Title: Green approach for the recovery of secondary metabolites from the roots of Nardostachys Jatamansi (D. Don) DC using microwave radiations: Process optimization and anti-alzheimer evaluation Arya A, Chahal R, Almutairi MH, Kaushik D, Aleya L, Kamel M, Abdel-Daim MM, Mittal V Ref: Front Plant Sci, 13:987986, 2022 : PubMed
Nardostachys jatamansi (D. Don) DC is a highly valued medicinal herb that has been used in traditional medicinal systems for its remedial effects. Owing to the over-exploitation and unethical trade of N. jatamansi, the accelerating global demand of herbal products from this plant cannot be satisfied by the conventional extraction approach. In view of the progressive demand and incredible biological potential of herb, the present research was designed to optimize various extraction parameters for microwave-assisted extraction (MAE). The extracts obtained from the traditional and green approach were also assessed for the recovery of secondary metabolites and anti-Alzheimer's potential. Various parameters like microwave power, temperature, and time of irradiation were optimized for MAE using Box Behkhen Design (BBD) The scanning electron microscopy of different plant samples was also done to observe the effect of microwave radiations. Further, the metabolite profiling of different extracts was also done by gas chromatography-mass spectrometry (GC-MS) analysis. Also the different behavioral and biochemical parameters along with acetylcholinesterase (AChE) inhibitory potential were assessed to evaluate the anti-Alzheimer's potential. Optimized parameters for MAE were found to be as microwave power 187.04 W, temperature 90C, and irradiation time 20 min. The extract yield in MAE was significantly enhanced as compared to the conventional method. Also, the total phenolic content and total flavonoid content (TFC) were improved pointedly from 32.13 0.55 to 72.83 1.1 mg of GAE/g of extract and 21.7 0.85 to 39.21 0.7 mg of RUE/g of extract respectively. Later, the GC-MS analysis of various extracts confirmed the enhancement in the concentration of various sesquiterpenes like jatamansone, spirojatamol, valerenal, valeric acid, globulol, nootkatone and steroidal compounds such as sitosterol, ergosterol, stigmastanone, etc. in the optimized extract. A significant improvement in anti-Alzheimer's potential was also observed owing to the better concentration of secondary metabolites in the optimized microwave extract. From the current findings, it could be concluded that the MAE could be a successful and green alternative for the extraction and recovery of secondary metabolites from the selected medicinal herb.
Pseudomonas aeruginosa is a severe threat to immunocompromised patients due to its numerous virulence factors and biofilm-mediated multidrug resistance. It produces and secretes various toxins with hydrolytic activities including phospholipases. However, the function of intracellular phospholipases for bacterial virulence has still not been established. Here, we demonstrate that the hypothetical gene pa2927 of P. aeruginosa encodes a novel phospholipase B named PaPlaB. At reaction equilibrium, PaPlaB purified from detergent-solubilized membranes of E. coli released fatty acids (FAs) from sn-1 and sn-2 positions of phospholipids at the molar ratio of 51:49. PaPlaB in vitro hydrolyzed P. aeruginosa phospholipids reconstituted in detergent micelles and phospholipids reconstituted in vesicles. Cellular localization studies indicate that PaPlaB is a cell-bound PLA of P. aeruginosa and that it is peripherally bound to both membranes in E. coli, yet the active form was predominantly associated with the cytoplasmic membrane of E. coli. Decreasing the concentration of purified and detergent-stabilized PaPlaB leads to increased enzymatic activity, and at the same time triggers oligomer dissociation. We showed that the free FA profile, biofilm amount and architecture of the wild type and deltaplaB differ. However, it remains to be established how the PLB activity of PaPlaB is regulated by homooligomerisation and how it relates to the phenotype of the P. aeruginosa deltaplaB. This novel putative virulence factor contributes to our understanding of phospholipid degrading enzymes and might provide a target for new therapeutics against P. aeruginosa biofilms.
Alzheimer's disease (AD) is a gradually growing irreversible illness of the brain that almost affects every fifth person (aged > 80 years) in the world. World Health Organization (WHO) also revealed that the prevalence of this disease will enhance (upto double) significantly upto 2030. The poor cholinergic transmission at the synapse is considered to be one of the main reasons behind the progression and occurrence of this disorder. Natural inhibitors of acetylcholine (ACh) such as galanthamine and rivastigmine are used commercially in the treatmentof AD. The biomolecules such assesquiterpenes, possess a great structural diversity and are responsible for a plethora of pharmacological properties. The potential of various sesquiterpenes as anticholinesterase has been reviewed in this article. For this purpose, the various databases, mainly PubMed, Scopus, and Web of Science were investigatedwith different keywords such as "sesquiterpenes+acetylcholinesterase" and "sesquiterpenes+cholinesterase+inhibitors" in the surveyed time frame (2010-2020). A vast literature was evident in the last decade, which affirms the potential of various sesquiterpenes in the improvement of cholinergic transmission by inhibiting the AChE. After data analysis, it was found that 12 compounds out of a total of 58 sesquiterpenes were reported to possess IC(50) < 9microM and can be considered as potential candidates for the improvement of learning and memory. Sesquiterpene is an important category of terpenoids, found to possess a large spectrum of biological activities. The outcome of the review clearly states that sesquiterpenes (such as amberboin, lipidiol,etc) from herbs could offer fresh, functional compounds for possible prevention and treatment of AD.
