title: The small intestine can both absorb and glucuronidate luminal flavonoids.
abstract: We have studied the perfusion of the jejunum and ileum in an isolated rat intestine model with flavonoids and hydroxycinnamates and the influence of glycosylation on the subsequent metabolism. Flavone and flavonol glucosides and their corresponding aglycones are glucuronidated during transfer across the rat jejunum and ileum and this glucuronidation occurs without the need for gut microflora. Furthermore, this suggests the presence of glycosidases as well as UDP-glucuronyl transferase in the jejunum. In contrast, quercetin-3-glucoside and rutin are mainly absorbed unmetabolised. The results suggest that the more highly reducing phenolics are absorbed predominantly as glucuronides (96.5%+/-4.6) of the amount absorbed, whereas monophenolic hydroxycinnamates and monophenolic B-ring flavonoids are less predisposed to glucuronidation and higher levels of aglycone (88.1%+/-10.1) are detected on absorption through both the jejunum and ileum.
authors.affiliation: International Antioxidant Research Centre, Guy's King's and St. Thomas's School of Biomedical Sciences, London, UK.
authors.forename: J P
authors.initials: JP
authors.lastname: Spencer
authors.forename: G
authors.initials: G
authors.lastname: Chowrimootoo
authors.forename: R
authors.initials: R
authors.lastname: Choudhury
authors.forename: E S
authors.initials: ES
authors.lastname: Debnam
authors.forename: S K
authors.initials: SK
authors.lastname: Srai
authors.forename: C
authors.initials: C
authors.lastname: Rice-Evans
mesh_terms: D000818:Animals; D002109:Caffeic Acids / Q000378:metabolism; D002726:Chlorogenic Acid / Q000378:metabolism; D003373:Coumaric Acids / Q000378:metabolism; D005419:Flavonoids / Q000378:metabolism*; D005965:Glucuronates / Q000378:metabolism*; D006569:Hesperidin / Q000378:metabolism; D007082:Ileum / Q000378:metabolism*; D066298:In Vitro Techniques; D007408:Intestinal Absorption; D007583:Jejunum / Q000378:metabolism*; D044949:Kaempferols; D008297:Male; D010477:Perfusion; D011422:Propionates; D011794:Quercetin / Q000031:analogs & derivatives / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012431:Rutin / Q000378:metabolism
chemical_list: D002109:Caffeic Acids; D003373:Coumaric Acids; D005419:Flavonoids; D005965:Glucuronates; D044949:Kaempferols; D011422:Propionates; C016527:isoquercitrin; D002726:Chlorogenic Acid; D012431:Rutin; C006552:kaempferol; D011794:Quercetin; C004999:ferulic acid; D006569:Hesperidin; C495469:p-coumaric acid; C013015:hesperetin; C040048:caffeic acid