title: Induction of metabolism and transport in human intestine: validation of precision-cut slices as a tool to study induction of drug metabolism in human intestine in vitro.
abstract: Induction of drug enzyme activity in the intestine can strongly determine plasma levels of drugs. It is therefore important to predict drug-drug interactions in human intestine in vitro. We evaluated the applicability of human intestinal precision-cut slices for induction studies in vitro. Morphological examination and intracellular ATP levels indicated tissue integrity up to 24 h of incubation, whereas in proximal jejunum slices, the metabolic rate toward most substrates remained at 40 to 50% of initial values. In colon slices, the cytochrome P450 conversions were below the detection limit, but conjugation rates remained relatively constant during incubation. The inducibility of drug-metabolizing enzymes and P-glycoprotein was evaluated using prototypical inducers for five induction pathways. beta-Naphthoflavone (aryl hydrocarbon receptor ligand) induced CYP1A1 (132-fold in colon and 362-fold in proximal jejunum) and UDP glucuronosyltransferase (UGT) 1A6 mRNA (9.8-fold in colon and 3.2-fold in proximal jejunum). In proximal jejunum, rifampicin (RIF) [pregnane X receptor (PXR) ligand] induced CYP3A4 (5.2-fold), CYP2B6 (2-fold), UGT1A6 (2.2-fold), and multidrug resistance-1 (MDR1)/ABCB1 mRNA (2.7-fold), whereas 6beta-hydroxytestosterone formation (CYP3A4) increased 2-fold. In colon, RIF induced UGT1A6 32-fold and MDR1 2.2-fold. Dexamethasone (glucocorticoid receptor and PXR ligand) induced CYP3A4 mRNA (3.5-fold) and activity (5-fold) in proximal jejunum. Phenobarbital (constitutive androstane receptor activator) induced CYP3A4 (4.1-fold, only in jejunum), CYP2B6 (4.9-fold in colon and 2.3-fold in proximal jejunum), and MDR1/ABCB1 mRNA and CYP3A4 activity (2-fold only proximal jejunum). Quercetin (nuclear factor-E2-related factor 2 activator) induced UGT1A6 mRNA (6.7-fold in colon and 2.2-fold in proximal jejunum). In conclusion, this study shows that human intestinal precision-cut slices are useful to study induction of drug-metabolizing enzymes and transporters in the human intestine.
authors: Department of Pharmacokinetics & Drug Delivery, Groningen Research Institute for Pharmacy, University of Groningen, Groningen, The Netherlands.
authors: Esther G
authors: EG
authors: van de Kerkhof
authors: Inge A M
authors: IA
authors: de Graaf
authors: Anna-Lena B
authors: AL
authors: Ungell
authors: Geny M M
authors: GM
authors: Groothuis
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D003106:Colon / Q000201:enzymology / Q000378:metabolism*; D019363:Cytochrome P-450 CYP1A1 / Q000096:biosynthesis / Q000235:genetics; D051544:Cytochrome P-450 CYP3A / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D066298:In Vitro Techniques; D007583:Jejunum / Q000201:enzymology / Q000378:metabolism*; D008867:Microtomy / Q000379:methods; D004364:Pharmaceutical Preparations / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D015203:Reproducibility of Results
chemical_list: D004364:Pharmaceutical Preparations; D012333:RNA, Messenger; D000255:Adenosine Triphosphate; D019363:Cytochrome P-450 CYP1A1; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human