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Sample records for dietary selenium se

  1. Selenium species in selenium fortified dietary supplements.

    PubMed

    Niedzielski, Przemyslaw; Rudnicka, Monika; Wachelka, Marcin; Kozak, Lidia; Rzany, Magda; Wozniak, Magdalena; Kaskow, Zaneta

    2016-01-01

    This article presents a study of dietary supplements available on the Polish market. The supplements comprised a large group of products with selenium content declared by the producer. The study involved determination of dissolution time under different conditions and solubility as well as content and speciation of selenium. The total content was determined as well as organic selenium and the inorganic forms Se(IV) and Se(VI). The organic selenium content was calculated as the difference between total Se and inorganic Se. The values obtained were compared with producers' declarations. The work is the first such study of selenium supplements available on the market of an EU Member State.

  2. Effects of dietary selenium (SE) on morphology of testis and cauda epididymis in rats.

    PubMed

    Kaur, R; Kaur, K

    2000-07-01

    Selenium is an essential micronutrient for animals. To determine whether its excess in diet induces morphological changes within the male reproductive system, a detailed qualitative and quantitative evaluation of the changes in the histology of the testis and cauda epididymis was undertaken in male rats. Adult male albino rats were fed 6 and 8 ppm Se in diet for 6 and 9 weeks. Each male consuming 6 ppm Se was mated with two untreated females, their offsprings were allowed to mature upto 12 weeks of age. The testes and cauda epididymes of male rats were prepared for light microscopy. Excess of dietary Se caused dose-time-dependent reduction in body weight and reproductive organ weights but increase in number of morphologically abnormal spermatozoa. Histopathological studies of the testes and cauda epididymis have revealed that Se-rich diets cause dose-time-dependent reduction in tubular diameter, epithelial height, number of spermatogenic cells and disintegration of cellular associations in the seminiferous tubules of testes along with reduction in the diameter of cauda epididymal tubules and pseudostratification of their epithelial lining. Progeny (feeding on normal diet) of paternally treated rats has shown retarded growth.

  3. Dietary Selenium (Se) and Copper (Cu) Interact to Affect Homocysteine Metabolism in Rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our previous studies have shown that selenium (Se) is protective against dimethylhydrazine (DMH)-induced preneoplastic colon cancer lesions, and protection against DNA damage has been hypothesized to be one mechanism for the anticancer effect of Se. The present study was designed to determine whethe...

  4. Toxicity and oxidative stress of different forms of organic selenium (Se) and dietary protein in mallard (Anas platyrhynchos) ducklings

    USGS Publications Warehouse

    Hoffman, D.; Heinz, G.; Eisemann, J.; Pendleton, G.

    1994-01-01

    High concentrations of Se have been found in aquatic food chains associated with irrigation drainwater and toxicity to fish and wildlife. Earlier studies have compared toxicities of Se as selenite and as seleno-DL-methionine (DL) in mallards. This study compares DL, seleno-L-methionine (L), selenized yeast (Y) and selenized wheat (W). Day-old mallard ducklings received an untreated diet (controls) containing 75% wheat (22% protein) or the same diet containing 15 or 30 ppm Se in the above forms. After 2 weeks blood and liver samples were collected for biochemical assays and Se analysis. All forms of selenium caused significant increases in plasma and hepatic glutathione peroxidase activities. Se as L was the most toxic, resulting in high mortality (64%) and impaired growth (>50%) and the greatest increase in ratio of oxidized to reduced glutathione with 30 ppm in the diet. Se as Y accumulated the least in liver. In a subsequent experiment with 30% dietary protein Se as L was less toxic.

  5. Determination of selenium in selected food samples from Argentina and estimation of their contribution to the Se dietary intake.

    PubMed

    Sigrist, Mirna; Brusa, Lucila; Campagnoli, Darío; Beldoménico, Horacio

    2012-10-15

    An optimised FI-HGAAS method was applied to determine the total selenium concentrations in selected high consumption food (fish, beef, chicken, milk, rice, wheat flour, egg) and to estimate their contribution to the Argentinean dietary intake, whose information is scarce nowadays. Through several optimisation steps a suitable method was achieved showing satisfactory figures of merit for all matrices. Average recovery was 96%, RSD<5%, LODs ranged 2.0-7.0 μg kg(-1) and the accuracy was assessed using DOLT-3 NRC certified reference material. Meat and eggs showed the highest values (in μg kg(-1), beef: 42-153; chicken: 62-205; fish: 94-314; canned tuna: 272-282; eggs: 134-217), minor values were found for wheat flour (22-42), rice: (<22), pasta (47-64) and milk (<7-9). An estimated intake of 32 and 24 μg day(-1) for adult men and women, respectively, suggested a deficient Se intake, leading to further comprehensive surveys of Se occurrence in Argentina.

  6. Use of dietary vitamin E and selenium (Se) to increase the shelf life of modified atmosphere packaged light lamb meat.

    PubMed

    Ripoll, G; Joy, M; Muñoz, F

    2011-01-01

    The aim of this work was to determine the increase in the shelf life of modified atmosphere packaged fresh lamb meat due to the effect of dietary vitamin E and selenium supplementation on colour and lipid oxidation. 128 lambs were fed on a concentrate with standard levels of vitamin E (C), a concentrate enriched with vitamin E (V), a concentrate with sodium selenite (S) and a concentrate enriched with both vitamin E and sodium selenite (VS). The lambs were slaughtered at 27.3±1.45 kg LW, and chops stored on MAP for 7, 9, 11 and 13 days. CIELab colour and TBARs were studied on these days. Use of dietary vitamin E extended the shelf life a further 4 days from the commercial sell-by date in terms of lightness, hue angle, metmyoglobin formation and lipid oxidation. Selenium could be used to increase the lightness of meat without vitamin E supplementation in lambs' diets.

  7. Dietary selenium (Se) and copper (Cu) interact to affect homocysteine metabolism in rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously we reported that both Se deficiency (SeD) and Cu deficiency (CuD) decreased plasma homocysteine (pHcys) and increased plasma glutathione (pGSH) in rats. We also showed that the catalytic subunit of glutamate-cysteine ligase (Gclc), which catalyzes the rate limiting step in glutathione bio...

  8. Effect of dietary selenium (Se) on the development of fusarium-induced tibial dyschondroplasia (FITD) in broiler chickens

    SciTech Connect

    Walser, M.M.; Levander, O.A.

    1986-03-01

    The purposes of this study were to determine the effect of low and high levels of dietary Se on the pathogenesis of FITD and to use the findings to assess the applicability of FITD as an animal model of Kashin-Beck disease. Day-old female broiler chickens were assigned to 1 or 3 diets: low Se (0.02 ppm), normal Se (0.15 ppm), and high Se (0.5 ppm). At 1 week of age, dosing of 15 of 26 chicks in each dietary group with TDP-1, the toxic component of fusarium roseum Graminearum was begun. Chicks were terminated from 24 to 30 days of age. The mortality rate of the TDP-1-treated chicks on the high Se diet was significantly less than that in the other TDP-treated groups. There were no differences in the incidence, severity, or character of the FITD lesions among the dietary groups. Neither diet nor TDP-1 treatment affected hematocrit levels. Plasma Se and hepatic glutathione peroxidase activity were significantly lower in the low Se dietary group than in other groups. The nature of the lesion of FITD and the time course of its development are distinct from the features of Kashin-Beck disease. Administration of a high dietary level of Se did not affect the development of FITD.

  9. Selenium in groundwater and its contribution towards daily dietary Se intake under different hydrogeological zones of Punjab, India

    NASA Astrophysics Data System (ADS)

    Dhillon, Karaj S.; Dhillon, Surjit K.

    2016-02-01

    More than 750 groundwater samples collected from different hydrological zones of Punjab state in India were analysed for selenium and some quality parameters to determine suitability of groundwater for irrigation and drinking purpose. Selenium content varied from 0.01 to 35.6 μg L-1. Average Se content in groundwater was the highest in Northeastern Siwalik foothill zone (NSFZ) followed by Central zone (CZ) and Southwestern zone (SWZ). Majority of the water samples contained <10 μg Se L-1 - the safe limit for drinking purpose except one location each in SWZ and CZ and three locations in NSFZ. Only at one location, water contained >20 μg Se L-1 which is considered unsuitable for irrigation of crops. On the basis of pH, 42% of the samples were unfit for drinking in SWZ, 41% in CZ and 6% in NSFZ. Only in SWZ, 24% of the samples with high total dissolved salts were unfit for drinking and 18% unfit for irrigation purpose due to high EC. Selenium content in groundwater was inversely related to depth of water and the degree of relationship was higher for NSFZ (r = -0.342∗∗) followed by CZ (r = -0.157∗) and SWZ (r = -0.126∗). Depending on the amount of water consumed from 2 to 5 L, average Se intake varied from 1.66 to 6.39 μg d-1 and its contribution towards the recommended daily Se allowance ranged from 3.0% to 11.6% for women and 2.4% to 9.1% for men. Among the grain samples, 94% of wheat and 46% of rice contained Se above the deficiency limit of 100 μg kg-1. Thus, the residents in the study area primarily consuming wheat grains and drinking groundwater are getting adequate supply of Se. Among the materials tested for decreasing Se from drinking waters, scrap iron fillings showed potential for commercial use.

  10. Lentils (Lens culinaris L.) as a source of dietary selenium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The chapter discusses the nutritional value of lentils, with a focus on factors affecting lentils as a source of dietary selenium. It addresses the chemical nature of lentil-selenium, pointing out that more than 90% is present in organic compounds which are generally well absorbed by humans. The se...

  11. Effects of maternal and dietary selenium (Se-enriched yeast) on oxidative status in testis and apoptosis of germ cells during spermatogenesis of their offspring in goats.

    PubMed

    Shi, Lei; Yue, Wenbin; Zhang, Chunxiang; Ren, Youshe; Zhu, Xiaomin; Wang, Qian; Shi, Liguang; Lei, Fulin

    2010-06-01

    To investigate the effect of maternal and dietary selenium on antioxidant status in testis and apoptosis of germ cells during spermatogenesis of their offspring, selected Taihang Black Goats (n=119) were randomly allotted to four treatment groups. They were fed the experimental diet with different Se levels (from Se-enriched yeast) for 174 d from 60 d prior to lactation to weaning of kids. The treatments were: (1) Group 1 (control), basal diet without Se supplementation, (2) Group 2, the same basal diet supplemented 0.5mg Se/kg DM, (3) Group 3, the same basal diet supplemented 2mg Se/kg DM and (4) Group 4, the same basal diet supplemented 4 mg Se/kg DM. Thirty days after weaning, testis samples of the young male goats were collected for mRNA expression and analyzing the antioxidant status and Se concentration, as well as the population of apoptotic germ cells by TUNEL assay. The results show that mRNA expression of apoptosis genes (Bcl-2, Bax and Caspase 8) were significantly higher in Groups 1 and 4 than that in Groups 2 and 3. The same trend was observed in the population of apoptotic cells analyzed by TUNEL assay. GSH-Px activity and Se concentration in testis of offspring was progressively increased with the increasing Se level in diet of dams. However, there was no significant difference in GSH-Px activity between Groups 3 and 4. The lowest MDA content was obtained in Group 2 and a significant decrease was observed in Groups 1, 3 and 4. These data suggest that doe maternal and dietary Se could influence antioxidant status in the testis of their offspring and the oxidative stress related to Se from the dam could modulate mRNA expression of apoptosis genes and apoptosis of germ cells during spermatogenesis. It is possible that Se supplementation of the dam's diet during gestation and lactation could be a way to supply the Se necessary for normal development of reproductive function of their offspring.

