Mycotoxins as human carcinogens-the IARC Monographs classification

Fluorometric determination of aflatoxin B1 using a labeled aptamer and gold nanoparticles modified with a complementary sequence acting as a quencher

A fluorometric aptamer based assay is described for rapid and sensitive detection of aflatoxin B1 (AFB1). It is making use of a fluorescein (FAM) labeled anti-AFB1 aptamer and complementary DNA-modified gold nanoparticles (GNPs). In the absence of AFB1, the FAM-labeled aptamers hybridize with complementary DNA strands that were covalently immobilized on GNPs. This results in quenching of the green fluorescence (with excitation/emission peaks at 485/525 nm). In the presence of AFB1, the aptamer probe binds AFB1 and is released from the GNPs. Hence, fluorescence is restored. Under optimized conditions, AFB1 in the concentration range from 61 pM to 4.0 μM can be detected, and the detection limit is 61 pM. This assay is highly selective for AFB1. It was applied to the determination of AFB1 spiked into 50-fold diluted wine and 20-fold diluted beer. Graphical abstract Schematic presentation of fluorometric detection of AFB1 using a fluorescein (FAM) labeled anti-AFB1 aptamer and complementary DNA-modified gold nanoparticles (GNPs).

Analysis of Fungi on Coix (Coix lacryma-jobi) Seed and the Effect of Its Aqueous Extract on the Growth of Aspergillus flavus

Coix (Coix lacryma-jobi) seeds are susceptible to fungal infections, making their surface fungi complex and diverse. Some fungi can produce mycotoxins under suitable conditions, and fungal growth is closely related to the production of mycotoxins. In this study, the surface fungi of coix seed were identified by Illumina HiSeq high-throughput sequencing. Simultaneously, the fungi cultured by the plate method were identified by microscopy and DNA barcoding; finally, the species of fungi were identified accurately and reliably by combining three methods. The aqueous extract of coix seed was cocultured with Aspergillus flavus spores, and the relationship between the aqueous extract and the growth of A. flavus was studied with the dry weight of mycelium as an indicator. The results showed that there were 89 genera and 96 species of fungi on coix seed, which were mainly distributed in Ascomycota (81.48%) and Basidiomycota (4.08%), and Xeromyces (8.50%), Gibberella (7.25%), and Aspergillus (4.74%) were the predominant genera. Four fungi were isolated from coix seed by plate culture and identified as Aspergillus fumigatus, A. flavus, Aspergillus oryzae, and Rhizopus oryzae by microscopy and DNA barcoding. The aqueous extract of coix seed at low concentrations has a promoting effect on the growth of A. flavus. When the concentration is 3.125%, the promotion effect is the most pronounced, and the promotion rate is 29.17%. These results reveal the diversity of fungi on the coix seed, which can provide a reference for the prevention and control of harmful fungi on coix seed.

UHPLC-ToF-MS method for determination of multi-mycotoxins in maize: Development and validation

An Ultra-High Performance Liquid Chromatography combined with Time-of-Flight Mass Spectrometry (UHPLC–ToF-MS) method has been developed for determination of nine mycotoxins, namely aflatoxins (AFB₁, AFB₂, AFG₁ and AFG₂), ochratoxin A (OTA), zearalenone (ZEA), toxin T2 (T2) and fumonisins (FB₁ and FB₂) in maize. The method included a two-step extraction with acetonitrile 80% (v/v). After optimization, the analytical method was validated. The different concentrations tested take in account the Maximum Levels (ML) for maize (Commission Regulation EC no. 1881/2006) and good results for repeatability (%RSD_r ≤ 15.4%), reproducibility (%RSD_R ≤ 15.9%) and recovery (77.8–110.4%, except for AFG2 at 2 μg/kg which presented a recovery of 73.4%) were achieved. These met the performance criteria imposed by Commission Regulation (EC) no. 401/2006. The method was applied to twenty-two samples from Portuguese producers of maize. Fumonisins were the most frequently detected mycotoxins, but the levels do not exceed those imposed by European legislation.

•

A UHPLC–ToF-MS method was developed for determination of nine mycotoxins in maize.

•

Validation of the method was performed taking in account the EU maximum legal limits for maize.

•

Good results for repeatability, reproducibility and recovery were achieved.

•

The method was applied to 22 samples from Portuguese producers of maize.

•

Fumonisins were the most frequently detected mycotoxins.

Identification of Patulin from Penicillium coprobium as a Toxin for Enteric Neurons

The identification and characterization of fungal commensals of the human gut (the mycobiota) is ongoing, and the effects of their various secondary metabolites on the health and disease of the host is a matter of current research. While the neurons of the central nervous system might be affected indirectly by compounds from gut microorganisms, the largest peripheral neuronal network (the enteric nervous system) is located within the gut and is exposed directly to such metabolites. We analyzed 320 fungal extracts and their effect on the viability of a human neuronal cell line (SH-SY5Y), as well as their effects on the viability and functionality of the most effective compound on primary enteric neurons of murine origin. An extract from P. coprobium was identified to decrease viability with an EC₅₀ of 0.23 ng/µL in SH-SY5Y cells and an EC₅₀ of 1 ng/µL in enteric neurons. Further spectral analysis revealed that the effective compound was patulin, and that this polyketide lactone is not only capable of evoking ROS production in SH-SY5Y cells, but also diverse functional disabilities in primary enteric neurons such as altered calcium signaling. As patulin can be found as a common contaminant on fruit and vegetables and causes intestinal injury, deciphering its specific impact on enteric neurons might help in the elaboration of preventive strategies.

