Mycotoxin exposure is associated with increased risk of esophageal squamous cell carcinoma in Huaian area, China

BACKGROUND

Consumption of moldy food has previously been identified as a risk factor for esophageal squamous cell carcinoma (ESCC) in high-risk countries; however, what contributing roles these dietary carcinogenic mycotoxins play in the etiology of ESCC are largely unknown.

METHODS

A mycotoxin biomarker-incorporated, population-based case-control study was performed in Huaian area, Jiangsu Province, one of the two high-risk areas in China. Exposure biomarkers of aflatoxins (AF) and fumonisins (FN) were quantitatively analyzed using HPLC-fluorescence techniques.

RESULTS

Among the cases (n = 190), the median levels of AF biomarker, serum AFB1-lysine adduct, and FN biomarker, urinary FB1, were 1.77 pg/mg albumin and 176.13 pg/mg creatinine, respectively. Among the controls (n = 380), the median levels of AFB1-lysine adduct and urinary FB1 were 1.49 pg/mg albumin and 56.92 pg/mg creatinine, respectively. These mycotoxin exposure biomarker levels were significantly higher in cases as compared to controls (p <  0.05 and 0.01, respectively). An increased risk to ESCC was associated with exposure to both AFB1 and FB1 (p <  0.001 for both).

CONCLUSIONS

Mycotoxin exposure, especially to AFB1 and FB1, was associated with the risk of ESCC, and a greater-than-additive interaction between co-exposures to these two mycotoxins may contribute to the increased risk of ESCC in Huaian area, China.

Chronic aflatoxin exposure in children living in Bhaktapur, Nepal: Extension of the MAL-ED study

Exposure to aflatoxin, a mycotoxin common in maize and groundnuts, has been associated with childhood stunting in sub-Saharan Africa. In an effort to further our understanding of growth impairment in relation to mycotoxins and other risk factors, biospecimens from a cohort of children enrolled in the Bhaktapur, Nepal MAL-ED study were assessed for aflatoxin exposure at 15, 24, and 36 months of age. Exposure was assessed through a well-established serum biomarker, the AFB₁-lysine adduct. In this manuscript, the levels of aflatoxin exposure in the Nepal cohort were compared with those observed in aflatoxin studies, with child growth parameters as a health outcome. Results from this preliminary analysis demonstrated chronic aflatoxin exposure in children residing in Bhaktapur with a geometric mean of 3.62 pg AFB₁-lysine/mg albumin. The range of exposure in this population is similar to those in African populations where associations with aflatoxin biomarkers and poor child growth have been observed. Future work will analyze the relationships between aflatoxin levels, growth, and other risk factors collected by the MAL-ED study.

Are Treated Celiac Patients at Risk for Mycotoxins? An Italian Case-Study

Urinary biomarkers of mycotoxin exposure were evaluated in a group of celiac patients (n = 55) and in a control group of healthy subjects (n = 50) following their habitual diet. Deoxynivalenol (DON), zearalenone (ZEN), and fumonisin B1 (FB1) were monitored in 105 urinary samples collected from the two groups. Dietary habits were also recorded through compilation of a seven-day weighed dietary diary. Biomarkers of mycotoxin exposure were detected in 21 celiac patients and in 15 control subjects, corresponding to about 34% of total participants. In particular, ZEN was the most detected mycotoxin among all the studied subjects with a total of 19 positive cases. Results did not show a statistically significant difference in mycotoxin exposure between the two groups, and the presence of specific mycotoxins was not related to the intake of any particular food category. Our findings suggest little urgency of specific regulation for gluten free products, although the prevalence of exposure observed in free-living diets of both celiac and healthy subjects underlines the need of a constant surveillance on mycotoxins occurrence at large.

A prospective study of growth and biomarkers of exposure to aflatoxin and fumonisin during early childhood in Tanzania

BACKGROUND

Aflatoxin and fumonisin are toxic food contaminants. Knowledge about effects of their exposure and coexposure on child growth is inadequate.

OBJECTIVE

We investigated the association between child growth and aflatoxin and fumonisin exposure in Tanzania.

METHODS

A total of 166 children were recruited at 6-14 months of age and studied at recruitment, and at the 6th and 12th month following recruitment. Blood and urine samples were collected and analyzed for plasma aflatoxin-albumin adducts (AF-alb) using ELISA, and urinary fumonisin B1 (UFB1) using liquid chromatography-mass spectrometry, respectively. Anthropometric measurements were taken, and growth index z-scores were computed.

