Is aqueous extract of soybeans neurotoxic? Preliminary evidence from histological evaluation of the cerebellum and cerebrum of Wistar rats.

BACKGROUND AND AIM: Reports indicate that there is a worldwide surge in plant-based eating patterns as typified by the increasing number of vegetarians and vegans. However, several medicinal and nutritional plants, seeds, and fruits can induce neurotoxicity. Accordingly, this study investigated the histological effects of aqueous Soybeans seed extract (ASSE) on the cerebellum and cerebrum of adult Wistar rats. METHODOLOGY: Following purchase and acclimatization, twenty-four rats were randomly divided into four groups of six rats per group as follows: Group A (control) received 1 ml distilled water daily, group B received 250 mg/kg body weight of ASSE daily, group C received 500 mg/kg body weight of ASSE daily and group D received 1000 mg/kg body weight of ASSE daily. All administration, via an oral gavage, lasted for twenty-eight days. After sacrifice, the cerebellum and cerebrum were separated, weighed, and processed for histological assessment. RESULTS: Results showed no significant difference (P>0.05) in the body, brain, cerebellar, relative cerebellar, cerebral, and relative cerebral weights of rats treated with all doses of ASSE compared to control. Also, no significant difference (P>0.05) was observed in the cerebellum-brain and cerebrum-brain ratios of treated rats in comparison to control. Histological findings revealed normal and intact histology of the cerebellum and cerebrum layers in treated rats when compared to control. CONCLUSION: Taken together, these findings provide preliminary histological evidence demonstrating that ASSE was safe for the experimental rats and had no adverse effect on the cerebellum and cerebrum.