Inhibitor Report for: Cynaroside

Triple-negative breast cancer (TNBC) cells reprogram their metabolism to provide metabolic flexibility for tumor cell growth and survival in the tumor microenvironment. While our previous findings indicated that endothelial lipase (EL/LIPG) is a hallmark of TNBC, the precise mechanism through which LIPG instigates TNBC metabolism remains undefined. Here, we report that the expression of LIPG is associated with long non-coding RNA DANCR and positively correlates with gene signatures of mitochondrial metabolism-oxidative phosphorylation (OXPHOS). DANCR binds to LIPG, enabling tumor cells to maintain LIPG protein stability and OXPHOS. As one mechanism of LIPG in the regulation of tumor cell oxidative metabolism, LIPG mediates histone deacetylase 6 (HDAC6) and histone acetylation, which contribute to changes in IL-6 and fatty acid synthesis gene expression. Finally, aided by a relaxed docking approach, we discovered a new LIPG inhibitor, cynaroside, that effectively suppressed the enzyme activity and DANCR in TNBC cells. Treatment with cynaroside inhibited the OXPHOS phenotype of TNBC cells, which severely impaired tumor formation. Taken together, our study provides mechanistic insights into the LIPG modulation of mitochondrial metabolism in TNBC and a proof-of-concept that targeting LIPG is a promising new therapeutic strategy for the treatment of TNBC.

CONTEXT: Bryophyllum pinnatum (Lam.) Oken (Crassulaceae) is used traditionally to treat many ailments. OBJECTIVES: This study characterizes the constituents of B. pinnatum flavonoid-rich fraction (BPFRF) and investigates their antioxidant and anticholinesterase activity using in vitro and in silico approaches. MATERIALS AND METHODS: Methanol extract of B. pinnatum leaves was partitioned to yield the ethyl acetate fraction. BPFRF was isolated from the ethyl acetate fraction and purified. The constituent flavonoids were structurally characterized using UPLC-PDA-MS(2). Antioxidant activity (DPPH), Fe(2+)-induced lipid peroxidation (LP) and anticholinesterase activity (Ellman's method) of the BPFRF and standards (ascorbic acid and rivastigmine) across a concentration range of 3.125-100 microg/mL were evaluated in vitro for 4 months. Molecular docking was performed to give insight into the binding potentials of BPFRF constituents against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). RESULTS: UPLC-PDA-MS(2) analysis of BPFRF identified carlinoside, quercetin (most dominant), luteolin, isorhamnetin, luteolin-7-glucoside. Carlinoside was first reported in this plant. BPFRF significantly inhibited DPPH radical (IC(50) = 7.382 +/- 0.79 microg/mL) and LP (IC(50) = 7.182 +/- 0.60 microg/mL) better than quercetin and ascorbic acid. Also, BPFRF exhibited potent inhibition against AChE and BuChE with IC(50) values of 22.283 +/- 0.27 microg/mL and 33.437 +/- 1.46 microg/mL, respectively compared to quercetin and rivastigmine. Docking studies revealed that luteolin-7-glucoside, carlinoside and quercetin interact effectively with crucial amino acid residues of AChE and BuChE through hydrogen bonds. DISCUSSION AND CONCLUSIONS: BPFRF possesses an excellent natural source of cholinesterase inhibitor and antioxidant. The material could be further explored for the potential treatment of oxidative damage and cholinergic dysfunction in Alzheimer's disease.

The effects of Angelica keiskei Koidz. on hepatic lipid peroxide and the activities of free radical generating and scavenging enzymes were investigated in bromobenzene-induced hepatic lipid peroxidation in rats. The level of lipid peroxide elevated by bromobenzene was significantly reduced by the methanol extract from the aerial parts of A. keiskei and its component, cynaroside. Epoxide hydrolase activity was decreased significantly by the treatment of bromobenzene. However, the enzyme activity was restored in the liver of rats given the methanol extract and cynaroside. The results suggest that the reduction of bromobenzene-induced hepatic lipid peroxidation by the extract of A. keiskei and cynaroside under our experimental conditions is thought to be through enhancing the activity of epoxide hydrolase, an enzyme removing bromobenzene epoxide.

