Deoxynivalenol as a new factor in the persistence of intestinal inflammatory diseases: an emerging hypothesis through possible modulation of Th17-mediated response

Ligilactobacillus animalis 506 Protects the Intestinal Barrier from the Damaging Effects of Enteric Pathogens and Deoxynivalenol

This study investigated the impact of L. animalis 506 on gut barrier integrity and regulation of inflammation in vitro using intestinal epithelial cell lines. Caco-2 or HT29 cell monolayers were challenged with enterotoxigenic E. coli (ETEC) or a ruminant isolate of Salmonella Heidelberg in the presence or absence of one of six probiotic Lactobacillus spp. strains. Among these, L. animalis 506 excelled at exerting protective effects by significantly mitigating the decreased transepithelial electrical resistance (TEER) as assessed using area under the curve (AUC) (p < 0.0001) and increased apical-to-basolateral fluorescein isothiocyanate (FITC) dextran translocation (p < 0.0001) across Caco-2 cell monolayers caused by S. Heidelberg or ETEC, respectively. Similarly, L. animalis 506 and other probiotic strains significantly attenuated the S. Heidelberg- and ETEC-induced increase in IL-8 from HT29 cells (p < 0.0001). Moreover, L. animalis 506 significantly counteracted the TEER decrease (p < 0.0001) and FITC dextran translocation (p < 0.0001) upon challenge with Clostridium perfringens. Finally, L. animalis 506 significantly attenuated DON-induced TEER decrease (p < 0.01) and FITC dextran translocation (p < 0.05) and mitigated occludin and zona occludens (ZO)-1 redistribution in Caco-2 cells caused by the mycotoxin. Collectively, these results demonstrate the ability of L. animalis 506 to confer protective effects on the intestinal epithelium in vitro upon challenge with enteric pathogens and DON known to be of particular concern in farm animals.

Recalling the reported toxicity assessment of deoxynivalenol, mitigating strategies and its toxicity mechanisms: Comprehensive review

Mycotoxins frequently contaminate a variety of food items, posing significant concerns for both food safety and public health. The adverse consequences linked to poisoning from these substances encompass symptoms such as vomiting, loss of appetite, diarrhea, the potential for cancer development, impairments to the immune system, disruptions in neuroendocrine function, genetic damage, and, in severe cases, fatality. The deoxynivalenol (DON) raises significant concerns for both food safety and human health, particularly due to its potential harm to vital organs in the body. It is one of the most prevalent fungal contaminants found in edible items used by humans and animals globally. The presence of harmful mycotoxins, including DON, in food has caused widespread worry. Altered versions of DON have arisen as possible risks to the environment and well-being, as they exhibit a greater propensity to revert back to the original mycotoxins. This can result in the buildup of mycotoxins in both animals and humans, underscoring the pressing requirement for additional investigation into the adverse consequences of these modified mycotoxins. Furthermore, due to the lack of sufficient safety data, accurately evaluating the risk posed by modified mycotoxins remains challenging. Our review study delves into conjugated forms of DON, exploring its structure, toxicity, control strategies, and a novel animal model for assessing its toxicity. Various toxicities, such as acute, sub-acute, chronic, and cellular, are proposed as potential mechanisms contributing to the toxicity of conjugated forms of DON. Additionally, the study offers an overview of DON's toxicity mechanisms and discusses its widespread presence worldwide. A thorough exploration of the health risk evaluation associated with conjugated form of DON is also provided in this discussion.

Emerging mycotoxins induce hepatotoxicity in pigs' precision-cut liver slices and HepG2 cells

Emerging mycotoxins are currently gaining more attention due to their high frequency of contamination in foods and grains. However, most data available in the literature are in vitro, with few in vivo results that prevent establishing their regulation. Beauvericin (BEA), enniatins (ENNs), emodin (EMO), apicidin (API) and aurofusarin (AFN) are emerging mycotoxins frequently found contaminating food and there is growing interest in studying their impact on the liver, a key organ in the metabolization of these components. We used an ex vivo model of precision-cut liver slices (PCLS) to verify morphological and transcriptional changes after acute exposure (4 h) to these mycotoxins. The human liver cell line HepG2 was used for comparison purposes. Most of the emerging mycotoxins were cytotoxic to the cells, except for AFN. In cells, BEA and ENNs were able to increase the expression of genes related to transcription factors, inflammation, and hepatic metabolism. In the explants, only ENN B1 led to significant changes in the morphology and expression of a few genes. Overall, our results demonstrate that BEA, ENNs, and API have the potential to be hepatotoxic.

Ribotoxin deoxynivalenol induces taurocholic acid malabsorption in an in vitro human intestinal model

The trichothecene toxin deoxynivalenol (DON) is a ribotoxic mycotoxin that contaminates cereal-based food. DON binds to ribosomes, thereby inhibiting protein translation and activating stress mitogen-activated protein kinases (MAPK). The activation of MAPK induces pro-inflammatory cytokine production. Emerging evidence showed that DON decreased bile acid reabsorption and apical sodium-dependent bile acid transporter (ASBT) expression in Caco-2 cell layers. We hypothesized that the effect of DON on decreased ASBT mRNA expression is regulated via pro-inflammatory cytokines. We observed that MAPK inhibitors prevented DON to induce IL-8 secretion and prevented the DON-induced downregulation of ASBT mRNA expression. However, DON-induced taurocholic acid (TCA) transport reduction was not prevent by the MAPK inhibitors. We next observed a similarity between the activity of the non-inflammatory ribotoxin cycloheximide and DON to decrease TCA transport, which is consistent with their common ability to inhibit protein synthesis. Together, our results suggest that DON-induced TCA malabsorption is regulated by MAPK activation-induced pro-inflammatory cytokine production and protein synthesis inhibition, both of which are initiated by DON binding to the ribosomes which therefore is the molecular initiating event for the adverse outcome of bile acid malabsorption. This study provides insights into the mechanism of ribotoxins-induced bile acid malabsorption in human intestine.

Short-term exposure to fumonisins and deoxynivalenol, on broiler growth performance and cecal Salmonella load during experimental Salmonella Enteritidis infection

Fumonisins (FUM) and deoxynivalenol (DON) are two common mycotoxins in poultry feed. Salmonella enterica ser. Enteritidis (S. Enteritidis) is a primary foodborne bacterium in broilers. This trial was conducted to evaluate the effects of naturally occurring FUM and DON and their combination at subclinical doses on broiler performance during a S. Enteritidis challenge. The experiment consisted of five treatments: NCC, no-challenge no-mycotoxin treatment; CC, Salmonella challenge + no-mycotoxin treatment; DON, DON 0.6 mg/kg + Salmonella challenge; FUM, FUM 14 mg/kg + Salmonella challenge; DON + FUM + T-2 + neosolaniol, DON 0.6 mg/kg + FUM 14 mg/kg + T-2 toxin 0.6 mg/kg + 0.8 mg/kg neosolaniol + Salmonella challenge. On d 4, birds were challenged with either 0 or 1 × 10⁹ CFU/mL S. Enteritidis orally. There were no significant effects on growth performance among treatments at 0, 3, 7, and 14 d of post-inoculation (dpi). On 14 dpi, the combined DON + FUM + T-2 + neosolaniol significantly increased the Salmonella load by 1.5 logs compared to the control groups (P < 0.05). FUM significantly increased the cecal tonsil IL-10 gene expression by 1.2-fold at 7 dpi (P < 0.05) and downregulated TNF-α by 1.8-fold on 14 dpi compared to the control, nonchallenge groups (P < 0.05). On 7 dpi, the combined DON + FUM + T-2 + neosolaniol reduced occludin by 4.4-fold (P < 0.05) when compared to the control groups. Similarly, combined DON + FUM+ T-2 + neosolaniol decreased zona-occluden transcription by 2.3 and 7.6-fold on 3 and 14 dpi, respectively (P < 0.05). Furthermore, combined DON + FUM + T-2 + neosolaniol decreased Claudin-1 by 2.2-fold and Claudin-4 by 5.1-fold on 14 dpi when compared to the control groups (P < 0.05). In conclusion, short-term exposure to a subclinical dose of combined DON + FUM + T-2 + neosolaniol had an impact on broiler intestinal tight junction proteins and cecal Salmonella abundance under experimental Salmonella challenge.

