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

Traditional medicine intervention has been used in rheumatoid arthritis (RA) treatment due to limitations of conventional drugs. 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. 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. 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. The findings suggest that the extracts of SBCP have good antiarthritic potentials comparable to indomethacin and hence could be used in rheumatoid arthritis management.