Aflatoxin Contamination: An Overview on Health Issues, Detection and Management Strategies

Aflatoxin M1 level and risk assessment in milk, yogurt, and cheese in Tabriz, Iran

AIM AND BACKGROUND

The objective of this study was to investigate the presence of aflatoxin M1 (AFM1) in milk, yogurt, and cheese samples collected from Tabriz, Iran. Additionally, the study conducted a risk assessment related to the consumption of milk and dairy products within Tabriz city.

STUDY METHOD

For this study, 56 samples (raw milk, pasteurized milk, ultra-high temperature milk (UHT), traditional yogurt, pasteurized yogurt, traditional cheese, and pasteurized cheese) were collected randomly in Tabriz from December 2021 to March 2022. The analysis was carried out using liquid chromatography, which was equipped with a fluorescence detector. The estimated dietary intake (EDI) and the hazard index (HI) were calculated for the risk assessment.

RESULTS AND DISCUSSION

AFM1 was detected in all samples. The highest concentration of AFM1 was observed in traditional cheese (P < 0.05). The lowest concentration was observed in UHT milk and there were no significant differences between the various milk types and pasteurized yogurt (P > 0.05). Moreover, in all samples, the levels of AFM1 were below the maximum limit permitted by Iranian national standards. AFM1 levels in traditional yogurt exceeded the European Union's permissible limit in 25% of the samples. The HI in all samples was less than one for both adult and child consumers, except for milk samples for children, which were more than one and indicated a medium risk. In conclusion, the levels of contamination in milk and dairy products and risk assessment appear not to pose a public health risk to Tabriz consumers.

Domino Reaction for the Synthesis of Substituted Pyrano[3',4':3,4]cyclopenta[1,2-c]chromenes Involving Double Ring Formation

Herein, we present a green cascade approach for synthesizing a range of chemoselective polysubstituted pyrano[3',4':3,4]cyclopenta[1,2-c]chromenes containing a chiral stereocenter. The strategy involves a metal-free nucleophilic reaction between dialkyl (2E)-2-{2-oxo-3-[(2E)-3-aryl-2-propenoyl]-2H-chromen-4-yl}-2-butenedioates and α,α-dicyanoolefins under reflux conditions in ethanol solvent. Mechanistic studies have shown that the reaction proceeds via a cascade of steps, including Michael addition, intramolecular C- and O-cyclization, intramolecular trans-esterification, [1,2]-H and [1,5]-methoxy- and ethoxy carbonyl shift, and finally aromatization to yield the desired product. In this method, three bonds (2C-C and C-O) form in one pot, simultaneously forming two new cyclopentane and pyrano rings by double cyclization reactions. Other advantages of this method are that it has a simple operation, readily available starting materials, a chemoselective cascade process, transition metal-free, synthetically useful yields, and green conditions by using ethanol as a solvent.

Vitamin U alleviates AFB1-induced hepatotoxicity in pregnant and lactating mice by regulating the Nrf2/Hmox1 pathway

This study investigated the protective effect of Vitamin U on liver injury induced by aflatoxin B1 (AFB1) in maternal mice. 25 pregnant ICR mice were randomly divided into five groups: the AFB1 group (AF, 0.3 mg AFB1/kg b.w.), the Vitamin U group (U, 50 mg Vitamin U/kg b.w.), the AFB1 + Vitamin U group (AU, 50 mg Vitamin U /kg b.w. + 0.3 mg AFB1/kg b.w.), the control group (DMSO), and the MOCK group (distilled water). They were administered substances by gavage every day for 28 days. Results indicated that exposure to AFB1 increased the liver index and caused histological disruptions. Elevated serum levels of ALT and ALP were observed, along with a significant increase in liver MDA content and a decrease in GSH-Px and T-SOD levels. Moreover, the Keap1 and Hmox1 gene was downregulated with statistical significance, while the IL1β and TNFα gene were significantly upregulated. Vitamin U was demonstrated by the organized structure of liver cells in tissue slices, effectively reducing liver cell necrosis. This intervention was associated with a significant decrease in serum ALT and ALP activities, as well as a significant decrease in liver MDA content. Additionally, there were significant increases in liver T-SOD and GSH-Px levels, along with upregulation of mRNA and protein expression of Nfr2, Hmox1 and Keap1, and downregulation of mRNA expression of the IL1β gene. In summary, Vitamin U mitigated oxidative stress-induced liver injury by modulating the Nrf2/Hmox1 signaling pathway and inflammatory factors affected by AFB1.

