Mechanism of triptolide-induced apoptosis of human hepatocytes

Objective To investigate the underlying mechanism of triptolide-induced apoptosis of human hepatocytes L-02.Methods L-02 cells were divided into two groups of A(normal control) and B(incubated with triptolide 50 nM).After treated for 48 hours,the cell viability was determined by MTT assay.The cell apoptosis and the fluorescence intensity of reactive oxygen species(ROS) were measured by flow cytometry.The concentration of cytochrome C and the activities of Caspase-9 and Caspase-3 were analyzed by commercial kits.The protein expressions of Bcl-2 and Bax were detected by Western blot.Results Compared with group A,the cell viability was decreased,the cell apoptosis was increased,the protein expression of Bcl-2 was downregulated,and the protein expression of Bax,concentration of cytochrome C,level of ROS and activities of Caspase-9 and Caspase-3 were all upregulated(P0.05 or P0.01).Conclusion Triptolide inhibits L-02 viability by activating the mitochondrial apoptosis pathway.Triptolide can downregulate the ratio of Bcl-2 to Bax,induce ROS generation,damage the mitochondrial membrane,and further promote cytochrome C release,activate Caspase-9 and Caspase-3-mediated apoptosis pathway,which ultimately enhance cell apoptosis.