Protective Effect And Mechanism Of Ginsenoside Rg3 Under Oxidative Stress Injury Induced By H₂O₂ In HepG2 Cell

Ginseng is a perennial herbaceous plant,which has long been known as the king of grass in China,widely distributed in northeast China,and has extremely high medicinal value.Ginsenoside Rg3 is a kind of saponins extracted from red ginseng,which has many functions.Besides anti-tumor effect,it has obvious anti-oxidative properties.This study intends to explore Rg3 ginsenosides can through the Nrf2-ARE signaling pathways,inducing the expression of antioxidant enzymes in the cell,thus protecting HepG2 cells from oxidative stress damage,for the invention of the antioxidant drug provides certain scientific basis.The research contents and results are as follows:1.Ginsenoside Rg3 has protective effect on H₂O₂ induced cell damage.The effects of different concentrations of ginsenoside Rg3 on HepG2 cells were detected by MTT assay.The results showed no effect on cell growth and no toxicity H₂O₂ treated HepG2 cells with different concentrations,and the optimal H₂O₂ concentration was selected by MTT colorimetric method.The result was 500μM,and the oxidative stress model was established and subsequent experiments were conducted.Detected by the MTT method Rg3 ginsenosides protection of H₂O₂,the experimental results are as follows,compared with the blank group,H₂O₂ treatment group of cell survival rate decreased significantly,but through the different concentrations of Rg3（1OμM、20μM、40μM）after pretreatment,cell survival rates rise significantly.2.Ginsenoside Rg3 has protective effect on the anti-apoptosis induced by H₂O₂.HepG2 cells can be divided into 5 groups:blank group,H₂O₂ damage group,different concentrations of ginseng saponin Rg3 protection group（1OμM.20μM、40μM）,the results are as follows:by using flow cytometry instrument detection,compared with the blank group,after H₂O₂ treatment,cell apoptosis rate increased significantly,however,through the different concentrations of Rg3（10μM、20μM、40μM）after processing,the cell apoptosis inhibition rate is falling,you can see extent of the average cell apoptosis rate is proportional to the concentration of Rg3 ginsenosides.Further experimental results show that the fluorescence microscope test also proved after H₂O₂ treatment,different concentrations of ginseng saponin Rg3 protection group（10μM 20μM、40μM）can reduce the level of ROS in the cells,can also make the mitochondrial membrane potential return to normal levels,thus to protect cells.Testing results of Western blotting,through different concentrations of Rg3（1OμM、20μM、40μM）after treatment,cells in promoting apoptosis protein expression of Bax is reduced,increased resistance to apoptosis protein expression of Bcl-2,thus inhibiting the activation of Caspase-3.3.The expression of antioxidant protein of HepG2 cells and the nuclear transfer of Nrf2 were induced by ginsenoside Rg3.HepG2 cells can be divided into 5 groups:blank group,H₂O₂ damage group,different concentrations of ginseng saponin Rg3 protection group（10μM、20μM、40μM）,Western blotting test results are as follows:Rg3 ginsenosides can significantly improve the nucleus Nrf2,heme oxygenase 1（HO-1）and quinone oxidoreductase 1（NQO-1）protein expression.It can be seen that the increase of cell protein expression is proportional to the concentration of ginsenoside Rg3.4.The activation of the MAPK signaling pathway and PI3K/AKT signaling pathway in HepG2 cells by ginsenoside Rg3.Western blotting test results showed that ginsenoside Rg3 showed time correlation and concentration dependence of protein phosphorylation expression of ERK1/2,JNK,p38 MAPK and AKT in HepG2 cells.The protein expression was the highest in 1h.Select the optimal time point 1h,as the drug concentration increases,the expression level gradually increases.Ginsenoside Rg3 enhances the protein phosphorylation level of-ERK1/2,JNK,p38 MAPK and AKT to protect cells from oxidative stress.To sum up,ginsenoside Rg3 can protect the cell damage induced by H₂O₂.Its action mechanism,Rg3 ginsenosides can improve the survival rate of the cells induced by H₂O₂,inhibiting cell apoptosis rate,reduce the levels of ROS in the cells,protect the mitochondrial membrane potential,promote the expression of apoptosis proteins Bax,reduce the increased resistance to apoptosis protein expression of Bcl-2,restrain the activation of Caspase-3,ginseng saponin Rg3 in HepG2 cells activation of Nrf2 nuclear transfer induced antioxidants heme oxygenase 1（HO-1）and quinone oxidoreductase 1（NQO-1）,the upstream mechanism of Nrf2 is achieved through the MAPK signaling pathway and the PI3K/AKT signaling pathway.