Occurrence and toxicity of a fusarium mycotoxin, zearalenone

Zearalenone disturbs the reproductive-immune axis in pigs: the role of gut microbial metabolites

BACKGROUND

Exposure to zearalenone (ZEN, a widespread Fusarium mycotoxin) causes reproductive toxicity and immunotoxicity in farm animals, and it then poses potential threats to human health through the food chain. A systematic understanding of underlying mechanisms on mycotoxin-induced toxicity is necessary for overcoming potential threats to farm animals and humans. The gastrointestinal tract is a first-line defense against harmful mycotoxins; however, it remains unknown whether mycotoxin (e.g., ZEN)-induced toxicity on the reproductive-immune axis is linked to altered gut microbial metabolites. In this study, using pigs (during the three phases) as an important large animal model, we investigated whether ZEN-induced toxicity on immune defense in the reproductive-immune axis was involved in altered gut microbial-derived metabolites. Moreover, we observed whether the regulation of gut microbial-derived metabolites through engineering ZEN-degrading enzymes counteracted ZEN-induced toxicity on the gut-reproductive-immune axis.

RESULTS

Here, we showed ZEN exposure impaired immune defense in the reproductive-immune axis of pigs during phase 1/2. This impairment was accompanied by altered gut microbial-derived metabolites [e.g., decreased butyrate production, and increased lipopolysaccharides (LPS) production]. Reduction of butyrate production impaired the intestinal barrier via a GPR109A-dependent manner, and together with increased LPS in plasma then aggravated the systemic inflammation, thus directly and/or indirectly disturbing immune defense in the reproductive-immune axis. To validate these findings, we further generated recombinant Bacillus subtilis 168-expressing ZEN-degrading enzyme ZLHY-6 (the Bs-Z6 strain) as a tool to test the feasibility of enzymatic removal of ZEN from mycotoxin-contaminated food. Notably, modified gut microbial metabolites (e.g., butyrate, LPS) through the recombinant Bs-Z6 strain counteracted ZEN-induced toxicity on the intestinal barrier, thus enhancing immune defense in the reproductive-immune axis of pigs during phase-3. Also, butyrate supplementation restored ZEN-induced abnormalities in the porcine small intestinal epithelial cell.

CONCLUSIONS

Altogether, these results highlight the role of gut microbial-derived metabolites in ZEN-induced toxicity on the gut-reproductive-immune axis. Importantly, targeting these gut microbial-derived metabolites opens a new window for novel preventative strategies or therapeutic interventions for mycotoxicosis associated to ZEN.

Maternal Zearalenone Exposure Affects Gut Microbiota and Follicular Development in Suckled Offspring

Zearalenone (ZEN) is a mycotoxin that is widely present in feed and agricultural products. Studies have demonstrated that ZEN, as a type of estrogen analogue, can significantly affect the female reproductive system. Breast milk is the best nutrient for infant growth and development, but it is still unknown whether ZEN influences the fertility of offspring through suckling. In this study, we collected fecal and ovarian tissue from neonatal female offspring, whose mothers were exposed to ZEN for 21 days, and explored the effects of maternal ZEN exposure on intestinal microecology and follicular development in the mouse using 16S rRNA amplicon sequencing technology. Our findings suggested that maternal ZEN exposure significantly diminished ovarian reserve, increased apoptosis of ovarian granulosa cell (GC), and impacted the developmental competence of oocytes in lactating offspring. In addition, the results of 16S rRNA sequencing showed that the abundance of gut microbiota in offspring was significantly changed, including Bacteroidetes, Proteobacteria, and Firmicutes. This leads to alterations of glutathione metabolism and the expression of antioxidant enzymes in ovaries. In summary, our findings supported a potential relationship between gut microbiota and abnormal ovarian development caused by ZEN, which offers novel insights for therapeutic strategies for reproductive disorders induced by ZEN exposure.

Characterization of zearalenone-induced hepatotoxicity and its mechanisms by transcriptomics in zebrafish model

Zearalenone is a mycotoxin produced by several species of Fusarium fungi, which contaminates crop and cereal products worldwide. It is widely distributed and can be transported from agricultural fields to the aquatic environment via soil run-off. Zearalenone exposure can cause serious health problems to humans and animals, including estrogenic, immunotoxic, and xenogenic effects. Though its hepatotoxicity has been reported by few studies, the underlying mechanisms are yet to be investigated. This study aimed to comprehensively evaluate the hepatotoxic effects of zearalenone and its molecular mechanism in the zebrafish model system. First, we found zearalenone exposure can cause liver injury, as evidenced by reduced liver size, decreased liver-specific fluorescence, increased aspartate aminotransferase (AST) activity, delayed yolk sac absorption and lipid accumulation. Then, RNA sequencing (RNA-seq) was performed using dissected zebrafish fry liver, which found genes involved in oxidation and reduction were significantly enriched. Quantitative real-time PCR further confirmed the dysregulated expression of several antioxidant enzymes. Additionally, lipid peroxidation was proved by increased malondialdehyde (MDA) production and gene expression at the mRNA level. In contrast to the previous study, apoptosis was likely decreased in response to zearalenone exposure. Last, glucuronidation and amino acid metabolism were also disrupted by zearalenone. Our results revealed the complex mechanism of zearalenone-induced hepatotoxicity, which is a valuable contribution to a more comprehensive understanding of the toxicity of zearalenone.

Evaluation of Zearalenones and Their Metabolites in Chicken, Pig and Lamb Liver Samples

Zearalenone (ZON), zearalanone (ZAN) and their phase I metabolites: α-zearalenol (α-ZOL), β-zearalenol (β-ZOL), α-zearalalanol (α-ZAL) and β-zearalalanol (β-ZAL) are compounds with estrogenic activity that are metabolized and distributed by the circulatory system in animals and can access the food chain through meat products from livestock. Furthermore, biomonitoring of zearalenones in biological matrices can provide useful information to directly assess mycotoxin exposure; therefore, their metabolites may be suitable biomarkers. The aim of this study was to determine the presence of ZON, ZAN and their metabolites in alternative biological matrices, such as liver, from three different animals: chicken, pig and lamb, in order to evaluate their exposure. A solid-liquid extraction procedure coupled to a GC-MS/MS analysis was performed. The results showed that 69% of the samples were contaminated with at least one mycotoxin or metabolite at varying levels. The highest value (max. 152.62 ng/g of β-ZOL) observed, and the most contaminated livers (42%), were the chicken liver samples. However, pig liver samples presented a high incidence of ZAN (33%) and lamb liver samples presented a high incidence of α-ZOL (40%). The values indicate that there is exposure to these mycotoxins and, although the values are low (ranged to 0.11-152.6 ng/g for α-ZOL and β-ZOL, respectively), analysis and continuous monitoring are necessary to avoid exceeding the regulatory limits and to control the presence of these mycotoxins in order to protect animal and human health.

Determination of Zearalenone and Its Derivatives in Feed by Gas Chromatography-Mass Spectrometry with Immunoaffinity Column Cleanup and Isotope Dilution

In this study, a gas chromatography-mass spectrometry (GC-MS) method was established for the determination of zearalenone and its five derivatives in feed, including zearalanone, α-zearalanol, β-zearalanol, α-zearalenol, and β-zearalenol. An effective immunoaffinity column was prepared for sample purification, which was followed by the silane derivatization of the eluate after an immunoaffinity chromatography analysis for target compounds by GC-MS. Matrix effects were corrected by an isotope internal standard of zearalenone in this method. The six analytes had a good linear relationship in the range of 2-500 ng/mL, and the correlation coefficients were all greater than 0.99. The limits of detection (LODs) and limits of quantification (LOQs) were less than 1.5 μg/kg and 5.0 μg/kg, respectively. The average spike recoveries for the six feed matrices ranged from 89.6% to 112.3% with relative standard deviations (RSDs) less than 12.6%. Twenty actual feed samples were analyzed using the established method, and at least one target was detected. The established GC-MS method was proven to be reliable and suitable for the determination of zearalenone and its derivatives in feed.

