Interactive effects of fumonisin B1 and α-zearalenol on proliferation and cytokine expression in Jurkat T cells

Aflatoxin B1 and fumonisin B1 exposure and adverse birth outcomes in HIV-infected and HIV-uninfected women from Harare, Zimbabwe

Aflatoxin B1 (AFB1) and fumonisin B1 (FB1) are toxic secondary products of fungi that frequently contaminate staple crops in resource-limited settings. Antenatal AFB1 and FB1 exposure may cause adverse birth outcomes. We conducted a retrospective substudy nested in a case-control cohort of HIV-infected and HIV-uninfected women ≥20 weeks gestation from Harare, Zimbabwe. Urinary aflatoxin M1 (AFM1) and FB1, biomarkers of AFB1 and FB1 exposure, respectively, were quantified in random antenatal urine via ELISA and grouped into tertiles. The adverse birth outcomes considered were low birth weight, preterm birth (PTB), small for gestational age, stillbirth, birth defects, neonatal death, neonatal jaundice and perinatal death (PD). We evaluated any associations between adverse birth outcomes and exposure to AFB1, FB1, or the AFB1-FB1 combination via a multivariable logistic regression controlled for potential confounders. We enrolled 94 HIV-infected and 81 HIV-uninfected women. In HIV-infected, AFM1 was detected in 46/94 (49%), and FB1 was detected in 86/94 (91%). In HIV-uninfected, AFM1 was detected in 48/81 (59%), and FB1 was detected in 74/81 (91%). Among all women, AFM1 tertile 3 was associated with PD (OR: 6.95; 95% CI: 1.21-39.78). In the same population, AFM1 tertiles 2 (OR: 13.46; 95% CI: 1.20-150.11) and 3 (OR: 7.92; 95% CI: 1.08-58.19) were associated with PTB. In HIV-infected, AFM1 tertile 2 was associated with PTB (OR: 64.73; 95% CI: 2.37-177.93). Our results revealed an association between AFB1 exposure and PD and PTB in women, including those infected with HIV. Public health and nutrition measures are necessary to mitigate mycotoxins.

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.

Recent Research on Fusarium Mycotoxins in Maize-A Review

Maize (Zea mays L.) is one of the most susceptible crops to pathogenic fungal infections, and in particular to the Fusarium species. Secondary metabolites of Fusarium spp.-mycotoxins are not only phytotoxic, but also harmful to humans and animals. They can cause acute or chronic diseases with various toxic effects. The European Union member states apply standards and legal regulations on the permissible levels of mycotoxins in food and feed. This review summarises the most recent knowledge on the occurrence of toxic secondary metabolites of Fusarium in maize, taking into account modified forms of mycotoxins, the progress in research related to the health effects of consuming food or feed contaminated with mycotoxins, and also the development of biological methods for limiting and/or eliminating the presence of the same in the food chain and in compound feed.

Co-occurrence of mycotoxins: A review on bioanalytical methods for simultaneous analysis in human biological samples, mixture toxicity and risk assessment strategies

Mycotoxins are the toxic chemical substances that are produced by various fungal species and some of these are harmful to humans. Mycotoxins are ubiquitous in nature and humans could be exposed to multiple mycotoxins simultaneously. Unfortunately, exposure to mixed mycotoxins is not very well studied. Various studies have demonstrated the capacity of mycotoxins to show synergistic effect in the presence of other mycotoxins, thus, increasing the risk of toxicity. Hence, it is important to monitor mixed mycotoxins in human biological samples which would serve as a crucial information for risk assessment. Through this review paper, we aim to summarize the mixture toxicity of mycotoxins and the various bio-analytical techniques that are being used for the simultaneous analysis of mixed mycotoxins in human biological samples. Different sample preparation and clean-up techniques employed till date for eliminating the interferences from human biological samples without affecting the analyses of the mycotoxins are also discussed. Further, a brief introduction of risk assessment strategies that have been or could be adopted for multiple mycotoxin risk assessments is also mentioned. To the best of our knowledge, this is the first review that focuses solely on the occurrence of multiple mycotoxins in human biological samples as well as their risk assessment strategies.

Deoxynivalenol and zearalenone: Different mycotoxins with different toxic effects in donkey (Equus asinus) endometrial epithelial cells

Deoxynivalenol (DON) and zearalenone (ZEA), which are commonly found in feed products, exhibit serious negative effects on the reproductive systems of domestic animals. However, the toxicity of mycotoxins on the uterine function of donkey (Equus asinus) remains unclear. This study investigated the biological effects of DON and ZEA exposure on donkey endometrial epithelial cells (EECs). It was administered 10 μM and 30 μM DON and ZEA to cells cultured in vitro. The results showed that 10 μM DON exposure markedly changed the expression levels of pyroptosis-associated genes and that 30 μM ZEA exposure changed the expression levels of inflammation-associated genes in EECs. The mRNA expression of cancer-promoting genes was markedly upregulated in cells exposed to DON and 30 μM ZEA; in particular, 10 μM and 30 μM DON and ZEA markedly disturbed the expression of androgen and estrogen secretion-related genes. Furthermore, Q-PCR, Western blot, and immunofluorescence analyses verified the different expression patterns of related genes in DON- and ZEA-exposed EECs. Collectively, these results illustrated the impact of exposure to different toxins and concrete toxicity on the mRNA expression of EECs from donkey in vitro.

