4,989 research outputs found

    Characterization of Fumonisin B1-GlucoseReaction Kinetics and Products

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    The reaction of fumonisin B1 with the reducing sugar D-glucose can block the primary amine group of fumonisin B1 and may detoxify this mycotoxin. A method to separate hundred milligram quantities of fumonisin B1-glucose reaction products from the excess D-glucose with a reversed-phase C18 cartridge was developed. Mass spectrometry revealed that there were four primary products in this chain reaction when fumonisin B1 was heated with D-glucose at 65 C for 48 h: N-methyl-fumonisin B1, N-carboxymethyl-fumonisin B1, N-(3-hydroxyacetonyl)-fumonisin B1, and N-(2-hydroxy, 2-car- boxyethyl)-fumonisin B1. The N-(1-deoxy-D-fructos-1-yl) fumonisin B1 (fumonisin B1-glucose Schiff’s base) was detected by mass spectrometry when fumonisin B1 was heated with D-glucose at 60 C. The nonenzymatic browning reaction of fumonisin B1 with excess D-glucose followed apparent first- order kinetics. The activation energy, Ea, was 105.7 kJ/mol. Fumonisin B1 in contaminated corn could precipitate the nonenzymatic browning reaction with 0.1 M D-glucose at 60 and 8

    Regulation of Lipid Biosynthesis in Saccharomyces cerevisiae by Fumonisin B\u3csub\u3e1\u3c/sub\u3e

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    The regulation of lipid biosynthesis in the yeast Saccharomyces cerevisiae by fumonisin B1 was examined. Fumonisin B1 inhibited the growth of yeast cells. Cells supplemented with fumonisin B1 accumulated free sphinganine and phytosphingosine in a dose-dependent manner. The cellular concentration of ceramide was reduced in fumonisin B1-supplemented cells. Ceramide synthase activity was found in yeast cell membranes and was inhibited by fumonisin B1. Fumonisin B1 inhibited the synthesis of the inositol-containing sphingo-lipids inositol phosphorylceramide, mannosylinositol phosphorylceramide, and mannosyldiinositol phosphorylceramide. Fumonisin B1 also caused a decrease in the synthesis of the major phospholipids synthesized via the CDP-diacylglycerol-dependent pathway and the synthesis of neutral lipids. The effects of fumonisin B1 and sphingoid bases on the activities of enzymes in the pathways leading to the synthesis of sphingolipids, phospholipids, and neutral lipids were also examined. Other than ceramide synthase, fumonisin B1 did not affect the activities of any of the enzymes examined. However, sphinganine and phytosphingosine inhibited the activities of inositol phosphorylceramide synthase, phosphatidylserine synthase, and phosphatidate phosphatase. These are key enzymes responsible for the synthesis of lipids in yeast. The data reported here indicated that the biosynthesis of sphingolipids, phospholipids and neutral lipids was coordinately regulated by fumonisin B1 through the regulation of lipid biosynthetic enzymes by sphingoid bases

    Efficacy of a Mycotoxin Binder against Dietary Fumonisin, Deoxynivalenol, and Zearalenone in Rats

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    It was hypothesized that a mycotoxin binder, Grainsure E, would inhibit adverse effects of a mixture of fumonisin B1, deoxynivalenol, and zearalenone in rats. For 14 and 28 days, 8–10 Sprague–Dawley rats were fed control diet, Grainsure E (0.5%), toxins (7 μg fumonisin B1/g, 8 μg of deoxynivalenol/g and 0.2 μg of zearalenone/g), toxins (12 μg of fumonisin B1/g, 9 μg of deoxynivalenol/g, and 0.2 μg of zearalenone/g + Grainsure E), or pair-fed to control for food intake of toxin-fed rats. After 28 days, decreased body weight gain was prevented by Grainsure E in toxin-fed female rats, indicating partial protection against deoxynivalenol and fumonisin B1. Two effects of fumonisin B1 were partly prevented by Grainsure E in toxin-fed rats, increased plasma alanine transaminase (ALT) and urinary sphinganine/sphingosine, but sphinganine/sphingosine increase was not prevented in females at the latter time point. Grainsure E prevented some effects of fumonisin B1 and deoxynivalenol in rats

    Characterization of a POROS\u3csup\u3eTM\u3c/sup\u3e-fumonisin B1 Affinity Column for Isolating Ceramide Synthase from Rat Liver

