Zearalenone induces immunotoxicity in mice: possible protective effects of radish extract (Raphanus sativus)

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.

Toxicity, biodegradation, and nutritional intervention mechanism of zearalenone

Zearalenone (ZEA), a global mycotoxin commonly found in a variety of grain products and animal feed, causes damage to the gastrointestinal tract, immune organs, liver and reproductive system. Many treatments, including physical, chemical and biological methods, have been reported for the degradation of ZEA. Each degradation method has different degradation efficacies and distinct mechanisms. In this article, the global pollution status, hazard and toxicity of ZEA are summarized. We also review the biological detoxification methods and nutritional regulation strategies for alleviating the toxicity of ZEA. Moreover, we discuss the molecular detoxification mechanism of ZEA to help explore more efficient detoxification methods to better reduce the global pollution and hazard of ZEA.

Phenolic compounds as natural microbial toxin detoxifying agents

Despite the abundance of promising studies, developments, and improvements about the elimination of microbial toxins from food matrices, they are still considered as one of the major food safety problems due to the lack of their complete avoidance even today. Every year, many crops and foodstuffs have to be discarded due to unconstrained contamination and/or production of microbial toxins. Furthermore, the difficulty for the detection of toxin presence and determination of its level in foods may lead to acute or chronic health problems in many individuals. On the other hand, phenolic compounds might be considered as microbial toxin detoxification agents because of their inhibition effect on the toxin synthesis of microorganisms or exhibiting protective effects against varying damaging mechanisms caused by toxins. In this study, the effect of phenolic compounds on the synthesis of bacterial toxins and mycotoxins is comprehensively reviewed. The potential curing effect of phenolic compounds against toxin-induced damages has also been discussed. Consequently, phenolic compounds are indicated as promising, and considerable natural preservatives against toxin damages and their detoxification potentials are pronounced.

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.

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.

Does probiotic Kefir reduce dyslipidemia, hematological disorders and oxidative stress induced by zearalenone toxicity in wistar rats?

Zearalenone (ZEA) is a toxic metabolite of the genus Fusarium, which causes hepatotoxicity and induces oxidative stress. Kefir is an important probiotic dairy-product showing important in vitro antioxidant potential. In this study, the effect of Kefir supplementation to mitigate ZEA toxicity in rats was investigated. Animals were divided into four groups of five rats each, which received sterile milk (200 μL/day) during the first week. Then, they were switched to Kefir (200 μL/day), ZEA (40 mg/kg b. w./day) and Kefir + ZEA for the second week. Hematological and biochemical parameters, as well as liver histological analysis were determined. Kefir administration prevented the changes occurred in the count of all blood cells, and improved the antioxidant enzymes in the liver, such as catalase, glutathione peroxidase and superoxide dismutase activities that increased by 6, 4.5 and 1.3 folds, respectively, compared to ZEA group. Interestingly, the concurrent regimen Kefir + ZEA removed ZEA residues in the serum and liver. Furthermore, the Kefir + ZEA group showed a reduction in the levels of bilirubin, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and hepatic malonaldehyde by ∼82, 54, 66, 50 and 36%, respectively, compared to the ZEA group. The histopathological analysis showed a normal liver histological architecture in Kefir + ZEA group, while degenerative changes were observed in ZEA group. These results suggest that Kefir as probiotic consortium may have a hepatoprotective effect against ZEA poisoning.

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Zearalenone caused oxidative stress and liver damage in rats.

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Zearalenone induced disruption of hematological and biochemical parameters.

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Kefir improved the antioxidant defense systems in rats subjected to Zearalenone.

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Kefir prevented Zearalenone-induced hepatotoxicity in rats.

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.

The Impact of Estrogens and Their Receptors on Immunity and Inflammation during Infection

Simple Summary

Human health is significantly affected by microbial infections. One of the largest determinants of the outcomes of such infections is the host immune response. Too weak of a response can lead to enhanced spread by the pathogen, while an overstimulated response can lead to immune-induced tissue damage. Thus, to effectively treat infected individuals, it is critical to understand the regulators that control inflammatory responses. Recently, it has become widely accepted that estrogens, a class of sex hormones, are capable of dramatically altering the responses of host cells to microbes. In this review, we discuss how estrogens change the host immune response, as well as how these changes can alter the outcome of the infection for the individual.

Abstract

Sex hormones, such as estrogen and testosterone, are steroid compounds with well-characterized effects on the coordination and development of vertebrate reproductive systems. Since their discovery, however, it has become clear that these “sex hormones” also regulate/influence a broad range of biological functions. In this review, we will summarize some current findings on how estrogens interact with and regulate inflammation and immunity. Specifically, we will focus on describing the mechanisms by which estrogens alter immune pathway activation, the impact of these changes during infection and the development of long-term immunity, and how different types of estrogens and their respective concentrations mediate these outcomes.

Zearalenone and the Immune Response

Zearalenone (ZEA) is an estrogenic fusariotoxin, being classified as a phytoestrogen, or as a mycoestrogen. ZEA and its metabolites are able to bind to estrogen receptors, 17β-estradiol specific receptors, leading to reproductive disorders which include low fertility, abnormal fetal development, reduced litter size and modification at the level of reproductive hormones especially in female pigs. ZEA has also significant effects on immune response with immunostimulatory or immunosuppressive results. This review presents the effects of ZEA and its derivatives on all levels of the immune response such as innate immunity with its principal component inflammatory response as well as the acquired immunity with two components, humoral and cellular immune response. The mechanisms involved by ZEA in triggering its effects are addressed. The review cited more than 150 publications and discuss the results obtained from in vitro and in vivo experiments exploring the immunotoxicity produced by ZEA on different type of immune cells (phagocytes related to innate immunity and lymphocytes related to acquired immunity) as well as on immune organs. The review indicates that despite the increasing number of studies analyzing the mechanisms used by ZEA to modulate the immune response the available data are unsubstantial and needs further works.

Occurrence, Impact on Agriculture, Human Health, and Management Strategies of Zearalenone in Food and Feed: A Review

Mycotoxins represent an assorted range of secondary fungal metabolites that extensively occur in numerous food and feed ingredients at any stage during pre- and post-harvest conditions. Zearalenone (ZEN), a mycotoxin categorized as a xenoestrogen poses structural similarity with natural estrogens that enables its binding to the estrogen receptors leading to hormonal misbalance and numerous reproductive diseases. ZEN is mainly found in crops belonging to temperate regions, primarily in maize and other cereal crops that form an important part of various food and feed. Because of the significant adverse effects of ZEN on both human and animal, there is an alarming need for effective detection, mitigation, and management strategies to assure food and feed safety and security. The present review tends to provide an updated overview of the different sources, occurrence and biosynthetic mechanisms of ZEN in various food and feed. It also provides insight to its harmful effects on human health and agriculture along with its effective detection, management, and control strategies.

