Oxidative stress-mediated cytotoxicity and metabolism of T-2 toxin and deoxynivalenol in animals and humans: an update

Identification of Biotransformation Products of T-2 Toxin in HepG2 Cells Using LC-Q-TOF MS

The T-2 toxin (T-2) is a type A trichothecene found in cereals. The formation of metabolites is a frequent cause of mycotoxin-induced toxicity. In this work, the conversion of T-2 during biotransformation reactions in HepG2 cells was evaluated. For this, HepG2 cells were exposed to 30 (IC50/2) and 60 (IC50) nM of T-2 for 0, 1, 2, 3, 6, 8 and 24 h, and the concentrations of T-2 and its metabolites HT-2, T2-triol, T2-tetraol and neosolaniol were determined in both the cell fraction and culture medium through liquid chromatography coupled to high-resolution mass spectrometry-time of flight (LC-Q-TOF MS). Results showed a fast metabolization of T-2 (>90%) during the first 2 h, with HT-2 as its main (>95%) biotransformation product. The cell fraction showed higher levels (p < 0.05) of HT-2 (39.9 ± 2.1 nM) compared to the culture medium (12.53 ± 2.4 nM). This trend was also observed for the identified metabolites. T2-triol reached its maximum concentration (1.7 ± 0.4 nM) at 2 h, and at later times a time-dependent increase in the T2-tetraol and neosolaniol concentrations was observed. The identification of T-2 metabolites shows the need to continue combined toxicity studies of mycotoxins for a correct risk characterization of these natural contaminants.

A comprehensive review of biodetoxification of trichothecenes: Mechanisms, limitations and novel strategies

Trichothecenes are Fusarium mycotoxins with sesquiterpenoid structure, which are widely occurred in grains. Due to high efficiency and environmental friendliness, biological detoxification methods have been of great interest to treat this global food and feed safety concern. This review summarized the biological detoxification methods of trichothecenes from three aspects, biosorption, biotransformation and biotherapy. The detoxification efficiency, characteristics, mechanisms and limitations of different strategies were discussed in detail. Computer-aided design will bring a new research paradigm for more efficient discovery of biodetoxifier. Integrating different detoxification approaches assisted with computational tools will become a promising research direction in the future, which will help to maximize the detoxification effect, or provide precise detoxification programs for the coexistence of various toxins at different levels in actual production. In addition, technical and regulatory issues in practical application were also discussed. These findings contribute to the exploration of efficient, applicable and sustainable methods for trichothecenes detoxification, ensuring the safety of food and feed to reduce the deleterious effects of trichothecenes on humans and animals.

Fhb7-GST catalyzed glutathionylation effectively detoxifies the trichothecene family

Trichothecene (TCN) contamination in food and feed is a serious challenge due to the negative health and economic impacts. Here, we confirmed that the glutathione S-transferase (GST) Fhb7-GST could broadly catalyze type A, type B and type D TCNs into glutathione epoxide adducts (TCN-13-GSHs). To evaluate the toxicity of TCN-13-GSH adducts, we performed cell proliferation assays in vitro, which demonstrated decreased cytotoxicity of the adducts. Moreover, in vivo assays (repeated-dose treatment in mice) confirmed that TCN-13-GSH adducts were dramatically less toxic than the corresponding TCNs. To establish whether TCN-13-GSH was metabolized back to free toxin during digestion, single-dose metabolic tests were performed in rats; DON-13-GSH was not hydrolyzed in vivo, but rather was quickly metabolized to another low-toxicity compound, DON-13-N-acetylcysteine. These results demonstrate the promise of Fhb7-GST as a candidate of detoxification enzyme potentially applied in TCN-contaminated agricultural samples, minimizing the detrimental effects of the mycotoxin.

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.

The Effect of Combined Exposure of Fusarium Mycotoxins on Lipid Peroxidation, Antioxidant Defense, Fatty Acid Profile, and Histopathology in Laying Hens' Liver

Fumonisin B1, T-2 toxin, and deoxynivalenol are frequently detected in feed materials. The mycotoxins induce free radical formation and, thereby, lipid peroxidation. The effects of mycotoxin exposure at the EU recommended limit (T-2/HT-2 toxin: 0.25 mg/kg; DON = 3AcDON/15-AScDON: 5 mg/kg; fumonisin B1: 20 mg/kg) and double dose (T-2/HT-2 toxin: 0.5 mg/kg, DON/3-AcDON/15-AcDON: 10 mg, and FB1: 40 mg/kg feed) were investigated during short-term (3 days) per os exposure in the liver of laying hens. On day 1 higher while on day 3 lower MDA concentrations were found in the low-dose group compared to the control. Fatty acid composition also changed: the proportion of monounsaturated fatty acids increased (p < 0.05) and the proportion of polyunsaturated fatty acids decreased by day 3. These alterations resulted in a decrease in the index of unsaturation and average fatty acid chain length. Histopathological alterations suggested that the incidence and severity of liver lesions were higher in the mycotoxin-treated laying hens, and the symptoms correlated with the fatty acid profile of total phospholipids. Overall, the findings revealed that mycotoxin exposure, even at the EU-recommended limits, induced lipid peroxidation in the liver, which led to changes in fatty acid composition, matched with tissue damage.

Melatonin alleviates T-2 toxin-induced oxidative damage, inflammatory response, and apoptosis in piglet spleen and thymus

T-2 toxin, an unavoidable contaminant in animal feeds, can induce oxidative stress and damage immune organs. Melatonin (MT), a natural and potent antioxidant, has shown promise as a detoxifier for various mycotoxins. However, the detoxifying effect of MT on T-2 toxin has not been previously reported. In order to investigate the protective effect of MT added to diets on the immune system of T-2 toxin-exposed piglets, twenty piglets weaned at 28d of age were randomly divided into control, T-2 toxin (1 mg/kg), MT (5 mg/kg), and T-2 toxin (1 mg/kg) + MT (5 mg/kg) groups(n = 5 per group). Our results demonstrated that MT mitigated T-2 toxin-induced histoarchitectural alterations in the spleen and thymus, such as hemorrhage, decreased white pulp size in the spleen, and medullary cell sparing in the thymus. Further research revealed that MT promoted the expression of Nrf2 and increased the activities of antioxidant enzymes CAT and SOD, while reducing the production of the lipid peroxidation product MDA. Moreover, MT inhibited the NF-κB signaling pathway, regulated the expression of downstream cytokines IL-1β, IL-6, TNF-α, and TGF-β1. MT also suppressed the activation of caspase-3 while down-regulating the ratio of Bax/Bcl-2 to reduce apoptosis. Additionally, MT ameliorated the T-2 toxin-induced disorders of immune cells and immune molecules in the blood. In conclusion, our findings suggest that MT may effectively protect the immune system of piglets against T-2 toxin-induced damage by inhibiting oxidative stress, inflammatory response, and apoptosis in the spleen and thymus. Therefore, MT holds the potential as an antidote for T-2 toxin poisoning.

Pathological consequences, metabolism and toxic effects of trichothecene T-2 toxin in poultry

Contamination of feed with mycotoxins has become a severe issue worldwide. Among the most prevalent trichothecene mycotoxins, T-2 toxin is of particular importance for livestock production, including poultry posing a significant threat to animal health and productivity. This review article aims to comprehensively analyze the pathological consequences, metabolism, and toxic effects of T-2 toxin in poultry. Trichothecene mycotoxins, primarily produced by Fusarium species, are notorious for their potent toxicity. T-2 toxin exhibits a broad spectrum of negative effects on poultry species, leading to substantial economic losses as well as concerns about animal welfare and food safety in modern agriculture. T-2 toxin exposure easily results in negative pathological consequences in the gastrointestinal tract, as well as in parenchymal tissues like the liver (as the key organ for its metabolism), kidneys, or reproductive organs. In addition, it also intensely damages immune system-related tissues such as the spleen, the bursa of Fabricius, or the thymus causing immunosuppression and increasing the susceptibility of the animals to infectious diseases, as well as making immunization programs less effective. The toxin also damages cellular processes on the transcriptional and translational levels and induces apoptosis through the activation of numerous cellular signaling cascades. Furthermore, according to recent studies, besides the direct effects on the abovementioned processes, T-2 toxin induces the production of reactive molecules and free radicals resulting in oxidative distress and concomitantly occurring cellular damage. In conclusion, this review article provides a complex and detailed overview of the metabolism, pathological consequences, mechanism of action as well as the immunomodulatory and oxidative stress-related effects of T-2 toxin. Understanding these effects in poultry is crucial for developing strategies to mitigate the impact of the T-2 toxin on avian health and food safety in the future.