Mycotoxin Contamination of Edible Non-Timber Forest Products in Cameroon

The prevalence and concentrations of three major mycotoxins, total aflatoxin (AFs), fumonisin (F), and zearalenone (ZEN), were determined on seven edible non-timber forest products (ENTFP) in Cameroon. A total of 210 samples consiting of 30 samples from each ENTFP commodity was collected from farmers and local markets in three agroecological zones of Cameroon and analyzed for moisture content and mycotoxins. Mycotoxins were analyzed using commercial enzyme-linked immunosorbent assay (ELISA) kits and results were validated using the VICAM fluorometric method. The European Union regulation of mycotoxins for human consumption (N°1881/2006) was adopted as reference. The moisture content of samples varied from 5.0% to 22.6%. Aflatoxin contamination was detected in 84.3% samples and only 5.7% exceeded the legal limit (10 ppb). Similarly, 53% of samples were contaminated with fumonisin and 5% of samples exceeded the legal limit (1000 ppb). Zearalenone contamination was detected in 92% of samples and 21% of samples exceeded the legal limit (100 ppb). This is the first report on mycotoxin contamination of ENTFP in the Congo Basin forest. The findings of this study will form a basis for educating farmers and other stakeholders of ENTFP values chain on mycotoxins and mycotoxin mitigation measures to produce safe ENTFP for local and international markets.

The effect of moderate-dose aflatoxin B1 and Salmonella Enteritidis infection on intestinal permeability in broiler chickens

The effect of dietary aflatoxin B₁ (AFB₁) and Salmonella Enteritidis infection on intestinal permeability was investigated. Two hundred 1-day-old male Ross 308 broiler chickens were randomly divided into 4 treatments of 5 replicates each (10 birds per replicate), which were fed ad libitum for 3 weeks with the following treatments: control, chickens fed an AFB₁-free diet; AF, chickens fed an AFB₁-contaminated diet at 470 ng/g; SE, chickens fed an AFB₁-free diet and challenged with 10⁸ cfu of S. Enteritidis per bird at 18 days old; AF + SE, chickens fed an AFB₁-contaminated diet and challenged with 10⁸ cfu of S. Enteritidis per bird at 18 days old. At day 21 of age, chicks received an oral gavage dose of fluorescein isothiocyanate dextran (FITC-dextran) to evaluate gastrointestinal leakage. Blood and intestinal samples were collected to evaluate serum biochemistry and total intestinal IgA secretion, respectively. Liver tissues were aseptically collected to assess bacterial invasiveness and for histomorphological studies. The results showed that chickens receiving AFB₁ presented a significant increment (up to 2.4-fold) in serum FITC-dextran concentration (p < 0.05). Nevertheless, S. Enteritidis infection had no additional effect on gastrointestinal leakage. Furthermore, the ingestion of AFB₁ had no impact on the invasive potential of S. Enteritidis. These results suggest that moderate-dose AFB₁ adversely affects intestinal barrier function resulting in increased gut permeability in broiler chickens.

Occurrence of the Ochratoxin A Degradation Product 2'R-Ochratoxin A in Coffee and Other Food: An Update

Food raw materials can contain the mycotoxin ochratoxin A (OTA). Thermal processing of these materials may result in decreased OTA levels but also in the formation of the thermal isomerization product 2′R-ochratoxin A (2′R-OTA). So far, only 2′R-OTA levels reported from 15 coffee samples in 2008 are known, which is little when compared to the importance of coffee as a food and trading good. Herein, we present results from a set of model experiments studying the effect of temperatures between 120 °C and 270 °C on the isomerization of OTA to 2′R-OTA. It is shown that isomerization of OTA starts at temperatures as low as 120 °C. At 210 °C and above, the formation of 25% 2′R-OTA is observed in less than one minute. Furthermore, 51 coffee samples from France, Germany, and Guatemala were analyzed by HPLC-MS/MS for the presence of OTA and 2′R-OTA. OTA was quantified in 96% of the samples, while 2′R-OTA was quantifiable in 35% of the samples. The highest OTA and 2′R-OTA levels of 28.4 µg/kg and 3.9 µg/kg, respectively, were detected in coffee from Guatemala. The OTA:2′R-OTA ratio in the samples ranged between 2.5:1 and 10:1 and was on average 5.5:1. Besides coffee, 2′R-OTA was also for the first time detected in a bread sample and malt coffee powder.

Occurrence of Deoxynivalenol and Ochratoxin A in Beers and Wines Commercialized in Paraguay

Alcoholic beverages can be contaminated with mycotoxins. Ochratoxin A (OTA) is the most frequently detected mycotoxinin wine and is produced by several species of Aspergillus. This mycotoxin is nephrotoxic and carcinogenic. In beer, the most commonly identified mycotoxin is deoxynivalenol (DON). Ingestion of food contaminated with DON has been associated with adverse gastrointestinal effects. Despite the harmful effects of mycotoxins on health, there are no regulations regarding their limits in alcoholic beverages in Paraguay. Here we determine the presence of OTA and DON in wine and beer, respectively. Four commercial brands of wine and twenty-nine brands of craft and industrial beerwere tested by the Agra quant ELISA method. One brand of wine was positive for OTA and seven brands of beer (one of them craft) were positive for DON. The values found for both toxins are below the recommended maximum intake proposed by international standards. Giving the high consumption of these products in the country, regulations and monitoring systems mustbe established to check the maximum levels of mycotoxins allowed in alcoholic beverages.

