ABSTRACT
OBJECTIVE: To analyze whether a combination of quercetin (Q) and resveratrol (RSV) would induce a white adipose tissue (WAT) browning effect. METHODS: Thirty-six rats were fed an obesogenic diet and divided into four groups: control, treated with RSV (15 mg/kg body weight/day; RSV group), treated with Q (30 mg/kg body weight/day; Q group), or treated with both polyphenols (RSV + Q group). RESULTS: After 6 weeks, body and WAT weights were significantly reduced in the RSV + Q group. In perirenal WAT of the control, RSV, and Q groups, white unilocular adipocytes appeared in the majority of cells, while in the RSV + Q group numerous multilocular adipocytes with positive immunostaining for UCP1 were observed. The presence of UCP1 was confirmed by Western blot. This group also revealed increased mRNA levels of Cidea, Hocx9, Bmp4, Slc27a1, Pat2, Atgl, and Atp5d. Interscapular brown adipose tissue weight showed no differences between groups, but the Cidea mRNA level was increased in the RSV group, the Cox-2 mRNA level in the RSV + Q group, and UCP1 protein expression in the RSV and the RSV + Q groups. CONCLUSIONS: This study demonstrated that the RSV + Q combination produces a brown-like remodeling effect in perirenal WAT, as well as increased UCP1 protein expression in interscapular brown adipose tissue.
Subject(s)
Adipose Tissue, White/drug effects , Quercetin/pharmacology , Stilbenes/pharmacology , Adipocytes/drug effects , Adipocytes/metabolism , Adipose Tissue, Brown/drug effects , Adipose Tissue, Brown/physiology , Adipose Tissue, White/physiology , Amino Acid Transport Systems, Neutral/genetics , Amino Acid Transport Systems, Neutral/metabolism , Animals , Apoptosis Regulatory Proteins/genetics , Apoptosis Regulatory Proteins/metabolism , Body Weight , Bone Morphogenetic Protein 4/genetics , Bone Morphogenetic Protein 4/metabolism , Cyclooxygenase 2/genetics , Cyclooxygenase 2/metabolism , Diet , Fatty Acid-Binding Proteins/genetics , Fatty Acid-Binding Proteins/metabolism , Lipase/genetics , Lipase/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Resveratrol , Symporters/genetics , Symporters/metabolism , Uncoupling Protein 1/genetics , Uncoupling Protein 1/metabolismABSTRACT
This work was designed to investigate the effect of different lipid sources on ob gene expression and serum leptin levels in rats with two different feeding protocols: (1) free access to food; or (2) energy-controlled feeding. Male Wistar rats were fed diets containing 40 % energy as fat (olive oil, sunflower oil or beef tallow), for 4 weeks. In Expt 1 rats had free access to food, and in Expt 2 rats were fed a controlled amount of food (16 g/d, equivalent to 300 kJ/d). Insulin and leptin were determined by ELISA and ob mRNA by Northern blot. When rats had free access to food, ob mRNA levels were higher in animals fed either olive oil or sunflower oil than in those fed beef tallow. In marked contrast with feeding ad libitum, no differences were found among dietary fat groups in rats fed energy-controlled diets. When both feeding protocols were compared, free access to food induced an increased expression of ob mRNA in perirenal and/or epididymal adipose tissues from rats fed either olive oil or sunflower oil, but not from rats fed beef tallow. Dietary lipid type did not induce modifications in serum leptin concentrations. A tendency to higher serum leptin levels was observed more in rats with free access to food than in rats fed energy-controlled feeding. No differences were found in insulin levels. Dietary fat type importantly affects ob mRNA expression in rat white adipose tissue under hyperphagic conditions. Further study is needed in order to elucidate the mechanism underlying this effect.
Subject(s)
Adipose Tissue/metabolism , Dietary Fats/pharmacology , Gene Expression Regulation/drug effects , Hyperphagia/metabolism , Leptin/metabolism , Adipose Tissue/pathology , Animals , Blotting, Northern , Body Weight , Dietary Fats, Unsaturated/pharmacology , Eating , Hyperphagia/pathology , Insulin/blood , Leptin/genetics , Male , RNA, Messenger/genetics , Rats , Rats, Wistar , Weight GainABSTRACT
It has been demonstrated that triacylglycerol (TAG) mobilization from adipose tissue is selective and depends on fatty acid (FA) chain length, unsaturation and positional isomerism. The present study was performed to determine the influence of dietary fat on the composition of TAG stored in rat perirenal and subcutaneous adipose tissues. These results may provide information on the susceptibility of stored TAG to hydrolysis and further mobilization, and may help to establish an interrelationship between dietary composition and the FA efflux from adipose tissue. TAG molecular species and FA composition were determined by HPLC and GLC respectively. No significant differences were found in either FA or TAG composition between perirenal and subcutaneous adipose depots. The major FA in the dietary fats were present in the adipose tissues of the animals; in most cases, in similar proportions. However, differences were found between dietary and adipose tissue content of minor FA, which suggests that dietary FA composition is altered between ingestion and deposition in adipose tissue. The TAG molecular species of rat adipose tissue were enriched with the FA characteristic of each dietary fat. Dietary sunflower oil was responsible for enrichment with the most polar TAG. This finding may suggest easier mobilization of stored TAG. In conclusion, the process of fatty acid and TAG deposition in rat adipose tissue is selective, and depends on the composition of the diet.