Effects of in vivo benzene treatment on cytochrome P450 and mixed-function oxidase activities of gilthead seabream (sparus aurata) liver microsomes

Cytochrome P450 enzymes (CYP) are a group of monooxygenases able to biotransform several kinds of xenobiotics including aflatoxin B1 (AFB1), a highly toxic mycotoxin. These enzymes have been widely studied in humans and others mammals, but there is not enough information in commercial poultry species about their biochemical characteristics or substrate specificity. The aim of the present study was to identify CYPs from avian liver microsomes with the use of prototype substrates specific for human CYP enzymes and AFB1. Biochemical characterization was carried out in vitro and biotransformation products were detected by high-performance liquid chromatography (HPLC). Enzymatic constants were calculated and comparisons between turkey, duck, quail and chicken activities were done. The results demonstrate the presence of four avian ortholog enzyme activities possibly related with a CYP1A1, CYP1A2, CYP2A6 (activity not previously identified) and CYP3A4 poultry orthologs, respectively. Large differences in enzyme kinetics specific for prototype substrates were found among the poultry species studied. Turkey liver microsomes had the highest affinity and catalytic rate for AFB1 whereas chicken enzymes had the lowest affinity and catalytic rate for the same substrate. Quail and duck microsomes showed intermediate values. These results correlate well with the known in vivo sensitivity for AFB1 except for the duck. A high correlation coefficient between 7-ethoxyresorufin-Odeethylase (EROD) and 7-methoxyresorufin- O-deethylase (MROD) activities was found in the four poultry species, suggesting that these two enzymatic activities might be carried out by the same enzyme. The results of the present study indicate that four prototype enzyme activities are present in poultry liver microsomes, possibly related with the presence of three CYP avian orthologs. More studies are needed in order to further characterize these enzymes.

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Probiotic properties and fatty acid composition of the yeast Kluyveromyces lactis M3. In vivo immunomodulatory activities in gilthead seabream (Sparus aurata)

Fish & Shellfish Immunology ◽

10.1016/j.fsi.2019.09.024 ◽

2019 ◽

Vol 94 ◽

pp. 389-397 ◽

Cited By ~ 2

Author(s):

Crystal Guluarte ◽

Martha Reyes-Becerril ◽

Daniel Gonzalez-Silvera ◽

Alberto Cuesta ◽

Carlos Angulo ◽

...

Keyword(s):

Fatty Acid Composition ◽

Fatty Acid ◽

Acid Composition ◽

Sparus Aurata ◽

Kluyveromyces Lactis ◽

Gilthead Seabream ◽

Probiotic Properties

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Effect of a New Prokinetic Agent DA-9701 Formulated with Corydalis Tuber and Pharbitidis Semen on Cytochrome P450 and UDP-Glucuronosyltransferase Enzyme Activities in Human Liver Microsomes

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2012/650718 ◽

2012 ◽

Vol 2012 ◽

pp. 1-7 ◽

Cited By ~ 6

Author(s):

Hye Young Ji ◽

Kwang Hyeon Liu ◽

Ji Hyeon Jeong ◽

Dae-Young Lee ◽

Hyun Joo Shim ◽

...

Keyword(s):

