Comparison of Anorectic Potencies of the Trichothecenes T-2 Toxin, HT-2 Toxin and Satratoxin G to the Ipecac Alkaloid Emetine

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

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

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.

Determination of T-2 and HT-2 Toxins in Seed of Milk Thistle [Silybum marianum (L.) Gaertn.] Using Immunoaffinity Column by UPLC-MS/MS

Milk thistle [Silybum marianum (L.) Gaertn.] achieved a significant increase in interest over the past few years from local and foreign pharmaceutical corporations. The silymarin complex of constituents extracted from milk thistle achenes provides compelling health benefits primarily thanks to antioxidant activities and hepatoprotective effects. However, consuming mycotoxin-contaminated plant material can cause immunosuppression and hepatotoxic problems. The aim of this study was to develop and validate a method for the determination of mycotoxin content in milk thistle. Fusarium toxins as T-2 and HT-2 toxins in grown milk thistle harvested from a breeding station in the Czech Republic during 2020-2021 were studied. The analysis of T-2 and HT-2 toxins was performed by UPLC-MS/MS after immunoaffinity columns EASI-EXTRACT® T-2 & HT-2 clean up. All analysed samples of milk thistle were contaminated with T-2 toxin and HT-2 toxin. The content of T-2 toxin in the samples from 2020 was in the range of 122.7-290.2 µg/kg and HT-2 toxin 157.0-319.0 µg/kg. In 2021, the content of T-2 toxin was in the range of 28.8-69.9 µg/kg and HT-2 toxin was 24.2-75.4 µg/kg. The results show that the climatic conditions of the year of harvesting have a highly statistically significant effect on the content of T-2 and HT-2 toxins in milk thistle.

Patulin and Trichothecene: characteristics, occurrence, toxic effects and detection capabilities via clinical, analytical and nanostructured electrochemical sensing/biosensing assays in foodstuffs

Patulin and Trichothecene as the main groups of mycotoxins in significant quantities can cause health risks from allergic reactions to death on both humans and animals. Accordingly, rapid and highly sensitive determination of these toxics agents is of great importance. This review starts with a comprehensive outlook regarding the characteristics, occurrence and toxic effects of Patulin and Trichothecene. In the following, numerous clinical and analytical approaches have been extensively discussed. The main emphasis of this review is placed on the utilization of novel nanomaterial based electrochemical sensing/biosensing tools for highly sensitive determination of Patulin and Trichothecene. Furthermore, a detailed and comprehensive comparison has been performed between clinical, analytical and sensing methods. Subsequently, the nanomaterial based electrochemical sensing platforms have been approved as reliable tools for on-site analysis of Patulin and Trichothecene in food processing and manufacturing industries. Different nanomaterials in improving the performance of detecting assays were investigated and have various benefits toward clinical and analytical methods. This paper would address the limitations in the current developments as well as the future challenges involved in the successful construction of sensing approaches with the functionalized nanomaterials and also allow exploring into core-research works regarding this area.

Confrontation assays and mycotoxin treatment reveal antagonistic activities of Trichoderma and the fate of Fusarium mycotoxins in microbial interaction

Mycotoxins are toxic fungal metabolites, contaminating cereal grains in field or during processing and storage periods. These environmental contaminants pose great threats to humans and animals' health due to their toxic effects. Type A trichothecenes, fumonisins and fusaric acid (FA) are commonly detected mycotoxins produced by various Fusarium species. Trichoderma spp. are promising antagonists in agriculture for their activities against plant pathogens, and also regarded as potential candidates for bioremediation of environmental contaminants. Managing toxigenic fungi by antagonistic Trichoderma is regarded as a sustainable and eco-friendly strategy for mycotoxin control. However, the metabolic activities of Trichoderma on natural occurring mycotoxins were less investigated. Our current work comprehensively explored the activities of Trichoderma against type A trichothecenes, fumonisins and FA producing Fusarium species via co-culture competition and indirect volatile assays. Furthermore, we investigated metabolism of type A trichothecenes and FA in Trichoderma isolates. Results indicated that Trichoderma were capable of bio-transforming T-2 toxin, HT-2 toxin, diacetoxyscirpenol and neosolaniol into their glycosylated forms and one Trichoderma strain could bio transform FA into low toxic fusarinol. These findings proved that Trichoderma isolates could manage toxigenic Fusarium via direct competition and volatile-mediated indirect inhibition. In addition, these antagonists possess defensive systems against mycotoxins for self-protection, which enriches our understanding on the interaction mechanism of Trichoderma spp. on toxigenic fungus.

