Identification and apoptotic potential of T-2 toxin metabolites in human cells

T-2 Toxin Induces Kidney Fibrosis via the mtROS-NLRP3-Wnt/β-Catenin Axis

T-2 toxin causes kidney fibrosis. Wnt/β-catenin signaling promotes kidney fibrosis when sustained and activated. However, whether T-2-induced kidney fibrosis involves Wnt/β-catenin signaling activation has not been explored yet. T-2 toxin causes renal mitochondrial damage, leading to mitochondrial reactive oxygen species (mtROS) overproduction and NLRP3-inflammasome activation. The activated NLRP3-inflammasome can mediate fibrosis. However, whether the NLRP3-inflammasome can be mediated by mtROS and further regulate T-2-induced kidney fibrosis through Wnt/β-catenin signaling is unclear. In this study, first, we confirmed that T-2 toxin caused Wnt/β-catenin signaling activation in mice kidneys and HK-2 cells. Second, we confirmed that mtROS activated the NLRP3-inflammasome in T-2-exposed mice kidneys and HK-2 cells. Third, we confirmed that the NLRP3-inflammasome regulated the Wnt/β-catenin signaling in T-2 toxin-exposed mice kidneys and HK-2 cells. Finally, we confirmed that Wnt/β-catenin signaling regulated fibrosis in T-2 toxin-exposed mice kidneys and HK-2 cells. The above results confirm that T-2 toxin induces kidney fibrosis via the mtROS-NLRP3-Wnt/β-catenin axis.

Metabolic profiling as a powerful tool for the analysis of cellular alterations caused by 20 mycotoxins in HepG2 cells

Mycotoxins are secondary fungal metabolites which exhibit toxic effects in low concentrations. Several mycotoxins are described as carcinogenic or immunosuppressive, but their underlying modes of action especially on molecular level have not yet been entirely elucidated. Metabolic profiling as part of the omics methods is a powerful tool to study the toxicity and the mode of action of xenobiotics. The use of hydrophilic interaction chromatography in combination with targeted mass spectrometric detection enables the selective and sensitive analysis of more than 100 polar and ionic metabolites and allows the evaluation of metabolic alterations caused by xenobiotics such as mycotoxins. For metabolic profiling, the hepato-cellular carcinoma cell line HepG2 was treated with sub-cytotoxic concentrations of 20 mycotoxins. Moniliformin and citrinin significantly affected target elements of the citric acid cycle, but also influenced glycolytic pathways and energy metabolism. Penitrem A, zearalenone, and T2 toxin mainly interfered with the urea cycle and the amino acid homeostasis. The formation of reactive oxygen species seemed to be influenced by T2 toxin and gliotoxin. Glycolysis was altered by ochratoxin A and DNA synthesis was affected by several mycotoxins. The observed effects were not limited to these metabolic reactions as the metabolic pathways are closely interrelated. In general, metabolic profiling proved to be a highly sensitive tool for hazard identification in comparison to single-target cytotoxicity assays as metabolic alterations were already observed at sub-toxic concentrations. Metabolic profiling could therefore be a powerful tool for the overall evaluation of the toxic properties of xenobiotics.

PINK1/Parkin-mediated mitophagy mitigates T-2 toxin-induced nephrotoxicity

T-2 toxin can cause mitochondrial impairment and subsequent renal damage. PINK1/Parkin-mediated mitophagy can mitigate renal impairment by alleviating mitochondrial damage. Nevertheless, the impact of PINK1/Parkin-mediated mitophagy in T-2 toxin-induced renal injury remains unclear. Here, we studied the role of PINK1/Parkin-mediated mitophagy in T-2 toxin-induced nephrotoxicity. Mitochondrial damage was accompanied by NLRP3-inflammasome activation and PINK1/Parkin-mediated mitophagy in the kidney of T-2 toxin-exposed C57BL/6N mice. Knocking out Parkin inhibited the mitophagy but aggravated the structural and functional damage, NLRP3-inflammasome activation, mitochondrial damage, and apoptosis. Correlation analysis revealed that NLRP3-inflammasome activation was correlated with apoptosis. These results show that PINK1/Parkin-mediated mitophagy mitigates T-2 toxin-induced nephrotoxicity.