Identification of ochratoxin-N-acetyl-L-cysteine as a new ochratoxin A metabolite and potential biomarker in human urine

Ochratoxin A (OTA) is a nephrotoxic mycotoxin with nephrocarcinogenic potential found in a broad spectrum of food commodities. The mode of action of this compound, as well as its metabolism, is still not fully understood. To determine whether the conjugation of OTA with glutathione plays an important role in human OTA metabolism, an ochratoxin-glutathione conjugate (OTB-GSH), as well as the corresponding urinary metabolite ochratoxin-N-acetyl-l-cysteine (OTB-NAC), were synthesized and their structures confirmed by NMR spectroscopy. By means of synthesized stable isotope-labeled d₅-OTB-GSH and d₅-OTB-NAC references, a sensitive HPLC-MS/MS method has been developed and applied for the screening of human urine samples. OTB-NAC could be detected in 11 of the analyzed 18 urine samples and was quantified in 5 urine samples in the range between 0.023 and 0.176 ng mg⁻¹ creatinine. OTB-GSH has not been detected in the urine samples. In OTB-NAC positive samples, this metabolite contributed to a comparable concentration range to the total OTA excretion as the parent compound. This is the first direct analysis of an OTA phase 2 metabolite in humans.

NMR-Based Metabolic Profiles of Intact Zebrafish Embryos Exposed to Aflatoxin B1 Recapitulates Hepatotoxicity and Supports Possible Neurotoxicity

Aflatoxin B1 (AFB1) is a widespread contaminant of grains and other agricultural crops and is globally associated with both acute toxicity and carcinogenicity. In the present study, we utilized nuclear magnetic resonance (NMR), and specifically high-resolution magic angle spin (HRMAS) NMR, coupled to the zebrafish (Danio rerio) embryo toxicological model, to characterize metabolic profiles associated with exposure to AFB1. Exposure to AFB1 was associated with dose-dependent acute toxicity (i.e., lethality) and developmental deformities at micromolar (≤ 2 µM) concentrations. Toxicity of AFB1 was stage-dependent and specifically consistent, in this regard, with a role of the liver and phase I enzyme (i.e., cytochrome P450) bioactivation. Metabolic profiles of intact zebrafish embryos exposed to AFB1 were, furthermore, largely consistent with hepatotoxicity previously reported in mammalian systems including metabolites associated with cytotoxicity (i.e., loss of cellular membrane integrity), glutathione-based detoxification, and multiple pathways associated with the liver including amino acid, lipid, and carbohydrate (i.e., energy) metabolism. Taken together, these metabolic alterations enabled the proposal of an integrated model of the hepatotoxicity of AFB1 in the zebrafish embryo system. Interestingly, changes in amino acid neurotransmitters (i.e., Gly, Glu, and GABA), as a key modulator of neural development, supports a role in recently-reported neurobehavioral and neurodevelopmental effects of AFB1 in the zebrafish embryo model. The present study reinforces not only toxicological pathways of AFB1 (i.e., hepatotoxicity, neurotoxicity), but also multiple metabolites as potential biomarkers of exposure and toxicity. More generally, this underscores the capacity of NMR-based approaches, when coupled to animal models, as a powerful toxicometabolomics tool.

Time-Course Effects of Acute Aflatoxin B1 Exposure on Hepatic Mitochondrial Lipids and Oxidative Stress in Rats

Aflatoxins are secondary metabolites of certain Aspergillus species, that contaminate staple foods, particularly in developing countries. Aflatoxin B1 (AFB1) is the most toxic and common of the major types of aflatoxins. AFB1 is hepatotoxic and has been implicated in increasing the risk of hepatocellular carcinoma (HCC). We have previously shown that subacute exposure to AFB1 for 7 days disrupts hepatic lipids; therefore, this study determined the time-course effects of acute aflatoxin exposure on hepatic mitochondrial lipids and oxidative stress. To achieve this, thirty male albino rats were randomly assigned to six groups. The groups received an oral dose of 1 mg/kg body weight AFB1 or vehicle only (controls) for one, four, or seven days, respectively. Twenty-four hours after the last dose, the animals were sacrificed and liver excised. Mitochondria and cytosolic fractions were obtained from the liver after which lipids (cholesterol, triacylglycerols) were determined in the mitochondria while biomarkers of oxidative stress (glutathione, glutathione transferase (GST), glutathione peroxidase (GPx), glutathione reductase, nitric oxide (NO), malonaldehyde (MDA), thioredoxin reductase (TR), and superoxide dismutase (SOD) were determined spectrophotometrically in the mitochondria and cytosolic fractions. The expression of genes (Nrf2, Acc, Nqo1, and HmgCoa) were determined using quantitative RT-PCR. Results showed that AFB1 significantly increased mitochondrial cholesterol at day seven (treatment vs. control, p = 0.016). It also increased the concentrations of NO and MDA at day one and day seven while the activity of GPx and concentration of GSH were increased at day seven (p = 0.030) and day one (p = 0.025) alone, respectively, compared to control. The activities of cytosolic GR (p = 0.014), TR (p = 0.046) and GST (p = 0.044) were increased at day seven. AFB1 significantly increased the expression of Nrf2 (p = 0.029) and decreased the expression of Acc (p = 0.005) at day one. This study revealed that AFB1 disrupts hepatic mitochondrial lipids and antioxidant capacity. These changes were dependent on the timing of exposure and did not follow a linear time-course trend. These alterations could be part of the hepatic mitochondria response mechanism to acute AFB1 toxicity.