Analysis of the roles of the Notch1 signalling pathway in modulating deoxynivalenol cytotoxicity

Deoxynivalenol (DON) is a trichothecenes produced by fungi that is widespread and poses a threat to human and animal health. The Notch1 signalling pathway is tightly involved in cell fate determination. The aim of this study was to investigate the role of the Notch1 signalling pathway in DON exposure. Herein, we found that the Notch1 signalling pathway was significantly activated after DON exposure, while Notch1 expression was negatively regulated by DON-induced ROS. Then, the Notch1 signalling pathway was blocked by the γ-secretase inhibitor DAPT in DON exposure. Flow cytometry analysis and antioxidant parameter measurements revealed that DAPT treatment significantly aggravated the oxidative stress induced by DON. The detection of apoptosis showed that DAPT treatment increased the cell apoptotic rate. Further analysis revealed that inhibiting the Notch1 signalling pathway reduced autophagy upon DON exposure. RT-qPCR and Western blot analysis showed that inhibiting the Notch1 signalling pathway aggravated cellular inflammation and activated the MAPK pathway, indicating that the MAPK pathway may be the downstream signalling pathway. Taken together, our research revealed that the Notch1 signalling pathway is essential for protection against DON. Inhibition of Notch1 signalling increases oxidative stress, causes cell apoptosis, reduces autophagy and aggravates cell inflammation after DON exposure. This study investigated the role of the Notch1 signalling pathway in DON exposure and provided a basis for exploring the mechanism of DON.

Mycotoxin surveillance on wheats in Shandong province, China, reveals non-negligible probabilistic health risk of chronic gastrointestinal diseases posed by deoxynivalenol

Abnormal climate changes have resulted in over-precipitation in many regions. The occurrence and contamination levels of mycotoxins in crops and cereals have been elevated largely. From 2017 to 2019, we did investigation targeting 15 mycotoxins shown in the wheat samples collected from Shandong, a region suffering over-precipitation in China. We found that deoxynivalenol (DON) was the dominant mycotoxin contaminating wheats, with detection rates 304/340 in 2017 (89.41%), 303/330 in 2018 (91.82%), and 303/340 in 2019 (89.12%). The ranges of DON levels were < 4 to 580 μg/kg in 2017, < 4 to 3070 μg/kg in 2018, and < 4 to 1540 μg/kg in 2019. The exposure levels were highly correlated with local precipitation. Male exposure levels were generally higher than female's, with significant difference found in 2017 (1.89-fold, p = 0.023). Rural exposure levels were higher than that of cities but not statistically significant (1.41-fold, p = 0.13). Estimated daily intake (EDI) and margin of exposure (MoE) approaches revealed that 8 prefecture cities have probabilistically extra adverse health effects (vomiting or diarrhea) cases > 100 patients in 100,000 residents attributable to DON exposure. As a prominent wheat-growing area, Dezhou city reached ~ 300/100,000 extra cases while being considered as a major regional contributor to DON contamination. Our study suggests that more effort should be given to the prevention and control of DON contamination in major wheat-growing areas, particularly during heavy precipitation year. The mechanistic association between DON and chronic intestinal disorder/diseases should be further investigated.

Costus speciosus extract protects against the oxidative damage of zearalenone via modulation of inflammatory cytokines, Nrf2 and iNOS gene expression in rats

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin that induces severe health disturbances in humans and animals. This study aimed to determine the bioactive compounds in Costus speciosus extract (CSE) using GC-MS and evaluate its protective capability against ZEN-induced oxidative damage, genotoxicity, and cytotoxicity in rats. Six groups of male Sprague Dawley rats were treated orally for 15 days including the control group, CSE-treated groups at low (200 mg/kg b. w) or high (400 mg/kg b. w) dose, ZEN-treated group (40 μg/kg b. w), and the groups treated with ZEN plus the low or the high dose of CSE. Blood and tissue samples were collected for different assays and pathological analyses. The results of GC-MS indicated the identification of 6 compounds and Azulene was the major. Animals that received ZEN showed severe disturbances in serum biochemical, cytokines, oxidative stress indicators, mRNA expression of iNOS, Nrf2, and inflammatory-related genes. ZEN also increased micronucleated polychromatic erythrocytes (MNPCEs) and comet tail formation in bone marrow cells along with the disturbances in the histological architecture of the liver and kidney. Co-administration of CSE plus ZEN could normalize the majority of the tested parameters and the histological picture at a dose as low as 200 mg/kg b. w. Therefore, CSE protects against ZEN toxicity via its antioxidant activity, modulation of iNOS, inflammatory-related genes, and the Nrf2 pathway and it could be used in the endemic regions.

The foodborne contaminant deoxynivalenol exacerbates DNA damage caused by a broad spectrum of genotoxic agents

Humans are exposed to different contaminants including mycotoxins. Deoxynivalenol (DON), a potent ribosome inhibitor, is a highly prevalent mycotoxin in the food chain worldwide. Although DON is not genotoxic, we previously showed that it exacerbates the genotoxicity of colibactin, a DNA-crosslinking toxin produced by bacteria in the gut. In the present study, we investigated whether this phenotype can be extended to other genotoxic compounds with different modes of action. Our data showed that, at a dose that can be found in food, DON exacerbated the DNA damage caused by etoposide, cisplatin and phleomycin. In contrast, de-epoxy-deoxynivalenol (DOM-1), a modified form of DON that does not induce ribotoxic stress, did not exacerbate DNA damage. The effect of DON was mimicked with other ribosome inhibitors such as anisomycin and cycloheximide, suggesting that ribotoxicity plays a key role in exacerbating DNA damage. In conclusion, a new effect of DON was identified, this toxin aggravates the DNA damage induced by a broad spectrum of genotoxic agents with different modes of action. These results are of utmost importance as our food can be co-contaminated with DON and DNA-damaging agents.

Effects of Fusarium metabolites beauvericin and enniatins alone or in mixture with deoxynivalenol on weaning piglets

The impact of the Fusarium-derived metabolites beauvericin, enniatin B and B1 (EB) alone or in combination with deoxynivalenol (DON) was investigated in 28-29 days old weaning piglets over a time period of 14 days. The co-application of EB and DON (EB + DON) led to a significant decrease in the weight gain of the animals. Liver enzyme activities in plasma were significantly decreased at day 14 in piglets receiving the EB + DON-containing diet compared to piglets receiving the control diet. All mycotoxin-contaminated diets led to moderate to severe histological lesions in the jejunum, the liver and lymph nodes. Shotgun metagenomics revealed a significant effect of EB-application on the gut microbiota. Our results provide novel insights into the harmful impact of emerging mycotoxins alone or with DON on the performance, gut health and immunological parameters in pigs.

Baicalin-Zinc Complex Alleviates Inflammatory Responses and Hormone Profiles by Microbiome in Deoxynivalenol Induced Piglets

This study aimed to investigate the beneficial effect of baicalin–zinc complex (BZN) on intestinal microorganisms in deoxynivalenol (DON)-challenged piglets and the association between intestinal microorganisms and host immunity and hormone secretion. Forty weaned piglets were randomly divided into four treatments with 10 piglets in each treatment: (1) control (Con) group (pigs fed basal diet); (2) DON group (pigs fed 4 mg DON/kg basal diet); (3) BZN group (pigs fed 0.5% BZN basal diet); and (4) DBZN group (pigs fed 4 mg DON/kg and 0.5% BZN basal diet). The experiment lasted for 14 days. The BZN supplementation in DON-contaminated diets changed the intestinal microbiota composition and increased intestinal microbial richness and diversity of piglets. The BZN supplementation in DON-contaminated diets also alleviated the inflammatory responses of piglets and modulated the secretion of hormones related to the growth axis. Moreover, microbiota composition was associated with inflammatory and hormone secretion. In conclusion, BZN alleviated inflammatory response and hormone secretion in piglets, which is associated with the intestinal microbiome.

