Abstract : Antioxidant plays a major role in protecting our body from disease by reducing the oxidative damage to cellular component caused by Reactive Oxygen Species. The antioxidant activity of plant extracts was determined by different in vitro methods such as the DPPH free radical scavenging assay, SOS activity, hydroxyl radical scavenging and ferric thiocynate activity. Decreased absorbance of the reaction mixture indicates stronger scavenging activity. DPPH radical scavenging activity of Betula utilis ethyl acetate and methanolic extract exhibited percent inhibition 72% and its IC50 value was found to be 30.16 μg/ml and 83.86% and its IC50 value was found to be 27.62 μg/ml respectively. Ascorbic acid was used as a reference compound which exhibited percent inhibition 91.81% and showed IC50 value of 25.82 μg/ml. The Betula utilis ethyl acetate extract displayed SOS activity which exhibited percent inhibition of 72.49% and showed IC50 value of 44.47μg/ml. Similarly, SOS scavenger activity of Betula utilis methanol extract exhibited percent inhibition 81.49% and its IC50 value was found to be 20μg/ml. For SOS activity, Ascorbic acid was used as a reference compound which exhibited percent inhibition 86.72% and showed IC50 value of 12.01μg/ml. Hydroxyl radical scavenging activity of Betula utilis ethyl acetate and methanol extract exhibited percent inhibition 76.93 and 81.62% and its IC50 value was found to be 48.003 and 27.14μg/ml. Similarly, ferric thiocynate activity of Betula utilis ethyl acetate and methanol extract exhibited percent inhibition 74.68 and 81.27% and its IC50 value was found to be 40.112 and 23.79μg/ml.The Betula utilis could be valuable natural source of antioxidants that could be further applied for the development of useful pharmaceutical products.

Keyword : —Ascorbic acid, Betula utilis, Ferric thiocynate activity, Methanolic extract