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Updated: Jul 4, 2025
Human Pluripotent Stem Cell Based Developmental Toxicity Assays for Chemical Safety Screening and Systems Biology Data Generation
Published on: June 17, 2015
Guidelines on Developmental Toxicity Tests: Brief Insights
Sofia Alves-Pimenta1,2, Luís Félix3,4, Bruno Colaço1,2
1Department of Animal Science, School of Agrarian and Veterinary Sciences (ECAV), University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal.
Abstract:
Developmental toxicology is a constantly evolving research field which needs to attend to a complex underlying regulatory network. In order to ensure human health and environmental safety, new substances have to be tested for toxic effects on reproduction and development, before being commercialized. Traditional in vivo mammalian models represent the intricacy of human development and provide more adequately an assessment of the interaction of chemical compounds with the reproductive system. However, in the last years, the directives are to reduce the use of vertebrate animals, promoting their use only as a last resort. Consequently, the interest on the development and validation of alternative tests, able to cover the various aspects of the reproductive cycle, has significantly increased. Reproductive toxicity is probably the most difficult endpoint to be replaced by alternative assays, since it should provide information on mechanism interactions essential for female and male fertility and also knowledge on the animal development during the first phases of its life cycle. This complexity explains the slow progress in implementing alternative models for reproductive toxicity safety assays. Alternative test models may be based on in vitro systems and nonmammalian animal models. Many biological processes have been successfully addressed using in vitro models, opening the possibility to study the interference of teratogenic compounds. Their validation and implementation have lagged behind, in part because of difficulties in establishing their predictability. Nevertheless, the advance toward the process of validation is crucial to replace and reduce the use of living animals. Based on the present state of the art, it is not probable that such testing strategies will completely replace the need to assess reproductive toxicity in vivo in the near future, but they will contribute to reduce animal tests and will provide important information. In this chapter, the approved guidelines for standard methods and alternative methods, according to their regulatory and scientific status, are enumerated and briefly described.
Insights
Developmental toxicology research is shifting towards alternative testing methods to reduce animal use. While in vitro and non-mammalian models show promise, they currently supplement, not replace, traditional in vivo studies for reproductive toxicity assessment.
Area of Science:
- Developmental toxicology
- Reproductive toxicology
- Regulatory science
Background:
- Ensuring human health and environmental safety necessitates rigorous testing of new substances for reproductive and developmental toxicity.
- Traditional in vivo mammalian models offer comprehensive assessment but face increasing ethical and regulatory pressure to reduce vertebrate animal use.
- The field is actively seeking and validating alternative testing strategies to meet these evolving demands.
Purpose of the Study:
- To review and describe approved guidelines for standard and alternative methods in reproductive and developmental toxicity testing.
- To discuss the challenges and progress in developing and validating alternative assays for reproductive toxicity endpoints.
- To assess the current regulatory and scientific status of these testing strategies.
Main Methods:
- Review of existing literature and regulatory guidelines for developmental and reproductive toxicity testing.
- Enumeration and brief description of both standard in vivo and emerging alternative in vitro and non-mammalian test models.
- Analysis of the scientific and regulatory standing of various testing approaches.
Main Results:
- Reproductive toxicity assessment is complex and challenging to replace entirely with alternative methods due to the intricate mechanisms involved in fertility and development.
- Alternative models, including in vitro systems and non-mammalian species, are advancing but face hurdles in validation and predictability.
- Current alternative strategies are expected to reduce, but not completely replace, in vivo animal testing for reproductive toxicity in the near future.
Conclusions:
- The development and validation of alternative testing methods are crucial for reducing animal use in developmental toxicology.
- While significant progress has been made, in vivo studies remain essential for comprehensive reproductive toxicity assessment.
- Continued research and validation efforts are needed to enhance the reliability and regulatory acceptance of alternative assays.
