Emerging mycotoxins induce hepatotoxicity in pigs' precision-cut liver slices and HepG2 cells.

Emerging mycotoxins are currently gaining more attention due to their high frequency of contamination in foods and grains. However, most data available in the literature are in vitro, with few in vivo results that prevent establishing their regulation. Beauvericin (BEA), enniatins (ENNs), emodin (EMO), apicidin (API) and aurofusarin (AFN) are emerging mycotoxins frequently found contaminating food and there is growing interest in studying their impact on the liver, a key organ in the metabolization of these components. We used an ex vivo model of precision-cut liver slices (PCLS) to verify morphological and transcriptional changes after acute exposure (4 h) to these mycotoxins. The human liver cell line HepG2 was used for comparison purposes. Most of the emerging mycotoxins were cytotoxic to the cells, except for AFN. In cells, BEA and ENNs were able to increase the expression of genes related to transcription factors, inflammation, and hepatic metabolism. In the explants, only ENN B1 led to significant changes in the morphology and expression of a few genes. Overall, our results demonstrate that BEA, ENNs, and API have the potential to be hepatotoxic.

Deoxynivalenol induces apoptosis and inflammation in the liver: Analysis using precision-cut liver slices.

Deoxynivalenol (DON) is one of the most common mycotoxins in cereals and their by-products. Its adverse effects on animal and human health have been extensively studied in the intestine, but little attention has been paid to another target organ for mycotoxins, the liver that is potentially exposed after intestinal absorption and enterohepatic circulation. To assess DON's toxicity in an ex vivo model structurally and physiologically closer to the whole liver, we developed a pig precision-cut liver slices (PCLS) model. PCLS contain all cell types and maintain intercellular and cell-matrix interactions, among other architectural features of the liver. The human HepG2 cell line was used for comparison. We observed that after a short exposure, DON reduced the cell viability of HepG2 cells and induced the expression of genes involved in apoptosis, inflammation and oxidative stress. When PCLS were exposed to DON, damage to the tissues was observed, with no changes in markers of liver function or injury. Exposure to the toxin also triggered liver inflammation and apoptosis, effects already observed in pigs fed DON-contaminated diets. Overall, these data demonstrate that DON had toxic effects on a liver cell line and on whole liver tissue, consistent with the effect observed during in vivo exposure. They also indicate that pig PCLS is a relevant and sensitive model to investigate the liver toxicity of food contaminants.

Co-occurrence of DON and Emerging Mycotoxins in Worldwide Finished Pig Feed and Their Combined Toxicity in Intestinal Cells.

Food and feed can be naturally contaminated by several mycotoxins, and concern about the hazard of exposure to mycotoxin mixtures is increasing. In this study, more than 800 metabolites were analyzed in 524 finished pig feed samples collected worldwide. Eighty-eight percent of the samples were co-contaminated with deoxynivalenol (DON) and other regulated/emerging mycotoxins. The Top 60 emerging/regulated mycotoxins co-occurring with DON in pig feed shows that 48%, 13%, 8% and 12% are produced by Fusarium, Aspergillus, Penicillium and Alternaria species, respectively. Then, the individual and combined toxicity of DON and the 10 most prevalent emerging mycotoxins (brevianamide F, cyclo-(L-Pro-L-Tyr), tryptophol, enniatins A1, B, B1, emodin, aurofusarin, beauvericin and apicidin) was measured at three ratios corresponding to pig feed contamination. Toxicity was assessed by measuring the viability of intestinal porcine epithelial cells, IPEC-1, at 48-h. BRV-F, Cyclo and TRPT did not alter cell viability. The other metabolites were ranked in the following order of toxicity: apicidin > enniatin A1 > DON > beauvericin > enniatin B > enniatin B1 > emodin > aurofusarin. In most of the mixtures, combined toxicity was similar to the toxicity of DON alone. In terms of pig health, these results demonstrate that the co-occurrence of emerging mycotoxins that we tested with DON does not exacerbate toxicity.