In vitro and in vivo studies to assess the effectiveness of cholestyramine as a binding agent for fumonisins

Several adsorbent materials were tested at 1 mg/ml for their in vitrocapacity to adsorb fumonisin B₁ (FB₁) from aqueous solutions. Cholestyramine showed the best adsorption capacity (85% from a solution containing 200 g/ml FB₁) followed by activated carbon (62% FB₁). Bentonite adsorbed only 12% of the toxin from a solution containing 13 g/ml FB₁, while celite was not effective even at the lowest tested FB₁ concentration (3.2 g/ml). Cholestyramine was tested in vivoto evaluate its capacity to reduce the bioavailability of fumonisins (FBs) in rats fed diet contaminated with toxigenic Fusarium verticillioidesculture material. Rats were exposed for one week to FBs-free diet, FBs-contaminated diet containing 6 or 20 g/g FB₁ + FB₂ and the same FBs-contaminated diet added of 20 mg/g cholestyramine. The increase of sphinganine/sphingosine (SA/SO) ratio in urine and kidney of treated rats was used as specific and sensitive biomarker of fumonisin exposure.The addition of cholestyramine to the FBs-contaminated diets consistently reduced the effect of FBs by reducing significantly (P < 0.05) both urinary and renal SA/SO ratios.This revised version was published online in October 2005 with corrections to the Cover Date.