Anti-arthritic potential of ethanol and aqueous extracts of stem bark of Cleistopholis patens on complete Freund's adjuvant-induced rheumatoid arthritis in rats

BACKGROUND: Traditional medicine intervention has been used in rheumatoid arthritis (RA) treatment due to limitations of conventional drugs. OBJECTIVE: This study aimed at evaluating the anti-arthritic potentials of ethanol and aqueous extracts of stem bark of Cleistopholis patens (SBCP) in complete Freund's adjuvant (CFA) induced rheumatoid arthritis in rats. MATERIALS AND METHODS: Rheumatoid arthritis was induced in groups 2 to 9 by intradermal injection of 0.1 mlkg(−1) chicken type II collagen in CFA into the left hind paw of the rats. Group 1 served as normal control. Group 2 (negative control) received 5 mlkg(−1) body weight normal saline while group 3 (positive control) received 10 mg/kg body weight standard drug (indomethacin). Groups 4 to 9 received varied doses of the extracts. After 10 days of RA induction, rats were treated with ethanol and aqueous extracts of SBCP orally at a dose of 400, 600 and 800 mgkg(−1) for 21 days. The paw size, body weight changes, inflammatory parameters, lipid peroxidation maker and malondialdehyde (MDA) were assessed. RESULTS: Rheumatoid arthritis induction caused marked (p < 0.05) increase in paw size, inflammatory makers and MDA while significant (p < 0.05) reduction was observed in body weight relative to normal control. Treatment with extracts analogous to indomethacin markedly (p < 0.05) decreased the paw size and caused weight gain while the altered inflammatory parameters and MDA were reversed relative to negative control. CONCLUSION: The findings suggest that the extracts of SBCP have good antiarthritic potentials comparable to indomethacin and hence could be used in rheumatoid arthritis management.