Many Human Pharmaceuticals Are Weak Inhibitors of the Cytochrome P450 System in Rainbow Trout () Liver S9 Fractions

Overview

Journal Front Toxicol

Date 2024 Jul 30

PMID 39077557

Authors

Tea Pihlaja

Timo Oksanen

Netta Vinkvist

Tiina Sikanen

Affiliations

Soon will be listed here.

Abstract

Introduction: Pharmaceutical residues are widely detected in aquatic environment and can be taken up by nontarget species such as fish. The cytochromes P450 (CYP) represent an important detoxification mechanism in fish, like in humans. In the present study, we assessed the correlation of the substrate selectivities of rainbow trout CYP1A and CYP3A homologues with those of human, through determination of the half-maximal inhibitory concentrations (IC) of a total sixteen human pharmaceuticals toward CYP1A-like ethoxyresorufin O-deethylase (EROD) and CYP3A-like 7-benzyloxy-4-trifluoromethylcoumarin O-debenzylase (BFCOD) in rainbow trout () liver S9 fractions (RT-S9).

Methods: The inhibitory impacts (IC) of atomoxetine, atorvastatin, azelastine, bimatoprost, clomethiazole, clozapine, desloratadine, disulfiram, esomeprazole, felbinac, flecainide, orphenadrine, prazosin, quetiapine, sulpiride, and zolmitriptan toward the EROD and BFCOD activities in RT-S9 were determined using the IC shift assay, capable of identifying time-dependent inhibitors (TDI). Additionally, the nonspecific binding of the test pharmaceuticals to RT-S9 was assessed using equilibrium dialysis.

Results: Most test pharmaceuticals were moderate to weak inhibitors of both EROD and BFCOD activity in RT-S9, even if most are noninhibitors of human CYP1A or CYP3A. Only bimatoprost, clomethiazole, felbinac, sulpiride, and zolmitriptan did not inhibit either activity in RT-S9. EROD inhibition was generally stronger than that of BFCOD and some substances (atomoxetine, flecainide, and prazosin) inhibited selectively only EROD activity. The strongest EROD inhibition was detected with azelastine and esomeprazole (unbound IC of 3.8 ± 0.5 µM and 3.0 ± 0.8 µM, respectively). None of the test substances were TDIs of BFCOD, but esomeprazole was a TDI of EROD. Apart from clomethiazole and disulfiram, the nonspecific binding of the test pharmaceuticals to the RT-S9 was extensive (unbound fractions <0.5) and correlated well ( = 0.7135) with their water-octanol distribution coefficients.

Discussion: The results indicate that the P450 interactions in RT-S9 cannot be explicitly predicted based on human data, but the data reported herein can shed light on the substrate selectivity of rainbow trout CYP1A1 and CYP3A27 in comparison to their human homologues. The IC concentrations are however many orders of magnitude higher than average environmental concentrations of pharmaceuticals. The time-dependent EROD inhibition by esomeprazole could warrant further research to evaluate its possible interlinkages with hepatotoxic impacts on fish.

References

Austin R, Barton P, Cockroft S, Wenlock M, Riley R . The influence of nonspecific microsomal binding on apparent intrinsic clearance, and its prediction from physicochemical properties. Drug Metab Dispos. 2002; 30(12):1497-503. DOI: 10.1124/dmd.30.12.1497. View

Zanger U, Turpeinen M, Klein K, Schwab M . Functional pharmacogenetics/genomics of human cytochromes P450 involved in drug biotransformation. Anal Bioanal Chem. 2008; 392(6):1093-108. DOI: 10.1007/s00216-008-2291-6. View

Laue H, Hostettler L, Badertscher R, Jenner K, Sanders G, Arnot J . Examining Uncertainty in In Vitro-In Vivo Extrapolation Applied in Fish Bioconcentration Models. Environ Sci Technol. 2020; 54(15):9483-9494. DOI: 10.1021/acs.est.0c01492. View

Muir D, Simmons D, Wang X, Peart T, Villella M, Miller J . Bioaccumulation of pharmaceuticals and personal care product chemicals in fish exposed to wastewater effluent in an urban wetland. Sci Rep. 2017; 7(1):16999. PMC: 5717258. DOI: 10.1038/s41598-017-15462-x. View

Berry L, Zhao Z . An examination of IC50 and IC50-shift experiments in assessing time-dependent inhibition of CYP3A4, CYP2D6 and CYP2C9 in human liver microsomes. Drug Metab Lett. 2009; 2(1):51-9. DOI: 10.2174/187231208783478407. View

