Modern Approaches to Chemical Toxicity Screening

Area of Science:

• Biochemistry
• Toxicology
• Analytical Chemistry

Background:

• Chemical toxicity poses significant public health risks and increases drug development costs due to candidate failures.
• Existing in vitro bioassays for toxicity screening are evolving towards high-throughput and high-content formats, with some utilizing electrochemical detection.
• Chemical toxicity often stems from metabolites, necessitating assays that incorporate metabolic conversion for accurate assessment.

Purpose of the Study:

• To develop and employ novel cell-free microfluidic arrays for assessing chemical genotoxicity.
• To measure DNA-metabolite adduct formation and DNA oxidation levels resulting from enzyme-generated metabolites.
• To identify reactive metabolites and investigate mechanistic details of toxicity.

Main Methods:

• Utilized electrochemical and electrochemiluminescent approaches in cell-free microfluidic arrays.
• Measured relative rates of DNA-metabolite adduct formation (genotoxicity) and DNA oxidation.
• Simultaneously studied enzymes from multiple organ types.
• Employed high-throughput LC-HPLC with enzyme/DNA-coated magnetic beads for mechanistic studies.

Main Results:

• Demonstrated the capability of microfluidic arrays to measure genotoxicity and DNA oxidation from enzyme-generated metabolites.
• Enabled simultaneous analysis of enzymes from various organ types.
• Facilitated the identification of the most reactive metabolites.

Conclusions:

• Cell-free microfluidic arrays offer a powerful tool for toxicity prediction by integrating metabolic conversion and electrochemical detection.
• This approach can help identify genotoxic metabolites and elucidate mechanisms of toxicity.
• Combining bioassays, computational predictions, and pathway elucidation enhances the reliability of toxicity assessments.