Clinical effects and biochemical mechanisms associated with exposure to the mycoestrogen zearalenone

MicroRNAs: exploring their role in farm animal disease and mycotoxin challenges

MicroRNAs (miRNAs) serve as key regulators in gene expression and play a crucial role in immune responses, holding a significant promise for diagnosing and managing diseases in farm animals. This review article summarizes current research on the role of miRNAs in various farm animal diseases and mycotoxicosis, highlighting their potential as biomarkers and using them for mitigation strategies. Through an extensive literature review, we focused on the impact of miRNAs in the pathogenesis of several farm animal diseases, including viral and bacterial infections and mycotoxicosis. They regulate gene expression by inducing mRNA deadenylation, decay, or translational inhibition, significantly impacting cellular processes and protein synthesis. The research revealed specific miRNAs associated with the diseases; for instance, gga-miR-M4 is crucial in Marek's disease, and gga-miR-375 tumor-suppressing function in Avian Leukosis. In swine disease such as Porcine Respiratory and Reproductive Syndrome (PRRS) and swine influenza, miRNAs like miR-155 and miR-21-3p emerged as key regulatory factors. Additionally, our review highlighted the interaction between miRNAs and mycotoxins, suggesting miRNAs can be used as a biomarker for mycotoxin exposure. For example, alterations in miRNA expression, such as the dysregulation observed in response to Aflatoxin B1 (AFB1) in chickens, may indicate potential mechanisms for toxin-induced changes in lipid metabolism leading to liver damage. Our findings highlight miRNAs potential for early disease detection and intervention in farm animal disease management, potentially reducing significant economic losses in agriculture. With only a fraction of miRNAs functionally characterized in farm animals, this review underlines more focused research on specific miRNAs altered in distinct diseases, using advanced technologies like CRISPR-Cas9 screening, single-cell sequencing, and integrated multi-omics approaches. Identifying specific miRNA targets offers a novel pathway for early disease detection and the development of mitigation strategies against mycotoxin exposure in farm animals.

Low Doses of Deoxynivalenol and Zearalenone Alone or in Combination with a Mycotoxin Binder Affect ABCB1 mRNA and ABCC2 mRNA Expression in the Intestines of Pigs

Mycotoxin binders, in combination with enzymes degrading some mycotoxins, contribute to feed detoxification. Their use reduces economic losses and the negative impacts of mycotoxins on animal health and productivity in farm animals. The aim of this study was to evaluate the efficacy of a mycotoxin detoxifier on the expression of the ATP-binding cassette efflux transporters ABCB1 mRNA and ABCC2 mRNA, which transport xenobiotics and thus have a barrier function, in the tissues of pigs exposed to low doses of deoxynivalenol (DON, 1 mg/kg feed) and zearalenone (ZEN, 0.4 mg/kg feed) for 37 days. The levels of expression were determined by an RT-PCR, and the effect of the mycotoxin detoxifier (Mycofix Plus3.E) was evaluated by a comparison of results between healthy pigs (n = 6), animals treated with DON and ZEN (n = 6), and a group that received both mycotoxins and the detoxifier (n = 6). A significant downregulation of ABCB1 mRNA and ABCC2 mRNA was observed in the jejunum (p < 0.05). A tendencies toward the downregulation of ABCB1 mRNA and ABCC2 mRNA were found in the ileum and duodenum, respectively. The mycotoxin detoxifier restored the expression of ABCB1 mRNA to the level found in healthy animals but did not restore that of ABCC2 mRNA to the level of healthy animals in the jejunum.

Effect of DON and ZEN and their metabolites DOM-1 and HZEN on B cell proliferation and antibody production

Introduction

The mycotoxins deoxynivalenol (DON) and zearalenone (ZEN), produced by Fusarium fungi, are frequently found in the cereal-rich diet of pigs and can modulate the immune system. Some enzymes or bacteria present in the digestive tract can de-epoxydize DON to deepoxy-deoxynivalenol (DOM-1) and biotransform ZEN into hydrolyzed ZEN (HZEN). The effects of these metabolites on immune cells, particularly with respect to the vaccine responses, are poorly documented. The aim of this study was to address the impact of DON and ZEN and their respective derivatives, on proliferation, and antibody production of porcine B cells in vitro.

Methods

Peripheral blood mononuclear cells (PBMCs), isolated from healthy pigs, were stimulated with the Toll-like receptor (TLR) 7/8-agonist Resiquimod (R848) or the TLR/1/2-agonist Pam3Cys-SKKKK in combination with DON [0.1-1.6 µM] or DOM-1 [1.6 µM and 16 µM] and ZEN [2.5-40 µM] or HZEN [40 µM].

Results

A strong decrease in B-cell proliferation was observed at DON concentrations equal to or exceeding 0.8 µM and at ZEN concentrations equal to or exceeding 20 µM. Treatment with 1.6 µM DON or 40 µM ZEN led to almost a complete loss of live CD79α+ B cells. Moreover, CD21 expression of proliferating IgG+ and IgM+ B-cell subsets was decreased at DON concentrations equal to and exceeding 0.4 µM and at ZEN concentrations equal to or exceeding 10 µM. ELISpot assays revealed a decrease of IgG-secreting B cells at concentrations of and exceeding 0.4 µM and at ZEN concentrations equal to and exceeding 10 µM. ELISA assays showed a decrease of IgM, IgG, and IgA secretion at concentrations equal to or exceeding 0.4 µM DON. ZEN reduced IgM secretion at 20-40 µM (both R848 and Pam3Cys-SKKKK), IgG secretion at 40 µM (both R848 and Pam3Cys-SKKKK) and IgA secretion at 20-40 µM.

Discussion

Our in vitro experiments show that while DON and ZEN impair immunoglobulin production and B-cell proliferation, this effect is abrogated by HZEN and DOM-1.

Effect of Mycotoxins in Silage on Biogas Production

Mycotoxins can pose a threat to biogas production as they can contaminate the feedstock used in biogas production, such as agricultural crops and other organic materials. This research study evaluated the contents of deoxynivalenol (DON), zearalenone (ZEA), fumonisin (FUM), and aflatoxin (AFL) mycotoxins in maize silage prior to it being processed in a biogas plant and in digestate produced at the end of the anaerobic digestion (AD) process. In the experiment, three samples of silage were collected from one silage warehouse: Variant 1 = low contamination, Variant 2 = medium contamination, and Variant 3 = heavy contamination, which were subjected to investigation. A significantly reduced biogas production was recorded that was proportional to the increasing contamination with molds, which was primarily due to the AD of silage caused by technologically erroneous silage treatment. The AD was connected with changes in silage composition expressed by the values of VS content, sugar content, lactic acid content, acetic acid content, and the ratio of lactic acid content to acetic acid content. The production of biogas and methane decreased with the increasing contents of NDF, ADF, CF, and lignin. The only exception was Variant 2, in which the content of ADF, CF, and lignin was lower (by 8-11%) than that in Variant 1, and only the content of NDF was higher (by 9%) than that in Variant 1. A secondary factor that also correlated with changes in the composition of the substrate was the development of undesirable organisms, which further contributed to its degradation and to the production of mycotoxins. It was also demonstrated in this study that during the AD process, the tested mycotoxins were degraded, and their content was reduced by 27-100%. Only the variant with low mold contamination showed a DON concentration increase of 27.8%.