Concentration and Prevalence of Aflatoxin M1 in Human Breast Milk in Iran: Systematic Review, Meta-Analysis, and Carcinogenic Risk Assessment: A Review

This meta-analysis was designed to review the published reports regarding the concentration and/or prevalence of aflatoxin M₁ (AFM₁) in human breast milk in Iran. The carcinogenic risk for Iranian infants consuming this milk was estimated with the hazard index. The PubMed and Scopus databases and the Scientific Information Database were screened for relevant studies between 1995 and 2017, and 11 of the 112 collected studies were included in the systematic review and meta-analysis. The mean (95% confidence interval) concentration of AFM₁ was 5.85 ng/L (4.54 to 7.15 ng/L), which was lower than the European Union standard (25 ng/L). The mean prevalence of AFM₁ in breast milk in Iran was 42% (11 to 77%). The estimated daily intakes for male and female infants were 0.02 to 5.57 ng/kg and 0.02 to 3.68 ng/kg of body weight per day, respectively. The rank order of estimated daily intake for both male and female infants according to age was 1 week > 1 month > 6 months > 12 months. The hazard index for all age groups of infants in all provinces in Iran was less than 1. Therefore, infants in Iran were not considered at carcinogenic risk from AFM₁ in human breast milk.

Development of a biotin-streptavidin-amplified nanobody-based ELISA for ochratoxin A in cereal

A biotin-streptavidin-amplified enzyme-linked immunosorbent assay using a biotinylated nanobody (BA-Nb ELISA) was developed to detect ochratoxin A (OTA) in cereal. The limit of detection (LOD) of the BA-Nb ELISA, which equals to 10% maximal inhibitory concentration, was 0.011 ng/mL for OTA in buffer, and the sensitivity was approximately improved by one order of magnitude compared with the traditional Nb ELISA (LOD = 0.112 ng/mL). Under optimal conditions, the developed assay could be accomplished in 40 min with maximal inhibitory concentration of 0.138 ng/mL and the linear detection range of 0.034-0.460 ng/mL. The average recovery rate of the BA-Nb ELISA ranged from 92.8% to 114%, and the relative standard deviation was in the range of 2.04-9.85%. The developed BA-Nb ELISA was validated by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the results indicated the reliability of BA-Nb ELISA for the detection of OTA in cereal.

Primer remodeling amplification-activated multisite-catalytic hairpin assembly enabling the concurrent formation of Y-shaped DNA nanotorches for the fluorescence assay of ochratoxin A

DNA can be configured into unique high-order structures due to its significantly high programmability, such as a three-way junction-based structure (denoted Y-shaped DNA), for further applications. Herein, we report a label-free fluorescent signal-on biosensor based on the target-driven primer remodeling rolling circle amplification (RCA)-activated multisite-catalytic hairpin assembly (CHA) enabling the concurrent formation of Y-shaped DNA nanotorches (Y-DNTs) for ultrasensitive detection of ochratoxin A (OTA). Two kinds of masterfully-designed probes, termed Complex I and II, were pre-prepared by the combination of a circular template (CT) with an OTA aptamer (S1), a substrate probe (S2) and hairpin probe 1 (HP1), respectively. Target OTA specifically binds to Complex I, resulting in the release of the remnant element in S2 and successive remodeling into a mature primer for RCA by phi29 DNA polymerase, thus a usable primer-CT complex is produced, which actuates primary RCA. Then, numerous Complex II probes can anneal with the first-generation RCA product (RP) with multiple sites to activate the CHA process. With the participation of endonuclease IV (Endo IV) and phi29, HP1 as a pre-primer containing a tetrahydrofuran abasic site mimic (AP site) in Complex II is converted into a mature primer to initiate additional rounds of RCA. So, countless Y-DNTs are formed concurrently containing a G-quadruplex structure that enables the N-methylmesoporphyrin IX (NMM) to be embedded, generating remarkably strong fluorescence signals. The biosensor was demonstrated to enable rapid and accurate highly efficient and selective detection of OTA with an improved detection limit of as low as 0.0002 ng mL^-1 and a widened dynamic range of over 4 orders of magnitude. Meanwhile, this method was proven to be capable of being used to analyze actual samples. Therefore, this proposed strategy may be established as a useful and practical platform for the ultrasensitive detection of mycotoxins in food safety testing.

