Genotoxicity and Cytotoxicity Exerted by Pesticides in Different Biotic Matrices-An Overview of More Than a Decade of Experimental Evaluation

Agrochemicals represent one of the most important sources of environmental pollution. Although attempts to reduce agrochemical use through organic agricultural practices and the use of other technologies to control pests continue, the problem is still unsolved. Recent technological advances in molecular biology and analytical science have allowed the development of rapid, robust, and sensitive diagnostic tests (biomarkers) that can be used to monitor exposure to, and the effects of pollution. One of the major goals of our research laboratory is to evaluate comparatively the genotoxic and cytotoxic effects exerted by several pure agrochemicals and their technical formulations commonly used in Argentina on vertebrate cells in vitro and in vivo employing several end-points for geno and cytotoxicity. Among them are listed the herbicides dicamba and flurochloridone, the fungicide zineb, the insecticides pirimicarb and imidacloprid. Overall, the results clearly demonstrated that the damage induced by the commercial formulations is in general greater than that produced by the pure pesticides, suggesting the presence of deleterious components in the excipients with either a putative intrinsic toxic effect Larramendy et al. 4 or with the capacity of exacerbating 52 the toxicity of the pure agrochemicals, or both. Accordingly, the results highlight that: 1) A complete knowledge of the toxic effect/s of the active ingredient is not enough in biomonitoring studies; 2) Pesticide/s toxic effect/s should be evaluated assaying to the commercial formulation available in market; 3) The deleterious effect/s of the excipient/s present within the commercial formulation should not be either discarded nor underestimated, and 4) A single bioassay is not enough to characterize the toxicity of a agrochemical under study.Fil: Larramendy, Marcelo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Citología; ArgentinaFil: Nikoloff, Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Citología; ArgentinaFil: Ruiz de Arcaute, Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Citología; ArgentinaFil: Soloneski, Sonia Maria Elsa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Citología; Argentin

Genotoxicity and Cytotoxicity Exerted by Pesticides in Different Biotic Matrices-An Overview of More Than a Decade of Experimental Evaluation

Agrochemicals represent one of the most important sources of environmental pollution. Although attempts to reduce agrochemical use through organic agricultural practices and the use of other technologies to control pests continue, the problem is still unsolved. Recent technological advances in molecular biology and analytical science have allowed the development of rapid, robust, and sensitive diagnostic tests (biomarkers) that can be used to monitor exposure to, and the effects of pollution. One of the major goals of our research laboratory is to evaluate comparatively the genotoxic and cytotoxic effects exerted by several pure agrochemicals and their technical formulations commonly used in Argentina on vertebrate cells in vitro and in vivo employing several end-points for geno and cytotoxicity. Among them are listed the herbicides dicamba and flurochloridone, the fungicide zineb, the insecticides pirimicarb and imidacloprid. Overall, the results clearly demonstrated that the damage induced by the commercial formulations is in general greater than that produced by the pure pesticides, suggesting the presence of deleterious components in the excipients with either a putative intrinsic toxic effect Larramendy et al. 4 or with the capacity of exacerbating 52 the toxicity of the pure agrochemicals, or both. Accordingly, the results highlight that: 1) A complete knowledge of the toxic effect/s of the active ingredient is not enough in biomonitoring studies; 2) Pesticide/s toxic effect/s should be evaluated assaying to the commercial formulation available in market; 3) The deleterious effect/s of the excipient/s present within the commercial formulation should not be either discarded nor underestimated, and 4) A single bioassay is not enough to characterize the toxicity of a agrochemical under study.Facultad de Ciencias Naturales y Muse

Erythrocytes modulate cell cycle progression but not the baseline frequency of sister chromatid exchanges in pig lymphocytes

