Evaluation of the antioxidant activity of fruit extracts of indigenous medicinal plant, Zizyphus xylopyrus (Retz.) Willd

Abstract

Aim: This study aims to investigate the antioxidant activity of fruit extracts of an indigenous medicinal plant, Zizyphus xylopyrus (Retz.) Willd. Materials and Methods: The coarsely powdered fruit of Z. xylopyrus Willd. was successfully extracted first with petroleum ether and chloroform, followed by ethyl acetate and at last ethanol. The total flavonoids content (TFC), total phenolic content (TPC), and total tannin content (TTC) were estimated using quercetin and tannic acid equivalents as standard. The antioxidant activity of different extracts was determined by different standard in vitro methods including. Results: Among all extracts, ethyl acetate extract (ZXEAE) possessed potent antioxidant activity, namely hydroxyl radical (OH°) scavenging assay (IC50 128.1 ± 0.63 μg/mL), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (DPPH°) scavenging assay (IC50 101.2 ± 1.75 μg/mL), nitric oxide radical (NOº) scavenging assay (IC50 122.5 ± 2.04 μg/mL), superoxide radical (O2¯) scavenging activity assay (IC50 64.1 ± 1.24 μg/mL), and inhibition of lipid peroxidation (98.6 ± 2.05 μg/mL). Study results suggested that antioxidant activity of ZXEAE might be due to presence of polyphenols, namely TFC (31.23 ± 0.39 quercetin equivalent [QE] mg/g extract), TPC (198.14 ± 0.69 gallic acid equivalent [GAE] mg/g extract), and TTC (18.38 ± 1.79 GAE mg/g extract). Conclusion: The present study demonstrated the presence of flavonoids in Z. xylopyrus fruits showing marked antioxidant activity, which can be used for establishing the hepatoprotective potential of Z. xylopyrus