PUBLICATION

Environmental concentrations of triclosan activate cellular defence mechanism and generate cytotoxicity on zebrafish (Danio rerio) embryos

Authors
Parenti, C.C., Ghilardi, A., Della Torre, C., Mandelli, M., Magni, S., Del Giacco, L., Binelli, A.
ID
ZDB-PUB-181003-12
Date
2018
Source
The Science of the total environment   650: 1752-1758 (Journal)
Registered Authors
Del Giacco, Luca, Ghilardi, Anna
Keywords
Biomarkers, Cytotoxicity, Danio rerio, Genotoxicity, Oxidative stress, Triclosan
MeSH Terms
  • Animals
  • Anti-Infective Agents, Local/toxicity
  • Antioxidants/metabolism*
  • Biomarkers/metabolism
  • DNA Damage*
  • Dose-Response Relationship, Drug
  • Embryo, Nonmammalian/drug effects
  • Embryo, Nonmammalian/immunology
  • Inactivation, Metabolic
  • Oxidative Stress/drug effects*
  • Reactive Oxygen Species/metabolism*
  • Triclosan/toxicity*
  • Water Pollutants, Chemical/toxicity*
  • Zebrafish/genetics
  • Zebrafish/immunology
  • Zebrafish/physiology*
PubMed
30273734 Full text @ Sci. Total Environ.
Abstract
Triclosan (TCS, 5‑chloro‑2‑(2,4‑dichlorophenoxy) phenol) is becoming a major surface waters pollutant worldwide at concentrations ranging from ng L-1 to μg L-1. Up to now, the adverse effects on aquatic organisms have been investigated at concentrations higher than the environmental ones, and the pathways underlying the observed toxicity are still not completely understood. Therefore, the aim of this study was to investigate the toxic effects of TCS at environmental concentrations on zebrafish embryos up to 120 hours post fertilization (hpf). The experimental design was planned considering both the quantity and the exposure time for the effects on the embryos, exposing them to two different concentrations (0.1 μg L-1, 1 μg L-1) of TCS, for 24 h (from 96 to 120 hpf) and for 120 h (from 0 to 120 hpf). A suite of biomarkers was applied to measure the induction of embryos defence system, the possible increase of oxidative stress and the DNA damage. We measured the activity of glutathione‑S‑transferase (GST), P‑glycoprotein efflux and ethoxyresorufin‑o‑deethylase (EROD), the level of ROS, the oxidative damage through the Protein Carbonyl Content (PCC) and the activity of antioxidant enzymes. The genetic damage was evaluated through DNA Diffusion Assay, Micronucleus test (MN test), and Comet test. The results showed a clear response of embryos defence mechanism, through the induction of P-gp efflux functionality and the activity of detoxifying/antioxidant enzymes, preventing the onset of oxidative damage. Moreover, the significant increase of cell necrosis highlighted a strong cytotoxic potential for TCS. The overall results obtained with environmental concentrations and both exposure time, underline the critical risk associated to the presence of TCS in the aquatic environment.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping