OpenTox Virtual Conference 2022
VALIDATION OF ZEBRAFISH EMBRYOTOXICITY TEST (ZET) AS A QUALIFIED ALTERNATIVE ASSAY FOR ITS REGULATORY USE
Irijalba I.(1), Gallego M.(1), Sainz L.(2), Fernández E.(2), Goñi-de-Cerio F. (2), Quevedo C.(1), Muriana A. (1), and Weiner A.(1).
(1) BIOBIDE, San Sebastian, Spain
(2) GAIKER Technology Centre, Basque Research and Technology Alliance (BRTA), Zamudio, Spain.
The ICH S5 (R3) guideline on reproductive toxicology that applies to all pharmaceuticals for which reproductive and/or developmental toxicity studies are appropriate, proposes the use of alternative assays to minimize the use of animals. The guide provides a list with 29 Reference compounds that have been shown to induce specific malformation or embryo-fetal lethality plus 3 Negative compounds to support the qualification of an alternative assay.
Our research focused on the predictivity of the zebrafish developmental toxicity assay. Zebrafish embryo model is highly popular in toxicology and provides an ethically acceptable small-scale analysis system with the complexity of a complete organism. Our goal is to further validate this model for its regulatory use by testing the 32 compounds indicated in the guideline. To determine the teratogenic risk of these chemicals, the presence of morphological alterations is analyzed at two different stages and the teratogenic indexes are established for each stage. The 32 compounds have been assayed with the zebrafish developmental toxicity test: i) 23 out of the 29 Reference Compounds evaluated have been correctly classified. ii) For compounds not properly identified, results obtained for Aspirin and Cytarabine were conclusive, but the number of concentrations assayed for the other 4 compounds was restricted due to their limited solubility in embryo medium, affecting their classification. iii) all negative compounds were correctly identified.
A total of three replicates have been conducted to study the reproducibility of the assay as well as the evaluation of the chemistry concentration in the external medium and internal in zebrafish embryos. This zebrafish assay gives an Accuracy of 88%, Sensitivity of 80%, Specificity of 100% and Repeatability of 99% comparing to mammals; therefore, it is a well-integrated strategy to minimize the use of animals in reproductive and/or developmental toxicity studies.
CV: MSc in Pharmacy and Master's degree in R+D+i of New Drugs at the Navarra University (Pamplona, Spain), with doctorate course in Design, Synthesis, and Evaluation of New drugs, in Pharmaceutical and Organic Chemistry. In addition, she has an MBA from the San Pablo CEU University of Madrid (Spain), where she improved her management and business development skills.
She began working in CRO´s 18 years ago, first in the field of Clinical Trials, and later in 2006, she moved to the Pre-Clinical field starting to work in Biobide, after a training period working with zebrafish in the Salk Institute of California. During those years she had different positions in Biobide, from Quality, Safety, and Environment Director, to I.P. and Business Development Director, leading to generate a deep understanding of the zebrafish services developed in the field.