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.