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

• Published in: Drug metabolism and disposition Vol. 36; no. 3; pp. 604 - 613
• Main Authors: VAN DE KERKHOF, Esther G, DE GRAAF, Inge A. M, UNGELL, Anna-Lena B, GROOTHUIS, Geny M. M
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Pharmacology and Experimental Therapeutics 01.03.2008
• Subjects: Adenosine Triphosphate - metabolism; Biological and medical sciences; Colon - enzymology; Colon - metabolism; Cytochrome P-450 CYP1A1 - biosynthesis; Cytochrome P-450 CYP1A1 - genetics; Cytochrome P-450 CYP3A - biosynthesis; Cytochrome P-450 CYP3A - genetics; Humans; In Vitro Techniques; Jejunum - enzymology; Jejunum - metabolism; Medical sciences; Microtomy - methods; Pharmaceutical Preparations - metabolism; Pharmacology. Drug treatments; Reproducibility of Results; RNA, Messenger - biosynthesis; RNA, Messenger - genetics; Human; Drug; Validation; Digestive system; Induction; Biological transport; Gut; Pharmacokinetics; Metabolism; In vitro
• ISSN: 0090-9556; 1521-009X
• DOI: 10.1124/dmd.107.018820

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. β-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 6β-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.