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

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.

Oxidative Status and Histological Evaluation of Wild Boars' Tissues Positive for Zearalenone Contamination in the Campania Region, Southern Italy

Zearalenone (ZEN) is a mycotoxin produced by fungi belonging to the genera Fusarium spp. and commonly found in feed and food. It is frequently related to reproductive disorders in farm animals and, occasionally, to hyperestrogenic syndromes in humans. Nowadays, knowledge about ZEN effects on wild boars (Sus scrofa) is extremely scarce, despite the fact that they represent one of the most hunted game species in Italy. The aim of this study was to investigate how ZEN affects the liver, kidney, and muscle oxidative status and morphology of wild boars hunted in various locations throughout the province of Avellino, Campania Region, Southern Italy, during the 2021-2022 hunting season. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities, as well as the malondialdehyde (MDA) levels, were assessed by colorimetric assays; tissue morphology was evaluated by hematoxylin-eosin and Masson's stains. Our data showed that ZEN contamination might result in oxidative stress (OS) and some histopathological alterations in wild boars' livers and kidneys rather than in muscles, emphasizing the importance of developing a wildlife monitoring and management strategy for dealing not only with the problem of ZEN but the surveillance of mycotoxins in general.

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

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

The impact of Zearalenone on heat-stressed skeletal muscle in pigs

Heat stress (HS) and Zearalenone (ZEN) exposure affect growth, production efficiency, and animal welfare; and, under extreme situations, both can be lethal. Given that both HS and ZEN independently cause oxidative stress, we hypothesized that simultaneous exposure to HS and ZEN would cause greater oxidative stress in porcine skeletal muscle than either condition, alone. To address this hypothesis, crossbred, prepubertal gilts were treated with either vehicle control (cookie dough) or ZEN (40 μg/kg) and exposed to either thermoneutral (TN; 21.0 °C) or 12-h diurnal HS conditions (night: 32.2 °C; day: 35.0 °C) for 7 d. Pigs were euthanized immediately following the environmental challenge and the glycolytic (STW) and oxidative (STR) portions of the semitendinosus muscle were collected for analysis. In STR, malondialdehyde (MDA) concentration, a marker of oxidative stress, tended to increase following ZEN exposure (P = 0.08). HS increased CAT (P = 0.019) and SOD1 (P = 0.049) protein abundance, while ZEN decreased GPX1 protein abundance (P = 0.064) and activity (P = 0.036). In STR, HS did not alter protein expression of HSP27, HSP70, or HSP90. Conversely, in STW, MDA-modified proteins remained similar between all groups. Consistent with STR, ZEN decreased GPX1 (P = 0.046) protein abundance in STW. In STW, ZEN decreased protein abundance of HSP27 (P = 0.032) and pHSP27 (P = 0.0068), while HS increased protein expression of HSP70 (P = 0.04) and HSP90 (P = 0.041). These data suggest a muscle fiber type-specific response to HS or ZEN exposure, potentially rendering STR more susceptible to HS- and/or ZEN-induced oxidative stress, however, the combination of HS and ZEN did not augment oxidative stress.

Research Progress of Safety of Zearalenone: A Review

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

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.

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.

Effects of Montmorillonite on Growth Performance, Serum Biochemistry and Oxidative Stress of Red-Crowned Crane (Grus japonensis) Fed Mycotoxin-Contaminated Feed

BACKGROUND

The red-crowned crane (Grus japonensis) is one of the most vulnerable bird species in the world. Mycotoxins are toxic secondary metabolites produced by fungi and considered naturally unavoidable contaminants in animal feed. Our recent survey indicated that the mycotoxins had the potential to contaminate redcrowned crane's regular diets in China.

OBJECTIVE

This experiment was conducted to investigate the protective effects of mycotoxin binder montmorillonite (Mont) on growth performance, serum biochemistry and oxidative stress parameters of the red-crowned crane.

METHODS

16 red-crowned cranes were divided into four groups and fed one of the following diets; a selected diet, regular diet, or the selected diet or regular diet with 0.5% montmorillonite added to the diets. The cranes' parameters of performance, hematology, serum biochemistry and serum oxidative stress were measured.

