Objective: To explore the renoprotective effect of Compound Xueshuantong Capsule (XST) on diabetic rat model with nephropathy.
Methods: Twenty-eight male Sprague Dawley diabetic rats were induced to hyperglycaemia (3 days later, fasting blood glucose > 16.7 mmol/L) by peritoneal injection with streptozotocin (STZ, 50 mg/kg). And they were divided into four groups: diabetic nephropathy (vehicle treatment), irbesartan (20 mg×kg(-1)×d(-1)), low-dosage XST (900 mg×kg(-1)×d(-1)) and high-dosage XST (1800 mg×kg(-1)×d(-1)). Seven normal rats were used as control. After a 12-week intervention, urine protein was examined. Pathological morphology was observed by hematoxylin-eosin (HE), Masson and (periodic acid Schiff) PAS stains. Blood nitric oxide (NO), malondialdehyde (MDA) and blood superoxide dismutase (SOD) and urine SOD were detected. And the expression of (matrix metalloproteinase-2) MMP-2 was detected by Western blot in each group.
Results: The model rats presented with hyperglycemia, polydipsia, hyperphagia, polyuria and hyper microalbuminuria. The intervention groups showed decreased microalbuminuria and there was no effect on blood glucose or body weight. Glomerular sclerosis and extracellular matrix (ECM) increased in model group and improved in irbesartan and XST groups as judged by HE, Masson and PAS stains. Three intervention groups had no effect on the elevated expression of MMP-2 in diabetic rats. Compared with the model group, the irbesartan, low-dosage and high-dosage XST groups had significantly decreased blood levels of NO ((104.9 ± 11.0) µmol/L vs (41.9 ± 9.6) µmol/L and (14.7 ± 1.9) µmol/L, P < 0.05) and MDA ((19.6 ± 1.6) nmol/L vs (6.6 ± 0.9) mol/L and (4.5 ± 1.2) nmol/L, P < 0.05), increased blood and urine activities of SOD (blood: (222 ± 20)×10(3) vs (231 ± 18)×10(3) and (237 ± 24)×10(3) U/L,P < 0.05), urine: (11.8 ± 1.1)×10(3) vs (23.3 ± 2.0)×10(3) and (25.7 ± 1.8)×10(3) U/L).
Conclusion: Compound Xueshuantong Capsule may decrease proteinuria through its suppression of oxidative stress and not its improvement of ECM metabolism.