Submitted to: International Symposium of Mycotoxicology Meeting
Publication Type: Book / Chapter
Publication Acceptance Date: November 1, 2003
Publication Date: November 6, 2004
Citation: Voss, K.A., Riley, R.T., Gelineau-Van Waes, J.B., Bacon, C.W. 2004. Fumonisins: toxicology, emerging issues, and prospects for control and detoxification. In: Yoshizawa, T., editor, New Horizon of Mycotoxicology for Assuring Food Safety, Proceedings International Symposium of Mycotoxicology Kagawa 2003. Takamatsu, Kagawa, Japan. p. 41-48. Interpretive Summary: Fumonisins are mycotoxins produced by molds that grow on corn. They are toxic to animals and cause cancer in rodents. While their adverse affects on human health are not certain, it has recently been suggested that fumonisins are a risk factor for a type of serious birth defect called neural tube defects (NTD) in populations consuming home-grown, contaminated corn as a diet staple. Efforts to study this have been hindered by lack of an animal model. However, an animal model for NTDs, using the LMBc mouse, has now been developed and this model will be useful to establish the biological mechanisms by which fumonisin cause NTDs in these and other mouse strains and to determine the relevance of fumonisins as an NTD risk for man. Another area of concern is how cooking effects fumonisins and fumonisin toxicity, as emerging evidence suggests that hidden or unknown fumonisins might form in foods. If so, this would lead to underestimation of potentially toxic fumonisins in foods when the foods are analyzed using routine chemical methods. Therefore, to investigate how cooking affects toxicity, rats were fed equal amounts of uncooked fumonisin-contaminated cornmeal, or baked, pan-fried, or deep-fried foods made from the contaminated cornmeal. We found that neither baking nor frying affected toxicity, suggesting that significant amounts of any unknown toxins did not form during cooking. These examples illustrate the diversity of ongoing research to more fully understand the toxic potential of fumonisins and to provide a scientifically sound basis for the development of mycotoxin management strategies.
Technical Abstract: Fumonisins are mycotoxins produced by Fusarium verticillioides and related fungi. They occur in corn and in corn-based products. Fumonisins are toxic to a variety of animal species and are carcinogenic to rodents. Their effects on human health are unclear, but fumonisins are implicated as a risk factor for esophageal cancer and, more recently, neural tube defects (NTDs) in populations relying on home-grown corn as a dietary staple. An in vivo model for studying the relationship between fumonisins and NTDs has been developed using the LMBc mouse. In this model, dose-related increases in NTDs were induced by administration of fumonisin B1 (FB1) (2-20 mg/kg BW) to pregnant dams at a critical time (Days 7.5-8.5) for NTD development during gestation. When given to the dams, folinic acid partially protected and glycosphingolipid ganglioside GM1 almost completely protected the fetuses against NTDs induction by FB1. This suggests that FB1 interferes with folic acid uptake, probably by disrupting complex sphingolipid metabolism, thereby increasing the risk of NTD development. The LMBc mouse model will be useful for comparative studies to determine the relevance of these findings for other mouse strains and species. The affect of cooking on fumonisins and fumonisin toxicity is another area of concern. This is because recent results suggest that routine chemical analyses might underestimate the amount of bioactive fumonisins or fumonisin reaction products in cooked foods. However, baking, pan-frying or deep-frying did not affect in vivo toxicity of fumonisin-contaminated cornmeal in a two-week rat feeding study bioassay. This result suggests that cooking did not convert fumonisins to toxic reaction products. These studies are examples of ongoing research that contributes to understanding the factors and conditions that influence fumonisin toxicity.