Potential Role of Individual and Combined Effects of T-2 Toxin, HT-2 Toxin and Neosolaniol on the Apoptosis of Porcine Leydig Cells

T-2 toxin usually co-occurs with HT-2 toxin and neosolaniol (NEO) in the grains and feed. Our previous studies found that T-2 toxin and its metabolites’ binary or ternary combination exposure to porcine Leydig cells (LCs) displayed synergism in certain range of dosage and cannot be predicted based on individual toxicity. However, the possible mechanism of these mycotoxins’ combined exposure to cell lesions remains unknown. Based on 50% cell viability, the mechanism of apoptosis in porcine Leydig cells was investigated after exposure to T-2, HT-2, NEO individual and binary or ternary combinations. Compared with control, the adenosine triphosphate (ATP) content decreased, reactive oxygen species (ROS) level increased, and mitochondrial membrane potential (MMP) decreased in all treated groups. Additionally, the cell apoptosis rates were significantly increased in test groups (p < 0.05), and the B-cell lymphoma 2 (Bcl-2) Associated X (Bax)/Bcl-2 ratio and the expression of caspase 3, caspase 8, cytochrome c (Cytc) in the treated group are all significantly higher than the control group. Moreover, the expression of Cytc and caspase 8 gene in NEO and T-2+NEO groups was significantly higher than that in other individual and combined groups. It can be concluded that the toxicities of T-2, HT-2, and NEO individually and in combination can induce apoptosis related to the oxidative stress and mitochondrial damage, and the synergistic effect between toxins may be greater than a single toxin effect, which is beneficial for assessing the possible risk of the co-occurrences in foodstuffs to human and animal health.

The Protective Effect of Selenium on T-2-Induced Nephrotoxicity Is Related to the Inhibition of ROS-Mediated Apoptosis in Mice Kidney

T-2 toxin is produced by the Fusarium genus. Ingestion of food or feed contaminated by T-2 toxin will cause damage to kidney. Selenium (Se), an essential trace element, showed the significant protective effects against kidney and renal cell damage induced by toxic substances. To explore the protective effects and mechanisms of Se against T-2-induced renal lesions, forty-eight male Kunming mice were exposed to T-2 toxin (1.0 mg/kg) and/or Se (0.2 mg/kg) for 28 days. In this study, we found that Se alleviated T-2-induced nephrotoxicity, presenting as increasing the body weight and kidney coefficient, relieving the renal structure injury, decreasing the contents of renal function-related biomarkers, decreasing the levels of reactive oxygen species (ROS), and increasing the mitochondrial membrane potential in T-2 toxin-treated mice. In addition, inhibition of renal cell apoptosis by Se was associated with blocking the mitochondrial pathway in T-2 toxin-treated mice, presenting as decreasing the protein expression of cytochrome-c, activities of caspase-3/9, as well as regulating the protein and mRNA expressions of Bax and Bcl-2. These results documented that the alleviating effect of Se on T-2-induced nephrotoxicity is related to the inhibition of ROS-mediated renal apoptosis.

T-2 toxin and its metabolites: Characterization, cytotoxic mechanisms and adaptive cellular response in human hepatocarcinoma (HepG2) cells

The T-2 toxin (T-2) is a type A trichothecene produced by Fusarium species, and the most cytotoxic mycotoxin of the group. A study was made to determine T-2 cytotoxicity in human hepatocarcinoma (HepG2) cells; evaluate whether there is an adaptive response of HepG2 cells exposed to low concentrations of T-2; identify the T-2 metabolites by LC-Q-TOF MS; and determine whether T-2 disrupts cell proliferation in HepG2 cells. The IC₅₀ values obtained ranged from 61.9 ± 2.4 nM to 70.7 ± 7.4 nM. No adaptive response was observed. There was no evidence of extra- or intracellular accumulation of T-2 after 24 h of exposure as determined by LC-Q-TOF MS. However, some T-2 metabolites such as HT-2 toxin, neosolaniol and T-2 triol showed important (>75%) intracellular accumulation. Cell distribution was significantly increased in SubG0/G1 phase (11.8-fold higher) and decreased (12%) in G2/M phase at 60 nM T-2, versus the control. Simultaneously, increased necrosis (238%) and apoptosis/necrosis (up to 35.5%) were observed in HepG2 cells exposed to T-2. In conclusion, the results show that T-2 leads to loss of cell viability without an adaptive response, and that the metabolites generated play an important role in T-2 cytotoxicity, increasing HepG2 cell damage.

