Bacopa monnieri modulates endogenous cytoplasmic and mitochondrial oxidative markers in prepubertal mice brain

Bacopa monnieri (BM) an herb, found throughout the Indian subcontinent in wet, damp and marshy areas
is used in Ayurvedic system of medicine for improving intellect/memory, treatment of anxiety and neuropharmacological
disorders. Although extensively given to children as a memory enhancer, no data
exists on its ability to modulate neuronal oxidative stress in prepubertal animal models. Hence in this
study, we examined if dietary intake of BM leaf powder has the propensity to modulate endogenous
markers of oxidative stress, redox status (reduced GSH, thiol status), response of antioxidant defenses
(enzymic), protein oxidation and cholinergic function in various brain regions of prepubertal (PP) mice.
PP mice maintained on a BM-enriched diet (0.5 and 1%) for 4 weeks showed a significant diminution of
basal oxidative markers (malondialdehyde levels, reactive species generation, hydroperoxide levels and
protein carbonyls) in both cytoplasm and mitochondria of all brain regions. This was accompanied with
enhanced reduced glutathione, thiol levels and elevated activities of antioxidant enzymes (catalase, glutathione
peroxidase, superoxide dismutase). Significant reduction in the activity of acetyl cholinesterase
enzyme in all brain regions suggested the potential of BM leaf powder to modulate cholinergic function.
Further evidence that dietary intake of BM leaf powder confers the prepubertal brain with additional
capacity to cope up with neurotoxic prooxidants was obtained by exposing cortical/cerebellar synaptosomes
of normal and BM fed mice to 3-nitropropionic acid (3-NPA). While synaptosomes from control
mice exhibited a concentration related lipid peroxidation and ROS generation, synaptosomes obtained
from BM fed mice showed only a marginal induction at the highest concentration clearly suggesting
their increased resistance to 3-NPA-induced oxidative stress. Collectively these data clearly indicate the
potential of Bacopa monnieri to modulate endogenous markers of oxidative stress in brain tissue of PP
mice. Based on these results, it is hypothesized that dietary intake of BM leaf powder confers neuroprotective
advantage and is likely to be effective as a prophylactic/therapeutic agent for neurodegenerative
disorders involving oxidative stress.