Renoprotective effect of Tanshinone IIA against kidney injury induced by ischemia-reperfusion in obese rats.

Objective: Obesity enhances the frequency and severity of acute kidney injury (AKI) induced by renal ischemia-reperfusion (IR). Tanshinone IIA (TIIA) pre-treatment was used to alleviate renal injury induced by renal IR, and whether TIIA can attenuate renal cell apoptosis via modulating mitochondrial function through PI3K/Akt/Bad pathway in obese rats was examined.

Methods: Male rates were fed a high-fat diet for 8 weeks to generate obesity, followed by 30 min of kidney ischemia and 24 h reperfusion induced AKI. The male obese rates were given TIIA (5 mg/kg.d, 10 mg/kg.d, and 20 mg/kg.d) for 2 weeks before renal IR.

Results: TIIA alleviated the pathohistological injury and apoptosis induced by IR. In addition, TIIA improved renal function, inflammatory factor, and balance of oxidation and antioxidation in obese rats after renal IR. At the same time, TIIA can inhibit cell apoptosis by improving mitochondrial function through the PI3K/Akt/Bad pathway. Mitochondrial dysfunction was supported by decreasing intracellular ATP, respiration controlling rate (RCR), mitochondrial membrane potential (MMP), and mitochondrial respiratory chain complex enzymes, and by increasing ROS, the opening of mitochondrial permeability transition pore (mPTP), and the mtDNA damage. The injury to mitochondrial dynamic function was assessed by decreasing Drp1, and increasing Mfn1/2; and the injury of mitochondrial biogenesis was assessed by decreasing PGC-1, Nrf1, and TFam.

Conclusions: Renal mitochondrial dysfunction occurs along with renal IR and can induce renal cell apoptosis. Obesity can aggravate apoptosis. TIIA can attenuate renal cell apoptosis via modulating mitochondrial function through PI3K/Akt/Bad pathway in obese rats.