Resveratrol attenuates inflammation and oxidative stress in epididymal white adipose tissue: implications for its involvement in improving steroidogenesis in diet-induced obese mice.

Chronic, low-grade systemic inflammation has been shown to play an important role in the development of obesity-related complications. Epididymal white adipose tissue (WAT) can influence testicular function through its endocrine function. The purpose of this study was to assess the effects of resveratrol on the epididymal WAT inflammatory response and on testicular steroidogenesis in obese individuals. Seven-week-old male C57BL/6J mice were fed a high-calorie and high-cholesterol diet (HCD group) or HCD supplemented with resveratrol (HCD+Res group) for 18 weeks. As we previously showed that resveratrol protects against Leydig cell steroidogenesis in HCD-induced obese mice, this study assessed macrophage infiltration in fat depots by measuring crown-like structure (CLS) density. Histological analysis showed that adipocyte size was significantly smaller and CLSs were less numerous in the HCD+Res group than the HCD group (P < 0.01). Additionally, resveratrol supplementation decreased Nfkb1 expression (P < 0.01) and increased the IκB-α protein abundance (P < 0.01) in epididymal WAT. Consistent with this alteration in NF-κB signaling, the expression of two classic proinflammatory cytokines, TNF-α (Tnfa) and IL-1β (Il1b), were significantly decreased in the HCD+Res group compared with the HCD group (P < 0.01). Significant differences were also found in the expression of sirtuin1 (Sirt1) (P < 0.01) and manganese superoxide dismutase (Sod2) (P < 0.01) between the HCD and HCD+Res groups. Our data suggest that resveratrol can attenuate obesity-induced inflammation and oxidative stress in epididymal WAT, which partly accounts for its beneficial effects in testicular steroidogenesis.