Global occurrence of deoxynivalenol in food commodities and exposure risk assessment in humans in the last decade: a survey

Smartphone-enabled colorimetric immunoassay for deoxynivalenol based on Mn2+-mediated aggregation of AuNPs

Deoxynivalenol (DON) is a common mycotoxin in food that mainly pollutes grain crops and feeds, such as barley, wheat and corn. DON has caused widespread concern in the field of food and feed safety. In this study, a colorimetric immunoassay was proposed based on the aggregation of gold nanoparticles (AuNPs) due to the decomposition of Mn2+ from gold-coated manganese dioxide (AuNP@MnO2) nanosheets. In this study, 2-(dihydrogen phosphate)-l-ascorbic acid (AAP) was hydrolyzed by alkaline phosphatase (ALP) and converted to ascorbic acid (AA). Then, AuNP@MnO2 was reduced to Mn2+ and AuNPs aggregation occurred. Using the unique optical characteristics of AuNPs and AuNP@MnO2, visible color changes realized simple detection of DON with high sensitivity and portability. With increasing DON content, the color changed more obviously. To quantitatively detect DON, pictures can be taken and the blue value can be read by a smartphone. The detection limit (Ic10) of this method was 0.098 ng mL-1, which was 326 times higher than that of traditional competitive ELISA, and the detection range was 0.177-6.073 ng mL-1. This method exhibited high specificity with no cross-reaction in other structural analogs. The average recovery rate of DON in corn flour samples was 89.1 %-110.2 %, demonstrating the high accuracy and stability of this assay in actual sample detection. Therefore, the colorimetric immunoassay can be used for DON-related food safety monitoring.

Deoxynivalenol triggers mitotic catastrophe and apoptosis in C2C12 myoblasts

Deoxynivalenol (DON), commonly known as vomitoxin, is a mycotoxin produced by fungi and is frequently found as a contaminant in various cereal-based food worldwide. While the harmful effects of DON have been extensively studied in different tissues, its specific impact on the proliferation of skeletal muscle cells remains unclear. In this study, we utilized murine C2C12 myoblasts as a model to explore the influence of DON on their proliferation. Our observations indicated that DON exhibits dose-dependent toxicity, significantly inhibiting the proliferation of C2C12 cells. Through the application of RNA-seq analysis combined with gene set enrichment analysis, we identified a noteworthy downregulation of genes linked to the extracellular matrix (ECM) and condensed chromosome. Concurrently with the reduced expression of ECM genes, immunostaining analysis revealed notable changes in the distribution of fibronectin, a vital ECM component, condensing into clusters and punctate formations. Remarkably, the exposure to DON induced the formation of multipolar spindles, leading to the disruption of the normal cell cycle. This, in turn, activated the p53-p21 signaling pathway and ultimately resulted in apoptosis. These findings contribute significant insights into the mechanisms through which DON induces toxicity within skeletal muscle cells.

Estrogenic, androgenic, and genotoxic activities of zearalenone and deoxynivalenol in in vitro bioassays including exogenous metabolic activation

Zearalenone (ZEN) and deoxynivalenol (DON) and their derivatives are well-known mycotoxins, which can occur not only in crops but also in water bodies, including drinking water sources. In vitro bioassays can be used to detect biological effects of hazardous compounds in water. To this, when studying biological effects and toxicity in vitro, metabolism is important to consider. In this study, ZEN, α-zearalenol (α-ZEL), DON, 3-acetyl DON, and 15-acetyl DON were evaluated in vitro for hormone receptor-mediated effects (estrogen receptor [ER] and androgen receptor [AR]) and genotoxicity (micronucleus assay) in the presence of an exogenous metabolic activation system (MAS). The ER bioassay proved to be a highly sensitive method to detect low concentrations of the ZEN compounds (EC10 values of 31.4 pM for ZEN, 3.59 pM for α-ZEL) in aqueous solutions. In the presence of the MAS, reduced estrogenic effects were observed for both ZEN compounds (EC10 values of 6.47 × 103 pM for ZEN, 1.55 × 102 pM for α-ZEL). Of the DON compounds, only 3-acetyl DON was estrogenic (EC10 of 0.31 µM), and the effect was removed in the presence of the MAS. Anti-androgenic effects of the ZEN compounds and androgenic effects of the DON compounds were detected in the micromolar range. No induction of genotoxicity was detected for ZEN or DON in the presence of the MAS. Our study highlighted that inclusion of exogenous MAS is a useful tool to detect biological effects of metabolites in in vitro bioassays.

Deoxynivalenol Induces Drp-1-Mediated Mitochondrial Dysfunction via Elevating Oxidative Stress

Mitochondrial dysfunction is often linked to neurotoxicity and neurological diseases and stems from oxidative stress, yet effective therapies are lacking. Deoxynivalenol (DON or vomitoxin) is one of the most common and hazardous type-B trichothecene mycotoxins, which contaminates crops used for food and animal feed. Despite the abundance of preliminary reports, comprehensive investigations are scarce to explore the relationship between these fungal metabolites and neurodegenerative disorders. The present study aimed to elucidate the precise role of DON in mitochondrial dynamics and cell death in neuronal cells. Excessive mitochondrial fission is associated with the pathology of several neurodegenerative diseases. Human SH-SY5Y cells were treated with different concentrations of DON (250-1000 ng/mL). Post 24 and 48 h DON treatment, the indexes were measured as follows: generation of reactive oxygen species (ROS), ATP levels, mitochondrial membrane potential, calcium levels, and cytotoxicity in SH-SY5Y cells. The results showed that cytotoxicity, intracellular calcium levels, and ROS in the DON-treated group increased, while the ATP levels and mitochondrial membrane potential decreased in a dose-dependent manner. With increasing DON concentrations, the expression levels of P-Drp-1, mitochondrial fission proteins Mff, and Fis-1 were elevated with reduced activities of MFN1, MFN2, and OPA1, further resulting in an increased expression of autophagic marker LC3 and beclin-1. The reciprocal relationship between mitochondrial damage and ROS generation is evident as ROS can instigate structural and functional deficiencies within the mitochondria. Consequently, the impaired mitochondria facilitate the release of ROS, thereby intensifying the cycle of damage and exacerbating the overall process. Using specific hydroxyl, superoxide inhibitors, and calcium chelators, our study confirmed that ROS and Ca2+-mediated signaling pathways played essential roles in DON-induced Drp1 phosphorylation. Therefore, ROS and mitochondrial fission inhibitors could provide critical research tools for drug development in mycotoxin-induced neurodegenerative diseases.

Comparative transcriptome analysis of Fusarium graminearum challenged with distinct fungicides and functional analysis of FgICL gene

Fusarium graminearum is an economically important phytopathogenic fungus. Chemical control remains the dominant approach to managing this plant pathogen. In the present study, we performed a comparative transcriptome analysis to understand the effects of four commercially used fungicides on F. graminearum. The results revealed a significant number of differentially expressed genes related to carbohydrate, amino acid, and lipid metabolism, particularly in the carbendazim and phenamacril groups. Central carbon pathways, including the TCA and glyoxylate cycles, were found to play crucial roles across all treatments except tebuconazole. Weighted gene co-expression network analysis reinforced the pivotal role of central carbon pathways based on identified hub genes. Additionally, critical candidates associated with ATP-binding cassette transporters, heat shock proteins, and chitin synthases were identified. The crucial functions of the isocitrate lyase in F. graminearum were also validated. Overall, the study provided comprehensive insights into the mechanisms of how F. graminearum responds to fungicide stress.

Are Infants and Children at Risk of Adverse Health Effects from Dietary Deoxynivalenol Exposure? An Integrative Review

Deoxynivalenol (DON) is a foodborne mycotoxin produced by Fusarium molds that commonly infect cereal grains. It is a potent protein synthesis inhibitor that can significantly impact humans' gastrointestinal, immune, and nervous systems and can alter the microbiome landscape. Low-dose, chronic exposure to DON has been found to stimulate the immune system, inhibit protein synthesis, and cause appetite suppression, potentially leading to growth failure in children. At higher doses, DON has been shown to cause immune suppression, nausea, vomiting, abdominal pain, headache, diarrhea, gastroenteritis, the malabsorption of nutrients, intestinal hemorrhaging, dizziness, and fever. A provisional maximum tolerable daily intake (PMTDI) limit of 1 µg/kg/body weight has been established to protect humans, underscoring the potential health risks associated with DON intake. While the adverse effects of dietary DON exposure have been established, healthcare communities have not adequately investigated or addressed this threat to child health, possibly due to the assumption that current regulatory exposure limits protect the public appropriately. This integrative review investigated whether current dietary DON exposure rates in infants and children regularly exceed PMTDI limits, placing them at risk of negative health effects. On a global scale, the routine contamination of cereal grains, bakery products, pasta, and human milk with DON could lead to intake levels above PMTDI limits. Furthermore, evidence suggests that other food commodities, such as soy, coffee, tea, dried spices, nuts, certain seed oils, animal milk, and various water reservoirs, can be intermittently contaminated, further amplifying the scope of the issue. Better mitigation strategies and global measures are needed to safeguard vulnerable youth from this harmful toxicant.

