Protective effect of a poly-phitocompound on early stage nephropathy secondary to experimentally-induced diabetes

Diabetic nephropathy (DN) is a severe and life-threatening complication of long-standing diabetes. As one of the main causes of end-stage renal disease, the prevention and treatment of DN in early stage, and the slowing down of DN progression are of utmost importance and are topics of several ongoing research studies. Nutraceuticals endowed with antioxidant-anti-inflammatory properties may offer an opportunity of integrative treatment for this condition. Male Wistar rats were randomly assigned to two groups. One group of rats (diabetic group) received a single tail-vein injection of STZ compound (50 mg/kg) under light anaesthesia. A protective dose of 0.5 ml of 5% dextrose was given intraperitoneally 30 min before the administration of STZ. One diabetic group was fed a normal pellet diet (group A) while group B was fed the diet added with DTS (panax pseudoginseng, eucommia ulmoides), (Kyotsu Jigyo, Tokyo, Japan) in the proportion of 50/25 (% weight/weight), at the dose of 50 mg/kg/day throughout the experimental period. At the end of 8 weeks, 24-hour urine was collected for the measurement of the albumin concentration: blood samples were collected for serum biochemistry and the rats were sacrificed for kidney measurement of oxidative stress- and histomorphological features. Nephrin and Macrophage Chemoattractant Protein-1 (MCP-1) gene expression were also assessed by fluorescence real-time quantitative PCR after RNA extraction and cDNA synthesis. STZ-treated animals showed significantly increased in lipid peroxidation in the kidney and in proteinuria. DTS supplementation did not affect plasma glucose but significantly decreased malonyldialdehyde (MDA) plasma level and the overall redox parameters together with a partial mitigation of proteinuria. Histological analysis showed also that DTS significantly reduced the glomerular volume together with glomerulosclerosis and interstitial fibrosis score (p<0.05), the latter two being correlated to proteinuria (p<0.05). DTS supplementation also enabled a reduction of diabetes-induced decrease of nephrin mRNA expression and a 67% reduction of MCP-1 mRNA up-regulation (p<0.01). Taken altogether, these data show that, besides the mandatory control of glycemia, intervention with a nutraceutical with antioxidant and anti-inflammatory properties may have beneficial effects when integrated in the mainstream of the therapeutic regimen. Copyright