Water Extracts Of Phellinus Linteus Fruit Bodies Induces Apoptosis In HepG2 Cells In Vitro

Phellinus linteus,a well-known Oriental medicinal fungus that has various biological activities,is being increasingly used treat a wide variety of disease processes such as oral ulcer, gastroenteric disorder,lymphatic disease and various cancers.Although it is generally believed that P.linteus does not induce direct toxicity in cancer cells,little is known about the direct effect of water extracts of P.linteus fruit bodies(WEPL) on cancer,the mechanism of it is poorly understood.We found that WEPL has a direct antiproliferative effect on HepG2 human colon cancer cells.MTT assay showed that the significantly growth inhibition of cells cultured in vitro and treated with 0.2,0.3,0.4,0.5,0.6mL/mL WEPL for 24,48,72h increased in doesand time dependently compared with the matched control group were.Microscope observation proved the occurrence of apoptotic bodies,condensation of nucleus and bubble of cytoplasm. Flow cytometry detection showed the more cells were positively stained by Annexin-V.These were the hallmark features of apoptosis.The present results suggest that WEPL induced apoptosis directly in HepG2 cells in vitro.Upon treatment with WEPL for 48h,DNA Ladder showed that HepG2 cells were in early and middle stage of apoptosis as same as microscope observation and flow cytometry detection.The anti-proliferative and apoptotic effects of WEPL were associated with marked inductions of the Bax and Bcl-2.Upon treated with WEPL, RT-PCR and Western Blot demonstrated that the mRNA expression level and protein level of Bax were adjusted up while that of Bcl-2 were adjusted down.It seems possible that WEPL can induces HepG2 human colon hepatoma cells apoposis through down-regulating the expression of Bcl-2 gene and up-regulating the expression of Bax gene.