T-2 toxin is hydroxylated by chicken CYP3A37

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.

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.

Chicken CYP1A5 is able to hydroxylate aflatoxin B1 to aflatoxin M1

Aflatoxin B1 (AFB1), a naturally-occurring mycotoxin, can cause severe toxicological and carcinogenic effects in livestock and humans. Given that the chicken is one of the most important food-producing animals, knowledge regarding AFB1 metabolism and enzymes responsible for AFB1 transformation in the chicken has important implications for chicken production and food safety. Previously, we have successfully expressed chicken CYP1A5 and CYP3A37 monooxygenases in E. coli, and reconstituted them into a functional CYP system consisting of CYP1A5 or CYP3A37, CPR and cytochrome b5. In this study, we aimed to investigate the roles of CYP1A5 and CYP3A37 in the bioconversion of AFB1 to AFM1. Our results showed that chicken CYP1A5 was able to hydroxylate AFB1 to AFM1. The formation of AFM1 followed the typical Michaelis-Menten kinetics. The kinetics parameters of Vmax and Km were determined as 0.83 ± 0.039 nmol/min/nmol P450 and 26.9 ± 4.52 μM respectively. Docking simulations further revealed that AFB1 adopts a "side-on" conformation in chicken CYP1A5, facilitating the hydroxylation of the C9a atom and the production of AFM1. On the other hand, AFB1 assumes a "face-on" conformation in chicken CYP3A37, leading to the displacement of the C9a atom from the heme iron and explaining the lack of AFM1 hydroxylation activity. The results demonstrate that chicken CYP1A5 possesses efficient hydroxylase activity towards AFB1 to form AFM1.

Toxicity and detoxification of T-2 toxin in poultry

This review summarizes the updated knowledge on the toxicity of T-2 on poultry, followed by potential strategies for detoxification of T-2 in poultry diet. The toxic effects of T-2 on poultry include cytotoxicity, genotoxicity, metabolism modulation, immunotoxicity, hepatotoxicity, gastrointestinal toxicity, skeletal toxicity, nephrotoxicity, reproductive toxicity, neurotoxicity, etc. Cytotoxicity is the primary toxicity of T-2, characterized by inhibiting protein and nucleic acid synthesis, altering the cell cycle, inducing oxidative stress, apoptosis and necrosis, which lead to damages of immune organs, liver, digestive tract, bone, kidney, etc., resulting in pathological changes and impaired physiological functions of these organs. Glutathione redox system, superoxide dismutase, catalase and autophagy are protective mechanisms against oxidative stress and apoptosis, and can compensate the pathological changes and physiological functions impaired by T-2 to some degree. T-2 detoxifying agents for poultry feeds include adsorbing agents (e.g., aluminosilicate-based clays and microbial cell wall), biotransforming agents (e.g., Eubacterium sp. BBSH 797 strain), and indirect detoxifying agents (e.g., plant-derived antioxidants). These T-2 detoxifying agents could alleviate different pathological changes to different degrees, and multi-component T-2 detoxifying agents can likely provide more comprehensive protection against the toxicity of T-2.

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.

Dimethyl Sulfoxide: Morphological, Histological, and Molecular View on Developing Chicken Liver

Dimethyl sulfoxide (DMSO) is widely used as a solvent for small hydrophobic drug molecules. However, the safe volume allowing to avoid its embryotoxic effect has been poorly studied. In this study, we documented the effects of dimethyl sulfoxide (DMSO) in the developing chicken embryo at morphological, histological, and molecular levels. We focused on the developing chicken liver as the main organ involved in the process of detoxification. In our study, 100% DMSO was administered subgerminally onto the eggshell membrane (membrana papyracea) at various volumes (5, 10, 15, 20, 25, 30, 35, and 50 µL) on 4th embryonic day (ED). We focused on histopathological alterations of the liver structure, and noticed the overall impact of DMSO on developing chicken embryos (embryotoxicity, malformation). At the molecular level, we studied cytochrome P450 complex (CYP) isoform's activities in relation to changes of CYP1A5, CYP3A37, and CYP3A80 gene expression. Total embryotoxicity after application of different doses of DMSO on ED 4, and the embryo lethality increased with increasing DMSO amounts. Overall mortality after DMSO administration ranged below 33%. Mortality was increased with higher amounts of DMSO, mainly from 20 µL. The highest mortality was observed for the highest dose of DMSO over 35 µL. The results also showed a decrease in body weight with increased application volumes of DMSO. At the histological level, we observed mainly the presence of lipid droplets and dilated bile canaliculi and sinusoids in samples over the administration of 25 µL of DMSO. While these findings were not statistically significant, DMSO treatment caused a significant different up-regulation of mRNA expression in all studied genes. For CYP1A5, CYP3A37, and CYP3A80 DMSO volumes needed were 15 µL, 10 µL, and 20 µL, respectively. A significant down-regulation of all studied CYP isoform was detected after application of a DMSO dose of 5 µL. Regarding the morphological results, we can assume that the highest safe dose of DMSO without affecting chicken embryo development and its liver is up to 10 µL. This conclusion is corroborated with the presence of number of malformations and body weight reduction, which correlates with histological findings. Moreover, the gene expression results showed that even the lowest administered DMSO volume could affect hepatocytes at the molecular level causing down-regulation of cytochrome P450 complex (CYP1A5, CYP3A37, CYP3A80).