Cerveny D, Grabic R, Grabicova K, Randak T, Larsson D, Johnson A . Neuroactive drugs and other pharmaceuticals found in blood plasma of wild European fish. Environ Int. 2020; 146:106188. DOI: 10.1016/j.envint.2020.106188. View

Hegelund T, Ottosson K, Radinger M, Tomberg P, Celander M . Effects of the antifungal imidazole ketoconazole on CYP1A and CYP3A in rainbow trout and killifish. Environ Toxicol Chem. 2004; 23(5):1326-34. DOI: 10.1897/03-155. View

Dragovic S, Gunness P, Ingelman-Sundberg M, Vermeulen N, Commandeur J . Characterization of human cytochrome P450s involved in the bioactivation of clozapine. Drug Metab Dispos. 2013; 41(3):651-8. DOI: 10.1124/dmd.112.050484. View

Oziolor E, Carey A, Matson C . A non-destructive BFCOD assay for in vivo measurement of cytochrome P450 3A (CYP3A) enzyme activity in fish embryos and larvae. Ecotoxicology. 2017; 26(6):809-819. DOI: 10.1007/s10646-017-1812-5. View

10.

Franco M, Schonenberger R, Hollender J, Schirmer K . Organ-specific biotransformation in salmonids: Insight into intrinsic enzyme activity and biotransformation of three micropollutants. Sci Total Environ. 2024; 925:171769. DOI: 10.1016/j.scitotenv.2024.171769. View

11.

Jobling S, Williams R, Johnson A, Taylor A, Gross-Sorokin M, Nolan M . Predicted exposures to steroid estrogens in U.K. rivers correlate with widespread sexual disruption in wild fish populations. Environ Health Perspect. 2006; 114 Suppl 1:32-9. PMC: 1874167. DOI: 10.1289/ehp.8050. View

12.

der Beek T, Weber F, Bergmann A, Hickmann S, Ebert I, Hein A . Pharmaceuticals in the environment--Global occurrences and perspectives. Environ Toxicol Chem. 2015; 35(4):823-35. DOI: 10.1002/etc.3339. View

13.

Li A . A review of the common properties of drugs with idiosyncratic hepatotoxicity and the "multiple determinant hypothesis" for the manifestation of idiosyncratic drug toxicity. Chem Biol Interact. 2002; 142(1-2):7-23. DOI: 10.1016/s0009-2797(02)00051-0. View

14.

Cohen L, van Leeuwen R, van Thiel G, Van Pelt J, Yap S . Equally potent inhibitors of cholesterol synthesis in human hepatocytes have distinguishable effects on different cytochrome P450 enzymes. Biopharm Drug Dispos. 2001; 21(9):353-64. DOI: 10.1002/bdd.249. View

15.

Wienkers L, Heath T . Predicting in vivo drug interactions from in vitro drug discovery data. Nat Rev Drug Discov. 2005; 4(10):825-33. DOI: 10.1038/nrd1851. View

16.

Grabicova K, Grabic R, Fedorova G, Fick J, Cerveny D, Kolarova J . Bioaccumulation of psychoactive pharmaceuticals in fish in an effluent dominated stream. Water Res. 2017; 124:654-662. DOI: 10.1016/j.watres.2017.08.018. View

17.

Eide M, Zhang X, Karlsen O, Goldstone J, Stegeman J, Jonassen I . The chemical defensome of five model teleost fish. Sci Rep. 2021; 11(1):10546. PMC: 8131381. DOI: 10.1038/s41598-021-89948-0. View

18.

Cannata C, Backhaus T, Bramke I, Caraman M, Lombardo A, Whomsley R . Prioritisation of data-poor pharmaceuticals for empirical testing and environmental risk assessment. Environ Int. 2023; 183:108379. DOI: 10.1016/j.envint.2023.108379. View

19.

Guengerich F . Cytochrome P450s and other enzymes in drug metabolism and toxicity. AAPS J. 2006; 8(1):E101-11. PMC: 2751428. DOI: 10.1208/aapsj080112. View

20.

Obach R, Walsky R, Venkatakrishnan K . Mechanism-based inactivation of human cytochrome p450 enzymes and the prediction of drug-drug interactions. Drug Metab Dispos. 2006; 35(2):246-55. DOI: 10.1124/dmd.106.012633. View