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Toxins Feb 2020The study of fungal species evolved radically with the development of molecular techniques and produced new evidence to understand specific fungal mechanisms such as the... (Review)
Review
The study of fungal species evolved radically with the development of molecular techniques and produced new evidence to understand specific fungal mechanisms such as the production of toxic secondary metabolites. Taking advantage of these technologies to improve food safety, the molecular study of toxinogenic species can help elucidate the mechanisms underlying toxin production and enable the development of new effective strategies to control fungal toxicity. Numerous studies have been made on genes involved in aflatoxin B1 (AFB1) production, one of the most hazardous carcinogenic toxins for humans and animals. The current review presents the roles of these different genes and their possible impact on AFB1 production. We focus on the toxinogenic strains and primary contaminants and major producers of AFB1 in crops. However, genetic reports on are also included because of the capacity of this fungus to produce sterigmatocystin, the penultimate stable metabolite during AFB1 production. The aim of this review is to provide a general overview of the AFB1 enzymatic biosynthesis pathway and its link with the genes belonging to the AFB1 cluster. It also aims to illustrate the role of global environmental factors on aflatoxin production and the recent data that demonstrate an interconnection between genes regulated by these environmental signals and aflatoxin biosynthetic pathway.
Topics: Aflatoxins; Animals; Gene-Environment Interaction; Humans
PubMed: 32121226
DOI: 10.3390/toxins12030150 -
Toxins May 2018Aflatoxins are fungal metabolites found in feeds and foods. When the ruminants eat feedstuffs containing Aflatoxin B1 (AFB1), this toxin is metabolized and Aflatoxin M1... (Review)
Review
Aflatoxins are fungal metabolites found in feeds and foods. When the ruminants eat feedstuffs containing Aflatoxin B1 (AFB1), this toxin is metabolized and Aflatoxin M1 (AFM1) is excreted in milk. International Agency for Research on Cancer (IARC) classified AFB1 and AFM1 as human carcinogens belonging to Group 1 and Group 2B, respectively, with the formation of DNA adducts. In the last years, some epidemiological studies were conducted on cancer patients aimed to evaluate the effects of AFB1 and AFM1 exposure on cancer cells in order to verify the correlation between toxin exposure and cancer cell proliferation and invasion. In this review, we summarize the activation pathways of AFB1 and AFM1 and the data already reported in literature about their correlation with cancer development and progression. Moreover, considering that few data are still reported about what genes/proteins/miRNAs can be used as damage markers due to AFB1 and AFM1 exposure, we performed a bioinformatic analysis based on interaction network and miRNA predictions to identify a panel of genes/proteins/miRNAs that can be used as targets in further studies for evaluating the effects of the damages induced by AFB1 and AFM1 and their capacity to induce cancer initiation.
Topics: Aflatoxin B1; Aflatoxin M1; Animals; Gene Expression; Humans; Neoplasms; Protein Interaction Maps
PubMed: 29794965
DOI: 10.3390/toxins10060214 -
Toxins Apr 2022Aflatoxin, a type of mycotoxin, is mostly produced by and It is responsible for the loss of billions of dollars to the world economy, by contaminating different crops... (Review)
Review
Aflatoxin, a type of mycotoxin, is mostly produced by and It is responsible for the loss of billions of dollars to the world economy, by contaminating different crops such as cotton, groundnut, maize, and chilies, and causing immense effects on the health of humans and animals. More than eighteen different types of aflatoxins have been reported to date, and among them, aflatoxins B1, B2, G1, and G2 are the most prevalent and lethal. Early detection of fungal infection plays a key role in the control of aflatoxin contamination. Therefore, different methods, including culture, chromatographic techniques, and molecular assays, are used to determine aflatoxin contamination in crops and food products. Many countries have set a maximum limit of aflatoxin contamination (2-20 ppb) in their food and agriculture commodities for human or animal consumption, and the use of different methods to combat this menace is essential. Fungal infection mostly takes place during the pre- and post-harvest stage of crops, and most of the methods to control aflatoxin are employed for the latter phase. Studies have shown that if correct measures are adopted during the crop development phase, aflatoxin contamination can be reduced by a significant level. Currently, the use of bio-pesticides is the intervention employed in many countries, whereby atoxigenic strains competitively reduce the burden of toxigenic strains in the field, thereby helping to mitigate this problem. This updated review on aflatoxins sheds light on the sources of contamination, and the on occurrence, impact, detection techniques, and management strategies, with a special emphasis on bio-pesticides to control aflatoxins.
