COMPARATIVE EVALUATION OF ABTS, DPPH, FRAP, NITRIC OXIDE ASSAYS FOR ANTIOXIDANT POTENTIAL, PHENOLIC & FLAVONOID CONTENT OF EHRETIA ACUMINATA R. BR. BARK

Abstract

Barks extracts of traditionally important medicinal plant, Ehretia acuminata R. Br. was screened for their free radical scavenging properties using ascorbic acid (A.A) and gallic acid (G.A) as standard antioxidant. Free radical scavenging activity was evaluated using 1,1 diphenyl 2 picrylhydrazyl (DPPH) radical, 2,2 azino bis 3 ethylbenzthiazoline 6 sulphonic acid (ABTS), Ferric oxide reducing assay (FRAP) and nitric oxide assay. There were positive correlations between antioxidant activity assessed by ABTS, DPPH, FRAP & Nitric oxide, between Total Phenolic and flavonoids content with all methods using five extract Petroleum ether (P.E), chloroform (CH), ethyl acetate (E.A), ethanol (EOL) & water (WTR). The overall antioxidant activity of bark was the strongest in ethyl acetate and weakest in water extract. The IC50 of the ethyl acetate extracts ranged between 22 and 140 $\mu$ g/ml and that of ascorbic acid was 28 $\mu$ g/ml. The study reveals that the consumption of this plant would exert several beneficial effects by virtue of their antioxidant activity.