Biotransformation of two proteratogenic anti-epileptics in the zebrafish (Danio rerio) embryo

02:572 years ago

The zebrafish (Danio rerio) embryo has gained interest as an alternative model for developmental toxicity testing, which still mainly relies on in vivo mammalian models (e.g., rat, rabbit). However, cytochrome P450 (CYP)-mediated drug metabolism, which is critical for the bioactivation of several proteratogens, is still under debate for this model. Therefore, we investigated the potential capacity of zebrafish embryos/larvae to bioactivate two known mammalian proteratogens, carbamazepine (CBZ) and phenytoin (PHE) into their mammalian active metabolites, carbamazepine-10,11-epoxide (E-CBZ) and 5-(4-hydroxyphenyl)-5-phenylhydantoin (HPPH), respectively. Zebrafish embryos were exposed to three concentrations (31.25, 85, and 250 μM) of CBZ and PHE from 51⁄4 to 120 hours post fertilization (hpf) at 28.5°C under a 14/10 hour light/dark cycle. For species comparison, also adult zebrafish, rat, rabbit and human liver microsomes (200 μg/ml) were exposed to 100 μM of CBZ or PHE for 240 minutes at 28.5°C. Potential formation of the mammalian metabolites was assessed in the embryo medium (48, 96, and 120 hpf); pooled (n=20) whole embryos/larvae extracts (24 and 120 hpf); and in the microsomal reaction mixtures (at 5 and 240 minutes) by targeted investigation using a UPLC–Triple Quadrupole MS system with lamotrigine (0.39 μM) as internal standard. Our study showed that zebrafish embryos metabolize CBZ to E-CBZ, but only at the end of organogenesis (from 96 hpf onwards), and no biotransformation of PHE to HPPH occurred. In contrast, our in vitro drug metabolism assay showed that adult zebrafish metabolize both compounds into their active mammalian metabolites. However, significant differences in metabolic rate were observed among the investigated species. These results highlight the importance of including the zebrafish in the in vitro drug metabolism testing battery
for accurate species selection in toxicity studies.


Five simple tricks for making your own video for videos

Five simple tricks for making your own video for

This video shows you how to make a video yourself. It's really not that difficult! See also for additional information.
01:234 years ago
Projects and initiatives


The EU Reference Laboratory for alternatives to animal testing (EURL ECVAM) promotes and facilitates the use of non-animal methods in testing and research. It validates, disseminates and shares knowledge on the 3Rs (Replacement, Reduction and Refinement of animal experiments). In this video, Raffaella Corvi explains what EURL ECVAM does in the field of safety testing of chemicals while reducing laboratory animal testing. Watch the accessible version of the video here ( ©European Union, 2021
02:3353 days ago
Stem cell derived Vessels-on-Chip to study brain disorders
Innovation examples
HealthIn vitroOrgan-on-Chip

Stem cell derived Vessels-on-Chip to study brain disorders

Dennis Nahon is a PhD candidate in the Department of Anatomy and Embryology at the Leiden University Medical Center. In his research, under supervision of Dr. Valeria Orlova ( and Prof. Dr. Christine Mummery, he aims to mimic a blood vessel in the brain by combining different stem cell derived cell types, in a 3D Vessel-on-Chip model. Here, an example of these in vitro blood vessels is shown in which certain brain cells known as astrocytes (in white) interact with the blood vessels (in red). This model paves the way for investigating brain vessels outside the human body, while reducing the need for animal models.
01:532 months ago
 From 2D hiPSC culture to developing a 3D vessel-on-chip
Innovation examples
In vitroOrgan-on-Chip

From 2D hiPSC culture to developing a 3D vessel-on-chip

Theano Tsikari is a 2nd year PhD student at the Orlova group at LUMC. As part of the LymphChip consortium, her project focuses on the development of immunocompetent organ-on-chip models of the cardiovascular system, and especially the integration of tissue-resident macrophages and lymphatic vasculature using human induced pluripotent stem cells. In this video, you can follow her as she presents you the backbone of her project, a 3D hiPSC-derived vessel-on-chip model, that has been previously developed in the Orlova group and can be employed for the generation of advanced in vitro models of vascular diseases.
01:292 months ago