Zebrafish Xenotransplant Cancer Model for Drug Screening

Tween-80 and impurity induce anaphylactoid reaction in zebrafish

A number of recent reports suspected that Tween-80 in injectable medicines, including traditional Chinese medicine injections could cause life-threatening anaphylactoid reaction, but no sound conclusion was drawn. A drug-induced anaphylactoid reaction is hard to be assayed in vitro and in conventional animal models. In this study, we developed a microplate-based quantitative in vivo zebrafish assay for assessing anaphylactoid reaction and live whole zebrafish mast cell tryptase activity was quantitatively measured at a wavelength of 405 nm using N-benzoyl-dl-arginine p-nitroanilide as a substrate. We assessed 10 batches of Tween-80 solutions from various national and international suppliers and three Tween-80 impurities (ethylene glycol, 2-chloroethanol and hydrogen peroxide) in this model and found that three batches of Tween-80 (nos 2, 20080709 and 20080616) and one Tween-80 impurity, hydrogen peroxide (H2 O2 ), induced anaphylactoid reactions in zebrafish. Furthermore, we found that H2 O2 residue and peroxide value were much higher in Tween-80 samples 2, 20080709 and 20080616. These findings suggest that H2 O2 residue in combination with oxidized fatty acid residues (measured as peroxide value) or more likely the oxidized fatty acid residues in Tween-80 samples, but not Tween-80 itself, may induce anaphylactoid reaction. High-throughput zebrafish tryptase assay developed in this report could be used for assessing safety of Tween-80-containing injectable medicines and potentially for screening novel mast cell-modulating drugs.

Human prokinetic drugs promote gastrointestinal motility in zebrafish

BACKGROUND

Gastrointestinal (GI) motility disorders are highly prevalent in populations worldwide and the development of effective and safe drug treatments for GI motility disorders has proven challenging. In this study, taking advantage of the transparency of larval zebrafish, we developed a novel zebrafish GI motility model for drug screening and efficacy assessment.

METHODS

Zebrafish at 5 days postfertilization were fed 10 μg/L Nile red for 16 h, followed by drug treatment for 6 h. Tested drugs were delivered into the zebrafish by direct soaking. Drug effect on zebrafish GI motility was quantitatively assessed using GI tract fluorescent image-based morphometric analysis. During all the periods of the experiments, the zebrafish were not fed any food.

KEY RESULTS

All four human prokinetic drugs (domperidone, metoclopramide, mosapride, and magnesium sulfate) increased zebrafish GI motility, whereas two drugs that inhibit human GI movement (atropine and anisodamine) and two negative control drugs (glucose and vitamin C) did not show statistically significant effect on zebrafish GI motility.

CONCLUSIONS & INFERENCES

These results suggest that larval zebrafish motility model developed here is a useful tool for whole-animal in vivo GI transit studies and for assessing prokinetic drugs.