Protective Effect Of Astragalus Membranaceus On Oxidative Damage In MRC-5 Cells Induced By Hydrogen Peroxide

Object: By investigating the effects of Astragalus polysaccharide(APS) and Astragaloside A(Astr) on the expressions of APE/Ref-1 and Trx in MRC-5 cells induced by hydrogen peroxide(H2O2), this study aimed to figure out the underlying mechanism of APS in protection from oxidative damage in MRC-5 cells.Methods: The MRC-5 cells were randomly divided into groups: the normal control group, groups induced by H2O2 with different concentrations, groups treated with APS and Astr. The inhibitory rate of cell proliferation in H2O2-induced MRC-5 cells was measured by MTT assay to make sure the oxidative damage model was established. With the best concentration of H2O2 and different concentrations of APS and Astr on MRC-5 cells, we determined the best concentrate of APS on oxidative damage in MRC-5 cells; The expression of 8-hydroxy-2’-deoxyguanosine(8-OHdG)of DNA oxidative damage was detected by immune fluorescence staining; The apoptotic cells were defined by flow cytometry(FCM); The levels of APE/Ref-1 and Trx mRNA and proteins were respectively detected by reverse transcription PCR and Western blotting.Result: The oxidative damage model was successfully set up with MRC-5 cells induced by 800μmol/L H2O2 for 24 h. Compared with H2O2 control groups, 200mg/L APS and 10mg/L Astr significantly increased the protein expressions of APE/Ref-1 and Trx and decreased the apoptosis of MRC-5 cells, while the cell viability was dramatically improved.Conclusion: H2O2 can induce oxidative damage in MRC-5 cells, APS and Astr promotes APE/Ref-1 and Trx expressions in oxidative damaged MRC-5 cells to relieve the oxidative damages and inhibits apoptosis. Astragalus extract by upregulating APE/Ref-1 and Trx gene expression levels of H2O2 and oxidative damage antagonistic MRC-5 has a protective effect.