Selenium

About: Selenium is a research topic. Over the lifetime, 21192 publications have been published within this topic receiving 429715 citations. The topic is also known as: Se & selen.

Multicenter, Phase 3 Trial Comparing Selenium Supplementation With Observation in Gynecologic Radiation Oncology

Abstract: Purpose We assessed whether adjuvant supplementation with selenium improves the selenium status and reduces side effects of patients treated by radiotherapy (RT) for cervical and uterine cancer. Methods and Materials Whole-blood selenium concentrations were measured in patients with cervical cancer ( n = 11) and uterine cancer ( n = 70) after surgical treatment, during RT, at the end of RT, and 6 weeks after RT. Patients with initial selenium concentrations of less than 84μg/L were randomized before RT either to receive 500 μg of selenium (in the form of sodium selenite [selenase®, biosyn Arzneimittel GmbH, Fellbach, Germany]) by mouth on the days of RT and 300 μg of selenium on the days without RT or to receive no supplement during RT. The primary endpoint of this multicenter Phase 3 study was to assess the efficiency of selenium supplementation during RT; the secondary endpoint was to decrease radiation-induced diarrhea and other RT-dependent side effects. Results A total of 81 patients were randomized. We enrolled 39 in the selenium group (SG) and 42 in the control group (CG). Selenium levels did not differ between the SG and CG upon study initiation but were significantly higher in the SG at the end of RT. The actuarial incidence of diarrhea of Grade 2 or higher according to Common Toxicity Criteria (version 2) in the SG was 20.5% compared with 44.5% in the CG ( p = 0.04). Other blood parameters, Eastern Cooperative Oncology Group performance status, and self-reported quality of life were not different between the groups. Conclusions Selenium supplementation during RT is effective in improving blood selenium status in selenium-deficient cervical and uterine cancer patients and reduces the number of episodes and severity of RT-induced diarrhea.

Effect of thyme essential oil and selenium on intestine integrity and antioxidant status of broilers

Abstract: 1. This study evaluated the duodenal wall integrity, antioxidant status as well as some immunological parameters of broiler chickens supplemented with 0.5 g Thymus vulgaris essential oil (EO)/kg diet and 0.4 mg Se/kg DM (dry matter) derived from sodium selenite. 2. A total of 192 one-d-old randomly divided chickens of both sexes (Ross 308 hybrid broilers) were divided into 4 treatment groups of 48 birds each. 3. The first group was fed on a nutritionally balanced basal diet (BD). The other three groups received BD supplemented with 0.5 g/kg thyme oil, or 0.4 mg Se/kg DM, or both feed additives together. 4. The results for the evaluated feed additives were (1) thyme oil - decreased malondialdehyde (MDA) concentration in duodenal mucosa and kidney, increased immunoglobulin A (IgA) concentration in duodenal mucosa, stimulated phagocytic activity in blood, improved intestinal barrier integrity (2) selenium - increased glutathione peroxidase (GPx) activity in blood and liver as well as thioredoxin reductase (TrxR) activity in duodenal mucosa, liver and in the kidney, (3) EO with selenium - increased thioredoxin reductase (TrxR) activity in duodenal mucosa. 5. These results demonstrated that thyme oil alone showed more effective potential to improve intestinal barrier integrity and antioxidant status as well as evoking an immune response in chickens, than if diets were supplemented with both thyme oil and selenium.

All Regions of Mouse Brain Are Dependent on Selenoprotein P for Maintenance of Selenium

Abstract: The brain and testis retain selenium better than other tissues during selenium deficiency. Studies of mice with selenoprotein P (Sepp1) deleted (Sepp1(-/-) mice) showed that brain and testis selenium levels are largely dependent on Sepp1. Therefore, we examined tissue selenium in mice fed varying amounts of selenium and in Sepp1(-/-) mice to characterize better the role(s) of Sepp1. Mice were fed a selenium-deficient diet for 8 wk supplemented with selenium as selenite from none to 0.25 mg/kg diet and tissue selenium was measured. Brain and testis maintained their selenium better than did liver, kidney, and muscle when dietary selenium was limiting but testis selenium fell sharply in the group fed the deficient diet. Brain retained its selenium well, even in the group fed the deficient diet. After intravenous injection of (75)Se-Sepp1 into Sepp1(-/-) and Sepp1(+/+) mice, qualitative differences between brain and testis (75)Se uptake were noted, further suggesting differences in their uptake of selenium from Sepp1. Finally, selenium was measured in brain regions of Sepp1(-/-) and Sepp1(+/+) mice fed the diet supplemented with 1 mg selenium/kg and Sepp1(+/+) mice fed the deficient diet. Deletion of Sepp1 and selenium deficiency each lowered selenium a similar amount in cortex, midbrain, brainstem, and cerebellum. Selenium in the hippocampus was lowered by deletion of Sepp1 but not by selenium deficiency. These results suggest that Sepp1 is more important for maintaining selenium in the hippocampus than in other brain regions. They also confirm the position of the brain at the apex of the organ selenium hierarchy.

Speciation of selenoamino acids, selenonium ions and inorganic selenium by ion exchange HPLC with mass spectrometric detection and its application to yeast and algae

Abstract: Cation and anion exchange HPLC were used to separate a mixture of 12 selenium species comprising selenoamino acids, selenonium ions and inorganic selenium. The cationic species were separated from each other and from the co-injected anions using a cation exchange column with gradient elution by aqueous pyridinium formate at pH⊕∼3 as the mobile phase. The anionic species were separated using an anion exchange column with isocratic elution by an aqueous salicylate–TRIS mobile phase at pH 8.5. The separated selenium species were detected as 80Se by ICP-dynamic reaction cell (DRC)-MS. The analytical methods were applied to the analysis of yeast and algae enriched in selenium. The yeast was treated with β-glucosidase followed by a protease mixture for dissolution of the cell walls and selenium-containing peptides, respectively. The second to largest HPLC peak after that corresponding to selenomethionine was ascribed to selenomethionine-Se-oxide (SeOMet) by retention time matching with a SeOMet standard, which was characterised by HPLC-electrospray (ES)-MS. Se-methylselenocysteine was detected based on co-chromatography with the standard substance spiked to the yeast hydrolysate. A trichloroacetic acid extract of Chlorella algae contained dimethylselenonium propionate (DMSeP), which was verified by HPLC-ES-MS. Se-allylselenocysteine and selenoethionine was detected at the low ng g−1 concentration level based on co-chromatography with the standard substances spiked to the algal extract.