Oxidative stress and DNA damage responses to phenanthrene exposure in the estuarine guppy Poecilia vivipara

• Guppies were acutely exposed in saltwater to relevant phenanthrene concentrations.
• Oxidative stress biomarkers, DNA strand breakage and clastogenicity were evaluated.
• Responses of biomarkers varied according to phenanthrene concentration and tissue.
• Response of antioxidant system prevented high levels of oxidative damage to lipids.
• Damage to DNA was observed at low concentrations of phenanthrene.

Despite ubiquitous phenanthrene contamination in aquatic coastal areas, little is known regarding its potential effects on estuarine fishes. The present work evaluated the response of a large suite of oxidative stress- and DNA damage-related biomarkers to phenanthrene exposure (10, 20 and 200 μg L−1, 96 h) using DMSO as the solvent in estuarine guppy Poecilia vivipara (salinity 24 psu). Phenanthrene affected oxidative stress-related parameters, and decreased antioxidant defenses and reactive oxygen species in the gills and muscle overall. Lipid peroxidation occurred in muscle at 200 μg L−1 phenanthrene. Genotoxicity was increased at 20 μg L−1, while 200 μg L−1 caused a relative decrease in erythrocyte release into the bloodstream. These findings indicated that phenanthrene is genotoxic and can induce oxidative stress, depending on tissue and phenanthrene concentration analyzed. Thus, some of the biomarkers analyzed in the present study are sufficiently sensitive to monitor the exposure of the guppy P. vivipara to phenanthrene in salt water. However, further studies are required for a better interpretation of the dose–response patterns observed.