Prevention of deoxynivalenol- and zearalenone-associated oxidative stress does not restore MA-10 Leydig cell functions

Global distribution, toxicity to humans and animals, biodegradation, and nutritional mitigation of deoxynivalenol: A review

Deoxynivalenol (DON) is one of the main types of B trichothecenes, and it causes health-related issues in humans and animals and imposes considerable challenges to food and feed safety globally each year. This review investigates the global hazards of DON, describes the occurrence of DON in food and feed in different countries, and systematically uncovers the mechanisms of the various toxic effects of DON. For DON pollution, many treatments have been reported on the degradation of DON, and each of the treatments has different degradation efficacies and degrades DON by a distinct mechanism. These treatments include physical, chemical, and biological methods and mitigation strategies. Biodegradation methods include microorganisms, enzymes, and biological antifungal agents, which are of great research significance in food processing because of their high efficiency, low environmental hazards, and drug resistance. And we also reviewed the mechanisms of biodegradation methods of DON, the adsorption and antagonism effects of microorganisms, and the different chemical transformation mechanisms of enzymes. Moreover, nutritional mitigation including common nutrients (amino acids, fatty acids, vitamins, and microelements) and plant extracts was discussed in this review, and the mitigation mechanism of DON toxicity was elaborated from the biochemical point of view. These findings help explore various approaches to achieve the best efficiency and applicability, overcome DON pollution worldwide, ensure the sustainability and safety of food processing, and explore potential therapeutic options with the ability to reduce the deleterious effects of DON in humans and animals.

Deoxynivalenol induces testicular ferroptosis by regulating the Nrf2/System Xc-/GPX4 axis

Deoxynivalenol (DON) is the most common mycotoxin contaminant in food and feed. DON accumulation in food chain severely threatens human and animal health due to the toxic effects on the reproduction system. However, the underlying mechanism of DON on male reproductive dysfunction is still in debate and there is little information about whether DON triggers testicular ferroptosis. In this study, male C57BL/6 mice were divided into 4 groups and treated by oral gavage with 0, 0.5, 1.0, 2.0 mg/kg BW DON for 28 days. Firstly, we proved that male reproduction dysfunction was induced by DON through assessing testicular histopathology, serum testosterone level as well as blood-testis barrier integrity. Then, we verified ferroptosis occurred in DON-induced testicular dysfunction model through disrupting iron homeostasis, increasing lipid peroxidation and inhibiting system Xc^-/Gpx4 axis. Notably, the present data showed DON reduced antioxidant capacity via blocking Nrf2 pathway to lead to the further weakness of ferroptosis resistance. Altogether, these results indicated that DON caused mice testicular ferroptosis associated with inhibiting Nrf2/System Xc-/GPx4 axis, which provided that maintaining testicular iron homeostasis and activating Nrf2 pathway may be a potential target for alleviating testicular toxicity of DON in the future.

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.

Lactoferrin Restores the Deoxynivalenol-Impaired Spermatogenesis and Blood-Testis Barrier Integrity via Improving the Antioxidant Capacity and Modifying the Cell Adhesion and Inflammatory Response

Deoxynivalenol (DON) is among the most prevalent contaminants in cereal crops and has been demonstrated to impair male spermatogenesis and induce oxidative stress, testicular apoptosis, and disruption of the blood-testis barrier (BTB). Lactoferrin (LF) is an iron-binding glycoprotein with multifunctions including anti-inflammation and antioxidation. Thus, this study aimed to investigate the effects of LF on the spermatogenesis and integrity of the BTB in DON-exposed mice. Thirty-two male mice were allotted to four groups for a 35-day feeding period: vehicle (basal diet), DON (12 mg/kg), LF (10 mg/d, p.o.), and DON + LF. The results showed that DON induced vacuolization of the spermatogenic epithelium, broke the adhesion junction between Sertoli cells and spermatids established by N-cadherin and induced testicular oxidative stress. LF administration restored sperm production, attenuated the DON-induced oxidative stress and reduced the breakages in adhesion junction. DON exposure enhanced the protein expression of occludin. Transcriptional profiling of the testis observed a disturbance in the expression profiles of cell adhesion and inflammatory response genes, and LF administration reversed these gene expressions. Furthermore, down-regulated signaling pathways, including the apical junction, TNFα signaling via NF-κB, and TGF-β in the DON group were observed. These were restored by LF. Enrichment analysis between DON + LF group and vehicle also confirmed the absence of these pathways. These findings indicated that LF eliminated the DON-induced detriment to spermatogenesis and cell connections between Sertoli cells and spermatids via improving antioxidant capacity and modifying the inflammatory response and cell adhesion genes.

