Carnosol, a component of rosemary (Rosmarinus officinalis L.) protects nigral dopaminergic neuronal cells.

Carnosol, a major component of Rosmarinus officinalis, is a phenolic diterpene that has potent antioxidant and anti-inflammatory activities. In this study, we investigated the protective effects of carnosol on rotenone-induced neurotoxicity in cultured dopaminergic cells. Results showed that cell viability was significantly improved with carnosol through downregulation of caspase-3. Furthermore, carnosol significantly increased the tyrosine hydroxylase, Nurr1, and extracellular signal-regulated kinase 1/2. These results suggest that carnosol may have potential as a possible compound for the development of new agents to treat Parkinson's disease.