Zearalenone Mycotoxicosis: Pathophysiology and Immunotoxicity

Mycotoxicosis refers to the deleterious pathological effects of different types of toxins produced by some worldwide distributing fungi. Mycotoxins, as secondary metabolites are affecting different organs and systems both in animals and human beings. Zearalenone (ZEA), the well-known estrogenic mycotoxins, is an immunotoxic agent. This macrocyclic beta-resorcyclic acid lactone is mycotoxin procreated as a secondary metabolic byproduct by several types of Fusarium, encompassing Fusarium roseum, Fusarium culmorum, Fusarium graminearum, and different other types. Attributing to its potent estrogenic activity, ZEA has been incriminated as one of the major causes of female reproductive disorders. Thus, the purpose of the present review article is to appraise the pathophysiological consequences and subsequent explore the progress in the research field of zearalenone immunotoxicities.

Zearalenone nephrotoxicity: DNA fragmentation, apoptotic gene expression and oxidative stress protected by Lactobacillus plantarum MON03

The present study was conducted to determine the abilities of the living Lactobacillus plantarum MON03 cells to degrade Zearalenone (ZEN) in liquid medium, and to elucidate the preventive effect in ZEN-contaminated balb/c mice showing kidney damage. The DNA fragmentation, Bcl-2 and Bax gene expression, caspase-3 activity, mRNA level of inflammation-regulating cytokines and histology of kidney tissues were examined. Female Balb/c mice were divided into four groups (10/group) and treated daily for 2 wk by oral gavage with lactic acid bacteria (L. plantarum MON03) 2 × 10⁹ CFU/L, ~2 mg/kg only, ZEN (40 mg/kg BW) only, ZEN (40 mg/kg BW) + lactic acid bacteria (L. plantarum MON03, 2 × 10⁹ CFU/L, ~2 mg/kg). Control group received vehicle. At the end of experiment, the kidney was collected for the determination of DNA fragmentation, Bcl-2 and Bax gene expression,caspase-3 activity, Malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) content, as well as for any alterations in expression of total antioxidant activity (TAC) and mRNA levels of inflammation-regulating cytokines (e.g., IL-10, IL-6, TNF-alpha). The results indicated that, kidney cells exposure to ZEN led to increased caspase-3 activity, MDA, and IL-10, IL-6, TNF-alpha and Bax mRNA levels, but decreased TAC content and down-regulated expression of GSH-Px and CAT and Bcl-2 mRNA. Co-treatment with ZEN plus LP suppressed the levels of DNA fragmentation; normalized kidney MDA and increased CAT levels, up-regulated expression of GSH-Px and CAT, and normalized mRNA levels of the analyzed cytokines. It's concluded that ZEN might have toxic effects in kidney. Further, it can be seen that use of LP induced protective effects against the oxidative stress and kidney toxicity of ZEN in part through adhesion (and so likely diminished bioavailability).

Deciphering the Nutraceutical Potential of Raphanus sativus-A Comprehensive Overview

Raphanus sativus (Radish) belongs to the Brassicaceae family and is a widely consumed root vegetable all around the world. The nutritional and medicinal values of radishes have been proven by several researches. Extracts prepared from the aerial and underground parts of radishes have been used in the treatment of stomach disorders, urinary infections, hepatic inflammation, cardiac disorders and ulcers in folk medicine since the ancient times. The pharmaceutical potential of radishes is attributed to the presence of its beneficial secondary metabolites, such as glucosinolates, polyphenols and isothiocyanates. The present review has focused on the impact of radish extract administration under pathological complications, such as cancer, diabetes, hepatic inflammation and oxidative stress. In addition, a comprehensive view of molecular mechanism behind the regulation of molecular drug targets associated with different types of cancers and diabetes by the bioactive compounds present in the radish extracts have been discussed in detail.

The detoxification effect of vitamin C on zearalenone toxicity in piglets

Zearalenone (ZEN), one of the more virulent mycotoxins occurred in various cereals and feed during recent decades and made serious health hazards to plants, animals and humans. Vitamin C (Vc) has been shown to be an effective antidote to zearalenone. In this paper, the effects of diets containing zearalenone on the growth performance, genital organ and immunoglobulin of weaning piglets and the toxicity alleviation of vitamin C were studied. Piglets were weaned at 21 days of age and 32 healthy female hybrid weaning piglets (Duroc × Landrace × Large white) with a mean weight of 12.27 ± 0.30 kg were randomly selected. The thirty-two female weaning piglets were divided into four treatment groups according to body weight: control; basal diet + vitamin C (150 mg/kg); basal diet + 1.0 mg/kg ZEN; basal diet + 1 mg/kg ZEN+vitamin C (150 mg/kg). There were eight replicates in each group. The test period was twenty-eight days. The results demonstrated that dietary zearalenone could significantly increase the length, width and area of vulva (P < 0.05), the genital organ coefficient (P < 0.05), the level of IgA, IgG and IgM (P < 0.05), the level of BUN, CRE, AST and TBIL (P < 0.05), and significantly decrease the level of E2, PROG, LH and FSH (P < 0.05). However, the addition of 150 mg/kg vitamin C to dietary zearalenone prevented deformities in the vulva, decrease in immune response capacity, changes in serum biochemical indicators and disorders in hormones level of the piglets that received the diet containing only zearalenone. In conclusion, feeding ZEN of 1.0 mg/kg can result in a deleterious effect on piglets, which was totally or partly ameliorated by dietary supplementation of vitamin C at concentrations about 150 mg/kg diet. This study systematically investigated the inhibition mechanism of vitamin C on ZEN-induced reproductive toxicity, immunotoxicity and hematological toxicity of piglets, and which provided new ideas for reducing the harm of mycotoxins to the animals through means of nutrition regulation.

Proanthocyanidins Protect Epithelial Cells from Zearalenone-Induced Apoptosis via Inhibition of Endoplasmic Reticulum Stress-Induced Apoptosis Pathways in Mouse Small Intestines

This study evaluated the protective effect of proanthocyanidins (PCs) on reducing apoptosis in the mouse intestinal epithelial cell model MODE-K exposed to zearalenone (ZEA) through inhibition of the endoplasmic reticulum stress (ERS)-induced apoptosis pathway. Our results showed that PCs could reduce the rate of apoptosis in MODE-K cells exposed to ZEA (p < 0.01). PCs significantly increased the ZEA-induced antioxidant protective effects on the enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and on the content of GSH. PCs also significantly decreased the ZEA-induced increase in the content of malondialdehyde (MDA). The analysis indicated that ZEA increased both mRNA and protein expression levels of C/EBP homologous protein (CHOP), GRP78, c-Jun N-terminal kinase (JNK), and cysteinyl aspartate specific proteinase 12 (caspase-12) (p < 0.05), which are related to the ERS-induced apoptosis pathway. ZEA decreased levels of the pro-apoptotic related protein Bcl-2 (p < 0.05) and increased the anti-apoptotic related protein Bax (p < 0.05). Co-treatment with PCs was also shown to significantly reverse the expression levels of these proteins in MODE-K cells. The results demonstrated that PCs could protect MODE-K cells from oxidative stress and apoptosis induced by ZEA. The underlying mechanism may be that PCs can alleviate apoptosis in mouse intestinal epithelial cells by inhibition of the ERS-induced apoptosis pathway.