  12. Dietary Selenium and Human Health

    PubMed Central

    Schomburg, Lutz

    2016-01-01

    Next year (2017), the micronutrient Selenium (Se) is celebrating its birthday—i.e., 200 years after first being identified by the Swedish chemist Jöns Jakob Berzelius. Despite its impressive age, research into the functions of this essential trace element is very alive and reaching out for new horizons. This special issue presents some recent fascinating, exciting, and promising developments in Se research in the form of eight original contributions and seven review articles. Collectively, aspects of Se supply, biochemical, physiological, and chemotherapeutic effects, and geobiological interactions are covered by leading scientists in the areas of nutritional, basic, and clinical research. It is obvious from the contributions that the bicentennial anniversary will celebrate a micronutrient still in its infancy with respect to being understood in terms of its biomedical importance. PMID:28042811

  13. Evaluation of selenium in dietary supplements using elemental speciation.

    PubMed

    Kubachka, Kevin M; Hanley, Traci; Mantha, Madhavi; Wilson, Robert A; Falconer, Travis M; Kassa, Zena; Oliveira, Aline; Landero, Julio; Caruso, Joseph

    2017-03-01

    Selenium-enriched dietary supplements containing various selenium compounds are readily available to consumers. To ensure proper selenium intake and consumer confidence, these dietary supplements must be safe and have accurate label claims. Varying properties among selenium species requires information beyond total selenium concentration to fully evaluate health risk/benefits A LC-ICP-MS method was developed and multiple extraction methods were implemented for targeted analysis of common "seleno-amino acids" and related oxidation products, selenate, selenite, and other species relatable to the quality and/or accuracy of the labeled selenium ingredients. Ultimately, a heated water extraction was applied to recover selenium species from non-selenized yeast supplements in capsule, tablet, and liquid forms. For selenized yeast supplements, inorganic selenium was monitored as a means of assessing selenium yeast quality. A variety of commercially available selenium supplements were evaluated and discrepancies between labeled ingredients and detected species were noted.

  14. Effect of dietary sulfur and selenium concentrations on selenium balance of lactating Holstein cows.

    PubMed

    Ivancic, J; Weiss, W P

    2001-01-01

    The effects of dietary sulfate and selenium concentrations on selenium balance in dairy cows were investigated. Midlactation Holstein cows (n = 30) were fed diets containing either 0.1 or 0.3 mg of supplemental Se (from sodium selenate)/kg of dry matter and 0, 0.2, or 0.4% added S from a mix of calcium and magnesium sulfate in a factorial arrangement. The experiment lasted 112 d. Dry matter intake was linearly reduced with increasing S, but the effect was greater when 0.3 mg/kg of Se was fed (significant interaction). Treatment effects for yields of milk, milk fat, and milk protein were similar to those for dry matter intake. Increased dietary S linearly reduced plasma Se concentrations. Increasing dietary S linearly reduced apparent (42.7, 33.1, and 30.1%) and estimated true (50.5, 46.0, and 42.3%) Se digestibility. Excretion of Se via feces (1.6 vs. 2.8 mg/d) and urine (0.5 vs. 1.3 mg/d) was higher and output in milk (0.4 vs. 0.3 mg/d) was lower for cows fed 0.3 mg/kg of Se compared with 0.1 mg/kg, but no Se effect was found for estimated true Se digestibility. Dietary S from sulfate reduced Se balance especially when cows were fed diets with less than 0.3 mg of Se/kg of diet dry matter.

  15. Effects of dietary selenium on host response to necrotic enteritis in young broilers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of dietary supplementation of young broiler chickens with a new organic selenium (Se) formulation, B-Traxim Se, on the host response to experimental necrotic enteritis (NE) were studied. Broiler chickens treated with three Se doses (0.25, 0.50, 1.00 mg/kg) from hatch were orally challeng...

  16. Spectrum of sodiumlike selenium - Se XXIV

    NASA Technical Reports Server (NTRS)

    Brown, C. M.; Seely, J. F.; Feldman, U.; Richardson, M. C.; Behring, W. E.; Cohen, L.

    1986-01-01

    High-resolution spectra of Se XXIV have been obtained with a 3-m grazing-incidence spectrograph. Thin plastic foils coated with selenium were irradiated with four or eight beams of the OMEGA laser in a line-focus configuration. Spectrograms were obtained by viewing the plasma axially. Prominent in the spectra were the 3s-3p and 3p-3d transitions in the 150-240-A region and the transitions nl-(n + 1)l-prime with n = 3, 4 in the 24-80-A region. The energy levels and ionization limit derived from the measured wavelengths are also presented.

  17. Toxicity and bioaccumulation of waterborne and dietary selenium in juvenile bluegill (Lepomis macrochirus)

    USGS Publications Warehouse

    Cleveland, Laverne; Little, Edward E.; Buckler, Denny R.; Wiedmeyer, Raymond H.

    1993-01-01

    Juvenile bluegill (Lepomis macrochirus) were exposed to waterborne selenium as a 6:1 mixture of selenate to selenite (as Se) for 60 d and to dietary seleno-l-methionine for 90 d. Measured concentrations of total selenium in the waterborne exposure ranged from 0.16 to 2.8 mg/l, and concentrations of seleno-l-methionine in the test diet ranged from 2.3 to 25.0 mg/kg wet weight. Mortality, body weight, condition factor, swimming and feeding behavior, aggression, and selenium tissue residues were monitored during the tests. Increased mortality at measured concentrations of 0.64 mg Se/l and greater was the primary adverse effect of waterborne selenium on the juvenile bluegill. Bluegill exposed to 2.8 mg/l of waterborne Se for 30 d exhibited a significant reduction in condition factor (K), whereas dietary exposure of bluegill to 25 mg Se/kg for 30 d and 13 mg Se/kg or greater for 90 d elicited significant reductions in K. Mortality and swimming activity of bluegill were not affected in the dietary exposure. Net accumulation of Se from both water and diet was directly related to exposure concentration. Bioconcentration factors ranged from 5 to 7 for bluegill exposed to waterborne Se and from 0.5 to 1.0 for fish exposed to dietary Se. Results of these laboratory tests indicate that survival of bluegill may be impaired in natural waters with elevated Se concentrations.

  18. Daily dietary selenium intake and hair selenium content in a high selenium area of Enshi, China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium is essential to humans and is widely distributed within the human body. Its content in blood, urine, hair and nails are important indicators to evaluate Se level in the human body. In China (Shadi, Enschi city), human selenosis of residents is reported to occur in high numbers. In this stud...

  19. Effect of dietary selenium concentration and duration of selenium feeding on hepatic glutathione concentrations in rats

    SciTech Connect

    LeBoeuf, R.A.; Zentner, K.L.; Hoekstra, W.G.

    1985-11-01

    Studies were conducted in rats to determine the effect of dietary selenium (Se) concentration on hepatic glutathione concentrations and enzyme activities associated with the maintenance of the cellular glutathione status. Male rats were fed 0.1, 3.0, or 6.0 ppm Se as Na/sub 2/SeO/sub 3/ for 2, 4, or 6 weeks at which time they were killed and analyses were performed. Both 3.0 and 6.0 ppm Se caused a significant dose-dependent increase in hepatic-reduced glutathione (GSH) by 4 weeks of feeding compared to 0.1 ppm Se. The increase in GSH was preceded by significant, dose-dependent increases in oxidized glutathione (GSSG) as well as the GSSG to GSH ratio. Increases in GSSG and the GSSG to GSH ratio as well as in glutathione reductase and glucose-6-phosphate dehydrogenase activities were observed by 2 weeks of high Se feeding. The current findings substantiate previous results demonstrating effects of high Se on hepatic glutathione concentrations and further suggest that increased cellular GSSG concentrations or the GSSG to GSH ratio caused by 3.0 and 6.0 ppm dietary Se signals for adaptive changes in hepatic glutathione metabolism.

  20. Effects of Dietary Selenium, Sulphur and Copper Levels on Selenium Concentration in the Serum and Liver of Lamb

    PubMed Central

    Netto, Arlindo Saran; Zanetti, Marcus Antonio; Correa, Lisia Bertonha; Del Claro, Gustavo Ribeiro; Salles, Márcia Saladini Vieira; Vilela, Flávio Garcia

    2014-01-01

    Thirty-two lambs were distributed in eight treatments under 2×2×2 factorial experiment to compare the effects of two levels of selenium (0.2 to 5 mg/kg dry matter [DM]), sulphur (0.25% and 0.37%) and copper (8 and 25 mg/kg DM) levels on selenium concentration in liver and serum of lambs. A liver biopsy was done on all animals and blood samples were collected from the jugular vein prior to the beginning of the treatments. The blood was sampled every thirty days and the liver was sampled after 90 days, at the slaughter. Increasing differences were noticed during the data collection period for the serum selenium concentration, and it was found to be 0.667 mg/L in animals fed with 5 mg Se/kg DM and normal sulphur and copper concentrations in their diet. However, a three-way interaction and a reduction of selenium concentration to 0.483 mg/L was verified when increasing copper and sulphur concentration levels to 25 ppm and 0.37% respectively. The liver selenium concentration was also high for diets containing higher selenium concentrations, but the antagonist effect with the increased copper and sulphur levels remained, due to interactions between these minerals. Therefore, for regions where selenium is scarce, increasing its concentration in animal diets can be an interesting option. For regions with higher levels of selenium, the antagonistic effect of interaction between these three minerals should be used by increasing copper and sulphur dietary concentrations, thus preventing possible selenium poisoning. PMID:25083101

  1. Effects of dietary selenium, sulphur and copper levels on selenium concentration in the serum and liver of lamb.

    PubMed

    Netto, Arlindo Saran; Zanetti, Marcus Antonio; Correa, Lisia Bertonha; Del Claro, Gustavo Ribeiro; Salles, Márcia Saladini Vieira; Vilela, Flávio Garcia

    2014-08-01

    Thirty-two lambs were distributed in eight treatments under 2×2×2 factorial experiment to compare the effects of two levels of selenium (0.2 to 5 mg/kg dry matter [DM]), sulphur (0.25% and 0.37%) and copper (8 and 25 mg/kg DM) levels on selenium concentration in liver and serum of lambs. A liver biopsy was done on all animals and blood samples were collected from the jugular vein prior to the beginning of the treatments. The blood was sampled every thirty days and the liver was sampled after 90 days, at the slaughter. Increasing differences were noticed during the data collection period for the serum selenium concentration, and it was found to be 0.667 mg/L in animals fed with 5 mg Se/kg DM and normal sulphur and copper concentrations in their diet. However, a three-way interaction and a reduction of selenium concentration to 0.483 mg/L was verified when increasing copper and sulphur concentration levels to 25 ppm and 0.37% respectively. The liver selenium concentration was also high for diets containing higher selenium concentrations, but the antagonist effect with the increased copper and sulphur levels remained, due to interactions between these minerals. Therefore, for regions where selenium is scarce, increasing its concentration in animal diets can be an interesting option. For regions with higher levels of selenium, the antagonistic effect of interaction between these three minerals should be used by increasing copper and sulphur dietary concentrations, thus preventing possible selenium poisoning.

  2. A Review of Dietary Selenium Intake and Selenium Status in Europe and the Middle East

    PubMed Central

    Stoffaneller, Rita; Morse, Nancy L.