Phytic acid modulates the morphology, immunological response of cytokines and β-defensins in porcine intestine exposed to deoxynivalenol and fumonisin B1

Occurrence of mycotoxins in agricultural products represents a risk for human and animal health. Therefore, there is a requirement of strategies to mitigate their harmful impacts. This study investigated the effects of phytic acid (IP6) on the immunological response of pro-(interleukin (IL)-1β, IL-6, IL-8, IL-10, interferon (IFN)-γ, tumour necrosis factor (TNF)-α) and anti-inflammatory (IL-10) cytokines and β-defensins 1 (pBD-1) and 2 (pBD-2) in porcine jejunal explants exposed to deoxynivalenol (DON) and fumonisin B1 (FB1). The explants were exposed to the following treatments: control, DON (10 μM), DON plus IP6 2.5 mM or 5 mM, FB1 (70 μM), FB1 IP6 plus 2.5 or 5 mM. The expression levels of the cytokines were measured by RT-qPCR. The exposure to FB1 and DON induced intestinal lesions. The presence of 2.5 and 5 mM IP6 inhibited the morphological changes induced by the mycotoxins. The explants exposed to DON showed an increase in the expression of IL-1β and IL-8 and a decrease in the levels of IL-6, IFN-γ, IL-10 and pBD-2. IP6 (5 mM) decreased the expression of IL-8 and increased the expression in pBD-1 and 2 compared to DON alone. FB1 induced a significant decrease in the levels of most of the pro-inflammatory cytokines, IL-10 and pBD-1, and an increase in IL-1β expression. The addition of IP6 5 mM induced significant increase in TNF-α expression compared to FB1. Taken together, the results suggest IP6 modulates immunological changes induced by DON and FB1 on intestinal mucosa resulting in beneficial effects that contribute to intestinal homeostasis and health.

Investigation of the inflammatory and oxidative stress-inducing effects of deoxynivalenol and T-2 toxin exposure in non-tumorigenic human intestinal cell model

Fungi in the Fusarium genus produce trichothecene mycotoxins including deoxynivalenol (DON) and T-2 toxin which may elicit their damaging effects on the gastrointestinal tract following the consumption of contaminated cereal-based foods. The aim of our study was to evaluate the effects of these commonly occurring fusarotoxins alone and in combination using the human, non-cancerous intestinal epithelial cell line HIEC-6. Based on our experimental data, 24 h after treatment with fusarotoxins, hydrogen peroxide levels, intracellular oxidative stress and the amounts of inflammatory interleukins IL-6 and IL-8 significantly increased. Cell membrane localization of the tight junction protein claudin-1 decreased, whereas distribution of occludin remained unchanged. Taken together, the HIEC-6 cell line appears to be a suitable experimental model for monitoring the combined effects of mycotoxins at the cellular level including changes in the redox states of cells.

Statistical Integration of 'Omics Data Increases Biological Knowledge Extracted from Metabolomics Data: Application to Intestinal Exposure to the Mycotoxin Deoxynivalenol

The effects of low doses of toxicants are often subtle and information extracted from metabolomic data alone may not always be sufficient. As end products of enzymatic reactions, metabolites represent the final phenotypic expression of an organism and can also reflect gene expression changes caused by this exposure. Therefore, the integration of metabolomic and transcriptomic data could improve the extracted biological knowledge on these toxicants induced disruptions. In the present study, we applied statistical integration tools to metabolomic and transcriptomic data obtained from jejunal explants of pigs exposed to the food contaminant, deoxynivalenol (DON). Canonical correlation analysis (CCA) and self-organizing map (SOM) were compared for the identification of correlated transcriptomic and metabolomic features, and O2-PLS was used to model the relationship between exposure and selected features. The integration of both 'omics data increased the number of discriminant metabolites discovered (39) by about 10 times compared to the analysis of the metabolomic dataset alone (3). Besides the disturbance of energy metabolism previously reported, assessing correlations between both functional levels revealed several other types of damage linked to the intestinal exposure to DON, including the alteration of protein synthesis, oxidative stress, and inflammasome activation. This confirms the added value of integration to enrich the biological knowledge extracted from metabolomics.

Comparative sensitivity of proliferative and differentiated intestinal epithelial cells to the food contaminant, deoxynivalenol

The intestinal epithelium is a functional and physical barrier formed by a cell monolayer that constantly differentiates from a stem cell in the crypt. This is the first target for food contaminants, especially mycotoxins. Deoxynivalenol (DON) is one of the most prevalent mycotoxins. This study compared the effects of DON (0-100 μM) on proliferative and differentiated intestinal epithelial cells. Three cell viability assays (LDH release, ATP content and neutral red uptake) indicated that proliferative Caco-2 cells are more sensitive to DON than differentiated ones. The establishment of transepithelial electrical resistance (TEER), as a read out of the differentiation process, was delayed in proliferative cells after exposure to 1 μM DON. Transcriptome analysis of proliferative and differentiated exposure to 0-3 μM DON for 24 h revealed 4862 differentially expressed genes (DEG) and indicated an effect of both the differentiation status and the DON treatment. KEGG enrichment analysis indicated involvement of metabolism, ECM receptors and tight junctions in the differentiation process, while ribosome biogenesis, mRNA surveillance, and the MAPK pathway were involved in the response to DON. The number of differentially expressed genes and the amplitude of the effect were higher in proliferative cells exposed to DON than that in differentiated cells. In conclusion, our study shows that proliferative cells are more susceptible than differentiated ones to DON and that the mycotoxin delays the differentiation process.

Fungal Toxins and Host Immune Responses

Fungi are ubiquitous organisms that thrive in diverse natural environments including soils, plants, animals, and the human body. In response to warmth, humidity, and moisture, certain fungi which grow on crops and harvested foodstuffs can produce mycotoxins; secondary metabolites which when ingested have a deleterious impact on health. Ongoing research indicates that some mycotoxins and, more recently, peptide toxins are also produced during active fungal infection in humans and experimental models. A combination of innate and adaptive immune recognition allows the host to eliminate invading pathogens from the body. However, imbalances in immune homeostasis often facilitate microbial infection. Despite the wide-ranging effects of fungal toxins on health, our understanding of toxin-mediated modulation of immune responses is incomplete. This review will explore the current understanding of fungal toxins and how they contribute to the modulation of host immunity.

Intestinal Health of Pigs Upon Weaning: Challenges and Nutritional Intervention

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

Transformation of Selected Trichothecenes during the Wheat Malting Production

The transformation of deoxynivalenol (DON), nivalenol (NIV), and their glucosides (DON3G and NIV3G) during the malting of grains of two wheat varieties was studied. The concentration of DON3G and NIV3G started to increase significantly before the concentration of DON and NIV increased. This may reflect the transformation of the parent mycotoxin forms into their glucosides due to xenobiotic detoxification reactions. After a sharp rise during the last 2 days of the process (day 6 and 7), the DON concentration reached 3010 ± 338 µg/kg in the Legenda wheat-based malt and 4678 ± 963 µg/kg in the Pokusa wheat-based malt. The NIV concentration, at 691 ± 65 µg/kg, remained the same as that in the dry grain. The concentration of DON3G in the Legenda and Pokusa wheat-based malt was five and three times higher, respectively, than that in the steeped grain. The concentration of NIV3G in the Legenda wheat-based malt was more than twice as high as that in the steeped grain. The sharp increase in the concentration of DON at the end of the malting process reflected the high pathogen activity. We set aside some samples to study a batch that was left undisturbed without turning and aeration, for the entire period of malting. The concentration of DON in the malt produced from the latter batch was 135% and 337% higher, for Legenda and Pokusa, respectively, than that in the malt produced from the batch that was turned and aerated. The NIV concentration was 22% higher in the latter batch.

Beneficial Effects of Rosmarinic Acid on IPEC-J2 Cells Exposed to the Combination of Deoxynivalenol and T-2 Toxin

Mycotoxin contamination in feedstuffs is a worldwide problem that causes serious health issues both in humans and animals, and it contributes to serious economic losses. Deoxynivalenol (DON) and T-2 toxin (T-2) are major trichothecene mycotoxins and are known to challenge mainly intestinal barrier functions. Polyphenolic rosmarinic acid (RA) appeared to have antioxidant and anti-inflammatory properties in vitro. The aim of this study was to investigate protective effects of RA against DON and T-2 or combined mycotoxin-induced intestinal damage in nontumorigenic porcine cell line, IPEC-J2. It was ascertained that simultaneous treatment of DON and T-2 (DT2: 1 μmol/L DON + 5 nmol/L T - 2) for 48 h and 72 h reduced transepithelial electrical resistance of cell monolayer, which was restored by 50 μmol/L RA application. It was also found that DT2 for 48 h and 72 h could induce oxidative stress and elevate interleukin-6 (IL-6) and interleukin-8 (IL-8) levels significantly, which were alleviated by the administration of RA. DT2 administration contributed to the redistribution of claudin-1; however, occludin membranous localization was not altered by combined mycotoxin treatment. In conclusion, beneficial effect of RA was exerted on DT2-deteriorated cell monolayer integrity and on the perturbated redox status of IPEC-J2 cells.

