Search results for "O-2"
showing 10 items of 854 documents
Study of the potential toxicity of commercial crispy breads by evaluation of bioaccessibility and bioavailability of minor Fusarium mycotoxins
2011
Abstract Enniatins (ENs) are bioactive compounds produced by the secondary metabolism of several Fusarium strains and known to have several biological activities, such as acting as enzyme inhibitors, antifungal and antibacterial agents, and immunomodulatory substances. This study has investigated the ENs bioaccessibility, spiked in commercial wheat crispy bread at 1.5 and 3.0 μmol/g concentrations, their transepithelial transport and bioavailability using Caco-2 cells as a model of the human intestinal epithelium. The content (%) of the four ENs contained in the gastric fluid has resulted variable from 69% to 91%, considering the two concentrations assayed. The mean bioaccessibility data fo…
Study of the potential toxicity of enniatins A, A(1), B, B(1) by evaluation of duodenal and colonic bioavailability applying an in vitro method by Ca…
2010
Abstract The bioavailability of the minor Fusarium mycotoxins enniatins (ENs) utilizing an in vitro method which allows the simulation of the small and large intestine tracts has been studied. This method, based on the application of the Caco-2 cells grown alone or in symbiosis with several strains characteristics of the gastrointestinal tract, has permitted to simulate the duodenal and colonic intestinal compartments, respectively. The duodenal bioavailability expressed as absorption value after 4 h of exposure, ranged from 57.7 to 76.8% for EN A, from 68.8 to 70.2% for EN A1, from 65.0 to 67.0% for EN B, and from 62.2 to 65.1% for EN B1. Colonic bioavailability after 48 h of incubation ra…
Interaction effects of Fusarium enniatins (A, A1, B and B1) combinations on in vitro cytotoxicity of Caco-2 cells
2014
Abstract Foodstuff is usually contaminated by more than one mycotoxin, however toxicological data are lacking as regards the effects in combinations compared to their individual effect. This study investigated the in vitro effects of enniatins (ENs) A, A1, B and B1, alone and in combinations, on Caco-2 cells viability by MTT assay after 24 h of exposure. Cells were treated with concentrations ranging from 0.9 to 15.0 μM, individually and in combination of two, three and four mycotoxins. Dose–response curves were generated for each mycotoxin and the isobologram method was used to determine the interactive effects of tested mixtures. Tested ENs produced significant cytotoxic effects both indi…
Isolation and purification of enniatins A, A1, B, B1, produced by Fusarium tricinctum in solid culture, and cytotoxicity effects on Caco-2 cells
2010
Enniatins (ENs) are antibiotic compounds of hexadepsipeptidic structure produced by several strains of Fusarium spp. The ENs A, A(1), B, B-1 were purified from extracts of Fusarium tricinctum grown on a solid medium of corn, by a low pressure liquid chromatography (LPLC) on reverse phase of Amberlite XAD-7 followed by semipreparative LC. The purity and the structure of the isolated compounds were confirmed by LC-MS/MS. The technique of the purification of the fungal extract enabled complete separation of the ENs A, A(1), B, B-1 with a mean purity of 97% for all the compounds. The cytoxicity of the ENs was tested in the cell lines of human origin (epithelial colorectal adenocarcinoma cells, …
Antibacterial activity of the enniatin B, produced by Fusarium tricinctum in liquid culture, and cytotoxic effects on Caco-2 cells.