Effects of dietary T-2 toxin on gut health and gut microbiota composition of the juvenile Chinese mitten crab (Eriocheir sinensis)

The current study aims to investigate the effects of dietary T-2 toxin on the intestinal health and microflora in the juvenile Chinese mitten crab (Eriocheir sinensis) with an initial weight 2.00 ± 0.05 g. Juvenile crabs were fed with experimental diets supplemented with T-2 toxin at 0 (control), 0.6 (T1 group), 2.5 (T2 group) and 5.0 (T3 group) mg/kg diet for 8 weeks. Dietary T-2 toxin increased the malondialdehyde (MDA) content and the expression of Kelch-like ECH-associated protein 1 (keap1) gene while the expression of cap 'n' collar isoform C (CncC) decreased in the intestine. The activities of glutathione peroxidase (GSH-Px) and total anti-oxidation capacity (T-AOC) in the intestine increased only in the lower dose of dietary T-2. Dietary T-2 toxin significantly increased the mRNA expression of caspase-3, caspase-8, Bax and mitogen-activated protein kinase (MAPK) genes and the ratio of Bax to Bcl-2 accompanied with a reduction of Bcl-2 expression. Furthermore, T-2 toxin decreased the mRNA levels of antimicrobial peptides (AMPs), peritrophic membrane (PM1 and PM2) and immune regulated nuclear transcription factors (Toll-like receptor: TLR, myeloid differentiation primary response gene 88: Myd88, relish and lipopolysaccharide-induced TNF-α factor: LITAF). The richness and diversity of the gut microbiota were also affected by dietary T-2 toxin in T3 group. The similar dominant phyla in the intestine of the Chinese mitten crab in the control and T3 groups were found including Bacteroidetes, Firmicutes, Tenericutes and Proteobacteria. Moreover, the inclusion of dietary T-2 toxin of 4.6 mg/kg significantly decreased the richness of Bacteroidetes and increased the richness of Firmicutes, Tenericutes and Proteobacteria in the intestine. At the genus level, Dysgonomonas and Romboutsia were more abundant in T3 group than those in the control. However, the abundances of Candidatus Bacilloplasma, Chryseobacterium and Streptococcus in T3 group were lower than those in the control. This study indicates that T-2 toxin could cause oxidative damage and immunosuppression, increase apoptosis and disturb composition of microbiota in the intestine of Chinese mitten crab.

Mycotoxin contamination of food and feed in the Gulf Cooperation Council countries and its detection

Mycotoxins are secondary metabolites produced by different fungal spices and are found in diverse agricultural crops worldwide; they pose a severe threat to public health. Mycotoxins can cause either acute or chronic symptoms, depending on the type and dose of mycotoxin one has been exposed to. Thus, a continuous monitoring of mycotoxins is needed. Since the discovery of mycotoxins, numerous countries, including the Gulf Cooperation Council (GCC) countries, have established mycotoxin-specific regulations for feed and food. Although a number of studies in GCC countries have investigated the presence of mycotoxins, till date, there are no reviews focusing on the mycotoxin contamination of the food and feed from this region. This review is the first study to present an up-to-date overview of the occurrence of mycotoxins in feed and food in the GCC countries and to discuss the techniques used for mycotoxin analysis.

