Computational Molecular Modeling for Evaluating the Toxicity of Environmental Chemicals: Prioritizing Bioassay Requirements

BACKGROUND The human health risk from exposure to environmental chemicals often must be evaluated when relevant elements of the preferred data are unavailable. Therefore, strategies are needed that can predict this information and prioritize the outstanding data requirements for the risk evaluation. Many modes of molecular toxicity require the chemical or one of its biotransformation products to interact with specific biologic macromolecules (i.e., proteins and DNA). Molecular modeling approaches may be adapted to study the interactions of environmental chemicals with biomolecular targets. OBJECTIVE In this commentary we provide an overview of the challenges that arise from applying molecular modeling tools developed and commonly used for pharmaceutical discovery to the problem of predicting the potential toxicities of environmental chemicals. DISCUSSION The use of molecular modeling tools to predict the unintended health and environmental consequences of environmental chemicals differs strategically from the use of the same tools in the pharmaceutical discovery process in terms of the goals and potential applications. It also requires consideration of the greater diversity of chemical space and binding affinity domains than is covered by pharmaceuticals. CONCLUSION Molecular modeling methods offer one of several complementary approaches to evaluate the risk to human health and the environment as a result of exposure to environmental chemicals. These tools can streamline the hazard assessment process by simulating possible modes of action and providing virtual screening tools that can help prioritize bioassay requirements. Tailoring these strategies to the particular challenges presented by environmental chemical interactions make them even more effective.