Proteomic analysis of zearalenone toxicity on mouse thymic epithelial cells

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

Updated Review of the Toxicity of Selected Fusarium Toxins and Their Modified Forms

Mycotoxins are one of the most dangerous food and feed contaminants, hence they have significant influence on human and animal health. This study reviews the information reported over the last few years on the toxic effects of the most relevant and studied Fusarium toxins and their modified forms. Deoxynivalenol (DON) and its metabolites can induce intracellular oxidative stress, resulting in DNA damage. Recent studies have also revealed the capability of DON and its metabolites to disturb the cell cycle and alter amino acid expression. Several studies have attempted to explore the mechanism of action of T-2 and HT-2 toxins in anorexia induction. Among other findings, two neurotransmitters associated with this process have been identified, namely substance P and serotonin (5-hydroxytryptamine). For zearalenone (ZEN) and its metabolites, the literature points out that, in addition to their generally acknowledged estrogenic and oxidative potentials, they can also modify DNA by altering methylation patterns and histone acetylation. The ability of the compounds to induce alterations in the expression of major metabolic genes suggests that these compounds can contribute to the development of numerous metabolic diseases, including type 2 diabetes.

Deoxynivalenol and Zearalenone: Different Mycotoxins with Different Toxic Effects in the Sertoli Cells of Equus asinus

(1) Background: Deoxynivalenol (DON) and zearalenone (ZEA) are type B trichothecene mycotoxins that exert serious toxic effects on the reproduction of domestic animals. However, there is little information about the toxicity of mycotoxins on testis development in Equus asinus. This study investigated the biological effects of DON and ZEA exposure on Sertoli cells (SCs) of Equus asinus; (2) Methods: We administered 10 μM and 30 μM DON and ZEA to cells cultured in vitro; (3) Results: The results showed that 10 μM DON exposure remarkably changed pyroptosis-associated genes and that 30 μM ZEA exposure changed inflammation-associated genes in SCs. The mRNA expression of cancer-promoting genes was remarkably upregulated in the cells exposed to DON or 30 μM ZEA; in particular, DON and ZEA remarkably disturbed the expression of androgen and oestrogen secretion-related genes. Furthermore, quantitative RT-PCR, Western blot, and immunofluorescence analyses verified the different expression patterns of related genes in DON- and ZEA-exposed SCs; (4) Conclusions: Collectively, these results illustrated the impact of exposure to different toxins and concrete toxicity on the mRNA expression of SCs from Equus asinus in vitro.

Parallel validation of a green-solvent extraction method and quantitative estimation of multi-mycotoxins in staple cereals using LC-MS/MS

In this study, 15 different mycotoxins were estimated in three staple cereals from selected agro-ecological regions in Nigeria using a 'novel' green extraction method, pressurized hot water extraction (PHWE) in comparison to a conventional solvent extraction method. Discrimination of the results of PHWE and solvent extraction using principal component analysis (PCA) and orthogonal projection to latent structures discriminate analysis (OPLS-DA) did not yield any differential clustering patterns. All maize samples (n = 16), 32% (n = 38) of sorghum and 35% (n = 37) of millet samples were positive for at least one of the 15 tested mycotoxins. Contamination levels for the cereals were higher in the warm humid rain forest region and gradually decreased towards the hot and arid region in the north of the country. The results demonstrate the applicability of PHWE as a possible alternative extraction method to conventional methods of extraction, which are solvent based.

Secretome Analysis of Mouse Dendritic Cells Interacting with a Probiotic Strain of Lactobacillus gasseri

Probiotics play a key role in the modulation of the gut immune system in health and disease and their action is mediated by molecules exposed on the microorganism surface or secreted probiotic-derived factors. In particular, Lactobacillus gasseri OLL2809, a probiotic microorganism isolated from human feces, has the potential to modulate various immune responses. The dendritic cells (DCs) are considered the main players in orchestrating the immune response, and their contact with intestinal microbiota is crucial for the development and homeostasis of gut immunity. To gain a perspective on the molecular mechanisms involved in the maturation process of DCs and investigate factors that could modulate these processes, a differential proteomic analysis was performed on the secretome of immature DCs, mature DCs (mDCs, induced by lipopolysaccharide (LPS)), and immature DCs challenged with L. gasseri OLL2809 before treatment with LPS (LGmDCs). The maturation process of DCs was associated to profound changes in the protein secretome and probiotic pre-treatment led to a dramatic modulation of several secreted proteins of mDC, not only classical immune mediators (i.e., cytokines, complement factors, T cell Receptor ligands) but also proteins involved in the contractile and desmosome machineries. The latter data highlight a novel mechanism by which L. gasseri can modulate the maturation process of DCs, reinforcing the concept of a protective anti-inflammatory role ascribed to this probiotic strain.

Zearalenone: A Mycotoxin With Different Toxic Effect in Domestic and Laboratory Animals' Granulosa Cells

Zearalenone (ZEA), one of the most prevalent estrogenic mycotoxins, is mainly produced by Fusarium fungi and has been proven to affect the reproductive capacity of animals. Exposure of farm animals to ZEA is a global public health concern because of its toxicity and wide distribution in animal feeds. In vitro and in vivo experiments indicate that ZEA possesses estrogenic activity in mice, swine, Equus asinus and cattle. The precise mechanism of the reproductive toxicity of ZEA has not been established yet. This article reviews evidence on the deleterious effects of ZEA on mammalian folliculogenesis from early to final oogenesis stages. Such effects include impaired granulosa cell (GC) development and follicle steroidogenesis, reduced oocyte nest breakdown, damaged meiotic progression, poor fetal oocyte survival, accelerated primordial follicle activation and enhanced follicle atresia. These phenomena may result in reproductive and non-reproductive problems in domestic animals. In addition, emerging data indicates that ZEA may cause mRNA expression changes in the GCs. In general, E. asinus is more sensitive than swine to ZEA exposure. Finally, results of in vivo animal studies and in vitro tests are reported and discussed.