Alternaria host-specific (HSTs) toxins: An overview of chemical characterization, target sites, regulation and their toxic effects

Alternaria causes pathogenic disease on various economically important crops having saprophytic to endophytic lifecycle. Pathogenic fungi of Alternaria species produce many primary and secondary metabolites (SMs). Alternaria species produce more than 70 mycotoxins. Several species of Alternaria produce various phytotoxins that are host-specific (HSTs) and non-host-specific (nHSTs). These toxins have various negative impacts on cell organelles including chloroplast, mitochondria, plasma membrane, nucleus, Golgi bodies, etc. Non-host-specific toxins such as tentoxin (TEN), Alternaric acid, alternariol (AOH), alternariol 9-monomethyl ether (AME), brefeldin A (dehydro-), Alternuene (ALT), Altertoxin-I, Altertoxin-II, Altertoxin-III, zinniol, tenuazonic acid (TeA), curvularin and alterotoxin (ATX) I, II, III are known toxins produced by Alternaria species. In other hand, Alternaria species produce numerous HSTs such as AK-, AF-, ACT-, AM-, AAL- and ACR-toxin, maculosin, destruxin A, B, etc. are host-specific and classified into different family groups. These mycotoxins are low molecular weight secondary metabolites with various chemical structures. All the HSTs have different mode of actions, biochemical reactions, and signaling mechanisms to causes diseases in the host plants. These HSTs have devastating effects on host plant tissues by affecting biochemical and genetic modifications. Host-specific mycotoxins such as AK-toxin, AF-toxin, and AC-toxin have the devastating effect on plants which causes DNA breakage, cytotoxic, apoptotic cell death, interrupting plant physiology by mitochondrial oxidative phosphorylation and affect membrane permeability. This article will elucidate an understanding of the disease mechanism caused by several Alternaria HSTs on host plants and also the pathways of the toxins and how they caused disease in plants.

Anorectic responses to T-2 toxin, HT-2 toxin, diacetoxyscirpenol and neosolaniol correspond to plasma elevations of neurotransmitters 5-hydroxytryptamine and substance P

Trichothecene mycotoxins commonly contaminate cereal grains and are often linked to human and animal food poisoning. The rapid onset of anorexia is a common hallmark of trichothecenes-induced toxicity. Although the neurotransmitters 5-hydroxytryptamine (5-HT) and substance P (SP) are known to regulate appetite, it remains unknown whether these two neurotransmitters are involved in type A trichothecenes-induced anorectic response. The goal of this study is to relate plasma 5-HT and SP to anorectic responses induced by type A trichothecenes T-2 toxin (T-2), HT-2 toxin (HT-2), diacetoxyscirpenol (DAS) and neosolaniol (NEO). These four toxins evoked robust anorectic response and secretion of plasma 5-HT and SP at 1 mg/kg bw. Following oral exposure, plasma 5-HT and SP were elevated and all peaked at 2 h for T-2, HT-2, DAS and NEO. Following intraperitoneal (IP) administration, plasma 5-HT and SP were peaked at 6 h, 6 h, 2 h, 2 h and 2 h, 6 h, 2 h, 2 h for T-2, HT-2, DAS and NEO, respectively. Elevations of plasma 5-HT and SP markedly corresponded to anorexia induction by T-2, HT-2, DAS and NEO. Altogether, the results presented herein indicated that 5-HT and SP play contributory roles in anorectic responses induced by T-2, HT-2, DAS and NEO.

Review article: Role of satiety hormones in anorexia induction by Trichothecene mycotoxins

The trichothecenes, produced by Fusarium, contaminate animal feed and human food in all stages of production and lead to a large spectrum of adverse effects for animal and human health. An hallmark of trichothecenes toxicity is the onset of emesis followed by anorexia and food intake reduction in different animal species (mink, mice and pig). The modulation of emesis and anorexia can result from a direct action of trichothecenes in the brain or from an indirect action in the gastrointestinal tract. The direct action of trichothecenes involved specific brain areas such as nucleate tractus solitarius in the brainstem and the arcuate nuclei in the hypothalamus. Activation of these areas in the brain leads to the activation of specific neuronal populations containing anorexigenic factors (POMC and CART). The indirect action of trichothecenes in the gastrointestinal tract involved, by enteroendocrine cells, the secretion of several gut hormones such as cholecystokinin (CCK) and peptide YY (PYY) but also glucagon-like peptide 1 (GLP-1), gastric inhibitory peptide (GIP) and 5-hydroxytryptamine (5-HT), which transmitted signals to the brain via the gut-brain axis. This review summarizes current knowledge on the effects of trichothecenes, especially deoxynivalenol, on emesis and anorexia and discusses the mechanisms underlying trichothecenes-induced food reduction.