Lactobacillus plantarum and Deoxynivalenol Detoxification: A Concise Review

ABSTRACT

Mycotoxins are toxic secondary fungal metabolites that contaminate feeds, and their levels remain stable during feed processing. The economic impact of mycotoxins on animal production happens mainly due to losses related to direct effects on animal health and trade losses related to grain rejection. Deoxynivalenol (DON) is a trichothecene mycotoxin that has contaminated approximately 60% of the grains worldwide. Ingestion of DON induces many toxic effects on human and animal health. Detoxification strategies to decrease DON levels in food and feeds include physical and chemical methods; however, they are not very effective when incorporated into the industrial production process. A valuable alternative to achieve this aim is the use of lactic acid bacteria. These bacteria can control fungal growth and thus overcome DON production or can detoxify the mycotoxin through adsorption and biotransformation. Some Lactobacillus spp. strains, such as Lactobacillus plantarum, have demonstrated preventive effects against DON toxicity in poultry and swine. This beneficial effect is associated with a binding capacity of lactic acid bacteria cell wall peptidoglycan with mycotoxins. Moreover, several antifungal compounds have been isolated from L. plantarum supernatants, including lactic, acetic, caproic, phenyl lactic, 3-hydroxylated fatty, and cyclic dipeptide acids. Biotransformation of DON by L. plantarum into other products is also hypothesized, but the mechanism remains unknown. In this concise review, we highlight the use of L. plantarum as an alternative approach to reduce DON levels and toxicity. Although the action mechanism of L. plantarum is still not fully understood, these bacteria are a safe, efficient, and low-cost strategy to reduce economic losses from mycotoxin contamination cases.

HIGHLIGHTS

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

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

Comparative Cytotoxic Effects and Possible Mechanisms of Deoxynivalenol, Zearalenone and T-2 Toxin Exposure to Porcine Leydig Cells In Vitro

Mycotoxins such as zearalenone (ZEN), deoxynivalenol (DON) and T-2 toxin (T-2) are the most poisonous biological toxins in food pollution. Mycotoxin contaminations are a global health issue. The aim of the current study was to use porcine Leydig cells as a model to explore the toxic effects and underlying mechanisms of ZEN, DON and T-2. The 50% inhibitory concentration (IC50) of ZEN was 49.71 μM, and the IC50 values of DON and T-2 were 2.49 μM and 97.18 nM, respectively. Based on the values of IC50, ZEN, DON and T-2 exposure resulted in increased cell apoptosis, as well as disrupted mitochondria membrane potential and cell cycle distribution. The results also showed that ZEN and DON significantly reduced testosterone and progesterone secretion in Leydig cells, but T-2 only reduced testosterone secretion. Furthermore, the expression of steroidogenic acute regulatory (StAR) protein and 3β-hydroxysteroid dehydrogenase (3β-HSD) were significantly decreased by ZEN, DON and T-2; whereas the protein expression of cholesterol side-chain cleavage enzyme (CYP11A1) was only significantly decreased by ZEN. Altogether, these data suggest that the ZEN, DON and T-2 toxins resulted in reproductive toxicity involving the inhibition of steroidogenesis and cell proliferation, which contributes to the cellular apoptosis induced by mitochondrial injury in porcine Leydig cells.

Glucosamine alleviates zearalenone damage to porcine trophectoderm cells by activating PI3K/AKT signaling pathway

As one of the mycotoxins commonly found in feed and food, zearalenone (ZEA) mainly harms the reproductive functions of humans and animals. In our study, we investigated the protective effects...

