Deoxynivalenol Toxicity Research Articles

3D “honeycomb” cell/carbon nanofiber/gelatin methacryloyl (GelMA) modified screen-printed electrode for electrochemical assessment of the combined toxicity of deoxynivalenol family mycotoxins

A “honeycomb” electrochemical biosensor based on 3D printing was developed to noninvasively monitor the viability of 3D cells and evaluate the individual or combined toxicity of deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-ADON), and 15-acetyldeoxynivalenol (15-ADON). Carbon nanofiber (CN)/gelatin methacryloyl (GelMA) conductive composite hydrogel with strong processability was printed on 8-channel screen-printed carbon electrodes (SPCEs) to maintain cell viability and form tight cell-to-cell contacts. A “3D honeycomb” printing infill pattern was selected in the construction of the biosensors to improve conductivity. Based on 3D printing technology, the electrochemical biosensor can prevent manual error and provide for high-throughput detection. Electrochemical impedance spectroscopy (EIS) was used to evaluate mycotoxin toxicity. The EIS response decreased with the concentration of DON, 3-ADON and 15-ADON in the range of 0.1–10, 0.05–100, and 0.1–10 μg/mL, respectively, with a limit of detection of 0.07, 0.10 and 0.06 μg/mL, respectively. Mycotoxin interactions were analyzed using the isobologram–combination index (CI) method. The electrochemical cytotoxicity evaluation result was confirmed by biological assays. Therefore, a novel method for evaluating the combined toxicity of mycotoxins is proposed, which exhibits potential for application to food safety and evaluation.

Combination of Lactobacillus species and yeast ameliorates adverse effect of deoxynivalenol contaminated diet on immune system, gut morphology and jejunal gene expression in broiler chickens

The aim of this study was to examine the effect of different levels of Lactobacillus species and yeast (Saccharomyces cerevisiae) as a toxin binder in deoxynivalenol (DON) diet on immune parameters, gut morphology and jejunal gene expression in broiler chickens. Three hundred sixty-one-day-old female broilers were assigned into nine treatments with four replicates each in a completely randomised design (3 × 3 factorial arrangement) including three levels of Lactobacillus (0, 0.20 and 0.40 g/kg) and yeast (0, 0.75 and 1.50 g/kg) in DON contaminated diets. The results showed that DON challenged birds showed suppressed spleen relative weight and reduced white blood cell and lymphocyte percentage, while inclusion the highest level of Lactobacillus sp. and yeast to DON diet improved these parameters (p < .05). Newcastle antibody titre was increased (p < .05) by increasing the level of Lactobacillus sp. and yeast in DON included diet. Increasing the level of Lactobacillus sp. and yeast in DON diet was linearly enhanced (p < .05) the villus height, muscular layer and absorptive surface area in ileum. Combination of 0.40 g/kg Lactobacillus sp. and 1.50 g/kg yeast caused an enhancement (p < .05) in mucosa and muscular layer thicknesses of jejunum and ileum, respectively. The expressions of toll like receptor-4 and claudin-5 were down-regulated and up-regulated respectively by administration of the highest level of Lactobacillus sp. and yeast. In conclusion, the results indicated that dietary inclusion of the highest level of Lactobacillus sp. and yeast improved the spleen weight, some immunological parameters, villus height, muscular layer thickness and gene expressions in DON- challenged broilers. HIGHLIGHTS Deoxynivalenol (DON) consumption (10 mg/kg) induce intestinal and immunological changes in broilers. Combination of Lactobacillus sp. and yeast reduce DON toxicity. Inclusion 0.4 g/kg lactobacillus and 1.5 g/kg yeast improve villus height and humoral immunity.