Overview of T-2 Toxin Enterotoxicity: From Toxic Mechanisms and Detoxification to Future Perspectives

Fusarium species produce a secondary metabolite known as T-2 toxin, which is the primary and most harmful toxin found in type A trichothecenes. T-2 toxin is widely found in food and grain-based animal feed and endangers the health of both humans and animals. T-2 toxin exposure in humans and animals occurs primarily through food administration; therefore, the first organ that T-2 toxin targets is the gut. In this overview, the research progress, toxicity mechanism, and detoxification of the toxin T-2 were reviewed, and future research directions were proposed. T-2 toxin damages the intestinal mucosa and destroys intestinal structure and intestinal barrier function; furthermore, T-2 toxin disrupts the intestinal microbiota, causes intestinal flora disorders, affects normal intestinal metabolic function, and kills intestinal epidermal cells by inducing oxidative stress, inflammatory responses, and apoptosis. The primary harmful mechanism of T-2 toxin in the intestine is oxidative stress. Currently, selenium and plant extracts are mainly used to exert antioxidant effects to alleviate the enterotoxicity of T-2 toxin. In future studies, the use of genomic techniques to find upstream signaling molecules associated with T-2 enterotoxin toxicity will provide new ideas for the prevention of this toxicity. The purpose of this paper is to review the progress of research on the intestinal toxicity of T-2 toxin and propose new research directions for the prevention and treatment of T-2 toxin toxicity.

Review of neurotoxicity of T-2 toxin

T-2 toxin is a representative trichothecene that is widely detected in corn, wheat and other grain feeds. T-2 toxin has stable physical and chemical properties, making it difficult to remove from food and feed. Hence, T-2 toxin has become an unavoidable pollutant in food for humans and animals. T-2 toxin can enter brain tissue by crossing the blood-brain barrier and leads to congestion, swelling and even apoptosis of neurons. T-2 toxin poisoning can directly lead to clinical symptoms (anti-feeding reaction and decline of learning and memory function in humans and animals). Maternal T-2 toxin exposure also exerted toxic effects on the central nervous system of offspring. Oxidative stress is the core neurotoxicity mechanism underlying T-2 toxin poison. Oxidative stress-mediated apoptosis, mitochondrial oxidative damage and inflammation are all involved in the neurotoxicity induced by T-2 toxin. Thus, alleviating oxidative stress has become a potential target for relieving the neurotoxicity induced by T-2 toxin. Future efforts should be devoted to revealing the neurotoxic molecular mechanism of T-2 toxin and exploring effective therapeutic drugs to alleviate T-2 toxin-induced neurotoxicity.

Multi-Fusarium mycotoxin exposure activates Nrf2 and Ahr pathway in the liver of laying hens

This study investigates gene expression changes in laying hens exposed to trichothecene mycotoxins, known to induce oxidative stress and affect xenobiotic transformation and antioxidants. A 3-day feeding trial tested low and high doses of T-2/HT-2 toxin, DON/3-AcDON/15-AcDON, and FB1 in hen feed. Results showed increased expression of AHR, AHRR, HSP90, and CYP1A2 genes on days 2 and 3, suggesting a response to mycotoxin exposure. High doses down-regulated CYP1A2, AHR, and AHRR on day 1. KEAP1 expression decreased on day 1 but increased dose-dependently on days 2 and 3. NRF2 was up-regulated by low and down-regulated by high doses on day 1, then increased on days 2 and 3. Antioxidant-related genes (GPX3, GPX4, GSS, GSR) showed dose-dependent responses. Low doses up-regulated GPX3 and GPX4 throughout, while high doses up-regulated GPX3 on days 2 and 3 and GPX4 on day 3. GSS was up-regulated on day 3. Results indicate that toxic metabolites formed by phase I biotransformation rapidly induce ROS formation at low doses through the AHR/Hsp90/CYP1A2 pathway at the gene expression level, but at high levels, ROS-induced oxidative stress manifests later. Study showed simultaneous activation of redox-sensitive pathways: aryl hydrocarbon receptor (Ahr) and nuclear factor erythroid-derived 2-like 2 (Nrf2) by multi-mycotoxin exposure.

Elucidating the mechanism of action of mycotoxins through machine learning-driven QSAR models: Focus on lipid peroxidation

Understanding the mechanisms of mycotoxin toxicity is crucial for establishing effective guidelines and preventive strategies. In this study, machine learning models based on quantitative structure-activity relationship (QSAR) were employed to predict the lipid peroxidation activity of mycotoxins. Two different algorithms using Linear Discriminant Analysis (LDA) and Artificial Neural Networks (ANNs) have been trained using a dataset of 70 mycotoxins. The LDA model had an average correct classification rate of 91%, while the ANN model achieved a perfect 100% classification rate. Following an internal validation process, the models were utilized to predict mycotoxins with known lipid peroxidation activity. The machine learning models achieved an 88% correct classification rate for these mycotoxins. Finally, by utilizing classified algorithms, the study aimed to infer the mechanism of action related to lipid peroxidation for 91 unstudied mycotoxins. These models provide a fast, accurate, and cost-effective means to assess the potential toxicity and mechanism of action of mycotoxins. The findings of this study contribute to a comprehensive understanding of mycotoxin toxicology and assist researchers and toxicologists in evaluating health risks associated with mycotoxin exposure and developing appropriate preventive strategies and potential therapeutic interventions to mitigate the effects of mycotoxins.

An integrated mycotoxin-mitigating agent can effectively mitigate the combined toxicity of AFB1, DON and OTA on the production performance, liver and oviduct health in broiler breeder hens

This study was to evaluate the efficacy of an integrated mycotoxin-mitigating agent in reducing the adverse effects of co-occurring dietary aflatoxin B1 deoxynivalenol and ochratoxin A on broiler breeder hens. 360 30-week-old Hubbard Efficiency Plus broiler breeder hens were allocated into four groups and received a basal diet (BD; Control), BD added 0.15 mg/kg aflatoxin B1+1.5 mg/kg deoxynivalenol+0.12 mg/kg ochratoxin A (Toxins), BD plus Toxins with 0.1% TOXO-XL (Toxins + XL1), and BD plus Toxins with 0.2% TOXO-XL (Toxins + XL2), respectively, for 8 weeks, and then received the same BD for another 4 weeks. Compared with control, mycotoxins decreased total egg weigh, egg laying rate, settable eggs rate, hatch of total eggs rate, egg quality, but increased feed/egg ratio and mortality rate, and impaired the liver and oviduct health during weeks 1-8 and(or) 9-12. It also increased PC and MDA concentrations, TUNEL-positive cells and IL-1β and IL-6 expression, and decreased T-AOC, GPX and CAT activities in liver and/or oviduct. Notably, most of these negative changes were mitigated by both dosages of TOXO-XL. Generally, 0.2% TOXO-XL displayed better mitigation effects than 0.1% TOXO-XL. Conclusively, these findings revealed that TOXO-XL could mitigate the combined mycotoxins-induced toxicity on the performance, liver and oviduct health, through the regulation of redox, immunity, and apoptosis in broiler breeder hens.

Deoxynivalenol Exposure Induced Colon Damage in Mice Independent of the Gut Microbiota

SCOPE

To investigate whether deoxynivalenol (DON) can induce intestinal damage through gut microbiota in mice.

METHODS AND RESULTS

Mice are orally administered DON (1 mg kg-1 bw day-1 ) for 4 weeks, and then recipient mice receive fecal microbiota transplantation (FMT) from DON-exposed mice after antibiotic treatment. Furthermore, the mice are orally treated with DON (1 mg kg-1 bw day-1 ) for 4 weeks after antibiotic treatment. Histological damage, disruption of tight junction protein expression, and increased oxidative stress and apoptosis in the colon as well as higher serum lipopolysaccharides are observed after DON exposure. Moreover, DON exposure changes the composition and diversity of the gut microbiota as well as the contents of fecal metabolites (mainly bile acids). Differential metabolic pathways may be related to mitochondrial metabolism, apoptosis, and inflammation following DON exposure. However, only a decrease in mRNA levels of occludin and claudin-3 is observed in the colon of recipient mice after FMT. After depleting the gut microbiota in mice, DON exposure can also cause histological damage, disorders of tight junction protein expression, and increased oxidative stress and apoptosis in the colon.

