Enniatin A

Enniatin B is an emerging mycotoxin known to present biological activity because of its ionophoric characteristics. This compound has demonstrated strong in vitro cytotoxicity against different cancer cells, also at low molecular concentrations. Its natural occurrence in food commodities and feed is highly reported world-wide, but few information is available about its stability in the human gastro-intestinal tract. The present work evaluates the catabolic fate of enniatin B upon in vitro simulated digestion and colonic fermentation. LC-MS target and untargeted analysis have been performed to quantify the extent of enniatin B degradation and the formation of catabolic products. The results obtained showed significant degradation of enniatin B (degradation rate 79 ± 5%) along the gastrointestinal tract and further degradation of residual enniatin B was observed during colonic fermentation after 24 h of incubation. Moreover, 5 catabolic metabolites of enniatin B were putatively identified after gastrointestinal digestion resulting from the oxidation and opening of the depsipeptide ring. As a final step, the pharmacokinetic properties of enniatin B degradation products were tested in silico revealing that some of them may be adsorbed at the gastrointestinal level more than the parent compound. Additionally, the smaller degradation products showed moderate blood-brain-barrier crossing.

Enniatin A (EN-A) is a Fusarium mycotoxin which is a common contaminant in grains and especially in maize and it causes serious loss of product. The aim of this study was to investigate the cytotoxic effects using 3-(4,5-dimethylthiazolyl-2)-2,5 diphenyltetrazolium bromide (MTT) assay in human cervix carcinoma (HeLa) cell line, and genotoxic effects of EN-A using chromosome aberrations (CAs), sister chromatid exchanges (SCEs), micronuclei (MN) and comet assays in human lymphocytes. The cells were treated with 0.07, 0.14, 0.29, 0.57, 1.15, 2.29, 4.59 and 9.17 μM concentrations of EN-A. It exhibited cytotoxic effects in HeLa cell lines especially when the concentrations were increased. The half-inhibitory value (IC50) was determined as 1.15 μM concentration for 24 h and 0.57 μM concentration for 48 h. However, EN-A failed to affect the frequency of CAs, SCEs and MN in human lymphocytes. Only a slight increase was observed in the frequency of SCEs at 0.57 μM concentration over 48 h. The replication (RI) and nuclear division (NDI) indices were not affected. On the contrary, EN-A decreased the mitotic index (MI) significantly at all concentrations compared to the negative control and solvent control (except at 0.29 μM for 24 h, and except at 0.14, 0.29 and 0.57 μM for 48 h). Treatments over 2.29 μM showed toxic effects in human lymphocytes. EN-A significantly increased comet tail intensity (except at 0.07 and 0.57 μM) in isolated human lymphocytes. The results of this study demonstrate that EN-A has an obvious cytotoxic effect especially when the EN-A concentration was increased. In addition, EN-A could exhibit a mild genotoxic effect.

The waste management occupational environment is recognized by the simultaneous presence of several substances and biologic agents. Therefore, workers are exposed simultaneously to multiple contaminants. Occupational exposure to aflatoxin B1in one Portuguese waste sorting plant was already reported. However, besides this mycotoxin, data regarding fungal contamination showed that exposure to other mycotoxins could be expected. A study was developed to analyze if exposure to other mycotoxins besides aflatoxin B1was occurring in the workers from the waste sorting plant previously assessed and to discuss how these findings need to be considered in the risk assessment process. In addition to aflatoxin B1detected previously by ELISA, two additional mycotoxins and one mycotoxin degradation product were detected and quantified by a multi-mycotoxin HPLC-MS/MS approach: Enniatin B and ochratoxin A as well as 2'R-ochratoxin A. Besides the confirmation of co-exposure to several mycotoxins, results probably indicate different exposure routes for the mycotoxins reported.