Emerging Fusarium and Alternaria mycotoxins gain more and more interest due to their frequent contamination of food and feed, although in vivo toxicity and toxicokinetic data are limited. Whereas the Fusarium mycotoxins beauvericin, moniliformin and enniatins particularly contaminate grain and grain-based products, Alternaria mycotoxins are also detected in fruits, vegetables and wines. Although contamination levels are usually low (µg/kg range), higher contamination levels of enniatins and tenuazonic acid may occasionally occur. In vitro studies suggest genotoxic effects of enniatins A, A1 and B1, beauvericin, moniliformin, alternariol, alternariol monomethyl ether, altertoxins and stemphyltoxin-III. Furthermore, in vitro studies suggest immunomodulating effects of most emerging toxins and a reproductive health hazard of alternariol, beauvericin and enniatin B. More in vivo toxicity data on the individual and combined effects of these contaminants on reproductive and immune system in both humans and animals is needed to update the risk evaluation by the European Food Safety Authority. Taking into account new occurrence data for tenuazonic acid, the complete oral bioavailability, the low total body clearance in pigs and broiler chickens and the limited toxicity data, a health risk cannot be completely excluded. Besides, some less known Alternaria toxins, especially the genotoxic altertoxins and stemphyltoxin III, should be incorporated in risk evaluation as well.

The goal of this study was to determine the absolute oral bioavailability, (presystemic) hydrolysis and toxicokinetic characteristics of deoxynivalenol, 3-acetyldeoxynivalenol, and 15-acetyldeoxynivalenol in broiler chickens and pigs. Crossover animal trials were performed with intravenous and oral administration of deoxynivalenol, 3-acetyldeoxynivalenol, and 15-acetyldeoxynivalenol to broilers and pigs. Plasma concentrations were analyzed by using liquid chromatography-tandem mass spectrometry, and data were processed via a tailor-made compartmental toxicokinetic analysis. The results in broiler chickens showed that the absorbed fraction after oral deoxynivalenol, 3-acetyldeoxynivalenol, and 15-acetyldeoxynivalenol administration was 10.6, 18.2, and 42.2%, respectively. This fraction was completely hydrolyzed presystemically for 3-acetyldeoxynivalenol to deoxynivalenol and to a lesser extent (75.4%) for 15-acetyldeoxynivalenol. In pigs, the absorbed fractions were 100% for deoxynivalenol, 3-acetyldeoxynivalenol, and 15-acetyldeoxynivalenol, and both 3-acetyldeoxynivalenol and 15-acetyldeoxynivalenol were completely hydrolyzed presystemically. The disposition properties of 3-acetyldeoxynivalenol and 15-acetyldeoxynivalenol demonstrate their toxicological relevance and consequently the possible need to establish a tolerable daily intake.

Fusarium fungi frequently infest crops in temperate regions such as Western Europe and North America. They can produce a wide range of mycotoxins, including several extensively studied compounds such as trichothecenes, zearalenone and fumonisins. They are also capable of producing other less well-known mycotoxins like enniatins (ENNs) (enniatin (ENN) A, A1, B and B1) and beauvericin (BEA). ENNs are cyclic hexadepsipeptides consisting of alternating D-α-hydroxyisovaleric acids and L-methyl-amino acids. Over the last decade, ENNs were found to be common contaminants of grains, maize and other feedstuffs. Several in vitro toxicity studies elucidated their antibacterial, antifungal, antihelmintic, insecticidal and herbicidal potency. Also their cytotoxic effect on a variety of cell types was demonstrated previously. However, the biological activity of ENNs has only been tested in few in vivo studies, demonstrating low acute toxicity, and there are no cases of mycotoxicosis in humans and animals reported.The aim of present study was to reveal the toxicokinetic properties and absolute oral bioavailability of enniatin B1 in pigs. Five pigs were administered this Fusarium mycotoxin per os and intravenously in a two-way cross-over design. The toxicokinetic profile fitted a two-compartmental model. Enniatin B1 is rapidly absorbed after oral administration (T 1/2a = 0.15 h, T max = 0.24 h) and rapidly distributed and eliminated as well (T 1/2elα = 0.15 h; T 1/2elβ = 1.57 h). The absolute oral bioavailability is high (90.9%), indicating a clear systemic exposure. After intravenous administration, the mycotoxin is distributed and eliminated rapidly (T 1/2elα = 0.15 h; T 1/2elβ = 1.13 h), in accordance with oral administration.Future research should focus on elucidating the phase I and II metabolisation pathways of ENNs and the toxicity of these metabolites. Next, toxicokinetic studies of ENN B1, and other ENNs should be performed in other animal species to compare mycotoxin and species dependent differences in toxicity and sensitivity. Finally, the present study may serve as a model for humans, indicating that systemic exposure of ENNs after oral intake of contaminated food cannot be neglected.

A toxicokinetic study of the Fusarium mycotoxins enniatin B1 (ENN B1) and enniatin B (ENN B) was performed in broiler chickens. Each animal received ENN B1 or B orally via an intracrop bolus and intravenously at a dose of 0.2 mg/kg body weight. Both enniatins were poorly absorbed after oral administration, with absolute oral bioavailabilities of 0.05 and 0.11 for ENNs B1 and B, respectively. Both enniatins were readily distributed to the tissues, with mean volumes of distribution of 25.09 and 33.91 L/kg for ENNs B1 and B, respectively. The mean total body clearance was rather high, namely, 6.63 and 7.10 L/h/kg for ENNs B1 and B, respectively. Finally, an UHPLC-HRMS targeted approach was used to investigate the phase I and II biotransformations of both mycotoxins. Oxygenation was the major phase I biotransformation pathway for both ENNs B1 and B. Neither glucuronide nor sulfate phase II metabolites were detected.

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