Modification of aflatoxin B₁ and ochratoxin A toxicokinetics in rats administered a yeast cell wall preparation

Abstract

The cell wall of Saccharomyces cerevisiae can bind mycotoxins in vitro, but there is scarce information on whether this property decreases the absorption of mycotoxins in vivo. The effect of a yeast cell wall preparation (YCW) on toxicokinetics and balance excretion (urine and faeces) of aflatoxin B₁ (AFB1) and ochratoxin A (OTA) was tested in rats after oral administration of each toxin. The ³H-labelled mycotoxins were used at low doses. Co-administration of YCW with AFB1 decreased the extent, but not the rate, of absorption. Concurrently, radioactivity excreted in faeces increased by up to 55% when compared with controls, whilst the excretion in urine decreased (p < 0.05). The effect of YCW on OTA was less marked, although it increased radioactivity excretion in faeces (up to 16%; p < 0.05) it did not result in changes in urine and toxicokinetic parameters. The in vivo effect is in agreement with the reported in vitro binding ability for these toxins (AFB1 > OTA). In conclusion, these results indicate that YCW could be used to protect monogastric animals against exposure to low dietary levels of selected mycotoxins.

Keywords:

• toxicology
• toxicokinetics
• mycotoxins
• aflatoxins
• ochratoxin A
• animal feed

Acknowledgements

S. Firmin was supported by a doctoral fellowship (CIFRE 1058/2007), jointly financed by the Alltech company, ANRT (Association Nationale de la Recherche Technique), and INRA (Institut National de la Recherche Agronomique). The authors would like to thank Professor J. Woodley for his help with the English language; and Dr J.P. Cravedi from the laboratory of Xenobiotics INRA-Toulouse for facilitating the analysis of carcasses.