CONCLUSIONS

DON exposure can induce colon damage in mice independent of the gut microbiota.

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.

Superoxide dismutase ameliorates oxidative stress and regulates liver transcriptomics to provide therapeutic benefits in hepatic inflammation

Background

Oxidative stress refers to the imbalance between oxidants and antioxidants in organisms and often induces hepatic inflammation. Supplementing exogenous superoxide dismutase is an effective way to alleviate oxidative stress; however, the effects and mechanisms by which superoxide dismutase alleviates hepatic inflammation remain unclear.

Methods

This study established a Kunming mouse model to verify and investigate the oxidative stress and hepatic inflammation-alleviating effects of the superoxide dismutase oral supplement that was prepared by our research group in a previous study.

Results

The superoxide dismutase product significantly restored the body weight and liver alanine transaminase, aspartate aminotransferase, superoxide dismutase, catalase, glutathione, and glutathione peroxidase levels of oxidative stress induced mice. Moreover, exogenous superoxide dismutase significantly inhibited interleukin 1β and interleukin 6 mRNA expression in the livers of mice with hepatic inflammation. Transcriptomic analysis indicated that superoxide dismutase had a significant inhibitory effect on Endog expression, alleviating oxidative stress damage, and mediating liver cell apoptosis by regulating the expression of Rab5if, Hnrnpab, and Ifit1.

Conclusion

Our research verified the oxidative stress remediation effects of superoxide dismutase and its therapeutic role against hepatic inflammation. This study can lay a foundation for investigating the mechanism by which superoxide dismutase alleviates hepatic disease.

Deoxynivalenol: Emerging Toxic Mechanisms and Control Strategies, Current and Future Perspectives

Deoxynivalenol (DON) is the most frequently present mycotoxin contaminant in food and feed, causing a variety of toxic effects in humans and animals. Currently, a series of mechanisms involved in DON toxicity have been identified. In addition to the activation of oxidative stress and the MAPK signaling pathway, DON can activate hypoxia-inducible factor-1α, which further regulates reactive oxygen species production and cancer cell apoptosis. Noncoding RNA and signaling pathways including Wnt/β-catenin, FOXO, and TLR4/NF-κB also participate in DON toxicity. The intestinal microbiota and the brain-gut axis play a crucial role in DON-induced growth inhibition. In view of the synergistic toxic effect of DON and other mycotoxins, strategies to detect DON and control it biologically and the development of enzymes for the biodegradation of various mycotoxins and their introduction in the market are the current and future research hotspots.

The evolution and ecology of psilocybin in nature

Fungi produce diverse metabolites that can have antimicrobial, antifungal, antifeedant, or psychoactive properties. Among these metabolites are the tryptamine-derived compounds psilocybin, its precursors, and natural derivatives (collectively referred to as psiloids), which have played significant roles in human society and culture. The high allocation of nitrogen to psiloids in mushrooms, along with evidence of convergent evolution and horizontal transfer of psilocybin genes, suggest they provide a selective benefit to some fungi. However, no precise ecological roles of psilocybin have been experimentally determined. The structural and functional similarities of psiloids to serotonin, an essential neurotransmitter in animals, suggest that they may enhance the fitness of fungi through interference with serotonergic processes. However, other ecological mechanisms of psiloids have been proposed. Here, we review the literature pertinent to psilocybin ecology and propose potential adaptive advantages psiloids may confer to fungi.

Integrated lncRNA transcriptomics, proteomics, and metabolomics to identify early cellular response variation in deoxynivalenol-treated IPEC-J2 cells

Mycotoxins, especially deoxynivalenol (DON), are common contaminants of food and feed, which also has serious threaten to human health and livestock production. Moreover, DON severely impair intestinal epithelial barrier function. Therefore, it is necessary to investigate the mechanism of intestinal epithelial cell injury induced by DON. Here, intestinal porcine enterocyte cell (IPEC-J2) was incubated with 200 ng/ml or 2000ng/ml DON for 6 h, then lncRNA sequencing, metabolomics and proteomics were applied. Combined with long coding transcriptomics, and proteomics, 200 ng/ml DON treatment (LDON group) significantly upregulated ribosome biogenesis in eukaryotes, spliceosome, and ubiquitin mediated proteolysis, RNA transport, and downregulated metabolic pathways in IPEC-J2, 2000 ng/ml of DON treatment (HDON group) significantly upregulated ribosome biogenesis in eukaryotes, and spliceosome, and downregulated base excision repair, cell cycle, DNA replication, homologous recombination, and mismatch repair in IPEC-J2. Combined with long coding transcriptomics, and proteomics, as compared with LDON group, HDON group significantly upregulated adherens junction, hippo signaling pathway, and pathways in cancer, and downregulated DNA replication pathways in IPEC-J2. In metabolomics, LDON group and HDON group was mainly downregulated biosynthesis of unsaturated fatty acids, and fatty acid metabolism. These results provide a new insight to prevent and treat DON induced intestinal epithelial cell injury.

Deoxynivalenol Mycotoxin Inhibits Rabies Virus Replication In Vitro

Rabies is a highly fatal disease, and it is vital to find effective ways to manage and control infection. There is a need for new effective antiviral drugs that are particularly effective treatments for rabies. Deoxynivalenol (DON) is known mainly for its toxicity, but at the molecular level, it can inhibit RNA and DNA replication, and there is increasing evidence that different doses of DON have a positive effect on inhibiting virus replication. Based on this, we evaluated the effect of DON on inhibiting the rabies virus in vitro. The inhibitory effect of DON on rabies virus activity was dose- and time-dependent, and 0.25 μg/mL of DON could inhibit 99% of rabies virus activity within 24 h. Furthermore, DON could inhibit the adsorption, entry, replication, and release of rabies virus but could not inactivate the virus. The inhibitory effect of DON on rabies virus may be achieved by promoting apoptosis. Our study provides a new perspective for the study of anti-rabies virus and expands the direction of action of mycotoxins.

Therapeutic Efficiency of Humic Acids in Intoxications

Humins, humic and fulvic acids represent molecules with complex structures. These compounds comprising humic substances (HS) exist naturally in soil, brown coal, peat, and water. They are formed during the decomposition and transformation of organic matter (animal and plant remains) and their formation explains several theories. Within their chemical structures, there are numerous phenolic and carboxyl groups and their derivatives that affect their different properties, such as their solubility in water or their absorption of cations or mycotoxins. The manifold chemical structure of HS alters their polyelectrolyte character and thus their chelating efficiency. For many years, HS have been studied due to their detoxification, anti-, and pro-inflammatory or anticancer and antiviral ability. This article summarizes the antioxidant and adsorption properties of humic acids, highlighting their usefulness in intoxications.

TET3-mediated DNA demethylation and chromatin remodeling regulate T-2 toxin-induced human CYP1A1 expression and cytotoxicity in HepG2 cells

T-2 toxin is a hazardous environmental pollutant that poses a risk to both farm animals and humans. Our previous research has reported that T-2 toxin highly induced the expression of human cytochrome P450 1A1 (CYP1A1), which may be a representative inducible marker of T-2 toxin and mediate the toxicity of T-2 toxin. In this study, we found that T-2 toxin decreased the DNA methylation levels of the CpG islands on the CYP1A1 promoter by inducing the expression of eleven translocation family protein 3 (TET3) and facilitating its binding to the promoter. These DNA methylation changes then generated an activated chromatin structure on the CYP1A1 promoter by releasing the repressor complex methyl-binding protein 2 (MeCP2) and histone deacetylase 2 (HDAC2), increasing the active histone modification markers, including H3K4ac, H3K9ac and H3K14ac, and facilitating RNA pol II and NRF1/Sp1 recruitment, which ultimately led to the transcriptional activation of CYP1A1. Interestingly, TET3-mediated CYP1A1 induction enhanced the cytotoxicity of T-2 toxin through inhibiting cell proliferation. Our results demonstrate that T-2 toxin-induced CYP1A1 expression is detrimental to cells and clearly show how T-2 toxin inhibits cell proliferation through regulating CYP1A1 expression from an epigenetic perspective. The findings broaden our current knowledge of the epigenetic mechanisms regulating environmental factors-induced CYP1A1 expression and cytotoxicity. TET3 may serve as a potential new target for toxicogenic detoxification.