    2015-01-01

    This is a systematic review of existing data on dietary selenium (Se) intake and status for various population groups in Europe (including the United Kingdom (UK)) and the Middle East. It includes English language systematic reviews, meta-analyses, randomised controlled trials, cohort studies, cross-sectional and case-control studies obtained through PUBMED searches from January, 2002, to November, 2014, for European data and from 1990 to November 2014, for Middle Eastern data. Reports were selected if they included data on Se intake and status. The search identified 19 European/UK studies and 15 investigations in the Middle East that reported Se intake and Se concentration in water and/or food and 48 European/UK studies and 44 investigations in the Middle East reporting Se status. Suboptimal Se status was reported to be widespread throughout Europe, the UK and the Middle East, and these results agreed with previous reports highlighting the problem. Eastern European countries had lower Se intake than Western European countries. Middle Eastern studies provided varying results, possibly due to varying food habits and imports in different regions and within differing socioeconomic groups. In conclusion, Se intake and status is suboptimal in European and Middle Eastern countries, with less consistency in the Middle East. PMID:25734564

  3. Acute Selenium Toxicity Associated With a Dietary Supplement

    PubMed Central

    MacFarquhar, Jennifer K.; Broussard, Danielle L.; Melstrom, Paul; Hutchinson, Richard; Wolkin, Amy; Martin, Colleen; Burk, Raymond F.; Dunn, John R.; Green, Alice L.; Hammond, Roberta; Schaffner, William; Jones, Timothy F.

    2011-01-01

    Background Selenium is an element necessary for normal cellular function, but it can have toxic effects at high doses. We investigated an outbreak of acute selenium poisoning. Methods A case was defined as the onset of symptoms of selenium toxicity in a person within 2 weeks after ingesting a dietary supplement manufactured by “Company A,” purchased after January 1, 2008. We conducted case finding, administered initial and 90-day follow-up questionnaires to affected persons, and obtained laboratory data where available. Results The source of the outbreak was identified as a liquid dietary supplement that contained 200 times the labeled concentration of selenium. Of 201 cases identified in 10 states, 1 person was hospitalized. The median estimated dose of selenium consumed was 41 749 μg/d (recommended dietary allowance is 55 μg/d). Frequently reported symptoms included diarrhea (78%), fatigue (75%), hair loss (72%), joint pain (70%), nail discoloration or brittleness (61%), and nausea (58%). Symptoms persisting 90 days or longer included fingernail discoloration and loss (52%), fatigue (35%), and hair loss (29%). The mean initial serum selenium concentration of 8 patients was 751 μg/L (reference range, ≤125 μg/L). The mean initial urine selenium concentration of 7 patients was 166 μg/24 h (reference range, ≤55 μg/24 h). Conclusions Toxic concentrations of selenium in a liquid dietary supplement resulted in a widespread outbreak. Had the manufacturers been held to standards used in the pharmaceutical industry, it may have been prevented. PMID:20142570

  4. Dietary Selenium (Se) and Copper (Cu) Affect the Activity and Expression of the Hepatic Selenoprotein Methionine Sulfoxide Reductase B (MrsB) in Rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As reported by Jenkinson et al. (J Nutr 1982) and Prohaska et al. (J Nutr Biochem 1992) Cu deficiency (CuD) decreases the activity and mRNA expression of the selenoprotein GPx. Because both Se and Cu are important in oxidative defense, we wanted to determine the effect of a combined deficiency on th...

  5. Incorporation of selenium into egg proteins from dietary selenite.

    PubMed

    Davis, R H; Fear, J

    1996-03-01

    1. The deposition of selenium in egg components has been investigated in two experiments in which sodium selenite was added to a conventional cereal-based layer diet. 2. Addition of graded amounts of selenite up to 4 mg Se/kg resulted in linear increases in the selenium content of egg white and yolk, and in protein fractions derived from them. The presence of selenium in yolk phosvitin indicates that deposition is not dependent upon the presence of cysteine. 3. Addition of sodium nitroprusside at 0.l5 and 0.3 g/kg to diets having an addition of selenite at the highest concentration, 4 mg Se/kg, resulted in substantial reductions in the selenium concentration in egg components. 4. Samples from eggs laid by hens receiving a diet containing an additional 8 mg selenite Se/kg were subjected to dialysis against sodium hydroxide or cysteine, or subjected to reduction with hydrochloric acid and zinc under anaerobic conditions. Comparisons were made with similar samples prepared from eggs laid by hens on the control diet. 5. Both sodium hydroxide and cysteine were more effective at extracting additional diet-derived selenium from whole white than from whole yolk. The proportion of selenium that could be extracted from the water-soluble or the high density fractions of yolk by either reagent was similar for both control and high selenium samples. However, neither reagent was effective at removing selenium from the ovalbumin or globin fractions of white from control eggs but substantial amounts were extracted from high selenium samples. 6. Most of the selenium was present in non-reducible forms in all samples. There was significantly more reducible selenium in ovalbumin from control eggs than from all other samples but even so non-reducible selenium accounted for two thirds of the selenium present. 7. The differential responses to chemical treatment suggest that selenium can be deposited in eggs in an unspecified number of different forms. These have still to be characterised

  6. High dietary selenium intake is associated with less insulin resistance in the Newfoundland population.

    PubMed

    Wang, Yongbo; Lin, Meiju; Gao, Xiang; Pedram, Pardis; Du, Jianling; Vikram, Chandurkar; Gulliver, Wayne; Zhang, Hongwei; Sun, Guang

    2017-01-01

    As an essential nutrient, Selenium (Se) is involved in many metabolic activities including mimicking insulin function. Data on Se in various biological samples and insulin resistance are contradictory, moreover there is no large study available regarding the relationship of dietary Se intake with insulin resistance in the general population. To investigate the association between dietary Se intake and variation of insulin resistance in a large population based study, a total of 2420 subjects without diabetes from the CODING (Complex Diseases in the Newfoundland Population: Environment and Genetics) study were assessed. Dietary Se intake was evaluated from the Willett Food Frequency questionnaire. Fasting blood samples were used for the measurement of glucose and insulin. Insulin resistance was determined with the homeostasis model assessment (HOMA-IR). Body composition was measured using dual energy X-ray absorptiometry. Analysis of covariance showed that high HOMA-IR groups in both males and females had the lowest dietary Se intake (μg/kg/day) (p < 0.01), being 18% and 11% lower than low HOMA-IR groups respectively. Insulin resistance decreased with the increase of dietary Se intake in females but not in males after controlling for age, total calorie intake, physical activity level, serum calcium, serum magnesium, and body fat percentage (p < 0.01). Partial correlation analysis showed that dietary Se intake was negatively correlated with HOMA-IR after adjusting for the Se confounding factors in subjects whose dietary Se intake was below 1.6 μg/kg/day (r = -0.121 for males and -0.153 for females, p < 0.05). However, the negative correlation was no longer significant when dietary Se intake was above 1.6 μg/kg/day. Our findings suggest that higher dietary Se intake is beneficially correlated with lower insulin resistance when total dietary Se intake was below 1.6 μg/kg/day. Above this cutoff, this beneficial effect disappears.

  7. Selenium species bioaccessibility in enriched radish (Raphanus sativus): a potential dietary source of selenium.

    PubMed

    Pedrero, Zoyne; Madrid, Yolanda; Cámara, Carmen

    2006-03-22

    An in vitro gastrointestinal method was employed to predict the potential bioavailability of selenium and its species from radish, belonging to the Brassicaceae family, grown in hydroponics media in the presence of inorganic selenium, such as Na2SeO3 and Na2SeO4. A low transformation of Se into organic forms was observed in radish plants grown in Se(VI)-enriched culture media. On the contrary, in those plants exposed to selenite, >95% of the total selenium was found as selenocystine (SeCys2), selenomethionine (SeMet), and Se-methylselenocysteine (SeMetSeCys). The concentrations of these species in fresh samples remained almost unaltered after a simulated gastrointestinal digestion. Therefore, a high selenium content of Se-methylselenocysteine (65%), previously reported as a cancer chemopreventive species, remained in the potentially bioabsorbable fraction. As these plants usually undergo a short development cycle, these results suggest that radish enriched in selenite could be a good choice as an organoselenium supplement for the human diet and animal feed.

  8. 2-Hydroxy-4-Methylselenobutanoic Acid as New Organic Selenium Dietary Supplement to Produce Selenium-Enriched Eggs.

    PubMed

    Tufarelli, V; Ceci, E; Laudadio, V

    2016-06-01

    Food-based strategies need to be developed to improve the selenium (Se) status of individuals. The aim of this study was to evaluate the effects of a new organic Se [2-hydroxy-4-methylselenobutanoic acid (HMSeBA)] on selected performance criteria and Se deposition in egg of laying hens. Isa Brown laying hens, 18 weeks of age were randomly allocated to two dietary treatments and fed for 10 weeks. The hens were fed two corn-soybean meal-based diets comprising a control basal diet without Se supplementation and a test diet supplemented with Se at 0.2 mg/kg from HMSeBA. No difference was observed among dietary treatments on feed intake, egg weight and laying rate, whereas egg yolk fatty acid profile and vitamin E content were positively influenced by HMSeBA supplementation. Hens fed Se-supplemented diet exhibited greater (P < 0.001) egg yolk total Se contents, which averaged 21.2 mg/100 g dry matter (DM) compared to control diet (11.7 mg/100 g DM). Our results suggested that HMSeBA as Se supplement influences positively egg yolk quality without affecting hens' productive traits. Moreover, HMSeBA offers an efficient alternative to fortify eggs with Se, which can consequently lead to greater supply of Se for humans.

  9. Interactive effects of arsenate, selenium, and dietary protein on survival, growth, and physiology in mallard ducklings

    USGS Publications Warehouse

    Hoffman, D.J.; Sanderson, C.J.; LeCaptain, L.J.; Cromartie, E.; Pendleton, G.W.

    1992-01-01

    High concentrations of arsenic (As) and selenium (Se) have been found in aquatic food chains associated with irrigation drainwater. Total biomass of invertebrates, a maJor source of protein for wild ducklings, may vary in environments that are contaminated with selenium. Dayold mallard (Anas platyrhynchos) ducklings received an untreated diet (controls) containing 22% protein or diets containing 15 ppm Se (as selenomethionine), 60 ppm Se, 200 ppm As (as sodium arsenate), 15 ppm Se with 200 ppm As, or 60 ppm Se with 200 ppm As. In a concurrent experiment, the same sequence was repeated with a proteinrestricted (7%) but isocaloric diet. After 4 weeks, blood and tissue samples were collected for biochemical and histological examination. With 22% protein and 60 ppm Se in the diet, duckling survival and growth was reduced and livers had histopathological lesions. Arsenic alone caused some reduction in growth. Antagonistic interactive effects occurred between As and Se, including complete to partial alleviation of the following Se effects: mortality, impaired growth, hepatic lesions and lipid peroxidation, and altered glutathione and thiol status. With 7% protein, survival and growth of controls was less than that with 22% protein, Se (60 ppm) caused 100% mortality, and As (200 ppm) caused mortality, decreased growth, and liver histopathology. These findings suggest the potential for antagonistic effects of Se and As on duckling survival, growth, and physiology with adequate dietary protein but more severe toxicological effects when dietary protein is diminished.

  10. Effect of dietary selenium source (organic vs. mineral) and muscle pH on meat quality characteristics of pigs.

    PubMed

    Calvo, Luis; Toldrá, Fidel; Rodríguez, Ana I; López-Bote, Clemente; Rey, Ana I

    2017-01-01

    This study evaluates the effect of organic (Se-enriched yeast; SeY) versus inorganic selenium (sodium selenite; SeS) supplementation and the different response of selenium source according to muscle pH on pork meat quality characteristics. Pigs (n = 30) were fed the Se-supplemented diets (0.3 mg/kg) for 65 days. Neither electric conductivity (EC) nor drip loss were affected by the selenium source. The SeY group had lower TBARS in muscle samples after day 7 of refrigerated storage and higher a* values on days 1 and 7 than the SeS group. The effect of dietary selenium source on some meat quality characteristics was affected by muscle pH. Hence, as the muscle pH increases, the drip loss decreases but this effect is more marked with the dietary organic Se enrichment. Muscle pH seems to modulate the action of selenium in pork, especially some meat characteristics such as drip loss.

