Effect of resveratrol on oxidative and inflammatory stress in liver and spleen of streptozotocin-induced type 1 diabetic rats

It has been well known that both oxidative stress and inflammatory activity play crucial roles in the pathogenesis of type 1 diabetes mellitus (T1DM). Resveratrol (RSV), a naturally occurring polyphenol found in grapes and red wine, has recently been shown to exert potent anti-diabetic, antioxidative and anti-inflammatory actions. In the present study, we investigated the effect of RSV on oxidative stress and inflammatory response in the liver and spleen of streptozotocin (STZ)-induced type 1 diabetic animal models. Male Long-Evans rats were injected with 65 mg/kg STZ to induce diabetes for 2 weeks, and subsequently administrated with the dosage of 0.1 or 1 mg/kg/day RSV for 7 consecutive days. Hepatic and splenic tissues were dissected for evaluation of oxidative and inflammatory stress. Oxidative stress was assessed by quantification of oxidative indicators including superoxide anion content, lipid and protein oxidative products, as well as manganese superoxide dismutase (Mn-SOD) and nitro-tyrosine protein expression levels. Inflammatory stress was evaluated by the levels of nuclear factor κB (NF-κB) and the proinflammatory cytokine tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β) and IL-6. The experimental results indicated that RSV significantly decreased oxidative stress (superoxide anion content, protein carbonyl level and Mn-SOD expression) in both tissues and hepatic inflammation (NF-κB and IL-1β), but implicated proinflammatory potential of RSV in diabetic spleen (TNF-α and IL-6). The results of this study suggest that RSV may serve as a potent antioxidant, but RSV possesses a proinflammatory potential in certain circumstances in diabetes.