PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Mycotoxin”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

The effects of mycotoxins, fungal food contaminants, on the intestinal epithelial cell-derived innate immune response.

Mycotoxins are structurally diverse fungal metabolites that can contaminate a variety of dietary components consumed by animals and humans. It is considered that 25% of the world crop production is contaminated by mycotoxins. The clinical toxicological syndromes caused by ingestion of moderate to high amounts of mycotoxins and their effect on the immune system have been well characterized. However, no particular attention has been focused on the effects of mycotoxins on the local intestinal immune response. Because of their location, intestinal epithelial cells (IECs) could be exposed to high doses of mycotoxins. As a component of the innate local immune response, intestinal epithelial cells have developed a variety of mechanisms which act to reduce the risk of infection by microorganisms or intoxication by toxic compounds. This review summarises the innate immune response developed by intestinal epithelial cells and reports the literature concerning the effects of mycotoxins on them. Particularly, the effects of mycotoxins on the maintenance of a physical barrier by epithelial cells will be discussed together with their effect on extrinsic protective components of the innate intestinal immunity: mucus secretion, antimicrobial peptide generation, IgA and pro-inflammatory cytokine release.

Animals↗

Sample preparation and high-resolution separation of mycotoxins possessing carboxyl groups.

The chromatographic analysis of carboxyl-containing mycotoxins, such as fumonisin B1, ochratoxin A, and citrinin, presents a continual challenge. Toxins must first be extracted from foods or tissues and then cleaned up before chromatographic separation and detection. Liquid-liquid extraction efficiencies for some carboxylic mycotoxins are marginal for spiked samples and uncertain for incurred residues. Immunoaffinity columns may be useful for concentrating mycotoxins from samples before chromatography. In almost every case, more than one analytical method must be used to confirm the identification of the mycotoxin. The fumonisins are especially troublesome to analyze because they are relatively insoluble in organic solvents, they are not separated easily by gas chromatography, and they do not respond to the usual absorbance or fluorescence detectors used in liquid chromatography. Fluorescence derivatization and electrospray liquid chromatography-mass spectrometry have now made it possible to detect trace levels of mycotoxins. The purity of mycotoxin standards for toxicological studies can be determined by liquid chromatography with either an evaporative light scattering detector or electrospray mass spectrometer. New developments in capillary electrophoresis, nonporous microsphere liquid chromatography, and detection methods for low-volatility compounds show promise for improving the analysis of mycotoxins in the future.

Chromatography, Gas↗

Mycotoxins in pet food: a review on worldwide prevalence and preventative strategies.

Mycotoxins contaminate cereal grains worldwide, and their presence in pet food has been a potential health threat to companion animals. Aflatoxins, ochratoxin A, and Fusarium mycotoxins have been found in both raw ingredients and final products of pet food around the globe. Aflatoxin, a hepatotoxin and carcinogen, has caused several food poisoning outbreaks in dogs, and aflatoxin content is regulated in pet food in many countries. Ochratoxin A and Fusarium mycotoxins including trichothecenes, zearalenone, and fumonisins may have chronic effects on the health of companion animals. Grain processing, sampling error, analytical methods, conjugated mycotoxins, storage conditions, and synergistic interactions are common challenges faced by the pet food industry. Food-processing techniques such as sieving, washing, pearling, ozonation, and acid-based mold inhibition reduce the mycotoxin content of cereal grains. Dietary supplementation with large neutral amino acids, antioxidants, and omega-3 polysaturated fatty acids as well as inclusion of mycotoxin-sequestering agents and detoxifying microbes may ameliorate the harmful effects of mycotoxins in contaminated pet food.

Aflatoxins↗

Recent advances on the use of adsorbent materials for detoxification of Fusarium mycotoxins.

