Indole-3-carbinol prevents diet-induced obesity through modulation of multiple genes related to adipogenesis, thermogenesis or inflammation in the visceral adipose tissue of mice.

Indole-3-carbinol (I3C) is a compound found in high concentrations in Brassica family vegetables, including broccoli, cauliflower and cabbage, and is regarded as a promising chemopreventive agent against various cancers. This study assesses the protective effect of I3C against diet-induced obesity in mice. Mice were randomly grouped to receive either a normal diet, high-fat (40% energy as fat) diet (HFD) or I3C-supplemented diet (1 g/kg diet) for 10 weeks. I3C supplementation significantly ameliorated HFD-induced increases in body weight gain, visceral fat pad weights and plasma lipid levels. The visceral adipose tissue mRNA levels of uncoupling proteins 1 and 3, crucial factors of thermogenesis, and their regulators such as sirtuin 1, peroxisome proliferator-activated receptor (PPAR) α and PPARγ coactivator 1α, which were down-regulated by HFD, were normalized by supplementation with I3C. In contrast, I3C supplementation significantly decreased expression levels of a key adipogenic transcription factor, PPARγ2, and its target genes, such as leptin and adipocyte protein 2, in the visceral adipose tissue of mice maintained on the HFD. Furthermore, HFD-induced up-regulation in mRNA levels of inflammatory cytokines (tumor necrosis factor α, interferon β and interleukin 6) was significantly ameliorated by I3C. These findings suggest that I3C has a potential benefit in preventing obesity and metabolic disorders, and the action for I3C in vivo may involve multiple mechanisms including decreased adipogenesis and inflammation, along with activated thermogenesis.

Choi Y ，Kim Y ，Park S ，Lee KW ，Park T ... -  《-》

Carvacrol prevents diet-induced obesity by modulating gene expressions involved in adipogenesis and inflammation in mice fed with high-fat diet.

Carvacrol (2-methyl-5-isopropylphenol) is a monoterpene phenolic constituent of the essential oil produced by numerous aromatic plants and spices. The main objective of this study was to investigate effects of carvacrol in mice fed with a high-fat diet (HFD), which is an important model of obesity, and to study the potential underlying mechanisms focusing on the gene expression involved in adipogenesis, thermogenesis and inflammation. Male C57BL/6N mice were divided in three groups: those who received a normal diet, those fed with HFD and those fed with 0.1% carvacrol-supplemented diet (CSD). Body weight, visceral fat-pads and biochemical parameters were determined. Adipose tissue genes and protein expression levels were also assessed through reverse transcription polymerase chain reaction and Western blot analyses. Mice fed with CSD exhibited significantly reduced body weight gain, visceral fat-pad weights and plasma lipid levels compared with mice fed with HFD. Furthermore, HFD-induced up-regulations of adipose tissue genes and protein associated with the signaling cascades that lead to adipogenesis and inflammation were significantly reversed by dietary carvacrol supplementation. In summary, the major novel finding in our experimental conditions is that carvacrol prevented obesity in HFD-fed mice by decreasing body weight, visceral fat-pad weights and lowering plasma lipid levels. The evidence obtained in this study suggests that carvacrol appears to inhibit visceral adipogenesis probably by suppressing bone morphogenic protein-, fibroblast growth factor 1- and galanin-mediated signaling, and it also attenuates the production of pro-inflammatory cytokines in visceral adipose tissues by inhibiting toll like receptor 2 (TLR2)- and TLR4-mediated signaling.

Cho S ，Choi Y ，Park S ，Park T ... -  《-》

Green tea (-)-epigallocatechin-3-gallate reduces body weight with regulation of multiple genes expression in adipose tissue of diet-induced obese mice.

