Selenium

The mutual influences of wheat selenium (Se) and n-3 polyunsaturated fatty acids (n-3 PUFA) on plasma Se and indicators of increased oxidative stress were investigated in a randomized, double-blind study with 31 women (23.5 +/- 3.4 yr). Groups 1 and 2 ingested 5.4 g n-3 PUFA daily (as ethyl esters), whereas groups 3 and 4 received placebo capsules. Groups 2 and 3 received 3 slices of high-Se bread daily, providing 115 micrograms Se, in addition to the 77 +/- 26 micrograms Se in the diet. Groups 1 and 4 received placebo slices. Blood samples were drawn at baseline and at 3 and 6 wk. Serum Se concentrations increased in both groups given Se-enriched bread, but significantly less in subjects given n-3 PUFA (group 2). There were no changes in the plasma ratio alpha-tocopherol:mg cholesterol or plasma ascorbic acid levels. In group 1, plasma-conjugated dienes and thiobarbituric acid-reactive substances (TBARS) rose by 130% (p < 0.005) and 126% (p < 0.005), respectively. Two-way ANO...

Purpose: We explored the efficacy of selenium and/or or N-acetyl-cysteine for improving semen parameters in infertile men, and the associations among semen quality and the concentrations of selenium and N-acetyl-cysteine in seminal plasma. Materials and Methods: The study included 468 infertile men with idiopathic oligo-asthenoteratospermia who were randomized to receive 200 g selenium orally daily (selenium group of 116), 600 mg N-acetyl-cysteine orally daily (N-acetyl-cysteine group of 118), 200 g selenium plus 600 mg N-acetyl-cysteine orally daily (selenium plus N-acetyl-cysteine group of 116) or similar regimen of placebo (control group of 118) for 26 weeks, followed by a 30-week treatment-free period. These patients provided blood samples for the measurement of serum testosterone, estradiol, follicle-stimulating hormone, luteinizing hormone, prolac-tin, inhibin B, selenium and N-acetyl-cysteine. Semen samples were also obtained for routine semen analysis, and the measurement of seminal plasma selenium and N-acetyl-cysteine. Results: In response to selenium and N-acetyl-cysteine treatment serum follicle-stimulating hormone decreased but serum testosterone and inhibin B increased. All semen parameters significantly improved with selenium and N-acetyl-cys-teine treatment. Administering selenium plus N-acetyl-cysteine resulted in additive beneficial effects. A significant positive correlation existed between the seminal plasma concentrations of selenium and N-acetyl-cysteine, and semen parameters. A strong correlation was observed between the sum of the selenium and N-acetyl-cysteine concentrations, and mean sperm concentration (r ϭ 0.67, p ϭ 0.01), sperm motility (r ϭ 0.64, p ϭ 0.01) and percent normal morphology (r ϭ 0.66, p ϭ 0.01). Conclusions: These results indicate that supplemental selenium and N-acetyl-cysteine improve semen quality. We advocate their use for male infertility treatment. Abbreviations and Acronyms E2 ϭ estradiol FSH ϭ follicle-stimulating hormone GSH ϭ glutathione LH ϭ luteinizing hormone NAC ϭ N-acetyl-cysteine PRL ϭ prolactin RIA ϭ radioimmunoassay assay ROS ϭ reactive oxygen species TEAE ϭ treatment emergent adverse event

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Single and double site mutants affecting the presumed catalytic centre of the selenoenzyme PHGPx were subjected to functional analysis. The rate constants k+1 and k'+2, for the oxidation and the regeneration of the ground state enzyme were estimated, respectively. Moreover, the alkylation rate of the reactive centre by iodoacetate (kinact.) was also analysed. The substitution of the catalytically competent selenocysteine 46 by cysteine (PHGPxcys46) decreased k+1 and k'+2 by about three orders of magnitude, although leaving unaffected kinact.. Furthermore, mutations of PHGPxcys46 involving the other residues of the triad decreased both kinact. and k+1, thus highlighting the involvement of Gln 81 and Trp 136 in the dissociation/activation of the nucleophilic cysteine thiol. In general, substitutions of Gln 81 or Trp 136 by acidic residues in PHGPxcys46 most dramatically depressed the k+1 values, because they practically prevented the dissociation of the thiol group, while neut...