Comparative Analysis of Zearalenone Effects on Thyroid Receptor Alpha (TRα) and Beta (TRβ) Expression in Rat Primary Cerebellar Cell Cultures

Thyroid receptors play an important role in postnatal brain development. Zearalenone (ZEN), a major mycotoxin of Fusarium fungi, is well known to cause serious health problems in animals and humans through various mechanisms, including the physiological pathways of thyroid hormone (TH). In the present study, we aimed to investigate the expression of thyroid receptors α (TRα) and β (TRβ) in primary cerebellar neurons in the presence or absence of glia and following ZEN treatment, using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot. Primary cerebellar granule cells were treated with low doses of ZEN (0.1 nM) in combination with physiologically relevant concentrations of l-thyroxine (T4), 3,3′,5-triiodo-l-thyronine (T3) and 17β-estradiol (E2). Expression levels of TRα and TRβ at mRNA and protein levels were slightly modified by ZEN administered alone; however, along with thyroid and steroid hormones, modelling the physiological conditions, expression levels of TRs varied highly depending on the given treatment. Gene expression levels were also highly modulated by the presence or absence of glial cells, with mostly contrasting effects. Our results demonstrate divergent transcriptional and translational mechanisms involved in the expression of TRs implied by ZEN and hormonal milieu, as well as culturing conditions.

Zearalenone (ZEN) and Its Influence on Regulation of Gene Expression in Carp (Cyprinus carpio L.) Liver Tissue

Zearalenone (ZEN) is a frequently-occurring mycotoxin in both animal and fish feeds. In order to characterize its effects on carp, three groups of fish were fed for 28 days with feeds contaminated with three different levels of ZEN (low: 332 µg kg⁻¹, medium: 621 µg kg⁻¹, and high: 797 µg kg⁻¹ feed). The reversibility of the effects of ZEN was assessed by feeding all of the groups with uncontaminated feed for a further 14 days. Gene expression of immune genes in the liver tissue of the fish was analysed, revealing reduced expressions of immune, antioxidative, and estrogen-related genes after the fish had been exposed to ZEN. However, the expression of vacuole-type H⁺ ATPase increased substantially with ZEN exposure, thus supporting the previously-reported sensitivity of lysosomal functions to ZEN. Feeding the fish with a ZEN-free diet for a further two weeks changed the effects of ZEN on the expression of some genes, including the expressions of the cytokines IL-1β, IL-8, IL-10, and arginase 2, which were not influenced after four weeks of treatment, but showed lower values after the recovery phase in fish previously treated with ZEN compared with the control group. In summary, this study confirmed the broad effects of ZEN on different essential functions in carp and suggests that the current maximum allowable levels in compound feed are too high to prevent damage to fish.

Effects of purified zearalenone on selected immunological and histopathologic measurements of spleen in post-weanling gilts

The present study was aimed at investigating the adverse effects of dietary zearalenone (ZEA) on the lymphocyte proliferation rate (LPR), interleukin-2 (IL-2), mRNA expressions of pro-inflammatory cytokines, and histopathologic changes of spleen in post-weanling gilts. A total of 20 crossbred piglets (Yorkshire × Landrace × Duroc) with an initial BW of 10.36 ± 1.21 kg (21 d of age) were used in the study. Piglets were fed a basal diet with an addition of 0, 1.1, 2.0, or 3.2 mg/kg purified ZEA for 18 d ad libitum. The results showed that LPR and IL-2 production of spleen decreased linearly (P < 0.05) as dietary ZEA increased. Splenic mRNA expressions of interleukin-1β (IL-1β) and interleukin-6 (IL-6) were linearly up-regulated (P < 0.05) as dietary ZEA increased. On the contrary, linear down-regulation (P < 0.05) of mRNA expression of interferon-γ (IFN-γ) was observed as dietary ZEA increased. Swelling splenocyte in 1.1 mg/kg ZEA treatments, atrophy of white pulp and swelling of red pulp in 2.0 and 3.2 mg/kg ZEA treatments were observed. The cytoplasmic edema in 1.1 mg/kg ZEA treatments, significant chromatin deformation in 2.0 mg/kg ZEA treatment and phagocytosis in 3.2 mg/kg ZEA treatment were observed. Results suggested that dietary ZEA at 1.1 to 3.2 mg/kg can induce splenic damages and negatively affect immune function of spleen in post-weanling gilts.

The Protective Effect of Selenium on Chronic Zearalenone-Induced Reproductive System Damage in Male Mice

This study aims to explore the protective effect of selenium (Se) on chronic zearalenone (ZEN)-induced reproductive system damage in male mice and the possible protective molecular mechanism against this. The chronic ZEN-induced injury mouse model was established with the continuous intragastric administration of 40 mg/kg body mass (B.M.) ZEN for 28 days. Then, interventions with different doses (0.1, 0.2, and 0.4 mg/kg B.M.) of Se were conducted on mice to analyse the changes in organ indexes of epididymis and testis, antioxidant capability of testis, serum level of testosterone, sperm concentration and motility parameters, and the expression levels of apoptosis-associated genes and blood testis barrier- (BTB) related genes. Our results showed that Se could greatly improve the ZEN-induced decrease of epididymis indexes and testis indexes. Results also showed that the decrease in sperm concentration, sperm normality rate, and sperm motility parameters, including percentage of motile sperm (motile), tropism percentage (progressive) and sperm average path velocity (VAP), caused by ZEN were elevated upon administration of the higher dose (0.4 mg/kg) and intermediate dose (0.2 mg/kg) of Se. Selenium also significantly reduced the content of malondialdehyde (MDA) but enhanced the activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) in the testis tissue. Further research demonstrated that ZEN increased the level of mRNA expression of BCL2-associated X protein (Bax) and caspase 3 (Casp3), decreased the level of mRNA expression of B cell leukemia/lymphoma 2 (Bcl2), vimentin (Vim) and cadherin 2 (Cdh2), whereas the co-administration of Se reversed these gene expression levels. Our results indicated that high levels of Se could protect against reproductive system damage in male mice caused by ZEN and the mechanism might such be that Se improved mice antioxidant ability, inhibited reproductive cell apoptosis, and increased the decrease of BTB integrity-related genes caused by ZEN.

