title: Development of an online-SPE-LC-MS method for the investigation of the intestinal absorption of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PHIP) and its bacterial metabolite PHIP-M1 in a Caco-2 Transwell system.
abstract: Heterocyclic aromatic amines such as PHIP are formed during the heat processing of food. PHIP undergoes bacterial metabolism leading to 7-hydroxy-5-methyl-3-phenyl-6,7,8,9-tetrahydropyrido[3',2':4,5]imidazo[1,2-a]pyrimidin-5-ium chloride (PHIP-M1) as main metabolite. We developed an LC-MS method with automated sample preparation by online-solid-phase-extraction for the simultaneous quantification of PHIP and its mammalian and bacterial metabolites N-hydroxy-PHIP, 4-OH-PHIP and PHIP-M1 in biological samples. The method was used to investigate the transport of PHIP-M1 through a Caco-2 cell monolayer. The experiments show that PHIP-M1 rapidly crosses the cell monolayer and that PHIP-M1 is a substrate for P-glycoprotein and the multiple drug resistance 2 transporter. The intestinal absorption of PHIP-M1 is comparable with that of PHIP and a moderate to high bioavailability has to be expected. Thus, not only the human metabolites of PHIP but also the bacterial metabolite PHIP-M1 formed in the gut could contribute to the toxic effects of PhIP.
authors: University of Veterinary Medicine Hannover, Institute for Food Toxicology and Analytical Chemistry, Bischofsholer Damm 15, 30173 Hannover, Germany.
authors: Ina
authors: I
authors: Willenberg
authors: University of Veterinary Medicine Hannover, Institute for Food Toxicology and Analytical Chemistry, Bischofsholer Damm 15, 30173 Hannover, Germany.
authors: Leonie
authors: L
authors: von Elsner
authors: University of Veterinary Medicine Hannover, Institute for Food Toxicology and Analytical Chemistry, Bischofsholer Damm 15, 30173 Hannover, Germany.
authors: Pablo
authors: P
authors: Steinberg
authors: University of Veterinary Medicine Hannover, Institute for Food Toxicology and Analytical Chemistry, Bischofsholer Damm 15, 30173 Hannover, Germany. Electronic address: schebb@wwu.de.
authors: Nils Helge
authors: NH
authors: Schebb
mesh_terms: D018938:Caco-2 Cells; D002273:Carcinogens / Q000032:analysis; D002853:Chromatography, Liquid; D006801:Humans; D007093:Imidazoles / Q000032:analysis*; D007408:Intestinal Absorption / Q000187:drug effects*; D011725:Pyridines / Q000032:analysis*; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry; D018675:Toxicity Tests
chemical_list: D002273:Carcinogens; D007093:Imidazoles; D011725:Pyridines; C060533:2-hydroxyamino-1-methyl-6-phenylimidazo(4,5-b)pyridine; C077584:2-amino-1-methyl-6-(4-hydroxyphenyl)imidazo(4,5-b)pyridine; C049584:2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine
keywords: Automated sample preparation; Caco-2 Transwell system; Intestinal absorption; PHIP; PHIP-M1