Recent advances and challenges in the analysis of natural toxins

Natural toxins (NTs) are poisonous secondary metabolites produced by living organisms developed to ward off predators. Especially low molecular weight NTs (MW<∼1 kDa), such as mycotoxins, phycotoxins, and plant toxins, are considered an important and growing food safety concern. Therefore, accurate risk assessment of food and feed for the presence of NTs is crucial. Currently, the analysis of NTs is predominantly performed with targeted high pressure liquid chromatography tandem mass spectrometry (HPLC-MS/MS) methods. Although these methods are highly sensitive and accurate, they are relatively expensive and time-consuming, while unknown or unexpected NTs will be missed. To overcome this, novel on-site screening methods and non-targeted HPLC high resolution mass spectrometry (HRMS) methods have been developed. On-site screening methods can give non-specialists the possibility for broad "scanning" of potential geographical regions of interest, while also providing sensitive and specific analysis at the point-of-need. Non-targeted chromatography-HRMS methods can detect unexpected as well as unknown NTs and their metabolites in a lab-based approach. The aim of this chapter is to provide an insight in the recent advances, challenges, and perspectives in the field of NTs analysis both from the on-site and the laboratory perspective.

Nutrition strategies to control post-weaning diarrhea of piglets: From the perspective of feeds

Post-weaning diarrhea (PWD) is a globally significant threat to the swine industry. Historically, antibiotics as well as high doses of zinc oxide and copper sulfate have been commonly used to control PWD. However, the development of bacterial resistance and environmental pollution have created an interest in alternative strategies. In recent years, the research surrounding these alternative strategies and the mechanisms of piglet diarrhea has been continually updated. Mechanically, diarrhea in piglets is a result of an imbalance in intestinal fluid and electrolyte absorption and secretion. In general, enterotoxigenic Escherichia coli (ETEC) and diarrheal viruses are known to cause an imbalance in the absorption and secretion of intestinal fluids and electrolytes in piglets, resulting in diarrhea when Cl- secretion-driven fluid secretion surpasses absorptive capacity. From a perspective of feedstuffs, factors that contribute to imbalances in fluid absorption and secretion in the intestines of weaned piglets include high levels of crude protein (CP), stimulation by certain antigenic proteins, high acid-binding capacity (ABC), and contamination with deoxynivalenol (DON) in the diet. In response, efforts to reduce CP levels in diets, select feedstuffs with lower ABC values, and process feedstuffs using physical, chemical, and biological approaches are important strategies for alleviating PWD in piglets. Additionally, the diet supplementation with additives such as vitamins and natural products can also play a role in reducing the diarrhea incidence in weaned piglets. Here, we examine the mechanisms of absorption and secretion of intestinal fluids and electrolytes in piglets, summarize nutritional strategies to control PWD in piglets from the perspective of feeds, and provide new insights towards future research directions.

Studies of Mycotoxins in Medicinal Plants Conducted Worldwide over the Last Decade: A Systematic Review, Meta-Analysis, and Exposure Risk Assessment

BACKGROUND

Mycotoxins have been reported to be present in medicinal plants. With the growing usage of medicinal plants, contamination of mycotoxins has emerged as one of the biggest threats to global food hygiene and ecological environment, posing a severe threat to human health.

PURPOSE

This study aimed to determine the mycotoxin prevalence and levels in medicinal plants and conduct a risk assessment by conducting a systematic review and meta-analysis.

METHODS

A thorough search on Web of Science and PubMed was conducted for the last decade, resulting in 54 studies (meeting the inclusion criteria) with 2829 data items that were included in the meta-analysis.

RESULTS

The combined prevalence of mycotoxins in medicinal plants was 1.7% (95% confidence interval, CI = 1.1% - 2.4%), with a mean mycotoxin concentration in medicinal plants of 3.551 µg/kg (95% CI = 3.461 - 3.641 µg/kg). Risk assessment results indicated that aflatoxins and ochratoxin A found in several medicinal plants posed a health risk to humans; additionally, emerging enniatins exhibited possible health risks.

CONCLUSION

Therefore, the study underlines the need for establishing stringent control measures to reduce the severity of mycotoxin contamination in medicinal plants.

Deoxynivalenol Detoxification by a Novel Strain of Pichia kudriavzevii via Enzymatic Degradation and Cell Wall Adsorption

Deoxynivalenol (DON) is a mycotoxin that significantly threatens the food and feed industry. Corn steep liquor (CSL) is an acidic byproduct of the corn starch industry, and DON is concentrated in CSL once the material is contaminated. In this work, a Pichia kudriavzevii strain that could remove DON from CSL was isolated and characterized. The strain P. kudriavzevii E4-205 showed detoxifying activity in a pH range of 4.0~7.0 and temperature of 25~42 °C, and 39.4% DON was reduced by incubating this strain in CSL supernatant diluted by 2-fold (5 μg/mL DON) for 48 h at pH 5.0 and 30 °C. Further mechanism studies showed that P. kudriavzevii E4-205 could adsorb DON by the cell wall and degrade DON by intracellular enzymes with NADH as a cofactor. The degradation product was identified as 3,7,8,15-tetrahydroxyscirpene by liquid chromatography-tandem mass spectrometry. DON adsorption by inactivated cells was characterized, and the adsorption followed pseudo first-order kinetics. This study revealed a novel mechanism by which microbes degrade DON and might serve as a guide for the development of DON biological detoxification methods.

A novel core-shell up-conversion nanoparticles immunochromatographic assay for the detection of deoxynivalenol in cereals

Deoxynivalenol (DON) toxin is a type B group of trichothecene mycotoxins mainly originating from specific Fusarium fungi, seriously harming human and livestock health. Herein, a novel core-shell up-conversion nanoparticles immunochromatographic assay (CS-UCNPs-ICA) was developed for deoxynivalenol based on the competitive reaction principle. By exploiting the fluorescence intensity of the T and C lines of CS-UCNPs-ICA, the concentrations of DON were obtained sensitively and precisely under optimized conditions in 5 min with a detection limit of 0.1 ng/mL. The CS-UCNPs-ICA strips only specifically detect DON and its derivatives (3-Ac-DON and 15-Ac-DON), with no cross-reaction with other mycotoxins. The low CV values illustrated a modest intra- and inter-assay variation, confirming the superior precision of this method. In the spiked experiment, the mean recoveries of corn and wheat ranged from 94.74% to 100.90% and 96.21%-104.81%, respectively. Furthermore, the approach generated results that were in good agreement with data from HPLC and ELISA analyses of naturally contaminated feed and cereals, confirming that the significant advantages of proposed strips were their high practicality, rapidness, and simplicity. Therefore, the CS-UCNPs-ICA strips platform serves as a promising candidate for developing new approaches for rapid testing or high throughput screening from DON in food products.

Utilization of a Novel Soil-Isolated Strain Devosia insulae FS10-7 for Deoxynivalenol Degradation and Biocontrol of Fusarium Crown Rot in Wheat

Deoxynivalenol (DON) is the most widespread mycotoxin contaminant hazardous to human and animal health globally. It acts as a crucial virulence factor to stimulate the spread of pathogenic Fusarium within wheat plants. Control of DON and Fusarium disease contributes enormously to food safety, which relies on chemical fungicides. Here, we report the biodegradation of DON using a novel soil bacterium, Devosia insulae FS10-7, and its biocontrol effect against Fusarium crown rot. We demonstrated that strain FS10-7 degraded DON to 3-epi-DON by forming a 3-keto-DON intermediate. Such degradation activity can be maintained at a wide range of pH (4 to 10) and temperature (16 to 42°C) values under aerobic conditions. Notably, strain FS10-7 exhibited practical inhibitory effects on Fusarium crown rot disease caused by F. graminearum and F. pseudograminearum in the in vitro Petri dish test under laboratory conditions and the pot experiment under greenhouse conditions. The mechanisms underlying the biocontrol ability of strain FS10-7 were preliminarily investigated to be associated with its high DON-degrading activity rather than direct antagonism. These results establish the foundation to develop further bioagents capable of biodegrading mycotoxins in cereals and derived products and, accordingly, biocontrol plant diseases caused by DON-producing pathogens.