AgPdNFs and AuNOs@GO nanocomposites for T-2 toxin detection by catalytic hairpin assembly

T-2 toxin is the most potent and toxic mycotoxin, produced by various Fusarium species that can potentially affect human health, and widely exists in field crops and stored grain. In this work, an electrochemical aptasensor with nonenzymatic signal amplification strategy for the detection of T-2 toxin is presented, using noble metal nanocomposites and catalytic hairpin assembly as signal amplification strategy. Silver palladium nanoflowers and gold octahedron nanoparticles@graphene oxide nanocomposites are used for synergistic amplification of electrical signals. Simultaneously, the catalytic hairpin assembly strategy based on artificial molecular technology was introduced to further amplify the signal. Under optimal conditions, T-2 toxin was measured within a linear concentration range 1 × 10^-2 ~ 1 × 10⁴ pg·mL^-1 with an extremely low detection limit of 6.71 fg·mL^-1. The aptasensor exhibited high sensitivity, good selectivity, satisfactory stability, and excellent reproducibility. Moreover, this method had high accuracy in detecting T-2 toxin in beer sample. The encouraging results show the potential application in foodstuff analysis. A dual signal amplification electrochemical biosensor for the detection of T-2 toxins was constructed, through the signal amplification of noble metal nanomaterials and CHA strategy.

The effects of gallic acid and vagotomy on motor function, intestinal transit, brain electrophysiology and oxidative stress alterations in a rat model of Parkinson's disease induced by rotenone

INTRODUCTION

The neuropathology of Parkinson's disease (PD) is complex and affects multiple systems of the body beyond the central nervous system. This study examined the effects of gallic acid (GA) and gastrointestinal vagotomy (VG) on motor, cognitive, intestinal transit time, and thalamic nuclei electrical power in an animal model of PD induced by rotenone.

MATERIALS AND METHODS

Male Wistar rats were divided into 4 groups: Sham, ROT, ROT+GA, VG + ROT. Sham rats received vehicle, those in ROT received rotenone (5 mg/kg/2 ml, ig), PD rats in ROT+GA were treated with GA (100 mg/kg, gavage/once daily, for 28 days), and in VG + ROT, the vagal nerve was dissected. Stride length, motor coordination and locomotion, intestinal transit time, cognitive and pain threshold, and thalamic local EEG were evaluated. Oxidative stress indexes in striatal tissue were also measured.

RESULTS

Rotenone diminished significantly the stride length (p < 0.001), motor coordination (p < 0.001), power of thalamic EEG (p < 0.01) and pain (p < 0.001). MDA increased significantly (p < 0.001) while GPx activity decreased (p < 0.001). Intestinal transit time rose significantly (p < 0.01). PD rats treated with GA improved all above disorders (p < 0.001, p < 0.01). Vagotomy prevented significant alterations of motor and non-motor parameters by rotenone.

CONCLUSION

According to current findings, rotenone acts as a toxin in GI and plays a role in the pathogenesis of PD through gastric vagal nerve. Thus, vagotomy could prevent the severity of toxicity by rotenone. In addition, GA improved symptoms of PD induced by rotenone. Therefore, GA can be regarded as a promising therapeutic candidate for PD patients.

Dietary T-2 toxin induces transcriptomic changes in hepatopancreas of Chinese mitten crab (Eriocheir sinensis) via nutrition metabolism and apoptosis-related pathways

Long-term feed route exposure to T-2 toxin was proved to elicit growth retarding effects and induction of oxidative stress and apoptosis in Chinese mitten crab (Eriocheir sinensis). However, no study with a holistic perspective has been conducted to date to further describe the in-depth toxicological mechanism of T-2 toxin in E.sinensis. In this study, an RNA-Sequencing (RNA-seq) was used in this study to investigate the effects of feed supplementation with 0 mg/kg and 4 mg/kg T-2 toxin on the hepatopancreas transcriptome of E.sinensis and establish a hepatopancreas transcriptome library of T-2 toxin chronically exposed crabs after five weeks, where 14 differentially expressed genes (DEGs) were screened out across antioxidant, apoptosis, autophagy, glucolipid metabolism and protein synthesis. The actual expression of all the DEGs (Caspase, ATG4, PERK, ACSL, CAT, BIRC2, HADHA, HADHB, ACOX, PFK, eEFe1, eIF4ɑ, RPL13Ae) was also analyzed by real-time quantitative PCR (RT-qPCR). It was demonstrated that long-term intake of large amounts of T-2 toxin could impair antioxidant enzyme activity, promote apoptosis and protective autophagy, disrupt lipid metabolism and inhibit protein synthesis in the hepatopancreas of E.sinensis. In conclusion, this study explored the toxicity mechanism of T-2 toxin on the hepatopancreas of E.sinensis at the mRNA level, which lays the foundation for further investigation of the molecular toxicity mechanism of T-2 toxin in aquatic crustaceans.

Dietary Catalase Supplementation Alleviates Deoxynivalenol-Induced Oxidative Stress and Gut Microbiota Dysbiosis in Broiler Chickens

Catalase (CAT) can eliminate oxygen radicals, but it is unclear whether exogenous CAT can protect chickens against deoxynivalenol (DON)-induced oxidative stress. This study aimed to investigate the effects of supplemental CAT on antioxidant property and gut microbiota in DON-exposed broilers. A total of 144 one-day-old Lingnan yellow-feathered male broilers were randomly divided into three groups (six replicates/group): control, DON group, and DON + CAT (DONC) group. The control and DON group received a diet without and with DON contamination, respectively, while the DONC group received a DON-contaminated diet with 200 U/kg CAT added. Parameter analysis was performed on d 21. The results showed that DON-induced liver enlargement (p < 0.05) was blocked by CAT addition, which also normalized the increases (p < 0.05) in hepatic oxidative metabolites contents and caspase-9 expression. Additionally, CAT addition increased (p < 0.05) the jejunal CAT and GSH-Px activities coupled with T-AOC in DON-exposed broilers, as well as the normalized DON-induced reductions (p < 0.05) of jejunal villus height (VH) and its ratio for crypt depth. There was a difference (p < 0.05) in gut microbiota among groups. The DON group was enriched (p < 0.05) with some harmful bacteria (e.g., Proteobacteria, Gammaproteobacteria, Enterobacteriales, Enterobacteriaceae, and Escherichia/Shigella) that elicited negative correlations (p < 0.05) with jejunal CAT activity, and VH. DONC group was differentially enriched (p < 0.05) with certain beneficial bacteria (e.g., Acidobacteriota, Anaerofustis, and Anaerotruncus) that could benefit intestinal antioxidation and morphology. In conclusion, supplemental CAT alleviates DON-induced oxidative stress and intestinal damage in broilers, which can be associated with its ability to improve gut microbiota, aside from its direct oxygen radical-scavenging activity.

T-2 Toxin Caused Mice Testicular Inflammation Injury via ROS-Mediated NLRP3 Inflammasome Activation

T-2 toxin treatment causes male reproduction system dysfunction, although the exact mechanism remains unclear. In this research, male Kunming mice and TM4 cells were treated with varying concentrations of the T-2 toxin for evaluating the adverse effect of T-2 toxin on male reproductive function. MCC950 or NAC was used to block NLRP3 inflammasome activation and eliminate reactive oxygen species (ROS) accumulation in the TM4 cell, respectively. The results showed that: (1) T-2 toxin caused testicular atrophy, destroyed the microstructure and ultrastructure of the testis, and caused sperm deformities; (2) T-2 toxin increased the content and gene expressions of TNF-α and IL-6 and decreased the IL-10 content and gene expression, causing testis and TM4 cell inflammatory injury; (3) T-2 toxin activated NLRP3 inflammasome in the testis and TM4 cells and caused ROS accumulation in the testis; (4) suppressing NLRP3 inflammasome activation using 20 nM MCC950 alleviated the TM4 cell inflammatory damage caused via the T-2 toxin; nevertheless, 20 nM MCC950 did not reduce ROS accumulation in TM4 cells; and (5) NAC relieved the inflammatory damage in TM4 cells by inhibiting NLRP3 inflammasome activation. Taken together, T-2 toxin caused testicular inflammation injury through ROS-mediated NLRP3 inflammasome activation, resulting in male reproductive dysfunction.

