Neuroprotective and Nootropic Effect of Bacopa monnieri (L.) Wettst. (Brahmi) through Its In vivo Data Focused on Alzheimer’s Disease

Bacopa monnieri (L.) Wettst. (Plantaginaceae) (BM), known as “brahmi”, is a reputed medicinal plant, particularly in Ayurvedic medicine. Since BM has been traditionally used for memory dysfunction, experimental studies at the pre-clinical level support the nootropic effect of the plant relevant to Alzheimer’s disease (AD) demonstrated through various mechanisms. It has been reported that saponins (e.g. bacosides, bacopasides, and bacopasaponins) are largely responsible for the memory-enhancing and other neuropharmacological effects of BM. Bacosides, which are non-polar molecules that can easily cross the blood-brain barrier, are reported to directly lead to anti-inflammatory and antioxidant effects in the brain. BM extracts rich in bacosides are considered advantageous due to their higher nootropic efficacy. The findings suggest that only bacoside enrichment increases antiamnesic activity; other components also contribute to the extract with a synergism. Adverse side effects of BM in humans have rarely been reported. In the current review, we aimed to scrutinize in vivo data derived from the studies related to the cognitive-enhancement effect of BM with a special focus on AD.