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Alzheimer's disease (AD) is an irreversible progressive neurodegenerative disease. Punica granatum L., (P. granatum) is one of the most important commercial crops of Oman with traditional medicinal claims. The study aimed to quantify the phenolic content of the Omani pomegranate peel extracts and to investigate their antioxidant, anti-cholinesterase activities along with computational studies for the development of AD therapy. The dried peels of P. granatum fruits were exhaustively extracted with chloroform, ethyl acetate and butanol. Peel extracts were subjected to the preliminary phytochemical screening. Colorimetric methods were used to quantify total phenolic and flavonoids contents. The neuroprotective potential of the peel extracts was evaluated by assessing the in-vitro antioxidant activity and their ability to inhibit acetylcholinesterase (AChE) enzyme activity. In-silico analysis and molecular docking of the most promising phenolic metabolite present in pomegranate peel was also carried out. The phytochemical screening showed the presence of flavonoids, tannins, alkaloids, carbohydrates and terpenoids. The total phenolic, flavonoids content & antioxidant activity was found to be higher in the butanol extract. Surprisingly, butanol extract showed slightly lower AChE inhibitory activity than chloroform extract. Catechin, a polyphenolic compound present in the peel showed lower binding energy for AChE in comparison to Beta-secretase-1 (BACE-1). It formed three and two hydrogen bonds with AChE and BACE-1, respectively. The results of the current study provided evidence that butanol extract is rich in phenolics and possesses excellent antioxidant activity. Furthermore, in silico and in-vitro studies conducted on P. granatum revealed promising anti-AD activity. Further investigations must be carried out to isolate and develop the chemical constituents of pomegranate peel as neuroprotective agent(s). [Display omitted] • Phytochemical screening and quantification of phenolic compounds in an agro-waste. • Evaluation of antioxidant and anticholinesterase activity of pomegranate peel extracts. • In silico studies and molecular docking studies on the polyphenolic compounds found in pomegranate peel. • Butanol solvent was found to be optimum for the isolation of polyphenolic compounds. • Pomegranate peel could be used as an alternative source of natural antioxidants. [ABSTRACT FROM AUTHOR]

Objective To perform phytochemical screening and to evaluate the in-vitro antioxidant and anti-inflammatory activities of ethanolic extract of seeds and fruits of Zizyphus spina-christi (ZSC) growing in Oman. Methods Alcoholic extract of the dry powdered seeds and fruits of ZSC was obtained by cold maceration method and was subjected to preliminary phytochemical screening. Total phenolic content were estimated by using Folin-Ciocalteu reagent and 1,1-diphenyl-2-picrylhydrazyl (DPPH) was used to determine in-vitro antioxidant activity of plant extracts. Anti-inflammatory activity was investigated by protein denaturation method. Results Phytochemical analysis of both the extracts revealed the presence of major classes of phytochemicals such as tannins, alkaloids, flavonoids, cardiac glycosides etc.. ZSC seeds were found to contain the highest total phenolics but ZSC fruits exhibited the maximum antioxidant activity. The anti-inflammatory activity of both parts of the plant extract was significant and comparable with the standard anti-inflammatory drug, diclofenac. Conclusions Based on the results of this pilot study, it can be concluded that ZSC is a good source of natural antioxidants which can be used to prevent progression of many chronic diseases. Further detailed phytochemical studies are needed to identify the chemical compounds responsible for exhibiting potent anti-inflammatory activity. [ABSTRACT FROM AUTHOR]