antioxidant, antibacterial, and enzyme inhibition activities. The TPC and TFC of the extract/fractions were assessed using the Folin-Ciocalteu and aluminum trichloride methods, respectively. To determine the antioxidant capacity, five different assays were used: DPPH, ABTS, CUPRAC, FRAP, and metal chelating assays. The inhibition activity against alpha-glucosidase, alpha-amylase, cholinesterases, and lipoxygenase enzymes was also analyzed. Furthermore, GC-MS was performed for chemical screening of non-polar fraction. The methanol extract showed the maximum TPC (167.34 +/- 2.23 mg GAE/g) and TFC (120.43 +/- 1.71 mg RE/g) values among all the tested samples. GC-MS screening of the n-hexane fraction showed the presence of 40 different phytoconstituents. The results demonstrated the highest scavenging potential of the methanol extract against DPPH (167.79 +/- 2.75 mg TE/g) and ABTS (255.32 +/- 2.91 mg TE/g) radicals, as well as the metal-reducing capacity measured by CUPRAC (321.34 +/- 3.09 mg TE/g), FRAP (311.32 +/- 2.91 mg TE/g), and metal chelating assay (246.78 +/- 10.34 mg EDTAE/g). Notably, the n-hexane fraction revealed the highest alpha-glucosidase and alpha-amylase inhibition activity (186.8 +/- 2.84 and 179.7 +/- 4.32 mg ACAE/g, respectively) while methanol extract showed highest acetylcholinesterase and butyrylcholinesterase inhibition activity (198.6 +/- 3.31 and 184.3 +/- 2.92 mg GALE/g, respectively). The GC-MS identified Lupeol showed best binding affinity with all docked enzymes as compared to standard compounds. The presence of bioactive phytoconstituents showed by GC-MS underscores the medicinal importance of R. tweediana, making it a promising candidate for natural medicine.
ESTHER : Kanwal_2024_Saudi.Pharm.J_32_101939
PubMedSearch : Kanwal_2024_Saudi.Pharm.J_32_101939
PubMedID: 38261891

Title : Secondary Metabolite Profiling, Antioxidant, Antidiabetic and Neuroprotective Activity of Cestrum nocturnum (Night Scented-Jasmine): Use of In Vitro and In Silico Approach in Determining the Potential Bioactive Compound - Ahmad_2023_Plants.(Basel)_12_
Author(s) : Ahmad S , Alrouji M , Alhajlah S , Alomeir O , Pandey RP , Ashraf MS , Khan S
Ref : Plants (Basel) , 12 : , 2023
Abstract : This study aims to describe the therapeutic potential of C. nocturnum leaf extracts against diabetes and neurological disorders via the targeting of alpha-amylase and acetylcholinesterase (AChE) activities, followed by computational molecular docking studies to establish a strong rationale behind the alpha-amylase and AChE inhibitory potential of C. nocturnum leaves-derived secondary metabolites. In our study, the antioxidant activity of the sequentially extracted C. nocturnum leaves extract was also investigated, in which the methanolic fraction exhibited the strongest antioxidant potential against DPPH (IC(50) 39.12 +/- 0.53 microg/mL) and ABTS (IC(50) 20.94 +/- 0.82 microg/mL) radicals. This extract strongly inhibited the alpha-amylase (IC(50)188.77 +/- 1.67 microg/mL) and AChE (IC(50) 239.44 +/- 0.93 microg/mL) in a non-competitive and competitive manner, respectively. Furthermore, in silico analysis of compounds identified in the methanolic extract of the leaves of C. nocturnum using GC-MS revealed high-affinity binding of these compounds with the catalytic sites of alpha-amylase and AChE, with binding energy ranging from -3.10 to -6.23 kcal/mol and from -3.32 to -8.76 kcal/mol, respectively. Conclusively, the antioxidant, antidiabetic, and anti-Alzheimer activity of this extract might be driven by the synergistic effect of these bioactive phytoconstituents.
ESTHER : Ahmad_2023_Plants.(Basel)_12_
PubMedSearch : Ahmad_2023_Plants.(Basel)_12_
PubMedID: 36986895

Title : Neuroprotective evaluation of diospyrin against drug-induced Alzheimer's disease - Alam_2023_Fitoterapia_171_105703
Author(s) : Alam A , Ali G , Nawaz A , AlOmar TS , Rauf A , Ayaz M , Ahmad S , Almasoud N , AlOmar AS , Khalil AA , Wilairatana P
Ref : Fitoterapia , 171 :105703 , 2023
Abstract : Alzheimer's disease (AD) is a progressive neurodegenerative disease linked to memory impairment. A current investigation was performed to assess the neuroprotective effect of Diospyrin, a novel therapeutic agent, for the curing of Alzheimer's disease. For this purpose, in-vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory assays and antioxidant studies were conducted, whereas in-vivo studies involved different behavioral animal models tests such as elevated plus maze (EPM), morris water maze (MWM) and paddling Y-maze test. Results of the in-vitro analysis showed IC(50) values of 95 microg/mL for AChE and 110 microg/mL for BChE as compared to the standard drug donepezil (IC(50): 95 & 85 microg/mL, respectively). DPPH antioxidant assay showed a maximum of 72.85% inhibition (IC(50): 139.74 microg/mL) of DPPH-free radicals at the highest concentration of 1000 microg/mL as compared to the ascorbic acid (IC(50): 13.72 microg/mL). Moreover, the in-vivo analysis revealed that diospyrin treatment demonstrated gradual betterment in memory and enhanced motor functionality. On the other hand, the computational analysis also showed that the diospyrin had exceptional binding affinities for both AChE and BChE enzymes. In the net shell, it may be deduced that our compound diospyrin could be a valuable drug candidate in managing neurodegenerative disorders like AD.
ESTHER : Alam_2023_Fitoterapia_171_105703
PubMedSearch : Alam_2023_Fitoterapia_171_105703
PubMedID: 37852388

Title : Neuroprotection against Aluminum Chloride-Induced Hippocampus Damage in Albino Wistar Rats by Leucophyllum frutescens (Berl.) I.M. Johnst. Leaf Extracts: A Detailed Insight into Phytochemical Analysis and Antioxidant and Enzyme Inhibition Assays - Ahmad_2023_Front.Biosci.(Landmark.Ed)_28_184
Author(s) : Ahmad I , Ahmad S , Akkol EK , Rao H , Shahzad MN , Nawaz M , Ghalloo BA , Shier WT , Sobarzo-Sanchez E
Ref : Front Biosci (Landmark Ed) , 28 :184 , 2023
Abstract : BACKGROUND: A previously unstudied medicinal plant, Leucophyllum frutescens (Berland.) I.M. Johnst. (Scrophulariaceae) was investigated to evaluate its potential in preventing and treating neurodegenerative diseases, including Alzheimer's disease. METHODS: Methanolic leaf extract (MELE) and its fractions (HELE, CHLE, and BULE) were evaluated for their polyphenolic content and antioxidant activity by five different methods, including in vitro enzyme inhibition assays, which are clinically linked to neurodegenerative diseases. The potentially active n-butanol fraction (BULE) was further evaluated for its neuroprotective effects using an albino rat animal model and phytoconstituents profiling using Liquid chromatography with tandem mass spectrometry (LC-MS/MS), and in silico molecular docking by Maestro(a) Schrodinger. RESULTS: The n-butanol fraction (BULE) in the hydroalcoholic leaf extract exhibited the highest total phenolic content (230.435 +/- 1.575 mg gallic acid equivalent gm-1+/- SD). The chloroform leaf extract exhibited the highest total flavonoid content (293.343 +/- 3.756 mg quercetin equivalent gm-1+/- SD) as well as the highest antioxidant content, which was equivalent to Trolox, with five assay methods. Similarly, the chloroform and n-butanol fractions from the hydroalcoholic leaf extract significantly inhibited human acetylcholinesterase and butyrylcholinesterase with their IC50 values of 12.14 +/- 0.85 and 129.73 +/- 1.14 microgmL-1, respectively. The in vivo study revealed that BULE exhibited a significant neuroprotective effect at doses of 200 and 400 mg/kg/day in an aluminum chloride-induced neurodegenerative albino rat model. The LC-MS/MS analysis of BULE tentatively confirmed the presence of biologically active secondary metabolites, such as theobromine, propyl gallate, quercetin-3-O-glucoside, myricetin-3-acetylrhamnoside, isoquercitrin-6'-O-malonate, diosmetin-7-O-glucuronide-3'-O-pentose, pinoresinol diglucoside, asarinin, eridictoyl, epigallocatechin, methyl gallate derivative, and eudesmin. The results from the computational molecular docking of the identified secondary metabolites revealed that diosmetin-7-O-glucuronide-3'-O-pentose had the highest binding affinity to human butyrylcholinesterase, while isoquercetin-6'-O-malonate had the highest to human acetylcholinesterase, and pinoresinol diglucoside to human salivary alpha-amylase. CONCLUSIONS: The present study concluded a need for further exploration into this medicinal plant, including the isolation of the bioactive compounds responsible for its neuroprotective effects.
ESTHER : Ahmad_2023_Front.Biosci.(Landmark.Ed)_28_184
PubMedSearch : Ahmad_2023_Front.Biosci.(Landmark.Ed)_28_184
PubMedID: 37664939

Title : In Silico Characterization and Analysis of Clinically Significant Variants of Lipase-H (LIPH Gene) Protein Associated with Hypotrichosis - Khan_2023_Pharmaceuticals.(Basel)_16_803
Author(s) : Khan HA , Asif MU , Ijaz MK , Alharbi M , Ali Y , Ahmad F , Azhar R , Ahmad S , Irfan M , Javed M , Naseer N , Aziz A
Ref : Pharmaceuticals (Basel) , 16 :803 , 2023
Abstract : Hypotrichosis is an uncommon type of alopecia (hair loss) characterized by coarse scalp hair caused by the reduced or fully terminated activity of the Lipase-H (LIPH) enzyme. LIPH gene mutations contribute to the development of irregular or non-functional proteins. Because several cellular processes, including cell maturation and proliferation, are inhibited when this enzyme is inactive, the hair follicles become structurally unreliable, undeveloped, and immature. This results in brittle hair, as well as altered hair shaft development and structure. Because of these nsSNPs, the protein's structure and/or function may be altered. Given the difficulty in discovering functional SNPs in genes associated with disease, it is possible to assess potential functional SNPs before conducting broader population investigations. As a result, in our in silico analysis, we separated potentially hazardous nsSNPs of the LIPH gene from benign representatives using a variety of sequencing and architecture-based bioinformatics approaches. Using seven prediction algorithms, 9 out of a total of 215 nsSNPs were shown to be the most likely to cause harm. In order to distinguish between potentially harmful and benign nsSNPs of the LIPH gene, in our in silico investigation, we employed a range of sequence- and architecture-based bioinformatics techniques. Three nsSNPs (W108R, C246S, and H248N) were chosen as potentially harmful. The present findings will likely be helpful in future large population-based studies, as well as in drug discovery, particularly in the creation of personalized medicine, since this study provides an initial thorough investigation of the functional nsSNPs of LIPH.
ESTHER : Khan_2023_Pharmaceuticals.(Basel)_16_803
PubMedSearch : Khan_2023_Pharmaceuticals.(Basel)_16_803
PubMedID: 37375751
Gene_locus related to this paper: human-LIPH

Title : Phytochemical Profiling, In Vitro Biological Activities, and In Silico Molecular Docking Studies of Dracaena reflexa - Ghalloo_2022_Molecules_27_
Author(s) : Ghalloo BA , Khan KU , Ahmad S , Aati HY , Al-Qahtani JH , Ali B , Mukhtar I , Hussain M , Shahzad MN , Ahmed I
Ref : Molecules , 27 : , 2022
Abstract : Dracaena reflexa, a traditionally significant medicinal plant, has not been extensively explored before for its phytochemical and biological potential. The present study was conducted to evaluate the bioactive phytochemicals and in vitro biological activities of D. reflexa, and perform in silico molecular docking validation of D. reflexa. The bioactive phytochemicals were assessed by preliminary phytochemical testing, total bioactive contents, and GC-MS analysis. For biological evaluation, the antioxidant (DPPH, ABTS, CUPRAC, and ABTS), antibacterial, thrombolytic, and enzyme inhibition (tyrosinase and cholinesterase enzymes) potential were determined. The highest level of total phenolic contents (92.72 +/- 0.79 mg GAE/g extract) was found in the n-butanol fraction while the maximum total flavonoid content (110 +/- 0.83 mg QE/g extract) was observed in methanolic extract. The results showed that n-butanol fraction exhibited very significant tyrosinase inhibition activity (73.46 +/- 0.80) and acetylcholinesterase inhibition activity (64.06 +/- 2.65%) as compared to other fractions and comparable to the standard compounds (kojic acid and galantamine). The methanolic extract was considered to have moderate butyrylcholinesterase inhibition activity (50.97 +/- 063) as compared to the standard compound galantamine (53.671 +/- 0.97%). The GC-MS analysis of the n-hexane fraction resulted in the tentative identification of 120 bioactive phytochemicals. Furthermore, the major compounds as identified by GC-MS were analyzed using in silico molecular docking studies to determine the binding affinity between the ligands and the enzymes (tyrosinase, acetylcholinesterase, and butyrylcholinesterase enzymes). The results of this study suggest that Dracaena reflexa has unquestionable pharmaceutical importance and it should be further explored for the isolation of secondary metabolites that can be employed for the treatment of different diseases.
ESTHER : Ghalloo_2022_Molecules_27_
PubMedSearch : Ghalloo_2022_Molecules_27_
PubMedID: 35164177

Title : Phytochemical Profiling, Antioxidant, Antimicrobial and Cholinesterase Inhibitory Effects of Essential Oils Isolated from the Leaves of Artemisia scoparia and Artemisia absinthium - Khan_2022_Pharmaceuticals.(Basel)_15_1221
Author(s) : Khan FA , Khan NM , Ahmad S , Nasruddin , Aziz R , Ullah I , Almehmadi M , Allahyani M , Alsaiari AA , Aljuaid A
Ref : Pharmaceuticals (Basel) , 15 :1221 , 2022
Abstract : The current studies were focused on the phytochemical profiling of two local wild Artemisia species, Artemisia scoparia and Artemisia absinthium leaves' essential oils, extracted via the hydro distillation method along with evaluation of their antioxidant as well as antimicrobial effects. The constituents of EOs were identified using a combined gas chromatography-mass spectrometric (GC-MS) technique. A total of 25 compounds in A. scoparia essential oil (EOAS) were identified, and 14 compounds with percentage abundance of >1% were tabulated, the major being tocopherol derivatives (47.55%). A total of nine compounds in Artemisia absinthium essential oil (EOAA) were enlisted (% age > 1%), the majority being oleic acid derivatives (41.45%). Strong antioxidant effects were pronounced by the EOAS in DPPH (IC(50) = 285 +/- 0.82 microg/mL) and in ABTS (IC(50) = 295 +/- 0.32 microg/mL) free radical scavenging assays. Both the EOs remained potent in inhibiting the growth of bacterial species; Escherichia coli (55-70%) and Shigella flexneri (60-75%) however remained moderately effective against Bacillus subtilis as well as Staphylococcus aureus. Both EOAS and EOAA strongly inhibited the growth of the tested fungal species, especially Aspergillus species (up to 70%). The oils showed anti-cholinesterase potential by inhibiting both Acetylcholinesterase (AChE; IC(50) = 30 +/- 0.04 microg/mL (EOAS), 32 +/- 0.05 microg/mL (EOAA) and Butyrylcholinesterase (BChE; IC(50) = 34 +/- 0.07 microg/mL (EOAS), 36 +/- 0.03 microg/mL (EOAA). In conclusion, the essential oils of A. scoparia and A. absinthium are promising antioxidant, antimicrobial and anticholinergic agents with a different phytochemical composition herein reported for the first time.
ESTHER : Khan_2022_Pharmaceuticals.(Basel)_15_1221
PubMedSearch : Khan_2022_Pharmaceuticals.(Basel)_15_1221
PubMedID: 36297333

Title : Anti-Alzheimer and Antioxidant Effects of Nelumbo nucifera L. Alkaloids, Nuciferine and Norcoclaurine in Alloxan-Induced Diabetic Albino Rats - Khan_2022_Pharmaceuticals.(Basel)_15_1205
Author(s) : Khan S , Khan HU , Khan FA , Shah A , Wadood A , Ahmad S , Almehmadi M , Alsaiari AA , Shah FU , Kamran N
Ref : Pharmaceuticals (Basel) , 15 : , 2022
Abstract : The present study is aimed to determine the efficacy and dose response of the nuciferine (1), norcoclaurine (2) and crude extract of Nelumbo nucifera in managements of diabetes, Alzheimer disease and related allergies. Experimentally, alloxan (100 mg/kg body weight (b.w.))-induced diabetic rats (200-250 g) were divided into seven groups (n = 6). Group I: normal control, Group II: diabetic control, Group III: standard treated with glibenclamide and Group lV-VII: treated with methanolic crude extracts (100, 200 mg/kg), nuciferine and norcoclaurine (10 mg/kg b.w.) for 15 days. Different tests were performed, including blood glucose, body weights and antioxidant enzyme assays, i.e., superoxide dismutase (SOD), catalase test (CAT), lipid peroxidation assay (TBARS), glutathione assay (GSH) and acetylcholinesterase (AChE) assay. Nuciferine and norcoclaurine significantly reduced blood glucose (p < 0.05) and restored body weight in diabetic rats. Moreover, nuciferine and norcoclaurine (10 mg/kg) significantly recovered the antioxidant enzymes (SOD, CAT, GPx and GSH) which decreased during induced diabetes. Significant increase in TBARS was also observed in the diabetic group and nuciferine as well as norcoclaurine (10 mg/kg) inhibited the increase in TBARS in diabetic animals (p < 0.05), as compared to glibenclamide. AChE activity was significantly recovered by nuciferine and norcoclaurine (10 mg/kg) both in the blood and brain of the diabetic group (p < 0.05). Nuciferine and norcoclaurine showed potent inhibitory effects against alpha-glucosidase and alpha-amylase with IC(50), 19.06 +/- 0.03, 15.03 +/- 0.09 microM and 24.07 +/- 0.05, 18.04 +/- 0.021 microM, as confirmed by molecular docking studies. This study concludes that nuciferine and norcoclaurine significantly improve memory and could be considered as an effective phytomedicine for diabetes, Alzheimer's disease (AD) and oxidative stress.
ESTHER : Khan_2022_Pharmaceuticals.(Basel)_15_1205
PubMedSearch : Khan_2022_Pharmaceuticals.(Basel)_15_1205
PubMedID: 36297317

