Oxidative stress plays a key role in several ailments including neurodegenerative conditions. The aim of the study was to demonstrate the effect of rosmarinic acid (RA) in preventing oxidative stress related death of neuronal cell lines.

In the present study, we demonstrated direct neuroprotective effect of RA using H₂O₂-induced oxidative challenge in N2A mouse neuroblastoma cells. The mechanism of neutralization of H₂O₂-induced toxicity by RA was evaluated using MTT, lactate dehydrogenase, mitochondrial membrane potential (MMP), intracellular ROS, and comet assays. Up-regulation of brain neuronal markers at molecular level was performed by RT-PCR.

Results presented in the paper indicate that H₂O₂-induced cytotoxicity in N2A cells was suppressed by treatment with RA. Moreover, RA is very effective in attenuating the disruption of lactate dehydrogenase, mitochondrial membrane potential and intracellular ROS. Pretreatment with RA significantly prevents genotoxicity (3.7-fold, p < 0.01) and promotes the up-regulation of tyrosine hydroxylase (TH) (4.5-fold, p < 0.01), and brain-derived neurotrophic factor (BDNF) genes (5.4-fold, p < 0.01) against H₂O₂-induced cytotoxicity in N2A cells.

Our results revealed that N2A cells are suitable cellular models to evaluate neuroprotective effects of RA, and suggest that RA may potentially serve as an agent for prevention of several human neurodegenerative diseases caused by oxidative stress.