Unexpected Effects of Propiconazole, Tebuconazole, and Their Mixture on the Receptors CAR and PXR in Human Liver Cells
Language English Country United States Media print
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
29420809
DOI
10.1093/toxsci/kfy026
PII: 4840690
Knihovny.cz E-resources
- MeSH
- Cell Culture Techniques MeSH
- Hepatocytes drug effects metabolism MeSH
- Constitutive Androstane Receptor MeSH
- Rats MeSH
- Humans MeSH
- Cell Line, Tumor MeSH
- Pregnane X Receptor agonists genetics MeSH
- Fungicides, Industrial pharmacology MeSH
- Receptors, Cytoplasmic and Nuclear agonists antagonists & inhibitors genetics MeSH
- Molecular Docking Simulation MeSH
- Substrate Specificity MeSH
- Drug Synergism MeSH
- Cytochrome P-450 Enzyme System genetics metabolism MeSH
- Transfection MeSH
- Triazoles pharmacology MeSH
- Cell Survival drug effects MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Constitutive Androstane Receptor MeSH
- NR1I2 protein, human MeSH Browser
- Pregnane X Receptor MeSH
- propiconazole MeSH Browser
- Fungicides, Industrial MeSH
- Receptors, Cytoplasmic and Nuclear MeSH
- Cytochrome P-450 Enzyme System MeSH
- tebuconazole MeSH Browser
- Triazoles MeSH
Analyzing mixture toxicity requires an in-depth understanding of the mechanisms of action of its individual components. Substances with the same target organ, same toxic effect and same mode of action (MoA) are believed to cause additive effects, whereas substances with different MoAs are assumed to act independently. Here, we tested 2 triazole fungicides, propiconazole, and tebuconazole (Te), for individual and combined effects on liver toxicity-related endpoints. Both triazoles are proposed to belong to the same cumulative assessment group and are therefore thought to display similar and additive behavior. Our data show that Te is an antagonist of the constitutive androstane receptor (CAR) in rats and humans, while propiconazole is an agonist of this receptor. Both substances activate the pregnane X-receptor (PXR) and further induce mRNA expression of CYP3A4. CYP3A4 enzyme activity, however, is inhibited by propiconazole. For common targets of PXR and CAR, the activation of PXR by Te overrides CAR inhibition. In summary, propiconazole and Te affect different hepatotoxicity-relevant cellular targets and, depending on the individual endpoint analyzed, act via similar or dissimilar mechanisms. The use of molecular data based on research in human cell systems extends the picture to refine cumulative assessment group grouping and substantially contributes to the understanding of mixture effects of chemicals in biological systems.
Department of Pesticides Safety German Federal Institute for Risk Assessment 10589 Berlin Germany
Department of Pharmacology and Toxicology
Institute of Chemistry Technical University Berlin 10623 Berlin Germany
Institute of Nutritional Science University of Potsdam 14558 Nuthetal Germany
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