Hyperoside Attenuates Zearalenone-induced spleen injury by suppressing oxidative stress and inhibiting apoptosis in mice

Zearalenone (ZEA) is a ubiquitous mycotoxin contaminant that causes immune toxicity, apoptosis, and oxidative stress in animals. Hyperoside (Hyp) is a flavonol glycoside compound with antioxidant and anti-apoptotic properties. However, the potential of Hyp to prevent ZEA-induced spleen injury remains unknown. To evaluate the chemoprotective effect of Hyp against ZEA-induced spleen injury, 60 male Kunming mice were randomly assigned into five groups. The first two groups were orally treated with ZEA (40 mg/kg) for 30 days, and combined with Hyp (0, 100 mg/kg) treatment. The other three groups are orally treated with normal saline, olive oil, or Hyp (100 mg/kg) for 30 days. Hyperoside had an inhibitory effect against ZEA-induced spleen lesions. In addition, Hyp significantly increased the activity of antioxidant enzymes [superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT)], the total antioxidant capacity (T-AOC), and significantly reduced the malondialdehyde (MDA) content reducing ZEA-induced oxidative stress in the spleen. Moreover, the translation of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream target genes (CAT, NQO1, SOD1, GSS, GCLM, and GCLC) were ameliorated using co-therapy with Hyp before treatment with ZEA. Hyperoside also significantly inhibited the translation and expression of apoptotic genes (caspase3, casepase9, Bax, Bcl-2) and the production of apoptotic bodies induced by ZEA in the spleen. In conclusion, the findings revealed that Hyp inhibited ZEA-induced spleen injury through its antioxidant and anti-apoptotic effects. Thus, it provides a new treatment option for immune system diseases caused by ZEA.

Deoxynivalenol induces apoptosis and autophagy in human prostate epithelial cells via PI3K/Akt signaling pathway

Phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway is one of the most deregulated signaling pathway in prostate cancer. It controls basic processes in cells: cell proliferation and death. Any disturbances in the balance between cell death and survival might result in carcinogenesis. Deoxynivalenol (DON) is one of the most common mycotoxins, a toxic metabolites of fungi, present in our everyday diet and feed. Although previous studies reported DON to induce oxidative stress, modulate steroidogenesis, DNA damage and cell cycle modulation triggering together its toxicity, its effect on normal prostate epithelial cells is not known. The aim of the study was to evaluate the effect of DON on the apoptosis and autophagy in normal prostate epithelial cells via modulation of PI3K/Akt signaling pathway. The results showed that DON in a dose of 30 µM and 10 µM induces oxidative stress, DNA damage and cell cycle arrest in G2/M cell cycle phase. The higher concentration of DON induces apoptosis, whereas lower one autophagy in PNT1A cells, indicating that modulation of PI3K/Akt by DON results in the induction of autophagy triggering apoptosis in normal prostate epithelial cells.

The NO-dependent caspase signaling pathway is a target of deoxynivalenol in growth inhibition in vitro

DON is commonly found in foods and feeds; it presents health risks, especially an increase of growth inhibition in humans, particularly infants and young children. However, there are relatively few research studies devoted to the mechanism of DON-mediated growth retardation. Interestingly, our results showed that DON does not cause any significant production of ROS but results in a persistent and significant release of NO with iNOS increasing activity, mitochondrial ultrastructural changes and decreasing ΔΨm. Moreover, the significant decreases in GH production and secretion induced by DON were dose-dependent, accompanied by an increase of caspase 3, 8 and 9, IL-11, IL-lβ and GHRH. NO scavenging agent (haemoglobin) and free radical scavenging agent (N-acetylcysteine) partially reversed mitochondrial damage, and Z-VAD-FMK increased the levels of GH and decreased the levels of caspase 3, 8 and 9, while haemoglobin decreased the levels of caspase 3, 8 and 9, indicating that NO is the primary target of DON-mediated inhibition. Present research study firstly demonstrated that NO is a key mediator of DON-induced growth inhibition and plays critical roles in the interference of GH transcription and synthesis. The current research is conducive to future research on the molecular mechanisms of DON-induced growth inhibition in humans, especially children.

In Vitro Analysis of Deoxynivalenol Influence on Steroidogenesis in Prostate

Deoxynivalenol (DON) is a type-B trichothecene mycotoxin produced by Fusarium species, reported to be the most common mycotoxin present in food and feed products. DON is known to affect the production of testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH) in male rats, consequently affecting reproductive endpoints. Our previous study showed that DON induces oxidative stress in prostate cancer (PCa) cells, however the effect of DON on the intratumor steroidogenesis in PCa and normal prostate cells was not investigated. In this study human normal (PNT1A) and prostate cancer cell lines with different hormonal sensitivity (PC-3, DU-145, LNCaP) were exposed to DON treatment alone or in combination with dehydroepiandrosterone (DHEA) for 48 h. The results of the study demonstrated that exposure to DON alone or in combination with DHEA had a stimulatory effect on the release of estradiol and testosterone and also affected progesterone secretion. Moreover, significant changes were observed in the expression of genes related to steroidogenesis. Taken together, these results indicate that DON might affect the process of steroidogenesis in the prostate, demonstrating potential reproductive effects in humans.