Involvement of estrogen receptor alpha (ERα) and impairment of steroidogenesis after exposure to tris(2,3-dibromopropyl) isocyanurate (TBC) in mouse spermatogenic (GC-1 spg) cells in vitro

Good-quality reproductive cells are essential for reproduction. Endocrine disruptors are widely available in the environment and are known to have an adverse effect on spermatogenesis and steroidogenesis. One of them is tris(2,3-dibromopropyl) isocyanurate (TBC), i.e. one of the novel brominated flame retardants (NBFR). TBC is a widely distributed ingredient used in the production of flame retardants. Currently, it is known to affect the hormonal system, but the exact mechanism of its action is unknown. Therefore, the aim of the study was to determine whether TBC alone and in cotreatment with BHPI (estrogen receptor alpha antagonist) has an impact on the expression of nuclear receptors involved in the formation of steroid hormones, proteins, and enzymes responsible for steroidogenesis and the levels of steroid hormones (E2, P4, and T) in the GC-1 spg cell line as a mouse model of spermatogenic cells in vitro. Our results indicate that ERα is involved in the mechanism of TBC action, while no activation of PPARγ, AhR, and IGF-1R was observed. In addition, a decrease in the levels of most of the analyzed proteins and enzymes involved in steroid conversion was observed. Only Cyp19a1 was upregulated after TBC, BHPI, and TBC with BHPI cotreatment. In all the analyzed groups, a significant decrease in P4 and a subtle decrease in T and E2 were observed in the production and secretion of the hormones to the culture medium, compared to the control. The obtained results confirm the involvement of TBC in the dysregulation of steroid biosynthesis, which may affect male fertility.

Cross-species analysis of transcriptome emphasizes a critical role of TNF-α in mediating MAP2K7/AKT2 signaling in zearalenone-induced apoptosis

Zearalenone (ZEN) is a widespread and transgenerational toxicant that can cause serious reproductive health risks, which poses a potential threat to global agricultural production and human health; its estrogenic activity can lead to reproductive toxicity through the induction of granulosa cell apoptosis. Herein, comparative transcriptome analysis, single-cell transcriptome analysis, and weighted gene co-expression network analysis (WGCNA) combined with gene knockout in vivo and RNA interference in vitro were used to comprehensively describe the damage caused by ZEN exposure on ovarian granulosa cells. Comparative transcriptome analysis and WGCNA suggested that the tumor necrosis factor (TNF)-α-mediated mitogen-activated protein kinase 7 (MAP2K7)/ AKT serine/threonine kinase 2 (AKT2) axis was disordered after ZEN exposure in porcine granulosa cells (pGCs) and mouse granulosa cells (mGCs). In vivo gene knockout and in vitro RNA interference verified that TNF-α-mediated MAP2K7/AKT2 was the guiding signal in ZEN-induced apoptosis in pGCs and mGCs. Moreover, single-cell transcriptome analysis showed that ZEN exposure could induce changes in the TNF signaling pathway in offspring. Overall, we concluded that the TNF-α-mediated MAP2K7/AKT2 axis was the main signaling pathway of ZEN-induced apoptosis in pGCs and mGCs. This work provides new insights into the mechanism of ZEN toxicity and provides new potential therapeutic targets for the loss of livestock and human reproductive health caused by ZEN.

Exploring the Toxic Effects of ZEA on IPEC-J2 Cells from the Inflammatory Response and Apoptosis

Zearalenone (ZEA) is the most common fungal toxin contaminating livestock and poultry feeding, especially in pigs, causing severe toxic effects and economic losses. However, the mechanism of ZEA damage to the intestine is unknown. We constructed an in vitro model of ZEA toxicity in a porcine small intestinal epithelial cell (IPEC-J2) line. ZEA causes severe oxidative stress in porcine small intestine cells, such as the production of ROS and a significant decrease in the levels of antioxidant enzymes GSH, CAT, SOD, and T-AOC. ZEA also caused apoptosis in porcine small intestine cells, resulting in a significant reduction in protein and/or mRNA expression of apoptosis-related pathway factors such as P53, caspase 3, caspase 9, Bax, and Cyt-c, which in turn caused a significant decrease in protein and/or mRNA expression of inflammatory-related factors such as IL-1β, IL-2, Cox-2, NF-κD, NLRP3, IL-6, and IL -18, which in turn caused a significant increase in protein and/or mRNA expression levels. The final results suggest that ZEA can cause a severe toxic response in porcine small intestine cells, with oxidative stress, apoptotic cell death and inflammatory damage.

Endocrine Effect of Some Mycotoxins on Humans: A Clinical Review of the Ways to Mitigate the Action of Mycotoxins

Fungi such as Aspergillus spp. and Fusarium spp., which are commonly found in the environment, pose a serious global health problem. This study aims to present the results of epidemiological studies, including clinical cases, on the relationship between human exposure to some mycotoxins, especially zearalenone and aflatoxin, and the occurrence of reproductive disorders. In addition, examples of methods to reduce human exposure to mycotoxins are presented. In March 2023, various databases (PubMed, Google Scholar, EMBASE and Web of Science) were systematically searched using Google Chrome to identify studies evaluating the association between exposure to mycotoxins and the occurrence of complications related to impaired fertility or cancer incidence. The analysed data indicate that exposure to the evaluated mycotoxins is widespread and correlates strongly with precocious puberty, reduced fertility and increased cancer incidence in women and men worldwide. There is evidence to suggest that exposure to the Aspergillus mycotoxin aflatoxin (AF) during pregnancy can impair intrauterine foetal growth, promote neonatal jaundice and cause perinatal death and preterm birth. In contrast, exposure to the Fusarium mycotoxin zearalenone (ZEA) leads to precocious sexual development, infertility, the development of malformations and the development of breast cancer. Unfortunately, the development of methods (biological, chemical or physical) to completely eliminate exposure to mycotoxins has limited practical application. The threat to human health from mycotoxins is real and further research is needed to improve our knowledge and specific public health interventions.

Foodborne Diseases Due to Underestimated Hazard of Joint Mycotoxin Exposure at Low Levels and Possible Risk Assessment

The subject of this review paper is to evaluate the underestimated hazard of multiple mycotoxin exposure of animals/humans for the appearance of foodborne ailments and diseases. The significance of joint mycotoxin interaction in the development of foodborne diseases is discussed, and appropriate conclusions are made. The importance of low feed/food levels of some target mycotoxins co-contaminations in food and feedstuffs for induction of target foodborne mycotoxicoses is also studied in the available literature. The appropriate hygiene control and the necessary risk assessment in regard to possible hazards for animals and humans are also discussed, and appropriate suggestions are made. Some internationally recognized prophylactic measures, management of the risk, and the necessity of elaboration of new international regulations in regard to the maximum permitted levels are also carefully discussed and analysed in the cases of multiple mycotoxin contaminations. The necessity of harmonization of mycotoxin regulations and control measures at international levels is also discussed in order to facilitate food trade between the countries and to ensure global food safety.

Novel insights into versatile nanomaterials integrated bioreceptors toward zearalenone ultrasensitive discrimination

Detrimental contamination of zearalenone (ZEN) in crops and foodstuffs has drawn intensive public attention since it poses an ongoing threat to global food security and human health. Highly sensitive and rapid response ZEN trace analysis suitable for complex matrices at different processing stages is an indispensable part of food production. Conventional detection methods for ZEN encounter many deficiencies and demerits such as sophisticated equipment and heavy labor intensity. Alternatively, the nanomaterial-based biosensors featured with high sensitivity, portability, and miniaturization are springing up and emerging as superb substitutes to monitor ZEN in recent years. Herein, we predominantly devoted to overview the progress in the fabrication strategies and applications of various nanomaterial-based biosensors, highlighting rationales on sensing mechanisms, response types, and practical analytical performance. Synchronously, the versatile nanomaterials integrating with diverse recognition elements for augmenting sensing capabilities are emphasized. Finally, critical challenges and perspectives to expedite ZEN detection are outlooked.

Effects of Exposure to Low Zearalenone Concentrations Close to the EU Recommended Value on Weaned Piglets’ Colon

Pigs are the most sensitive animal to zearalenone (ZEN) contamination, especially after weaning, with acute deleterious effects on different health parameters. Although recommendations not to exceed 100 µg/kg in piglets feed exists (2006/576/EC), there are no clear regulations concerning the maximum limit in feed for piglets, which means that more investigations are necessary to establish a guidance value. Due to these reasons, the present study aims to investigate if ZEN, at a concentration lower than the EC recommendation for piglets, might affect the microbiota or induce changes in SCFA synthesis and can trigger modifications of nutritional, physiological, and immunological markers in the colon (intestinal integrity through junction protein analysis and local immunity through IgA production). Consequently, the effect of two concentrations of zearalenone were tested, one below the limit recommended by the EC (75 µg/kg) and a higher one (290 µg/kg) for comparison reasons. Although exposure to contaminated feed with 75 µg ZEN/kg feed did not significantly affect the observed parameters, the 290 µg/kg feed altered several microbiota population abundances and the secretory IgA levels. The obtained results contribute to a better understanding of the adverse effects that ZEN can have in the colon of young pigs in a dose-dependent manner.

