Effects of fipronil in biomarkers responses in a native species (Cyphocharax voga): branchial ex vivo exposure

SANTILLAN A; LOZANO I; ONDARZA PAOLA MARIANA; MIGLIORANZA KARINA SILVIA BEATRIZ; DE LA TORRE FERNANDO

Congreso; 12th Biennial Meeting Society of Environmental Toxicology and Chemistry; 2017

Fipronil (Fp) is a current use pesticide, highly toxic with potential nocive effects onaquatic organisms. Biomarkers responses are frequently used to detect these effects infish either on laboratory exposure or in situ assessments. In ex vivo experimentalmodels, the use of gills is justified since it is the first organ in contact withenvironmental pollutants. Biomarkers responses promoted by two sublethalconcentrations of Fp were evaluated in Cyphocharax voga after a branchial ex vivoexposure model. After sacrificing the fish (n=4), branchial arches were dissected andrandomly assigned to four treatment groups: saline solution (Ctrl); methanol in salinesolution (CtrlSv); and two nominal concentrations of Fp (9 µg/L, C1 and 100 µg/L,C2) prepared from a stock solution on methanol. Gills remained submerged in thesolutions under continuous agitation for 1h at 25°C in glass containers. Levels of Fpwere also analyzed with liquid-liquid extaction and GC-ECD. After incubation period,enzymatic activities of superoxide dismutase (SOD), antioxidant capacity againstperoxyl radicals (ACAP), lipid peroxidation levels by TBARS and reduced glutathionelevels (GSH) were evaluated. Differences between groups were analyzed by one wayANOVA (p< 0.05) and Tukey?s multiple comparisons. No significant differencesbetween the parameters of Ctrl and CtrlSv were detected. Gills exposure to C1concentration promoted an increase (15%) in SOD activity. Furthermore, a significantincrease (40%) in TBARS levels was detected in C1 group respect to Ctrl. Expositionto C2 concentration promoted a decrease (38%) in GSH levels. No significantdifferences were observed in total antioxidant capacity (ACAP). These results indicatethat the assayed concentrations of Fp proved to be an inducer of oxidative stress ingills. Enzymatic and non-enzymatic activities were not enough to prevent oxidativedamage to lipid levels