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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]

The study aimed to characterize the volatile constituents of Mentha spicata L., grown in Oman, and to investigate in vitro cytotoxic and antioxidant activities of the volatile oil. The pale-yellow color essential oil (% yield 0.55% v/w) showed the presence of thirteen compounds representing 99.19% of the total constituents. d-Carvone (65.21%) and dl -limonene (27.28%) were identified as the major volatile chemical constituents. Mint oil exhibited promising antioxidant (IC 50 = 26.64 μg/mL) and cytotoxic activity (LC 50 = 245 μg/mL). CLC predicted d-carvone to be active against thyroid gland undifferentiated (anaplastic) carcinoma, pancreatic carcinoma, brain carcinoma, and lymphoblastic leukemia while dl -limonene could be effective against skin melanoma, breast adenocarcinoma in addition to the above carcinomas. Omani spearmint volatile oil exhibited promising cytotoxic and antioxidant activities. However, further detailed studies are warranted to develop mint oil as a natural antioxidant and to unlock its hidden cytotoxic potential. [Display omitted] • Chemical profiling of Omani Mentha spicata species was done by GC-MS analysis. • The GC-MS analysis of mentha volatile oil established it to be a carvone chemotype. • Mentha essential oil exhibited promising antioxidant and cytotoxic activities. • Computational studies revealed carvone and limonene to possess useful bioactivities including cytotoxicity. [ABSTRACT FROM AUTHOR]

This preliminary study was undertaken to evaluate and compare the physicochemical properties, total phenolic content, total flavonoid content and in vitro antioxidant activity of 22 types of monofloral and heterofloral Omani honey. Total phenolic and flavonoid contents were quantified colorimetrically while antioxidant activity was evaluated by 1,1 diphenyl picrylhydrazyl (DPPH) free radical scavenging assay method. Our result clearly shows significant variations among honey samples for all evaluated parameters. Monofloral honey from Salalah, Samail, and Al-Khaboora showed good inhibition of DPPH radicals. The highest amount of total phenol was found in monofloral honey from Al-Dahirah while the highest amount of flavonoid was observed in a monofloral variety from Salalah. A direct relationship between phenol, flavonoid and inhibition of DPPH was also observed. It can be concluded that the monofloral types of honey can be considered particularly useful for human nutrition because of their high phenolic and flavonoid contents which are known for their antioxidant activity. [Display omitted] • Quantification of total phenol and flavonoids of 22 honey samples collected from different regions of Oman. • Free radical scavenging activity of honey samples is reported to predict the nutritional value of honey. • Antibacterial activity of four honey samples is reported. • A comparison of honey samples with respect to refractive index, Brix%, acidity and % of water. [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]