Low-dose deoxynivalenol exposure inhibits hepatic mitophagy and hesperidin reverses this phenomenon by activating SIRT1

Deoxynivalenol (DON) is by far the most common mycotoxin contaminating cereal foods and feeds. Furthermore, cleaning up DON from contaminated cereal items is challenging. Low-dose DON consumption poses a danger to humans and agricultural animals. The benefits of hesperidin (HDN) include liver protection, anti-oxidative stress, nontoxicity, and a broad range of sources. The study used immunoblotting, immunofluorescence, and transmission electron microscopy to identify factors associated with mitophagy in vitro and in vivo. We demonstrated that low-dose DON exposure inhibited mitophagy in the liver tissue of mice. SIRT1 was a crucial regulator of mitophagy. Moreover, DON stimulated the dephosphorylation of SIRT1 and the acetylation-regulated FOXO3 protein, which resulted in the transcriptional inhibition of FOXO3-driven BNIP3 and compromised the stability of the PINK1 protein mediated by BNIP3. Moreover, HDN's effect was comparable to that of a SIRT1 agonist, which led to a significant decrease in the level of mitophagy inhibition caused by low-dose DON exposure. When combined, these findings suggested that HDN might be a useful treatment approach for liver damage brought on by low-dose DON exposure. Above all, this research will offer fresh perspectives on a viable approach that will encourage further research into risk reduction initiatives for low-dose DON exposure.

Deoxynivalenol and T-2 toxin cause liver damage and egg quality degradation through endoplasmic reticulum stress in summer laying hens

The present study aimed to find whether low doses of mixed mycotoxins would affect egg quality in laying hens, and to explore the oxidative stress induced liver damage through endoplasmic reticulum during summer stress. A total of 96 Jinghong laying hens, 36 wks of age, were divided into four treatments, with eight repetitions per treatment and three hens per repetition. All the hens were raised in summer (average temperature: 31.3 ± 0.5℃; average humidity: 85.5 ± 0.2%) for 28d. One treatment was fed a basal diet as control (CON), and the other three treatments were fed the same diets containing 3.0 mg/kg deoxynivalenol (DON), 0.5 mg/kg T-2 toxin (T-2), and 1.5 mg/kg DON + 0.25 mg/kg T-2 toxin (Mix). Albumen height and Haugh unit were decreased (P < 0.05) in the Mix group on day 14 and 28. The activity of total antioxidant capacity, glutathione peroxidase, catalase, and superoxide dismutase were decreased (P < 0.05) in the DON, T-2, and Mix groups. The alkaline phosphatase level in DON, T-2, and Mix groups was significantly increased (P < 0.05). The level of interleukin-1β, interferon-γ, and tumor necrosis factor-α in the Mix group were higher (P < 0.05) than CON, DON, and T-2 groups. Mix group upregulated the mRNA expressions of protein kinase RNA-like ER kinase, activating transcription factor4, IL-1β, nuclear factor-κ-gene binding, and nuclear respiratory factor 2 in the liver (P < 0.05). The results showed that low doses of DON and T-2 toxin could cause oxidative stress in the liver, but DON and T-2 toxin have a cumulative effect on virulence, which can reduce egg quality and cause endoplasmic reticulum stress in the liver.

Agaro-oligosaccharides mitigate deoxynivalenol-induced intestinal inflammation by regulating gut microbiota and enhancing intestinal barrier function in mice

Agarose-derived agaro-oligosaccharides (AgaroS) have been extensively studied in terms of structures and bioactivities; they reportedly possess antioxidant and anti-inflammatory activities that maintain intestinal homeostasis and host health. However, the protective effects of AgaroS on deoxynivalenol (DON)-induced intestinal dysfunction remain unclear. We investigated the effects of AgaroS on DON-induced intestinal dysfunction in mice and explored the underlying protective mechanisms. In total, 32 mice were randomly allocated to four treatments (n = 8 each) for 28 days. From day 1 to day 21, the control (CON) and DON groups received oral phosphate-buffered saline (200 μL per day); the AgaroS and AgaroS + DON groups received 200 mg AgaroS per kg body weight once daily by orogastric gavage. Experimental intestinal injury was induced by adding DON (4.8 mg per kg body weight) via gavage from day 21 to day 28. Phosphate-buffered saline was administered once daily by gavage in the CON and AgaroS groups. Herein, AgaroS supplementation led to a higher final body weight and smaller body weight loss and a lower concentration of plasma inflammatory cytokines, compared with the DON group. The DON group showed a significantly reduced ileal villus height and villus height/crypt depth, compared with the CON and AgaroS + DON groups. However, AgaroS supplementation improved DON-induced intestinal injury in mice. Compared with the DON group, ileal and colonic protein expression levels of claudin, occludin, Ki67, and mucin2 were significantly higher in the AgaroS supplementation group. Colonic levels of the anti-inflammatory cytokine IL-1β tended to be higher in the DON group than in the AgaroS + DON group. AgaroS altered the gut microbiota composition, accompanied by increased production of short-chain fatty acids in mice. In conclusion, our findings highlight a promising anti-mycotoxin approach whereby AgaroS alleviate DON-induced intestinal inflammation by modulating intestinal barrier functional integrity and gut microbiota in mice.

Novel mechanism by which extracellular vesicles derived from Lactobacillus murinus alleviates deoxynivalenol-induced intestinal barrier disruption

Deoxynivalenol (DON) is a common environmental pollutant that poses a serious health risk to humans worldwide. This study was aim to explore whether gut microbiota is involved in DON-induced intestinal toxicity as well as to reveal effect of probiotics derived from gut microbiota in protecting intestinal barrier and to elucidate mechanism. We found that DON caused disturbed gut microbiota, particularly Lactobacillus murinus (L. murinus) deficiency. DON enhanced M1 macrophage polarization and decreased tight junction protein expression. Microbiota transplantation experiments showed that transfer of DON-disrupted microbiota to healthy mice resulted in delivery of DON-induced intestinal toxicity. Besides, DON lost its damaging effect on macrophage and intestinal barrier in antibiotic-treated mice. Further intervention experiments revealed that L. murinus induce macrophage conversion from M1 to M2 phenotype through secreted extracellular vesicles (EVs) to alleviate DON-induced intestinal barrier disruption. Mechanistically, EVs activate TLR2 to promote M2 macrophage polarization and release IL-10, which in turn enhances intestinal barrier function. Upon successful translation of its efficacy into clinical practice, EVs created from L. murinus could be a novel possible treatment strategy for DON-induced gut disease.

Self-cascade deoxynivalenol detoxification by an artificial enzyme with bifunctions of dehydrogenase and aldo/keto reductase from genome mining

Due to the severe health risks for human and animal caused by the intake of toxic deoxynivalenol (DON) derived from Fusarium species, elimination DON in food and feed has been initiated as a critical issue. Enzymatic cascade catalysis by dehydrogenase and aldo-keto reductase represents a fascinating strategy for DON detoxification. Here, one quinone-dpendent alcohol dehydrogenase DADH oxidized DON into less-toxic 3-keto-DON and NADPH-dependent aldo-keto reductase AKR13B3 reduced 3-keto-DON into relatively non-toxic 3-epi-DON were identified from Devosia strain A6-243, indicating that degradation of DON on C3 are two-step sequential cascade processes. To establish the bifunctions, fusion enzyme linking DADH and AKR13B3 was successfully assembled to promote one-step DON degradations with accelerated specific activity and efficiency, resulting 93.29 % of DON removal rate in wheat sample. Three-dimensional simulation analysis revealed that the bifunctional enzyme forms an artificial intramolecular channel to minimize the distance of intermediate from DADH to AKR13B3 for two-step enzymatic reactions, and thereby accelerates this enzymatic process. As the first report of directing single step DON detoxification by an interesting bifunctional artificial enzyme, this work revealed a facile and eco-friendly approach to detoxify DON with application potential and gave valuable insights into execute other mycotoxin detoxification for ensuring food safety.

Mitochondria-Associated Protein FgNdk1 Regulates the Development, Pathogenicity, and SDHI Fungicide Sensitivity of Fusarium graminearum by Interacting with Succinate Dehydrogenase

Nucleoside diphosphate kinase (NDK) plays an important role in many cellular processes in all organisms. In this study, we functionally characterized a nucleoside diphosphate kinase (FgNdk1) in Fusarium graminearum, a causal agent of Fusarium head blight (FHB). FgNdk1 was involved in the generation of energy in the electron-transfer chain by interacting with succinate dehydrogenase (FgSdhA, FgSdhC1, and FgSdhC2). Deletion of FgNdk1 not only resulted in abnormal mitochondrial morphology, decreased ATP content, defective fungal development, and impairment in the formation of the toxisome but also led to the suppressed expression level of DON biosynthesis enzymes, decreased DON biosynthesis, and declined pathogenicity as well. Furthermore, deletion of FgNdk1 caused increasing transcriptional levels of FgSdhC1 and FgdhC2, in the presence of pydiflumetofen, related to the decreased sensitivity to SDHI fungicides. Overall, this study identified a new regulatory mechanism of FgNdk1 in the pathogenicity and SDHI fungicide sensitivity of Fusarium graminearum.