The aim of this study was to investigate the antiobesity effect of (-)-epigallocatechin-3-gallate (EGCG) in diet-induced obese mice. Male C57BL/6J mice were fed on a high-fat diet for 8 weeks to induce obesity. Subsequently they were divided into 3 groups and were maintained on a high-fat control diet or high-fat diets supplemented with 0.2 or 0.5% EGCG (w/w) for a further 8 weeks. Changes in the expression of genes related to lipid metabolism and fatty acid oxidation were analyzed in white adipose tissue, together with biometric and blood parameters. Experimental diets supplemented with EGCG resulted in reduction of body weight and mass of various adipose tissues in a dose-dependent manner. EGCG diet also considerably lowered the levels of plasma triglyceride and liver lipid. In the epididymal white adipose tissue of EGCG diet-fed mice, the mRNA levels of adipogenic genes such as peroxisome proliferator-activated receptor-gamma (PPAR-gamma), CCAAT enhancer-binding protein-alpha (C/EBP-alpha), regulatory element-binding protein-1c (SREBP-1c), adipocyte fatty acid-binding protein (aP2), lipoprotein lipase (LPL) and fatty acid synthase (FAS) were significantly decreased. However, the mRNA levels of carnitine palmitoyl transferase-1 (CPT-1) and uncoupling protein 2 (UCP2), as well as lipolytic genes such as hormone sensitive lipase (HSL) and adipose triglyceride lipase (ATGL), were significantly increased. These results suggest that green tea EGCG effectively reduces adipose tissue mass and ameliorates plasma lipid profiles in high-fat diet-induced obese mice. These effects might be at least partially mediated via regulation of the expression of multiple genes involved in adipogenesis, lipolysis, beta-oxidation and thermogenesis in white adipose tissue.

Lee MS ，Kim CT ，Kim Y 《-》

Chitooligosaccharide ameliorates diet-induced obesity in mice and affects adipose gene expression involved in adipogenesis and inflammation.

Chitooligosaccharide (CO) has been reported to have potential antiobestic effects in a few studies, but the antiobesity properties of CO and its related mechanisms in models of dietary obesity remain unclear. We investigated the effect of CO on body weight gain, size of adipocytes, adipokines, and lipid profiles in high-fat (HF) diet-induced obese mice and on the gene expression in adipose tissue using a complementary DNA microarray approach to test the hypothesis that CO supplementation would alleviate HF diet-induced obesity by the alteration of adipose tissue-specific gene expression. Male C57BL/6N mice were fed a normal diet (control), HF diet, or CO-supplemented HF diet (1% or 3%) for 5 months. Compared with the HF diet mice, mice fed the 3% CO-supplemented diet gained 15% less weight but did not display any change in food and energy intake. Chitooligosaccharide supplementation markedly improved serum and hepatic lipid profiles. Histologic examination showed that epididymal adipocyte size was smaller in mice fed the HF + 3% CO. Microarray analysis showed that dietary CO supplementation modulated adipogenesis-related genes such as matrix metallopeptidases 3, 12, 13, and 14; tissue inhibitor of metalloproteinase 1; and cathepsin k in the adipose tissues. Twenty-five percent of the CO-responsive genes identified are involved in immune responses including the inflammatory response and cytokine production. These results suggest that CO supplementation may help ameliorate HF diet-induced weight gain and improve serum and liver lipid profile abnormalities, which are associated, at least in part, with altered adipose tissue gene expression involved in adipogenesis and inflammation.

Choi EH ，Yang HP ，Chun HS 《-》

Ethanolic extract of seabuckthorn (Hippophae rhamnoides L) prevents high-fat diet-induced obesity in mice through down-regulation of adipogenic and lipogenic gene expression.

Phenolic compounds and flavonoids ameliorate bodyweight, blood glucose, and serum lipid profile. Since seabuckthorn (Hippophae rhamnoides L.) is known as a rich source of isoflavones and flavonoids, we hypothesized that ethanolic extract of seabuckthorn leaves (SL) may have anti-obesity and hypoglycemic effects. To investigate the effect of ethanolic extract of SL, 32 C57BL/6J mice were randomly divided into 4 dietary groups, containing 8 mice in each group: normal diet group; high-fat diet (HD) control group; high-fat diet with SL extract, 500 mg/kg body weight (BW) (SL1) group; and high-fat diet with SL extract, 1000 mg/kg BW (SL2) group. After 13 weeks, it was observed that oral administration of SL extract significantly reduced the energy intake; BW gain; epididymal fat pad weight; hepatic triglyceride, hepatic, and serum total cholesterol levels; and serum leptin levels in the SL groups compared to the HD group. However, differences in serum triglyceride and insulin levels in the SL groups were not significant in comparison to the HD group. The hepatic mRNA expression of peroxisome proliferator-activated receptor (PPAR) α and carnitine palmitoyltransferase 1 along with PPAR-γ were significantly increased in SL groups, whereas the level of acetyl-CoA carboxylase was significantly reduced in SL groups compared to HD group. Our results indicated that SL is effective in preventing BW gain and fat accumulation in the liver; it also reduced adipose tissue mass, hepatic lipid profile, and serum leptin level in the mouse. Together, these observations suggest that SL is a potential agent to study in the management of obesity and related disorders.

Pichiah PB ，Moon HJ ，Park JE ，Moon YJ ，Cha YS ... -  《-》