EFFECTS OF LONG-TERM DIETARY-SUPPLEMENT OF TEA POLYPHENOLS ON LIPID PEROXIDE LEVELS IN RATS

We examined the effects of tea polyphenols (TP) on the bodyweight gain and contents of lipids and lipid peroxides in rat plasma, kidney and liver. The supplementation of TP (0.5% and 1.0%) in the diet was performed from weanling (3 weeks of age) to 19 months old. A significant suppression of body weight gain was observed only at 7-11 weeks of age, but there were no significant changes in liver and kidney weight between control group and TP-feeding group (TP group). Daily food intake of animals in two TP groups was almost the same as the control group. In the older rats (13-19 months of age), thiobarbituric acid reactive substances(TBARS) in the plasma in 1.0% TP group were significantly lower than that of the control group (p<0.01). The contents of plasma lipids (triglyceride, total cholesterol, and phospholipid) in 1.0% TP group at 19 months old were significantly lower as compared with the control group (p<0.05). There was a positive correlation in an age group 13-19 months old between these lipid contents and TBARS. These results suggest that long-term dietary supplementation of TP caused the decrease of plasma TBARS, mainly due to the hypolipidemic activity and antioxidative effect of TP in vivo.