Fig. 1Effects of resveratrol (RSV) on the differentiation of brown adipocytes. (A) Oil-red-O staining of primary cultured brown preadipocytes. RSV treatment was performed with induction medium at doses of 50 and 100 µM and maintained thereafter. Adipogenesis was significantly increased with RSV treatment. (B) Western blotting for mitochondrial activity and estrogen receptor α (ER-α) in brown adipocytes. Brown preadipocytes were cultured and differentiated with or without RSV treatment. The protein lysates were collected after the differentiation of brown adipocytes was confirmed. UCP-1, uncoupling protein 1; p-AMPK, phospho-AMP-activated protein kinase; AMPK, AMP-activated protein kinase.
Fig. 2Effects of resveratrol (RSV) on metabolic parameters in Otsuka Long Evans Tokushima Fatty (OLETF) rats. (A) Body weight changes after RSV treatment of OLETF rats. RSV had been provided since the age of 9 weeks and maintained for 27 weeks. (B) Insulin tolerance test of OLETF rats at 35 weeks of age. (C) Organ weights at 36 weeks of age. (D) Changes in leptin and adiponectin levels. Serum samples from 36-week-old rats were collected and evaluated with an enzyme-linked immunoassay kit. SD, standard diet; HF, high fat; AUC, area under the curve. aP value below 0.05 with treatment of RSV in each diet group (Mann-Whitney U test).
Fig. 3Effects of resveratrol (RSV) on the differentiation and activation of brown adipocytes in Otsuka Long Evans Tokushima Fatty (OLETF) rats. (A) Hematoxylin and eosin staining for brown adipocytes. Brown adipose tissue was collected from OLETF rats at 36 weeks of age. With the treatment of RSV and feeding of the high fat diet (HFD), the differentiation of brown adipocytes increased. (B) The number of brown adipocytes visible in the high-power field increased significantly with RSV treatment and HFD feeding. The average number of brown adipocytes was calculated at four sites of each section. The number of rats in each group is described in the Methods. (C) Western blotting for mitochondrial activity and estrogen receptor α (ER-α). (D) Relative expression in Western blotting, determined using a densitometer. All protein lysates were evaluated and compared with those of rats on the standard diet. SD, standard diet; HF, high fat; UCP-1, uncoupling protein 1; p-AMPK, phospho-AMP-activated protein kinase; GAPDH, glyceraldehyde 3-phosphate dehydrogenase. aP value below 0.05 with treatment of RSV in each diet group (Mann-Whitney U test).