Alternative testing strategies for predicting developmental toxicity of antifungal compound

H. Li

Research output: Thesisinternal PhD, WUAcademic

Abstract

Determination of safe human exposure levels of chemicals in toxicological risk assessments largely relies on animal toxicity data. In these toxicity studies, the highest number of animals are used for reproductive and developmental toxicity testing. Because of economic and ethical reasons, there is large interest in the development of in vitro and/or in silico test systems as alternatives for the animal studies. The aim of the present thesis was to evaluate the applicability of combined in vitro approaches taking toxicokinetic and toxicodynamic aspects into account, as well as of an integrated in vitro and in silico approach for prediction of developmental toxicity using a series of antifungal compounds as the model compounds.

Transplacental transfer of compounds is highly likely to play an important role in developmental toxicity, so we developed and validated an in vitro placental barrier model using BeWo b30 cells to predict placental transfer. Then we investigated the applicability of the ES-D3 cell differentiation assay combined with the in vitro BeWo transport model to predict the relative in vivo developmental toxicity potencies of two sets of selected antifungal compounds. The data obtained show that the combined in vitro approach provided a correct prediction for the relative in vivo developmental toxicity, whereas the ES-D3 cell differentiation assay as stand-alone did not. In order to detect specific structural alterations induced by chemicals, we investigated the applicability of the ex ovo assay of chicken embryos to predict the specific alterations induced by the antifungal compounds. Data revealed that the ex ovo assay of chicken embryos is able to assess the teratogenic potential of antifungal compounds, and, when combined with the in vitro BeWo transport model, is able to better predict relative in vivo prenatal developmental toxicity potencies.

Subsequently, we translated in vitro concentration–response data of the antifungal compound tebuconazole, obtained in the ES-D3 cell differentiation assay and the ex ovo assay of chicken embryos, into predicted in vivo dose–response data using physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry. The results show that the BMD10 values from predicted dose–response data from both assays are in concordance with BMD10 values derived from in vivo data (within 5-fold difference). This revealed that PBK modeling is a promising tool to predict in vivo dose-response curves based on the results of in vitro toxicity assays, and may therefore be used to set a point of departure for deriving safe exposure limits in risk assessment.

It is concluded the combined in vitro approaches and the integrated in vitro-in silico approaches appear to be promising for the screening and prioritization of chemicals and to provide reference values, such as BMD10 values, without using animals, therefore contributing to the 3R principle of animal testing.

 

 

LanguageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • Wageningen University
Supervisors/Advisors
  • Rietjens, Ivonne, Promotor
  • van Ravenzwaay, Bennard, Promotor
  • Louisse, Jochem, Co-promotor
Award date8 Apr 2016
Place of PublicationWageningen
Publisher
Print ISBNs9789462576780
Publication statusPublished - 2016

Fingerprint

Computer Simulation
Cell Differentiation
Chickens
Embryonic Structures
In Vitro Techniques
Toxicology
Reference Values
Economics
Toxicokinetics
tebuconazole

Keywords

  • toxicity
  • fetal development
  • transfer
  • infant development
  • adolescent development
  • child development
  • pregnancy
  • in vivo experimentation
  • modeling
  • placenta
  • in vitro
  • risk assessment
  • tebuconazole
  • conazole fungicides
  • antifungal agents
  • alternative methods