Topics: Aflatoxins; Animals; Aspergillus flavus; Crops, Agricultural; Pesticides; Zea mays
PubMed: 35622554
DOI: 10.3390/toxins14050307 -
Toxins Jun 2021In the early 1960s the discovery of aflatoxins began when a total of 100,000 turkey poults died by hitherto unknown turkey "X" disease in England. The disease was... (Review)
Review
In the early 1960s the discovery of aflatoxins began when a total of 100,000 turkey poults died by hitherto unknown turkey "X" disease in England. The disease was associated with Brazilian groundnut meal affected by . The toxin was named toxin-aflatoxin. From the point of view of agriculture, aflatoxins show the utmost importance. Until now, a total of 20 aflatoxins have been described, with B, B, G, and G aflatoxins being the most significant. Contamination by aflatoxins is a global health problem. Aflatoxins pose acutely toxic, teratogenic, immunosuppressive, carcinogenic, and teratogenic effects. Besides food insecurity and human health, aflatoxins affect humanity at different levels, such as social, economical, and political. Great emphasis is placed on aflatoxin mitigation using biocontrol methods. Thus, this review is focused on aflatoxins in terms of historical development, the principal milestones of aflatoxin research, and recent data on their toxicity and different ways of mitigation.
Topics: Aflatoxins; Animals; Food Contamination; History, 20th Century; History, 21st Century; Humans
PubMed: 34205163
DOI: 10.3390/toxins13060399 -
Toxins Jan 2021Mycotoxin contamination causes significant economic loss to food and feed industries and seriously threatens human health. Aflatoxins (AFs) are one of the most harmful... (Review)
Review
Mycotoxin contamination causes significant economic loss to food and feed industries and seriously threatens human health. Aflatoxins (AFs) are one of the most harmful mycotoxins, which are produced by , , and other fungi that are commonly found in the production and preservation of grain and feed. AFs can cause harm to animal and human health due to their toxic (carcinogenic, teratogenic, and mutagenic) effects. How to remove AF has become a major problem: biological methods cause no contamination, have high specificity, and work at high temperature, affording environmental protection. In the present research, microorganisms with detoxification effects researched in recent years are reviewed, the detoxification mechanism of microbes on AFs, the safety of degrading enzymes and reaction products formed in the degradation process, and the application of microorganisms as detoxification strategies for AFs were investigated. One of the main aims of the work is to provide a reliable reference strategy for biological detoxification of AFs.
Topics: Aflatoxins; Animals; Food Contamination; Humans; Lactobacillus; Saccharomyces
PubMed: 33435382
DOI: 10.3390/toxins13010046 -
International Journal of Environmental... Aug 2018In Mozambique, aflatoxin research started in the 1960's and has been carried through apparently unrelated efforts according to opportunities. However, they can be... (Review)
Review
In Mozambique, aflatoxin research started in the 1960's and has been carried through apparently unrelated efforts according to opportunities. However, they can be grouped in two sets: early epidemiological studies and recent agricultural research. Early investigators found a strong correlation between aflatoxin contamination and primary liver cancer. Since then, there have been efforts to examine the extent of contamination, especially in groundnuts and maize. More recent investigations and interventions aimed mostly to reduce the level of contamination, enough to allow such commodities to gain acceptance in the international market. The current status of knowledge is still marginal but the increasing involvement of local authorities, academia, and international organizations seems promising.
Topics: Aflatoxins; Food Contamination; Foodborne Diseases; History, 20th Century; History, 21st Century; Liver Neoplasms; Mozambique
PubMed: 30087243
DOI: 10.3390/ijerph15081673 -
Toxins Jul 2023Aflatoxins are potent carcinogenic compounds, mainly produced by fungi species of the genus in the soil. Because of their stability, they are difficult to remove... (Review)
Review
Aflatoxins are potent carcinogenic compounds, mainly produced by fungi species of the genus in the soil. Because of their stability, they are difficult to remove completely, even under extreme conditions. Aflatoxin contamination is one of the main causes of safety in peanuts, maize, wheat and other agricultural products. Aflatoxin contamination originates from the soil. Through the investigation of soil properties and soil microbial distribution, the sources of aflatoxin are identified, aflatoxin contamination is classified and analysed, and post-harvest crop detoxification and corresponding contamination prevention measures are identified. This includes the team's recent development of the biofungicide ARC-BBBE (Aflatoxin Rhizobia Couple-, . , . , . ) for field application and nanomaterials for post-production detoxification of cereals and oilseed crops, providing an effective and feasible approach for the prevention and control of aflatoxin contamination. Finally, it is hoped that effective preventive and control measures can be applied to a large number of cereal and oilseed crops.
Topics: Aflatoxins; Soil; Aflatoxin B1; Agriculture; Arachis; Crops, Agricultural; Edible Grain
PubMed: 37624232
DOI: 10.3390/toxins15080475 -
Toxins Jan 2022Aflatoxins B (AFB) and G (AFG) are carcinogenic mycotoxins that contaminate crops such as maize and groundnuts worldwide. The broadly accepted method to assess chronic...
Aflatoxins B (AFB) and G (AFG) are carcinogenic mycotoxins that contaminate crops such as maize and groundnuts worldwide. The broadly accepted method to assess chronic human aflatoxin exposure is by quantifying the amount of aflatoxin adducted to human serum albumin. This has been reported using ELISA, HPLC, or LC-MS/MS to measure the amount of AFB-lysine released after proteolysis of serum albumin. LC-MS/MS is the most accurate method but requires both isotopically labelled and unlabelled AFB-lysine standards, which are not commercially available. In this work, we report a simplified synthetic route to produce unlabelled, deuterated and C N labelled aflatoxin B-lysine and for the first-time aflatoxin G-lysine. Additionally, we report on the stability of these compounds during storage. This simplified synthetic approach will make the production of these important standards more feasible for laboratories performing aflatoxin exposure studies.