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.

Zearalenone Exposure Enhanced the Expression of Tumorigenesis Genes in Donkey Granulosa Cells via the PTEN/PI3K/AKT Signaling Pathway

Zearalenone (ZEA) is a natural contaminant existing in food and feed products that exhibits a negative effect on domestic animals' reproduction. Donkeys possess high economic value in China and are at risk of exposure to ZEA. However, few information is available on ZEA-induced toxicity and no report on toxicity in donkeys can be found in scientific literature. We investigated the biological effects of ZEA exposure on donkey granulosa cells (dGCs) by using RNA-seq analysis. ZEA at 10 and 30 μM were administered to GCs within 72 h of in vitro culture. ZEA at 10 μM significantly altered the tumorigenesis associated genes in dGCs. Exposure to 10 and 30 μM ZEA treatment significantly reduced mRNA expression of PTEN, TGFβ, ATM, and CDK2 genes, particularly, the ZEA treatment significantly increased the expression of PI3K and AKT genes. Furthermore, immunofluorescence, RT-qPCR, and Western blot analysis verified the gene expression of ZEA-exposed GCs. Collectively, these results demonstrated the deleterious effect of ZEA exposure on the induction of ovarian cancer related genes via the PTEN/PI3K/AKT signaling pathway in dGCs in vitro.

Differentiation of sow and mouse ovarian granulosa cells exposed to zearalenone in vitro using RNA-seq gene expression

Zearalenone (ZEA), a natural contaminant found in feed, has been shown to have a negative impact on domestic animal reproduction, particularly in pigs. There are species-specific differences in the ZEA-induced toxicity pattern. Here, we investigated the different biological effects of ZEA exposure on porcine and mouse granulosa cells, using RNA-seq analysis. We treated murine and porcine granulosa cells with 10 μM and 30 μM ZEA during 72 h of culturing, in vitro. The results showed that 10 μM ZEA exposure significantly altered mitosis associated genes in porcine granulosa cells, while the same treatment significantly altered the steroidogenesis associated genes in mouse granulosa cells. Exposure to 30 μM ZEA resulted in significantly up-regulated expression of inflammatory related genes in porcine granulosa cells as well as the cancer related genes in mouse granulosa cells. Similarly, 30 μM ZEA exposure significantly decreased the expression of tumor suppressor factors in the mouse granulosa cells. Furthermore, immunofluorescence, RT-qPCR as well as western-blot analysis verified the different expression of related genes in ZEA exposed porcine and mouse granulosa cells. Collectively, these results illustrate the presence of species differences with regards to ZEA effects between porcine and mouse ovarian granulosa cells, in vitro.

Transcriptional profiling analysis of Zearalenone-induced inhibition proliferation on mouse thymic epithelial cell line 1

Zearalenone (ZEA) was a mycotoxin biosynthesized by a variety of Fusarium fungi via a polypeptide pathway. ZEA has significant toxic reaction on immune cells. Thymic epithelial cells (TECs) as a crucial constituent of thymic stroma can provide unique microenvironment for thymocyte maturation, but the mechanism of ZEA affecting the TECs is poorly understood. The basic data about gene expression differences for the ZEA on thymic epithelial cell line 1 (MTEC1) will help us to elucidate this mechanism. Here, cell viability and proliferation assay and transcriptome sequencing on MTEC1 treated with ZEA were performed. 4188 differentially expressed genes (DEGs) between ZEA treated and control groups were identified, confirmed and analyzed. Our results showed that 10-50μg/ml ZEA significantly inhibited MTEC1 proliferation and arrested cell cycle at G2/M phase. Gene ontology and KEGG pathway analysis revealed that Chemokine, JAK-STAT and Toll-like receptor signaling pathway, were involved in the cell cycle pathway. 16 key genes involved in the cell cycle processes were validated and the results suggested that Mitotic catastrophe (MC) may take part in ZEA inhibition of METC1 cell proliferation. These data highlighted the importance of cell cycle pathway in MTEC1 treated with ZEA, and will contribute to get the molecular mechanisms of ZEA inhibition of MTEC1 cell proliferation.

Modified Fusarium Mycotoxins in Cereals and Their Products-Metabolism, Occurrence, and Toxicity: An Updated Review

Mycotoxins are secondary fungal metabolites, toxic to humans, animals and plants. Under the influence of various factors, mycotoxins may undergo modifications of their chemical structure. One of the methods of mycotoxin modification is a transformation occurring in plant cells or under the influence of fungal enzymes. This paper reviews the current knowledge on the natural occurrence of the most important trichothecenes and zearalenone in cereals/cereal products, their metabolism, and the potential toxicity of the metabolites. Only very limited data are available for the majority of the identified mycotoxins. Most studies concern biologically modified trichothecenes, mainly deoxynivalenol-3-glucoside, which is less toxic than its parent compound (deoxynivalenol). It is resistant to the digestion processes within the gastrointestinal tract and is not absorbed by the intestinal epithelium; however, it may be hydrolysed to free deoxynivalenol or deepoxy-deoxynivalenol by the intestinal microflora. Only one zearalenone derivative, zearalenone-14-glucoside, has been extensively studied. It appears to be more reactive than deoxynivalenol-3-glucoside. It may be readily hydrolysed to free zearalenone, and the carbonyl group in its molecule may be easily reduced to α/β-zearalenol and/or other unspecified metabolites. Other derivatives of deoxynivalenol and zearalenone are poorly characterised. Moreover, other derivatives such as glycosides of T-2 and HT-2 toxins have only recently been investigated; thus, the data related to their toxicological profile and occurrence are sporadic. The topics described in this study are crucial to ensure food and feed safety, which will be assisted by the provision of widespread access to such studies and obtained results.