The Influence of Selenium Yeast on Hematological, Biochemical and Reproductive Hormone Level Changes in Kunming Mice Following Acute Exposure to Zearalenone

Healthy male Kunming mice received selenium yeast for 14 days prior to a single oral administration of zearalenone (ZEN). After 48 h, blood samples were collected for analysis and showed that mice in the ZEN-treated group has significantly decreased lymphocytes (P < 0.05) and platelets (P < 0.05) along with an increased white blood cell (WBC) count and other constituents (P < 0.05). The serum biochemistry analysis of the ZEN group indicated that glutamic pyruvic transaminase (ALT), glutamic oxaloacetic transaminase (AST), urea, and uric acid were significantly increased (P < 0.05), whilst total bilirubin (TB) and albumin (ALB) were decreased along with serum testosterone and estrogen (P < 0. 05). The level of malondialdehyde (MDA) in the serum of the ZEN group was significantly increased whilst glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) had significantly decreased (P < 0.05). Treatment with selenium yeast had a significant effect on response with most of the experimental parameters returning to levels similar to those observed in the untreated control mice. From these data, it can be concluded that ZEN is highly poisonous in Kunming mice with high levels of toxicity on the blood, liver, and kidneys. High levels of oxidative stress were observed in mice and pre-treatment with selenium yeast by oral gavage is effective in the ameliorated effects of ZEN-induced damage.

Evaluation of cellular and molecular impact of zearalenone and Escherichia coli co-exposure on IPEC-1 cells using microarray technology

Background

The gastrointestinal tract is the primary site of toxin interaction, an interface between the organism and its surroundings. In this study, we assessed the alteration of intestinal mRNA profile in the case of co-occurrence of zearalenone (ZEA), a secondary Fusarium metabolite, and Escherichia coli (E. coli), on the intestinal porcine epithelial cells IPEC-1. We chose this model since the pig is a species which is susceptible to pathogen and mycotoxin co-exposure.

Results

After treating the cells with the two contaminants, either separately or in combination, the differential gene expression between groups was assessed, using the microarray technology. Data analysis identified 1691 upregulated and 797 downregulated genes as a response to E. coli exposure, while for ZEA treated cells, 303 genes were upregulated and 49 downregulated. The co-contamination led to 991 upregulated and 800 downregulated genes. The altered gene expression pattern was further classified into 8 functional groups. In the case of co-exposure to ZEA and E.coli, a clear increase of proinflammatory mechanisms.

Conclusions

These results demonstrate the complex effect of single or multiple contaminants exposure at cellular and molecular level, with significant implications that might lead to the activation of pathological mechanisms. A better understanding of the effects of co-contamination is mandatory in developing novel exposure regulations and prevention measures.

Effects of purified zearalenone on selected immunological measurements of blood in post-weaning gilts

Zearalenone (ZEA), an estrogenic mycotoxin, is produced mainly by Fusarium fungi. Previous studies have indicated that acute ZEA exposure induced various damages in different species; however, its transparent hematotoxicity in female piglets at dietary levels of 1.1 to 3.2 mg/kg has not been shown. The present study was conducted to investigate the effects of dietary ZEA (1.1–3.2 mg/kg) on hematology, T lymphocyte subset, immunoglobulin, antibody titer, lymphocyte proliferation rate (LPR), and interleukin-2 (IL-2) in peripheral blood of post-weaning gilts. A total of 20 female piglets (Landrace × Yorkshire × Duroc), weaned at 42 d with an average body weight of 10.36 ± 1.21 kg were used in the study. Female piglets were kept in a temperature controlled room, divided into four treatments, and fed a diet based on corn-soybean meal-fishmeal-whey, with an addition of 0, 1.1, 2.0, or 3.2 mg/kg purified ZEA for 18 d ad libitum. Feed intake and refusal were measured daily and individual pigs were weighed weekly. Blood and serum samples were collected for selected immunological measurements. Female piglets fed different levels of dietary ZEA grew similarly with no difference in feed intake. Hematological values including leukocytes, platelets, lymphocytes, hematocrit, and mean corpuscular hemoglobin (MCH) decreased linearly (P < 0.05) as dietary ZEA increased. Female piglets fed diets containing 2.0 mg/kg ZEA or greater showed significantly decreased CD4⁺CD8⁺, CD4⁺, and CD4⁺/CD8⁺ in comparison to the control (P < 0.05), whereas CD8⁺ was significantly increased (P = 0.026) in the gilts which were fed the diet containing 3.2 mg/kg ZEA. Serum immunoglobulin G (IgG) and the antibody titer on d 18 were reduced linearly as dietary ZEA levels increased (P < 0.001). Linear decrease in LPR was observed (P < 0.05). Female piglets fed diets containing 2.0 mg/kg ZEA or more showed significantly decreased IL-2 in comparison to the control (P < 0.05). The results suggested that dietary ZEA at the levels of 1.1 to 3.2 mg/kg can induce different degrees of hematotoxicity and negatively affect immune function in female piglets.

Evaluation of Microbiological and Chemical Contaminants in Poultry Farms

The aim of the study was to evaluate the microbiological and chemical contamination in settled dust at poultry farms. The scope of research included evaluating the contributions of the various granulometric fractions in settled dust samples, assessing microbial contamination using culture methods, concentrations of secondary metabolites in dust and their cytotoxicity against hepatocyte chicken cells by means of MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) tests. In addition, we also evaluated the concentration of selected volatile odorous compounds (VOCs) using gas chromatographic and spectrophotometric methods and airborne dust concentration in the air with DustTrak™ DRX Aerosol Monitor. Studies were carried out on chicken broilers and laying hens at 13 poultry farms, with numbers of birds ranging from 8000 to 42,000. The airborne total dust concentration at poultry farms averaged 1.44 mg/m³ with a high percentage of the PM10 fraction (particulate matter with a diameter less than 10 μm). Microorganism concentrations in the settled dust were: 3.2 × 10⁸ cfu/g for bacteria and 1.2 × 10⁶ cfu/g for fungi. Potential pathogens (Enterococcus spp., Escherichia coli, Salmonella spp., Aspergillus fumigatus, Paecilomyces variotii) were also found. Secondary metabolites included aurofusarin, deoxynivalenol, 15-hydroxyculmorin zearalenone, zearalenone-sulfate, infectopyron, and neochinulin A. However, the dust samples showed weak cytotoxicity towards chicken hepatocyte cells, which ranged between 9.2% and 29.7%. Among volatile odorous compounds ammonia, acrolein, methyloamine, acetic acid, acetoaldehyde and formaldehyde were detected in the air. In conclusion, settled dust can be a carrier of microorganisms, odours and secondary metabolites in poultry farms, which can be harmful to workers' health.