Multi-trichothecene mycotoxin exposure activates glutathione-redox system in broiler chicken

Co-occurrence of mycotoxin contamination of feeds is a frequent problem, therefore the purpose of this study was to evaluate the combined effect of T-2 toxin and deoxynivalenol (DON) on lipid peroxidation, parameters and regulation of the glutathione redox system in broiler chickens in a sub-chronic (7 day) study. The applied doses were: low mix: 0.23 mg T-2 toxin and 4.96 mg DON/kg feed; medium mix: 1.21 mg T-2 toxin and 12.38 mg DON/kg feed; and high mix: 2.42 T-2 toxin and 24.86 mg DON/kg feed. Liver samples were taken on days 0, 1, 2, 3, and 7 of the feeding trial. Lipid peroxidation decreased significantly as compared to the control on days 3 and 7 as effect of low and high doses, which can be related to the activation of the antioxidant system, which is supported by the elevated glutathione peroxidase activity and reduced glutathione concentration as compared to the control on day 3 in the medium and high dose groups. Gene expression of glutathione peroxidase 4 (GPX4) elevated on day 1 in a dose dependent manner, and showed continuous elevation in the highest dose group thereafter. The results suggested that common exposure of T-2 toxin and DON induced oxidative stress in the liver of broiler chickens, which activated the enzymatic antioxidant system, and consequently decreased lipid peroxidation.

Role of Glucagon-Like Peptide-1 and Gastric Inhibitory Peptide in Anorexia Induction Following Oral Exposure to the Trichothecene Mycotoxin Deoxynivalenol (Vomitoxin)

Deoxynivalenol (DON), which is a Type B trichothecene mycotoxin produced by Fusarium, frequently contaminates cereal staples, such as wheat, barley and corn. DON threatens animal and human health by suppressing food intake and impairing growth. While anorexia induction in mice exposed to DON has been linked to the elevation of the satiety hormones cholecystokinin and peptide YY3-36 in plasma, the effects of DON on the release of other satiety hormones, such as glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP), have not been established. The purpose of this study was to determine the roles of GLP-1 and GIP in DON-induced anorexia. In a nocturnal mouse food consumption model, the elevation of plasma GLP-1 and GIP concentrations markedly corresponded to anorexia induction by DON. Pretreatment with the GLP-1 receptor antagonist Exendin9-39 induced a dose-dependent attenuation of both GLP-1- and DON-induced anorexia. In contrast, the GIP receptor antagonist Pro3GIP induced a dose-dependent attenuation of both GIP- and DON-induced anorexia. Taken together, these results suggest that GLP-1 and GIP play instrumental roles in anorexia induction following oral exposure to DON, and the effect of GLP-1 is more potent and long-acting than that of GIP.

Comparison of Anorectic Potencies of Type A Trichothecenes T-2 Toxin, HT-2 Toxin, Diacetoxyscirpenol, and Neosolaniol

