Structural determinants of developmental toxicity in hamsters.

Area of Science:

• Toxicology
• Computational Chemistry
• Pharmacology

Background:

• Developmental toxicity is a significant concern in chemical safety assessment.
• Structure-activity relationship (SAR) models are valuable tools for predicting chemical toxicity.
• Existing models often focus on specific mechanisms, like mutagenicity.

Purpose of the Study:

• To develop and evaluate a CASE/MULTICASE structure-activity relationship (SAR) model for predicting chemical developmental toxicity in hamsters (HaDT).
• To compare the HaDT SAR model's performance and characteristics with established models, such as those for mutagenicity.
• To investigate the underlying mechanisms and structural determinants associated with hamster developmental toxicity.

Main Methods:

• Development of a CASE/MULTICASE quantitative structure-activity relationship (QSAR) model.
• Utilizing a dataset of chemicals tested for developmental toxicity in hamsters.
• Comparative analysis with an existing SAR model for Salmonella mutagenicity.

Main Results:

• The developed HaDT SAR model achieved a predictive performance of 74%.
• The model's predictivity and informational content were comparable to the Salmonella mutagenicity SAR model.
• Unlike the mutagenicity model, the HaDT model did not identify specific reactive chemical groups.
• Analysis of structural determinants suggested developmental toxicity in hamsters involves diverse mechanisms and molecular targets, not a single one.

Conclusions:

• The developed HaDT SAR model provides a useful tool for predicting developmental toxicity.
• Developmental toxicity in hamsters appears to be a complex endpoint, not driven by a single mechanism or molecular target.
• Expanding the dataset with more experimental data is recommended to enhance the SAR model's predictive accuracy.