Mycotoxins in Food: Cancer Risks and Strategies for Control

Mycotoxins are toxic compounds produced by fungi such as Aspergillus, Penicillium, and Fusarium, contaminating various food crops and posing severe risks to food safety and human health. This review discusses mycotoxins' origins, significance, and impact, particularly in relation to cancer risk. Major mycotoxins like aflatoxins, ochratoxins, fumonisins, zearalenone, and patulin are examined, along with their sources and affected foods. The carcinogenic mechanisms of these toxins, including their biochemical and molecular interactions, are explored, as well as epidemiological evidence linking mycotoxin exposure to cancer in high-risk populations. The review also highlights critical methodologies for mycotoxin detection, including HPLC, GC-MS, MS, and ELISA, and the sample preparation techniques critical for accurate analysis. Strategies for controlling mycotoxin contamination, both pre- and post-harvest, are discussed, along with regulations from organizations like the FAO and WHO. Current challenges in detection sensitivity, cost, and control effectiveness are noted. Future research is needed to develop innovative analytical techniques, improve control strategies, and address the influence of climate change on mycotoxin production. Finally, global collaboration and emerging technologies are essential for advancing mycotoxin control and enhancing food safety.

Physicochemical characteristics, mycoflora and aflatoxins in corn grown and stored in Northern Tamaulipas, Mexico

In northern Tamaulipas, México, the contamination of corn by toxigenic fungi reduces grain production and quality. Corn contaminated by mycotoxins puts humans and livestock at risk. Continuous monitoring of the sanitary quality of grain at harvest and in storage will define preventive and corrective strategies for contamination by mycotoxigenic fungi. In this work, we identified toxigenic fungi associated with corn grown and stored in northern Tamaulipas, identified and quantified aflatoxins and their relationships with the physicochemical characteristics of the grain, and identified the main genes responsible for aflatoxin production in A. flavus. Fungal incidence was evaluated in vitro, aflatoxin production was evaluated via HPLC, and physicochemical traits were evaluated via spectrophotometry. Three genera were identified: Fusarium, Aspergillus, and Penicillium; the latter had the highest incidence in both 2011 and 2012. The incidence was higher in 2012 (82.3%) than in 2011 (4.5%), and storage did not affect the incidence. Associations among fungal incidences and physicochemical traits were significant and intermediate in both years. AFB1 production was negatively associated with hectoliter weight, and total fungal incidence was positively related to the incidence of Penicillium, Fusarium, and Aspergillus and negatively related to the flotation index. AFB1 was detected in 13.18% of the samples, with values ranging from 3.4881.33 ppb upon receipt and from 4.3245.92 ppb after storage. Two samples exceeded the allowed limits for Mexico (20 ppb). The aflD and aflQ genes were detected in 52.1 and 56.3%, respectively, of the A. flavus isolates.

Removal of aflatoxin M1 in milk using magnetic laccase/MoS2/chitosan nanocomposite as an efficient sorbent

The current study tries to find the impact of the integration of laccase enzyme (Lac) onto magnetized chitosan (Cs) nanoparticles composed of molybdenum disulfide (MoS2 NPs) (Fe3O4/Cs/MoS2/Lac NPs) on the removal of AFM1 in milk samples. The Fe3O4/Cs/MoS2/Lac NPs were characterized by FT-IR, XRD, BET, TEM, FESEM, EDS, PSA, and VSM analysis. The cytotoxic activity of the synthesized nanoparticles in different concentrations was evaluated using the MTT method. The results show that the synthesized nanoparticles don't have cytotoxic activity at concentrations less than 20 mg/l. The ability of the prepared nanoparticles to remove AFM1 was compared by bare laccase enzyme, MoS2, and Fe3O4/Cs/MoS2 composite, indicating that the Fe3O4/Cs/MoS2/Lac NPs the highest adsorption efficiency toward AFM1. Besides, the immobilization efficiency of laccase with a concentration range of 0.5-2.0 was investigated, indicating that the highest activity recovery of 96.8% was obtained using 2 mg/ml laccase loading capacity. The highest removal percentage of AFM1 (68.5%) in the milk samples was obtained by the Fe3O4/Cs/MoS2/Lac NPs at a contact time of 1 h. As a result, Fe3O4/MoS2/Cs/Lac NPs can potentially be utilized as an effective sorbent with high capacity and selectivity to remove AFM1 from milk samples.

