Toxicity and analgesic studies of leaf methanolic extract of Maytenus senegalensis (Lam.) Exell (Celastraceae)

Objective; This study was conducted to investigate the toxicity and analgesic effects of the leaf methanolic extract of Maytenus senegalensis (Lam.) Exell. Methods; Acute toxicity was investigated via intraperitoneal route using mice and rats, analgesic activity was investigated using two models; acetic acid-induced writhing in mice and formalin induced pain in rats. Results; The extract was determined to have LD (50) of 1264.91 mg/kg in both mice and rats. It significantly (0.001) inhibited acetic acid-induced writhes in mice at all doses administered (75, 150 and 300 mg/kg) in a dose dependent manner and significantly (0.01) inhibited formalin induced pain in rats, in a non-dose dependent manner. The inhibitory effect observed was higher in the extract compared to the standard used (piroxicam). Conclusion; The results obtained suggested the extract to be relatively toxic in both mice and rats with a dose dependent anti-nociceptive activity.