Effects of Qidi Tangshen granules and their separate prescriptions on podocytes in mice with diabetic nephropathy

Objective: Previous studies have found that Qidi Tangshen granules（QDTS）, a combination therapy of supplementing essence（Tianjing, TJ） and unblocking the collaterals（Tongluo, TL）, can reduce kidney damage in db/db mice. This study aimed to explore the effect of QDTS and their separate prescriptions on podocytes in mice with diabetic nephropathy.Methods: The db/db mice were used in this experiment as an animal model, while wild-type C57 BL/6 J mice were used as normal controls. At the age of 12 weeks, the db/db mice were randomly divided into 5 groups（db/db, db/db t valsartan, db/db t QDTS, db/db t TJ and db/db t TL）. The urine albumin excretion ratio（UAE） was measured by enzyme-linked immunosorbent assay before and after the intervention. The ultrastructure of the kidney podocytes was observed by transmission electron microscopy. The protein expression levels of nephrin and desmin were detected by immunohistochemistry.Results: QDTS and their separate prescriptions significantly decreased the UAE and attenuated the renal pathological injury. QDTS and their separate prescriptions also reduced the fusion rate of the foot processes and increased the expression of nephrin protein. In contrast, QDTS and their separate prescriptions（TJ and TL） reduced the expression level of desmin protein.Conclusion: QDTS and their separate prescriptions might reduce diabetes-induced renal injury by reducing podocyte damage. The therapeutic effect of QDTS was more pronounced than TJ and TL.