Co- and Post-Treatment with Lysine Protects Primary Fish Enterocytes against Cu-Induced Oxidative Damage

The aim of the work was primarily to explore the protective activity pathways of lysine against oxidative damage in fish in vivo and in enterocytes in vitro. First, grass carp were fed diets containing six graded levels of lysine (7.1-19.6 g kg-1 diet) for 56 days. Second, the enterocytes were treated with different concentrations of lysine (0-300 mg/L in media) prior to (pre-treatment), along with (co-treatment) or following (post-treatment) with 6 mg/L of Cu for 24 h. The results indicated that lysine improved grass carp growth performance. Meanwhile, lysine ameliorated lipid and protein oxidation by elevating the gene expression and activity of antioxidant enzymes (superoxide dismutase (SOD), glutathioneperoxidase (GPx), glutathione-S-transferase (GST) and reductase (GR)), and nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA levels in fish intestine. The in vitro studies showed that co- and post-treatment with lysine conferred significant protection against Cu-induced oxidative damage in fish primary enterocytes as measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) OD values, along with alkaline phosphatase (ALP) and lactate dehydrogenase activities, and the depletion of protein carbonyl (PC), malondialdehyde (MDA) and 8-hydroxydeoxyguanosine contents. Moreover, lysine co-treatment decreased the activities and mRNA level of cellular SOD, GPx, GST and GR compared with the Cu-only exposed group. Gene expression of the signalling molecule Nrf2 showed the same pattern as that of SOD activity, whereas Kelch-like ECH-associated protein 1b (Keap1b) followed the opposite trend, indicating that co-treatment with lysine induced antioxidant enzymes that protected against oxidative stress through Nrf2 pathway. In addition, post-treatment with lysine increased proteasomal activity and blocked the Cu-stimulated increase in mRNA levels of GST and associated catalase (CAT) and GST activities (P<0.01 and P<0.001). GR activity and gene expression, and glutathione (GSH) content followed an opposite trend to GST activity (P<0.05). Thus, post-treatment of lysine elevated protein and DNA repair abilities and ameliorated the cellular redox state of enterocytes. The overall results suggest that lysine plays a significant role in the protection of fish intestine in vivo and in vitro through the induction of key antioxidant protection.

Endoplasmic Reticulum Stress Cooperates in Zearalenone-Induced Cell Death of RAW 264.7 Macrophages

Zearalenone (ZEA) is a fungal mycotoxin that causes cell apoptosis and necrosis. However, little is known about the molecular mechanisms of ZEA toxicity. The objective of this study was to explore the effects of ZEA on the proliferation and apoptosis of RAW 264.7 macrophages and to uncover the signaling pathway underlying the cytotoxicity of ZEA in RAW 264.7 macrophages. This study demonstrates that the endoplasmic reticulum (ER) stress pathway cooperated in ZEA-induced cell death of the RAW 264.7 macrophages. Our results show that ZEA treatment reduced the viability of RAW 264.7 macrophages in a dose- and time-dependent manner as shown by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay (MTT) and flow cytometry assay. Western blots analysis revealed that ZEA increased the expression of glucose-regulated protein 78 (GRP78) and CCAAT/enhancer binding protein homologous protein (CHOP), two ER stress-related marker genes. Furthermore, treating the cells with the ER stress inhibitors 4-phenylbutyrate (4-PBA) or knocking down CHOP, using lentivirus encoded short hairpin interfering RNAs (shRNAs), significantly diminished the ZEA-induced increases in GRP78 and CHOP, and cell death. In summary, our results suggest that ZEA induces the apoptosis and necrosis of RAW 264.7 macrophages in a dose- and time-dependent manner via the ER stress pathway in which the activation of CHOP plays a critical role.

The effect of in vivo exposure to zearalenone on cytokine secretion by Th1 and Th2 lymphocytes in porcine Peyer's patches after in vitro stimulation with LPS

Most research studies investigating the estrogenic effects of zearalenone (ZEN) focus on the mycotoxin's effect on the reproductive system. Since estrogen receptors are present on various types of immunocompetent cells, ZEN can also modify diverse immune functions. This study analyzed immunocompetent cells isolated from Peyer's patches in the ileum of pigs administered ZEN in the estimated daily dose of 8 μg kg(-1) BW (equivalent of 100 μg kg(-1) feed per day(-1)). The objective of the study was to determine whether long-term exposure to low ZEN doses below the NOEL threshold leads to changes in the percentages of lymphocyte subpopulations and cytokine secretion by Th1 (IL-2, IFN-γ) and Th2 (IL-4 and IL-10) lymphocytes in Peyer's patches of the ileum after in vitro stimulation with lipopolysaccharides (LPS). Immunocompetent cells isolated from Payer's patches on experimental days 0, 14, 28 and 42 were cultured in vitro and stimulated with LPS. The presence of IL-2, IFN-γ, IL-4 and IL-10 in culture media was determined by the ELISA method. The results of the study indicate that ZEN inhibits IL-2 and IFN-γ secretion and stimulates IL-4 and IL-10 produc- tion by Th1 and Th2 lymphocytes by shifting the Th1/Th2 balance towards the humoral immune response. The above can promote allergic responses, as demonstrated by the increase in the size of B1 cell populations producing more autoantibodies. ZEN can also lower resistance to viruses and tumors by inhibiting the proliferation of NK cells and IFN-γ secretion.

Toxic effects of maternal zearalenone exposure on intestinal oxidative stress, barrier function, immunological and morphological changes in rats

The present study was conducted to investigate the effects of maternal zearalenone (ZEN) exposure on the intestine of pregnant Sprague-Dawley (SD) rats and its offspring. Ninety-six pregnant SD rats were randomly divided into four groups and were fed with diets containing ZEN at concentrations of 0.3 mg/kg, 48.5 mg/kg, 97.6 mg/kg or 146.0 mg/kg from gestation days (GD) 1 to 7. All rats were fed with mycotoxin-free diet until their offspring were weaned at three weeks of age. The small intestinal fragments from pregnant rats at GD8, weaned dams and pups were collected and studied for toxic effects of ZEN on antioxidant status, immune response, expression of junction proteins, and morphology. The results showed that ZEN induced oxidative stress, affected the villous structure and reduced the expression of junction proteins claudin-4, occludin and connexin43 (Cx43) in a dose-dependent manner in pregnant rats. Different effects on the expression of cytokines were also observed both in mRNA and protein levels in these pregnant groups. Ingestion of high levels of ZEN caused irreversible damage in weaned dams, such as oxidative stress, decreased villi hight and low expression of junction proteins and cytokines. Decreased expression of jejunal interleukin-8 (IL-8) and increased expression of gastrointestinal glutathione peroxidase (GPx2) mRNA were detected in weaned offspring, indicating long-term damage caused by maternal ZEN. We also found that the Nrf2 expression both in mRNA and protein levels were up-regulated in the ZEN-treated groups of pregnant dams and the high-dose of ZEN group of weaned dams. The data indicate that modulation of Nrf2-mediated pathway is one of mechanism via which ZEN affects gut wall antioxidant and inflammatory responses.