Complementary transcriptomic and proteomic analyses elucidate the toxicological molecular mechanisms of deoxynivalenol-induced contractile dysfunction in enteric smooth muscle cells

Deoxynivalenol (DON) is one of the frequent Fusarium mycotoxins and poses a serious threat to public health worldwide. DON-induced weight loss is tightly connected with its ability to decrease feed intake by influencing gastrointestinal tract (GIT) motility. Our previous reports indicated that DON interfered with intestinal motility by injuring the contractility of enteric smooth muscle cells (SMC). Here, we further explored the potential mechanisms by employing a complementary method of transcriptomics and proteomics using the porcine enteric smooth muscle cell line (PISMC) as an experimental model. The transcriptomic and proteomic data uncover that the expression of numerous extracellular matrix (ECM) proteins and multiple integrin subunits were downregulated in PISMC under DON exposure, suppressing the ECM-integrin receptor interaction and its mediated signaling. Furthermore, DON treatment could depress actin polymerization, as reflected by the upregulated expression of Rho GTPase-activating proteins and cofilin in PISMC. Meanwhile, the expression levels of downstream contractile apparatus genes were significantly inhibited after challenge with DON. Taken together, the current results suggest that DON inhibits enteric SMC contractility by regulating the ECM-integrin-actin polymerization signaling pathway. Our findings provide novel insights into the potential mechanisms behind the DON toxicological effects in the GIT of humans and animals.

Degradation of deoxynivalenol by a microbial consortia C1 from duck intestine

Deoxynivalenol (DON), one of the most widespread mycotoxins in food and feed, poses a persistent health threat to humans and farm animals, and is difficult to eliminate. The utilization of the biotransformation mechanism by microorganisms to detoxify DON is a promising strategy. Although individual strains are capable of DON degradation, their isolation and purification are challenging and time-consuming. Recently, the microbial consortia concept has been proposed, owing to their ability to perform more complex tasks and are more tolerant to environmental changes than individual strains or species. In this study, the novel microbial consortia C1 that could efficiently convert DON to de-epoxy DON (DOM-1) was screened from the cecum contents of ducks. After 24 h anaerobic incubation, 100 μg/ml DON was completely degraded by C1. In vitro, C1 can effectively degrade DON in corn steep liquor (CSL) with an efficiency of 49.44% within 14 days. Furthermore, C1 effectively alleviated the DON poisoning in mice. After C1 treatment, the serum DON level decreased by 40.39%, and the reduction in serum total protein and albumin levels were mitigated. Additionally, C1 is effective in protecting the mouse liver against 5 mg/kg DON. These findings suggest that C1 could be a promising DON biological detoxifier and provide novel microbial resources for preventing DON contamination.

Cytotoxic Effects of Major and Emerging Mycotoxins on HepaRG Cells and Transcriptomic Response after Exposure of Spheroids to Enniatins B and B1

Mycotoxins, produced by fungi, frequently occur at different stages in the food supply chain between pre- and postharvest. Globally produced cereal crops are known to be highly susceptible to contamination, thus constituting a major public health concern. Among the encountered mycotoxigenic fungi in cereals, Fusarium spp. are the most frequent and produce both regulated (i.e., T-2 toxin, deoxynivalenol -DON-, zearalenone -ZEA-) and emerging (i.e., enniatins -ENNs-, beauvericin -BEA-) mycotoxins. In this study, we investigated the in vitro cytotoxic effects of regulated and emerging fusariotoxins on HepaRG cells in 2D and 3D models using undifferentiated and differentiated cells. We also studied the impact of ENN B1 and ENN B exposure on gene expression of HepaRG spheroids. Gene expression profiling pinpointed the differentially expressed genes (DEGs) and overall similar pathways were involved in responses to mycotoxin exposure. Complement cascades, metabolism, steroid hormones, bile secretion, and cholesterol pathways were all negatively impacted by both ENNs. For cholesterol biosynthesis, 23/27 genes were significantly down-regulated and could be correlated to a 30% reduction in cholesterol levels. Our results show the impact of ENNs on the cholesterol biosynthesis pathway for the first time. This finding suggests a potential negative effect on human health due to the essential role this pathway plays.

Maintaining the Mitochondrial Quality Control System Was a Key Event of Tanshinone IIA against Deoxynivalenol-Induced Intestinal Toxicity

Deoxynivalenol (DON) is the one of the most common mycotoxins, widely detected in various original foods and processed foods. Tanshinone IIA (Tan IIA) is a fat-soluble diterpene quinone extracted from Salvia miltiorrhiza Bunge, which has multi-biological functions and pharmacological effects. However, whether Tan IIA has a protective effect against DON-induced intestinal toxicity is unknown. In this study, the results showed Tan IIA treatment could attenuate DON-induced IPEC-J2 cell death. DON increased oxidation product accumulation, decreased antioxidant ability and disrupted barrier function, while Tan IIA reversed DON-induced barrier function impairment and oxidative stress. Furthermore, Tan IIA dramatically improved mitochondrial function via mitochondrial quality control. Tan IIA could upregulate mitochondrial biogenesis and mitochondrial fusion as well as downregulate mitochondrial fission and mitochondrial unfolded protein response. In addition, Tan IIA significantly attenuated mitophagy caused by DON. Collectively, Tan IIA presented a potential protective effect against DON toxicity and the underlying mechanisms were involved in mitochondrial quality control-mediated mitophagy.

ZIF-8 labelled a new electrochemical aptasensor based on PEI-PrGO/AuNWs for DON detection

In this work, a novel ultrasensitive aptasensor for deoxynivalenol (DON) detection based on the polyethyleneimine-functionalised porous reduced graphene oxide loaded gold nanowires (PEI-PrGO/AuNWs) and methylene blue (MB)-labelled zeolitic imidazolate framework-8 (ZIF-8) signal amplification strategy was proposed. PEI-PrGO/AuNWs with large surface area and excellent conductivity were used as modification materials on bare gold electrodes, which could increase the combining of complementary strand (cDNA) on the electrode substrate and accelerate the electron transfer efficiency. Furthermore, a novel electrochemical signal probe was synthesized using streptavidin-modified zeolitic imidazolate framework-8 (ZIF-8/SA) as a carrier loaded with MB and reverse complementary chain (sDNA). In the presence of DON, the signal probe was introduced to the electrode surface by Watson-Crick base pairing after specific binding of DON to the aptamer (Apt). As expected, under the optimal conditions, the DON concentration was linearly related to the peak current generated by the prepared aptasensor, and the measured data were combined with theoretical calculations to obtain a detection limit of 2.23 × 10-9 mg/mL.

Structure-Guided Steric Hindrance Engineering of Devosia Strain A6-243 Quinone-Dependent Dehydrogenase to Enhance Its Catalytic Efficiency

Deoxynivalenol (DON), the most widely distributed mycotoxin worldwide, causes severe health risks for humans and animals. Quinone-dependent dehydrogenase derived from Devosia strain A6-243 (DADH) can degrade DON into less toxic 3-keto-DON and then aldo-keto reductase AKR13B3 can reduce 3-keto-DON into relatively nontoxic 3-epi-DON. However, the poor catalytic efficiency of DADH made it unsuitable for practical applications, and it has become the rate-limiting step of the two-step enzymatic cascade catalysis. Here, structure-guided steric hindrance engineering was employed to enhance the catalytic efficiency of DADH. After the steric hindrance engineering, the best mutant, V429G/N431V/T432V/L434V/F537A (M5-1), showed an 18.17-fold increase in specific activity and an 11.04-fold increase in catalytic efficiency (kcat/Km) compared with that of wild-type DADH. Structure-based computational analysis provided information on the increased catalytic efficiency in the directions that attenuated steric hindrance, which was attributed to the reshaped substrate-binding pocket with an expanded catalytic binding cavity and a favorable attack distance. Tunnel analysis suggested that reshaping the active cavity by mutation might alter the shape and size of the enzyme tunnels or form one new enzyme tunnel, which might contribute to the improved catalytic efficiency of M5-1. These findings provide a promising strategy to enhance the catalytic efficiency by steric hindrance engineering.

Metabolomics study reveals increased deoxycholic acid contributes to deoxynivalenol-mediated intestinal barrier injury

AIMS

Deoxynivalenol (DON), namely vomitoxin, is one of the most prevalent fungal toxins in cereal crops worldwide. However, the underlying toxic mechanisms of DON remain largely unknown.

MAIN METHODS

DON exposure-caused changes in the murine plasma metabolome and gut microbiome were investigated by an LC-MS/MS-based nontargeted metabolomics approach and sequencing of 16S rRNA in fecal samples, respectively. Cellular models were then used to validate the findings from the metabolomics study.

