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1.
Toxigenic fungi and mycotoxins in mature corn silage   总被引:1,自引:0,他引:1  
To investigate the exposure of livestock and farm workers to mycotoxins during the last months of silage use, the mycoflora and the mycotoxins in a mature silage (11-months-old) were studied. A multimycotoxin method was developed to evaluate the toxigenic in vitro ability of fungal strains. The screening of potentially toxigenic fungi isolated from the mature silage showed that six Fusaria (Fusarium culmorum, Fusarium equiseti, Fusarium graminearum, Fusarium oxysporum,Fusarium solani and Fusarium verticillioides) and one Aspergillus (Aspergillus fumigatus) were able to produce mycotoxins on nutrient agar. Seven major mycotoxins (aflatoxin B1, citrinin, deoxynivalenol, fumonisin B1, gliotoxin, ochratoxin A and zearalenone) were also searched in the corn silage by high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS). Among the three mycotoxins (citrinin, gliotoxin and deoxynivalenol) detected in the silage, gliotoxin, a strongly immunosuppressive mycotoxin, occured in the mature silage at level up to 877 ppb, which was associated with the presence of A. fumigatus in the silage.  相似文献   

2.
The Fusarium mycotoxins fumonisin B1 (FB1) (1) and B2 (FB2) (2), their hydrolysed analogues HFB1 (3) and HFB2 (4) and the recently discovered fumonisin derivatives N-palmitoyl-HFB1 (5) and N-carboxymethyl-FB1 (6) were compared for their toxicity in a short term bioassay using brine shrimp (Artemia salina). The brine shrimp were hatched in artificial sea water and exposed to the fumonisins in microwell plates with a mortality endpoint after 48 hours. LC50 values were calculated after Probit transformation of the resulting data. Of the substances tested, fumonisin B1 emerged to be the most toxic whereas its N-carboxymethyl analogue was 100-fold less effective. The hydrolysed fumonisins showed a four- to sixfold reduced toxicity compared to FB1. N-Palmitoyl-HFB1 had a higher LC50 value than its precursor HFB1. The brine shrimp assay proved to be a convenient and rapid system for toxicity assessment of this group of mycotoxins.  相似文献   

3.
Cyclopiazonic acid and aflatoxin B1 are mycotoxins which can both be produced by the same moulds. Men can be exposed to these mycotoxins directly via ingestion of plant-derived food, as well as, indirectly via consumption of animal products. Although it is well known that aflatoxin B1 is mutagenic, contradictory results exist on the mutagenicity of cyclopiazonic acid. Using the Ames test cyclopiazonic acid was not found to be mutagenic either with or without metabolic activation by S9-mix of Arochlor treated rats. However, the mutagenicity of aflatoxin B1 was inhibited in the presence of cyclopiazonic acid. Since cyclopiazonic acid inhibited the formation of certain metabolites of caffeine and testosterone, it was concluded that the reduction of the mutagenicity of aflatoxin B1 in the presence of cyclopiazonic acid results from the inhibition of the bioactivation of aflatoxin B1 by certain cytochrome P450 enzymes.  相似文献   

4.
目的:建立高效液相色谱-荧光检测器测定安神益脑丸中黄曲霉毒素G2、G1、B2、B1的方法;分析安神益脑丸中黄曲霉毒素的污染情况.方法:待测样品采用80%乙腈作为提取溶剂,经免疫亲和柱净化、高效液相色谱分离、光化学柱后衍生后,通过荧光检测器测定其中黄曲霉毒素的含量;采用超高效液相色谱串联三重四极杆质谱法对以上实验测定结果...  相似文献   

5.
Corn throughout the world is frequently contaminated by the fungus Fusarium moniliforme, which produces toxic fumonisins. Ammonia has been shown to detoxify effectively aflatoxins in corn and cottonseed. Since corn can be contaminated by both fumonisins and aflatoxins, we investigated the effects of ammoniation of corn either cultured with or naturally contaminated by F. moniliforme. Fumonisin B1 levels in the culture material and in naturally contaminated corn were reduced by 30 and about 45%, respectively, by the ammonia treatment. Despite the apparent reduction in fumonisin content, the toxicity of the culture material in rats was not altered by ammoniation. Reduced weight gains, elevated serum enzyme levels and histopathological lesions, typical of F. moniliforme toxicity, occurred in rats fed either the ammoniated or non-ammoniated culture material. Atmospheric ammoniation of corn does not appear to be an effective method for the detoxification of F. moniliforme-contaminated corn.  相似文献   

