Purpose: The aim of this paper is to evaluate the capacity of several yeasts to decrease genotoxicity of OTA and establish if the decrease is only due to adsorption of OTA on yeast product
Methods: Human renal cells were exposed to OTA (10 µM) alone or in presence of yeast enriched with glutathione (GSH) (10µM) or with selenomethinonine (SE) (10µM). In parallel 10 poultries per group were fed two days with feed including yeast product, and then were fed seven days with feed including yeast product and OTA. Viability of cells was evaluated using MTS test. Genotoxicity was evaluated by detection of DNA-adduct using P32 post labelling method. In addition OTA derivatives formed in human renal cells or in liver and kidney of poultry were analyzed after extraction by HPLC coupled to fluorimetric detection
Results: OTA significantly decreases cell viability (60%; P < 0.01) and induces formation of two OTA-DNA-adducts. Adjunction of pure GSH or GSH-yeast partially restores cells viability (70% versus 60%; P < 0.05) and avoid DNA adduct formation, explained by conversion of OTA into OTB and 4 OH OTA. Pure SE does not restore viability whereas SE-yeast has antagonistic effect (110% versus 60%; P < 0.01). SE and SE-yeast increase OTA-DNA adduct formation correlated to the appearance of new OTA metabolites
Significance: The decrease of OTA toxicity observed with yeast was not only correlated to adsorption but also to biotransformation of OTA which is modulated by yeast. DNA adduct patterns were correlated with OTA derivatives formed in the kidney. GSH-yeast is better to decrease OTA genotoxicity