Zearalenone Induces Apoptosis in Porcine Endometrial Stromal Cells through JNK Signaling Pathway Based on Endoplasmic Reticulum Stress

Zearalenone (ZEA) is an estrogen-like mycotoxin characterized mainly by reproductive toxicity, to which pigs are particularly sensitive. The aim of this study was to investigate the molecular mechanism of ZEA-induced apoptosis in porcine endometrial stromal cells (ESCs) by activating the JNK signaling pathway through endoplasmic reticulum stress (ERS). In this study, ESCs were exposed to ZEA, with the ERS inhibitor sodium 4-Phenylbutyrate (4-PBA) as a reference. The results showed that ZEA could damage cell structures, induce endoplasmic reticulum swelling and fragmentation, and decreased the ratio of live cells to dead cells significantly. In addition, ZEA could increase reactive oxygen species and Ca²⁺ levels; upregulate the expression of GRP78, CHOP, PERK, ASK1 and JNK; activate JNK phosphorylation and its high expression in the nucleus; upregulate the expression Caspase 3 and Caspase 9; and increase the Bax/Bcl-2 ratio, resulting in increased apoptosis. After 3 h of 4-PBA-pretreatment, ZEA was added for mixed culture, which showed that the inhibition of ERS could reduce the cytotoxicity of ZEA toward ESCs. Compared with the ZEA group, ERS inhibition increased cell viability; downregulated the expression of GRP78, CHOP, PERK, ASK1 and JNK; and decreased the nuclear level of p-JNK. The Bax/Bcl-2 ratio and the expression of Caspase 3 and Caspase 9 were downregulated, significantly alleviating apoptosis. These results demonstrate that ZEA can alter the morphology of ESCs, destroy their ultrastructure, and activate the JNK signaling via the ERS pathway, leading to apoptosis.

Further insight into the potential toxicity of zearalenone-14-glucoside based on toxicokinetics, tissue distribution, transformation, and excretion in rats

Bioaccumulation and biotransformation are critical factors that affect the release of easily metabolizable chemicals to cause human toxicity. The glucoside-type modified mycotoxin Zearalenone-14-Glucoside (Z14G) has attracted global attention for its high occurrence in foodstuffs and the potential threat to humans as its high rate of transformation into parent forms. Given the limited toxicokinetics information, this study assessed the absorption, distribution, biotransformation and excretion of Z14G, aiming to define the potential risk of Z14G. The toxicokinetics of Z14G were assessed after intravenous (IV) or oral administration (PO) in SD rats at doses of 10 mg/kg·b.w. In addition, comparative work with the parent mycotoxin ZEN was performed in parallel. The determination of Z14G and its metabolites (ZEN, α-zearalenol, β-zearalenol, α-zearalanol, β-zearalanol) proceeded with a sensitive UHPLC-MS/MS method. Our research indicated that Z14G readily disappeared from the blood, and distributed throughout the tissues via transformation into its parent form ZEN, and excreted primarily through urine. More importantly, the metabolite α-ZEL was observed in most analyzed tissue, urine and feces samples. Overall, our findings highlight the importance of biotransformation with regard to Z14G, providing critical insight for the health risk assessment of co-exposure of humans to glucoside-type modified mycotoxins.

Role of PI3K/Akt-Mediated Nrf2/HO-1 Signaling Pathway in Resveratrol Alleviation of Zearalenone-Induced Oxidative Stress and Apoptosis in TM4 Cells

Zearalenone (ZEA) is a common mycotoxin that induces oxidative stress (OS) and affects the male reproductive system in animals. Resveratrol (RSV) has good antioxidant activity and can activate nuclear factor erythroid 2-related factor (Nrf2) to protect cells through the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. The objective of this study was to investigate the protective effect and the mechanism of RSV on OS and apoptosis in TM4 cells induced by ZEA. Prior to being exposed to ZEA, TM4 cells were pretreated with RSV or the PI3K/Akt inhibitor LY294002. Cell viability was measured by Cell Counting Kit-8 (CCK-8) assays. Flow cytometry was used to determine the level of apoptosis and intracellular reactive oxygen species (ROS). The expression of poly ADP-ribose polymerase (PARP), caspase-3, BCL2-associated X (Bax)/B-cell lymphoma-2 (Bcl-2), and PI3K/Akt-mediated Nrf2/heme oxygenase 1 (HO-1) signaling pathway-related proteins was evaluated by Western blotting. Nrf2 siRNA transfection and LY294002 treatment were used to investigate the role of the Nrf2/HO-1 and PI3K/Akt signaling pathways in RSV alleviation of ZEA-induced OS. The results showed that pretreatment with RSV significantly reduced the expression of apoptosis-related proteins and increased cell viability. Catalase (CAT) activity and glutathione (GSH) levels were also increased, whereas malondialdehyde (MDA) and ROS levels decreased (p < 0.05). RSV also upregulated Akt phosphorylation, Nrf2 nuclear translocation, and HO-1 expression under conditions of OS (p < 0.05). Transfection with Nrf2 siRNA abolished the protective effects of RSV against ZEA-induced cytotoxicity (p < 0.05), ROS accumulation (p < 0.05), and apoptosis (p < 0.05). LY294002 completely blocked the RSV-mediated increase in Nrf2 nuclear translocation (p < 0.05), HO-1 expression (p < 0.05), and cytoprotective activity (p < 0.05). Collectively, the above findings indicate that RSV can protect against ZEA-induced OS and apoptosis in TM4 cells by PI3K/Akt-mediated activation of the Nrf2/HO-1 signaling pathway.

Quantitative Proteomic Analysis of Zearalenone Exposure on Uterine Development in Weaned Gilts

The aim of this study was to explore the effect of zearalenone (ZEA) exposure on uterine development in weaned gilts by quantitative proteome analysis with tandem mass spectrometry tags (TMT). A total of 16 healthy weaned gilts were randomly divided into control (basal diet) and ZEA3.0 treatments groups (basal diet supplemented with 3.0 mg/kg ZEA). Results showed that vulva size and uterine development index were increased (p < 0.05), whereas serum follicle stimulation hormone, luteinizing hormone and gonadotropin-releasing hormone were decreased in gilts fed the ZEA diet (p < 0.05). ZEA, α-zearalenol (α-ZOL) and β-zearalenol (β-ZOL) were detected in the uteri of gilts fed a 3.0 mg/kg ZEA diet (p < 0.05). The relative protein expression levels of creatine kinase M-type (CKM), atriopeptidase (MME) and myeloperoxidase (MPO) were up-regulated (p < 0.05), whereas aldehyde dehydrogenase 1 family member (ALDH1A2), secretogranin-1 (CHGB) and SURP and G-patch domain containing 1 (SUGP1) were down-regulated (p < 0.05) in the ZEA3.0 group by western blot, which indicated that the proteomics data were dependable. In addition, the functions of differentially expressed proteins (DEPs) mainly involved the cellular process, biological regulation and metabolic process in the biological process category. Some important signaling pathways were changed in the ZEA3.0 group, such as extracellular matrix (ECM)-receptor interaction, focal adhesion and the phosphoinositide 3-kinase−protein kinase B (PI3K-AKT) signaling pathway (p < 0.01). This study sheds new light on the molecular mechanism of ZEA in the uterine development of gilts.

