Aflatoxin Exposure Research Articles

Estimation of Urinary Concentration of Aflatoxin M1 in Chinese Pregnant Women

Aflatoxin M1 (AFM1 ) is a main cause of hepatocarcenogenoma in Chinese population. Measurement of aflatoxin exposure in human may help in providing clear evidence for the exposure of specific environmental pollutants in certain population. "One child policy" in China offered parents more careful to choose safe food during pregnancy, but no reports published on the efficacy of their endeavor. In present study, we aimed to assess the exposure of AFM1 in Chinese pregnant women. The urine samples were collected from 600 volunteers from Zhejiang province, China and the urinary concentration of AFM1 was measured using ELISA kit. AFM1 was detected in 84% of the pregnant women. The geometric mean and 95th percentile concentration of AFM1 in pregnant women were 50.3 ng/L and 633.5 ng/L, respectively. Our results point out that pregnant women especially are at the high risk of exposure to AFM1 . Our results also indicate that although "one child policy" offered parents to pay more attention for the selection of safe food, but detection of AFM1 in urine of pregnant women indicate that more foods containing AFM1 still need to be detected. Highest exposure of AFM1 in pregnant women indicates that awareness campaigns must be started especially in the rural areas of China regarding the possible hazardous effects of AFM1 exposure in pregnant women.

Common African cooking processes do not affect the aflatoxin binding efficacy of refined calcium montmorillonite clay

Aflatoxins are common contaminants of staple crops, such as corn and groundnuts, and a significant cause of concern for food safety and public health in developing countries. Aflatoxin B1 (AFB1) has been implicated in the etiology of acute and chronic disease in humans and animals, including growth stunting, liver cancer and death. Cost effective and culturally acceptable intervention strategies for the reduction of dietary AFB1 exposure are of critical need in populations at high risk for aflatoxicosis. Fermented gruels consisting of cornmeal are a common source for such exposure and are consumed by both children and adults in many countries with a history of frequent, high-level aflatoxin exposure. One proposed method to reduce aflatoxins in the diet is to include a selective enterosorbent, Uniform Particle Size NovaSil (UPSN), as a food additive in contaminated foods. For UPSN to be effective in this capacity, it must be stable in complex, acidic mixtures that are often exposed to heat during the process of fermented gruel preparation. Therefore, the objective of the present study was to test the ability of UPSN to sorb aflatoxin while common cooking conditions were applied. The influence of fermentation, heat treatment, acidity, and processing time were investigated with and without UPSN. Analyses were performed using the field-practical Vicam assay with HPLC verification of trends. Our findings demonstrated that UPSN significantly reduced aflatoxin levels (47–100%) in cornmeal, regardless of processing conditions. Upon comparison of each element tested, time appeared to be the primary factor influencing UPSN efficacy. The greatest decreases in AFB1 were reported in samples allowed to incubate (with or without fermentation) for 72h. This data suggests that addition of UPSN to staple corn ingredients likely to contain aflatoxins would be a sustainable approach to reduce exposure.

A limited survey of mycotoxins in traditional maize based opaque beers in Malawi

A total of 9 traditional maize based opaque beers were randomly collected from tribal (chewa) rituals and commercial village brewers from Lilongwe and Dowa districts, Malawi in August 2012 for evaluation of mycotoxins using a multi-mycotoxin method based on liquid chromatography-tandem mass spectrometry. Samples were analyzed for aflatoxins B1 (AFB1), AFB2, AFG1, AFG2, fumonisin B1 (FB1), FB2, FB3, zearalenone, ochratoxin A, nivalenol, deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, neosolaniol, fusarenon-X diacetoxyscirpenol, HT-2 toxin, T-2 toxin, alternariol, alternariol methyl ether, and sterigmatocystin. All beer samples were positive for fumonisins with FB1+FB2 and FB1+FB2+FB3 content of 1745±1294μg/kg (mean±std. dev.) and 1898±1405μg/kg respectively. With exception of one beer sample, all the beers also contained aflatoxins at a mean concentration of 90±95μg/kg. Consumption of 1.0–6.0L of the traditional beer from this study translates to daily FB1+FB2 exposure of 29–174μg/kg body weight (bw)/day (i.e. >provisional maximum tolerable daily intake of 2μg/kg bw/day set by the Joint FAO/WHO Expert Committee on Food Additives) and aflatoxin exposure of 1.5–9.0μg/kg bw/day for a 60kg adult. The study demonstrated that the consumption of the maize based traditional home-made beer in Malawi can significantly enhance aflatoxins and fumonisin dietary exposure among beer consumers.

