Dioscin promotes apoptosis of HepG2 cells by inhibiting Wnt/β-catenin signaling pathway
Objective To detect the apoptosis effects of dioscin in HepG2 cells and its possible anti-hepatocellular carcinoma mechanisms.Methods HepG2 human hepatocellular carcinoma cells were exposed to 0.25,0.5,1,2,4,6,or 8 μmol/L dioscin,and cell proliferation was measured via MTT assay.The half-maximal inhibitory concentration(IC50)was calculated with the software.A scratch test was used to analyze cell migration ability.Western blot was employed to evaluate the expression of apoptosis and Wnt/β-catenin-pathway-related proteins.Results Compared with the control group,the dioscin-treated HepG2 cells'proliferation was significantly more inhibited,and the inhibition increased in a time-and dose-dependent manner(P<0.01).HepG2 cells showed morphological characteristics of apoptosis after they were treated with 1 μmol/L or 2 μmol/L dioscin.The scratch test indicated that the migration distance of HepG2 cells was remarkably reduced when treated with dioscin.In the Western blot experiment,the expression levels of Caspase-3 and cleaved Caspase-3 were visibility up-regulated,while those of Bcl-2 and β-catenin were significantly down-regulated when the cells were treated with dioscin for 24 h(P<0.05,P<0.01).When LiCl reagent was added to the HepG cells to activate the Wnt/β-catenin signaling pathway,the expression levels of Wnt1 and β-catenin were remarkably increased compared with those of the control group(P<0.01).Compared with the LiCl group,the LiCl+DIO group's expression of Wnt1,β-catenin,and GSK-3β was significantly decreased(P<0.01).Conclusions DIO can promote the apoptosis of HepG2 cells by inhibiting β-catenin protein expression and thereby down-regulating the Wnt/β-catenin signaling pathway.This inhibits apoptosis-related gene Bcl-2 expression,which leads to the induction of cell apoptosis.Therefore,DIO can have an anti-hepatocellular carcinoma effect.