茶カテキンによるラットの抗肥満作用は高脂肪食から標準脂肪食への切り替えにより増強される

抄録

The purpose of the present study was to examine whether anti-obesity effects of tea catechin (TC) intake are enhanced by the switch from high-fat to normal-fat diet in mildly obese rats. Five-week-old male SD rats were fed with 35% high-fat diet (HF) for 5 weeks, and then with four types of diet: HF, HF supplemented with 0.5% TC (HFTC), 5% normal-fat diet (NF), and NF supplemented with 0.5% TC (NFTC) for 8 weeks. Food intake (FI) and body weight (BW) were daily measured. On the final day of the experiment, perirenal and epididymal white adipose tissues (WATs) were isolated and weighed. Total FI and BW in HFTC and NFTC were not significantly different from HF and NF, respectively. In NFTC, perirenal WAT weight was significantly lower and epididymal WAT weight tended to be lower, as compared with in NF. However, there were no significant differences in the weights between HFTC and HF. Plasma total cholesterol level was significantly lower in NFTC than in NF, while plasma HDL cholesterol level was not different between NFTC and NF. Plasma insulin level was significantly lower in NFTC than in NF although plasma glucose level was not different between NFTC and NF. On the other hand, there were no significant differences in plasma levels of total and HDL cholesterols, insulin and glucose between HFTC and HF. These results suggest that the switch from HF to NF plays an important role in enhancing anti-obesity effects of TC intake. [J Physiol Sci. 2007;57 Suppl:S184]