KEY FINDINGS

DON exposure increased intestinal barrier permeability evidenced by its-mediated decrease in colonic Claudin 5 and E-cadherin, as well as increases in colonic Ifn-γ, Cxcl9, Cxcl10, and Cxcr3. Furthermore, DON exposure resulted in a significant increase in murine plasma levels of deoxycholic acid (DCA). Also, DON exposure led to gut microbiota dysbiosis, which was associated with DON exposure-caused increase in plasma DCA. In addition, we found not only DON but also DCA dose-dependently caused a significant increase in the levels of IFN-γ, CXCL9, CXCL10, and/or CXCR3, as well as a significant decrease in the expression levels of Claudin 5 and/or E-cadherin in the human colonic epithelial cells (NCM460).

SIGNIFICANCE

DON-mediated increase in DCA contributes to DON-caused intestinal injury. DCA may be a potential therapeutic target for DON enterotoxicity.

Tanshinone IIA protects intestinal epithelial cells from deoxynivalenol-induced pyroptosis

Deoxynivalenol (DON) is the most common mycotoxin in food and feed, which can cause undesirable effects, including diarrhea, emesis, weight loss, and growth delay in livestock. Intestinal epithelial cells were the main target of DON, which can cause oxidative stress and inflammatory injury. Tanshinone IIA (Tan IIA) is fat-soluble diterpene quinone, which is the most abundant active ingredient in salvia miltiorrhiza plant with antioxidant and anti-inflammatory characteristics. However, it is not clear whether Tan IIA can protect against or inhibit intestinal oxidative stress and inflammatory injury under DON exposure. This study aimed to explore the protective effect of Tan IIA on DON-induced toxicity in porcine jejunum epithelial cells (IPEC-J2). Cells were exposed to 0, 0.5, 1.0, 2.0 µM DON and/or 45 µg/mL TAN ⅡA to detect oxidative stress indicators. inflammatory cytokines, NF-κB expression, NLRP3 inflammasome and pyroptosis-related factors. In this study, DON exposure caused IPEC-J2 cells oxidative stress by elevating ROS and 8-OHdG content, inhibited GSH-Px activity. Furthermore, DON increased pro-inflammatory factor (TNF-α, IL-1β, IL-18 and IL-6) expression and decreased the anti-inflammatory factor (IL-10) expression, causing inflammatory response via triggering NF-κB pathway. Interestingly, above changes were alleviated after Tan IIA treatment. In addition, Tan IIA relieved DON-induced pyroptosis by suppressing the expression of pyroptosis-related factors (NLRP3, Caspase-1, GSDMD, IL-1β, and IL-18). In general, our data suggested that Tan IIA can ameliorate DON-induced intestinal epithelial cells injury associated with suppressing the pyroptosis signaling pathway. Our findings pointed that Tan IIA could be used as the potential therapeutic drugs on DON-induced enterotoxicity.

Combined exposure to deoxynivalenol facilitates lipid metabolism disorder in high-fat-diet-induced obesity mice

Deoxynivalenol (DON) is a trichothecene toxin that mainly produced by strains of Fusarium spp. DON contamination is widely distributed and is a global food safety threat. Existing studies have expounded its harmful effects on growth inhibition, endocrine disruption, immune function impairment, and reproductive toxicity. In energy metabolism, DON suppresses appetite, reduces body weight, triggers lipid oxidation, and negatively affects cholesterol and fatty acid homeostasis. In this study, high-fat diet (HFD) induced obese C57BL/6J mice were orally treated with 0.1 mg/kg bw/d and 1.0 mg/kg bw/d DON for 4 weeks. The lipid metabolism of mice and the molecular mechanisms were explored. The data showed that although DON reduced body weight and fat mass in HFD mice, it significantly increased their serum triglyceride concentrations, disturbance of serum lipid metabolites, impaired glucose, and resulted in insulin intolerance in mice. In addition, the transcriptional and expression changes of lipid metabolism genes in the liver and epididymis (EP) adipose indicate that the DON-mediated increase in serum triglycerides is caused by lipoprotein lipase (LPL) inhibition in EP adipose. Furthermore, DON down-regulates the expression of LPL through the PPARγ signaling pathway in EP adipose. These results are further confirmed by the serum lipidomics analysis. In conclusion, DON acts on the PPARγ pathway of white adipose to inhibit the expression of LPL, mediate the increase of serum triglyceride in obese mice, disturb the homeostasis of lipid metabolism, and increase the risk of cardiovascular disease. This study reveals the interference mechanism of DON on lipid metabolism in obese mice and provides a theoretical basis for its toxic effect in obese individuals.

Indoor metabolites and chemicals outperform microbiome in classifying childhood asthma and allergic rhinitis

Indoor microorganisms impact asthma and allergic rhinitis (AR), but the associated microbial taxa often vary extensively due to climate and geographical variations. To provide more consistent environmental assessments, new perspectives on microbial exposure for asthma and AR are needed. Home dust from 97 cases (32 asthma alone, 37 AR alone, 28 comorbidity) and 52 age- and gender-matched controls in Shanghai, China, were analyzed using high-throughput shotgun metagenomic sequencing and liquid chromatography-mass spectrometry. Homes of healthy children were enriched with environmental microbes, including Paracoccus, Pseudomonas, and Psychrobacter, and metabolites like keto acids, indoles, pyridines, and flavonoids (astragalin, hesperidin) (False Discovery Rate < 0.05). A neural network co-occurrence probability analysis revealed that environmental microorganisms were involved in producing these keto acids, indoles, and pyridines. Conversely, homes of diseased children were enriched with mycotoxins and synthetic chemicals, including herbicides, insecticides, and food/cosmetic additives. Using a random forest model, characteristic metabolites and microorganisms in Shanghai homes were used to classify high and low prevalence of asthma/AR in an independent dataset in Malaysian schools (N = 1290). Indoor metabolites achieved an average accuracy of 74.9% and 77.1% in differentiating schools with high and low prevalence of asthma and AR, respectively, whereas indoor microorganisms only achieved 51.0% and 59.5%, respectively. These results suggest that indoor metabolites and chemicals rather than indoor microbiome are potentially superior environmental indicators for childhood asthma and AR. This study extends the traditional risk assessment focusing on allergens or air pollutants in childhood asthma and AR, thereby revealing potential novel intervention strategies for these diseases.

Detoxification of mycotoxins in agricultural products by non-thermal physical technologies: a review of the past five years

Mycotoxins produced by Aspergillus spp., Penicillium spp. and Fusarium spp. with small molecular weight and thermal stability, are highly toxic and carcinogenic secondary metabolites. Mycotoxins have caused widespread concern regarding food safety internationally because of their adverse effects on the health of humans and animals, and the major economic losses they cause. There is an urgent need to find ways to reduce or eliminate the impact of mycotoxins in food and feed without introducing new safety issues, or reducing nutritional quality. Non-thermal physical technology is the basis for new techniques to degrade mycotoxins, with great potential for practical detoxification applications in the food industry. Compared with conventional thermal treatments, non-thermal physical detoxification technologies are easier to apply and effective, with less adverse impact on the nutritional value of agricultural products. The advantages, limitations and development prospects of these new detoxification technologies are discussed. Further studies are recommended to standardize the treatment conditions for each detoxification technology, evaluate the safety of the degradation products, and to combine different detoxification technologies to achieve synergistic effects. This will facilitate realization of the great potential of the new technologies and the development of practical applications.

Chronic oral exposure to low-concentration fumonisin B2 significantly exacerbates the inflammatory responses of allergies in mice via inhibition of IL-10 release by regulatory T cells in gut-associated lymphoid tissue

Contamination with fumonisins produced by Fusarium spp. is rapidly growing in both developing and developed countries. The purpose of this study was to determine whether oral exposure to fumonisin contributed to the development of allergic diseases. We initially examined the immunotoxic potential of short-term, oral administration of fumonisin B1 (FB1, 1 mg/kg) and fumonisin B2 (FB2, 1 mg/kg), both naturally occurring fumonisins, using a BALB/c mouse model of allergic contact dermatitis and Dermatophagoides farina-induced asthma. Using an NC/nga mouse model of atopic dermatitis (AD), we evaluated the adverse effects of subchronic oral exposure to low concentrations of FB2 (2 or 200 μg/kg). Finally, we explored the influence of FB2 on regulatory T cell proliferation and function in mesenteric lymph nodes after 1-week oral exposure to FB2 in BALB/c mice. Oral exposure to FB2 markedly exacerbated the symptoms of allergy, including skin thickness, histological evaluation, immunocyte proliferation, and proinflammatory cytokine production, although no change was observed following exposure to FB1. Furthermore, oral exposure to low concentrations of FB2 considerably exacerbated the AD scores, skin thickness, transepidermal water loss, histological features, and proinflammatory cytokine production. The aggravated allergic symptoms induced by oral exposure to FB2 could be attributed to the direct inhibition of IL-10 production by regulatory T cells in mesenteric lymph nodes. Our findings indicate that the recommended maximum fumonisin level should be reconsidered based on the potential for allergy development.

