Anti-amnesic effect of ethanol stem bark extract and fractions of Milicia excelsa (Moraceae) in mice

Abstract

Background: Amnesia is associated with normal aging and neuropsychiatric disorders with no known medical cure. Medicinal plants used in traditional medicines to combat neuropsychiatric disorders may be a veritable vehicle towards providing the appropriate drug candidate(s).

Methods: Hence, this study assessed the anti-amnesic potential of Milicia excelsa stem bark upon its widespread use in traditional medicine for treating mental illnesses. The anti-amnesic potentials of ethanol stem bark extract and fractions were investigated using mouse models of scopolamine-, and diazepam-induced amnesia on Y-maze.  Results: The result obtained showed that the crude ethanol extract, ethyl acetate and n-butanol fractions at all the doses used (75, 150 and 300 mg/kg, p.o.) significantly (p<0.05) reversed the amnesia induced by scopolamine (1 mg/kg, i.p.) and diazepam (1 mg/kg, i.p.) in mice. The n-hexane at 300 mg/kg and aqueous fraction at 75 and 150 mg/kg significantly (p<0.05) ameliorated the amnesia induced by scopolamine in scopolamine-induced amnesia. 

Conclusion: This study, therefore, concludes that the extract and its fractions may possess anti-amnesic effect. However, further studies may be carried out to isolate and characterize the anti-amnesic bioactive principle(s) in ethyl acetate and n-butanol fractions that showed consistent anti-amnesic potentials in the scopolamine-, and diazepam-induced amnesic models used. The in-vivo antioxidant and acetylcholinesterase assays of these active fractions should also be carried out to corroborate the observed anti-amnesic effect.