The Future of Toxicity Testing Is In Vitro
Chemical toxicity testing is approaching a major transformation that involves a move away from animal testing, according to a recent report by the National Research Council (NRC). The U.S. Environmental Protection Agency asked the NRC to conduct a comprehensive review of current toxicity testing methods and propose a strategy for future toxicity testing. The NRC found that current testing methods, which are primarily animal tests, are time-consuming, expensive, and often unreliable in predicting human toxicity, partly because of interspecies differences in pharmacokinetic processes. The council also found that the animal tests provide little to no information on the mechanism of action of toxicity or for assessing variability in human susceptibility.
In contrast to animal tests, cellular-based methods not only are proving to be cheaper, faster, and easier to use, but also are providing more relevant information. Scientists are increasingly able to assess both acute and chronic toxicity by evaluating cellular pathways and biomarkers indicative of toxicity. In vitro (test tube) tests can be automated to evaluate thousands of chemicals over a wide concentration range and can identify a chemical’s action on gene and cell function and mode of action of toxicity. The NRC concludes, “Over time, the need for traditional animal testing should be greatly reduced and possibly even eliminated.”
Committee on Toxicity Testing and Assessment of Environmental Agents, National Research Council. Toxicity testing in the twenty-first century: a vision and a strategy.