Metabolism of T-2 Toxin in Farm Animals and Human In Vitro and in Chickens In Vivo Using Ultra High-Performance Liquid Chromatography- Quadrupole/Time-of-Flight Hybrid Mass Spectrometry Along with Online Hydrogen/Deuterium Exchange Technique

After being incubated with animal and human liver microsomes, metabolites of phase I and II were investigated. A comparison was performed by ultrahigh performance liquid chromatography-quadrupole/time-of-flight coupled to mass spectrometry (UHPLC-Q/TOF). Consequently, a total of four phase I metabolites and three glucuronide binding metabolites of T-2 toxin were discovered. Although a significant metabolic difference was observed among six species, HT-2 toxin was the major product in all species. In addition, the in vivo metabolism of T-2 toxin after oral administration was also investigated in chickens, In total, 18 metabolites were detected, of which 13 were novel, to our knowledge, and reported for the first time. To elucidate the structures of these metabolites, besides accurate mass data from their MS and MS² spectra, online hydrogen/deuterium (H/D) exchange technique was also carried out. These new metabolites were regarded as 3'-hydroxy-T-2 3-sulfate, 3'-hydroxy-HT-2 3-sulfate, 4'-hydroxy-HT-2, 3',4'-dihydroxy-HT-2, 4'-carboxyl-T-2, 4'-carboxyl-HT-2, 4'-carboxyl-4'-hydroxy-T-2, and their isomers, implying that T-2 toxin was metabolized more extensively in animals than previously thought. Furthermore, 3'-hydroxy-HT-2, 4'-carboxyl-T-2, 3'-hydroxy-T-2, HT-2 toxin, and neosolaniol were identified to be the major metabolites of T-2 toxin in chickens. The present study expands existing knowledge about T-2 toxin metabolism, informing assessments of the impact T-2 toxin exposure and metabolism on health.

Impact of Mechanical and Thermal Energies on the Degradation of T-2 and HT-2 Toxins during Extrusion Cooking of Oat Flour

The type A trichothecenes T-2 toxin (T-2) and HT-2 toxin (HT-2) are naturally occurring toxic food contaminants, with the highest concentrations found in contaminated oats. The influence of thermal food processing on these toxins is poorly understood, and only a few publications address the degradation rates. Therefore, we systematically investigated the degradation of T-2 and HT-2 during both laboratory and industrial-scale extrusion cooking of oats. Extrusion cooking under laboratory conditions was performed with oats fortified with T-2 or HT-2 as well as with naturally contaminated oat flour dust. The experiments were designed according to industrial conditions in terms of temperature, water content, pressure, residence time, and oat content. Flour mixtures containing naturally contaminated oats were used for industrial-scale processing. Degradation rates under laboratory conditions were up to 59.6 ± 1.51 and 47.2 ± 0.53% for T-2 and HT-2, respectively, in fortified extrudates but were decreased to 35.1 ± 1.55 and 22.0 ± 4.68% when naturally contaminated flour samples were used. The results show a higher degradation of T-2 during extrusion cooking than of HT-2. Moisture content, mechanical shear, and temperature showed an impact on the toxin degradation and can be optimized to counteract food contamination.

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.

Cytotoxicity and apoptosis induced by mixed mycotoxins (T-2 and HT-2 toxin) on primary hepatocytes of broilers in vitro

T-2 and HT-2 (T-2/HT-2) induced cytotoxicity and apoptosis in hepatocytes from broilers. In this study, hepatocytes treated with T-2/HT-2 were analyzed for cytotoxic effects and apoptosis and for the associated mechanisms. To assay cytotoxicity, we used the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) viability assay, hematoxylin-eosin staining and aspartase transaminase and alanine transaminase (ALT/AST) activities. We evaluated apoptosis by fluorescence microscopy using the Terminal transferase nick-end labeling (TUNEL) assay. The apoptotic ratio and the apoptotic stage of the hepatocytes were next assessed with fluorescently labeled (FITC) Annexin V and propidium iodide (PI) staining. Finally, expression levels of apoptosis-related mRNAs were assessed by real-time PCR and those of apoptosis-related proteins by western blotting. We found that cells treated with T-2/HT-2 showed, in a dose dependent manner, significantly lower cell viabilities (P < 0.05) and markedly increased intercellular spaces, dead cells and ALT/AST activities. T-2/HT-2 treatment also significantly increased the number of apoptotic cells and the apoptotic ratio (P < 0.05). T-2/HT-2 induced early stage apoptosis of the hepatocytes and levels of apoptosis-related mRNAs and proteins changed in a manner implicating them in the apoptotic process. These changes occurred from 0 to 24 h of T-2/HT-2 exposure. Expression of bax and caspase-7 mRNAs was significantly upregulated, in a time-dependent manner, during this period (P < 0.05). Levels of mRNAs for caspase-3 and caspase-9 were increased from 0 to 12 h (P < 0.05) and then decreased after 12 h (P < 0.05). There were no significant effects on expression of bcl-2 mRNA (P > 0.05). Expression of all apoptosis-related proteins examined, except for bcl-2, was significantly increased from 0 to 24 h in a time-dependent manner (P < 0.05). Overall, T-2/HT-2 induced cytotoxicity and apoptosis in hepatocytes. The resulting changes in mRNA and protein expression were shown that several apoptosis-related proteins were involved in the liver toxicity of these agents.