Betulinic Acid Ameliorates the T-2 Toxin-Triggered Intestinal Impairment in Mice by Inhibiting Inflammation and Mucosal Barrier Dysfunction through the NF-κB Signaling Pathway

T-2 toxin, a trichothecene mycotoxin produced by Fusarium, is widely distributed in crops and animal feed and frequently induces intestinal damage. Betulinic acid (BA), a plant-derived pentacyclic lupane-type triterpene, possesses potential immunomodulatory, antioxidant and anti-inflammatory biological properties. The current study aimed to explore the protective effect and molecular mechanisms of BA on intestinal mucosal impairment provoked by acute exposure to T-2 toxin. Mice were intragastrically administered BA (0.25, 0.5, or 1 mg/kg) daily for 2 weeks and then injected intraperitoneally with T-2 toxin (4 mg/kg) once to induce an intestinal impairment. BA pretreatment inhibited the loss of antioxidant capacity in the intestine of T-2 toxin-treated mice by elevating the levels of CAT, GSH-PX and GSH and reducing the accumulation of MDA. In addition, BA pretreatment alleviated the T-2 toxin-triggered intestinal immune barrier dysregulation by increasing the SIgA level in the intestine at dosages of 0.5 and 1 mg/kg, increasing IgG and IgM levels in serum at dosages of 0.5 and 1 mg/kg and restoring the intestinal C3 and C4 levels at a dosage of 1 mg/kg. BA administration at a dosage of 1 mg/kg also improved the intestinal chemical barrier by decreasing the serum level of DAO. Moreover, BA pretreatment improved the intestinal physical barrier via boosting the expression of ZO-1 and Occludin mRNAs and restoring the morphology of intestinal villi that was altered by T-2 toxin. Furthermore, treatment with 1 mg/kg BA downregulated the expression of p-NF-κB and p-IκB-α proteins in the intestine, while all doses of BA suppressed the pro-inflammatory cytokines expression of IL-1β, IL-6 and TNF-α mRNAs and increased the anti-inflammatory cytokine expression of IL-10 mRNA in the intestine of T-2 toxin-exposed mice. BA was proposed to exert a protective effect on intestinal mucosal disruption in T-2 toxin-stimulated mice by enhancing the intestinal antioxidant capacity, inhibiting the secretion of inflammatory cytokines and repairing intestinal mucosal barrier functions, which may be associated with BA-mediated inhibition of the NF-κB signaling pathway activation.

The Effects of Deoxynivalenol on the Ultrastructure of the Sacculus Rotundus and Vermiform Appendix, as Well as the Intestinal Microbiota of Weaned Rabbits

Deoxynivalenol (DON) is a mycotoxin found in grains that poses a potential threat to human and animal health, and the gastrointestinal tract is the primary target organ. There are few studies focused on the toxicology of DON to rabbits, especially on the relation among DON, microbiota, and the gut-associated lymphoid tissue. A total of 30 weaned rabbits (35 d) were evenly divided into the control group and DON group (1.5 mg/kg bodyweight (BW)) based on their body weight. After a 24-day trial, the ultrastructures of the sacculus rotundus and vermiform appendix were observed using a scanning electron microscope and transmission electron microscopy. The morphology and microflora in the ileum, caecum, and colon were also examined. The results proved that the ultrastructure of the sacculus rotundus and vermiform appendix, as well as the integrity of the intestinal barrier (especially for the ileum), were impaired after DON was administrated to the rabbits. Compared to the control group, the relative abundance and diversity of the microflora decreased in all three intestinal segments in the DON group, particularly in the ileum and caecum. In conclusion, the toxic effect of DON on weaned rabbits may be performed by destroying the structure of the sacculus rotundus and vermiform appendix, as well as affecting the structure and diversity of the intestinal flora.

Low doses of individual and combined deoxynivalenol and zearalenone in naturally moldy diets impair intestinal functions via inducing inflammation and disrupting epithelial barrier in the intestine of piglets

The intestinal epithelium is the first barrier against food contaminants and is highly sensitive to Fusarium toxins, especially deoxynivalenol (DON) and zearalenone (ZEA). Here, we explored the effects of low doses of DON and/or ZEA in naturally moldy diets on intestinal functions in piglets, including inflammatory responses, epithelial barrier, and microbial composition. Piglets were treated with a control diet (CON), DON diet (1000.6 μg/kg), ZEA diet (269.1 μg/kg), and DON + ZEA diet (1007.5 + 265.4 μg/kg), respectively, for 3 weeks and then switched to the same CON diet for another 2 weeks. In the first period, even the selected low doses of DON or ZEA in the diet resulted in intestinal inflammation, diminish protein expression (claudin-4) and altered gut microbiota populations. Whereas upon switching to the CON diet for another 2 weeks, the deleterious effect of ZEA and DON on IL-1β and Bifidobacterium population could not be recovered. Additionally, combined DON and ZEA negatively affected body weight gain and feed consumption of piglets, as well as shown synergistic effects on evoking pro-inflammatory cytokines contents (TNF-α, IL-1β, and IL-6) and perturbing the cecum microbiota profile (E. coli, Lactobacillus, and Bifidobacterium). Collectively, chronic consumption of DON and ZEA contaminated feed or food, even at low doses, can induce intestinal damage and may have consequences for animal and human health.

Maternal Supplementation of Food Ingredient (Prebiotic) or Food Contaminant (Mycotoxin) Influences Mucosal Immune System in Piglets

The early life period is crucial for the maturation of the intestinal barrier, its immune system, and a life-long beneficial host-microbiota interaction. The study aims to assess the impact of a beneficial dietary (short-chain fructooligosaccharides, scFOS) supplementation vs. a detrimental dietary environment (such as mycotoxin deoxynivalenol, DON) on offspring intestinal immune system developmental profiles. Sows were given scFOS-supplemented or DON-contaminated diets during the last 4 weeks of gestation, whereas force-feeding piglets with DON was performed during the first week of offspring life. Intestinal antigen-presenting cell (APC) subset frequency was analyzed by flow cytometry in the Peyer's patches and in lamina propria and the responsiveness of intestinal explants to toll-like receptor (TLR) ligands was performed using ELISA and qRT-PCR from post-natal day (PND) 10 until PND90. Perinatal exposure with scFOS did not affect the ontogenesis of APC. While it early induced inflammatory responses in piglets, scFOS further promoted the T regulatory response after TLR activation. Sow and piglet DON contamination decreased CD16+ MHCII+ APC at PND10 in lamina propria associated with IFNγ inflammation and impairment of Treg response. Our study demonstrated that maternal prebiotic supplementation and mycotoxin contamination can modulate the mucosal immune system responsiveness of offspring through different pathways.

The food contaminant, deoxynivalenol, modulates the Thelper/Treg balance and increases inflammatory bowel diseases

The incidence of inflammatory bowel diseases (IBD) is increasing in both Western and developing countries. IBD are multifactorial disorders involving complex interactions between genetic, immune, and environmental factors such as exposure to food contaminants. Deoxynivalenol (DON) is the most prevalent mycotoxin that contaminates staple food and induces intestinal breakdown and inflammatory response. To delineate the role of DON oral exposure in IBD, we used a Dextran sulfate sodium (DSS) colitis model in rats fed with a DON-contaminated diet or a control diet for 4 weeks. Colitis was induced in the 4th week by increasing concentrations of DSS in the drinking water (0, 2, 3 or 5%). DON exacerbated body weight loss and accelerated the appearance of symptoms in animals treated with DSS. DON increased morphological damage, pro-inflammatory markers (myeloperoxidase, CXCL-1 and IL-1β) and immune cell responses. In lamina propria of the rat with colitis, DON increased adaptive and innate immune responses after anti-CD3/28 or LPS stimulation, respectively. In the spleen, DON increased IFNγ secretion and reduced Treg populations. Interestingly, De-epoxy-DON (DOM-1) a detoxified form of DON did not have any consequences on colitis. These results suggest that DON is a risk factor in the onset of IBD.