6.
The effect of esterified glucomannan on aflatoxin B1 toxicity in ducklings was studied by immunohistochemical staining of proliferating cell nuclear antigen (PCNA) in hepatic cells on formalin-fixed paraffin-embedded liver samples. Cherry Valley ducklings were divided into five groups, 20 birds in each. One of the groups was fed with conventional feed, and the other groups were fed with diet containing 100 ppb aflatoxin B1, that containing 0.05% esterified glucomannan, or that containing 100 ppb aflatoxin B1 supplemented with 0.05 or 0.1% esterified glucomannan, from five days of age for one month, and subsequently all the groups were fed with conventional feed for 20 days. Four birds of each group were sacrificed on the 30th, 35th, 40th, 45th and 50th day of feeding, and PCNA on the liver tissue sections was quantitatively analyzed by immunohistochemical staining. The percentage of PCNA-positive hepatocytes was significantly higher in the group given diet containing aflatoxin B1 than in the other groups, which were not significantly different from each other. The results demonstrate that supplementation of feed with esterified glucomannan is effective in reduction of aflatoxin B1-induced hepatic injury in ducklings.  相似文献   

7.
A cDNA clone coding for the guinea pig leukotriene B4 (BLT) receptor has been isolated from a lung cDNA library. The guinea pig BLT receptor has an open reading frame corresponding to 348 amino acids and shares 73% and 70% identity with human and mouse BLT receptors, respectively. Scatchard analysis of membranes prepared from guinea pig and human BLT receptor-transfected human embryonic kidney (HEK) 293 EBNA (Epstein–Bar Virus Nuclear Antigen) cells showed that both receptors displayed high affinity for leukotriene B4 (Kd value of 0.4 nM) and were expressed at high levels (Bmax values ranging from 9 to 12 pmol/mg protein). The rank order of potency for leukotrienes and related analogs in competition for [3H]leukotriene B4 specific binding at the recombinant guinea pig BLT receptor is leukotriene B4>20-OH-leukotriene B4>12(R)-HETE ((5Z,8Z,10E,12(R)14Z)-12-hydroxyeicosatetraen-1-oic acid)>12(S)-HETE ((5Z,8Z,10E,12(S)14Z)-12-Hydroxyeicosatetraen-1-oic acid)>20-COOH-leukotriene B4>U75302 (6-(6-(3-hydroxy-1E,5Z-undecadienyl)-2-pyridinyl)-1,5-hexanediol)leukotriene C4=leukotriene D4=leukotriene E4. For the human receptor the rank order of 12(S)-HETE, 20-COOH-leukotriene B4 and U75302 was reversed. Xenopus melanophore and HEK aequorin-based reporter gene assays were used to demonstrate that the guinea pig and human BLT receptors can couple to both the cAMP inhibitory and intracellular Ca2+ mobilization signaling pathways. However, in the case of the aequorin-expressing HEK cells (designated AEQ17-293) transfected with either the guinea pig or human BLT receptor, expression of G16 was required to achieve a robust Ca2+ driven response. Leukotriene B4 was a potent agonist in functional assays of both the guinea pig and human BLT receptors. U-75302 a leukotriene B4 analogue which possesses both agonistic and antagonistic properties behaved as a full agonist of the guinea pig and human BLT receptors in AEQ17-293 cells and not as an antagonist. The recombinant guinea pig BLT receptor will permit the comparison of the intrinsic potencies of leukotriene B4 receptor antagonists used in guinea pig in vivo models of allergic and inflammatory disorders.  相似文献   

