Effects of a commercial formulation of a neonicotinoid insecticide (Assail® 70) and its active ingredient (acetamiprid) on Biomphalaria straminea (Mollusca: Planorbidae)

HERBERT, L.T.; KRISTOFF, G.; COSSI, P.F.; PEREZ, A.F.; YUSSEPPONE, M.S

ACTA TOXICOLóGICA ARGENTINA

ASOCIACIÓN TOXICOLÓGICA ARGENTINA

Lugar: Buenos Aires; Año: 2019 vol. 27

0327-9286

The use of neonicotinoids in agriculture has rap-idly expanded at a large scale in recent years.They emerged as a new generation of environ-mentally safe insecticides in order to replacemore toxic and persistent compounds such asorganophosphates. Neonicotinoids act as ago-nists of the nicotinic acetylcholine receptors inthe target pest but they may also cause lethaland sublethal effects on non-target organisms.We aimed to study the effects of the commer-cial formulation Assail® 70 and its active ingre-dient (a.i. acetamiprid (ACP)) on biochemicalbiomarkers in a non-target native freshwatergastropod from Argentina, Biomphalaria stra-minea. The assay included five treatments:dechlorinated tap water (control), a.i. ACP at150 and 1500 μg L-1 (ACP 1 and ACP 2), andthe equivalent to those concentrations of theformulation Assail® 70 (ACP F1 and ACP F2).Seven glass vessels per treatment were usedwith six snails each. After 14 days of exposure,homogenates were made with the organisms?soft tissues. The following parameters weremeasured: cholinesterases (ChEs), carboxyles-terases (CEs) with two substrates (p-NPA andp-NPB), glutathione S-transferase (GST), su-peroxide dismutase (SOD), glutathione (GSH),catalase (CAT), total antioxidant capacity (TAC)and reactive oxygen species (ROS). ChE andCE (p-NPA) activities were not altered by thea.i. nor the formulation of ACP. Conversely, thelowest concentration of the formulation and thehighest concentration of both a.i. and formula-tion (ACP F1, ACP 2 and ACP F2) significantlyincreased CE (p-NPB) activity (by 18, 32 and37 %, respectively). Both concentrations ofthe formulation (ACP F1 and ACP F2) causeda significant increase in GST activity (by 17 and15 %, respectively). The lowest concentrationof both a.i. and formulation (ACP 1 and ACPF1) significantly decreased SOD activity (by 23and 25 %, respectively) and only the highest concentration (ACP F2) significantly decreasedCAT activity (by 25 %). Both concentrations ofthe a.i. and formulation (ACP 1, ACP 2, ACP F1and ACP F2) significantly increased GSH con-tent (by 15, 38, 36 and 52 %, respectively). Thehighest concentration of both a.i. and formula-tion caused a significant decrease in ROS pro-duction (both by 18%) but ACP did not affectTAC. A subchronic exposure to Assail® 70 andits a.i. ACP did not affect ChE activity, which isconsistent with neonicotinoids mode of action.Nevertheless, they triggered a toxic responseon B. straminea where detoxifying (CE andGST) and antioxidant parameters (GSH, SODand CAT) are involved. The formulation showedto be more toxic than the a.i. since it caused agreater response in the measured parameters.