Anxiogenic-like Effects of a Root Extract of Sphenocentrum jollyanum Pierre in Murine Behavioural Models

This study has characterized the effect of an ethanolic extract of roots of Sphenocentrum jollyanum (SJE) which are chewed or taken in alcoholic bitters in Ghana for its stimulant effect on the CNS and as an aphrodisiac agent Four widely used animal models of anxiety: the open field test, elevated plus maze, hole-board and light/dark box were employed. Results were compared qualitatively to those obtained for diazepam and caffeine which served as anxiolytic and anxiogenic drugs, respectively. Acute administration of SJE (100-1000 mg kg super(-1), p.o.) exhibited anxiety-like effects dose-dependently, which were qualitatively similar to those induced by caffeine (10-100 mg kg super(-1)). Both drugs decreased the number of entries and time spent on the open arms of the elevated-plus maze and increased the number of visits to the corners of the open field. In addition, SJE decreased the number and duration of head dips compared to vehicle-treated mice. Also, the extract exhibited anxiogenic properties in hole-board and light/dark box by significantly decreasing the number of head-dips and the time spent in the dark portion of the light/dark box, respectively. In contrast, diazepam (0.1-1 mg kg super(-1)) exhibited a typical profile of an anxiolytic drug. At all doses tested, SJE produced no motor deficits in animals using the rotarod test but decreased spontaneous locomotor activity in the activity cage apparatus. In conclusion, the results indicate that the root extract of S. jollyanum has anxiogenic like effects in mice and thus supports the use of the plant in traditional medicine.