Title : Chemical Composition and Biological Evaluation of Typha domingensis Pers. to Ameliorate Health Pathologies: In Vitro and In Silico Approaches - Dilshad_2022_Biomed.Res.Int_2022_8010395
Author(s) : Dilshad R , Khan KU , Saeed L , Sherif AE , Ahmad S , Ovatlarnporn C , Nasim J , Hussain M , Ghalloo BA , Basit A , Mukhtar I
Ref : Biomed Res Int , 2022 :8010395 , 2022
Abstract : Human diseases are becoming more prevalent, necessitating the development of modalities to overcome the challenges of treating various disorders. In the current research, we analyzed the biomedicinal role of Typha domingensis which is an important medicinal plant. The species is traditionally used in the treatment of neurological disorders and skin malignancies. The chloroform (CFTD) and n-butanol fractions of T. domingensis (BFTD) were subjected to chemical profiling through the determination of total polyphenolic contents and GC-MS analysis. The oral toxicity test was applied to investigate the toxicity of the extracts. Antioxidant capacity was analyzed by four in vitro methods: DPPH, ABTS, FRAP, and CUPRAC. The pharmacological potential was evaluated through clinically significant enzyme inhibition assays, thrombolytic, and antimicrobial activities. In silico molecular docking approach was applied to confirm the role of T. domingensis against the enzymes. The polyphenolic quantification revealed that the BFTD was comparatively rich in total phenolic and flavonoid contents (97.14 milligrams gallic acid equivalent (mg GAE/g) and 362.5 milligrams quercetin equivalent per gram of dry extract (mg QE/g DE), respectively), as compared to the CFTD. The GC-MS analysis of the CFTD and BFTD resulted in the tentative identification of 67 and 29 compounds, respectively, with the major components of fatty acids and essential oil. The oral toxicity test revealed the safety and biocompatibility of CFTD and BFTD. Both the fractions showed promising antioxidant activity. Tyrosinase was found as the major enzyme inhibited by BFTD (78.67%) and CFTD (68.09%), whereas the standard kojic acid showed 85.58% inhibition. The inhibition results of acetylcholinesterase and butyrylcholinesterase by BFTD (71.65 and 60.79%, respectively) are higher than CFTD. Both the fractions were found active against various strains of bacteria. Furthermore, the molecular docking studies of the compounds showed a good docking score against all the docked enzymes among which deoxycaesaldekarin C was found with the highest binding affinities in comparison to the standard. The current study suggests that T. domingensis is nontoxic and can be a potential source of phytoconstituents with promising pharmacological potential.
ESTHER : Dilshad_2022_Biomed.Res.Int_2022_8010395
PubMedSearch : Dilshad_2022_Biomed.Res.Int_2022_8010395
PubMedID: 35872856

Title : Attenuation of Scopolamine-Induced Amnesia via Cholinergic Modulation in Mice by Synthetic Curcumin Analogs - Hussain_2022_Molecules_27_2468
Author(s) : Hussain H , Ahmad S , Shah SWA , Ullah A , Ali N , Almehmadi M , Ahmad M , Khalil AAK , Jamal SB , Ahmad H , Halawi M
Ref : Molecules , 27 :2468 , 2022
Abstract : Alzheimer's disease is an emerging health disorder associated with cognitive decline and memory loss. In this study, six curcumin analogs (1a-1f) were synthesized and screened for in vitro cholinesterase inhibitory potential. On the basis of promising results, they were further investigated for in vivo analysis using elevated plus maze (EPM), Y-maze, and novel object recognition (NOR) behavioral models. The binding mode of the synthesized compounds with the active sites of cholinesterases, and the involvement of the cholinergic system in brain hippocampus was determined. The synthesized curcumin analog 1d (p < 0.001, n = 6), and 1c (p < 0.01, n = 6) showed promising results by decreasing retention time in EPM, significantly increasing % SAP in Y-maze, while significantly (p < 0.001) enhancing the % discrimination index (DI) and the time exploring the novel objects in NORT mice behavioral models. A molecular docking study using MOE software was used for validation of the inhibition of cholinesterase(s). It has been indicated from the current research work that the synthesized curcumin analogs enhanced memory functions in mice models and could be used as valuable therapeutic molecules against neurodegenerative disorders. To determine their exact mechanism of action, further studies are suggested.
ESTHER : Hussain_2022_Molecules_27_2468
PubMedSearch : Hussain_2022_Molecules_27_2468
PubMedID: 35458662

Title : Trigonella foenum-graecum Methanolic Extract on Isolated Smooth Muscles and Acetylcholinesterase Enzyme: An In Vitro and Mechanistic In Silico Investigation - Ghayur_2022_Biomed.Res.Int_2022_4849464
Author(s) : Ghayur MN , Abdalla M , Khalid A , Ahmad S , Gilani AH
Ref : Biomed Res Int , 2022 :4849464 , 2022
Abstract : RESULTS: When tested on the baseline of isolated tissues, Tfg.Cr was devoid of any activity (stimulant or relaxant) till 10 mg/ml. This is an interesting finding, keeping in mind that the fenugreek seeds are used to alleviate constipation and diarrhoea. When Tfg.Cr was tried for any potential AChE inhibitory activity, it did show an inhibitory effect in increasing concentrations (47-380 microg/ml). This inhibitory effect was comparable to the effect produced by a standard AChE inhibitor physostigmine. One of the known fenugreek constituents, diosgenin, was also tested, and it also showed an AChE inhibitory effect in a concentration-dependent manner (11-190 microg/ml). Interaction between diosgenin and AChE was further investigated by molecular docking and molecular dynamics simulations for 100 ns, which showed that diosgenin interacted with the active-site gorge of AChE through hydrophobic, pi-pi stacking, and hydrogen bonds with various amino acids of the AChE enzyme. CONCLUSION: The results show that the fenugreek extract does not possess any GI stimulant or relaxant activity even though it is used traditionally in GI motility disorders. The extract and diosgenin could inhibit the AChE enzyme pointing towards their benefit to enhance the memory.
ESTHER : Ghayur_2022_Biomed.Res.Int_2022_4849464
PubMedSearch : Ghayur_2022_Biomed.Res.Int_2022_4849464
PubMedID: 35425837

Title : Phytochemical Profiling, Antioxidant, Anti-Inflammatory, Thrombolytic, Hemolytic Activity In Vitro and In Silico Potential of Portulacaria afra&\;nbsp - Tabassum_2022_Molecules_27_
Author(s) : Tabassum S , Ahmad S , Rehman Khan KU , Tabassum F , Khursheed A , Zaman QU , Bukhari NA , Alfagham A , Hatamleh AA , Chen Y
Ref : Molecules , 27 : , 2022
Abstract : The use of complementary herbal medicines has recently increased in an attempt to find effective alternative therapies that reduce the adverse effects of chemical drugs. Portulacaria afra is a rich source of phytochemicals with high antioxidant activity, and thus may possess health benefits. This study used the latest developments in GC-MS coupling with molecular docking techniques to identify and quantify the phytoconstituents in P. afra tissue extracts. The results revealed that n-butanol P. afra (BUT-PA) dry extracts contained total phenolic and flavonoids contents of 21.69 +/- 0.28 mgGAE/g and 196.58 +/- 6.29 mgGAE/g, respectively. The significant potential of antioxidants was observed through CUPRIC, FRAP, and ABTS methods while the DPPH method showed a moderate antioxidants potential for P. afra. Enzymatic antioxidants, superoxide dismutase, peroxidase and catalase also showed a better response in the BUT-PA dry extracts. The thrombolytic activity of the BUT-PA extracts ranged from 0.4 +/- 0.32 to 11.2 +/- 0.05%. Similarly, hemolytic activity ranged from 5.76 +/- 0.15 to 9.26 +/- 0.15% using the standard (triton x) method. The BUTPA and CHPA showed moderate acetylcholinesterase and butrylcholinesterase inhibition, ranging from 40.78 +/- 0.52 to 58.97 +/- 0.33, compared to galantamine. The carrageenan induced hind-paw edema assay, while BUT-PA extracts showed anti-inflammatory properties in a dose-dependent manner. Furthermore, 20 compounds were identified in the BUTPA extracts by GC-MS. Molecular docking was performed to explore the synergistic effect of the GC-MS-identified compounds on COX-1 and COX-2 inhibition. A high binding affinity was observed for Stigmastan-3, 5-diene, Phthalic acid, 3. Alpha-Hydroxy-5, 16-androstenol. The computed binding energies of the compounds revealed that all the compounds have a synergistic effect, preventing inflammation. It was concluded that active phytochemicals were present in P. afra, with the potential for multiple pharmacological applications as a latent source of pharmaceutically important compounds. This should be further explored to isolate secondary metabolites that can be employed in the treatment of different diseases.
ESTHER : Tabassum_2022_Molecules_27_
PubMedSearch : Tabassum_2022_Molecules_27_
PubMedID: 35458576

Title : A study on green synthesis, characterization of chromium oxide nanoparticles and their enzyme inhibitory potential - Zainab_2022_Front.Pharmacol_13_1008182
Author(s) : Zainab , Ahmad S , Khan I , Saeed K , Ahmad H , Alam A , Almehmadi M , Alsaiari AA , Haitao Y , Ahmad M
Ref : Front Pharmacol , 13 :1008182 , 2022
Abstract : The conventional chemical methods of nanoparticles synthesis have been effectively replaced by nanoparticle synthesis mediated by plants. The current study describes the environmental friendly synthesis of chromium oxide nanoparticles (Cr(2)O(3) NPs) using Erythrophleum guineense plant extract. The synthesis of Cr(2)O(3) NPs was validated by UV/VIS spectroscopy, Energy Dispersive X-Ray (EDX), Scanning Electron Microscopy (SEM), and X-ray diffraction (XRD) studies. The appearance of the Sharpe peak at 460 nm in the UV/Vis spectrum and the colour change caused by surface plasma resonance confirmed the formation of Cr(2)O(3) NPs. The EDX spectrum of Cr(2)O(3) nanoparticles revealed the presence of carbon, oxygen, and chromium, while SEM analysis revealed an irregular round morphology (with a size below 400 nm). In addition, XRD studies suggested their crystalline nature by the characteristic peaks at 34 degrees and 36 degrees and 42 degrees (2), respectively. The green synthesized Cr(2)O(3) NPs showed promise as in-vitro cholinesterase inhibitor at tested concentrations (62.5-1,000 microg/ml), with IC(50) values of 120 and 100 microg/ml against Acetylcholinesterase (AChE) and Butyrylcholinesterase (BChE), respectively. The results suggested that the green synthesized Cr(2)O(3) NPs could be used in the future to stop enzyme from working and for other biological activities.
ESTHER : Zainab_2022_Front.Pharmacol_13_1008182
PubMedSearch : Zainab_2022_Front.Pharmacol_13_1008182
PubMedID: 36313367

Title : In Vitro and In Silico Investigation of Diterpenoid Alkaloids Isolated from Delphinium chitralense - Ahmad_2022_Molecules_27_
Author(s) : Ahmad S , Ahmad M , Almehmadi M , Shah SAA , Khan FA , Khan NM , Khan A , Zainab , Halawi M , Ahmad H
Ref : Molecules , 27 : , 2022
Abstract : This study reports the isolation of three new C(20) diterpenoid alkaloids, Chitralinine A-C (1-3) from the aerial parts of Delphinium chitralense. Their structures were established on the basis of latest spectral techniques and single crystal X-rays crystallographic studies of chitralinine A described basic skeleton of these compounds. All the isolated Compounds (1-3) showed strong, competitive type inhibition against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in comparison to standard allanzanthane and galanthamine however, chitralinine-C remained the most potent with IC(50) value of 11.64 +/- 0.08 microM against AChE, and 24.31 +/- 0.33 microM against BChE, respectively. The molecular docking reflected a binding free energy of -16.400 K Cal-mol(-1) for chitralinine-C, having strong interactions with active site residues, TYR334, ASP72, SER122, and SER200. The overall findings suggest that these new diterpenoid alkaloids could serve as lead drugs against dementia-related diseases including Alzheimer's disease.
ESTHER : Ahmad_2022_Molecules_27_
PubMedSearch : Ahmad_2022_Molecules_27_
PubMedID: 35889221

Title : Isolation, crystal structure, DFT calculation and molecular docking of uncinatine-A isolated from Delphinium uncinatum - Ahmad_2022_Fitoterapia__105268
Author(s) : Ahmad S , Gul N , Ahmad M , Almehmadi M , Shafie A , Shah SAA , Rahman NU , Ahmad H
Ref : Fitoterapia , :105268 , 2022
Abstract : The main objective of our present research work was to explore molecular insight for potentially active new acetylcholinesterase inhibitor from the aerial parts of Delphinium uncinatum. New norditerpenoid alkaloids, uncinatine-A, was isolated from the basic alkaloidal fraction of D. uncinatum, based on bioactivity guided isolation. The structure of uncinatine-A was determined through latest spectroscopic techniques including single X-Ray diffraction technique. The structural data and electronic properties of uncinatine-A was also calculated by Density Functional Theory (DFT) using B3LYP/6-31 G (p) basis set. The isolated natural product was evaluated for their acetyl cholinesterase inhibitory potential in dose dependent protocol (62.5-1000 microg/mL), followed by molecular docking studies. Significant competitive type inhibition activity (IC(50 =) 207.73 +/- 0.3) was shown by isolated natural norditerpenoid against cholinesterase targets in comparison with standard drugs available in the market such as galanthamine. The molecular docking results showed that isolated natural product was well accommodated by AChE in the active site with docking scores -11.0326. This is the first report indicating uncinatine-A as a potent acetylcholinesterase inhibitor and can be used as a target drug in cerebral dementia and Alzheimer diseases.
ESTHER : Ahmad_2022_Fitoterapia__105268
PubMedSearch : Ahmad_2022_Fitoterapia__105268
PubMedID: 35963483

Title : Substrate access mechanism in a novel membrane-bound 1 phospholipase A of Pseudomonas aeruginosa concordant with specificity and regioselectivity - Ahmad_2021_Biorxiv__
Author(s) : Ahmad S , Strunk CH , Schott-Verdugo SN , Jaeger KE , Kovacic F , Gohlke H
Ref : Biorxiv , : , 2021
Abstract : PlaF is a cytoplasmic membrane-bound phospholipase A1 from Pseudomonas aeruginosa that alters the membrane glycerophospholipid (GPL) composition and fosters the virulence of this human pathogen. PlaF activity is regulated by a dimer-to-monomer transition followed by tilting of the monomer in the membrane. However, how substrates reach the active site and how the characteristics of the active site tunnels determine the activity, specificity, and regioselectivity of PlaF for natural GPL substrates has remained elusive. Here, we combined unbiased and biased all-atom molecular dynamics (MD) simulations and configurational free energy computations to identify access pathways of GPL substrates to the catalytic center of PlaF. Our results map out a distinct tunnel through which substrates access the catalytic center. PlaF variants with bulky tryptophan residues in this tunnel revealed decreased catalysis rates due to tunnel blockage. The MD simulations suggest that GPLs preferably enter the active site with the sn-1 acyl chain first, which agrees with the experimentally demonstrated PLA1 activity of PlaF. We propose that the acyl chain-length specificity of PlaF is determined by the structural features of the access tunnel, which results in favorable free energy of binding of medium-chain GPLs. The suggested egress route conveys fatty acid products to the dimerization interface and, thus, contributes to understanding the product feedback regulation of PlaF by fatty acid-triggered dimerization. These findings open up opportunities for developing potential PlaF inhibitors, which may act as antibiotics against P. aeruginosa.
ESTHER : Ahmad_2021_Biorxiv__
PubMedSearch : Ahmad_2021_Biorxiv__
Gene_locus related to this paper: pseae-PA2949

