title: Dietary flavonoids as cancer-preventive and therapeutic biofactors.
abstract: Flavonoids are present in many plants, and hence, in foods and ingredients derived from them. These polyphenolic compounds have attracted renewed attention as potential anticarcinogens, and the molecular mechanisms of their anticarcinogenic effects and their bioavailability have been extensively explored. In this review, we focus on the major dietary flavonoids; flavones, flavonols, and flavan-3-ols (catechins), and evaluate their roles in cancer prevention. After absorption with or without metabolic conjugation, flavonoids are transported to target organs where they exert their anticarcinogenic activity. The molecular mechanisms of the anticarcinogenic effects of flavonoids include their antagonistic effect on the aryl hydrocarbon receptor (AhR), and regulation of phase I and II drug metabolizing enzymes and phase III transporters. Experimental evidence suggests that flavonoids modulate signal transduction pathways at each stage of carcinogenesis. The interactions between flavonoids and biomolecules in vivo must be investigated in detail to identify specific targets. In addition, the potential side effects should be considered when flavonoid supplements are used for cancer prevention. Therefore, the use of flavonoids as chemopreventive agents should be further investigated to establish safe levels of flavonoid intake.
authors.affiliation: Department of Internal Medicine, Graduate School of Medicine, Kobe University, Kobe, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Nishiumi
authors.forename: Shingo
authors.initials: S
authors.lastname: Miyamoto
authors.forename: Kyuichi
authors.initials: K
authors.lastname: Kawabata
authors.forename: Kohta
authors.initials: K
authors.lastname: Ohnishi
authors.forename: Rie
authors.initials: R
authors.lastname: Mukai
authors.forename: Akira
authors.initials: A
authors.lastname: Murakami
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ashida
authors.forename: Junji
authors.initials: J
authors.lastname: Terao
mesh_terms: D000042:Absorption; D000818:Animals; D019587:Dietary Supplements; D004789:Enzyme Activation / Q000502:physiology; D005419:Flavonoids / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism* / Q000627:therapeutic use*; D006801:Humans; D051379:Mice; D015394:Molecular Structure; D009369:Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D005419:Flavonoids; D018336:Receptors, Aryl Hydrocarbon