Luteolin is one of the most common flavonoids present in edible plants and its potential benefits to the central nervous system include decrease of microglia activation, neuronal damage and high antioxidant properties. The aim of this research was to evaluate the neuroprotective, antioxidant and anti-inflammatory activities of luteolin-7-O-glucoside (Lut7). Undifferentiated and retinoic acid (RA)-differentiated SH-SY5Y cells were pretreated with Lut7 and incubated with 6-hydroxydopamine (6-OHDA). Cytotoxic and neuroprotective effects were determined by MTT assay. Antioxidant capacity was determined by DPPH, FRAP, and ORAC assays. ROS production, mitochondrial membrane potential (deltam), Caspase-3 activity, acetylcholinesterase inhibition (AChEI) and nuclear damage were also determined in SH-SY5Y cells. TNF-alpha, IL-6 and IL-10 release were evaluated in LPS-induced RAW264.7 cells by ELISA. In undifferentiated SH-SY5Y cells, Lut7 increased cell viability after 24 h, while in RA-differentiated SH-SY5Y cells, Lut7 increased cell viability after 24 and 48 h. Lut7 showed a high antioxidant activity when compared with synthetic antioxidants. In undifferentiated cells, Lut7 prevented mitochondrial membrane depolarization induced by 6-OHDA treatment, decreased Caspase-3 and AChE activity, and inhibited nuclear condensation and fragmentation. In LPS-stimulated RAW264.7 cells, Lut7 treatment reduced TNF-alpha levels and increased IL-10 levels after 3 and 24 h, respectively. In summary, the results suggest that Lut7 has neuroprotective effects, thus, further studies should be considered to validate its pharmacological potential in more complex models, aiming the treatment of neurodegenerative diseases.

Triple-negative breast cancer (TNBC) cells reprogram their metabolism to provide metabolic flexibility for tumor cell growth and survival in the tumor microenvironment. While our previous findings indicated that endothelial lipase (EL/LIPG) is a hallmark of TNBC, the precise mechanism through which LIPG instigates TNBC metabolism remains undefined. Here, we report that the expression of LIPG is associated with long non-coding RNA DANCR and positively correlates with gene signatures of mitochondrial metabolism-oxidative phosphorylation (OXPHOS). DANCR binds to LIPG, enabling tumor cells to maintain LIPG protein stability and OXPHOS. As one mechanism of LIPG in the regulation of tumor cell oxidative metabolism, LIPG mediates histone deacetylase 6 (HDAC6) and histone acetylation, which contribute to changes in IL-6 and fatty acid synthesis gene expression. Finally, aided by a relaxed docking approach, we discovered a new LIPG inhibitor, cynaroside, that effectively suppressed the enzyme activity and DANCR in TNBC cells. Treatment with cynaroside inhibited the OXPHOS phenotype of TNBC cells, which severely impaired tumor formation. Taken together, our study provides mechanistic insights into the LIPG modulation of mitochondrial metabolism in TNBC and a proof-of-concept that targeting LIPG is a promising new therapeutic strategy for the treatment of TNBC.

The aim of this study was to investigate the chemical composition, antioxidant and enzyme inhibitory activities of methanol (MeOH) extracts from Onosma bourgaei (Boiss.) and O. trachytricha (Boiss.). In addition, the interactions between phytochemicals found in extracts in high amounts and the target enzymes in question were revealed at the molecular scale by performing in silico molecular docking simulations. While the total amount of flavonoid compounds was higher in O. bourgaei, O. trachytricha was richer in phenolics. Chromatographic analysis showed that the major compounds of the extracts were luteolin 7-glucoside, apigenin 7-glucoside and rosmarinic acid. With the exception of the ferrous ion chelating assay, O. trachytricha exhibited higher antioxidant activity than O. bourgaei. O. bourgaei exhibited also slightly higher activity on digestive enzymes. The inhibitory activities of the Onosma species on tyrosinase were almost equal. In addition, the inhibitory activities of the extracts on acetylcholinesterase (AChE) were stronger than the activity on butyrylcholinesterase (BChE). Molecular docking simulations revealed that luteolin 7-glucoside and apigenin 7-glucoside have particularly strong binding affinities against ChEs, tyrosinase, alpha-amylase and alpha-glucosidase when compared with co-crystallized inhibitors. Therefore, it was concluded that the compounds in question could act as effective inhibitors on cholinesterases, tyrosinase and digestive enzymes.