Detection of serum AFB1-lysine adduct in Malaysia and its association with liver and kidney functions

Aflatoxin is ubiquitously found in many foodstuffs and produced by Aspergillus species of fungi. Of many aflatoxin metabolites, AFB1 is classified by the International Agency for Research on Cancer (IARC) as group one carcinogen and linked to the development of hepatocellular carcinoma (HCC). The study on molecular biomarker of aflatoxin provides a better assessment on the extent of human exposure to aflatoxin. In Malaysia, the occurrences of aflatoxin-contaminated foods have been documented, but there is a lack of data on human exposure to aflatoxin. Hence, this study investigated the occurrence of AFB1-lysine adduct in serum samples and its association with liver and kidney functions. 5ml fasting blood samples were collected from seventy-one subjects (n=71) for the measurement of AFB1-lysine adduct, albumin, total bilirubin, AST (aspartate aminotransferase), ALT (alanine transaminase), ALP (alkaline phosphatase), GGT (gamma-glutamyl transpeptidase), creatinine and BUN (blood urea nitrogen). The AFB1-lysine adduct was detected in all serum samples (100% detection rate) with a mean of 6.85±3.20pg/mg albumin (range: 1.13-18.85pg/mg albumin). Male subjects (mean: 8.03±3.41pg/mg albumin) had significantly higher adduct levels than female subjects (mean: 5.64±2.46pg/mg albumin) (p<0.01). It was noteworthy that subjects with adduct levels greater than average (>6.85pg/mg albumin) had significantly elevated level of total bilirubin (p<0.01), GGT (p<0.05) and creatinine (p<0.01). Nevertheless, only the level of total bilirubin, (r=0.347, p-value=0.003) and creatinine (r=0.318, p-value=0.007) showed significant and positive correlation with the level of AFB1-lysine adduct. This study provides a valuable insight on human exposure to aflatoxin in Malaysia. Given that aflatoxin can pose serious problem to the health, intervention strategies should be implemented to limit/reduce human exposure to aflatoxin. Besides, a study with a big sample size should be warranted in order to assess aflatoxin exposure in the general population of Malaysia.

Genetic Polymorphisms in DNA Repair Genes XRCC4 and XRCC5 and Aflatoxin B1–related Hepatocellular Carcinoma

Genetic polymorphisms in DNA repair genes may influence individual variation in DNA repair capacity and may play an important role in carcinogenesis. We investigated the role of genetic polymorphisms at XRCC4 codon 247 (rs3734091, XRCC4P) and XRCC5 codon 180 (rs80309960, XRCC5P) in liver cancer (hepatocellular carcinoma) caused by aflatoxin B1 (AFB1). A hospital-based case-control study, including 1499 liver cancer cases and 2045 controls without any liver disease, was conducted in a high aflatoxin exposure area in the Guangxi region of China to assess the relationship between these two polymorphisms and aflatoxin-related liver cancer risk and prognosis. Genotypes, mRNA levels, and the hot-spot mutation of TP53 gene (TP53M) related to AFB1 exposure was tested using TaqMan-PCR technique. XRCC4 protein level was analyzed by immunohistochemistry. For XRCC4P and XRCC5P, only XRCC4P modified liver cancer risk. Compared with the homozygote of XRCC4 codon 247 Ala alleles (XRCC4-AA), the genotypes of XRCC4 codon 247 Ser alleles (namely XRCC4-AS or -SS) increased liver cancer risk (odds ratio [OR] = 1.35 and 2.02, respectively). Significant interactive effects between risk genotypes (OR > 1) and aflatoxin exposure status were also observed in the joint effects analysis. Moreover, this polymorphism was associated not only with lower XRCC4 expression levels but also with higher AFB1-DNA adduct levels and increasing TP53M and portal vein tumor risk. Additionally, XRCC4P modified the recurrence-free survival and overall survival of cases, especially under conditions of high aflatoxin exposure. XRCC4P may be a genetic modifier for the risk and outcome of hepatocellular carcinoma induced by AFB1 exposure.

