Bacopa monnieri extract ameliorates core autistic behavioural deficits of sodium valproate-induced autism spectrum disorder in mice, and its mechanism of action related to PTEN protein

Abstract

Our previous study demonstrated the effect of Bacopa monnieri extract (BME) on behavioural deficits in sodium valproate (VPA)-induced autism spectrum disorder in mice. The present study aims to further investigate the effect of BME on neurobehaviors of autism spectrum disorder (ASD) in mice and the biochemical mechanism(s) involved. Female pregnant mice were divided into control and VPA treated groups at 12-13 days of gestation (saline/sodium valproate 500 mg/kg respectively, i.p.). Control group pups of saline-treated mothers received distilled water. The VPA-treated mothers received either distilled water or BME (50 mg/kg, p.o.) after birth until 13 days later. Then, from postnatal day 14, ASD pups were orally treated with BME (50 mg/kg)/distilled water for the duration of the study. Behavioural deficits (repetitive behaviour and social behaviour deficit) were measured by a self-grooming test and a three-chamber test on postnatal days 20 and 30. On postnatal day 40, the cerebral cortex of pups was isolated for evaluation of  the expression level of PTEN using the Western blot method. The results showed that BME (50 mg/kg, p.o.) significantly improved repetitive behaviour and social behaviour deficits in ASD mice on postnatal day 20 and 30, and also increased PTEN expression level in the brain of ASD mice. These results demonstrated that BME ameliorates core behaviours of autism and concurrently restores decreases in PTEN protein expression in the cerebral cortex of valproate-treated mice.