Oral deoxynivalenol toxicity in Harlan Sprague Dawley (Hsd:Sprague Dawley® SD®) rat dams and their offspring

There is widespread human exposure to deoxynivalenol (DON), a fungal mycotoxin found globally in many grain-based foods and animal feed. Acute exposures to high levels of DON are associated with gastrointestinal effects and emesis in humans and some animals, but the effects of low-dose exposures throughout the lifetime, a more likely exposure scenario in humans, are understudied. Therefore, this study was designed to identify doses of DON that could be used to evaluate long-term toxicity following perinatal exposure. Time-mated Harlan Sprague Dawley (Hsd:Sprague Dawley® SD®) rats were administered 0, 0.03, 0.1, 0.3, 1, or 3 mg/kg/day of DON once daily via gavage starting on gestational day 6 through postnatal day (PND) 27. F1 animals were administered the same dose as their respective dams via gavage starting on PND 12 until PND 27. Animals were euthanized on PND 28. DON had no effect on maternal body weight or feed consumption at any dose. Findings were limited to the 3 mg/kg/day group: F0 females had smaller live litter sizes than controls and F1 pups had lower body weight (4–13%) compared to controls. By PND 28, F1 body weight, after adjustments for litter effects, was 10–13% lower than controls. Blood samples obtained on PND 28 showed no increases in frequencies of micronucleated immature erythrocytes in either F0 or F1 animals. In summary, doses of DON up to 3 mg/kg/day did not affect maternal survival or body weight. Doses of 3 mg/kg/day resulted in slight toxicity manifested as decreased body weight in the offspring. The no-observed effect level was 1 mg/kg/day.

Transfer of Mycotoxins from Lactation Feed to Colostrum of Sows.

Simple SummaryMycotoxin risk levels are known to vary depending on the type of mycotoxins, animal species, age and type of production. In lactating animals, mycotoxins can be transferred from feed consumed to colostrum and milk. This has been well documented for aflatoxicosis in cattle, but not in sows and not for the most diffused mycotoxins. Samples of in-house produced complete feed for lactating sows were obtained from Italian farms. Samples of colostrum were obtained at farrowing from each farm. The feed content of the mycotoxins was generally low. Of the 19 samples analyzed, 10, 12, 17 and 2 were positive for aflatoxins, fumonisins, deoxynivalenol (DON) and zearalenone, respectively; however, only two were above the risk limit. The colostrum samples were all negative for aflatoxins while a faint analytical signal was detected for fumonisins in five samples, notwithstanding very low values in the feed. Deoxynivalenol was frequently present in the colostrum; the highest value was seen in the farm presenting the highest value in the feed. However, this colostrum value was far from the presumed risk value for suckling piglets. More controls regarding feed on the farm are suggested while more studies are advisable regarding the risk of DON toxicosis in suckling pigs.Studies regarding the transfer of mycotoxins from sow feed to colostrum are scarce. A sample of in-house produced lactation feed and one of colostrum were collected from two or three sows per farm (total 49) from 19 farms. The feed contents of aflatoxins (AFs), fumonisins (FUs), deoxynivalenol (DON) and zearalenone (ZEA) were assessed using ELISA and confirmed by liquid chromatography-mass spectrometry (LC-MS), The values were very low (10, 12, 17 and 2 positive samples for AFs, FUs, DON and ZEA, respectively), except for two samples (one AF, one DON). Based on feed values, colostrum samples from 13 farms were tested for at least one mycotoxin (Total 35). Aflatoxins were not found in any sample. A signal for FUs was observed in 5 of 11 colostra, despite low feed values; DON was frequently present in the colostrum (10/14). On the farm where the feed exceeded the DON suggested limits, a higher colostrum content was seen, 10.9 µg/kg, approximately 1/69 of the value showing toxicity in young pigs. The absence of reference values for neonate pigs, and the risk of higher and longer ingestion of DON by sows suggested considering routine checks of sow feed; more research on DON transfer and toxicity in piglets is needed.

