The human population is exposed to organophosphate and pyrethroid pesticides due to their extensive use in agriculture and household products. Once up-taken, these compounds are metabolized relatively quickly by cytochrome P450 enzymes and excreted via the urine. The measurement of a metabolite allows thus to identify its precursor compound. Some pesticides are suspected metabolism-disrupting chemicals (MDCs) and are associated, amongst others, with the onset of diabetes. Since validated test methods for the identification of MDCs are still lacking, the European Union is funding several projects that aim to develop and establish (pre-) validated test methods, one of the being EDCMET (Metabolic effects of endocrine disrupting chemicals: novel test methods and adverse outcome pathways). Here, we recently finalized an in vitro assay for hepatic triglyceride accumulation (TGA), which is currently under pre-validation with the PEPPER platform. This high-throughput assay uses the metabolically competent human hepatoma cell line HepaRG, known for its high expression of major cytochrome P450 enzymes, which is comparable to primary human hepatocytes. Using this assay, we already screened more than 100 compounds regarding their potential to induce steatosis in vitro and further extended our database including 12 organophosphate and pyrethroid pesticides and their metabolites, which we measured in urine and serum samples of different cohorts. In parallel to the TGA assay, we determined the half-life of both, the parent compound and metabolite, under the HepaRG treatment conditions aiming to clarify the contribution of either of them to the development of steatosis in vitro.

Peer reviewed