Cytochrome P450 ◽

Human Liver ◽

Liver Microsomes ◽

Human Liver Microsomes ◽

Udp Glucuronosyltransferase ◽

Index Value ◽

Tuber Extract ◽

Corydalis Tuber

DA-9701 is a new botanical drug composed of the extracts of Corydalis tuber and Pharbitidis semen, and it is used as an oral therapy for the treatment of functional dyspepsia in Korea. The inhibitory potentials of DA-9701 and its component herbs, Corydalis tuber and Pharbitidis semen, on the activities of seven major human cytochrome P450 (CYP) enzymes and four UDP-glucuronosyltransferase (UGT) enzymes in human liver microsomes were investigated using liquid chromatography-tandem mass spectrometry. DA-9701 and Corydalis tuber extract slightly inhibited UGT1A1-mediated etoposide glucuronidation, with 50% inhibitory concentration (IC50) values of 188 and 290 μg/mL, respectively. DA-9701 inhibited CYP2D6-catalyzed bufuralol1′-hydroxylation with an inhibition constant (Ki) value of 6.3 μg/mL in a noncompetitive manner. Corydalis tuber extract competitively inhibited CYP2D6-mediated bufuralol1′-hydroxylation, with aKivalue of 3.7 μg/mL, whereas Pharbitidis semen extract showed no inhibition. The volume in which the dose could be diluted to generate an IC50equivalent concentration (volume per dose index) value of DA-9701 for inhibition of CYP2D6 activity was 1.16 L/dose, indicating that DA-9701 may not be a potent CYP2D6 inhibitor. Further clinical studies are warranted to evaluate thein vivoextent of the observedin vitrointeractions.

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Assessment of inhibitory effects on major human cytochrome P450 enzymes by spasmolytics used in the treatment of overactive bladder syndrome

Therapeutic Advances in Urology ◽

10.1177/1756287217708951 ◽

2017 ◽

Vol 9 (7) ◽

pp. 163-177

Author(s):

Dominik Dahlinger ◽

Sevinc Aslan ◽

Markus Pietsch ◽

Sebastian Frechen ◽

Uwe Fuhr

Keyword(s):

Cytochrome P450 ◽

Liver Microsomes ◽

Fold Increase ◽

Pharmacokinetic Data ◽

Cytochrome P450 Enzymes ◽

Trospium Chloride ◽

Screening Experiments ◽

Human Cytochrome

Background: The objective of this study was to examine the inhibitory potential of darifenacin, fesoterodine, oxybutynin, propiverine, solifenacin, tolterodine and trospium chloride on the seven major human cytochrome P450 enzymes (CYP) by using a standardized and validated seven-in-one cytochrome P450 cocktail inhibition assay. Methods: An in vitro cocktail of seven highly selective probe substrates was incubated with human liver microsomes and varying concentrations of the seven test compounds. The major metabolites of the probe substrates were simultaneously analysed using a validated liquid chromatography tandem mass spectrometry (LC-MS/MS) method. Enzyme kinetics were estimated by determining IC50 and Ki values via nonlinear regression. Obtained Ki values were used for predictions of potential clinical impact of the inhibition using a static mechanistic prediction model. Results: In this study, 49 IC50 experiments were conducted. In six cases, IC50 values lower than the calculated threshold for drug–drug interactions (DDIs) in the gut wall were observed. In these cases, no increase in inhibition was determined after a 30 min preincubation. Considering a typical dosing regimen and applying the obtained Ki values of 0.72 µM (darifenacin, 15 mg daily) and 7.2 µM [propiverine, 30 mg daily, immediate release (IR)] for the inhibition of CYP2D6 yielded a predicted 1.9-fold and 1.4-fold increase in the area under the curve (AUC) of debrisoquine (CYP2D6 substrate), respectively. Due to the inhibition of the particular intestinal CYP3A4, the obtained Ki values of 14 µM of propiverine (30 mg daily, IR) resulted in a predicted doubling of the AUC for midazolam (CYP3A4 substrate). Conclusions: In vitro/ in vivo extrapolation based on pharmacokinetic data and the conducted screening experiments yielded similar effects of darifenacin on CYP2D6 and propiverine on CYP3A4 as obtained in separately conducted in vivo DDI studies. As a novel finding, propiverine was identified to potentially inhibit CYP2D6 at clinically occurring concentrations.

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Comprehensive In Vitro Analysis of Voriconazole Inhibition of Eight Cytochrome P450 (CYP) Enzymes: Major Effect on CYPs 2B6, 2C9, 2C19, and 3A

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01123-08 ◽

2008 ◽

Vol 53 (2) ◽

pp. 541-551 ◽

Cited By ~ 81

Author(s):

Seongwook Jeong ◽

Phuong D. Nguyen ◽

Zeruesenay Desta

Keyword(s):