Zearalenone and alpha-zearalenol inhibit the synthesis and secretion of pig follicle stimulating hormone via the non-classical estrogen membrane receptor GPR30

Zearalenone (ZEA) is one of the most popular endocrine-disrupting chemicals and is mainly produced by fungi of the genus Fusarium. The excessive intake of ZEA severely disrupts human and animal fertility by affecting the reproductive axis. However, most studies on the effects of ZEA and its metabolite α-zearalenol (α-ZOL) on reproductive systems have focused on gonads. Few studies have investigated the endocrine-disrupting effects of ZEA and α-ZOL on pituitary gonadotropins, including follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The present study was designed to investigate the effects of ZEA and α-ZOL on the synthesis and secretion of FSH and LH and related mechanisms in female pig pituitary. Our in vivo and in vitro results demonstrated that ZEA significantly inhibited the synthesis and secretion of FSH in the pig pituitary gland, but ZEA and α-ZOL had no effects on LH. Our study also showed that ZEA and α-ZOL decreased FSH synthesis and secretion through non-classical estrogen membrane receptor GPR30, which subsequently induced protein kinase cascades and the phosphorylation of PKC, ERK and p38MAPK signaling pathways in pig pituitary cells. Furthermore, our study showed that the LIM homeodomain transcription factor LHX3 was involved in the mechanisms of ZEA and α-ZOL actions on gonadotropes in the female pig pituitary. These findings elucidate the mechanisms behind the physiological alterations resulting from endocrine-disrupting chemicals and further show that the proposed key molecules of the α-ZOL signaling pathway could be potential pharmacological targets.

Mycotoxins co-contamination: Methodological aspects and biological relevance of combined toxicity studies

Mycotoxins are secondary fungal metabolites produced mainly by Aspergillus, Penicillium, and Fusarium. As evidenced by large-scale surveys, humans and animals are simultaneously exposed to several mycotoxins. Simultaneous exposure could result in synergistic, additive or antagonistic effects. However, most toxicity studies addressed the effects of mycotoxins separately. We present the experimental designs and we discuss the conclusions drawn from in vitro experiments exploring toxicological interactions of mycotoxins. We report more than 80 publications related to mycotoxin interactions. The studies explored combinations involving the regulated groups of mycotoxins, especially aflatoxins, ochratoxins, fumonisins, zearalenone and trichothecenes, but also the "emerging" mycotoxins beauvericin and enniatins. Over 50 publications are based on the arithmetic model of additivity. Few studies used the factorial designs or the theoretical biology-based models of additivity. The latter approaches are gaining increased attention. These analyses allow determination of the type of interaction and, optionally, its magnitude. The type of interaction reported for mycotoxin combinations depended on several factors, in particular cell models and the tested dose ranges. However, synergy among Fusarium toxins was highlighted in several studies. This review indicates that well-addressed in vitro studies remain valuable tools for the screening of interactive potential in mycotoxin mixtures.

Combined toxicity of prevalent mycotoxins studied in fish cell line and zebrafish larvae revealed that type of interactions is dose-dependent

While, Aflatoxin B₁ (AFB₁), deoxynivalenol (DON) and zearalenone (ZEN) are the most prevalent mycotoxins co-existing in grain products and animal feeds, little is known about their combinatorial toxicities on aquatic life-forms. We studied the individual and combined effects of these mycotoxins in a fish cell line (BF-2) and zebrafish larvae (wild-type and transgenic). The types of interactions in mycotoxins combinations on cell viability were determined by using Chou-Talalay model. Induction of oxidative stress pathway in mycotoxins-exposed BF-2 cells was assessed using high content screening (HCS). Mycotoxin-exposed wild-type zebrafish larvae were examined for mortality and morphological abnormalities and transgenic zebrafish larvae (expressing DsRed in the liver) were imaged using HCS and examined for liver abnormalities. Results showed that the cytotoxicity of mycotoxins in a decreasing order was AFB₁>DON>ZEN, however, the highest mortality rate and liver damage in zebrafish were observed for AFB₁ followed by ZEN. AFB₁+DON and AFB₁+ZEN synergistically enhanced the toxic effects on BF-2 cells and zebrafish while DON+ZEN showed antagonism. Interestingly, in the tertiary combination, the synergism seen at lower individual concentrations of mycotoxins progressively turned to an overall antagonism at higher doses. The results provide a scientific basis for the necessity to consider co-exposure when formulating risk-management strategies.

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.

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.

