The Consequence of Drug-Drug Interactions Influencing the Interplay between P-Glycoprotein and Cytochrome P450 3a: An Ex Vivo Study with Rat Precision-Cut Intestinal Slices

Abstract

P-glycoprotein (P-gp) and cytochrome P450 3A (CYP3A) are differentially expressed along the intestine and work coordinately to reduce the intracellular concentration of xenobiotics and the absorption of orally taken drugs. Drug-drug interactions (DDIs) based on P-gp/CYP3A interplay are of clinical importance and require preclinical investigation. We investigated the P-gp/Cyp3a interplay and related DDIs with different P-gp inhibitors in the various regions of the rat intestine ex vivo using precision-cut intestinal slices (PCIS) with quinidine (Qi), a dual substrate of P-gp and Cyp3a, as the probe. The results showed that P-gp efflux was the main factor limiting the intracellular Qi content at concentrations below 5 mM, whereas both efflux and metabolism were saturated at [Qi] > 50 mM. The selective P-gp inhibitors CP100356 [N-(3,4-dimethoxyphenethyl)-4-(6,7-dimethoxy-3,4-dihydroisoquinolin-2[1H]-yl)-6,7-dimethoxyquinazolin-2-amine] and PSC833 [valspodar, 6-[(2S,4R,6E)-4-methyl-2-(methylamino)-3-oxo-6-octenoic acid]-7-Lvaline-cyclosporin A] enhanced the Qi accumulation in slices in line with the different P-gp expression in the intestinal regions and, as a result, also enhanced metabolism in the jejunum and ileum. Dual inhibitors of both P-gp and Cyp3a (verapamil and ketoconazole) increased the concentration of Qi in the jejunum and ileum, but less 3-hydroxy-quinidine was produced due to inhibition of Cyp3a. The results indicate that the P-gp/Cyp3a interplay depends on the concentration of the drug and on the intestinal region under study. Furthermore, due to the P-gp/Cyp3a interplay, DDIs can lead to remarkable changes in the intracellular concentration of both the parent drug and the metabolite, which varies among the intestinal regions and depends on the selectivity of the inhibitors, with potentially important implications for disposition and toxicity of drugs and their metabolites.

CP100356 Hydrochloride, a P-Glycoprotein Inhibitor, Inhibits Lassa Virus Entry: Implication of a Candidate Pan-Mammarenavirus Entry Inhibitor

“…CP100356 specifically binds to the drug-binding site at the transmembrane region of P-gp and inhibits the efflux of various substrates [ 33 , 34 ]. Because P-gp overexpressing cells with increased efflux pump function also show resistance to several enveloped virus infections [ 35 ], inhibition of the efflux pump is unlikely responsible for the antiviral activity.…”

Effects of Digested Onion Extracts on Intestinal Gene Expression: An Interspecies Comparison Using Different Intestine Models

“…The procedure for preparing rat precision cut slices has been extensively described by [ 15 ] and [ 16 ]. Approximately 8 weeks old male Sprague-Dawley rats were sacrificed and the small intestine was taken out as quickly as possible and directly put in ice cold Krebs-Henseleit buffer (KHB) previously flushed with carbogen gas (5% CO2 and 95% oxygen).…”

Approaches to minimize the effects of P‐glycoprotein in drug transport: A review

“…On the contrary, co‐administration of Rifampicin (potent inducer of CYP3A4 and P‐gp) with Cyclosporin A, reduced the bioavailability of Cyclosporin A (Inglese et al, 2011; Ward et al, 2004). The intracellular concentration of Quinidine increased in different regions of the human intestine (2.1 and 2.6 folds in the jejunum, 2.6 and 3.8 folds in the ileum) when co‐administered with Verapamil and Ketoconazole (dual inhibitors of P‐gp and CYP3A4) (Li et al, 2017; Li et al, 2016). Dipeptidyl peptidase 4 (DPP4) inhibitors (Gemigliptin, Sitagliptin, Saxagliptin, Teneligliptin, and Linagliptin) is identified as substrates for both P‐gp as well as CYP3A4.…”