[Toxic effects of sublethal acetochlor with sublethal doses on earthworms in soil using multi-endpoints system]

Area of Science:

• Environmental Toxicology
• Ecotoxicology
• Biomarker Discovery

Background:

• Acetochlor is a widely used herbicide with potential environmental impacts.
• Earthworms are crucial soil organisms, serving as indicators of soil health.
• Understanding sublethal effects is vital for ecological risk assessment.

Purpose of the Study:

• To investigate the toxic effects of sublethal acetochlor doses on earthworms.
• To identify sensitive biomarkers for acetochlor exposure.
• To elucidate the toxicity mechanisms of acetochlor in earthworms.

Main Methods:

• Earthworms were exposed to varying sublethal doses of acetochlor (1-8 mg·kg⁻¹).
• Growth inhibition, cytochrome P450 isozyme (CYP1A2, 2C9, 3A4) activities, and metabolomic profiles were analyzed.
• Changes in individual, enzyme, and metabolite levels were assessed after seven days.

Main Results:

• Significant inhibition of CYP1A2, 2C9, and 3A4 activities observed.
• Ten metabolites decreased (e.g., fructose-6-diphosphate, adenosine monophosphate) and six increased (e.g., succinic acid, arginine) significantly.
• Acetochlor exposure induced oxidative damage, impaired glycolysis, disturbed the TCA cycle, and disrupted purine/pyrimidine and amino acid metabolism.

Conclusions:

• CYP isozyme activities and specific small molecule metabolites are sensitive biomarkers for acetochlor pollution.
• These biomarkers offer a more sensitive and accurate method for diagnosing acetochlor contamination compared to individual-level endpoints.
• The findings provide insights into the toxicological mechanisms of acetochlor in soil invertebrates.