Cytochrome P450 ◽

Liver Microsomes ◽

Competitive Inhibitor ◽

Major Effect ◽

Cyp Enzymes ◽

Human Cytochrome ◽

Vitro Analysis ◽

In Vitro Analysis

ABSTRACT Voriconazole is an effective antifungal drug, but adverse drug-drug interactions associated with its use are of major clinical concern. To identify the mechanisms of these interactions, we tested the inhibitory potency of voriconazole with eight human cytochrome P450 (CYP) enzymes. Isoform-specific probes were incubated with human liver microsomes (HLMs) (or expressed CYPs) and cofactors in the absence and the presence of voriconazole. Preincubation experiments were performed to test mechanism-based inactivation. In pilot experiments, voriconazole showed inhibition of CYP2B6, CYP2C9, CYP2C19, and CYP3A (half-maximal [50%] inhibitory concentrations, <6 μM); its effect on CYP1A2, CYP2A6, CYP2C8, and CYP2D6 was marginal (<25% inhibition at 100 μM voriconazole). Further detailed experiments with HLMs showed that voriconazole is a potent competitive inhibitor of CYP2B6 (Ki < 0.5), CYP2C9 (Ki = 2.79 μM), and CYP2C19 (Ki = 5.1 μM). The inhibition of CYP3A by voriconazole was explained by noncompetitive (Ki = 2.97 μM) and competitive (Ki = 0.66 μM) modes of inhibition. Prediction of the in vivo interaction of voriconazole from these in vitro data suggests that voriconazole would substantially increase the exposure of drugs metabolized by CYP2B6, CYP2C9, CYP2C19, and CYP3A. Clinicians should be aware of these interactions and monitor patients for adverse effects or failure of therapy.

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The interaction of temelastine with cytochrome P450 mixed-function oxidase enzymes in vivo and in vitro

Biochemical Pharmacology ◽

10.1016/0006-2952(89)90172-x ◽

1989 ◽

Vol 38 (1) ◽

pp. 209-213

Author(s):

R.J. Chenery ◽

P.J. Cox ◽

L.C. Rath ◽

P. Standring ◽

H.G. Oldham

Keyword(s):

Cytochrome P450 ◽

Mixed Function Oxidase

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Inhibitory effects of H2-receptor antagonists on cytochrome P450 in male ICR mice

Human & Experimental Toxicology ◽

10.1177/096032719501400801 ◽

1995 ◽

Vol 14 (8) ◽

pp. 623-629 ◽

Cited By ~ 2

Author(s):

DH Kim ◽

EJ Kim ◽

SS Han ◽

JK Roh ◽

TC Jeong ◽

...

Keyword(s):

Cytochrome P450 ◽

Liver Microsomes ◽

Receptor Antagonists ◽

Sleeping Time ◽

Icr Mice ◽

In Vitro Effects ◽

Hexobarbital Metabolism ◽

Dose Dependent

1 The present study was undertaken to examine the effects of H2-receptor antagonists including newly developed mifentidine derivatives, IY-80843 and IY-80845, on cytochrome P450(P450) in vitro and in vivo. 2 Initially, 3-methylcholanthrene-, phenobarbital-, ethanol- and dexamethasone-induced liver microsomes were prepared from male ICR mice to study in vitro effects of above chemicals on ethoxyresorufin O- deethylase(EROD), pentoxyresorufin O-dealkylase(PROD), p-nitrophenol hydroxylase and erythromycin N-demethy lase(ERDM) activities, respectively. It was found that hist amine, cimetidine and famotidine were not inhibitory to four enzyme activities. Meanwhile, mifentidine slightly inhibited EROD and PROD activities and its derivatives IY-80843 and IY-80845 strongly inhibited PROD, EROD and ERDM activities. 3 Prolongation of hexobarbital-induced sleeping time was determined in male ICR mice to confirm in vitro inhibito ry effects of mifentidine and its derivatives in vivo. It was observed that cimetidine, mifentidine, IY-80843 and IY- 80845 caused dose-dependent increases in the sleeping time, indicating the inhibition of P450 responsible for hexobarbital metabolism. 4 It was concluded that mifentidine and its derivatives are P450 inhibitors and that our newly synthesized IY-80843 is most inhibitory. 5 The present results indicate that mifentidine and its derivatives not only antagonise the H 2-receptor but also inhibit P450 enzymes.

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