HIF-1α inhibits T-2 toxin-mediated "immune evasion" process by negatively regulating PD-1/PD-L1

Trichothecene mycotoxins have a strong immunosuppressive effect, which may even escape host immune surveillance and damage the immune repair to show an "immune evasion" effect. Increasing lines of evidence have shown that hypoxia and hypoxia-inducible factors (HIFs) are key mediators of trichothecenes, and these toxins appear to be closely related to the "immune evasion" mechanisms. Therefore, we used RAW264.7 cell model to explore the association of T-2 toxins with "immune evasion" process and hypoxia, as well as their cross-linking effects induced by T-2 toxin. Our results showed that HIF-1α is an important toxicity target of T-2 toxin, which could induce intracellular hypoxia. T-2 toxin induced an "immune evasion" process by activating the PD-1/PD-L1 signaling pathway. Interestingly, when HIF-1α activation was blocked, the "immune evasion" process regulated by PD-1/PD-L1 signaling was activated, resulting in the cells damage, suggesting that hypoxia induced by T-2 toxin plays a protective role for RAW264.7 cell damage. Thus, our work shows that HIF-1α inhibits T-2 toxin-mediated "immune evasion" process by negatively regulating PD-1/PD-L1signaling. This study contributes to a better understanding of the immunotoxicity mechanism of trichothecenes.

Mycotoxins occurrence in milk and cereals in North African countries - a review

North African countries; Algeria, Egypt, Libya, Morocco and Tunisia suffer from mycotoxin contamination. Various studies have indicated the presence of mycotoxins in raw milk and cereals (i.e. wheat, barley, maize and cereal-based products). Aflatoxins (AFs), Aflatoxin M1 (AFM1), Ochratoxin A (OTA), Fumonisin (FB1) and Zearalenone (ZEN)-mycotoxin are the most detected due to climatic change in the region. In this review, we will present the kind of foods and feeds cereals and milk based products contaminated and the level of their contaminated mycotoxin. On the other hand, researchers try to find biologic methods to remove/mitigate mycotoxins in food and feed using bio-products. But the research works concerning legislations and mycotoxin risk assessment still rare. Therefore, it appears necessary to make review on the current status of mycotoxins in North African countries in order to explore data related to contamination of basic food in this region and to highlight the problem to the policy-makers to establish a serious legislation on this matter. On the other hand, to give more information to the worldwide readers about the impact of climate change on the food and feed pollution on mycotoxins in the Mediterranean Sea region.

An update on T2-toxins: metabolism, immunotoxicity mechanism and human assessment exposure of intestinal microbiota

Mycotoxins are naturally produced secondary metabolites or low molecular organic compounds produced by fungus with high diversification, which cause mycotoxicosis (food contamination) in humans and animals. T-2 toxin is simply one of the metabolites belonging to fungi trichothecene mycotoxin. Specifically, Trichothecenes-2 (T-2) mycotoxin of genus fusarium is considered one of the most hotspot agricultural commodities and carcinogenic compounds worldwide. There are well-known examples of salmonellosis in mice and pigs, necrotic enteritis in chickens, catfish enteric septicemia and colibacillosis in pigs as T-2 toxic agent. On the other hand, it has shown a significant reduction in the Salmonella population's aptitude in the pig intestinal tract. Although the impact of the excess Fusarium contaminants on humans in creating infectious illness is less well-known, some toxins are harmful; for example, salmonellosis and colibacillosis have been frequently observed in humans. More than 20 different metabolites are synthesized and excreted after ingestion, but the T-2 toxin is one of the most protuberant metabolites. Less absorption of mycotoxins in intestinal tract results in biotransformation of toxic metabolites into less toxic variants. In addition to these, effects of microbiota on harmful mycotoxins are not limited to intestinal tract, it may harm the other human vital organs. However, detoxification of microbiota is considered as an alternative way to decontaminate the feed for both animals and humans. These transformations of toxic metabolites depend upon the formation of metabolites. This study is complete in all perspectives regarding interactions between microbiota and mycotoxins, their mechanism and practical applications based on experimental studies.

Mycotoxins of Concern in Children and Infant Cereal Food at European Level: Incidence and Bioaccessibility

Cereals are of utmost importance for the nutrition of infants and children, as they provide important nutrients for their growth and development and, in addition, they are easily digestible, being the best choice for the transition from breast milk/infant formula to solid foods. It is well known that children are more susceptible than adults to toxic food contaminants, such as mycotoxins, common contaminants in cereals. Many mycotoxins are already regulated and controlled according to strict quality control standards in Europe and around the world. There are, however, some mycotoxins about which the level of knowledge is lower: the so-called emerging mycotoxins, which are not yet regulated. The current review summarizes the recent information (since 2014) published in the scientific literature on the amounts of mycotoxins in infants’ and children’s cereal-based food in Europe, as well as their behaviour during digestion (bioaccessibility). Additionally, analytical methods used for mycotoxin determination and in vitro methods used to evaluate bioaccessibility are also reported. Some studies demonstrated the co-occurrence of regulated and emerging mycotoxins in cereal products used in children’s food, which highlights the need to adopt guidelines on the simultaneous presence of more than one mycotoxin. Although very little research has been done on the bioaccessibility of mycotoxins in these food products, very interesting results correlating the fiber and lipid contents of such products with a higher or lower bioaccessibility of mycotoxins were reported. LC-MS/MS is the method of choice for the detection and quantification of mycotoxins due to its high sensibility and accuracy. In vitro static digestion models are the preferred ones for bioaccessibility evaluation due to their simplicity and accuracy.

Effects of deoxynivalenol on the histomorphology of the liver and kidneys and the expression of MAPKs in weaned rabbits

Deoxynivalenol (DON) is widely present in grain-based feeds and food. It has attracted great attention due to its high contamination rate and strong toxicity. The objective of this study was to analyse the toxic effects of DON on the liver and kidneys of weaned rabbits. 45 weaned male rabbits were allocated into control, low DON dose (0.5 mg/kg body weight), and high DON dose (1.5 mg/kg body weight) groups. Saline or DON was administrated intragastrically in the empty stomach of rabbits every morning. After 24 days of treatment, liver and kidney samples were collected for histological, reverse transcription-quantitative polymerase chain reaction (qRT-PCR), and immunohistochemistry analyses. Haematoxylin eosin staining showed that 0.5 mg/kg BW DON caused mild damage to the liver and kidney morphology, while 1.5 mg/kg body weight DON resulted in hepatic vacuolation and necrosis, as well as tubular stenosis and lesions. Data from qRT-PCR, Western blot, and immunohistochemistry revealed that the mRNA and protein expression and the distribution range of extracellular signal-regulated kinase, p38, and c-Jun NH2-terminal kinase were increased in the liver and kidneys. In conclusion, DON at the tested concentrations damaged the liver and kidneys of rabbits by affecting the expression of key proteins from the mitogen-activated protein kinase signalling pathway. The damage extent was proportional to the amount of DON ingested.

T-2 toxin and its cardiotoxicity: New insights on the molecular mechanisms and therapeutic implications

T-2 toxin is one of the most toxic and common trichothecene mycotoxins, and can cause various cardiovascular diseases. In this review, we summarized the current knowledge-base and challenges as it relates to T-2 toxin related cardiotoxicity. The molecular mechanisms and potential treatment approaches were also discussed. Pathologically, T-2 toxin-induced cardiac toxicity is characterized by cell injury and death in cardiomyocyte, increased capillary permeability, necrosis of cardiomyocyte, hemorrhage, and the infiltration of inflammatory cells in the heart. T-2 toxin exposure can cause cardiac fibrosis and finally lead to cardiac dysfunction. Mechanistically, T-2 toxin exposure-induced cardiac damage involves the production of ROS, mitochondrial dysfunction, peroxisome proliferator-activated receptor-gamma (PPAR-γ) signaling pathway, endoplasmic reticulum (ER stress), transforming growth factor beta 1 (TGF-β1)/smad family member 2/3 (Smad2/3) signaling pathway, and autophagy and inflammatory responses. Antioxidant supplementation (e.g., catalase, vitamin C, and selenium), induction of autophagy (e.g., rapamycin), blockade of inflammatory signaling (e.g., methylprednisolone) or treatment with PPAR-γ agonists (e.g., pioglitazone) may provide protective effects against these detrimental cardiac effects caused by T-2 toxin. We believe that our review provides new insights in understanding T-2 toxin exposure-induced cardiotoxicity and fuels effective prevention and treatment strategies against this important food-borne toxin-induced health problems.

