Evaluation of antioxidant activity of Salix caprea flowers

The study was aimed at evaluating the antioxidant activity of an ethanol extract of Salix caprea L. (Salicaceae) flowers. The extract was found to possess a large amount of polyphenols and also exhibited a high reducing ability. The extract significantly and dose dependently scavenged DPPH, superoxide (O-2(.-)), hydrogen peroxide (H2O2) and nitric oxide (NO). At a concentration of 250 mu g/mL, 85.04% of DPPH radicals and at 500 mu g/mL 45.97%, 17.97% and 56.53% of O-2(.-), H2O2 and NO, respectively, were scavenged by the S. caprea flower extract. A significant amount of protection was also afforded by the extract in the acute oxidative tissue injury animal model constituted by ferric nitrilotriacetate (FeNTA) induced hepatotoxicity in mice. An intraperitoneal administration of FeNTA at a dose of 9 mg/kg of body weight caused an elevation in hepatic lipid peroxidation (LPO) to 176.90% and a suppression in hepatic glutathione (GSH) content and the activities of antioxidant enzymes namely, catalase (CAT), glutathione reductase (GR) and glutathione peroxidase (GPX) to 46.49%, 64.37%, 41.71% and 48.76%, respectively, of the saline treated control. The pretreatment of mice with S. caprea flower extract at a dose range of 50-150 mg/kg of body weight for 7 days followed by FeNTA treatment caused preservation of all these parameters. The present study indicates that the flowers of S. caprea possess a significant antioxidant and hepatoprotective property, the former being implicated in the latter. Copyright (c) 2006 John Wiley & Sons, Ltd.