title: Breast cancer resistance protein (Bcrp1/Abcg2) limits net intestinal uptake of quercetin in rats by facilitating apical efflux of glucuronides.
abstract: The intestinal absorption of the flavonoid quercetin in rats is limited by the secretion of glucuronidated metabolites back into the gut lumen. The objective of this study was to determine the role of the intestinal efflux transporters breast cancer resistance protein (Bcrp1)/Abcg2 and multidrug resistance-associated protein 2 (Mrp2)/Abcc2. To study the possible involvement of Mrp2, we compared intestinal uptake of quercetin-3-glucoside between control and Mrp2-deficient rats, using an in situ intestinal perfusion system. The contribution of Bcrp1 was determined using the specific inhibitor fumitremorgin C (FTC) in Mrp2-deficient rats. Furthermore, vectorial transport of quercetin was studied in Madin-Darby canine kidney (MDCK)II cells transfected with either human MRP2 or murine Bcrp1. In these MDCKII cells, we showed an efficient efflux-directed transport of quercetin by mouse Bcrp1, whereas in control and MRP2-transfected cells no vectorial transport of quercetin was observed. In Mrp2-deficient rats, intestinal uptake of quercetin from quercetin-3-glucoside, efflux of quercetin glucuronides to the gut lumen, and plasma concentration of quercetin were similar to that in control rats. When intestinal Bcrp1 was inhibited by FTC in Mrp2-deficient rats, total plasma concentrations of quercetin and its methylated metabolite isorhamnetin after 30 min of perfusion were more than twice that of controls (12.3 +/- 1.5 versus 5.6 +/- 1.3 muM; p < 0.01), whereas uptake of free quercetin from the intestinal lumen was not affected. Instead, inhibition of Bcrp1 lowered the efflux of quercetin glucuronides into the perfusion fluid by approximately 4-fold. In conclusion, Bcrp1 limits net intestinal absorption of quercetin by pumping quercetin glucuronides back into the lumen.
authors.affiliation: Department of Pharmacology and Toxicology 233, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, P.O Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: Aloys L A
authors.initials: AL
authors.lastname: Sesink
authors.forename: Ilja C W
authors.initials: IC
authors.lastname: Arts
authors.forename: Vincent C J
authors.initials: VC
authors.lastname: de Boer
authors.forename: Pauline
authors.initials: P
authors.lastname: Breedveld
authors.forename: Jan H M
authors.initials: JH
authors.lastname: Schellens
authors.forename: Peter C H
authors.initials: PC
authors.lastname: Hollman
authors.forename: Frans G M
authors.initials: FG
authors.lastname: Russel
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D000818:Animals; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D020719:Glucuronides / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000187:drug effects; D008297:Male; D024101:Mitochondrial Proteins / Q000172:deficiency / Q000235:genetics; D000089762:Multidrug Resistance-Associated Protein 2; D011794:Quercetin / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D011922:Rats, Mutant Strains; D017208:Rats, Wistar; D012269:Ribosomal Proteins / Q000172:deficiency / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics
chemical_list: C000715087:ABCC2 protein, human; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; C489249:Abcg2 protein, rat; D020719:Glucuronides; C093947:MRP2 protein, S cerevisiae; D024101:Mitochondrial Proteins; D000089762:Multidrug Resistance-Associated Protein 2; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; D011794:Quercetin