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    Fumonisin B1 is a mycotoxin produced by fungi of the genus Fusarium, common pathogens of corn and other grain plants. Toxic effects associated with fumonisin B1 include equine leukoencephalomacia, porcine pulmonary edema, rat renal carcinoma, and murine hepatocellular carcinoma. Increased risk for esophageal cancer in humans has been epidemiologically associated with consumption of corn contaminated with Fusarium, suggesting that fumonisin B1 may be involved. The biological effects of fumonisin B1 exposure result primarily from disruption of de novo sphingolipid biosynthesis via inhibition of ceramide synthase. Exposure of animals or cultured cells to fumonisin B1 results in the characteristic accumulation of sphinganine, a toxic sphingolipid intermediate, concomitant with depletion of essential complex sphingolipids. Ceramide synthase has not been purified to homogeniety and characterized. We prepared crude ceramide synthase from detergent-extracted rat liver homogenates using PEG-precipitation and cation exchange chromatography. Ceramide synthase activity was then sequestered, using fumonisin B1 covalently coupled to POROS-NH particles, and eluted selectively. The observed 119-fold enrichment in specific activity demonstrates the utility of fumonisin-POROS affinity chromatography in the purification of ceramide synthase

    Isolation of Arabidopsis extracellular ATP‐binding proteins by affinity proteomics and identification of PHOSPHOLIPASE C‐LIKE 1 as an extracellular protein essential for fumonisin B1 toxicity

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    ATP is secreted to the extracellular matrix where it activates plasma membrane receptors for controlling plant growth and stress‐adaptive processes. DOES NOT RESPOND TO NUCLEOTIDES 1 (DORN1), the first plant ATP receptor was identified, but key downstream proteins are sought after. Here, we identified 120 proteins secreted by Arabidopsis cell cultures and screened them for putative stress‐responsive proteins using ATP‐affinity purification. We report three Arabidopsis proteins isolated by ATP‐affinity: PEROXIDASE 52, SUBTILASE‐LIKE SERINE PROTEASE 1.7, and PHOSPHOLIPASE C‐LIKE 1. In wildtype Arabidopsis, expression of genes encoding all three proteins responded to fumonisin B1, a cell death‐activating mycotoxin. Expression of PEROXIDASE 52 and PHOSPHOLIPASE C‐LIKE 1 genes was altered in fumonisin B1‐resistant salicylic acid induction‐deficient (sid2) mutants. Exposure to fumonisin B1 suppressed PHOSPHOLIPASE C‐LIKE 1 expression in sid2 mutants, suggesting that inactivation of this gene might provide mycotoxin tolerance. Accordingly, gene knockout mutants of PHOSPHOLIPASE C‐LIKE 1 were resistant to fumonisin B1‐induced death. Activation of PHOSPHOLIPASE C‐LIKE 1 gene expression by exogenous ATP was not blocked in dorn1 loss‐of‐function mutants, indicating that DORN1 is not required. Furthermore, exogenous ATP rescued both wildtype and dorn1 mutants from fumonisin B1 toxicity, suggesting that different ATP receptor(s) are operational in this process. Our results point to the existence of additional plant ATP receptor(s) and provide crucial downstream targets for use in designing screens to identify these receptors. Finally, PHOSPHOLIPASE C‐LIKE 1 serves as a convergence point for fumonisin B1 and extracellular ATP signalling, and functions in Arabidopsis stress response to fumonisin B1

    Fumonisin B1 and zearalenone contamination of wheat in Croatia and influence of fungicide treatments

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    In Croatia, a trial was conducted to determine the presence of the Fusarium mycotoxins fumonisin B1 and zearalenone in wheat kernels and to evaluate the efficacy of nine fungicides on Fusarium head blight severity as well as fumonisin B1 and zearalenone accumulation in wheat grain. Fumonisin B1 and zearalenone were detected in all grain samples in mean concentrations ranging from 182.0 to 446.6 µg kg-1 (fumonisin B1) and from 2.59 to 5.33 µg kg-1 (zearalenone). No significant differences were found among fumonisin B1 and zearalenone content in wheat grain for the different fungicide treatments. No correlation was revealed between Fusarium head blight severity and fumonisin B1 or zearalenone content in wheat grain, nor between fungicide efficacy and fumonisin B1 or zearalenone content in wheat grain. Under conditions of high disease pressure, efficacy of the fungicides was between 85.7% (tebuconazole + triadimefon) and 72.1% (carbendazim).Un essai a été effectué en Croatie afin de déterminer la présence de fumonisine B1 et de zéaralenone, des mycotoxines de Fusarium, dans des grains de blé et d'évaluer l'efficacité de neuf fongicides à réduire la gravité de la brûlure de l’épi causée par le fusarium ainsi que l’accumulation de fumonisine B1 et de zéaralenone dans les grains de blé. La fumonisine B1 et la zéaralenone ont été détectées dans tous les échantillons de grains, avec des concentrations moyennes variant entre 182,0 et 446,6 µg kg-1 (fumonisine B1) et entre 2,59 et 5,33 µg kg-1 (zéaralenone). Aucune différence significative n’a été trouvée entre les différents traitements fongicides quant à la teneur en fumonisine B1 et en zéaralenone dans les grains de blé. Aucune corrélation positive n’a été obtenue entre la gravité de la brûlure de l’épi causée par le fusarium et la teneur en fumonisine B1 ou en zéaralenone dans les grains de blé, ou encore entre l’efficacité des fongicides et la teneur en fumonisine B1 ou en zéaralenone dans les grains de blé. Sous des conditions sévères de maladie, l’efficacité des fongicides se situait entre 85,7 % (tébuconazole + triadiméfon) et 72,1 % (carbendazime)

