Potential molecular mechanisms mediating the protective effects of tetrahydroxystilbene glucoside on MPP+-induced PC12 cell apoptosis.

Our previous work demonstrated that tetrahydroxystilbene glucoside (TSG) was able to effectively attenuate 1-methyl-4-phenylpyridinium (MPP+)-induced apoptosis in PC12 cells partially via inhibiting reactive oxygen species (ROS) generation. However, the precise molecular mechanisms of TSG responsible for suppressing neuronal apoptosis have not been fully elucidated. To investigate the possible mechanism, we studied the neuroprotective effects of TSG on MPP+-induced PC12 cells apoptosis and explored the molecular mechanisms that mediated the effects of TSG. Our results showed that treatment with TSG prior to MPP+ exposure effectively attenuated the cell viability decrease in PC12 cells, reversed the cell apoptosis, and further restored the mitochondria membrane potential (MMP). In addition, TSG remarkably enhanced the anti-oxidant enzyme activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px), and efficiently reduced the malondialdehyde (MDA) content in the PC12 cells. Meanwhile, TSG markedly upregulated the Bcl-2/Bax ratio, reversed release of Cytochrome c, and inhibited the activation of caspase-3 induced by MPP+. Furthermore, TSG significantly inhibited the activation of p38 mitogen-activated protein kinase (p38MAPK) signaling pathway, while extracellular signal-regulated protein kinases (ERK) phosphorylation was not affected. Together, these findings provide the basis for TSG clinical application as a new therapeutic strategy in the treatment of neurodegenerative diseases.