ABSTRACT
Neurodegenerative diseases are the consequences of imbalance between the production of oxidative stress and its nullification by cellular defense mechanisms. Hydrogen peroxide (HO), a precursor of deleterious reactive oxygen species, elicits oxidative stress, resulting in severe brain injuries. Bacopa monnieri is well known for its nerve relaxing and memory enhancing properties. The present study was designed to evaluate the protective effects of extracts from Bacopa monnieri against HO induced oxidative stress using a cellular model, neuroblastoma IMR32 cell line. The protective potential of methanolic, ethanolic, and water extracts of B. monnieri (BM-MEx, BM-EEx, and BM-WEx) was evaluated using MTT assay. Although, all the B. monnieri extracts were found to protect cells against HO-mediated stress but BM-MEx showed significantly greater protection. UPLC analysis of BM-MEx revealed various polyphenols, including quercetin, catechin, umbelliferone, and caffeic acid predominance. Further, BM-MEx was found to possess considerable greater neuroprotective potential in comparison to the standard polyphenols such as quercetin, catechin, umbelliferone, and caffeic acid. The levels of antioxidant enzymes were significantly elevated after the pretreatment of BM-MEx and quercetin. The expression levels of oxidative stress markers, such as NF200, HSP70, and mortalin, were significantly alleviated after the pretreatment of BM-MEx as shown by immunofluorescence and RT-PCR. In conclusion, the present study demonstrated the protective effects of BM-MEx, suggesting that it could be a candidate for the development of neuropathological therapeutics.