Oxidative stress as a mechanism of combined OTA and CTN toxicity in rat plasma, liver and kidney.

Ochratoxin A (OTA) and citrinin (CTN) commonly coexist in grains. Aiming to evaluate oxidative stress in OTA + CTN toxicity, male Wistar rats were orally treated with two doses of OTA (0.125 and 0.250 mg kg-1 of body weight (b.w.)), CTN (2 mg kg-1 of b.w.) and resveratrol (RSV; 20 mg kg-1 of b.w.) and combined daily during 3 weeks. Protein carbonyl concentrations were measured in kidneys and liver; catalytic activity of glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) level in plasma, kidneys and liver, while malondialdehyde (MDA) concentration was measured in plasma, kidneys, liver and urine. Mycotoxin treatment significantly increased MDA concentration in plasma and kidney and decreased SOD activity in the liver. Rats treated with CTN and OTA125 + CTN had lower plasma GPx activity. Concentration of GSH in the kidney and protein carbonyls in the kidney and liver as well as GPx activity in the kidney and liver, SOD activity in the kidney and CAT activity in the liver were not affected. Protective effect of RSV was observed on GSH in the kidney and plasma and MDA in the kidney, plasma and urine. Oxidative stress is involved in OTA + CTN toxicity in vivo because such treatment affects parameters of oxidative stress, particularly in plasma. RSV can reduce but not overcome oxidative stress induced by combined OTA and CTN treatment.