title: Differential biliary excretion of genistein metabolites following intraduodenal and intravenous infusion of genistin in female rats.
abstract: The purpose of this study was to determine whether bioflavonoid glucoside O-conjugates are absorbed from the intestine in the intact form or as their aglycones following hydrolysis by intestinal beta-glucosidases. In this study, the intestinal absorption of genistin, the beta-glucoside of the isoflavone genistein, was examined in anesthetized, adult female rats fitted with indwelling biliary cannulas. To first establish whether genistein, once absorbed, was converted into unique metabolites, genistin was infused into the femoral or portal veins and bile samples quantitatively collected. Analysis of bile samples by HPLC-mass spectrometry revealed that almost full recovery of the genistein component occurred in the form of unreacted genistin ( approximately 20%) and genistein 7beta-O-glucuronide ( approximately 80%). However, when genistin was infused into the upper small intestine, only genistein 7beta-O-glucuronide and the aglycone genistein appeared in the bile. There was no evidence for any biliary secretion of the unreacted genistin, thereby excluding its uptake in the intact form from the small intestine in this animal model.
authors.affiliation: Department of Pharmacology and Toxicology, University of Alabama at Birmingham Botanicals Center for Age-Related Disease, Birmingham, AL 35294, USA. jeevan.prasain@ccc.uab.edu
authors.forename: Jeevan K
authors.initials: JK
authors.lastname: Prasain
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.forename: Marion
authors.initials: M
authors.lastname: Kirk
authors.forename: Michelle
authors.initials: M
authors.lastname: Smith Johnson
authors.forename: Jeff
authors.initials: J
authors.lastname: Sfakianos
authors.forename: Stephen
authors.initials: S
authors.lastname: Barnes
mesh_terms: D000818:Animals; D001646:Bile / Q000737:chemistry / Q000502:physiology*; D001774:Blood Chemical Analysis; D004386:Duodenum / Q000502:physiology*; D005260:Female; D005268:Femoral Vein; D005704:Gallbladder / Q000378:metabolism*; D019833:Genistein / Q000008:administration & dosage / Q000302:isolation & purification / Q000493:pharmacokinetics*; D005966:Glucuronidase / Q000378:metabolism; D007262:Infusions, Intravenous; D007408:Intestinal Absorption; D007529:Isoflavones / Q000032:analysis; D011169:Portal Vein; D051381:Rats; D017207:Rats, Sprague-Dawley; D013429:Sulfatases / Q000378:metabolism
chemical_list: D007529:Isoflavones; D019833:Genistein; D013429:Sulfatases; D005966:Glucuronidase