Comparison of T-2 Toxin and HT-2 Toxin Distributed in the Skeletal System with That in Other Tissues of Rats by Acute Toxicity Test

Twelve healthy rats were divided into the T-2 toxin group receiving gavage of 1 mg/kg T-2 toxin and the control group receiving gavage of normal saline. Total relative concentrations of T-2 toxin and HT-2 toxin in the skeletal system（thighbone, knee joints, and costal cartilage） were significantly higher than those in the heart, liver, and kidneys（P 〈 0.05）. The relative concentrations of T-2 toxin and HT-2 toxin in the skeletal system（thighbone and costal cartilage） were also significantly higher than those in the heart, liver, and kidneys. The rats administered T-2 toxin showed rapid metabolism compared with that in rats administered HT-2 toxin, and the metabolic conversion rates in the different tissues were 68.20%-90.70%.

T-2 toxin-induced apoptosis involving Fas,p53,Bcl-xL,Bcl-2,Bax and caspase-3 signaling pathways in human chondrocytes

Objective:To investigate the effects of T-2 toxin on expressions of Fas,p53,Bcl-xL,Bcl-2,Bax and caspase-3 on human chondrocytes.Methods:Human chondrocytes were treated with T-2 toxin(1～20 ng/ml)for 5 d.Fas,p53 and other apoptosis-related proteins such as Bax,Bcl-2,Bcl-xL,caspase-3 were determined by Western blot analysis and their mRNA expressions were determined by reverse transcriptase-polymerase chain reaction(RT-PCR).Results:Increases in Fas,p53 and the pro-apoptotic factor Bax protein and mRNA expressions and a decrease of the anti-apoptotic factor Bcl-xL were observed in a dose-dependent manner after exposures to 1～20 ng/ml T-2 toxin,while the expression of the anti-apoptotic factor Bcl-2 was unchanged.Meanwhile,T-2 toxin could also up-regulate the expressions of both pro-caspase-3 and caspase-3 in a dose-dependent manner.Conclusion:These data suggest a possible underlying molecular mechanism for T-2 toxin to induce the apoptosis sig- naling pathway in human chondrocytes by regulation of apoptosis-related proteins.

Promotion of the articular cartilage proteoglycan degradation by T-2 toxin and selenium protective effect

Objective: To identify the relationship between T-2 toxin and Kashin-Beck disease (KBD),the effects of T-2 toxin on aggrecan metabolism in human chondrocytes and cartilage were investigated in vitro. Methods: Chondrocytes were isolated from human articular cartilage and cultured in vitro. Hyaluronic acid (HA),soluble CD44 (sCD44),IL-1β and TNF-α levels in super-natants were measured by enzyme-linked immunosorbent assay (ELISA). CD44 content in chondrocyte membrane was deter-mined by flow cytometry (FCM). CD44,hyaluronic acid synthetase-2 (HAS-2) and aggrecanases mRNA levels in chondrocytes were determined using reverse transcription polymerase chain reaction (RT-PCR). Immunocytochemical method was used to investigate expressions of BC-13,3-B-3(-) and 2-B-6 epitopes in the cartilage reconstructed in vitro. Results: T-2 toxin inhibited CD44,HAS-2,and aggrecan mRNA expressions,but promoted aggrecanase-2 mRNA expression. Meanwhile,CD44 expression was found to be the lowest in the chondrocytes cultured with T-2 toxin and the highest in control plus selenium group. In addition,ELISA results indicated that there were higher sCD44,IL-1β and TNF-α levels in T-2 toxin group. Similarly,higher HA levels were also observed in T-2 toxin group using radioimmunoprecipitation assay (RIPA). Furthermore,using monoclonal antibodies BC-13,3-B-3 and 2-B-6,strong positive immunostaining was found in the reconstructed cartilage cultured with T-2 toxin,whereas no positive staining or very weak staining was observed in the cartilage cultured without T-2 toxin. Selenium could partly inhibit the effects of T-2 toxin above. Conclusion: T-2 toxin could inhibit aggrecan synthesis,promote aggrecanases and pro-inflammatory cytokines production,and consequently induce aggrecan degradation in chondrocytes. These will perturb metabolism balance between aggrecan synthesis and degradation in cartilage,inducing aggrecan loss in the end,which may be the initiation of the cartilage degradation.

