Grape seed proanthocyanidin extract ameliorates albuminuria and renal sclerosis in experimental diabetic nephropathy rats

Abstract

Background: Grape seed proanthocyanidin extracts (GSPE) prevent and treat a variety of disorders caused by oxidative stress. However, it is unclear whether GSPE has protective effect on rats with diabetic nephropathy. Objectives: We investigated the effects of GSPE on kidney of diabetic nephropathy rats. Materials and methods: Thirty male Sprague-Dawley rats were divided into three groups; control, diabetic nephropathy, and diabetic nephropathy, that received GSPE 500 mg/kg for six week. The first, 24 hours urinary albumin excretion (UAE) was studied two weeks after induction of diabetes. Then the UAE was studied each week until the end of the experimental period in all of groups. At the end, the experimental animals were sacrificed and both kidneys were collected and prepared for light microscopy and electron microscopy evaluation and measurement of lipid peroxidation content. Results: The results showed that the UAE and kidney weight in diabetic nephropathy rats were significantly higher than in controls. Increases of the mesangial matrix, glomerular basement membrane thickness, broadening of foot process, and lipid peroxidation content in diabetic nephropathy group rats were observed. In addition, apoptosis cells were present in this group when compared to controls. These features were reversed when the GSPE was administered to the experimental rats. Conclusion: GSPE prevented the progression of diabetic nephropathy in rats by its antioxidant properties. Keywords: Apoptosis, diabetic nephropathy, glomerular basement membrane, GSPE, lipid peroxidation