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

DOGI, CECILIA; CRISTOFOLINI ANDREA; FOCHESATO ANALIA; ARMANDO ROMINA; PENA GABRIELA; CHULZE SOFIA; DALCERO ANA; CAVAGLIERI LILIA

Congreso; 7th conference of The World Mycotoxin Forum and XIIIth IUPAC International Symposium on Mycotoxins and Phycotoxins; 2012

Aflatoxin contamination is a worldwide problem that compromises food and feed safety. Crhonic AFB1 exposure is linked to impaired growth an immune function and chronic diseases. In previous studies we have demonstrated that Saccharomyces cereviciae RC016 has benefical properties and mycotoxin binding abilities in vitro. The aim of the present study was to evaluate the toxic effect of crhonic AFB1 exposure on rat gut villi in the presence of probiotic S. cereviciae RC016 strain in vivo. Male Wistar rats (36) were divided into six diet groups: (i) commercial diet and PBS (1 ml)orally administered; (ii) control diet and S. cereviciae (1 x 109 cells/ml in PBS) orally administered; (iii) commercial diet with AFB1 40 µg/kg; (iv) commercial diet with AFB1 100 µg/kg; (v)commercial diet with AFB1 40 µg/kg and S. cereviciae (1 x 109 cells/ml in PBS); and (vi)commercial diet with AFB1 100 µg/kg and S. cereviciae (1 x 109 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 globlet cells. The results showed a higher apoptotic index in rat cells receiving the diet (ii), even though higher than that observed in the control diet (i). Both doses of AFB1 (iii and iv) diminished the apoptosis index whereas the index increased again when AFB1 and the yeast were combined in the diet (v and vi) The same trend was observed for all the morphometric parameters evaluated and S. cereviciae RC016 appears to exerts its benefical effect only in the presence of high toxin levels. The results agree with previous in vitro studies demonstrating that AFB1 removal 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. cereviciae RC016 would favour this tissue remodelling, allowing gut remodel their cells and thereby improves tissue homeostasis.