AIMS

The aim of this study was to investigate the antiobesity effect of (-)-epigallocatechin-3-gallate (EGCG) in diet-induced obese mice.

METHODS

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.

RESULTS

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.

CONCLUSION

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.