New Approach Methods for Hazard Identification: A Case Study with Azole Fungicides Affecting Molecular Targets Associated with the Adverse Outcome Pathway for Cholestasis

Triazole fungicides such as propiconazole (Pi) or tebuconazole (Te) show hepatotoxicity in vivo, e.g., hypertrophy and vacuolization of liver cells following interaction with nuclear receptors such as PXR (pregnane-X-receptor) and CAR (constitutive androstane receptor). Accordingly, azoles affect ge...

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Main Authors: Constanze Knebel, Roderich D. Süssmuth, Helen S. Hammer, Albert Braeuning, Philip Marx-Stoelting
Format: Article
Language:English
Published: MDPI AG 2022-10-01
Series:Cells
Subjects:
Online Access:https://www.mdpi.com/2073-4409/11/20/3293
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author Constanze Knebel
Roderich D. Süssmuth
Helen S. Hammer
Albert Braeuning
Philip Marx-Stoelting
author_facet Constanze Knebel
Roderich D. Süssmuth
Helen S. Hammer
Albert Braeuning
Philip Marx-Stoelting
author_sort Constanze Knebel
collection DOAJ
description Triazole fungicides such as propiconazole (Pi) or tebuconazole (Te) show hepatotoxicity in vivo, e.g., hypertrophy and vacuolization of liver cells following interaction with nuclear receptors such as PXR (pregnane-X-receptor) and CAR (constitutive androstane receptor). Accordingly, azoles affect gene expression associated with these adverse outcomes in vivo but also in human liver cells in vitro. Additionally, genes indicative of liver cholestasis are affected in vivo and in vitro. We therefore analyzed the capability of Pi and Te to cause cholestasis in an adverse outcome pathway (AOP)-driven approach in hepatic cells of human origin in vitro, considering also previous in vivo studies. Bile salt export pump (BSEP) activity assays confirmed that both azoles are weak inhibitors of BSEP. They alternate the expression of various cholestasis-associated target genes and proteins as well as the mitochondrial membrane function. Published in vivo data, however, demonstrate that neither Pi nor Te cause cholestasis in rodent bioassays. This discrepancy can be explained by the in vivo concentrations of both azoles being well below their EC50 for BSEP inhibition. From a regulatory perspective, this illustrates that toxicogenomics and human in vitro models are valuable tools to detect the potential of a substance to cause a specific type of toxicity. To come to a sound regulatory conclusion on the in vivo relevance of such a finding, results will have to be considered in a broader context also including toxicokinetics in a weight-of-evidence approach.
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spelling doaj.art-d949b29fe11a42e0ba78bcdc32af96ef2023-11-23T23:28:45ZengMDPI AGCells2073-44092022-10-011120329310.3390/cells11203293New Approach Methods for Hazard Identification: A Case Study with Azole Fungicides Affecting Molecular Targets Associated with the Adverse Outcome Pathway for CholestasisConstanze Knebel0Roderich D. Süssmuth1Helen S. Hammer2Albert Braeuning3Philip Marx-Stoelting4Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Street 8-10, 10589 Berlin, GermanyInstitute of Chemistry, Technical University Berlin, Straße des 17. Juni 124, 10623 Berlin, GermanySignatope GmbH, Markwiesenstrasse 55, 72770 Reutlingen, GermanyDepartment Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Street 8-10, 10589 Berlin, GermanyDepartment Pesticides Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Street 8-10, 10589 Berlin, GermanyTriazole fungicides such as propiconazole (Pi) or tebuconazole (Te) show hepatotoxicity in vivo, e.g., hypertrophy and vacuolization of liver cells following interaction with nuclear receptors such as PXR (pregnane-X-receptor) and CAR (constitutive androstane receptor). Accordingly, azoles affect gene expression associated with these adverse outcomes in vivo but also in human liver cells in vitro. Additionally, genes indicative of liver cholestasis are affected in vivo and in vitro. We therefore analyzed the capability of Pi and Te to cause cholestasis in an adverse outcome pathway (AOP)-driven approach in hepatic cells of human origin in vitro, considering also previous in vivo studies. Bile salt export pump (BSEP) activity assays confirmed that both azoles are weak inhibitors of BSEP. They alternate the expression of various cholestasis-associated target genes and proteins as well as the mitochondrial membrane function. Published in vivo data, however, demonstrate that neither Pi nor Te cause cholestasis in rodent bioassays. This discrepancy can be explained by the in vivo concentrations of both azoles being well below their EC50 for BSEP inhibition. From a regulatory perspective, this illustrates that toxicogenomics and human in vitro models are valuable tools to detect the potential of a substance to cause a specific type of toxicity. To come to a sound regulatory conclusion on the in vivo relevance of such a finding, results will have to be considered in a broader context also including toxicokinetics in a weight-of-evidence approach.https://www.mdpi.com/2073-4409/11/20/3293hepatotoxicityazole fungicidesmolecular targetsadverse outcome pathwayliver cholestasis
spellingShingle Constanze Knebel
Roderich D. Süssmuth
Helen S. Hammer
Albert Braeuning
Philip Marx-Stoelting
New Approach Methods for Hazard Identification: A Case Study with Azole Fungicides Affecting Molecular Targets Associated with the Adverse Outcome Pathway for Cholestasis
Cells
hepatotoxicity
azole fungicides
molecular targets
adverse outcome pathway
liver cholestasis
title New Approach Methods for Hazard Identification: A Case Study with Azole Fungicides Affecting Molecular Targets Associated with the Adverse Outcome Pathway for Cholestasis
title_full New Approach Methods for Hazard Identification: A Case Study with Azole Fungicides Affecting Molecular Targets Associated with the Adverse Outcome Pathway for Cholestasis
title_fullStr New Approach Methods for Hazard Identification: A Case Study with Azole Fungicides Affecting Molecular Targets Associated with the Adverse Outcome Pathway for Cholestasis
title_full_unstemmed New Approach Methods for Hazard Identification: A Case Study with Azole Fungicides Affecting Molecular Targets Associated with the Adverse Outcome Pathway for Cholestasis
title_short New Approach Methods for Hazard Identification: A Case Study with Azole Fungicides Affecting Molecular Targets Associated with the Adverse Outcome Pathway for Cholestasis
title_sort new approach methods for hazard identification a case study with azole fungicides affecting molecular targets associated with the adverse outcome pathway for cholestasis
topic hepatotoxicity
azole fungicides
molecular targets
adverse outcome pathway
liver cholestasis
url https://www.mdpi.com/2073-4409/11/20/3293
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