Screening of anticarcinogenic ingredients in tea polyphenols.
A batch of short-term tests were used to test the antimutagenic activities of Chinese green tea water extract (TWE), tea polyphenols (TP), and tea catechins (EGCG, ECG, EGC, EC). In the V79 cell forward gene mutation and V79 cell cytokinesis-block micronuclei tests, all samples showed significant inhibitory effects on mitomycin, which indicates their effects on the initiation stage of chemical carcinogenesis. However, none of the catechins and TP had effects as strong as the TWE on the basis of their relative contents in tea. Of the four catechins, ECG and EGCG were the most potent. Using the V79 cell metabolic co-operation test as an indicator for the promotion stage, TWE and TP showed weak inhibitory effects and the individual catechins showed much stronger inhibition. The test samples also showed non-specific inhibitory effects on HeLa cell growth in soft agar, which was designed to test their effects on the progression stage.
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Institute of Nutrition and Food Hygiene, Chinese Academy of Preventive Medicine, Beijing.
D016475:3T3 Cells; D000818:Animals; D016588:Anticarcinogenic Agents / Q000737:chemistry / Q000494:pharmacology; D016587:Antimutagenic Agents / Q000494:pharmacology*; D001853:Bone Marrow / Q000187:drug effects; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism; D002392:Catechin / Q000737:chemistry / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008937:Mitomycins / Q000037:antagonists & inhibitors; D009152:Mutagenicity Tests; D010636:Phenols / Q000737:chemistry* / Q000494:pharmacology*; D011108:Polymers / Q000737:chemistry* / Q000494:pharmacology*; D013662:Tea / Q000737:chemistry*; D014407:Tumor Cells, Cultured
D016588:Anticarcinogenic Agents; D016587:Antimutagenic Agents; D005419:Flavonoids; D008937:Mitomycins; D010636:Phenols; D011108:Polymers; D013662:Tea; D002392:Catechin