Studies on antioxidant potential of methanol extract/fractions of Acacia auriculiformis A. Cunn

Antioxidant activities of the methanol extract/fractions of Acacia auriculiformis A. Cunn were evaluated by three in vitro experiments, namely, DPPH, relative reducing power and hydroxyl radical (site specific and non site specific) assays. The differential activities of methanol extract/fractions could be correlated with their respective total phenolic contents and compared with standards (BHT and l-ascorbic acid.). The bark powder of the plant was extracted with different solvents of increasing and decreasing polarity by a maceration extraction method and then the methanol extract was further partitioned with ethyl acetate and water. The scavenging activity of extract was found to be enhanced on fractionating the extract. Moreover, among the two fractions (ethyl acetate and water fraction) and the crude extract, the water fraction exhibited good scavenging responses of 72.0%, (57.2%), 1.76 (1.52), 88.0% (82.6%) and 93.6% (83.47) in DPPH, reducing power, site specific and non-site specific hydroxyl radical scavenging assay in increasing and (decreasing) order of solvent polarity at maximum concentration, respectively. Studies are in progress to evaluate the effect of extracts/fractions in other antioxidant assays and to identify the factors responsible for the activity.