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

02:5723 months 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.

Related

VitalTissue: scientific research can be more human(e)
Projects and initiatives
HealthInnovationIn vitro

VitalTissue: scientific research can be more human(e)

The goal of VitalTissue is to facilitate the availability of vital human residual tissue for all researchers in the Netherlands. This video shows how VitalTissue works. From a request from a researcher, the donation of the residual tissue by the patient and the transport to the lab. This process is the result of a feasibility study conducted with many stakeholders. The national tissue bank ETB-BISLIFE will implement VitalTissue in practice.
04:214 months ago
Helpathon #9 – Can you help Juan?
Meeting videos
HealthInnovationIn vitro

Helpathon #9 – Can you help Juan?

Juan is an experienced immunologist and scientific director of the cutting edge O2Flow facility for cytometry and cell sorting at the Amsterdam VU University Medical Center. Can you help Juan explore if and how he can transition his facility towards animal free antibodies? Are you using antibodies in your research do you want others to help you find animal free alternatives for your specific research let us know. More information can be found [here] (https://www.helpathonhotel.org/coming-up).
02:024 months ago
Development of 3D liver spheroids
Innovation examples
HealthToxicologyInnovationIn vitro

Development of 3D liver spheroids

Human-based in vitro models are increasingly being used in the hepatology field. And in addition to the obvious ethical arguments, they offer several advantages over the classical animal models. One of them is the ability to perform mechanistic research at the molecular level in a well-controlled setting and reduce species differences. These liver-based in vitro models can range from simple monolayer cultures of hepatocytes to the liver-on-chips systems in which all liver cells are cultured in a 3D configuration on a microfluidic platform. Liver-based in vitro models must be selected on a case-by-case basis and should fit the purpose of the research, which might go from fundamental to translational research.
01:045 months ago
Platform for in vitro airborne inhalation testing
Innovation examples
HealthToxicologyInnovationIn vitro

Platform for in vitro airborne inhalation testing

The air-liquid interface (ALI) technique uses lung cells cultured on a tiny polymer membrane in a cup. On one side of the membrane is a liquid containing the medium necessary for the cells to survive, while the other side is in contact with air. This is similar to the situation in the human lung. The compound to be tested is administered via an aerosol, vapor, or gas to mimic the situation in human lungs. By monitoring different parameters in the cell model before and after the compound is added, it is possible to measure the effects on lung cells. Depending on the test to be carried out, the lung cells can come from different regions in the respiratory tract and even from a variety of people, including individuals who smoke a lot or have specific diseases such as chronic obstructive pulmonary disease or asthma. In vitro ALI inhalation testing (https://doi.org/10.1021/acs.est.7b00493) adds value for e.g. pre-clinical trials and research in the pharmaceutical industry and testing (new) compounds for the chemical sector and beyond. The advantages of ALI inhalation testing are that it is a non-animal method, it reduces the use of in vivo experiments, pre-clinical testing with human-derived cell models is more realistic and limits clinical trial failures and it provides faster and more efficient testing of compound
04:135 months ago