The extensive use of adsorbents in the livestock industry has led to the introduction of a wide range of new products on the market, most of them claiming high in vitro mycotoxin adsorption capacity. However, adsorbents that may appear effective in vitro do not necessarily retain their efficacy when tested in vivo. Studies performed in our laboratory during the past few years aiming to evaluate the efficacy of various adsorbent materials in binding Fusarium mycotoxins are reported. Adsorption experiments were performed in in vitro screening tests for Fusarium mycotoxins at different pHs; by in vivo tests using the increase of the sphinganine to sphingosine ratio in rat urine and tissues as a biomarker of fumonisin exposure; and by a dynamic, computer-controlled, gastrointestinal model simulating the gastrointestinal tract of healthy pigs. Most of the commercially available mycotoxin-binders failed in sequestering in vitro Fusarium mycotoxins. Only for a small number of adsorbent materials was the ability to bind more than one mycotoxin demonstrated. Cholestyramine was proven to be an effective binder for fumonisins and zearalenone in vitro, which was confirmed for zearalenone in experiments using a dynamic gastrointestinal model and for fumonisins in in vivo experiments. No adsorbent materials, with the exception of activated carbon, showed relevant ability in binding deoxynivalenol and nivalenol. The in vitro efficacy of activated carbon toward fumonisins was not confirmed in vivo by the biomarker assay. The dynamic gastrointestinal model was a reliable tool to study the effectiveness of adsorbent materials in reducing the bioaccessibility of Fusarium mycotoxins, as an alternative to the more difficult and time-consuming studies with domestic livestock.

Adsorption↗

Advances in the analysis of mycotoxins and its quality assurance.

This article covers the latest activities in mycotoxin analysis and the advances of its respective quality assurance. The majority of mycotoxin analyses carried out in the laboratories is still based on physicochemical methods, which are continually improved. For example, immunoaffinity columns and multifunctional clean-up columns have become of increasing importance and in some areas of mycotoxin analysis they have more or less displaced conventional liquid-liquid partitioning or column chromatography during clean-up. The need for rapid yes/no decisions on the other hand has led to a number of new screening methods. In particular, rapid and easy-to-use test kits based on immunoanalytical principles or the generation of artificial macromolecular receptors employed in molecularly imprinted polymers (MIPs) have made good progress. Further research in mycotoxin analysis is pursued in the field of biosensors and also the potential of infrared spectroscopic techniques as screening method has been demonstrated. In the area of multi mycotoxin analysis the most promising development was observed in mass spectrometry. At the same time, several interlaboratory studies in the field of mycotoxin analysis revealed problems proven by high between laboratory standard deviation and non-traceable results. This not only shows the necessity of reliable methods and well defined performance characteristics but also the need for appropriate calibrants of defined concentration and stated purity. A certified zearalenone (ZON) calibrant is already available and a certified calibrant containing various trichothecenes is currently under development. (Certified) reference materials are available for aflatoxins in a number of commodities, ochratoxin A (OTA) in wheat, deoxynivalenol (DON) in maize and wheat, and ZON in maize. With these measures important steps towards traceability of results in mycotoxin analysis have been achieved.

Food Analysis↗

Natural occurrence of Alternaria mycotoxins in olives--their production and possible transfer into the oil.

A limited survey of the natural occurrence of the major Alternaria mycotoxins, i.e. alternariol (AOH), alternariol methyl ether (AME), altenuene (ALT), altertoxin-I (ATX-I), and tenuazonic acid (TA) has been carried out on olives and related processing products (oil and husks). The toxigenicity of Alternaria strains isolated from olives and the possible mycotoxin transfer into the oil have also been investigated. Four out of 13 olive samples were contaminated by 2 to 4 Alternaria mycotoxins. The highest contamination was found in a badly damaged sample containing 2.9, 2.3, 1.4 and 0.3 mg/kg of AME, AOH, ALT and TA, respectively. No mycotoxins were detected in olive-oil destined for human consumption (6 samples) or olive-husks (3 samples) collected from oil-mills after the first pressing of olives. An oil sample produced in our laboratory by processing the most contaminated olive sample contained AME (0.79 mg/kg) and AOH (0.29 mg/kg). The estimated mycotoxin amount transferred into the oil was 4% for AME, 1.8% for AOH, and zero for ALT and TA (considering 15% the oil yield). Although Alternaria species, mostly A. alternata (Fr.) Keissler, were present at various extent on all the examined olive samples, mycotoxins were only detected in samples of physically damaged olives. The production of mycotoxins by A. alternata isolated from olives was much higher (up to 3 order of magnitude for TA) on rice cultures than on olive cultures.

