Bioavailability and biotransformation of paralytic shellfish toxins assessed by permeability assays using Caco‐2 monolayers

Caco-2 cells are well established models of intestinal epithelium, being routinely used to evaluate toxicity and bioavailability. Although usually overlooked, Caco-2 monolayers may also be used to assess biotransformation by epithelial cells, which may lead to significant changes in the composition and properties of the ingested matrix. In this work we characterize paralytic shellfish toxins (PSTs) extracted from the dinoflagellate Gymnodinium catenatum strain regarding their permeability through and biotransformation by polarized Caco-2 monolayers. The results show that biotransformation influences the apparent permeability measured for the different PSTs in the extract, and alters the extract effective toxicity.