8.
Fumonisins, mycotoxins that commonly contaminate corn, induce cardiovascular toxicity and pulmonary edema in pigs, leukoencephalomalacia in horses, and nephropathy in rats, rabbits, and lambs. The mechanisms of these species-specific target organ toxicoses are poorly understood. We have previously reported perinuclear accumulation of membranous material in pulmonary capillary endothelial cells of pigs fed fumonisin-containing culture material. We hypothesized that these endothelial accumulations may be important in the pathogenesis of fumonisin-induced pulmonary edema and target organ toxicity in other species. Both target and non-target tissues from fumonisin-exposed pigs, sheep, rabbits, and rats were examined ultrastructurally. Specifically, lung, liver, heart and kidney were examined. In agreement with our previous work (Gumprecht, L.A., Beasley, V.R., Weigel, R.M., Parker, H.M., Tumbleson, M.E., Bacon, C.W., Meredith, F.I., Haschek, W.M., 1998. Development of fumonisin-induced hepatotoxicity and pulmonary edema in orally dosed swine: morphological and biochemical parameters. Tox. Pathol. 26, 777–788), endothelial alterations were present in the pulmonary capillary endothelial cells of pigs fed fumonisin-containing culture material, but at doses that did not induce pulmonary edema, as well as in pigs injected intravenously with purified fumonisin B1. These alterations were present only in the pulmonary capillary endothelium of pigs and not in other species. In addition, these endothelial alterations were not present in any other organ of pigs or other species examined. Thus, these endothelial alterations are induced by fumonisin B1, but only in pulmonary capillary endothelium and only in pigs. Although evidence that these alterations play a role in fumonisin-induced pulmonary edema is limited, other endothelial functions may be affected by fumonisin treatment.  相似文献   

9.
目的:建立测定人血清中水溶性维生素B1、B2、B6和B9的高效液相色谱串联质谱联用法。方法:常规送检患者血清经乙酸乙酯萃取,经反相高效液相色谱分离,采用电喷雾离子化四级杆串联质谱多反应监测模式测定维生素B1、B2、B6和B9浓度。结果:维生素B1、B2、B6、B9线性范围分别为1~200,5~40,1~80,5~40 ng·mL-1;R2值分别为0.991 6,0.996 8,0.992 2,0.991 4;最低定量限分别为1,5,1,5 ng·mL-1;日内、日间RSD均小于8.5%。结论:所建立方法可用于常规送检患者血清水溶性维生素B1、B2、B6和B9测定。  相似文献   

10.
Fumonisins and deoxynivalenol in corn-based food products in Portugal   总被引:2,自引:0,他引:2  
A great diversity of crops is vulnerable to fungal attack and might be contaminated with mycotoxins. Currently it is estimated that 25% of the world's harvest production is contaminated to some level with these toxins. The presence of fumonisins and deoxynivalenol in corn-based foods, available in Portugal, was analyzed in order to produce some data that may be useful for hazard characterization. A total of 105 samples were screened, including, corn meal (41), sweet corn (49) and corn flakes (15). None of the 15 samples of corn flakes contained some detectable amount of fumonisins. However, fumonisin B1 (FB1) and fumonisin B2 (FB2) contamination was found in 100.0% and 70.7% of the corn meal samples, respectively. Sweet corn samples were positive in 73.4% for FB1, although no FB2 was detected. The highest levels of fumonisin were found in corn meal (maximum: 1300 microg FB1/kg and 450 microg FB2/kg). The presence of deoxynivalenol was not detected in any of the analyzed samples. Nevertheless these results indicate the need to establish, by corn products manufacturers, a continuous monitoring program to prevent and manage the occurrence of these contaminants.  相似文献   