In vitro effect of zearalenone on sperm parameters, oocyte maturation and embryonic development in buffalo

The negative impact of zearalenone (ZEN; potent estrogenic mycotoxin) exposure on buffalo embryo production has not yet been determined. In the current study, buffalo sperm and oocytes were exposed to ZEN at different concentrations during maturation. Sperms (with and without ZEN exposure) were incubated for 2 h and evaluated for motility, viability, acrosome integrity, normality, and ultrastructure. Matured oocytes exposed to ZEN were stained to determine their nuclear maturation. Further, their developmental ability was evaluated after in vitro fertilization. Our results showed the toxic effects of ZEN at high concentrations (2000 ng/mL) on different buffalo sperm parameters. The number of acrosome-intact sperm was reduced at 0 h after exposure to a concentration of ≥ 100 ng/mL. Furthermore, the maturation rate of buffalo oocytes (telophase I + metaphase II) was significantly decreased in ZEN-treated oocytes with a higher degeneration rate. Oocytes matured in 1000 ng/mL ZEN and subsequently exhibited considerable reduction in cleavage rate and blastocyst formation compared with control oocytes (2.6% vs. 13.1%). Moreover, the morula rate was decreased (p < 0.001) in ZEN-treated oocytes at concentrations of ≥ 10 ng/mL. Overall, the adverse effects of in vitro ZEN exposure on buffalo sperm parameters and oocyte meiotic progression with a notable reduction in cleavage, morula, and blastocyst rates were defined by these results. Altogether, buffaloes should be considered sensitive to ZEN exposure with respect to their reproductive function.

Chronic exposure to zearalenone induces intestinal inflammation and oxidative injury in adult Drosophila melanogaster midgut

In the past decade, mycotoxin zearalenone (ZEN)-induced gastrointestinal adverse effects have been increasingly attracting worldwide attention. This study aimed to determine the gastrointestinal adverse effects of ZEN in Drosophila melanogaster (D. melanogaster) and reveal possible mechanisms of action of ZEN in insects. Here, chronic exposure of D. melanogaster to ZEN killed flies in a dose-dependent manner (2-20 µM). ZEN (20 µM) decreased the survival rates and climbing ability of flies, and activated immune deficiency-mediated intestinal immunity in midgut, leading to the production of antimicrobial peptides. Meanwhile, ZEN exposure induced morphological alteration of adult midgut. Further study suggested that high levels of oxidative stress was observed in ZEN-treated midgut due to the imbalance between the production of reactive oxygen species and the expression and activities of cellular antioxidant enzyme, including superoxide dismutase and catalase. ZEN-induced oxidative stress then caused cell death, impaired gut barrier function and increased gut permeability, leading to oxidative injury in midgut. Subsequently, ZEN-induce midgut injury further disrupted intestinal stem cell (ISC) homeostasis, stimulating ISC proliferation and tissue regeneration, but did not alter cell fate specification of ISC. Additionally, activation of Jun N-terminal kinase pathway was involved in ZEN-induced oxidative injury and tissue regeneration in midgut. Antioxidant vitamin E alleviated ZEN-induced oxidative injury to midgut epithelium. Collectively, this study provided additional evidences for ZEN-induced gastrointestinal adverse effects from an invertebrate model, extended our understanding of the mechanisms mediating mycotoxin toxicity in organisms.

circITGB1 Regulates Adipocyte Proliferation and Differentiation via the miR-23a/ARRB1 Pathway

Adipose tissues represent an important energy storage organ in animals and are the largest endocrine organ. It plays an important regulatory role in the pathogenesis of insulin resistance, cardiovascular disease, and metabolic syndrome. Adipose development is a complex biological process involving multiple key genes, signaling pathways, and non-coding RNAs, including microRNAs and circular RNAs. In this study, we characterized circITGB1 and named its host gene ITGB1, which is differentially expressed in sheep of different months based on sequencing data. We collated and analyzed the sequencing data to select miRNA-23a with strong binding to ARRB1. We found that miRNA-23a regulates the development and differentiation of sheep adipocytes by targeting ARRB1. As a competing endogenous RNA, circITGB1 overexpression effectively alleviated the inhibitory effect of miR-23a on ARRB1. Conclusively, we provide evidence that circITGB1 regulates the proliferation and differentiation of sheep adipocytes via the miR-23a/ARRB1 pathway. This study provides a scientific basis for further studies on adipose tissue development at the circRNA level.

Enzymatic Degradation of Zearalenone in the Gastrointestinal Tract of Pigs, Chickens, and Rainbow Trout

The estrogenic mycotoxin zearalenone (ZEN) is a common contaminant of animal feed. Effective strategies for the inactivation of ZEN in feed are required. The ZEN-degrading enzyme zearalenone hydrolase ZenA (EC 3.1.1.-, commercial name ZENzyme^®, BIOMIN Holding GmbH, Getzersdorf, Austria) converts ZEN to hydrolyzed ZEN (HZEN), thereby enabling a strong reduction in estrogenicity. In this study, we investigated the efficacy of ZenA added to feed to degrade ZEN in the gastrointestinal tract of three monogastric animal species, i.e., pigs, chickens, and rainbow trout. For each species, groups of animals received (i) feed contaminated with ZEN (chickens: 400 µg/kg, pigs: 200 µg/kg, rainbow trout: 2000 µg/kg), (ii) feed contaminated with ZEN and supplemented with ZenA, or (iii) uncontaminated feed. To investigate the fate of dietary ZEN in the gastrointestinal tract in the presence and absence of ZenA, concentrations of ZEN and ZEN metabolites were analyzed in digesta of chickens and rainbow trout and in feces of pigs. Upon ZenA administration, concentrations of ZEN were significantly decreased and concentrations of the degradation product HZEN were significantly increased in digesta/feces of each investigated animal species, indicating degradation of ZEN by ZenA in the gastrointestinal tract. Moreover, upon addition of ZenA to the diet, the concentration of the highly estrogenic ZEN metabolite α-ZEL was significantly reduced in feces of pigs. In conclusion, ZenA was effective in degrading ZEN to HZEN in the gastrointestinal tract of chickens, pigs, and rainbow trout, and counteracted formation of α-ZEL in pigs. Therefore, ZenA could find application as a ZEN-degrading feed additive for these animal species.

Zearalenone Promotes Uterine Development of Weaned Gilts by Interfering with Serum Hormones and Up-Regulating Expression of Estrogen and Progesterone Receptors

In this study, we aimed to assess the effect of diet ZEA on serum hormones, the location and expression of estrogen receptor ERα/β and progesterone receptor (PR) of the uterus in weaned piglets and to reveal the mechanism underneath. A total of 40 healthy weaned gilts were randomly allocated to basal diet supplemented with 0 (Control), 0.5 (ZEA0.5), 1.0 (ZEA1.0) and 1.5 (ZEA1.5) mg ZEA/kg and fed individually for 35 days. Meanwhile, the porcine endometrial epithelial cells (PECs) were incubated for 24 h with ZEA at 0 (Control), 5 (ZEA5), 20 (ZEA20) and 80 (ZEA80) μmol/L, respectively. The results showed that nutrient apparent digestibility (CP and GE), nutrient apparent availability (ME/GE, BV and NPU), the uterine immunoreactive integrated optic density (IOD), relative mRNA and protein expression of ER-α, ER-β and PR and the relative mRNA and protein expression of ER-α and ER-β in PECs all increased linearly (p < 0.05) with ZEA. Collectively, ZEA can interfere with the secretion of some reproductive hormones in the serum and promote the expression of estrogen/progesterone receptors in the uterus and PECs. All these indicate that ZEA may promote the development of the uterus in weaned gilts through estrogen receptor pathway.