Title : Evaluation of analgesic, antiamnesic and antidiarrheal potentials of Medicago denticulata extract using animal model - Ahmad_2021_Saudi.J.Biol.Sci_28_6352
Author(s) : Ahmad S , Khan S , Zeb A , Shah SWA , Ahmad B , Khan AA , Ali W , Khan NZ , Zamani GY
Ref : Saudi J Biol Sci , 28 :6352 , 2021
Abstract : The analgesic, antidiarrheal, and neuro-pharmacological potentials of Medicago denticulata leaves extract were screened in animal models. Potential analgesic response was noted (*P < 0.05, (**)P < 0.01, (***)P < 0.001) in formalin, acetic acid and heat-induced pain models in a dose-dependent manner. Maximum activity by means of writhing inhibition was documented for Medicago denticulata at 300 mg/kg that was found to be 71.79% (17.43 +/- 1.31). In first phase, the Medicago denticulata at a dose of 150 and 300 mg/kg showed analgesic activity and reduced the pain by 54.18% (18.39 +/- 1.67) and 62.90% (14.89 +/- 1.56), respectively. In second phase, the Medicago denticulata at a dose of 150 and 300 mg/kg showed analgesic activity and reduced the pain by 69.48% (19.78 +/- 1.44) and 70.89% (18.86 +/- 1.58), respectively. In hot plate method, the Medicago denticulata at a dose of 150 and 300 mg/kg showed the maximum response of 61.16% (8.47 +/- 1.23) and 67.39% (10.09 +/- 1.04), respectively at 60 min. Scopolamine significantly reduces spontaneous alteration in Y-maze model for antiamnesic activity. Medicago denticulata significantly increased the discrimination index in a dose-dependent manner using novel object recognition test (NORT) model. Exploration time in sec for the novel object was increased significantly (P < 0.001) by donepezil decreased for familiar one with a discrimination index (DI) of 62.18%. Medicago denticulata significantly increased the discrimination index by 60.86% and 57.24% at 300 and 150 mg/kg b.w, respectively. The lowest DI of 53.80% at 75 mg/kg was observed in comparison to the amnesic group. The Medicago denticulata significant decreased the elevated levels of acetylcholinesterase (AChE) and malondialdehyde (MDA and enhancing level of acetylcholine (ACh), superoxide dismutase (SOD) and catalase (CAT) acting as an antioxidant agent. Medicago denticulata reduced the total number of diarrheal feces to lesser extent at dose-dependent manner. From the study results, it is suggested that the Medicago denticulata extract possess good analgesic and antiamnesic activity however the antidiarrheal effects of plant were negligible. In the current study, the traditional use of the plant as a source of medicine has been validated.
ESTHER : Ahmad_2021_Saudi.J.Biol.Sci_28_6352
PubMedSearch : Ahmad_2021_Saudi.J.Biol.Sci_28_6352
PubMedID: 34759754

Title : Neuroprotective Potential of Synthetic Mono-Carbonyl Curcumin Analogs Assessed by Molecular Docking Studies - Hussain_2021_Molecules_26_
Author(s) : Hussain H , Ahmad S , Shah SWA , Ghias M , Ullah A , Rahman SU , Kamal Z , Khan FA , Khan NM , Muhammad J , Almehmadi M , Abdulaziz O , Alghamdi S
Ref : Molecules , 26 : , 2021
Abstract : Cognitive decline in dementia is associated with deficiency of the cholinergic system. In this study, five mono-carbonyl curcumin analogs were synthesized, and on the basis of their promising in vitro anticholinesterase activities, they were further investigated for in vivo neuroprotective and memory enhancing effects in scopolamine-induced amnesia using elevated plus maze (EPM) and novel object recognition (NOR) behavioral mice models. The effects of the synthesized compounds on the cholinergic system involvement in the brain hippocampus and their binding mode in the active site of cholinesterases were also determined. Compound h2 (p < 0.001) and h3 (p < 0.001) significantly inhibited the cholinesterases and reversed the effects of scopolamine by significantly reducing TLT (p < 0.001) in EPM, while (p < 0.001) increased the time exploring the novel object. The % discrimination index (DI) was significantly increased (p < 0.001) in the novel object recognition test. The mechanism of cholinesterase inhibition was further validated through molecular docking study using MOE software. The results obtained from the in vitro, in vivo and ex vivo studies showed that the synthesized curcumin analogs exhibited significantly higher memory-enhancing potential, and h3 could be an effective neuroprotective agent. However, more study is suggested to explore its exact mechanism of action.
ESTHER : Hussain_2021_Molecules_26_
PubMedSearch : Hussain_2021_Molecules_26_
PubMedID: 34885751

Title : Neuroprotective and antioxidant effect of Curcuma longa (Rhizome) methanolic extract on SH-SY5Y cells and Javanese medaka - Hassan_2021_Pak.J.Pharm.Sci_34_47
Author(s) : Hassan IM , Wan Ibrahim WN , Yusuf FM , Ahmad SA , Ahmad S
Ref : Pak J Pharm Sci , 34 :47 , 2021
Abstract : Diseases caused by oxidative stress can be prevented by antioxidant. Current treatments for those neurodegenerative diseases are not effective and cause many side effects. Thus, the search for alternative medicines is in high demand. Therefore, the main purposed of this study is to evaluate the neuroprotective effects of Curcuma longa (rhizome) 80% methanol extract. Antioxidant using dichlorofuoresence diacetate (DCF-DA) assay on SH-SY5Y cells revealed high activities of Curcuma longa (rhizome) extract with IC50 of 105.9+/-0.8 microg/mL. Sub-acute and chronic toxicity tests of the plant extract on adult Javanese medaka (Oryzias javanicus) showed high toxicity effect with LC(50) of 24.15+/-0.8 mg/L and 13.69+/-0.7 mg/L respectively. Neuroprotective tests using cholinesterase assay disclose significant differences at P<0.05 between the group that are exposed to arsenic and treated with the crude extract and the group that are exposed to only arsenic. Identification of vitexin and isovitexin justified the high antioxidant potential of this plant leaf and it highest benefit to be used as medicinal supplement.
ESTHER : Hassan_2021_Pak.J.Pharm.Sci_34_47
PubMedSearch : Hassan_2021_Pak.J.Pharm.Sci_34_47
PubMedID: 34248002

Title : Characterization and genomic analysis of an efficient dibutyl phthalate degrading bacterium Microbacterium sp. USTB-Y - Zhao_2021_World.J.Microbiol.Biotechnol_37_212
Author(s) : Zhao Z , Liu C , Xu Q , Ahmad S , Zhang H , Pang Y , Aikemu A , Liu Y , Yan H
Ref : World J Microbiol Biotechnol , 37 :212 , 2021
Abstract : A promising bacterial strain for biodegrading dibutyl phthalate (DBP) was successfully isolated from activated sludge and characterized as a potential novel Microbacterium sp. USTB-Y based on 16S rRNA sequence analysis and whole genome average nucleotide identity (ANI). Initial DBP of 50 mg/L could be completely biodegraded by USTB-Y both in mineral salt medium and in DBP artificially contaminated soil within 12 h at the optimal culture conditions of pH 7.5 and 30 degC, which indicates that USTB-Y has a strong ability in DBP biodegradation. Phthalic acid (PA) was identified as the end-product of DBP biodegraded by USTB-Y using GC/MS. The draft genome of USTB-Y was sequenced by Illumina NovaSeq and 29 and 188 genes encoding for putative esterase/carboxylesterase and hydrolase/alpha/beta hydrolase were annotated based on NR (non redundant protein sequence database) analysis, respectively. Gene3781 and gene3780 from strain USTB-Y showed 100% identity with dpeH and mpeH from Microbacterium sp. PAE-1. But no phthalate catabolic gene (pht) cluster was found in the genome of strain USTB-Y. The results in the present study are valuable for obtaining a more holistic understanding on diverse genetic mechanisms of PAEs biodegrading Microbacterium sp. strains.
ESTHER : Zhao_2021_World.J.Microbiol.Biotechnol_37_212
PubMedSearch : Zhao_2021_World.J.Microbiol.Biotechnol_37_212
PubMedID: 34738191
Gene_locus related to this paper: 9mico-DpeH , 9mico-MpeH

Title : Tryptophan lessens reserpine induced anxiety, depression and memory impairment by modulating oxidative stress and serotonergic activity - Samad_2021_Pak.J.Pharm.Sci_34_1499
Author(s) : Samad N , Khaliq S , Alam M , Yasmin F , Ahmad S , Mustafa S , Azizuddin , Raza U
Ref : Pak J Pharm Sci , 34 :1499 , 2021
Abstract : Reserpine (Res)-induced depletion of monoamines and altered neurotransmission and produces oxidative stress. Tryptophan (TRP) regulated the serotonin neurotransmission. Because systemically injected Res induced behavioral deficits and oxidative stress, while, dietary components prevented these adverse effects, we used TRP a pharmacological tool to prevent Res- induced changes in behavior, memory impairments, oxidative stress and regulation of serotonin neurotransmission in rats. Anxiolytic, antidepressant, cognitive functions, lipid peroxidation, antioxidant enzymes serotonin metabolism were studied in Res and vehicle treated animals following administration of 50 and 100 mg/ml/kg of tryptophan. Following administration of TRP [50 and 100mg/ml/kg], Res induced anxiety-and/or depression like behaviors normalized. Res-induced impaired cognitive function and increased acetylcholinesterase activity also improved following administration of TRP at both doses. Res induced increased brains' malondialdehyde (MDA) and decreased antioxidant enzymes activity also normalized by TRP. Res-induced decreased 5-HT metabolism also regulated by administration of TRP at both doses. In conclusion it can be recommended that administration/supplementation of TRP in daily life can aid in battling the anxiety, depression, modulating serotonergic activity and oxidative stress. Study also exhibits the anti-acetylcholinesterase role of TRP which may be possible reason for improved cognition following stress situation.
ESTHER : Samad_2021_Pak.J.Pharm.Sci_34_1499
PubMedSearch : Samad_2021_Pak.J.Pharm.Sci_34_1499
PubMedID: 34799325

Title : Heavy metals bioaccumulation and subsequent multiple biomarkers based appraisal of toxicity in the critically endangered Tor putitora - Ullah_2021_Ecotoxicol.Environ.Saf_228_113032
Author(s) : Ullah S , Li Z , Hassan S , Ahmad S , Guo X , Wanghe K , Nabi G
Ref : Ecotoxicology & Environmental Safety , 228 :113032 , 2021
Abstract : The construction of hydropower projects discharges effluents to aquatic bodies. The effluents consist of different chemicals including heavy metals. The current study assessed the effects of effluents discharged from an under-construction hydropower project on the bioaccumulation of heavy metals in the tissues of critically endangered Tor putitora (Hamilton, 1822) in the river Panjkora. The subsequent toxic impacts of higher bioaccumulation of heavy metals on different biochemical, hematological, and serum biochemical profiles were also studied. Different biochemical changes were observed in the tissues of T. putitora including stress biomarkers such as reactive oxygen species, lipid peroxidation, total protein contents, antioxidant enzymes (peroxidase, superoxide dismutase, catalase, reduced glutathione, glutathione reductase, and glutathione-s-transferase), acetylcholinesterase, and whole-body cortisol. The hematotoxic effects were also observed as the count of red blood cells, hematocrit, and hemoglobin decreased whereas the count of white blood cells increased. Serum biochemical analysis revealed that cholesterol, urea, total bilirubin, and glucose concentration increased, whereas total proteins and albumin decreased with an increase in the concentration of heavy metals across the sampling sites. The fish from the river was found to be under severe stress as compared to the fish from the reference site. To mitigate the current scenario, stocking fish in an appropriate amount is suggested. The fish diversity and water quality should be assessed at regular intervals to avoid further deterioration and diversity loss. The safety and conservation of wild fisheries should be ensured by implementing strict environmental protection and fishing laws.
ESTHER : Ullah_2021_Ecotoxicol.Environ.Saf_228_113032
PubMedSearch : Ullah_2021_Ecotoxicol.Environ.Saf_228_113032
PubMedID: 34856487

Title : Development of Synergy-Based Combination for Learning and Memory Using in vitro, in vivo and TLC-MS-Bioautographic Studies - Khan_2021_Front.Pharmacol_12_678611
Author(s) : Khan MA , Srivastava V , Kabir M , Samal M , Insaf A , Ibrahim M , Zahiruddin S , Ahmad S
Ref : Front Pharmacol , 12 :678611 , 2021
Abstract : The present study is aimed at developing a synergistic combination to enhance learning and memory in Alzheimer's patients with the help of eight common medicinal plants used in the AYUSH system. Aqueous and hydroalcoholic extracts of eight medicinal plants from the AYUSH system of medicine were prepared. These were subjected to in vitro anticholinesterase activity, to find out the combination index of synergistic combination. The synergistic combination and their individual extracts were subjected to total phenol, flavonoid and antioxidant activity estimation. Further, in vivo neurobehavioral studies in rats were carried out followed by TLC-MS-bioautographic identification of bioactive metabolites. Out of the sixteen extracts, aqueous extracts of Withania somnifera (L.) Dunal (WSA) and Myristica fragrans (L.) Dunal (MFA) were selected for the development of synergistic combination based on their IC(50) value in vitro anticholinesterase assay. The synergistic combination inhibited the anticholinesterase activity significantly as compared to the individual extracts of WSA and MFA. The synergistic combination also showed more phenolic and flavonoid contents with potential antioxidant activity. The TLC-bioautography showed four white spots in WSA, signifying sitoindosides VII, VIII, quercetin, isopelletierine and Withanolide S as AChE inhibitory compounds while showing five white spots of anti-cholinesterase active metabolites identified as eugenol, methyl eugenol, myristic acid, galbacin and beta-sitosterol in MFA. The observation of neurocognitive behavior in amnesia induced subjects manifested that both the synergistic combinations showed comparable results to that of standard piracetam, though the synergistic combination containing a higher concentration of WSA showed more appreciable results in ameliorating dementia in rats. The study suggests that the synergy based combination successfully enhanced memory and learning by abating free radical and acetylcholine levels, and increased learning and memory in rats, providing a strong rationale for its use in the treatment of dementia and Alzheimer's disease.
ESTHER : Khan_2021_Front.Pharmacol_12_678611
PubMedSearch : Khan_2021_Front.Pharmacol_12_678611
PubMedID: 34276370

Title : Effect of Berberis vulgaris L. root extract on ifosfamide-induced in vivo toxicity and in vitro cytotoxicity - Ilyas_2021_Sci.Rep_11_1708
Author(s) : Ilyas S , Tabasum R , Iftikhar A , Nazir M , Hussain A , Ali MS , Saleem F , Saleem U , Froeyen M , Abdullah I , Mirza MU , Ahmad S
Ref : Sci Rep , 11 :1708 , 2021
Abstract : Ifosfamide is a widely used chemotherapeutic agent having broad-spectrum efficacy against several tumors. However, nephro, hepato, neuro cardio, and hematological toxicities associated with ifosfamide render its use limited. These side effects could range from organ failure to life-threatening situations. The present study aimed to evaluate the attenuating efficiency of Berberis vulgaris root extract (BvRE), a potent nephroprotective, hepatoprotective, and lipid-lowering agent, against ifosfamide-induced toxicities. The study design comprised eight groups of Swiss albino rats to assess different dose regimes of BvRE and ifosfamide. Biochemical analysis of serum (serum albumin, blood urea nitrogen, creatinine, alanine transaminase, aspartate transaminase, alkaline phosphatase, lactate dehydrogenase, total cholesterol, and triglycerides) along with complete blood count was performed. Kidney, liver, brain, and heart tissue homogenates were used to find malondialdehyde, catalase, and glutathione S-transferase levels in addition to the acetylcholinesterase of brain tissue. The results were further validated with the help of the histopathology of the selected organs. HeLa cells were used to assess the effect of BvRE on ifosfamide cytotoxicity in MTT assay. The results revealed that pre- and post-treatment regimens of BvRE, as well as the combination therapy exhibited marked protective effects against ifosfamide-induced nephro, hepato, neuro, and cardiotoxicity. Moreover, ifosfamide depicted a synergistic in vitro cytotoxic effect on HeLa cells in the presence of BvRE. These results corroborate that the combination therapy of ifosfamide with BvRE in cancer treatment can potentiate the anticancer effects of ifosfamide along with the amelioration of its conspicuous side effects.
ESTHER : Ilyas_2021_Sci.Rep_11_1708
PubMedSearch : Ilyas_2021_Sci.Rep_11_1708
PubMedID: 33462261

Title : Phytochemical profile and pharmacological properties of Trifolium repens - Ahmad_2020_J.Basic.Clin.Physiol.Pharmacol__
Author(s) : Ahmad S , Zeb A
Ref : J Basic Clin Physiol Pharmacol , : , 2020
Abstract : Trifolium repens belongs to the family Leguminosae and has been used for therapeutic purposes as traditional medicine. The plant is widely used as fodder and leafy vegetables for human uses. However, there is a lack of a detailed review of its phytochemical profile and pharmacological properties. This review presents a comprehensive overview of the phytochemical profile and biological properties of T. repens. The plant is used as antioxidants and cholinesterase inhibitors and for anti-inflammatory, antiseptic, analgesic, antirheumatic ache, and antimicrobial purposes. This review has summarized the available updated useful information about the different bioactive compounds such as simple phenols, phenolic acids, flavones, flavonols, isoflavones, pterocarpans, cyanogenic glucosides, saponins, and condensed tannins present in T. repens. The pharmacological roles of these secondary metabolites present in T. repens have been presented. It has been revealed that T. repens contain important phytochemicals, which is the potential source of health-beneficial bioactive components for food and nutraceuticals industries.
ESTHER : Ahmad_2020_J.Basic.Clin.Physiol.Pharmacol__
PubMedSearch : Ahmad_2020_J.Basic.Clin.Physiol.Pharmacol__
PubMedID: 32776902