Risk associated with the intake of aflatoxin M1 from milk in Iran

Aflatoxin M1 is an oxidative metabolite of aflatoxin B1 formed in liver and excreted into milk, urine and faeces of dairy cattle and other mammalian species. The International Agency for Research on Cancer classified aflatoxin M1 in Group 2B because of its potential to get bioactivated to a mutagen analogous to aflatoxin B1. Risk assessments are undertaken to guide food regulators and scientists in risk management processes, such as the legislative levels or guideline targets for mycotoxins in food supplies. Using existing international resources for hazard data and local exposure data, and based on cancer potency as the endpoint, the risk of exposure to aflatoxin M1 in milk for the Iranian population was calculated considering various scenarios. During 2014-2015, 518 samples were collected from the market and tested for aflatoxin M1 contamination by HPLC-FLD. The most probable scenarios calculated as mean occurrence multiplied by the mean consumption in consumers of milk, and for maximum level allowed for aflatoxin M1 in milk with 99 percentiles of milk consumption showed the risk of 0.08 and 0.72 additional liver cancer cases per year for the Iranian population, respectively. Thus, our study reveals a low risk and that the current maximum limit of 100 ng/l for aflatoxin M1 in milk, heat treated milk and flavoured milk is sustainable.

Detection of Five Mycotoxins in Different Food Matrices in the Malaysian Market by Using Validated Liquid Chromatography Electrospray Ionization Triple Quadrupole Mass Spectrometry

Mycotoxins are common food contaminants which cause poisoning and severe health risks to humans and animals. The present study applied chemometric approach in liquid chromatography-tandem mass spectrometry (LC-MS/MS) optimization for simultaneous determination of mycotoxins, i.e., aflatoxins B1, B2, G1, and G2, and ochratoxin A. The validated quick, easy, cheap, effective, rugged, and safe (QuEChERS)-LC-MS/MS method was used to study the occurrence of mycotoxins in 120 food matrices. The recovery ranges from 81.94% to 101.67% with relative standard deviation (RSD) lesser than 11%. Through the developed method, aflatoxins were detected in raisin, pistachio, peanut, wheat flour, spice, and chili samples with concentration ranges from 0.45 to 16.93 µg/kg. Trace concentration of ochratoxin A was found in wheat flour and peanut samples which ranged from 1.2 to 3.53 µg/kg. Some of the tested food samples contained mycotoxins of above the European legal maximum limit.

Exonuclease I-assisted fluorescent method for ochratoxin A detection using iron-doped porous carbon, nitrogen-doped graphene quantum dots, and double magnetic separation

In this paper, a fluorescent method was developed for ochratoxin A (OTA) detection that uses iron-doped porous carbon (MPC) and aptamer-functionalized nitrogen-doped graphene quantum dots (NGQDs-Apt) as probes. In this method, the adsorbance of the NGQDs-Apt on the MPC due to a π-π interaction between the aptamer and the MPC results in the quenching of the fluorescence of the NGQDs-Apt. However, since OTA interacts strongly with the aptamer, the presence of OTA leads to the detachment of the NGQDs-Apt from the MPC, resulting in the resumption of fluorescence from the NGQDs-Apt. When exonuclease I (Exo I) is also added to the solution, this exonuclease specifically digests the aptamer, leading to the release of the OTA back into the solution. This free OTA then interacts with another MPC-NGQDs-Apt system, inducing the release of more NGQDs into the solution, which enhances the fluorescent intensity compared to that of the system with no Exo I. Utilizing this behavior of OTA in the presence of NGQDs-Apt, it was possible to detect concentrations of OTA ranging from 10 to 5000 nM, with a limit of detection of 2.28 nM. Our method was tested by applying it to the detection of OTA in wheat and corn samples. This method has four advantages: (1) the magnetic porous carbon is easy to prepare, its porosity enhances its loading capacity for NGQDs, it highly efficiently quenches the fluorescence of the NGQDs, and its magnetic properties facilitate the separation of the MPC from other species in solution; (2) applying double magnetic separation decreases the background signal; (3) Exo I digests the free aptamer effectively, which allows the resulting free OTA to induce the release of more NGQDs-Apt, ultimately enhancing the fluorescent signal; and (4) the proposed method presented high sensitivity and a wide linear detection range. This method may prove helpful in food safety analysis and new biosensor development (achieved by using different aptamer sequences to that used in the present work). Graphical abstract Exonuclease I (Exo I)-assisted fluorescent method for ochratoxin A (OTA) detection using magnetic porous carbon (MPC), nitrogen-doped graphene quantum dots (NGQDs), and double magnetic separation.

Mycotoxins produced by Fusarium proliferatum and F. pseudonygamai on maize, sorghum and pearl millet grains in vitro

Maize (Zea mays), sorghum (Sorghum bicolor) and pearl millet (Pennisetum glaucum) are basic staple foods for many rural or poorer communities. These crops are susceptible to plant diseases caused by multiple species of Fusarium, some of which also produce mycotoxins, including fumonisins and moniliformin that are detrimental to both humans and domesticated animals. Eighteen potentially toxigenic Fusarium strains were isolated from maize (n = 10), sorghum (n = 7) and pearl millet (n = 1) growing in the same field in Nigeria. The 17 strains from maize and sorghum were all F. proliferatum and the one strain from pearl millet was F. pseudonygamai. Under conducive conditions, the 17 F. proliferatum strains produced fumonisins, 11 in relatively large quantities (700-17,000 mg total fumonisins, i.e., FB₁ + FB₂ + FB₃/kg culture material), and six at <45 mg/kg. Ten F. proliferatum strains produced >100 mg of moniliformin per kg culture material with a maximum of 8900 mg/kg culture material. All strains could use all grains for growth and toxin production, regardless of the host from which they were isolated. Isolates varied in the amount of toxin produced on each substrate, with toxin production a property of the strain and not the host from which the strain was recovered. However, the extent to which a toxin-producing phenotype could be altered by the grain on which the fungus was grown is consistent with subtle genetic × environment interactions that require a larger data set than the one presented here to rigorously identify. In conclusion, there is significant variation in the ability of strains of F. proliferatum to produce fumonisins and moniliformin on maize, sorghum and millet. If the amount of toxin produced on the various grains in this study reflects real-world settings, e.g., poor storage, then the consumers of these contaminated grains could be exposed to mycotoxin levels that greatly exceed the tolerable daily intakes.