Quantitative Proteomic Analysis of Zearalenone-Induced Intestinal Damage in Weaned Piglets

Zearalenone (ZEN), also known as the F-2 toxin, is a common contaminant in cereal crops and livestock products. This experiment aimed to reveal the changes in the proteomics of ZEN-induced intestinal damage in weaned piglets by tandem mass spectrometry tags. Sixteen weaned piglets either received a basal diet or a basal diet supplemented with 3.0 mg/kg ZEN in a 32 d study. The results showed that the serum levels of ZEN, α-zearalenol, and β-zearalenol were increased in weaned piglets exposed to ZEN (p < 0.05). Zearalenone exposure reduced apparent nutrient digestibility, increased intestinal permeability, and caused intestinal damage in weaned piglets. Meanwhile, a total of 174 differential proteins (DEPs) were identified between control and ZEN groups, with 60 up-regulated DEPs and 114 down-regulated DEPs (FC > 1.20 or <0.83, p < 0.05). Gene ontology analysis revealed that DEPs were mainly involved in substance transport and metabolism, gene expression, inflammatory, and oxidative stress. The Kyoto Encyclopedia of Genes and Genomes analysis revealed that DEPs were significantly enriched in 25 signaling pathways (p < 0.05), most of which were related to inflammation and amino acid metabolism. Our study provides valuable clues to elucidate the possible mechanism of ZEN-induced intestinal injury.

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.

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.

Elimination of Deoxynivalenol, Aflatoxin B1, and Zearalenone by Gram-Positive Microbes (Firmicutes)

Mycotoxin contaminations in the feed and food chain are common. Either directly or indirectly, mycotoxins enter the human body through the consumption of food of plant and animal origin. Bacteria with a high mycotoxin elimination capability can reduce mycotoxin contamination in feed and food. Four Gram-positive endospore-forming bacteria (Bacillus thuringiensis AMK10/1, Lysinibacillus boronitolerans AMK9/1, Lysinibacillus fusiformis AMK10/2, and Rummeliibacillus suwonensis AMK9/2) were isolated from fermented forages and tested for their deoxynivalenol (DON), aflatoxin B1 (AFB1), and zearalenone (ZEA) elimination potentials. Notably, the contribution of bacterial cell wall fractions to the observed outstanding ZEA elimination rates was demonstrated; however, the ZEA elimination differed considerably within the tested group of Gram-positive bacteria. It is worth noting that the purified cell wall of L. boronitolerans AMK9/1, L. fusiformis AMK10/2 and B. thuringiensis AMK10/1 were highly efficient in eliminating ZEA and the teichoic acid fractions of B. thuringiensis AMK10/1, and L. fusiformis AMK10/2 could also be successfully used in ZEA binding. The ZEA elimination capacity of viable R. suwonensis AMK9/2 cells was outstanding (40%). Meanwhile, R. suwonensis AMK9/2 and L. boronitolerans AMK9/1 cells produced significant esterase activities, and ZEA elimination of the cell wall fractions of that species did not correlate with esterase activity. DON and AFB1 binding capabilities of the tested bacterial cells and their cell wall fractions were low, except for B. thuringiensis AMK10/1, where the observed high 64% AFB1 elimination could be linked to the surface layer (S-layer) fraction of the cell wall.

Estrogenic in vitro evaluation of zearalenone and its phase I and II metabolites in combination with soy isoflavones

Humans and animals are exposed to multiple substances in their food and feed that might have a negative health impact. Among these substances, the Fusarium mycoestrogen zearalenone (ZEN) and its metabolites α-zearalenol (α-ZEL) and α-zearalanol (α-ZAL) are known to possess endocrine disruptive properties. In a mixed diet or especially animal feed, these potential contaminants might be ingested together with naturally occurring phytoestrogens such as soy isoflavones. So far, risk assessment of potential endocrine disruptors is usually based on adverse effects of single compounds whereas studies investigating combinatorial effects are scarce. In the present study, we investigated the estrogenic potential of mycoestrogens and the isoflavones genistein (GEN), daidzein (DAI) and glycitein (GLY) as well as equol (EQ), the gut microbial metabolite of DAI, in vitro alone or in combination, using the alkaline phosphatase (ALP) assay in Ishikawa cells. In the case of mycoestrogens, the tested concentration range included 0.001 to 10 nM with multiplication steps of 10 in between, while for the isoflavones 1000 times higher concentrations were investigated. For the individual substances the following order of estrogenicity was obtained: α-ZEL > α-ZAL > ZEN > GEN > EQ > DAI > GLY. Most combinations of isoflavones with mycoestrogens enhanced the estrogenic response in the investigated concentrations. Especially lower concentrations of ZEN, α-ZEL and α-ZAL (0.001—0.01 nM) in combination with low concentrations of GEN, DAI and EQ (0.001—0.1 µM) strongly increased the estrogenic response compared to the single substances.

Comparative Effects of Deoxynivalenol, Zearalenone and Its Modified Forms De-Epoxy-Deoxynivalenol and Hydrolyzed Zearalenone on Boar Semen In Vitro

Deoxynivalenol (DON) and zearalenone (ZEN) are described as detrimental factors to sow and boar fertility. In comparison, literature reports on the impact of modified forms of DON and ZEN, such as de-epoxy-DON (DOM-1) and hydrolyzed ZEN (HZEN), on swine reproduction are scarce. The aim of our study was to compare the effects of DON, DOM-1, ZEN and HZEN on boar semen in vitro. To this end, pooled boar semen ejaculates from two adult boars were treated with either 50.6 μM DON, 62.8 μM ZEN or equimolar concentrations of DOM-1 and HZEN, respectively (dilution volume of v/v 0.7% DMSO in all cases). Effects on semen motility, morphology, viability, hypo-osmotic swelling test reaction and DNA integrity were investigated hourly up to four hours of incubation. DON negatively affected particular parameters evaluated with a computer-assisted sperm analysis system (CASA), such as immotile spermatozoa and progressive motile spermatozoa, whereas those effects were absent in the case of DOM-1 treatment. In contrast to HZEN, ZEN affected almost all CASA parameters. Furthermore, only ZEN decreased the proportion of viable spermatozoa and increased the proportion of spermatozoa with abnormalities. In conclusion, DON and ZEN negatively affected boar semen in vitro, whereas equimolar concentrations of DOM-1 and HZEN did not induce harmful effects.

Adverse Effects of Fusarium Toxins in Ruminants: A Review of In Vivo and In Vitro Studies

With an increased knowledge of the mechanism of action of Fusarium mycotoxins, the concept that these substances are deleterious only for monogastric species is obsolete. Indeed, most mycotoxins can be converted into less toxic compounds by the rumen microflora from healthy animals. However, mycotoxin absorption and its conversion to more toxic metabolites, as well as their impact on the immune response and subsequently animal welfare, reproductive function, and milk quality during chronic exposure should not be neglected. Among the Fusarium mycotoxins, the most studied are deoxynivalenol (DON), zearalenone (ZEN), and fumonisins from the B class (FBs). It is remarkable that there is a paucity of in vivo research, with a low number of studies on nutrient digestibility and rumen function. Most of the in vitro studies are related to the reproductive function or are restricted to rumen incubation. When evaluating the production performance, milk yield is used as an evaluated parameter, but its quality for cheese production is often overlooked. In the present review, we summarize the most recent findings regarding the adverse effects of these mycotoxins with special attention to dairy cattle.

