The roles of polyphenols in cancer chemoprevention.
Oxidative stress imposed by reactive oxygen species (ROS) plays a crucial role in the pathophysiology associated with neoplasia, atherosclerosis, and neurodegenerative diseases. The ROS-induced development of cancer involves malignant transformation due to altered gene expression through epigenetic mechanisms as well as DNA mutations. Considerable attention has been focused on identifying naturally occurring antioxidative phenolic phytochemicals that are able to decrease ROS levels, but the efficacies of antioxidant therapies have been equivocal at best. Several studies have shown that some antioxidants exhibit prooxidant activity under certain conditions and potential carcinogenicity under others, and that dietary supplementation with large amounts of a single antioxidant may be deleterious to human health. This article reviews the intracellular signaling pathways that respond to oxidative stress and how they are modulated by naturally occurring polyphenols. The possible toxicity and carcinogenicity of polyphenols is also discussed.
Lee
Ki Won
KW
Department of Food Science and Technology, School of Agricultural Biotechnology, Seoul National University, Seoul 151-742, Republic of Korea.
Lee
Hyong Joo
HJ
D000818:Animals; D016588:Anticarcinogenic Agents / Q000627:therapeutic use*; D000975:Antioxidants / Q000502:physiology*; D002273:Carcinogens / Q000494:pharmacology; D002392:Catechin / Q000031:analogs & derivatives / Q000494:pharmacology; D002450:Cell Communication / Q000187:drug effects; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004032:Diet; D005419:Flavonoids / Q000502:physiology*; D017629:Gap Junctions / Q000187:drug effects; D019833:Genistein / Q000494:pharmacology; D006801:Humans; D020782:Matrix Metalloproteinases / Q000096:biosynthesis; D009369:Neoplasms / Q000209:etiology / Q000517:prevention & control*; D018384:Oxidative Stress / Q000187:drug effects; D010636:Phenols; D059808:Polyphenols; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011794:Quercetin / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors; D000077185:Resveratrol; D015398:Signal Transduction / Q000187:drug effects; D013267:Stilbenes / Q000494:pharmacology
D016588:Anticarcinogenic Agents; D000975:Antioxidants; D002273:Carcinogens; D016861:Cyclooxygenase Inhibitors; D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D017382:Reactive Oxygen Species; D013267:Stilbenes; D002392:Catechin; D011794:Quercetin; C045651:epigallocatechin gallate; D019833:Genistein; D011451:Prostaglandin-Endoperoxide Synthases; D020782:Matrix Metalloproteinases; D000077185:Resveratrol