Schisandrin B Protects The Tubular Apoptotic And Autophagy Of Cisplatin Nephrotoxicity

Objects: In this study, we evaluated the beneficial effect as well as the underlying mechanism of Schisandrin B(Sch B) on the cisplatin related tubular apoptosis and autophagy in vitro and vivo.Methods: In vivo, 25 Male BALB/c mice were treated with vehicle, Sch B alone, cisplatin alone, cisplatin plus Sch B(20 mg/kg) and cisplatin plus Sch B(100 mg/kg), separately(n =5). Schisandrin B was administrated by gavage at the dose of 20 mg/kg or 100 mg/kg body weight per day for 5 days in cisplatin plus Sch B group and Sch B alone(100 mg/kg) group. On the third day, cisplatin nephrotoxicity model was established by intraperitoneal injection of cisplatin(20 mg/kg body weight) once in cisplatin alone and cisplatin plus Sch B group. Serum creatinine concentration, apoptotic cells and tubular injury index was evaluated. In vitro, human proximal renal tubular epithelial(HK-2) cells were randomly assigned to five groups: control group: in which cells were untreated; cisplatin group: in which cells were treated with cisplatin for 24 hours; low dose Sch B pretreat group: in which cells were pretreated with 1μmol/L Sch B for 2 hours, then treated by the same method as group cisplatin; high dose Sch B pretreat group: in which cells were pretreated with 10μmol/L Sch B for 2 hours, then treated by the same method as group cisplatin;Sch B group: cells were treated with 10μmol/L Sch B for 2 hours. Cell viability and apoptotic level were measured with CCK-8 assay and Flow cytometry. Furthermore, expressional level of p53 and LC3 was tested by western blot both in vivo and in vitro.Results: In vivo, compared with control group, cisplatin significantly increases the serum creatinine concentration, apoptotic cells and tubular injury index(tissues damage index was indicated by cellular necrosis, tubular lysis, cast formation, vacuolization, and tubular atrophy/dilation); while compared with cisplatin group, treatment with Sch B significantly decreases the serum creatinine concentration, apoptotic cells and tubular injury index in the mouse model of cisplatin nephrotoxicity. In vitro, compared with control group, cisplatin decreases cellular viability and increase apoptotic level in cultured HK-2 cells, while treatment with Sch B attenuates the decrease of cellular viability and increase of apoptotic level. Moreover, expression level of p53 and LC3 decreases with the administration of cisplatin while treatment of Sch B prevents the loss of p53 and LC3 both in vivo and in vitro.Conclusions: Our studies suggest that intraperitoneal injection of cisplatin(20 mg/kg body weight) once can successfully induce mouse model of cisplatin nephrotoxicity. Administration of Sch B exerts the beneficial role in the nephrotoxicity of cisplatin, significantly corrects the renal dysfunction, improves the pathological changes and reduces apoptosis. Cisplatin induces HK-2 cells’ injury in a time and dose-dependent manner. Treated with 50μmol/L cisplatin for 24 hours on HK-2 cells can significantly increases apoptosis. The protective effect on p53 and LC3 might mediate the apoptotic and autophagy effect of Sch B on the injury of primary tubular cells induced by cisplatin.