Binary and tertiary combination of alternariol, 3-acetyl-deoxynivalenol and 15-acetyl-deoxynivalenol on HepG2 cells: Toxic effects and evaluation of degradation products

Fungi producers of mycotoxins are able to synthesize more than one toxin. Alternariol (AOH) is one of the mycotoxins produced by several Alternaria species, the most common one being Alternaria alternata. The toxins 3-Acetyl-deoxynivalenol (3-ADON) and 15-Acetyl-deoxynivalenol (15-ADON) are acetylated forms of deoxynivalenol (DON) produced by Fusarium graminearum. In the present work it is determined and evaluated the toxic effects of binary and tertiary combination treatment of HepG2 cells with AOH, 3-ADON and 15-ADON, by using the MTT assay (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide), to subsequently apply the isobologram method and elucidate if the mixtures of these mycotoxins produced synergism, antagonism or additive effect; and lastly, to analyze mycotoxins conversion into metabolites produced and released by HepG2 cells after applying the treatment conditions by liquid chromatography tandem mass spectrometry (LC-MS/MS) equipment and extracted from culture media. HepG2 cells were treated at different concentrations over 24, 48 and 72h. IC50 values detected at all times assayed, ranged from 0.8 to >25μM in binary combinations; while in tertiary it ranged from 7.5 to 12μM. Synergistic, antagonism or additive effect detected in the mixtures of these mycotoxins was different depending on low or high concentration. Among all four mycotoxins combinations assayed, 15-ADON+3-ADON presented the highest toxic potential. At all assayed times, recoveries values oscillated depending on the time and combination studied.

Natural Co-Occurrence of Mycotoxins in Foods and Feeds and Their in vitro Combined Toxicological Effects

Some foods and feeds are often contaminated by numerous mycotoxins, but most studies have focused on the occurrence and toxicology of a single mycotoxin. Regulations throughout the world do not consider the combined effects of mycotoxins. However, several surveys have reported the natural co-occurrence of mycotoxins from all over the world. Most of the published data has concerned the major mycotoxins aflatoxins (AFs), ochratoxin A (OTA), zearalenone (ZEA), fumonisins (FUM) and trichothecenes (TCTs), especially deoxynivalenol (DON). Concerning cereals and derived cereal product samples, among the 127 mycotoxin combinations described in the literature, AFs+FUM, DON+ZEA, AFs+OTA, and FUM+ZEA are the most observed. However, only a few studies specified the number of co-occurring mycotoxins with the percentage of the co-contaminated samples, as well as the main combinations found. Studies of mycotoxin combination toxicity showed antagonist, additive or synergic effects depending on the tested species, cell model or mixture, and were not necessarily time- or dose-dependent. This review summarizes the findings on mycotoxins and their co-occurrence in various foods and feeds from all over the world as well as in vitro experimental data on their combined toxicity.

The Fusarium toxin zearalenone and deoxynivalenol affect murine splenic antioxidant functions, interferon levels, and T-cell subsets

This study aimed to evaluate the effects of the Fusarium toxin zearalenone (ZEA) and deoxynivalenol (DON) on splenic antioxidant functions, IFN levels, and T-cell subsets in mice. Herein, 360 mice were assigned to nine groups for a 12-day study. Mice were administered an intraperitoneal injection for 4 consecutive days with different concentrations of ZEA alone, DON alone, or ZEA+DON. Spleen and blood samples were collected on days 0, 3, 5, 8, and 12. Mice in each of the experimental groups showed dysreglated splenic antioxidant functions, IFN levels, and T-cell subset frequencies, suggesting that the immune system had been affected. The ZEA+DON-treated groups, especially the group that received a higher concentration of ZEA+DON (Group D2Z2), showed more obvious effects on the dysregulation of splenic antioxidant functions, IFN levels, and T-cell subsets. This finding suggested that DON and ZEA exerted synergistic effects.

Induction of pro-inflammatory gene expression by Escherichia coli and mycotoxin zearalenone contamination and protection by a Lactobacillus mixture in porcine IPEC-1 cells

This work investigated the effect of Escherichia coli K88 and zearalenone contamination on pro-inflammatory gene expression (Toll like receptors, cytokines) and signalling molecules and the protective activity of a mixture of Lactobacilli sp. (Lactobacillus plantarum, Lactobacillus acidofilus and Lactobacillus paracasei) in porcine intestinal epithelial cells as part of the local immune system. IPEC-1 cell monolayer was exposed for 1 h to the individual or combined action of E. coli, zearalenone and lactobacilli mixture. Our results showed that TLRs (1-10) and cytokine (IL-1,-6,-8,-10, TNF-α, IFN-γ) genes expressed early (after 1 h of culture) in IPEC-1 cells. E. coli alone increased the TLRs mRNA expression, especially TLR4 and the inflammatory cytokines while ZEA alone showed either no effect or a marginally effect on TLRs, cytokines, and signalling genes when compared to untreated cells. The combined actions of the two contaminants lead to a synergistically up-regulation of key cytokines (IFN-γ, IL-10 and TNF-α) and TLRs (-2,-3,-4,-6, and -10). The live lactobacilli mixture was able to attenuate the pathogen and mycotoxin-induced response by downregulated the majority of inflammatory related genes suggesting that this mixture has an immunomodulatory potential and may be used to lower the inflammatory response.

