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ABSTRACT: Fumonisins (FBs) are bioactive compounds produced by several strains of Fusarium spp. which contain a polyketide structure similar to sphinganine. These mycotoxins contain a free amino group that could work as an electron donor and react with the electrophile carbon present within the isothiocyanate (ITC) group. The objective of this study was to determine the effect of ITCs (allyl, benzyl and phenyl) on the stability of FB(1), FB(2) and FB(3). Firstly, PBS solutions at three pH levels (4, 7 and 9) were prepared and added with pairs of one FB (1mg/L) plus one ITC (1 mg/L). Then, gaseous ITC was used to fumigate corn kernels and corn flour contaminated with FBs produced by Gibberella moniliformis CECT 2987 in situ. Mycotoxin levels were evaluated using liquid chromatography coupled to mass spectrometry in tandem (LC-MS/MS), while products formed from the reaction of FBs and ITCs were examined by liquid chromatography coupled to mass spectrometry-linear ion trap (LC-MS-LIT). The reduction of FB(1) and FB(2) in solution ranged from 42 to 100% on a time-dependent manner. This variance was greatly influenced by pH. In general, lower pH levels eased the reaction between ITCs and FBs. ITC fumigation treatment (50, 100 and 500 μL/L) was able to reduce 53 to 96% of FB(1) levels, 29 to 91% of FB(2) and 29 to 96% of FB(3). Four reaction products between the bioactive compounds employed in this study were identified, corresponding to FB + ITC conjugates.
Toxicon 12/2012; · 2.51 Impact Factor
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ABSTRACT: Enniatins (ENs) A, A(1), B and B(1) are produced by Fusarium species. They are known as emerging fusariotoxins, and can cause outbreaks in both humans and animals. ENs elicit a wide range of different biological properties and toxicological effects, and their co-occurrence may enhance the extent of these hazards. As the potential toxins reach in vitro cells in the same way as they would in vivo, cytotoxicity was studied with CHO-K1, which is considered one of the most sensitive cell lines for preliminary screening of cytotoxicity studies. In this study, individual cytotoxic effects of ENs were evaluated by MTT assay after exposing ENs to CHO-K1 cells for 24, 48, and 72 h. The IC(50) values obtained for ENs A, A(1), B and B(1) ranged from >7.5 to 2.83 ± 0.49, from 8.8 ± 2.29 to 1.65 ± 0.06, from 11.0 ± 2.65 to 2.80 ± 0.16 and from 4.53 ± 1.23 to 2.47 ± 0.29 μM, respectively. The ENs cytotoxic interaction was evaluated by the isobologram method. The IC(50) values for ENs combination ranged from 0.44 ± 0.15 (ENs A(1)+B(1)) to 0.97 ± 0.48 (ENs A(1)+B+B(1)). The binary combinations ENs A+B(1), ENs A(1)+B and ENs B+B(1) showed additive effect thought all concentrations tested. Sinergistic effect of combined ENs A+A(1), A+B, A(1)+B(1), A+A(1)+B, A+A(1)+B(1), A+B+B(1) and A(1)+B+B(1) at higher concentrations occurred. Synergism effect (CI from 0.37 ± 0.08 to 0.74 ± 0.22) was observed at higher concentrations with binary and tertiary combinations of EN A, while antagonism effect was obtained at lower concentrations for ENs A+A(1)+B(1) (CI= 2.67 ± 1.32) and ENs A(1)+B+B(1) (CI= 3.14 ± 1.91). These results provide quantitative evidence that ENs cytotoxicity depend on their concentrations, and also on their combination with other mycotoxins.
Toxicology in Vitro 11/2012; · 2.78 Impact Factor
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ABSTRACT: a b s t r a c t Biogenic amines on fish tissue are formed as a result of bacterial contamination and spoilage during stor-age. A new method based on liquid chromatography (LC) and tandem mass spectrometry (MS/MS) using a triple quadrupole (QqQ) analyser was developed for the analysis of eight biogenic amines (cadaverine, histamine, phenylethylamine, putrescine, spermine, spermidine, tyramine and tryptamine) in fish tis-sues. Sample preparation was performed by extraction with trichloroacetic acid 5% and solid phase extraction clean up with STRATA X cartridge. The MS/MS method was validated and compared with a method based on the analysis of dansyl derivatives by LC and fluorescence detector (FD). MS/MS achieved higher sensitivity (from 0.02 mg kg À1 for spermidine and phenylethylamine to 0.2 mg kg À1 for spermine) when compared to FD (from 1 mg kg À1 for putrescine and tyramine to 4 mg kg À1 for histamine); MS/MS method showed higher precision too, with intraday relative standard deviations (RSDs) from 1% to 4% with respect to those obtained with FD method (from 3% to 17%). Recovery study was conducted at two different fortification levels and the average ranged from 71% to 93% for all of the studied compounds with RSDs lower than 18%. Matrix-matched standards were used to counteract matrix effect observed in MS/MS determination. The applicability of the method was demon-strated by the analysis of biogenic amines in fish obtained from commercials of Valencia.