Trichothecene mycotoxins are common contaminants in cereal grains and negatively impact human and animal health. Although anorexia is a common hallmark of type B trichothecenes-induced toxicity, less is known about the anorectic potencies of type A trichothecenes. The purpose of this study was to compare the anorectic potencies of four type A trichothecenes (T-2 toxin (T-2), HT-2 toxin (HT-2), diacetoxyscirpenol (DAS), and neosolaniol (NEO)) in mice. Following oral exposure to T-2, HT-2, DAS, and NEO, the no observed adverse effect levels (NOAELs) and lowest observed adverse effect levels (LOAELs) were 0.01, 0.01, 0.1, and 0.01 mg/kg body weight (BW), and 0.1, 0.1, 0.5, and 0.1 mg/kg BW, respectively. Following intraperitoneal (IP) exposure to T-2, HT-2, DAS, and NEO, the NOAELs were 0.01 mg/kg BW, except for DAS (less than 0.01 mg/kg BW), and the LOAELs were 0.1, 0.1, 0.01, and 0.1 mg/kg BW, respectively. Taken together, the results suggest that (1) type A trichothecenes could dose-dependently elicit anorectic responses following both oral gavage and IP exposure in mice; (2) the anorectic responses follow an approximate rank order of T-2 = HT-2 = NEO > DAS for oral exposure, and DAS > T-2 = HT-2 = NEO for IP administration; (3) IP exposure to T-2, HT-2, DAS, and NEO evoked stronger anorectic effects than oral exposure. From a public health perspective, comparative anorectic potency data should be useful for establishing toxic equivalency factors for type A trichothecenes.

Anorectic response to the trichothecene T-2 toxin correspond to plasma elevations of the satiety hormone glucose-dependent insulinotropic polypeptide and peptide YY3-36

T-2 toxin, a potent type A trichothecene mycotoxin, is produced by various Fusarium species and can negatively impact animal and human health. Although anorexia induction is a common hallmark of T-2 toxin-induced toxicity, the underlying mechanisms for this adverse effect are not fully understood. The goal of this study was to determine the roles of two gut satiety hormones, glucose-dependent insulinotropic polypeptide (GIP) and Peptide YY_3-36 (PYY_3-36) in anorexia induction by T-2 toxin. Elevations of plasma GIP and PYY_3-36 markedly corresponded to anorexia induction following oral exposure to T-2 toxin using a nocturnal mouse anorexia model. Direct administration of exogenous GIP and PYY_3-36 similarly induced anorectic responses. Furthermore, the GIP receptor antagonist Pro3GIP dose-dependently attenuated both GIP- and T-2 toxin-induced anorectic responses. Pretreatment with NPY2 receptor antagonist JNJ-31020028 induced a dose-dependent attenuation of both PYY_3-36- and T-2 toxin-induced anorectic responses. To summarize, these findings suggest that both GIP and PYY_3-36 might be critical mediators of anorexia induction by T-2 toxin.

Mycotoxin: Its Impact on Gut Health and Microbiota

The secondary metabolites produced by fungi known as mycotoxins, are capable of causing mycotoxicosis (diseases and death) in human and animals. Contamination of feedstuffs as well as food commodities by fungi occurs frequently in a natural manner and is accompanied by the presence of mycotoxins. The occurrence of mycotoxins' contamination is further stimulated by the on-going global warming as reflected in some findings. This review comprehensively discussed the role of mycotoxins (trichothecenes, zearalenone, fumonisins, ochratoxins, and aflatoxins) toward gut health and gut microbiota. Certainly, mycotoxins cause perturbation in the gut, particularly in the intestinal epithelial. Recent insights have generated an entirely new perspective where there is a bi-directional relationship exists between mycotoxins and gut microbiota, thus suggesting that our gut microbiota might be involved in the development of mycotoxicosis. The bacteria-xenobiotic interplay for the host is highlighted in this review article. It is now well established that a healthy gut microbiota is largely responsible for the overall health of the host. Findings revealed that the gut microbiota is capable of eliminating mycotoxin from the host naturally, provided that the host is healthy with a balance gut microbiota. Moreover, mycotoxins have been demonstrated for modulation of gut microbiota composition, and such alteration in gut microbiota can be observed up to species level in some of the studies. Most, if not all, of the reported effects of mycotoxins, are negative in terms of intestinal health, where beneficial bacteria are eliminated accompanied by an increase of the gut pathogen. The interactions between gut microbiota and mycotoxins have a significant role in the development of mycotoxicosis, particularly hepatocellular carcinoma. Such knowledge potentially drives the development of novel and innovative strategies for the prevention and therapy of mycotoxin contamination and mycotoxicosis.

