The protective effect of Xuebijing on paraquat-induced HK-2 cells apoptosis and the underlying mechanisms

Abstract

Objective: To investigate the protective effect and mechanism of Xuebijing (XBJ) on paraquat (PQ) -induced apoptosis in Human kidney cell line-2 (HK-2) cells. Methods: Routinely cultured HK-2 cells, (1) Cell growth inhibition experiment after PQ and XBJ intervention: PQ was divided into 0、200、400、800、1600 and 3200 μmol/L PQ groups, and the cell survival rate was detected after intervening 24、48 and 72 h. XBJ was divided into 0、5、10、20、40 mg/ml XBJ groups, and the cell survival rate was detected after intervening 24、48 and 72 h.To determine the rational drug concentration and the duration of action of XBJ and PQ. (2) PQ-induced HK-2 cell growth inhibition experiment antagonized by XBJ: The cells were divided into normal control group, PQ group (800 μmol/L) and PQ+XBJ group (The cells were pretreated with 5、10 and 20 mg/ml XBJ for 1 h, then cultured with PQ of 800 μmol/L) , After cultured 24 h、48 h and 72 h separately, the cell survival rate was detected. (3) HK-2 cells were divided into normal control group、PQ group (800 μmol/L PQ cultured for 24 h) 、PQ+XBJ group (pretreated with 10 mg/ml XBJ for 1 h, and then 800 μmol/L PQ cultured for 24 h) and XBJ group (10 mg/ml XBJ cultured 24 h). The apoptosis of cells was detected by flow cytometry. The protein expression of Bcl-2 and BAX in each group was detected by Western blotting. The expressions of caspase-3 and caspase-9 were detected by caspase-3 and caspase-9 activity kit active. Results: (1) PQ could significantly reduced the survival rate of HK-2 cells and showed time and concentration dependence. The survival rate of HK-2 cells was about 55% after 800 μmol/L PQ contacted 24 h, XBJ under 20 mg/ml was no significant effect on the survival rate of HK-2 cells after cultured 72 h. (2) Compared with the PQ group, the survival rate of HK-2 cells of PQ+XBJ group was significantly increased (P<0.05). (3) Compared with the normal control group, the cell apoptosis rate of PQ group was significantly increased (P<0.05). Compared with the PQ group, the cell apoptosis rate of PQ+XBJ group was significantly decreased (P<0.05). (4) Compared with the normal control group, Bcl-2 protein expression in PQ group was significantly decreased and BAX protein expression in PQ group was significantly increased (P<0.05) ; compared with PQ group, Bcl-2 protein expression in PQ+XBJ group was significantly increased, BAX protein expression in PQ+XBJ group was significantly decreased (P<0.05). (5) Compared with the normal control group, the activities of caspase-3 and caspase-9 in PQ group were significantly increased (P<0.05). Compared with PQ group, the activities of caspase-3 and caspase-9 in PQ+XBJ group were decreased significantly (P<0.05) . Conclusion: XBJ (10 mg/ml) has obvious protective effect on HK-2 cell injuried by PQ (800 μmol/L) , It can improve the survival rate of cells through reducing the apoptosis of HK-2 cells which induced by PQ.