Title : Multidirectional insights into the phytochemical, biological, and multivariate analysis of the famine food plant (Calligonum polygonoides L).: A novel source of bioactive phytocompounds - Pervaiz_2020_Food.Res.Int_137_109606
Author(s) : Pervaiz I , Saleem H , Sarfraz M , Imran Tousif M , Khurshid U , Ahmad S , Zengin G , Ibrahime Sinan K , Locatelli M , Mahomoodally FM , Asnawi Zainal Abidin S , Ahemad N
Ref : Food Res Int , 137 :109606 , 2020
Abstract : Calligonum polygonoides L. also known as famine food plant, is normally consumed in times of food scarcity in India and Pakistan and also used traditionally in the management of common diseases. The present design aims to provide an insight into the medicinal potential of four solvent extracts of C. polygonoides via an assessment of its phytochemical profile, antioxidant and enzyme inhibitory potential. Phytochemical composition was estimated by deducing total bioactive constituents, UHPLC-MS secondary metabolites profile, and HPLC phenolic quantification. Antioxidant potential was determined via six methods (radical scavenging (DPPH and ABTS), reducing power (FRAP and CUPRAC), phosphomolybdenum total antioxidant capacity and metal chelation activity). Enzyme inhibitory potential was assessed against clinical enzymes (acetylcholinesterase -AChE, butyrylcholinesterase -BChE, tyrosinase, and alpha-amylase). The highest amounts of phenolic contents were found in chloroform extract (76.59 mg GAE/g extract) which may be attributed to its higher radical scavenging, reducing power and tyrosinase inhibition potential. The n-butanol extract containing the maximum amount of flavonoids (55.84 mg RE/g extract) exhibited highest metal chelating capacity. Similarly, the n-hexane extract was found to be most active against AChE (4.65 mg GALAE/g extract), BChE (6.59 mg GALAE/g extract), and alpha-amylase (0.70 mmol ACAE/g extract) enzymes. Secondary metabolite assessment of the crude methanol extract as determined by UHPLC-MS analysis revealed the presence of 24 (negative ionization mode) and 15 (positive ionization mode) secondary metabolites, with most of them belonging to phenolic, flavonoids, terpene, and alkaloid groups. Moreover, gallic acid and naringenin were the main phenolics quantified by HPLC-PDA analysis in all the tested extracts (except n-butanol extract). PCA statistical analysis was also conducted to establish any possible relationship amongst bioactive contents and biological activities. Overall, the C. polygonoides extracts could be further considered to isolate bioactive enzyme inhibitory and antioxidant natural phytocompounds.
ESTHER : Pervaiz_2020_Food.Res.Int_137_109606
PubMedSearch : Pervaiz_2020_Food.Res.Int_137_109606
PubMedID: 33233202

Title : New naphthalene derivative for cost-effective AChE inhibitors for Alzheimer's treatment: In silico identification, in vitro and in vivo validation - Anwar_2020_Comput.Biol.Chem_89_107378
Author(s) : Anwar F , Saleem U , Ahmad B , Ashraf M , Rehman AU , Froeyen M , Kee LY , Abdullah I , Mirza MU , Ahmad S
Ref : Comput Biol Chem , 89 :107378 , 2020
Abstract : Neurodegenerative diseases have complex etiology and pose a challenge to scientists to develop simple and cost-effective synthetic compounds as potential drug candidates for such diseases. Here, we report an extension of our previously published in silico screening, where we selected four new compounds as AChE inhibitors. Further, based on favorable binding possess, MD simulation and MMGBSA, two most promising compounds (3a and 3b) were selected, keeping in view the ease of synthesis and cost-effectiveness. Due to the critical role of BChE, LOX and alpha-glucosidase in neurodegeneration, the selected compounds were also screened against these enzymes. The IC(50) values of 3a against AChE and BChE found to be 12.53 and 352.42 muM, respectively. Moderate to slight inhibitions of 45.26 % and 28.68 % were presented by 3a against LOX and alpha-glucosidase, respectively, at 0.5mM. Insignificant inhibitions were observed with 3b against the four selected enzymes. Further, in vivo trial demonstrated that 3a could significantly diminish AChE levels in the mice brain as compared to the control. These findings were in agreement with the histopathological analysis of the brain tissues. The results corroborate that selected compounds could serve as a potential lead for further development and optimization as AChE inhibitors to achieve cost-effective anti-Alzheimer's drugs.
ESTHER : Anwar_2020_Comput.Biol.Chem_89_107378
PubMedSearch : Anwar_2020_Comput.Biol.Chem_89_107378
PubMedID: 33002716

Title : In silico studies, nitric oxide, and cholinesterases inhibition activities of pyrazole and pyrazoline analogs of diarylpentanoids - Mohd_2020_Arch.Pharm.(Weinheim)__e2000161
Author(s) : Mohd Faudzi SM , Leong SW , Auwal FA , Abas F , Wai LK , Ahmad S , Tham CL , Shaari K , Lajis NH , Yamin BM
Ref : Arch Pharm (Weinheim) , :e2000161 , 2020
Abstract : A new series of pyrazole, phenylpyrazole, and pyrazoline analogs of diarylpentanoids (excluding compounds 3a, 4a, 5a, and 5b) was pan-assay interference compounds-filtered and synthesized via the reaction of diarylpentanoids with hydrazine monohydrate and phenylhydrazine. Each analog was evaluated for its anti-inflammatory ability via the suppression of nitric oxide (NO) on IFN-gamma/LPS-activated RAW264.7 macrophage cells. The compounds were also investigated for their inhibitory capability toward acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), using a modification of Ellman's spectrophotometric method. The most potent NO inhibitor was found to be phenylpyrazole analog 4c, followed by 4e, when compared with curcumin. In contrast, pyrazole 3a and pyrazoline 5a were found to be the most selective and effective BChE inhibitors over AChE. The data collected from the single-crystal X-ray diffraction analysis of compound 5a were then applied in a docking simulation to determine the potential binding interactions that were responsible for the anti-BChE activity. The results obtained signify the potential of these pyrazole and pyrazoline scaffolds to be developed as therapeutic agents against inflammatory conditions and Alzheimer's disease.
ESTHER : Mohd_2020_Arch.Pharm.(Weinheim)__e2000161
PubMedSearch : Mohd_2020_Arch.Pharm.(Weinheim)__e2000161
PubMedID: 32886410

Title : Evaluation of neuroprotective and anti-amnesic effects of Elaeagnus umbellata Thunb. On scopolamine-induced memory impairment in mice - Nazir_2020_BMC.Complement.Med.Ther_20_143
Author(s) : Nazir N , Zahoor M , Nisar M , Karim N , Latif A , Ahmad S , Uddin Z
Ref : BMC Complement Med Ther , 20 :143 , 2020
Abstract : BACKGROUND: Elaeagnus umbellata is abundantly found in Himalayan regions of Pakistan which is traditionally used to treat various health disorders. However, the experimental evidence supporting the anti-amnesic effect is limited. Therefore the study was aimed to evaluate the prospective beneficial effect of E. umbellata on learning and memory in mice. OBJECTIVES: To assess neuroprotective and anti-amnesic effects of E. umbellata fruit extracts and isolated compounds on the central nervous system. METHODS: Major phytochemical groups present in methanolic extract of E. umbellata were qualitatively determined. The total phenolic and flavonoid contents were also determined in extract/fractions of E. umbellata. On the basis of in vitro promising anticholinesterases (AChE & BChE) and antioxidant activities observed for CHF. Ext and isolated compound-I (Chlorogenic acid = CGA), they were further evaluated for learning and memory in normal and scopolamine-induced cognitive impairment in mice using memory behavioral tests such as the Y maze and Novel object recognition using standard procedures. The test sample were further assessed for in vivo anticholinesterases (AChE & BChE) and DPPH free radical scavenging activities in mice brain sample and finally validated by molecular docking study using GOLD software. RESULTS: The extract/fractions and isolated compounds were tested for their anticholinesterase and antioxidant potentials. The CHF. Ext and CGA showed maximum % inhibition of tested cholinesterases and free radicals. The CHF. Ext and CGA reversed the effects of scopolamine in mice. The CHF. Ext and CGA significantly increased the alternate arm returns and % spontaneous alteration performance while escape latency times (second) significantly decreased in Y maze test. The CHF. Ext and CGA significantly increased the time spent with novel object and also increased the discrimination index in the Novel object recognition test. Furthermore, molecular docking was used to validate the mechanism of cholinesterases inhibition of isolated compounds. CONCLUSION: The data obtained from behavioral and biochemical studies (AChE/BChE and DPPH/ABTS inhibition) have shown that E. umbellata possessed significant memory enhancing potency. These results suggest that E. umbellata extract possess potential antiamnesic effects and amongst the isolated compounds, compound I could be more effective anti-amnesic therapeutics. However, further studies are needed to identify the exact mechanism of action.
ESTHER : Nazir_2020_BMC.Complement.Med.Ther_20_143
PubMedSearch : Nazir_2020_BMC.Complement.Med.Ther_20_143
PubMedID: 32397979

Title : Functional characterization of the endolysins derived from mycobacteriophage PDRPxv - Eniyan_2020_World.J.Microbiol.Biotechnol_36_83
Author(s) : Eniyan K , Sinha A , Ahmad S , Bajpai U
Ref : World J Microbiol Biotechnol , 36 :83 , 2020
Abstract : Bacteriophage-derived endolysin enzymes play a critical role in disintegration of the host bacterial cell wall and hence have gained considerable attention as possible therapeutics for the treatment of drug-resistant infections. Endolysins can target both dividing and non-dividing cells and given the vital role peptidoglycan plays in bacterial survival, bacteria are less likely to modify it even if continuously exposed to lysins. Hence, probability of bacteria developing resistance to lysins appear bleak. Endolysins from mycobacteriophages offer great potential as alternative therapeutics for the drug-resistant TB. However, considering that a large number of mycobacteriophages have been discovered so far, the information on endolysins come from only a few mycobacteriophages. In this study, we report the structural and functional characterization of endolysins (LysinA and LysinB) encoded by mycobacteriophage PDRPxv which belongs to B1 sub cluster. On in silico analysis, we found LysinA to be a modular protein having peptidase domain at the N-terminal (104 aa), a central amidase domain (174 aa) and the peptidoglycan binding domain (62 aa) at the C-terminal. Additionally, 'H-X-H', which is a conserved motif and characteristic of peptidase domains, and the conserved residues His-His-Asp, which are characteristic of amidase domain were also observed. In LysinB enzyme, a single alpha/beta hydrolase domain having a catalytic triad (Ser-Asp-His) and G-X-S-X-G motif, which are characteristic of the serine esterase enzymes were predicted to be present. Both the enzymes were purified as recombinant proteins and their antimycobacterial activity against M. smegmatis was demonstrated through turbidimetric experiments and biochemical assay. Interesting observation in this study is the secretory nature of LysinA evident by its periplasmic expression in E.coli, which might explain the ability of PDRPxv to lyse the bacterial host in the absence of transmembrane Holin protein.
ESTHER : Eniyan_2020_World.J.Microbiol.Biotechnol_36_83
PubMedSearch : Eniyan_2020_World.J.Microbiol.Biotechnol_36_83
PubMedID: 32468233

Title : Naringenin protects AlCl3\/D-galactose induced neurotoxicity in rat model of AD via attenuation of acetylcholinesterase levels and inhibition of oxidative stress - Haider_2020_PLoS.One_15_e0227631
Author(s) : Haider S , Liaquat L , Ahmad S , Batool Z , Siddiqui RA , Tabassum S , Shahzad S , Rafiq S , Naz N
Ref : PLoS ONE , 15 :e0227631 , 2020
Abstract : Currently prescribed medications for the treatment of Alzheimer's disease (AD) that are based on acetylcholinesterase inhibition only offer symptomatic relief but do not provide protection against neurodegeneration. There appear to be an intense need for the development of therapeutic strategies that not only improve brain functions but also prevent neurodegeneration. The oxidative stress is one of the main causative factors of AD. Various antioxidants are being investigated to prevent neurodegeneration in AD. The objective of this study was to investigate the neuroprotective effects of naringenin (NAR) against AlCl3+D-gal induced AD-like symptoms in an animal model. Rats were orally pre-treated with NAR (50 mg/kg) for two weeks and then exposed to AlCl3+D-gal (150 mg/kg + 300 mg/kg) intraperitoneally for one week to develop AD-like symptoms. The standard drug, donepezil (DPZ) was used as a stimulator of cholinergic activity. Our results showed that NAR pre-treatment significantly protected AD-like behavioral disturbances in rats. In DPZ group, rats showed improved cognitive and cholinergic functions but the neuropsychiatric functions were not completely improved and showed marked histopathological alterations. However, NAR not only prevented AlCl3+D-gal induced AD-like symptoms but also significantly prevented neuropsychiatric dysfunctions in rats. Results of present study suggest that NAR may play a role in enhancing neuroprotective and cognition functions and it can potentially be considered as a neuroprotective compound for therapeutic management of AD in the future.
ESTHER : Haider_2020_PLoS.One_15_e0227631
PubMedSearch : Haider_2020_PLoS.One_15_e0227631
PubMedID: 31945778

Title : Biochemical Constituent of Ginkgo biloba (Seed) 80\% Methanol Extract Inhibits Cholinesterase Enzymes in Javanese Medaka (Oryzias javanicus) Model - Hassan_2020_J.Toxicol_2020_8815313
Author(s) : Hassan I , Wan Ibrahim WN , Yusuf FM , Ahmad SA , Ahmad S
Ref : J Toxicol , 2020 :8815313 , 2020
Abstract : BACKGROUND: Pathophysiological changes leading to the death of nerve cells present in the brain and spinal cord are referred to as neurodegenerative diseases. Presently, treatment of these diseases is not effective and encounters many challenges due to the cost of drug and side effects. Thus, the search for the alternative agents to replace synthetic drugs is in high demand. Therefore, the aim of this study is to evaluate the anticholinesterase properties of Ginkgo biloba seed. METHODS: The seed was extracted with 80% methanol. Toxicity studies and evaluation of anticholinesterase activities were carried out in adult Javanese medaka (Oryzias javanicus). Phytochemical study to identify the bioactive lead constituents of the crude extract was also carried out using high performance liquid chromatography (HPLC). RESULTS: The result shows activities with high significant differences at P < 0.001 between the treated and nontreated groups. A bioactive compound (vitaxin) was identified with the aid of HPLC method. CONCLUSION: The presence of bioactive compound vitaxin is among the major secondary metabolites that contribute to increasing activities of this plant extract. High anticholinesterase activities and low toxicity effect of this plant show its benefit to be used as natural medicine or supplements.
ESTHER : Hassan_2020_J.Toxicol_2020_8815313
PubMedSearch : Hassan_2020_J.Toxicol_2020_8815313
PubMedID: 33029137

Title : Diet supplements of banana fruit pulp mitigates repeated noise stress induced behavioral deficits and oxidative stress - Samad_2020_Pak.J.Pharm.Sci_33_2293
Author(s) : Samad N , Yasmin F , Khaliq S , Ahmad S , Azizuddin , Mustafa S
Ref : Pak J Pharm Sci , 33 :2293 , 2020
Abstract : The current study was designed to determine the outcome of banana fruit pulp (BFP) on repeated noise stress exposure (NSE)-induced behavioral deficits and oxidative stress in male mice. BFP (600mg/kg b.w) was administered orally once daily for 2 weeks prior exposure to noise stress. Mice were exposed to NS for 4 h after administration of BFP for 2 weeks. Control mice were administered drinking water and similar treatment as given to test animals. At the end of the treatment behavioral changes were monitored. Animals were sacrificed following behavioral assessment and the brain and plasma samples were collected for biochemical analysis. Repeated NS-induced behavioral deficits (anxiety and depression), impaired learning and memory and produced oxidative stress. Administration of BFP inhibited NS-induced behavioral deficits (anxiolytic and antidepressant effects) and improved cognitive abilities. Brain lipid per oxidation was also decreased with concomitant increase of antioxidant enzyme activities. Repeated noise stress increased plasma corticosterone levels. A significant decrease of plasma corticosterone was observed on unstressed BFP treated animals while this decrease was comparable in stressed + BFP animals. Decreased levels of acetylcholinesterase in BPF+NS treated animals indicated increased cholinergic function which improves learning and memory. Repeated oral administration of BFP induced cognitive improving ability, anti-stress effect and potentiated antioxidant defence mechanism in both control and NS mice. Thus, it is suggested that dietary supplementation of BFP has a curative effect against NS-induced psychiatric and cognitive related disorders which merits deliberation and additional appraisal.
ESTHER : Samad_2020_Pak.J.Pharm.Sci_33_2293
PubMedSearch : Samad_2020_Pak.J.Pharm.Sci_33_2293
PubMedID: 33832903

Title : Pharmacological Evaluation of Aldehydic-Pyrrolidinedione Against HCT-116, MDA-MB231, NIH\/3T3, MCF-7 Cancer Cell Lines, Antioxidant and Enzyme Inhibition Studies - Ahmad_2019_Drug.Des.Devel.Ther_13_4185
Author(s) : Ahmad A , Ullah F , Sadiq A , Ayaz M , Rahim H , Rashid U , Ahmad S , Jan MS , Ullah R , Shahat AA , Mahmood HM
Ref : Drug Des Devel Ther , 13 :4185 , 2019
Abstract : Purpose: The current work was designed to synthesize a bioactive derivative of succinimide and evaluate it for anti-Alzheimer, anticancer and anti-diabetic potentials. Methods: The compound was synthesized by Michael addition of butyraldehyde with N-phenylmaleimide. The synthesized compound was screened for biological potentials including anti-cholinesterase, in-vitro anti-diabetic, antioxidant and anthelmintic potentials. The anti-cholinesterase potential was evaluated against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), anti-diabetic potential against alpha-glucosidase, antioxidant potential against ABTS, DPPH and H2O2 and anthelmintic potential against Perethima posthuma and Ascaridia galli respectively. Results: The compound demonstrated significant AChE and BChE inhibition i.e., 71.34+/-1.92 and 73.42 +/-1.92 at the concentration of 1000 microg/mL respectively. Other dilutions exhibited concentration-dependent inhibitory activity against both enzymes. In the MTT assay, the newly synthesized compound was found active against all of the cell lines viz, HCT-116, MDA-MB231, NIH/3T3 and MCF-7 and the highest cytotoxicity potential was observed against the colon cancer cell line (HCT-116) with an IC50 value of 78 microg/mL exhibiting its highest potential. Moreover, the compound exhibited prominent alpha-glucosidase inhibitory potentials (79.86+/-2.54% at 1000 microg/mL) with IC50 value of 156.23 microg/mL. Further, our test compound exhibited considerable scavenging activity against DPPH, ABTS and H2O2 free radicals with percent inhibitions of 75.84+/-1.58, 72.85+/-1.17 and 54.82+/-1.82 and IC50 values of 84.36, 139.74 and 752.21 microg/mL respectively. Our test sample exhibited significant anthelmintic potentials. It demonstrated significant paralysis and death of the test worms in an unbelievably short time in comparison with albendazole. Conclusion: Going into the detail of all observations, it may be deduced that the newly synthesized succinimide derivative could be an important drug candidate against neurodegenerative disorders like Alzheimer's disease, cancer, diabetes mellitus and worms. Further detailed studies in animal models are required for in-vivo analysis of the compound.
ESTHER : Ahmad_2019_Drug.Des.Devel.Ther_13_4185
PubMedSearch : Ahmad_2019_Drug.Des.Devel.Ther_13_4185
PubMedID: 31849450