Food Chemistry 12/2011; · 3.65 Impact Factor
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ABSTRACT: Cytotoxic effects of aldicarb, its sulfone and sulfoxide, and propoxur, lipid peroxidation and antioxidant parameters in Chinese Hamster Ovary (CHO-K1) cells were determined. D,L-buthionine-(S,R)-sulfoximine (BSO) was assayed to determine the role of GSH in the protection against carbamate cytotoxicity. Pre-treatment with 60 microM BSO, induced a significant decrease in the glutathione reductase (GR; 64-141%), the glutathione peroxidase (GPx; 10-30%) and the glutathione S-transferase (GST; 59-93%) activities, and its GSH levels (79-85%), while the oxidized glutathione (GSSG) levels significantly increased (64-78%) respect to experiment non-BSO-pretreated. Carbamates BSO pre-treated vs. non-BSO pre-treated showed a significant increase in malondialdehyde (MDA) production (from 13% to 52% vs. 25% to 93%). These data suggest that carbamates could injure CHO-K1 cells via oxidative stress by the increase of MDA production; moreover, BSO enhance the oxidative damage caused by carbamates. However, the glutathione system protects cells from carbamates damage.
Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 03/2010; 48(6):1592-6. · 2.99 Impact Factor
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ABSTRACT: Fumonisin B1 (FB1) content in corn products decreases during the heating process in foods
containing reducing sugars, mainly because of the formation of N-(carboxymethyl)fumonisin B1. In
this study, a rapid method has been developed for the determination of both compounds in corn
products using a high-speed blender, Ultra-Turrax, for solvent extraction and liquid chromatographytandem
mass spectrometry. The kinetics of FB1 degradation and the formation of the Maillard
adduct were studied in a model system constituted by corn bread spiked with FB1 and heated at
160, 180, and 200 �C for 3, 6, 10, 15, and 20 min. FB1 decreased from 0.96 to 0.3 mg/kg and
N-(carboxymethyl)fumonisin B1 increased to 0.1 mg/kg. Cytotoxicity and lipid peroxidation were
studied in monkey kidney cells (Vero cells). After 24 h exposure, FB1 revealed an IC50 (median
inhibitory concentration) of 55 ( 7 μM with neutral red uptake, but no IC50 was obtained after
N-(carboxymethyl)fumonisin B1 exposure at the studied concentrations. Lipid peroxidation was
assessed using the thiobarbituric acid reactive substance (TBARS) method for 90 min and 24 and
48 h. FB1 significantly increased the production of malondialdehyde in Vero cells exposed to 1 μM
FB1 after 24 h, while malondialdehyde increased after 5 μM N-(carboxymethyl)fumonisin B1
exposure. These findings showed that the transformation products exhibit lower cytotoxicity than
fumonisin B1 and lipid peroxidation may be involved in the cytotoxicity induced by both toxins.
Journal of Agricultural and Food Chemistry 01/2010; 58:1359-1365. · 2.82 Impact Factor
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ABSTRACT: In this stir bar sorptive extraction (SBSE) method, 16 pesticides were extracted from surface water samples by sorption onto 1 mm polydimethylsiloxane layer coated on a 10-mm-length stir bar magnet. After liquid desorption of the analytes with 1 ml of methanol, the detection was performed on a liquid chromatography-tandem mass spectrometry with a triple quadrupole (QqQ) analyzer using selected reaction monitoring mode via electrospray ionization. Parameters affecting SBSE operation, including sample volume, salt addition, extraction time, stirring rate, and desorption conditions, have been evaluated. The optimized SBSE method required two 50 ml aliquots of surface water samples, one aliquot was added of 30% NaCl and stirred at 900 rpm during 1 h for testing five pesticides with log K(o/w) < 3, and the other aliquot was directly extracted following the same procedure for the rest of the pesticides with log K(o/w) > 3. The method was validated in spiked surface water samples at limits of quantifications (LOQs) and ten times the LOQs showing recoveries <62%, and the LOQs reached were from 0.03 microg l(-1) for diazinon to 3 microg l(-1) for simazine. The proposed methodology was applied to the determination of these compounds in samples from Albufera Lake and surrounding channels, showing that SBSE is a powerful tool for routine control analysis of pesticide residues in surface water.
Analytical and Bioanalytical Chemistry 02/2009; 393(6-7):1733-43. · 3.78 Impact Factor
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ABSTRACT: Cytotoxic effects of aldicarb, its sulfone and sulfoxide, and propoxur, lipid peroxidation and antioxidant parameters in Chinese Hamster Ovary (CHO-K1) cells were determined. d,l-buthionine-(S,R)-sulfoximine (BSO) was assayed to determine the role of GSH in the protection against carbamate cytotoxicity. Pre-treatment with 60 μM BSO, induced a significant decrease in the glutathione reductase (GR; 64–141%), the glutathione peroxidase (GPx; 10–30%) and the glutathione S-transferase (GST; 59–93%) activities, and its GSH levels (79–85%), while the oxidized glutathione (GSSG) levels significantly increased (64–78%) respect to experiment non-BSO-pretreated. Carbamates BSO pre-treated vs. non-BSO pre-treated showed a significant increase in malondialdehyde (MDA) production (from 13% to 52% vs. 25% to 93%). These data suggest that carbamates could injure CHO-K1 cells via oxidative stress by the increase of MDA production; moreover, BSO enhance the oxidative damage caused by carbamates. However, the glutathione system protects cells from carbamates damage.
Food and Chemical Toxicology.