Pro-Inflammatory Effects of NX-3 Toxin Are Comparable to Deoxynivalenol and not Modulated by the Co-Occurring Pro-Oxidant Aurofusarin

The type A trichothecene NX-3, produced by certain Fusarium graminearum strains, is similar to the mycotoxin deoxynivalenol (DON), with the exception that it lacks the carbonyl moiety at the C-8 position. NX-3 inhibits protein biosynthesis and induces cytotoxicity to a similar extent as DON, but so far, immunomodulatory effects have not been assessed. In the present study, we investigated the impact of NX-3 on the activity of the nuclear factor kappa B (NF-κB) signaling pathway in direct comparison to DON. Under pro-inflammatory conditions (IL-1β treatment), the impact on cytokine mRNA levels of NF-κB downstream genes was studied in human colon cell lines, comparing noncancer (HCEC-1CT) and cancer cells (HT-29). In addition, potential combinatory effects with the co-occurring Fusarium secondary metabolite aurofusarin (AURO), a dimeric naphthoquinone known to induce oxidative stress, were investigated. NX-3 and DON (1&nbsp;μM, 20 h) significantly activated a NF-κB regulated reporter gene to a similar extent. Both trichothecenes also enhanced transcript levels of the known NF-κB-dependent pro-inflammatory cytokines IL-8, IL-6, TNF-α and IL-1β. Comparing the colon cancer HT-29 and noncancer HCEC-1CT cells, significant differences in cytokine signaling were identified. In contrast, AURO did not affect NF-κB pathway activity and respective cytokine expression levels at the tested concentration. Despite its pro-oxidant potency, the combination with AURO did not significantly affect the immunomodulatory effects of the tested trichothecenes. Taken together, the present study reveals comparable potency of DON and NX-3 with respect to immunomodulatory and pro-inflammatory potential. Consequently, not only DON but also NX-3 should be considered as factors contributing to intestinal inflammatory processes.

Minimal Concentrations of Deoxynivalenol Reduce Cytokine Production in Individual Lymphocyte Populations in Pigs

Deoxynivalenol (DON) is a mycotoxin frequently found in cereals, and pigs are one of the most sensitive farm species to DON. The aim of this study was to determine the effects of DON in very low doses on peripheral blood mononuclear cells (PBMC) and on particular lymphocyte subpopulations. The cells were exposed to 1, 10 and 100 ng/mL of DON and lymphocyte viability, proliferation, and cytokine (Interleukin (IL)-1β, IL-2, IL-8, IL-17, Interferon (IFN) γ and tumor necrosis factor (TNF) α production were studied. Cells exposed to DON for 5 days in concentrations of 1 and 10 ng/mL showed higher viability compared to control cells. After 18 h of DON (100 ng/mL) exposure, a significantly lower proliferation after mitogen stimulation was observed. In contrast, an increase of spontaneous proliferation induced by DON (100 ng/mL) was detected. After DON exposure, the expression of cytokine genes decreased, with the exception of IL-1β and IL-8, which increased after 18 h exposure to 100 ng/mL of DON. Among lymphocyte subpopulations, helper T-cells and γδ T-cells exhibiting lower production of IL-17, IFNγ and TNFα were most affected by DON exposure (10 ng/mL). These findings show that subclinical doses of DON lead to changes in immune response.

Reduced toxicity of 3-epi-deoxynivalenol and de-epoxy-deoxynivalenol through deoxynivalenol bacterial biotransformation: In vivo analysis in piglets

Ingestion of deoxynivalenol (DON), one of the most common mycotoxin contaminants of cereals, leads to adverse effects for animal and human health. Bacterial biotransformation is a strategy to mitigate the toxicity of this mycotoxin. The present study aims to evaluate the toxicity of two bacterial biotranformation products of DON: 3-epi-deoxynivalenol (3-epi-DON) and de-epoxy-deoxynivalenol (DOM-1) through zootechnical, hematological, histological and immunological assays. Twenty-four 4-weeks-old piglets received a control diet or a diet contaminated with 3 mg kg^-1 DON, DOM-1, or 3-epi-DON for 7 days. Sample tissues were collected for histomorphometrical analysis, expression of cytokines and cell protein junctions. The zootechnical and hematological parameters were not modulated by any treatment. Ingestion of DON induced histological alterations in the intestine, liver and lymphoid organs, as well as an overexpression of pro-inflammatory cytokines, E-cadherin and occludin. These changes were not observed in piglets receiving the DOM-1 and 3-epi-DON contaminated diets. Pigs fed 3-epi-DON contaminated diet showed an increase in IgM levels in comparison with other diets, while no change was observed in IgA and IgG levels among the diets. Our results indicate that DOM-1 and 3-epi-DON are not toxic for piglets; thus bacterial biotransformation seems to be a sustainable alternative to reduce mycotoxin toxicity.

Combinatory effects of cereulide and deoxynivalenol on in vitro cell viability and inflammation of human Caco-2 cells

Deoxynivalenol (DON), one of the most abundant mycotoxins in cereal products, was recently detected with other mycotoxins and the emetic bacterial toxin cereulide (CER) in maize porridge. Within a cereal-based diet, co-exposure to these toxins is likely, hence raising the question of combinatory toxicological effects. While the toxicological evaluation of DON has quite progressed, consequences of chronic, low-dose CER exposure are still insufficiently explored. Information about the combinatory toxicological effects of these toxins is lacking. In the present study, we investigated how CER (0.1-100 ng/mL) and DON (0.01-10 µg/mL) alone and in a constant ratio of 1:100 (CER:DON) affect the cytotoxicity and immune response of differentiated human intestinal Caco-2 cells. While DON alone reduced cell viability only in the highest concentration (10 µg/mL), CER caused severe cytotoxicity upon prolonged incubation (starting from 10 ng/mL after 24 h and 48 h, 2.5 ng/mL and higher after 72 h). After 72 h, synergistic effects were observed at 2.5 ng/mL CER and 0.25 µg/mL DON. Different endpoints of inflammation were investigated in interleukin-1β-stimulated Caco-2 cells. Notably, DON-induced interleukin-8 transcription and secretion were diminished by the presence of 10 and 25 ng/mL CER after short-term (5 h) incubation, indicating immunosuppressive properties. We hypothesise that habitual consumption of cereal-based foods co-contaminated with CER and DON may cause synergistic cytotoxic effects and an altered immune response in the human intestine. Therefore, further research concerning effects of co-occurring bacterial toxins and mycotoxins on the impairment of intestinal barrier integrity, intestinal inflammation and the promotion of malnutrition is needed.

Deoxynivalenol Induces Intestinal Damage and Inflammatory Response through the Nuclear Factor-κB Signaling Pathway in Piglets

Deoxynivalenol (DON) is highly toxic to animals and humans, but pigs are most sensitive to it. The porcine mucosal injury related mechanism of DON is not yet fully clarified. Here, we investigated DON-induced injury in the intestinal tissues of piglet. Thirty weanling piglets [(Duroc × Landrace) × Yorkshire] were randomly divided into three groups according to single factor experimental design (10 piglets each group). Piglets were fed a basal diet in the control group, while low and high dose groups were fed a DON diet (1300 and 2200 μg/kg, respectively) for 60 days. Scanning electron microscopy results indicated that the ultrastructure of intestinal epithelial cells in the DON-treated group was damaged. The distribution and optical density (OD) values of zonula occludens 1 (ZO-1) protein in the intestinal tissues of DON-treated groups were decreased. At higher DON dosage, interleukin (IL)-1β, IL-6, and tumor necrosis factor-α mRNA levels were elevated in the intestinal tissues. The mRNA and protein levels of NF-κB p65, IκB-α, IKKα/β, iNOS, and COX-2 in the small intestinal mucosa were abnormally altered with an increase in DON concentration. These results indicate that DON can persuade intestinal damage and inflammatory responses in piglets via the nuclear factor-κB signaling pathway.

