Natural environmental contaminants and One Health in vitro integrated approach for toxicological evaluation

Emerging mycotoxins, i.e. beauvericin, enniatins etc., are natural environmental contaminants of commodities. Toxicological information is still controversial and a risk assessment is required. The aim of this study is to evaluate possible toxicological effects of enniatin B1 (ENNB1), alone and in association with beauvericin (BEA) and zearalenone (ZEA) through an in vitro Integrated Testing Strategy with 3D epithelial barriers: 1- Human intestinal barrier with Caco-2 cells cultured on inserts, were exposed to ENNB1 (0.5-1.5-3-6 µM) alone and combined with BEA (3 µM) and ZEA (20 µM) with the following endpoints: • (i) barrier tight junction integrity by measurement of trans-epithelial electrical resistance (TEER) • (ii) interleukin-8 (IL-8) determination in the culture medium from apical size 2- Reconstructed human tissues, for topical exposure (dermal and ocular), were exposed to ENNB1 (0.5-1.5-3 µM) with the following endpoint: • in vitro toxicity evaluation with MTT test Results showed that, with regard to Caco-2 cells, a significant TEER increase (p< 0.05) was observed after 24 h of exposure and in particular a positive correlation was found between ENNB1 concentration and TEER values (r=0.84, p<0.01). Regarding the IL-8 release, preliminary results showed a tendency towards higher levels of IL-8 after 24 h of exposure as the ENNB1 concentration increased and a possible synergic action of ENNB1 in co-exposure with BEA and ZEA. No cytotoxic effects have been observed on reconstructed cornea model after 1 h of exposure at any of the tested concentrations. Further studies are currently underway to investigate also the species-specific effects with an intestinal porcine barrier model with IPEC-J2 cells, following the One Health perspective, from environment, to human and animal, with a cell based integrated approach.