Effects of Resveratrol on the Kidney in Rats with Streptozotocin Induced Diabetic Nephropathy

Objective: Diabetic nephropathy is one of the most significant causes of end-stage renal failure and is a common microvascular complication of diabetes (D). Resveratrol (RSV), a natural compound found in grape skins and red wine, has potent antioxidant properties. This study aimed to evaluate the effects of RSV in a streptozotocin (STZ)-induced diabetic rat model. Methods: Animals were divided into four groups: control, RSV, D, and D + RSV. The diabetic group received a single intraperitoneal dose of STZ (65 mg/kg). After 2 weeks, rats with basal blood glucose levels >250 mg/dL were considered diabetic. RSV(10 mg/kg/day) was administered orally by gavage for 8 weeks. Metabolic analyses were conducted throughout the study. At the study's end, transmission electron microscopy and immunohistochemical analyses were performed. Additionally, the left kidney was isolated and suspended in an organ bath to study the functional changes without damaging the renal artery. Results: In the study, increased transforming growth factor-beta, fibronectin and inducible nitric oxide synthase immunoreactivity, which are markers of D-induced renal degeneration, were partially reduced by RSV treatment. In group D, decreased endothelial nitric oxide synthase uptake (weak immune reactivity) was observed, whereas this uptake increased with RSV treatment (moderate immune reactivity). Furthermore, both angiotensin II and phenylephrine responses were reduced in group D treated with RSV. Vasodilator responses to acetylcholine were also reduced in this group. Conclusion: RSV may protect against diabetic nephropathy by modulating key pathways involved in renal degeneration and vascular function and may have potential as a therapeutic agent for slowing disease progression.