Rosmarinic acid protects human dopaminergic neuronal cells against hydrogen peroxide-induced apoptosis.

In this study, we investigated the protective effects of rosmarinic acid (RA) on H(2)O(2)-induced neurotoxicity in human dopaminergic cell line, SH-SY5Y. Results showed that RA significantly attenuated H(2)O(2)-induced reactive oxygen species (ROS) generation and apoptotic cell death. Rosmarinic acid effectively suppressed the up-regulation of Bax and down-regulation of Bcl-2. Furthermore, RA stimulated the antioxidant enzyme heme oxygenase-1 (HO-1). We also demonstrated that the HO-1 induction by RA was associated with the protein kinase A (PKA) and phosphatidylinositiol-3-kinase (PI3K) signaling pathways. These results suggest that RA can protect SH-SY5Y cells under oxidative stress conditions by regulating apoptotic process. Thus, RA should be clinically evaluated for the prevention of neurodegenerative diseases.