Analgesic,anti-inflammatory and antipyretic activities of methanolic leaf extract of Maerua crassifolia

Objective:To investigate the the analgesic,anti-inflammatory and antipyretic activities of the methanolic leaf extract of Maerua crassifolia in mice and rats.Methods:Acetic acid-induced writhing and tail immersion methods were used to assess analgesic activity,while xylene and carrageenan-induced paw oedema methods were used to evaluate the anti-inflammatory effect of the leaf extract.Yeast and amphetamine-induced pyrexia were used to investigate the antipyretic activity.The phytochemical analysis and oral acute toxicity of the methanolic leaf extract of Maerua crassifolia were also evaluated.Results:The leaf extract(100,200,and 400 mg/kg)showed a dose dependent and significant(P<0.05)inhibition of pain in acetic acid-induced writhing and tail immersion tests.The extract also produced significant(P<0.05)anti-inflammatory activity in both paradigms.A significant(P<0.05)reduction in hyperpyrexia was also observed with the leaf extract.The phytochemical screening revealed the presence of alkaloids,flavonoids,terpenoids,tannins,steroids,resins,saponins and cardiac glycosides.The oral median lethal dose of the leaf extract was estimated to be greater than 5000 mg/kg in rats.Conclusions:The findings confirmed its ethnomedical use in the treatment of pains and feverish conditions.