The toxicity mechanisms of DON to humans and animals and potential biological treatment strategies

Deoxynivalenol, also known as vomitotoxin, is produced by Fusarium, belonging to the group B of the trichothecene family. DON is widely polluted, mainly polluting cereal crops such as wheat, barley, oats, corn and related cereal products, which are closely related to lives of people and animals. At present, there have been articles summarizing DON induced toxicity, biological detoxification and the protective effect of natural products, but there is no systematic summary of this information. In addition to ribosome and endoplasmic reticulum, recent investigations support that mitochondrion is also organelles that DON can damage. DON can't directly act on mitochondria, but can indirectly cause mitochondrial damage and changes through other means. DON can indirectly inhibit mitochondrial biogenesis and mitochondrial electron transport chain activity, ATP production, and mitochondrial transcription and translation. This review will provide the latest progress on mitochondria as the research object, and systematically summarizes all the toxic mechanisms of DON. Here, we discuss DON induced mitochondrial-mediated apoptosis and various mitochondrial toxicity. For the toxicity of DON, many methods have been derived to prevent or reduce the toxicity. Biological detoxification and the antioxidant effect of natural products are potentially effective treatments for DON toxicity.

Effects of deoxynivalenol exposure at peripuberty over testicles of rats: structural and functional alterations

Deoxynivalenol (DON) is related to reduced reproductive performance in males and females in several species. Children and adolescents showed a high risk of exposure to DON, however, no study has evaluated reproductive effects of DON at puberty. The present study aimed to evaluate the effects of DON at peripuberty on the testicles of pubertal rats. To achieve this, 10 Wistar rats (28 days old) were fed for 28 days with a DON-contaminated diet (9.4 mg/kg) or a control diet. After the experimental period, rats (56 days old) were euthanised and the following evaluations were performed in the testicles: dynamics of spermatogenesis, tubular morphometry, number of Sertoli cells and Leydig cells, analysis of caspase-3 expression, and the index of cell proliferation using the nucleolus organising regions (NOR) method. Ingestion of DON-contaminated diet induced a significant reduction in the number of Sertoli and Leydig cells and the number of seminiferous tubules in stage XIV. A significant increase in the number of NORs in seminiferous tubules in stage I-VI was observed in animals receiving the DON diet. No significant difference was noted in tubular morphometry or caspase-3 expression. Taken together, our results unravelled that the peripubertal exposure to DON compromised the testicular structure of pubertal rats, changing the dynamics of spermatogenesis.

Does low concentration mycotoxin exposure induce toxicity in HepG2 cells through oxidative stress?

The purpose of this study was to determine whether exposure to low concentrations of deoxynivalenol (DON), T-2 toxin (T-2) and patulin (PAT) in a human hepatocellular carcinoma cell line (HepG2) exerts toxic effects through mechanisms related to oxidative stress, and how cells deal with such exposure. Cell viability was determined by the MTT and protein content (PC) assays over 24, 48 and 72 h. The IC₅₀ values detected ranged from >10 to 2.53 ± 0.21 μM (DON), 0.050 ± 0.025 to 0.034 ± 0.007 μM (T-2) and 2.66 ± 0.66 to 1.17 ± 0.21 µM (PAT). The key players in oxidative stress are the generation of reactive oxygen species (ROS), lipid peroxidation (LPO) and mitochondrial membrane potential (MMP) dysfunction. The results obtained showed that PAT, DON and T-2 did not significantly increase LPO or ROS production with respect to the controls. Moreover, PAT and DON did not alter MMP, though T-2 increased MMP at the higher concentrations tested (17 and 34 nM). In conclusion, the exposure of HepG2 cells to nontoxic concentrations of T-2 condition them against subsequent cellular oxidative conditions induced by even higher concentrations of mycotoxin.