119 Effect of DON on the porcine acquired immune response and potential remediation by a novel modified HSCAS binder

Abstract The objective of the current study was to evaluate the immunotoxic effects of deoxynivalenol (DON) in weaning piglets, and potential efficacy of a novel modified hydrated sodium calcium aluminosilicate (HSCAS) binder to detoxify DON toxicity. Four groups of 21-day-old male piglets (n = 7/group) were fed a control diet or diet adding 1.0 or 3.0 mg DON/kg, or 3.0 mg DON/kg plus 0.05% modified HSCAS for 4 weeks. Compared to the control, the DON diets reduced serum porcine circovirus antibody titer and the dermal hypersensitivity response to OVA at day 21 or 28. DON also induced focal necrosis and proliferation of cortical lymphocytes and apoptosis and increased the total antioxidant capacity and reduced protein carbonyl concentrations in thymus. DON increased thymus mRNA and(or) protein levels, cytokines (TNF-α, IL-6, and IL-10) and apoptosis-related genes (Caspase-3). Interestingly, the modified HSCAS mitigated the DON-induced alterations on serum antibody titer, and thymic histopathology, apoptosis, redox status, inflammation and apoptosis signaling. In conclusion, these findings help to explain the toxic effects and mechanisms of DON and demonstrated the modified HSCAS binder could be used to detoxify the toxicity of DON in weaning piglets.

121 Effects of DON on the porcine growth performance and intestinal microbiota and potential remediation by a novel modified HSCAS adsorbent

Abstract The objective of the current study was to evaluate the effects of deoxynivalenol (DON) on growth performance and intestinal microbiota in weaning piglets, and potential efficacy of a modified hydrated sodium calcium aluminosilicate (HSCAS) binder to detoxify DON toxicity. Four groups of 21-day-old male piglets (n = 7/group) were fed either a control diet, or diet adding 1.0 or 3.0 mg/kg DON, or 3.0 mg/kg DON plus 0.05% modified HSCAS for 28 d. Compared to the control, dietary DON at 1.0 and/or 3.0 mg/kg decreased (P &amp;lt; 0.05) the feed intake (18.1–38.7%) and body weight gain (16.0–60.8%) during the whole experiment, and increased (P &amp;lt; 0.05) the feed/gain ratio (12.8–33.8%) during d 1–14. Worse results were obtained at 3.0 mg/kg DON in comparison to 1.0 mg/kg for most of these variables. DON exposure reshaped gut microbial structure by drastically dysregulating the abundance of several bacterial phyla, families, and genera, such as dysbiosis of Actinobacteria, Cyanobacteria, Firmicutes, and Proteobacteria in small intestine. Notably, dietary modified HSCAS binder supplementation mitigated the negative effects of DON on growth performance of piglets and improved the intestinal flora disorder. Therefore, this study has revealed that the modified HSCAS binder can mitigate DON-induced adverse effects and could be used as a promising countermeasure for detoxifying DON toxicity.

Agricultural trichothecene mycotoxin contamination affects the life-history and reduced glutathione content of Folsomia candida Willem (Collembola)

There is limited data available concerning the effect of T-2/HT-2 toxin or deoxynivalenol (DON) on invertebrates such as springtails, and no data on their life history and oxidative stress. Control maize and DON or T-2 toxin contaminated maize were fed to Folsomia candida with a toxin content of 16324 mg DON kg–1 or 671 mg T-2 kg–1 maize. Ten to twelve days old animals were investigated in a life-history test and a stress protein test.T-2 toxin did not affect Folsomia candida in any measured parameters. The DON exposed group showed decreased growth and reproduction, and a higher survival rate. DON treatment resulted in lower protein content, while reduced glutathione content was higher than in control. It suggests that DON activated the glutathione-related detoxification pathway, which possibly causes a higher survival rate. The results also suggest that the oral toxicity of DON or T-2 is lower than through physical contact.For that reason, DON and T-2 toxin contaminated maize is not suggested to be used as green manure in the native state. Alternative solutions could be using mycotoxin contaminated maize for biogas production, or after decontamination by bacterial strains, it can be used as organic fertilizer.