The Effect of Probiotic Supplementation on Performance and the Histopathological Changes in Liver and Kidneys in Broiler Chickens Fed Diets with Aflatoxin B₁

The aim of the study was to investigate the toxic effects of aflatoxin B₁ (AFB₁) and efficacy of a probiotic preparation containing L. reuteri, L. plantarum, L. pentosus, L. rhamnosus and L. paracasei and Saccharomyces cerevisiae yeasts to ameliorate their effects in broiler chickens. A total of 168 one-day-old female Ross 308 broilers were randomly allocated to six groups. Three wheat and soybean meal-based diets were prepared: Control diet and diets contaminated with 1 or 5 mg/kg AFB₁ supplied in moldy wheat. All diets were unsupplemented or supplemented with probiotic, cold pelleted and fed from 1 to 35 day of life. Feeding diet with 1 mg AFB₁/kg did not affect performance, but a diet with 5 mg AFB₁ resulted in a significant reduction of feed intake and BWG, both diets induced liver and kidneys enlargement. The probiotic supplementation of the diets partially ameliorated those negative effects and resulted in a significant increase of AFB₁ excretion. It was accompanied by the reduced level of AFB₁ residues in the liver from 8.9 to 3.7 and from 11.8 to 5.9 µg/kg, in kidneys from 7.9 to 2.5 and from 13.7 to 4.1 µg/kg in birds fed the less and more contaminated diets, respectively. AFB₁ exposure caused many severe histopathological changes in the liver and kidneys of broilers, probiotic supplementation significantly reduced the changes of these organs. It may be concluded that the probiotic supplementation can be used to alleviate the negative effects of contamination of broiler feed with AFB₁ on bird health and product security.

Advantageous Extraction, Cleanup, and UHPLC-MS/MS Detection of Patulin Mycotoxin in Dietary Supplements and Herbal Blends Containing Hawberry from Crataegus spp

Patulin (PAT) is a highly genotoxic mycotoxin still found as the common contaminant of various kinds of spoiled fruits and related commodities which are often endorsed as the health-enhancing products. Thus, a fast and convenient liquid-solid extraction followed by a solid-phase cleanup with the MycoSep®228 AflaPat multifunctional column was used for the highly efficient isolation of PAT with an average recovery of 112.7% from commercial dietary supplements and herbal blends formulated with dried hawberry. Analysis of the PAT content was carried out using gradient elution with a Synergi Polar C18 column (150 × 2 mm, 4 μm) and UHPLC system equipped with a mass spectrometer. PAT was detected in all (n=14) commercial single-component dietary supplements formulated with dried hawberry belonging to Crataegus monogyna and/or Crataegus laevigata. Similarly, PAT was detected in 67% of the studied multicomponent commercial herbal blends (n=6) that contained-in addition to hawberry-different amounts of apple, chokeberry, elderberry, hibiscus, or mallow. Moreover, the PAT content was determined in the hawberry collected from the mature wild hawthorn trees belonging to three botanical species, Crataegus monogyna Jacq., Crataegus laevigata (Poiret) DC, and Crataegus rhipidophylla Gand, growing in the recreational forest areas and in the law-protected state national forest park in Poland. In conclusion, to prevent PAT accumulation and reduce the health risk of consumers in globalizing markets, the implementation of improved cultivation/processing practices of hawthorn trees and hawberry as well as increased analytical control related to the presence of PAT in dietary supplements and herbal blends formulated with fresh, dried, or frozen hawberry should be urgently recommended.

Liquid Chromatography Analysis of Common Nutritional Components, in Feed and Food

Food and feed laboratories share several similarities when facing the implementation of liquid-chromatographic analysis. Using the experience acquired over the years, through application chemistry in food and feed research, selected analytes of relevance for both areas were discussed. This review focused on the common obstacles and peculiarities that each analyte offers (during the sample treatment or the chromatographic separation) throughout the implementation of said methods. A brief description of the techniques which we considered to be more pertinent, commonly used to assay such analytes is provided, including approaches using commonly available detectors (especially in starter labs) as well as mass detection. This manuscript consists of three sections: feed analysis (as the start of the food chain); food destined for human consumption determinations (the end of the food chain); and finally, assays shared by either matrices or laboratories. Analytes discussed consist of both those considered undesirable substances, contaminants, additives, and those related to nutritional quality. Our review is comprised of the examination of polyphenols, capsaicinoids, theobromine and caffeine, cholesterol, mycotoxins, antibiotics, amino acids, triphenylmethane dyes, nitrates/nitrites, ethanol soluble carbohydrates/sugars, organic acids, carotenoids, hydro and liposoluble vitamins. All analytes are currently assayed in our laboratories.