EFFECT OF MYCOTOXIN ON REPRODUCTIVE PERFORMANCE IN DAIRY CATTLE

The present study was determined the effect of combined mycotoxins caused by Aflatoxin and zearalenone exposure on reproductive performance and their relation to the incidence of ovarian cysts in dairy cattle. The present study used 28 lactating cows kept at dairy farm in Dakahlia governorate. Cows were classified into two groups First group (10 cows) were received ration where the percentage of aflatoxin and zearalenone not exceed permissible limit which is (5 ppb and 200 ppb respectively) and show normal estrous behavior and have mature large follicles >22mm<25mm in diameter and have corpus luteum. The second group (18 cows) received ration containing aflatoxin which found exceed permissible limit (19.7 ppb) and zearalenone which was present at high levels (400 ppb), these cows exhibit“constant” estrus (nymphomania), excessive vaginal discharge, until day 45 postpartium and have ovarian cysts based on the presence of follicular structure (≥25 mm in diameter) with anovulation and the absence of corpus luteum. Blood samples was collected from each cow around 45 days postpartium for evaluation of serum progesterone (P4), estrogen (E2), Luteinizing hormone (LH), triiodothyronine (T3), thyroxin (T4), prolactin (PRL) total protein, calcium, inorganic phosphorus, Liver enzymatic activities alanine aminotransferase (ALT) and aspartate aminotransferase (AST) immunologlobins (IgG, IgM, IgA). The results of hormonal assay showed significant increase (p < 0.05) in levels of prolactin and estrogen, while levels of LH, progestone, T3 and T4 showed significant decrease (p < 0.05) in cows received contaminated ration with zearalenone and aflatoxins in compared with control one. Regarding to results of biochemical and immunological parameters revealed a significant increase (p < 0.05) in enzymatic activities (AST), (ALT), while total protein, calcium, inorganic phosphorus and immunological parameters (IgG, IgM, IgA) showed significant decrease (p < 0.05) in cows received contaminated ration with zearalenone and aflatoxins compared with control one. Our results using transrectal ultrasonography revealed that mean diameter of follicular cyst was 42.3±3 mm of cows received contaminated ration with zearalenone and aflatoxins while mean diameter of mature follicles was 22.1±1.7 mm of control cows. We concluded that zearalenone have been shown to competitive bind to oestrogen receptors and affect reproductive performance generating hormonal imbalance inducing cell toxicity, immunosuppression due to the combined effect of aflatoxins which may predispose cows to the incidence of ovarian cysts

Simultaneous analysis of aflatoxins B1, B2, G1, G2, M1 and ochratoxin A in breast milk by high-performance liquid chromatography/fluorescence after liquid–liquid extraction with low temperature purification (LLE–LTP)

The aims of this study were to optimize and validate a methodology for the simultaneous analysis of aflatoxins B1, B2, G1, G2, M1 (AFB1, AFB2, AFG1, AFG2, AFM1) and ochratoxin A (OTA) in breast milk, and to analyze these mycotoxins in samples obtained from human milk banks in the Federal District, Brazil. The optimized analytical method was based on liquid–liquid extraction with low temperature purification (3.25mL of acidified acetonitrile+0.75mL of ethyl acetate), followed by analysis by high-performance liquid chromatography with fluorescence detector (HPLC/FLD) and a photochemical post-column reactor. Limits of quantification (LOQ) ranged from 0.005 to 0.03ng/mL, recoveries from 73 to 99.5%, and relative standard deviations (RSD) from 1.8 to 17.3%. The LLE–LTP extraction method was shown to be simple and cost-effective, since no columns were needed for clean-up. Only 2 of the 224 breast milk samples analyzed were positive for the mycotoxins, both samples containing AFB2 at the LOQ level (0.005ng/mL). The identity of the mycotoxin detected was confirmed by liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS). This result indicates that infants who are fed with breast milk from the milk banks are not at risk from aflatoxin and ochratoxin exposure.