Gene expression profile and toxic effects in human bronchial epithelial cells exposed to zearalenone

Zearalenone (ZEA), a mycoestrogen produced by Fusarium fungal species, is mainly found in cereal crops such as maize, wheat and barley. Although ZEA has been reported to be present in air, little is known about the health risk or the molecular basis of action when lung cells are exposed to ZEA. As ZEA has a similar structure to estrogen, its potential risk as an endocrine disrupting chemical (EDC) has thus aroused both environmental and public health concerns. The purpose of this study is to identify the responses and underlying molecular changes that occur when human bronchial epithelial BEAS-2B cells are exposed to ZEA. Differential gene expression profiles were identified in cells that were treated with 40 µM ZEA for 6 h and 24 h by high-throughput microarray analysis using Affymetrix Human Gene 2.0 GeneChip. The array results showed that after ZEA treatment, 262 genes at 6 h and 1073 genes at 24 h were invovled in the differential regulation. Pathway analysis revealed that diverse cellular processes were affected when lung cells were exposed to ZEA resulting in impaired response to DNA damage, cell cycle arrest, down-regulation of inflammatory responses and alterations of epigenetic marks. Results of further experiments indicated that 40 µM ZEA decreased cell viability, induced apoptosis and promoted reactive oxygen species (ROS) generation in a time-dependent manner. Immuno-suppressive effects of ZEA were further revealed through the suppression of lipopolysaccharide (LPS)-induced expression of pro-inflammatory cytokines (IL-6, IL-8 and IL-1β). Interestingly, the level of global DNA methylation was markedly decreased after 24 h exposure to ZEA. Collectively, these observations suggested that a broad range of toxic effects are elicited by ZEA. Particularly, ROS may play a pivotal role in ZEA-induced cell death. These adverse effects observed in lung cells suggest that exposure to ZEA may increase susceptibility of lung cells to diseases and required further investigations.

The immunomodulatory effects induced by dietary Zearalenone in pregnant rats

CONTEXT

Zearalenone (ZEN) is a common contaminant that is present in feedstuff of high humidity and high temperatures.

OBJECTIVE

The aim of this study was to investigate the effects of diets contaminated with different concentrations of ZEN on immunomodulation in early pregnant rats.

MATERIALS AND METHODS

Forty-eight pregnant Sprague Dawley (SD) rats were randomly divided into four treatment groups fed on a diet supplemented with one of four concentrations of ZEN: 0 mg/kg (ZEN 0), 50 mg/kg (ZEN 50), 100 mg/kg (ZEN 100) and 150 mg/kg (ZEN 150). The pregnant rats were fed ZEN-treated diets from gestation days 0 to 7 and a basal diet from gestation days 8 to 20.

RESULTS

ZEN exposure (ZEN 100 and 150) caused significant decreases in splenic coefficients, viability of splenocyte and T-cell proliferation and induced histopathological damage in the spleen of early pregnant rats compared with other groups. Levels of IgG and IgA were decreased, while IgM was increased, in high doses of ZEN (ZEN 100 and ZEN 150) compared with other groups. ZEN 150 caused increases in white blood cells and hemoglobin and induced a significant decrease in platelets in blood of the pregnant rats compared with other groups. ZEN 150 increased the mRNA expression levels of interleukin (IL)-6, IL-18 and IL-1β and decreased the mRNA expression levels of interferon-γ, tumor necrosis factor-α and IL-10 in the spleen of pregnant rats compared with ZEN 0.

CONCLUSION

High doses of ZEN-induced immunomodulatory effects on early pregnant rats by altering immunological parameters.

Biochemical changes and oxidative stress induced by zearalenone in the liver of pregnant rats

The aim of the present research was to examine the toxic influence of different doses of zearalenone (ZEN) on the liver, especially oxidative stress induced by ZEN on the liver. A total of 48 pregnant Sprague-Dawley rats were randomly assigned into 4 treatments groups with 12 animals in each. The rats were fed with a normal diet treated with 0 mg/kg (control), 50 mg/kg (treatment 1), 100 mg/kg (treatment 2), or 150 mg/kg (treatment 3) ZEN in feed on gestation days (GDs) 0–7 and then all the rats were fed with a normal diet on GDs 8–20. The experimental period lasted 21 days. The results showed that exposure to ZEN induced increase in aspartate amino transferase, alanine aminotransferase, and alkaline phosphatase activities and decrease in total protein and albumin content in a dose-dependent manner and also induce decrease in superoxide dismutase and glutathione peroxidase activities and increase in malondialdehyde content in a dose-dependent manner in the serum and the liver. The increased transcription of cytochrome P450 2E1 (CYP2E1) was detected in the liver after exposure to ZEN. These results suggested that ZEN not only caused damage in the liver of pregnant rats in a dose-dependent manner but also induced the messenger RNA expression of CYP2E1 in the liver.

Zearalenone, an estrogenic mycotoxin, is an immunotoxic compound

The aim of this study was to assess the toxic effects of zearalenone (ZEA) on the immune function. Ovariectomised rats were treated daily by gavage with 3.0 mg/kg of ZEA for 28 days. Body weight gain, food consumption, haemotological parameters, lymphoid organs, and their cellularities were evaluated. Moreover, acquired immune responses and macrophage activity were also assessed. ZEA promoted reduction in body weight gain, which is not fully explained by diminished food consumption. Despite no effect on haematological parameters, ZEA caused thymic atrophy with histological and thymocyte phenotype changes and decrease in the B cell percentage in the spleen. With respect to acquired and innate immune responses, no statistically significant differences in delayed-type hypersensitivity were noticed; however, in the ZEA-treated rats, antibody production and peroxide release by macrophages were impaired. The observed results could be related to ZEA activity on ERs; thus, ZEA is an immunotoxic compound similar to estrogen and some endocrine disruptors.

Toxic effects of zearalenone on oxidative stress, inflammatory cytokines, biochemical and pathological changes induced by this toxin in the kidney of pregnant rats

An experiment was conducted to determine the toxic effects of zearalenone (ZEN) on oxidative stress, inflammatory cytokines, biochemical and pathological changes in the kidney of pregnant rats, and to explore the possible mechanism in ZEN induced kidney damage. The rats were fed a normal diet treated with 0.3, 48.5, 97.6 or 146 mg/kg ZEN in feed on gestation days (GDs) 0 through 7, and then all the rats were fed with a normal diet on GDs 8 through 20. The results showed that ZEN induced kidney dysfunction, oxidative damage, pathological changes and increased mRNA and protein expression of TLR4 and inflammatory cytokines in kidney in dose-dependent manner. The results indicated that ZEN caused kidney damage of pregnant rats and TLR4-mediated inflammatory reactions signal pathway was one of the mechanisms of ZEN mediated toxicity in kidney.

