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Organoselenium Compound (organoselenium + compound)
Selected AbstractsEvaluation of the antimicrobial activity of ebselen: Role of the yeast plasma membrane H+ -ATPaseJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 5 2007Grace Chan Abstract Ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one) is a selenium-containing antioxidant demonstrating anti-inflammatory and cytoprotective properties in mammalian cells and cytotoxicity in lower organisms. The mechanism underlying the antimicrobial activity of ebselen remains unclear. It has recently been proposed that, in lower organisms like yeast, the plasma membrane H+ -ATPase (Pma1p) could serve as a potential target for this synthetic organoselenium compound. Using yeast and bacteria, the present study found ebselen to inhibit microbial growth in a concentration- and time-dependent manner, and yeast and Gram-positive bacteria to be more sensitive to this action (IC50 , 2,5 ,M) than Gram-negative bacteria (IC50 < 80 ,M). Washout experiments and scanning electron microscopic analysis revealed ebselen to possess fungicidal activity. In addition, ebselen was found to inhibit medium acidification by PMA1 -proficient haploid yeast in a concentration-dependent manner. Additional studies comparing PMA1 (+/,) and PMA1 (+/+) diploid yeast cells revealed the mutant to be more sensitive to treatment with ebselen than the wild type. Ebselen also inhibited the ATPase activity of Pma1p from S. cerevisae in a concentration-dependent manner. The interaction of ebselen with the sulfhydryl-containing compounds L -cysteine and reduced glutathione resulted in the complete and partial prevention, respectively, of the inhibition of Pma1p ATPase activity by ebselen. Taken together, these results suggest that the fungicidal action of ebselen is due, at least in part, to interference with both the proton-translocating function and the ATPase activity of the plasma membrane H+ -ATPase. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:252,264, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20189 [source] Protective effect of binaphthyl diselenide, a synthetic organoselenium compound, on 2-nitropropane-induced hepatotoxicity in ratsCELL BIOCHEMISTRY AND FUNCTION, Issue 4 2010Mohammad Ibrahim Abstract Organoselenides have been documented as promising pharmacological agents against a number of diseases associated with oxidative stress. Here we have investigated, for the first time, the potential antioxidant activity of binaphthyl diselenide ((NapSe)2; 50,mg,kg,1, p.o.) against the 2-nitropropane (2-NP)-induced hepatoxicity in rats, using different end points of toxicity (liver histopathology, plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatinine). In addition, in view of the association of oxidative stress with 2-NP exposure, hepatic lipid peroxidation, ascorbic acid levels, ,-aminolevulinate dehydratase (,-ALA-D) and catalase (CAT) activities were evaluated. 2-NP caused an increase of AST, ALT and hepatic lipid peroxidation. 2-NP also caused hepatic histopathological alterations and ,-ALA-D inhibition. (NapSe)2 (50,mg,kg,1) prevented 2-NP-induced changes in plasmatic ALT and AST activities and also prevented changes in hepatic histology, ,-ALA-D and lipid peroxidation. Results presented here indicate that the protective mechanism of (NapSe)2 against 2-NP hepatotoxicity is possibly linked to its antioxidant activity. Copyright © 2010 John Wiley & Sons, Ltd. [source] Volatile organoselenium monitoring in production and gastric digestion processes of selenized yeast by solid-phase microextraction-multicapillary gas chromatography coupled microwave-induced plasma atomic emission spectrometry,APPLIED ORGANOMETALLIC CHEMISTRY, Issue 12 2004J. Sanz Landaluze Abstract Evolution of volatile organoselenium compounds in the production and gastric digestion of selenized yeast has been monitored. The industrial production of these kinds of material, employed as food supplements, has been simulated in a process of yeast enrichment with inorganic selenium selenium (IV) in different growth media, with variation of the pH value. The in vitro gastric digestion process was carried out with pepsin in an acid and salt mixture. Determination of volatile species of selenium was achieved coupling solid-phase microextraction (SPME) for preconcentration and sample,matrix separation and microwave-induced plasma atomic emission spectrometry, in combination with multicapillary (MC) gas chromatography for separation and detection of the selenium species. The MC column was operated at low temperatures (,30 °C). The method was optimized, using a chemometric approach, with respect to the detection of organoselenium species such as dimethylselenide, diethylselenide and dimethyldiselenide. SPME sampling was carried out in the headspace above the corresponding solutions. Separation is fast, with a chromatogram being obtained in less than 5 min, and the detection limits were at the low parts per billion level for all species investigated. The results of the yeast enrichment process demonstrate inorganic selenium transformation into volatile organic species. The presence of inorganic selenium gave rise to at least five different volatile species after metabolization by yeast, with dimethylselenide and dimethyldiselenide being the predominant species. Commercial pasteurized yeast, containing mainly selenomethionine for use as a food supplement, and tablets were found to be still active under conditions of the simulation of the digestion process, even though producing relatively low amounts of organoselenium compounds. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||