Human aflatoxin exposure in Kenya, 2007: a cross-sectional study

Aflatoxins contaminate approximately 25% of agricultural products worldwide. They can cause liver failure and liver cancer. Kenya has experienced multiple aflatoxicosis outbreaks in recent years, often resulting in fatalities. However, the full extent of aflatoxin exposure in Kenya has been unknown. Our objective was to quantify aflatoxin exposure across Kenya. We analysed aflatoxin levels in serum specimens from the 2007 Kenya AIDS Indicator Survey – a nationally representative, cross-sectional serosurvey. KAIS collected 15,853 blood specimens. Of the 3180 human immunodeficiency virus-negative specimens with ≥1 mL sera, we randomly selected 600 specimens stratified by province and sex. We analysed serum specimens for aflatoxin albumin adducts by using isotope dilution MS/MS to quantify aflatoxin B1-lysine, and normalised with serum albumin. Aflatoxin concentrations were then compared by demographic, socioeconomic and geographic characteristics. We detected serum aflatoxin B1-lysine in 78% of serum specimens (range = <LOD–211 pg/mg albumin, median = 1.78 pg/mg albumin). Aflatoxin exposure did not vary by sex, age group, marital status, religion or socioeconomic characteristics. Aflatoxin exposure varied by province (p < 0.05); it was highest in Eastern (median = 7.87 pg/mg albumin) and Coast (median = 3.70 pg/mg albumin) provinces and lowest in Nyanza (median = <LOD) and Rift Valley (median = 0.70 pg/mg albumin) provinces. Our findings suggest that aflatoxin exposure is a public health problem throughout Kenya, and it could be substantially impacting human health. Wide-scale, evidence-based interventions are urgently needed to decrease exposure and subsequent health effects.

Global Risk Assessment of Aflatoxins in Maize and Peanuts: Are Regulatory Standards Adequately Protective?

The aflatoxins are a group of fungal metabolites that contaminate a variety of staple crops, including maize and peanuts, and cause an array of acute and chronic human health effects. Aflatoxin B1 in particular is a potent liver carcinogen, and hepatocellular carcinoma (HCC) risk is multiplicatively higher for individuals exposed to both aflatoxin and chronic infection with hepatitis B virus (HBV). In this work, we sought to answer the question: do current aflatoxin regulatory standards around the world adequately protect human health? Depending upon the level of protection desired, the answer to this question varies. Currently, most nations have a maximum tolerable level of total aflatoxins in maize and peanuts ranging from 4 to 20ng/g. If the level of protection desired is that aflatoxin exposures would not increase lifetime HCC risk by more than 1 in 100,000 cases in the population, then most current regulatory standards are not adequately protective even if enforced, especially in low-income countries where large amounts of maize and peanuts are consumed and HBV prevalence is high. At the protection level of 1 in 10,000 lifetime HCC cases in the population, however, almost all aflatoxin regulations worldwide are adequately protective, with the exception of several nations in Africa and Latin America.

Hepatocellular carcinoma and liver cirrhosis TP53 mutation analysis reflects a moderate dietary exposure to aflatoxins in Espírito Santo State, Brazil

The close relationship between aflatoxins and 249ser TP53 gene mutation (AGG to AGT, Arg to Ser) in hepatocellular carcinoma (HCC) makes this mutation an indirect indicator of dietary contamination with this toxin. We have examined the prevalence of codon 249 TP53 mutation in 41 HCC and 74 liver cirrhosis (without HCC) cases diagnosed at the HUCAM University Hospital in Vitoria, Espírito Santo State, Brazil. DNA was extracted from paraffin sections and from plasma. The mutation was detected by DNA amplification, followed by restriction endonuclease digestion and confirmed by direct sequencing. DNA restriction showed 249ser mutation in 16 HCC and 13 liver cirrhosis, but sequencing confirmed mutations in only 6 HCC and 1 liver cirrhosis. In addition, sequencing revealed 4 patients with mutations at codon 250 (250ser and 250leu) in HCC cases. The prevalence of TP53 mutation was 10/41 (24.3%) in HCC and 1/74 (1.4%) in liver cirrhosis. No relationship between the presence of mutations and the etiology of HCC was observed. TP53 exon 7 mutations, which are related to aflatoxins exposure, were found at 14.6% (249ser), 7.3% (250leu) and 2.4% (250ser) in 41 cases of HCC and 1.4% in 74 liver cirrhosis (without HCC) cases, suggesting a moderate dietary exposure to aflatoxins in the Espírito Santo State, Brazil.

