Semecarpus anacardium Linn. nut milk extract, an indigenous drug preparation, modulates reactive oxygen/nitrogen species levels and antioxidative system in adjuvant arthritic rats.

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are highly reactive transient chemical species, which play an important role in the etiology of tissue injury in rheumatoid arthritis (RA). The effects of milk extract of Semecarpus anacardium Linn. nut (SA) was studied on adjuvant arthritis in rats. Arthritis was induced by injecting 0.1 ml of heat killed mycobacterium tuberculosis (10 mg/ml of paraffin oil) intradermally into the left hind paw. A significant increase in the levels of lipid peroxides (LPO), ROS (superoxide radical, hydroxyl radical, H(2)O(2) and myeloperoxidase) and RNS (nitrate+nitrite) observed in adjuvant arthritic animals were found to be significantly decreased on administration of the drug at 150 mg/kg body weight/day. The antioxidant defense system studied in arthritic animals were altered significantly as evidenced by the decrease in antioxidants. Treatment with SA recouped the altered antioxidant defense components to near normal levels. These evidences suggest that the free radical mediated damage during arthritis could have been controlled by SA by its free radical quenching and antioxidative potential. (Mol Cell Biochem 276: 97-104, 2005).