The most common mycotoxin found in European foodstuffs, especially unprocessed grains, is deoxynivalenol (DON), which inhibits proteosynthesis and induces oxidative stress. The sorption properties of humic acids (HA) indicate a promising potential in the reduction of mycotoxin intoxication. In an experimental biomodel lasting 35 days, we investigated the effect of a dietary supplement containing HA on the antioxidant status in the liver, heart and kidney mitochondria and in the blood plasma of rats exposed to the stress factor of orally administered DON. DON was administered at doses of 100 and 200% above the maximum tolerable daily intake (1.0 μg/kg body weight/day). We evaluated the activities of the following enzymes: superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase and tripeptide glutathione. Administration of DON has been shown to induce oxidative stress, the intensity of which appears to be directly dependent on the concentration of mycotoxin. Supplementation with 1% HA (10 g/kg of feed) resulted in alleviation of this stress, in which the preventive effect of HA may have been implicated partly by affecting the adsorption of DON through the GIT and limiting its bioavailability. There were also signs that it can act by actively interfering with ROS inhibition to help achieve redox homeostasis. However, there is another aspect that deserves attention, namely, the metabolism of HA. The results presented in our work suggest that the mechanism of possible metabolism occurs predominantly in the liver, including an oxidative increase in polarity and subsequent conjugation reactions mediated by the GST-GSH system.
Keywords: Antioxidant enzymes; Deoxynivalenol; Glutathione; Humic acids; Mycotoxin.