Objective: To study the effects of Shenqi Fuzheng injection on proliferation and apoptosis of basal-like type human breast cancer MDA-MB-231 cells

and investigate the treatment mechanism of Shenqi Fuzheng injection for triple negative breast cancer. Method: The human breast cancer MDA-MB-231 cells cultured in vitro were divided into Fuzheng injection groups (six groups with different concentrations of Shenqi Fuzheng injection) and blank group. Methyl thiazolyl tetrazolium (MTT) assay was used to detect the effect of Shenqi Fuzheng injection on proliferation of MDA-MB-231 cells at 24

48 and 74 h. Flow cytometry (FCM) was used to detect the cell cycle distribution and apoptosis of MDA-MB-231 cells. Real-time PCR and Western blot assay were used to detect the effect of Shenqi Fuzheng injection on p53 up-regulated modulators of apoptosis (PUMA) in MDA-MB-231 cells. Result: Shenqi Fuzheng injection could inhibit the proliferation of MDA-MB-231 cells in a concentration-dependent manner

and the inhibitory effect was most obvious at 48 h in vitro culture. Shenqi Fuzheng injection blocked cell cycle at S phase of the MDA-MB-231 cells

and thus induced apoptosis of MDA-MB-231 cells. Real-time PCR and Western blot assay showed that Shenqi Fuzheng injection could up-regulate PUMA expression of MDA-MB-231 cells. Conclusion: Shenqi Fuzheng injection can significantly inhibit proliferation and block cell cycle at S phase of the MDA-MB-231 cells

thus induce apoptosis of the cells

and the mechanism may be associated with up-regulating PUMA mRNA expression.