ABSTRACT
Objective To study the effects of schisandrin B (Sch B) on the apoptosis of human breast cancer MDA-MB-231 cells and its mechanism. Methods Cell counting reagent (CCK-8) was used to detect the effect of Sch B on the survival rate of MDA-MB-231 cells. MDA-MB-231 cells were treated with Sch B (10, 20, 40 μmol/L) for 24 hours. The cell death was detected by Annexin V-FITC/PI. The levels of intracellular reactive oxygen species (ROS) were detected by DCFA-DA fluorescent probe. Apoptosis and the expression of endoplasmic reticulum stress related proteins (Bcl-2、Bax、CHOP、GPR78、PERK、p-PERK、p-eIF2α、eIF2) were detected by Western blot. Results Compared with the blank group, the cell survival rate decreased significantly (P<0.01) with the increase of Sch B concentration, and its IC50 was 19.16 μmol/L. Compared with the control group, Sch B groups (10, 20, 40 μmol/L) inhibited cell clone formation in a dose-dependent manner (P<0.05). Sch B groups (10, 20, 40 μmol/L) induced apoptosis (P<0.05), significantly reduced the expression of anti-apoptotic protein Bcl-2 and significantly increased the expression of pro-apoptotic protein Bax (P<0.05). Sch B groups (10, 20, 40 μmol/L) significantly increased the level of intracellular ROS in a dose-dependent manner (P<0.05). Sch B groups (10, 20, 40 μmol/L) stimulated endoplasmic reticulum stress and increased the expressions of endoplasmic reticulum stress-related proteins CHOP, GPR78 and p-eIF2α in a dose-dependent manner (P<0.05). Conclusion Sch B induces apoptosis of MDA-MB-231 cells through ROS mediated endoplasmic reticulum stress.