Combined toxicological effects of pesticides: A fish multi-biomarker approach

Abstract

The combined effects of two synthetic insecticides on a wide array of biomarkers in the freshwaterfish Piaractus mesopotamicus were studied. Fish were exposed to sublethal concentrations of endosul-fan (ED), lambda-cyhalothrin (LC), and the combination of both pesticides for 96 h. The set of analyzedbiomarkers included morphometric and hematological parameters, transaminases and alkaline phos-phatase activities, antioxidant enzymes activities and oxidative damage biomarkers measured in gills,liver, kidney, brain and muscle. According to the principal component analysis, the most significant effectswere produced by the ED?LC combination. So, the mixture of both insecticides produced an increase inthe liver-somatic index, hematological changes related to immunological biomarkers (increased whiteblood cells count, and alterations in the differential leukocytes count), decreased liver transaminasesactivity, antioxidant enzymes induction in almost every tissue, and lipid peroxidation levels increases inliver, kidney and brain of exposed fish. Our results suggest deleterious effects of ED and LC insecticidesin combination, and support the usefulness of the multi-biomarker approach for the characterization oftoxicological mechanisms induced by pesticides.