  11. Elemental selenium at nano size (Nano-Se) as a potential chemopreventive agent with reduced risk of selenium toxicity: comparison with se-methylselenocysteine in mice.

    PubMed

    Zhang, Jinsong; Wang, Xufang; Xu, Tongwen

    2008-01-01

    Selenium (Se) is an essential trace element with a narrow margin between beneficial and toxic effects. As a promising chemopreventive agent, its use requires consumption over the long term, so the toxicity of Se is always a crucial concern. Based on clinical findings and recent studies in selenoprotein gene-modified mice, it is likely that the antioxidant function of one or more selenoproteins is responsible for the chemopreventive effect of Se. Furthermore, upregulation of phase 2 enzymes by Se has been implicated as a possible chemopreventive mechanism at supranutritional dietary levels. Se-methylselenocysteine (SeMSC), a naturally occurring organic Se product, is considered as one of the most effective chemopreventive selenocompounds. The present study revealed that, as compared with SeMSC, elemental Se at nano size (Nano-Se) possessed equal efficacy in increasing the activities of glutathione peroxidase, thioredoxin reductase, and glutathione S-transferase, but had much lower toxicity as indicated by median lethal dose, acute liver injury, survival rate, and short-term toxicity. Our results suggest that Nano-Se can serve as a potential chemopreventive agent with reduced risk of Se toxicity.

  12. Dietary selenium deficiency exacerbates lipopolysaccharide-induced inflammatory response in mouse mastitis models.

    PubMed

    Wei, Zhengkai; Yao, Minjun; Li, Yimeng; He, Xuexiu; Yang, Zhengtao

    2014-12-01

    Selenium (Se) is an essential micronutrient that plays a critical role in anti-inflammatory processes and antioxidant defense system. In this study, we investigated the effects of dietary selenium deficiency on lipopolysaccharide (LPS)-induced mastitis in mouse models. Se content in the liver was assessed by fluorescent atomic absorption spectrometry. Glutathione peroxidase (GPx) activity in the blood, myeloperoxidase (MPO) activity, tumor necrosis actor alpha (TNF-α), and interleukin (IL)-1β in the supernatant of the mammary tissue were determined according to the corresponding kits. Cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expressions were evaluated by Western blotting. The results showed that the Se-deficient mouse model was successfully replicated, and selenium deficiency exacerbated mammary gland histopathology, increased the expressions of TNF-α and IL-1β, and facilitated the activation of iNOS and COX-2 in LPS-induced mouse mastitis. In conclusion, our studies demonstrated that selenium deficiency resulted in more severe inflammatory response in LPS-induced mouse mastitis.

  13. Dietary selenium intake increases exon-specific DNA methylation of p53 gene in rat liver and colon mucosa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The regulation of site-specific DNA methylation of tumor suppressor genes has been considered as a leading mechanism by which certain nutrients exert their anticancer property. Our previous studies suggest that dietary selenium (Se) may alter DNA methylation, and the purpose of this study was to inv...

  14. Interactive effects of selenium, methionine, and dietary protein on survival, growth, and physiology in mallard ducklings

    USGS Publications Warehouse

    Hoffman, D.J.; Sanderson, C.J.; LeCaptain, L.J.; Cromartie, E.; Pendleton, G.W.

    1992-01-01

    Concentrations of over 100 ppm (100 mg/kg) selenium (Se) have been found in aquatic food chains associated with irrigation drainwater. Both quantity and composition of dietary protein for wild ducklings may vary in selenium-contaminated environments. Day-old mallard (Anas platyrhynchos) ducklings received one of the following diets containing 22% protein: unsupplemented (controls), 15 ppm Se (as selenomethionine), 60 ppm Se, methionine supplemented, 15 ppm Se with methionine supplement, or 60 ppm Se with methionine supplement. In a second concurrent experiment the above sequence was repeated with a protein-restricted (11%) but isocaloric diet. In a third concurrent experiment all ducklings received 44% protein with 0, 15, or 60 ppm Se added. After 4 weeks, blood and tissue samples were collected for biochemical and histological examination. With 22% protein and 60 ppm Se in the diet, duckling survival and growth was reduced and histopathological lesions of the liver occurred. Antagonistic interactive effects occurred between supplementary methionine and Se, including complete to partial alleviation of the following Se effects by methionine: mortality, hepatic lesions, and altered glutathione and thiol status. With 11% protein, growth of controls was less than that with 22% protein, Se (60 ppm) caused 100% mortality, and methionine supplementation, although protective afforded less protection than it did with 22% protein. With 44% protein, ducklings experienced physiological stress, and Se was more toxic than with methionine-supplemented 22% protein. These findings suggest the potential for antagonistic effects of Se, methionine, and protein on duckling survival and physiology.

  15. Effect of alcohol consumption on selenium (Se) bioavailability in rats

    SciTech Connect

    Cho, H.K.; Snook, J.T.; Yang, F.L.

    1986-03-01

    This study was done to determine the effects of alcohol ingestion on Se bioavailability in initially Se-depleted rats. Weanling male rats were fed a Se deficient (0.012 mg/kg) basal diet for 4 weeks and then for the subsequent 4 weeks were supplemented at 0.031 mg Se/kg or at 0.085 mg Se/kg of diet in the form of high Se yeast. During the Se repletion period alcohol replaced medium chain triglycerides in the diet at 3 levels: 0%, 10%, and 20% of calories. Dietary Se level significantly (P < .0001) affected urinary Se, fecal Se, Se absorption, Se balance, whole blood Se, whole blood glutathione peroxidase activity, and liver Se. In rats fed the higher Se diet total liver Se increased 50% when 20% rather than 0% alcohol was given. In rats fed the lower Se diet total liver Se decreased 12% as dietary alcohol increased from 0 to 20%. There was a significant (P < .0015) interaction between alcohol and Se level. All the other parameters for Se bioavailability were not affected by alcohol consumption. However, alcohol consumption significantly reduced growth rate at both Se levels.

  16. Mercury and Selenium in Muscle and Target Organs of Scalloped Hammerhead Sharks Sphyrna lewini of the SE Gulf of California: Dietary Intake, Molar Ratios, Loads, and Human Health Risks.

    PubMed

    Bergés-Tiznado, Magdalena E; Márquez-Farías, Fernando; Lara-Mendoza, Raúl E; Torres-Rojas, Yassir E; Galván-Magaña, Felipe; Bojórquez-Leyva, Humberto; Páez-Osuna, Federico

    2015-11-01

    Selenium and mercury were evaluated in muscle, liver, kidney, brain, and the stomach contents of juvenile scalloped hammerhead shark Sphyrna lewini. Se:Hg molar ratios were calculated. The average Hg levels in muscle ranged from 0.12 to 1.17 μg/g (wet weight); Hg was <0.39 μg/g in liver and kidneys and <0.19 μg/g in brain. The lowest value of Se was found in muscle (0.4 μg/g) and the highest in kidney (26.7 μg/g). An excess of Se over Hg was found, with Se:Hg molar ratios >1. Correlations were found for Hg in muscle with size, age, and weight, and also for Hg in liver with size, age, and weight. Hg in muscle was significantly positive correlated to Hg in brain as well as Hg in liver was correlated to Hg in kidney. The highest Hg in preys was for carangid fishes; scombrid and carangid fishes contributed with the highest Se levels. Results suggest that more than 98 % of the total Hg and 62 % of Se end up in muscle and might be affected by factors, such as geographical area, age, size, and feeding habits. The muscle of S. lewini should be consumed by people cautiously so as not to exceed the recommended intake per week.

  17. Effect of dietary copper on selenium toxicity in Fischer 344 rats.

    PubMed

    Tatum, L; Shankar, P; Boylan, L M; Spallholz, J E

    2000-12-01

    The purpose of this study was to investigate the ameliorating effects of dietary copper supplementation on selenium toxicity. Nine groups (n = 6) of weanling Fischer 344 female rats were randomly assigned to treatment groups and fed diets containing nontoxic levels of copper as CuCl2 and/or selenium as selenite or selenocystamine. Weight gain, liver and spleen weights, plasma lipid peroxidation, and liver selenium and copper content were analyzed after the 6-wk treatment period. Concentrations of up to 10 times the daily lethal dose of dietary selenium were well tolerated in rats supplemented with dietary copper. As the dietary level of selenium was increased, the ratio of selenium to copper measured in the liver decreased. In the groups of rats in which dietary copper supplementation was absent and dietary selenium was supplemented, copper stores in the liver remained unchanged from control values. Copper's protective effects from dietary selenium toxicity may come from the formation of a copper-selenide complex that renders both selenium and copper metabolically unavailable and nontoxic.

  18. Benefits of Selenium Supplementation on Leukocyte DNA Integrity Interact with Dietary Micronutrients: A Short Communication

    PubMed Central

    Karunasinghe, Nishi; Zhu, Shuotun; Ferguson, Lynnette R.

    2016-01-01

    A male cohort from New Zealand has previously shown variability in Selenium (Se) supplementation effects on measured biomarkers. The current analysis is to understand the reasons for variability of the H2O2-induced DNA damage recorded after Se supplementation. We have looked at the variation of demographic, lifestyle, medication, genetic and dietary factors and biomarkers measured at baseline and post-supplementation in these two extreme subgroups A and B. Group A showed increased H2O2-induced DNA damage and group B showed decreased damage after Se supplementation. We have also considered correlations of biomarkers and dietary factors in the complete dataset. The glutathione peroxidase (GPx) activity and DNA damage were significantly lower at post-supplementation in Group B compared to Group A. Post-supplementation, Group B showed a significant reduction in the GPx activity, while Group A showed a significant increase in DNA damage compared to baseline levels. Dietary methionine intake was significantly higher and folate intake was significantly lower in Group B compared to Group A. Se supplementation significantly increased the caspase-cleaved keratin 18 levels in both groups, indicating increased apoptotic potential of this supplement. Parameter correlation with the complete dataset showed dietary methionine to have a significant negative correlation with H2O2-induced DNA damage post-supplementation. The data suggest that Se supplementation is beneficial for the leukocyte DNA integrity only in interaction with the dietary methionine and folate intake. PMID:27128937

  19. Hepatic selenoprotein P (SePP) expression restores selenium transport and prevents infertility and motor-incoordination in Sepp-knockout mice.

    PubMed

    Renko, Kostja; Werner, Margarethe; Renner-Müller, Ingrid; Cooper, Trevor G; Yeung, Ching Hei; Hollenbach, Birgit; Scharpf, Marcus; Köhrle, Josef; Schomburg, Lutz; Schweizer, Ulrich

    2008-02-01

    SePP (selenoprotein P) is central for selenium transport and distribution. Targeted inactivation of the Sepp gene in mice leads to reduced selenium content in plasma, kidney, testis and brain. Accordingly, activities of selenoenzymes are reduced in Sepp(-/-) organs. Male Sepp(-/-) mice are infertile. Unlike selenium deficiency, Sepp deficiency leads to neurological impairment with ataxia and seizures. Hepatocyte-specific inactivation of selenoprotein biosynthesis reduces plasma and kidney selenium levels similarly to Sepp(-/-) mice, but does not result in neurological impairment, suggesting a physiological role of locally expressed SePP in the brain. In an attempt to define the role of liver-derived circulating SePP in contrast with locally expressed SePP, we generated Sepp(-/-) mice with transgenic expression of human SePP under control of a hepatocyte-specific transthyretin promoter. Secreted human SePP was immunologically detectable in serum from SEPP1-transgenic mice. Selenium content and selenoenzyme activities in serum, kidney, testis and brain of Sepp(-/-;SEPP1) (SEPP1-transgenic Sepp(-/-)) mice were increased compared with Sepp(-/-) controls. When a selenium-adequate diet (0.16-0.2 mg/kg of body weight) was fed to the mice, liver-specific expression of SEPP1 rescued the neurological defects of Sepp(-/-) mice and rendered Sepp(-/-) males fertile. When fed on a low-selenium diet (0.06 mg/kg of body weight), Sepp(-/-;SEPP1) mice survived 4 weeks longer than Sepp(-/-) mice, but ultimately developed the neurodegenerative phenotype. These results indicate that plasma SePP derived from hepatocytes is the main transport form of selenium supporting the kidney, testis and brain. Nevertheless, local Sepp expression is required to maintain selenium content in selenium-privileged tissues such as brain and testis during dietary selenium restriction.