11.
Sprague-Dawley rats were given either ten daily doses of aflatoxin B1 (AFB1) or the solvent tricaprylin intragastrically over a 2-wk period and were fed diets containing either 1.6 or 20% corn oil throughout the study. Hepatic lipid composition was analysed in groups of five rats both 3 and 13 wk after the start of treatment, in order to determine short-term and longer-term alterations. Total lipid and cholesterols (total, free and esterified) increased on the high-fat diet at wk 3. At wk 13 only total and esterified cholesterol were increased by 20% corn oil. AFB1 treatment resulted in large intra-group variations in total lipid and cholesterol at wk 3, but these were no longer apparent by wk 13. AFB1 produced various alterations in the fatty acid composition of hepatic phosphatidylcholine (PC) and phosphatidylethanolamine (PE), apparent at wk 3 but not at wk 13. The unsaturation index decreased but no changes were seen in the saturated fatty acids. Only in animals fed 20% corn oil did AFB1 result in significant changes in 18:2, 20:3 and 22:6 fatty acids, while 20:4 and 22:5 tended to decrease and 18:1 to increase in response to AFB1 treatment with both diets in both phospholipids. The high-corn oil diet was found to increase 18:2, 22:6, and total unsaturation in PC and PE, while the ratio of 20:4 to 18:2 tended to decrease in these phospholipids, γ-Glutamyltranspeptidase, an indicator of liver damage, was significantly increased in AFB1-treated animals, with the greatest increase over controls in those fed the high-fat diet.  相似文献   

12.
Voltammetric determination of vitamins in a pharmaceutical formulation   总被引:2,自引:0,他引:2  
Direct current polarography and differential pulse polarographic methods have been developed for the qualitative as well as quantitative analysis of vitamin B1, B2 and B6. Thiamin (Vitamin B1) produced a well-defined wave in 0.1 M KCl at pH 5.2 with E1/2=−1.2 V and Ep=−1.22 V versus saturated calomal electrode (SCE). Riboflavin (Vitamin B2) gave two distinct waves in Britton Robinson buffer at pH 1.8 with E1/2 VALUES=−0.13 and −0.34 V versus SCE and at pH 6.5 with E1/2=−1.10 V and Ep=−1.2 V versus SCE. Pyridoxin (Vitamin B6) produced a well-defined wave in Britton Robinson buffer at pH 6.5 with E1/2=−1.7 V and Ep=−1.68 V versus SCE. All the three Vitamins under study are reversibly reduced at the electrode surface. The number of electrons involved in the electrode process for vitamin B1 and B6 is one in each case where as for the two waves of B2 it is one and two, respectively. This has been confirmed by the measurement of E3/4E1/4 values and also from the log plot slopes for the reduction waves. The wave height of polarogram was found to be proportional to the vitamin concentration. The developed methods have been standardised for the determination of these compounds in pharmaceutical formulation. The concentration of Vitamin B1, B2 and B6 are found to be 9.96, 9.92 and 3.01 mg, respectively in 240 mg of capsule powder of a standard company (name has not been disclosed due to secrecy purpose). The results have been found to be in excellent agreement to that claimed by the manufacturer. The observed data has been subjected to statistical analysis, which revealed high reliability and precision.  相似文献   

13.
目的:比较不同来源甲硫氨酸维B1注射剂体外细胞毒性的差别并寻找差别形成的主要原因。方法:将不同来源甲硫氨酸维B1注射剂不同浓度的稀释液与小鼠成纤维细胞L-929接触培养,通过倒置相差显微镜观察细胞形态,采用四甲基偶氮唑盐比色法(MTT法)量化细胞毒性,计算相对增殖率,并进行细胞毒性评价。建立甲硫氨酸维B1注射剂中枸橼酸含量的高效液相色谱检测方法,考察枸橼酸含量与制剂细胞毒性的相关性。结果:7个生产厂家的甲硫氨酸维B1注射液细胞毒性无明显差别。12个生产厂家的注射用甲硫氨酸维B1中有11个厂家的样品不同浓度组对L-929的细胞毒性级别为1级或2级。但J厂家的注射用甲硫氨酸维B1样品(20 mg·mL-1和10 mg·mL-1)对L-929的细胞毒性级别为4级,表现为重度毒性。枸橼酸质量浓度3,1.5,0.75 mg·mL-1的相对增殖率分别为7%、45%、74%,而对应的含等量枸橼酸的制剂浓度(以甲硫氨酸计)20,10,5 mg·mL-1的相对增殖率分别为6%、28%、53%,细胞毒性试验结果吻合。结论:不同厂家生产的甲硫氨酸维B1注射剂由于处方工艺不同等,其细胞毒性存在差别。枸橼酸作为注射剂的常用辅料,在高于0.188 mg·mL-1的浓度下存在细胞毒性,枸橼酸含量与细胞毒性呈正相关性,J厂家样品的重度细胞毒性可能主要源于过高浓度的辅料枸橼酸。建议生产厂家降低枸橼酸添加量,以减少制剂的细胞毒性,提高药品的安全性。  相似文献   

