Alkoxyresorufin (methoxy-, ethoxy-, pentoxy- and benzyloxyresorufin) O-dealkylase activities by in vitro-expressed cytochrome P450 1A4 and 1A5 from common cormorant (Phalacrocorax carbo)

Background: There is a large inter-individual variation in cytochrome P450 2C19 (CYP2C19) activity. The variability can be caused by the genetic polymorphism of CYP2C19 gene. This study aimed to investigate the molecular and kinetics basis for activity changes in three alleles including CYP2C19*23, CYP2C19*24 and CYP2C19*25found in the Chinese population. Methods: The three variants expressed by bacteria were investigated using substrate (omeprazole and 3- cyano-7-ethoxycoumarin[CEC]) and inhibitor (ketoconazole, fluoxetine, sertraline and loratadine) probes in enzyme assays along with molecular docking. Results: All alleles exhibited very low enzyme activity and affinity towards omeprazole and CEC (6.1% or less in intrinsic clearance). The inhibition studies with the four inhibitors, however, suggested that mutations in different variants have a tendency to cause enhanced binding (reduced IC50 values). The enhanced binding could partially be explained by the lower polar solvent accessible surface area of the inhibitors relative to the substrates. Molecular docking indicated that G91R, R335Q and F448L, the unique mutations in the alleles, have caused slight alteration in the substrate access channel morphology and a more compact active site cavity hence affecting ligand access and binding. It is likely that these structural alterations in CYP2C19 proteins have caused ligand-specific alteration in catalytic and inhibitory specificities as observed in the in vitro assays. Conclusion: This study indicates that CYP2C19 variant selectivity for ligands was not solely governed by mutation-induced modifications in the active site architecture, but the intrinsic properties of the probe compounds also played a vital role.

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In vitro inhibitory mechanisms and molecular docking of 1′-S-1′-acetoxychavicol acetate on human cytochrome P450 enzymes

Phytomedicine ◽

10.1016/j.phymed.2017.05.002 ◽

2017 ◽

Vol 31 ◽

pp. 1-9 ◽

Cited By ~ 6

Author(s):

A.K.M. Mahmudul Haque ◽

Kok Hoong Leong ◽

Yoke Lin Lo ◽

Khalijah Awang ◽

Noor Hasima Nagoor

Keyword(s):

Cytochrome P450 ◽

Molecular Docking ◽

Cytochrome P450 Enzymes ◽

Inhibitory Mechanisms ◽

Human Cytochrome

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Proteomic profiling of murine biliary-derived hepatic organoids and their capacity for drug disposition, bioactivation and detoxification

Archives of Toxicology ◽

10.1007/s00204-021-03075-3 ◽

2021 ◽

Author(s):

Lawrence Howell ◽

Rosalind E. Jenkins ◽

Stephen Lynch ◽

Carrie Duckworth ◽

B. Kevin Park ◽

...

Keyword(s):

Cytochrome P450 ◽

Drug Metabolism ◽

Rna Polymerase Ii ◽

Liver Tissue ◽

Drug Disposition ◽

Multiple Drug ◽

Proteomic Profiling ◽

Cytochrome P450 3A ◽

Drug Induced

AbstractHepatic organoids are a recent innovation in in vitro modeling. Initial studies suggest that organoids better recapitulate the liver phenotype in vitro compared to pre-existing proliferative cell models. However, their potential for drug metabolism and detoxification remains poorly characterized, and their global proteome has yet to be compared to their tissue of origin. This analysis is urgently needed to determine what gain-of-function this new model may represent for modeling the physiological and toxicological response of the liver to xenobiotics. Global proteomic profiling of undifferentiated and differentiated hepatic murine organoids and donor-matched livers was, therefore, performed to assess both their similarity to liver tissue, and the expression of drug-metabolizing enzymes and transporters. This analysis quantified 4405 proteins across all sample types. Data are available via ProteomeXchange (PXD017986). Differentiation of organoids significantly increased the expression of multiple cytochrome P450, phase II enzymes, liver biomarkers and hepatic transporters. While the final phenotype of differentiated organoids is distinct from liver tissue, the organoids contain multiple drug metabolizing and transporter proteins necessary for liver function and drug metabolism, such as cytochrome P450 3A, glutathione-S-transferase alpha and multidrug resistance protein 1A. Indeed, the differentiated organoids were shown to exhibit increased sensitivity to midazolam (10–1000 µM) and irinotecan (1–100 µM), when compared to the undifferentiated organoids. The predicted reduced activity of HNF4A and a resulting dysregulation of RNA polymerase II may explain the partial differentiation of the organoids. Although further experimentation, optimization and characterization is needed relative to pre-existing models to fully contextualize their use as an in vitro model of drug-induced liver injury, hepatic organoids represent an attractive novel model of the response of the liver to xenobiotics. The current study also highlights the utility of global proteomic analyses for rapid and accurate evaluation of organoid-based test systems.