Preparation of T-2-glucoronide with Rat Hepatic Microsomes and Its Use along with T-2 for Activation of the JAK/STAT Signaling Pathway in RAW264.7 Cells

T-2 toxin (T-2), one of the most toxic trichothecene A-type mycotoxins, is biotransformed in animal tissues to modified T-2s (mT-2s) including T-2-glucuronide (T-2-GlcA). In this study, the optimal conditions for T-2-GlcA synthesis were established, and the JAK/STAT pathway in RAW264.7 cells was used to study the toxicity of T-2-GlcA. Because many mT-2 standards are not readily available, optimal conditions for T-2-GlcA synthesis in vitro were established by incubating T-2 with rat liver microsomes, UDPGA, and 0.2% Triton X-100 for 90 min. qRT-PCR and Western blot results showed 21- and 760-fold increases in IL-6 mRNA expression induced by T-2-GlcA and T-2, respectively. Similar differences were observed in JAK3, SOCS2/3, and CIS mRNA expression. T-2-GlcA induced a dose-responsive decrease in STAT1 mRNA expression, whereas the result with T-2 was the opposite. Moreover, the phosphorylation of STAT3 induced by T-2-GlcA was higher than that by T-2, whereas the phosphorylation of STAT1 was to the contrary. Overall, the results show that T-2-GlcA was somewhat toxic, but activation of the JAK/STAT pathway in RAW264.7 was higher by T-2.

Cytotoxicity of T-2 and modified T-2 toxins: induction of JAK/STAT pathway in RAW264.7 cells by hepatopancreas and muscle extracts of shrimp fed with T-2 toxin

T-2 can be biotransformed in animal tissues to modified T-2s (mT-2s). Food contaminated with T-2 and/or mT-2s is a hazard to both animals and humans, including the immune system. In this study, Litopenaeus vannamei were fed T-2 orally for 20 d, and hepatopancreas and muscle extracts, T-2, and T-2-glucuronide (T-2-GluA) were added to RAW264.7 in vitro and their effects on the JAK/STAT pathway were examined. STAT2 mRNA gene expression induced by hepatopancreas and muscle extracts was markedly higher compared with that of T-2 or T-2-GluA group. SCOSs, IL-6 and IL-1β mRNA gene expressions induced by hepatopancreas extract were greater than those induced by muscle extract. Muscle extract significantly activated STAT3 phosphorylation but inhibited STAT1 phosphorylation. Activation of the JAK/STAT pathway by hepatopancreas mT-2s was significantly higher than that by muscle extracts. Muscle and hepatopancreas extracts and T-2 also significantly induced IL-6 mRNA gene expression. With reference to phosphorylation levels, significant activation of JAK1 and STAT2 occurred with T-2 and JAK3 by muscle extract, JAK2 by hepatopancreas extract and STAT1 by T-2-GluA. This study showed that both T-2 and mT-2s are cytotoxic but the activation of the JAK/STAT pathway in RAW264.7 cells by T-2 was greater than that by mT-2s in hepatopancreas and muscle extracts from T-2-fed Litopenaeus vannamei.

Appropriateness to set a group health based guidance value for T2 and HT2 toxin and its modified forms

The EFSA Panel on Contaminants in the Food Chain (CONTAM) established a tolerable daily intake (TDI) for T2 and HT2 of 0.02 μg/kg body weight (bw) per day based on a new in vivo subchronic toxicity study in rats that confirmed that immune- and haematotoxicity are the critical effects of T2 and using a reduction in total leucocyte count as the critical endpoint. An acute reference dose (ARfD) of 0.3 μg for T2 and HT2/kg bw was established based on acute emetic events in mink. Modified forms of T2 and HT2 identified are phase I metabolites mainly formed through hydrolytic cleavage of one or more of the three ester groups of T2. Less prominent hydroxylation reactions occur predominantly at the side chain. Phase II metabolism involves conjugation with glucose, modified glucose, sulfate, feruloyl and acetyl groups. The few data on occurrence of modified forms indicate that grain products are their main source. The CONTAM Panel found it appropriate to establish a group TDI and a group ARfD for T2 and HT2 and its modified forms. Potency factors relative to T2 for the modified forms were used to account for differences in acute and chronic toxic potencies. It was assumed that conjugates (phase II metabolites of T2, HT2 and their phase I metabolites), which are not toxic per se, would be cleaved releasing their aglycones. These metabolites were assigned the relative potency factors (RPFs) of their respective aglycones. The RPFs assigned to the modified forms were all either 1 or less than 1. The uncertainties associated with the present assessment are considered as high. Using the established group, ARfD and TDI would overestimate any risk of modified T2 and HT2.