Tunisian radish (Raphanus sativus) extract prevents cadmium-induced immunotoxic and biochemical alterations in rats

Cadmium (Cd), a known carcinogen and potent immunotoxicant in humans and animals, is dispersed throughout the environment as a result of pollution from a variety of sources. Tunisian radish (Raphanus sativus) extract (TRE) is a known anti-oxidant and free radical scavenger that has been shown to help alleviate immune system disorders, including some induced by environmental toxicants. The present study was undertaken to investigate potential protective effects of TRE against Cd-induced immunotoxicities (and general toxicities) in situ. Cadmium chloride (at 2.5 mg CdCl2/kg BW) and TRE (5, 10, or 15 mg/kg BW) were given (alone or in combination [actually, in sequence of Cd and then TRE]) to rats daily by oral gavage for 2 weeks. Results indicated that treatment with CdCl2 alone resulted in significant decreases in plasma levels of total protein, triglycerides, creatine kinase, creatinine, IgG and IgA, T-lymphocyte sub-types (CD4(+), CD3(+), CD56(+), and CD8(+)), and in thymic and hepatic indices (relative weights). In contrast, CdCl2 treatment caused significant increases in serum LDH, AST, and ALT, in the formation/release of pro-inflammatory cytokines (IL-1 and TNFα), and in the relative weights of host spleen and kidneys. Rats treated with TRE alone had no discernable changes compared to the controls with regard to all test parameters. Combined treatment of CdCl2 and TRE-at any dose-resulted in a significant improvement of all test parameters compared to those seen with Cd alone. These results illustrated (and provided further support for a continuing belief in) the beneficial effects of TRE in reducing the harmful outcomes of commonly encountered toxicants (like Cd) on the immune system and on overall host health status.

Zearalenone affects immune-related parameters in lymphoid organs and serum of rats vaccinated with porcine parvovirus vaccine

Rats were administered zearalenone (ZEA) via gavage at dosages of 0, 1, 5, and 30 mg/kg for 36 days. On treatment day 8, inactivated porcine parvovirus vaccine (Vac) was injected intraperitoneally. Antibody production against porcine parvovirus was then measured as a function of ZEA treatment. Compared to the vaccine alone, ZEA treatment, with or without Vac, decreased the serum level of IgG. The level of IgM decreased in all ZEA groups at day 22, but the decrease was sustained only in the medium-dose ZEA group at day 36. The level of IgA was unchanged in the Vac only and ZEA groups at day 22, but was decreased in the 5 mg/kg ZEA plus Vac group compared to the Vac only group at day 36. The level of IgE was decreased by all doses of ZEA at day 22, but was unaffected in ZEA plus Vac groups compared to the Vac only group. The levels of IL-1 in the thymus and spleen; INF-γ in serum; IL-2, IL-6, and IL-10 in the thymus; and IL-10 and IFN-γ in the spleen decreased after ZEA administration. Furthermore, the levels of IL-1β in the spleen and mesenteric lymph node, IL-1β in the thymus, IL-2 in the thymus and spleen, IL-6 in the thymus, IL-10 and IFN-γ in the spleen, and GM-CSF and TNF-α in the thymus decreased after vaccination in rats exposed to ZEA. In conclusion, these results suggest that ZEA exposure via drinking water can cause an immunosuppressive effect by decreasing immunoglobulins in serum and cytokines in lymphoid organs.

Natural feed contaminant zearalenone decreases the expressions of important pro- and anti-inflammatory mediators and mitogen-activated protein kinase/NF-κB signalling molecules in pigs

Zearalenone (ZEA) is an oestrogenic mycotoxin produced byFusariumspecies, considered to be a risk factor from both public health and agricultural perspectives. In the presentin vivostudy, a feeding trial was conducted to evaluate thein vivoeffect of a ZEA-contaminated diet on immune response in young pigs. The effect of ZEA on pro-inflammatory (TNF-α, IL-8, IL-6, IL-1β and interferon-γ) and anti-inflammatory (IL-10 and IL-4) cytokines and other molecules involved in inflammatory processes (matrix metalloproteinases (MMP)/tissue inhibitors of matrix metalloproteinases (TIMP), nuclear receptors: PPARγ and NF-κB1, mitogen-activated protein kinases (MAPK): mitogen-activated protein kinase kinase kinase 7 (TAK1)/mitogen-activated protein kinase 14 (p38α)/mitogen-activated protein kinase 8 (JNK1)/ mitogen-activated protein kinase 9 (JNK2)) in the liver of piglets was investigated. The present results showed that a concentration of 316 parts per billion ZEA leads to a significant decrease in the levels of pro- and anti-inflammatory cytokines at both gene expression and protein levels, correlated with a decrease in the levels of other inflammatory mediators, MMP and TIMP. The results also showed that dietary ZEA induces a dramatic reduction in the expressions ofNF-κB1andTAK1/p38αMAPK genes in the liver of the experimentally intoxicated piglets, and has no effect on the expression ofPPARγmRNA. The present results suggest that the toxic action of ZEA begins in the upstream of the MAPK signalling pathway by the inhibition of TAK1, a MAPK/NF-κB activator. In conclusion, the present study shows that ZEA alters several important parameters of the hepatic cellular immune response. From an economic point of view, these data suggest that, in pigs, ZEA is not only a powerful oestrogenic mycotoxin but also a potential hepatotoxin when administered through the oral route. Therefore, the present results represent additional data from cellular and molecular levels that could be taken into account in the determination of the regulation limit of the tolerance to ZEA.

Effects of zearalenone on oxidative stress and inflammation in weanling piglets

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by the fungi of Fusarium genera. Piglets were fed for 18 days with a control or a ZEN (316 ppb) contaminated diet. At the end of the experiment tissue samples were taken for assessment of: lymphocyte proliferation, monocytes and granulocytes respiratory burst, inflammatory cytokine synthesis in blood and liver, expression of genes involved in oxidative stress or in inflammation, plasma biochemical parameters, total antioxidant status and nitric oxide synthesis. In blood, ZEN increases the respiratory burst of monocytes and the inflammatory cytokine (TNF alpha, IL-1 beta, IFN gamma) synthesis, while in liver, ZEN decreases the synthesis of all inflammatory cytokines investigated. In liver and spleen, different effect on the expression of genes involved in oxidative stress and inflammation was observed. While in liver, ZEN decrease the expression of cyclooxigenase gene, but increase the expression of glutathione peroxydase and catalase genes; in spleen, ZEN induces a decrease of the superoxide dismutase gene expression together with an increase of the cyclooxigenase. In conclusion, our results showed that liver, spleen and blood may also be target tissues in weanling piglets fed ZEN contaminated diet, with different effects on oxidative stress and inflammation.

Interaction of Lactobacillus plantarum MON03 with Tunisian montmorillonite clay and ability of the composite to immobilize Zearalenone in vitro and counteract immunotoxicity in vivo

BACKGROUND AND AIM

The present study was conducted to determine the abilities of the living Lactobacillus plantarum MON03 (LP) cells, Tunisian montmorillonite clay and their composites to accumulate Zearalenone (ZEA) from a liquid medium and elucidate the preventive effect of their composite in ZEA-contaminated balb/c mice showing immunotoxicity disorders.

