ABSTRACT
Mycotoxins are a group of chemically diverse naturally occurring substances resulting from the secondary metabolism of pathogenic filamentous fungi. They are produced mainly by the genera Fusarium, Alternaria, Aspergillus and Penicillium which can contaminate grains and cereals such as wheat, corn and soy. According to the nature and the concentration levels, mycotoxins can induce toxic effects in food-production animals and humans. An in vitro study was conducted to evaluate the susceptibility of broiler chickens lymphocytes to different concentrations of ochratoxin A, deoxynivalenol and zearalenone. Each toxin was added to the cell medium at different concentrations (0.001, 0.01, 0.1 and 1μg/mL). Cell viability and ecto-adenosine deaminase activity were assessed at 24, 48 and 72 hours by colorimetric assays. Thus, it were used 0.7x10(5) lymphocytes/mL in RPMI 1640 medium, supplemented with 10% fetal bovine serum and 2.5 IU of penicillin/streptomycin per mL, incubated at 37°C in a 5% CO2 atmosphere. All the experiments were carried out in triplicate and the results were expressed as mean ± standard error of the mean. The results showed that OTA and DON induced lymphocyte proliferation and reduced enzymatic activity in vitro (P<0,05), whereas ZEA also promoted proliferation (P<0,05), but neither alteration on enzymatic activity (P>0,05). It was possible to correlate the results about viability cell and ecto-adenosine deaminase activity, suggesting that, at minimal concentrations, the evaluated mycotoxins do not stimulated the enzymatic activity, which has proinflammatory action and contributes for the immunosuppression process, thus, avoiding a decrease on the viability cell. This is the first in vitro study conducted with OTA, DON and ZON in broiler chickens lymphocytes evaluating these parameters.
Micotoxinas representam um vasto grupo de contaminantes químicos naturais originados a partir do metabolismo secundário de fungos filamentosos patogênicos. Elas são produzidas, principalmente, pelos gêneros Fusarium, Alternaria, Aspergillus e Penicillium, os quais podem contaminar grãos e cereais, como trigo, milho e soja. Conforme sua natureza e níveis de concentração, micotoxinas podem induzir efeitos tóxicos em animais de produção e humanos. Um estudo in vitro foi realizado para avaliar a susceptibilidade das células linfocitárias de frangos de corte a diferentes concentrações de ocratoxina A, deoxinivalenol e zearalenona. Cada micotoxina foi adicionada ao meio celular em diferentes concentrações (0,001; 0,01; 0,1 e 1μg/mL). A viabilidade celular e atividade de ecto-adenosina desaminase foram analisadas em 24, 48 e 72 horas através de ensaios colorimétricos. Para isso, foram utilizados 0,7x10(5) linfócitos/mL em meio RPMI 1640, suplementado com 10% de soro fetal bovino e 2,5 UI de penicilina/estreptomicina por mL, incubados em atmosfera de 5% de CO2 a 37 °C. Todos os experimentos foram realizados em triplicata e os resultados foram expressos como média e erro padrão da média. Os resultados obtidos demonstraram que tanto ocratoxina A como deoxinivalenol induziram proliferação linfocitária e baixa atividade enzimática in vitro (P<0,05), enquanto zearalenona também induziu proliferação (P<0,05), mas nenhuma alteração na atividade enzimática (P>0,05). Foi possível correlacionar os dados referentes à viabilidade celular e atividade de ecto-adenosina desaminase, sugerindo que, em concentrações mínimas, as micotoxinas testadas não estimularam a atividade da enzima, que possui ação pró-inflamatória e contribui para o processo de imunossupressão e, portanto, evitando um decréscimo na viabilidade celular. Este é o primeiro estudo feito com OCRA, DON e ZEA sobre linfócitos de frangos de corte em cultivos in vitro na avaliação desses parâmetros.
