Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus and Penicillium, and it is found in many foods. Acrylamide (AA) can be produced in foods treated at high temperatures. In this study, we investigated the combined toxicity of OTA and AA against human renal and hepatic cells in vitro. The concentration at which the synergistic effect of OTA and AA occurs was determined using the combination index obtained from the cell viability results for OTA and AA individually or in combination. The synergistic toxicity of both substances was evaluated by cell viability and the production of reactive oxygen species. In addition, apoptosis-related markers were significantly upregulated by OTA and AA individually or in combination. To determine the combined toxic effects of OTA and AA on the cells, the levels of enzymes involved in the phase I reaction and apoptosis-related markers were determined using quantitative (q)PCR and Western blot. The expression levels of CYP enzymes CYP1A1 and CYP1A2 involved in the phase I reaction significantly increased when the cells were treated with OTA and AA in combination. The expression of apoptosis-related markers, Bcl2-associated X protein (Bax) and caspase 3, also increased when the cells were treated with OTA and AA in combination. Therefore, the synergistic toxicity of OTA and AA suggests that such effects may contribute to nephrotoxicity and hepatotoxicity.
Keywords: CYP; acrylamide; apoptosis; combined toxicity; ochratoxin A.