The food contaminant deoxynivalenol provokes metabolic impairments resulting in non-alcoholic fatty liver (NAFL) in mice

The ribotoxin deoxynivalenol (DON) is a trichothecene found on cereals responsible for mycotoxicosis in both humans and farm animals. DON toxicity is characterized by reduced food intake, diminished nutritional efficiency and immunologic effects. The present study was designed to further characterize the alterations in energy metabolism induced by DON intoxication. We demonstrated that acute DON intoxication triggered liver steatosis associated with an altered expression of genes related to lipids oxidation, lipogenesis and lipolysis. This steatosis was concomitant to anorexia, hypoglycemia and a paradoxical transient insulin release. DON treatment resulted also in stimulation of central autonomic network regulating sympathetic outflow and adrenaline and glucocorticoids secretion. Furthermore, an increased expression of genes linked to inflammation and reticulum endoplasmic stress was observed in the liver of DON-treated mice. Finally, we propose that lipids mobilization from adipose tissues (AT) induced by DON intoxication drives hepatic steatosis since (1) genes encoding lipolytic enzymes were up-regulated in AT and (2) plasma concentration of triglycerides (TGs) and non-esterified fatty acids were increased during DON intoxication. Altogether, these data demonstrate that DON induced hormonal and metabolic dysregulations associated with a spectrum of hepatic abnormalities, evocative of a non-alcoholic fatty liver disease.

Celecoxib reduces Deoxynivalenol induced proliferation, inflammation and protein kinase C translocation via modulating downstream targets in mouse skin

Exposure to mycotoxins is mostly by ingestion but also occurs by the dermal and inhalation routes. The present study for the first time demonstrated that mycotoxin Deoxynivalenol (DON), permeates through Swiss albino mice skin, which demands awareness of health risks in people who are dermally exposed to mycotoxins especially agricultural farmers. Despite the widespread contamination of DON in food commodities studies to alleviate DON's toxicity are sparsely reported. Thus effective measures to combat mycotoxins associated toxicity remains an imperative aspect to be considered from the angle of dermal exposure. Topical application of Celecoxib (1–2 mg), followed by DON (100 μg) application on the dorsal side of mice, resulted in substantial decrease in DON-induced (i) edema, hyperplasia, cell proliferation (ii) inhibition of cytokine and prostaglandin-E2 levels (iii) phosphorylation of ERK1/2, JNK, p38, MAPKKs, CREB, P90-RSK (iv) downregulation of c-Jun, c- Fos, phospho-NF-kB and their downstream target proteins cyclin D1 and COX-2. Using Ro-31-8220 (Protein-Kinase-C inhibitor), it was observed PKC was responsible for DON induced upregulation of COX-2 and iNOS proteins. Treatment of Celecoxib decreased DON-induced translocation of Protein Kinase C isozymes (α,ε,γ), demonstrating the role of PKC in DON-mediated biochemical and molecular alterations responsible for its dermal toxicity. The present findings indicate that topical application of celecoxib is effective in the management of inflammatory skin disorders induced by foodborne fungal toxin DON. The skin permeation potential of Celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor NSAID, was also assessed, and the results indicated that the permeation was relatively lower as compared to the oral mode of administration. Hence topical use of celecoxib may be preferred over oral dosing because of lower systemic absorption and to avoid the unwanted side effects. This study provides a prospect for exploring the clinical efficacy of topically applied COX-2 inhibitors for the management of inflammatory skin disorders induced by foodborne fungal toxins.

Efficacy of Mycotoxin Detoxifiers on Health and Growth of Newly-Weaned Pigs under Chronic Dietary Challenge of Deoxynivalenol.