CONTEXT: Bryophyllum pinnatum (Lam.) Oken (Crassulaceae) is used traditionally to treat many ailments. OBJECTIVES: This study characterizes the constituents of B. pinnatum flavonoid-rich fraction (BPFRF) and investigates their antioxidant and anticholinesterase activity using in vitro and in silico approaches. MATERIALS AND METHODS: Methanol extract of B. pinnatum leaves was partitioned to yield the ethyl acetate fraction. BPFRF was isolated from the ethyl acetate fraction and purified. The constituent flavonoids were structurally characterized using UPLC-PDA-MS(2). Antioxidant activity (DPPH), Fe(2+)-induced lipid peroxidation (LP) and anticholinesterase activity (Ellman's method) of the BPFRF and standards (ascorbic acid and rivastigmine) across a concentration range of 3.125-100 microg/mL were evaluated in vitro for 4 months. Molecular docking was performed to give insight into the binding potentials of BPFRF constituents against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). RESULTS: UPLC-PDA-MS(2) analysis of BPFRF identified carlinoside, quercetin (most dominant), luteolin, isorhamnetin, luteolin-7-glucoside. Carlinoside was first reported in this plant. BPFRF significantly inhibited DPPH radical (IC(50) = 7.382 +/- 0.79 microg/mL) and LP (IC(50) = 7.182 +/- 0.60 microg/mL) better than quercetin and ascorbic acid. Also, BPFRF exhibited potent inhibition against AChE and BuChE with IC(50) values of 22.283 +/- 0.27 microg/mL and 33.437 +/- 1.46 microg/mL, respectively compared to quercetin and rivastigmine. Docking studies revealed that luteolin-7-glucoside, carlinoside and quercetin interact effectively with crucial amino acid residues of AChE and BuChE through hydrogen bonds. DISCUSSION AND CONCLUSIONS: BPFRF possesses an excellent natural source of cholinesterase inhibitor and antioxidant. The material could be further explored for the potential treatment of oxidative damage and cholinergic dysfunction in Alzheimer's disease.

Onosma species have been used as a dye for hundreds of years due to their dark red pigments. These species have also been used by mankind in the treatment of various diseases since ancient times. This work analyzed the phytochemical composition in methanol extract of two endemic Onosma species (O. lycaonica and O. papillosa). Methanolic extract of these species varied in the content of flavonoids and phenolics. The flavonoids were found higher in O. papillosa [32.9 +/- 0.3 mg QEs (quercetin equivalent)/g extracts] while the phenolics were higher in O. lycaonica [43.5 +/- 1.5 mg GAEs (gallic acid equivalent)/g extracts]. ESI-MS/MS (electrospray ionization-mass spectrometry) revealed the presence of 25 compounds in O. lycaonica and 24 compounds in O. papillosa. The former was richer than the latter for apigenin, luteolin, eriodictyol, pinoresinol, apigenin 7-glucoside, rosmarinic acid, luteolin 7-glucoside, ferulic acid, vanillin, caffeic acid, 4-hydroxybenzoic acid, (+)-catechin3,4-dihydroxyphenylacetic acid. The O. papillosa exhibited low EC(50) (1.90 +/- 0.07 mg/mL) which indicated its strong phosphomolybdenum scavenging activity as compared to O. lycaonica. However, the O. lycaonica showed low IC(50) or EC(50) for 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+), cupric reducing antioxidant power (CUPRAC), ferric reducing antioxidant power (FRAP) and ferrous ion chelating activity, as compared to O. papillosa. The results proved the presence of potent antioxidant compounds in O. lycaonica. Further, the plant extracts significantly varied for enzyme inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), but the plant extracts did not significantly differ for inhibition of alpha-glucosidase, alpha-amylase, and tyrosinase. Onosma species deserve further research towards developing novel drugs to treat oxidative diseases.

This work reports for the first time the in vitro anti-oxidant (towards DPPH, ABTS, copper and iron), enzymatic inhibitory (on AChE, BuChE, alpha-glucosidase, alpha-amylase and tyrosinase), cytotoxicity (towards HepG2 and HEK 293 cells), and metabolomics (by HPLC-MS) of extracts from organs of Malcolmia littorea (L.) R.Br. Extracts were constituted mainly by phenolic acids and flavonoids, and main compounds were salicylic acid and luteolin-7-O-glucoside. Samples showed reduced radical scavenging and metal chelating capacity, and only the methanol extracts reduced iron. The root's ethanol and methanol extracts, and the aerial organ's ethanol extract exhibited the highest AChE inhibition. The root's ethanol extract displayed dual anti-cholinesterase activity. Samples showed a low capacity to inhibit alpha-amylase, but a high alpha-glucosidase inhibition was obtained with the root's and flower's ethanol extracts, and flower's methanol extract. Overall, samples displayed a high inhibition against tyrosinase, reduced HepG2 cellular viability and were less toxic towards HEK 293 cells.

