Organoselenium Compounds

The aim of this study was to investigate the possible involvement of the glutamatergic system in the toxicity of organochalcogens, since this is an important neurotransmitter system for signal transduction and neural function. The results indicated that 100 μM diphenyl diselenide ( ...

Selenium-containing amino acids, selenocystine (CysSeSeCys), methylseleno-cysteine (MeSeCys), and selenomethionine (SeMet) have been examined for anti-hemolytic and peroxyl radical scavenging ability. Effect of these compounds on membrane lipid peroxidation, ...

Organoselenium compounds find applications in organic
synthesis, materials synthesis, ligand chemistry and biologically
relevant processes. This review deals with the use
of various synthetic organoselenium compounds as mimics
of glutathione peroxidase (GPx), a selenoenzyme which
catalyses the reduction of a variety of hydroperoxides and
protects the cell membranes from oxidative damage. The
mechanism by which these compounds catalyse the reduction
of peroxides is also reviewed. The cyclic selenenamides
and diselenides with suitably positioned substituents exert
their catalytic activity by a mechanism similar to that of the
natural enzyme.

Hypothyroidism has been associated to psychiatric disorder development and tissue oxidative damage. In this study, we evaluated the effect of diphenyl diselenide supplementation on depressive-like behavior triggered by methimazole exposure in female rats. Additionally, thiobarbituric acid reactive substances (TBARS), reactive oxygen species (ROS) and non-protein thiol (NP-SH) levels were analyzed in cerebral cortex, hippocampus and striatum structures of rats. Monoamine oxidase (MAO) activity was evaluated in total brain. Firstly, female rats received methimazole (MTZ) 20mg/100ml in the drinking water for 30days and were evaluated in open-field and forced swimming tests (FST). In this set of experiments, the rats exposed to MTZ presented a depressive-like behavior, which was evidenced by a significant increase in the immobility time when compared to control group. Thereafter, MTZ-induced hypothyroid rats received either a standard or a diet containing 5ppm of diphenyl diselenide, an...

The simple organoselenium compound diphenyl diselenide (PhSe)2 is a promising new pharmacological agent. However, few toxicological evaluations of this molecule have been reported. We evaluated the effects of acute administration of (PhSe)2 on toxicological parameters in rabbits. Adult New Zealand rabbits were exposed to (PhSe)2 (5–500 µmol kg−1, intraperitoneally) once a day for 5 days. Exposure to 500 µmol kg−1 caused 85% mortality. Exposure to 50 µmol kg−1 of (PhSe)2 increased the glutathione levels in the hippocampus, kidney, heart, muscle and blood, whereas lipoperoxidation (TBARS) decreased in the cerebellum and kidney after exposure to 5 µmol kg−1. The activity of glutathione peroxidase increased in the heart and muscle of rabbits treated with 50 µmol kg−1 of (PhSe)2 and glutathione reductase activity was reduced in the cerebellum, cerebral cortex and kidney. Treatment with (PhSe)2 reduced the activity of δ-aminolevulinate dehydratase in the hippocampus and increased this activity in the heart, but did not alter the activity of complexes I and II of the respiratory chain in the liver and brain. Hepatic and renal biochemical and histological parameters were not modified by (PhSe)2 and apoptosis was not detected in these tissues; however, the hepatic cells tended to accumulate fat vacuoles. These results indicated that acute toxicology to (PhSe)2 in rabbit is dependent on the dose, which should motivate further experiments on the therapeutic properties of this compound. Copyright © 2010 John Wiley & Sons, Ltd.

ABSTRACTColonization of central venous catheters (CVCs) by pathogenic bacteria leads to catheter-related bloodstream infections (CRBSIs). These colonizing bacteria form highly antibiotic-resistant biofilms.Staphylococcus aureusis one of the most frequently isolated pathogens in CRBSIs. Impregnating CVC surfaces with antimicrobial agents has various degrees of effectiveness in reducing the incidence of CRBSIs. We recently showed that organoselenium covalently attached to disks as an antibiofilm agent inhibited the development ofS. aureusbiofilms. In this study, we investigated the ability of an organoselenium coating on hemodialysis catheters (HDCs) to inhibitS. aureusbiofilmsin vitroandin vivo.S. aureusfailed to develop biofilms on HDCs coated with selenocyanatodiacetic acid (SCAA) in either static or flowthrough continuous-culture systems. The SCAA coating also inhibited the development ofS. aureusbiofilms on HDCsin vivofor 3 days. The SCAA coating was stable and nontoxic to cell c...

In search for better mimics of the glutathione peroxidase enzymes, pyridoxine-like diselenides 6 and 11, carrying a 6-bromo substituent, were prepared. Reaction of 2,6-dibromo-3-pyridinol 5 with sodium diselenide provided 6 via aromatic nucleophilic substitution of the 2-bromo substituent. LiAlH4 caused reduction of all four ester groups and returned 11 after acidic work-up. The X-ray structure of 6 showed that the dipyridyl diselenide moiety was kept in an almost planar, transoid conformation. According to NBO-analysis, this was due to weak intramolecular Se...O (1.1 kcal/mol) and Se...N-interactions (2.5 kcal/mol). That the 6-bromo substituent increased the positive charge on selenium was confirmed by NPA-analysis and seen in calculated and observed 77Se NMR-shifts. Diselenide 6 showed a more than 3-fold higher reactivity than the corresponding des-bromo compound 3a and ebselen when evaluated in the coupled reductase assay. Experiments followed for longer time (2 h) confirmed that...