Alternaria↗

Strategies to prevent mycotoxin contamination of food and animal feed: a review.

Mycotoxins are fungal secondary metabolites that have been associated with severe toxic effects to vertebrates produced by many important phytopathogenic and food spoilage fungi including Aspergillus, Penicillium, Fusarium, and Alternaria species. The contamination of foods and animal feeds with mycotoxins is a worldwide problem. We reviewed various control strategies to prevent the growth of mycotoxigenic fungi as well as to inhibit mycotoxin biosynthesis including pre-harvest (resistance varieties, field management and the use of biological and chemical agents), harvest management, and post-harvest (improving of drying and storage conditions, the use of natural and chemical agents, and irradiation) applications. While much work in this area has been performed on the most economically important mycotoxins, aflatoxin B(1) and ochratoxin A much less information is available on other mycotoxins such as trichothecenes, fumonisin B(1), zearalenone, citrinin, and patulin. In addition, physical, chemical, and biological detoxification methods used to prevent exposure to the toxic and carcinogenic effect of mycotoxins are discussed. Finally, dietary strategies, which are one of the most recent approaches to counteract the mycotoxin problem with special emphasis on in vivo and in vitro efficacy of several of binding agents (activated carbons, hydrated sodium calcium aluminosilicate, bentonite, zeolites, and lactic acid bacteria) have also been reviewed.

Animal Feed↗

Health effects of mycotoxins: a toxicological overview.

Diseases caused by fungi are spread by direct implantation or inhalation of spores. Fungi can cause adverse human health effects to many organ systems. In addition to infection and allergy, fungi can produce mycotoxins and organic chemicals that are responsible for various toxicologic effects. We reviewed the published literature on important mycotoxins and systemic effects of mycotoxins. Scientific literature revealed a linkage between ingesting mycotoxin contaminated food and illness, especially hepatic, gastrointestinal, and carcinogenic diseases. Issues related to mycotoxin exposure, specific diseases, and management are discussed. Although there is agreement that diet is the main source of mycotoxin exposure, specific health effects and risk assessment from indoor nonagricultural exposure are limited by the paucity of scientific evidence currently available. Further research on the health effects of inhaling mycotoxins in indoor settings is needed.

Animals↗

Effects of feed-borne Fusarium mycotoxins on hematology and immunology of turkeys.

Feeding grains naturally-contaminated with Fusarium mycotoxins has been shown to alter the metabolism and performance of turkeys. The objectives of the current experiment were to examine the effects of feeding turkeys with grains naturally contaminated with Fusarium mycotoxins on their hematology and immunological indices (including functions), and the possible protective effect of feeding a polymeric glucomannan mycotoxin adsorbent (GMA). Two hundred twenty-five 1-d-old male turkey poults were fed corn, wheat, and soybean meal-based starter (0 to 3 wk), grower (4 to 6 wk), developer (7 to 9 wk), and finisher (10 to 12 wk) diets formulated with uncontaminated grains, contaminated grains, or contaminated grains with 0.2% GMA. The chronic consumption of Fusarium mycotoxins caused minor and transient changes in hematocrit (0.33 L/L) and hemoglobin (10(6) g/L) concentrations as well as in blood basophil (0.13 x 10(9)/L) and monocyte counts (3.42 x 10(9)/L) compared with controls. Supplementation of the contaminated diet with GMA prevented these effects on blood cell counts. Biliary IgA concentrations were significantly increased (4.45-fold) when birds were fed contaminated grains compared with controls, but serum IgA concentrations were not affected. Contact hypersensitivity to dinitrochlorobenzene, which is a CD8+ T-cell-mediated delayed-type hypersensitivity response, was decreased (48%) by feed-borne mycotoxins compared with the control. By contrast, the primary and secondary antibody response to sheep red blood cells, a CD4+ T-cell-mediated response, was not affected. It was concluded that chronic consumption of grains naturally contaminated with Fusarium mycotoxins exerts only minor adverse effects on the hematology and some immunological indices of turkeys. Consumption of grains naturally contaminated with Fusarium mycotoxins may, however, increase the susceptibility of turkeys to infectious agents against which CD8+ T cells play a major role in defense.

