The aim of the present work was to study the in-vitro cytotoxic effects of different concentrations of aflatoxin B1 (AFB1) on broiler lymphocytes. Lymphocyte-rich mononuclear cells were separated by Ficoll-Histopaque density and cultured in 96-wellplates containing the evaluated AFB1 concentrations in 5% CO2 atmosphere at 39°C. Thereafter, MTT, PicoGreen, and reactive oxygen species assays were performed. Cell viability decreased in the presence of 10 µg/mL AFB1 at 48 h (p < 0.05) and of 10 and 20 µg/mL AFB1 at 72 h (p < 0.01 and p < 0.001, respectively) when compared to the control (0 µg/mL). However, a dose-dependent increase in the cell-free DNA at 24 h was observed at 1, 10 and 20 µg/mL (p < 0.001). ROS formation significantly increased at 24 h at all concentrations (p < 0.001). The in-vitro results demonstrate that AFB1 is cytotoxic and causes biomolecular oxidative damage in broiler lymphocytes.

Esta revisão tem como objetivo principal mostrar, baseado em dezenas de pesquisas realizadas, os efeitos tóxicos das micotoxinas aflatoxinas, tricotecenos, zealenona e fumonisinas sobre o desempenho das aves. O descobrimento das propriedades hepatotóxicas e hepatocarcinogênicas de algumas linhagens de Aspergillus flavus e A. parasiticus em perus, na Inglaterra, no início da década de 1960, seguida pela elucidação da estrutura de seus metabólitos tóxicos, as aflatoxinas, deu novo enfoque e prioridade para a pesquisa sobre micotoxinas. Análises de aflatoxinas realizadas no Laboratório de Análises Micotoxicológicas (LAMIC) da Universidade Fedaral de Santa Maria, entre os anos de 1986 e janeiro de 2000, em 15.600 amostras de alimentos destinados principalmente ao consumo animal, demonstram que no milho analisado, 41,9% das amostras estavam contaminadas por aflatoxinas. Em surtos de aflatoxicose no campo, uma das características mais marcantes é a má absorção que se manifesta como partículas de ração mal digeridas na excreta das aves. Também observa-se, em frangos e poedeiras que recebem AFL, extrema palidez das mucosas e pernas. Dietas deficientes em riboflavina ou colecalciferol (vit. D) tornaram frangos sensíveis, nos índices de desenvolvimento corporal, a concentrações muito baixas de AFL. O efeito aflatoxina nos frangos é maior na fase inicial de crescimento, ou seja, quando as aves ingeriram aflatoxina nos primeiros 21 dias de vida, e quanto maior o nível de stress do lote, menor a quantidade de AFL para afetar negativamente seu desempenho, seja na produção de carne ou de ovos. As principais micotoxinas do grupo dos tricotecenos são: toxina T-2; deoxynivalenol (DON); diacetoxyscirpenol (DAS), todas produzidas através de diversas espécies de fungos do gênero Fusarium. Além dos tricotecenos, o fusarium também pode produzir zearalenona e fumonisinas. Dessas fusarium-toxinas, somente toxina T-2 gera patologias sérias nas aves, como lesões orais e imunodepressão. As fumonisinas afetam o desempenho de frangos de corte a partir de uma ingestão de 75 ppm. Já zearalenona e DON são inócuas quando ingeridas por aves. Para o controle de contaminação de micotoxinas nos alimentos, o melhor método é prevenir o crescimento de fungos, apertando-se no controle de qualidade da matéria prima. Métodos alternativos podem ser usados, utilizando-se antifúngicos ou adsorventes na ração. O monitoramento dos grãos recebidos ou a receber é o ponto fundamental num programa de controle de micotoxinas. Isso deve ser feito através de um programa amostral consistente da massa de grãos recebida ou a ser adquirida, com análises periódicas das micotoxinas.

This article is aimed at briefly reviewing the toxic effects of mycotoxins aflatoxins, trichothecenes, zearalenone and fumonisins in the growth performance of poultry. The discovery of hepatotoxic and carcinogenic properties of some lineages of Aspergillus flavus and A. parasiticus for turkey in England in the 60’s, followed by the determination of the chemical structure of their toxic components - the aflatoxins (AFL) - brought a new focus and paved the way for the modern mycotoxicologic research. From 1986 to January of 2000, 15,600 food samples, mostly for animal consumption, were submitted to aflatoxin analysis at the Laboratory for Mycotoxicologic Analysis (LAMIC-UFSM, Brazil). Among the corn samples tested, 41.9% were positive for aflatoxins. In field outbreaks o aflatoxicosis, the most prominent feature is the low absorption of nutrients, leading to the appearance of particles of feed in the feaces. Paleness of the legs and mucosas is also often observed in broilers and laying hens.Diets deficient in riboflavin and colecarciferol (vitamin D) may significantly increase the susceptibility of broilers to AFLs, resulting in a poor growth performance. The adverse effects of AFLs are more intense during the initial periods of growth, i.e. when the animals are fed AFL-contaminated food during the first 21 days of life. The level of stress has also been shown to enhance the toxic effects of AFLs, by reducing the toxic threshold and leading to a reduction in growth and egg production. The main mycotoxins belonging to the trichothecenes group are toxin T-2, deoxynivalenol (DON) and diacetoxyscirpenol (DAS), produced by several fungi species of the genera Fusarium. Fungi belonging to the Fusarium genus also produce zearalenona and fumonisin. Among the Fusarium mycotoxins, only toxin T-2 is a severe pathogen for poultry, causing oral lesions and immunodepression. The fumonisins can affect the growth performance of broilers at doses as low as 75ppm. In contrast, no toxic effects of zearalenona and DON have been demonstrated for poultry. The method of choice to prevent food contamination with mycotoxins is to avoid fungal growth, narrowing the quality control of the grains in the farm or during storage/transportation. Alternative methods such as antifungic drugs or adsorbents may also be used with success. Monitoring grains before or as they enter the food industry is the key point in a mycotoxin control program. This can be accomplished through a systematic and consistent mycotoxicologic analysis of grain samples already received at the plant or to be purchased.