stilbenes and nephrin

Resveratrol is well known for its anti-inflammation and anti-oxidant properties, and has been shown to be effective in alleviating the development of obesity. The purpose of this investigation was to analyze the effect of resveratrol on renal damage in obese rats induced by a high-fat diet (HFD) and its possible mechanisms. Male Sprague-Dawley rats were divided into three groups: control, HFD, and HFD plus resveratrol (treated with 100 mg/kg/day resveratrol). Body weight, serum and urine metabolic parameters, and kidney histology were measured. Meanwhile, the activities of nuclear factor-κB (NF-κB) and superoxide dismutase (SOD), the content of malondialdehyde (MDA), and the protein levels of tumor necrosis factor (TNF-α), monocyte chemotactic protein-1 (MCP-1), nephrin and podocin in kidney were detected. Our work showed that resveratrol alleviated dyslipidemia and renal damage induced by HFD, decreased MDA level and increased SOD activity. Furthermore, the elevated NF-κB activity, increased TNF-α and MCP-1 levels, and reduced expressions of nephrin and podocin induced by HFD were significantly reversed by resveratrol. These results suggest resveratrol could ameliorate renal injury in rats fed a HFD, and the mechanisms are associated with suppressing oxidative stress and NF-κB signaling pathway that in turn up-regulate nephrin and podocin protein expression.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Blood Glucose; Body Weight; Chemokine CCL2; Diet, High-Fat; Glucose Tolerance Test; Intracellular Signaling Peptides and Proteins; Kidney; Male; Malondialdehyde; Membrane Proteins; NF-kappa B; Oxidative Stress; Rats; Rats, Sprague-Dawley; Resveratrol; Stilbenes; Superoxide Dismutase; Tumor Necrosis Factor-alpha

Diabetic nephropathy (DN) is the major cause of end-stage renal disease. The early changes in DN are characterized by an increased in kidney size, glomerular volume, and kidney function, followed by the accumulation of glomerular extracellular matrix, increased urinary albumin excretion (UAE), glomerular sclerosis, and tubular fibrosis. Resveratrol (RSV) has been shown to ameliorate hyperglycemia and hyperlipidemia in streptozotocin-induced diabetic rats. In the present study, we examined the beneficial effects of RSV on DN and explored the possible mechanism of RSV action. Male Sprague-Dawley rats were injected with streptozotocin at 65mg/kg body weight. The induction of diabetes mellitus (DM) was confirmed by a fasting plasma glucose level ≥300mg/dL and symptoms of polyphagia and polydipsia. The DM rats were treated with or without RSV at 0.75mg/kg body weight 3 times a day for 8 weeks. Animals were sacrificed and kidney histology was examined by microscopy. Urinary albumin excretion, glomerular hypertrophy and expressions of fibronectin, collagen IV, and TGF-β in the glomeruli were alleviated in RSV-treated DM rats, but not in untreated DM rats. In addition, RSV treatment reduced the thickness of the glomerular basement membrane (GBM) to the original thickness and increased nephrin expressions to normal levels in DM rats. Moreover, RSV inhibited phosphorylation of smad2, smad3 and ERK1/2 in diabetic rat kidneys. This is the first report showing that RSV alleviates early glomerulosclerosis in DN through TGF-β/smad and ERK1/2 inhibition. In addition, podocyte injuries of diabetic kidneys are lessened by RSV.

Topics: Animals; Collagen Type IV; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Disease Models, Animal; Fibronectins; Hypoglycemic Agents; Kidney; Male; Membrane Proteins; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Phosphorylation; Rats; Rats, Sprague-Dawley; Resveratrol; Signal Transduction; Smad Proteins; Stilbenes; Transforming Growth Factor beta