The Effect of Low and High Dose Deoxynivalenol on Intestinal Morphology, Distribution, and Expression of Inflammatory Cytokines of Weaning Rabbits

Deoxynivalenol (DON) is a potential pathogenic factor to humans and animals, and intestinal tract is the primary target organ of DON. Data concerning the effects of DON on rabbits are scarce, especially for weaning rabbits. In this study, 45 weaning rabbits (35 d) were randomly and equally assigned into three groups. Group A was fed basic diet, while groups B and C were added DON at 0.5 mg/kg BW/d and 1.5 mg/kg BW/d, respectively, based on the basic diet. The experiment lasted for 24 days and the intestinal morphology, expression, and distribution of several cytokines in intestinal segments have been examined. The results indicated that ADG decreased while F/G increased significantly compared with the control group after DON added at 1.5 mg/kg BW/d. Some of the morphometric parameters (villi length, crypt depth, and goblet cells density) changed after DON was added. Meanwhile, the concentration as well as the expression levels of relative protein and mRNA of IL-1β, IL-2, IL-6, and IL-8 increased significantly. The immunohistochemistry results illustrated that the quantity and distribution of positive cells of inflammatory cytokines were changed after DON was added. In conclusion, the addition of DON damaged the intestinal morphology and changed the distribution and expression of inflammatory cytokines. The toxic effect depended on the dosage of DON.

Immunoproteomic analysis of Lawsonia intracellularis identifies candidate neutralizing antibody targets for use in subunit vaccine development

Lawsonia intracellularis is an obligate intracellular microorganism and the causative agent of porcine proliferative enteropathy. Due to its obligate intracellular nature, characterization of antigens and proteins involved in host-pathogen interaction and immune recognition have been difficult to achieve using conventional microbiological techniques. In this work, we used 2-dimensional gel electrophoresis coupled with Western-immunoblotting, mass spectrometry and bioinformatics to identify bacterial proteins that interact in vitro with pig intestinal cells (IPEC-1), have immunogenic properties and the potential to be used as subunit vaccine antigens. We detected eleven immunogenic bacterial proteins from which fliC (LI0710), LI1153 (annotated by NCBI as Putative protein N), and LI0649 (annotated as autotransporter) were predicted to be expressed on the outer membrane while LI0169 (oppA; annotated as ABC dipeptide transport system) was predicted to be periplasmic with a transmembrane domain forming a central pore through the plasma membrane. Genes coding for these four proteins were cloned and expressed in Escherichia coli and the corresponding recombinant proteins were purified using affinity chromatography. Porcine hyperimmune serum against whole Lawsonia lysate established that all four recombinant proteins were immunogenic. Further, rabbit hyperimmune sera generated against the vaccine strain of L. intracellularis and rabbit serum specific for each recombinant protein showed an inhibitory effect on the attachment and penetration of live, avirulent L. intracellularis, thus indicating that each protein is a potential neutralizing antibody target and a candidate for subunit vaccine formulation.

Progress in Mycotoxins Affecting Intestinal Mucosal Barrier Function

Mycotoxins, which are widely found in feed ingredients and human food, can exert harmful effects on animals and pose a serious threat to human health. As the first barrier against external pollutants, the intestinal mucosa is protected by a mechanical barrier, chemical barrier, immune barrier, and biological barrier. Firstly, mycotoxins can disrupt the mechanical barrier function of the intestinal mucosa, by destroying the morphology and tissue integrity of the intestinal epithelium. Secondly, mycotoxins can cause changes in the composition of mucin monosaccharides and the expression of intestinal mucin, which in turn affects mucin function. Thirdly, mycotoxins can cause damage to the intestinal mucosal immune barrier function. Finally, the microbiotas of animals closely interact with ingested mycotoxins. Based on existing research, this article reviews the effects of mycotoxins on the intestinal mucosal barrier and its mechanisms.

Nontoxic concentrations of OTA aggravate DON-induced intestinal barrier dysfunction in IPEC-J2 cells via activation of NF-κB signaling pathway

Deoxynivalenol (DON) is well-known enteropathogenic mycotoxin which can alter intestinal barrier functions. Consistently, Ochratoxin A (OTA) ingestion has been found to induce intestinal injuries, including inflammation and diarrhea. However, little is known whether OTA aggravates DON-induced toxicity. This study is designed to explore the effects of OTA on DON-induced intestinal barrier function and involved mechanism. Our results showed either DON or OTA could disrupt intestinal barrier function in a time- and dose-dependent manner, as demonstrated by decreased transepithelial electrical resistance (TEER) and increased paracellular permeability to 4 kDa dextran. However, to eliminate the involvement of cell death, nonlethal concentrations of DON and OTA were used in following experiments. The nontoxic concentration of OTA was observed to aggravate DON-induced intestinal barrier dysfunction, accompanied with tight junction disruption (Claudin-3 and Claudin-4). Moreover, nontoxic concentrations of OTA aggravated DON-induced up-regulation of pro-inflammatory cytokines expression and activated nuclear factor-κB (NF-κB) in IPEC-J2 cells. Adding NF-κB inhibitor (PDTC) alleviated the aggravating effects of nontoxic concentrations of OTA on DON-induced intestinal barrier dysfunction and inflammation. These findings indicate that nontoxic concentrations of OTA promoted DON-induced barrier dysfunction via NF-κB signaling pathway. Our experiment suggests that exposure to nontoxic concentrations of toxins also poses potentially harmful effects.

An acute challenge with a deoxynivalenol-contaminated diet has short- and long-term effects on performance and feeding behavior in finishing pigs

Mycotoxins are toxic secondary metabolites produced by various fungi and are known to contaminate animal feed ingredients especially cereals. One of the most common mycotoxins in swine diets is deoxynivalenol (DON) which is known to decrease growth performance. The objective of the present study was to evaluate the effects of single or repeated short-term DON challenges on growth performance, and feeding behavior in finishing pigs. A total of 160 pigs were distributed to four experimental groups in two successive replicates with each pig individually measured for live BW and individually fed using an electronic feeding station. The pigs in control group CC were fed with a standard finisher diet during the whole duration of the experimental period. Groups DC, CD, and DD were given the DON-contaminated diet (3.02 mg DON/kg feed) for 7 d at 113 d, at 134 d, and at 113 and 134 d of age, respectively. The DON-contaminated diet was formulated with a naturally contaminated corn. During challenge periods, ADFI was decreased by 26% to 32% (P < 0.05) and ADG by 40% to 60% (P < 0.05). The drop in ADFI during DON challenges was associated with changes in the feeding behavior: when compared to the nonchallenged pigs, pigs fed with DON-contaminated diet had lower number of meals per day (9.6 versus 8.2 meals per day on average; P < 0.05) and slower feeding rate (42.0 g/min versus 39.9 g/min on average; P < 0.05). For the whole trial period, pigs submitted to the DON challenge at the end of the experiment (i.e., first time for CD group and second time for DD group) had a lower (P < 0.05) ADFI (2.67 and 2.59 kg/d, respectively) when compared to the control CC group of pigs (2.87 kg/d). An intermediate value was reported for the DC groups (2.79 kg/d). All challenged groups, i.e., DC, CD, and DD pigs, had lower (P < 0.05) overall ADG (970, 940, and 900 g/day, respectively) than CC (1,050 g/day) for the whole trial period. Pigs challenged early in the trial, i.e., DC and DD groups, had a higher (P < 0.05) FCR than CC group (3.00 and 3.06 versus 2.80, respectively) while group CD showed intermediate results (2.92). This study demonstrates that the severity of DON toxicity in pig performance can be related to the age of exposure (113 or 134 d) and the number of exposures to the toxin (one or two). Exposure to DON also resulted to long-term effects because challenged pigs showed limited ability to recover after the DON-induced reduction of feed intake.

