In vitro free radical scavenging activities of aerial parts’ aqueous extract and extract fractions of Ampelocissus latifolia (Roxb.) Planch. in relation to total phenolics and flavonoid contents

Abstract

Discovery of new antioxidants of plant origin is of current interest. Ampelocissus latifolia (Roxb.) Planch. is a traditionally used medicinal plant. The present study was aimed to investigate the in vitro free radical scavenging activities of aerial parts’ aqueous extract of A. latifolia (AAEAL) and its organic solvent extract fractions in relation to their total phenolics and flavonoid contents. The AAEAL was fractionated with the organic solvents like petroleum ether (AAEALPE), chloroform (AAEALCH), ethyl acetate (AAEALEA), and n-butanol (AAEALNB). For the determination of antioxidant activity of AAEAL and its extract fractions, Fe3+ ion reducing antioxidant power (FRAP), 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, and total antioxidant assays were performed and the total phenolics and flavonoid contents were also estimated. The EC50 of the ferric ion reduction by AAEALEA and ascorbic acid were calculated as 90.8 ± 4.70 and 84.86 ± 7.22 µg/mL respectively. The IC50 of DPPH free radical scavenging with AAEALEA and ascorbic acid were calculated as 19.5 ± 0.5 and 18.35 ± 1.15 µg/mL respectively. The overall data indicate that the AAEALEA possesses the highest total antioxidant activity (37.85 ± 1.55 µg ascorbic acid equivalents/100 µg dry extract matter), the highest total phenolics (65.89 ± 1.33 mg tannic acid equivalent phenolics/100 mg dry extract) and flavonoid (30.67 ± 0.28 mg quercetin equivalent flavonoids/100 mg dry extract) contents. The antioxidant activities were also positively correlated with the total phenolics and flavonoid contents of the extract fractions. In summary, AAEAL may be considered as a natural source of antioxidants and its ethyl acetate extract fraction seems to be equally effective to the ascorbic acid as an antioxidant.