Location: Toxicology & Mycotoxin ResearchTitle: Hepatotoxic mycotoxins
|Eaton, David - University Of Washington|
|Beima, Kristin - University Of Washington|
|Bammler, Theo - University Of Washington|
Submitted to: Comprehensive Toxicology
Publication Type: Book / Chapter
Publication Acceptance Date: 11/10/2016
Publication Date: 12/1/2017
Citation: Eaton, D., Beima, K., Bammler, T., Riley, R.T., Voss, K.A. 2017. Hepatotoxic mycotoxins. In: McQueen, C. A., Comprehensive Toxicology, Third Edition. Vol. 2, pp. 483–521. Oxford: Elsevier Ltd. ISBN: 9780081006016
Interpretive Summary: Aflatoxins and fumonisins are common fungal toxins found in commodities including corn. This chapter provides an update of experimental and epidemiological findings related to the liver toxicity of these mycotoxins. Aflatoxins are known causes of liver disease, including cancer, in humans but the role of fumonisins in human health remains unclear. Fumonsins have however been shown to promote aflatoxin-induced cancer in animal models, making co-exposure a health concern for populations consuming co-contaminated foods on a regular basis.
Technical Abstract: Aflatoxins are produced by Aspergillus species including A. flavus and A. parasiticus. Fumonisins are produced by Fusarium species, mainly F. verticillioides and F. parasiticus. These mycotoxins are common contaminants of commodities and have been shown to co-contaminate corn. Aflatoxins are known human hepatotoxins and carcinogens whereas there are no human diseases proven to be caused by fumonisins. Both are liver carcinogens in mice and rats but have quite different and possibly complementary mechanisms of action. Aflatoxins are metabolized extensively to DNA reactive compounds. In contrast, fumonisins are not metabolized to DNA reactive species. Their mechanism of action involves inhibition of sphingolipid biosynthesis and disruption of multiple sphingolipid-dependent cell functions. Fumonisins are potent tumor promoters in animal models and promotion of liver tumors in aflatoxin-treated animals has been demonstrated. Because the fungi that produce aflatoxins and fumonisins co-occur on corn, co-exposures are a concern for humans consuming large amounts of mycotoxin contaminated corn as a dietary staple.