The Effects of Epigallocatechin on Adipogenesis of 3T3-L1 Preadipocytes

Preadipocyte cell lines are useful models for investigating adipogenesis process. 3T3-L1 preadipocyte, which can be induced to differentiate into adipocyte in cell culture, is one of the most studied preadipocyte cell lines. When exposed to the appropriate differentiation inducer, including insulin, dexamethasone and 3-isobutyl- 1-methylxanthine, 3T3-L1 preadipocytes differentiate into adipocytes. This study was undertaken to evaluate the effect of epigallocatechin on differentiation of 3T3-L1 preadipocyte, and to test whether epigallocatechin can be useful to reduce fat deposition. Cell proliferation was determined by MTT(3,4,5-Dimethylthiazol-2,5-Diphenyl- Tetrazoliumbromide) spectro-photometry, fat content followed by cell differentiation was determined by Oil Red O staining, and the degree of differentiation into adipocytes were determined by measuring mRNA content and activity of glyceraldehydes 3-phosphate dehydrogenase (G3PDH). Epigallocatechin inhibited proliferation of preadipocytes, not into adipocytes. Fat storage during 3T3-L1 preadipocyte conversion into adipocyte was inhibited by epigallocathechin. Epigallocatechin decreased G3PDH, leptin mRNA and peroxisome proliferator-activated receptor(PPAR)γ mRNA which were increased by differentiation of preadipocyte into adipocyte. These results suggest that epigallocatechin has a potential to serve as a fat-reducing drug.