The effect of co-culturing varying concentrations of pig and human red blood cells (RBCs) on the baseline frequency of sister chromatid exchanges (SCEs) and cell-cycle progression in pig plasma (PLCs) and whole blood leukocyte cultures (WBCs) was studied. No variation in SCE frequency was observed between pig control WBC and PLC. Addition of pig and human RBCs to pig PLCs did not modify the baseline frequency of SCEs. On the other hand, cell proliferation was slower in PLCs than in WBCs. The addition of pig or human RBCs to PLCs accelerated the cell-cycle progression of pig lymphocytes. When RBCs were added to PLCs the concentration and time sequence of RBC incorporation affected the cell-cycle progression of swine lymphocytes. When doses of pig or human RBCs equivalent to those present in WBCs were added immediately after PLC stimulation, the cell-cycle kinetics were similar to those of WBCs. Shorter co-incubation periods or a reduction in the dose of RBCs made cell-cycle progression intermediate between PLC and WBC values. Thus, pig and human RBCs modulated the in vitro cell-cycle progression of pig lymphocytes in a time- and dose-dependent manner, and the low baseline frequency of SCEs of pig lymphocytes is independent of the presence or absence of erythrocytes in culture.Facultad de Ciencias Naturales y Muse

GENOTOXICIDAD INDUCIDA POR EL HERBICIDA FITOHORMONAL ÁCIDO 2,4-DICLOROFENOXIACÉTICO CONTENIDO EN LA FORMULACIÓN COMERCIAL DMA® EN Cnesterodon decemmaculatus (PISCES: POECILIIDAE)

El 2,4- diclorofenoxiacético (2,4-D) es un herbicida sistémico ampliamente usado en Argentina que imita la acción de las fitohormonas auxinas. Estas actúan alterando el desarrollo y crecimiento de las plantas. El presente trabajo tiene como objetivo evaluar los efectos letales y genotóxicos inducidos por el formulado DMA® (58,4% 2,4-D como sal de dimetilamina) en ejemplares adultos de C. decemmaculatus expuestos en condiciones de laboratorio. Se determinó la CL5096h, y a partir de ésta se expusieron individuos a concentraciones subletales de 252, 504 y 756 mg 2,4-D mg/l (correspondientes al 25, 50 y 75% de CL5096h) durante 48 y 96 h. Se utilizó ciclofosfamida (10 mg/l) y agua de red declorinada como control positivo y negativo, respectivamente. Como método de estudio se emplearon el ensayo de micronúcleos (MN) y de anormalidades nucleares (AN) en células circulantes sanguíneas. Los datos fueron analizados estadísticamente por ANOVA simple y test a posteriori de Dunnett. La CL5096h obtenida fue 1008,16 mg 2,4-D/l (LC95% 928,72-1070,31 mg 2,4-D/l). Los resultados demuestran que el 2,4-D incrementó la frecuencia de micronúcleos con todas las concentraciones ensayadas tanto a las 48 como a las 96 h de exposición (p<0,05). Asimismo, se observó un incremento significativo de AN (hendiduras nucleares y buds nucleares) en individuos expuestos a 756 mg 2,4-D/l por 48 h y a 504 mg 2,4-D/l por 96 h. Nuestros estudios evidencian la capacidad de 2,4-D de inducir daño en el ADN de células sanguíneas de esta especie autóctona. Asimismo, nuestros resultados constituyen la primera evidencia de evaluación genotóxica de 2,4-D sobre C. decemmaculatus

Acute toxicity of chromium on Cnesterodon decemmaculatus (pisces: poeciliidae) (La toxicidad aguda del cromo en Cnesterodon decemmaculatus (pisces: poeciliidae))

