| Brief Introduction |
The project ？？Prevention of Tea on Cancer？？ was funded five times by the National Natural Sciences Foundation from 1988 to 2002. The effects of tea on cancer prevention were systematically studied from the following four aspects: the whole animal carcinogenesis studies, screening of effective ingredients of tea, related mechanisms and intervention trials.
Animal carcinogenesis studies demonstrated that green tea, black tea, jasmine tea and oolong tea as well as their main ingredients tea polyphenols and tea pigments inhibited the formation of esophagus, lung, liver, oral and colorectal cancer. Six short-period screening tests were selected to screen 18 ingredients of tea. The results showed that tea polyphenols and tea catechins were the main ingredients of green tea and tea pigments was the main ingredients of black tea. Most importantly, the study demonstrated that tea pigments, the oxidation products of tea polyphenols had the same effect as tea polyphenols for the first time. In addition, a kind of mixed tea whose effect was better than the other kinds of tea and their ingredients was developed based on the study. The research also demonstrated that anti-oxidation, inhibition of oncogene expression, inhibition of cell proliferation, induction of apoptosis, inhibition of telomerase activity and immune regulation may be the possible mechanisms, and interaction among these mechanisms may be existed.
The prominent characteristic of the project is the intervention trials using biomarkers as the immediate endpoints, especially the intervention trial of mixed tea on oral preneoplastic lesions. The results showed that mixed tea had significant effect on DNA damage and cancer cell proliferation, which provided the direct evidence of tea on human cancer prevention. Another intervention trial demonstrated that tea drinking protected the oxidation damage induced by smoking.
The present project systematically clarified the effects of tea on cancer prevention. The whole results obtained from this project had important effects at home and abroad and reached the international level. The intervention trials conducted in the present project ranked the first level of the world. In addition, the project provided valuable data for the use of tea in the field of cancer prevention and the research and development of tea preparations in the field of medicine and health foods.
The project trained 1 post-doctor, 4 doctors and 4 masters. A total of 56 papers were published. Among those, 16 papers were cited by SCI and 39 papers were cited by MEDLINE. |
