Effect of puerarin on the expression of extracellular matrix in rats with streptozotocin-induced diabetic nephropathy.

BACKGROUND: Inhibition of the formation of advanced glycation end-products delays the development of diabetic nephropathy. Puerarin decreases the formation of these products. We studied the effect of puerarin in a rat model of diabetic nephropathy. METHODS: Three groups of rats were studied: a control group, a diabetic group in whom diabetic nephropathy was induced by intraperitoneal injection of streptozotocin, and a puerarin group in which diabetic rats were treated with puerarin. During and after treatment, measurements were made on the rats' general status, blood glucose level, blood urea nitrogen, serum creatinine, creatinine clearance rate and urinary albumin excretion over 24 hours. The expression of collagen I and heparan sulphate proteoglycan in the extracellular matrix of the glomerulus was assessed by immunohistochemistry. RESULTS: Rats in the puerarin group had a better general condition than those with diabetes. They also had lower blood urea nitrogen, serum creatinine and urinary albumin excretion rate over 24 hours compared with those in the diabetic group. The creatinine clearance and expression of heparan sulphate proteoglycan in the kidney also increased significantly in the puerarin group compared with that in the diabetic group. CONCLUSION: Puerarin seems to have certain protective effects on diabetic nephropathy induced by streptozotocin. This is caused possibly by regulating the expression of glomerular extracellular matrix.