Selenium-chitosan alleviates the toxic effects of Zearalenone on antioxidant and immune function in mice

This study assessed the protective effects of selenium-chitosan (SC) against antioxidant and immune function-related damage induced by zearalenone (ZEN) in mice. In total, 150 female mice were allotted to five groups for a 30-day study. Control mice were fed a basal diet. Mice in the ZEN, ZEN-Se1, ZEN-Se2 and ZEN-Se3 groups were fed the basal diet supplemented with same dose of ZEN (2 mg/kg) and different doses of SC, 0.0, 0.2, 0.4 and 0.6 mg/kg, respectively (calculated by selenium). After 30 days, the total antioxidant capacity (T-AOC) level, glutathione peroxidase (GSH-Px) activity, total superoxide dismutase (T-SOD) activity and malondialdehyde (MDA) content in plasma and liver, as well as Con A-induced splenocyte proliferation, plasma interleukins concentrations and liver interleukin mRNA expression levels were determined. The plasma and liver GSH-Px activities, liver T-AOC levels, Con A-induced splenocyte proliferation, interleukin (IL) contents and mRNA expression levels in the ZEN group were significantly lower than in the control group (P < 0.01 or P < 0.05), whereas plasma and liver MDA contents in the ZEN group were significantly higher than in the control group (P < 0.01 or P < 0.05). Additionally, plasma and liver GSH-Px activities, liver T-AOC levels, Con A-induced splenocyte proliferation, IL-1β, IL-17A, IL-2 and IL-6 contents and mRNA expression levels in ZEN+Se2 and ZEN+Se3 groups were significantly higher than in the ZEN group (P < 0.01 or P < 0.05), whereas plasma and liver MDA contents in the ZEN+Se2 and ZEN+Se3 groups were significantly lower than in the ZEN group (P < 0.01 or P < 0.05). The plasma and liver GSH-Px activities, Con A-induced splenocyte proliferation, IL-1β and IL-6 contents, IL-2 and IL-17A mRNA expression levels in the ZEN+Se1 group were also significantly higher than in the ZEN group (P < 0.01 or P < 0.05), whereas the plasma MDA content in the ZEN+Se1 group was also significantly lower than in the ZEN group (P < 0.01). Thus, SC may alleviate antioxidant function-related damage and immunosuppression induced by ZEN in mice.

Recent Progress in Aptamer-Functionalized Metal-Organic Frameworks-Based Optical and Electrochemical Sensors for Detection of Mycotoxins

Mycotoxin contamination in foodstuffs and agricultural products has posed a serious hazard to human health and raised international concern. The progress of cost-effective, facile, rapid and reliable analytical tools for mycotoxin determination is in urgent need. In this regard, the potential utility of metal-organic frameworks (MOFs) as a class of crystalline porous materials has sparked immense attention due to their large specific surface area, adjustable pore size, nanoscale framework structure and good chemical stability. The amalgamation of MOFs with high-affinity aptamers has resulted in the progress of advanced aptasensing methods for clinical and food/water safety diagnosis. Aptamers have many advantages over classical approaches as exceptional molecular recognition constituents for versatile bioassays tools. The excellent sensitivity and selectivity of the MOF-aptamer biocomposite nominate them as efficient lab-on-chip tools for portable, label-free, cost-effective and real-time screening of mycotoxins. Current breakthroughs in the concept, progress and biosensing applications of aptamer functionalized MOFs-derived electrochemical and optical sensors for mycotoxins have been discussed in this study. We first highlighted an overview part, which provides some insights into the functionalization mechanisms of MOFs with aptamers, offering a foundation to create MOFs-based aptasensors. Then, we discuss various strategies to design high-performance MOFs-based aptamer scaffolds, which serve as either signal nanoprobe carriers or signal nanoprobes and their applications. We perceived that applications of optical aptamers are in their infancy in comparison with electrochemical MOFs-derived aptasensors. Finally, current challenges and prospective trends of MOFs-aptamer sensors are discussed.

Toxicity of zearalenone and its nutritional intervention by natural products

Zearalenone (ZEN) is a toxic secondary metabolite mainly produced by fungi of the genus Fusarium, and is often present in various food and feed ingredients such as corn and wheat. The structure of ZEN is similar to that of natural estrogen, and it can bind to estrogen receptors and has estrogenic activity. Therefore, it can cause endocrine-disrupting effects and promote the proliferation of estrogen receptor-positive cell lines. In addition, ZEN can cause oxidative damage, endoplasmic reticulum stress, apoptosis, and other hazards, resulting in systemic toxic effects, including reproductive toxicity, hepatotoxicity, and immunotoxicity. In the past few decades, researchers have tried many ways to remove ZEN from food and feed, but it is still a challenge to eliminate it. In recent years, natural compounds have become of interest for their excellent protective effects on human health from food contaminants. Researchers have discovered that natural compounds often used as dietary supplements can effectively alleviate ZEN-induced systemic toxic effects. Most of the compounds mitigate ZEN-induced toxicity through antioxidant effects. In this article, the contamination of food and feed by ZEN and the various toxic effects and mechanisms of ZEN are reviewed, as well as the mitigation effects of natural compounds on ZEN-induced toxicity.

Effects of Zearalenone on Production Performance, Egg Quality, Ovarian Function and Gut Microbiota of Laying Hens

Zearalenone (ZEN) is a ubiquitous contaminant in poultry feed, since ZEN and its metabolites can interfere with estrogen function and affect the reproductive ability of animals. The estrogen-like effect of ZEN on mammal is widely reported, while little information is available, regarding the effect of relatively low dose of ZEN on estrogen function and production performance of laying hens, and the relationship between them. This work was aimed to investigate the effects of ZEN on the production performance, egg quality, ovarian function and gut microbiota of laying hens. A total of 96 Hy-line brown laying hens aged 25-week were randomly divided into 3 groups including basal diet group (BD group), basal diet supplemented with 250 μg/kg (250 μg/kg ZEN group) and 750 μg/kg (750 μg/kg ZEN group) ZEN group. Here, 750 μg/kg ZEN resulted in a significant increase in the feed conversion ratio (FCR) (g feed/g egg) (p < 0.05), a decrease in the egg production (p > 0.05), albumen height and Haugh unit (p > 0.05), compared to the BD group. The serum Follicle-stimulating hormone (FSH) levels significantly decreased in ZEN supplemented groups (p < 0.05). Serum Luteinizing hormone (LH) and Progesterone (P) levels in the 750 μg/kg ZEN group were significantly lower than those in the BD group (p < 0.05). 16S rRNA sequencing indicated that ZEN reduced cecum microbial diversity (p < 0.05) and altered gut microbiota composition. In contrast to 250 μg/kg ZEN, 750 μg/kg ZEN had more dramatic effects on the gut microbiota function. Spearman’s correlation analysis revealed negative correlations between the dominant bacteria of the 750 μg/kg ZEN group and the production performance, egg quality and ovarian function of hens. Overall, ZEN was shown to exert a detrimental effect on production performance, egg quality and ovarian function of laying hens in this study. Moreover, alterations in the composition and function of the gut microbiota induced by ZEN may be involved in the adverse effects of ZEN on laying hens.

Zearalenone and Its Masked Forms in Cereals and Cereal-Derived Products: A Review of the Characteristics, Incidence, and Fate in Food Processing

Zearalenone (ZEA) is known as a Fusarium-produced mycotoxin, representing a risk to cereal food safety with repercussions for economies and worldwide trade. Recent studies have reported the co-occurrence of ZEA and masked ZEA in a variety of cereals and cereal-based products, which may exert adverse effects on public health due to additive/synergistic interactions. However, the co-contamination of ZEA and masked ZEA has received little attention. In order to minimize the threats of co-contamination by ZEA and masked ZEA, it is necessary to recognize the occurrence and formation of ZEA and masked ZEA. This review focuses on the characteristics, incidence, and detection of ZEA and its masked forms. Additionally, the fate of ZEA and masked ZEA during the processing of bread, cake, biscuits, pasta, and beer, as well as the ZEA limit, are discussed. The incidence of masked ZEA is lower than that of ZEA, and the mean level of masked ZEA varies greatly between cereal samples. Published data showed a considerable degree of heterogeneity in the destiny of ZEA during cereal-based food processing, mostly as a result of the varying contamination levels and complicated food processing methods. Knowledge of the fate of ZEA and masked ZEA throughout cereal-based food processing may reduce the likelihood of severe detrimental market and trade ramifications. The revision of legislative limits of masked ZEA may become a challenge in the future.

