The study of the inhibition effects of SIRT1 on the apoptosis induced by Galangin in HepG2 cells / 医学研究生学报

ABSTRACT

Objective Galangin is a natural flavonoid with antineoplastic activity .SIRT1 is an important member of Sirtuin family which parcitipate in many physiological process .The aim of this study was to investigate the effect of SIRT 1 on HepG2 cell apop-tosis induced by galangin . Methods HepG2 cells were pre-treated with SIRT1 inhibitor EX-527 for 2 hours, and then galangin for 24 hours.DMSO solvent control group, EX-527 treatment group, galangin treatment group and EX-527 and galangin co-treatment group were established.Hoechst 33342 staining, flow cytometry and western blot were performed to detect the apoptosis of HepG2 cells.After regu-lating the expression of SIRT1 in HepG2 cells with RNA interference and transfection of exogenous genes , these cells were treated with ga-langin for 24 hours.Negative control group , vector control group , SIRT1 knock down group , blank control group , blank vector group ,and SIRT1 upregulation group were established .Western blot and Flow cytometry were performed to detect the apoptosis of HepG 2 cells. Results The apoptosis rate and the gray level ratio of shear band of PARP 1 and GAPDH that of galangin group [(11.62± 0.55) %, 0.89±0.01]and EX-527+galangin group[(25.75±0.61) %, 1.15±0.06] were all increased(P<0.01),when these were compared with DMSO solvent control group [(2.49±0.22) %, 0.06±0.00];and those in EX-527+galangin group were also markedly increased compared with galangin group (P<0.01).The result of western bolt was that the gray level ratio of PARP 1 and GAPDH of SIRT1 knocked down group(0.06±0.01) was markedly decreased compared with vector control group (1.11±0.05)and without adenovi-rus infection group (1.10±0.04)(P<0.01).The apoptosis rate and the gray level ratio of shear band of PARP 1 and GAPDH that of SIRT1 knocked down group were markedly increased compared with vector control group and without adenovirus infection group ( P<0.01).The gray level ratio of PARP1 and GAPDH of SIRT1 up-regulated group (1.63±0.04) was markedly increased compared with blank control group (0.89±0.02) and without plasmid transfection group (0.87±0.03) (P<0.01).The apoptosis rate and the gray lev-el ratio of shear band of PARP 1 and GAPDH that of SIRT1 up-regulated group were markedly decreased compared with blank control group and without plasmid transfection group (P<0.01). Conclusion SIRT1 inhibited galangin-induced apoptosis in HepG2 cells.