Free Radical Scavenging Activity of Aqueous Root Extract of Argyreia nervosa (Burm.f.) Boj. (Convolvulaceae)

Aqueous extract of Argyreia nervosa, which is widely used in the indigenous system of medicine, was studied for its in vitro scavenging activity by different methods viz. DPPH radical scavenging, ABTS radical scavenging, lipid peroxidation, iron chelating activity, superoxide scavenging, total antioxidant capacity, Nitric oxide scavenging and Non-enzymatic Glycosylation of Haemoglobin assay. The results were analyzed statistically by regression method. Its antioxidant activity was estimated by IC₅₀ value and the values are 88.86 μg/ml for DPPH radical scavenging, 66.64 μg/ml for ABTS radical scavenging, 31.57 μg/ml for lipid peroxidation, 8.0 μg/ml for iron chelating activity, 113.20 μg/ml for Nitric oxide scavenging and 7.51 μg/ml for superoxide scavenging. Total antioxidant capacity was found to be 22.0 μg/ml. In Haemoglobin glycosylation the % scavenging was found to be 43.77% and 64.42% for concentration 0.5 mg/ml and 1.0 mg/ml respectively. In all the methods, the extract showed its ability to scavenge free radicals in a concentration dependent manner. The results indicate that Argyreia nervosa has significant antioxidant activity.