The efficacy of yeast-based mycotoxin detoxifiers on health and growth performance of newly-weaned pigs (27-d-old) fed diets naturally contaminated with deoxynivalenol was investigated. Sixty pigs were individually assigned to five treatments for 34 d: NC (negative control, 1.2 mg/kg of deoxynivalenol); PC (positive control, 3.2 mg/kg of deoxynivalenol); CYC (PC + clay/yeast culture-based product, 0.2%); CYE (PC + clay/yeast cell wall/plant extracts/antioxidants-based product, 0.2%); and CYB (PC + clay/inactivated yeast/botanicals/antioxidants-based product, 0.2%). Blood and jejunal mucosa were sampled, and data were analyzed using Proc Mixed of SAS with pre-planned contrasts. Deoxynivalenol reduced the average daily gain (ADG) in phase 3. Pigs fed CYC had greater overall ADG, average daily feed intake during phase 3, and gain to feed ratio during phase 2 than PC. At d 14, deoxynivalenol reduced blood urea nitrogen/creatinine and tended to reduce blood urea nitrogen. Pigs fed CYB tended to have greater aspartate aminotransferase than PC. At d 34, pigs fed CYC and CYB tended to have lower serum creatine phosphokinase than PC. Pigs fed CYE had lower blood urea nitrogen/creatinine than PC. In jejunal mucosa, deoxynivalenol tended to increase malondialdehydes and decrease glutathione. Pigs fed CYE and CYB had lower malondialdehydes, pigs fed CYB had greater glutathione and tended to have lower immunoglobulin A than PC. Pigs fed CYC and CYE tended to have lower interleukin 8 than PC. In summary, deoxynivalenol challenge (1.2 vs. 3.2 mg/kg) mildly compromised growth performance and increased the oxidative stress of pigs. Mycotoxin detoxifiers could partially overcome deoxynivalenol toxicity enhancing liver health, whereas CYE and CYB reduced oxidative stress, and CYC and CYB reduced immune activation. In conclusion, yeast-based detoxifiers with functional components as clay/inactivated yeast/botanicals/antioxidants had increased detoxifying properties in newly-weaned pigs challenged with deoxynivalenol, potentially by enhancing adsorbability, immune function, gut health, and reducing oxidative stress.

Effects of deoxynivalenol on the porcine growth performance and intestinal microbiota and potential remediation by a modified HSCAS binder

The objectives of this study were to determine the effects of deoxynivalenol (DON) on growth performance and intestinal microbiota in weaning piglets, and potential efficacy of a modified hydrated sodium calcium aluminosilicate (HSCAS) adsorbent to reduce DON toxicity. Four groups of 21-day-old male piglets (n = 7/group) were fed either a control diet, or diet containing 1.0 or 3.0 mg/kg DON, or 3.0 mg/kg DON plus 0.05% modified HSCAS for 28 d. Compared to the control, dietary DON at 1.0 and/or 3.0 mg/kg reduced (P < 0.05) the body weight gain (16.0–60.8%) and feed intake (18.1–38.7%) during the whole experiment, and increased (P < 0.05) the feed/gain ratio (12.8–33.8%) between d 1–28. The body weight gain and feed intake were further decreased (P < 0.05) in 3.0 mg/kg DON in comparison to 1.0 mg/kg DON during d 15–28. DON exposure reshaped gut microbial structure by drastically affecting the abundance of several bacterial phyla, families and genera, including dysbiosis of Actinobacteria, Cyanobacteria, Firmicutes, and Proteobacteria in small intestine. Notably, dietary Amdetox™ supplementation alleviated the adverse effects of DON on growth performance of piglets and improved the intestinal flora disorder. Therefore, the current study has revealed that Amdetox™, the modified HSCAS binder, can alleviate DON-induced negative effects and could be used as a promising countermeasure for reducing DON toxicity.

Metabolomic profiling reveals similar cytotoxic effects and protective functions of quercetin during deoxynivalenol- and 15-acetyl deoxynivalenol-induced cell apoptosis

Among the family of mycotoxins of deoxynivalenol (DON) detected in nature, high proportions of 15-acetyldeoxynivalenol (15ADON) co-occur with the prototype DON and increase the combined exposure and synergistic health risks. The current study aimed to explore the mechanisms underlying the toxicity of 15ADON and compare them with those of DON. As the natural flavonoid compound quercetin (QUE) possesses antioxidant properties, we also aimed to determine the antioxidant effects of QUE on the tested mycotoxins. First, the global metabolomics approach was applied and showed that the metabolites produced from 15ADON or DON were almost identical, while QUE reversed the changes in the levels of key metabolites. Specifically, both DON and 15ADON activated the cell apoptosis pathway mediated by p38 and JNK, but inhibited the cell survival pathway mediated by ERK1/2 in GES-1 cells. Simultaneously, 15ADON induced FOXO3a nuclear translocation, similar to the results described for DON in our recent report. Furthermore, the addition of QUE appeared to counteract the detrimental effects of 15ADON and DON. We observed the effects of QUE treatment on mutant yeast strains with defects in their antioxidant system. More interestingly, QUE also substantially restored the increased ROS levels and the inhibited the growth rate following exposure to the mycotoxins DON and 15ADON. The data reported here support the hypothesis that QUE rescues the toxic effects of DON or 15ADON due to the similar mechanisms of DON and 15ADON toxicity.