Beneficial effects of Saccharomyces cerevisiae RC016 in weaned piglets: in vivo and ex vivo analysis

Probiotics represents an alternative to replace antibiotics as growth promoters in animal feed and are able to control enteric bacterial diseases and to improve gut immunity. Saccharomyces cerevisiae RC016 showed previously inhibition/coagregation of pathogens) and mycotoxins adsorbent ability (aflatoxin B₁, ochratoxin A and zearalenone). The aim of this work was to evaluate beneficial properties of S. cerevisiae RC016 in a non-inflammatory in vivo model in weaned piglets and in an intestinal inflammation ex vivo model induced by the mycotoxin deoxynivalenol (DON). Secretory immunoglobulin A (s-IgA) levels, intestinal cytokines, goblet cells and production parameters were evaluated in a pig model. For the in vivo assays, twelve pigs were weaned at 21 days and assigned to two groups: Control (n=6) and Yeast (n=6). Animals received yeast strain for three weeks. After 22 days the small intestine was recovered for determination of goblet cells and s-IgA. For the ex vivo assay, jejunal explants were obtained from 5 weeks old crossbred piglets and treated as follow: (1) control; (2) treated for 3 h with 10 μM DON used as an inflammatory stressor; (3) incubated with 10⁷ cfu/ml yeast strain; (4) pre-incubated 1 h with 10⁷ cfu/ml yeast strain and then treated for 3 h with 10 μM DON. CCL20, interleukin (IL)-1β, IL-8 and IL-22 gene expression was determined by qPCR. Oral administration of S. cerevisiae RC016 increased s-IgA, the number of goblet cells in small intestine and all the growth parameters measured. In the ex vivo model, the cytokine profile studied showed a potential anti-inflammatory effect of the administration of the yeast. In conclusion, S. cerevisiae RC016 is a promising candidate for feed additives formulation to improve animal growth and gut immune system. This yeast strain could be able to improve the gut health through counteracting the weaning-associated intestinal inflammation in piglets.

Enzymatic hydrolysis of fumonisins in the gastrointestinal tract of broiler chickens

Fumonisins (FB) are among the most frequently detected mycotoxins in feedstuffs and finished feed, and recent data suggest that the functions of the gastrointestinal tract (GIT) in poultry species might be compromised at doses ranging from 10 to 20 mg/kg, close to field incidences and below the US and EU guidelines. Strategies are therefore necessary to reduce the exposure of poultry to FB. In the present study, we assessed the efficacy of fumonisin esterase FumD (EC 3.1.1.87, commercial name FUMzyme®) to cleave the tricarballylic acid side chains of FB, leading to the formation of non-toxic hydrolyzed fumonisins in the GIT of broiler chickens. Broiler chickens were fed for 14 d (7 to 21 d of age) 3 different diets (6 birds/cage, 6 cages/diet), i) control feed (negative control group), ii) feed contaminated with 10 mg FB/kg (FB group), and iii) feed contaminated with 10 mg FB/kg and supplemented with 100 units of FUMzyme®/kg (FB+FUMzyme® group). To determine the degree of reduction of FB in the GIT, 2 characteristics were analyzed. First, the sphinganine-to-sphingosine ratio in the serum and liver was determined as a biomarker of effect for exposure to FB. Second, the concentration of fumonisin B1 and its hydrolyzed forms was evaluated in the gizzard, the proximal and distal parts of the small intestine, and the excreta. Significantly reduced sphinganine-to-sphingosine ratios in the serum and liver of the FB+FUMzyme® group (serum: 0.15 ± 0.01; liver: 0.17 ± 0.01) compared to the FB group (serum: 0.20 ± 0.01; liver: 0.29 ± 0.03) proved that supplementation of broiler feed with FUMzyme® was effective in partially counteracting the toxic effect of dietary FB. Likewise, FB concentrations in digesta and excreta were significantly reduced in the FB+FUMzyme® group compared to the FB group (P < 0.05; up to 75%). FUMzyme® furthermore partially counteracted FB-induced up-regulation of cytokine gene expression (IL-8 and IL-10) in the jejunum. The FB group showed significantly higher gene expression of IL-8 and IL-10 compared to the negative control group (IL-8: fold change = 2.9 ± 1.1, P < 0.05; IL-10: fold change = 3.6 ± 1.4, P < 0.05), whereas IL-8 and IL-10 mRNA levels were not significantly different in the FB+FUMzyme®® group compared to the other 2 groups. In conclusion, FUMzyme® is suitable to detoxify FB in chickens and maintain gut functions.

Saccharomyces cerevisiae Boulardii Reduces the Deoxynivalenol-Induced Alteration of the Intestinal Transcriptome

Type B trichothecene mycotoxin deoxynivalenol (DON) is one of the most frequently occurring food contaminants. By inducing trans-activation of a number of pro-inflammatory cytokines and increasing the stability of their mRNA, trichothecene can impair intestinal health. Several yeast products, especially Saccharomyces cerevisiae, have the potential for improving the enteric health of piglets, but little is known about the mechanisms by which the administration of yeast counteracts the DON-induced intestinal alterations. Using a pig jejunum explant model, a whole-transcriptome analysis was performed to decipher the early response of the small intestine to the deleterious effects of DON after administration of S. cerevisiae boulardii strain CNCM I-1079. Compared to the control condition, no differentially expressed gene (DE) was observed after treatment by yeast only. By contrast, 3619 probes-corresponding to 2771 genes-were differentially expressed following exposure to DON, and 32 signaling pathways were identified from the IPA software functional analysis of the set of DE genes. When the intestinal explants were treated with S. cerevisiae boulardii prior to DON exposure, the number of DE genes decreased by half (1718 probes corresponding to 1384 genes). Prototypical inflammation signaling pathways triggered by DON, including NF-κB and p38 MAPK, were reversed, although the yeast demonstrated limited efficacy toward some other pathways. S. cerevisiae boulardii also restored the lipid metabolism signaling pathway, and reversed the down-regulation of the antioxidant action of vitamin C signaling pathway. The latter effect could reduce the burden of DON-induced oxidative stress. Altogether, the results show that S. cerevisiae boulardii reduces the DON-induced alteration of intestinal transcriptome, and point to new mechanisms for the healing of tissue injury by yeast.

Ergot Alkaloids at Doses Close to EU Regulatory Limits Induce Alterations of the Liver and Intestine

An increase in the occurrence of ergot alkaloids (EAs) contamination has been observed in North America and Europe in recent years. These toxins are well known for their effects on the circulatory and nervous systems. The aim of this study was to investigate the effect of EAs on the liver and on the intestine using the pig both as a target species and as a non-rodent model for human. Three groups of 24 weaned piglets were exposed for 28 days to control feed or feed contaminated with 1.2 or 2.5 g of sclerotia/kg, i.e., at doses close to EU regulatory limits. Contaminated diets significantly reduced feed intake and consequently growth performance. In the liver, alteration of the tissue, including development of inflammatory infiltrates, vacuolization, apoptosis and necrosis of hepatocytes as well as presence of enlarged hepatocytes (megalocytes) were observed. In the jejunum, EAs reduced villi height and increased damage to the epithelium, reduced the number of mucus-producing cells and upregulated mRNA coding for different tight junction proteins such as claudins 3 and 4. In conclusion, in term of animal health, our data indicate that feed contaminated at the regulatory limits induces lesions in liver and intestine suggesting that this limit should be lowered for pigs. In term of human health, we establish a lowest observed adverse effect level (LOAEL) of 100 μg/kg body weight (bw) per day, lower than the benchmark dose limit (BMDL) retained by European Food Safety Authority (EFSA) to set the tolerable daily intake, suggesting also that regulatory limit should be revised.

The Effects of Deoxynivalenol and Zearalenone on the Pig Large Intestine. A Light and Electron Microscopy Study

The contamination of feed with mycotoxins results in reduced growth, feed refusal, immunosuppression, and health problems. Deoxynivalenol (DON) and zearalenone (ZEN) are among the most important mycotoxins. The aim of the study was to examine the effects of low doses of these mycotoxins on the histological structure and ultrastructure of the large intestine in the pig. The study was performed on 36 immature gilts of mixed breed (White Polish Big &times; Polish White Earhanging), which were divided into four groups administrated per os with ZEN at 40 &micro;g/kg BW, DON at 12 &micro;g/kg BW, a mixture of ZEN (40 &micro;g/kg BW) and DON (12 &micro;g/kg BW) or a placebo. The pigs were killed by intravenous overdose of pentobarbital after one, three, and six weeks of treatment. The cecum, ascending and descending colon samples were prepared for light and electron microscopy. Administration of toxins did not influence the architecture of the mucosa and submucosa in the large intestine. ZEN and ZEN + DON significantly decreased the number of goblet cells in the cecum and descending colon. The mycotoxins changed the number of lymphocytes and plasma cells in the large intestine, which usually increased in number. However, this effect differed between the intestine segments and toxins. Mycotoxins induced some changes in the ultrastructure of the mucosal epithelium. They did not affect the expression of proliferative cell nuclear antigen and the intestinal barrier permeability. The obtained results indicate that mycotoxins especially ZEN may influence the defense mechanisms of the large intestine.