Antioxidative and Antimycotoxigenic Efficacies of Thunbergia laurifolia Lindl. for Addressing Aflatoxicosis in Cherry Valley Ducks

This study aimed to assess the effectiveness of aflatoxin B1 (AFB1) and Thunbergia laurifolia extract (TLE) in the diets of Cherry Valley ducklings. Our investigation covered growth indicators, blood biochemical indices, meat quality, intestinal morphology, immune response, and CP450 enzyme-related gene expression. We conducted the study with 180 seven-day-old Cherry Valley ducks, randomly divided into five dietary treatments. These treatments included a basal diet without AFB1 (T1 group), TLE, or a commercial binder; the basal diet containing 0.1 mg AFB1/kg (T2 group), 0.1 mg AFB1/kg and 100 mg TLE/kg (T3 group), 0.1 mg AFB1/kg and 200 mg TLE/kg (T4 group), and 0.1 mg AFB1/kg and 0.5 g/kg of a commercial binder (T5 group), respectively. Ducklings fed with the T2 diet exhibited lower final body weight (BW), average body weight gain (ADG), and poor feed conversion ratio (FCR) during the 42-day trials. However, all ducklings in the T3, T4, and T5 groups showed significant improvements in final BW, ADG, and FCR compared to the T2 group. Increased alanine transaminase (ALT) concentration and increased expression of CYP1A1 and CYP1A2 indicated hepatotoxicity in ducklings fed the T2 diet. In contrast, ducklings fed T3, T4, and T5 diets all showed a decrease in the expression of CYP1A1 and CYP1A2, but only the T4 treatment group showed improvement in ALT concentration. AFB1 toxicity considerably raised the crypt depth (CD) in both the duodenum and jejunum of the T2 group, while the administration of 200 mg TLE/kg (T4) or a commercial binder (T5) effectively reduced this toxicity. Additionally, the villus width of the jejunum in the T2 treatment group decreased significantly, while all T3, T4, and T5 groups showed improvement in this regard. In summary, T. laurifolia extract can detoxify aflatoxicosis, leading to growth reduction and hepatic toxicosis in Cherry Valley ducklings.

Nanobody and CuS Nanoflower-Au-Based Lateral Flow Immunoassay Strip to Enhance the Detection of Aflatoxin B1

In the realm of analysis, the lateral flow immunoassay (LFIA) is frequently utilized due to its capability to be fast and immediate. However, the biggest challenge of the LFIA is its low detection sensitivity and tolerance to matrix interference, making it impossible to enable accurate, qualitative analyses. In this study, we developed a new LFIA with higher affinity and sensitivity, based on a nanobody (G8-DIG) and CuS nanoflowers-Au (CuS NFs-Au), for the detection of aflatoxin B1 (AFB1) in maize. We synthesized the immunoprobe G8-DIG@CuS NFs-Au, stimulated the in situ development of Au nanoparticles (Au NPs) on Cu NFs by electrical displacement, and obtained Cu NFs-Au for fixing the G8-DIG. G8-DIG@CuS NFs-Au probe-based LFIAs may, in ideal circumstances, use a strip chromatography reader to accomplish sensitive quantitative detection and qualitative visualization. AFB1 has a detection range of 2.82-89.56 µg/L and a detection limit of 0.87 µg/L. When compared with an LFIA based on CuS NFs, this sensitivity is increased by 2.76 times. The practical application of this method in corn flour demonstrated a recovery rate of 81.7% to 117%. Therefore, CuS NFs-Au show great potential for detecting analytes.

The Potential of Multi-Screening Methods and Omics Technologies to Detect Both Regulated and Emerging Mycotoxins in Different Matrices

Mycotoxins are well-known secondary metabolites produced by several fungi that grow and occur in different crops during both pre-harvest and post-harvest conditions. The contamination and occurrence of mycotoxins currently represent some of the major issues in the entire agri-food system. The quantification of mycotoxins in different feeds and foodstuffs is extremely difficult because of the low concentration ranges; therefore, both sample collection and preparation are essential to providing accurate detection and reliable quantification. Currently, several analytical methods are available for the detection of mycotoxins in both feed and food products, and liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) represents the most reliable instrumental approach. In particular, the fast development of high-throughput methods has made it possible to screen and analyze, in the same analytical run and with high accuracy, multiple mycotoxins, such as those regulated, masked, or modified, and emerging ones. Therefore, the aim of this review is to provide an overview of the state of the art of mycotoxins occurrence, health-related concerns, and analyses, discussing the need to perform multi-screening approaches combined with omics technologies to simultaneously analyze several mycotoxins in different feed and food matrices. This approach is expected to provide more comprehensive information about the profile and distribution of emerging mycotoxins, thus enhancing the understanding of their co-occurrence and impact on the entire production chain.

