title: Comparison of the effects of various flavonoids on ethoxycoumarin deethylase activity of rat intestinal and hepatic microsomes.
abstract: Fifteen flavonoids were examined for their effects on the activity of 7-ethoxycoumarin O-deethylase in rat hepatic and intestinal microsomes. The effect depended on both the chemical structure of the flavonoid and the origin of the microsomes. Polyhydroxylated flavonoids with a C2-C3 double bond (flavones and flavonols) were more effective inhibitors of the enzyme in both hepatic and intestinal microsomes than were the reduced homologues (flavanonols, flavanones and flavan-3-ols). In contrast, flavones lacking hydroxyl substituents (e.g. 5,6-benzoflavone, 7,8-benzoflavone and flavone) increased ethoxycoumarin deethylase activity in liver microsomes although they had an inhibitory effect in intestinal microsomes.
mesh_terms: D015660:7-Alkoxycoumarin O-Dealkylase; D000818:Animals; D004789:Enzyme Activation / Q000187:drug effects; D005419:Flavonoids / Q000494:pharmacology*; D007422:Intestines / Q000201:enzymology*; D007700:Kinetics; D008297:Male; D008861:Microsomes / Q000201:enzymology; D008862:Microsomes, Liver / Q000201:enzymology*; D010105:Oxygenases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013329:Structure-Activity Relationship
chemical_list: D005419:Flavonoids; D010105:Oxygenases; D015660:7-Alkoxycoumarin O-Dealkylase