Title : Bioassay Directed Isolation, Biological Evaluation and in Silico Studies of New Isolates from Pteris cretica L - Saleem_2019_Antioxidants.(Basel)_8_
Author(s) : Saleem F , Mehmood R , Mehar S , Khan MTJ , Khan ZU , Ashraf M , Ali MS , Abdullah I , Froeyen M , Mirza MU , Ahmad S
Ref : Antioxidants (Basel) , 8 : , 2019
Abstract : Members of genus Pteris have their established role in the traditional herbal medicine system. In the pursuit to identify its biologically active constituents, the specie Pteris cretica L. (P. cretica) was selected for the bioassay-guided isolation. Two new maleates (F9 and CB18) were identified from the chloroform extract and the structures of the isolates were elucidated through their spectroscopic data. The putative targets, that potentially interact with both of these isolates, were identified through reverse docking by using in silico tools PharmMapper and ReverseScreen3D. On the basis of reverse docking results, both isolates were screened for their antioxidant, acetylcholinesterase (AChE) inhibition, alpha-glucosidase (GluE) inhibition and antibacterial activities. Both isolates depicted moderate potential for the selected activities. Furthermore, docking studies of both isolates were also studied to investigate the binding mode with respective targets followed by molecular dynamics simulations and binding free energies. Thereby, the current study embodies the poly-pharmacological potential of P. cretica.
ESTHER : Saleem_2019_Antioxidants.(Basel)_8_
PubMedSearch : Saleem_2019_Antioxidants.(Basel)_8_
PubMedID: 31331076

Title : Norditerpenoid alkaloids of Delphinium denudatum as cholinesterase inhibitors - Ahmad_2018_Bioorg.Chem_78_427
Author(s) : Ahmad H , Ahmad S , Ali M , Latif A , Shah SAA , Naz H , Ur Rahman N , Shaheen F , Wadood A , Khan HU , Ahmad M
Ref : Bioorg Chem , 78 :427 , 2018
Abstract : Three new norditerpenoids alkaloids, 1beta-hydroxy,14beta-acetyl condelphine (1), jadwarine-A (2), jadwarine-B (3) along with two known alkaloids isotalatizidine hydrate (4) and dihydropentagynine (5) were isolated from medicinal plant Delphinium denudatum. The structures of natural products 1-5 were established on the basis of HR-EIMS, (1)H and (13)C NMR (1D & 2D) spectroscopic data as well as by comparison from literature data. The structures of compound 1 and 4 were also confirmed by single crystal X-ray diffraction studies. In-vitro AChE and BChE enzyme inhibitory activities of compounds 1-5 and molecular docking studies were performed to investigate the possible molecular inhibitory mechanism of the isolated natural products. Compound 2, 4 and 5 showed competitive inhibitory effects by inhibiting AChE and BChE, respectively, while 1 and 3 showed non-competitive inhibition. This work is the first report that provides a supporting evidence about the use of constituents of Delphinium denudatum in cerebral dementia and Alzheimer diseases.
ESTHER : Ahmad_2018_Bioorg.Chem_78_427
PubMedSearch : Ahmad_2018_Bioorg.Chem_78_427
PubMedID: 29698893

Title : Walnut supplementation reverses the scopolamine-induced memory impairment by restoration of cholinergic function via mitigating oxidative stress in rats: a potential therapeutic intervention for age related neurodegenerative disorders - Haider_2018_Metab.Brain.Dis_33_39
Author(s) : Haider S , Batool Z , Ahmad S , Siddiqui RA , Haleem DJ
Ref : Metabolic Brain Disease , 33 :39 , 2018
Abstract : The brain is highly susceptible to the damaging effects of oxidative reactive species. The free radicals which are produced as a consequence of aerobic respiration can cause cumulative oxygen damage which may lead to age-related neurodegeneration. Scopolamine, the anti-muscarinic agent, induces amnesia and oxidative stress similar to that observed in the older age. Studies suggest that antioxidants derived from plant products may provide protection against oxidative stress. Therefore, the present study was designed to investigate the attenuation of scopolamine-induced memory impairment and oxidative stress by walnut supplementation in rats. Rats in test group were administrated with walnut suspension (400 mg/kg/day) for four weeks. Both control and walnut-treated rats were then divided into saline and scopolamine-treated groups. Rats in the scopolamine group were injected with scopolamine (0.5 mg/kg dissolved in saline) five minutes before the start of each memory test. Memory was assessed by elevated plus maze (EPM), Morris water maze (MWM), and novel object recognition task (NOR) followed by estimation of regional acetylcholine levels and acetylcholinesterase activity. In the next phase, brain oxidative status was determined by assaying lipid peroxidation, and measuring superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activities. Results showed that scopolamine-treatment impaired memory function, caused cholinergic dysfunction, and induced oxidative stress in rats compared to that saline-treated controls. These impairments were significantly restored by pre-administration of walnut. This study demonstrates that antioxidant properties of walnut may provide augmented effects on cholinergic function by reducing oxidative stress and thus improving memory performance.
ESTHER : Haider_2018_Metab.Brain.Dis_33_39
PubMedSearch : Haider_2018_Metab.Brain.Dis_33_39
PubMedID: 29027091

Title : The protective effect of alpha-lipoic acid against bisphenol A-induced neurobehavioral toxicity - Khan_2018_Neurochem.Int_118_166
Author(s) : Khan J , Salhotra S , Ahmad S , Sharma S , Abdi SAH , Banerjee BD , Parvez S , Gupta S , Raisuddin S
Ref : Neurochem Int , 118 :166 , 2018
Abstract : Bisphenol A (BPA), a well-known xenoestrogen, is ubiquitously utilized in manufacturing of polycarbonated plastics. Convincing evidence suggests that BPA induces neurotoxicity and certain behavioral deficits. alpha-Lipoic acid (ALA) supplementation has shown protective effect against heart and liver diseases, diabetes, and neurological debility associated with aging. We studied the neuromodulatory effect of ALA against neurotoxicity of BPA in vitro in C8-D1A mouse astrocyte cell line and in vivo in C57BL/6J male mice. In vitro ALA (100muM) protected cells from BPA (30muM)-induced reactive oxygen species generation and increased activity of glial fibrillary acidic protein. ALA showed reduction in cell death in astrocytes treated with BPA. In vivo ALA (50mg/kg) increased the neurospecific acetylcholinesterase activity and decreased the monoamine oxidase activity altered by BPA exposure (10mg/kg, per os x 30 days). In addition to neuroprotective effects, ALA also showed protective effects against BPA-induced oxidative stress. We observed that ALA significantly replenished the declined neurobehavioral and cognitive performances, decreased muscle coordination and alerted short-term recognition memory in mice exposed to BPA. Our results suggest that ALA has a promising role in modulating BPA-induced neurotoxicity in C8-D1A mouse astrocyte cells as well as neurochemical and neurobehavioral deficits in C57BL/6J male mice and its antioxidant and free radical scavenging activities may in part be responsible for such an effect.
ESTHER : Khan_2018_Neurochem.Int_118_166
PubMedSearch : Khan_2018_Neurochem.Int_118_166
PubMedID: 29908256

Title : Chemical Characterization, Analgesic, Antioxidant, and Anticholinesterase Potentials of Essential Oils From Isodon rugosus Wall. ex. Benth - Sadiq_2018_Front.Pharmacol_9_623
Author(s) : Sadiq A , Zeb A , Ullah F , Ahmad S , Ayaz M , Rashid U , Muhammad N
Ref : Front Pharmacol , 9 :623 , 2018
Abstract : Isodon rugosus Wall. ex. Benth is an important species and is used in folk medicine for different types of pains such as abdominal pain, earache, toothache, gastric, and generalized body pain. Recently, we also have reported the antinociceptive potential of chloroform fraction of I. rugosus. In this research, we have investigated the antinociceptive, antioxidant and anti-cholinesterase potentials of essential oils from I. rugosus (Ir.EO), and have determined a possible mechanism of anti-nociception. The Ir.EO was subjected to gas chromatography-mass spectroscopy analysis to find out its chemical constituents. The Ir.EO was assayed for analgesic potential following acetic acid induced writhing, formalin test and hot plate method in animal models. The antioxidant activity was conducted against DPPH and ABTS free radicals following spectroscopic analysis. The cholinesterase inhibitory assays were performed using Ellman's assay. The GC-MS analysis of Ir.EO revealed the identification of 141 compounds. Ir.EO demonstrated strong antinociceptive potential in all three in-vivo models. With the use of nalaxone, it was confirmed that the essential oil was acting on the central pathway of nociception. The Ir.EO also exhibited strong free radicals scavenging potential, exhibiting IC50 values of 338 and 118 mug/ml for DPPH and ABTS free radicals respectively. In AChE and BChE inhibitory assays, the observed IC50 values were 93.56 and 284.19 mug/ml respectively. The encouraging antinociceptive, antioxidant and anticholinesterase results revealed that Ir.EO is a rich source of bioactive compounds as obvious from the GC-MS results.
ESTHER : Sadiq_2018_Front.Pharmacol_9_623
PubMedSearch : Sadiq_2018_Front.Pharmacol_9_623
PubMedID: 29950997

Title : Selective dual cholinesterase inhibitors from Aconitum laeve - Ahmad_2017_J.Asian.Nat.Prod.Res__1
Author(s) : Ahmad H , Ahmad S , Shah SAA , Khan HU , Khan FA , Ali M , Latif A , Shaheen F , Ahmad M
Ref : J Asian Nat Prod Res , :1 , 2017
Abstract : New lycoctonine-type dual cholinesterase inhibitor, swatinine-C (1), along with three known norditerpenoid alkaloids, hohenackerine (2), aconorine (5) and lappaconitine (6) and two synthetically known but phytochemically new benzene derivatives, methyl 2-acetamidobenzoate (3) and methyl 4-[2-(methoxycarbonyl)anilino]-4-oxobutanoate (4), was isolated from the roots of A. laeve. Structures of new and known compounds (1-6) were established on the basis of latest spectroscopic techniques and by close comparison with the data available in literature. In vitro, compounds (1-6) were tested against AChE and BChE inhibitory activities. Compounds 1 and 2 showed competitive inhibition against AChE (IC50 = 3.7 muM, 4.53 muM) and BChE (IC50 = 12.23 muM, 9.94 muM), respectively. Compounds 5 and 6 showed promising noncompetitive type of inhibitory profile against AChE (IC50 = 2.51 and 6.13 muM) only. Compounds 3 and 4 showed weak inhibitory profile against both AChE and BChE.
ESTHER : Ahmad_2017_J.Asian.Nat.Prod.Res__1
PubMedSearch : Ahmad_2017_J.Asian.Nat.Prod.Res__1
PubMedID: 28463565

Title : Anti-Alzheimer's Studies on beta-Sitosterol Isolated from Polygonum hydropiper L - Ayaz_2017_Front.Pharmacol_8_697
Author(s) : Ayaz M , Junaid M , Ullah F , Subhan F , Sadiq A , Ali G , Ovais M , Shahid M , Ahmad A , Wadood A , El-Shazly M , Ahmad N , Ahmad S
Ref : Front Pharmacol , 8 :697 , 2017
Abstract : The family Polygonaceae is known for its traditional use in the management of various neurological disorders including Alzheimer's disease (AD). In search of new anti-AD drugs, beta-sitosterol isolated from Polygonum hydropiper was subjected to in vitro, in vivo, behavioral and molecular docking studies to confirm its possibility as a potential anti-Alzheimer's agent. The in vitro AChE, BChE inhibitory potentials of beta-sitosterol were investigated following Ellman's assay. The antioxidant activity was tested using DPPH, ABTS and H2O2 assays. Behavioral studies were performed on a sub-strain of transgenic mice using shallow water maze (SWM), Y-maze and balance beam tests. beta-sitosterol was tested for in vivo inhibitory potentials against cholinesterase's and free radicals in the frontal cortex (FC) and hippocampus (HC). The molecular docking study was performed to predict the binding mode of beta-sitosterol in the active sites of AChE and BChE as inhibitor. Considerable in vitro and in vivo cholinesterase inhibitory effects were observed in the beta-sitosterol treated groups. beta-sitosterol exhibited an IC50 value of 55 and 50 mug/ml against AChE and BChE respectively. Whereas, the activity of these enzymes were significantly low in FC and HC homogenates of transgenic animals. Molecular docking studies also support the binding of beta-sitosterol with the target enzyme and further support the in vitro and in vivo results. In the antioxidant assays, the IC50 values were observed as 140, 120, and 280 mug/ml in the DPPH, ABTS and H2O2 assays respectively. The free radicals load in the brain tissues was significantly declined in the beta-sitosterol treated animals as compared to the transgenic-saline treated groups. In the memory assessment and coordination tasks including SWM, Y-maze and balance beam tests, beta-sitosterol treated transgenic animals showed gradual improvement in working memory, spontaneous alternation behavior and motor coordination. These results conclude that beta-sitosterol is a potential compound for the management of memory deficit disorders like AD.
ESTHER : Ayaz_2017_Front.Pharmacol_8_697
PubMedSearch : Ayaz_2017_Front.Pharmacol_8_697
PubMedID: 29056913

Title : Development of AD like symptoms following co-administration of AlCl3 and D-gal in rats: A neurochemical, biochemical and behavioural study - Liaquat_2017_Pak.J.Pharm.Sci_30_647
Author(s) : Liaquat L , Ahmad S , Sadir S , Batool Z , Khaliq S , Tabassum S , Emad S , Madiha S , Shahzad S , Haider S
Ref : Pak J Pharm Sci , 30 :647 , 2017
Abstract : Alzheimer's disease (AD) is an age-related neurodegenerative disorder associated with neurochemical and neurobehavioural alterations. Aluminium (Al) is considered as a contributing factor in the etiology of several neurodegenerative disorders like AD. D-galactose (D-gal) is a physiological nutrient but over supply induces some neurochemical and biochemical changes that exacerbate natural aging process. In this study, we aimed to develop AD animal model by co-administration of Al and D-gal in rats. Male albino Wistar rats were intraperitoneally injected with AlCl3 and D-gal at a dose of 150mg/kg and 300mg/kg respectively for one week. After one week rats were subjected to behavioural analysis. After behavioural analysis rats were decapitated to remove their brain. Biochemical and neurochemical analysis were conducted in whole brain. AlCl3+D-gal significantly induced depressive and anxious behaviour in rats. Rats cognitive abilities were also significantly impaired following AlCl3 and D-gal co-administration. AlCl3+D-gal significantly altered antioxidant enzyme activities and biogenic amine levels in whole brain. A marked increase in brain lipid peroxidation and acetylcholinesterase activity was found in test rats. These findings suggest that co-administration of AlCl3 and D-gal for one week could induce AD like symptoms and may be used to develop AD animal model.
ESTHER : Liaquat_2017_Pak.J.Pharm.Sci_30_647
PubMedSearch : Liaquat_2017_Pak.J.Pharm.Sci_30_647
PubMedID: 28650335

Title : Isolation, crystal structure determination and cholinesterase inhibitory potential of isotalatizidine hydrate from Delphinium denudatum - Ahmad_2017_Pharm.Biol_55_680
Author(s) : Ahmad H , Ahmad S , Khan E , Shahzad A , Ali M , Tahir MN , Shaheen F , Ahmad M
Ref : Pharm Biol , 55 :680 , 2017
Abstract : CONTEXT: Delphinium denudatum Wall (Ranunculaceae) is a rich source of diterpenoid alkaloids and is widely used for the treatment of various neurological disorders such as epilepsy, sciatica and Alzheimer's disease. OBJECTIVE: The present study describes crystal structure determination and cholinesterase inhibitory potential of isotalatazidine hydrate isolated from the aerial part of Delphinium denudatum. MATERIALS AND
METHODS: Phytochemical investigation of Delphinium denudatum resulted in the isolation of isotalatazidine hydrate in crystalline form. The molecular structure of the isolated compound was established by X-ray diffraction. The structural data (bond length and angles) of the compound were calculated by Density Functional Theory (DFT) using B3LYP/6-31 + G (p) basis set. The cholinesterase inhibitory potential of the isolated natural product was determined at various concentrations (62.5, 125, 250, 500 and 1000 mug/mL) followed by molecular docking to investigate the possible inhibitory mechanism of isotalatazidine hydrate.
RESULTS: The compound crystallized in hexagonal unit cell with space group P65. Some other electronic properties such as energies associated with HOMO-LUMO, band gaps, global hardness, global electrophilicity, electron affinity and ionization potential were also calculated by means of B3LYP/6-31 + G (p) basis set. The compound showed competitive type inhibition of both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with IC50 values of 12.13 muM and 21.41 muM, respectively. DISCUSSION AND CONCLUSION: These results suggest that isotalatazidine hydrate is a potent dual cholinesterase inhibitor and can be used as a target drug in Alzheimer diseases. This is first report indicating isotalatazidine hydrate with anticholinesterase potential.
ESTHER : Ahmad_2017_Pharm.Biol_55_680
PubMedSearch : Ahmad_2017_Pharm.Biol_55_680
PubMedID: 28033733