  20. Dynamic selenium assimilation, distribution, efflux, and maternal transfer in japanese medaka fed a diet of se-enriched mayflies.

    PubMed

    Conley, Justin M; Watson, Atlee T D; Xie, Lingtian; Buchwalter, David B

    2014-01-01

    Selenium (Se) trafficking in oviparous species remains understudied and a major source of uncertainty in developing sound Se regulations. Here, we utilized (75)Se to follow Se through a simulated natural food chain (water, periphyton, mayflies (Centroptilum triangulifer), fish (Japanese medaka)). We specifically examined Se assimilation efficiency, tissue distribution, efflux rate, and maternal transfer in medaka. Selenium assimilation efficiency (AE) averaged 63.2 ± 8.8% from mayfly diets and was not affected by mayfly [Se] across a dietary range of 5.6-38.7 μg g(-1) (dry wt). However, AE decreased significantly as mayfly larva size increased. Efflux rate constants (ke) were consistent between reproductively inactive (0.066 d(-1)) and spawning females (0.069 d(-1)). Total Se loss rate constant (ke+egg; efflux and egg deposition) was 0.17 d(-1) in spawning females. Interestingly, medaka appeared to rapidly shuttle Se to their eggs directly from their diet via the ovary, as opposed to mobilization from surrounding tissues, resulting in dynamic egg [Se] that was more attributable to recent dietary Se ingestion than female whole body [Se] in this asynchronous spawning fish. Spawning strategy likely plays a large role in the process of fish egg Se deposition and requires further attention to understand risk and toxicity of Se to fish.

  1. DIETARY ANTIOXIDANTS (SELENIUM & N-ACETYLCYSTEINE) MODULATE PARAOXONASE 1 (PON1) IN PCB126-EXPOSED RATS

    PubMed Central

    Shen, Hua; Li, Miao; Wang, Bingxuan; Lai, Ian K.; Robertson, Larry W.; Ludewig, Gabriele

    2013-01-01

    The environmental pollutants polychlorinated biphenyls (PCBs), especially dioxin-like PCBs, cause oxidative stress and associated toxic effects, including cancer and possibly atherosclerosis. We previously reported that PCB 126, the most potent dioxin-like PCB congener, decreases antioxidants such as hepatic selenium (Se), selenium-dependent glutathione peroxidase and glutathione (GSH), but also increases levels of the anti-atherosclerosis enzyme paraoxonase 1 (PON1) in liver and serum. To probe the interconnection of these three antioxidant systems, Se, GSH, and PON1, we examined the influence of varying levels of dietary Se and N-acetylcysteine (NAC), a scavenger of reactive oxygen species (ROS) and precursor for GSH synthesis, on PON1 in the absence and presence of PCB 126 exposure. Male Sprague Dawley rats, fed diets with differing Se levels (0.02, 0.2, or 2 ppm) or NAC (1%), were treated with a single intraperitoneal injection of corn oil or various doses of PCB 126 and euthanized 2 weeks later. PCB126 significantly increased liver PON1 mRNA, protein level and activity and serum PON1 activity in all dietary groups, but did not consistently increase thiobarbituric acid levels (TBARS), an indicator for lipid oxidation and oxidative stress, in liver or serum. Inadequate (high or low) dietary Se decreased baseline and PCB 126-induced aryl hydrocarbon receptor expression but further increased PCB 126-induced cytochrome P450 1A1 expression, the enzyme believed to be the cause for PCB 126-induced oxidative stress. In addition, a significant inverse relationship was observed between dietary Se levels and PON1 mRNA and PON1 activity, but also with TBARS levels in the liver, suggesting significant antioxidant protection from dietary Se. NAC lowered serum baseline TBARS levels in the controls and increased serum PON1 activity but lowered liver PON1 activities in animals treated with 1 μmol/kg PCB 126, suggesting antioxidant activity by NAC primarily in serum. These

  2. Dietary selenium increases the antioxidant levels and ATPase activity in the arteries and veins of poultry.

    PubMed

    Cao, Changyu; Zhao, Xia; Fan, Ruifeng; Zhao, Jinxin; Luan, Yilin; Zhang, Ziwei; Xu, Shiwen

    2016-07-01

    Selenium (Se) deficiency is associated with the pathogenesis of vascular diseases. It has been shown that oxidative levels and ATPase activity were involved in Se deficiency diseases in humans and mammals; however, the mechanism by how Se influences the oxidative levels and ATPase activity in the poultry vasculature is unclear. We assessed the effects of dietary Se deficiency on the oxidative stress parameters (superoxide dismutase, catalase, and hydroxyl radical) and ATPase (Na(+)K(+)-ATPase, Ca(++)-ATPase, Mg(++)-ATPase, and Ca(++)Mg(++)-ATPase) activity in broiler poultry. A total of 40 broilers (1-day old) were randomly divided into a Se-deficient group (L group, fed a Se-deficient diet containing 0.08 mg/kg Se) and a control group (C group, fed a diet containing sodium selenite at 0.20 mg/kg Se). Then, arteries and veins were collected following euthanasia when typical symptoms of Se deficiency appeared. Antioxidant indexes and ATPase activity were evaluated using standard assays in arteries and veins. The results indicated that superoxide dismutase activity in the artery according to dietary Se deficiency was significantly lower (p < 0.05) compared with the C group. The catalase activity in the veins and hydroxyl radical inhibition in the arteries and veins by dietary Se deficiency were significantly higher (p < 0.05) compared with the C group. The Se-deficient group showed a significantly lower (p < 0.05) tendency in Na(+)K(+)-ATPase activity, Ca(++)-ATPase activity, and Ca(++)Mg(++)-ATPase activity. There were strong correlations between antioxidant indexes and Ca(++)-ATPase activity. Thus, these results indicate that antioxidant indexes and ATPases may have special roles in broiler artery and vein injuries under Se deficiency.

  3. Interactive effects of boron, selenium, and dietary protein on survival, growth and physiology in mallard ducklings

    USGS Publications Warehouse

    Hoffman, D.J.; Sanderson, C.J.; LeCaptain, L.J.; Cromartie, E.; Pendleton, G.W.

    1991-01-01

    High concentrations of boron (B) and selenium (Se) have been found in aquatic food chains associated with irrigation drainwater. Total biomass of invertebrates, a maJor source of protein for wild ducklings, is sometimes diminished in agricultural drainwater ponds contaminated with Se and B. Dayold mallard (Anas platyrhynchos) ducklings received an untreated diet (controls) containing 22% protein or diets containing 15 ppm (microgram/g) Se (as selenomethionine), 60 ppm Se, 1,000 ppm B (as boric acid), 15 ppm Se with 1,000 ppm B, or 60 ppm Se with 1,000 ppm B. In a concurrent experiment, the above sequence was repeated with a proteinrestricted (7%) but isocaloric diet. After four weeks, blood and tissue samples were collected for biochemical and histological examination. With 22% protein and 60 ppm Se in the diet, duckling survival and growth was reduced and histopathological lesions of the liver occurred. Boron alone caused some reduction in growth. Several interactive effects occurred between B and Se, including further reduction in growth, and increases in plasma glutathione reductase activity, hematocrit, hemoglobin and plasma protein concentrations. With 7% protein, the growth of controls was less than that with 22% protein, 60 ppm Se caused 100% mortality, and growth effects of 15 ppm Se and 1,000 ppm B alone were more pronounced than with 22% protein. Selenium accumulation increased in the liver with 7% protein. Interactive effects were greater for Se and B with 7% protein than with 22% protein and included significant mortality and enhanced accumulation of Se in the liver. These findings suggest the potential for more severe toxicological effects of Se and B independently and interactively on duckling survival and development when dietary protein is diminished.

  4. Effect of supranutritional level of dietary alpha-tocopheryl acetate and selenium on rabbit semen.

    PubMed

    Castellini, Cesare; Lattaioli, Paolo; Bosco, Alessandro Dal; Beghelli, Daniela

    2002-12-01

    This research examined the effects of dietary alpha-tocopheryl acetate (50 or 200 mg/kg diet) and selenium (Se, 0 or 0.5 ppm) supplementation on motion characteristics, oxidative stability and fertilizing ability of rabbit spermatozoa, fresh and stored for 24 h at 5 degrees C. The higher amount of dietary alpha-tocopheryl acetate increased the level of Vitamin E in the fresh semen (1.75 mmol/l versus 0.95 mmol/l) and its oxidative stability (thiobarbituric acid reactive substances-TBARS 12.44 nmol malondialdehyde/10(8) sperm versus 21.4 nmol malondialdehyde/10(8) sperm). Dietary Se increased gluthatione peroxidase activity (GPx) in erythrocytes (285 U/g Hb versus 207 U/g Hb), seminal plasma (270 U/l versus 190 U/l) and spermatozoa (1338 mU/10(9) sperm versus 1103 mU/10(9) sperm), whereas it did not show any effect on alpha-tocopherol level and TBARS. No synergy between Vitamin E and Se was shown. Storage for 24 h at 5 degrees C increased the TBARS level in all the experimental groups. Neither live and acrosome reacted spermatozoa, nor kinetic parameters, nor fertility rate were modified by dietary supplementation.

  5. The bioaccumulation and effects of selenium in the oligochaete Lumbriculus variegatus via dissolved and dietary exposure routes.

    PubMed

    Xie, Lingtian; Wu, Xing; Chen, Hongxing; Luo, Yongju; Guo, Zhongbao; Mu, Jingli; Blankson, Emmanuel R; Dong, Wu; Klerks, Paul L

    2016-09-01

    Aquatic organisms take up selenium from solution and from their diets. Many questions remain regarding the relative importance of selenium accumulation from these sources and resulting effects in benthic invertebrates. The present study addressed the toxicity and accumulation of Se via dissolved and dietary exposures to three different Se species, in the freshwater oligochaete Lumbriculus variegatus. Worms were exposed to 20μg/g dry weight of selenite (Se(IV)), selenate (Se(VI)), or seleno-l-methionine (Se-Met) in their diet (sediment) or to 15μg/L dissolved Se in water-only exposures. While the dissolved and sediment Se levels differed greatly, such levels may co-occur at a Se-contaminated site. Se accumulation, worm population growth, lipid peroxidation (as TBARS), and Na(+)/K(+)-ATPase activity were quantified at the end of the 2-week exposure. The sediment Se-Met exposure caused 100% mortality, while worm densities were reduced by the other exposures except the Se(VI) one. Se bioaccumulation was generally higher for the sediment-Se exposure than the dissolved-Se ones, and was higher for Se(IV) than Se(VI) in the dissolved-Se exposure but not the sediment-Se one. The Se accumulation was highest for Se-Met. The oligochaetes that accumulated Se had higher levels of lipid peroxidation and reduced Na(+)/K(+)-ATPase activity. The present study's findings of differences in Se accumulation and toxicity for the three Se species, with effects generally but not exclusively a function of Se body burdens, underscore the need for research on these issues in invertebrates. Moreover, the results imply that the dietary uptake route is the predominant one for Se accumulation in L. variegatus.