Potential roles for calcium-sensing receptor (CaSR) and transient receptor potential ankyrin-1 (TRPA1) in murine anorectic response to deoxynivalenol (vomitoxin)

Food contamination by the trichothecene mycotoxin deoxynivalenol (DON, vomitoxin) has the potential to adversely affect animal and human health by suppressing food intake and impairing growth. In mice, the DON-induced anorectic response results from aberrant satiety hormone secretion by enteroendocrine cells (EECs) of the gastrointestinal tract. Recent in vitro studies in the murine STC-1 EEC model have linked DON-induced satiety hormone secretion to activation of calcium-sensing receptor (CaSR), a G-coupled protein receptor, and transient receptor potential ankyrin-1 (TRPA1), a TRP channel. However, it is unknown whether similar mechanisms mediate DON's anorectic effects in vivo. Here, we tested the hypothesis that DON-induced food refusal and satiety hormone release in the mouse are linked to activation of CaSR and TRPA1. Oral treatment with selective agonists for CaSR (R-568) or TRPA1 (allyl isothiocyanate (AITC)) suppressed food intake in mice, and the agonist's effects were suppressed by pretreatment with corresponding antagonists NPS-2143 or ruthenium red (RR), respectively. Importantly, NPS-2143 or RR inhibited both DON-induced food refusal and plasma elevations of the satiety hormones cholecystokinin (CCK) and peptide YY_3-36 (PYY_3-36); cotreatment with both antagonists additively suppressed both anorectic and hormone responses to DON. Taken together, these in vivo data along with prior in vitro findings support the contention that activation of CaSR and TRPA1 contributes to DON-induced food refusal by mediating satiety hormone exocytosis from EEC.

Modelling the anorectic potencies of food-borne trichothecenes by benchmark dose and incremental area under the curve methodology

Fusarium spp. fungi produce a spectrum of trichothecene mycotoxins that often simultaneously contaminate cereal grains. These have the potential to contribute jointly to adverse effects such as anorexia and emesis. For the purposes of risk assessment and regulation, it is desirable to assign toxic equivalency factors (TEFs) to each of these trichothecenes, as has been successfully done for anthropogenic toxicants such as polyhalogenated aromatic hydrocarbons. As a first step towards this end, we employed a mouse model to compare the anorectic potencies of deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), nivalenol (NIV), fusarenon-X (FUS-X), T-2 and HT-2 toxin (T-2 and HT-2) following oral exposure by gavage using two approaches. In the first approach, the US Environmental Protection Agency (US EPA) benchmark dose (BMD) method for continuous data was used to calculate the BMD relative to DON 2 h after dosing. The order of potency based on BMD values was: DON(1) ≈ 3-ADON(1) ≈ 15-ADON(1) < NIV(3) < HT-2(5) < FUS-X(9) << T-2(124). In a second approach, time course effects of each toxin at fixed doses were measured by calculating the incremental area under the curve (IAUC) over 16 h. DON caused significant feed refusal within the first 30 min after exposure, lasting only 3 h while for 3-ADON and 15-ADON, feed refusal lasted 6 h. NIV, FUS-X, T-2, and HT-2 toxins caused the longest duration of feed refusal, lasting up to 16 h. Based on IAUC values, the order of relative potency was as follows: DON(1) < 3-ADON(2) ≈ 15-ADON(2) < NIV(7) < FUS-X(10) << T-2(31) < HT-2(34). These results provide a foundation for developing consensus TEFs that will be amenable to future risk assessment of trichothecene mixtures.