14.
The pharmacokinetics, tissue distribution and excretion of 14C-labelled aflatoxin B1 (AFB1) were examined after oral administration (250 μg/kg body weight) in channel catfish (Ictalurus punctatus). Plasma concentrations of parent AFB1 were best described by a one-compartment pharmacokinetic model, in which peak plasma concentration (503 ppb) occurred at 4.1 hr after dosing. The absorption and elimination half-lives were 1.5 and 3.7 hr, respectively. AFB1 was highly bound (95%) to plasma proteins. Concentrations of 14C (in AFB1 equivalents) measured in the tissues were highest at 4 hr, ranging from 596 ppb in the plasma to 40 ppb in the muscle. AFB1 residues were rapidly depleted; at 24 hr the concentrations in the plasma and muscle were 32 and <5 ppb, respectively. Concentrations in the bile exceeded 2000 ppb (at 24 hr), whereas the highest concentration in the urine was 51 ppb (4–6-hr collection interval). Renal and biliary excretion accounted for <5% of the administered dose, indicating incomplete absorption. Pharmacokinetic modelling and tissue data demonstrate a very low potential for the accumulation of AFB1 and its metabolites in the edible flesh of channel catfish through the consumption of AFB1-contaminated feed.  相似文献   

15.
Arninopentol (AP1) is the total hydrolysis product of fumonisin B1 (FBI), the major and best characterized of the fumonisins, which are mycotoxins that are common contaminants of corn and corn meal. Some human populations expected to have significant exposure to AP1 have a high incidence of babies born with neural tube defects (NTD). The embryotoxicity of AP1 was evaluated in cultured rat embryos. Gestation day 9.5 embryos were exposed to 0, 3, 10, 30, 100 or 300 μM AP1 throughout the entire 45-hr culture period. At 100 μM AP1, growth and overall development were reduced significantly. There was also a significant increase in the incidence of abnormal embryos. 29% of the embryos had NTD, and 36% of the embryos had other abnormalities. At 300 μM API, the incidence of NTD was 15%, and 85% of the embryos had other abnormalities. These findings suggest that AP1, at concentrations of 100μM and above, can induce NTD in organogenesis-stage cultured rat embryos. However, these NTD are in conjunction with significant overall retardation of growth and development as well as significant increases in the incidence of other defects. These studies also showed, when compared with previous findings, that API is over 100-fold less toxic than FB1 to cultured rat embryos.  相似文献   

16.
Hens fed a diet containing 3310 μg of AFB1 and 1680 μg of AFB2 per kg feed for 28 days showed a significant decrease in egg production and egg weights by wk 3 and 4 of feeding, respectively. Transfer of aflatoxins to the eggs occurred rapidly, reaching maximum levels after 4–5 days, and remained relatively constant throughout aflatoxin feeding. The mean values for combined residue levels in eggs were less than 0.5 μg/kg. Levels of AFB2, AFM1 and AFM2 were similar in yolk and albumen while levels of B1 and B2a were higher in the yolk. Upon removal of the aflatoxin-containing diet, residues in eggs decreased rapidly. Clearance of aflatoxin residues from the albumen occurred faster than from the yolk. Thus, no residues were detected in the albumen and in the yolk after 5 and 7 days of withdrawal, respectively. No aflatoxin residues could be recovered from whole eggs after feeding the aflatoxin-free diet for 4 days.  相似文献   

17.
《Toxin reviews》2013,32(2-3):327-350
Many species of insects can facilitate the entry of mycotoxin‐producing fungi to commodities such as cotton seed, maize, peanuts, and tree nuts. The mycotoxins most commonly associated with insect damage are aflatoxin and fumonisin. Insecticides will likely remain an important management tool, especially as predictive models for forecasting mycotoxigenic fungi or mycotoxins become available. Plants with high levels of resistance to insects that facilitate mycotoxins are likely to assist in mycotoxin management. Several studies now indicate Bt maize hybrids that express the protein throughout the plant can prevent fumonisin levels rising above guideline levels of 1–2 ppm when European corn borers (Ostrinia nubilalis) are the predominant insect pests.  相似文献   

