Species extrapolation for the 21st century

Area of Science:

• Environmental toxicology
• Computational toxicology
• Ecotoxicology

Background:

• Safety factors in ecological risk assessment rely on extrapolating lab species' toxic responses to environmental populations.
• Current extrapolation methods have limitations, necessitating more accurate cross-species predictions.
• Understanding toxicological mechanisms and molecular pathways is key to improving interspecies extrapolation.

Purpose of the Study:

• To present a conceptual approach for cross-species extrapolation in ecological risk assessment.
• To highlight development goals for predictive in silico extrapolation of wildlife species' toxic responses.
• To identify critical information needed for evidence-based species extrapolation.

Main Methods:

• Reviewing advances in mechanistic toxicology and molecular response pathways.
• Presenting a case study on steroidogenesis inhibition in fish (fadrozole, prochloraz).
• Utilizing homology modeling to predict chemical interactions with enzymes like CYP19 aromatase.

Main Results:

• Similar steroidogenesis inhibition effects in fathead minnow, medaka, and zebrafish were linked to shared pharmacokinetic/pharmacodynamic profiles and CYP19A1/2 sequences.
• Homology modeling shows promise for predicting chemical interactions with enzymes across species.
• Substantial research is still needed to develop robust predictive models.

Conclusions:

• Mechanistic understanding and molecular pathway analysis are vital for improving cross-species extrapolation in toxicology.
• In silico approaches, aided by advances in homology modeling, offer future potential for predicting wildlife toxicity.
• Further research into life history, gene expression, and metabolism is required to refine interspecies extrapolation methods.