Identification of an Acinetobacter pittii acyltransferase involved in transformation of deoxynivalenol to 3-acetyl-deoxynivalenol by transcriptomic analysis

Deoxynivalenol (DON), a mycotoxin primarily produced by Fusarium graminearum (F. graminearum), is widely present in food and feed, posing great hazards to human and livestock health. In this study, a strain of Acinetobacter pittii (A. pittii) S12 capable of degrading DON was isolated from soil samples and identified through morphological characterization, biochemistry analysis, and 16 S rRNA gene sequencing. The results of HPLC-MS indicated that the degradation products underwent a conversion from [M-H]- to [M+CH3CO], with concomitant transformation of the hydroxyl group into an acetyl moiety. Based on transcriptome sequencing analysis, the acyltransferase encoded by DLK06_RS13370 was predicted to be the pivotal gene responsible for DON biotransformation. The result of molecular docking analysis suggest a high affinity between the enzyme and DON. The recombinant protein encoded by DLK06_RS13370 was expressed in Escherichia coli (E. coli) and demonstrated the capacity to catalyze the conversion of DON into 3-Acetyl-deoxynivalenol (3-ADON), as confirmed by HPLC analysis. In conclusion, our findings confirm that the acyltransferase encoded by DLK06-RS13370 is responsible for the acetylation of DON. This sheds light on the co-occurrence of DON and its acetyl-derivatives in wheat-based products. DATA AVAILABILITY: Not applicable.

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

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

Adverse associations between maternal deoxynivalenol exposure and birth outcomes: a prospective cohort study in China

BACKGROUND

Deoxynivalenol (DON), one of the most prevalent mycotoxins, has been found to cause fetal growth retardation in animals. However, limited evidence exists regarding its effects on pregnant women.

METHODS

Maternal urinary concentration of total DON (tDON) and free DON (fDON) in the second trimester was measured using liquid chromatography with tandem mass spectrometry. Provisional daily intake (PDI) of DON was calculated based on tDON concentration. Linear and logistic regression models were used to evaluate the association between DON exposure levels and birth weight, birth length, and the risk of small for gestational age (SGA).

RESULTS

Among 1538 subjects, the median concentrations of tDON and fDON were 12.1 ng/mL and 5.1 ng/mL, respectively. The PDI values revealed that the median DON intake was 0.7 µg/kg bw, and 35.9% of the total population exceeded the provisional maximum tolerable daily intake (PMTDI) of 1 µg/kg bw. Compared with the lowest tertile, birth weight decreased by 81.11 g (95% CI: -127.00, -35.23) for tDON (P-trend < 0.001) and 63.02 g (95% CI: -108.72, -17.32) for fDON (P-trend = 0.004) in the highest tertile. Each unit increase in Ln-tDON and Ln-fDON was also inversely associated with birth weight. Furthermore, compared to those who did not exceed PMTDI, pregnant women whose PDI exceeded PMTDI had lower birth weight (β = -79.79 g; 95% CI: -119.09, -40.49) and birth length (β = -0.21 cm; 95% CI: -0.34, -0.07), and a higher risk of SGA (OR = 1.48; 95% CI: 1.02, 2.15) in their offspring. Similar associations with birth weight, birth length, and SGA were found when comparing the highest tertile of PDI to the lowest tertile (all P-trend < 0.05).

CONCLUSIONS

Maternal DON exposure is related to decreased birth weight. Our findings implicate that DON exposure during pregnancy may cause fetal growth faltering, and measures should be taken to reduce DON exposure in pregnant women.

Zeolitic Imidazolate Framework-8 Composite-Based Enzyme-Linked Aptamer Assay for the Sensitive Detection of Deoxynivalenol

The mycotoxin deoxynivalenol (DON) is a prevalent contaminant in cereals that threatens the health of both humans and animals and causes economic losses due to crop contamination. The rapid and sensitive detection of DON is essential for food safety. Herein, a colorimetric biosensor based on horseradish peroxidase- and gold nanoparticle-encapsulated zeolitic imidazolate framework-8 (HRP&Au@ZIF-8) was developed for the sensitive screening of DON. The synthesized HRP&Au@ZIF-8 probes not only held great potential for signal amplification but also exhibited stable catalytic activity even under extreme conditions, which endowed the biosensor with both good sensitivity and stability. Under the optimized conditions, qualitative measurement of DON can be achieved through visual inspection, and quantitative evaluation can be performed via absorbance measurements at a characteristic wavelength of 450 nm. The proposed method has demonstrated high sensitivity with a linear detection range of 1-200 ng/mL and a detection limit of 0.5068 ng/mL. It also presented good selectivity and reliability. Furthermore, DON in spiked cereal samples has been quantified successfully using this method. This novel approach demonstrates significant potential for the facile and expeditious detection of DON in cereal products and brings us one step closer to enhancing food safety.

Biotransformation of Deoxynivalenol by a Dual-Member Bacterial Consortium Isolated from Tenebrio molitor Larval Feces

In this study, a dual-member bacterial consortium with the ability to oxidize deoxynivalenol (DON) to 3-keto-DON, designated SD, was first screened from the feces of Tenebrio molitor larvae. This consortium consisted of Pseudomonas sp. SD17-1 and Devosia sp. SD17-2, as determined by 16S rRNA-based phylogenetic analysis. A temperature of 30 °C, a pH of 8.0-9.0, and an initial inoculum concentration ratio of Devosia to Pseudomonas of 0.1 were optimal single-factor parameters for the DON oxidation activity of the bacterial consortium SD. Genome-based bioinformatics analysis revealed the presence of an intact PQQ biosynthesis operon (pqqFABCDEG) and four putative pyrroloquinoline quinone (PQQ)-dependent alcohol dehydrogenase (ADH) genes in the genomes of Pseudomonas strain SD17-1 and Devosia strain SD17-2, respectively. Biochemical analyses further confirmed the PQQ-producing phenotype of Pseudomonas and the DON-oxidizing enzymatic activities of two of four PQQ-dependent ADHs in Devosia. The addition of PQQ-containing a cell-free fermentation supernatant from Pseudomonas activated DON-oxidizing activity of Devosia. In summary, as members of the bacterial consortium SD, Pseudomonas and Devosia play indispensable and complementary roles in SD's oxidation of DON. Specifically, Pseudomonas is responsible for producing the necessary PQQ cofactor, whereas Devosia expresses the PQQ-dependent DON dehydrogenase, together facilitating the oxidation of DON.

Sodium Butyrate Ameliorates Deoxynivalenol-Induced Oxidative Stress and Inflammation in the Porcine Liver via NR4A2-Mediated Histone Acetylation

Mycotoxin-induced liver injury is often accompanied by oxidative stress (OS) and inflammation. This research aimed to explore the potential mechanism of sodium butyrate (NaBu) in modulating hepatic anti-oxidation and anti-inflammation pathways in deoxynivalenol (DON)-exposed piglets. The results show that DON induced liver injury, increased mononuclear cell infiltration, and decreased serum total protein and albumin concentrations. Transcriptomic analysis revealed that reactive oxygen species (ROS) and TNF-α pathways were highly activated upon DON exposure. This is associated with disturbed antioxidant enzymes and increased inflammatory cytokines secretion. Importantly, NaBu effectively reversed the alterations caused by DON. Mechanistically, the ChIP-seq result revealed that NaBu strongly depressed DON-increased enrichment of histone mark H3K27ac at the genes involved in ROS and TNF-α-mediated pathways. Notably, we demonstrated that nuclear receptor NR4A2 was activated by DON and remarkably recovered with the treatment of NaBu. In addition, the enhanced NR4A2 transcriptional binding enrichments at the promoter regions of OS and inflammatory genes were hindered by NaBu in DON-exposed livers. Consistently, elevated H3K9ac and H3K27ac occupancies were also observed at the NR4A2 binding regions. Taken together, our results indicated that a natural antimycotic additive, NaBu, could mitigate hepatic OS and inflammatory responses, possibly via NR4A2-mediated histone acetylation.

Mycotoxin deoxynivalenol-induced intestinal flora disorders, dysfunction and organ damage in broilers and pigs

Deoxynivalenol (DON) is a common environmental contaminant that causes food refusal and growth retardation in animals. DON targets the intestine and is hazardous to animal, however, it is not clear whether its effect on animals is consistent. Chickens and pigs are the two main animals affected by DON exposure with different susceptibilities. In this study, we found that DON inhibited animal growth and caused damage to the intestine, liver and kidney. DON caused intestinal flora disorders in both chickens and pigs, such as changes of flora diversity and the relative abundance of dominant phyla. Functional analysis showed that changes in the intestinal flora induced by DON were mainly related to metabolic and digestive functions, indicated that the intestinal flora may be associated with the DON-induced intestinal dysfunction. Comparative analysis of differentially altered bacteria suggested that Prevotella may play an important role in maintaining intestinal health, and the presence of differentially altered bacteria in the two animals suggested that DON may have different toxicity modes in animals. In summary, we confirmed the multi-organ toxicity of DON in two major livestock and poultry animals, and speculated that the intestinal flora may be related to the toxic damage caused by DON through species comparison analysis.