Effect-Directed Analysis Based on the Reduced Human Transcriptome (RHT) to Identify Organic Contaminants in Source and Tap Waters along the Yangtze River

Since a large number of contaminants are detected in source waters (SWs) and tap waters (TWs), it is important to perform a comprehensive effect evaluation and key contributor identification. A reduced human transcriptome (RHT)-based effect-directed analysis, which consisted of a concentration-dependent RHT to reveal the comprehensive effects and noteworthy pathways and systematic identification of key contributors based on the interactions between compounds and pathway effects, was developed and applied to typical SWs and TWs along the Yangtze River. By RHT, 42% more differentially expressed genes and 33% more pathways were identified in the middle and lower reaches, indicating heavier pollution. Hormone and immune pathways were prioritized based on the detection frequency, sensitivity, and removal efficiency, among which the estrogen receptor pathway was the most noteworthy. Consistent with RHT, estrogenic effects were widespread along the Yangtze River based on in vitro evaluations. Furthermore, 38 of 100 targets, 39 pathway-related suspects, and 16 estrogenic nontargets were systematically identified. Among them, diethylstilbestrol was the dominant contributor, with the estradiol equivalent (EEQ) significantly correlated with EEQ_water. In addition, zearalenone and niclosamide explained up to 54% of the EEQ_water. The RHT-based EDA method could support the effect evaluation, contributor identification, and risk management of micropolluted waters.

Nutritional impact of mycotoxins in food animal production and strategies for mitigation

Mycotoxins are toxic secondary metabolites produced by filamentous fungi that are commonly detected as natural contaminants in agricultural commodities worldwide. Mycotoxin exposure can lead to mycotoxicosis in both animals and humans when found in animal feeds and food products, and at lower concentrations can affect animal performance by disrupting nutrient digestion, absorption, metabolism, and animal physiology. Thus, mycotoxin contamination of animal feeds represents a significant issue to the livestock industry and is a health threat to food animals. Since prevention of mycotoxin formation is difficult to undertake to avoid contamination, mitigation strategies are needed. This review explores how the mycotoxins aflatoxins, deoxynivalenol, zearalenone, fumonisins and ochratoxin A impose nutritional and metabolic effects on food animals and summarizes mitigation strategies to reduce the risk of mycotoxicity.

ZEA and DON inhibited inflammation after L. monocytogenes infection and induced ribosomal hyperfunction

The complex microbial community in food environment is a major problem of human or animal health and safety. Mycotoxins and food-borne bacteria can both induce inflammation in the body and cause a series of changes in biological functions. In this study, mice were gavaged with low doses of ZEA, DON, or ZEA + DON, and then infected with L. monocytogenes. A cytokine microarray, including 40 inflammation-related serum cytokines, and proteomics were used to verify the effects of ZEA, DON, and ZEA + DON on the host inflammation and biological function after L. monocytogenes infection. The results showed that mononucleosis after bacterial infection was inhibited by ZEA, DON, and ZEA + DON, while the balance of macrophage differentiation was shifted toward M2-type. ZEA, DON, and ZEA + DON decreased the levels of serum proinflammatory cytokines IL-1β and IL-12 after infection. In addition, the signal of the NF-κB pathway was inhibited. Proteomic results showed that ZEA, DON, and ZEA + DON led to biological dysfunction in ribosomal and metabolic cells, primarily leading to abnormal ribosomal hyperfunction. This study showed that ZEA, DON, and ZEA + DON can aggravate disease progression by inhibiting the inflammatory response following foodborne bacterial infection. These metabolites may also disrupt normal biological functions, which may lead to ribosomal hyperfunction, making bacterial clearance more difficult.

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.

Practical Application of Urinary Zearalenone Monitoring System for Feed Hygiene Management of a Japanese Black Cattle Breeding Herd—The Relationship between Monthly Anti-Müllerian Hormone and Serum Amyloid A Concentrations

This study addresses an advantageous application of a urinary zearalenone (ZEN) monitoring system not only for surveillance of ZEN exposure at the production site of breeding cows but also for follow-up monitoring after improvement of feeds provided to the herd. As biomarkers of effect, serum levels of the anti-Müllerian hormone (AMH) and serum amyloid A (SAA) concentrations were used. Based on the results of urinary ZEN measurement, two cows from one herd had urinary ZEN concentrations which were two orders of magnitude higher (ZEN: 1.34 mg/kg, sterigmatocystin (STC): 0.08 mg/kg in roughages) than the levels of all cows from three other herds (ZEN: not detected, STC: not detected in roughages). For the follow-up monitoring of the herd with positive ZEN and STC exposure, urine, blood, and roughage samples were collected from five cows monthly for one year. A monitoring series in the breeding cattle herd indicated that feed concentrations were not necessarily reflected in urinary concentrations; urinary monitoring assay by ELISA may be a simple and accurate method that reflects the exposure/absorption of ZEN. Additionally, although the ZEN exposure level appeared not to be critical compared with the Japanese ZEN limitation in dietary feeds, a negative regression trend between the ZEN and AMH concentrations was observed, indicating that only at extremely universal mycotoxin exposure levels, ZEN exposure may affect the number of antral follicles in cattle. A negative regression trend between the ZEN and SAA concentrations could also be demonstrated, possibly indicating the innate immune suppression caused by low-level chronic ZEN exposure. Finally, significant differences (p = 0.0487) in calving intervals between pre-ZEN monitoring (mean ± SEM: 439.0 ± 41.2) and post-ZEN monitoring (349.9 ± 6.9) periods were observed in the monitored five cows. These preliminary results indicate that the urinary ZEN monitoring system may be a useful practical tool not only for detecting contaminated herds under field conditions but also provides an initial look at the effects of long-term chronic ZEN/STC (or other co-existing mycotoxins) exposure on herd productivity and fertility.

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.

Evaluation of a Yeast Hydrolysate from a Novel Strain of Saccharomyces cerevisiae for Mycotoxin Mitigation using In Vitro and In Vivo Models

Mycotoxicoses in animals are caused by exposure to mycotoxin-contaminated feeds. Disease risk is managed using dietary adsorbing agents which reduce oral bioavailability. The objective of this work was to evaluate the efficacy of three selected yeast products as mycotoxin binders using in vitro and in vivo models. Their capacity to adsorb deoxynivalenol (DON), zearalenone (ZEA), and ochratoxin A (OTA) was evaluated using an in vitro model designed to simulate the pH conditions during gastric passage in a monogastric animal. Results showed that only one product, an enzymatic yeast hydrolysate (YHY) of a novel strain Saccharomyces cerevisiae, adsorbed about 45% of DON in solution. Next, we determined the effect of YHY on oral absorption of a DON, ZEA, and OTA mixture using a toxicokinetic model in swine. Toxicokinetic modeling of the plasma concentration-time profiles of DON, OTA, and zearalenone-glucuronide (ZEA-GlcA) showed that YHY tended to reduce the maximal plasma concentration of OTA by 17%. YHY did not reduce oral bioavailability of OTA, DON, and ZEA-GlcA. Within the context of this experiment, and despite some positive indications from both the in vitro and in vivo models employed, we conclude that the YHY prototype was not an effective agent for multiple mycotoxin adsorption.

Isoflavones in Animals: Metabolism and Effects in Livestock and Occurrence in Feed

Soybeans are a common ingredient of animal feed. They contain isoflavones, which are known to act as phytoestrogens in animals. Isoflavones were described to have beneficial effects on farm animals. However, there are also reports of negative outcomes after the consumption of isoflavones. This review summarizes the current knowledge of metabolization of isoflavones (including the influence of the microbiome, phase I and phase II metabolism), as well as the distribution of isoflavones and their metabolites in tissues. Furthermore, published studies on effects of isoflavones in livestock species (pigs, poultry, ruminants, fish) are reviewed. Moreover, published studies on occurrence of isoflavones in feed materials and co-occurrence with zearalenone are presented and are supplemented with our own survey data.

