Reactive oxygen species induced by beauvericin, patulin and zearalenone in CHO-K1 cells.

The cytotoxic effects of mycotoxins, induction of reactive oxygen species (ROS) and generation of lipid peroxidation products in CHO-K1 cells were determined as function of increasing time of exposure and concentrations of beauvericin (BEA), patulin (PAT) and zearalenone (ZEA). The end points were evaluated after 24h of exposure, by the tetrazolium salt (MTT) and neutral red (NR) assays. The IC(50) values obtained on the MTT and NR assays ranged from 0.69 to 79.40 microM and 4.40 to 108.76 microM, respectively. To determine the intracellular production of ROS, the intensity of fluorescence emitted from the probe H(2)-DCFDA was measured. The relative intensity of fluorescence from cells incubated with BEA, PAT and ZEA was approximately 4-, 7- and 4-fold higher in comparison with control cells at 0 min, respectively. Lipid peroxidation induced by ROS generation was assessed using the thiobarbituric acid reactive substances (TBARS) method for 2, 24 and 48 h. The malondialdehyde (MDA) production was increased with BEA and PAT exposure in a concentration- and time-dependent manner. MDA was not increased after 1 and 5 microM ZEA exposures for 2h, but was slightly increased at 50 microM. In conclusion, PAT was the most cytotoxic mycotoxin to CHO-K1 cells, followed by BEA and ZEA. Mycotoxins reduce cell viability correlated with the increases of ROS generation and MDA formation in concentration- and time-dependent manner. These data suggested that cytotoxicity and ROS generation are mechanisms of mycotoxins mediated toxicity.