Mycotoxins and oxidative stress: where are we?

Mycotoxins are the most common contaminants of food and feed worldwide and are considered an important risk factor for human and animal health. Oxidative stress occurs in cells when the concentration of reactive oxygen species exceeds the cell’s antioxidant capacity. Oxidative stress causes DNA damage, enhances lipid peroxidation, protein damage and cell death. This review addresses the toxicity of the major mycotoxins, especially aflatoxin B1, deoxynivalenol, nivalenol, T-2 toxin, fumonisin B1, ochratoxin, patulin and zearalenone, in relation to oxidative stress. It summarises the data associated with oxidative stress as a plausible mechanism for mycotoxin-induced toxicity. Given the contamination caused by mycotoxins worldwide, the protective effects of a variety of natural compounds due to their antioxidant capacities have been evaluated. We review data on the ability of vitamins, flavonoids, crocin, curcumin, green tea, lycopene, phytic acid, L-carnitine, melatonin, minerals and mixtures of anti-oxidants to mitigate the toxic effect of mycotoxins associated with oxidative stress.

Protective capabilities of silymarin and inulin nanoparticles against hepatic oxidative stress, genotoxicity and cytotoxicity of Deoxynivalenol in rats

Deoxynivalenol (DON) is a Fusarium mycotoxin that frequently contaminates cereal and cereal-based food and induces liver injury. This study evaluated the protective role of silymarin nanoparticles (SILNPs) and inulin nanoparticles (INNPs) against DON-induced liver injury in rats. Eleven groups of rats were treated orally for 3 weeks as follows: the control group, DON-treated group (5 mg/kg b.w.); INNPs-treated groups at low (LD) or high (HD) dose (100 or 200 mg/kg b.w.); SILPNs-treated group (50 mg/kg b.w.); SILNPs plus INNPs(LD) or INNPs(HD)-treated groups; INNPs(LD) or INNPs(HD) plus DON-treated groups and DON plus SILNPs and INNPs(LD) or INNPs(HD)-treated groups. Blood and tissue samples were collected for different analyses. The results revealed that the practical sizes were 200 and 98 nm for SILNPs and INNPs respectively. DON increased liver enzymes activity, lipid profile, serum cytokines, number and percentage of chromosomal aberration, DNA fragmentation and comet score. It disturbed the oxidative stress markers, down regulated gene expression and induced histological changes in the liver tissue. Treatment with DON and SILNPs and/or INNPs at the two tested doses improved all the tested parameters and SILNPs plus INNPs(HD) normalized most of these parameters in DON-treated animals. SILNPs and INNPs could be promising candidates as hepatoprotective against DON or other hepatotoxins.

The Food Contaminants Nivalenol and Deoxynivalenol Induce Inflammation in Intestinal Epithelial Cells by Regulating Reactive Oxygen Species Release

Fusarium mycotoxins are fungal metabolites whose ability to affect cereal grains as multi-contaminants is progressively increasing. The trichothecene mycotoxins nivalenol (NIV) and deoxynivalenol (DON) are often found in almost all agricultural commodities worldwide. They are able to affect animal and human health, including at the intestinal level. In this study, NIV, both alone and in combination with DON, induced inflammation and increased the inflammatory response induced by lipopolysaccharide (LPS) plus Interferon-γ (IFN) in the non-tumorigenic intestinal epithelial cell line (IEC-6). The inflammatory response induced by NIV and DON involves tumor necrosis factor-α (TNF-α) production, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, nitrotyrosine formation, reactive oxygen species (ROS) release, Nuclear Factor-κB (NF-κB), Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and inflammasome activation. The pro-inflammatory effect was strongly induced by NIV and by the mycotoxin mixture, when compared to DON alone. Mechanistic studies indicate a pivotal role for ROS in the observed pro-inflammatory effects induced by mycotoxins. In this study, the interactions between NIV and DON point out the importance of their food co-contamination, further highlighting the risk assessment process that is of growing concern.

Trichothecenes: immunomodulatory effects, mechanisms, and anti-cancer potential

Paradoxically, trichothecenes have both immunosuppressive and immunostimulatory effects. The underlying mechanisms have not been fully explored. Early studies show that dose, exposure timing, and the time at which immune function is assessed influence whether trichothecenes act in an immunosuppressive or immunostimulatory fashion. Recent studies suggest that the immunomodulatory function of trichothecenes is also actively shaped by competing cell-survival and death-signaling pathways. Autophagy may also promote trichothecene immunosuppression, although the mechanism may be complicated. Moreover, trichothecenes may generate an "immune evasion" milieu that allows pathogens to escape host and vaccine immune defenses. Some trichothecenes, especially macrocyclic trichothecenes, also potently kill cancer cells. T-2 toxin conjugated with anti-cancer monoclonal antibodies significantly suppresses the growth of thymoma EL-4 cells and colon cancer cells. The type B trichothecene diacetoxyscirpenol specifically inhibits the tumor-promoting factor HIF-1 in cancer cells under hypoxic conditions. Trichothecin markedly inhibits the growth of multiple cancer cells with constitutively activated NF-κB. The type D macrocyclic toxin Verrucarin A is also a promising therapeutic candidate for leukemia, breast cancer, prostate cancer, and pancreatic cancer. The anti-cancer activities of trichothecenes have not been comprehensively summarized. Here, we first summarize the data on the immunomodulatory effects of trichothecenes and discuss recent studies that shed light on the underlying cellular and molecular mechanisms. These mechanisms include autophagy and major signaling pathways and their crosstalk. Second, the anti-cancer potential of trichothecenes and the underlying mechanisms will be discussed. We hope that this review will show how trichothecene bioactivities can be exploited to generate therapies against pathogens and cancer.

Effects of deoxynivalenol- and zearalenone-contaminated feed on the gene expression profiles in the kidneys of piglets

Objective

Fusarium mycotoxins deoxynivalenol (DON) and zearalenone (ZEN), common contaminants in the feed of farm animals, cause immune function impairment and organ inflammation. Consequently, the main objective of this study was to elucidate DON and ZEN effects on the mRNA expression of pro-inflammatory cytokines and other immune related genes in the kidneys of piglets.

Methods

Fifteen 6-week-old piglets were randomly assigned to three dietary treatments for 4 weeks: control diet, and diets contaminated with either 8 mg DON/kg feed or 0.8 mg ZEN/kg feed. Kidney samples were collected after treatment, and RNA-seq was used to investigate the effects on immune-related genes and gene networks.

Results

A total of 186 differentially expressed genes (DEGs) were screened (120 upregulated and 66 downregulated). Gene ontology analysis revealed that the immune response, and cellular and metabolic processes were significantly controlled by these DEGs. The inflammatory stimulation might be an effect of the following enriched Kyoto encyclopedia of genes and genomes pathway analysis found related to immune and disease responses: cytokine-cytokine receptor interaction, chemokine signaling pathway, toll-like receptor signaling pathway, systemic lupus erythematosus (SLE), tuberculosis, Epstein-Barr virus infection, and chemical carcinogenesis. The effects of DON and ZEN on genome-wide expression were assessed, and it was found that the DEGs associated with inflammatory cytokines (interleukin 10 receptor, beta, chemokine [C-X-C motif] ligand 9, CXCL10, chemokine [C-C motif] ligand 4), proliferation (insulin like growth factor binding protein 4, IgG heavy chain, receptor-type tyrosine-protein phosphatase C, cytochrome P450 1A1, ATP-binding cassette sub-family 8), and other immune response networks (lysozyme, complement component 4 binding protein alpha, oligoadenylate synthetase 2, signaling lymphocytic activation molecule-9, α-aminoadipic semialdehyde dehydrogenase, Ig lambda chain c region, pyruvate dehydrogenase kinase, isozyme 4, carboxylesterase 1), were suppressed by DON and ZEN.

Conclusion

In summary, our results indicate that high concentrations of DON and ZEN suppress the inflammatory response in kidneys, leading to potential effects on immune homeostasis.