Zearalenone Induces MLKL-Dependent Necroptosis in Goat Endometrial Stromal Cells via the Calcium Overload/ROS Pathway

Zearalenone (ZEA) is a fungal mycotoxin known to exert strong reproductive toxicity in animals. As a newly identified type of programmed cell death, necroptosis is regulated by receptor-interacting protein kinase 1 (RIPK1), receptor-interacting protein kinase 3 (RIPK3), and mixed-lineage kinase domain-like pseudokinase (MLKL). However, the role and mechanism of necroptosis in ZEA toxicity remain unclear. In this study, we confirmed the involvement of necroptosis in ZEA-induced cell death in goat endometrial stromal cells (gESCs). The release of lactate dehydrogenase (LDH) and the production of PI-positive cells markedly increased. At the same time, the expression of RIPK1 and RIPK3 mRNAs and P-RIPK3 and P-MLKL proteins were significantly upregulated in ZEA-treated gESCs. Importantly, the MLKL inhibitor necrosulfonamide (NSA) dramatically attenuated gESCs necroptosis and powerfully blocked ZEA-induced reactive oxygen species (ROS) generation and mitochondrial dysfunction. The reactive oxygen species (ROS) scavengers and N-acetylcysteine (NAC) inhibited ZEA-induced cell death. In addition, the inhibition of MLKL alleviated the intracellular Ca²⁺ overload caused by ZEA. The calcium chelator BAPTA-AM markedly suppressed ROS production and mitochondrial damage, thus inhibiting ZEA-induced necroptosis. Therefore, our results revealed the mechanism by which ZEA triggers gESCs necroptosis, which may provide a new therapeutic strategy for ZEA poisoning.

Mycotoxins occurrence in milk and cereals in North African countries - a review

North African countries; Algeria, Egypt, Libya, Morocco and Tunisia suffer from mycotoxin contamination. Various studies have indicated the presence of mycotoxins in raw milk and cereals (i.e. wheat, barley, maize and cereal-based products). Aflatoxins (AFs), Aflatoxin M1 (AFM1), Ochratoxin A (OTA), Fumonisin (FB1) and Zearalenone (ZEN)-mycotoxin are the most detected due to climatic change in the region. In this review, we will present the kind of foods and feeds cereals and milk based products contaminated and the level of their contaminated mycotoxin. On the other hand, researchers try to find biologic methods to remove/mitigate mycotoxins in food and feed using bio-products. But the research works concerning legislations and mycotoxin risk assessment still rare. Therefore, it appears necessary to make review on the current status of mycotoxins in North African countries in order to explore data related to contamination of basic food in this region and to highlight the problem to the policy-makers to establish a serious legislation on this matter. On the other hand, to give more information to the worldwide readers about the impact of climate change on the food and feed pollution on mycotoxins in the Mediterranean Sea region.

Study of Competitive Displacement of Curcumin on α-zearalenol Binding to Human Serum Albumin Complex Using Fluorescence Spectroscopy

α-zearalenol (α-ZOL) is a mycotoxin with a strong estrogen effect that affects the synthesis and secretion of sex hormones and is transported to target organs through human serum albumin (HSA). Additionally, it has been reported that curcumin can also bind to HSA with high affinity at the same binding site as α-ZOL. Additionally, several studies reported that reducing the bound fraction of α-ZOL contributes to speeding up the elimination rate of α-ZOL to reduce its hazard to organs. Therefore, to explore the influence of a nutrition intervention with curcumin on α-ZOL effects, the competitive displacement of α-ZOL from HSA by curcumin was investigated using spectroscopic techniques, ultrafiltration techniques and HPLC methods. Results show that curcumin and α-ZOL share the same binding site (subdomain IIA) on HSA, and curcumin binds to HSA with a binding constant of 1.12 × 10⁵ M⁻¹, which is higher than that of α-ZOL (3.98 × 10⁴ M⁻¹). Ultrafiltration studies demonstrated that curcumin could displace α-ZOL from HSA to reduce α-ZOL’s binding fraction. Synchronous fluorescence spectroscopy revealed that curcumin could reduce the hydrophobicity of the microenvironment of an HSA–α-ZOL complex. This study is of great significance for applying curcumin and other highly active foodborne components to interfere with the toxicokinetics of α-ZOL and reduce its risk of its exposure.

Effects of zearalenone on ovarian development of prepubertal gilts through growth hormone axis

This experiment aimed to establish the effects of zearalenone (ZEN) on ovarian development in prepubertal gilts through the growth hormone axis [growth hormone-releasing hormone (GHRH) / growth hormone (GH) / growth hormone receptor (GHR)]. In a 40-day experiment, 48 Landrace × Yorkshire crossbred prepubertal gilts were randomly allocated to four dietary treatments, including a basal diet supplemented with 0 (control), 400 (T1), 800 (T2), and 1,600 (T3) μg/kg ZEN. The ovary index of T2 (P = 0.058) and T3 (P = 0.065) increased compared to the control group. Besides, histopathological examination revealed that ZEN promoted the development of ovaries and follicles. The GHR content, relative expression levels of GHR, janus activated kinase 2 (JAK2) mRNA, and mean optical density of GHR in the ovaries of prepubertal gilts in the T2 experimental group increased significantly at P &lt; 0.05 compared to the control group. The T3 group had significantly higher GHR content, relative JAK2 expression levels, and signal transducer and activator of transcriptions 3 (STAT3) mRNA. In conclusion, ZEN enhances the biological effect of GH, promotes the development of the ovary (follicle), and exerts reproductive toxicity by increasing the expression level of GHR, JAK2, and STAT3 mRNA ovary and immune intensity of GHR protein.

Zearalenone affects the growth of endometriosis via estrogen signaling and inflammatory pathways

Endometriosis is a chronic, inflammatory, estrogen-dependent gynecological disease characterized by the growth of endometrial stromal cells and glands outside the uterine cavity in response to hormones, which commonly occurs in reproductive-age women. Zearalenone (ZEA) is a toxic metabolite produced by Fusarium, which acts as estrogen activity because of the similarity of its structure to estrogen. In this study, we used an endometriosis mouse model: 15 days after ovariectomy, endometrial fragments were sutured on the pelvic wall, and exogenous estrogen was supplied using an estrogen-releasing silicone tube embedded subcutaneously. Mice were treated with different doses of ZEA by gavage for 21 days. The results show that ZEA significantly inhibited the growth of ectopic endometrium in a dose-dependent manner. The proliferation of cells decreased while apoptosis increased in the ectopic tissues of ZEA-treated mice compared to the vehicle group. The expression of estrogen receptor-α and its downstream targets MUC1 and p-AKT decreased, indicating an impaired estrogen signaling activity by ZEA treatment. In addition, the decreased expression of pro-inflammatory cytokine Tnf-α, Il-1β, and Il-6, the lower number of macrophages and neutrophils cells, and the inhibited NF-κB signaling pathway suggest the inflammatory response in the ectopic endometrium was also suppressed by ZEA treatment. However, when the exogenous estrogen supply is removed, ZEA, in turn, plays an estrogen-like role that promotes cell proliferation in the ectopic endometrium. In summary, our data suggest ZEA acts as an antagonist in endometriotic tissue when estrogen is sufficient but turns to estrogenic activity in the absence of estrogen in the development of endometriosis. ZEA also inhibits ectopic tissue growth by inhibiting inflammatory response in the endometriosis model.

Transcriptomic responses of the zearalenone (ZEN)-detoxifying yeast Apiotrichum mycotoxinivorans to ZEN exposure

Zearalenone (ZEN) is a potent oestrogenic mycotoxin that is mainly produced by Fusarium species and is a serious environmental pollutant in animal feeds. Apiotrichum mycotoxinivorans has been widely used as a feed additive to detoxify ZEN. However, the effects of ZEN on A. mycotoxinivorans and its detoxification mechanisms remain unclear. In this study, transcriptomic and bioinformatic analyses were used to investigate the molecular responses of A. mycotoxinivorans to ZEN exposure and the genetic basis of ZEN detoxification. We detected 1424 significantly differentially expressed genes (DEGs), of which 446 were upregulated and 978 were downregulated. Functional and enrichment analyses showed that ZEN-induced genes were significantly associated with xenobiotic metabolism, oxidative stress response, and active transport systems. However, ZEN-inhibited genes were mainly related to cell division, cell cycle, and fungal development. Subsequently, bioinformatic analysis identified candidate ZEN-detoxification enzymes. The Baeyer-Villiger monooxygenases and carboxylesterases, which are responsible for the formation and subsequent hydrolysis of a new ZEN lactone, respectively, were significantly upregulated. In addition, the expression levels of genes related to conjugation and transport involved in the xenobiotic detoxification pathway were significantly upregulated. Moreover, the expression levels of genes encoding enzymatic antioxidants and those related to growth and apoptosis were significantly upregulated and downregulated, respectively, which made it possible for A. mycotoxinivorans to survive in a highly toxic environment and efficiently detoxify ZEN. This is the first systematic report of ZEN tolerance and detoxification in A. mycotoxinivorans. We identified the metabolic enzymes that were potentially involved in detoxifying ZEN in the GMU1709 strain and found that ZEN-induced transcriptional regulation of genes is key to withstanding highly toxic environments. Hence, our results provide valuable information for developing enzymatic detoxification systems or engineering this detoxification pathway in other species.

