Association between Tortilla Consumption and Human Urinary Fumonisin B1 Levels in a Mexican Population

Abstract

Fumonisins are mycotoxins produced by Fusarium spp. and commonly contaminate maize and maize products worldwide. Fumonisins are rodent carcinogens and have been associated with human esophageal cancer. However, the lack of a valid exposure biomarker has hindered both the assessment of human exposure and the evaluation of disease risk. A sensitive liquid chromatography-mass spectrometry method to measure urinary fumonisin B1 (FB1) following extraction on Oasis MAX cartridges was established and applied to urine samples from women in a cohort recruited in Morelos County, Mexico. Urinary FB1 was compared with dietary information on tortilla consumption. FB1 recovery in spiked samples averaged 94% as judged by deuterium-labeled FB1 internal standard. Urinary FB1 was determined in 75 samples from women selected based on low, medium, or high consumption of maizebased tortillas. The geometric mean (95% confidence interval) of urinary FB1 was 35.0 (18.8-65.2), 63.1 (36.8-108.2), and 147.4 (87.6-248.0) pg/mL and the frequency of samples above the detection limit (set at 20 pg FB1/mL urine) was 45%, 80%, and 96% for the low, medium, and high groups, respectively. Women with high intake had a 3-fold higher average FB1 levels compared with the ''low intake'' group (F = 7.3; P = 0.0015). Urinary FB1 was correlated with maize intake (P trend = 0.001); the correlation remained significant after adjusting for age, education, and place of residence. This study suggests that measurement of urinary FB1 is sufficiently sensitive for fumonisin exposure assessment in human populations and could be a valuable tool in investigating the associated health effects of exposure. (Cancer Epidemiol Biomarkers Prev 2008;17(3):688 -94)

The role of biomarkers in evaluating human health concerns from fungal contaminants in food

“…Here, urinary FB 1 was measured on two consecutive days whilst FB 1 intake was assessed using plate-ready food (a maize porridge) on the days immediately before urine collection. Here, the resulting urinary FB 1 concentrations were roughly of the same order as those in both Mexico (79) and Fusui County, China (81) , but significantly lower than those reported in Huaian County, China (81) . In the South African (82) .…”

“…Urinary FB 1 was detected more frequently in the high (96 %) compared with the medium (80 %) and the low (45 %) consumption groups, and the geometric means were associated (P , 0·001) with consumption of tortillas (geometric means and 95th percentiles were 147 (88, 248), 63 (37,108) and 35 (19, 65) pg/ml, respectively). No food samples were collected from this survey; though based on the urinary measures, Gong et al (79) cautiously estimated FB 1 intake in this region to range from non-detectable to 23 mg/kg body weight (BW) per d, using a number of assumptions, including estimated average transfer from animal models. The provisional maximum tolerable daily intake for FB 1 , FB 2 and FB 3 combined or individually is 2 mg/kg BW per d (80) and, consequently, fumonisin exposure is a significant health concern in this region.…”

Fumonisin B1 as a Urinary Biomarker of Exposure in a Maize Intervention Study Among South African Subsistence Farmers

“…The urine samples were cleaned-up by solid-phase extraction and analyzed for FB 1 by HPLC-MS with a limit of detection (LOD) of 20 pg/mL (19). Urinary creatinine was determined according to the alkalinepicrate method (23) with minor modifications to adapt to a 96-well plate format.…”

“…The sphingolipid bases, sphinganine and sphingosine, as well as their ratio, have also been investigated in several human studies in blood and urine, but could not be correlated with fumonisin exposure (11,12,18). A recent study has reported a high-performance liquid chromatography-mass spectrometry (HPLC-MS) method for urinary fumonisin B 1 (UFB 1 ), which was sufficiently sensitive to be positively correlated with fumonisin exposure in a Mexican population consuming different amounts of maize-based tortillas (19).…”

A direct assessment of mycotoxin biomarkers in human urine samples by liquid chromatography tandem mass spectrometry

“…Furthermore, FB 1 was recovered unaltered in the urine faeces and bile of dosed animals. For these reasons, recent studies have recommended the use of the parent analyte (FB 1 ) as an alternative biomarker [9]. Hydrolysis of the two tricarballylic acid ester groups of FB 1 has been reported to occur in the gut of vervet monkeys [10][11] and could possibly serve as an alternative biomarker.…”