Toxicodynamic of combined mycotoxins: MicroRNAs and acute-phase proteins as diagnostic biomarkers

Mycotoxins, ubiquitous contaminants in food, present a global threat to human health and well-being. Mitigation efforts, such as the implementation of sound agricultural practices, thorough food processing, and the advancement of mycotoxin control technologies, have been instrumental in reducing mycotoxin exposure and associated toxicity. To comprehensively assess mycotoxins and their toxicodynamic implications, the deployment of effective and predictive strategies is imperative. Understanding the manner of action, transformation, and cumulative toxic effects of mycotoxins, moreover, their interactions with food matrices can be gleaned through gene expression and transcriptome analyses at cellular and molecular levels. MicroRNAs (miRNAs) govern the expression of target genes and enzymes that play pivotal roles in physiological, pathological, and toxicological responses, whereas acute phase proteins (APPs) exert regulatory control over the metabolism of therapeutic agents, both endogenously and posttranscriptionally. Consequently, this review aims to consolidate current knowledge concerning the regulatory role of miRNAs in the initiation of toxicological pathways by mycotoxins and explores the potential of APPs as biomarkers following mycotoxin exposure. The findings of this research highlight the potential utility of miRNAs and APPs as indicators for the detection and management of mycotoxins in food through biological processes. These markers offer promising avenues for enhancing the safety and quality of food products.

Dietary supplementation of Capsicum powder affects the growth, immunoglobulins, pro-inflammatory cytokines, adipokines, meat, and liver histology of aflatoxin B1 exposed broiler chickens

The effects of dietary supplementation with Capsicum annuum fruit pericarp powder (CPP) and Capsicum annuum fruit seed powder (CSP) on the health and performance of broiler chickens exposed to aflatoxin B1 (AFB1) was investigated. Four dietary groups were established: CON (control), AFT (0.5 mg/kg AFB1), CPAF (0.5 g/kg CPP and 0.5 mg/kg AFB1), and CSAF (0.5 g/kg CSP and 0.5 mg/kg AFB1). The AFT group shows a significant (P < 0.05) reduction in the relative growth rate compared to CON, CPAF, and CSAF. In contrast, the latter two groups exhibit growth rates similar (P > 0.05) to CON. Additionally, immunoglobulin levels (IgG, IgM, and IgA) in the AFT group are significantly (P < 0.05) lower compared to the other treatment groups. Serum interleukin-6 levels in the CPAF and CSAF groups were similar (P > 0.05) to CON but higher (P < 0.05) than in AFT. Tumor necrosis factor-alpha levels were elevated (P < 0.05) in AFT compared to the other treatment groups. Interferon-gamma concentrations in AFT were significantly (P < 0.05) lower than in the other treatment groups. The liver histology reveals that the AFT treatment group has periportal hepatic inflammation. In contrast, the CPAF and CSAF treatment groups exhibit normal hepatic microanatomy. In conclusion, 0.5 g/kg CPAF dietary supplementation may help to ameliorate the adverse effects of AFB1 exposure on broiler chicken health, specifically the growth, immune parameters and liver histology.

How Does Radiation Affect Curcumin Raw Material?

Turmeric, known for its curcuminoid-rich rhizome, particularly curcumin, exhibits notable antioxidant and antiviral properties. The likelihood of microbial contamination necessitates finding reliable techniques for subjecting the sample to radiation from this plant-based raw material. One alternative is to expose curcumin to radiation (e-beam), which was carried out as part of this research. Confirmation of the lack of curcumin decomposition was carried out using HPLC-DAD/MS techniques. Additionally, using the EPR technique, the generated free radicals were defined as radiation effects. Using a number of methods to assess the ability to scavenge free radicals (DPPH, ABTS, CUPRAC, and FRAP), a slight decrease in the activity of curcumin raw material was determined. The analysis of the characteristic bands in the FT-IR spectra allowed us to indicate changes in the phenolic OH groups as an effect of the presence of radicals formed.

