Long-term resveratrol administration improves diabetes-induced pancreatic oxidative stress, inflammatory status, and ß cell function in male rats

Abstract Diabetes is a metabolic disorder caused by insulin resistance or a defect in the pancreatic beta cells in insulin secretion. The aim of this study was to evaluate the possible effectiveness of long-term administration of resveratrol on inflammatory and oxidative stress markers in the pancreatic tissue of diabetic rats. Male Wistar rats (n = 24) were randomly divided into four groups of six animals, namely a healthy group, a healthy group receiving resveratrol, a diabetic control group, and a diabetic group receiving resveratrol. Diabetes was induced by single dose injection of streptozotocin (50 mg/kg; ip), 15 min after injection of nicotinamide (110 mg/kg; ip). Resveratrol was also administered by gavage (5 mg/kg/day) for 4 months. Administration of resveratrol alleviated hyperglycemia, weight loss and pancreatic ß cell function measured by HOMA-ß. Resveratrol improved oxidative stress (nitrate/nitrite, 8-isoprostane and glutathione) and proinflammatory markers (tumor necrosis factor α, cyclooxygenase 2, interleukin 6 and nuclear factor kappa B) in the pancreatic tissue of diabetic rats. Resveratrol administration had no significant effect on the activity of superoxide dismutase and catalase enzyme. These observations indicate that resveratrol administration may be effective as a beneficial factor in improving pancreatic function and reducing the complications of diabetes

The Risk for Insulin Resistance according to the Degree of Non-Alcoholic Fatty Liver Disease in Korean Men

Insulin resistance (IR) plays a significant role in the development and progression of non-alcoholic fatty liver disease (NAFLD). However, the natural course of insulin sensitivity under NAFLD remained unclear. Accordingly, this study was designed to investigate the effect of NAFLD on insulin resistance. A total of 20,628 Korean men without homeostasis model assessment of insulin resistance (HOMA-IR < 2.7) were followed-up for 5 years. They were serially checked for HOMA-IR to monitor the development of IR (HOMA-IR ≥ 2.7). The incidence rate of IR increased according to the degree of NAFLD (normal: 11.6%, mild: 28.8%, moderate to severe: 40.5%, P < 0.001). Cox proportional hazards model showed that HRs (95% CI) for IR increased proportionally to the degree of NAFLD (mild: 1.19 [1.02–1.39], moderate to severe: 1.32 [1.08–1.57]). IR was more potentially associated with the more progressive NAFLD than normal and milder state. In addition, NAFLD was the independent risk factor of the development of IR. These results suggest the potential availability of NAFLD as a predictor of IR.