Cytotoxicity, apoptosis, DNA damage and methylation in mammary and kidney epithelial cell lines exposed to ochratoxin A

This study aimed to investigate the in vitro damage induced by Ochratoxin A (OTA) using BME-UV1 and MDCK epithelial cells. Both cells lines were treated with OTA (0 up to 10 μg/mL) and cell viability (MTT assay), membrane stability (LDH release assay), and apoptotic cell rate (Tunel assay) were investigated. Further, the effect of the incubation with OTA has been evaluated at DNA level by the determination of DNA integrity, by the quantification of DNA adduct formation (8-OHdG) and by the assessment of the global DNA methylation status (5-mC). The obtained results showed that after 24 hours of OTA treatment, BME-UV1and MDCK cell viability was reduced in a dose-dependent way. OTA significantly (P<0.05) increased LDH release in BME-UV1 cells at all concentrations tested. OTA (1.25 μg/mL) induced 35% LDH release in MDCK cells (P<0.05). A significant (P<0.05) change in percentages of apoptotic BME-UV1 (10±0.86) and MDCK (25±0.88) cells respectively were calculated when the cells were co-incubated with OTA. The level of 8-OHdG adduct formation was significantly (P<0.05) increased in BME-UV1 cells treated with 1.25 μg/mL of OTA. The results of the present study suggest that a different mechanism of action may occur in these cell lines.