Title : Attenuation of cadmium-induced decline in spatial, habituation and recognition memory by long-term administration of almond and walnut supplementation: Role of cholinergic function - Batool_2017_Pak.J.Pharm.Sci_30_273
Author(s) : Batool Z , Agha F , Ahmad S , Liaquat L , Tabassum S , Khaliq S , Anis L , Sajid I , Emad S , Perveen T , Haider S
Ref : Pak J Pharm Sci , 30 :273 , 2017
Abstract : Excessive exposure of cadmium which is regarded as a neurotoxin can stimulate aging process by inducing abnormality in neuronal function. It has been reported that supplementation of almond and walnut attenuate age-related memory loss. Present study was designed to investigate the weekly administration of cadmium for one month on learning and memory function with relation to cholinergic activity. Cadmium was administered at the dose of 50 mg/kg/week. Whereas, almond and walnut was supplemented at the dose of 400 mg/kg/day along with cadmium administration to separate set of rats. At the end of experiment, memory function was assessed by Morris water maze, open field test and novel object recognition test. Results of the present study showed that cadmium administration significantly reduced memory retention. Reduced acetylcholine levels and elevated acetyl cholinesterase activity were also observed in frontal cortex and hippocampus of cadmium treated rats. Malondialdehyde levels were also significantly increased following the administration of cadmium. Daily supplementation of almond and walnut for 28 days significantly attenuated cadmium-induced memory impairment in rats. Results of the present study are discussed in term of cholinergic activity in cadmium-induced memory loss and its attenuation by nuts supplementation in rats.
ESTHER : Batool_2017_Pak.J.Pharm.Sci_30_273
PubMedSearch : Batool_2017_Pak.J.Pharm.Sci_30_273
PubMedID: 28625954

Title : Chemical composition, antioxidant and anticholinesterase potentials of essential oil of Rumex hastatus D. Don collected from the North West of Pakistan - Ahmad_2016_BMC.Complement.Altern.Med_16_29
Author(s) : Ahmad S , Ullah F , Sadiq A , Ayaz M , Imran M , Ali I , Zeb A , Shah MR
Ref : BMC Complement Altern Med , 16 :29 , 2016
Abstract : BACKGROUND: Ethnomedicinally Rumex hastatus D. Don has been used since long for various ailments especially in neurological disorders. The reported data and the importance of Rumex genus demonstrate the vital medicinal value of R. hastatus.
METHODS: In the current investigational study, isolation of essential oil and its antioxidant and anticholinesterase assays were performed. The essential oil of R. hastatus was analyzed by GC-MS for the first time. The essential oil was evaluated for anticholinesterase and antioxidant assays. The anticholinesterase assay was conducted at various concentrations (62.5 to 1000 mug/ml) against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Similarly, the antioxidant potential was determined using DPPH and ABTS free radicals.
RESULTS: The GC-MS analysis of essential oil showed 123 components. The result recorded for the anticholinesterase assays demonstrated a marked potential against AChE and BChE with IC50 values of 32.54 and 97.38 mug/ml respectively which were comparable with the positive control i.e., galanthamine (AChE, IC50 = 4.73 mug/ml and BChE, IC50 = 11.09 mug/ml). The antioxidant assays against DPPH and ABTS free radicals also exhibited significant scavenging potential with IC50 values of 3.71 and 6.29 mug/ml respectively, while for ascorbic acid the IC50 value was <0.1 mug/ml against both free radicals.
CONCLUSIONS: Based on the current investigational studies, it may be concluded that R. hastatus is an effective source of essential oil's components having anticholinesterase and antioxidant potentials, which after subjecting to drug development may lead to novel drug candidates against neurodegenerative disorders.
ESTHER : Ahmad_2016_BMC.Complement.Altern.Med_16_29
PubMedSearch : Ahmad_2016_BMC.Complement.Altern.Med_16_29
PubMedID: 26810212

Title : Phenolic, flavonoid contents, anticholinesterase and antioxidant evaluation of Iris germanica var\; florentina - Ullah_2015_Nat.Prod.Res__1
Author(s) : Ullah F , Ayaz M , Sadiq A , Hussain A , Ahmad S , Imran M , Zeb A
Ref : Nat Prod Res , :1 , 2015
Abstract : This study was designed to investigate antioxidant and anticholinesterase potential of Iris germanica var; florentina. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potential of plant samples were investigated by Ellman's assay. Antioxidant activity was performed using DPPH, H2O2 and ABTS free radical scavenging assays. Total phenolics and flavonoids contents were expressed in mg GAE/g dry weight and mg RTE/g, respectively. In AChE inhibition assay, Ig.Fl, Ig.Sp and Ig.Cf fractions exhibited highest activity with IC50 values of < 0.1, 5.64 and 19 mug/mL, respectively. In BChE inhibitory assay, Ig.Fl, Ig.Sp, Ig.Cf and Ig.Cr were most active with IC50 of < 0.1, < 0.1, 31 and 78 mug/mL, respectively. In DPPH assay, Ig.Fl and Ig.Cf exhibited highest inhibition of free radicals, 80.52% (IC50 = 9 mug/mL) and 78.30% (IC50 = 8 mug/mL), respectively. In ABTS assay Ig.Cr, Ig.Cf, Ig.Fl and Ig.Sp exhibited IC50 values of < 0.1, 2, 2 and 3 mug/mL, respectively.
ESTHER : Ullah_2015_Nat.Prod.Res__1
PubMedSearch : Ullah_2015_Nat.Prod.Res__1
PubMedID: 26166432

Title : Antioxidant and anticholinesterase investigations of Rumex hastatus D. Don: potential effectiveness in oxidative stress and neurological disorders - Ahmad_2015_Biol.Res_48_20
Author(s) : Ahmad S , Ullah F , Ayaz M , Sadiq A , Imran M
Ref : Biol Res , 48 :20 , 2015
Abstract : BACKGROUND: Rumex species are traditionally used for the treatment of neurological disorders including headache, migraine, depression, paralysis etc. Several species have been scientifically validated for antioxidant and anticholinestrase potentials. This study aims to investigate Rumex hastatus D. Don crude methanolic extract, subsequent fractions, saponins and flavonoids for acetylcholinestrase, butyrylcholinestrase inhibition and diverse antioxidant activities to validate its folkloric uses in neurological disorders. Rumex hastatus crude methanolic extract (Rh. Cr), subsequent fractions; n-hexane (Rh. Hex), chloroform (Rh. Chf), ethyl acetate (Rh. EtAc), aqueous fraction (Rh. Aq), crude saponins (Rh. Sp) and flavonoids (Rh. Fl) were investigated against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) at various concentrations (125, 250, 500, 1000 mug/mL) using Ellman's spectrophotometric analysis. Antioxidant potentials of Rh. Sp and Rh. Fl were evaluated using DPPH, H2O2 and ABTS free radical scavenging assays at 62.5, 125, 250, 500, 1000 mug/mL.
RESULTS: All the test samples showed concentration dependent cholinesterase inhibition and radicals scavenging activity. The AChE inhibition potential of Rh. Sp and Rh. Fl were most prominent i.e., 81.67 +/- 0.88 and 91.62 +/- 1.67 at highest concentration with IC50 135 and 20 mug/mL respectively. All the subsequent fractions exhibited moderate to high AChE inhibition i.e., Rh. Cr, Rh. Hex, Rh. Chf, Rh. EtAc and Rh. Aq showed IC50 218, 1420, 75, 115 and 1210 mug/mL respectively. Similarly, against BChE various plant extracts i.e., Rh. Sp, Rh. Fl, Rh. Cr, Rh. Hex, Rh. Chf, Rh. EtAc and Rh. Aq resulted IC50 165, 175, 265, 890, 92, 115 and 220 mug/mL respectively. In DPPH free radical scavenging assay, Rh. Sp and Rh. Fl showed comparable results with the positive control i.e., 63.34 +/- 0.98 and 76.93 +/- 1.13% scavenging at 1 mg/mL concentration (IC50 312 and 104 mug/mL) respectively. The percent ABTS radical scavenging potential exhibited by Rh. Sp and Rh. Fl (1000 mug/mL) were 82.58 +/- 0.52 and 88.25 +/- 0.67 with IC50 18 and 9 mug/mL respectively. Similarly in H2O2 scavenging assay, the Rh. Sp and Rh. Fl exhibited IC50 175 and 275 mug/mL respectively. CONCLUSION: The strong anticholinesterase and antioxidant activities of Rh. Sp, Rh. Fl and various fractions of R. hastatus support the purported ethnomedicinal uses and recommend R. hastatus as a possible remedy for the treatment of AD and neurodegenerative disorders.
ESTHER : Ahmad_2015_Biol.Res_48_20
PubMedSearch : Ahmad_2015_Biol.Res_48_20
PubMedID: 25857346

Title : Anticholinesterse and antioxidant investigations of crude extracts, subsequent fractions, saponins and flavonoids of atriplex laciniata L.: potential effectiveness in Alzheimer's and other neurological disorders - Kamal_2015_Biol.Res_48_21
Author(s) : Kamal Z , Ullah F , Ayaz M , Sadiq A , Ahmad S , Zeb A , Hussain A , Imran M
Ref : Biol Res , 48 :21 , 2015
Abstract : BACKGROUND: Atriplex laciniata L. was investigated for phenolic, flavonoid contents, antioxidant, anticholinesterase activities, in an attempt to explore its effectiveness in Alzheimer's and other neurological disorders. Plant crude methanolic extract (Al.MeF), subsequent fractions; n-hexane (Al.HxF), chloroform (Al.CfF), ethyl acetate (Al.EaF), aqueous (Al.WtF), Saponins (Al.SPF) and Flavonoids (Al.FLVF) were investigated for DPPH, ABTS and H2O2 free radical scavenging activities. Further these extracts were subjected to acetylcholinesterase (AChE) & butyrylcholinesterase (BChE) inhibitory activities using Ellman's assay. Phenolic and Flavonoid contents were determined and expressed in mg Gallic acid GAE/g and Rutin RTE/g of samples respectively.
RESULTS: In DPPH free radicals scavenging assay, Al.FLVF, Al.SPF and Al.MeF showed highest activity causing 89.41 +/- 0.55, 83.37 +/- 0.34 and 83.37 +/- 0.34% inhibition of free radicals respectively at 1 mg/mL concentration. IC50 for these fractions were 33, 83 and 82 mug/mL respectively. Similarly, plant extracts showed high ABTS scavenging potential, i.e. Al.FLVF (90.34 +/- 0.55), Al.CfF (83.42 +/- 0.57), Al.MeF (81.49 +/- 0.60) with IC50 of 30, 190 and 70 mug/ml respectively. further, H2O2 percent scavenging was highly appraised in Al.FLVF (91.29 +/- 0.53, IC50 75), Al.SPF (85.35 +/- 0.61, IC50 70) and Al.EaF (83.48 +/- 0.67, IC50 270 mug/mL). All fractions exhibited concentration dependent AChE inhibitory activity as; Al.FLVF, 88.31 +/- 0.57 (IC50 70 mug/mL), Al.SPF, 84.36 +/- 0.64 (IC50 90 mug/mL), Al.MeF, 78.65 +/- 0.70 (IC50 280 mug/mL), Al.EaF, 77.45 +/- 0.46 (IC50 270 mug/mL) and Al.WtF 72.44 +/- 0.58 (IC50 263 mug/mL) at 1 mg/mL. Likewise the percent BChE inhibitory activity was most obvious in Al.FLVF 85.46 +/- 0.62 (IC50 100 mug/mL), Al.CfF 83.49 +/- 0.46 (IC50 160 mug/mL), Al.MeF 82.68 +/- 0.60 (IC50 220 mug/mL) and Al.SPF 80.37 +/- 0.54 (IC50 120 mug/mL).
CONCLUSIONS: These results stipulate that A. laciniata is enriched with phenolic and flavonoid contents that possess significant antioxidant and anticholinestrase effects. This provide pharmacological basis for the presence of compounds that may be effective in Alzheimer's and other neurological disorders.
ESTHER : Kamal_2015_Biol.Res_48_21
PubMedSearch : Kamal_2015_Biol.Res_48_21
PubMedID: 25889712

Title : Comparative chemical profiling, cholinesterase inhibitions and anti-radicals properties of essential oils from Polygonum hydropiper L: A Preliminary anti- Alzheimer's study - Ayaz_2015_Lipids.Health.Dis_14_141
Author(s) : Ayaz M , Junaid M , Ullah F , Sadiq A , Khan MA , Ahmad W , Shah MR , Imran M , Ahmad S
Ref : Lipids Health Dis , 14 :141 , 2015
Abstract : BACKGROUND: Cholinesterase inhibition is a vital target for the development of novel and mechanism based inhibitors, owing to their role in the breakdown of acetylcholine (ACh) neurotransmitter to treat various neurological disorders including Alzheimer's disease (AD). Similarly, free radicals are implicated in the progression of various diseases like neurodegenerative disorders. Due to lipid solubility and potential to easily cross blood brain barrier, this study was designed to investigate the anticholinesterase and antioxidant potentials of the standardized essential oils from the leaves and flowers of Polygonum hydropiper.
METHODS: Essential oils from the leaves (Ph.LO) and flowers (Ph.FO) of P. hdropiper were isolated using Clevenger apparatus. Oil samples were analyzed by GC-MS to identify major components and to attribute the antioxidant and anticholinesterase activity to specific components. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potentials of the samples were determined following Ellman's assay. Antioxidant assays were performed using 1,1-diphenyl,2-picrylhydrazyl (DPPH), 2,2-azinobis[3-ethylbenzthiazoline]-6-sulfonic acid (ABTS) and hydrogen peroxide (H2O2) free radical scavenging assays.
RESULTS: In the GC-MS analysis 141 and 122 compounds were indentified in Ph.LO and Ph.FO respectively. Caryophylene oxide (41.42 %) was the major component in Ph.FO while decahydronaphthalene (38.29 %) was prominent in Ph.LO. In AChE inhibition, Ph.LO and Ph.FO exhibited 87.00** and 79.66***% inhibitions at 1000 mug/ml with IC50 of 120 and 220 mug/ml respectively. The IC50 value for galanthamine was 15 mug/ml. In BChE inhibitory assay, Ph.LO and Ph.FO caused 82.66*** (IC50 130 mug/ml) and 77.50***% (IC50 225 mug/ml) inhibitions respectively at 1000 mug/ml concentration. In DPPH free radical scavenging assay, Ph.LO and Ph.FO exhibited IC50 of 20 and 200 mug/ml respectively. The calculated IC50s were 180 & 60 mug/ml for Ph.LO, and 45 & 50 mug/ml for Ph.FO in scavenging of ABTS and H2O2 free radicals respectively.
CONCLUSIONS: In the current study, essential oils from leaves and flowers of P. hydropiper exhibited dose dependent anticholinesterase and antioxidant activities. Leaves essential oil were more effective and can be subjected to further in-vitro and in-vivo anti-Alzheimer's studies.
ESTHER : Ayaz_2015_Lipids.Health.Dis_14_141
PubMedSearch : Ayaz_2015_Lipids.Health.Dis_14_141
PubMedID: 26530857

Title : A single nucleotide polymorphism in the acetylcholinesterase gene of the predatory mite Kampimodromus aberrans (Acari: Phytoseiidae) is associated with chlorpyrifos resistance. - Cassanelli_2015_Biol.Control_90_75
Author(s) : Cassanelli S , Ahmad S , Duso C , Tirello P , Pozzebon A
Ref : Biol Control , 90 :75 , 2015
Abstract : The predatory mite Kampimodromus aberrans (Oudemans) (Acari: Phytoseiidae) is one of the most important biocontrol agents of herbivorous mites in European perennial crops. The use of pesticides, such as organophosphate insecticides (OPs), is a major threat to the success of biocontrol strategies based on predatory mites in these cropping systems. However, resistance to OPs in K. aberrans has recently been reported. The present study investigated the target site resistance mechanisms that are potentially involved in OP insensitivity. In the herbivorous mite Tetranychus urticae Koch (Acari: Tetranychidae), resistance to OPs is due to a modified and insensitive acetylcholinesterase (AChE; EC: that bears amino acid substitution F331W (AChE Torpedo numbering). To determine whether the predators and prey have evolved analogous molecular mechanisms to withstand the same selective pressure, the AChE cDNA from a putative orthologous gene was cloned and sequenced from susceptible and resistant strains of K. aberrans. No synonymous mutation coding for a G119S substitution was determined to be strongly associated with the resistant phenotype instead of the alternative F331W. Because the same mutation in T. urticae AChE was not associated with comparable levels of chlorpyrifos resistance, the role of the G119S substitution in defining insensitive AChE in K. aberrans remains unclear. G119S AChE genotyping can be useful in ecological studies that trace the fate of resistant strains after field release or in marker-assisted selection of improved populations of K. aberrans to achieve multiple resistance phenotypes through gene pyramiding. The latent complexity of the target site resistance in K. aberrans vs. that of T. urticae is also discussed in the context of data from the genome project of the predatory mite Metaseiulus occidentalis (Nesbitt) (Acari: Phytoseiidae).
ESTHER : Cassanelli_2015_Biol.Control_90_75
PubMedSearch : Cassanelli_2015_Biol.Control_90_75
Gene_locus related to this paper: 9acar-r4zgq0