MATERIALS AND METHODS

In the in vitro study, LP (2 × 10(9) CFU/mL), TM (0.5 mg) and LP+TM were incubated with 50 µg mL(-1) ZEA for 0, 12 and 24 h. For the in vivo study, the composite MT+LP was evaluated also for possible protection regarding ZEA-immunotoxicity in Balb/c mice as a sensitive model.

RESULTS

Results indicated that TM and LP+TM had a high capacity of adsorbing ZEA 87.2 ± 2.1 and 94.2 ± 2.1%, respectively. However, LP alone able to remove only 78% after 24 h of incubation. The quantity of adsorbed ZEA by LP, TM and LP+TM were 39, 43,5 and 47 µg mL(-1) of PBS, respectively. The in vivo results indicated that mice orally exposed to ZEA- (40 mg/kg bw) for 2 weeks showed severe immunotoxicity typical of fusarotoxicosis regarding thymocytes and splenocytes cell viability count, IFN-γ, IL-12, TNF-α production and B-cell activation. Mice treated with LP and TM alone, and LP+MT in combination with ZEA were comparable to the control.

CONCLUSION

Both LP and TM are safe by themselves and their composite succeeded to exert a potential prevention by counteracting ZEA-immunotoxicity and can be implicated in the biotechnology of ZEA removal in human food and animal feed.

Effects of zearalenone and its derivatives on porcine immune response

Zearalenone (ZEN), a mycotoxin produced by several Fusarium spp., is most commonly found as a contaminant in stored grain and has chronic estrogenic effects on mammals. In this in vitro study, we compared the effects of zearalenone (ZEN) and some of its derivatives: α-zearalenol (α-ZOL), β-zearalenol (β-ZOL), and zearalanone (ZAN) on several peripheral blood mononuclear cell (PBMC) parameters: cytotoxicity, proliferation, as well as antibody and cytokine synthesis. The amounts of toxins necessary to inhibit viability, in a dehydrogenase enzyme activity assay (MTT test), by 50% were: 22.7 μM for ZEN, 29.1 μM for α-ZOL, 17.3 μM for β-ZOL and 26.3 μM for ZAN. The administration of 10 μM toxin induced a decrease in the ConA stimulated proliferation of PBMC by 19.6% for ZAN, 45.4% for ZEN, 43.6% for α-ZOL and 85.2% for β-ZOL, when compared to the control stimulated cells. Also, ZEN and its metabolites at concentrations higher than 5 μM induced a significant decrease of the IgG, IgA or IgM levels. Concentrations of 5 and 10 μM of ZEN and ZAN significantly decreased the TNF-α synthesis in the supernatant of the stimulated cells; 10 μM of ZAN also decreased IL-8 synthesis. In conclusion, our results show that ZEN and ZEN derivatives altered several parameters of the humoral and cellular immune response. Therefore, our results are clinically relevant as ZEN and its metabolites are frequent contaminants of animal feed and we have shown that intoxicated animals are incapable of inducing an adequate immune response.

Effects of purified zearalenone on growth performance, organ size, serum metabolites, and oxidative stress in postweaning gilts

Zearalenone (ZEA), an estrogenic mycotoxin, is produced mainly by Fusarium fungi. Previous studies indicated that acute ZEA exposure induced oxidative stress and damage in multiple organs. Therefore, the present study was designed to investigate the adverse effects of dietary ZEA (1.1 to 3.2 mg/kg of diet) on oxidative stress and organ damage in postweaning gilts. A total of 20 gilts (Landrace × Yorkshire × Duroc) weaned at d 21 with an average BW of 10.36 ± 1.21 kg was used in the study. Gilts were housed in a temperature-controlled room, divided into 4 treatments, and fed a basal diet only (control) or basal diet supplemented with purified ZEA at a dietary concentration of 1 (ZEA1), 2 (ZEA2), or 3 (ZEA3) mg/kg of diet for 18 d ad libitum. The actual ZEA contents (analyzed) were 0, 1.1 ± 0.02, 2.0 ± 0.01, and 3.2 ± 0.02 mg/kg for control, ZEA1, ZEA2, and ZEA3, respectively. Gilts fed different amounts of dietary ZEA grew similarly with no difference (P > 0.05) in feed intake. Vulva size increased linearly over the 18 d of feeding in gilts fed diets containing 1.1 mg of ZEA/kg or greater (P < 0.001). Relative weight of genital organs, liver, and kidney increased linearly (P < 0.05) in a ZEA-dose-dependent manner. Serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, γ-glutamate transferase, urea, and creatinine (P < 0.05), and malondialdehyde concentrations in both serum and liver (P < 0.001) were also increased linearly in a ZEA-dose-dependent manner. However, spleen relative weight (P = 0.002) and activities of total superoxide dismutase and glutathione peroxidase (in both serum and liver (P < 0.05) were decreased linearly as dietary ZEA increased. Results showed that besides genital organs, the liver, kidney, and spleen may also be target tissues in young gilts fed diets containing 1.1 to 3.2 mg of ZEA/kg for 18 d. Increased key liver enzymes in the serum suggest progressive liver damage caused by feeding ZEA, and an increase in oxidative stress in gilts is another potential impact of ZEA toxicity in pigs.

In-vitro free radical scavenging, antiproliferative and anti-zearalenone cytotoxic effects of 4-(methylthio)-3-butenyl isothiocyanate from Tunisian Raphanus sativus

Objectives

The aim of this study was to investigate the antiradical and antioxidant properties of 4-(methylthio)-3-butenyl isothiocyanate (MTBITC) extracted from Raphanus sativus and to assess the effects of MTBITC on tumour cell growth, cytotoxicity induced by zearalenone, an oestrogenic mycotoxin, and modulation of the expression of the genes involved in these aspects of cell behaviour.

Methods

A murine leukaemia cell line (L1210) was grown in vitro and supplemented with MTBITC (2, 4, 8, 16 and 32 μm) for 48 h. Cell growth was evaluated by the MTT assay. The chemopreventive role of MTBITC on the cytotoxic effect of zearalenone in a Balb/c mice keratinocyte cell line (C5-O) was also evaluated. Apoptosis and lipid peroxidation were assessed, as well as the expression of genes involved following zearalenone treatment alone or in combination with MTBITC.

Key findings

MTBITC showed a significant ability to inhibit nitroblue tetrazolium reduction by superoxide radicals in a non-enzymatic superoxide generating system, to scavenge free radicals and to cause a decrease in L1210 cell growth. The C5-O cells treated with zearalenone alone showed a high frequency of apoptotic cells and lipid peroxidation, typical of oxidative stress generated by zearalenone. The cotreatment with MTBITC reduced the cytotoxicity of zearalenone and the subsequent gene expression analysis demonstrated that MTBITC decreased the expression of caspase 8, implicated in the physiological mechanism to eliminate injured or abnormal cells.

Conclusions

The results suggest that MTBITC was able to inhibit L1210 cell growth and counteract the zearalenone oxidative stress to C5-O cells through caspase 8 inhibition of apoptosis.