Anti-inflammatory activities of Cassia alata leaf extract in complete Freund's adjuvant arthritis in rats.

OBJECTIVE: To investigate the anti-inflammatory effects of a hexane extract of Cassia alata leaves in complete Freund's adjuvant (CFA) arthritis in rats.

METHOD: A hexane extract of Cassia alata leaves was administered by oral gavage to CFA arthritic rats (500 mg/kg, n = 6). Controls received corn oil (2 ml, n = 6). The CFA arthritic model was induced by the injection of 0.5 ml (CFA) into the synovial cavity of the right knee joint of the hind leg of rats. The ability of the plant extract to reduce swelling as a sign of arthritic inflammation was assessed by obtaining the circumference of the knee joint before and for twenty eight days post arthritis induction. Reduction of leukocyte infiltration into the blood and synovial cavity of the arthritic rats were assessed using automated counting and Wrights method. Protection against cartilage erosion was also assessed histologically.

RESULTS: Cassia alata extract significantly (p = 0.0032) reduced knee circumference (swelling) in the CFA arthritic rats. Total and differential leukocyte counts in both blood and synovial fluid from Cassia alata treated animals were significantly (p < or = 0.05) lower than in control animals. Protective effects against cartilage degradation on the femoral head of the knee joint were observed in Cassia alata treated animals, as normal cartilage structure and chondrocyte arrangement were maintained.

CONCLUSIONS: The results suggest that Cassia alata exhibits anti-inflammatory activities that should be further examined and potentially exploited for anti-arthritic therapies.