ANTIOXIDANT FRACTION FROM BARK OF DILLENIA INDICA

Abstract

Barks of various plants have been reported to possess both in vitro and in vivo antioxidant activity. In this study, antioxidant activity of the extract from the barks of Dillenia indica was evaluated by various in vitro methods.. The bark of D. indica was extracted with 70% aqueous acetone. The total phenolic content was determined by Folin-Ciocalteu method and the antioxidant activity was assayed through various in vitro methods such as antioxidant capacity by phosphomolybdenum method, radical scavenging activity using alpha, alpha-diphenyl-beta-picrylhydrazyl method, hydroxyl radical (degrees OH) scavenging activity by deoxyribose method, and superoxide anion (O-2 degrees(-)) scavenging activity by phenazine methosulphate/NADH-nitroblue tetrazolium system. The total phenolic content of the extract as tannic acid equivalents was 54%. The total antioxidant capacity of the extract was found to be 3.12 mmoles/g as equivalent to ascorbic acid at 50 ppm concentration. At 25 ppm concentration, the radical scavenging activity of butylated hydroxyanisole and extract showed 90.9% and 91.0%, respectively. The degrees OH scavenging activity of the extract was shown to be 53.9% at 100 ppm concentration. At a concentration of 50 mu g, the O-2 degrees(-) scavenging activity of the extract was 31.7% as compared to 47.7% by gallic acid. These results indicated that Dillenia indica barks contained large amount of phenolics and possessed potent antioxidant property.