Se evaluó la toxicidad aguda del Cr(VI) durante 96 h de exposición continua en ejemplares de madrecitas de agua, Cnesterodon decemmaculatus (Jenyns 1842), pez ovovivíparo de amplia distribución neotropical. Se evaluó la CL50/24-96h por exposición a concentraciones de 0-45,5 mg L-1 de Cr(VI). Los resultados mostraron que la CL-50 alcanzó valores de 35,1, 27,5, 24,0 y 21,4 mg L-1 luego de 24, 48, 72 y 96 h de exposición, respectivamente. No se observó mortalidad tanto en los controles como en aquellos peces expuestos a 3,2 mg L-1. Sin embargo, dicho parámetro alcanzó valores del 63% en aquellos ejemplares expuestos a la mayor concentración luego de 24 h de exposición. Estos resultados sugieren que Cr(VI) podría ser utilizado control positivo en la evaluación de la toxicidad en peces, al menos cuando C. decemmaculatus es empleado como modelo experimental.AbstractThe acute toxicity of Cr(VI) upon 96 h of continuous exposure of the ten-spotted live-bearing fish Cnesterodon decemmaculatus (Jenyns 1842) was evaluated (LC50/96h) in the concentration from 0 to 45.5 mg L-1 Cr(VI) and found to be 21 mg L-1; Upon 24, 48, 72, and 96 h of exposure, the LC50 values are 35.1, 27.5, and 24.0 and 21.4 mg L-1, respectively. No mortality was observed for controls or for the fish exposed at 3.2 mg L-1. Mortality at the highest Cr(VI) concentration within 24 h exposure was 63 % Cr(VI) is suggested to be used as positive control agent in piscine toxicity assessment, at least when C. decemmaculatus is involved

Long term consumption of thiamethoxam coated seeds causes multilevel effects to the passerine Agelaiodes badius

Presentación en diapositivasBirds and pesticide treated seeds Birds and pesticide treated seedsBirds and pesticide treated seeds Birds and pesticide treated seedsInstituto de Recursos BiológicosFil: Poliserpi, María Belén. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina.Fil: Fernández-Vizcaino, E. CSIC. Instituto de Investigación de Recursos Cinegéticos (IREC) SCIC-UCLM; EspañaFil: Ruíz de Arcaute, C. Universidad Nacional de La Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Soloneski, S. Universidad Nacional de La Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Brodeur, Julie Celine. Universidad Nacional de La Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina

Vitamin E prevents ethylene bis(dithiocarbamate) pesticide zineb-induced sister chromatid exchange in Chinese hamster ovary cells

The in vitro effect of the antioxidant α-tocopherol, vitamin E, on deleterious effects induced by the dithiocarbamate fungicide zineb and its commercial formulation azzurro on Chinese hamster ovary (CHO) cells was studied by using frequency of sister chromatid exchanges (SCEs), cell cycle progression and mitotic index (MI) as genetic end points. Both zineb and azzurro activities were tested within the range 0.1-100.0 μg/ml on exponentially growing CHO cells preincubated for 24 h in the presence or absence of 50.0 μg/ml vitamin E. SCE frequencies increased significantly over control values in a concentration-dependent manner in zineb- and azzurro-treated cultures at concentrations of 0.1-10.0 and 0.1-25.0 μg/ml, respectively. When target cells were preincubated with vitamin E, the number of SCEs was significantly lower than that observed in cells exposed only to 1.0-10.0 μg/ml zineb or 1.0-25.0 μg/ml azzurro, but higher than control values. Cytotoxicity was observed at concentrations higher than 25.0 and 50.0 μg/ml zineb and azzurro, respectively, regardless of the absence or presence of vitamin E. Regression analysis showed that the proliferative rate index decreased as a function of the concentration of zineb (0.1-10.0 μg/ml concentration range) and azzurro (0.1-25.0 μg/ml concentration range) titrated into cultures. For both chemicals, progressive concentration-related inhibition of the mitotic activity from cultures was observed when 10.0 μg/ml zineb or 1.0-25.0 μg/ml azzurro was employed. However, no significant alteration in cell cycle progression or MI was observed between vitamin E-preincubated cultures and those treated only with zineb and azzurro.Facultad de Ciencias Naturales y Muse