OBJECTIVETo determine the anti-obesity effects of oolong tea on diet-induced overweight or obesity.

METHODSA total of 8 g of oolong tea a day for 6 weeks was ingested by 102 diet-induced overweight or obese subjects. The body fat level of the subjects was determined at the same time by taking body weight, height and waist measurements. The thickness of the subcutaneous fat layer was also determined on the abdomen 3 cm to the right of the navel by the ultrasonic echo method. On the other hand, effects of oolong tea ingestion on plasma triglyceride (TG) and total cholesterol (TC) were determined. Inhibitions of pancreatic lipase by oolong tea extract and catechins in vitro were also determined.

RESULTSA total of 70% of the severely obese subjects did show a decrease of more than 1 kg in body weight, including 22% who lost more than 3 kg. Similarly, 64% of the obese subjects and 66% of the overweight subjects lost more than 1 kg during the experiment, and the subcutaneous fat content decreased in 12% of the subjects. The correlation between weight loss and subcutaneous fat decrease in men (r=0.055) was obviously lower than that in women (r=0.440, P<0.01). Body weight loss was signifificantly related to the decrease of the waist size in men (r=0.730, P<0.01) and women (r=0.480, P<0.01). Also, the correlation between subcutaneous fat reduction and decreased waist size was signifificant in women (r=0.554, P<0.01), but not in men (r=0.050, P>0.05). Moreover, the plasma levels of TG and TC of the subjects with hyperlipidemia were remarkably decreased after ingesting oolong tea for 6 weeks. In vitro assays for the inhibition of pancreatic lipase by oolong tea extract and catechins suggest that the mechanism for oolong tea to prevent hyperlipidemia may be related to the regulative action of oolong tea catechins in lipoprotein activity.

CONCLUSIONSOolong tea could decrease body fat content and reduce body weight through improving lipid metabolism. Chronic consumption of oolong tea may prevent against obesity.

Adult ; Aged ; Animals ; Beverages ; Body Height ; drug effects ; Body Weight ; drug effects ; Catechin ; pharmacology ; Cholesterol ; blood ; Diet ; Feeding Behavior ; drug effects ; Female ; Humans ; Lipase ; antagonists & inhibitors ; Male ; Middle Aged ; Obesity ; blood ; drug therapy ; Overweight ; blood ; drug therapy ; Phytotherapy ; Plant Extracts ; pharmacology ; therapeutic use ; Subcutaneous Fat ; drug effects ; Sus scrofa ; Tea ; metabolism ; Triglycerides ; blood ; Young Adult

OBJECTIVETo investigate the effect of immunization with prokaryotically expressed recombinant fusion protein of extracellular near-transmembrane domain of Tibet minipig leptin receptor (OBR) on fat deposition in SD rats.

METHODSA pair of specific primers containing BamHI and HindIII restriction enzyme sites was designed to amplify the extracellular near-transmembrane domain (1705-2364 bp) of Tibet minipig OBR gene. After digestion, the amplified fragment was inserted into the plasmid pRSETA between BamHI and HindIII sites. The recombinant plasmid was transformed and expressed in E.coli BL21(DE3) and the product was analyzed by SDS-PAGE and Western blotting. SD rats were immunized with the fusion protein, and the changes in body weight, feed intake, body length, Lee's index, percentage of abdominal fat, liver fat deposition and subcutaneous fat deposition were assessed.

RESULTSThe recombinant fusion protein obtained (about 27.6 kD) was expressed in E.coli induced by IPTG and identified by SDS-PAGE and Western blotting. The rats immunized with the fusion protein showed no significant changes in body weight, body length, Lee's index, percentage of abdominal fat or liver fat deposition as compared with the control rats. Nevertheless, the immunization caused significantly increased feed intake and significantly decreased volume of subcutaneous fat cells.

CONCLUSIONImmunization with the fusion protein of extracellular near-transmembrane domain of Tibet minipig OBR can promote feed intake and suppress subcutaneous fat deposition in SD rats.

Adiposity ; drug effects ; Animals ; Base Sequence ; Female ; Gene Expression ; Genetic Vectors ; Obesity ; Plasmids ; Rats ; Rats, Sprague-Dawley ; Receptors, Leptin ; administration & dosage ; genetics ; Recombinant Fusion Proteins ; administration & dosage ; genetics ; Subcutaneous Fat ; physiology ; Swine ; Swine, Miniature

People with upper body or visceral obesity have a much higher risk of morbidity and mortality from obesity-related metabolic disorders than those with lower body obesity. In an attempt to develop therapeutic strategies targeting visceral obesity, depot- specific differences in the expression of genes in omental and subcutaneous adipose tissues were investigated by DNA array technology, and their roles in adipocyte differentiation were further examined. We found that levels of metallothionein-II (MT-II) mRNA and protein expression were higher in omental than in subcutaneous adipose tissues. The study demonstrates that MT-II may play an important role in adipocyte differentiation of 3T3L1 preadipocytes, and that N-acetylcysteine (NAC) inhibits the adipocyte differentiation of 3T3L1 cells by repressing MT-II in a time- and dose-dependent manner. Furthermore, the intraperitoneal administration of NAC to rats and mice resulted in a reduction of body weights, and a marked reduction in visceral fat tissues. These results suggest that MT-II plays important roles in adipogenesis, and that NAC may be useful as an anti-obesity drug or supplement.
Viscera/drug effects/metabolism ; Time Factors ; Subcutaneous Fat/drug effects ; Rats, Sprague-Dawley ; Rats ; Middle Aged ; Mice, Inbred C57BL ; Mice ; Metallothionein/*genetics/metabolism/physiology ; Male ; Humans ; Female ; Down-Regulation/drug effects/genetics ; Dose-Response Relationship, Drug ; Cell Differentiation/drug effects ; Body Weight/drug effects ; Anti-Obesity Agents/*pharmacology ; Animals ; Aged ; Adipose Tissue/cytology/drug effects/metabolism ; Adipocytes/cytology/drug effects/metabolism ; Acetylcysteine/*pharmacology ; 3T3-L1 Cells