Biotransformations mycotoxins

Absorption of a mycotoxin will occur when it crosses body membranes and enters the blood stream. The primary sites of mycotoxin absorption are the gastrointestinal tract (ingestion of contaminated food), lungs (inhalation of contaminated particles or toxin-containing fungal spores) and the skin (direct contact with contaminated materials or pure mycotoxins). When the mycotoxin enters the blood it is then available for distribution. Livers and kidneys have a high capacity to bind many mycotoxins while other mycotoxins are highly lipophilic and can concentrate in body fat. In the final outcome a toxic response by a mycotoxin will be critically influenced by the rate of absorption, distribution, biotransformation and excretion (Smith et al., 1994). 

Finally, biological detoxification or biotransformation, or degradation of mycotoxins, especially aflatoxin by microbial systems to a metabolite(s) that is... 

The development of procedures for the isolation of hepatocytes from livers of different species, including man, have allowed the use of this model for comparative studies on the species-related biotransformation and toxicity of xenobiotics. In vitro studies with aflatoxin Bj showed that rat hepatocytes were more sensitive than those from mice, as became apparent by the death of the cells at much lower concentrations, the much higher levels of binding of metabolites of aflatoxin B1 to TCA-precipitable cell-material 33, 34), and the much higher levels of unscheduled DNA-synthesis (55). In addition, the mycotoxin caused segregation of nucleolar components in rat hepatocytes, but not in cells from mice 36). 

In summary, then, very little of the parent trichothecene mycotoxin is excreted intact. Rather, elimination by detoxification of the toxin is the result of extensive and rapid biotransformation. 

Baldwin NCP, Bycroft BW, Dewick PM, Gilbert J (1986) Metabolic Conversions of Trichothecene Mycotoxins Biotransformation of 3-Acetyldeoxynivalenol into Fusarenone X. Z Naturforsch 41C 845... 

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