Glycyrrhinic acid and probiotics alleviate deoxynivalenol-induced cytotoxicity in intestinal epithelial cells

Deoxynivalenol (DON) is one of the most prevalent mycotoxin contaminants, which posing a serious health threat to animals and humans. Previous studies have found that individually supplemented probiotic or glycyrrhinic acid (GA) could degrade DON and alleviate DON-induced cytotoxicity. The present study investigated the effect of combining GA with Saccharomyces cerevisiae (S. cerevisiae) and Enterococcus faecalis (E. faecalis) using orthogonal design on alleviating IPEC-J2 cell damage induced by DON. The results showed that the optimal counts of S. cerevisiae and E. faecalis significantly promoted cell viability. The optimal combination for increasing cell viability was 400 µg/mL GA, 1 × 10⁶ CFU/mL S. cerevisiae and 1 × 10⁶ CFU/mL E. faecalis to make GAP, which not only significantly alleviated the DON toxicity but also achieved the highest degradation rate of DON (34.7%). Moreover, DON exposure significantly increased IL-8, Caspase3 and NF-κB contents, and upregulated the mRNA expressions of Bax, Caspase 3, NF-κB and the protein expressions of Bax, TNF-α and COX-2. However, GAP addition significantly reduced aforementioned genes and proteins. Furthermore, GAP addition significantly increased the mRNA expressions of Claudin-1, Occludin, GLUT2 and ASCT2, and the protein expressions of ZO-1, Claudin-1 and PePT1. It was inferred that the combination of GA, S. cerevisiae, and E. faecalis had the synergistic effect on enhancing cell viability and DON degradation, which could protect cells from DON-induced damage by reducing DON cytotoxicity, alleviating cell apoptosis and inflammation via inhibiting NF-κB signaling pathway, improving intestinal barrier function, and regulating nutrient absorption and transport. These findings suggest that GAP may have potential as a dietary supplement for livestock or humans exposed to DON-contaminated food or feed.

"Lollipop" particle counting immunoassay based on antigen-powered CRISPR-Cas12a dual signal amplification for the sensitive detection of deoxynivalenol in the environment and food samples

Deoxynivalenol is one of the most widely distributed mycotoxins in cereals and poses tremendous threats to the agricultural environment and public health. Therefore, it is particularly important to develop sensitive and interference-resistant deoxynivalenol analysis methods. Here, we establish a "Lollipop" particle counting immunoassay (LPCI) based on antigen-powered CRISPR-Cas12a dual signal amplification. LPCI achieves high sensitivity and accuracy through antigen-powered CRISPR-Cas dual signal amplification combined with particle counting immunoassay. This strategy not only broadens the applicability of the CRISPR-Cas system in the field of non-nucleic acid target detection; it also improves the sensitivity of particle counting immunoassay. The introduction of a polystyrene "lollipop" immunoassay carrier further enables efficiently simultaneous pre-treatment of multiple samples and overcomes complex matrix interference in real samples. The linear detection range of LPCI for deoxynivalenol was 0.1-500 ng/mL with a detection limit of 0.061 ng/mL. The platform greatly broadens the scope of the CRISPR-Cas sensor for the detection of non-nucleic acid hazards in the environment and food samples.

Relationship Between Mycotoxin Production and Gene Expression in Fusarium graminearum Species Complex Strains Under Various Environmental Conditions

The Fusarium graminearum species complex (FGSC) can produce various mycotoxins and is a major concern for food quantity and quality worldwide. In this study, we determined the effects of water activity (a_w), temperature, incubation time and their interactions on mycotoxin accumulation and the expression levels of biosynthetic genes in FGSC strains from maize samples in China. The highest deoxynivalenol (DON), 3-acetyldeoxynivalenol(3ADON) and 15-acetyldeoxynivalenol (15ADON) levels of the F. boothii and F. graminearum strains were observed at 0.98 a_w/30 °C or 0.99 a_w/25 °C. F. asiaticum and F. meridionale reached maximum nivalenol (NIV) and 4-acetylnivalenol (4ANIV) contents at 0.99 a_w and 30 °C. With the extension of the incubation time, the concentrations of DON and NIV gradually increased, while those of their derivatives decreased. F. boothii, F. meridionale and one F. asiaticum strain had the highest zearalenone (ZEN) values at 0.95 a_w and 25 °C, while the optimum conditions for the other F. asiaticum strain and F. graminearum were 0.99 a_w and 30 °C. Four genes associated with trichothecene and zearalenone synthesis were significantly induced under higher water stress in the early stage of production. The results indicated independence of mycotoxin production and gene expression, as maximum amounts of these toxic metabolites were observed at higher a_w in most cases. This study provides useful information for the monitoring and prevention of such toxins entering the maize production chain.

Combined Transcriptome and Metabolome Analysis Reveals Adaptive Defense Responses to DON Induction in Potato

Phytophthora infestans poses a serious threat to potato production, storage, and processing. Understanding plant immunity triggered by fungal elicitors is important for the effective control of plant diseases. However, the role of the potato stress response to Fusarium toxin deoxynivalenol (DON)-induced stress is still not fully understood. In this study, the metabolites of DON-treated potato tubers were studied for four time intervals using UPLC-MS/MS. We identified 676 metabolites, and differential accumulation metabolite analysis showed that alkaloids, phenolic acids, and flavonoids were the major differential metabolites that directly determined defense response. Transcriptome data showed that differentially expressed genes (DEGs) were significantly enriched in phenylpropane and flavonoid metabolic pathways. Weighted gene co-expression network analysis (WGCNA) identified many hub genes, some of which modulate plant immune responses. This study is important for understanding the metabolic changes, transcriptional regulation, and physiological responses of active and signaling substances during DON induction, and it will help to design defense strategies against Phytophthora infestans in potato.

Identification of Fcl-29 as an Effective Antifungal Natural Product against Fusarium graminearum and Combinatorial Engineering Strategy for Improving Its Yield

Fusarium head blight (FHB), caused by Fusarium graminearum, whose occurrence and prevalence causes 10-70% wheat production loss, is one of the most destructive diseases influencing the production of wheat globally. To identify the potential natural products (NPs) against F. graminearum, we screened 59 Xenorhabdus strains and discovered that the cell-free supernatant (CFS) of X. budapestensis 14 (XBD14) displays the highest bioactivity. Multiple genetic methods coupled with HRMS/MS analysis determined the major antifungal NP to be Fcl-29, a fabclavine derivative. Fcl-29 was found to effectively control FHB of wheat in the field test and demonstrated broad-spectrum antifungal activity against important pathogenic fungi. The production of Fcl-29 was dramatically improved by 33.82-fold with the combinatorial strategy of genetic engineering (1.66-fold) and fermentation engineering (20.39-fold). The exploration of a new biofungicide in global plant protection is now possible.

Impact of Enniatin and Deoxynivalenol Co-Occurrence on Plant, Microbial, Insect, Animal and Human Systems: Current Knowledge and Future Perspectives

Fusarium mycotoxins commonly contaminate agricultural products resulting in a serious threat to both animal and human health. The co-occurrence of different mycotoxins in the same cereal field is very common, so the risks as well as the functional and ecological effects of mycotoxins cannot always be predicted by focusing only on the effect of the single contaminants. Enniatins (ENNs) are among the most frequently detected emerging mycotoxins, while deoxynivalenol (DON) is probably the most common contaminant of cereal grains worldwide. The purpose of this review is to provide an overview of the simultaneous exposure to these mycotoxins, with emphasis on the combined effects in multiple organisms. Our literature analysis shows that just a few studies on ENN-DON toxicity are available, suggesting the complexity of mycotoxin interactions, which include synergistic, antagonistic, and additive effects. Both ENNs and DON modulate drug efflux transporters, therefore this specific ability deserves to be explored to better understand their complex biological role. Additionally, future studies should investigate the interaction mechanisms of mycotoxin co-occurrence on different model organisms, using concentrations closer to real exposures.