RESULTS

AF-alb geometric mean concentrations (95% CIs) were 4.7 (3.9, 5.6), 12.9 (9.9, 16.7), and 23.5 (19.9, 27.7) pg/mg albumin at recruitment, 6 months, and 12 months from recruitment, respectively. At these respective sampling times, geometric mean UFB1 concentrations (95% CI) were 313.9 (257.4, 382.9), 167.3 (135.4, 206.7), and 569.5 (464.5, 698.2) pg/mL urine, and the prevalence of stunted children was 44%, 55%, and 56%, respectively. UFB1 concentrations at recruitment were negatively associated with length-for-age z-scores (LAZ) at 6 months (p = 0.016) and at 12 months from recruitment (p = 0.014). The mean UFB1 of the three sampling times (at recruitment and at 6 and 12 months from recruitment) in each child was negatively associated with LAZ (p < 0.001) and length velocity (p = 0.004) at 12 months from recruitment. The negative association between AF-alb and child growth did not reach statistical significance.

CONCLUSIONS

Exposure to fumonisin alone or coexposure with aflatoxins may contribute to child growth impairment.

Dietary exposure to aflatoxin and fumonisin among Tanzanian children as determined using biomarkers of exposure

SCOPE

The study aims to evaluate the status of dietary exposure to aflatoxin and fumonisin in young Tanzanian children, using previously validated biomarkers of exposure.

METHODS AND RESULTS

A total of 148 children aged 12-22 months, were recruited from three geographically distant villages in Tanzania; Nyabula, Kigwa, and Kikelelwa. Plasma aflatoxin-albumin adducts (AF-alb) and urinary fumonisin B1 (UFB1) were measured by ELISA and LC-MS, respectively. AF-alb was detectable in 84% of children, was highest in fully weaned children (p < 0.01) with higher levels being associated with higher maize intake (p < 0.05). AF-alb geometric mean (95% CI) was 43.2 (28.7-65.0), 19.9 (13.5-29.2), and 3.6 (2.8-4.7) pg/mg albumin in children from Kigwa, Nyabula, and Kikelelwa, respectively. UFB1 was detectable in 96% of children and the level was highest in children who had been fully weaned (p < 0.01). The geometric UFB1 mean (95% CI) was 327.2 (217.1-493.0), 211.7 (161.1-278.1), and 82.8 (58.3-117.7) pg/mL in Kigwa, Nyabula, and Kikelelwa, respectively. About 82% of all the children were exposed to both mycotoxins.

CONCLUSION

Young children in Tanzania are chronically exposed to both aflatoxin and fumonisin through contaminated diet, although the level of exposure varies markedly between the three villages studied.

Multimycotoxin analysis in urines to assess infant exposure: a case study in Cameroon

This study was conducted to investigate mycotoxin exposure in children (n=220, aged 1.5-4.5years) from high mycotoxin contamination regions of Cameroon and to examine the association between the mycotoxin levels (in total 18 analytes) and several socio-demographic factors and anthropometric characteristics. A cross-sectional study was conducted in six villages in Cameroon with 220 children. Mycotoxins and their metabolites were detected in 160/220 (73%) urine samples. There were significant differences in the mean contamination levels of ochratoxin A (p=0.01) and β-zearalenol (p=0.017) between the two agro-ecological zones investigated. Likewise significant differences were observed in the mean levels of aflatoxin M1 (p=0.001) across the weaning categories of these children. The mean concentration of aflatoxin M1 detected in the urine of the partially breastfed children (1.43ng/mL) was significantly higher (p=0.001) than those of the fully weaned children (0.282ng/mL). Meanwhile, the mean concentrations of deoxynivalenol (3.0ng/mL) and fumonisin B1 (0.59ng/mL) detected in the urine of the male children was significantly (p value 0.021 for deoxynivalenol and 0.004 for fumonisin B1) different from the levels detected in the urine of female children; 0.71ng/mL and 0.01ng/mL for deoxynivalenol and fumonisin B1 respectively. In this study, there was no association between the different malnutrition categories (stunted, wasting and underweight) and the mycotoxin concentrations detected in the urine of these children. However, there is sufficient evidence to suggest that children in Cameroon under the age 5 are exposed to high levels of carcinogenic substances such as fumonisin B1, aflatoxin M1 and ochratoxin A through breastfeeding. To the best of our knowledge, this is the first report of its kind carried out in West Africa to determine multi-mycotoxin exposure in infants.

