Xylopic Acid Suppresses Adjuvant-induced Arthritis in Sprague Dawley Rats via Reduction in Serum Levels of IL-6 and TNF-alpha

Background: Xylopic acid (XA) is the principal constituent obtained from the biofractionation of the dried fruits of Xylopia aethiopica. Our initial reports have established the acute anti-inflammatory activity of this kaurene diterpene. Objective: Currently, we investigate the chronic anti-inflammatory activity of xylopic acid. Methods: The adjuvant-induced arthritis model in rats was employed in carrying out the study. Results: It was observed from the study that XA significantly (P < 0.05) suppressed the oedema associated with adjuvant arthritis while preventing associated joint deformation as identified from the radiographs. Histopathological analysis of joints of treated animals revealed signs of bone reformation and re-calcification following XA administration. From the haematological analysis, xylopic acid significantly decreased eosinophil sedimentation rate (ESR) while also decreasing white blood cells (WBC), which were increased after arthritis induction. Serum analysis showed the inhibitory effect of XA on serum expression of IL-6 and TNF-alpha in arthritic rats. Conclusion: Our study demonstrates the anti-arthritic activity of orally administered XA while pointing to a possible mechanism of its anti-inflammatory action.