Nitric oxide-related toxicity in culture of rat astrocytes: effect of BACOPA MONNIERA

There is growing evidence that high concentrations of nitric oxide (NO), generated by activated astrocytes,might be involved in a variety of neurodegenerative diseases, such as Alzheimer’s disease, ischemia and epilepsy.It has recently been suggested that glial cells may produce NO under superoxide radical stimulation by enzymeindependentmechanism. This suggests that also natural antioxidants may have therapeutical relevance inneurodegenerative diseases. Studies of Bhattacharya et al. have evidenced that Bacopa monniera (BM) (familyScrophulariaceae), an Ayurvedic medicinal plant clinically used for memory enhancing, epilepsy, insomnia and asa mild sedative, is able to reduce the memory-dysfunction in rat models of Alzheimer’s disease, but the molecularmechanisms of this action are yet to be determined. In the present study, we examined the effect of a methanolicextract of BM on toxicity induced by the nitric oxide donor, S-nitroso-N-acetyl-penicillamine (SNAP), in culture ofpurified rat astrocytes. Our results indicate that, after 18 h of treatment, SNAP induced an increase in theproduction of reactive species, but did not induce the rupture of cellular membrane. Conversely, this NO donorinduced a fragmentation of genomic DNA compared to control astrocytes. The extract of BM inhibited theformation of reactive species and DNA damage in a dose dependent manner. This data supports the traditional useof BM and indicates that this medicinal plant has a therapeutic potential in treatment or prevention of neurologicaldiseases.