Adverse effects promoted by a commercial formulation of the insecticide Fipronil in gill biomarkers of sábalos (Prochilodus lineatus).

SAGER, E; LOCH, LAUREANO; DE LA TORRE, F.R.

Santos

Congreso; 12th SETAC Latin America Biennial Meeting, pag 111. 2017; 2017

SETAC

Fipronil (fp) is a pesticide whose toxicity ininsects is well documented although limited knowledge concerningsublethal effects is available in other non-target organisms (eg, fish).Gills are the first target organ where pollutants impact in aquaticorganisms, therefore gill biomarker responses elicited by sublethalcontrations of fipronil could be indicative for evaluating the immediatedamage produced by this insecticide in fish. In this context, biomarkerresponses promoted in juveniles of P. lineatus were evaluated after 48hof exposure to two nominal concentrations (10 and 100 ug/L) of acommercial formulation of fipronil (Clap Bayer ®) dissolved inunchlorinated tap water. Fish (34 ± 9 g, n=15) were kept in aquariaunder controlled conditions and fresh media was renewed twice dailyusing a flow-through system. Control fish remained in aquaria with tapwater. After experimental period, fish were weighed, anesthetized andgills were dissected. Condition factor (CF) and liver somatic index (LSI)were calculated, antioxidant defenses (catalase activity, CAT;glutathione-S-transferase activity, GST; antioxidant capacity againstperoxyls, ACAP) as well as oxidative damage parameters (levels of lipidperoxidation by TBARS and oxidized protein profile, Pox). Differencesbetween groups were analyzed using one way ANOVA and Tukey´smultiple comparisons. No significant differences were detected amonggroups in CF, LSI and CAT. Exposure to 10 ug/L Fp elicited only GSTantioxidant response (+19,6 %), however both TBARS (+29,1%) andPox (+83,0%) levels were increased. Considering the effects promotedafter 100 ug/L Fp exposure, almost all of the antioxidant defenses wereactivated respect to Ctrl group. In this context, GST activity activated(+21,0 %), a depletion of GSH levels ( -39,5 %) was observed, besidesACAP values increased (+192,6 %) showing a decrease in theantioxidant capacity. In spite of this antioxidant response of biomarkers,oxidative damage was evident in exposed fish showing an increase ofTBARS values (+11, 3 %). These results indicated that short termexposure to sublethal concentrations of formulated fipronil promotedadverse effects in gills of this native species showing that antioxidantdefenses were exceeded leading to oxidative damage on lipids andproteins, these fact was evident even in ecologically relevantconcentrations.