Costus speciosus extract protects against the oxidative damage of zearalenone via modulation of inflammatory cytokines, Nrf2 and iNOS gene expression in rats

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin that induces severe health disturbances in humans and animals. This study aimed to determine the bioactive compounds in Costus speciosus extract (CSE) using GC-MS and evaluate its protective capability against ZEN-induced oxidative damage, genotoxicity, and cytotoxicity in rats. Six groups of male Sprague Dawley rats were treated orally for 15 days including the control group, CSE-treated groups at low (200 mg/kg b. w) or high (400 mg/kg b. w) dose, ZEN-treated group (40 μg/kg b. w), and the groups treated with ZEN plus the low or the high dose of CSE. Blood and tissue samples were collected for different assays and pathological analyses. The results of GC-MS indicated the identification of 6 compounds and Azulene was the major. Animals that received ZEN showed severe disturbances in serum biochemical, cytokines, oxidative stress indicators, mRNA expression of iNOS, Nrf2, and inflammatory-related genes. ZEN also increased micronucleated polychromatic erythrocytes (MNPCEs) and comet tail formation in bone marrow cells along with the disturbances in the histological architecture of the liver and kidney. Co-administration of CSE plus ZEN could normalize the majority of the tested parameters and the histological picture at a dose as low as 200 mg/kg b. w. Therefore, CSE protects against ZEN toxicity via its antioxidant activity, modulation of iNOS, inflammatory-related genes, and the Nrf2 pathway and it could be used in the endemic regions.

Effect of Compactin on the Mycotoxin Production and Expression of Related Biosynthetic and Regulatory Genes in Toxigenic Fusarium culmorum

Zearalenone (ZEN) and deoxynivalenol (DON) are mycotoxins produced by various species of Fusarium fungi. They contaminate agricultural products and negatively influence human and animal health, thus representing a serious problem of the agricultural industry. Earlier we showed that compactin, a secondary metabolite of Penicillium citrinum, is able to completely suppress the aflatoxin B1 biosynthesis by Aspergillus flavus. Using the F. culmorum strain FC-19 able to produce DON and ZEN, we demonstrated that compactin also significantly suppressed both DON (99.3%) and ZEN (100%) biosynthesis. The possible mechanisms of this suppression were elucidated by qPCR-based analysis of expression levels of 48 biosynthetic and regulatory genes. Expression of eight of 13 TRI genes, including TRI4, TRI5, and TRI101, was completely suppressed. A significant down-regulation was revealed for the TRI10, TRI9, and TRI14 genes. TRI15 was the only up-regulated gene from the TRI cluster. In the case of the ZEN cluster, almost complete suppression was observed for PKS4, PKS13, and ZEB1 genes, and the balance between two ZEB2 isoforms was altered. Among regulatory genes, an increased expression of GPA1 and GPA2 genes encoding α- and β-subunits of a G-protein was shown, whereas eight genes were down-regulated. The obtained results suggest that the main pathway for a compactin-related inhibition of the DON and ZEN biosynthesis affects the transcription of genes involved in the G-protein-cAMP-PKA signaling pathway. The revealed gene expression data may provide a better understanding of genetic mechanisms underlying mycotoxin production and its regulation.

Oxidative stress as a plausible mechanism for zearalenone to induce genome toxicity

Zearalenone (ZEN), a common non-steroidal estrogenic mycotoxin of the Fusarium genus, is one of the most frequent and powerful contaminant of grains and cereal products representing a serious threat for people and livestock health. In fact, ZEN causes cytotoxicity and genotoxicity in a variety of cell types at least in part through binding to estrogen receptors (ERs). The main pathways through which ZEN induces such effects remain, however, elusive. In particular, how the mycotoxin causes DNA damage, dysregulates DNA repair mechanisms, changes epigenome of targeted cells and, not least, affects chromatin conformation and non-coding RNA (ncRNA), is unclear. In the present paper, following extensive review of the literature about such ZEN effects and our own experience in studying the effects of this compound on reproductive processes, we propose that increased production of reactive oxygen species (ROS) and consequently oxidative stress (OS) are central in ZEN genotoxicity. Besides to shed light on the action mechanisms of the mycotoxin, this notion might help to develop effective strategies to counteract its deleterious biological effects.

Dual-Target Electrochemical Sensor Based on 3D MoS2-rGO and Aptamer Functionalized Probes for Simultaneous Detection of Mycotoxins

A dual-target aptamer functionalized probes (DTAFP) was applied for the detection of aflatoxin B1 (AFB1) and zearalenone (ZEN) simultaneously, which has not been reported. Meanwhile, two functional materials for signal amplification of the DTAFP were synthesized: 1) a three-dimensional molybdenum disulfide-reduced graphene oxide (MoS₂-rGO) as a favorable loading interface; 2) a double-probes gold nanoparticles (AuNPs) modified by Thionin (Thi) and 6-(Ferrocenyl) hexanethiol (FC6S) as distinguishable and non-interfering signals. Mycotoxins on the electrode surface release into solution under the function of the DTAFP, leading a reduction of the differential peak impulse in signal response. Under the optimum conditions, the aptasensor exhibited a detection range of 1.0 pg mL⁻¹–100 ng mL⁻¹ for AFB1 and ZEN, with no observable cross reactivity. In addition, the aptasensor performed excellent stability, reproducibility, specificity, and favorable recovery in the detection of edible oil. This work demonstrated a novel method for the construction of a simple, rapid, and sensitive aptasensor in the detection of multiple mycotoxins simultaneously.

Roles of stress response-related signaling and its contribution to the toxicity of zearalenone in mammals

Zearalenone (ZEA) is a mycotoxin frequently found in cereal crops and cereal-derived foodstuffs worldwide. It affects plant productivity, and is also a serious hazard to humans and animals if being exposed to food/feed contaminated by ZEA. Studies over the last decade have shown that the toxicity of ZEA in animals is mainly mediated by the various stress responses, such as endoplasmic reticulum (ER) stress, oxidative stress, and others. Accumulating evidence shows that oxidative stress and ER stress signaling are actively implicated in and contributes to the pathophysiology of various diseases. Biochemically, the deleterious effects of ZEA are associated with apoptosis, DNA damage, and lipid peroxidation by regulating the expression of genes implicated in these biological processes. Despite these findings, the underlying mechanisms responsible for these alterations remain unclear. This review summarized the characteristics, metabolism, toxicity and the deleterious effects of ZEA exposure in various tissues of animals. Stress response signaling implicated in the toxicity as well as potential therapeutic options with the ability to reduce the deleterious effects of ZEA in animals were highlighted and discussed.

The control of Fusarium growth and decontamination of produced mycotoxins by lactic acid bacteria

Global crop and food contamination with mycotoxins are one of the primary worldwide concerns, while there are several restrictions regarding approaching conventional physical and chemical mycotoxins decontamination methods due to nutrition loss, sensory attribute reduction in foods, chemical residual, inconvenient operation, high cost of equipment, and high energy consumption of some methods. In this regard, the overarching challenges of mycotoxin contamination in food and food crops require the development of biological decontamination strategies. Using certain lactic acid bacteria (LAB) as generally recognized safe (GRAS) compounds is one of the most effective alternatives due to their potential to release antifungal metabolites against various fungal factors species. This review highlights the potential applications of LAB as biodetoxificant agents and summarizes their decontamination activities against Fusarium growth and Fusarium mycotoxins released into food/feed. Firstly, the occurrence of Fusarium and the instrumental and bioanalytical methods for the analysis of mycotoxins were in-depth discussed. Upgraded knowledge on the biosynthesis pathway of mycotoxins produced by Fusarium offers new insightful ideas clarifying the function of these secondary metabolites. Moreover, the characterization of LAB metabolites and their impact on the decontamination of the mycotoxin from Fusarium, besides the main mechanisms of mycotoxin decontamination, are covered. While the thematic growth inhibition of Fusarium and decontamination of their mycotoxin by LAB is very complex, approaching certain lactic acid bacteria (LAB) is worth deeper investigations.