Increased Chondrocyte Apoptosis in Kashin-Beck Disease and Rats Induced by T-2 Toxin and Selenium Deficiency

Objective To investigate chondrocyte apoptosis and the expression of biochemical markers associated with apoptosis in Kashin-Beck disease（KBD） and in an established T-2 toxin-and selenium（Se） deficiency-induced rat model. Methods Cartilages were collected from the hand phalanges of five patients with KBD and five healthy children. Sprague-Dawley rats were administered a selenium-deficient diet for 4 weeks prior to T-2 toxin exposure. The apoptotic chondrocytes were observed by terminal deoxynucleotidyl transferase d UTP nick end labeling staining. Caspase-3, p53, Bcl-2, and Bax proteins in the cartilages were visualized by immunohistochemistry, their protein levels were determined by Western blotting, and m RNA levels were determined by real-time reverse transcription polymerase chain reaction. Results Increased chondrocyte apoptosis was observed in the cartilages of children with KBD. Increased apoptotic and caspase-3-stained cells were observed in the cartilages of rats fed with normal and Se-deficient diets plus T-2 toxin exposure compared to those in rats fed with normal and Se-deficient diets. Caspase-3, p53, and Bax proteins and m RNA levels were higher, whereas Bcl-2 levels were lower in rats fed with normal or Se-deficiency diets supplemented with T-2 toxin than the corresponding levels in rats fed with normal diet. Conclusion T-2 toxin under a selenium-deficient nutritional status induces chondrocyte death, which emphasizes the role of chondrocyte apoptosis in cartilage damage and progression of KBD.

Effects of T-2 Toxin Exposure on Bone Metabolism and Bone Development of Mice

T-2 toxin is the most widespread mycotoxin in crops,feed and food,which poses a serious threat to body health.Bone is the main target tissue for T-2 toxin accumulation.Ingestion of food contaminated by T-2 toxin is the main cause of Kashin-Beck disease.However,the specific mechanism of bone damage caused by T-2 toxin is still unclear.In this study,a total of 40 male C57BL/6N mice were divided into four groups and orally treated with 0,0.5,1.0 and 2.0 mg·kg^(-1) body weight T-2 toxin for 28 days.The results showed that exposure to T-2 toxin led to weight loss,bone mineral density reduction and femoral structural damage of mice.In addition,osteoblast-mediated bone formation was inhibited,and osteoclast-mediated bone resorption was enhanced.Meanwhile,the levels of bone metabolism-related hormones including parathyroid hormone,calcitonin and 1,25-dihydroxyvitamin D3 were reduced.More importantly,it was found that the level of neuropeptide Y(a neurohormone)was decreased.These results provided a new perspetive for understanding the osteotoxicity of T-2 toxin.

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 two 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- Qq Q 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.Conclusions: 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 metabolite produced by carboxylesterase is HT-2, and the 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.

Experimental Haematobiochemical Alterations in Broiler Chickens Fed with T-2 Toxin and Co-Infected with IBV

The purpose of this experimental study was to evaluate and record the effects of T-2 toxicity alone and in association with IBV infection on haematobiochemical parameters. A total of 128 one-week-old chicks were divided into four groups of 32 birds each and were treated respectively with T-2 toxin alone, IBV alone, T-2 toxin and co-infected with IBV, and no treatment (control) for a period of 6 weeks. Haematologically, the birds treated with T-2 toxin developed anaemia as indicated by significant decrease in haemoglobin levels, total erythrocyte counts and packed cell volume values;leucopenia, lymphocytopenia heterophilia and thrombocytopenia. The IBV infected birds exhibited lymphocytophilia and heteropoenia;the degrees of severity of leucopenia, lymphocytopenia heterophilia and thrombocytopenia were more pronounced in T-2+IBV groups. The serum biochemistry revealed hypoproteinemia and hypoalbuminemia in all the treated groups consistently. Besides, hypoglobulinemia and increased levels of alanine aminotransferase in T-2+IBV, and increased levels of alkaline phosphatase in toxin group alone were recorded. The changes in biochemical parameters were more in magnitude in the combination treatment group and their severity increased with duration of treatment. It was concluded that T-2 toxin made the birds more susceptible to IBV infection.

