CURRENT TRENDS IN MYCOTOXIN RESEARCH: DEOXYNIVALENOL AND FUMONISINS

Authors: Voss, Kenneth; Plattner, Ronald; GELINEAU-VAN WAES, JANEE - GENETICS/U NEB/OMAHA, NE; Riley, Ronald; Bacon, Charles

Submitted to: National Food Research Institute's International Symposium on Food Safety
Publication Type: Proceedings
Publication Acceptance Date: 10/30/2003
Publication Date: 12/30/2003
Citation: Voss, K.A., Plattner, R.D., Gelineau-Van Waes, J.B., Riley, R.T., Bacon, C.W. 2003. Current trends in mycotoxin research: deoxynivalenol and fumonisins. National Food Research Institute's International Symposium on Food Safety (Japan). November, 1-5, 2003, Tsukuba, Japan, p. 9-12.

Interpretive Summary: Deoxynivalenol (DON) and fumonisins are mycotoxins that are produced by Fusarium fungi. They are toxic to animals and occur in cereal-based foods. A connection to human disease has not been proven for either, but both are considered potential health risks. USDA-ARS scientists and collaborators are involved in diverse research activities having the ultimate goal of reducing mycotoxin-associated risks to consumers. One initiative is to reduce the growth of DON-producing fungi in wheat and fumonisin-producing fungi in corn by introducing mycotoxin non-producing fungi or bacteria, which then replace the mycotoxin-producing fungal species (competitive exclusion) in the plants. It is also important to determine how mycotoxins exert their toxic effects. Fumonisins have recently been implicated as risk factors for birth defects called neural tube defects (NTDs). An animal model for NTDs using the LMBc mouse has been developed. Experiments to establish the mechanisms by which fumonisin cause NTDs in the LMBc and other mice will help determine the relevance of fumonisins as NTDs risks in humans. The effects of cooking on fumonisins is poorly understood and, if cooking converts fumonisins to unknown toxins, is potentially important because chemical analysis might underestimate the toxic potential of cooked foods. To address this possibility, rats were fed uncooked fumonisin contaminated cornmeal or baked, pan-fried, or deep-fried foods made from the contaminated cornmeal. Neither baking nor frying affected toxicity, indicating that unknown toxins were not formed during cooking. These examples illustrate the diversity of ongoing research initiatives for reducing mycotoxins in grains and for providing the scientific data needed for developing sound mycotoxin management strategies.

Technical Abstract: Reducing mycotoxin-related risks to consumers requires a multi-discipline approach that includes developing methods for reducing mycotoxin-producing fungi in crops, investigating the mechanisms by which mycotoxins induce disease, and determining how cooking affects mycotoxins. Competitive exclusion using mycotoxin non-producing fungi, fungi having reduced virulence, or nontoxic bacteria as competitive exclusion agents has been shown to be a potentially useful strategy for reducing deoxynivalenol-producing Fusarium graminearum and fumonisin-producing F. verticillioides in wheat and corn, respectively. Fumonisins have been implicated as a risk factor for neural tube defects (NTDs) in humans. Using the LMBc mouse model, dose-related increases in NTDs were induced by administration of fumonisin B1 (FB1) at a critical time during gestation. Folinic acid partially protected and glycosphingolipid ganglioside GM1 almost completely protected the fetuses against NTDs when given to the dams. This suggesting that FB1 interferes with folic acid uptake, probably by disrupting complex sphingolipid metabolism. The LMBc mouse is a useful model for studying the mechanistic relationships between fumonisins and NTDs and as a basis for comparative studies to determine the relevance of these findings for other species. The affect of cooking on fumonisin-related toxicity of foods is not well understood. Using a rat feeding bioassay, it was found that baking, pan-frying or deep-frying did not affect in vivo toxicity of the fumonisin-contaminated cornmeal. This finding together with chemical analyses of the uncooked and cooked cornmeal provided no evidence that cooking converted fumonisins to unknown toxins. These examples illustrate the diversity of ongoing research that contributes to efforts to reduce mycotoxin-related health risks.