Risk assessment of peanut aflatoxins exposure by margin of exposure in China

To explore the MOE(margin of exposure) application in risk assessment of peanut aflatoxins in consumers,data of aflatoxins contamination in post-harvest peanut of China and the data of Chinese peanut consumption were collected.Based on aflatoxins toxicological data,MOE values of different regions from population of different age-groups were evaluated.Results indicated no significant differences between urban and rural regions,but children were at higher risk than other populations.Compared to low-dose extrapolation,MOE was recommended due to its effective performance in posterior analysis.

Serum concentrations of an aflatoxin-albumin adduct in the National Health and Nutrition Examination Survey (NHANES) 1999–2000

BackgroundDuring 1998, weather conditions in the United States favored the growth of Aspergillus species leading to widespread contamination of Midwestern and Southern corn with hepatotoxic and hepatocarcinogenic aflatoxins. We designed a study to provide the first national prevalence estimate of aflatoxin exposure using the National Health and Nutrition Examination Survey (NHANES), a representative cross-sectional survey of the noninstitutionalized civilian population of the US. MethodsIsotope dilution liquid chromatography–tandem mass spectrometry was used to quantitate serum concentrations of aflatoxin B1-lysine in a one-third random subset of participants from NHANES 1999–2000. ResultsAbout 1% of the U.S. population had detectable levels (≥0.02μg/l) of aflatoxin B1-lysine. Of those with detectable levels, the geometric mean (95% confidence interval) was 0.038 (0.024–0.060) μg/l (equivalent to 0.842 (0.530–1.34) pg/mg albumin). The highest value was 0.2μg/l (4.43pg/mg albumin). Based on liver function biomarkers, there was no evidence of increased liver dysfunction in these persons. ConclusionsDuring a time when exposure to aflatoxins in food products might have been expected to be increased, we identified few exposed persons. Although none of the subgroup analyses provided reliable estimates due to high relative standard errors, they suggested that additional targeted surveillance may be warranted.

Abstract SY14-04: Global burden of liver cancer: Emerging needs in Asia.

Globally, driven by increased life expectancy, the overall incidence of cancer is expected to nearly double over the next 20 years. Nonetheless, the target organs where these diagnoses will occur will still vary widely from country to country because of divergent exposures and other etiologic factors (1). One cancer that currently illustrates this geographic disparity is primary liver cancer (PLC). Currently, PLC is the third leading cause of cancer mortality worldwide with an estimated 696,000 deaths in 2008. Half of these PLC deaths of those deaths occur in the People9s Republic of China. The major etiological factors associated with PLC in China, as established from prospective cohort studies, are chronic infection with hepatitis B virus (HBV) and extended exposure to high levels of aflatoxin in the diet, especially from corn and groundnuts (2). The largest study, comprising more than 18,000 men residing in Shanghai in the 1980s, examined HBV infection and aflatoxin exposure as independent and interactive risk factors for PLC (3). This nested case control study revealed a statistically significant increase in the relative risk (RR) of 7.3 for men who were chronically infected with HBV (HBsAg) but unexposed to aflatoxin. In men on whom urinary aflatoxin but not HBV biomarkers were detected, the RR was 3 (4). Furthermore, in men exhibiting both urinary aflatoxin biomarkers and positive HBsAg status, the RR was 59.4.3 A subsequent cohort study in Taiwan confirmed these results.4 In light of this synergistic interaction, programs to eliminate either factor, or both, should have substantial impact on the burden of PLC. Chronic infection with HBV has been long regarded as the major cause of PLC and initiatives have been undertaken to implement universal immunization programs. It is estimated that more than 90% of countries now routinely vaccinate newborns against HBV, and approximately 70% are now delivering 3 immunization doses. Newborns are targeted because HBV transmission is often vertical from mother to child at birth or during the perinatal period. In 1986, Taiwan became the first region to vaccinate all newborns against HBV. Since then, the number of HBV carriers in the juvenile population has declined dramatically. As of 2009, incidence of hepatocellular carcinoma was significantly lower among children aged 6-19 years in vaccinated compared with antecedent unvaccinated birth cohorts (5). For many years, we have been working with colleagues in Qidong, China, located at the mouth of the Yangtze River, an endemic area for liver cancer, where early age of onset and high mortality rates from PLC are reported (6). HBV vaccination of newborns in the rural townships was initiated during the 1980s but did not become universal until 2002. Crude rates of PLC per 100,000 residents of Qidong rose slightly from 1972 through 1990 at levels around 50/100,000 before increasing in the 1990s to a stable rate of about 75/100,000. Such data have led to the perception that Qidong remains an irrevocably high-risk region (7). However, the latter PLC mortality rate increase largely reflects a dramatically altered age distribution in the population rising from 17.0% over 50 years of age in 1973 to 22.7% in 1988 and 34.2% in 2003. Prognosis for survival from liver cancer following diagnosis remains poor: currently In order to accurately describe aflatoxin exposures over the past quarter century, frozen serum samples collected since 1989 were measured for aflatoxin-albumin adduct content (9–11). There has been a dramatic decline in levels of exposure from the 1980s to the present. Median levels of aflatoxin-albumin adducts from residents of the villages of Daxin and HeZuo declined from 19.3 pg/mg albumin in 1989, to 3.6 in 1995, to 2.3 in 1999, to 1.4 in 2003 and undetectable (i.e., Acknowledgments This work has been funded by the National Institutes of Health USA (P01 ES 006052) and the National Science and Technology Mega-Projects of China (No. 2008ZX10002-015, No. 2012ZX10002-008. Citation Format: John D. Groopman, Thomas W. Kensler. Global burden of liver cancer: Emerging needs in Asia. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr SY14-04. doi:10.1158/1538-7445.AM2013-SY14-04