Efficacy of Biological Control and Cultivar Resistance on <i>Fusarium</i>Head Blight and T-2 Toxin Contamination in Wheat

Laboratory and green house experiments were carried out to evaluate the efficacy of fungicides, biological agents and host resistance in managing FHB and the associated T-2 toxin. In vitro activity of fungicides and antagonists was determined by paired culture method. Effect of microbial agents on FHB severity and mycotoxin content was determined by co-inoculating F. graminearum and F. poae with Alternaria spp., Epicoccum spp. and Trichoderma spp. Fungicides Pearl? (500 g/L carbendazim), Cotaf? (50 g/L hexaconacole), Thiovit? (micronised sulphur 80% w/w) and Folicur? (430 g/L tebuconazole) were the standard checks. Host resistance was determined by inoculating F. poae and F. graminearum to four wheat cultivars and fifteen lines in pot ex-periments. Fungicides resulted in 100% inhibition of pathogen radial growth in in vitro while microbial agents suppressed pathogen growth by up to 53%. Thiovit? and Trichoderma were the most effective in reducing FHB severity in green house pot experiments. The wheat cultivars and lines varied in susceptibility with cultivar Njoro BW II showing least susceptibility while line R1104, cv. Mbuni and cv. KIBIS were most susceptible. All the wheat cultivars and lines accumulated T-2 toxin by up to 5 to 28 μg/kg. The results indicated that neither fungicides nor antagonists can solely be relied on in managing FHB and toxin accumulation. Therefore, integration of biocontrol agents, fungicides and further breeding efforts to improve lines and cultivars with promising resistance to FHB and T2-toxin contamina-tion is recommended.

Evaluation of Gojiextract and Charcoal as Antioxidant on T-2 Toxin Administration Onliver Male Mice

With a view to study the effects of exposure to T-2 toxin and their amelioration by Goji extract or charcoal, male mice were treated with a sublethal dose of T-2 toxin (200 μg/kg B.W) intraperitoneally. T-2 Toxin showed an increase (P ≤ 0.05) in blood of ALT, ALP, Total Lipids, TAS, and TNF. These were decreased by Goji extracts or charcoal, and were improved partially by the two treatments. It is concluded that the treatment of rats with Goji extract or charcoal ameliorated the adverse effects of toxins but the results suggest that Goji extracts may be used as antioxidant and antidote rather than charcoal for T-2 Toxin in mice.

Effective protective agents against the organ toxicity of T-2 toxin and corresponding detoxification mechanisms:A narrative review

T-2 toxin is one of the most widespread and toxic fungal toxins in food and feed.It can cause gastrointestinal toxicity,hepatotoxicity,immunotoxicity,reproductive toxicity,neurotoxicity,and nephrotoxicity in humans and animals.T-2 toxin is physicochemically stable and does not readily degrade during food and feed processing.Therefore,suppressing T-2 toxin-induced organ toxicity through antidotes is an urgent issue.Protective agents against the organ toxicity of T-2 toxin have been recorded widely in the literature,but these protective agents and their molecular mechanisms of detoxification have not been comprehensively summarized.In this review,we provide an overview of the various protective agents to T-2 toxin and the molecular mechanisms underlying the detoxification effects.Targeting appropriate targets to antagonize T-2 toxin toxicity is also an important option.This review will provide essential guidance and strategies for the better application and development of T-2 toxin antidotes specific for organ toxicity in the future.

T-2 toxin induces developmental toxicity and apoptosis in zebrafish embryos

T-2 toxin is one of the most important trichothecene mycotoxins occurring in various agriculture products. The developmental toxicity of T-2 toxin and the exact mechanism of action at early life stages are not understood precisely. Zebrafish embryos were exposed to different concentrations of the toxin at 4-6 hours post fertilization （hpf） stage of development, and were observed for different developmental toxic effects at 24, 48, 72, and 144 hpf. Exposure to 0.20 Ixmol/L or higher concentrations of T-2 toxin significantly increased the mortality and malformation rate such as tail deformities, cardiovascular defects and behavioral changes in early developmental stages of zebrafish. T-2 toxin exposure resulted in significant increases in reactive oxygen species （ROS） production and cell apoptosis, mainly in the tall areas, as revealed by Acridine Orange staining at 24 hpf. In addition, T-2 toxin-induced severe tail deformities could be attenuated by co-exposure to reduced glutathione （GSH）. T-2 toxin and GSH co-exposure induced a significant decrease of ROS production in the embryos. The overall results demonstrate that T-2 toxin is able to produce oxidative stress and induce apoptosis, which are involved in the developmental toxicity of T-2 toxin in zebrafish embryos.

