Annickia polycarpastem bark is used in West Africa to treat ailments related to pain and inflammation in traditional medicine. Yet, these biological activities of the plant have not been investigated. To investigate the antiinflammatory and analgesic activities of A. polycarpa stem bark (ASE) and its constituents. The compounds were isolated using column chromatography and their structures identified by spectroscopic methods. Anti-inflammatory activity was evaluated by carrageenan induced edema test. Analgesic activity was evaluated using the hot plate and the acetic acid-induced writhing tests. ASE at 10 mg/kg p.o demonstrated significant (p<0.01) anti-inflammatory activity of 69.64 %, analgesic activity of 82.54 % and 36.81 % in the hot plate and writhing tests respectively. The results also showed that the chloroform fraction of ASE was the most active. Palmatine and jatrorrhizine were isolated from the chloroform fraction. Palmatine and jatrorrhizine produced (p<0.01) anti-inflammatory and analgesic effects. Their analgesic activity range from 85-94 % at 9 mg/kg p.o. (which was higher than 43.3 % givenby tramadol at the same dose) in the hot plate assay. The analgesic activity range from 47.28 - 44.25 % in the writhing assay which was higher than 32.92 %produced by diclofenac at 6 mg/kg p.o. Naloxone abolished the analgesic effects of ASE and palmatine in the hot plate test. This indicates that ASE and its constituents acts as opioids to relive pain. The findings provide scientific backing for traditional use of A polycarpa stem barkas antiinflammatory and analgesic agent.