    Excretion of Fumonisin B1, Hydrolyzed Fumonisin B1, and the Fumonisin B1−Fructose Adduct in Rats

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    The excretion of fumonisin B1 (FB1), hydrolyzed FB1 (HFB1), and FB1−fructose addition products (FB1−fructose) was determined in male Fisher 344/NHsd rats. Rats were dosed by gavage with 0.69, 6.93, or 69.3 μmol/kg of body weight FB1, HFB1, or FB1−fructose. Excretion of unchanged FB1, HFB1, and HFB1 after hydrolysis was determined in urine and feces by analytical reverse phase HPLC and fluorometric detection of the o-phthaldialdehyde derivatives. Average total FB1 backbone excretion in feces was 101, 76, and 50% of the dose for FB1, HFB1, and FB1−fructose, respectively. No effect of dose level was found on the percentage of the dose excreted as total FB1 after hydrolysis. FB1−fructose appears to be absorbed to the highest extent, followed by HFB1. FB1 appears to be excreted nearly completely in the feces. The greater absorption of HFB1 may explain the greater toxicity of HFB1 compared to FB1 on a molar basis. However, the detoxification of FB1 by formation of the fructose adduct cannot be explained by reduced absorption. Average total FB1 backbone excretion in urine was 2.7, 5.0, and 5.3% of the dose for FB1, HFB1, or FB1−fructose, respectively

    Rapid determination of fumonisin (FB\u3csub\u3e1\u3c/sub\u3e) by syringe SPE coupled with solid-phase fluorescence spectrometry

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    © 2019 Fumonisin B1 is the most prevalent member of a family of toxins, known as fumonisins, which occurs mainly in maize, wheat and other cereals. Due to its hepatotoxic and nephrotoxic in all animal species, very strict regulations have been imposed on the levels of fumonisin B1 in cereal and cereal-based foods worldwide. In this work, a rapid determination method of fumonisin B1 by membrane solid phase extraction coupled with solid-phase fluorescence analysis is developed. A rhodamine based fluorescent probe was used for derivatization with fumonisin B1. After derivatization and extraction by nylon membrane, the enriched fumonisin B1 can be detected directly on the membrane without further elution process that is placed in a designed spectra collection device. The established method showed a linear relationship in concentration range of 0.5–5.0 μg/L, with the R2 = 0.991, and a limit of detection of 0.119 μg/L. Method accuracy was further confirmed using LC-MS method by comparing the detection results of 3 corn powder samples spiked with FB1, that demonstrated equivalent results. The results of this study indicated that the proposed method was simple, sensitive, reliable and suitable for trace fumonisins B1 quantitation in corn-based feeds

    Excretion of 14C-Fumonisin B1, 14C-Hydrolyzed Fumonisin B1, and 14C-Fumonisin B1-Fructose in Rats

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    14C-Fumonisin B1 (FB1) was produced by Fusarium proliferatum M-5991 in modified Myro liquid medium and purified to \u3e95% purity with a specific activity of 1.7 mCi/mmol. Nine male and nine female F344/N rats were each dosed by gavage with 0.69 μmol of 14C-FB1, 14C-hydrolyzed FB1, or 14C-FB1-fructose/kg body weight. Urinary excretion of 14C-FB1 and 14C-FB1-fructose was 0.5% and 4.4% of the total dose, respectively, and was similar between male and female rats. Urinary excretion of 14C-hydrolyzed HFB1 was significantly greater (P \u3e 0.05) in female rats as compared with male rats (17.3% vs 12.8% of the total dose, respectively). There were no significant (P \u3e 0.05) differences in biliary excretion of the three fumonisin compounds with a mean of 1.4% of the dose excreted at 4 h after dosing. Lesser amounts continued to be excreted up to 9.25 h after dosing. Although biliary excretion of the14C-FB1, 14C-hydrolyzed FB1, and 14C-FB1-fructose was similar, increased urinary excretion of the 14C-hydrolyzed FB1 as compared to 14C-FB1 and 14C-FB1-fructose indicated a greater absorption of the hydrolyzed form