Mycotoxin mechanisms of action and health impact: ‘in vitro’ or ‘in vivo’ tests, that is the question

The aim of this paper is to present examples of in vitro and in vivo tests for mycotoxin mechanisms of action and evaluation of health effects, with a focus on the gut environment and toxicity testing. In vivo investigations may provide information on the net effects of mycotoxins in whole animals, whereas in vitro models represent effective tools to perform simplified experiments under uniform and well-controlled conditions and a suitable alternative to in vivo animal testing providing insights not achievable with animal studies. The main limits of in vitro models are the lack of interactions with other cells and extracellular factors, lack of hormonal or immunological influences, and lack or different levels of in vitro expression of genes involved in the overall response to mycotoxins. The translation of in vitro data into meaningful in vivo effects remains an unsolved problem. The main issues to be considered are the mycotoxin concentration range in accordance with levels encountered in realistic situations, the identification of reliable biomarkers of mycotoxin toxicity, the measurement of the chronic toxicity, the evaluation of single- or multi-toxin challenge. The gastrointestinal wall is the first barrier preventing the entry of undesirable substances. The intestinal epithelium can be exposed to high concentrations of mycotoxins upon ingestion of contaminated food and the amount of mycotoxin consumed via food does not always reflect the amount available to exert toxic actions in a target organ. In vitro digestion models in combination with intestinal epithelial cells are powerful tools to screen and predict the in vivo bioavailability and digestibility of mycotoxins in contaminated food and correctly estimate health effects. In conclusion, in vitro and in vivo tests are complementary approaches for providing a more accurate picture of the health impact of mycotoxins and improved understanding and evaluation of relevant dietary exposure and risk scenarios.

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.

Cell-based models for mycotoxin screening and toxicity evaluation: an update

This review presents the applications of cell-based models in mycotoxin research, with a focus on models for mycotoxin screening and cytotoxicity evaluation. Various cell-based models, cell and cell culture condition related factors, toxicity endpoints and culture systems as well as predictive value of cell-based bioassays are reviewed. Advantages, drawbacks and technical problems regarding set up and validation of consistent, robust, reproducible and high-throughput cell-based models are discussed. Various cell-based models have been developed and used as screening tests for mycotoxins but the data obtained are difficult to compare. However, the results highlight the potential of cell-based models as promising in vitro platforms for the initial screening and cytotoxicity evaluation of mycotoxins and as a significant analytical approach in mycotoxin research before any animal or human clinical studies. To develop cell-based models as powerful high-throughput laboratory platforms for the analysis of large numbers of samples, there are mainly two fundamental requirements that should be met, i.e. the availability of easy-to-use and, if possible, automated cell platforms and the possibility to obtain reproducible results that are comparable between laboratories. The transition from a research model to a test model still needs optimisation, standardisation, and validation of analytical protocols. The validation of a cell-based bioassay is a complex process, as several critical points, such as the choice of the cellular model, the assay procedures, and the appropriate use and interpretation of the results, must be strictly defined to ensure more consistency in the results. The development of cell-based models exploring the third dimension together with automation and miniaturisation will bring cellular platforms to a level appropriate for cost-effective and large-scale analysis in the field of mycotoxin research.

