Submitted to: Toxicologist
Publication Type: Abstract Only
Publication Acceptance Date: 11/15/1995
Publication Date: N/A
Technical Abstract: Fusarium moniliforme commonly contaminates corns, and produces the fumonisin mycotoxins. These toxins cause equine leucoencephalomalacia and porcine pulmonary edema. Fumonisins also cause liver and kidney toxicity in rats, are tumor promoters, and may have cancer-initiating ability. The mode of action of the fumonisins is thought to be their ability to inhibit ceramide synthase, which catalyzes the conversion of sphinganine (Sa) and sphingosine (So) to ceramide. This disrupts sphingolipid biosynthesis, and causes accumulation of sphingoid bases, primarily Sa, in tissues. Tissue slices can be used as a bioassay for fumonisin-like activity. Slices exposed to fumonisins were found to have elevated Sa content. We investigated whether extracts of fumonisin-contaminated corn could elevate Sa in rat liver slices. The extracts elevated Sa, even when dosed with extract equivalent to as little as 0.5 mg of corn. We determined if other hepatotoxins could elevate Sa. These toxins included aflatoxin B1, beauvericin, carbon tetrachloride, cyclopiazonic acid, carbonyl cyanide, and Sa. Only fumonisin B1 (FB1) and Sa significantly elevated Sa.