Intestinal absorption of zearalenone and in vitro study of non-nutritive sorbent materials

Zearalenone is a mycotoxin produced by several members of the genus Fusarium that elicits oestrogenic effects on mammalian reproductive systems. Methods for an effective detoxification of contaminated feedstuffs are not currently available, but one of the new approaches to the problem is the addition of non-nutritive sorptive materials to the diets of animals in order to reduce gastrointestinal absorption of mycotoxins. The objectives of this study were to examine the intestinal absorption of zearalenone, to evaluate several sorbent materials for zearalenone affinity in vitro, and to select a potentially efficacious candidate for protection against zearalenone intoxication. In situ results obtained showed that the absorption of zearalenone in the rat small intestine follows first-order kinetics, with an absorption rate constant k(a), of 9.27 +/- (0.69)/h. In vitro adsorption tests of zearalenone by selected materials showed that cholestyramine was the best adsorbent, followed in decreasing order by crospovidone, montmorillonite, bentonite, sepiolite and magnesium trisilicate. The Freundlich isotherm showed a better fit than the Langmuir isotherm. This could suggest the existence 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 montmorillonite, bentonite, sepiolite and magnesium trisilicate were able to adsorb 192.2, 112.4, 74.37 and 22.61 mu g zearalenone/g adsorbent, respectively. Cholestyramine adsorption parameters were above these levels.