Subject(s)
Animals , Ochratoxins/administration & dosage , Ochratoxins/analysis , Ochratoxins/chemistry , In Vitro Techniques/classification , In Vitro Techniques/veterinary , Zearalenone/analysis , Zearalenone/chemistryABSTRACT
The productivity of wheat and corn crops depends on climatic conditions and resistance against phytopathogenic fungi such as those of the genus Fusarium. Some species of this genus produce zearalenone (ZEA), a mycotoxin with hyperestrogenic effects. The objective of this study was to investigate the presence of ZEA in samples of cracked wheat (n = 109), popcorn (n = 51) and corn grits (n = 50) commercialized in the State of Paraná, Brazil. Commercial samples of each crop were collected between September 2007 and June 2008 and analyzed by thin-layer chromatography. The method used for detection of the mycotoxin in wheat and corn derivatives presented a recovery rate of 94.5% and 99.5%, respectively, detection limit of 40 μg.kg-1 and quantification limit of 55 μg.kg-1. No contamination with ZEA was detected in cracked wheat samples. Among the corn derivatives, only one cracked corn sample was contaminated with ZEA (64 μg.kg-1). Despite the low contamination observed, monitoring the occurrence of mycotoxins in foods is important to ensure safety.
Subject(s)
Triticum/chemistry , Zea mays/chemistry , Zearalenone/analysis , Brazil , Chromatography, Thin LayerABSTRACT
The aim of this work was to offer a new method of high performance liquid chronomatography (HPLC) to evaluate commercial swine rations (CSR) contaminated by zearalenone (ZEA). After ZEA extraction and purification from CSR, the samples were eluted with acetonitrile, methanol and water solvent system. The results indicated that the proposed method showed to be rapid and efficient for the detection and quantification of ZEA in CSR, since its recovery was 102.62 percent, it offered excellent precision with a coefficient of variation of 0.9992. Furthermore, it is also proposed a as a biocontrol assay for micotoxigenic fungi isolated and maintained in the laboratory. The test was performed with the killer yeast Trichosporum insectorum CBS 10422 against Fusarium sp and Aspergillus flavus, which demonstrated to be effective against the latter.
El propósito de este articulo es ofrecer un nuevo método de cromatografía líquida de alta resolución (CLAR) para evaluar las raciones especiales para cerdos (REC) contaminado con zearalenona (ZEA). Después de la extracción y purificación de ZEA, las muestras se eluyeron con acetonitrilo, metanol y agua del sistema disolvente. Los resultados indican que el método propuesto demostró ser rápido y eficaz para la detección y cuantificación de ZEA en REC, ya que sus indicadores se presentan capaces de recuperación de 102,62 por ciento, además de ofrece una excelente precision, con un çõefiCiênte de variación de 0,9992. Por otra parte, también se propone una prueba de control biológico de hongos micotoxige-nic aislados y mantenidos en el laboratorio. La prueba se realizó con la levadura killer Trichosporum insectorum CBS 10422 contra Fusarium sp y Aspergillus flavus, mostrando eficaces sólo contra Aspergillus.
Subject(s)
Animals , Animal Feed/analysis , Chromatography, High Pressure Liquid , Food Contamination/analysis , Zearalenone/analysis , Antibiosis , Aspergillus flavus , Fusarium , Yeasts/physiology , Mycotoxins/analysis , Solvents , Swine , Trichosporon/physiologyABSTRACT
Se ha desarrollado un método para la determinación simultánea de Aflatoxina B1 y zearalenona en alimentos balanceados para cerdos. Los reactivos han sido seleccionados por su bajo costo y disponibilidad en nuestro país. La técnica incluye la extracción de ambas micotoxinas con uan solución acuosa de metanol, participación con cloroformo y cromatografía en capa delgada bidimensional (TLC) para evitar resultados falsos positivos causados por uma gran cantidad de interferencias. También se ha estudiado el efecto de la concentración de metanol (55, 60, 65, 70%) en el solvente de extracción, diferentes solventes para el primer desarrollo de la TCL y distintos tamaños de placas cromatográficas, seleccionando la proporción (65 + 35) de metanol: agua, el desarrollo con éter anhidro en la primera dirección y cloroformo: acetona (90 + 10) en la segunda dirección de la TLC, el uso de placas cromatográficas presuntivas de 10 x 10 cm. y de 20 x 20 cm. para la identificación en los positivos