Imidacloprid promotes genetic damage and oxidative stress in different tissues of the Neotropical fish Prochilodus lineatus

VIEIRA, CARLOS EDUARDO DELFINO; PÉREZ , MA RITA; DOS REIS MARTINEZ, CLÁUDIA BUENO

Orlando

Congreso; 7th SETAC World Congress-SETAC North America 37th Annual Meeting; 2016

Society of Environmental Toxicology and Chemistry (SETAC)

IMIDACLOPRID PROMOTES GENETIC DAMAGE AND OXIDATIVE STRESS IN DIFFERENT TISSUES OF THE NEOTROPICAL FISH PROCHILODUS LINEATUSC.D. Vieira, Univ Estadual de Londrina / Departamento de Ciências Fisiológicas; M. Perez, Instituto de Limnología ? INALI / Laboratorio de Ictiología; C.B. Martinez, Univ Estadual de Londrina / Ciencias FisiologicasImidacloprid (IMI) is a systemic neonicotinoid insecticide widely used around the world, and recent data highlight this compound among the ten active ingredients commercialized in Brazil. However, despite its increasing use only few toxicity studies have been performed about its effects on non-target organisms. The aim of the study was to identify the potential hazard of the commercial formulation Imidacloprid® (48% imidacloprid- Nortox S.A. Brazil) in juveniles of Prochilodus lineatus (14.1 ± 1.14 g, 10.77 ± 0.6 cm [mean ± SD, n=40]). Fish were exposed to IMI at nominal concentrations of 5 (IMI5), 50 (IMI50), 500 (IMI500) and 5000 (IMI5000) μg/L or only to clean water (CTR) for 120 h, under static condition and daily water renewal. Biochemical parameters such as glutathione content (GSH), activity of the glutathione-S-transferase (GST) and acetylcholinesterase (AChE), lipoperoxidation (LPO), protein carbonylation (PC), genotoxic biomarkers (DNA damage), micronuclei (MN) and the erythrocytic nuclear abnormalities (ENAs) were evaluated in various organs. When compared to CTR fish, significant increases of LPO and PC were observed in the liver of fish exposed to IMI5000. In the gills we observed a significant increase of LPO in fish exposed to IMI50 and IMI500, and an increase of PC together with reduced GST activity in fish exposed to IMI5000. Fish exposed to IMI500 and IMI5000 showed significant increases of PC in the kidney. In addition, an increase of LPO and decrease of GST activity were observed in the kidney of fish from IMI5000 group. In the brain, a raise of GSH with concomitant increase of GST activity was observed at IMI500 and IMI5000. LPO also increased in the brain of fish exposed to IMI5 and IMI50, suggesting that the activation of antioxidant defenses (GSH and GST), observed at higher concentrations prevented oxidative stress in this organ. The comet assay showed increase DNA damage (p = 0,018) in the erythrocytes of fish exposed in all IMI concentrations tested. Also, there was a significant increase in ENAS frequency in fish exposed to IMI5000 (p= 0,043), relative to others groups. Taking together, these results suggest that IMI has the potential to promote oxidative stress and genotoxicity in P. lineatus, and kidney and gills proved to be the most affected organs, followed by the brain which showed oxidative damage in fish exposed to the lower IMI concentrations, which are the most environmentally relevant.