Fumonisins: Toxicokinetics, mechanism of action and toxicity

Fumonisins are mycotoxins produced by Fusarium verticillioides and F. proliferatum. They occur worldwide and are found predominantly in maize and in maize-based animal feeds. Of the fumonisins, fumonisin B1 (FB1) is the most common and the most thoroughly studied. FB1 causes the same toxicities in animals as F. verticillioides- and F. proliferatum-contaminated feeds including equine leukoencephalomalacia (ELEM) and porcine pulmonary edema (PPE), diseases long associated with the consumption of mouldy feed by horses and pigs, respectively. FB1 is toxic to the liver in all species and the kidney in a range of laboratory and farm animal species, causing apoptosis followed by mitosis in the affected tissues. FB1 is also toxic to the cardiovascular system in pigs and horses. FB1 and other fumonisins inhibit ceramide synthase in all species including laboratory and farm animals and disrupt sphingolipid metabolism, a process underlying the mechanism of toxicity and pathogenesis of fumonisin-related diseases. The USFDA has set guidances for fumonisin concentrations in animal feeds that range from 1 to 50 ppm in the formulated rations depending upon the animal species. The European Union Commission has recommended guidance levels for fumonisins B1 plus B2 in feed materials and formulated feedstuffs. The levels also vary according to species and range from 5 ppm for horses, pigs, rabbits and pet animals to 50 ppm for adult ruminants and mink. Awareness of fumonisin-related animal diseases, monitoring feed and feed components, and adherence to guidance recommendations are important for reducing fumonisin-induced diseases in agriculturally important species.