Abstract 1381: Reduction in aflatoxin exposure drives decrease in primary liver cancer in Qidong, China.

Abstract Primary liver cancer (PLC) causes nearly 700,000 annual deaths worldwide predominately in Asia and sub-Saharan Africa; &amp;gt;370,000 deaths occur in the People's Republic of China, alone. Two factors synergistically associated with PLC are chronic infection with hepatitis B (HBV) and repetitive ingestion of aflatoxin (AFB)-contaminated foods. Utilizing information collected over several decades by the Qidong Cancer Registry, mortality rates from PLC were compared to timelines for regional implementation of HBV vaccination and levels of AFB exposure. The concentration of the AFB-lysine adduct was quantified by isotope dilution mass spectrometry in randomized, age-matched subsets of archived serum samples collected from 1989-2012. Economic, social and public health changes occurring during this time period were examined including implementation of a universal vaccination program and the adaptation of an open policy of food provisionment which led to rice replacing maize as the major dietary staple in the Qidong region. Although the crude rates of PLC increased from 1972-1990s (50/100,000 to a steady-state rate of 75/100,000), much of the increase can be attributed to a proportionate aging population. Upon stratifying by birth cohort, no significant change in mortality rate from PLC was found for individuals over 40 years of age. However, 60-75% mortality declines in 20-24, 25-29, 30-34 year olds born 1973-177 compared to similar birth cohorts of 1958-1962 were observed. The prevalence of HBV surface antigen positivity was unchanged; moreover, all these birth cohorts were born before the universal HBV vaccination of newborns. Median levels of the aflatoxin biomarker dropped from 19.3 pg/mg albumin in 1989 to non-detectable by 2009. The estimated population attributable risk of AFB-related PLC decreased from 45% in 1989 to 11% in 2012. Significant reductions in PLC mortality occurred prior to the introduction of universal hepatitis vaccination in Qidongese newborns. Agricultural and economic reforms instituted in the 1980s leading to the establishment of rice as a dietary staple was associated with a 40-fold reduction in AFB exposure. Thus, by extrapolation, changes in food-based policies altering exposure to carcinogens in the diet can have a dramatic impact on PLC mortality worldwide. Supported by NIEHS P01 ES 006052, NST China No. 2008ZX10002-015, No. 2012ZX10002-008. Citation Format: Patricia A. Egner, Jian-Guo Chen, Derek Ng, Lisa P. Jacobson, Alvaro Munoz, Jian-Hua Lu, Yuan-Rong Zhu, Geng-Sun Qian, Tao-Yang Chen, Felicia Wu, Jian-Min Wang, John D. Groopman, Thomas W. Kensler. Reduction in aflatoxin exposure drives decrease in primary liver cancer in Qidong, China. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1381. doi:10.1158/1538-7445.AM2013-1381

Environmental Hygiene, Food Safety and Growth in less than Five Year Old Children in Zimbabwe and Ethiopia