BACKGROUND: Triple-negative breast cancer (TNBC) is an aggressive and deadly breast cancer subtype with limited treatment options. It is necessary to seek complementary strategies for TNBC management. Taraxacum mongolicum, commonly named as dandelion, is a herb medicine with anti-cancer activity and has been utilized to treat mammary abscess, hyperplasia of mammary glands from ancient time in China, but the scientific evidence and action mechanisms still need to be studied. AIM OF THE STUDY: This study was intended to investigate the therapeutic effect and molecular mechanisms of dandelion extract in TNBC cell line. METHODOLOGY: Dandelion extract was prepared and purified, and then its chemical composition was determined. Cell viability was evaluated by MTT assay. Analysis of cell apoptosis and cell cycle was assessed by flow cytometry. The expression levels of mRNA and proteins were determined by real-time PCR and Western blotting, respectively. Caspase inhibitor Z-VAD-FMK and CHOP siRNA were used to confirm the cell apoptosis induced by dandelion extract. RESULTS: Dandelion extract significantly decreased MDA-MB-231cell viability, triggered G2/M phase arrest and cell apoptosis. Concurrently, it caused a markedly increase of cleaved caspase-3 and PARP proteins. Caspase inhibitor Z-VAD-FMK abolished the apoptosis triggered by dandelion extract. The three ER stress-related signals were strongly induced after dandelion treatment, including increased mRNA expressions of ATF4, ATF6, XBP1s, GRP78 and CHOP genes, elevated protein levels of phosphorylated PERK, eIF-2alpha, IRE1, as well as the downstream molecules of CHOP and GRP78. MDA-MB-231 cells transfected with CHOP siRNA significantly reduced apoptosis induced by dandelion extract. The underlying mechanisms at least partially ascribe to the strong activation of PERK/p-eIF2alpha/ATF4/CHOP axis. CONCLUSION: ER stress related cell apoptosis accounted for the anti-cancer effect of dandelion extract, and these findings support dandelion extract might be a potential therapeutic approach to treat TNBC.

Bidens tripartita L. is a traditional phyto-remedy used in several countries, yet there is still a paucity of data on its biological potential. We aimed to provide new insights on the pharmacological potential of extracts prepared from B. tripartita via highlighting its antioxidant, key enzymes inhibitory potency, and DNA protecting effects. Phytochemical profile was established using High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) and bioactive compound(s) docked against target enzymes using in silico methods. Cytotoxicity against three cancer cell lines was assessed using the methylthiazolyldiphenyl-tetrazolium bromide (MTT) cell viability test. The main compounds were luteolin-7-glucoside (cynaroside), chlorogenic acid, and epicatechin in the extracts. The methanol extract exhibited the highest radical scavenging activity. Ethyl acetate extract showed strongest alpha-amylase inhibitory activity, while the best alpha-glucosidase inhibitory effect recorded for the methanol extract. Molecular docking showed that cynaroside strongly interact to alpha-glucosidase cavity by establishing six hydrogen bonds. B. tripartita extracts were found to protect supercoiled form of pUC19 plasmid (>70%) and also showed anti-proliferative properties. Results amassed in the present study add on to a growing body of literature on the multi-pharmacological potency of B. tripartita which can be applied to bio-products development geared towards management of common diseases.

In this research, the total phenolic content of a Lavandula viridis methanol extract was evaluated and the phenolic identification and quantification was assessed. Rosmarinic acid and luteolin-7-O-glucoside were the two major compounds identified by HPLC-DAD (ca. 39 and 13g/kg, respectively). This extract showed a strong antioxidant activity in ORAC (2858.39+/-70.97micromolTE/gextract) and TEAC (967.18+/-22.57micromolTE/gextract) assays, as well as Fe(2+) chelating and OH scavenging abilities. Furthermore, the extract prevented Fe(2+)-induced lipid peroxidation, by reducing MDA content in mouse brains (in vitro), and inhibited AChE and BChE activities both in vitro and in vivo. These findings demonstrate that the methanol extract from L. viridis is a potential source of natural antioxidants and cholinesterase inhibitors.

The effects of Angelica keiskei Koidz. on hepatic lipid peroxide and the activities of free radical generating and scavenging enzymes were investigated in bromobenzene-induced hepatic lipid peroxidation in rats. The level of lipid peroxide elevated by bromobenzene was significantly reduced by the methanol extract from the aerial parts of A. keiskei and its component, cynaroside. Epoxide hydrolase activity was decreased significantly by the treatment of bromobenzene. However, the enzyme activity was restored in the liver of rats given the methanol extract and cynaroside. The results suggest that the reduction of bromobenzene-induced hepatic lipid peroxidation by the extract of A. keiskei and cynaroside under our experimental conditions is thought to be through enhancing the activity of epoxide hydrolase, an enzyme removing bromobenzene epoxide.