Proteomic analysis of zearalenone toxicity on mouse thymic epithelial cells

Zearalenone (ZEA) is one of the most major food contaminants in cereal crops worldwide, risking health of both livestock and humans. This study aimed to assess the cytotoxicity and the underlying mechanism of ZEA on thymic epithelial cells. By using proteomics analysis, we identified 596 differentially expressed proteins in MTEC1 cells upon zearalenone exposure, of which 245 were upregulated and 351 were downregulated. Gene ontology (GO) analysis suggested that differentially expressed proteins were participated in protein synthesis, oxidative phosphorylation, and ATP binding. KEGG pathway enrichment analysis showed that differentially expressed proteins were mainly related to mitochndrial metabolism, such as citrate cycle (TCA cycle) and oxidative phosphorylation. We demonstrated that ZEA treatment was able to increase the intracellular reactive oxygen species (ROS) level, to decrease ΔΨm, ATP level, and the copy number of mtDNA, leading to necrotic cell death. Moreover, we showed that ZEA treatment inhibited cell proliferation and induced G2/M phase arrest by downregulation of proliferation-associated proteins ERK, p-ERK, CDK1, and p-CHK1. Taken together, we found that the toxicity of ZEA on thymic epithelial cells is mainly caused by the inhibition of mitochondrial dysfunction and cell proliferation. Our study might open new avenues for treatment strategies.

Intestinal Barrier, Claudins and Mycotoxins

The intestinal barrier is the main barrier against all of the substances that enter the body. Proper functioning of this barrier guarantees maintained balance in the organism. Mycotoxins are toxic, secondary fungi metabolites, that have a negative impact both on human and animal health. It was postulated that various mycotoxins may affect homeostasis by disturbing the intestinal barrier. Claudins are proteins that are involved in creating tight junctions between epithelial cells. A growing body of evidence underlines their role in molecular response to mycotoxin-induced cytotoxicity. This review summarizes the information connected with claudins, their association with an intestinal barrier, physiological conditions in general, and with gastrointestinal cancers. Moreover, this review also includes information about the changes in claudin expression upon exposition to various mycotoxins.

Male reproductive toxicity of zearalenone-meta-analysis with mechanism review

Zearalenone (ZEA) is an oestrogen-like mycotoxin produced by Fusarium fungi, which has a considerable impact on human and animal health and results in substantial economic losses worldwide. This study aimed to demonstrate the reproductive injury induced by ZEA in rodents. We conducted a rigorous meta-analysis of the related literature via PubMed, Embase, and Web of Science. The scope of the study includes the following: development of reproductive organs, serum testosterone, oestradiol, and luteinizing hormone (LH) levels; parameters of Leydig cells; and parameters of semen. In total, 19 articles were reviewed. Compared with the control group, the increased relative epididymis weight, increased serum oestradiol level, and decreased LH levels in the prenatally exposed group were observed. In pubertal and adult rodents, the relative testicular weight, serum oestradiol level, Leydig cell number, and percentage of ST (+) Leydig cells decreased under ZEA exposure. In rodents at all ages, decreased serum testosterone level, sperm concentration, sperm motility rate, and increased serum deformity rate were observed in exposed groups compared with control groups. Although subgroup analysis failed to identify a clear dose-response relationship between ZEA exposure and reproductive system damage in male rodents, we still managed to confirm that zearalenone could decrease the serum testosterone level at the dosage of 50 mg/kg*day, 1.4 mg/kg*day, and 84 mg/kg*day, of prenatal, pubertal, and mature rodents respectively; pubertal zearalenone exposure impairs the quality and quantity of sperms of rodents at the dosage of 1.4 mg/kg*day and mature zearalenone exposure has the same effect at the dosage of 84 mg/kg*day. In conclusion, we found that ZEA exposure can cause considerable damage to the reproductive system of rodents of all ages. While the exact underlying mechanism of ZEA-induced toxicity in the reproductive system remains largely unknown, the theories of oestrogen-like effects and oxidative stress damage are promising.

Serological biomarkers of zearalenone exposure in beef heifers receiving anti-mycotoxin additive

The inclusion of anti-mycotoxin additives (AMA) in the diet of production animals has been widely used to avoid mycotoxin exposure. In order to confirm the efficacy of such products in vivo, measurement of mycotoxins and/or their metabolites in biological fluids is preconized. This study aimed at determining the serological biomarkers of zearalenone (ZEN), α-zearalenol, β-zearalenol, α-zearalanol, β-zearalanol (β-ZAL) and zearalanone, to evaluate the efficacy of an AMA in beef heifers. The trial lasted 37 days: 11 days of adaptation, 21 days of actual experiment, and 5 days of regression. Twenty-four heifers were randomly assigned to receive one of the following treatments (n=6/group): (T1) basal diet (control); (T2) basal diet + 5 mg/kg of ZEN; (T3) basal diet + 5 mg/kg of ZEN + 2.5 kg/t of AMA; and (T4) basal diet + 5 mg/kg of ZEN + 5.0 kg/t of AMA. Blood sampling was performed on different days after the diet was given. The samples were centrifuged to obtain the blood serum, and then analysed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). β-ZAL was detected above the limit of quantification both in the unconjugated (>0.60 ng/ml) and conjugated (>0.90 ng/ml) forms. The remaining metabolites presented concentrations under the limit of detection. In the efficacy evaluation of the AMA, there was no significant difference (P>0.05) between the treatments with and without additive at the tested levels of inclusion. Thus, β-ZAL may be employed as a biomarker of ZEN exposure via diet to evaluate the efficacy of an AMA through serological parameters. The technique applied in this study proved to be an adequate alternative for in vivo confirmation of the efficacy of products in adsorbing the toxin.

The Influence of Zearalenone on Selected Hemostatic Parameters in Sexually Immature Gilts

Vascular toxicity induced by xenobiotics is associated with dysfunctions or damage to endothelial cells, changes in vascular permeability or dysregulation of the vascular redox state. The aim of this study was to determine whether per os administration of zearalenone (ZEN) influences selected hemostatic parameters in prepubertal gilts. This study was performed on female gilts divided into a control group which received placebo and an experimental group which received ZEN at a dose of 5.0 µg·kg⁻¹ b.w. × day⁻¹. On days 14, 28 and 42, blood samples were collected from the animals for analyses of hematological, coagulation and fibrinolysis parameters, nitric oxide, von Willebrand factor antigen content and catalase activity. The results demonstrated that the treatment of gilts with ZEN at a dose below no observable adverse effect level did not affect the primary hemostasis and the blood coagulation cascade. However, ZEN could have temporarily affected the selected indicators of endothelial cell function (increase of von Willebrand factor, decrease of nitric oxide levels) and the oxidative status plasma (decrease of catalase activity) of the exposed gilts. In summary, these results suggest that the adaptive response to ZEN-exposure can induce a transient imbalance in the vascular system by acting on vascular endothelial cells.

The Effects of Mixed Fusarium Mycotoxins at EU-Permitted Feed Levels on Weaned Piglets' Tissue Lipids

At exactly the individual permitted EU-tolerance dietary limits, fumonisins (FB: 5 mg/kg diet) and mixed fusariotoxins (DZ: 0.9 mg deoxynivalenol + 0.1 mg zearalenone/kg diet, and FDZ: 5 mg fumonisins + 0.9 mg deoxynivalenol + 0.1 mg zearalenone/kg diet) were administered to piglets (n = 6/group) for three weeks. Bodyweights of intoxicated piglets increased, while feed conversion ratios decreased. In FDZ, both the absolute and relative weight of the liver decreased. In the renal-cellular membrane, the most pronounced alterations were in FDZ treatment, followed by individual FB exposure. In both treatments, high proportions of C20:0 and C22:0 with low fatty acid (FA) unsaturation were found. In hepatocyte phospholipids, FDZ toxins exerted antagonistic interactions, and FB had the strongest increasing effect on FA monounsaturation. Among all investigated organs, the spleen lipids were the least responsive, in which FDZ expressed synergistic reactions on C20:0 (↑ FDZ vs. FB) and C22:0 (↓ FDZ vs. DZ). The antioxidant defense of the kidney was depleted (↓ glutathione concentration by FB-exposure). Blood plasma indicated renal injury (profound increase of urea and creatinine in FB vs. DZ and FDZ). FB strongly increased total-cholesterol and low density lipoprotein concentrations, whereas FDZ synergistically increased gamma-glutamyltransferase, alkaline-phosphatase, calcium and phosphorus levels. Summarized, individual and combined multiple fusariotoxins modified the membrane lipid profile and antioxidant defense of splanchnic organs, and serum biochemicals, without retarding growth in piglets.