Childhood stunting remains a significant public health challenge with adverse developmental and health outcomes in life and over generations. This study explored novel causes of poor growth in infants and young children. Using in‐depth observation methods, soil and chicken feces ingestion were identified as key pathways for fecal‐oral transmission of bacteria in infants and young children in rural Zimbabwe. In a cross‐sectional survey, poor environmental hygiene was associated with linear growth faltering (p =0.032), independent of socioeconomic status, infant feeding and recent morbidity, in 24–59 month old Ethiopian children. Significant aflatoxin exposure in mothers was associated with severe stunting in 6 to 59 months old Zimbabwean children in a dose response manner (p=0.035). We identified poor environmental hygiene and aflatoxin exposure as two novel causes of stunting in African children. Existing WASH interventions are not sufficient to protect infants and young children from fecal bacteria ingestion through soil and poultry feces. In addition, existing hygiene interventions do not directly address improving household environmental hygiene. Our findings raise the need for low cost strategies for aflatoxin control and a holistic approach in designing context‐ and age‐specific hygiene interventions to prevent childhood stunting.Grant Funding Source: Cornell International Institute for Food, Agriculture and Development (CIIFAD); the Department for International Development (DFID), UK and Borlaug Leadership in Agriculture Enhancement Program (LEAP), UC, Davis, USA; Bill &amp; Melinda Gates Foundation.

Exploration of non‐nutritional factors associated with stunting in 24 month old children of rural Bangladesh

Nutrition interventions in the critical first 2 years of life have had only modest effects on stunting, a length for age Z‐score (LAZ) &lt; ‐ 2, suggesting that non‐nutritional factors contribute to compromised growth. We are assessing gut permeability and environmental exposures at 24 mo of age as potential causes of linear growth deceleration in 180 children of rural Bangladesh, where over half of children are stunted. Data on health, maternal and infant diet, and growth were characterized from the intrauterine period to 24 mo of age in children in the context of a community‐based, randomized trial to assess maternal antenatal micronutrient supplements on birth outcomes. Mean (±SD) LAZ (% stunted) was −1.47±1.2 (29%) at birth (n=178), −1.37±1.19 (22%) at 6 mo (n=169), −1.86±1.12 (42%) at 12 mo (n=162), and −1.97±1.11 (46%) (n=121) at 24 mo, revealing increasingly compromised linear growth after 6 mo, consistent with timing of complementary feeding and enhanced exposure to pathogenic stimuli. Gut permeability assessed by the lactulose:mannitol test; chronic pathogenic exposure assessed by elevated immunoglobulins, cytokines, and acute phase markers; and aflatoxin exposure at 24 mo will be presented. Associations of these factors with LAZ and individual growth trajectories will be explored. Support: Gates Foundation Grant 614, Grand Challenges Exploration

Histological study on the effect of aflatoxin B1 on the renal tubules of adult rats

Introduction Aflatoxins are secondary metabolites of the fungi Aspergillus flavus and Aspergillus parasiticus. These species are prevalent in food crops, particularly in maize, groundnuts, and oilseeds. Chronic aflatoxin exposure is associated with damage to the kidney. Aim of the work The aim of this study was to investigate the effect of aflatoxin B1 on the renal tubules of female albino rats using light and electron microscopy. Materials and methods Thirty adult female rats were used in this study. They were divided into two groups. The first group was considered the control group. The second group was given 0.05 μg/kg aflatoxin orally every week for 8 consecutive weeks. At the end of the experiment the animals were sacrificed and specimens of the kidneys were extracted and processed for light and electron microscopy. Results In the aflatoxin-treated group there were necrosis and sloughing of the proximal convoluted tubules in some areas; other areas showed mitotic division and cell crowding. Ultramicroscopic results revealed cytoplasmic vacuolations, scanty mitochondria, and widely spaced microvilli. The distal convoluted tubules showed loss of cell polarity and basolateral infoldings. The interstitium was wide, edematous, and contained congested blood capillaries and a few mononuclear cells. Conclusions Aflatoxin had a cytotoxic effect on the renal tubules of albino rats. Regulations should be implemented to avoid the presence of aflatoxins in high concentrations in human food and minimize their negative effects on agriculture and health.