Adsorption↗

The influence of gamma radiation and substrate on mycotoxin production by Fusarium culmorum IMI 309344.

Mycotoxin production (deoxynivalenol (DON), acetyl deoxynivalenol (A DON) and zearalenone) by Fusarium culmorum inoculated on to maize (heat sterilized, irradiation sterilized and non-sterile) and irradiated to 1 kGy or 3 kGy, or unirradiated, was investigated over a period of time. Lowest mycotoxin production was observed on non-sterile maize which may be due to the presence of a competitive microflora on non-sterile maize which may be due to the presence of a competitive microflora on non-sterile maize. In general, mycotoxin production was higher on heat-sterilized grain as compared to irradiation-sterilized maize. It was suggested that this pattern of mycotoxin production was possibly caused by changes in the grain brought about by autoclaving, which favoured mycotoxin production and possibly induced changes in irradiation-sterilized maize which inhibited mycotoxin production. On sterile maize, there was no significant difference in DON production by unirradiated, 1 kGy and 3 kGy irradiated cultures up to 56 d of incubation; between days 56 and 77 of incubation, DON production increased rapidly with largest increases occurring in irradiated (1 kGy and 3 kGy) cultures. On non-sterile grain, neither DON nor A DON were detected in unirradiated cultures of F. culmorum but were detected in cultures irradiated to 1 kGy and 3 kGy. In practice grain should be stored under conditions of temperature and moisture content which prevent fungal growth. However, in this study, the grain was stored under conditions that were approaching ideal for growth of the test organism. The results highlight that irradiation disinfestation of grain must be combined with good grain handling practices so that excessive mycotoxin production can be prevented during storage.

Fusarium↗

Mycotoxin interactions in poultry and swine.

Mycotoxins are toxic compounds produced by fungi. When one mycotoxin is detected, one should suspect that others also are present in a contaminated feed ingredient or finished feeds. The toxicity and clinical signs of observed in animals when more than one mycotoxin is present in feed are complex and diverse. Some mycotoxins, such as the combination of aflatoxin with either ochratoxin A or T-2 toxin, interact to produce synergistic toxicity in broiler chicks. The effects observed during multiple mycotoxin exposure can differ greatly from the effects observed in animals exposed to a single mycotoxin. For example, fatty livers in poultry are used for presumptive diagnostic identification of aflatoxicosis. However, simultaneous presence of ochratoxin A prevents fatty livers. Of the mycotoxin combinations that have been investigated in poultry and swine, the aflatoxin + ochratoxin A and aflatoxin + T-2 toxin interactions appear to be the most toxic.

Aflatoxins↗

Biological action of mycotoxins.

Mycotoxins are ubiquitous, mold-produced toxins that contaminate a wide variety of foods and feeds. Ingestion of mycotoxins cause a range of toxic responses, from acute toxicity to long-term or chronic health disorders. Some mycotoxins have caused outbreaks of human toxicoses, and at least one mycotoxin, aflatoxin B1, is a presumed human hepatocarcinogen. As part of a comprehensive effort to curtail the adverse health effects posed by mycotoxins, substantial research has been conducted to determine the mechanism of action of mycotoxins in animals. This review presents some of the current knowledge on the biological action of four diverse classes of mycotoxins--aflatoxin B1, tricothecenes, zearalenone, and fumonisin B1--with particular emphasis on mechanisms of action.

