Short-term effects of deoxynivalenol, T-2 toxin, fumonisin B1 or ochratoxin on lipid peroxidation and glutathione redox system and its regulatory genes in common carp (Cyprinus carpio L.) liver

The effects of a single oral dose of 1.82 mg kg −1 bw of T-2 and HT-2 toxin (T-2), 1.75 mg kg −1 bw deoxynivalenol (DON) and 15-acetyl DON, 1.96 mg kg −1 bw fumonisin B 1 (FB 1 ) or 1.85 mg kg −1 bw ochratoxin A (OTA) were investigated in common carp juveniles on lipid peroxidation, the parameters of the glutathione redox system including the expression of their encoding genes in a short-term (24 h) experiment. Markers of the initiation phase of lipid peroxidation, conjugated dienes, and trienes, were slightly affected by DON and OTA treatment at 16-h sampling. The termination marker, malondialdehyde, concentration increased only as an effect of FB 1 . Glutathione content and glutathione peroxidase activity showed significantly higher levels in the T-2 and FB 1 groups at 8 h, and in the DON and FB 1 groups at 16 h. The expression of glutathione peroxidase genes ( gpx4a, gpx4b ) showed a dual response. Downregulation of gpxa was observed at 8 h, as the effect of DON, FB 1 , and OTA, but an upregulation in the T-2 group. At 16 h gpx4a upregulated as an effect of DON, T-2, and FB 1, and at 24 h in the DON and T-2 groups. Expression of gpx4b downregulated at 8 h, except in the T-2 group, and upregulation observed as an effect of T-2 at 24 h. The lack of an increase in the expression of nrf2, except as the effect of DON at 8 h, and a decrease in the keap1 expression suggests that the antioxidant defence system was activated at gene and protein levels through Keap1–Nrf2 independent pathways.