Topics: Aflatoxin B1; Aflatoxins; Chromatography, High Pressure Liquid; Enzyme-Linked Immunosorbent Assay; Lysine; Mycotoxins; Tandem Mass Spectrometry
PubMed: 35051035
DOI: 10.3390/toxins14010056 -
The American Journal of Tropical... Apr 2017AbstractPregnant women and their developing fetuses are vulnerable to multiple environmental insults, including exposure to aflatoxin, a mycotoxin that may contaminate... (Review)
Review
AbstractPregnant women and their developing fetuses are vulnerable to multiple environmental insults, including exposure to aflatoxin, a mycotoxin that may contaminate as much as 25% of the world food supply. We reviewed and integrated findings from studies of aflatoxin exposure during pregnancy and evaluated potential links to adverse pregnancy outcomes. We identified 27 studies (10 human cross-sectional studies and 17 animal studies) assessing the relationship between aflatoxin exposure and adverse birth outcomes or anemia. Findings suggest that aflatoxin exposure during pregnancy may impair fetal growth. Only one human study investigated aflatoxin exposure and prematurity, and no studies investigated its relationship with pregnancy loss, but animal studies suggest aflatoxin exposure may increase risk for prematurity and pregnancy loss. The fetus could be affected by maternal aflatoxin exposure through direct toxicity as well as indirect toxicity, via maternal systemic inflammation, impaired placental growth, or elevation of placental cytokines. The cytotoxic and systemic effects of aflatoxin could plausibly mediate maternal anemia, intrauterine growth restriction, fetal loss, and preterm birth. Given the widespread exposure to this toxin in developing countries, longitudinal studies in pregnant women are needed to provide stronger evidence for the role of aflatoxin in adverse pregnancy outcomes, and to explore biological mechanisms. Potential pathways for intervention to reduce aflatoxin exposure are urgently needed, and this might reduce the global burden of stillbirth, preterm birth, and low birthweight.
Topics: Aflatoxins; Anemia; Female; Food Contamination; Humans; Pregnancy; Pregnancy Complications; Pregnancy Outcome
PubMed: 28500823
DOI: 10.4269/ajtmh.16-0730 -
The American Journal of Clinical... Apr 2021Naturally occurring aflatoxins may contribute to poor growth and nutritional statuses in children.
BACKGROUND
Naturally occurring aflatoxins may contribute to poor growth and nutritional statuses in children.
OBJECTIVES
We analyzed the relationship between contemporary and lagged aflatoxin exposure and 1) length-for-age z-score (LAZ); and 2) length, knee-heel length, stunting, weight-for-age z-score (WAZ), and weight-for-length z-score (WLZ).
METHODS
We conducted a longitudinal birth cohort study involving 1675 mother-infant dyads in rural Nepal. Participants were repeatedly visited from pregnancy to 2 years of age (2015-2019). One blood sample was collected during pregnancy and 4 samples were collected from the children at 3, 6, 12, and 18-22 months of age to measure concentrations of aflatoxin B1 (AFB1)-lysine adduct. Multivariate linear fixed-effects and logistic models with generalized estimating equations were used to identify associations between child growth and aflatoxin exposure.
RESULTS
AFB1-lysine adducts were detected in the majority of children (at 3 months, 80.5%; at 6 months, 75.3%; at 12 months, 81.1%; and at 18-22 months, 85.1%) and in 94.3% of pregnant women. Changes in contemporary ln child AFB1-lysine adduct concentrations were significantly associated with changes in LAZ (β, -0.05; 95% CI, -0.09 to -0.02; P = 0.003), length (β, -0.19; 95% CI, -0.29 to -0.10; P < 0.001), knee-heel length (β, -0.09; 95% CI, -0.13 to -0.05; P < 0.001), and WAZ (β, -0.04; 95% CI, -0.07 to -0.005; P = 0.022). Serum aflatoxin concentrations were associated with stunting (OR, 1.18; 95% CI, 1.05-1.32; P = 0.005). Similar results were found in the models using changes in contemporary ln AFB1 adjusted for changes in child weight, with significant associations with changes in WLZ (β, -0.07; 95% CI, -0.10 to -0.03; P < 0.001). Changes in time-lagged ln AFB1 (unadjusted and adjusted for changes in child weight) were associated with changes in length and knee-heel length.
CONCLUSIONS
Our results add to the growing body of evidence confirming chronic aflatoxin exposure and suggest that exposure is significantly correlated with various negative growth outcomes, which may vary by child weight status. This trial was registered at clinicaltrials.gov as NCT03312049.
Topics: Adolescent; Adult; Aflatoxins; Bone Development; Child; Child Development; Child Nutritional Physiological Phenomena; Child, Preschool; Cohort Studies; Environmental Exposure; Female; Growth Disorders; Humans; Infant; Male; Middle Aged; Nepal; Pregnancy; Young Adult
PubMed: 33677532
DOI: 10.1093/ajcn/nqaa397