Ameliorative effect of betulinic acid against zearalenone exposure triggers testicular dysfunction and oxidative stress in mice via p38/ERK MAPK inhibition and Nrf2-mediated antioxidant defense activation

Zearalenone (ZEA) is a nonsteroidal estrogenic mycotoxin, which mainly contaminates grains and has estrogen-like effects on the reproductive system. Betulinic acid (BA), a natural lupane-type pentacyclic triterpene, has anti-oxidative and anti-inflammatory properties. This study aimed to investigate whether BA alleviates ZEA-induced testicular damage and explore the possible mechanism. Here, BA ameliorated testicular damage by mitigating the disordered arrangement of seminiferous tubules, the exfoliation of lumen cells, and the increase of cell apoptosis caused by ZEA. Meanwhile, BA alleviated ZEA-triggered testicular damage by restoring hormone levels and sperm motility, and reconstructing the blood-testis-barrier. Moreover, BA alleviated ZEA-exposed testicular oxidative stress by activating Nrf2 pathway. Furthermore, BA moderated ZEA-evoked testicular inflammation by inhibiting p38/ERK MAPK pathway. Overall, our results revealed that BA has a therapeutic protective effect on ZEA-induced testicular injury and oxidative stress via p38/ERK MAPK inhibition and Nrf2-mediated antioxidant defense activation, which provides a viable alternative to alleviate ZEA-induced male reproductive toxicology.

Research Progress of Safety of Zearalenone: A Review

Zearalenone, a mycotoxin produced by fungi of the genus Fusarium, widely exists in animal feed and human food. The structure of zearalenone is similar to estrogen, so it mainly has estrogenic effects on various organisms. Products contaminated with zearalenone can pose risks to animals and humans. Therefore, it is imperative to carry out toxicological research on zearalenone and evaluate its risk to human health. This paper briefly introduces the production, physical, and chemical properties of zearalenone and the research progress of its toxicity kinetics, focusing on its genetic toxicity, reproductive toxicity, hepatotoxicity, immunotoxicity, carcinogenicity, endocrine interference, and its impact on intestinal health. Finally, the progress of the risk assessment of human exposure is summarized to provide a reference for the follow-up study of zearalenone.

Integrated Metabolomics and Transcriptomics Analyses Reveal Metabolic Mechanisms in Porcine Intestinal Epithelial Cells under Zearalenone Stress

Zearalenone (ZEA) is a mycotoxin that frequently occurs in agricultural crops and related products and seriously threatens both animal feed and human food safety. To identify key metabolites and regulators involved in ZEA toxicological processes, we performed metabolomic and transcriptomic analyses of porcine IPEC-J2 intestinal epithelial cells upon ZEA exposure using liquid chromatography-mass spectrometry (LC-MS)/MS and RNA-seq techniques. A total of 325 differential metabolites and 5646 differentially expressed genes were detected. Integrated analyses of metabolomic and transcriptomic data indicated that metabolic processes including lipid metabolism, amino acid metabolism, and carbohydrate metabolism were most affected. Exogenous addition of the key metabolite l-arginine significantly facilitated ZEA metabolism and ameliorated ZEA-induced reactive oxygen species levels and cell apoptosis. Furthermore, l -arginine contributed to the expression of phase II detoxification genes (SULT2B1, GSTA1, GSTM3, and GPX4). l-Arginine addition also increased the protein levels of LC3-II and Beclin 1, and downregulated p62/SQSTM1 levels, indicating its regulatory roles in autophagic flux activation upon ZEA exposure. This study provided global insights into metabolic and transcriptional changes as well as key metabolites and regulators underlying the cellular response to ZEA exposure, and paved the way for the identification of metabolic and molecular targets for biomonitoring and controlling contamination by ZEA.

Diet composition affects long-term zearalenone exposure on the gut-blood-liver axis metabolic dysfunction in mice

Zearalenone (ZEN), one of the most contaminated Fusarium toxins worldwide, is very common in contaminating wheat, corn oil and other foods. People are more vulnerable to ZEN exposure with more daily caloric intake, yet little is known about the combined effect of different dietary patterns with mycotoxins. This study aimed to compare the effects of long-term ZEN exposure on the overall biochemical landscape of the "gut-blood-liver axis" under normal diet and high-fat diet (HFD) using a combined multi-omics approach. The results indicated that ZEN exposure, possibly via the phenylalanine metabolic pathway, led to dysbiosis of mouse flora, suppression of short-chain fatty acids (SCFAS) metabolism, systemic inflammatory responses, and disturbances in serum and liver metabolism, which were exacerbated in synergy with HFD and ultimately led to a more severe state of lipid metabolism in the liver. We further found that ZEN exposure attenuated the indole-3-propionic acid (IPA) metabolic pathway, enhanced 2-hydroxybutyric acid metabolism in serum, and attenuated β-alanine metabolism in liver which was positively correlated with the abundance of Prevotellaceae UCG-004, Prevotellaceae UCG-001, and Prevotellaceae NK3B31 groups. The results highlighted the damaging effects of ZEN on the gut-blood-liver axis under different dietary patterns, which might serve as a reference for future studies exploring the combined effects of fungal toxins and multiple dietary patterns.

Impact of a Natural Fusarial Multi-Mycotoxin Challenge on Broiler Chickens and Mitigation Properties Provided by a Yeast Cell Wall Extract and a Postbiotic Yeast Cell Wall-Based Blend

Yeast cell wall-based preparations have shown efficacy against Aspergillus-based toxins but have lower impact against type-B trichothecenes. Presently, we investigated a combination of deoxynivalenol (DON), T-2 toxin (T2) and zearalenone (ZEA), and the effect of a yeast cell wall extract (YCWE) and a post-biotic yeast cell wall-based blend (PYCW) with the objectives of preventing mycotoxins’ negative effects in commercial broilers. A total of 720 one-day-old male Cobb broilers were randomly allocated to: (1) control diet, (aflatoxins 6 µg/kg; cyclopiazonic acid 15 µg/kg; fusaric acid 25 µg/kg; fumonisin B1 310 µg/kg); (2) Diet1 + 0.2% YCWE; (3) Diet1 + 0.2% PYCW; (4) Contaminated diet (3.0 mg/kg DON; 2.17 mg/kg 3-acetyldeoxynivalenol; 104 g/kg T2; 79 g/kg ZEA); (5) Diet4 + 0.2% YCWE; and (6) Diet4 + 0.2% PYCW. Naturally contaminated diets adversely affected performance, serum biochemistry, liver function, immune response, altered cecal SCFA goblet cell count and architecture of intestinal villi. These adverse effects were reduced in birds fed PYCW and to a lesser extent YCWE, indicating protection against toxic assault. PYCW yielded better production performance and stimulated liver function, with higher response to NDV and IBV vaccination. Furthermore, mycotoxins were found to affect production outputs when evaluated with the European poultry production efficiency factor compared to control or YCWE and PYCW supplemented treatments. Taken together, YCWE, when complemented with nutritional add-ons (PYCW), could potentiate the remediation of the negative effects from a multi mycotoxins dietary challenge in broiler birds.