RESULTS

Consuming regular diets decreased the average daily feed intake (ADFI), levels of haemoglobin (Hb), platelet count (PLT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), but increased the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase (CK) and lactate dehydrogenase (LDH). The supplementation of 0.5% Mont provided protection for the red-crowned crane in terms of feed intake, serum biochemistry and oxidative stress. Moreover, Mont supplementation had no adverse effect on the health of red-crowned crane.

CONCLUSIONS

Taken together, these findings suggested that the addition of dietary Mont is effective in improving the health of red-crowned crane.

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.

Intestinal Health of Pigs Upon Weaning: Challenges and Nutritional Intervention

The primary goal of nursery pig management is making a smooth weaning transition to minimize weaning associated depressed growth and diseases. Weaning causes morphological and functional changes of the small intestine of pigs, where most of the nutrients are being digested and absorbed. While various stressors induce post-weaning growth depression, the abrupt change from milk to solid feed is one of the most apparent challenges to pigs. Feeding functional feed additives may be viable solutions to promote the growth of nursery pigs by enhancing nutrient digestion, intestinal morphology, immune status, and by restoring intestinal balance. The aim of this review was to provide available scientific information on the roles of functional feed additives in enhancing intestinal health and growth during nursery phase. Among many potential functional feed additives, the palatability of the ingredient and the optimum supplemental level are varied, and these should be considered when applying into nursery pig diets. Considering different stressors pigs deal with in the post-weaning period, research on nutritional intervention using a single feed additive or a combination of different additives that can enhance feed intake, increase weight gain, and reduce mortality and morbidity are needed to provide viable solutions for pig producers. Further research in relation to the feed palatability, supplemental level, as well as interactions between different ingredients are needed.

Polydatin Protects Bovine Mammary Epithelial Cells Against Zearalenone-Induced Apoptosis By Inhibiting Oxidative Responses and Endoplasmic Reticulum Stress

Zearalenone (ZEA) is a mycotoxin of the Fusarium genus that can cause endoplasmic reticulum (ER) stress and Apoptosis in bovine mammary epithelial cells (MAC-T). Polydatin (PD), a glycoside purified from Polygonum cuspidatum, has antioxidant properties. This study aimed to explore whether PD can alleviate ZEA-induced damage on bovine mammary epithelial cells (MAC-T). We found that incasing the concentration of ZEA (0, 7.5, 15, 30, 60, 90, 120, and 240 μM) gradually decreased the cell viability. PD treatment alone at 5, 10, and 20 μM did not affect cell viability. Follow-up studies then applied 30 μM of ZEA and 5 μM of PD to treat cells; the results showed that the ZEA + PD treatment group effectively reduced cell oxidative damage compared with the ZEA treatment group. The qPCR analysis showed that ZEA treatment significantly up-regulated the expression of ER stress-related genes, relative to the control. However, adding PD significantly down-regulated the expression of ER stress-related genes. The cell apoptosis detection results showed that, compared with the ZEA treatment group, the ZEA + PD treatment group down-regulated the Bax gene and up-regulated the Bcl-2 gene expressions, which reduced the cell apoptosis rate and Caspase-3 activity. Taken together, these results indicate that PD reduces ZEA-induced apoptosis by inhibiting oxidative damage and ER stress.

Effects of zearalenone on genital organ development, serum immunoglobulin, antioxidant capacity, sex hormones and liver function of prepubertal gilts

