In vivo studies of chronic aflatoxin B1 exposure on rat gut villi in the presence of probiotic Saccharomyces cerevisiae RC016 strain

DOGI, CA; ; CRISTOFOLINI ; FOCHESATO ; ARMANDO R, ; PENA, G., ; CHULZE S., ; DALCERO A. ; CAVAGLIERI L

Congreso; World Mycotoxin Forum, Holanda; 2012

Aflatoxin contamination is a worldwide problem that compromises food and feed safety. Chronic AFB1 exposure is linked to impaired growth and immune function and chronic diseases. In previous studies we have demonstrated that Saccharomyces cerevisiae RC016 has beneficial properties and mycotoxin binding abilities in vitro. The aim of the present study was: to evaluate the toxic effect of chronic AFB1 exposure on rat gut villi in the presence of probiotic S. cerevisiae RC016 strain in vivo. Male Wistar rats (36) were divided into six diet groups, a) commercial diet and PBS (1 ml) orally administered; b) control diet and S. cerevisiae (1x109 cells/ml in PBS) orally administered; c) commercial diet with AFB1 40 µg kg-1; d) commercial diet with AFB1 100 µg kg-1; e) commercial diet with AFB1 40 µg kg-1 and S. cerevisiae (1x109 cells/ml in PBS) and f) commercial diet with AFB1 100 µg kg-1 and S. cerevisiae (1x109 cells/ml in PBS). The assay was carried out during 60 days. At the end of the experiment rats were sacrificed by decapitation and the small intestines were recovered and histologically evaluated. Cell apoptosis was evaluated by Tunel?s technique. The morphometric parameters included villi length and width, intestinal crypt depth and quantification of goblet cells. The results showed a higher apoptotic index in rat cells receiving the diet b, even though higher than that observed in the control diet a. Both doses of AFB1 (c and d) diminished the apoptosis index whereas the index increased again when AFB1 and the yeast were combined in the diet (e and f). The same trend was observed for all the morphometric parameters evaluated and, S. cerevisiae RC016 appears to exert its beneficial effect only in the presence of high toxin levels. The results agree with previous in vitro studies that demonstrated that AFB1 remotion increased in relation to AFB1 concentration. Apoptosis plays a fundamental role in cellular remodelling to maintain tissue homeostasis. The presence of the toxin inhibits tissue remodelling leading to atrophy or at least not allow adequate remodelling. The results obtained in the present study showed that S. cerevisiae RC016 would favour this tissue remodelling, allowing gut remodel their cells and thereby improves tissue homeostasis.