Zearalenone induced toxicity in SHSY-5Y cells: The role of oxidative stress evidenced by N-acetyl cysteine

Zearalenone (ZEN) is a mycotoxin from Fusarium species commonly found in many food commodities and are known to cause reproductive disorders, genotoxic and immunosuppressive effects. Although many studies have demonstrated the cytotoxic effects of ZEN, the mechanisms by which ZEN mediates its cytotoxic effects appear to differ according to cell type and route of exposure. Meantime, the available information on the neurotoxic effects of ZEN is very much limited. In the present study we evaluated the role of oxidative stress in ZEN mediated neurotoxicity in SH-SY5Y cells and investigated the possible underlying mechanism. ZEN induced ROS formation and elevated levels of MDA, loss of mitochondrial membrane potential (MMP) and increase in DNA damage in a dose dependent manner as assessed by COMET assay and agarose gel electrophoresis. However, there was no DNA damage by plasmid breakage assay at 6, 12 and 24h time points. DAPI staining showed apoptotic nuclei at 12 and 24h. Further, ZEN treated SH-SY5Y cells showed a marked suppressive effect on the neuronal gene expression. Use of an antioxidant N-acetylcysteine (NAC) reversed the toxin-induced generation of ROS and also attenuated loss of MMP. Collectively, these results suggest that ROS is the main upstream signal leading to increased ZEN mediated neurotoxicity in SH-SY5Y cells.

Differential modulation of innate immunity in vitro by probiotic strains of Lactobacillus gasseri

Background

Probiotics species appear to differentially regulate the intestinal immune response. Moreover, we have shown that different immune-modulatory abilities can be found among probiotic strains belonging to the same species. In this study, we further addressed this issue while studying L. gasseri, a species that induces relevant immune activities in human patients.

Results

We determined the ability of two strains of L. gasseri, OLL2809 and L13-Ia, to alter cell surface antigen expression, cytokine production and nuclear erythroid 2-related factor 2 (Nrf2)-mediated cytoprotection in murine bone marrow-derived dendritic cells (DCs) and MODE-K cells, which represent an enterocyte model. Differential effects of L. gasseri strains were observed on the expression of surface markers in mature DCs; nevertheless, both strains dramatically induced production of IL-12, TNF-α and IL-10. Distinctive responses to OLL2809 and L13-Ia were also shown in MODE-K cells by analyzing the expression of MHC II molecules and the secretion of IL-6; however, both L. gasseri strains raised intracellular glutathione. Treatment of immature DCs with culture medium from MODE-K monolayers improved cytoprotection and modified the process of DC maturation by down-regulating the expression of co-stimulatory markers and by altering the cytokine profile. Notably, bacteria-conditioned MODE-K cell medium suppressed the expression of the examined cytokines, whereas cytoprotective defenses were significantly enhanced only in DCs exposed to OLL2809-conditioned medium. These effects were essentially mediated by secreted bacterial metabolites.

Conclusions

We have demonstrated that L. gasseri strains possess distinctive abilities to modulate in vitro DCs and enterocytes. In particular, our results highlight the potential of metabolites secreted by L. gasseri to influence enterocyte-DC crosstalk. Regulation of cellular mechanisms of innate immunity by selected probiotic strains may contribute to the beneficial effects of these bacteria in gut homeostasis.

Interactive effects of zearalenone and its metabolites on cytotoxicity and metabolization in ovarian CHO-K1 cells

Zearalenone (ZEA) is a non-steroidal estrogen mycotoxin with high binding affinity to estrogen receptors. ZEA is rapidly absorbed and metabolized in vivo to α-zearalenol (α-ZOL) and β-zearalenol (β-ZOL). So, mixtures of them may be present in biological systems and suppose a hazard to animals and human health. The aims of this study were to determine the cytotoxic effects of ZEA and its metabolites, alone and in combination in ovarian (CHO-K1) cells during 24, 48 and 72h by the MTT assay; and to investigate the metabolism of the CHO-K1 cells on ZEA, and its conversion into α-ZOL and β-ZOL by CHO-K1 cell after 24 and 48h of exposure. The IC50 value obtained for individual mycotoxins range from 60.3 to >100.0μM, from 30.0 to 33.0μM and from 55.0 to >75.0μM for ZEA, α-ZOL and β-ZOL, respectively. Cytotoxic interactions were assayed by the isobologram method, which provides a combination index (CI) value as a quantitative measure of the degree of the three mycotoxin interaction. The CI values for binary combinations ranged from 0.56±0.15 (synergism at low concentrations) to 5.25±5.10 (addition at high concentrations) and tertiary combinations from 2.95±0.75 (antagonism at low concentrations) to 0.41±0.23 (synergism at high concentrations). The concentration of ZEA and its metabolites was determined with liquid chromatography coupled to the mass spectrometer detector-linear ion trap (LC-MS-LIT). The percentage of ZEA degradation ranged from 4% (24h) to 81% (48h). In the same conditions, α-ZOL and β-ZOL concentration decreased from 8% to 85%. No conversion of ZEA in α-ZOL and β-ZOL was detected. However, at 24h of exposure other degradation products of ZEA and its derived were detected.

Individual and combined cytotoxic effects of Fusarium toxins (deoxynivalenol, nivalenol, zearalenone and fumonisins B1) on swine jejunal epithelial cells

Fusarium mycotoxins occur worldwide in foods such as cereals and animal forages, leading to acute and chronic exposures in human and animals. Intestinal epithelial cells (IECs) are an important first target site for these dietary toxins. This study investigated the cytotoxicity of four common Fusarium mycotoxins, deoxynivalenol (DON), nivalenol (NIV), zearalenone (ZEA) and fumonisin B1 (FB1) on a normal porcine jejunal epithelial cell line, IPEC-J2. A dose response relationship between individual mycotoxins and cell viability (MTT assay) was initially investigated, and subsequently cytotoxic and non-cytotoxic concentrations were selected to investigate combinations of two, three and all four of the mycotoxins. For individual mycotoxins, a dose response was observed with cell viability, such that the potency ranking was NIV>DON>ZEA>FB1. At cytotoxic doses of individual mycotoxins, all mixtures gave reduced cell viability compared to control. At noncytotoxic concentrations of individual mycotoxins, all mixtures were cytotoxic with DON-NIV, DON-ZEA, DON-NIV-FB1, DON-ZEA-FB1, NIV-ZEA-FB1 and all four mixed causing the greatest loss of cell viability. The latter observation in particular raises concerns over safety margins based on single toxin species, and suggests that the effects of multiple complex mixtures need to be better understood to assess health risks.