Aflatoxin B1↗

Fungal toxicity with special reference to mycotoxins.

Mycotoxins are fungal secondary metabolites formed by consecutive series of enzyme-catalysed reactions from a few biochemically simple intermediates of primary metabolism. These mycotoxins can enter the human and animal food chain by direct or indirect contamination. Mycotoxins are equally harmful to animal and human beings. Realizing the importance of mycotoxins to the health of man and animals there have been concentrated efforts to develop highly sensitive analytical methods for detection and proper determination of mycotoxins in food, mixed feeds and feed ingredients, animal tissue, blood, urine and milk. Most of the mycotoxins are identified and most current research on it is concentrated on increasing sensitivity accuracy and reproducibility and above all to decrease the time of determination. A detailed review of mycotoxin and their detection is summarised in the paper.

Animals↗

[Nutritional health aspects of mycotoxins].

Mycotoxins produced by mould fungi can enter into the human food chain directly through foods of plant origin (cereal grains), consumer goods (coffee and bear) and indirectly through foods of animal origin (kidney, liver, milk and eggs). Mycotoxins occur in small amount in the foods; however their continuous intake even in microdoses can result in accumulation in the organism. Synergic effects of the mycotoxins as well as their possible additive multi-toxic effects seem to be especially dangerous. Mycotoxin problems are very important in Hungary because these natural toxins occur mainly in those cereals (e.g. wheat, maize) that amount to high proportion of the sowing area in Hungary and provide the main foods to the inhabitants. Public health risks of the toxins accumulating in the human and animal bodies during the long term consumption of the mycotoxins containing foods--even in small doses--have not been evaluated yet as thoroughly as their importance would require. However, there are more and more direct and indirect expressions of the danger resulting from the toxins. The most frequently observed human health effects are carcinogen effects (aflatoxin, ochratoxin A, fumonisins, patulin); effects causing developmental abnormalities (zearalenon, ochratoxin); effects harmful to the reproduction (zearalenon, and trichotecenes), effects decreasing the resistance; immunosuppressive effects (trichotecenes), and effects causing injury of the nervous system (ochratoxin A, fumonisins). Prevention of the injury of the health caused by mycotoxins can be completed by joint and integrated activity of the various disciplines only and requires a comprehensive interdisciplinary cooperation. This paper gives a discussion on health injuring effects of the most frequently occurring mycotoxins that are very important from human health aspects in Hungary; on their occurrence in the foods and on their human risk.

Aflatoxins↗

Enhanced surveillance of foodborne mycotoxins by immunochemical assay.

Mycotoxins are a chemically diverse group of fungal secondary metabolites with a wide range of toxic effects. Conventional thin-layer and instrumental methods of mycotoxin analysis are time-consuming and make routine safety and quality control screening of these compounds in agricultural commodities difficult. As an alternative, specific polyclonal and monoclonal antibodies have been raised against mycotoxin-protein conjugates and used in sensitive radioimmunoassays (RIAs) and enzyme-linked immunosorbent assays (ELISAs). One of the simplest ELISA approaches involves competition for a solid-phase antibody between a mycotoxin-enzyme conjugate and an unconjugated mycotoxin in the sample extract. ELISAs have been developed for aflatoxins B1 and M1, zearalenone, T-2 toxin, and deoxynivalenol, which are highly specific, rapid (10 min), easily adaptable for analyzing large numbers of samples, and directly applicable to assaying methanol-water extracts of a wide range of foods. Several commercial mycotoxin ELISAs using this approach (most typically for aflatoxin B1) are currently being marketed. Since ELISAs will be used in large part by personnel with limited technical expertise, individual kits must be critically evaluated by analytical chemists for suggested sampling procedures, efficiency of extraction, cross-reactivity, mycotoxin recovery, assay reproducibility, and product shelf-life prior to routine use in food safety and quality control screening.

