Bacopa monnieri Extract Offsets Rotenone-Induced Cytotoxicity in Dopaminergic Cells and Oxidative Impairments in Mice Brain

Bacopa monnieri (BM), an ayurvedic medicinal herb is widely known for its memory enhancing ability and improvement of brain function. In this study, we tested the hypothesis that BM extract (BME) could offset neurotoxicant-induced oxidative dysfunctions in developing brain in a rotenone (ROT) mouse model. Pretreatment of dopaminergic (N27 cell lines) cells with BME exhibited significant cytoprotective effect as evidenced by the attenuation of ROT-induced oxidative stress and cell death. Further, the neuroprotective efficacy of BME was assessed in prepubertal mice administered ROT (i.p. 1.0 mg/kg b.w./day) for 7 days. BME treatment significantly offset ROT-induced oxidative damage in striatum (St) and other brain regions as evident by the normalized levels of oxidative markers (malondialdehyde, ROS levels, and hydroperoxides) and restoration of depleted GSH levels. Further, BME effectively normalized the protein carbonyl content in all brain regions suggesting its ability to prevent protein oxidation. Furthermore, BME treatment restored the activity levels of cytosolic antioxidant enzymes, neurotransmitter function, and dopamine levels in St. Based on our findings, we hypothesize that the neuroprotective effects of BM extract may be at least in part related to its ability to enhance reduced glutathione and antioxidant defenses in brain regions. It is suggested that BM may be effectively exploited as a prophylactic/therapeutic adjuvant for neurodegenerative disorders involving oxidative stress.