Title : Synthesis, anticholinesterase and antioxidant potentials of ketoesters derivatives of succinimides: a possible role in the management of Alzheimer's - Sadiq_2015_Chem.Cent.J_9_31
Author(s) : Sadiq A , Mahmood F , Ullah F , Ayaz M , Ahmad S , Haq FU , Khan G , Jan MS
Ref : Chem Cent J , 9 :31 , 2015
Abstract : BACKGROUND: Based on the pharmacological potency and structural features of succinimides, this study was designed to synthesize new ketoesters derivatives of succinimides. Furthermore, the synthesized compounds were evaluated for their possible anticholinesterase and antioxidant potentials. The compounds were synthesized by organocatalytic Michael additions of alpha-ketoesters to N-aryl maleimides. Acetyl and butyrylcholinesterase inhibitory activities were determined using Ellman's spectrophotometric assay. The antioxidant activity was performed with DPPH and ABTS free radicals scavenging assay.
RESULTS: The Michael additions of alpha-ketoesters to maleimides was promoted by 8-hydroxyquinoline. The organocatalyst (8-hydroxyquinoline, 20 mol %) produced the compounds in relatively shorter time (20-24 h) and with excellent isolated yields (84-98 %). The synthesized compounds (1-4) showed outstanding acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potentials, i.e., 98.75 and 90.00 % respectively for compound 2, with IC50 < 0.1 mug/mL. Additionally, compounds 1-4 revealed moderate antioxidant activity at different concentrations. In DPPH free radical scavenging assay, compound 1 showed dominant result with 72.41 +/- 0.45, 52.49 +/- 0.78 and 35.60 +/- 0.75 % inhibition at concentrations of 1000, 500 and 250 mug/mL respectively, IC50 value of 440 mug/mL. However, the free radical scavenging was better when used ABTS free radicals. In ABTS free radicals scavenging assay compound 1 exhibited 88.51 +/- 0.62 % inhibition at highest tested concentration i.e., 1000 mug/mL.
CONCLUSIONS: Herein, we have synthesized four ketoesters derivatives of succinimides in a single step reaction and high yields. As a highlight, we have showed a first report on the anticholinesterase and antioxidant potentials of succinimides. All the compounds showed overwhelming enzyme inhibitions and moderate antioxidant potentials. Graphical AbstractGraphical representation of synthesis, anticholinesterase and antioxidant potentials of ketoester derivatives of succinimides.
ESTHER : Sadiq_2015_Chem.Cent.J_9_31
PubMedSearch : Sadiq_2015_Chem.Cent.J_9_31
PubMedID: 26064188

Title : Active compounds from a diverse library of triazolothiadiazole and triazolothiadiazine scaffolds: Synthesis, crystal structure determination, cytotoxicity, cholinesterase inhibitory activity, and binding mode analysis - Khan_2014_Bioorg.Med.Chem_22_6163
Author(s) : Khan I , Ibrar A , Zaib S , Ahmad S , Furtmann N , Hameed S , Simpson J , Bajorath J , Iqbal J
Ref : Bioorganic & Medicinal Chemistry , 22 :6163 , 2014
Abstract : In an effort to identify novel cholinesterase candidates for the treatment of Alzheimer's disease (AD), a diverse array of potentially bioactive compounds including triazolothiadiazoles (4a-h and 5a-f) and triazolothiadiazines (6a-h) was obtained in good yields through the cyclocondensation reaction of 4-amino-5-(pyridin-3-yl)-4H-1,2,4-triazole-3-thiol (3) with various substituted aryl/heteroaryl/aryloxy acids and phenacyl bromides, respectively. The structures of newly prepared compounds were confirmed by IR, (1)H and (13)C NMR spectroscopy and, in case of 4a, by single crystal X-ray diffraction analysis. The purity of the synthesized compounds was ascertained by elemental analysis. The newly synthesized conjugated heterocycles were screened for cholinesterase inhibitory activity against electric eel acetylcholinesterase (EeAChE) and horse serum butyrylcholinesterase (hBChE). Among the evaluated hybrids, several compounds were identified as potent inhibitors. Compounds 5b and 5d were most active with an IC50 value of 3.09+/-0.154 and 11.3+/-0.267muM, respectively, against acetylcholinesterase, whereas 5b, 6a and 6g were most potent against butyrylcholinesterase, with an IC50 of 0.585+/-0.154, 0.781+/-0.213, and 1.09+/-0.156muM, respectively, compared to neostigmine and donepezil as standard drugs. The synthesized heteroaromatic compounds were also tested for their cytotoxic potential against lung carcinoma (H157) and vero cell lines. Among them, compound 6h exhibited highest antiproliferative activity against H157 cell lines, with IC50 value of 0.96+/-0.43muM at 1mM concentration as compared to vincristine (IC50=1.03+/-0.04muM), standard drug used in this study.
ESTHER : Khan_2014_Bioorg.Med.Chem_22_6163
PubMedSearch : Khan_2014_Bioorg.Med.Chem_22_6163
PubMedID: 25257911

Title : Phenolic contents, antioxidant and anticholinesterase potentials of crude extract, subsequent fractions and crude saponins from Polygonum hydropiper L - Ayaz_2014_BMC.Complement.Altern.Med_14_145
Author(s) : Ayaz M , Junaid M , Ahmed J , Ullah F , Sadiq A , Ahmad S , Imran M
Ref : BMC Complement Altern Med , 14 :145 , 2014
Abstract : BACKGROUND: We investigated Polygonum hydropiper L. (P. hydropiper) for phenolic contents, antioxidant, anticholinesterase activities, in an attempt to rationalize its use in neurological disorders.
METHODS: Plant crude extract (Ph.Cr), its subsequent fractions: n-hexane (Ph.Hex), chloroform (Ph.Chf), ethyl acetate (Ph.EtAc), n-Butanol (Ph.Bt), aqueous (Ph.Aq) and saponins (Ph.Sp) were evaluated for 1,1-diphenyl,2-picrylhydrazyl (DPPH), 2,2-azinobis[3-ethylbenzthiazoline]-6-sulfonic acid (ABTS) free radical scavenging potential. Further, acetylcholinesterase (AChE) & butyrylcholinesterase (BChE) inhibitory activities were performed using Ellman's assay. Moreover, total phenolic contents of plant extracts were determined and expressed in mg of gallic acid equivalent per gram of dry sample (mg GAE/g dry weight).
RESULTS: Among different fractions, Ph.Cr (90.82), Ph.Chf (178.16), Ph.EtAc (203.44) and Ph.Bt (153.61) exhibited high phenolic contents. All fractions showed concentration dependent DPPH scavenging activity, with Ph.EtAc 71.33% (IC50 15 mug/ml), Ph.Bt 71.40% (IC50 3 mug/ml) and Ph.Sp 71.40% (IC50 35 mug/ml) were most potent. The plant extracts exhibited high ABTS scavenging ability i.e. Ph.Bt (91.03%), Ph.EtAc (90.56%), Ph.Sp (90.84%), Ph.Aq (90.56%) with IC50 < 0.01 mug/ml. All fractions showed moderate to high AChE inhibitory activity as; Ph.Cr, 86.87% (IC50 330 mug/ml), Ph.Hex, 87.49% (IC50 35 mug/ml), Ph.Chf, 84.76% (IC50 55 mug/ml), Ph.Sp, 87.58% (IC50 108 mug/ml) and Ph.EtAc 79.95% (IC50 310 mug/ml) at 1 mg/ml). Furthermore the BChE inhibitory activity was most prominent in Ph.Hex 90.30% (IC50 40 mug/ml), Ph.Chf 85.94% (IC50 215 mug/ml), Ph.Aq 87.62% (IC50 3 mug/ml) and Ph.EtAc 81.01% (IC50 395 mug/ml) fractions.
CONCLUSIONS: In this study, for the first time, we determined phenolic contents, isolated crude saponins, investigated antioxidant and anticholinestrase potential of P. hydropiper extracts. The results indicate that P. hydropiper is enriched with potent bioactive compounds and warrant further investigation by isolation and structural elucidation to find novel and affordable compounds for the treatment of various neurological disorders.
ESTHER : Ayaz_2014_BMC.Complement.Altern.Med_14_145
PubMedSearch : Ayaz_2014_BMC.Complement.Altern.Med_14_145
PubMedID: 24884823

Title : The impact of insecticides applied in apple orchards on the predatory mite Kampimodromus aberrans (Acari: Phytoseiidae) - Duso_2014_Exp.Appl.Acarol_62_391
Author(s) : Duso C , Ahmad S , Tirello P , Pozzebon A , Klaric V , Baldessari M , Malagnini V , Angeli G
Ref : Exp Appl Acarol , 62 :391 , 2014
Abstract : Kampimodromus aberrans is an effective predatory mite in fruit orchards. The side-effects of insecticides on this species have been little studied. Field and laboratory experiments were conducted to evaluate the effects of insecticides on K. aberrans. Field experiments showed the detrimental effects of etofenprox, tau-fluvalinate and spinosad on predatory mites. Spider mite (Panonychus ulmi) populations reached higher densities on plots treated with etofenprox and tau-fluvalinate than in the other treatments. Single or multiple applications of neonicotinoids caused no detrimental effects on predatory mites. In the laboratory, spinosad and tau-fluvalinate caused 100 % mortality. Etofenprox caused a significant mortality and reduced fecundity. The remaining insecticides did not affect female survival except for imidacloprid. Thiamethoxam, clothianidin, thiacloprid, chlorpyrifos, lufenuron and methoxyfenozide were associated with a significant reduction in fecundity. No effect on fecundity was found for indoxacarb or acetamiprid. Escape rate of K. aberrans in laboratory was relatively high for etofenprox and spinosad, and to a lesser extent thiacloprid. The use of etofenprox, tau-fluvalinate and spinosad was detrimental for K. aberrans and the first two insecticides induced spider mite population increases. The remaining insecticides caused no negative effects on predatory mites in field trials. Some of them (reduced fecundity and repellence) should be considered with caution in integrated pest management programs.
ESTHER : Duso_2014_Exp.Appl.Acarol_62_391
PubMedSearch : Duso_2014_Exp.Appl.Acarol_62_391
PubMedID: 24114337

Title : Investigations of anticholinestrase and antioxidant potentials of methanolic extract, subsequent fractions, crude saponins and flavonoids isolated from Isodon rugosus - Zeb_2014_Biol.Res_47_76
Author(s) : Zeb A , Sadiq A , Ullah F , Ahmad S , Ayaz M
Ref : Biol Res , 47 :76 , 2014
Abstract : BACKGROUND: Based on the ethnomedicinal uses and the effective outcomes of natural products in various diseases, this study was designed to evaluate Isodon rugosus as possible remedy in oxidative stress, alzheimer's and other neurodegenerative diseases. Acetylecholinestrase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of crude methanolic extract (Ir.Cr), resultant fractions (n-hexane (Ir.Hex), chloroform (Ir.Cf), ethyl acetate (Ir.EtAc), aqueous (Ir.Aq)), flavonoids (Ir.Flv) and crude saponins (Ir.Sp) of I. rugosus were investigated using Ellman's spectrophotometric method. Antioxidant potential of I. rugosus was determined using DPPH, H2O2 and ABTS free radicals scavenging assays. Total phenolic and flavonoids contents of plant extracts were determined and expressed in mg GAE/g dry weight and mg RTE/g of dry sample respectively.
RESULTS: Among different fractions Ir.Flv and Ir.Cf exhibited highest inhibitory activity against AChE (87.44 +/- 0.51, 83.73 +/- 0.64%) and BChE (82.53 +/- 0.71, 88.55 +/- 0.77%) enzymes at 1 mg/ml with IC50 values of 45, 50 for AChE and 40, 70 mug/ml for BChE respectively. Activity of these fractions were comparable to galanthamine causing 96.00 +/- 0.30 and 88.61 +/- 0.43% inhibition of AChE and BChE at 1 mg/ml concentration with IC50 values of 20 and 47 mug/ml respectively. In antioxidant assays, Ir.Flv, Ir.Cf, and Ir.EtAc demonstrated highest radicals scavenging activities in DPPH and H2O2 assays which were comparable to ascorbic acid. Ir.Flv was found most potent with IC50 of 19 and 24 mug/ml against DPPH and H2O2 radicals respectively. Whereas antioxidant activates of plant samples against ABTS free radicals was moderate. Ir.Cf, Ir.EtAc and Ir.Cr showed high phenolic and flavonoid contents and concentrations of these compounds in different fractions correlated well to their antioxidant and anticholinestrase activities. CONCLUSION: It may be inferred from the current investigations that the Ir.Sp, Ir.Flv and various fractions of I. rugosus are good sources of anticholinesterase and antioxidant compounds. Different fractions can be subjected to activity guided isolation of bioactive compounds effective in neurological disorders.
ESTHER : Zeb_2014_Biol.Res_47_76
PubMedSearch : Zeb_2014_Biol.Res_47_76
PubMedID: 25723481

Title : Draft Genome Sequence of Sphingobium chinhatense Strain IP26T, Isolated from a Hexachlorocyclohexane Dumpsite - Niharika_2013_Genome.Announc_1_e00680
Author(s) : Niharika N , Sangwan N , Ahmad S , Singh P , Khurana JP , Lal R
Ref : Genome Announc , 1 : , 2013
Abstract : Sphingobium chinhatense strain IP26(T) is a conducive hexachlorocyclohexane (HCH) degrader isolated from a heavily contaminated (450 mg HCH/g soil) HCH dumpsite. IP26(T) degrades alpha-, beta-, gamma-, and delta-HCH, which are highly persistent in the environment. Here we report the draft genome sequence (~5.8 Mbp) of this strain.
ESTHER : Niharika_2013_Genome.Announc_1_e00680
PubMedSearch : Niharika_2013_Genome.Announc_1_e00680
PubMedID: 23990581
Gene_locus related to this paper: sphju-d4z7y1 , sphju-d4z363

Title : Antioxidant, antityrosinase, anticholinesterase, and nitric oxide inhibition activities of three malaysian macaranga species - Mazlan_2013_ScientificWorldJournal_2013_312741
Author(s) : Mazlan NA , Mediani A , Abas F , Ahmad S , Shaari K , Khamis S , Lajis NH
Ref : ScientificWorldJournal , 2013 :312741 , 2013
Abstract : The methanol extracts of three Macaranga species (M. denticulata, M. pruinosa, and M. gigantea) were screened to evaluate their total phenolic contents and activities as cholinesterase inhibitors, nitric oxide (NO) production inhibitors, tyrosinase inhibitors, and antioxidants. The bark of M. denticulata showed the highest total phenolic content (2682 mg gallic acid equivalent (GAE)/100 g) and free radical scavenging activity (IC50 = 0.063 mg/mL). All of the samples inhibited linoleic acid peroxidation by greater than 80%, with the leaves of M. gigantea exhibiting the highest inhibition of 92.21%. Most of the samples exhibited significant antioxidant potential. The bark of M. denticulata and the leaves of both M. pruinosa and M. gigantea exhibited greater than 50% tyrosinase inhibition, with the bark of M. denticulata having the highest percentage of inhibition (68.7%). The bark and leaves of M. denticulata exhibited greater than 50% inhibition (73.82% and 54.50%, resp.) of the acetylcholinesterase enzyme (AChE), while none of the samples showed any significant inhibition of butyrylcholinesterase (BChE). Only the bark of M. denticulata and M. gigantea displayed greater than 50% inhibition of nitric oxide production in cells (81.79% and 56.51%, resp.). These bioactivities indicate that some Macaranga spp. have therapeutic potential in medicinal research.
ESTHER : Mazlan_2013_ScientificWorldJournal_2013_312741
PubMedSearch : Mazlan_2013_ScientificWorldJournal_2013_312741
PubMedID: 24319356

Title : Probing protein stability and proteolytic resistance by loop scanning: a comprehensive mutational analysis - Ahmad_2012_Protein.Sci_21_433
Author(s) : Ahmad S , Kumar V , Ramanand KB , Rao NM
Ref : Protein Science , 21 :433 , 2012
Abstract : Improvement in protein thermostability was often found to be associated with increase in its proteolytic resistance as revealed by comparative studies of homologous proteins from extremophiles or mutational studies. Structural elements of protein responsible for this association are not firmly established although loops are implicated indirectly due to their structural role in protein stability. To get a better insight, a detailed study of protein wide mutants and their influence on stability and proteolytic resistance would be helpful. To generate such a data set, a model protein, Bacillus subtilis lipase was subjected to loop scanning site-saturation mutagenesis on 86 positions spanning all loops including termini. Upon screening of ~16,000 clones, 17 single mutants with improved thermostability were identified with increment in apparent melting temperature (Tm(app) ) by 1-6 degrees C resulting in an increase in free energy of unfolding (DeltaG(unf) ) by 0.04-1.16 kcal/mol. Proteolytic resistance of all single mutants upon incubation with nonspecific protease, Subtilisin A, was determined. Upon comparison, post-proteolysis residual activities as well as kinetics of proteolysis of mutants showed excellent correlation with DeltaG(unf) , (r > 0.9), suggesting that proteolysis was strongly correlated with the global stability of this protein. This significant correlation in this set, with least possible sequence changes (single aa substitution), while covering >60% of protein surface strongly argues for the covariance of these two variables. Compared to studies from extremophiles, with large sequence heterogeneity, the observed correlation in such a narrow sequence space (DeltaDeltaG(unf) = 1.57 kcal(-)(1)) justifies the robustness of this relation.
ESTHER : Ahmad_2012_Protein.Sci_21_433
PubMedSearch : Ahmad_2012_Protein.Sci_21_433
PubMedID: 22246996