Food Contamination↗

Isolation, purification, toxicity and some physicochemical properties of mycotoxins produced by aspergillus quadrilineatus isolated from acha (Digitaria exilis stapf) in Plateau State of Nigeria.

Some physico-chemical and toxicological studies were carried out on mycotoxins elaborated by Aspergillus quadrilineatus isolated from a grain foodstuff, acha (Digitaria exilis) in the Plateau State of Nigeria. The mycotoxins produced by A quadrilineatus were extractable from rice culture by chloroform. Column chromatographic separations of the crude extract in silica gel using different elution solvents and biological tests showed that the mycotoxins came off in the diethylether, chloroform and mostly in the ethyl acetate fractions. Use of different available mycotoxin standards on silica gel G coated chromatoplates revealed that 1 of the mycotoxins produced by A quadrilineatus was sterigmatocystin. Two other more toxic mycotoxins were isolated and purified from the crude chloroform extract; their column, preparative thin-layer chromatographic, infrared and UV-spectrophotometric characteristics were established. The infrared spectra of the 2 purified mycotoxins suggested that the carbonyl group of their structures were similar to that of aflatoxin.

Animals↗

Application of Biomarkers to Assessment of Risk to Human Health from Exposure to Mycotoxins

Mycotoxins, the toxic compounds produced by mold secondary metabolism, represent a relevant source of danger to humans through alimentary channels. Efforts have been made by researchers and by national authorities to assess mycotoxin incidence in food, but often results are to be considered approximate or inaccurate due to the huge difficulties posed by sampling procedures. More recently the evaluation of mycotoxins in biological fluids have been given increasing attention since the results may offer valuable indications, although general on the overall status of mycotoxin contamination in food and feed. The assessment of the degree of exposure to these contaminants in the population or in specific groups can also be pursued. Researches on mycotoxins in biological fluids greatly contribute to clarify the mechanism of health impairment attributable to these toxic compounds and to elucidate the dose-response relationship. Despite the considerable efforts devoted to mycotoxin research in the past few decades, improvements in methodology has to be achieved mainly in sampling procedures and in quality assurance of the laboratories involved in mycotoxin analysis, as well as in the selection of appropriate biomarkers.

Journal Article↗

Mycotoxin risk assessment for the purpose of setting international regulatory standards.

The 2003 Council for Agricultural Science and Technology Mycotoxin report states that one 21st century goal is the development of uniform regulations worldwide for foodborne mycotoxin contamination. This study informs that endeavor by a risk assessment and economic analysis of two important mycotoxins: fumonisins and aflatoxins. The goals are to identify the nations that would be most heavily impacted by tighter mycotoxin regulations, examine costs and benefits as a function of regulatory stringency, and address risk-risk tradeoffs between health benefits and economic losses from compliance with those regulations. Among industrial nations, the United States would experience the heaviest economic losses from more precautionary mycotoxin standards. Environmental conditions in the developing world, however, are more conducive to mycotoxin accumulation in crops. Contrary to concerns expressed among policymakers, the less developed countries that would likely experience the greatest loss from tighter mycotoxin standards are not sub-Saharan African nations, but China and Argentina. If a fumonisin standard of 0.5 mg/kg were adopted worldwide, total export losses from fumonisins in corn may exceed 300 million dollars annually: 3-fold higher than if the less stringent U.S. standard of 2 mg/kg were adopted. Likewise, export losses from aflatoxins in peanuts may exceed 450 million dollars under the current EU regulatory standard of 4 microg/kg: almost 5-fold higher than if the U.S. standard of 20 microg/kg were adopted. Stricter standards are unlikely to improve health significantly. In developing nations such as China where hepatitis B and C are prevalent, tighter aflatoxin standards may increase health risks until improved control methods for aflatoxins are found, as high-quality crops may be exported instead of being consumed domestically.

Aflatoxins↗