  6. Effects of dietary selenium on host response to necrotic enteritis in young broilers.

    PubMed

    Xu, Shouzhen; Lee, Sung-Hyen; Lillehoj, Hyun S; Hong, Yeong Ho; Bravo, David

    2015-02-01

    The effects of dietary supplementation of young broiler chickens with an organic selenium (Se) formulation, B-Traxim Se, on experimental necrotic enteritis (NE) were studied. Chickens treated with three Se doses (0.25, 0.50, 1.00 mg/kg) from hatch were orally challenged with Eimeria maxima at 14 days of age followed by Clostridium perfringens to induce NE. Chickens fed with 0.50 mg/kg Se showed significantly increased body weights and antibody levels against NetB, and significantly reduced gut lesions compared with non-supplemented chickens. However, there were no significant differences in Eimeria oocyst shedding between the Se-treated and non-supplemented groups. Levels of IL-1β, IL-6, IL-8, iNOS, LITAF, TNFSF15, AvBD6, AvBD8, and AvBD13 transcripts were increased in the gut and spleen of at least one of the three Se-treated groups compared with the non-treated group. These results suggest that dietary supplementation of young broilers with Se might be beneficial to reduce the negative consequence of NE.

  7. Plasma selenium levels and dietary selenium intakes of formula-fed (FF) and cow's milk-fed (CMF) infants

    SciTech Connect

    Gropper, S.; Anderson, K.; Landing, W.; Acosta, P. Florida State Univ., Tallahassee Ross Labs., Columbus, OH )

    1990-02-26

    The plasma selenium concentrations of 57 infants eight to 12 months of age ingesting either cow's milk or milk-based infant formula as their primary beverage as part of a mixed diet for at least three months was assessed using flameless atomic absorption spectrophotometry. The mean ({plus minus}SD) daily dietary selenium intake of 26 cow's milk-fed infants (34{plus minus} 13 ug) was significantly greater than that of 31 formula-fed infants (22{plus minus}11 ug). The mean ({plus minus}SD) plasma selenium concentration of infants fed cow's mild (39{plus minus}11 ug/L) was also significantly greater than that of infants fed formula (31{plus minus}12 ug/L). Both groups of infants ingested similar total energy intakes; however, the infants fed cow's milk received more total protein and selenium and a greater percentage of protein and selenium from their primary beverage than the infants receiving formula. Both groups of infants were consuming a mixed diet with similar sources of selenium. These data suggest that cow's milk is a richer source of selenium than infant formulas.

  8. Selenium redox cycling during weathering of Se-rich shales: A selenium isotope study

    NASA Astrophysics Data System (ADS)

    Zhu, Jian-Ming; Johnson, Thomas M.; Clark, Scott K.; Zhu, Xiang-Kun; Wang, Xiang-Li

    2014-02-01

    Selenium isotopes are becoming an important paleoenvironmental proxy. However, few studies have focused on the behavior of Se isotopes during oxidative weathering. In this paper, a comprehensive set of Se isotopic composition and concentration data were collected from the weathering profiles of Se-rich shales of the Permian Maokou Formation in Yutangba and Shadi, China to investigate Se isotopic fractionation and Se enrichment during weathering processes. The δ82/76Se in fresh shales (148 ± 118 mg/kg Se, 1SD, n = 40) from Shadi and Yutangba drill cores varies from -1.69‰ to 1.74‰ with an average of 0.40 ± 0.71‰ (1SD, n = 40), consistent with the range in other Phanerozoic shales, suggesting that Se isotopes are not strongly fractionated during Se sequestration in the primary sedimentary environment. However, the strongly weathered Se-rich shales from Shadi and Yutangba profiles are isotopically lighter with average δ82/76Se values of -1.96 ± 1.08‰ (1SD, n = 5) and -1.08 ± 1.83‰ (1SD, n = 23), respectively. These data suggest that Se isotopes can be fractionated during oxidation and reduction processes associated with weathering, with heavier isotopes removed preferentially during oxidative weathering of shales. Such a shift, if found to be a global phenomenon, would have implications for models of the global Se cycle and interpretation of Se isotope data from past biogeochemical regimes. Locally altered shales exposed in a quarry at Yutangba are extremely enriched in Se with 1642 ± 1505 mg/kg (1SD, n = 45), approximately 10 times greater than that in unaltered drill core samples. These rocks display very strong variation in δ82/76Se over short distances, with a single 60 cm transect showing the most strongly negative and positive δ82/76Se values (-14.20‰ to +11.37‰) observed to date in natural samples. This suggests that Se has undergone multiple cycles of oxidation, mobilization, and re-reduction, resulting in a Se-rich redox front that has

  9. Influence of dietary selenium on mouse lung biochemical response and tolerance to ozone inhalation

    SciTech Connect

    Elsayed, N.M.

    1983-01-01

    This study examined whether altered selenium (Se) intake with or without ozone (O/sub 3/) stress would result in a possible 1) dose-response relationship between lung Se and glutathione peroxidase, 2) influence of Se on other lung parameters, 3) interrelationship between lung Se and vitamin E contents, and 4) alteration of lung sensitivity or tolerance to O/sub 3/. The results showed the following: 1) Omission of dietary Se resulted in a drastic decline in GP activity but did not affect the other enzyme activities studied. 2) A stimulation of the PPC and CAC activites with low-level O/sub 3/ exposure occurred only in Se-supplemented mice. The stimulation was greater in the lungs of mice fed 1.0 ppm Se compared to 0.15 ppm, i.e., the response was Se-dose dependent in this range. 3) Diminished GP activity possibly resulted in a decreased demand for NADPH produced via not only the PPC but also the CAC. 4) An inverse relationship was observed between Se and vitamin E contents in lung tissue, showing that a compensatory relationship existed between the two. 5) After each O/sub 3/ exposure Se content increased in lung tissue of both dietary groups, suggesting a possible mobilization of Se to the lung under O/sub 3/ stress. 6) Decreased GP activity due to Se deficiency and the ensuring lack of stimulated NADPH production in the lung did not alter the animal sensitivity to O/sub 3/, suggesting that GP reaction and NADPH production cycles were not crucial for animal tolerance.

  10. Dietary Selenium in Adjuvant Therapy of Viral and Bacterial Infections12

    PubMed Central

    Steinbrenner, Holger; Al-Quraishy, Saleh; Dkhil, Mohamed A; Wunderlich, Frank; Sies, Helmut

    2015-01-01

    Viral and bacterial infections are often associated with deficiencies in macronutrients and micronutrients, including the essential trace element selenium. In selenium deficiency, benign strains of Coxsackie and influenza viruses can mutate to highly pathogenic strains. Dietary supplementation to provide adequate or supranutritional selenium supply has been proposed to confer health benefits for patients suffering from some viral diseases, most notably with respect to HIV and influenza A virus (IAV) infections. In addition, selenium-containing multimicronutrient supplements improved several clinical and lifestyle variables in patients coinfected with HIV and Mycobacterium tuberculosis. Selenium status may affect the function of cells of both adaptive and innate immunity. Supranutritional selenium promotes proliferation and favors differentiation of naive CD4-positive T lymphocytes toward T helper 1 cells, thus supporting the acute cellular immune response, whereas excessive activation of the immune system and ensuing host tissue damage are counteracted through directing macrophages toward the M2 phenotype. This review provides an up-to-date overview on selenium in infectious diseases caused by viruses (e.g., HIV, IAV, hepatitis C virus, poliovirus, West Nile virus) and bacteria (e.g., M. tuberculosis, Helicobacter pylori). Data from epidemiologic studies and intervention trials, with selenium alone or in combination with other micronutrients, and animal experiments are discussed against the background of dietary selenium requirements to alter immune functions. PMID:25593145

  11. Effect of dietary selenium deficiency on the in vitro fertilizing ability of mice spermatozoa.

    PubMed

    Sánchez-Gutiérrez, M; García-Montalvo, E A; Izquierdo-Vega, J A; Del Razo, L M

    2008-08-01

    Selenium is an essential micronutrient for mammals, being integral part of antioxidant system. The aim of the study was to evaluate the effect of selenium deficiency on in vitro fertilization (IVF) capacity of spermatozoa and on oxidative stress in these cells. Male C57BL/6N mice were maintained on selenium-deficient or selenium-sufficient diets (0.02 or 0.2 ppm of selenium as selenomethionine, respectively) for 4 months. Liver glutathione peroxidase activity measurements were used to confirm selenium deficiency. Sperm quality and IVF capability among both groups were evaluated. To assess oxidative damage, lipid peroxidation as malondialdehyde production was determined in spermatozoa as well as the testes. Ultrastructural analyses of spermatozoa nuclei using transmission electron microscopy were also performed. The percentage of eggs fertilized with sperm from selenium-deficient mice was significantly decreased by approximately 67%. This reduced fertilization capacity was accompanied by increased levels of lipid peroxidation in both the testes and sperm, indicating that selenium deficiency induced oxidative stress. Consistent with this finding, spermatozoa from selenium-deficient animals exhibited altered chromatin condensation. Deficiency in dietary selenium decreases the reproductive potential of male mice and is associated with oxidative damage in spermatozoa.

  12. Comparison of selenium levels and sources and dietary fat quality in diets for broiler breeders and layer hens.

    PubMed

    Leeson, S; Namkung, H; Caston, L; Durosoy, S; Schlegel, P

    2008-12-01

    Two experiments were carried out with broiler breeders (experiment 1) and laying hens (experiment 2) to study the effects of Se sources, in interaction with dietary level of Se or dietary fats on performance, Se incorporation into tissues (blood, liver, breast muscle, and egg) and eggs, hatchability, and glutathione peroxidase (GPX) activities in tissues and blood. Both experiments involved a 3 x 2 factorial arrangement of 3 Se sources (selenite, Se yeast, or B-Traxim Se) and either 2 levels of each source (0.1 or 0.3 mg/kg) or 2 fats (fresh or oxidized). Egg production was not affected by Se source or dietary fat in both experiments. Egg production was greater (P < 0.01) in breeder hens fed 0.3 mg/kg of Se in experiment 1. Hatchability of eggs from hens fed 0.1 mg/kg of Se was lower (P < 0.05) in hens fed Se yeast, whereas from hens fed 0.3 mg/kg of Se, it was comparable across treatments. Selenium in egg, liver, and breast muscle was greater (P < 0.01 or <0.05) in hens fed the greater concentration of Se. Eggs from breeder hens fed organic Se sources had greater (P < 0.01) Se content than those of inorganic source. Egg albumen from breeder fed Se yeast had the greatest Se (P < 0.01), whereas egg yolk from hens fed B-Traxim Se had the greatest Se (P < 0.05). These parameters were affected by interaction between dietary Se level and source (P < 0.01 or < 0.05). Selenium contents in liver and breast muscle were greater (P < 0.01) in hens fed Se yeast compared with hens fed other sources of Se. In experiment 1, liver GPX was greater (P < 0.01) in hens fed selenite or Se yeast, whereas plasma GPX was greater (P < 0.01) in hens fed selenite compared with B-Traxim Se or Se yeast. Supplementation with oxidized fat increased (P < 0.05) GPX in blood and liver. B-Traxim Se decreased (P < 0.05) malondialdehyde content in breast muscle of layers. It is concluded that broiler breeders require supplementation of 0.3 mg/kg of Se, and that there are numerous measurable advantages

  13. Effects of dietary supplementation of selenium and iodine on growth performance, carcass characteristics and histology of thyroid gland in goats.

