Adverse Outcome Pathways as Versatile Tools in Liver Toxicity Testing

Area of Science:

• Toxicology
• Chemical Risk Assessment

Background:

• Adverse outcome pathways (AOPs) provide a framework to understand and visualize the mechanistic basis of toxicological effects.
• AOPs consist of a molecular initiating event, key events, key event relationships, and an adverse outcome.
• Development and evaluation of AOPs should align with Organization for Economic Cooperation and Development guidelines.

Purpose of the Study:

• To highlight the utility and applications of Adverse Outcome Pathways (AOPs) in toxicology and chemical risk assessment.
• To emphasize the role of AOPs in understanding hepatotoxicity.
• To explore the application of AOPs in quantitative structure-activity relationships, prioritization, and in vitro testing.

Main Methods:

• Conceptual framework development for Adverse Outcome Pathways.
• Review of existing AOPs, particularly those related to hepatotoxicity.
• Analysis of proposed applications in risk assessment and testing strategies.

Main Results:

• AOPs offer a structured approach to toxicological mechanisms.
• The liver is a common target for systemic toxicity, leading to AOP development for hepatotoxicity.
• AOPs facilitate quantitative structure-activity relationships, prioritization, and novel in vitro toxicity testing.

Conclusions:

• Adverse outcome pathways are valuable tools for understanding and predicting toxicological effects.
• AOPs have significant potential to advance chemical risk assessment and the development of predictive toxicology methods.
• The structured nature of AOPs supports their integration into regulatory science and testing strategies.