Bacopa monniera Linn. as an antioxidant: mechanism of action.

Bacopa monniera, Linn. (Brahmi: Scrophulariaceae) an Ayurvedic medicine is clinically used for memory enhancing, epilepsy, insomnia and as mild sedative. For the first time the effect of alcohol and hexane fraction of Brahmi has been studied on FeSO4 and cumene hydroperoxide induced lipid peroxidation. Alcohol fraction showed greater protection with both inducers. Results were compared with known antioxidants tris, EDTA and a natural-antioxidant vitamin E. The effect of Brahmi was also examined on hepatic glutathione content. The mechanism of action could be through metal chelation at the initiation level and also as chain breaker. The results suggested that Brahmi is a potent antioxidant. The response of Brahmi was dose dependent. Tris, an hydroxyl trapper did not show any protection in comparison to Brahmi where as EDTA and vitamin E did protect against FeSO4. In experimental conditions 100 micrograms Brahmi extract (alcoholic) was equivalent to 247 micrograms of EDTA (0.66 microM) and 58 micrograms of vitamin E. Interestingly Brahmi only slightly protected the autooxidation and FeSO4 induced oxidation of reduced glutathione on lower doses 100 micrograms/ml and below, but on higher concentrations it enhanced the rate of oxidation.