Prevalence and probabilistic health risk assessment of aflatoxins B1, B2, G1, and G2 in Iranian edible oils

The prevalence of aflatoxins (AFs) B₁, B₂, G₁, and G₂ in Iranian edible oils were assessed by immunoaffinity column cleanup and HPLC equipped with a fluorescence detector (HPLC-FLD). Ninety-seven samples including sunflower, canola, refined olive, unrefined olive, frying, and blend oils were collected from eight provinces (n = 15 samples of refined olive oil, n = 15 samples of unrefined olive oil, n = 15 samples of sunflower oil, n = 15 samples of canola oil, n = 17 samples of frying oil, and n = 20 samples of blend oil). Also, cancer risk of aflatoxins in the adults and children due to ingestion of edible oils was estimated via margin of exposure (MOE) estimation in the Monte Carlo simulation (MCS) model. Considering the limit of detection (LOD) of the current study, two unrefined olive oil samples from Zanjan Province were contaminated with AFB₂ in the concentrations of 0.2 and 0.4 ng/g while other samples were free from AFB₁, AFB₂, AFG₁, and AFG₂. This study revealed that about 98% of the collected samples were free from AFs and the concentrations of AFs in the polluted samples were within the standard range suggested by European Commission regulation (20 μg/kg). However, health risk assessment indicated that both adult and children in the Zanjan Province are at considerable liver cancer risk (percentile 95% of MOE < 10,000 value). Therefore, national plan to address this issue and strict inspection of edible oil products by the regulatory bodies are suggested.

Effect of potassium sorbate (E-202) and the antifungal PgAFP protein on Aspergillus carbonarius growth and ochratoxin A production in raisin simulating media

BACKGROUND

Ochratoxin A (OTA) is a mycotoxin produced by several species of Aspergillus and Penicillium fungi. The presence of OTA in raisins is mainly related to black Aspergillus spp. contamination. This toxin poses risks to human and animal health due to its high toxicity and carcinogenicity. New strategies to avoid the risk associated with OTA are therefore necessary.

RESULTS

A comparison was made between the effects of the antifungal protein PgAFP and potassium sorbate (E-202) on the growth of Aspergillus carbonarius, biosynthetic- and stress-related gene expression and its OTA production at two water activity (a_w ) levels, 0.95 and 0.93 a_w . The results showed that PgAFP successfully controlled OTA production, whereas E-202, despite being able to reduce Aspergillus carbonarius growth, caused a significant increase in OTA production by the fungus.

CONCLUSION

PgAFP protein, a biological compound with an antifungal activity, is safer to use than E-202 and may be proposed as a food preservative and a useful strategy to control ochratoxigenic A. carbonarius in raisins. © 2018 Society of Chemical Industry.

Nanobody-Alkaline Phosphatase Fusion Protein-Based Enzyme-Linked Immunosorbent Assay for One-Step Detection of Ochratoxin A in Rice

Ochratoxin A (OTA) has become one a focus of public concern because of its multiple toxic effects and widespread contamination. To monitor OTA in rice, a sensitive, selective, and one-step enzyme-linked immunosorbent assay (ELISA) using a nanobody-alkaline phosphatase fusion protein (Nb28-AP) was developed. The Nb28-AP was produced by auto-induction expression and retained an intact antigen-binding capacity and enzymatic activity. It exhibited high thermal stability and organic solvent tolerance. Under the optimal conditions, the developed assay for OTA could be finished in 20 min with a half maximal inhibitory concentration of 0.57 ng mL^-1 and a limit of detection of 0.059 ng mL^-1, which was 1.1 times and 2.7 times lower than that of the unfused Nb28-based ELISA. The Nb28-AP exhibited a low cross-reactivity (CR) with ochratoxin B (0.92%) and ochratoxin C (6.2%), and an ignorable CR (<0.10%) with other mycotoxins. The developed Nb-AP-based one-step ELISA was validated and compared with a liquid chromatography-tandem mass spectrometry method. The results show the reliability of Nb-AP-based one-step ELISA for the detection of OTA in rice.

Controlling aflatoxin contamination and propagation of Aspergillus flavus by a soy-fermenting Aspergillus oryzae strain

Aflatoxins (AFs) are a group of carcinogenic and immunosuppressive mycotoxins that threaten global food safety. Globally, over 4.5 billion people are exposed to unmonitored levels of AFs. Aspergillus flavus is the major source of AF contamination in agricultural crops. One approach to reduce levels of AFs in agricultural commodities is to apply a non-aflatoxigenic competitor, e.g., Afla-Guard, to crop fields. In this study, we demonstrate that the food fermenting Aspergillus oryzae M2040 strain, isolated from Korean Meju (a brick of dry-fermented soybeans), can inhibit aflatoxin B1 (AFB1) production and proliferation of toxigenic A. flavus in lab culture conditions and peanuts. In peanuts, 1% inoculation level of A. oryzae M2040 could effectively displace the toxigenic A. flavus and inhibit AFB1 production. Moreover, cell-free culture filtrate of A. oryzae M2040 effectively inhibited AFB1 production and A. flavus growth, suggesting A. oryzae M2040 secretes inhibitory compounds. Whole genome-based comparative analyses indicate that the A. oryzae M2040 and Afla-Guard genomes are 37.9 and 36.4 Mbp, respectively, with each genome containing ~100 lineage specific genes. Our study establishes the idea of using A. oryzae and/or its cell-free culture fermentate as a potent biocontrol agent to control A. flavus propagation and AF contamination.

