Free radical scavenging: a possible mechanism of action for the anti-inflammatory activity of Russelia equisetiformis (Schlect & Chan) (Scrophulariacae).

The methanol extract of Russelia equisetiformis (MRE), which exhibited significant antiinflammatory activity, was evaluated for the possible mode of action by studying its antioxidant potential in adjuvant- induced arthritic rats. 1, 1 diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect was determined by spectrophotometric method. The enzymatic activity of the superoxide dismutase, glutathione peroxidase, showed a significant increase, while the lipid peroxide content was found to decrease to a large extent in MRE and indomethacin-treated rats. There was also significant and concentration-dependent increase in the percentage inhibition of DPPH, comparable to that of vitamin E and butylated hydroxyanisole (BHA) which are natural and synthetic antioxidants, respectively. The results obtained in the present study indicate that MRE possesses free radical scavenging and antioxidant properties.