Reasearch On The Growth Inhibition And Apoptosis Inducing Effects Of Apigenin On Human Glioma SHG-44 Cells

ObjectiveTo investigate the effect of apigenin on the proliferation and apoptosis of human glioma SHG-44 cell line in vitro.MethodsInitially we treat human glioma SHG-44 cells with different concentrations of 20,40,80 ?mol/L apigenin at different treatment times of 24 h,48 h and 72 h.To compare the effects of the different concentrations and times of apigenin on human glioma SHG-44 cells,we used MTT method to detect the effect of apigenin on the cell growth activity.Then we detected the effect of apigenin on cell cycle by PI staining flow cytometry analysis.Meanwhile,we examined changes in nuclear morphology and DNA fragmentation by terminal deoxynucleotidyl transferasemediated dUTP nick-end labeling(TUNEL)stain and Hoechst 33258 stain.Cell apoptosis was assessed by flow cytometry using AnnexinV-FITC/PI double staining.Finally,western blot analysis was used to observe the expression levels of CDK6,CDC25 A,Bax and Bcl-2 protein.ResultsOur data showed that apigenin significantly inhibited the proliferation of SHG-44 cells compared with normal culture condition of SHG-44 cells,which was in a time-and-dose-dependent manner.The cell cycle analysis showed that treatment groups were blocked at G2/M phase with the inhibition of cell proliferation.Hoechst33258 staining revealed that apigenin could cause typically apoptosis morphological changes including chromatin fragmentation and apoptotic bodies.TUNEL staining showed that apigenin triggered apoptosis of SHG-44 cells.Annexin V-FITC/PI double staining flow cytometry disclosed that apigenin could induce apoptosis of SHG-44 cells in a dose-dependent manner.Compared with the control group,the protein expression of CDK6 and CDC25 A was decreased after treated by apigenin,while Bax was increased after apigenin treatment,and the protein expression of Bcl-2 was also decreased,which was in a significant dose-dependent manner.ConclusionApigenin could inhibit human glioma SHG-44 cells proliferation in a time-and-dose-dependent manner,which affects human glioma SHG-44 cell cycle by blocking cell cycle in G2/M phase.The mechanisms may be involved in down-regulation of the CDK6 and CDC25 A proteins.In addition,Apigenin induces apoptosis in human glioma SHG-44 cells in a dose dependent way,which mechanism may be involved in the regulation of the Bcl-2 protein family.