Deoxynivalenol: toxicological profiles and perspective views for future research

Deoxynivalenol (DON) is a secondary metabolite mainly produced by the fungiFusarium in agricultural crops, widely existing in feeds and cereal-based foodstuffs. Because of the high occurrence and potentials to induce a variety of toxic effects on animals and humans, DON has been a very harmful exogenous dietary toxicant threating public health. The focus of this review is to summarise the DON-induced broad spectrum of adverse health effects, to probe the current state of knowledge of combined toxicity of DON with other mycotoxins and its derivatives, and to put forward prospective ideas that multi-generational toxicity of DON and its overall impacts on intestinal-immuno-neuroendocrine system could receive more attention in future investigations. The general aim is to provide a scientific basis for the necessity to re-consider risk-assessment and regulations.

Porcine milk exosome miRNAs protect intestinal epithelial cells against deoxynivalenol-induced damage

Porcine milk exosomes play an important role in mother-infant communication. Deoxynivalenol (DON) is a toxin which causes serious damage to the animal intestinal mucosa. Our previous study showed porcine milk exosomes facilitate mice intestine development, but the effects of these exosomes to antagonize DON toxicity is unclear. Our in vivo results showed that milk exosomes attenuated DON-induced damage on the mouse body weight and intestinal epithelium growth. In addition, these exosomes could reverse DON-induced inhibition on cell proliferation and tight junction proteins (TJs) formation and reduce DON-induced cell apoptosis. In vitro, exosomes up-regulated the expression of miR-181a, miR-30c, miR-365-5p and miR-769-3p in IPEC-J2 cells and then down-regulated the expression of their targeting genes in p53 pathway, ultimately attenuating DON-induced damage by promoting cell proliferation and TJs and by inhibiting cell apoptosis. In conclusion, porcine milk exosomes could protect the intestine against DON damage, and these protections may take place through the miRNAs in exosomes. These results indicated that the addition of miRNA-enriched exosomes to feed or food could be used as a novel preventative measure for necrotizing enterocolitis.

Effect of deoxynivalenol on the porcine acquired immune response and potential remediation by a novel modified HSCAS adsorbent

The objective of this study was to determine the immunotoxic effects of deoxynivalenol (DON) in weaning piglets, and potential efficacy of a modified hydrated sodium calcium aluminosilicate (HSCAS) adsorbent to reduce DON toxicity. Four groups of 21-day-old male piglets (n = 7/group) were fed a control diet or diet containing 1.0 or 3.0 mg DON/kg, or 3.0 mg DON/kg plus 0.05% modified HSCAS for 4 weeks. Compared to the control, the DON diets decreased serum porcine circovirus antibody titer and the dermal hypersensitivity response to OVA at day 21 or 28. DON also induced focal necrosis and proliferation of cortical lymphocytes and apoptosis and increased the total antioxidant capacity and reduced glutathione, protein carbonyl concentrations in thymus. DON increased thymus mRNA, protein and (or) enzyme levels, cytokines (IL-6, IL-10, and TNF-α) and apoptosis-related genes (Caspase-3), while hematopoietic cell kinase (HCK) decreased. Intriguingly, the modified HSCAS alleviated the DON-induced changes on serum antibody titer, and thymic histopathology, apoptosis, redox status, inflammation and apoptosis signaling. In conclusion, these findings help to explain the toxic effects and mechanisms of DON and demonstrated the modified HSCAS adsorbent could be used to reduce the toxicity of DON in weaning piglets.

