Psychopharmacological studies of Mammea africana stem bark extract

Abstract

Herbal medicine is an integral part of the health care system in most developed and developing countries of the world. Objective: The stem bark of Mammea africana used traditionally in the treatment of mental disorders was evaluated for depressive effect on the central nervous system (CNS). Materials and Method: The stem bark extract was investigated for depressive activity in the open field, force swimming and tail suspension tests as well as its anticonvulsant potential against pentylene tetrazol and aminophylline-induced convulsions. The effect of the extract on phenobarbitone induced sleeping time was also evaluated. Results: The extract was found to significantly (p<0.001) decrease the frequency of line crossing, rearing and walling activities of the rats in open field test as well as increased the immobility time in both tail suspension and force swimming tests. The stem bark extract also significantly (p<0.001) shortened the onset time of sleep and prolonged the duration of sleep induced by phenobarbitone sodium. The stem bark extract and fractions (30 – 90 mg/kg), could not offered significant protection against PTZand aminophylline induced convulsion, but were found to delay significantly (p<0.05 – 0.001) the onset of tonic/clonic convulsion and also prolonged the time of death of the treated mice. Conclusion: The stem bark of M. africana has depressant, sedating and anticonvulsant properties.