Following the oral feeding of a polyphenolic fraction isolated from green tea (GTP) in drinking water, an increase in the activities of antioxidant and phase II enzymes in skin, small bowel, liver, and lung of female SKH-1 hairless mice was observed. GTP feeding (0.2%, w/v) to mice for 30 days significantly increased the activities of glutathione peroxidase, catalase, and quinone reductase in small bowel, liver, and lungs, and glutathione S-transferase in small bowel and liver. GTP feeding to mice also resulted in considerable enhancement of glutathione reductase activity in liver. In general, the increase in antioxidant and phase II enzyme activities was more pronounced in lung and small bowel as compared to liver and skin. The significance of these results can be implicated in relation to the cancer chemopreventive effects of GTP against the induction of tumors in various target organs.
Supported by USPHS Grants ES-1900 and P-30-AR-39750, American Institute for Cancer Research Grant 90A47, and research funds from the Department of Veterans Affairs.