Silibinin induces apoptosis in human hepatoma HepG2 cells and enhances its chemo-sensitivity

Aim:To investigate the inhibitory effect of Silibinin and its ability of enhancing chemo-sensitivity to human hepatoma HepG2 cells lines.Methods: The effects of Silibinin on the proliferation of HepG2 cells were evaluated by the MTT assays and colony formation assays.The cellular morphology of HepG2 cells was observed using fluorescence microscopy after Hoechst 33258 staining.Western blotting was used to detect the expression of caspase-3 and-9 protein levels.HepG2 cells were treated with Silibinin in combination with different concentrations of 5-fluorouracil(5-FU) or cisplatin(DDP),cell proliferatory inhibition rates were detected by MTT method.Results: Silibinin inhibited the proliferation of HepG2 cell lines in a dose dependent manner(P0.05).The IC50 of the Silibinin on human hepatoma HepG2 cells for 48 hours was 195.38 μmol/L.Cell clone formation inhibition assay demonstrated that cell clones decreased with the increase of Silibinin's concentrations.Hoechst 33258 staining showed the occurrence of nuclear fragmentation and chromosomal condensation,cell detachment of HepG2 cells treated with Silibinin.Western-blotting assay showed that Caspase-3 and Caspase-9 protein expression levels decreased gradually as the concentration of Silibinin increased.MTT assay indicated that the chemo-therapeutic effects of 5-FU and DDP on HepG2 cells were enhanced independently when they were combined with Silibinin(150 μmol/L),and the sensitivities increased were enhanced about 39.63 and 21.54 times respectively.Conclusion:Silibinin inhibited the proliferation by inducing apoptotic of human hepatoma HepG2 cells and enhanced the chemo-sensitivity to 5-FU and DDP.