Etiological and molecular profile of hepatocellular cancer from India

Hepatocellular carcinoma (HCC) cases are underreported in India. Our study was designed to investigate the etiological profile of HCC cases in India and compare with global incidence. The study included 348 HCC and 375 chronic liver disease cases without HCC as controls. Samples were screened for hepatitis B virus (HBV)/hepatitis C virus (HCV) infections using enzyme-linked immunosorbent assay and polymerase chain reaction (PCR). HBV-DNA and HCV-RNA genotyping was performed by PCR-restriction fragment length polymorphism. All cases were also assessed for other possible risk factors of HCC. Among HCC cases, 62.6% were positive for HBV, 26.7% for HCV and 3.2% had coinfection. Around 17% of HCC cases had aflatoxin-B1 exposure. HBV genotype D (odds ratio, OR = 1.76) and mixed genotypes (OR = 6.86) had higher risk of HCC development. The risk of HCC was twofold (OR = 2.26) in patients with high HBV-DNA levels. Moreover, our findings were unable to establish a clear differential effect of HCV genotype (OR = 1.48) and high viral load (OR = 1.21) on HCC development. In India, HBV is the major risk factors, whereas alcohol, smoking and diabetes are nonsignificantly associated. Asian countries such as Hong Kong and Taiwan also had high incidence of HBV-related HCC. Contrarily, countries from Europe and USA reported HCV as predominant cause of HCC. Further, aflatoxin could be a possible risk of HCC in the population. However, in comparison to the countries such as China and Taiwan (high Aflatoxin exposure), the aflatoxin level is relatively low in our patients. High HBV-DNA levels and HBV/D increased the risk of HCC. However, neither genotype nor virus loads of HCV affected prognosis of HCC patients in our study.

Dramatic reduction of liver cancer incidence in young adults: 28 year follow-up of etiological interventions in an endemic area of China.

Qidong City, China, has had high liver cancer incidence from endemic hepatitis B virus (HBV) infection and dietary exposure to aflatoxin. Based on etiologic studies, we began interventions in 1980 to reduce dietary aflatoxin and initiate neonatal HBV vaccination. We studied trends in liver cancer incidence rates in the 1.1 million inhabitants of Qidong and examined trends in aflatoxin exposure, staple food consumption, HBV infection markers and annual income. Aflatoxin exposure declined greatly in association with economic reform, increased earnings and educational programs to shift staple food consumption in the total population from moldy corn to fresh rice. A controlled neonatal HBV vaccination trial began in 1983 and ended in November, 1990, when vaccination was expanded to all newborns. Liver cancer incidence fell dramatically in young adults. Compared with 1980-83, the age-specific liver cancer incidence rates in 2005-08 significantly decreased 14-fold at ages 20-24, 9-fold at ages 25-29, 4-fold at ages 30-34, 1.5-fold at ages 35-39, 1.2-fold at ages 40-44 and 1.4-fold at ages 45-49, but increased at older ages. The 14-fold reduction at ages 20-24 might reflect the combined effects of reduced aflatoxin exposure and partial neonatal HBV vaccination. Decrease incidence in age groups >25 years could mainly be attributable to rapid aflatoxin reduction. Compared with 1980-83, liver cancer incidence in 1990-93 significantly decreased 3.4-fold at ages 20-24, and 1.9-fold at ages 25-29 when the first vaccinees were <11 years old.

Global geographical overlap of aflatoxin and hepatitis C: controlling risk factors for liver cancer worldwide

About 85% of hepatocellular carcinoma (HCC, liver cancer) cases occur in low-income countries, where the risk factors of dietary aflatoxin exposure and chronic hepatitis B and C (HBV and HCV) viral infection are common. While studies have shown synergism between aflatoxin and HBV in causing HCC, much less is known about whether aflatoxin and HCV synergise similarly. From an exposure perspective, it was examined whether there is a geographical overlap in populations worldwide exposed to high dietary aflatoxin levels and with high HCV prevalence. While HCV is one of the most important risk factors for HCC in high-income nations (where aflatoxin exposure is low), it is found that HCV prevalence is much higher in Africa and Asia, where aflatoxin exposure is also high. However, within a given world region, there are some inconsistencies regarding exposure and cancer risk. Therefore, there is a need to control risk factors such as aflatoxin and hepatitis viruses in a cost-effective manner to prevent global HCC, while continuing to evaluate biological mechanisms by which these risk factors interact to increase HCC risk.