Autophagy protects PC12 cells against deoxynivalenol toxicity via the Class III PI3K/beclin 1/Bcl-2 pathway.

Deoxynivalenol (DON) is a major mycotoxin from the trichothecene family of mycotoxins produced by Fusarium fungi. It can cause a variety of adverse effects on human and farm animal health. Here, we determined the effect of DON on the Class III phosphatidylinositol 3-kinase (PIK3C3)/beclin 1/B cell lymphoma-2 (Bcl-2) pathway in PC12 cells and the relationship between autophagy and apoptosis. The effects of DON were evaluated based on the apoptosis ratio; the typical indicators of autophagy, including cellular morphology, acridine orange- and monodansylcadaverine-labeled vacuoles, green fluorescent protein-microtubule associated protein 1 light chain 3 (LC3) localization, and LC3 immunofluorescence; and the expression of key autophagy-related genes and proteins, that is, PIK3C3, beclin 1, Bcl-2, LC3, and p62. The relationship between autophagy and apoptosis was analyzed by western blot analysis and flow cytometry. DON-induced PC12 cell morphological changes and autophagy significantly. PIK3C3, beclin 1, and LC3 increased in tandem with the DON concentration used; Bcl-2 and p62 expression decreased as DON concentrations increased. Moreover, the PIK3C3/beclin 1/Bcl-2 signaling pathway played a role in DON-induced autophagy. Our findings suggest that DON can induce autophagy by activating the PIK3C3/beclin 1/Bcl-2 signaling pathway and that autophagy may play a positive role in reducing DON-induced apoptosis.

Biodegradation of Deoxynivalenol by a Novel Microbial Consortium.

Deoxynivalenol (DON), a common mycotoxin of type B trichothecene, is produced mainly by several Fusarium species. DON causes great losses in farming and poses severe safety risks to human and animal health. Thus, DON contamination in cereals and DON toxicity are of worldwide concern. In this study, we screened the bacterial consortium C20, which efficiently degraded almost 70 μg ml−1 DON within 5 days. The bacterial consortium also had the ability to degrade 15-acetyl-DON, 3-acetyl-DON, and T-2 toxin. The bacterial consortium C20 was able to degrade DON under a wide range of pH and temperature conditions. The optimal temperature and pH for DON degradation were 30°C and pH 8.0, respectively. The bacterial consortium C20 comprised of different bacterial genera, and several strains were found to significantly increase when cultured in Mineral Medium with 100 μg ml−1 DON based on the analysis of the sequences of the hypervariable V3-V4 region of the 16S rRNA gene. 3-keto-DON was confirmed as a degradation product of DON by liquid chromatography/time-of-flight/mass spectrometry (LC-TOF-MS) and nuclear magnetic resonance (NMR) analyses. The results indicated that the bacterial consortium C20 is a potential candidate for the biodegradation of DON in a safe and environmentally friendly manner.

Deoxynivalenol and Nivalenol (2nd edition) [Assuring the Maximum Level of Deoxynivalenol in Wheat] (Natural Toxins and Mycotoxins).

