Disease relevance of selenium

• This study was conducted to determine whether oral and/or topical selenium (Se) supplementation can reduce the incidence of acute and/or chronic damage to the skin (i.e., sunburn and pigmentation and/or skin cancer, respectively) induced by ultraviolet (UV) irradiation in mice [1].
• Mice treated with Se showed no signs of toxicity and had significantly less skin damage by UV irradiation, as indicated by reduced inflammation and pigmentation and by later onset and lesser incidence of skin cancer [1].
• Therefore, we performed a randomised, placebo-controlled prospective study to investigate the effects of Se treatment on patients with autoimmune thyroiditis (AIT) [2].
• Fish exposed to SeMe for 90 days exhibited a significant decrease in body weight and fork length in the 4.6 and 12 microg/g Se treatments compared with controls [3].
• Selenium (Se) is known to affect the immune system, and decreased Se-levels in blood of patients with moderate or severe psoriasis have been reported [4].

High impact information on selenium

• EXPERIMENTAL DESIGN: Selenomethionine was given orally as a single daily dose containing 2,200 mug of elemental selenium (Se) starting 1 week before the first dose of irinotecan [5].
• Effects of Se-depletion on glutathione peroxidase and selenoprotein W gene expression in the colon [6].
• The possible implications of these results for humans are discussed, including the reasons for poor correlations of GPX activity and blood Se levels [7].
• The correlation coefficient for blood Se level and erythrocyte GPX activity was 0.92 in monkeys given selenite but only 0.37 in those given SeMet [7].
• The trace elements iron (Fe), copper (Cu), zinc (Zn), selenium (Se), chromium (Cr), manganese (Mn), nickel (Ni), rubidium (Rb), and bromine (Br) were determined in serum from 18 children, ages 4 to 65 months, who received long-term total parenteral nutrition (TPN) [8].

Chemical compound and disease context of selenium

• Here, we analyse the effect of protein deficiency on muscle Cu, Fe, Zn, Mn and Se in carbon-tetrachloride (CCl(4)) induced liver cirrhosis [9].
• A case-case study comparing the usefulness of serum trace elements (Cu, Zn and Se) and tumor markers (CEA, SCC and SLX) in non-small cell lung cancer patients [10].

Biological context of selenium

• The animals' weights and food intakes and the Se concentrations of skin and liver were measured [1].
• RESULTS: In the pharmacokinetics study, basal serum concentration of Se (75+/-6 microg/l) was within the reference range (70-125 microg/l), it promptly increased at 2 h, peaked at 4 h (147+/-17 microg/l; P<0.0001) and it was abundant in serum at 24 h [2].
• Both organic and inorganic forms of selenium (Se) can be utilized in the body, and the biotransformation of selenite into an organic form of Se in the bloodstream is the first step for the utilization of inorganic Se [11].
• Trace element (Cd, Cu, Hg, Se, Zn) accumulation and tissue distribution in loggerhead turtles (Caretta caretta) from the Western Mediterranean Sea (southern Italy) [12].
• Based on decreased growth after 90 days, a dietary Se lowest observed-effect concentration (LOEC) value of 4.6 microg/g and a Se body burden LOEC of 1.20 microg/g (wet weight) were estimated [3].

Anatomical context of selenium

• Blood was collected at monthly to bimonthly intervals, and the plasma and erythrocytes were subjected to gel filtration to determine the distribution of Se among proteins of various molecular weights [7].
• Synergistic regulation of endothelial tight junctions by antioxidant (Se) and polyunsaturated lipid (GLA) via Claudin-5 modulation [13].
• The placental transfer and distribution pattern of selenium (Se) in embryonic and fetal tissues after intravenous injection of Na2(75)SeO3 (Se4+) or Na2(75)SeO4 (Se6+) has been investigated in mice in early, mid, and late pregnancy by use of whole-body autoradiography combined with gamma-counting [14].
• Contents and uptake rates of Mn, Fe, Co, Zn, and Se in Se-deficient rat liver cell fractions [15].
• Plasma trace element (Se, Zn, Cu) concentrations in maternal and umbilical cord blood in Poland. Relation with birth weight, gestational age, and parity [16].

Associations of selenium with other chemical compounds

• OBJECTIVE: Selenium (Se) in the form of selenocysteine is an essential component of the family of the detoxifying enzymes glutathione peroxidase (Gpx) and of the iodothyronine selenodeiodinases that catalyse the extrathyroidal production of tri-iodothyronine (T(3)) [2].
• In a rat model of severe iodine deficiency, we investigated the distribution pattern of trace elements (iodine [I], selenium [Se], and bromine [Br] in brain tissue samples; potassium [K], calcium [Ca], manganese [Mn], iron [Fe], copper [Cu], zinc [Zn], rubidium [Rb], and lead [Pb] in erythrocytes) after supplementing the rats with I and/or Se [17].
• Thus, I and I + Se supplementation improves thyroid hormone metabolism but affects the content of selected trace elements in erythrocytes and of Br in the brain [17].
• Volatilization of dimethyldiselenide (DMDSe) is one of the most important processes for removing selenium (Se) from Se-contaminated environments [18].
• 2. Acclimation to 60 or 100% O2 did not change Se GSH-Px or non-Se GSH-Px [19].

Gene context of selenium

• Then, the concentration of labelled Se started to increase slowly as selenoprotein P and extracellular glutathione peroxidase, and attained a maximum level at about 6 h after injection [20].
• Effect of long-term Se deficiency on the antioxidant capacities of rat vascular tissue [21].
• The results indicate that the interaction between transition metals and Se occurs through the general mechanism, i.e., transition metal ions and selenide form the unit complex (metal-Se)n, and then the complex binds to selenoprotein P to form the ternary complex ¿(metal-Se)n¿m--seleno-protein P in the bloodstream [22].
• In this study, the effect of Se-supplementation (400 micrograms/day for 6 weeks as Se-yeast, containing about 70% selenomethionine, SeMet) on skin and blood Se-content, on skin glutathione peroxidase activity and on various chemical and immunological parameters of blood and skin was investigated in 7 psoriatic patients [4].
• Godwin's study of White Muscle Disease in lambs describes Se protection [23].

References