Antioxidant Activity of Selected Medicinal Plants of Nepal.

Abstract

Introduction: Many natural products are the source of therapeutic agents  having potential pharmacological activity. Traditional  medicinal practices have long history for serving human  kind.The present study was designed to collect, identify, prepare herbarium and to  evaluate the antioxidant activity of selected medicinal  plants. Method : Collected plant species were subjected to maceration in methanol for 72 hrs. Antioxidant activity of plant  extracts was assessed by using DPPH free radical scavenging method in different concentrations (1 μg/ml,  3 μg/ml, 5 μg/ml, 7 μg/ml and 10 μg/ml) and percentage inhibition and effective concentration (EC50) was  calculated. Result Result indicates that EC50 of D. boryanum (3.75 μg/ml) and P. guajava (3.89 μg/ml) was less, EC50 of R. nepalensis (5.03 μg/ml) and S. japonica (6.75 μg/ml) was comparable and EC50 of M. macrophylla (7.86 μg/ml), B. asiatica (9.14 μg/ml), E. adenophorum (7.78 μg/ml), E. crassipes (8.21 μg/ml) and N. arbortritis (8.16 μg/ml) was higher than ascorbic acid (4.73 μg/ml). Conclusion Our result shows that D. boryanum and P. gvajava possess higher antioxidant activity than the ascorbic acid  implying that, they could be potential free radical scavenging agents and could be developed as pharmaceutical agents.