Food Safety Analysis, LLC


Zebrafish Toxicology

When preparing new products for market and especially when attempting to register these products for sale in various markets, there is good reason to know (and to be able to produce data which confirms) that a given ingredient, combination of ingredients, entire product or residue remaining after a particular treatment is safe.

Toxicological studies have generally been expensive and slow. These days, preliminary toxicological data may be determined quickly by monitoring the effect an unknown sample has upon the normal development of the embryos of zebrafish, Danio rerio, and sometimes other fish species. By way of example, consider that food manufacturing facilities must often be sanitized. Sanitizers are often potent, highly toxic chemicals capable of causing considerable environmental damage were they to leave the confines of the plant. Yet, spent sanitizers must always be removed after production to make way for the next day's work. Since 2005, for example, fish embryo toxicity testing has been made mandatory for routine sewage surveillance in Germany.

This is not to say that such relatively inexpensive and rapid acute toxicity testing is meant to replace all toxicity testing with various kinds of rodents, dogs, cats, or even primates. Consumers all want their food products to be safe, yet many would disapprove of your using dogs and cats and even rodents like rats, hamsters, mice and guinea pigs for in-plant toxicity testing. They would consider the use of these species to test toxicity as a kind of torture, which, in a way, it certainly is. On the other hand, it would appear that humans don't seem to have a similar emotional attachment to fish. Indeed there is also the philosophical argument that the parental care given by zebrafish to their offspring is notably lacking. Indeed, if the same parental pair who spawned the embryos were to come across them a few hours later, they would eat them, without recognition, ceremony or remorse.

Toxicology is also possible using animal tissue culture cells. It is quite surprising to consider that most of the time, zebrafish embryo toxicological studies correlated quite well with other test animals, despite the evolutionary "distance" presumed by humans. Zebrafish embryo toxicity testing has been seen to correlate well with results obtained in the mouse model. In fact, zebrafish seem to be especially well-suited to model cardiotoxicity in humans. Especially useful is the fact that the zebrafish embryos are initially quite transparent. This means that if a problem does develop it may be possible, through simple microscopic observation (at relatively low magnification), pinpoint exactly where the problem lies.

All this is not to say that the world of toxicology has been turned on its ear and that it is time to let all the rats and mice out of their cages. But the point remains that when a simple, relatively inexpensive toxicology assay exists and has an extensive history of use by hospitals and research centers, it should find its way into the food industry both as guide for safe plant operation and as a test for the safety of ingredients, which FSMA holds is the ultimate responsibility of food manufacturers. These embryos may yet become a workable definition of what is and what isn't generally recognized as safe (GRAS) and may allow a bit more creativity in the assignment of preservatives in food formulation than has been the case hitherto.

Any zebrafish toxicology studies performed here will take a bit of lead time. Interested parties should contact Food Safety Analysis, LLC and describe the problem. It is perfectly understandable and, indeed, preferable if you would like to execute a non-disclosure agreement before you disclose the nature of the study you will require, including the controls you believe will be necessary. Once the scope of the problem has been outlined, you will receive two proposals, one predicated upon prepayment and the other invoice-based. Sign and return one or the other (but not both) and work will begin.

Copyright © 2012 by M. Mychajlonka, Ph. D.