Background: The ethnomedicinal uses of Erythrina senegalensis including its antinociceptive and sedative properties have been documented in literature. Objective: This study evaluated the analgesic and behavioural effects of the ethanol root bark extract of E. senegalensis in mice. Methodology: Phytochemical screening and acute toxicity studies were conducted. Analgesic activity in mice was assessed using acetic acid induced writhing and hot plate method, while behavioural effects were evaluated using diazepam-induced sleeping test and hole-board test. These evaluations were carried out on E. senegalensis ethanol root bark extract at doses of 75, 150 and 300 mg/kg. Results: The intraperitoneal median lethal dose was found to be 1,137 mg/kg, while alkaloids, flavonoids, saponins, tannins and reducing sugars were found to be present in the plant material. E. senegalensis ethanol root bark extract at 150 and 300 mg/kg exhibited significant (p< 0.001) analgesic activity which offered 17.6% and 25.8% inhibition above ketoprofen in the acetic acid test respectively. At 300 mg/kg, E. senegalensis ethanol root bark extract demonstrated comparative analgesia with pentazocine in hot plate test. At the same dose, it produced a significant (p< 0.05) potentiation of diazepam-induced sleeping time. A significant increase in number of head-dips was demonstrated by E. senegalensis ethanol root bark extract at 150 mg/kg. Conclusion: The study shows that E. senegalensis ethanol root bark extract possesses analgesic, sedative and anxiolytic principles, thus supporting the ethnomedicinal rationale for its uses in management of painful conditions and sleep disturbances. Keywords: Erythrina senegalensis, analgesic, sedative, behavioura
