Hwansodan protects PC12 cells against serum-deprivation-induced apoptosis via a mechanism involving Ras and mitogen-activated protein (MAP) kinase pathway

Hwansodan has been used as a prescription for senile and vascular dementia in Oriental medicine. We investigated the neuroprotective effects of Hwansodan water extract on the apoptotic death of PC12 cells by serum deprivation. Hwansodan significantly rescued PC12 cells from apoptotic death by serum deprivation in a dose-dependent manner. The nuclear staining of PC12 cells clearly showed that Hwansodan attenuated nuclear condensation and fragmentation, which represents typical neuronal apoptotic characteristics. Hwansodan also prevents DNA fragmentation and caspase-3-like protease activation in serum-deprived PC12 cells and induces the tyrosine phosphorylation of proteins around 44 kDa, which was identified as ERK1 with electrophoretic gel mobility shift by Western blot. In addition, MEK inhibitor PD98059 and Ras inactivator, α-hydroxyfarnesylphosphonic acid and mevastatin, attenuated the neuroprotective effects of Hwansodan in serum-deprived PC12 cells. These results indicate that Ras/MEK/ERK signaling pathway plays a role in neuroprotective effects of Hwansodan in serum-deprived PC12 cells.