Mycotoxins Affecting Animals, Foods, Humans, and Plants: Types, Occurrence, Toxicities, Action Mechanisms, Prevention, and Detoxification Strategies-A Revisit

Mycotoxins are produced by fungi and are known to be toxic to humans and animals. Common mycotoxins include aflatoxins, ochratoxins, zearalenone, patulin, sterigmatocystin, citrinin, ergot alkaloids, deoxynivalenol, fumonisins, trichothecenes, Alternaria toxins, tremorgenic mycotoxins, fusarins, 3-nitropropionic acid, cyclochlorotine, sporidesmin, etc. These mycotoxins can pose several health risks to both animals and humans, including death. As several mycotoxins simultaneously occur in nature, especially in foods and feeds, the detoxification and/or total removal of mycotoxins remains challenging. Moreover, given that the volume of scientific literature regarding mycotoxins is steadily on the rise, there is need for continuous synthesis of the body of knowledge. To supplement existing information, knowledge of mycotoxins affecting animals, foods, humans, and plants, with more focus on types, toxicity, and prevention measures, including strategies employed in detoxification and removal, were revisited in this work. Our synthesis revealed that mycotoxin decontamination, control, and detoxification strategies cut across pre-and post-harvest preventive measures. In particular, pre-harvest measures can include good agricultural practices, fertilization/irrigation, crop rotation, using resistant varieties of crops, avoiding insect damage, early harvesting, maintaining adequate humidity, and removing debris from the preceding harvests. On the other hand, post-harvest measures can include processing, chemical, biological, and physical measures. Additionally, chemical-based methods and other emerging strategies for mycotoxin detoxification can involve the usage of chitosan, ozone, nanoparticles, and plant extracts.

Impact of Fusarium-Derived Mycoestrogens on Female Reproduction: A Systematic Review

Contamination of the world’s food supply and animal feed with mycotoxins is a growing concern as global temperatures rise and promote the growth of fungus. Zearalenone (ZEN), an estrogenic mycotoxin produced by Fusarium fungi, is a common contaminant of cereal grains and has also been detected at lower levels in meat, milk, and spices. ZEN’s synthetic derivative, zeranol, is used as a growth promoter in United States (US) and Canadian beef production. Experimental research suggests that ZEN and zeranol disrupt the endocrine and reproductive systems, leading to infertility, polycystic ovarian syndrome-like phenotypes, pregnancy loss, and low birth weight. With widespread human dietary exposure and growing experimental evidence of endocrine-disrupting properties, a comprehensive review of the impact of ZEN, zeranol, and their metabolites on the female reproductive system is warranted. The objective of this systematic review was to summarize the in vitro, in vivo, and epidemiological literature and evaluate the potential impact of ZEN, zeranol, and their metabolites (commonly referred to as mycoestrogens) on female reproductive outcomes. We conducted a systematic review (PROSPERO registration CRD42020166469) of the literature (2000–2020) following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The data sources were primary literature published in English obtained from searching PubMed, Web of Science, and Scopus. The ToxR tool was applied to assess risk of bias. In vitro and in vivo studies (n = 104) were identified and, overall, evidence consistently supported adverse effects of mycoestrogens on physiological processes, organs, and tissues associated with female reproduction. In non-pregnant animals, mycoestrogens alter follicular profiles in the ovary, disrupt estrus cycling, and increase myometrium thickness. Furthermore, during pregnancy, mycoestrogen exposure contributes to placental hemorrhage, stillbirth, and impaired fetal growth. No epidemiological studies fitting the inclusion criteria were identified.

Concentrations of zearalenone and its metabolites in female wild boars from woodlands and farmlands

As a valuable food base and safe shelter, large agricultural fields create favourable living conditions for wild boars for most of the year. The occurrence of mould in these fields, causing hormonal disturbances, may lead to a lower age of sexual maturity and a prolonged breeding season, and therefore, the population growth in farmlands can be markedly higher than that in extensive woodlands. This study was initiated because of reproductive cycle disturbances in wild boar populations, which were presumably linked with habitat and food types, especially rotten maize. To determine if the major sources of zearalenone (ZEN) in female wild boars are maize cobs infected with mycotoxins, we compared the concentrations of ZEN and its metabolites in organs, tissues and body fluids of wild boars hunted in extensive maize fields and in extensive woodlands where no large maize fields were located within a distance of several km. Samples of blood, bile, liver, kidneys, muscles, urine, stomach and colon contents as well as ovaries from young female wild boars (40-60 kg) were collected in 2011-2014 and prepared for liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The results showed that ZEN was present in most of the samples, from both farmlands and woodlands, but its concentration within individual types of the analysed body fluids or tissues differed depending mainly on habitat type. In nearly all the analysed cases, higher concentrations of ZEN and its derivatives were detected in the samples collected from wild boars in farmlands, suggesting that wild boars living and feeding in extensive maize fields take in markedly higher amounts of mycoestrogens.

Metabolism of Zearalenone in the Rumen of Dairy Cows with and without Application of a Zearalenone-Degrading Enzyme

The mycotoxin zearalenone (ZEN) is a frequent contaminant of animal feed and is well known for its estrogenic effects in animals. Cattle are considered less sensitive to ZEN than pigs. However, ZEN has previously been shown to be converted to the highly estrogenic metabolite α-zearalenol (α-ZEL) in rumen fluid in vitro. Here, we investigate the metabolism of ZEN in the reticulorumen of dairy cows. To this end, rumen-fistulated non-lactating Holstein Friesian cows (n = 4) received a one-time oral dose of ZEN (5 mg ZEN in 500 g concentrate feed) and the concentrations of ZEN and ZEN metabolites were measured in free rumen liquid from three reticulorumen locations (reticulum, ventral sac and dorsal mat layer) during a 34-h period. In all three locations, α-ZEL was the predominant ZEN metabolite and β-zearalenol (β-ZEL) was detected in lower concentrations. ZEN, α-ZEL and β-ZEL were eliminated from the ventral sac and reticulum within 34 h, yet low concentrations of ZEN and α-ZEL were still detected in the dorsal mat 34 h after ZEN administration. In a second step, we investigated the efficacy of the enzyme zearalenone hydrolase ZenA (EC 3.1.1.-, commercial name ZENzyme^®, BIOMIN Holding GmbH, Getzersdorf, Austria) to degrade ZEN to the non-estrogenic metabolite hydrolyzed zearalenone (HZEN) in the reticulorumen in vitro and in vivo. ZenA showed a high ZEN-degrading activity in rumen fluid in vitro. When ZenA was added to ZEN-contaminated concentrate fed to rumen-fistulated cows (n = 4), concentrations of ZEN, α-ZEL and β-ZEL were significantly reduced in all three reticulorumen compartments compared to administration of ZEN-contaminated concentrate without ZenA. Upon ZenA administration, degradation products HZEN and decarboxylated HZEN were detected in the reticulorumen. In conclusion, endogenous metabolization of ZEN in the reticulorumen increases its estrogenic potency due to the formation of α-ZEL. Our results suggest that application of zearalenone hydrolase ZenA as a feed additive may be a promising strategy to counteract estrogenic effects of ZEN in cattle.

Zearalenone and Its Metabolites-General Overview, Occurrence, and Toxicity

Mycotoxins are secondary metabolites of filamentous fungi and represent one of the most common groups of food contaminants with low molecular weight. These toxins are considered common and can affect the food chain at various stages of production, harvesting, storage and processing. Zearalenone is one of over 400 detected mycotoxins and produced by fungi of the genus Fusarium; it mainly has estrogenic effects on various organisms. Contaminated products can lead to huge economic losses and pose risks to animals and humans. In this review, we systemize information on zearalenone and its major metabolites.