Deoxynivalenol and its modified forms: key enzymes, inter-individual and interspecies differences in metabolism

Deoxynivalenol (DON) and its modified forms, including DON-3-glucoside (DON-3G), pose a major agricultural and food safety issue in the world. Their metabolites are relatively well-characterized; however, their metabolizing enzymes have not been fully explored. UDP-glucuronosyltransferases, 3-O-acetyltransferase, and glutathione S-transferase are involved in the formation of DON-glucuronides, 3-acetyl-DON, and DON-glutathione, respectively. There are interindividual differences in the metabolism of these toxins, including variation with respect to sex. Furthermore, interspecies differences in DON metabolism have been revealed, including differences in the major metabolites of DON, the role of de-acetylation, and the hydrolysis of DON-3G. In this review, we summarized the major enzymes involved in metabolizing DON to its modified forms, focusing on the differences in metabolism of DON and its modified forms between individuals and species. This work provides important insight into the toxicity of DON and its derivatives in humans and animals, and provides scientific basis for the development of safer and more efficient biological detoxification methods.

Deoxynivalenol: An Overview on Occurrence, Chemistry, Biosynthesis, Health Effects and Its Detection, Management, and Control Strategies in Food and Feed

Mycotoxins are fungi-produced secondary metabolites that can contaminate many foods eaten by humans and animals. Deoxynivalenol (DON), which is formed by Fusarium, is one of the most common occurring predominantly in cereal grains and thus poses a significant health risk. When DON is ingested, it can cause both acute and chronic toxicity. Acute signs include abdominal pain, anorexia, diarrhea, increased salivation, vomiting, and malaise. The most common effects of chronic DON exposure include changes in dietary efficacy, weight loss, and anorexia. This review provides a succinct overview of various sources, biosynthetic mechanisms, and genes governing DON production, along with its consequences on human and animal health. It also covers the effect of environmental factors on its production with potential detection, management, and control strategies.

Low-Concentration T-2 Toxin Attenuates Pseudorabies Virus Replication in Porcine Kidney 15 Cells

Pseudorabies, caused by pseudorabies virus (PRV), is the main highly infectious disease that severely affects the pig industry globally. T-2 toxin (T2), a significant mycotoxin, is widely spread in food and feeds and shows high toxicity to mammals. The potential mechanism of the interaction between viruses and toxins is of great research value because revealing this mechanism may provide new ideas for their joint prevention and control. In this study, we investigated the effect of T2 on PRV replication and the mechanism of action. The results showed that at a low dose (10 nM), T2 had no significant effect on porcine kidney 15 (PK15) cell viability. However, this T2 concentration alleviated PRV-induced cell injury and increased cell survival time. Additionally, the number of PK15 cells infected with PRV significantly reduced by T2 treatment. Similarly, T2 significantly decreased the copy number of PRV. Investigation of the mechanism revealed that 10 nM T2 significantly inhibits PRV replication and leads to downregulation of oxidative stress- and apoptosis-related genes. These results suggest that oxidative stress and apoptosis are involved in the inhibition of PRV replication in PK15 cells by low-concentration T2. Taken together, we demonstrated the protective effects of T2 against PRV infection. A low T2 concentration inhibited the replication of PRV in PK15 cells, and this process was accompanied by downregulation of the oxidative stress and apoptosis signaling pathways. Our findings partly explain the interaction mechanism between T2 and PRV, relating to oxidative stress and apoptosis, though further research is required.

Resveratrol Improves Intestinal Morphology and Anti-Oxidation Ability in Deoxynivalenol-Challenged Piglets

Simple Summary

Deoxynivalenol (DON)-contaminated feed may cause anorexia, vomiting, immunosuppression, and intestinal dysfunction in pigs, which would lead to growth retardation and great losses in the pig industry. In this study, the effects of resveratrol (RES) on growth performance, the intestinal barrier, antioxidant capacity, and mitochondrial function in weaned pigs fed with DON-contaminated diets were investigated. Dietary supplementation with resveratrol increased the average daily feed intake of piglets. Diets supplemented with resveratrol increased the villus height and the ratio of the jejunum villus height to crypt depth, increased the activities of superoxide dismutase (SOD), and increased the total antioxidant capacity in the jejunum mucosa. After being supplemented with RES, the level of reactive oxygen species (ROS) in mitochondria was decreased, while the mitochondrial membrane potential in the jejunum was increased. In conclusion, these results suggested that resveratrol effectively relieved DON-induced oxidative stress in weaned piglets, improved intestinal barrier function, enhanced mitochondrial function, and improved the growth performance of piglets.

Abstract

This study aimed to investigate the potential effects of resveratrol (RES) on intestinal function and oxidative stress in deoxynivalenol (DON)-challenged piglets. Twenty-four healthy Duroc × Yorkshire × Landrace weaned piglets at the age of 28 ± 1 days were randomly divided into four groups with six repetitions per group. The four groups were as follows: the control group (CON), fed with a basic diet; the RES group, fed with a basal diet + 300 mg/kg RES; the DON group, fed with a basal diet containing 2.65 mg/kg DON; and the DON + RES group, fed with a basal diet containing 2.65 mg/kg DON + 300 mg/kg RES. The results showed that the growth performance and intestinal function of DON-challenged piglets were significantly decreased (p < 0.05). Compared with the DON group, the average daily feed intake of piglets in the DON + RES group was significantly increased (p < 0.05). Additionally, dietary RES ameliorated DON-induced intestinal morphology impairment, as indicated by the increased (p < 0.05) jejunal villi height and the ratio of the jejunal villi height/crypt depth. Furthermore, after the addition of RES, the activities of superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) in the jejunum mucosa were significantly increased, and the content of malondialdehyde (MDA) was significantly declined (p < 0.05). In addition, the level of reactive oxygen species (ROS) in the mitochondria was significantly reduced by RES, while the mitochondrial membrane potential in jejunum was significantly increased by RES (p < 0.05). However, there was no obvious difference between DON + RES and DON groups on average daily gain and the ratio of feed togain, except for the significant inhibition of average daily feed intake (p < 0.05). In conclusion, RES could effectively alleviate the DON-induced oxidative stress on weaned piglets, and reduce the damage to mitochondria and intestinal morphology, so as to improve the growth performance of piglets.

Protective Effect of Selenomethionine on T-2 Toxin-Induced Rabbit Immunotoxicity

T-2 toxin is a trichothecene mycotoxin produced by fusarium species, which is mainly prevalent in grain and livestock feed. One of the main effects of this toxin is immunodepression. Previous studies have shown that T-2 toxin can cause damage to immune organs and impaired immune function in animals. However, selenomethionine (SeMet) as an organic selenium source can not only promote the growth and development of the body but also effectively improve the body's immune function. In this study, rabbits were exposed to 0.4-mg/kg T-2 toxin, and abnormal blood routine indicators were found in the rabbits. HE staining also showed obvious lesions in the spleen and thymus tissue structures, accompanied by a large number of bleeding points. In addition, rabbits showed strong oxidative stress and inflammatory response after T-2 toxin action. 0.2 mg/kg, 0.4 mg/kg, and 0.6 mg/kg organic selenium were added to the feed. However, it was found that 0.2 mg/kg selenium can effectively improve the abnormal changes of blood routine and spleen and thymus tissue of rabbits. On the other hand, it can significantly increase the expression of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and total antioxidant capacity (T-AOC) in the spleen and thymus, and downregulate the expression of reactive oxygen species (ROS) and malondialdehyde (MDA). In addition, inflammatory factors interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in blood were also significantly inhibited; the expression of proliferating cell nuclear antigen (PCNA) in the spleen and thymus was also significantly increased after low-dose selenium treatment. Surprisingly, 0.4 mg/kg and 0.6 mg/kg of selenium did not effectively alleviate the immunotoxic effects caused by T-2 toxin, and cause damage to a certain extent. In summary, our results show that 0.2 mg/kg of SeMet can effectively alleviate the immunotoxicity caused by T-2 toxin. Selenium may protect rabbits from T-2 toxin by improving its antioxidant and anti-inflammatory capabilities.