Modulation of porcine β-defensins 1 and 2 upon individual and combined Fusarium toxin exposure in a swine jejunal epithelial cell line

Defensins are small antimicrobial peptides (AMPs) that play an important role in the innate immune system of mammals. Since the effect of mycotoxin contamination of food and feed on the secretion of intestinal AMPs is poorly understood, the aim of this study was to elucidate the individual and combined effects of four common Fusarium toxins, deoxynivalenol (DON), nivalenol (NIV), zearalenone (ZEA), and fumonisin B1 (FB1), on the mRNA expression, protein secretion, and corresponding antimicrobial effects of porcine β-defensins 1 and 2 (pBD-1 and pBD-2) using a porcine jejunal epithelial cell line, IPEC-J2. In general, upregulation of pBD-1 and pBD-2 mRNA expression occurred following exposure to Fusarium toxins, individually and in mixtures (P < 0.05). However, no significant increase in secreted pBD-1 and pBD-2 protein levels was observed, as measured by enzyme-linked immunosorbent assay (ELISA). Supernatants from IPEC-J2 cells exposed to toxins, singly or in combination, however, possessed significantly less antimicrobial activity against Escherichia coli than untreated supernatants. When single toxins and two-toxin combinations were assessed, toxicity effects were shown to be nonadditive (including synergism, potentiation, and antagonism), suggesting interactive toxin effects when cells are exposed to mycotoxin combinations. The results show that Fusarium toxins, individually and in mixtures, activate distinct antimicrobial defense mechanisms possessing the potential to alter the intestinal microbiota through diminished antimicrobial effects. Moreover, by evaluating toxin mixtures, this improved understanding of toxin effects will enable more effective risk assessments for common mycotoxin combinations observed in contaminated food and feed.

Co-exposure of Fusarium mycotoxins: in vitro myelotoxicity assessment on human hematopoietic progenitors

Mycotoxins such as beauvericin (BEA), deoxynivalenol (DON), enniatin B (ENB), fumonisin B1 (FB1), T-2 toxin and zearalenone (ZEA) can co-occur in food commodities. This aim of this study was to assess the myelotoxicity of these mycotoxins in couple using in vitro human granulo-monocytic (Colony Forming Unit-Granulocyte and Macrophage, CFU-GM) hematopoietic progenitors. Clonogenic assays have been performed in the presence of the following couples of fusariotoxins: DON + BEA, DON + FB1, DON + T-2, DON + ZEA, T-2 + ZEA and BEA + ENB. Co-exposure of human CFU-GM to DON + BEA resulted in synergic myelotoxic effects. The combination of DON + T-2 presented additive or synergic myelotoxic effects. The couples DON + ZEA, T-2 + ZEA and BEA + ENB had additive myelotoxic effects, while the combination of DON + FB1 showed antagonist myelotoxic effects. These in vitro results suggested that the simultaneous presence of mycotoxins in food commodities and diet may be more myelotoxic than the presence of one mycotoxin alone. Diminution of hematopoietic progenitors could give rise to a decrease number of mature blood cells, inducing agranulocytosis and/or thrombocytopenia and in severe cases aplastic anemia.

Effects of zearalenone on IL-2, IL-6, and IFN-γ mRNA levels in the splenic lymphocytes of chickens

Zearalenone (ZEN) is an estrogenic mycotoxin produced by several Fusarium species, which can contaminate food and feed. These compounds elicit a wide spectrum of toxic effects, including the capacity to alter normal immune function. In this study, the in vitro effects of the treatment of ConA-stimulated splenic lymphocytes with ZEN (0-25 μg/mL) were examined. ZEN modulates the expression of IL-2, IL-6, and IFN-γ. The IL-2 levels were up to fourfold higher (P < 0.05) compared with the levels in the control at toxin concentrations of 25 μg/mL after 48 h of treatment. The IL-6 levels were critically suppressed at this concentration; these changes were very statistically significant (P < 0.05). At lower ZEN concentrations (0.1, 0.4 and 1.6 μg/mL), the IFN-γ levels changed slightly; however at 6.25 and 25 μg/mL, the IFN-γ results reached statistical significance compared with the control levels (P < 0.05). These data suggest that ZEN has potent effects on the expression of chicken splenic lymphocytes cytokines at the mRNA level.

Modulation of macrophage activity by aflatoxins B1 and B2 and their metabolites aflatoxins M1 and M2

Aflatoxins are natural contaminants frequently found both in food and feed. Many of them exert immunomodulatory properties in mammals; therefore, the aim of the current study was to investigate immune-effects of AFB1, AFB2, AFM1 and AFM2, alone and differently combined, in J774A.1 murine macrophages. MTT assay showed that AFB1, alone and combined with AFB2, possess antiproliferative activity only at the highest concentration; such effect was not shown by their hydroxylated metabolites, AFM1 and AFM2, respectively. However, the immunotoxic effects of the aflatoxins evaluated in the current study may be due to the inhibition of production of active oxygen metabolites such as NO. Cytofluorimetric assay in macrophages exposed to aflatoxins (10-100 μM) revealed that their cytoxicity is not related to apoptotic pathways. Nevertheless, a significant increase of the S phase cell population accompanied by a decrease in G0/G1 phase cell population was observed after AFB1 treatment. In conclusion, the results of the current study suggest that aflatoxins could compromise the macrophages functions; in particular, co-exposure to AFB1, AFB2, AFM1 and AFM2 may exert interactions which can significantly affect immunoreactivity.

