Abstract This study was designed to evaluate the effects of Rauwolfia vomitoria Oliv. ethanol and aqueous root extracts on adjuvant induced arthritis in albino rats. A total of 135 female albino rats were used for this study. The albino rats were divided into nine groups, each containing 15 animals. Arthritis was induced by intradermal administration of 0.1ml Chicken type 11 collagen-Complete Freund’s adjuvant into the left hind paw of the albino rats. Treatment with the extracts at doses of 400, 600 and 800 mg/kg body weight commenced on day 10 of the 32-day study period. The parameters were analysed using a well known standard methods. The result showed that in the arthritic rats, the levels of interleukin- 6 (IL-6), interleukin-1 β (IL-1β), erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), C-reactive protein and tumor necrosis factor alpha (TNF-α) were significantly (P<0.05) higher than the control. Treatment of the arthritic rats with the extracts at the specified doses caused a significant reversal (P< 0.05) of the effect of the chicken type II collagen –Complete Freund’s adjuvant in the rats. The ameliorative effect of the extracts on the arthritic rats was both time and dose dependent. The anti-arthritic potentials of the root extracts was significantly (P<0.05) comparable to that of the standard drug (indomethacine). The results also showed that the potentials of Rauwofia vomitoria ethanol and aqueous root extracts to reverse the effect of the adjutant on the arthritic rats were significant (P>0.05). The plant extracts contain principles that have the potential to suppress antigen presentation and reverse arthritic conditions developed in adjuvant induced arthritic rats. Hence, this present study provides scientific evidence that Rauwolfia vomitoria ethanol and aqueous roots have anti-arthritic potentials.
Keywords Rauwolfia vomitoria, weight, paw size, Erythrocyte sedimentation rate, C-reactive protein and Cytokines.