Effect of phenylacetate on apoptosis in rat C6 glioma cells and its mechanism

Objective To investigate the effect of phenylacetate(PA) on apoptosis in rat C6 glioma cells and explore the possible mechanism.Methods C6 cells cultivated in vitro were induced by PA,then the apoptosis was detected by TUNEL assay and the expressions of bcl-2,bax,and caspase-3 were determined by immunocytochemistry.Results After treated with PA at concentrations of 0,2.5,and 5.0 mmol·L-1 for 24 h,the apoptotic rates(%) were 2.5±0.2,10.3±0.5,and 20.6±1.1,respectively; while for 72 h,the apoptotic rates (%) were 2.7±0.3,24.9±0.7,and 42.0±1.7,respectively. The apoptotic rate was remarkably increased with the increasing of PA concentration and treatment time.There were significant differences of apoptotic rates of C6 cells after treated with different conentrations and for different time between experimental and control groups(P0.05).In C6 cells,the expression levels of bcl-2,bax and caspase-3 were 0.275±0.022,0.214±0.019,and 0.149±0.004,respectively; while treated with PA(5.0 mmol·L-1) for 72 h,the expression levels of bcl-2,bax,and caspase-3 were 0.244±0.024,0.399±0.030,and 0.206±0.033,respectively. The expression levels of bax and caspase-3 were enhanced by PA (P0.01),whereas the expression level of bcl-2 didn't change (P0.05).Conclusion PA can induce apoptosis in rat C6 glioma cells,which shows a time-and dose-dependent manner.The mechanism of PA on apoptosis might be related to the up-regulation of bax and caspase-3 expression.