Worms' Turn at Toxins

A tiny worm that spends its brief life dining on microbes in the soil may soon be used to substantially reduce--and in some cases eliminate--the need for expensive large-scale rodent studies to screen chemicals for several kinds of toxicity. Duke toxicologists are evaluating the lowly roundworm, Caenorhabditis elegans (C. elegans), as a cheaper and quicker alternative to rats and mice in testing chemicals for toxicity. For one thing, the worm's 959 cells contain many genes and proteins that function similarly to those of higher animals, including humans. Jonathan Freedman of Duke's Nicholas School of the Environment and Earth Sciences is seeking to apply knowledge about the roundworm's biology to answer questions of toxicology.

"The idea is to quickly screen chemicals with C. elegans so you don't have to do so many mega-rat studies," Freedman says. "If Company X thinks it has a chemical that may be a nerve toxin or cause cancer, we will put it through our system to help find out. What we've done is save that company millions of dollars because it no longer has to do as large a rat study.

"It can cost a company $10 million, and it may have to go through 100,000 rats over a year or two just to do a complete study on one chemical. With our worms, I envision we'll be able to get the whole thing done in a couple of weeks to maybe a month."

During a three-year evaluation, Freedman and his colleagues plan to study the worm's response to 200 different chemicals.