18.
Effects of aflatoxin B1 (AFB1) administration (7 mg/kg body weight i.p.) on rat hepatic mitochondrial respiratory components have been examined. Succinoxidase and cytochrome oxidase activities were decreased in liver mitochondria isolated from rats 12–24 h after AFB1 treatment. Both enzyme activities returned to normal levels after 48 h. Glutamate dehydrogenase and β-hydroxybutyrate dehydrogenase activities did not show any alterations up to 24 h and thereafter increased at 48–72 h. Succinate dehydrogenase activity was impaired by 41% at 12 h and thereafter was found to be normal. The intramitochondrial cytochrome b content declined at 24–72 h, whereas cytochrome aa3 content was decreased maximally at 72 h after AFB1 administration. These observations on mitochondrial enzyme activities and cytochrome contents correlate well with our earlier observations made on hepatic mitochondrial respiratory rates after AFB1 treatment. The impairment of respiratory functions possibly results from membrane damage and selective modification of gene expression in mitochondria imparted by AFB1.  相似文献   

19.
Experiments were designed to investigate the role of kinin B1 and B2 receptors in Freund's adjuvant (CFA)-induced inflammation and nociception responses by the use of B1 and B2 null mutant mice. Intradermal (i.d.) injection of CFA produced time-dependent and marked hyperalgesic responses in both ipsilateral and contralateral paws of wild-type mice. Gene disruption of the kinin B2 receptor did not interfere with CFA-induced hyperalgesia, but ablation of the gene of the B1 receptor reduced the hyperalgesia in both ipsilateral (48±13%, at 12 h) and contralateral (91±22%, at 12 h) paws. Treatment of wild-type mice with the selective B1 antagonist des-Arg9-[Leu8]-BK (150 nmol/kg, s.c.) reduced CFA-evoked thermal hyperalgesia, to an extent which was similar to that observed in mice lacking kinin B1 receptor. I.d. injection of CFA produced a time-related and long-lasting (up to 72 h) increase in paw volume in wild-type mice. A similar effect was observed in B1 knockout mice. In mice lacking B2 receptor, the earlier stage of the CFA-induced paw oedema (6 h) was significantly greater compared with the wild-type animals, an effect which was almost completely reversed (76±5%) by des-Arg9-[Leu8]-BK. This data demonstrates that kinin B1 receptor, but not B2 receptor, exerts a critical role in controlling the persistent inflammatory hyperalgesia induced by CFA in mice, while B2 receptor appears to have only a minor role in the amplification of the earlier stage of CFA-induced paw oedema formation. The results of the present study, taken together with those of previous studies, suggest that B1 receptor antagonists represent a potential target for the development of new drugs to treat persistent inflammatory pain.  相似文献   

20.
Three compounds, hypothesized as fumonisin A1 (FA1), fumonisin A2 (FA2), and fumonisin A3 (FA3), were detected in a corn sample contaminated with mycotoxins by high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitrap MS). One of them has been identified as FA1 synthesized by the acetylation of fumonisin B1 (FB1), and established a method for its quantification. Herein, we identified the two remaining compounds as FA2 and FA3, which were acetylated fumonisin B2 (FB2) and fumonisin B3 (FB3), respectively. Moreover, we examined a method for the simultaneous analysis of FA1, FA2, FA3, FB1, FB2, and FB3. The corn samples were prepared by extraction using a QuEChERS kit and purification using a multifunctional cartridge. The linearity, recovery, repeatability, limit of detection, and limit of quantification of the method were >0.99, 82.9%–104.6%, 3.7%–9.5%, 0.02–0.60 μg/kg, and 0.05–1.98 μg/kg, respectively. The simultaneous analysis of the six fumonisins revealed that FA1, FA2, and FA3 were present in all corn samples contaminated with FB1, FB2, and FB3. The results suggested that corn marketed for consumption can be considered as being contaminated with both the fumonisin B-series and with fumonisin A-series. This report presents the first identification and quantification of FA1, FA2, and FA3 in corn samples.  相似文献   

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