Effect of silibinin combined with doxorubicin on apoptosis of gastric cancer SGC-7901 cells and relevant mechanism

Objective To investigate the effect of silibinin combined with doxorubicin on the apoptosis of gastric cancer SGC-7901 cells and the relevant mechanism. Methods SGC-7901 cells were treated with silibinin and doxorubicin at various concentrations, alone or in combination, and determined for proliferation activity by MTT method, for cell cycle and apoptosis by flow cytometry, and for expression levels of cell cycle regulatory proteins Cdk1 and Cyclin B1, cell apoptosis proteins pro-caspase 3, pro-caspase 8, pro-caspase 9, PARP, Fas and Fas L as well as ratio of Bcl-2 / Bax, were determined by Western blot. Results Doxorubicin at a concentration of 0. 01 μmol / L in combination with silibinin at concentrations of 25, 50, 100 and 200 μmol / L showed significantly synergistic effect on SGC-7901 cells, with combined indexes(CIs)of 0. 634, 0. 418, 0. 224 and 0. 472 respectively, which increased the inhibitory rates to cells, decreased the expression levels of Cdk 1 and Cyclin B1, resulting in the cell arrest at G2/ M phase. The expression levels of Fas and Fas L increased, while those of pro-caspase 3 / 8 / 9 decreased, PARP was cleaved, the ratio of Bcl-2 / Bax decreased, and the apoptosis of SGC-7901 was induced. Conclusion Silibinin in combaintion with doxorubicin effectively decreased the concentration of doxorubicin, and promoted the induction of apoptosis.