Neurotoxicity and Behavioral Changes Following Sub-Chronic Administration of Aqueous Extract of Erythrophleum Ivorense Stem Bark in Mice

Erythrophleum ivorense (EI) is a tree found across tropical Africa. The bark of EI is widely used as hunting poisons for animals and ordeal poison in humans. Ingestion of this plant causes paralysis, respiratory distress and amnesia. In folklore, these behavioral changes have been attributed to guilt in victims; nonetheless, scientific evidence in support of this claim does not exist. Thus, there is the need to validate the mechanism of neurotoxicity and behavioral alteration of this plant. Methods: BALB/c male mice (n=48) were randomly divided into four groups. The test groups were administered aqueous extract of EI in a single daily graded doses (5, 10 and 15 mg/kg according to the body weight) for a duration 28 days while the control received distilled water. Motor coordination, learning, memory and grip strength was thereafter accessed with wire grip, Morris water maze and inverted wire mesh grid grip tests respectively. Histological staining of brain sections was also carried out. At all tested doses aqueous extract of EI caused significant reduction in hanging latency, significantly increased escape latency and decreased duration in the target platform during the Morris water maze test relative to the control. Decreased grip strength was also observed in the test groups compared to control. Histology revealed dysmorphic and disoriented Purkinje cells and loss of Purkinje cell layer of the cerebellum. Erythrophleum ivorense administration altered motor coordination, learning and memory and grip strength in mice in a dose-dependent manner. It also caused disruption of granule cells layer, loss of Purkinje cells and altered cerebellar anatomy leading to motor deficits in mice.