    PubMed

    Aghwan, Zeiad Amjad; Sazili, Awis Qurni; Kadhim, Khalid Kamil; Alimon, Abdul Razak; Goh, Yong Meng; Adeyemi, Kazeem Dauda

    2016-05-01

    This study assessed the effects of dietary selenium (Se), iodine (I) and a combination of both on growth performance, thyroid gland activity, carcass characteristics and the concentration of iodine and selenium in Longissimus lumborum (LL) muscle in goats. Twenty-four bucks were randomly assigned to four dietary treatments: control (CON), basal diet without supplementation, basal diet + 0.6 mg Se/kg dry matter (DM) (SS), 0.6 mg I/kg DM (IP), or combination of 0.6 mg/kg DM Se and 0.6 mg/kg DM I (SSIP) and fed for 100 days. Animals fed diet SSIP exhibited higher (P < 0.05) body weight and better feed conversion ratio (FCR) than those fed other diets. Dressing percentage of goats fed the supplemented diets was higher (P < 0.05) than that of the control. Carcasses from the IP group had higher (P < 0.05) total fat proportion than the SSIP group. The levels of both elements were significantly elevated (P < 0.05) in LL muscle in supplemented goats. Thyroid follicular epithelial cells of IP and SSIP animals were significantly higher than those of CON and SS groups. The study demonstrated that the combined Se and I dietary supplementation improves growth performance, carcass dressing percentage and increases the retention of Se and I in goat meat.

  14. Deficient and excess dietary selenium levels affect growth performance, blood cells apoptosis and liver HSP70 expression in juvenile yellow catfish Pelteobagrus fulvidraco.

    PubMed

    Hu, Jun-Ru; Huang, Yan-Hua; Wang, Guo-Xia; Wu, Ying-Xia; Xian, Jian-An; Wang, An-Li; Cao, Jun-Ming

    2016-02-01

    We investigated the effects of deficient and excess dietary selenium (Se) on growth, blood cells apoptosis and liver heat shock protein 70 (HSP70) expression in juvenile yellow catfish (Pelteobagrus fulvidraco). After 8 weeks, yellow catfish (initial weight: 2.12 ± 0.01 g) fed isonitrogenous and isolipid diets containing <0.05 (deficient dietary Se) or 6.5 (excess dietary Se) mg Se/kg displayed a significantly lower weight gain ratio (WGR) than those fed a diet containing 0.23 (normal dietary Se) mg Se/kg. As dietary Se levels increased, liver Se concentration, glutathione peroxidase activity and the hepatosomatic index increased significantly. Plasma glucose concentration was highest in the normal treatment compared with the excess dietary Se treatment. Both deficient and excess dietary Se lead to increased reactive oxygen species (ROS) production and apoptosis ratio in blood cells, whereas only excess dietary Se increased their cytoplasmic free-Ca(2+) (CF-Ca(2+)) concentration. Excess dietary Se also resulted in the highest level of HSP70 expression, thereby possibly providing a protective mechanism against oxidative stress. These results indicate that both deficient and excess dietary Se restrained the growth of juvenile yellow catfish and caused oxidative stress. The overproduction of ROS may act as a signal molecule mediate apoptosis when dietary Se deficiency. Both ROS and CF-Ca(2+) were recorded when dietary Se excess, suggesting that Ca(2+) may be activated by Se and play a major role during Se-induced oxidative stress and cell apoptosis.

  15. The effect of dietary selenium source on embryonic development in Turkeys.

    PubMed

    Stepińska, Monika; Mróz, Emilia; Jankowski, Jan

    2012-01-01

    The objective of this study was to determine the effect of dietary selenium source on the growth and development of turkey embryos, and egg hatchability. White broad-breasted BUT Big 6 turkeys (1800 females and 150 males) were placed under optimum management conditions. Turkey diets were supplemented with organic selenium, and in the other with inorganic selenium, in the amount of 0.3 ppm. Eggs intended for incubation and examination were collected in week 2, 10, 18 and 23 of the laying season. The average egg weight was higher (p < or = 0.05) in laying hens fed a diet with organic selenium than in layers receiving inorganic selenium. The rate of yolk sac retraction was faster in embryos from the group fed a diet with inorganic selenium, and it reached 0.59 of the complete yolk sac on day 25 of incubation (p < or = 0.05). Selenium source had no effect on the hatching rates of fertilized eggs, which reached 79.61% and 79.84% in laying hens fed organic and inorganic selenium, respectively. In the flocks fed diets supplemented with organic selenium, dead embryos were more frequently characterized by problems with protein utilization (19.28%) and delayed pipping (10.83%). Embryo death rates at the first mortality peak were higher in layers fed inorganic selenium than in those receiving organic selenium (15% vs. 13.5%). The second embryo mortality peak occurred earlier (day 26) in laying hens fed inorganic selenium than in those fed organic selenium (day 28).

  16. The importance of pyridoxine for the impact of the dietary selenium sources on redox balance, embryo development, and reproductive performance in gilts.

    PubMed

    Dalto, Danyel Bueno; Audet, Isabelle; Lapointe, Jérôme; Matte, J Jacques

    2016-03-01

    This study aimed to determine the effects of dietary pyridoxine and selenium (Se) on embryo development, reproductive performance and redox system in gilts. Eighty-four gilts were fed one of five diets: CONT) basal diet; MSeB60) CONT+0.3mg/kg of Na-selenite; MSeB610) diet 2+10mg/kg of HCl-pyridoxine; OSeB60) CONT+0.3mg/kg of Se-enriched yeast; and OSeB610) diet 4+10mg/kg of HCl-pyridoxine. Blood samples were collected for long-term (each estrus and slaughter) and peri-estrus (fourth estrus d -4 to d +3) profiles. At slaughter (gestation d 30), organs and embryos were collected. For long-term and peri-estrus profiles, Se level and source affected (P<0.01) blood Se concentration whereas B6 level increased (P<0.01) erythrocyte pyridoxal-5-phosphate concentration. A B6 level (P<0.05) effect was observed on long-term plasma Se-dependent glutathione peroxidase (Se-GPX) activity whereas peri-estrus Se-GPX was minimum on d -1 (P<0.01). Selenium level increased sows' organs and embryo Se concentration (P<0.01). Selenium source tended to enhance embryo Se content (P=0.06). Within-litter embryo Se content was increased by B6 level (P<0.01). Selenium level tended to affect Se-GPX and total GPX activities in organs mitochondria (P=0.09 and 0.07, respectively). Selenium source affected kidney ATP synthesis (P=0.05). In conclusion, B6 level affected the Se-GPX activity on a long-term basis, whereas the basal level of Se was adequate during the peri-estrus period. Embryo quality was not improved by dietary Se, and B6 impaired within-litter homogeneity.

  17. Dietary selenium, glutathione peroxidase activity, and toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Hassan, M.Q.; Stohs, S.J.; Murray, W.J.; Birt, D.F.

    1985-01-01

    TCDD has been shown to inhibit selenium-dependent glutathione peroxidase activity. The role of selenium in TCDD toxicity is not known. The authors have therefore examined the effect of TCDD administration on hepatic glutathione peroxidase, aryl hydrocarbon hydroxlase, glutathione reductase, and glutathione S-transferase activities, glutathione content, and lipid peroxidation in rats fed 0, 0.10, and 2.0 ppm dietary selenium. TCDD treatment significantly inhibited selenium-dependent glutathione peroxidase in animals on diets containing 0.10 and 2.0 ppm selenium. The selenium-dependent glutathione peroxidase activities in rats on 0.10 and 2.0 ppm dietary selenium were 8.3- and 4.7-fold greater than in animals fed a diet containing 0 ppm selenium. TCDD administration enhanced hepatic microsomal lipid peroxidation by factors of 4.0, 4.9, and 9.8 in animals fed diets containing 0, 0.10, and 2.0 ppm selenium, respectively. The administration of a lethal dose of TCDD to rats fed diets containing 0, 0.10, and 2.0 ppm selenium, respectively. The administration of a lethal dose of TCDD to rats fed diets containing 0, 0.10, and 2.0 ppm selenium resulted in 0, 46, and 7% survival, respectively, after 66 d. Aryl hydrocarbon hydroxylase, glutathione S-transferase, and glutathione reductase activities were induced by TCDD. The results indicate that optimum dietary selenium provides partial protection from the toxic effects of TCDD.

  18. Effects of selenium dietary enhancement on hatchery-reared coho salmon, Oncorhynchus kisutch (Walbaum), when compared with wild coho: hepatic enzymes and seawater adaptation evaluated.

    USGS Publications Warehouse

    Felton, S.P.; Landolt, M.L.; Grace, R.; Palmisano, A.N.

    1996-01-01

    Hatchery-reared coho salmon, Oncorhynchus kisutch (Walbaum), were fed elevated levels of selenium (as Na2SeO3) to raise eviscerated body burdens to the level measured in wild counterparts. The goal was to find a dietary concentration that would achieve the desired effect without causing damage to growth and normal development. To measure some indices of health, the detoxifying enzymes chosen were hepatic glutathione peroxidase (GSH-Px) and hepatic superoxide dismutase (SOD). Eviscerated body selenium (Se) concentration, GSH-Px and SOD levels were measured during and at the end of the 9 month freshwater feeding trial. Selenium retention and enzyme activity were also measured during 6 months’residence in sea water (SW). Selenium supplements were added to a commercial ration to give final concentrations of 1.1, 8.6, 11.1, 13.6 μg g-1 Se in the four respective diets. The results indicated that a dietary concentration of 8.6 μg g-1selenium was capable of inducing eviscerated body burdens similar to those found in wild fish. The elevated selenium levels persisted throughout the freshwater (FW) rearing phase, but declined when the fish were fed an unsupplemented ration upon SW entry. Superoxide dismutase levels did not increase above control levels. Glutathione peroxidase levels increased in fish fed the supplemented diets. GSH-Px activity declined in the higher supplemented dietary groups when all groups were reduced to the control group level of 1.1 μg g-1. Cumulative mortality in SW was 20% in fish fed either the 1.1 or the 8.6 μg g-1 Se diets. The 8.6 μg g-1 Se supplemented diets did produce healthy coho, comparable to their wild counterparts.

  19. Effect of selenium and vitamin E dietary deficiencies on chick lymphoid organ development (42361)

    SciTech Connect

    Marsh, J.A.; Combs, G.F. Jr.; Whitacre, M.E.; Dietert, R.R.

    1986-09-01

    Diets specifically deficient in selenium (Se) and/or vitamin E or adequate in both nutrients were fed to chicks from the time of hatching. Lymphoid organs (bursa, thymus, and in some instances, spleen) were collected from chicks 7-35 days of age. Growth of the chicks fed these diets was monitored over the experimental period as was lymphoid organ growth. The development of the primary lymphoid organs was further assessed by histological techniques and the organ contents of vitamin E (..cap alpha..-tocopherol) and Se were determined. Specific deficiencies of either Se or vitamin E were found to significantly impair bursal growth as did a combined deficiency. Thymic growth was impaired only by the combined deficiency diet. Severe histopathological changes in the bursa resulted from the combined deficiency and these were detectable by 10-14 days after hatching. These changes were characterized by a gradual degeneration of the epithelium and an accompanying depletion of lymphocytes. Similar changes, although slower to develop and less severe, were observed in the thymus as a result of the combined deficiency. When both serum and tissue levels of vitamin E and Se were monitored, it was observed that these were rapidly and independently depleted by the specific deficiency diets. These data suggest that the primary lymphoid organs are major targets of Se and vitamin E dietary deficiencies and provide a possible mechanism by which immune function may be impaired.

  20. Dietary Selenium Supplementation Modulates Growth of Brain Metastatic Tumors and Changes the Expression of Adhesion Molecules in Brain Microvessels.