Maltose-binding protein isolated from Escherichia coli induces Toll-like receptor 2-mediated viability in U937 cells

BACKGROUND

Stimulation of Toll-like receptors (TLRs) by microbial products has been utilised to potentiate immune responses against haematologic malignancies. The maltose-binding protein (MBP) of Escherichia coli could induce the activation of immune cells via TLR4. The aim of the present study was to investigate whether TLRs mediated the biological effects of MBP on U937 and Jurkat cells in vitro. METHODS We observed the effect of MBP on U937 and Jurkat cells by using the WST, cell cycle analysis and morphological observation. Further, cells were stimulated with MBP for indicated times and doses, and detected by RT-PCR, western blotting, immunohistochemistry and immunofluorescence staining to investigate the mechanisms involved in cell viability.

RESULTS

MBP enhanced the viability of U937 and Jurkat cells, and the effects were blocked by anti-TLR2, but not anti-TLR4 in U937 cells. Further studies confirmed that MBP was able to directly bind to U937 and Jurkat cells and modulate TLR expression. The effects of MBP depended on the activation of NF-κB and MAP kinase in U937 and Jurkat cells.

CONCLUSIONS

Our results demonstrated that MBP could directly promote U937 cell viability via TLR2. It suggested that MBP may be used as an adjuvant for participating in the immunotherapy of haematologic malignancies.

In vitro and in vivo induction of chromosome aberrations by alpha- and beta-zearalenols: comparison with zearalenone

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by Fusarium fungi. It contaminates different components of the food chain and can cause serious economic and public health problems. The major metabolites of ZEN in various animal species are alpha- and beta-zearalenol (α-, β-ZOL). Some in vivo studies have shown that these two metabolites are as toxic as the mother molecule (ZEN), but other investigations have demonstrated that α- and β-ZOL are less toxic than ZEN. Thus, the aim of the present study was to evaluate cytotoxicity and genotoxicity of α- and β-ZOL in vivo, in mouse bone-marrow cells and in vitro, in cultured HeLa cells, and to compare it with ZEN. ZEN showed the same cytotoxicity as α-ZOL and both are more cytotoxic than β-ZOL. Genotoxicity of ZEN and its derivatives was assessed by the chromosome aberration assay. Our results show that ZEN as well as α- and β-ZOL increased the percentage of chromosome aberrations in mouse bone-marrow cells and in HeLa cells. In the two systems, ZEN and α-ZOL exhibited the same range of genotoxicity and both were more genotoxic than β-ZOL. Furthermore, our results show that either ZEN or its two metabolites inhibited cell viability in a dose-dependent manner. We conclude that biotransformation of ZEN may be considered as only a partial detoxification pathway since the resulting metabolites remain relatively toxic.

Some food-associated mycotoxins as potential risk factors in humans predisposed to chronic intestinal inflammatory diseases

Mycotoxins are fungal metabolites able to affect the functions of numerous tissues and organs in animals and humans, including intestinal and immune systems. However, the potential link between exposure to some mycotoxins and human chronic intestinal inflammatory diseases, such as celiac and Crohn's diseases or ulcerative colitis, has not been investigated. Instead, several theories based on bacterial, immunological or neurological events have been elaborated to explain the etiology of these pathologies. Here we reviewed the literature on mycotoxin-induced intestinal dysfunctions and compared these perturbations to the impairments of intestinal functions typically observed in human chronic intestinal inflammatory diseases. Converging evidence based on various cellular and animal studies show that several mycotoxins induce intestinal alterations that are similar to those observed at the onset and during the progression of inflammatory bowel diseases. Although epidemiologic evidence is still required, existing data are sufficient to suspect a role of some food-associated mycotoxins in the induction and/or persistence of human chronic intestinal inflammatory diseases in genetically predisposed patients.

Cytotoxicity effects induced by Zearalenone metabolites, alpha Zearalenol and beta Zearalenol, on cultured Vero cells

Zearalenone (Zen) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium. It has been implicated in several mycotoxicosis in farm animals and in humans. The major metabolites of this mycotoxin in various species are alpha and beta Zearalenol. In vivo, Zen is mainly reduced to these alcoholic metabolites which cause reproductive tract disorders and impaired fertility due to their estrogenic activities. In this study, we examined the cytotoxicity of alpha and beta Zearalenol in cultured cells. For this purpose, the MTT assay was carried out and the influence of alpha and beta Zearalenol on protein and DNA syntheses was assessed. To evaluate the cell stress caused by these two metabolites, oxidative stress measured by MDA induction and stress protein induction (Hsp 70, Hsp 27) were tested. Results showed that alpha and beta Zearalenol were metabolites that caused cytotoxicity by inhibiting cell viability, protein and DNA syntheses and inducing oxidative damage and over-expression of stress proteins. However, the Zen metabolites exhibited lower toxicity than Zen, with beta zearalenol being the more active of the two metabolites.