Effect of berberine on renal pathology and bone morphogenetic protein-7 expressions in rats with early diabetic nephropathy

Objective: To determine the effect of berberine(BBR) on the pathological change and expression of bone morphogenetic protein-7(BMP-7) in the kidney of rats with early diabetic nephropathy(DN).Methods: DN was induced by injection of streptozotocin(STZ).The rats were intragastrically administered with BBR and enalapril once daily.After 5 weeks,the kidney weight,24-h urinary volume,kidney/body weight ratio,fasting blood glucose(FBG),blood urea nitrogen(BUN),serum creatinine(Scr),insulin(INS),urinary protein(Upro),and urinary microalbumin were tested.The pathological changes and ultrastructures in renal tissue were examined by optical or electron microscopy.Immunohistochemistry and RT-PCR were used to detect the expression of BMP-7 protein and mRNA in the renal tissues.Results: In BBR-treated rats,serum levels of FBG,BUN,Scr,Upro and UmAlb were decreased,while the insulin level increased.The expression of BMP-7 protein and mRNA in renal tissues was decreased.BBR ameliorated the pathological changes and ultrastructureal lesions in the kidney of DN rats.Conclusion: BBR can obviously improve renal function and increase the expression of BMP-7 in the kidney,and delay the progression of diabetic nephropathy in DN rats.