Paraquat exposure delays late-stage Leydig cell differentiation in rats during puberty

Paraquat is a fast and non-selective herbicide that is widely used in crop cultivation and conservation tillage systems. Animal experiments have shown that paraquat decreases sperm quality and testicular organ coefficient, but its effects on the development of Leydig cells remain unclear. The objective of the current study was to investigate the effects of paraquat exposure on the Leydig cell development in rats during puberty. Twenty-eight male 35-day-old Sprague-Dawley rats were divided into 4 groups: 0, 0.5, 2.0, and 8 mg kg^-1 d^-1 paraquat. Paraquat was gavaged for 10 d. Adult Leydig cells were isolated and treated with paraquat for 24 h. Paraquat in vivo significantly decreased body and testis weights at 8 mg kg^-1 and lowered serum testosterone levels at 2 and 8 mg kg^-1 without affecting the levels of serum luteinizing hormone and follicle-stimulating hormone. Paraquat did not alter Leydig cell number and PCNA labeling index. Real-time PCR showed that paraquat down-regulated the expression of Lhcgr, Scarb1, Cyp11a1, Cyp17a1, and Hsd17b3 genes and their proteins at 2 or 8 mg kg^-1, while it up-regulated the expression of Srd5a1 at 8 mg kg^-1. Paraquat increased ROS and decreased testosterone production by Leydig cells at 1 and 10 μM after in vitro 24-h exposure. Vitamin E (40 μg/ml) reversed paraquat-induced ROS and suppression of testosterone synthesis in vitro. In conclusion, paraquat directly delays Leydig cell differentiation to block testosterone synthesis via down-regulating the expression of critical testosterone synthesis-related genes and up-regulating the expression of testosterone metabolic enzyme (Srd5a1) gene and possibly via increasing ROS production.

Deoxynivalenol Modulates the Viability, ROS Production and Apoptosis in Prostate Cancer Cells

Deoxynivalenol (DON), known as vomitoxin, a type B trichothecene, is produced by Fusarium. DON frequently contaminates cereal grains such as wheat, maize, oats, barley, rye, and rice. At the molecular level, it induces ribosomal stress, inflammation and apoptosis in eukaryotic cells. Our findings indicate that DON modulates the viability of prostate cancer (PCa) cells and that the response to a single high dose of DON is dependent on the androgen-sensitivity of cells. DON appears to increase reactive oxygen species (ROS) production in cells, induces DNA damage, and triggers apoptosis. The effects of DON application in PCa cells are influenced by the mitogen-activated protein kinase (MAPK) and NFΚB- HIF-1α signaling pathways. Our results indicate that p53 is a crucial factor in DON-associated apoptosis in PCa cells. Taken together, our findings show that a single exposure to high concentrations of DON (2-5 µM) modulates the progression of PCa.

Effects of zearalenone and its derivatives on the synthesis and secretion of mammalian sex steroid hormones: A review

Zearalenone (ZEA), a non-steroidal estrogen mycotoxin produced by several species of Fusarium fungi, can be metabolized into many other derivatives by microorganisms, plants, animals and humans. It can affect mammalian reproductive capability by impacting the synthesis and secretion of sex hormones, including testosterone, estradiol and progesterone. This review summarizes the mechanisms in which ZEA and its derivatives disturb the synthesis and secretion of sex steroid hormones. Because of its structural analogy to estrogen, ZEA and its derivatives can exert a variety of estrogen-like effects and engage in estrogen negative feedback regulation, which can result in mediating the production of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in the pituitary gland. ZEA and its derivatives can ultimately reduce the number of Leydig cells and granulosa cells by inducing oxidative stress, endoplasmic reticulum (ER) stress, cell cycle arrest, cell apoptosis, and cell regeneration delay. Additionally, they can disrupt the mitochondrial structure and influence mitochondrial functions through overproduction of reactive oxygen species (ROS) and aberrant autophagy signaling ways. Finally, ZEA and its derivatives can disturb the expressions and activities of the related steroidogenic enzymes through cross talking between membrane and nuclear estrogen receptors.

