The acute anti-inflammatory action of xylopic acid isolated from Xylopia aethiopica.

Background Our earlier studies had given evidence of the traditional application of Xylopia aethiopica in the management of inflammation. The principal constituent obtained from its bio-fractionation is xylopic acid. It is a crystalline diterpene that belongs to the class of kauranes. This work sets out to investigate the anti-inflammatory potential of the xylopic acid isolated from the dried fruit of X. aethiopica. Methods A preliminary anti-inflammatory study, using the protein denaturation model, and in vivo anti-inflammatory assay were employed in the investigation of acute inflammation. The modulation of the effect of the pro-inflammatory markers histamine, serotonin, bradykinin, and prostaglandin E2 by xylopic acid was investigated by in vivo mice paw oedema models. Results Xylopic acid showed a concentration-dependent inhibition of albumen denaturation with an IC50 of 15.55 μg mL-1. Xylopic acid (10, 30, 100 mg kg-1) inhibited the maximal oedema and the average paw thickness (oedema) over the period of each study considerably for all phlogistic agents employed (i.e. carrageenan, histamine, serotonin, bradykinin, and prostaglandin E2) in the inflammation induction for both prophylactic and therapeutic protocols. Conclusion This study establishes that xylopic acid has anti-inflammatory action in acute inflammation.