INTESTINAL-ABSORPTION OF ZEARALENONE AND IN-VITRO STUDY OF NONNUTRITIVE SORBENT MATERIALS

Zearalenone is a mycotoxin produced by several members of the genus Fu sarium that elicits oestrogenic effects on mammalian reproductive syst ems. Methods for an effective detoxification of contaminated feedstuff s are not currently available, but one of the new approaches to the pr oblem is the addition of non-nutritive sorptive materials to the diets of animals in order to reduce gastrointestinal absorption of mycotoxi ns. The objectives of this study were to examine the intestinal absorp tion of zearalenone, to evaluate several sorbent materials for zearale none affinity in vitro, and to select a potentially efficacious candid ate for protection against zearalenone intoxication. In situ results o btained showed that the absorption of zearalenone in the rat small int estine follows first-order kinetics, with an absorption rate constant k(a), of 9.27 +/- (0.69)/h. In vitro adsorption tests of zearalenone b y selected materials showed that cholestyramine was the best adsorbent , followed in decreasing order by crospovidone, montmorillonite, bento nite, sepiolite and magnesium trisilicate. The Freundlich isotherm sho wed a better fit than the Langmuir isotherm. This could suggest the ex istence of a heterogeneous sorbent surface, the existence of different adsorption mechanisms or both. Results demonstrated that crospovidone was able to adsorb 313.7 mu g zearalenone/g adsorbent, whereas montmo rillonite, bentonite, sepiolite and magnesium trisilicate were able to adsorb 192.2, 112.4, 74.37 and 22.61 mu g zearalenone/g adsorbent, re spectively. Cholestyramine adsorption parameters were above these leve ls.