Puerarin Attenuates Podocyte Damage in Mice With Diabetic Kidney Disease by Modulating the AMPK/Nrf2 Pathway

Background: This study aimed to investigate the potential mechanisms of puerarin in alleviating diabetic nephropathy (DKD) in mice. Method: The DKD model was induced by multiple low-dose injections of streptozotocin (STZ) and a high-sugar and high-fat diet in male C57BL/6J mice. After confirming the onset of DKD, mice were given irbesartan, distilled water, or different concentrations of puerarin (40 and 80 mg/kg/d) by gavage for 8 weeks. HE staining and PAS staining were adopted to assess the pathological changes in the kidney tissues. Meanwhile, the levels of superoxide dismutase, catalase, creatinine, and cystatin C in the serum and the urine albumin and creatinine were measured, and the renal indices as well as the urinary albumin-to-creatinine ratio (UACR) were calculated. The changes of podocin and protein expression levels associated with AMPK/Nrf2 signaling pathway were evaluated by western blot. Results: Puerarin significantly reduced the level of fasting blood glucose, renal index, glomerular mesangial expansion index, renal function, and oxidative stress induced by STZ (p < 0.05). The pathological injuries in kidney tissues were also alleviated. Furthermore, we demonstrated that the expression level of podocin and protein related to the AMPK/Nrf2 signaling pathway was also decreased significantly by the treatment of puerarin. At the same time, the efficacy of puerarin in the treatment of DKD was better than that of irbesartan, and the treatment effect of the high-dose group (80 mg/kg/d) was also significantly better than that of the low-dose group (40 mg/kg/d). Conclusion: Puerarin could attenuate the severity of DKD and protect the podocyte in mice in a dose-dependent way. Also, it might be performed by regulating the AMPK/Nrf2 pathway. These findings may provide a theoretical basis for updating the clinical management of DKD.