Reduction of Smad2 caused by oxidative stress leads to necrotic death of hypertrophic chondrocytes associated with an endemic osteoarthritis

OBJECTIVE

The occurrence and development of an endemic OA, Kashin-Beck disease (KBD), is closely related to oxidative stress induced by free radicals. The aim of the study was to find the key signalling molecules or pathogenic factors as a potential treatment strategy for KBD.

METHODS

Real-time PCR and western blotting were performed to detect the mRNA and protein expression levels in cells and tissues. Immunohistochemical staining was assayed in rat models and human samples obtained from children. The type of cell death was identified by annexin V and propidium iodide staining with flow cytometry.

RESULTS

Oxidative stress decreased levels of Smad2 and Smad3 in hypertrophic chondrocytes both in vitro and in vivo. In the cartilage of KBD patients, the expression of Smad2 and Smad3 proteins in the middle and deep zone was significantly decreased with an observed full deletion in the deep zone of some samples. Reduction of Smad2 protein induced necrotic death of hypertrophic chondrocytes, while reduction of Smad3 protein induced apoptosis. The reduction of Smad2 protein was not accompanied by Smad3 protein reduction in hypertrophic chondrocyte necrosis. Furthermore, the reduction of Smad2 also impaired the construction of tissue-engineered cartilage in vitro.

CONCLUSION

These studies reveal that oxidative stress causes necrosis of hypertrophic chondrocytes by downregulating Smad2 protein, which increases the pathogenesis of KBD cartilage. The importance of Smad2 in the development of KBD provides a new potential target for the treatment of KBD.

The Effect of Mycotoxins and Silymarin on Liver Lipidome of Mice with Non-Alcoholic Fatty Liver Disease

Milk thistle-based dietary supplements have become increasingly popular. The extract from milk thistle (Silybum marianum) is often used for the treatment of liver diseases because of the presence of its active component, silymarin. However, the co-occurrence of toxic mycotoxins in these preparations is quite frequent as well. The objective of this study was to investigate the changes in composition of liver lipidome and other clinical characteristics of experimental mice fed by a high-fat methionine-choline deficient diet inducing non-alcoholic fatty liver disease. The mice were exposed to (i) silymarin, (ii) mycotoxins (trichothecenes, enniatins, beauvericin, and altertoxins) and (iii) both silymarin and mycotoxins, and results were compared to the controls. The liver tissue extracts were analyzed by ultra-high performance liquid chromatography coupled with high-resolution tandem mass spectrometry. Using tools of univariate and multivariate statistical analysis, we were able to identify 48 lipid species from the classes of diacylglycerols, triacylglycerols, free fatty acids, fatty acid esters of hydroxy fatty acids and phospholipids clearly reflecting the dysregulation of lipid metabolism upon exposure to mycotoxin and/or silymarin.

Construction and potential application of bacterial superoxide dismutase expressed in Bacillus subtilis against mycotoxins

Oxidative stress, which could be evoked by numerous inducements including mycotoxins like deoxynivalenol (DON), cause severe damages to organisms. Antioxidants are promising protectants against oxidative stress that could be applied in pharmaceutical, cosmetic, and food and feed industries. In this study, a thermostable and acidophilic superoxide dismutase (AaSOD) was used to develop an antioxidant product that can potentially protect organisms from oxidative stress related damages. The enzyme was successfully expressed as an extracelluar protein in Bacillus subtilis with a high yield. To obtain a feasible protocol for industrial production of AaSOD, the fermentation mediums that are commonly used for culturing B. subtilis were screened, the feasibility of expressing AaSOD without antibiotic as selection pressure was confirmed, and the effect of using lactose as an inducer instead of isopropyl-β-d-thiogalactoside (IPTG) was investigated. Batch fermentation was conducted to validate the optimized conditions for AaSOD production, and 6530 U mL^-1 of SOD activity was obtained in the fermentation broth. The dry powder product of AaSOD with an activity of 22202 U g^-1 was prepared by spray-drying and was administrated on zebrafish to test its function as a protectant against DON, and thus gained a significant redress of the reactive oxygen species (ROS) accumulation induced by DON. Taken together, this study provides a feasible protocol to prepare the AaSOD-based antioxidant product that is potentially applied in livestock industry.

T-2 Toxin-The Most Toxic Trichothecene Mycotoxin: Metabolism, Toxicity, and Decontamination Strategies

Among trichothecenes, T-2 toxin is the most toxic fungal secondary metabolite produced by different Fusarium species. Moreover, T-2 is the most common cause of poisoning that results from the consumption of contaminated cereal-based food and feed reported among humans and animals. The food and feed most contaminated with T-2 toxin is made from wheat, barley, rye, oats, and maize. After exposition or ingestion, T-2 is immediately absorbed from the alimentary tract or through the respiratory mucosal membranes and transported to the liver as a primary organ responsible for toxin's metabolism. Depending on the age, way of exposure, and dosage, intoxication manifests by vomiting, feed refusal, stomach necrosis, and skin irritation, which is rarely observed in case of mycotoxins intoxication. In order to eliminate T-2 toxin, various decontamination techniques have been found to mitigate the concentration of T-2 toxin in agricultural commodities. However, it is believed that 100% degradation of this toxin could be not possible. In this review, T-2 toxin toxicity, metabolism, and decontamination strategies are presented and discussed.

Mycotoxins—Prevention, Detection, Impact on Animal Health

Mycotoxins are defined as secondary metabolites of some species of mold fungi. They are present in many foods consumed by animals. Moreover, they most often contaminate products of plant and animal origin. Fungi of genera Fusarium, Aspergillus, and Penicillum are most often responsible for the production of mycotoxins. They release toxic compounds that, when properly accumulated, can affect many aspects of breeding, such as reproduction and immunity, as well as the overall liver detoxification performance of animals. Mycotoxins, which are chemical compounds, are extremely difficult to remove due to their natural resistance to mechanical, thermal, and chemical factors. Modern methods of analysis allow the detection of the presence of mycotoxins and determine the level of contamination with them, both in raw materials and in foods. Various food processes that can affect mycotoxins include cleaning, grinding, brewing, cooking, baking, frying, flaking, and extrusion. Most feeding processes have a variable effect on mycotoxins, with those that use high temperatures having the greatest influence. Unfortunately, all these processes significantly reduce mycotoxin amounts, but they do not completely eliminate them. This article presents the risks associated with the presence of mycotoxins in foods and the methods of their detection and prevention.

MicroRNA Expression Profiling in Porcine Liver, Jejunum and Serum upon Dietary DON Exposure Reveals Candidate Toxicity Biomarkers

Deoxynivalenol (DON), a frequent mycotoxin worldwide, impairs human and animal health. The response of microRNAs, small non-coding RNAs, to DON has been scarcely investigated, but holds remarkable potential for biomarker applications. Hence, we aimed to investigate DON-induced changes in the microRNA expression in porcine liver, jejunum and serum by combining targeted and untargeted analyses. Piglets received uncontaminated feed or feed containing 900 µg/kg and 2500 µg/kg DON for four weeks, followed by a wash-out period. In tissue, only slight changes in microRNA expression were detected, with ssc-miR-10b being downregulated in liver of DON-exposed piglets. In serum, several microRNAs were differentially expressed upon DON exposure, four of which were validated by qPCR (ssc-miR-16, ssc-miR-128, ssc-miR-451, ssc-miR-205). The serum microRNA response to DON increased over time and declined after removal of contaminated diets. Receiver operating curve analyses for individual microRNAs were significant, and a combination of the four microRNAs increased the predictive capacity for DON exposure. Predicted microRNA target genes showed enrichment of several pathways including PIK3-AKT, Wnt/β-catenin, and adherens junctions. This study gives, for the first time, a comprehensive view of the porcine microRNA response to DON, providing a basis for future research on microRNAs as biomarkers for mycotoxins.