Cite this

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title = "Alternative testing strategies for predicting developmental toxicity of antifungal compound",
abstract = "Determination of safe human exposure levels of chemicals in toxicological risk assessments largely relies on animal toxicity data. In these toxicity studies, the highest number of animals are used for reproductive and developmental toxicity testing. Because of economic and ethical reasons, there is large interest in the development of in vitro and/or in silico test systems as alternatives for the animal studies. The aim of the present thesis was to evaluate the applicability of combined in vitro approaches taking toxicokinetic and toxicodynamic aspects into account, as well as of an integrated in vitro and in silico approach for prediction of developmental toxicity using a series of antifungal compounds as the model compounds. Transplacental transfer of compounds is highly likely to play an important role in developmental toxicity, so we developed and validated an in vitro placental barrier model using BeWo b30 cells to predict placental transfer. Then we investigated the applicability of the ES-D3 cell differentiation assay combined with the in vitro BeWo transport model to predict the relative in vivo developmental toxicity potencies of two sets of selected antifungal compounds. The data obtained show that the combined in vitro approach provided a correct prediction for the relative in vivo developmental toxicity, whereas the ES-D3 cell differentiation assay as stand-alone did not. In order to detect specific structural alterations induced by chemicals, we investigated the applicability of the ex ovo assay of chicken embryos to predict the specific alterations induced by the antifungal compounds. Data revealed that the ex ovo assay of chicken embryos is able to assess the teratogenic potential of antifungal compounds, and, when combined with the in vitro BeWo transport model, is able to better predict relative in vivo prenatal developmental toxicity potencies. Subsequently, we translated in vitro concentration–response data of the antifungal compound tebuconazole, obtained in the ES-D3 cell differentiation assay and the ex ovo assay of chicken embryos, into predicted in vivo dose–response data using physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry. The results show that the BMD10 values from predicted dose–response data from both assays are in concordance with BMD10 values derived from in vivo data (within 5-fold difference). This revealed that PBK modeling is a promising tool to predict in vivo dose-response curves based on the results of in vitro toxicity assays, and may therefore be used to set a point of departure for deriving safe exposure limits in risk assessment. It is concluded the combined in vitro approaches and the integrated in vitro-in silico approaches appear to be promising for the screening and prioritization of chemicals and to provide reference values, such as BMD10 values, without using animals, therefore contributing to the 3R principle of animal testing.    ",
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Li, H 2016, 'Alternative testing strategies for predicting developmental toxicity of antifungal compound', Doctor of Philosophy, Wageningen University, Wageningen.

Alternative testing strategies for predicting developmental toxicity of antifungal compound. / Li, H.

Wageningen : Wageningen University, 2016. 197 p.

Research output: Thesisinternal PhD, WUAcademic

TY - THES

T1 - Alternative testing strategies for predicting developmental toxicity of antifungal compound

AU - Li, H.

N1 - WU thesis 6314

PY - 2016

Y1 - 2016

N2 - Determination of safe human exposure levels of chemicals in toxicological risk assessments largely relies on animal toxicity data. In these toxicity studies, the highest number of animals are used for reproductive and developmental toxicity testing. Because of economic and ethical reasons, there is large interest in the development of in vitro and/or in silico test systems as alternatives for the animal studies. The aim of the present thesis was to evaluate the applicability of combined in vitro approaches taking toxicokinetic and toxicodynamic aspects into account, as well as of an integrated in vitro and in silico approach for prediction of developmental toxicity using a series of antifungal compounds as the model compounds. Transplacental transfer of compounds is highly likely to play an important role in developmental toxicity, so we developed and validated an in vitro placental barrier model using BeWo b30 cells to predict placental transfer. Then we investigated the applicability of the ES-D3 cell differentiation assay combined with the in vitro BeWo transport model to predict the relative in vivo developmental toxicity potencies of two sets of selected antifungal compounds. The data obtained show that the combined in vitro approach provided a correct prediction for the relative in vivo developmental toxicity, whereas the ES-D3 cell differentiation assay as stand-alone did not. In order to detect specific structural alterations induced by chemicals, we investigated the applicability of the ex ovo assay of chicken embryos to predict the specific alterations induced by the antifungal compounds. Data revealed that the ex ovo assay of chicken embryos is able to assess the teratogenic potential of antifungal compounds, and, when combined with the in vitro BeWo transport model, is able to better predict relative in vivo prenatal developmental toxicity potencies. Subsequently, we translated in vitro concentration–response data of the antifungal compound tebuconazole, obtained in the ES-D3 cell differentiation assay and the ex ovo assay of chicken embryos, into predicted in vivo dose–response data using physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry. The results show that the BMD10 values from predicted dose–response data from both assays are in concordance with BMD10 values derived from in vivo data (within 5-fold difference). This revealed that PBK modeling is a promising tool to predict in vivo dose-response curves based on the results of in vitro toxicity assays, and may therefore be used to set a point of departure for deriving safe exposure limits in risk assessment. It is concluded the combined in vitro approaches and the integrated in vitro-in silico approaches appear to be promising for the screening and prioritization of chemicals and to provide reference values, such as BMD10 values, without using animals, therefore contributing to the 3R principle of animal testing.    