Food Safety Commission of Japan (FSCJ) was requested by the Ministry of Health, Labour and Welfare (MHLW) to conduct a risk assessment of deoxynivalenol (DON) to assure the maximal level for DON in foods. Previously, FSCJ had conducted a self-tasking risk assessment of DON and nivalenol (NIV) in 2010. In the current 2nd edition, only the assessment of DON has been revised. Grains contaminated with DON may be also contaminated with its derivatives, namely, 3-acetyldeoxynivalenol (3-Ac-DON), 15-acetyldeoxynivalenol (15-Ac-DON) and deoxynivalenol-3-glucoside (DON-3-glucoside). However, these substances orally ingested are rapidly biotransformed into DON. Therefore, FSCJ identified the total DON (sum of DON and its derivatives) to be assessed. The toxicity of DON was assessed based on the data of absorption-distribution-metabolism-excretion (ADME), acute toxicity, sub-acute toxicity, chronic toxicity, carcinogenicity, reproductive/developmental toxicity, genotoxicity, and immunotoxicity. DON was considered to have no significant genotoxic activity in vivo. The no-observed-adverse-effect level (NOAEL), based on the two-year chronic toxicity study in mice, was set at 0.1 mg DON/kg bw/day. By applying an uncertainty factor (UF) of 100, the TDI for DON was determined as 1 µg /kg bw/day. The average estimated exposure levels of total DON were 0.09 µg /kg bw/day and 0.22 µg/kg bw/day in the whole population and the 1-6 years group, respectively, by the Monte-Carlo method. The average exposure level in Japan was thus judged to be below the TDI, although a chance to exceed the TDI remains possible in the 1-6 years group depending on eating habits and DON contamination. For NIV, the genotoxic property was not able to be assessed due to the limited availability of the experimental data. No carcinogenic effect was observed in a two-year chronic toxicity study in mice, and the International Agency for Research on Cancer (IARC) also classifies Fusarium spp toxins including NIV to be in group 3. FSCJ thus judged that TDI can be set for NIV. Based on various toxicity studies, the TDI of NIV was determined at 0.4 µg/kg bw/day by taking into account of LOAEL 0.4 mg NIV/kg bw/day in a subacute toxicity study in rats with 90-day oral administration and UF of 1,000. The exposure level of NIV in Japan was estimated to be below the TDI. FSCJ judged it’s unlikely that NIV intake leads to adverse health effects in general population.

Co-occurrence of DON and Emerging Mycotoxins in Worldwide Finished Pig Feed and Their Combined Toxicity in Intestinal Cells.

Food and feed can be naturally contaminated by several mycotoxins, and concern about the hazard of exposure to mycotoxin mixtures is increasing. In this study, more than 800 metabolites were analyzed in 524 finished pig feed samples collected worldwide. Eighty-eight percent of the samples were co-contaminated with deoxynivalenol (DON) and other regulated/emerging mycotoxins. The Top 60 emerging/regulated mycotoxins co-occurring with DON in pig feed shows that 48%, 13%, 8% and 12% are produced by Fusarium, Aspergillus, Penicillium and Alternaria species, respectively. Then, the individual and combined toxicity of DON and the 10 most prevalent emerging mycotoxins (brevianamide F, cyclo-(L-Pro-L-Tyr), tryptophol, enniatins A1, B, B1, emodin, aurofusarin, beauvericin and apicidin) was measured at three ratios corresponding to pig feed contamination. Toxicity was assessed by measuring the viability of intestinal porcine epithelial cells, IPEC-1, at 48-h. BRV-F, Cyclo and TRPT did not alter cell viability. The other metabolites were ranked in the following order of toxicity: apicidin > enniatin A1 > DON > beauvericin > enniatin B > enniatin B1 > emodin > aurofusarin. In most of the mixtures, combined toxicity was similar to the toxicity of DON alone. In terms of pig health, these results demonstrate that the co-occurrence of emerging mycotoxins that we tested with DON does not exacerbate toxicity.

Degradation and ozonolysis pathway elucidation of deoxynivalenol

To explore the degradation products and ozonolysis pathway of deoxynivalenol (DON), DON (~50 mg/L) in acetonitrile solution was treated by ozone at a concentration of 10.84 g/m3 and a flow rate of 80 mL/min for the times ranging from 0 to 9 min. The results showed that DON concentration rapidly reduced from 51.11 mg/L to 14.97 mg/L within 9 min of ozone exposure with 98.30% of degradation rate, and the ozonolysis of DON followed the first-order kinetic model. Four ozonolysis products of DON were identified based on the analysis of Liquid chromatography–quadrupole time-of-flight mass spectra (LC-QTOF/MS). Their structures were similar to that of DON, while the double bond at C9–C10, 12,13-epoxide ring, and the hydroxyl group at C3 or C7 of DON were all destroyed by ozone. It is deduced that the toxicity of ozonolysis products significantly reduced based on the relationship between structure and toxicity of DON. The ozonolysis pathway of DON followed the Criegee reaction mechanism of ozone according to the chemical structures, accurate mass and molecular formulas of these products.