engleski

Oxidative brain tissue damage in rats treated with ochratoxin A and citrinin

Ochratoxin A (OTA) and citrinin (CTN) are nephrotoxic mycotoxins both produced by several fungal strains belonging to the genera Penicillium and Aspergilus. Both mycotoxins contaminate cereals and are usually found together. The mechanism of OTA toxicity is much studied in contrast to the mechanism of CTN toxicity. Although they are frequently found together, studies of their common toxicity are rare and the results controversial. In this study adult male Wistar rats in groups by six were treated orally as follows: 1. OTA (125 µg/kg b.w. daily for 21 days), 2. CTN (20 mg/kg b.w. for two days), 3. OTA (125 µg/kg b.w. daily for 21 days) + CTN (20 mg/kg b.w. for the last two days of OTA treatment), 4. controls (treated with vehicle - 51mM NaHCO3). Animals were sacrificed 24 hours after the last treatment ; brain tissue was collected and frozen until parameters of oxidative stress were analyzed. The concentration of glutathione (GSH) and malondialdehyde (MDA) was measured using spectrophotometric and HPLC methods, respectively. OTA and OTA+CTN treatment caused insignificant decrease in concentration of GSH as compared to controls (0.46±0.04 and 0.40±0.04 µmol/g tissue ; 0.53±0.07 and 0.47±0.05 µmol/g tissue) while CTN treatment did not change GSH concentration. The concentration of MDA was higher in OTA- (5.27±0.68 and 5.42±1.01 nmol/g tissue) and CTN-treated animals (6.62±0.22 and 8.25±0.93 nmol/g tissue) than in controls. When animals were treated with both mycotoxins, the MDA concentration increased significantly (6.64±0.56 and 8.46±0.87 nmol/g tissue ; P<0.05). These results indicate that GSH has not important role in brain tissue protection against reactive oxygen species produced by OTA and CTN. The significant increase of MDA, which is the final product of lipid peroxidation, in animals treated with both mycotoxins shows that the common exposure to OTA and CTN increases the oxidative damage produced by single mycotoxin.

oxidative stress; malondialdehyde; glutathione

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