AB - Determination of safe human exposure levels of chemicals in toxicological risk assessments largely relies on animal toxicity data. In these toxicity studies, the highest number of animals are used for reproductive and developmental toxicity testing. Because of economic and ethical reasons, there is large interest in the development of in vitro and/or in silico test systems as alternatives for the animal studies. The aim of the present thesis was to evaluate the applicability of combined in vitro approaches taking toxicokinetic and toxicodynamic aspects into account, as well as of an integrated in vitro and in silico approach for prediction of developmental toxicity using a series of antifungal compounds as the model compounds. Transplacental transfer of compounds is highly likely to play an important role in developmental toxicity, so we developed and validated an in vitro placental barrier model using BeWo b30 cells to predict placental transfer. Then we investigated the applicability of the ES-D3 cell differentiation assay combined with the in vitro BeWo transport model to predict the relative in vivo developmental toxicity potencies of two sets of selected antifungal compounds. The data obtained show that the combined in vitro approach provided a correct prediction for the relative in vivo developmental toxicity, whereas the ES-D3 cell differentiation assay as stand-alone did not. In order to detect specific structural alterations induced by chemicals, we investigated the applicability of the ex ovo assay of chicken embryos to predict the specific alterations induced by the antifungal compounds. Data revealed that the ex ovo assay of chicken embryos is able to assess the teratogenic potential of antifungal compounds, and, when combined with the in vitro BeWo transport model, is able to better predict relative in vivo prenatal developmental toxicity potencies. Subsequently, we translated in vitro concentration–response data of the antifungal compound tebuconazole, obtained in the ES-D3 cell differentiation assay and the ex ovo assay of chicken embryos, into predicted in vivo dose–response data using physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry. The results show that the BMD10 values from predicted dose–response data from both assays are in concordance with BMD10 values derived from in vivo data (within 5-fold difference). This revealed that PBK modeling is a promising tool to predict in vivo dose-response curves based on the results of in vitro toxicity assays, and may therefore be used to set a point of departure for deriving safe exposure limits in risk assessment. It is concluded the combined in vitro approaches and the integrated in vitro-in silico approaches appear to be promising for the screening and prioritization of chemicals and to provide reference values, such as BMD10 values, without using animals, therefore contributing to the 3R principle of animal testing.    

KW - toxicity

KW - fetal development

KW - transfer

KW - infant development

KW - adolescent development

KW - child development

KW - pregnancy

KW - in vivo experimentation

KW - modeling

KW - placenta

KW - in vitro

KW - risk assessment

KW - tebuconazole

KW - conazole fungicides

KW - antifungal agents

KW - alternative methods

KW - toxiciteit

KW - foetale ontwikkeling

KW - overdracht

KW - zuigelingenontwikkeling

KW - adolescentenontwikkeling

KW - kinderontwikkeling

KW - zwangerschap

KW - in vivo experimenten

KW - modelleren

KW - placenta

KW - in vitro

KW - risicoschatting

KW - tebuconazool

KW - conazoolfungiciden

KW - antimycotica

KW - alternatieve methoden

M3 - internal PhD, WU

SN - 9789462576780

PB - Wageningen University

CY - Wageningen

ER -