Selenium (Se), an essential micronutrient, exerts its biological functions through selenoproteins. There are evidences that show Se to have an impact on the course and outcome of a number of etiologically inflammatory diseases. Leukotriene B4 (LTB4) is an inflammatory mediator, and its production is mediated through two specific enzymes—lipooxygenase (LOX) and leukotriene A4 hydrolase (LTA4H). We examined the effect of Se on LTB4 synthesis during isoproterenol (ISP)-induced myocardial infarction (MI) in rats. Rats were divided as: control, ISP, Se, and Se + ISP. Sodium selenite was administered at dose of 8 μg/100 g/day. ISP was injected subcutaneously twice (10 mg/100 g body weight). The rats pretreated with Se had increased concentration of phospholipids and enhanced biosynthetic enzymes compared with that of ISP. The activities of phospholipases decreased on Se treatment. The level of calcium was increased in ISP group whereas, on Se treatment, it was near normal levels. Activities of LOX and expression of LTA4H were down-regulated in the case of Se-pretreated rats. Our study shows the anti-inflammatory mechanism of selenium during MI.

This study investigates the antidiabetic and antioxidant potential of chitosan-encapsulated selenium nanoparticles in streptozotocin-induced diabetic model. Glibenclamide was used as a reference antidiabetic drug. Forty-eight adult male Wistar rats were used along the study and divided equally into 6 groups of (I) normal control, (II) chitosan-encapsulated selenium nanoparticles (CTS-SeNPs), (III) glibenclamide, (IV) streptozotocin (STZ), (V) STZ + CTS-SeNPs, and (VI) STZ + Glib. The animals were sacrificed on the 35th day of the experiment. Serum glucose, insulin, IGF-1, ALT, AST, CK-MB, oxidative stress, lipid profile, and inflammatory parameters were subsequently assessed. Also, the expression level of TCF7L2, CAPN10, and PPAR-γ genes were evaluated using qPCR. In addition, histopathological studies on pancreatic tissue were carried out. The results revealed that STZ induced both diabetes and oxidative stress in normal rats, manifested by the significant changes in the studied parameters and in the physical structure of pancreatic tissue. Oral administration of CTS-SeNPs or Glib results in a significant amelioration of the levels of serum fasting blood glucose, insulin, IGF-1, AST, ATL, and CK-MB as compared with STZ-induced diabetic rats. CTS-SeNPs and Glib diminished the level of lipid peroxidation, increased total antioxidant capacity level, as well as possessed strong inhibition against serum α-amylase and α-glucosidase activities. Diabetic animals received CTS-SeNPs, or Glib demonstrated a significant (p < 0.05) decrease in the expression level of TCF7L2 and CAPN10 genes with a significant increase in the expression level of PPAR-γ gene, compared to STZ group. The above findings clarify the promising antidiabetic and antioxidant effect of CTS-SeNPs, recommending its inclusion in the currently used protocols for the treatment of diabetes and in the prevention of its related complications.

The review on iron, iodine, zinc, selenium, copper, molybdenum, vitamin C, vitamin E, vitamin K, carotenoids and polyphenols recommendations for Venezuela comprise the definitions adopted worldwide known as Dietary Reference Intakes (DRIs) that include Recommended Dietary Allowance (RDA), Estimated Average Requirement (EAR), Adequate Intake (AI) and Tolerable Upper Intake Levels (UL). The RDA for iron: 11 mg/day for infants &lt; 1 year of age, 7-10 mg/day for children, 8-11 mg/day for males, 8-18 mg/day for females and 27 mg/day during pregnancy. RDA for iodine: 110-130 microg/day for infants, 90-120 microg/ day for children and adolescents, 150 microg/day for adults, 220 microg/ day for pregnancy and 290 microg/day during lactation. RDA Zinc: 2-3 mg/day for infants, 3-5 mg/day for children, 8-11 mg/day for male adolescents and adults, 8-9 mg/day for female adolescents and adults, 12 mg/day during pregnancy and 13 mg/day for lactation. RDA Vitamin C: 40-50 mg/day for infants, 15-45 ...