# The triggered antioxidant response and corresponding metabolomics expression of Caenorhabditis elegans for chronic exposure to moxifloxacin and trace copper

## TL;DR

This study examines how moxifloxacin and trace copper affect the health and antioxidant responses of C. elegans over time.

## Contribution

The study reveals new insights into the combined toxic effects of moxifloxacin and trace copper on C. elegans at multiple biological levels.

## Key findings

- Prolonged exposure to moxifloxacin inhibits genes related to cellular health and antioxidant defense in C. elegans.
- Chronic exposure to moxifloxacin and copper reduces ROS levels and promotes antioxidant defenses through gene regulation.
- The study identifies specific gene and metabolic responses to chronic exposure of moxifloxacin and trace copper in C. elegans.

## Abstract

As the terminal management for evaluating the engineering effectiveness of antibiotics production and utilization, the toxic effects of moxifloxacin (MOX) and trace concentration of Cu2+ (MOX-Cu) on Caenorhabditis elegans (C. elegans) were investigated at physiological, biochemical, and molecular level. Although the stimulate effects were observed after prolonged exposure (72 h) to MOX (0.2-2.0 mg/L), the expressions of HSPs, ace genes, and daf-16 were inhibited, indicating its adverse impact on cellular health, locomotion behaviors, and antioxidant defense of C. elegans. Similarly, the down-regulation of oxidative stress (sod-1 and daf-16) and cell damage (HSPs) related genes and the up-regulation of apoptosis-related genes (cep-1 and ape-1) indicated the oxidative stress and genotoxicity after prolonged exposure to MOX-Cu. For the chronic exposure (10 days) to MOX, the level of ROS was reduced due to the increased expressions of daf-16, sod-3, and hsp-16, accompanied with and the down-regulation of cep-1. Meanwhile, at the exposure to MOX-Cu, the levels of ROS and lipofuscin were decreased due to the up-regulation of sod-1 and daf-16, and the antioxidant defense was promoted and confirmed by the increase of amino acids and their related metabolic pathways. These results can provide a theoretical basis for the toxicity evaluation of typical antibiotics (MOX) that co-existing with trace heavy metals in natural environment media and bioresources processes.

The online version contains supplementary material available at 10.1186/s40643-026-01033-4.