Metabolic pathways of T-2 toxin in in vivo and in vitro systems of Wistar rats

In the present study, metabolites of T-2 toxin in in vivo and in vitro systems of Wistar rats were identified and elucidated by ultraperformance liquid chromatography-quadrupole/time-of-flight tandem mass spectrometry (UPLC-Q/TOF-MS). Expected and unexpected metabolites were detected by Metabolynx(XS) software, which could automatically compare MS(E) data from the sample and control. A total of 19 metabolites of T-2 toxin were identified in this research, 9 of them being novel, which were 15-deacetyl-T-2, 3'-OH-15-deacetyl-T-2, 3',7-dihydroxy-T-2, isomer of 3',7-dihydroxy-T-2, 7-OH-HT-2, isomer of 7-OH-HT-2, de-epoxy-3',7-dihydroxy-HT-2, 9-OH-T-2, and 3',9-dihydroxy-T-2. The results showed that the main metabolic pathways of T-2 toxin were hydrolysis, hydroxylation, and de-epoxidation. In addition, the results also revealed one novel metabolic pathway of T-2 toxin, hydroxylation at C-9 position, which was demonstrated by the metabolites 9-OH-T-2 and 3',9-dihydroxy-T-2. In addition, hydroxylation at C-9 of T-2 toxin was also generated in in vitro of liver systems. Interestingly, several metabolites of hydroxylation at C-7 of T-2 toxin were also detected in in vivo male Wistar rats, but they were not found in in vivo female rats and in in vitro systems of Wistar rats.

Natural sesquiterpenoids

This review covers the isolation, structural determination, synthesis and chemical and microbiological transformations of natural sesquiterpenoids. The literature from January to December 2012 is reviewed, and 471 references are cited.

Influence of T-2 and HT-2 toxin on the blood-brain barrier in vitro: new experimental hints for neurotoxic effects

The trichothecene mycotoxin T-2 toxin is a common contaminant of food and feed and is also present in processed cereal derived products. Cytotoxic effects of T-2 toxin and its main metabolite HT-2 toxin are already well described with apoptosis being a major mechanism of action. However, effects on the central nervous system were until now only reported rarely. In this study we investigated the effects of T-2 and HT-2 toxin on the blood-brain barrier (BBB) in vitro. Besides strong cytotoxic effects on the BBB as determined by the CCK-8 assay, impairment of the barrier function starting at low nanomolar concentrations were observed for T-2 toxin. HT-2 toxin, however, caused barrier disruption at higher concentrations compared to T-2 toxin. Further, the influence on the tight junction protein occludin was studied and permeability of both toxins across the BBB was detected when applied from the apical (blood) or the basolateral (brain) side respectively. These results clearly indicate the ability of both toxins to enter the brain via the BBB.

Cytotoxicity and fluorescence visualization of ergot alkaloids in human cell lines

The ergot alkaloids as secondary metabolites from fungi of the genus Claviceps are the focus of many investigations because of their pharmacological and toxicological properties. The main effects of ergot alkaloids are referred to an interaction with several receptor systems in the human body. It is well-known that ergot alkaloids are able to isomerize with one isomer being biologically active and one being only weakly active, whereas the activity is restricted to receptor interactions. Latest investigations have proven that ergot alkaloids also show cytotoxic effects and induce apoptosis in human primary cells. These effects seem to correlate with accumulation properties. It was the aim of our current study to determine such effects in cancer cell lines, because ergot derivatives are also used in tumor therapy. Our results confirm the apoptotic effects in two cancer cell lines (HepG2 and HT-29) in a high range, and accumulation measurements show an interesting correlation between the alkaloid concentration in the cell lysate of the receptor-inactive isomers and cytotoxicity. In addition, the strong accumulative effects were first visualized by fluorescence microscopy by taking advantage of the natural fluorescence properties of ergot alkaloids.

HT-2 toxin 4-glucuronide as new T-2 toxin metabolite: enzymatic synthesis, analysis, and species specific formation of T-2 and HT-2 toxin glucuronides by rat, mouse, pig, and human liver microsomes

Glucuronides of the mycotoxin T-2 toxin and its phase I metabolite HT-2 toxin are important phase II metabolites under in vivo and in vitro conditions. Since standard substances are essential for the direct quantitation of these glucuronides, a method for the enzymatic synthesis of T-2 and HT-2 toxin glucuronides employing liver microsomes was optimized. Structure elucidation by nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry revealed that besides T-2 toxin glucuronide and HT-2 toxin 3-glucuronide also the newly identified isomer HT-2 toxin 4-glucuronide was formed. Glucuronidation of T-2 and HT-2 toxin in liver microsomes of rat, mouse, pig, and human was compared and metabolites were analyzed directly by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). A distinct, species specific pattern of glucuronidation of T-2 and HT-2 toxin was observed with interesting interindividual differences. Until recently, glucuronides have frequently been analyzed indirectly by quantitation of the aglycone after enzymatic cleavage of the glucuronides by β-glucuronidase. Therefore, the hydrolysis efficiencies of T-2 and HT-2 toxin glucuronides using β-glucuronidases from Helix pomatia, bovine liver, and Escherichia coli were compared.