霉菌毒素T-2Toxin酶联免疫吸附测定方法

用T - 2毒素免疫家兔 ,获得了抗T - 2毒素的多克隆抗体 ,运用该抗体建立了检测玉米中T - 2毒素的间接竞争性酶联免疫吸附测定法 .该法最低检出量为 1 0 ppb ,平均回收率为 32 %～43%.

基于转录组学分析T-2毒素诱导细胞凋亡作用机制

T-2毒素是一种强毒性单端孢霉烯族毒素,具有多器官效应毒性。为了解T-2毒素对不同细胞系毒性的影响及作用机制,作者分析了T-2毒素暴露对4种细胞系氧化应激、Ca^(2+)水平和凋亡的影响,采用细胞转录组学等技术分析了T-2毒素作用于敏感细胞的关键基因和信号通路。结果表明,相同诱导剂量下,BV2小胶质细胞和HepG2肝癌细胞对T-2毒素敏感,细胞内活性氧(ROS)和Ca^(2+)水平显著升高(P<0.05),细胞凋亡程度高。转录组学和逆转录-聚合酶链式反应(RT-PCR)结果显示,T-2毒素可通过MAPK/AP-1、TNF-NF-κB信号通路并上调AP-1、白细胞介素-6(IL-6)等因子水平引起BV2细胞炎症反应。而与氧化应激和凋亡相关的PI3K/AKT、PERK/P53/Casp3信号通路,通过下调Akt、SIRT1等促凋亡因子并上调超氧化物歧化酶促进了HepG2细胞的凋亡。T-2毒素分别通过促炎和氧化应激相关信号通路诱导BV2细胞和HepG2细胞凋亡,说明T-2毒素可通过不同的分子机制对不同器官产生特异性毒性效应。

辉光放电等离子体降解啤酒中T-2毒素

目的:探讨辉光放电等离子体(GDP)降解啤酒中T-2毒素的最佳工艺及对啤酒理化指标的影响。方法:通过Box-Behnken方法进行四因素三水平的响应面优化试验,确定啤酒中T-2毒素的最佳降解条件。结果:当放电电压为570 V,作用时间为18 min,放电电流为99 mA,T-2毒素初始质量浓度为8.5μg/mL时,T-2毒素降解效率最高(89.21%);经GDP处理后,啤酒泡持性显著降低(P<0.05),其他指标无明显变化。结论:通过响应面优化模型获得的GDP最佳降解条件可以用于啤酒中T-2毒素的降解;GDP处理能够影响啤酒泡持性,但对其他指标无明显影响。

氧化锌纳米颗粒光催化降解T-2毒素性能分析

为了利用光催化技术实现T-2毒素的高效、绿色降解,本研究采用绿色温和的溶剂水热法制备出结晶度高、分散性良好的0D ZnO纳米颗粒光催化材料,并通过高分辨透射电子显微镜、瞬态光电流响应等表征手段对其性质以及光催化降解T-2毒素性能、影响因素和机理进行探究。结果表明:成功制备得到平均粒径约为43.23 nm的ZnO纳米颗粒,经条件优化后可以在240 min内通过光催化降解去除超过95%初始质量浓度为5μg/mL的T-2毒素,降解动力学常数达0.0299μg/(mL·min),催化剂最佳质量浓度为0.5 mg/mL,最佳适用体系的pH值为5~9。光电表征结果确定了ZnO具有良好的光吸收和响应性能以及电荷分离性能,并确定羟自由基在T-2毒素降解中起主导作用。本实验结果可为相关领域绿色高效降解、转化和去除T-2毒素提供有效理论参考和技术支持。

