Tetrahydroxystilbene Glucoside Improves Neurotrophic Factors Release in Cultured Astroglia

Tetrahydroxystilbene glucoside (TSG), one of the main ingredients of Polygonum multiflorum, has a great number of beneficial effects for health including anti-oxidant, free radicalscavenging and anti-inflammatory properties. However, the potential effects of TSG on neurotrophic factors release remain unclear. In this study, rat primary astroglia cultures were applied to investigate TSG-mediated neurotrophic effects. The protein levels and production of glial cell-line derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in astroglia and the culture medium were determined by western blotting assay and ELISA, respectively. Results indicated that TSG increased the production of neurotrophic factors in a concentration-dependent manner. At different time points of TSG treatment, the BDNF and NGF production in the culture medium was increased 48 h after treatment, while GDNF secretion was initially induced 24 h after TSG treatment. Consistent with the neurotrophic factors release, TSG significantly increased the BDNF, GDNF and NGF protein expressions in astroglia. Furthermore, TSG significantly induced the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 and a specific ERK inhibitor-U0126 inhibited TSG-mediated secretion of BDNF, GDNF and NGF. Overall, this study demonstrated that TSG induces astroglia-derived neurotrophic factors release, suggesting TSG might hold a therapeutic potential for neurological disorders.