Induction of Apoptosis of HeLa Cells with Pu-erh Tea Extracts

Objective To investigate the induction of apoptosis of HeLa cells with Pu-erh tea extracts and the relevant mechanism.Methods HeLa cells were treated with Pu-erh tea extracts at various concentrations(15,30,60,120,250 and 500 μg/ml),then determined for proliferation level by MTT method,observed for morphology by DAPI staining,determined for apoptosis at early stage by flow cytometry with Annexin V-FITC / PI staining,and analyzed for expression levels of pro-caspase-3 and pro-caspase-9 by Western blot.Results Pu-erh tea extract showed significantly dose-dependent inhibitory effect on proliferation of HeLa cells.Typical morphology of apoptosis was observed in the HeLa cells treated with Pu-erh tea extracts by fluorescent microscopy.The apoptosis rate at early stage of HeLa cells treated with Pu-erh tea extract was significantly higher than those untreated(P 0.05).Both pro-caspase-3 and pro-caspase-9 were activated in the cells treated with Pu-erh tea extract.Conclusion Pu-erh tea extracts contained natural active ingredients inducing the apoptosis of HeLa cells through a potential mitochondrial pathway associated with caspase-3 and caspase-9.