Oxidative reactive species play an important role in pathological conditions such as aging, fatty liver and cancers. Secondary metabolites enriched fraction derived from medicinal plants showed the inhibition of free radical generation by playing an important role in precluding various diseases. The aim of present study was to evaluate the antioxidant activity of different extracts by using the DPPH method. We assayed the free radicals scavenging activity of extracts at 50, 100, 200, 400 and 500 µg/ml concentration and phytochemical study of Petroleum ether, Chloroform, Methanol and Aqueous whole plant extracts of Catharanthus roseus. Amid the five absorption concentrations tested, it was observed that dose of 500 µg/ml showed the higher antioxidant activity for each extract. All samples displayed an increasing antioxidant effect with increase in concentration i.e. concentration dependant. The IC50 value of Petroleum ether, Chloroform, Methanol and Aqueous extract was found as 330.73 µg/ml, 596.13 µg/ml, 801.92 µg/ml and 504.12 µg/ml respectively. The petroleum ether extract at the concentration of 500 µg/ml showed the highest % inhibition of 67.441% compare to other extracts. DPPH method provides an easy and fast way to analyze potential antioxidants. The C. roseus extracts can be considered a rich natural source of antioxidants and can be used to develop pharmaceutical products for therapeutic treatment of various disorders caused by free radicals in human body.

Keywords : Antioxidant; DPPH; Free radical