In vitro antioxidant and antithrombotic activity of Hemidesmus indicus (L) R.Br.

The methanolic extract of Hemidesmus indicus (L) R.Br. (Asclepiadaceae) roots was found to inhibit lipid peroxidation and scavenge hydroxyl and superoxide radicals in vitro. The amount required for 50% inhibition of lipid peroxide formation was 217.5 micro g/ml. The concentrations needed to scavenge hydroxyl and superoxide radicals were 73.5 and 287.5 micro g/ml, respectively. The intravenous administration of this extract (5mg/kg body weight) in rabbits delayed the plasma recalcification time and enhanced the release of lipoprotein lipase enzyme significantly. The extract also inhibited ADP-induced platelet aggregation in vitro (50-250 micro g), which was comparable to commercial heparin.