Mycotoxins: Biotransformation and Bioavailability Assessment Using Caco-2 Cell Monolayer

The determination of mycotoxins content in food is not sufficient for the prediction of their potential in vivo cytotoxicity because it does not reflect their bioavailability and mutual interactions within complex matrices, which may significantly alter the toxic effects. Moreover, many mycotoxins undergo biotransformation and metabolization during the intestinal absorption process. Biotransformation is predominantly the conversion of mycotoxins meditated by cytochrome P450 and other enzymes. This should transform the toxins to nontoxic metabolites but it may possibly result in unexpectedly high toxicity. Therefore, the verification of biotransformation and bioavailability provides valuable information to correctly interpret occurrence data and biomonitoring results. Among all of the methods available, the in vitro models using monolayer formed by epithelial cells from the human colon (Caco-2 cell) have been extensively used for evaluating the permeability, bioavailability, intestinal transport, and metabolism of toxic and biologically active compounds. Here, the strengths and limitations of both in vivo and in vitro techniques used to determine bioavailability are reviewed, along with current detailed data about biotransformation of mycotoxins. Furthermore, the molecular mechanism of mycotoxin effects is also discussed regarding the disorder of intestinal barrier integrity induced by mycotoxins.

Disruption of cytochrome P450 enzymes in the liver and small intestine in chicken embryos in ovo exposed to glyphosate

Glyphosate is the active component of several commercial formulations as in Roundup®. The present study was investigated the toxic effects of pure glyphosate or Roundup® on the liver and small intestine of chick embryos. On day 6, a total of 180 fertile eggs injected with deionized water (control group), 10 mg pure glyphosate, or 10 mg of the active ingredient glyphosate in Roundup®/kg egg mass. The results showed an increase in relative weights of the liver in embryos that treated with Roundup®. Furthermore, oxidative stress was observed in the embryos treated with glyphosate or Roundup®, increased total superoxide dismutase, and content of malondialdehyde in the liver and intestine; moreover, decrease of glutathione peroxidase in the liver with increased in the intestine compared with the control. Besides, glutamic-pyruvic transaminase was increased in Roundup® group compared with other groups. Moreover, histopathological alterations in the liver and intestine tissues were observed in treated groups. Suppression of hepatic CYP1A2, CYP1A4, CYP1B1, and MDR1 mRNA expression after exposed to Roundup®. Furthermore, inhibition of CYP1A4 in the duodenum, CYP1A4, and MRP2 in the jejunum in embryos exposed to glyphosate or Roundup®. In addition, glyphosate treatment caused an increase of CYP3A5, CYP1C1, and IFNY mRNA expression in the jejunum and CYP1A2 expression in the ileum, while IFN-Y gene increase in embryos treated with Roundup®. In conclusion, in ovo exposure to glyphosate caused histopathological alterations and induced oxidative stress in the liver and small intestines. Moreover, the expression of cytochrome P450, MDR1, and MRP2 transporters was also modulated in the liver and small intestines for chick embryos.

Detoxification of Mycotoxins through Biotransformation

Mycotoxins are toxic fungal secondary metabolites that pose a major threat to the safety of food and feed. Mycotoxins are usually converted into less toxic or non-toxic metabolites through biotransformation that are often made by living organisms as well as the isolated enzymes. The conversions mainly include hydroxylation, oxidation, hydrogenation, de-epoxidation, methylation, glycosylation and glucuronidation, esterification, hydrolysis, sulfation, demethylation and deamination. Biotransformations of some notorious mycotoxins such as alfatoxins, alternariol, citrinin, fomannoxin, ochratoxins, patulin, trichothecenes and zearalenone analogues are reviewed in detail. The recent development and applications of mycotoxins detoxification through biotransformation are also discussed.

