title: Toxicity evaluation of new agricultural fungicides in primary cultured cortical neurons.
abstract: Fungicides are crucial for food protection as well as for the production of crops of suitable quality and quantity to provide a viable economic return. Like other pesticides, fungicides are widely sprayed on agricultural land, especially in wine-growing areas, from where they can move-off after application. Furthermore, residues of these agrochemicals can remain on crops after harvest and even after some food processing operations, being a major exposure pathway. Although a relatively low toxicity has been claimed for this kind of compounds, information about their neurotoxicity is still scarce. In the present study, nine fungicides recently approved for agricultural uses in the EU - ametoctradin, boscalid, cyazofamid, dimethomorph, fenhexamid, kresoxim-methyl, mepanipyrim, metrafenone and pyraclostrobin - have been evaluated for their toxicity in primary cultured mouse cortical neurons. Exposure to 0.1-100µM for 7 days in vitro resulted in a dose-dependent toxicity in the MTT cell viability assay. Strobilurin fungicides kresoxim-methyl (KR) and pyraclostrobin (PY) were the most neurotoxic compounds (lethal concentration 50 were in the low micromolar and nanomolar levels, respectively) causing a rapid raise in intracellular calcium [Ca(2+)]i and strong depolarization of mitochondrial membrane potential. KR- and PY-induced cell death was reversed by the calcium channels blockers MK-801 and verapamil, suggesting that calcium entry through NMDA receptors and voltage-operated calcium channels are involved in KR- and PY-induced neurotoxicity. These results highlight the need for further evaluation of their neurotoxic effects in vivo.
authors.affiliation: Department of Neurochemistry and Neuropharmacology, Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), IDIBAPS, CIBERESP, Barcelona, Spain; Department of Analytical Chemistry and Food Science, Nutrition and Bromatology Group, Faculty of Food Science and Technology, University of Vigo, Ourense Campus, Ourense, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Regueiro
authors.affiliation: Department of Neurochemistry and Neuropharmacology, Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), IDIBAPS, CIBERESP, Barcelona, Spain.
authors.forename: Nair
authors.initials: N
authors.lastname: Olguín
authors.affiliation: Department of Analytical Chemistry and Food Science, Nutrition and Bromatology Group, Faculty of Food Science and Technology, University of Vigo, Ourense Campus, Ourense, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Simal-Gándara
authors.affiliation: Department of Neurochemistry and Neuropharmacology, Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), IDIBAPS, CIBERESP, Barcelona, Spain. Electronic address: csenqi@iibb.csic.es.
authors.forename: Cristina
authors.initials: C
authors.lastname: Suñol
mesh_terms: D016573:Agrochemicals / Q000633:toxicity*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005659:Fungicides, Industrial / Q000633:toxicity*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D011247:Pregnancy; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D016573:Agrochemicals; D005659:Fungicides, Industrial; D002118:Calcium
keywords: Calcium channels; Cortical neurons; Fungicides; Mitochondrial membrane potential; Neurotoxicity; Strobilurin