Induction of autophagy via the ROS-dependent AMPK/mTOR pathway protects deoxynivalenol exposure grass carp hepatocytes damage

Deoxynivalenol (DON) is one of the most frequently found mycotoxin sources in feed and raw food products, endangering human and animal health. The mechanism of grass carp (Ctenopharyngodon idellus) liver cell (L8824) toxicity induced by DON is still unknown. The DON was administered to the L8824 cells in concentrations of 150, 200, and 250 ng/mL for 24 h. The results of this study suggested that DON could enable L8824 cells to significantly increase the levels of autophagy. Concurrently, DON could trigger autophagy through the AMPK-mTOR pathway, which upregulated the expression of p-AMPK and p-ULK1 while downregulating the expression of p-mTOR. In the meantime, DON treatment could alter the levels of expression of the related proteins in autophagy. Additionally, DON treatment dramatically reduced the activity of the antioxidant enzymes as well as increased the levels of oxidase, which increased the production of ROS in L8824 cells. This indicates that DON could induce oxidative stress. Furthermore, we discovered that DON exposure caused apoptosis, which is characterized by elevated levels of BAX, Caspase 9, Caspase 3, and decreased Bcl-2 levels. Next, it was investigated how oxidative stress affected DON-induced autophagy. The research revealed that the oxidative stress inhibitor (NAC) attenuated DON-induced autophagy. Additionally, the study also investigated how autophagy worked under the L8824 cells induced by DON. The ROS production, however, was enhanced by the addition of the autophagy inhibitor (3-MA). Additionally, co-treatment with the apoptosis inhibitor Z-VAD-FMK had no influence on autophagy. The combined findings showed that induction of autophagy via the ROS-dependent AMPK-mTOR pathway protects DON-induced L8824 cells from damage.

Metagenome Analysis Identifies Microbial Shifts upon Deoxynivalenol Exposure and Post-Exposure Recovery in the Mouse Gut

Deoxynivalenol (DON) is one of the most prevalent food-associated mycotoxins, and is known to cause a variety of adverse health effects on human and animals. Upon oral exposure, the intestine is the main target organ of DON. The current study unraveled that DON exposure (2 mg/kg bw/day or 5 mg/kg bw/day) can significantly reshape the gut microbiota in a mouse model. The study characterized the specific gut microbial strains and genes changed after DON exposure and also investigated the recovery of the microbiota upon either 2 weeks daily prebiotic inulin administration or 2 weeks recovery without intervention after termination of DON exposure (spontaneous recovery). The results obtained reveal that DON exposure causes a shift in gut microorganisms, increasing the relative abundance of Akkermansia muciniphila, Bacteroides vulgatus, Hungatella hathewayi, and Lachnospiraceae bacterium 28-4, while the relative abundance of Mucispirillum schaedleri, Pseudoflavonifractor sp. An85, Faecalibacterium prausnitzii, Firmicutes bacterium ASF500, Flavonifractor plautii, Oscillibacter sp. 1-3, and uncultured Flavonifractor sp. decreased. Notably, DON exposure enhanced the prevalence of A. muciniphila, a species considered as a potential prebiotic in previous studies. Most of the gut microbiome altered by DON in the low- and high-dose exposure groups recovered after 2 weeks of spontaneous recovery. Inulin administration appeared to promote the recovery of the gut microbiome and functional genes after low-dose DON exposure, but not after high-dose exposure, at which changes were exacerbated by inulin-supplemented recovery. The results obtained help to better understand the effect of DON on the gut microbiome, and the gut microbiota's recovery upon termination of DON exposure.

Comparison of Synthetic Methods and Identification of Several Artificial Antigens of Deoxynivalenol

The purpose of this experiment was to study the design and modification of hapten molecules and artificial antigen molecules of deoxynivalenol (DON), and to compare the preparation and identification methods of four artificial antigens. According to the characteristics of the molecular structure of DON, four artificial antigen coupling methods were designed—namely, N,N′-carbonyldiimidazole (CDI), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC), isobutyl chloroformate (IBCF), and N-hydroxysuccinimide (NHS)—to prepare artificial antigens and detection antigens. Through ultraviolet (UV), infrared (IR), and SDS–polyacrylamide gel electrophoresis (SDS–PAGE), along with other physical and chemical identification methods and animal immunisation, the best artificial antigen coupling method was screened. The results showed that the CDI method achieved the best effect among the synthesis methods. The titre of anti-DON polyclonal antibody (pAb) produced by animal immunisation reached 1: (6.4 × 103). The half inhibitory concentration (IC50) was 47.75 ng/mL, the cross-reaction rate with 3-acetyldeoxynivalenol (3-AcDON) was slightly higher at 35.3%, and there was no cross-reaction with other compounds; therefore, four artificial antigens were successfully prepared by using the molecular structure of DON. Through identification, the CDI method was screened as the best artificial antigen synthesis method, with the highest DON pAb titre, the best sensitivity, and the strongest specificity. This will lay a solid antigenic foundation for the preparation of better anti-DON monoclonal antibodies (mAbs) in the future.

Development of a time-resolved immunochromatographic strip for rapid and quantitative determination of deoxynivalenol

Deoxynivalenol (DON) contamination of food crops and feeds is almost impossible to avoid completely; however, through best management practices, this risk can be effectively managed and maximumly mitigated. Accurate and rapid detection of DON contamination as early in the entire value chain as possible is critical. To achieve this goal, we developed a DON test strip based on time-resolved fluorescence immunoassay (TRFIA) and a specific DON monoclonal antibody for the rapid quantification of DON in food crops and feeds. The strip displayed a good linearity (R2 = 0.9926), with a limit of quantification of 28.16 μg/kg, a wide linear range of 50 ~ 10,000 μg/kg. The intra-batch coefficient of variation (CV) and the inter-batch CV was &lt;5.00 and 6.60%, respectively. This TRFIA-DON test strip was applied to detect DON in real samples, and the accuracy and reliability were confirmed by liquid chromatography-mass spectrometry (LC-MS/MS). Results showed that the relative standard deviation between the DON strips and LC-MS/MS was &lt;9%. The recovery rates in corn samples ranged from 92 to 104%. The established TRFIA-DON test strip had the characteristics of high sensitivity, high accuracy, and a wide linear range which was suitable for rapid and quantitative determination of DON in food crops and feeds at both on-site and laboratory.

Deoxynivalenol hijacks the pathway of Janus kinase 2/signal transducers and activators of transcription 3 (JAK2/STAT-3) to drive caspase-3-mediated apoptosis in intestinal porcine epithelial cells

Deoxynivalenol (DON) can easily injure the intestinal tract, which represents the first barrier against food contaminants. The intestinal toxicity induced by DON was mainly focused on mitogen-activated protein kinase (MAPK) activation, however, the underlying mechanisms by which DON triggers apoptosis by other pathways remain poorly understood. In this study, the Janus kinase 2/signal transducers and activators of transcription 3 (JAK2/STAT-3) pathway was proposed to regulate the intrinsic apoptosis induced by DON and thoroughly investigated in intestinal porcine epithelial cells (IPEC-J2). First, DON was found to be able to efficiently inhibit cell viability and increase the release of lactate dehydrogenase. It could also enhance the activity of the cleaved caspase-3 in a time-dependent manner, accompanied by a loss of mitochondrial membrane potential and an up-regulation of the apoptosis rate. Then, the expression of genes associated with inflammation and apoptosis were investigated. DON increased the expression of IL-6, IL-1β, TNF-α, SOCS3 and Bax, but decreased the expression of Bcl-2 and Bcl-xL. Moreover, we discovered that DON robustly inhibited STAT-3 activity together with the down-regulation of JAK2, Bcl-2 and Bcl-xL, paralleling the increase in p38 phosphorylation. Furthermore, a pharmacological activation of JAK2/STAT-3 alleviated DON induced-apoptosis. Concurrent with the apoptotic pathway, during the initial exposure to DON (first 4 h), a survival pathway involving phosphorylated Erk1/2, Akt, and FoxO1 was also observed. Thus, apoptosis induced by DON was Janus faced: although the survival pathway was activated, the DON-induced apoptotic JAK2/STAT-3/caspase-3 pathway dominated, leading to an imbalance in cell homeostasis. This study provides a novel avenue to comprehensively reveal the pathological mechanisms of DON-induced intestinal disorders, which is promising for future applications to other contaminants in food and feed.

Quantification and classification of deoxynivalenol-contaminated oat samples by near-infrared hyperspectral imaging

Deoxynivalenol (DON) is the most occurring mycotoxin in oat and oat-based products. Near-infrared hyperspectral imaging (NIR-HSI) has been proposed as a promising methodology for analysing DON contamination in the food industry. The present study aims to apply NIR-HSI for DON detection in oat kernels and to quantify and classify naturally DON-contaminated oat samples. Unground and ground oat samples were scanned by NIR-HSI before their DON content was determined by HPLC. The data were pre-treated and analysed by PLS regression and four classification methods. The most efficient DON prediction model was for unground samples (R² = 0.75 and RMSEP = 403.18 μg/kg), using twelve characteristic wavelengths with a special interest in 1203 and 1388 nm. The random forest algorithm of unground samples according to the EU maximum limit for unprocessed oats (1750 μg/kg) achieved a classification accuracy of 77.8 %. These findings indicate that NIR-HSI is a promising tool for detecting DON in oats.

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

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