Ameliorative effects of selenium on the excess apoptosis of the jejunum caused by AFB1 through death receptor and endoplasmic reticulum pathways

Aflatoxin B1 (AFB1), one of most potent and common mycotoxins in human food and animal feed, has hepatotoxic and carcinogenic effects on humans and poultry. Recent studies indicated that selenium (Se) has a protective effect on apoptosis induced by toxin poisoning. The present study was designed to reveal the ameliorative effects of selenium on the expression of apoptosis related molecules in the jejunum of broilers exposed to an AFB1 diet for 3 weeks. A total of 216 one-day-old healthy Cobb broilers were randomly divided into the control group (0 mg kg-1 AFB1), AFB1 group (0.6 mg kg-1 AFB1), AFB1 + Se group (0.6 mg kg-1 AFB1 + 0.4 mg kg-1 supplement Se) and Se group (0.4 mg kg-1 supplement Se), respectively. TUNEL and flow cytometry assays both indicated that 0.4 mg kg-1 selenium could ameliorate excess apoptosis caused by AFB1 in jejunal cells. Moreover, the expressions of FAS, FASL, TNF-α, TNF-R1, CASPASE-3, CASPASE-8, CASPASE-10, GRP78 and GRP94 analyzed by qRT-PCR demonstrated that 0.4 mg kg-1 selenium restored these parameters to be close to those in the control group. In summary, supplementation of selenium at a concentration of 0.4 mg kg-1 selenium could protect the chicken's jejunum from excess apoptosis caused by 0.6 mg kg-1 AFB1 through down-regulating the expression of death receptor pathway and endoplasmic reticulum pathway related molecules. According to this conclusion, this study may contribute to a better understanding of selenium's protective role against AFB1 poisoning.

Evaluation of Aflatoxin M1 Effects on the Metabolomic and Cytokinomic Profiling of a Hepatoblastoma Cell Line

Hepatoblastoma incidence has been associated with different environmental factors even if no data are reported about a correlation between aflatoxin exposure and hepatoblastoma initiation. Considering that hepatoblastoma develops in infants and children and aflatoxin M1 (AFM1), the aflatoxin B1 (AFB1) hydroxylated metabolite, can be present in mothers' milk and in marketed milk products, in this study we decided to test the effects of AFM1 on a hepatoblastoma cell line (HepG2). Firstly, we evaluated the effects of AFM1 on the cell viability, apoptosis, cell cycle, and metabolomic and cytokinomic profile of HepG2 cells after treatment. AFM1 induced: (1) a decrease of HepG2 cell viability, reaching IC50 at 9 µM; (2) the blocking of the cell cycle in the G0/G1 phase; (3) the decrease of formiate levels and incremented level of some amino acids and metabolites in HepG2 cells after treatment; and (4) the increase of the concentration of three pro-inflammatory cytokines, IL-6, IL-8, and TNF-α, and the decrease of the anti-inflammatory interleukin, IL-4. Our results show that AFM1 inhibited the growth of HepG2 cells, inducing both a modulation of the lipidic, glycolytic, and amino acid metabolism and an increase of the inflammatory status of these cells.

Encapsulation of cinnamon essential oil in whey protein enhances the protective effect against single or combined sub-chronic toxicity of fumonisin B1 and/or aflatoxin B1 in rats

Fumonisin B₁ (FB₁) and aflatoxin B₁ (AFB₁) are fungal metabolites that frequently co-occur in foodstuffs and are responsible for mycotoxicosis and several primary cancers. Cinnamon essential oil (CEO) has a spacious range of benefit effects but also has some limitations owing to its strong taste or its interaction with some drugs. This study aimed to use the cinnamon oil emulsion droplets (COED) for the protection against oxidative stress, cytotoxicity, and reproductive toxicity in male Sprague-Dawley rats sub-chronically exposed to FB₁ and/or AFB₁. The composition of CEO was identified using GC-MS then was encapsulated using whey protein as wall material. Male rats were divided into eight groups and treated orally for 8 weeks as follows: control group, AFB₁-trreated group (80 μg/kg b.w), FB₁-treated group (100 mg/kg b.w), FB₁ plus AFB₁-treated group, and the groups treated with COED plus FB₁ and/or AFB₁. Blood and samples of the kidney, liver, and testis were collected for different analysis and histopathological examination. The GC-MS analysis revealed that cinnamaldehyde, α-copaene, trans-cinnamaldehyde, caryophyllene, and delta-cadinene were the main compounds in COE. The average size of COED was 235 ± 1.4 nm and the zeta potential was - 6.24 ± 0.56. Treatment with FB₁ and/or AFB₁ induced significant disturbances in the serum biochemical analysis, oxidative stress parameters, DNA fragmentation, gene expression, and testosterone and severe pathological changes in the tested organs. Moreover, treatment with both mycotoxins induced synergistic toxic effects. COED did not induce toxic effects and could normalize the majority of the tested parameters and improve the histological picture in rats treated with FB₁ and/or AFB₁. It could be concluded that COED induce potential protective effects against the single or combined exposure to FB₁ and AFB₁.