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In Silico Structural Modeling and Analysis of Interactions of Tremellomycetes Cytochrome P450 Monooxygenases CYP51s with Substrates and Azoles

International Journal of Molecular Sciences ◽

10.3390/ijms22157811 ◽

2021 ◽

Vol 22 (15) ◽

pp. 7811

Author(s):

Olufunmilayo Olukemi Akapo ◽

Joanna M. Macnar ◽

Justyna D. Kryś ◽

Puleng Rosinah Syed ◽

Khajamohiddin Syed ◽

...

Keyword(s):

Cytochrome P450 ◽

Structural Analysis ◽

In Silico ◽

Web Application ◽

Cytochrome P450 Monooxygenases ◽

Agglomerative Clustering ◽

Ligand Complex ◽

P450 Monooxygenase ◽

Study Results

Cytochrome P450 monooxygenase CYP51 (sterol 14α-demethylase) is a well-known target of the azole drug fluconazole for treating cryptococcosis, a life-threatening fungal infection in immune-compromised patients in poor countries. Studies indicate that mutations in CYP51 confer fluconazole resistance on cryptococcal species. Despite the importance of CYP51 in these species, few studies on the structural analysis of CYP51 and its interactions with different azole drugs have been reported. We therefore performed in silico structural analysis of 11 CYP51s from cryptococcal species and other Tremellomycetes. Interactions of 11 CYP51s with nine ligands (three substrates and six azoles) performed by Rosetta docking using 10,000 combinations for each of the CYP51-ligand complex (11 CYP51s × 9 ligands = 99 complexes) and hierarchical agglomerative clustering were used for selecting the complexes. A web application for visualization of CYP51s’ interactions with ligands was developed (http://bioshell.pl/azoledocking/). The study results indicated that Tremellomycetes CYP51s have a high preference for itraconazole, corroborating the in vitro effectiveness of itraconazole compared to fluconazole. Amino acids interacting with different ligands were found to be conserved across CYP51s, indicating that the procedure employed in this study is accurate and can be automated for studying P450-ligand interactions to cater for the growing number of P450s.

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In vitro study on the effect of cornin on the activity of cytochrome P450 enzymes

BMC Complementary Medicine and Therapies ◽

10.1186/s12906-021-03309-y ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Qun Zhang ◽

Zengqiang Qu ◽

Yanqing Zhou ◽

Jin Zhou ◽

Junwei Yang ◽

...

Keyword(s):

Cytochrome P450 ◽

Drug Interaction ◽

Liver Microsomes ◽

In Vitro Study ◽

Inhibitory Effect ◽

Dependent Manner ◽

Cytochrome P450 Enzymes ◽

Drug Drug Interaction ◽

Dose Dependent

Abstract Background Cornin is a commonly used herb in cardiology for its cardioprotective effect. The effect of herbs on the activity of cytochrome P450 enzymes (CYP450s) can induce adverse drug-drug interaction even treatment failure. Therefore, it is necessary to investigate the effect of cornin on the activity of CYP450s, which can provide more guidance for the clinical application of cornin. Methods Cornin (100 μM) was incubated with eight isoforms of CYP450s, including CYP1A2, 2A6, 3A4, 2C8, 2C9, 2C19, 2D6, and 2E1, in pooled human liver microsomes. The inhibition model and corresponding parameters were also investigated. Results Cornin exerted significant inhibitory effect on the activity of CYP3A4, 2C9, and 2E1 in a dose-dependent manner with the IC50 values of 9.20, 22.91, and 14.28 μM, respectively (p < 0.05). Cornin inhibited the activity of CYP3A4 non-competitively with the Ki value of 4.69 μM, while the inhibition of CYP2C9 and 2E1 by cornin was competitive with the Ki value of 11.31 and 6.54 μM, respectively. Additionally, the inhibition of CYP3A4 by cornin was found to be time-dependent with the KI/Kinact value of 6.40/0.055 min− 1·μM− 1. Conclusions The inhibitory effect of cornin on the activity of CYP3A4, 2C9, and 2E1 indicated the potential drug-drug interaction between cornin and drugs metabolized by these CYP450s, which needs further investigation and validation.

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