Opinion of the Scientific Panel on Contaminants in Food Chain on a request from the Commission related to fumonisins as undesirable substances in animal feed Request No. EFSA-Q-2003-040 Adopted on 22 June

Fumonisins are a distinct group of mycotoxins produced by several field fungi, including Fusarium verticillioides and Fusarium proliferatum. Fumonisins are occurring particularly in maize and maize-based products. Co-occurrence with other Fusarium toxins, such as zearalenone and deoxynivalenol, is regularly observed. Fumonisin B-1 is considered to be the most prevalent and most toxic derivative within the group of fumonisins. It is a prototypic inhibitor of cellular sphingosine (sphinganine) N-acetyltransferase. Inhibition of this enzyme is followed by an accumulation of sphinganine (Sa) and sometimes also sphingosine (So) and a depletion of complex sphingolipids in eukaryotic cells, which in turn results in impairment of cell cycle regulation and cellular differentiation, and in oxidative stress as well as apoptosis and necrosis. Fumonisin B-1 is carcinogenic in rodents, but it is devoid of significant genotoxic activity. In vivo rodent experiments suggest that fumonisins are tumour promoters. The increased Sa: So ratio in body fluids and tissues serves as a sensitive biomarker of exposure to fumonisins. Equidae and porcine species are considered to be the most sensitive animal species to fumonisins, developing species-specific clinical syndromes such as equine leukoencephalomalacia and porcine pulmonary oedema. Ruminants and poultry show a low responsiveness to fumonisins. Few data are available on the effects of fumonisins on farmed fish and on minor species, such as rabbits, goats and minks. The available data on animal exposure via feedingstuffs are limited and monitoring of feed materials is needed to improve exposure assessment. Available data on carry-over of fumonisins from animal feeds into edible tissues, including milk and eggs, indicate that transfer is limited, and thus residues in animal tissues contribute insignificantly to total human exposure.