Hepatic transcriptional profile and tissue distribution of cytochrome P450 1-3 genes in the red-crowned crane Grus japonensis

The endangered red-crowned crane (Grus japonensis) is a protected species in eastern Hokkaido and injured specimens are treated with medication. The present study aimed at understanding the expression profiles of cytochrome P450 (CYP) 1-3 genes in red-crowned crane tissues. We used 14 individuals found dead in the wild in eastern Hokkaido or in Kushiro City Zoo. Nine CYP1-3 genes expressed in the liver of the red-crowned crane were identified by high-throughput sequencing, and phylogenetically classified as CYP1A5, CYP2C23, CYP2C45, CYP2D49, CYP2G19, CYP2U1, CYP2AC1, CYP3A37, and CYP3A80. Based on the quantitative real-time PCR of 13 samples, the rank order of their median expression levels was as follows: CYP3A37 > CYP2AC1 > CYP2C45 > CYP2D49 > CYP2G19 > CYP1A5 > CYP3A80 > CYP2C23. The tissue distribution of the CYP transcripts indicated that many of the CYP1-3 genes examined were mainly expressed in the tissues where drug metabolism occurs, such as the liver, kidneys, and lungs. We found that CYP3A37 was dominant at the transcript level in the liver, indicating it might play a crucial role in liver physiology and xenobiotic metabolism. Similarly, an "orphan" CYP2AC1 was expressed at relatively high levels in the kidneys and liver, suggesting a possible role in renal and liver physiology and xenobiotic metabolism. Our results establish a foundation for future studies on red-crowned cranes aiming to further understand drug sensitivity and develop medication protocols, but also contribute to national and local projects for the conservation of red-crowned crane.

T-2 toxin in the diet suppresses growth and induces immunotoxicity in juvenile Chinese mitten crab (Eriocheir sinensis)

The T-2 toxin is a trichothecene mycotoxin and is highly toxic to aquatic animals, but little is known on its toxic effect in crustaceans. In the present study, the crab juveniles were fed with diets containing four levels of T-2 toxin: 0 (control), 0.6 (T1), 2.5 (T2) and 5.0 (T3) mg/kg diet for 56 days to evaluate its impact on the juvenile of Chinese mitten crab (Eriocheir sinensis). The crabs fed the T-2 toxin diets had significantly lower weight gain and specific growth rate than those fed the control diet. Moreover, crab survival in T3 group was obviously lower than that in the control. Oxidative stress occurred in all the treatment groups as indicated by higher activities of total superoxide dismutase, glutathione peroxidase, and total antioxidant capacity than those in the control. The total hemocyte count, respiratory burst, phenoloxidase in the hemolymph, and phenoloxidase, acid phosphatase and alkaline phosphatase in the hepatopancreas of crabs fed T-2 toxin were significantly lower than those in the control. The transcriptional expressions of lipopolysaccharide-induced TNF-alpha factor, relish, and the apoptosis genes in the hepatopancreas were induced by dietary T-2 toxin. The genes related to detoxication including cytochrome P450 gene superfamily and glutathione S transferase were induced in low concentration, then decreased in high concentration. Dietary T-2 toxin damaged the hepatopancreas structure, especially as seen in the detached basal membrane of hepatopancreatic tubules. This study indicates that dietary T-2 toxin can reduce growth performance, deteriorate health status and cause hepatopancreas dysfunction in crabs.

Activated FXR promotes xenobiotic metabolism of T-2 toxin and attenuates oxidative stress in broiler chicken liver

The transmission of T-2 toxin and its metabolites into the edible tissues of poultry has potential effects on human health. The bile acid and xenobiotic system composes an intricate physiological network of chemoprotective and transporter-related functions, which ensures the detoxification and removal of harmful xenobiotic and endobiotic compounds from the body. This study revealed that cholic acid (CA), as one of the bile acids, promoted the metabolism of T-2 toxin in vivo by inducing the xenobiotic metabolism enzymes expression, thereby increasing the stress resistance and attenuating the oxidative stress. This study also indicated that dietary supplementation of 1% CA alleviated the mortality caused by T-2 toxin. Liver histology results demonstrated that CA supplementation significantly reduced inflammatory cell infiltration, sinusoidal expansion and congestion. Biochemistry results showed that the elevations of plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and the increase in concentration of hydrogen peroxide (H₂O₂) in liver induced by the T-2 toxin were decreased by dietary supplementation of 1% CA. Additionally, CA supplementation led to the increase in superoxide dismutase (SOD) activity, but the decrease in catalase (CAT) activity in broiler chicken livers. Based on these findings, we propose that activation of FXR promotes T-2 toxin xenobiotic metabolism, and FXR plays a hepatoprotection role in liver injury induced by T-2 toxin.

