Pulse and spiked sediments bioassay with a commercial formulation of the insecticide fipronil: biomarker responses in the fish Prochilodus lineatus

LAGRAÑA, ALDANA; LOZANO, ISMAEL ESTEBAN; MIGLIORANZA, KARINA; DE LA TORRE, FERNANDO

Valdivia

Congreso; SETAC Latin America 14th Biennial Meeting; 2021

Society of Environmental Toxicology and Chemistry (SETAC)

Toxicity offipronil (FP) is well documented in insects although limited knowledge of sublethaleffects is available on fish. Fipronil can often reach aquatic environments vialocal inputs or surface runoff. Environmental concentrations previouslyreported in sediments were up to 5.5 µg/kg. In this work, we evaluated biomarkerresponses in target organs of Prochiloduslineatus juveniles after exposure to a commercial formulation of FP (ClapBayer®) in a sediment static bioassay. Fish (4.2 ± 0.9 gb.w; n=27) were exposed during 14 days to three experimental conditions: fishexposure to sediments spiked with Clap (Sp)(5.5 µg/kg); fish exposure to sediments with a contaminant pulse with Clap (Pu) (50 µg/l), and control sediments (Ctrl). Following exposure, liver, brain,gills and muscle were collected. Antioxidant defenses (catalase activity, CAT; glutathione-S-transferaseactivity, GST; antioxidant capacity against peroxyls, ACAP; reducedglutathione content GSH) and oxidative damage parameters (levels of lipidperoxidation by TBARS) were determined in liver, brain and gills. Brain-motorparameter (acetylcholinesterase activity (AChE)) was evaluated in brain andmuscle. Sediments, water and suspended particulate matter weretaken for analytical quantification of FP. Differencesbetween groups were analyzed by ANOVA followed by Tukey test (p<0.05). In liver, the adverse effect of CLAP in Pu was evident by the significant inhibitionof the GST activity (-44%), and an increase (+20%) in GSH content, while in Spelicited a significative increase (+129%) of ACAP. In gills, spiked sediments produceda significantly decrease (-42%) of GSH content and ACAP levels (-31%); while inPu a decrease (-23%) in ACAP was observed. Antioxidant responses were alsoobserved in brain from Sp (42% increase in CAT activity and asignificant increase in the ACAP values 167%), while a decrease in theantioxidant capacity was evident for ACAP (157%) from Pu. Muscle AChE activity was significantly inhibited in Sp (-31%) and in Pu (-42%). Our resultsindicate that both (pulse and spiked) exposure conditions induced adverse responsesin biomarkers of P. lineatus juvenilesat different levels. Antioxidant capacity was the most sensible parameter,while gills was the less affected organ.