Abstract
Green tea contains high levels of polyphenols that are believed to prevent lifestyle-related diseases. The main tea polyphenols are tea catechins (TCs), which are thought to be useful compounds for the treatment of obesity. Although the mechanisms have not yet been determined, several studies suggest that TCs may reduce adiposity by inducing thermogenesis. To test this notion, we examined the effect of dietary TC intake on body fat accumulation in rats and uncoupling protein family (UCP1, 2 and 3) gene expression in brown adipose tissues (BATs). Male Sprague Dawley rats were fed for 5 weeks with a high-fat (HF; 35% fat) diet, then randomly divided into 4 groups and fed for 8 weeks with a HF, HF with 0.5% TC (HFTC), normal fat (NF; 5% fat), or NF with 0.5% TC (NFTC) diet. At the end of the experimental period, perirenal and epididymal white adipose tissues (WATs) and interscapular BAT were isolated. The NFTC group had significantly lower perirenal WAT weights than the NF group but the HF and HFTC groups did not differ significantly. TC intake had no effects on epididymal WAT weights. The NFTC group had significantly higher UCP1 mRNA levels in BAT than the NF group but the HF and HFTC groups did not differ significantly. TC intake had no effect on the UCP2 and 3 mRNA levels in BAT. These results suggest that the suppressive effect of TC on body fat accumulation in rat is closely associated with BAT UCP1 expression. [J Physiol Sci. 2008;58 Suppl:S105]