Impaired primordial follicle assembly in offspring ovaries from zearalenone-exposed mothers involves reduced mitochondrial activity and altered epigenetics in oocytes

Previous works have shown that zearalenone (ZEA), as an estrogenic pollutant, has adverse effects on mammalian folliculogenesis. In the present study, we found that prolonged exposure of female mice to ZEA around the end of pregnancy caused severe impairment of primordial follicle formation in the ovaries of newborn mice and altered the expression of many genes in oocytes as revealed by single-cell RNA sequencing (scRNA-seq). These changes were associated with morphological and molecular alterations of mitochondria, increased autophagic markers in oocytes, and epigenetic changes in the ovaries of newborn mice from ZEA-exposed mothers. The latter increased expression of HDAC2 deacetylases was leading to decreased levels of H3K9ac and H4K12ac. Most of these modifications were relieved when the expression of  Hdac2 in newborn ovaries was reduced by RNA interference during in vitro culture in the presence of ZEA. Such changes were also alleviated in offspring ovaries from mothers treated with both ZEA and the coenzyme Q10 (CoQ10), which is known to be able to restore mitochondrial activities. We concluded that impaired mitochondrial activities in oocytes caused by ZEA are at the origin of metabolic alterations that modify the expression of genes controlling autophagy and primordial follicle assembly through changes in epigenetic histones.

Application of a Validated Method for the Identification and Quantification of Mycotoxins in Wines Using UPLC-MS/MS

The aim of the present study was to develop a rapid, simple and reliable method for the identification and quantification of six mycotoxins in wine using liquid chromatography with electrospray ionization tandem mass spectrometry. The analytical method was fully validated, and calibration curves were made with correlation coefficients >0.9970. A short analysis time and acceptable extraction efficiency were achieved by a direct extraction method of analytes (ochratoxin A, aflatoxin B1, B2, G1, G2 and Zearalenone) with acetonitrile. LOD values were from 0.03 to 0.27 μg kg−1, and LOQ values were from 0.08 to 0.81 μg kg−1, with recoveries at various values from 77 to 108%. The expanded uncertainty was 5–21% expressed at a coverage level of k = 2, at a confidence level of approximately 95%. The performance criteria of the method were fully met according to European legislation (EC) 401/2006. The method was successfully applied to wine samples from Cyprus. The method was simple, low cost, quick, accurate, and sensitive.

Involvement of O2·- release in zearalenone-induced hormesis of intestinal porcine enterocytes: An electrochemical sensor-based analysis

Relationship between mycotoxin-induced hormesis and reactive oxygen species (ROS) has not been systematically investigated due to the lack of an effective analysis method. To monitor cellular release and intracellular level of O2·-, carboxymethyl cellulose-Mn3(PO4)2 nanocomposite was synthesized to fabricate an electrochemical biosensor, which selectively detects O2·- over the range of 57.50 nM ∼ 2.95 μM (R2 = 0.99) with the sensitivity of 78.67 μA μM-1 cm-2 and the detection limit of 8.47 nM. Transient exposure to zearalenone (ZEA) induces the enhancement on cell viability, immediate O2·- release from cells, and reduction of intracellular O2·- level. After post-treatment culture, intracellular O2·- initially increases to a high level and then decreases to the normal level. Concurrently, the ZEA-induced hormesis disappears. Based on the findings, we propose a mechanism, involving the ROS release, increase of succinate dehydrogenase activity and recovery of intracellular ROS, to explain the occurrence and disappearance of hormesis in intestinal porcine enterocytes.

Development of a Highly Sensitive and Specific Monoclonal Antibody Based on Indirect Competitive Enzyme-Linked Immunosorbent Assay for the Determination of Zearalenone in Food and Feed Samples

Zearalenone (ZEN) contamination in food and feed is prevalent and has severe effects on humans and animals post-consumption. Therefore, a sensitive, specific, rapid, and reliable method for detecting a single residue of ZEN is necessary. This study aimed to establish a highly sensitive and specific ZEN monoclonal antibody (mAb) and an indirect competitive enzyme-linked immunosorbent assay (icELISA) for the detection of ZEN residues in food and feed. The immunogen ZEN-BSA was synthesized via the amino glutaraldehyde (AGA) and amino diazotization (AD) methods and identified using 1H nuclear magnetic resonance (1H NMR), a high-resolution mass spectrometer (HRMS), and an ultraviolet spectrometer (UV). The coating antigens ZEN-OVA were synthesized via the oxime active ester (OAE), formaldehyde (FA), 1,4-butanediol diglycidyl ether (BDE), AGA, and AD methods. These methods were used to screen the best antibody/antigen combination of a heterologous icELISA. Balb/c mice were immunized with a low ZEN-BSA dose at long intervals and multiple sites. Suitable cell fusion mice and positive hybridoma cell lines were screened using a homologous indirect non-competitive ELISA (inELISA) and an icELISA. The ZEN mAbs were prepared by inducing ascites in vivo. The immunological characteristics of ZEN mAbs were then assessed. The standard curves of the icELISA for ZEN were constructed under optimal experimental conditions, and the performance of the icELISA was validated. The two ZEN-BSA immunogens (conjugation ratios, 11.6:1 (AGA) and 9.2:1 (AD)) were successfully synthesized. Four hybridoma cell lines (2B6, 4D9, 1A10, and 4G8) were filtered, of which 2B6 had the best sensitivity and specificity. The mAb 2B6-based icELISA was then developed. The limit of detection (LOD), the 50% inhibitive concentration (IC50), and the linear working range (IC20 to IC80) values of the icELISA were 0.76 μg/L, 8.69 μg/L, and 0.92–82.24 μg/L, respectively. The cross-reactivity (CR) of the icELISA with the other five analogs of ZEN was below 5%. Three samples were spiked with different concentrations of ZEN and detected using the icELISA. The average intra-assay recoveries, inter-assay recoveries, intra-assay coefficients of variations (CVs), and inter-assay CVs were 93.48–99.48%, 94.18–96.13%, 12.55–12.98%, and 12.53–13.58%, respectively. The icELISA was used to detect ZEN in various samples. The results were confirmed using high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) (correlation coefficient, 0.984). The proposed icELISA was highly sensitive, specific, rapid, and reliable for the detection of ZEN in food and feed samples.

Study on Contamination with Some Mycotoxins in Maize and Maize-Derived Foods

Crops can be contaminated by fungi which produce mycotoxins. Many fungal strains are responsible for producing varied mycotoxins. The research carried out so far has described over 400 different mycotoxins. They have chemical and physical properties that significantly differ, and they are produced by several different existing fungi. The intake of mycotoxins through food can be achieved directly, by feeding on contaminated food, or indirectly from foods of animal origin. The mycotoxin contamination of food and food products for certain animals is a phenomenon studied worldwide, in countries in Europe but also in Asia, Africa and America. The purpose of this study is to develop an evaluation of the mycotoxins prevalent in corn and corn-derived products produced in Romania. A total of 38 maize samples and 19 corn-derivative samples were investigated for the presence of mycotoxins specific to these products, such as deoxynivalenol, zearalenone and fumonisins. Fumonisins had the highest presence and zearalenone had the lowest. The limits determined for the three mycotoxins were always in accordance with legal regulations.

Zearalenone promotes follicle development through activating the SIRT1/PGC-1α signaling pathway in the ovaries of weaned gilts

This study aimed to investigate the effect of zearalenone (ZEA) exposure on follicular development in weaned gilts, and its mechanism based on the silent information regulator 1 (SIRT1)/peroxisome proliferator-activated receptor-γ co-activator 1α (PGC-1α) signaling pathway. A total of 32 healthy female weaned piglets (Landrace × Yorkshire × Duroc) with an average body weight of 12.39 ± 0.24 kg were randomly allotted to a basal diet supplemented with 0, 0.15, 1.5, or 3.0 mg/kg ZEA for a 32-d feeding test. Blood and ovarian samples were obtained at the end of the experiment to determine serum toxin concentrations, ovarian histology, and the expressions of proliferating cell nuclear antigen (PCNA) and SIRT1/PGC-1α signaling pathway-related genes. Results showed that the vulva area, serum concentrations of ZEA, α-zearalenol and β-zearalenol, the thickness of the growing follicular layer, and the diameter of the largest growing follicles, as well as the expressions of SIRT1, PGC-1α, estrogen-related receptor α (ERRα), ATP synthase subunit beta (ATP5B), and PCNA, increased linearly (P < 0.05) with increasing dietary ZEA, whereas the thickness of the primordial follicle layer decreased linearly (P < 0.05). Immunohistochemical analysis showed that the immunoreactive substances of SIRT1 and PGC-1α in the ovaries enhanced with the increasing dietary ZEA (P < 0.05). In addition, the thickness of the growing follicular layer and the diameter of the largest growing follicle were positively correlated with relative mRNA and protein expressions of SIRT1, PGC-1α, ERRα, ATP5B, and PCNA (P < 0.05). However, the thickness of the primordial follicle layer was negatively correlated with the mRNA and protein expression of SIRT1, PGC-1α, ERRα, ATP5B, and PCNA (P < 0.05). Interestingly, the 1.5 mg/kg ZEA treatment had highly hyperplastic follicles, whereas 3.0 mg/kg ZEA resulted in a large number of follicular atresia, which indicated that low-dose ZEA exposure accelerated follicular proliferation, while high-dose ZEA promoted follicular atresia, although the critical value interval needs further confirmation. Results provide a theoretical basis for finding the therapeutic target of ZEA-induced reproductive disorders in weaned gilts.

