Toxicity and Analgesic Studies of Leaf Methanolic Extract of Maytenus Senegalensis (Lam.) Exell (Celastraceae)

The leaf methanolic extract of Maytenus senegalensis (Lam.) Exell was investigated for toxicity and analgesic effects. 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. 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). The results obtained suggested the extract to be relatively toxic in both mice and rats with a dose dependent anti-nociceptive activity.