Hypolipidemic effect of green tea leaves through induction of antioxidant and phase II enzymes including superoxide dismutase, catalase, and glutathione S-transferase in rats

In this animal study, Wistar rats were fed 2.5% green tea (longjing) leaves, for 27 and 63 weeks; the changes of GOT, GPT, gamma-GT, and creatinine were not significant in the treated group as compared with the control. These results suggested that long-term feeding of green tea leaves was not toxic to the liver or kidney. Serum total cholesterol, triglyceride, and LDL-C were decreased in the tested group. Interestingly, the dietary intakes of the two groups were approximately the same, but the body weights of the tea-fed group were decreased 10-18% compared viith those of the control. The activities of antioxidant enzymes (SOD and catalase) and phase II enzyme (GST) and glutathione concentration in the liver of Wistar rats were significantly higher in the treated group. The biological significance of these results can be implicated in relation to the hypolipidemic effect as well as the cancer chemopreventive action of green tea.