Diphenyl diselenide supplementation delays the development of N-nitroso-N-methylurea-induced mammary tumors

Archive für Toxikologie (Impact Factor: 5.08). 09/2008; 82(9):655-663. DOI: 10.1007/s00204-007-0271-9

ABSTRACT The effect of dietary diphenyl diselenide (1ppm) on N-nitroso-N-methylurea (NMU)-induced mammary carcinogenesis was examined in female Wistar rats. Beginning at 5weeks of age, the animals
were fed with either control or diphenyl-diselenide-supplied diets until the end of the study (210days). At 50days of age,
mammary tumor was induced by the administration of three doses of NMU (50mg/kg body wt, intraperitoneally) once a week for
3weeks. In experimental trials, latency to tumor onset was extended in rats fed with diet supplemented with diphenyl diselenide
(P<0.05). The incidence and frequency of tumors were significantly small in animals supplemented with diphenyl diselenide.
However, the multiplicity of tumors was not altered by dietary diphenyl diselenide. Diphenyl diselenide supplementation also
restored superoxide dismutase (SOD) activity and vitamin C levels altered in the NMU group (P<0.05). Our results suggest that diphenyl diselenide can be considered a chemopreventive agent, even when supplemented at
a relatively low concentration.

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    ABSTRACT: Introduction: Cellular antioxidant signaling can be altered either by thyroid disturbances or by selenium status. Aims: To investigate whether or not dietary diphenyl diselenide could modify the expression of genes of antioxidant enzymes and endpoint markers of oxidative stress under hypothyroid condition. Methods: Female rats were rendered hypothyroid by continuous exposure to methimazole (MTZ; 20 mg/100 ml in the drinking water) for 3 months. Concomitantly, MTZ treated rats were either fed or not with a diet containing 5 ppm of diphenyl diselenide. mRNA levels of antioxidant enzymes and antioxidant/oxidant status were determined in cerebral cortex, hippocampus and striatum. Results: Hypothyroidism caused a marked up-regulation in mRNA expression of catalase (CAT), superoxide dismutase (SOD-1, SOD-3), glutathione peroxidase (GPx-1, GPx-4) and thioredoxin reductase (TrxR1) in brain structures. SOD-2 was increased in cortex and striatum, while TrxR2 increased in cerebral cortex. The increase in mRNA expression of antioxidant enzymes was positively correlated with the Nrf-2 transcription in cortex and hippocampus. Hypothyroidism caused oxidative stress, namely an increase in lipid peroxidation and ROS levels in hippocampus and striatum, and a decrease in non-protein thiols (NPSH) in cerebral cortex. Diphenyl diselenide was effective in reducing brain oxidative stress and normalizing most of changes observed in gene expression of antioxidant enzymes. Conclusion: The present work corroborates and extends that hypothyroidism disrupts the antioxidant enzyme gene expression and causes oxidative stress in the brain. Furthermore, diphenyl diselenide may be considered a promising molecule in counteracting these effects under hypothyroidism state. © 2014 S. Karger AG, Basel.
    Neuroendocrinology 07/2014; 100(1). DOI:10.1159/000365515 · 4.93 Impact Factor
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    ABSTRACT: Oxidative stress caused by reactive species, including reactive oxygen species, reactive nitrogen species, and unbound, adventitious metal ions (e.g., iron [Fe] and copper [Cu]), is an underlying cause of various neurodegenerative diseases. These reactive species are an inevitable by-product of cellular respiration or other metabolic processes that may cause the oxidation of lipids, nucleic acids, and proteins. Oxidative stress has recently been implicated in depression and anxiety-related disorders. Furthermore, the manifestation of anxiety in numerous psychiatric disorders, such as generalized anxiety disorder, depressive disorder, panic disorder, phobia, obsessive-compulsive disorder, and posttraumatic stress disorder, highlights the importance of studying the underlying biology of these disorders to gain a better understanding of the disease and to identify common biomarkers for these disorders. Most recently, the expression of glutathione reductase 1 and glyoxalase 1, which are genes involved in antioxidative metabolism, were reported to be correlated with anxiety-related phenotypes. This review focuses on direct and indirect evidence of the potential involvement of oxidative stress in the genesis of anxiety and discusses different opinions that exist in this field. Antioxidant therapeutic strategies are also discussed, highlighting the importance of oxidative stress in the etiology, incidence, progression, and prevention of psychiatric disorders.
    Current Neuropharmacology 03/2014; 12(2):120-39. DOI:10.2174/1570159X11666131120232135 · 2.35 Impact Factor
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    ABSTRACT: The organoselenium compound, dicholesteroyl diselenide (DCDS) is a structural analogue of diphenyl diselenide (DPDS) and may be considered as a promising antioxidant drug in vivo. Nevertheless, little is known about the toxicological properties of DCDS. In the present study we evaluated the cytotoxic, genotoxic and mutagenic properties of DCDS in Chinese hamster lung fibroblasts (V79) and in strains of the yeast Saccharomyces cerevisiae, proficient and deficient in several DNA-repair pathways. The results with V79 cells show that DCDS induced cytotoxicity, GSH depletion and elevation of lipid peroxidation at lower concentrations than did DPDS. DCDS also generated single- and double-strand DNA breaks in V79 cells, both in the presence and in the absence of metabolic activation, as revealed by alkaline and neutral comet assays. Moreover, the induction of oxidative DNA base-damage was demonstrated by means of a modified comet assay with formamidopyrimidine-DNA glycosylase and endonuclease III. Treatment with DCDS also induced micronucleus formation in V79 cells as well as point and frame-shift mutations in a haploid wild-type strain of S. cerevisiae. Yeast mutants defective in base excision-repair proteins were the most sensitive to DCDS. Pre-incubation with N-acetylcysteine reduced DCDS's oxidative, genotoxic and mutagenic effects in yeast and in V79 cells. Our findings indicate that the presence of cholesteroyl substituents in DCDS results in elevation of its cytotoxic and genotoxic potential compared with that of DPDS in yeast and in V79 cells. However, due to dose-dependent contrasting behaviour of organoselenium compounds and differences in their toxicity in in vitro and in vivo systems, further studies are needed in order to establish the non-toxic concentration range for treatment in mammals.
    Mutation Research/Genetic Toxicology and Environmental Mutagenesis 03/2014; DOI:10.1016/j.mrgentox.2013.12.007 · 2.48 Impact Factor

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