碳化钒免疫层析法检测玉米中T-2毒素

旨在构建一种碳化钒免疫层析试纸条,用于现场灵敏检测玉米中T-2毒素。通过超声辅助-液相剥离法合成碳化钒纳米片(vanadium carbide nanosheets,VCNSs),与T-2单克隆抗体(T-2 monoclonal antibody,T-2-mAb)偶联标记,作为信号探针。基于竞争原理,样品中的T-2毒素与检测线(T线)上T-2抗原竞争结合黑色的VCNSs-mAb探针,试纸条T线读值与T-2毒素质量浓度呈反比。以空白试纸条T线显色情况(信号读值>800,MD-600金标读数仪检测)和0.5、1.5 ng/mL T-2毒素的抑制率为优化指标,获得最佳实验条件,建立标准曲线。结果表明:该方法检测T-2毒素的线性范围在0.14~0.78 ng/mL之间、视觉检出限为0.25 ng/mL、消线值为1.5 ng/mL、半抑制浓度为0.344 ng/mL,灵敏度较传统胶体金试纸条提高了5.6倍。此外,该方法与其他5种常见真菌毒素均无交叉反应。针对玉米样品进行真实检测,回收率在92.8%~117.2%之间、变异系数均小于9.13%、检出限为5.06μg/kg。综上所述,该方法具有操作简便、快速灵敏和成本低等优点,为谷物中T-2的检测提供一定的现场快速检测技术。

T-2毒素毒性分子作用机制与脱毒的研究进展

T-2毒素是一种A类单端孢霉烯族毒素,具有高度致毒作用、毒性较难降解等特点,严重威胁人类和动物安全。目前,用于T-2毒素脱毒的方法有物理吸附法、化学试剂中和法、微生物分解法等。但T-2毒素导致的中毒反应的分子机制还尚未明确,可能涉及多个方面,如线粒体损伤、细胞自噬、免疫逃逸、细胞凋亡等。因此,文章主要探讨了T-2毒素毒性作用分子机制以及T-2毒素脱毒的研究进展,为T-2毒素的深入研究提供参考。

我国饲料原料和配合饲料中T-2毒素、赭曲霉毒素A和伏马毒素的污染研究

本试验旨在研究我国饲料原料和配合饲料中T-2毒素、赭曲霉毒素A(OTA)和伏马毒素(FUM)的单独及联合污染情况。分别对从我国不同地区采集474、385和1905份饲料原料和配合饲料样品,进行T-2毒素、OTA和FUM含量检测。结果显示:饲料原料和配合饲料中T-2毒素、OTA和FUM总污染率分别为26.8%、61.8%和59.3%,其含量平均值分别为0~45.8μg/kg、0.3~11.1μg/kg和0~16.3 mg/kg。值得注意的是,分别有0.4%、0.3%和0.5%的饲料原料和配合饲料中T-2毒素、OTA和FUM含量超过了我国《饲料卫生标准》,并且,60%以上的饲料原料中霉菌毒素的联合污染率达30.3%~88.9%。由此可见,我国饲料原料和配合饲料中T-2毒素、OTA和FUM的污染较严重,生产中加强监测我国饲料原料和配合饲料中上述霉菌毒素的污染情况和实施相关防控措施尤为重要。

QuEChERS-质谱联用仪法测定发酵茶中T-2毒素含量

本文建立QuEChERS-液相质谱联用法测定发酵茶中T-2毒素的含量。茶叶样品粉碎后,样品经乙腈超声均质提取,HC-C18去除大部分杂质,采用增强型碳氢键的非极性化合物PSA净化后,使用高性能液相色谱-串联质谱法多反应监测扫描模式进行定性定量分析。T-2毒素在5~100 ng·mL^(-1)浓度范围内呈现良好的线性关系,线性相关系数为0.999,检出限为5μg·kg^(-1),在5、20、80μL三个不同加标水平下,T-2毒素回收率在85.01%~87.80%内,相对标准偏差(RSD)为1.05%。该方法灵敏度高、回收率稳定、检测快速、定量准确。适用于检测发酵茶叶中的T-2毒素。

EFFECT OF T-2 TOXIN ON WHEAT LEAF PROTOPLASTS

Ⅰ. INTRODUCTIONCooking was the first who succeeded in getting a large number of protoplasts by using the enzymatic method in the 1960s. Now protoplasts have become an important tool in the research of plant physiology, plant genetics, phytopathology and membrane physiology. In the research of inter-relationship between protoplasts and pathotoxin,