Deoxynivalenol: Mechanisms of action and its effects on various terrestrial and aquatic species

Deoxynivalenol, a type B trichothecene mycotoxin produced by Fusarium species of fungi, is a ubiquitious contaminant of cereal grains worldwide. Chronic, low dose consumption of feeds contaminated with DON is associated with a wide range of symptoms in terrestrial and aquatic species including decreased feed intake and feed refusal, reduced weight gain, and altered nutritional efficiency. Acute, high dose exposure to DON may be associated with more severe symptoms such as vomiting, diarrhea, intestinal inflammation and gastrointestinal hemorrhage. The toxicity of DON is partly related to its ability to disrupt eukaryotic protein synthesis via binding to the peptidyl transferase site of the ribosome. Moreover, DON exerts its effects at the cellular level by activating mitogen activated protein kinases (MAPK) through a process known as the ribotoxic stress response (RSR). The outcome of DON-associated MAPK activation is dose and duration dependent; acute low dose exposure results in immunostimulation characterized by the upregulation of cytokines, chemokines and other proinflammatory-related proteins, whereas longer term exposure to higher doses generally results in apoptosis, cell cycle arrest, and immunosuppression. The order of decreasing sensitivity to DON is considered to be: swine > rats > mice > poultry ≈ ruminants. However, studies conducted within the past 10 years have demonstrated that some species of fish, such as rainbow trout, are highly sensitive to DON. The aims of this review are to explore the effects of DON on terrestrial and aquatic species as well as its mechanisms of action, metabolism, and interaction with other Fusarium mycotoxins. Notably, a considerable emphasis is placed on reviewing the effects of DON on different species of fish.

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

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

The administration of diets contaminated with low to intermediate doses of deoxynivalenol and supplemented with antioxidants and binding agents slightly affects the growth, antioxidant status, and vaccine response in weanling pigs

This study aimed to evaluate the impact of grading levels of deoxynivalenol (DON) in the diet of weaned pigs, as well as the effects of a supplementation with antioxidants (AOX), hydrated sodium calcium aluminosilicates (HSCAS), and their combination on the growth, AOX status, and immune and vaccine responses against the porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2). At weaning, 336 piglets were allocated to six dietary treatments according to a randomized complete block design. Treatments were as follows: basal diet (CTRL); basal diet containing DON at 1.2 mg/kg (DON1.2); basal diet containing DON at 2.4 mg/kg (DON2.4); DON2.4 diet + a mix of AOX which included vitamins A and E at 20,000 IU and 200 IU/kg feed respectively, selenized yeast at 0.3 mg/kg, and a grape seed extracts at 100 mg/kg feed (DON2.4 + AOX); DON2.4 diet + the mix of AOX and the modified HSCAS mentioned above (DON2.4 + AOX + HSCAS); DON2.4 + AOX + HSCAS. Pigs were vaccinated against PRRSV and PCV2 at 7 d; on 0, 14, and 35 d, growth performance was recorded, and blood samples were collected in order to evaluate the oxidative status, inflammatory blood markers, lymphocyte blastogenic response, and vaccine antibody response. Increasing intake of DON resulted in a quadratic effect at 35 d in the lymphocyte proliferative response to concanavalin A and PCV2 as well as in the anti-PRRSV antibody response, whereas the catalase activity decreased in DON2.4 pigs compared with the CTRL and DON1.2 groups (P ≤ 0.05). Compared with the DON2.4 diet, the AOX supplementation slightly reduced gain to feed ratio (P = 0.026) and increased the ferric reducing ability of plasma as well as α-tocopherol concentration (P < 0.05), whereas the association of AOX + HSCAS increased the anti-PRRSV IgG (P < 0.05). Furthermore, the HSCAS supplement reduced haptoglobin levels in serum at 14 d compared with the DON2.4 group; however, its concentration decreased in all the experimental treatments from 14 to 35 d and particularly in the DON2.4 + AOX pigs, whereas a different trend was evidenced in the DON2.4 + HSCAS group, where over the same period haptoglobin concentration increased (P < 0.05). Overall, our results show that the addition of AOX and HSCAS in the diet may alleviate the negative effects due to DON contamination on the AOX status and immune response of vaccinated weanling pigs.

Comparative analysis of the detrimental in vitro effects of three fusariotoxins on the selected structural and functional characteristics of rabbit spermatozoa

In this study, we evaluated the in vitro effects of 1-50 μM zearalenone (ZEA), deoxynivalenol (DON) and T-2 toxin (T-2) on rabbit spermatozoa for as much as 8 h of in vitro exposure. Our results indicate that all sperm quality parameters were negatively affected by these fusariotoxins in a time- and dose-dependent manner. The most prominent structure affected by ZEA was the plasma membrane, exhibiting alterations consistent with the onset of apoptosis and reactive oxygen species (ROS) overproduction. This correlated with the most prominent decline of the sperm motility among all selected fusariotoxins. Significant necrotic changes and mitochondrial dysfunction were primarily responsible for the sperm damage in the presence of T-2. Finally, exposure of spermatozoa to DON led to a significant decrease in the DNA integrity. This study may provide new information on the specific mechanisms of action involved in the in vitro toxic behavior of fusariotoxins on male gametes.

Role of DNA methylation-related chromatin remodeling in aryl hydrocarbon receptor-dependent regulation of T-2 toxin highly inducible Cytochrome P450 1A4 gene

Mycotoxins are toxic secondary metabolites produced by food-contaminating fungi, which lead to global epigenetic changes and cause toxicity to both farm animals and humans. However, whether mycotoxins induce gene-specific epigenetic alterations associated with inducible downstream gene expression is unclear as are the underlying regulatory mechanisms. Here, we found that T-2 toxin and its deacetylated metabolites but not deoxynivalenol (DON) or other representative mycotoxins highly induced the expression of cytochrome P450 1A4 (CYP1A4) in both Leghorn male hepatoma (LMH) cells and chicken primary hepatocytes, and this effect was related to the regulation of both aryl hydrocarbon receptor (AhR) and DNA methylation. We used methylation-sensitive restriction enzyme digestion-qPCR (MSRE-qPCR) and chromatin immunoprecipitation (ChIP) assays and found that the binding of DNA methyltransferase 1 (DNMT1) and histone deacetylase 2 (HDAC2) to highly methylated CpG island 3-2 at the enhancer of CYP1A4 was accompanied by the recruitment of the repressive histone modification marker H3K27me3, inducing a silent state. In turn, T-2 toxin stimulation enriched the binding of AhR to demethylated CpG island 3-2, which facilitated p300 and H3K9ac recruitment and ultimately generated an activated chromatin structure at the enhancer by increasing the active histone modification markers, including H3K4me3, H3K27ac, and H3K14ac. Interestingly, T-2 toxin-induced AhR activation also facilitated RNA polymerase II binding to CpG island 2, which may form a transcriptionally active chromatin structure at the promoter and ultimately transactivate CYP1A4. Our findings provide novel insights into the epigenetic regulation of T-2 toxin-induced gene expression.

Hypothesis: Long non-coding RNA is a potential target of mycotoxins

The molecular target of mycotoxins is not fully understood. Extensive data derived from cell and animal experimental studies demonstrate that long non-coding RNAs (lncRNAs) play crucial roles in mycotoxin-induced toxicities. Mycotoxins stimulate the upregulation/downregulation of lncRNA expression, which further promote apoptosis, is related to the mTOR/FoxO signaling pathway, and contributes to tumor cell growth, death, and liver and chondrocyte damage. Moreover, lncRNA can establish interactions with NF-κB and cause immune evasion. These preliminary data suggest that lncRNAs are involved in potential upstream regulatory events and further regulate downstream apoptosis, oxidative stress, and anti-apoptotic events that affect cell death and survival. Therefore, we hypothesize that lncRNAs are potential targets of mycotoxins. Investigation of the expression of the potential target lncRNAs by mycotoxin-mediated stimulation, and exploration of the upstream and downstream relationship between lncRNA and the key proteins involved in mycotoxin toxicity, should be performed. This Hypothesis provides clues for further understanding of the molecular mechanisms of mycotoxins.