Development and application of salting-out assisted liquid/liquid extraction for multi-mycotoxin biomarkers analysis in pig urine with high performance liquid chromatography/tandem mass spectrometry

Direct determination of urinary mycotoxins is a better approach to assess individual's exposure than the indirect estimation from average dietary intakes. In this study, a new analytical method was developed and validated for simultaneous analysis of aflatoxin B1, deoxynivalenol, fumonisin B1, ochratoxin A, zearalenone and T2 toxin and their metabolites in pig urine. In total 12 analytes were selected. A salting-out assisted liquid-liquid extraction procedure was used for sample preparation. High performance liquid chromatography/tandem mass spectrometry was used for the separation and detection of all the analytes. The extraction recoveries were in a range of 70-108%, with the intra-day relative standard deviation and inter-day relative standard deviation lower than 25% for most of the compounds at 3 different concentration levels. Meanwhile the method bias for all the analytes did not exceed 20%. The limits of quantification ranged from 0.07ngmL(-1) for ochratoxin A to 3.3ngmL(-1) for deoxynivalenol. Matrix effect was evaluated in this study and matrix-matched calibration was used for quantification. The developed method was also validated for human urine as an extension of its application. Finally, the developed method was applied in a pilot study to analyze 28 pig urine samples. Deoxynivalenol, aflatoxin B1, fumonisin B1 and ochratoxin A were detected in these samples.

Mycotoxin detection in urine samples from patients with chronic kidney disease of uncertain etiology in Sri Lanka

This was a screening study that aimed to determine the presence of nephrotoxic mycotoxins in urine samples from patients with chronic kidney disease of uncertain etiology in the North Central Province of Sri Lanka. The percentage detection of aflatoxins, ochratoxins and fumonisins in 31 patients were 61.29%, 93.5% and 19.4%, respectively. Geometric means of urinary aflatoxins and ochratoxins were 30.93 creatinine and 34.62 ng/g creatinine in chronic kidney disease of uncertain etiology stage 1-2 patients and 84.12 ng/g creatinine and 63.52 ng/g creatinine in unaffected relatives of patients. In chronic kidney disease of uncertain etiology stage 3-5 patients, geometric means of urinary aflatoxins and ochratoxins were 10.40 and 17.08 ng/g creatinine, respectively. Non-affected relatives of patients (n = 6) had comparable levels of these mycotoxins, but healthy Japanese individuals (n = 4) had lower levels than in Sri Lanka. The higher detection rate of urinary ochratoxins in Sri Lankans indicates that exposure is common in the region.

Association between tortilla consumption and human urinary fumonisin B1 levels in a Mexican population

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 maize-based 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.

Toxicological effects of chronic low doses of aflatoxin B(1) and fumonisin B(1)-containing Fusarium moniliforme culture material in weaned piglets

The effects of chronic oral exposure (28 days) to aflatoxin B(1) (AFB(1)) and fumonisin B(1) (FB(1)) were studied in weaned piglets. Six experimental groups, each comprising two neutered males and two females, were fed ad libitum with rations containing: (A) 0 mg of FB(1) and 0 mg of AFB(1)/kg of feed (control); (B) 10 mg of FB(1)/kg of feed; (C) 30 mg of FB(1)/kg of feed; (D) 50 microg of AFB(1)/kg of feed; (E) 10 mg of FB(1) plus 50 microg of AFB(1)/kg of feed; (F) 30 mg of FB(1) plus 50 microg of AFB(1)/kg of feed. The animals were inspected twice daily and their body weight and feed consumption were recorded weekly and daily, respectively. Samples of feces and urine were collected 24 h after the start of the experiment, to check for fumonisin residues by HPLC analysis. Blood samples were drawn at the start of the experiment and after 28 days for quantification of hematological and biochemical parameters. Necropsies were performed after 28 days; at necropsy, the organs were weighed, inspected macroscopically and processed for histopathological and toxicological analyses. All piglets from groups C and F presented typical signs of pulmonary edema, with reduced feed consumption and body weight gain as well as pathological alterations. FB(1) was detected in feces and urine at 24 h of intoxication and in liver after 28 days of intoxication. Increases were detected regarding the following hematological and biochemical parameters in animals from treatments C and F: erythrocyte number; hematocrit; total bilirubin; total protein; activity of serum alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase. Cholesterol levels were significantly aumented only in animals from groups C and F, whereas albumin concentrations increased in groups C, F, B and E. The average organ/body weight ratio of piglets (hearth, liver and lung) were significantly greater in groups C and F. The only joint effects of FB(1) and AFB(1) detected (group F) were a decrease in feed consumption during the last week of intoxication and in feed conversion throughout the 28 days of intoxication. Chronic intoxication of piglets with AFB(1) and FB(1) leads to important losses of productivity.