Resveratrol is a natural polyphenolic stilbene derivative found in a variety of edible fruits, including nuts, berries, and grape skin(Reference Ren and Lien1). Although resveratrol has been suggested to improve thermogenesis in the brown adipose tissues of obese animals, there have been no reports on the anti-adipogenic and anti-inflammatory effects of resveratrol in the white adipose tissues of obese animals. The primary aim of this study was to investigate whether resveratrol attenuates high-fat diet (HFD)-induced adipogenesis and inflammation in the epididymal fat tissues of mice and to explore the underlying mechanisms involved in this attenuation. Male C57BL/6N mice were fed a normal diet (n 10), HFD (n 10) or a 0.4% resveratrol-supplemented diet (RSD, n 10) for 10 weeks. The plasma and hepatic lipid levels were determined by enzymatic kits, and the adipose tissue gene and protein expression levels were analysed via RT-PCR and Western blotting, respectively. These data were analysed using ANOVA with Duncan's multiple-range tests.
In comparison with HFD mice, mice fed with a RSD showed significantly (P<0.05) lower body weight gain (−48%), visceral fat-pad weights (−58%) and plasma levels of TAG, FFA, total cholesterol, glucose, TNFα and MCP1. Resveratrol significantly (P<0.05) reversed the HFD-induced up-regulation of galanin-mediated signalling molecules (GalR1/2, PKCδ, Cyc-D, E2F1 and p-ERK) and key adipogenic genes (PPARγ2, C/EBPα, SREBP-1c, FAS, LPL, aP2 and leptin) in the epididymal adipose tissues of mice. Furthermore, resveratrol significantly (P<0.05) attenuated the HFD-induced up-regulation of pro-inflammatory cytokines (TNFα, IFNα, IFNβ and IL-6) and their upstream signalling molecules (TLR2/4, MyD88, Tirap, TRIF, TRAF6, IRF5, p-IRF3 and NF-κB) in the adipose tissues of mice. The results of this study suggest that resveratrol inhibits visceral adipogenesis by suppressing the galanin-mediated adipogenesis signalling cascade. It may also attenuate cytokine production in the adipose tissue by repressing the TLR2- and TLR4-mediated pro-inflammatory signalling cascades in HFD-fed mice (Fig. 1). The results of this study suggest that resveratrol inhibits visceral adipogenesis by suppressing the galanin-mediated adipogenesis signalling cascade. It may also attenuate cytokine production in the adipose tissue by repressing the TLR2- and TLR4-mediated pro-inflammatory signalling cascades in HFD-fed mice.
Fig. 1. The possible molecular mechanisms of dietary resveratrol in attenuating adipogenesis and inflammation induced by HFD.