Mycotoxins’ Toxicological Mechanisms Involving Humans, Livestock and Their Associated Health Concerns: A Review

Mycotoxins are well established toxic metabolic entities produced when fungi invade agricultural/farm produce, and this happens especially when the conditions are favourable. Exposure to mycotoxins can directly take place via the consumption of infected foods and feeds; humans can also be indirectly exposed from consuming animals fed with infected feeds. Among the hundreds of mycotoxins known to humans, around a handful have drawn the most concern because of their occurrence in food and severe effects on human health. The increasing public health importance of mycotoxins across human and livestock environments mandates the continued review of the relevant literature, especially with regard to understanding their toxicological mechanisms. In particular, our analysis of recently conducted reviews showed that the toxicological mechanisms of mycotoxins deserve additional attention to help provide enhanced understanding regarding this subject matter. For this reason, this current work reviewed the mycotoxins’ toxicological mechanisms involving humans, livestock, and their associated health concerns. In particular, we have deepened our understanding about how the mycotoxins’ toxicological mechanisms impact on the human cellular genome. Along with the significance of mycotoxin toxicities and their toxicological mechanisms, there are associated health concerns arising from exposures to these toxins, including DNA damage, kidney damage, DNA/RNA mutations, growth impairment in children, gene modifications, and immune impairment. More needs to be done to enhance the understanding regards the mechanisms underscoring the environmental implications of mycotoxins, which can be actualized via risk assessment studies into the conditions/factors facilitating mycotoxins’ toxicities.

Development of isotope dilution-liquid chromatography/tandem mass spectrometry for the accurate determination of zearalenone and its metabolites in corn

A method using isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC/MS/MS) was developed for the accurate determination of zearalenone (ZEN) and its five major metabolites in corn. ¹³C- or ²H-labeled analogues of the target mycotoxins were used as internal standards. As the immunoaffinity columns used demonstrated selectivity to a specific chiral isomer of a racemic mixture of zearalanone-d₆, a clean-up cartridge without stereoselectivity (Mycosep 226 column) was selected for the same recovery of the analyte and its internal standard with adequate elimination of matrix interferences. The method demonstrated sufficient selectivity, sensitivity, accuracy and precision over a concentration range of 20-400 µg/kg. The limit of detections and limit of quantifications were 0.14-0.33 µg/kg and 0.45-1.11 µg/kg, respectively. The accuracy values were 96.7%-103.6%, with intra and inter-day precisions of less than 3% and 4%, respectively. The expanded measurement uncertainty was less than 7% (with a 95% confidence level).

Prussian blue immunochromatography with portable smartphone-based detection device for zearalenone in cereals

In this study, we developed a prussian blue nanoparticles (PBNPs) immunochromatographic assay (ICA) integrated with smartphone-based detection device for ZEN in cereals. PBNPs, as probe labels, were synthesized with properties of controllable structure, environment friendliness, and high affinities to antibody (Ab). PBNPs-ICA quantitative analysis was performed with a hand-held smartphone-based device coupled with a user-friendly and self-programmed detection App. This integrated strategy demonstrated high sensitivity for ZEN with a cut-off value of 10 μg/kg, a detection limit of 0.12 μg/kg, a quantitation limit of 0.27 μg/kg, and recovery rates of 92.0%-105.0% and 88.0%-98.0% for maize and wheat, respectively. The results of 20 naturally contaminated cereal samples showed good correlation (R²＞0.99) between LC-MS/MS and developed system. Moreover, the stability experiment revealed that PBNPs-ICA maintained high stability and bioactivity against competitive antigen (Ag). The proposed strategy exhibited great potential for the rapid monitoring of mycotoxins or other small molecule hazards.

Recent Progress in Rapid Determination of Mycotoxins Based on Emerging Biorecognition Molecules: A Review

Mycotoxins are secondary metabolites produced by fungal species, which pose significant risk to humans and livestock. The mycotoxins which are produced from Aspergillus, Penicillium, and Fusarium are considered most important and therefore regulated in food- and feedstuffs. Analyses are predominantly performed by official laboratory methods in centralized labs by expert technicians. There is an urgent demand for new low-cost, easy-to-use, and portable analytical devices for rapid on-site determination. Most significant advances were realized in the field bioanalytical techniques based on molecular recognition. This review aims to discuss recent progress in the generation of native biomolecules and new bioinspired materials towards mycotoxins for the development of reliable bioreceptor-based analytical methods. After brief presentation of basic knowledge regarding characteristics of most important mycotoxins, the generation, benefits, and limitations of present and emerging biorecognition molecules, such as polyclonal (pAb), monoclonal (mAb), recombinant antibodies (rAb), aptamers, short peptides, and molecularly imprinted polymers (MIPs), are discussed. Hereinafter, the use of binders in different areas of application, including sample preparation, microplate- and tube-based assays, lateral flow devices, and biosensors, is highlighted. Special focus, on a global scale, is placed on commercial availability of single receptor molecules, test-kits, and biosensor platforms using multiplexed bead-based suspension assays and planar biochip arrays. Future outlook is given with special emphasis on new challenges, such as increasing use of rAb based on synthetic and naïve antibody libraries to renounce animal immunization, multiple-analyte test-kits and high-throughput multiplexing, and determination of masked mycotoxins, including stereoisomeric degradation products.

High-Throughput Determination of Major Mycotoxins with Human Health Concerns in Urine by LC-Q TOF MS and Its Application to an Exposure Study

Human biomonitoring constitutes a suitable tool to assess exposure to toxins overcoming the disadvantages of traditional methods. Urine constitutes an accessible biological matrix in biomonitoring studies. Mycotoxins are secondary metabolites produced naturally by filamentous fungi that produce a wide range of adverse health effects. Thus, the determination of urinary mycotoxin levels is a useful tool for assessing the individual exposure to these food contaminants. In this study, a suitable methodology has been developed to evaluate the presence of aflatoxin B2 (AFB2), aflatoxin (AFG2), ochratoxin A (OTA), ochratoxin B (OTB), zearalenone (ZEA), and α-zearalenol (α-ZOL) in urine samples as exposure biomarkers. For this purpose, different extraction procedures, namely, the Solid Phase Extraction (SPE); Dispersive Liquid–Liquid Microextraction (DLLME); and Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) methods were assessed, followed by Liquid Chromatography coupled to Quadrupole Time of Flight Mass Spectrometry with Electrospray Ionization (LC-ESI-QTOF-MS) determination. Then, the proposed methodology was applied to determine mycotoxin concentrations in 56 human urine samples from volunteers and to estimate the potential risk of exposure. The results obtained revealed that 55% of human urine samples analyzed resulted positive for at least one mycotoxin. Among all studied mycotoxins, only AFB2, AFG2, and OTB were detected with incidences of 32, 41, and 9%, respectively, and levels in the range from <LOQ to 69.42 µg/L. Risk assessment revealed a potential health risk, obtaining MoE values < 10,000. However, it should be highlighted that few samples were contaminated, and that more data about mycotoxin excretion rates and their BMDL10 values are needed for a more accurate risk assessment.

Visual detection of aflatoxin B1 and zearalenone via activating a new catalytic reaction of “naked” DNAzyme

It was found for the first time that the catalytic activity of “naked” DNAzyme can be modulated by aflatoxins and zearalenone to generate different color changes, which could be applied to the visual detection for the above two analytes.