Effect of Gamma-Radiation on Zearalenone-Degradation, Cytotoxicity and Estrogenicity

Zearalenone (ZEA) is produced in cereals by different species of Fusarium, being a non-steroidal estrogenic mycotoxin. Despite having a low acute toxicity, ZEA strongly interferes with estrogen receptors. Gamma-radiation has been investigated to eliminate mycotoxins from food and feed, showing promising results. The present study aims to investigate the gamma-radiation effect on ZEA at different moisture conditions and to evaluate the cytotoxicity and estrogenicity of the irradiated ZEA. Different concentrations of dehydrated ZEA and aqueous solutions of ZEA were exposed to gamma-radiation doses ranging from 0.4 to 8.6 kGy and the mycotoxin concentration determined after exposure by high performance liquid chromatography (HPLC) with fluorescence detection. Following this, the cytotoxicity of irradiated samples was assessed in HepG2 cells, by measuring alterations of metabolic activity, plasma membrane integrity and lysosomal function, and their estrogenicity by measuring luciferase activity in HeLa 9903 cells. Gamma-radiation was found to be effective in reducing ZEA, with significant increases in degradation with increased moisture content. Furthermore, a reduction of cytotoxicity with irradiation was observed. ZEA estrogenicity was also increasingly reduced with increasing radiation doses, but mainly in aqueous solutions. These results suggest reduction of ZEA levels and of its toxicity in food and feed commodities may be achieved by irradiation.

A mycotoxin-deactivating feed additive counteracts the adverse effects of regular levels of Fusarium mycotoxins in dairy cows

Little is known about the effects of commonly found levels of Fusarium mycotoxins on the performance, metabolism, and immunity of dairy cattle. We investigated the effects of regular contamination levels, meaning contamination levels that can be commonly detected in dairy feeds, of deoxynivalenol (DON) and fumonisins (FB) in total mixed ration (TMR) on the performance, diet digestibility, milk quality, and plasma liver enzymes in dairy cows. This trial examined 12 lactating Holstein dairy cows using a 3-period × 3-treatment Latin square design. The experimental period was 21 d of mycotoxin exposure followed by 14 d of washout. During treatment periods, cows received one of 3 diets: (1) CTR (control) diet of TMR contaminated with 340.5 µg of DON/kg of dry matter (DM) and 127.9 µg FB/kg of DM; (2) MTX diet of TMR contaminated with Fusarium mycotoxins at levels higher than CTR but below US and European Union guidelines (i.e., 733.0 µg of DON/kg of DM and 994.4 µg of FB/kg of DM); or (3) MDP diet, which was MTX diet supplemented with a mycotoxin deactivator product (i.e., 897.3 µg of DON/kg of DM and 1,247.1 µg of FB/kg of DM; Mycofix, 35 g/animal per day). During washout, all animals were fed the same CTR diet. Body weight, body condition score, DM intake, dietary nutrient digestibility, milk production, milk composition and rennet coagulation properties, somatic cell count, blood serum chemistry, hematology, serum immunoglobulin concentrations, and expression of multiple genes in circulating leucocytes were measured. Milk production was significantly greater in the CTR group (37.73 kg/d) than in the MTX (36.39 kg/d) and the MDP (36.55 kg/d) groups. Curd firmness and curd firming time were negatively affected by the MTX diet compared with the other 2 diets. Furthermore, DM and neutral detergent fiber digestibility were lower after the MTX diet than after the CTR diet (67.3 vs. 71.0% and 42.8 vs. 52.3%). The MDP diet had the highest digestibility coefficients for DM (72.4%) and neutral detergent fiber (53.6%) compared with the other 2 diets. The activities of plasma liver transaminases were higher after the MTX diet than after the CTR and MDP diets. Compared with the CTR diet, the MTX diet led to slightly lower expression of genes related to immune and inflammatory functions, indicating that Fusarium mycotoxins had an immunosuppressive effect. Our results indicated that feed contaminated with regular levels of Fusarium mycotoxins adversely affected the performance, milk quality, diet digestibility, metabolic variables, and immunity of dairy cows, and that supplementation with mycotoxin deactivator product counteracted most of these negative effects.

Zearalenone (ZEN) in Livestock and Poultry: Dose, Toxicokinetics, Toxicity and Estrogenicity

One of the concerns when using grain ingredients in feed formulation for livestock and poultry diets is mycotoxin contamination. Aflatoxin, fumonisin, ochratoxin, trichothecene (deoxynivalenol, T-2 and HT-2) and zearalenone (ZEN) are mycotoxins that have been frequently reported in animal feed. ZEN, which has raised additional concern due to its estrogenic response in animals, is mainly produced by Fusarium graminearum (F. graminearum), F. culmorum, F. cerealis, F. equiseti, F. crookwellense and F. semitectums, and often co-occurs with deoxynivalenol in grains. The commonly elaborated derivatives of ZEN are α-zearalenol, β-zearalenol, zearalanone, α-zearalanol, and β-zearalanol. Other modified and masked forms of ZEN (including the extractable conjugated and non-extractable bound derivatives of ZEN) have also been quantified. In this review, common dose of ZEN in animal feed was summarized. The absorption rate, distribution (“carry-over”), major metabolites, toxicity and estrogenicity of ZEN related to poultry, swine and ruminants are discussed.

The Effect of Zearalenone on the Cytokine Environment, Oxidoreductive Balance and Metabolism in Porcine Ileal Peyer's Patches

The aim of the present study was to determine the effect of zearalenone (ZEN), administered per os to gilts at doses equivalent to 50%, 100%, and 150% of no-observed-adverse-effect level (NOAEL) values for 14, 28, and 42 days during weaning, on changes in the parameters of the oxidoreductive balance, cytokine secretion, and basal metabolism in ileal Payer’s patches. Immunoenzymatic ELISA tests and biochemical methods were used to measure the concentrations of interleukin 1α, interleukin 1β, interleukin 12/23p40, interleukin 2, interferon γ, interleukin 4, interleukin 6, interleukin 8, tumor necrosis factor α, interleukin 10, transforming growth factor β, malondialdehyde, sulfhydryl groups, fructose, glucose, and proline, as well as the activity of peroxidase, superoxide dismutase and catalase. The study demonstrated that ZEN doses corresponding to 50%, 100%, and 150% of NOAEL values, i.e., 5 µg, 10 µg, and 15 µg ZEN/kg BW, respectively, have proinflammatory properties, exacerbate oxidative stress responses, and disrupt basal metabolism in ileal Payer’s patches in gilts.

Proteome changes induced by a short, non-cytotoxic exposure to the mycoestrogen zearalenone in the pig intestine

Intestinal epithelial homeostasis is regulated by a complex network of signaling pathways. Among them is estrogen signaling, important for the proliferation and differentiation of epithelial cells, immune signaling and metabolism. The mycotoxin zearalenone (ZEN) is an estrogen disruptor naturally found in food and feed. The exposure of the intestine to ZEN has toxic effects including alteration of the immune status and is possibly implicated in carcinogenesis, but the molecular mechanisms linked with these effects are not clear. Our objective was to explore the proteome changes induced by a short, non-cytotoxic exposure to ZEN in the intestine using pig jejunal explants. Our results indicated that ZEN promotes little proteome changes, but significantly related with an induction of ERα signaling and a consequent disruption of highly interrelated signaling cascades, such as NF-κB, ERK1/2, CDX2 and HIF1α. The toxicity of ZEN leads also to an altered immune status characterized by the activation of the chemokine CXCR4/SDF-1 axis and an accumulation of MHC-I proteins. Our results connect the estrogen disrupting activity of ZEN with its intestinal toxic effect, associating the exposure to ZEN with cell-signaling disorders similar to those involved in the onset and progression of diseases such as cancer and chronic inflammatory disorders. SIGNIFICANCE: The proteomics results presented in our study indicate that the endocrine disruptor activity of ZEN is able to regulate a cascade of highly inter-connected signaling events essential for the small intestinal crypt-villus cycle and immune status. These molecular mechanisms are also implicated in the onset and progress of intestinal immune disorders and cancer indicating that exposure to ZEN could play an important role in intestinal pathogenesis.