Effect of T-2 toxin-injected shrimp muscle extracts on mouse macrophage cells (RAW264.7)

Following intramuscular injections of 0.1 mL, 3 mg kg^-1BW^-1(1/10 LD₅₀) T-2 toxin (T-2), the tissue concentration of T-2 in shrimp was quantitatively detected using LC-MS/MS. The biological half-time (t_1/2) of T-2 in blood was 40.47 ± 0.24 min. The highest number of intramuscular T-2 shrimp could tolerate when given at blood t_1/2 intervals was 4. The shrimps which were injected 5 T-2 died. The T-2 toxin highest accumulation was 0.471 ± 0.012 ng g^-1BW^-1. The effect of toxic shrimp muscle subjected to different processing conditions (high pressure, trifluoroacetic acid, acid and alkali digestions, artificial digestive juice [to simulate exposure to gastric and intestinal juices]) on mouse macrophage cells (RAW267.4) were evaluated by the MTT assay. The inhibition ratio of 2% muscle extract on RAW267.4 was 85.70 ± 2.63%. The immunocytotoxicity of muscle extracts to RAW264.7 was highest in muscle extracts subjected to physical and chemical digestion (high pressure > NaOH > trifluoroacetic acid > 0.02 M HCl > 0.2 M HCl > controls), and also artificial digestion (artificial intestinal juice > artificial gastric juice > N type intestinal juice > N type gastric liquid > controls). Results showed that high-pressure and artificial intestinal juice were most effective in the release of modified T-2 to free T-2 thus enhancing toxicity. These results can be interpreted as measurement of T-2 in food being of little value because of enhanced toxicity of T-2-contaminated food as they pass through the gastrointestinal tract.

Mycotoxins: cytotoxicity and biotransformation in animal cells

Mycotoxins are secondary metabolites produced by many microfungi. Hitherto, over 300 mycotoxins with diverse structures have been identified. They contaminate most cereals and feedstuffs, which threaten human and animal health by exerting acute, sub-acute and chronic toxicological effects, with some considered as carcinogens. Many mycotoxins at low concentrations are able to induce the expression of cytochrome P450 and other enzymes implicated in the biotransformation and metabolization of mycotoxins in vivo and in vitro. Mycotoxins and their metabolites elicit different cellular disorders and adverse effects such as oxidative stress, inhibition of translation, DNA damage and apoptosis in host cells, thus causing various kinds of cytotoxicities. In this review, we summarize the biotransformation of mycotoxins in animal cells by CYP450 isoforms and other enzymes, their altered expression under mycotoxin exposure, and recent progress in mycotoxin cytotoxicity in different cell lines. Furthermore, we try to generalize the molecular mechanisms of mycotoxin effects in human and animal cells.

The roles of carboxylesterase and CYP isozymes on the in vitro metabolism of T-2 toxin

BACKGROUND

T-2 toxin poses a great threat to human health because it has the highest toxicity of the currently known trichothecene mycotoxins. To understand the in vivo toxicity and transformation mechanism of T-2 toxin, we investigated the role of one kind of principal phase I drug-metabolizing enzymes (cytochrome P450 [CYP450] enzymes) on the metabolism of T-2 toxin, which are crucial to the metabolism of endogenous substances and xenobiotics. We also investigated carboxylesterase, which also plays an important role in the metabolism of toxic substances.

METHODS

A chemical inhibition method and a recombinant method were employed to investigate the metabolism of the T-2 toxin by the CYP450 enzymes, and a chemical inhibition method was used to study carboxylesterase metabolism. Samples incubated with human liver microsomes were analyzed by high performance liquid chromatography-triple quadrupole mass spectrometry (HPLC- QqQ MS) after a simple pretreatment.

RESULTS

In the presence of a carboxylesterase inhibitor, only 20 % T-2 toxin was metabolized. When CYP enzyme inhibitors and a carboxylesterase inhibitor were both present, only 3 % of the T-2 toxin was metabolized. The contributions of the CYP450 enzyme family to T-2 toxin metabolism followed the descending order CYP3A4, CYP2E1, CYP1A2, CYP2B6 or CYP2D6 or CYP2C19.

CONCLUSION

Carboxylesterase and CYP450 enzymes are of great importance in T-2 toxin metabolism, in which carboxylesterase is predominant and CYP450 has a subordinate role. CYP3A4 is the principal member of the CYP450 enzyme family responsible for T-2 toxin metabolism. The primary metabolite produced by carboxylesterase is HT-2, and the main metabolite produced by CYP 3A4 is 3'-OH T-2. The different metabolites show different toxicities. Our results will provide useful data concerning the toxic mechanism, the safety evaluation, and the health risk assessment of T-2 toxin.

