Objective

To study the effects and mechanism of ginsenoside Rg3 combined with tumstatin 19 peptide on apoptosis of liver cancer HepG2 cells.

Methods

The two-level factorial-analysis design was used in the experiment with factor A of ginsenoside Rg3 with two levels of 0 mg/L and 40mg/L

and factor B of tumstatin 19 peptide with two levels of 0 mg/L and 200 mg/L. The proliferation of HepG2 cells was measured by using the CCK-8 kit.Hoechst33342 staining was used to detect the morphological changes of the apoptosis of HepG2 cells.The apoptosis rates of HepG2 cells were detected with flow cytometry.The cell membrane potential change of HepG2 cells was measured by fluorescence probe JC-1.The expression ofphosphatase and tensin homology deleted on chromosometen(PTEN)

phosphated phosphatidylinositol phosph atidylinositol 3-kinase (p-PI3K) and p-Akt was evaluated by using Western blot assay.The activities of caspase-3 and caspase-9 were measured with the Caspase-activity assay kit.

Results

Ginsenoside Rg3

tumstatin 19 peptide and the combined therapyhad in hibitory effect on the proliferation of HepG2 cells.Ginsenoside Rg3

tumstatin 19 peptide had a positive synergistic effect.The IC

50

of Rg3 was 45.06 mg/L

and that of 19 peptide was 214.03mg/L. Results of Hoechst33342 staining showed that changes of apoptosis in combined therapy was more evident.The results of flow cytometry were consistent with Hoechst33342 staining

and the apoptosis rate was the highest in combined therapy. Fluorescence probe JC-1 showed that combined therapy emitted the strongest green fluorescence. The combined therapy was more significant in up-regulating the expression of PTEN protein and down-regulating the expression of p-PI3K and p-Akt protein.The activities of caspase-3 and caspase-9 enzyme were significantly increased in combined therapy(

P

<

0.001).

Conclusion

Ginsenoside Rg3 and tumstatin 19 peptide can inhibit proliferation and induce apoptosis of HepG2 cells.They manifest a positive synergistic effect.The synergistic effect might be achieved through the PTEN/PI3K/Akt signaling pathway.