RESUMO
The Ascomycete fungus Claviceps gigantea infects maize kernels and synthetizes several alkaloids, mostly dihydrolysergamides. There is limited information on the damage these toxins cause in mammals, despite reports from infested areas with 90% presence of the fungus sclerotia. With this background, it was decided to determine the biological activity of chemical compounds present in sclerotia of C. gigantea in rabbits 38 days after weaning. Sclerotia of C. gigantea were collected in fields with high incidence of the disease, ground and analysed for nutrients. Experimental diets were prepared with four treatments, where sclerotial powder was added, substituting for alfalfa flour in increasing proportions [C. gigantea/alfalfa flour (0:100, 5:95, 15:85 and 25:75)]. Total ergot alkaloid content was analysed by high-performance liquid chromatography. Male juvenile rabbits were utilised and distributed in completely randomised design with four replications. Initial weight was recorded in each animal, and experimental diet was offered. In this study, weight of animals, feed consumption and feed conversion were evaluated in individual animals. Blood samples were taken for haemograms, and finally euthanasia was practiced. The consumption of C. gigantea had a negative effect on body weight and feed consumption. The necropsies showed anomalies proportional to the consumption of feed contaminated with the fungus.
Assuntos
Ração Animal/microbiologia , Claviceps/química , Dieta/métodos , Alcaloides de Claviceps/toxicidade , Contaminação de Alimentos , Intoxicação/patologia , Animais , Peso Corporal , Cromatografia Líquida de Alta Pressão , Modelos Animais de Doenças , Alcaloides de Claviceps/análise , Masculino , Coelhos , DesmameRESUMO
An increase in the occurrence of ergot alkaloids (EAs) contamination has been observed in North America and Europe in recent years. These toxins are well known for their effects on the circulatory and nervous systems. The aim of this study was to investigate the effect of EAs on the liver and on the intestine using the pig both as a target species and as a non-rodent model for human. Three groups of 24 weaned piglets were exposed for 28 days to control feed or feed contaminated with 1.2 or 2.5 g of sclerotia/kg, i.e., at doses close to EU regulatory limits. Contaminated diets significantly reduced feed intake and consequently growth performance. In the liver, alteration of the tissue, including development of inflammatory infiltrates, vacuolization, apoptosis and necrosis of hepatocytes as well as presence of enlarged hepatocytes (megalocytes) were observed. In the jejunum, EAs reduced villi height and increased damage to the epithelium, reduced the number of mucus-producing cells and upregulated mRNA coding for different tight junction proteins such as claudins 3 and 4. In conclusion, in term of animal health, our data indicate that feed contaminated at the regulatory limits induces lesions in liver and intestine suggesting that this limit should be lowered for pigs. In term of human health, we establish a lowest observed adverse effect level (LOAEL) of 100 μg/kg body weight (bw) per day, lower than the benchmark dose limit (BMDL) retained by European Food Safety Authority (EFSA) to set the tolerable daily intake, suggesting also that regulatory limit should be revised.
Assuntos
Alcaloides de Claviceps/toxicidade , Intestinos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Ração Animal/análise , Ração Animal/normas , Animais , Relação Dose-Resposta a Droga , Ingestão de Alimentos , Alcaloides de Claviceps/análise , União Europeia , Feminino , Contaminação de Alimentos/análise , Contaminação de Alimentos/legislação & jurisprudência , Regulamentação Governamental , Intestinos/patologia , Intestinos/fisiologia , Fígado/patologia , Masculino , Concentração Máxima Permitida , RNA Mensageiro/metabolismo , SuínosRESUMO
A new and sensitive analytical methodology for ergot alkaloids (EA) determination from cereal samples based on cloud point extraction (CPE) prior to CE-UV absorbance was developed. The methodology involves extraction under acid conditions and subsequent preconcentration by applying a simple, rapid and environmentally friendly low volume surfactant extraction procedure. After extraction, CE analysis was carried out by performing dilutions on preconcentrated surfactant rich phase, achieving a single peak or simultaneous alkaloids determination. A real preconcentration factor of 22 of total EA was obtained, demonstrating the efficiency of this methodology. The limits of detection were 2.6 and 2.2 µg/kg for ergotamine and ergonovine, respectively. Validation procedure revealed suitable linearity, accuracy and precision. The average extraction and clean-up recoveries were compared with the theoretical values and were better than 92%. This method was successfully applied to the determination of EA in different varieties of commercial flour samples, two grain samples and one of the leading brands cereal-based product for infant feeding. The high sensitivity achieved for EA determinations in real samples suggests CPE procedure as an interesting approach to improve CE-UV visible detection limits. Moreover, the whole process could be considered as a contribution to green chemistry because nonorganic solvents were involved, demonstrating its great potential over conventional techniques.
Assuntos
Grão Comestível/química , Eletroforese Capilar/métodos , Alcaloides de Claviceps/análise , Contaminação de Alimentos/análise , Farinha/análise , Limite de Detecção , Extração Líquido-Líquido/métodos , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta , Tensoativos/químicaRESUMO
A pilot study for monitoring mycotoxin contamination in food and feeds was implemented by the Technological Laboratory of Uruguay (LATU) with the technical assistance of the Food and Agriculture Organization of the United Nations (FAO). The scope of the study was to determine the potential hazard posed by priority food-contaminant and feed-contaminant combinations. The choice of foods and contaminants to be monitored was based on the importance of the food in the total diet, the economic importance of the product and the potential health risk posed by the specific combination. The principal commodities selected were wheat, barley and rice. Also included were com, soy, dairy products, feeds, dried fruits and legumes, oil seeds, cocoa beans and organ meats. Mycotoxins analyzed (TLC/densitometry) were aflatoxins, zearalenone, ochratoxin A, deoxynivalenol (DON) and ergot alkaloids. The survey results (1993-95) showed differences in both incidence and levels of mycotoxin content for the principal commodities. Of all food/feed categories analyzed, feed had the highest values for all mycotoxins. Samples containing DON in levels above 1000 ng/g were found in all groups. Ochratoxin A was not detected in any of the samples. Rice and soy beans were the categories with lowest aflatoxin incidence. Uruguayan regulatory limits for all toxins analyzed were exceeded for wheat, barley and rice in less than 3, 9 and 7% of samples, respectively. The data on actual mycotoxin levels in different foods will help identify sources of contaminations and areas where control measures should be improved, enable better risk assessment by proper estimation of mycotoxin intake, assist in the establishment of tolerances and adequate guidelines, aid in the implementation of a national program and provide economic benefits by improving grain quality.