Fusariotoxins in Avian Species: Toxicokinetics, Metabolism and Persistence in Tissues

Fusariotoxins are mycotoxins produced by different species of the genus Fusarium whose occurrence and toxicity vary considerably. Despite the fact avian species are highly exposed to fusariotoxins, the avian species are considered as resistant to their toxic effects, partly because of low absorption and rapid elimination, thereby reducing the risk of persistence of residues in tissues destined for human consumption. This review focuses on the main fusariotoxins deoxynivalenol, T-2 and HT-2 toxins, zearalenone and fumonisin B1 and B2. The key parameters used in the toxicokinetic studies are presented along with the factors responsible for their variations. Then, each toxin is analyzed separately. Results of studies conducted with radiolabelled toxins are compared with the more recent data obtained with HPLC/MS-MS detection. The metabolic pathways of deoxynivalenol, T-2 toxin, and zearalenone are described, with attention paid to the differences among the avian species. Although no metabolite of fumonisins has been reported in avian species, some differences in toxicokinetics have been observed. All the data reviewed suggest that the toxicokinetics of fusariotoxins in avian species differs from those in mammals, and that variations among the avian species themselves should be assessed.

In vitro and in vivo metabolite profiling of valnemulin using ultraperformance liquid chromatography-quadrupole/time-of-flight hybrid mass spectrometry

Valnemulin, a semisynthetic pleuromutilin derivative related to tiamulin, is broadly used to treat bacterial diseases of animals. Despite its widespread use, metabolism in animals has not yet been fully investigated. To better understand valnemulin biotransformation, in this study, metabolites of valnemulinin in in vitro and in vivo rats, chickens, swines, goats, and cows were identified and elucidated using ultraperformance liquid chromatography-quadrupole/time-of-flight hybrid mass spectrometry (UPLC-Q/TOF-MS). As a result, there were totally 7 metabolites of valnemulin identified in vitro and 75, 61, and 74 metabolites detected in in vivo rats, chickens, and swines, respectively, and the majority of metabolites were reported for the first time. The main metabolic pathways of valnemulin were found to be hydroxylation in the mutilin part (the ring system) and the side chain, oxidization on the sulfur of the side chain to form S-oxides, hydrolysis of the amido bond, and acetylization in the amido of the side chain. In addition, hydroxylation in the mutilin part was proposed to be the primary metabolic route. Furthermore, the results revealed that 2β-hydroxyvalnemulin (V1) and 8α-hydroxyvalnemulin (V2) were the major metabolites for rats and swines and S-oxides (V6) in chickens.

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

Trichothecenes are a large family of structurally related toxins mainly produced by Fusarium genus. Among the trichothecenes, T-2 toxin and deoxynivalenol (DON) cause the most concern due to their wide distribution and highly toxic nature. Trichothecenes are known for their inhibitory effect on eukaryotic protein synthesis, and oxidative stress is one of their most important underlying toxic mechanisms. They are able to generate free radicals, including reactive oxygen species, which induce lipid peroxidation leading to changes in membrane integrity, cellular redox signaling, and in the antioxidant status of the cells. The mitogen-activated protein kinases signaling pathway is induced by oxidative stress, which also induces caspase-mediated cellular apoptosis pathways. Several new metabolites and novel metabolic pathways of T-2 toxin have been discovered very recently. In human cell lines, HT-2 and neosolaniol (NEO) are the major metabolites of T-2 toxin. Hydroxylation on C-7 and C-9 are two novel metabolic pathways of T-2 toxin in rats. The metabolizing enzymes CYP3A22, CYP3A29, and CYP3A46 in pigs, as well as the enzymes CYP1A5 and CYP3A37 in chickens, are able to catalyze T-2 toxin and HT-2 toxin to form the C-3'-OH metabolites. Similarly to carboxylesterase, CYP3A29 possesses the hydrolytic ability in pigs to convert T-2 toxin to NEO. T-2 toxin is able to down- or upregulate cytochrome P-450 enzymes in different species. The metabolism of DON in humans is region-dependent. Free DON and DON-glucuronide are considered to be the biomarkers for humans. The masked mycotoxin DON-3-β-D-glucoside can be hydrolyzed to free DON in the body. This review will provide useful information on the progress of oxidative stress as well as on the metabolism and the metabolizing enzymes of T-2 toxin and DON. Moreover, the literature will throw light on the blind spots of metabolism and toxicological studies in trichothecenes that have to be explored in the future.