Anti-oxidant activity of methanolic extract of aquatic flowering plant Nymphaea capensis leaf

Abstract

Background: Nymphaea capensis is an aquatic flowering plant which is included in the family of Nymphaeaceae. Literature review on the plants of Nymphaeaceae family exhibited significant medicinal activities. Therefore, the objective of the present study is to evaluate possible anti-oxidant activity of crude methanol extract of N. capensis leaf.Method: In antioxidant study, methanolic plant extract was evaluated for 1,1-diphenyl,2-picrylhydrazyl (DPPH) and reducing power capacity. Moreover, total phenolic and total flavonoid content of plant extracts were determined and expressed in mg of gallic acid equivalent per gram of dry sample (mg GAE/g dry weight).Result: In the DPPH free radical scavenging assay, methanol extract showed concentration dependent inhibition of the free radicals. IC50 of Ascorbic acid was 14.84 µg/ml whereas N. capensis was 130.94 µg/ml. In case of reducing capacity, at conc. 62.5, 125, 250, 500, 1000 ug/ml, the absorbances of Ascorbic acid were 0.65, 1.12, 1.45, 1.78 and 1.89 respectively. In case of N. capensis, the absorbances were 0.46, 0.75, 1.04, 1.27 and 1.50 respectively. The extract displayed a concentration dependent increase in reducing power. In the case of total phenolic content, the methanol extract of N. capensis contained a considerable amount of phenolic contents which was 215±7 of GAE/g. In the case of total flavonoid content, methanol extract of N. capensis contained significant amount of flavonoid contents which was 184.75±6.78 of GAE/g.