Title : New class of acetylcholinesterase inhibitors from the stem bark of Knema laurina and their structural insights - Akhtar_2011_Bioorg.Med.Chem.Lett_21_4097
Author(s) : Akhtar MN , Lam KW , Abas F , Maulidiani , Ahmad S , Shah SA , Atta ur R , Choudhary MI , Lajis NH
Ref : Bioorganic & Medicinal Chemistry Lett , 21 :4097 , 2011
Abstract : Bioassay-guided extraction of the stem bark of Knema laurina showed the acetylcholinesterase (AChE) inhibitory activity of DCM and hexane fractions. Further repeated column chromatography of hexane and DCM fractions resulted in the isolation and purification of five alkenyl phenol and salicylic acid derivatives. New compounds, (+)-2-hydroxy-6-(10'-hydroxypentadec-8'(E)-enyl)benzoic acid (1) and 3-pentadec-10'(Z)-enylphenol (2), along with known 3-heptadec-10'(Z)-enylphenol (3), 2-hydroxy-6-(pentadec-10'(Z)-enyl)benzoic acid (4), and 2-hydroxy-6-(10'(Z)-heptadecenyl)benzoic acid (5) were isolated from the stem bark of this plant. Compounds (1-5) were tested for their acetylcholinesterase inhibitory activity. The structures of these compounds were elucidated by the 1D and 2D NMR spectroscopy, mass spectrometry and chemical derivatizations. Compound 5 showed strong acetylcholinesterase inhibitory activity with IC(50) of 0.573 +/- 0.0260 uM. Docking studies of compound 5 indicated that the phenolic compound with an elongated side chain could possibly penetrate deep into the active site of the enzyme and arrange itself through - interaction, H-bonding, and hydrophobic contacts with some critical residues along the complex geometry of the active gorge.
ESTHER : Akhtar_2011_Bioorg.Med.Chem.Lett_21_4097
PubMedSearch : Akhtar_2011_Bioorg.Med.Chem.Lett_21_4097
PubMedID: 21641207

Title : In vitro evolved non-aggregating and thermostable lipase: structural and thermodynamic investigation - Kamal_2011_J.Mol.Biol_413_726
Author(s) : Kamal MZ , Ahmad S , Molugu TR , Vijayalakshmi A , Deshmukh MV , Sankaranarayanan R , Rao NM
Ref : Journal of Molecular Biology , 413 :726 , 2011
Abstract : Rational and in vitro evolutionary approaches to improve either protein stability or aggregation resistance were successful, but empirical rules for simultaneous improvement of both stability and aggregation resistance under denaturing conditions are still to be ascertained. We have created a robust variant of a lipase from Bacillus subtilis named "6B" using multiple rounds of in vitro evolution. T(m) and optimum activity temperature of 6B is 78 degrees C and 65 degrees C, respectively, which is ~22 degrees C and 30 degrees C higher than that of wild-type lipase. Most significantly, 6B does not aggregate upon heating. Physical basis of remarkable thermostability and non-aggregating behavior of 6B was explored using X-ray crystallography, NMR and differential scanning calorimetry. Our structural investigations highlight the importance of tightening of mobile regions of the molecule such as loops and helix termini to attain higher thermostability. Accordingly, NMR studies suggest a very rigid structure of 6B lipase. Further investigation suggested that reduction/perturbation of the large hydrophobic patches present in the wild-type protein structure, decreased propensity of amino acid sequence for aggregation and absence of aggregation-prone intermediate during thermal unfolding of 6B can account for its resistance to aggregation. Overall, our study suggest that better anchoring of the loops with the rest of the protein molecule through mutations particularly on the sites that perturb/disturb the exposed hydrophobic patches can simultaneously increase protein stability and aggregation resistance.
ESTHER : Kamal_2011_J.Mol.Biol_413_726
PubMedSearch : Kamal_2011_J.Mol.Biol_413_726
PubMedID: 21925508
Gene_locus related to this paper: bacsu-lip

Title : A homogeneous cell-based assay for measurement of endogenous paraoxonase 1 activity - Ahmad_2010_Anal.Biochem_400_1
Author(s) : Ahmad S , Carter JJ , Scott JE
Ref : Analytical Biochemistry , 400 :1 , 2010
Abstract : Paraoxonase 1 (PON1) is a high-density lipoprotein-associated enzyme that plays an important role in organophosphate detoxification and prevention of atherosclerosis. Thus, there is significant interest in identifying nutritional and pharmacological enhancers of PON1 activity. To identify such compounds, we developed a rapid homogeneous assay to detect endogenous cell-associated PON1 activity. PON1 activity was measured by the simple addition of fluorigenic PON1 substrate DEPFMU to live Huh7 cells in medium and monitoring change in fluorescence. A specific PON1 inhibitor, 2-hydroxyquinoline, was used to confirm that the observed activity was due to PON1. The assay was optimized and characterized with regard to time course, substrate and sodium chloride concentration, number of cells, and tolerance to dimethyl sulfoxide and serum. Aspirin, quercetin, and simvastatin are compounds reported to increase PON1 expression. Consistent with the literature and Western blot data, these compounds enhanced PON1 activity in this assay with comparable efficacies and potencies. A known toxic compound did not increase assay signal. This assay method also detected PON1 activity in normal hepatocytes. Thus, a novel homogeneous assay for detection of endogenous PON1 expression has been developed and is amenable to high-throughput screening for the identification of small molecules that enhance PON1 expression.
ESTHER : Ahmad_2010_Anal.Biochem_400_1
PubMedSearch : Ahmad_2010_Anal.Biochem_400_1
PubMedID: 20096260

Title : Mutations in salt-bridging residues at the interface of the core and lid domains of epoxide hydrolase StEH1 affect regioselectivity, protein stability and hysteresis - Lindberg_2010_Arch.Biochem.Biophys_495_165
Author(s) : Lindberg D , Ahmad S , Widersten M
Ref : Archives of Biochemistry & Biophysics , 495 :165 , 2010
Abstract : Epoxide hydrolase, StEH1, shows hysteretic behavior in the catalyzed hydrolysis of trans-2-methylstyrene oxide (2-MeSO)(1). Linkage between protein structure dynamics and catalytic function was probed in mutant enzymes in which surface-located salt-bridging residues were substituted. Salt-bridges at the interface of the alpha/beta-hydrolase fold core and lid domains, as well as between residues in the lid domain, between Lys(179)-Asp(202), Glu(215)-Arg(41) and Arg(236)-Glu(165) were disrupted by mutations, K179Q, E215Q, R236K and R236Q. All mutants displayed enzyme activity with styrene oxide (SO) and 2-MeSO when assayed at 30 degrees C. Disruption of salt-bridges altered the rates for isomerization between distinct Michaelis complexes, with (1R,2R)-2-MeSO as substrate, presumably as a result of increased dynamics of involved protein segments. Another indication of increased flexibility was a lowered thermostability in all mutants. We propose that the alterations to regioselectivity in these mutants derive from an increased mobility in protein segments otherwise stabilized by salt bridging interactions.
ESTHER : Lindberg_2010_Arch.Biochem.Biophys_495_165
PubMedSearch : Lindberg_2010_Arch.Biochem.Biophys_495_165
PubMedID: 20079707
Gene_locus related to this paper: soltu-3epoxy

Title : Stability curves of laboratory evolved thermostable mutants of a Bacillus subtilis lipase - Kamal_2010_Biochim.Biophys.Acta_1804_1850
Author(s) : Kamal MZ , Ahmad S , Yedavalli P , Rao NM
Ref : Biochimica & Biophysica Acta , 1804 :1850 , 2010
Abstract : Shape of the protein stability curves changes to achieve higher melting temperature. Broadly, these changes have been classified as upward shift (increased G(s)), rightward shift (increase in T(s)) and flattening of the stability curves (decrease in C(p)). Comparative studies on homologous mesophilic-thermophilic protein pairs highlighted the differential contribution of these three strategies amongst proteins. But unambiguous way of identification of the strategies, which will be preferred for a protein, is still not achieved. We have performed comparative thermodynamic studies using differential scanning calorimeter (DSC) on thermostable variants of a lipase from Bacillus subtilis. These variants are products of 1, 2, 3 and 4 rounds of directed evolution and harbor mutations having definite contribution in thermostability unlike natural thermophilic proteins. We have shown that upward and rightward shift in stability curves are prime strategies in this lipase. Our results along with that from the other study on laboratory evolved xylanase A suggest that optimization of suboptimal thermodynamic parameters is having a dominant influence in selection of thermodynamic strategies for higher thermostability.
ESTHER : Kamal_2010_Biochim.Biophys.Acta_1804_1850
PubMedSearch : Kamal_2010_Biochim.Biophys.Acta_1804_1850
PubMedID: 20599630

Title : Thermally denatured state determines refolding in lipase: mutational analysis - Ahmad_2009_Protein.Sci_18_1183
Author(s) : Ahmad S , Rao NM
Ref : Protein Science , 18 :1183 , 2009
Abstract : Irreversibility of thermally denatured proteins due to aggregation limits thermodynamic characterization of proteins and also confounds the identification of thermostable mutants in protein populations. Identification of mutations that prevent the aggregation of unfolded proteins provides insights into folding pathways. In a lipase from Bacillus subtilis, evolved by directed evolution procedures, the irreversibility due to temperature-mediated aggregation was completely prevented by a single mutation, M137P. Though the parent and the mutants unfold completely on heating, mutants having substitutions M137P, along with M134E and S163P, completely or partially prevent the formation of aggregation-prone intermediate(s) at 75 degrees C. The three mutants show only a marginal increase in free energy of unfolding (DeltaG(H(2)O)), however, the profiles of the residual activity with temperature shows remarkable shift to higher temperature compared to parent. The intermediate(s) were characterized by enhanced binding of bis-ANS, a probe to titrate surface hydrophobicity, aggregation profiles and by estimation of soluble protein. Inclusion of salt in the refolding conditions prevents the reversibility of mutant having charge substitution, while the reversibility of mutant with the introduction of proline was unaffected, indicating the role of charge mediated interaction in M134E in preventing aggregation. Partial prevention of thermal aggregation in wild-type lipase with single substitution, M137P, incorporated by site-directed mutagenesis, suggests that the affect of M137P is independent of the intrinsic thermostability of lipase. Various effects of the mutations suggest their role is in prevention of the formation of aggregation prone intermediate(s). These mutations, describe yet another strategy to enhance the thermotolerance of proteins, where their influence is observed only on the denatured ensemble.
ESTHER : Ahmad_2009_Protein.Sci_18_1183
PubMedSearch : Ahmad_2009_Protein.Sci_18_1183
PubMedID: 19472328

Title : Thermostable Bacillus subtilis lipases: in vitro evolution and structural insight - Ahmad_2008_J.Mol.Biol_381_324
Author(s) : Ahmad S , Kamal MZ , Sankaranarayanan R , Rao NM
Ref : Journal of Molecular Biology , 381 :324 , 2008
Abstract : In vitro evolution methods are now being routinely used to identify protein variants with novel and enhanced properties that are difficult to achieve using rational design. However, one of the limitations is in screening for beneficial mutants through several generations due to the occurrence of neutral/negative mutations occurring in the background of positive ones. While evolving a lipase in vitro from mesophilic Bacillus subtilis to generate thermostable variants, we have designed protocols that combine stringent three-tier testing, sequencing and stability assessments on the protein at the end of each generation. This strategy resulted in a total of six stabilizing mutations in just two generations with three mutations per generation. Each of the six mutants when evaluated individually contributed additively to thermostability. A combination of all of them resulted in the best variant that shows a remarkable 15 degrees C shift in melting temperature and a millionfold decrease in the thermal inactivation rate with only a marginal increase of 3 kcal mol(-1) in free energy of stabilization. Notably, in addition to the dramatic shift in optimum temperature by 20 degrees C, the activity has increased two- to fivefold in the temperature range 25-65 degrees C. High-resolution crystal structures of three of the mutants, each with 5 degrees increments in melting temperature, reveal the structural basis of these mutations in attaining higher thermostability. The structures highlight the importance of water-mediated ionic networks on the protein surface in imparting thermostability. Saturation mutagenesis at each of the six positions did not result in enhanced thermostability in almost all the cases, confirming the crucial role played by each mutation as revealed through the structural study. Overall, our study presents an efficient strategy that can be employed in directed evolution approaches employed for obtaining improved properties of proteins.
ESTHER : Ahmad_2008_J.Mol.Biol_381_324
PubMedSearch : Ahmad_2008_J.Mol.Biol_381_324
PubMedID: 18599073
Gene_locus related to this paper: bacsu-lip

Title : Structural basis for the remarkable stability of Bacillus subtilis lipase (Lip A) at low pH - Rajakumara_2008_Biochim.Biophys.Acta_1784_302
Author(s) : Rajakumara E , Acharya P , Ahmad S , Sankaranaryanan R , Rao NM
Ref : Biochimica & Biophysica Acta , 1784 :302 , 2008
Abstract : Understanding the structural basis of altered properties of proteins due to changes in temperature or pH provides useful insights in designing proteins with improved stability. Here we report the basis for the pH-dependent thermostability of the Bacillus subtilis lipase (Lip A) using spectroscopic and X-ray crystallographic studies. At pH values above 7, lipase denatures and aggregates when heated at temperatures above 45 degrees C. However, at pH below 6 lipase denatures upon heating but the activity and its native structure is completely recovered upon cooling. In order to obtain the structural basis of this unusual stability of lipase, we determined high-resolution crystal structures of the lipase in two different crystal forms at pH 4.5 and 5. These structures show linear oligomerization of lipase using only two types of dimeric associations and these inter-molecular interactions are completely absent in several crystal forms of wild-type and mutant proteins obtained at basic pH. In accordance with the crystallographic studies, spectroscopic investigations reveal an invariant secondary structure in the pH range of 4-10. Quaternary organization of lipase at low pH resulted in changes in the tryptophan environment and binding of 1-anilino-8-naphthalene sulfate (ANS) at low pH. Low pH stability of the lipase is not observed in the presence of sodium chloride (>0.2 M) indicating the importance of ionic interactions at low pH. Inter- and intra-molecular ionic interactions that occur at pH below 6.0 are proposed to trap the molecule in a conformation that allows its complete refolding upon cooling.
ESTHER : Rajakumara_2008_Biochim.Biophys.Acta_1784_302
PubMedSearch : Rajakumara_2008_Biochim.Biophys.Acta_1784_302
PubMedID: 18053819
Gene_locus related to this paper: bacsu-lip

Title : Crystallization and preliminary X-ray crystallographic investigations on several thermostable forms of a Bacillus subtilis lipase - Rajakumara_2004_Acta.Crystallogr.D.Biol.Crystallogr_60_160
Author(s) : Rajakumara E , Acharya P , Ahmad S , Shanmugam VM , Rao NM , Sankaranarayanan R
Ref : Acta Crystallographica D Biol Crystallogr , 60 :160 , 2004
Abstract : Bacillus subtilis lipase loses activity above pH 10.5 and below pH 6.0. However, at low pH, i.e. below pH 5.0, the lipase acquires remarkable thermostability. Activity was unaltered for 2 h at 323 K at pH 4.0-5.0, although at pH values above 7.0 the activity was lost rapidly within minutes. Circular-dichroism studies indicate significant changes in the tertiary structure of the lipase, whereas the secondary-structural content remained unaltered. To elucidate the structural basis of the enhanced thermostability, three different forms have been crystallized at low pH along with three crystal forms of two thermostable mutants obtained using a directed-evolution approach.
ESTHER : Rajakumara_2004_Acta.Crystallogr.D.Biol.Crystallogr_60_160
PubMedSearch : Rajakumara_2004_Acta.Crystallogr.D.Biol.Crystallogr_60_160
PubMedID: 14684916
Gene_locus related to this paper: bacsu-lip

Title : Poster: Differential labeling of presynaptic and postjunctional muscarinic receptors by 3H-N-metflylscopolamine (NMS) in dog ileum -
Author(s) : Kostka P , Ahmad S , Niles LP , Kwan CY , Daniel EE
Ref : Trends in Pharmacological Sciences , Suppl :108 , 1989

Title : Nonoxidative enzymes in the metabolism of insecticides - Ahmad_1976_Ann.Clin.Biochem_13_141
Author(s) : Ahmad S , Forgash AJ
Ref : Annals of Clinical Biochemistry , 13 :141 , 1976
Abstract : Two major classes of enzymes, i.e., hydrolases and transferases, comprise all the nonoxidative enzymes, and together these enzymes catalyze a wide variety of biotransformations of insecticides. The hydrolytic enzymes involved in insecticide metabolism are carboxylesterase (EC, arylesterase (EC 3,1.1.2), alkylamidase, and DFPase (EC Recent experimental evidence suggests that carboxylesterase enzymes(s), formerly known to hydrolyze malathion-type insecticides, can also catalyze hydrolysis of a variety of diversified insecticidal esters such as benzilic acid derivatives, carbanilate compounds, and pyrethroids. These organo-phosphate-sensitive esterases, with the exception of the enzyme which hydrolyzes malathion, are all present in microsomes. Similarly, the action of amidases now extends to those insecticidal compounds or their intermediates which contain an aminoformyl (N--CHO) moiety. Arylesterase and DFPase catalyze the P--anhydride bond cleavage of the leaving group, a major hydrolytic pathway for organophosphate insecticides. Transferal enzymes which are presently known to metabolize insecticidal organophosphates are GSH-S-alkyltransferase (EC and GSH-S-aryltransferase (EC These enzymes cleave P--O--R (R = alkyl) or P--O--X (X = aromatic), with subsequent transfer of the R or X group to glutathione. Regarding the other conjugating enzymes, UDP-glucuronyltransferase (EC, UDP-glucosyltransferase (EC, and arylamine acetyltransferase (EC, much work is needed to understand their interactions with insecticidal compounds. There is some evidence that arylsulfotransferase (EC may play a prominent role in the conjugative mechanisms of insects.
ESTHER : Ahmad_1976_Ann.Clin.Biochem_13_141
PubMedSearch : Ahmad_1976_Ann.Clin.Biochem_13_141
PubMedID: 802086

Title : An electrophoretic study of the negative correlation of certain carboxylesterases to insecticide resistance in Musca domestica L -
Author(s) : Ahmad S
Ref : Experientia , 30 :331 , 1974
PubMedID: 4366007

Title : Localization of aliesterase and acetylcholinesterase enzymes in various tissues of susceptible and organophosphate resistant Musca domestica L -
Author(s) : Ahmad S
Ref : Comp General Pharmacology , 1 :273 , 1970
PubMedID: 5527564