Desmodium velutinum (family Papilionaceae) is used in Nigeria and Lokoja in particular for the treatment of abdominal pain among others. The LD50 was evaluated along with analgesic properties. The analgesic effects of the methanol extract of D. velutinum were investigated at three dose levels (100, 200, 300) mg/kg on the experimental models of pain in mice. The result of LD50 was greater than 3000mg/kg showing D. velutinum extract is relatively safe for human consumption. The anti-nociceptive activity was evaluated using the hot-plate and abdominal constriction tests. The extracts produced significant (P<0.05) inhibition of thermal nociception induced by hot plate. On chemical nociception induced by intra-peritoneal acetic acid, the extracts significantly (P<0.05) decreased the number of writhing episodes and the time spent before jumping off the hot-plate in a dose independent manner. These results suggest that the extract of D.velutinum may act by inhibiting the mediators of pain. These findings may justify the use of the plant in traditional medicine in the management of pain and related diseases in Nigeria.
Keywords: Activity, Anlgesic, Desmodium Velutinum, Evaluation, Papilionaceae