Effect of Iridoid Glycosides from Boschniakia rossica on Apoptosis and Expression of Bax and Bcl-2 in Liver Cancer Cells

Abstract:

Observation of diethyl nitrosamine（DEN） induced rat liver cancer tissue pathological changes，discusses Boschniakia rossica iridoid glycoside（IGBR） on apoptosis the influence of Bax， Bcl-2 protein expression.Wistar male rats were randomly divided into control group，model group，5-FU group and IGBR group. were injected intraperitoneally once a day for 200 mg / kg DEN intra peritoneally on the 1st day，Rats in the control group were given equal volume of saline；then given free access to 0.05% DEN solution for up to 28 weeks. The IGBR group was gavaged 500 mg/kg IGBR once dailyk，and 5-FU group was injected with 25 mg/kg 5-FU 3 times a wee. The animals were sacrificed in batches after 12，20 or 28 weeks of DEN exposure，and the pathological changes and apoptosis of liver were observed. The expression of Bax and Bcl-2 were detected with the immunohistochemical method.The results showed that，compared with the control group，the cell apoptosis increased significantly，and the cytoplasm was brownish yellow. Apoptotic hepatocyte showed cytoplasmic and nuclear shrinkage，disappearance of nucleolus. The apoptotic of the 5-FU and IGBR groups were higher than those of model group（P <0.05），But there was no significant difference between the two groups（P >0.05）.The Bax and Bcl-2 positive cells were mainly distributed in the atypical hyperplasia and neoplastci foci. In the 5-FU and IGBR groups，the expression of Bax was up-regulated and Bcl-2 was down-regulated as compared with the model group（P <0.05），there was no significant difference between the two groups（P >0.05）. The expression of Bax and Bcl-2 in the model group，5-FU group and IGBR group were negatively correlated. IGBR can induce apoptosis，Inhibit the proliferation of liver cancer cells Its mechanism is likely related to the up-regulation of Bax and down-regulation of Bcl-2．