Individual and combined effects of low oral doses of deoxynivalenol and nivalenol in mice.

Deoxynivalenol (DON) and nivalenol (NIV) are toxic Fusarium secondary trichothecene metabolites that often co-occur regularly in cereal grains. These compounds were compared for their toxicity towards C57BL/6 mice on several parameters including alteration in plasma biochemistry, immune system reactivity and hepatic drug metabolism capacity. Mice received individual or combined oral doses of each toxin: 0.071 or 0.355 mg/kg of body weight, administrated three days a week for 4 weeks. Food consumption was altered by the single administration of 0.355 mg/kg of NIV, although no noticeable change of body and organ weights or liver protein contents was detected. NIV administration did cause also significant changes in total CO2 and uric acid concentrations in plasma. Individual toxin exposures led to increases in plasma IgA without no detectable change in the ex vivo production of cytokine by splenocytes. The liver ethoxyresorufin O-deealkylase, pentoxyresorufin O-depenthylase and glutathione S-transferase activities were increased in concert with cytochrome P4501a and P4502b subfamily expression. Administration of combinations of DON and NIV resulted in responses similar to that observed using individual doses of each toxin. However, depending on the ratio of toxin doses and biochemical parameters, some responses could be also additive (plasma IgA and hepatic DCNB conjugation) or synergistic (plasma uric acid).