The study aimed to examine the effects of zearalenone on genital organ development, serum immunoglobulin, antioxidant capacity, sex hormones and liver function of prepubertal gilts. Forty-eight prepubertal gilts (Landrace × Yorkshire) were randomly divided into three treatment (T1, T2 and T3) groups and a control group (12 replicates per group, 1 gilt per replicate). Prepubertal gilts in the control group were fed with basal diet, and those in T1, T2 and T3 groups were fed with basal diets supplemented with 200 μg/kg, 800 μg/kg and 1600 μg/kg zearalenone during the experiment period, which lasted for 14 d. Feed intake was counted and vulvar area was measured. The blood samples were collected from the anterior vena cava of 6 prepubertal gilts in each group, and immunoglobulins, antioxidant indexes, inflammatory cytokines, genital hormones, and biochemical indexes were analyzed by enzyme-linked immunosorbent assay. The results showed that the average daily feed intake of prepubertal gilts in each group had no significant change (p > 0.05). On 14 d, compared with the control group, the vulva area of prepubertal gilts in each treatment group was significantly increased (p < 0.05). Compared with the control group, the serum immunoglobulin G content in the T3 group was significantly reduced (p < 0.05). The activities of total antioxidant capacity and the superoxide dismutase of serum in the T3 group were significantly reduced (p < 0.05). Compared with the control group, the serum interleukin-4 content in each test group were extremely significantly increased (p < 0.01). The serum contents of luteinizing hormone in the T2 and T3 groups and estradiol in the T3 group were significantly reduced (p < 0.05) than that of control group. Compared with the control group, the activity of aspartate aminotransferase in T3 group was significantly increased (p < 0.05). In conclusion, zearalenone has no significantly effect on the feed intake of prepubertal gilts, but it can reduce its serum immunoglobulin contents and antioxidant properties, disrupt the secretion of sex hormones, increase the vulva area, produce reproductive toxicity and cause liver damage. Therefore, in pig production, the use of antimould reagent together with products of immunity-boosting, antioxidant, anti-inflammatory and hepatoprotective may enhance protection.

Protective effect of resveratrol against toxicity induced by the mycotoxin, zearalenone in a rat model

Contamination of cereal crops with zearalenone (ZEA), a mycotoxin produced by Fusarium fungi, is a worldwide health concern. The study assessed the ameliorative potential of resveratrol (RSV), a potent antioxidant against ZEA induced toxicity in adult male Wistar rats. Rats (n = 40), with an average weight of 100-150 g were used for the exposure study for three weeks. The animals were divided into four groups (I to IV) each comprising 10 rats. Group I was kept as negative control and was administered normal saline. Group II and III were exposed to 2 mg/kg of the mycotoxin, ZEA administered intraperitoneally once every week. Group III was treated with resveratrol (RSV) orally (5 mg/kg) daily. Group IV was treated only with resveratrol (5 mg/kg/daily) as a positive control. The protective effect of resveratrol was evaluated on; biochemical variables, biomarkers of oxidative stress, markers of immunotoxicity, and DNA damage. The findings showed that exposure to ZEA elicited oxidative stress and modulated the antioxidant enzyme activities. A disarray in the lipid profile, parameters of the humoral and cellular immune response; serum cytokines and immunoglobulins was also observed. Further, COMET assay showed detectable DNA lesions. Taken together, RSV was efficacious in reducing and/or reversing the ZEA induced toxicity.

Mechanism and effects of Zearalenone on mouse T lymphocytes activation in vitro

Zearalenone (ZEA) is particularly toxic to the female reproductive system. Nevertheless, the effect of ZEA on the immune system is still not fully understood. The following study investigates the effects and mechanism of ZEA on mouse T cell activation in vitro. Briefly, T lymphocytes were extracted from primary splenic lymphocyte in mice, activated by concanavalin A, and then were exposed to different concentrations of ZEA for a certain period of time. Flow cytometry was used to detect the expression of activating and co-stimulatory molecules, and the secretion of cytokines in T cells at various stages. The expression of initiation regulatory protein in T cell activation, nuclear factor protein and co-stimulatory molecule related PI3K-Akt-mTOR signaling pathway proteins were detected by western blot. Our data showed that ZEA exposure inhibits the activity of T cell, and inhibits the expression of different activation signals in T cell. Additionally, ZEA exposure reduces the expression of initiative regulatory protein, i.e. LAT, Lck, Zap-70 during the activation of T cells. Thus, the results showed that ZEA exposure inhibits the formation and transmission of activated signal in T cells, interferes with signal pathway of T cell activation nuclear factor NFAT and NFκB, and decreases the secretion of cytokines after activation. Moreover, ZEA exposure interferes with co-stimulatory molecule CD28 during T cell activation, and with the activity of the PI3K-Akt-mTOR signaling pathway downstream of CD28. To conclude, our results indicated that ZEA toxin interferes with the activation of mouse T lymphocytes by affecting TCR signal and co-stimulatory signal, thus playing an essential role in immune toxicity.