title: Induction of monooxygenase and transferase activities in rat by dietary administration of flavonoids.
abstract: 1. The influence of the dietary flavonoids, chrysin, quercetin, tangeretin, flavone and flavanone, on the components of the rat liver drug-metabolizing enzyme system was examined and compared with two well-known synthetic flavonoids 7,8-benzoflavone and 5,6-benzoflavone. 2. Polyhydroxylated molecules such as quercetin and chrysin, produced no significant changes on phase I and phase II enzyme activities. 3. Flavone was the most potent inducer, and resulted in a mixed type of induction. 7-Ethoxycoumarin O-deethylase (ECOD), 7-ethoxyresorufin O-deethylase (EROD) and pentoxyresorufin depentylase (PROD) activities were increased 2, 30 and 15-fold respectively. p-Nitrophenol UDP-glucuronyltransferase (UDPGT 1), p-hydroxybiphenyl UDP-glucuronyltransferase (UDPGT 2) and glutathione transferase (GST) activities were also induced. 4. Flavanone, which differs from flavone only by the degree of unsaturation of the pyrone ring, produced only a weak increase in monooxygenase activity, but the increase in phase II enzyme activities was as great as that for flavone treatment. 5. Tangeretin displayed a mixed pattern of induction, with increases in ECOD, EROD and PROD, and UDPGT 1 and UDPGT 2 activities, but these were less than with flavone treatment. 6. 7,8-Benzoflavone and 5,6-benzoflavone showed induction patterns similar to those of 3-methylcholanthrene. Nevertheless dietary treatment with 5,6-benzoflavone caused changes which were not as great as those usually described when this compound is administered i.p.
authors.affiliation: Station de Recherches sur la Qualité des Aliments de l'Homme, INRA, Dijon, France.
authors.forename: M H
authors.initials: MH
authors.lastname: Siess
authors.forename: M
authors.initials: M
authors.lastname: Guillermic
authors.forename: A M
authors.initials: AM
authors.lastname: Le Bon
authors.forename: M
authors.initials: M
authors.lastname: Suschetet
mesh_terms: D000818:Animals; D019363:Cytochrome P-450 CYP1A1; D019362:Cytochrome P-450 CYP2B1; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis; D003600:Cytosol / Q000187:drug effects / Q000201:enzymology; D004032:Diet; D004790:Enzyme Induction / Q000187:drug effects; D005419:Flavonoids / Q000494:pharmacology*; D014453:Glucuronosyltransferase / Q000096:biosynthesis; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology; D006899:Mixed Function Oxygenases / Q000096:biosynthesis*; D009929:Organ Size / Q000187:drug effects; D010088:Oxidoreductases / Q000096:biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D014166:Transferases / Q000096:biosynthesis*
chemical_list: D005419:Flavonoids; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases; D019363:Cytochrome P-450 CYP1A1; D019362:Cytochrome P-450 CYP2B1; D014166:Transferases; D014453:Glucuronosyltransferase