Toxic Effects and Possible Mechanisms of Deoxynivalenol Exposure on Sperm and Testicular Damage in BALB/c Mice

Deoxynivalenol (DON, vomitoxin) is the most common mycotoxin in cereals and grains. DON contamination can cause a serious health threat to humans and farm animals. DON has been reported to exert significant toxicity effects on the male reproductive system. However, the causes and mechanisms underlying efforts of DON on sperm and testicular damage remain largely unclear. In the present study, we thoroughly investigated this issue. Eighty male BALB/c mice were randomly divided into a control group ( n = 40) and DON treatment group (2.4 mg/kg of body weight, n = 40). The ratio of testes and seminal vesicle to body, sperm survival and motility, and morphology of sperm and testis were observed in DON-treated and control mice. In addition, the concentrations of reactive oxygen species (ROS) and malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and glutathione (GSH), and also the expression levels of JNK/c-Jun signaling and apoptotic factors such as caspase-3, caspase-8, caspase-9, Bim, and Bid were analyzed and compared between the two groups. The results demonstrated that a single topical application of DON significantly increased the percentage of abnormal sperm and decreased the motility of sperm, indicating the sperms are damaged by DON. Additionally, the reduced relative body weight of testis and severe destruction of testicular morphology were observed. Moreover, the increased levels of ROS and MDA levels and decreased activities of SOD and GSH were found in testicular tissues, suggesting that oxidative stress is induced by DON treatment. Furthermore, DON upregulated the expression of stress-induced JNK/c-Jun signaling pathway proteins as well as JNK/c-Jun phosphorylation proteins. In addition, DON could enhance testicular apoptosis by increasing expression levels of apoptotic genes including Bim, cytochrome c, caspase 3, caspase 8, and caspase 9. These results suggest that DON exposure can cause sperm damage, oxidative stress, testicular apoptosis, and phosphorylation of JNK/c-Jun signaling pathway. The underlying mechanisms may be that DON induces sperm damage by exacerbating oxidative stress-mediated testicular apoptosis via JNK/c-Jun signaling pathway.

Mycotoxin zearalenone exposure impairs genomic stability of swine follicular granulosa cells in vitro

Zearalenone (ZEA), a metabolite of Fusarium fungi, is commonly found on moldy grains. Because it can competitively combine to estrogen receptor to disrupt estrogenic signaling, it has been reported to have serious adverse effects on animal reproduction systems. In order to explore the genotoxic effects of ZEA exposure on ovarian somatic cells, porcine granulosa cells were exposed to 10 μM and 30 μM ZEA for 24 or 72 h in vitro. The results showed that ZEA exposure for 24 h remarkably reduced the proliferation of porcine granulosa cells in a dose-dependent manner as determined by MTT analysis and flow cytometry. Furthermore, exposure to ZEA for 72 h induced apoptosis, and RNA sequence analysis also revealed that the expression of apoptosis related genes were altered. RT-qPCR, immunofluorescence and western blot analysis further confirmed the expression of DNA damage and repair related genes (γ-H2AX, BRCA1, RAD51 and PRKDC) were increased in ZEA exposed granulosa cells. When the estrogen antagonist, tamoxifen, was added with ZEA in the culture medium, the DNA damage and repairment by ZEA returned to normal level. Collectively, these results illustrate that ZEA disrupts genome stability and inhibits growth of porcine granulosa cells via the estrogen receptors which may promote granulosa cell apoptosis when the DNA repair system is not enough to rescue this serious damage.

Mechanism of deoxynivalenol effects on the reproductive system and fetus malformation: Current status and future challenges

Deoxynivalenol (DON) is a toxic fungal secondary metabolite produced by molds of the Fusarium genus, and it is known to cause a spectrum of diseases both in humans and animals, such as emesis, diarrhea, anorexia, immunotoxicity, hematological disorders, impairment of maternal reproduction, and fetal development. The recently revealed teratogenic potential of DON has received much attention. In various animal models, it has been shown that DON led to skeletal deformities of the fetus. However, the underlying mechanisms are not yet fully understood, and toxicological data are also scarce. Several animal research studies highlight the potential link between morphological abnormalities and changes of autophagy in the reproductive system. Because autophagy is involved in fetal development, maintenance of placental function, and bone remodeling, this mechanism has become a high priority for future research. The general aim of the present review is to deliver a comprehensive overview of the current state of knowledge of DON-induced reproductive toxicity in different animal models and to provide some prospective ideas for further research. The focus of the current review is to summarize toxic and negative effects of DON exposure on the reproductive system and the potential underlying molecular mechanisms in various animal models.

