[The antioxidative mechanisms of tea polyphenols in inhibiting tumor promotion by TPA].
In the mouse study, topical application of green tea polyphenols (GTP) significantly inhibited TPA-induced increasing of epidermal ornithine decarboxylase (ODC) and increased the activities of several antioxidant enzymes (CAT, GR and GST). In another in vitro study, when GTP was incubated with TPA and mice polymorphonuclear leukocytes (PMNs), TPA induced hydrogen peroxide formation was markedly suppressed with a dose-dependent relationship. The results suggest that the antioxidative effect of GTP may play an important role in inhibiting tumor promotion.
Qi
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Institute of Nutrition and Food Hygiene, Chinese Academy of Preventive Medicine, Beijing, China.
Han
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C
D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D002273:Carcinogens; D005260:Female; D005419:Flavonoids; D051379:Mice; D010636:Phenols / Q000302:isolation & purification / Q000494:pharmacology*; D011108:Polymers / Q000302:isolation & purification / Q000494:pharmacology*; D059808:Polyphenols; D012878:Skin Neoplasms / Q000517:prevention & control; D013662:Tea / Q000737:chemistry*; D013755:Tetradecanoylphorbol Acetate / Q000037:antagonists & inhibitors
D016588:Anticarcinogenic Agents; D000975:Antioxidants; D002273:Carcinogens; D005419:Flavonoids; D010636:Phenols; D011108:Polymers; D059808:Polyphenols; D013662:Tea; D013755:Tetradecanoylphorbol Acetate