In-silico and in-vitro evaluation of antifungal bioactive compounds from Streptomyces sp. strain 130 against Aspergillus flavus

Streptomyces spp. are considered excellent reservoirs of natural bioactive compounds. The study evaluated the bioactive potential of secondary metabolites from Streptomyces sp. strain 130 through PKS-I and NRPS gene-clusters screening. GC-MS analysis was done for metabolic profiling of bioactive compounds from strain 130 in the next set of experiments. Identified antifungal compounds underwent ADMET analyses to screen their toxicity. All compounds' molecular docking was done with the structural gene products of the aflatoxin biosynthetic pathway of Aspergillus flavus. MD simulations were utilized to evaluate the stability of protein-ligand complexes under physiological conditions. Based on the in-silico studies, compound 2,4-di-tert butyl-phenol (DTBP) was selected for in-vitro studies against Aspergillus flavus. Simultaneously, bioactive compounds were extracted from strain 130 in two different solvents (ethyl-acetate and methanol) and used for similar assays. The MIC value of DTBP was found to be 314 µg/mL, whereas in ethyl-acetate extract and methanol-extract, it was 250 and 350 µg/mL, respectively. A mycelium growth assay was done to analyze the effect of compounds/extracts on the mycelium formation of Aspergillus flavus. In agar diffusion assay, zone of inhibitions in DTBP, ethyl-acetate extract, and methanol extract were observed with diameters of 11.3, 13.3, and 7.6 mm, respectively. In the growth curve assay, treated samples have delayed the growth of fungi, which signified that the compounds have a fungistatic nature. Spot assay has determined the fungal sensitivity to a sub-minimum inhibitory concentration of antifungal compounds. The study's results suggested that DTBP can be exploited for antifungal-drug development.Communicated by Ramaswamy H. Sarma.

Removal of aflatoxin B1 from contaminated milk and water by nitrogen/carbon-enriched cobalt ferrite -chitosan nanosphere: RSM optimization, kinetic, and thermodynamic perspectives

In view of the feed/foods inevitably contaminated by toxic and carcinogenic aflatoxin B1 (AFB1), efficient mesoporous metformin-chitosan/silica‑cobalt ferrite nanospheres (Mt-CS/CFS NSs) was prepared to remove AFB1 from aqueous/non-aqueous media. The morphological, functional, and structural characteristics and adsorption properties of C/N-enriched CS/CFS were investigated systematically. The interactive operating variables (temperature (5.0-35 °C); time (10-100 min); AFB1 dose (50-100 μg/mL); and Mt-CS/CFS dosage (0.5-3.5 mg) were optimized via the Box-Behnken design (BBD), which demonstrated good agreement between the experimental data and proposed model. The adsorption efficiency in artificially contaminated cow's milk as well as aqueous environment reached over 91.0 % in a wide pH range (3.0-9.0), without significant change in the nutritional value of milk. Freundlich isotherm and second-order adsorption kinetics were regarded as the most suitable models to fit the adsorption results, and the adsorption rate is dominated by the intra-particle diffusion and boundary layer diffusion. Thermodynamic analyses proved that the process was spontaneous and exothermic. The adsorption mechanism could be explained as physisorption via hydrogen bonding, n-π interaction, and hydrophobic/hydrophilic interactions. The porous Mt-CS/CFS NS derived from chitosan nanoparticles is therefore outstanding adsorbent, offering great adsorptive performance and recycabilities, which impedes economic losses in the food industry.

A New Benzaldehyde Derivative Exhibits Antiaflatoxigenic Activity against Aspergillus flavus

Aflatoxin B1 (AFB1) is the most potent naturally occurring carcinogen for humans and animals produced by the common fungus Aspergillus flavus (A. flavus). Aflatoxin (AF) contamination in commodities is a global concern related to the safety of food and feed, and it also impacts the agricultural economy. In this study, we investigated the AFB1-inhibiting activity of a new benzaldehyde derivative, 2-[(2-methylpyridin-3-yl)oxy]benzaldehyde (MPOBA), on A. flavus. It was found that MPOBA inhibited the production of AFB1 by A. flavus, with an IC50 value of 0.55 mM. Moreover, the inhibition of conidiation was also observed at the same concentration. The addition of MPOBA resulted in decreased transcript levels of the aflR gene, which encodes a key regulatory protein for the biosynthesis of AF, and also decreased transcript levels of the global regulator genes veA and laeA. These results suggested that MPOBA has an effect on the regulatory mechanism of the development and differentiation of conidia, leading to the inhibition of AFB1 production. In addition, the cytotoxicity study showed that MPOBA had a very low cytotoxic effect on the Madin-Darby canine kidney (MDCK) cell line. Therefore, MPOBA may be a potential compound for developing practically effective agents to control AF contamination.