Location: Toxicology and Mycotoxin Research
Title: Fumonisin biomarkers in maize eaters and implications for human disease Authors
|Van Der Westhuizen, Liana -|
|Shephard, Gordon -|
|Gelderblom,, Wentzel C. -|
|Torres, Olga -|
Submitted to: World Mycotoxin Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 4, 2013
Publication Date: July 24, 2013
Citation: van der Westhuizen, L., Shephard, G.S., Gelderblom,, W.A., Torres, O., Riley, R.T. 2013. Fumonisin biomarkers in maize eaters and implications for human disease. World Mycotoxin Journal. DOI: 10.3920/WMJ2013.1589. Interpretive Summary: Fumonisins (FB) are toxic chemicals produced by a mold found in corn. The purpose of this study was to evaluate the use of various biochemicals in urine and blood (biomarkers) as a means for determining indirectly how much fumonisin was consumed by individuals and whether or not the fumonisins consumed had any effect. The results of the evaluation show that fumonisin in urine can be used to indirectly assess internal exposure to fumonisin. The results also support the use of urinary fumonisin B1 to assess ongoing exposure in population based studies and conclude that the urinary fumonisin B1 biomarker could contribute considerably in assessing the adverse health impact of fumonisin exposure.
Technical Abstract: Maize is the predominant food source contaminated by fumonisins and this has particular health risks for communities consuming maize as a staple diet. The main biochemical effect of fumonisins is the inhibition of ceramide biosynthesis causing an increase in sphingoid bases and sphingoid base 1-phosphates and a depletion of the complex sphingolipids thereby disrupting lipid metabolism and sphingolipid-mediated processes and signalling systems. Attempts to use the elevation of sphinganine as a human biomarker of fumonisin exposure have to date been unsuccessful. Consequently, recent research has focused on developing a urinary exposure biomarker. In animals, fumonisins are poorly absorbed in the gut and are mostly excreted unmetabolised in feces, with only a small percentage (0.25 - 2.0 %) in urine. This appears to also be true in humans where fumonisin B1 is detectable in urine soon after exposure but in very small amounts relative to total intake. However, with modern sensitive and selective analytical methods such as liquid chromatography-tandem mass spectrometry (LC-MS/MS), these low levels can be readily determined. The first study to show a positive correlation between consumption of maize and urinary fumonisin B1 (FB1) was conducted in a Mexican population consuming tortillas as a staple food. Further validation of this relationship was achieved in a South African subsistence farming community with a positive correlation between urinary FB1 and fumonisin exposure, as assessed by food analysis and food intake data. The most recent developments are aimed at measuring multiple mycotoxin biomarkers in urine, including FB1. Current exposure studies in Guatemala are combining the urinary biomarker with measurement of sphinganine-1-phosphate in blood spots as a measure of biochemical effect. Thus the urinary FB1 biomarker could contribute considerably in assessing the adverse health impact of fumonisin exposure.