    Učinak resveratrola na razinu ekspresije SIRT2, SIRT3 i oksidacijsko oštećenje DNK kod hepatotoksičnosti izazvane fumonizinom u BALB/c miševa

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    Oxidative stress, which is characterized by disruption of the oxidant/antioxidant balance, causes pathological processes, including toxicities induced by certain mycotoxins. The present study was designed to investigate the effects of resveratrol on sirtuin deacetylases (SIRT2 and SIRT3), nitric oxide (NO), reduced glutathione (GSH) and malondialdehyde (MDA) in fumonisin B1-induced hepatotoxicity. Regarding the experimental design, forty BALB/c mice were divided into four groups corresponding to the control, resveratrol (10 mg/kg, i.p), fumonisin B1 (2.25 mg/ kg, i.p) and resveratrol + fumonisin B1 (10 mg/kg + 2.25 mg/kg) groups. At the end of the 14 day-treatment, expression levels of SIRT2 and SIRT3 protein in the serum and liver were revealed by western blotting and antioxidant/oxidant activity analysis. SIRT2 and SIRT3 expression levels in the liver were significantly decreased by fumonisin B1 in comparison to the control. However, resveratrol supplementation coupled with fumonisin B1 increased the expression levels of SIRT2 and SIRT3, in relation to the fumonisin B1 treatments alone, but did not exhibit significant differences from those of the control group. As substantial indicators of stress and damage, the 8-OH-2-deoxyguanosine, NO and MDA levels of the liver tissue were assayed, and were higher in the fumonisin B1-treated groups, in relation to the control. As expected, resveratrol treatment significantly reduced the levels of NO and MDA in comparison to the fumonisin B1 treatments alone. Also, resveratrol attenuated the liver 8-OH-2- deoxyguanosine levels in the resveratrol + fumonisin B1 group. In conclusion, the findings revealed that resveratrol might possess protective effects against fumonisin-induced hepatotoxicity through modulation of the expression of sirtuin proteins, and by protecting the cell from oxidative/nitrosative stress.Oksidacijski stres, koji obilježava poremećaj ravnoteže oksidansa i antiksidansa, uzrokuje patološke procese, uključujući toksičnost potaknutu određenim mikotoksinima. U ovom je radu istražen učinak resveratrola na sirtuin-deacetilazu (SIRT2 i SIRT3), dušikov oksid (NO), sniženi glutation (GSH) i malondialdehid (MDA) kod hepatotoksičnosti izazvane fumonizinom B1. Istraživanje je postavljeno tako da je 40 BALB/c miševa podijeljeno u četiri skupine: kontrolnu, skupinu koja je dobivala resveratrol (10 mg/kg, ip.), skupinu koja je dobivala fumonizin B1 (2,25 mg/kg, ip) i skupinu koja je dobivala resveratrol i fumonizin B1 (10 mg/kg+2,25 mg/kg). Nakon 14 dana određena je razina ekspresije proteina SIRT2 i SIRT3 metodom western blotting te analiza aktivnosti antioksidansa i oksidansa u serumu i jetri. Razina ekspresije SIRT2 i SIRT3 u jetri bila znakovito smanjena u skupini s fumonizinom B1 u usporedbi s kontrolnom skupinom. U skupini s dodatkom resveratrola i fumonizina B1, međutim, povećana je razina ekspresije SIRT2 i SIRT3 u usporedbi sa skupinom koja je dobivala fumonizin B1, no bez znakovite razlike između tih skupina i kontrolne skupine. Analizirani su ključni pokazatelji stresa i oštećenja, razine OH-2-deoksigvanozin, NO i MDA u tkivu jetre, koje su bile veće u skupini s fumonizinom B1, u usporedbi s kontrolnom skupinom. Kao što se očekivalo, primjena resveratrola znakovito je smanjila razine NO i MDA u usporedbi sa skupinom kojoj je primijenjen samo fumonizin B1. Također, resveratrol je smanjio razinu 8-OH-2- deoksigvanozina u jetri u skupini kojoj su dani i resveratrol i fumonizin. Rezultati pokazuju da bi resveratrol mogao imati zaštitni učinak u slučaju hepatotoksičnosti uzrokovane fumonizinom putem modulacije ekspresije sirtuin proteina i zaštite stanice od oksidacijskog/nitrosativnog stresa
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