Cytotoxicity of ochratoxin A and citrinin in different cell typesin vitro

Cytotoxic effects resulting from the two mycotoxins ochratoxin A (OTA) and citrinin were evaluatedin vitro using cell cultures of different origin. Cytotoxicity was estimated by the neutral red (NR) uptake assay which allows to determine the viability of cells by detecting dye uptake into the cells and its storage in the lysosomes. The assay was performed with primary cell cultures derived from isolated porcine urinary bladder epithelial cells (PUBEC), which are competent in metabolism of xenobiotics, and with V79 hamster fibroblasts, a well established and frequently used cell line. In both systems, OTA was more cytotoxic compared to citrinin. When both mycotoxins were applied simultaneously no additive or synergistic effects were detected. Obviously, the primary cell culture system which represents a target tissue of the mycotoxins was more susceptible to the toxins, expressed in lower IC50-values. These results indicate that origin of a cell system and its competence in metabolism of xenobiotics have to be considered inin vitro investigations particularly when different systems were used.