Apoptosis inducing factor gene depletion inhibits zearalenone-induced cell death in a goat Leydig cell line

Zearalenone (ZEA) is a contaminant of human food and animal feedstuffs that causes health hazards. However, the signal pathways underlying ZEA toxicity remain elusive. The aims of this study were to determine which pathways are involved in ZEA-induced cell death and investigate the effect of apoptosis inducing factor (AIF) on cell death during ZEA treatment in the immortalized goat Leydig cell line hTERT-GLC. This study showed that ZEA-induced cell death in hTERT-GLCs works via endoplasmic reticulum (ER) stress, the caspase-dependent pathway, the caspase-independent pathway and autophagy. Recombinant lentiviral vectors were constructed to silence AIF expression in hTERT-GLCs. Flow cytometry results showed that knockdown of AIF diminished ZEA-induced cell apoptosis in hTERT-GLCs. Furthermore, we found AIF depletion down-regulated phosphoIRE1α, GRP78, CHOP and promoted the switch of LC3-I to LC3-II. Therefore, ZEA induces cytotoxicity in hTERT-GLCs via different pathways, while AIF-mediated signaling plays a critical role in ZEA-induced cell death in hTERT-GLCs.

Zearalenone as an endocrine disruptor in humans

Zearalenone (ZEA), a fungal mycotoxin, is present in a wide range of human foods. Many animal studies have found ZEA to possess a disruptive effect on the hormonal balance, mainly due to its similarity to naturally-occurring estrogens. With increasing consciousness of the adverse effects of endocrine disruptors on human health, it is becoming more important to monitor ZEA concentrations in food and identify its potential effects on human health. Based on a review of recent studies on animal models and molecular pathways in which ZEA is reported to have an influence on humans, we postulate that ZEA might act as an endocrine disruptor in humans in a similar way to animals. Moreover, its endocrine-disrupting effect might be also a causative factor in carcinogenesis. This review article summarizes the latest knowledge about the influence of ZEA on the human hormonal balance.

Fate of deoxynivalenol and deoxynivalenol-3-glucoside during cereal-based thermal food processing: a review study

Deoxynivalenol (DON), the most commonly occurring trichothecene in nature, may affect animal and human health through causing diarrhea, vomiting, gastrointestinal inflammation, and immunomodulation. DON-3-glucoside (DON-3G) as a major plant metabolite of the mycotoxin is another "emerging" food safety issue in recent years. Humans may experience potential health risks by consuming DON-contaminated food products. Thus, it is crucial for human and animal health to study also the degradation of DON and DON-3G during thermal food processing. Baking, boiling, steaming, frying, and extrusion cooking are commonly used during thermal food processing and have promising effects on the reduction of mycotoxins in food. For DON, however, the observed effects of these methods, as reported in numerous studies, are ambiguous and do not present a clear picture with regard to reduction or transformation. This review summarized the influence of thermal processing on the stability of DON and the formation of degradation/conversion products. Besides this, also a release of DON and DON-3G from food matrix as well as the release of DON from DON-3G during processing is discussed. In addition, some conflicting findings as reported from the studies on thermal processing as well as cause-effect relationships of the different thermal procedures are explored. Finally, the potential toxic profiles of DON degradation products are discussed as well when data are available.

The Protective Effect of Grape-Seed Proanthocyanidin Extract on Oxidative Damage Induced by Zearalenone in Kunming Mice Liver

Although grape-seed proanthocyanidin extract (GSPE) demonstrates strong anti-oxidant activity, little research has been done to clearly reveal the protective effects on the hepatotoxicity caused by zearalenone (ZEN). This study is to explore the protective effect of GSPE on ZEN-induced oxidative damage of liver in Kunming mice and the possible protective molecular mechanism of GSPE. The results indicated that GSPE could greatly reduce the ZEN-induced increase of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities. GSPE also significantly decreased the content of MDA but enhanced the activities of antioxidant enzymes SOD and GSH-Px. The analysis indicated that ZEN decreased both mRNA expression levels and protein expression levels of nuclear erythroid2-related factor2 (Nrf2). Nrf2 is considered to be an essential antioxidative transcription factor, as downstream GSH-Px, γ-glutamyl cysteine synthetase (γ-GCS), hemeoxygenase-1 (HO-1), and quinone oxidoreductase 1 (NQO1) decreased simultaneously, whereas the pre-administration of GSPE groups was shown to elevate these expressions. The results indicated that GSPE exerted a protective effect on ZEN-induced hepatic injury and the mechanism might be related to the activation of the Nrf2/ARE signaling pathway.