2011
The enniatins (ENs) are bioactive compounds of hexadepsipeptidic structure produced by several strains of Fusarium sp. The EN B was purified from extracts of Fusarium tricinctum growth on liquid culture of potato dextrose broth (PDB), using a semipreparative liquid chromatography (LC) followed by an analytical LC. The purity and the structure of the isolated compound were confirmed by the determination of the extinction coefficient and with electrospray ionization-mass spectrometry (ESI-MS) study. The pure fraction of EN B was utilized to determine the antibiotic effects on several bacterial strains that are considered normally pathogens of the intestinal tract: Escherichia coli, Enterococc…
As2O3-induced oxidative stress and cycle progression in a human intestinal epithelial cell line (Caco-2)
2007
Foods and drinking water are the main routes for human exposure to inorganic arsenic, the intestinal epithelium being the first barrier against such exogenous toxicants. The present study evaluates the effect of As(III) (0.5-25 microM) upon Caco-2 cells as an intestinal epithelia model. Cell viability, intracellular formation of reactive oxygen species (ROS), mitochondrial membrane potential (Deltapsim) changes, and cell cycle distribution in exposed cultures were evaluated. The intracellular production of ROS was seen to increase in a non-dose dependent manner at all concentrations tested, with impairment of cell mitochondrial enzyme function secondary to a loss of Deltapsim. Concentration…
CD133 Expression Is Not Synonymous to Immunoreactivity for AC133 and Fluctuates throughout the Cell Cycle in Glioma Stem-Like Cells.
2015
A transmembrane protein CD133 has been implicated as a marker of stem-like glioma cells and predictor for therapeutic response in malignant brain tumours. CD133 expression is commonly evaluated by using antibodies specific for the AC133 epitope located in one of the extracellular domains of membrane-bound CD133. There is conflicting evidence regarding the significance of the AC133 epitope as a marker for identifying stem-like glioma cells and predicting the degree of malignancy in glioma cells. The reasons for discrepant results between different studies addressing the role of CD133/AC133 in gliomas are unclear. A possible source for controversies about CD133/AC133 is the widespread assumpt…
Beauvericin-induced cytotoxicity via ROS production and mitochondrial damage in Caco-2 cells.
2013
The cytotoxicity of beauvericin (BEA) on human colon adenocarcinoma (Caco-2) cells was studied as a function of time. Moreover, the oxidative damage and cell death endpoints were monitored after 24, 48 and 72 h. After BEA exposure, the IC₅₀ values ranged from 1.9 ± 0.7 to 20.6 ± 6.9 μM. A decrease in reduced glutathione (GSH; 31%) levels, as well as an increase in oxidized glutathione (GSSG, 20%) was observed. In the presence of BEA, reactive oxygen species (ROS) level was highly increased at an early stage with the highest production of 2.0-fold higher than the control that was observed at 120 min. BEA induced cell death by mitochondria-dependent apoptotic process with loss of the mitochon…
RAB3GAP1 and RAB3GAP2 modulate basal and rapamycin-induced autophagy
2014
Macroautophagy is a degradative pathway that sequesters and transports cytosolic cargo in autophagosomes to lysosomes, and its deterioration affects intracellular proteostasis. Membrane dynamics accompanying autophagy are mostly elusive and depend on trafficking processes. RAB GTPase activating proteins (RABGAPs) are important factors for the coordination of cellular vesicle transport systems, and several TBC (TRE2-BUB2-CDC16) domain-containing RABGAPs are associated with autophagy. Employing C. elegans and human primary fibroblasts, we show that RAB3GAP1 and RAB3GAP2, which are components of the TBC domain-free RAB3GAP complex, influence protein aggregation and affect autophagy at basal an…
Effect of retinoids on UDP-glucuronosyltransferase 2B7 mRNA expression in Caco-2 cells.
2008
Human UDP-glucuronosyltransferase 2B7 (UGT2B7) is one of the major isoforms involved in the glucuronidation of endogenous compounds and xenobiotics. This isoform is the only human UGT shown to glucuronidate retinoids and their oxidized derivatives. In this study, the effects of all-trans retinoic acid (atRA), 9-cis RA, and the RAR agonist TTNPB, on UGT2B7 and UGT2B15 mRNA expression in Caco-2 cells have been examined. Each of these retinoids significantly suppressed UGT2B7 mRNA expression in a concentration-dependent manner with IC50 values of 3.5, 0.3, and 0.2 microM, respectively. However, no inhibition was observed when two other UGTs, UGT2B15 or -1A6, were exposed to atRA, 9-cis RA, or …