    PubMed

    Wrobel, Jagoda K; Wolff, Gretchen; Xiao, Rijin; Power, Ronan F; Toborek, Michal

    2016-08-01

    Various dietary agents can modulate tumor invasiveness. The current study explored whether selenoglycoproteins (SeGPs) extracted from selenium-enriched yeast affect tumor cell homing and growth in the brain. Mice were fed diets enriched with specific SeGPs (SeGP40 or SeGP65, 1 mg/kg Se each), glycoproteins (GP40 or GP65, 0.2-0.3 mg/kg Se each) or a control diet (0.2-0.3 mg/kg Se) for 12 weeks. Then, murine Lewis lung carcinoma cells were infused into the brain circulation. Analyses were performed at early (48 h) and late stages (3 weeks) post tumor cell infusion. Imaging of tumor progression in the brain revealed that mice fed SeGP65-enriched diet displayed diminished metastatic tumor growth, fewer extravasating tumor cells and smaller metastatic lesions. While administration of tumor cells resulted in a significant upregulation of adhesion molecules in the early stage of tumor progression, overexpression of VCAM-1 (vascular call adhesion molecule-1) and ALCAM (activated leukocyte cell adhesion molecule) messenger RNA (mRNA) was diminished in SeGP65 supplemented mice. Additionally, mice fed SeGP65 showed decreased expression of acetylated NF-κB p65, 48 h post tumor cell infusion. The results indicate that tumor progression in the brain can be modulated by specific SeGPs. Selenium-containing compounds were more effective than their glycoprotein controls, implicating selenium as a potential negative regulator of metastatic process.

  1. Effect of dietary selenium and cancer cell xenograft on peripheral T and B lymphocytes in adult nude mice.

    PubMed

    Cheng, Wen-Hsing; Holmstrom, Alexandra; Li, Xiangdong; Wu, Ryan T Y; Zeng, Huawei; Xiao, Zhengguo

    2012-05-01

    Selenium (Se) is known to regulate tumorigenesis and immunity at the nutritional and supranutritional levels. Because the immune system provides critical defenses against cancer and the athymic, immune-deficient NU/J nude mice are known to gradually develop CD8(+) and CD4(+) T cells, we investigated whether B and T cell maturation could be modulated by dietary Se and by tumorigenesis in nude mice. Fifteen homozygous nude mice were fed a Se-deficient, Torula yeast basal diet alone (Se-) or supplemented with 0.15 (Se+) or 1.0 (Se++) mg Se/kg (as Na(2)SeO(4)) for 6 months, followed by a 7-week time course of PC-3 prostate cancer cell xenograft (2 × 10(6) cells/site, 2 sites/mouse). Here, we show that peripheral B cell levels decreased in nude mice fed the Se -  or Se++ diet and the CD4(+) T cell levels increased in mice fed the Se++ diet. During the PC-3 cell tumorigenesis, dietary Se status did not affect peripheral CD4(+) or CD8(+) T cells in nude mice whereas mice fed with the Se++ diet appeared to exhibit greater peripheral CD25(+)CD4(+) T cells on day 9. Dietary Se status did not affect spleen weight in nude mice 7 weeks after the xenograft. Spleen weight was associated with frequency of peripheral CD4(+), but not CD8(+) T cells. Taken together, dietary Se at the nutritional and supranutritional levels regulates peripheral B and T cells in adult nude mice before and after xenograft with PC-3 prostate cancer cells.

  2. Epigenetic and antioxidant effects of dietary isothiocyanates and selenium: potential implications for cancer chemoprevention.

    PubMed

    Barrera, Lawrence N; Cassidy, Aedin; Johnson, Ian T; Bao, Yongping; Belshaw, Nigel J

    2012-05-01

    There is evidence from epidemiological studies suggesting that increased consumption of cruciferous vegetables may protect against specific cancers more effectively than total fruit and vegetable intake. These beneficial effects are attributed to the glucosinolate breakdown products, isothiocyanates (ITC). Similarly, selenium (Se) consumption has also been inversely associated with cancer risk and as an integral part of many selenoproteins may influence multiple pathways in the development of cancer. This paper will briefly review the current state of knowledge concerning the effect of Se and ITC in cancer development with a particular emphasis on its antioxidant properties, and will also address whether alterations in DNA methylation may be a potential mechanism whereby these dietary constituents protect against the carcinogenic process. Furthermore, we will discuss the advantages of combining ITC and Se to benefit from their complementary mechanisms of action to potentially protect against the alterations leading to neoplasia. Based on this review it may be concluded that an understanding of the impact of ITC and Se on aberrant DNA methylation in relation to factors modulating gene-specific and global methylation patterns, in addition to the effect of these food constituents as modulators of key selenoenzymes, such as gastrointestinal glutathione peroxidase-2 (GPx2) and thioredoxin reductase-1 (TrxR1), may provide insights into the potential synergy among various components of a plant-based diet that may counteract the genetic and epigenetic alterations that initiate and sustain neoplasia.

  3. Selenium concentration and speciation in biofortified flour and bread: Retention of selenium during grain biofortification, processing and production of Se-enriched food.

    PubMed

    Hart, D J; Fairweather-Tait, S J; Broadley, M R; Dickinson, S J; Foot, I; Knott, P; McGrath, S P; Mowat, H; Norman, K; Scott, P R; Stroud, J L; Tucker, M; White, P J; Zhao, F J; Hurst, R

    2011-06-15

    The retention and speciation of selenium in flour and bread was determined following experimental applications of selenium fertilisers to a high-yielding UK wheat crop. Flour and bread were produced using standard commercial practices. Total selenium was measured using inductively coupled plasma-mass spectrometry (ICP-MS) and the profile of selenium species in the flour and bread were determined using high performance liquid chromatography (HPLC) ICP-MS. The selenium concentration of flour ranged from 30ng/g in white flour and 35ng/g in wholemeal flour from untreated plots up to >1800ng/g in white and >2200ng/g in wholemeal flour processed from grain treated with selenium (as selenate) at the highest application rate of 100g/ha. The relationship between the amount of selenium applied to the crop and the amount of selenium in flour and bread was approximately linear, indicating minimal loss of Se during grain processing and bread production. On average, application of selenium at 10g/ha increased total selenium in white and wholemeal bread by 155 and 185ng/g, respectively, equivalent to 6.4 and 7.1μg selenium per average slice of white and wholemeal bread, respectively. Selenomethionine accounted for 65-87% of total extractable selenium species in Se-enriched flour and bread; selenocysteine, Se-methylselenocysteine selenite and selenate were also detected. Controlled agronomic biofortification of wheat crops for flour and bread production could provide an appropriate strategy to increase the intake of bioavailable selenium.

  4. Diagnostic criteria for selenium toxicosis in aquatic birds: dietary exposure, tissue concentrations, and macroscopic effects

    USGS Publications Warehouse

    Albers, P.H.; Green, D.E.; Sanderson, C.J.

    1996-01-01

    A feeding study with mallard ducks (Anas platyrhynchos) was conducted during March-July, 1988 in Laurel, Maryland, to identify diagnostic criteria for selenium toxicosis in birds. One-year-old male mallards in groups of 21 were fed diets containing 0, 10, 20, 40, or 80 parts per million (ppm) selenium, as seleno-DL-methionine, for 16 weeks. All ducks receiving 80 ppm died. Ducks receiving 40 or 80 ppm selenium consumed less feed than ducks in the other treatment groups. Body weights of ducks receiving 40 or 80 ppm selenium declined during the study. The post-breeding molt was delayed in ducks receiving 40 ppm; most ducks receiving 80 ppm selenium died prior to the onset of molt. At necropsy, numerous abnormalities were observed in ducks that died but only a small number of abnormalities were observed in ducks surviving to the end of the study in the 40 ppm group. Weights of the heart, spleen, and pancreas were mostly lower and weights of the kidney were higher for ducks dying during the study than for euthanized ducks. Liver weights were unaffected. Selenium accumulated in soft tissues approximately in proportion to dietary concentrations. Selenium concentrations in tissues of all ducks that died were different from those of surviving ducks in the 0, 10, and 20 ppm groups, but were not different from those of surviving ducks in the 40 ppm group. Proposed diagnostic criteria for fatal chronic selenosis were derived from body weight, macroscopic abnormalities, organ weights, and concentrations of selenium in the liver. Proposed diagnostic criteria for non-fatal chronic selenosis were derived from body weight, plumage condition, macroscopic abnormalities, concentrations of selenium in the liver, reproductive failure, and alterations of blood and tissue chemistries. Lead or dioxin poisoning have diagnostic criteria most similar to selenium toxicosis.

  5. Synthesis of CdSe quantum dots using selenium dioxide as selenium source and its interaction with pepsin.

    PubMed

    Wang, Yilin; Mo, Yunchuan; Zhou, Liya

    2011-09-01

    A novel method has been developed for the synthesis of thioglycolic acid (TGA)-capped CdSe quantum dots (QDs) in an aqueous medium when selenium dioxide worked as a selenium source and sodium borohydride acted as a reductant. The interaction between CdSe QDs and pepsin was investigated by fluorescence spectroscopy. It was proved that the fluorescence quenching of pepsin by CdSe QDs was mainly a result of the formation of CdSe-pepsin complex. Based on the fluorescence quenching results, the Stern-Volmer quenching constant (Ksv), binding constant (KA) and binding sites (n) were calculated. According to the Foster's non-radiative energy transfer theory, the binding distance (r) between pepsin and CdSe QDs was obtained. The influence of CdSe QDs on the conformation of pepsin has been analyzed by synchronous fluorescence spectra, which provided that the secondary structure of pepsin has been changed by the interaction of CdSe QDs with pepsin.

  6. Synthesis of CdSe quantum dots using selenium dioxide as selenium source and its interaction with pepsin

    NASA Astrophysics Data System (ADS)

    Wang, Yilin; Mo, Yunchuan; Zhou, Liya

    2011-09-01

    A novel method has been developed for the synthesis of thioglycolic acid (TGA)-capped CdSe quantum dots (QDs) in an aqueous medium when selenium dioxide worked as a selenium source and sodium borohydride acted as a reductant. The interaction between CdSe QDs and pepsin was investigated by fluorescence spectroscopy. It was proved that the fluorescence quenching of pepsin by CdSe QDs was mainly a result of the formation of CdSe-pepsin complex. Based on the fluorescence quenching results, the Stern-Volmer quenching constant ( Ksv), binding constant ( KA) and binding sites ( n) were calculated. According to the Foster's non-radiative energy transfer theory, the binding distance ( r) between pepsin and CdSe QDs was obtained. The influence of CdSe QDs on the conformation of pepsin has been analyzed by synchronous fluorescence spectra, which provided that the secondary structure of pepsin has been changed by the interaction of CdSe QDs with pepsin.

  7. Selenium.

    PubMed

    Barceloux, D G

    1999-01-01

    The 4 natural oxidation states of selenium are elemental selenium (0), selenide (-2), selenite (+4), and selenate (+6). Inorganic selenate and selenite predominate in water whereas organic selenium compounds (selenomethionine, selenocysteine) are the major selenium species in cereal and in vegetables. The principal applications of selenium include the manufacture of ceramics, glass, photoelectric cells, pigments, rectifiers, semiconductors, and steel as well as use in photography, pharmaceutical production, and rubber vulcanizing. High concentrations of selenium in surface and in ground water usually occur in farm areas where irrigation water drains from soils with high selenium content (Kesterson Reservoir, California) or in lakes receiving condenser cooling water from coal-fired electric power plants (Belews Lake, North Carolina). For the general population, the primary pathway of exposure to selenium is food, followed by water and air. Both selenite and selenate possess substantial bioavailability. However, plants preferentially absorb selenates and convert them to organic compounds. Aquatic organisms (e.g., bivalves) can accumulate and magnify selenium in the food chain. Selenium is an essential component of glutathione peroxidase, which is an important enzyme for processes that protect lipids in polyunsaturated membranes from oxidative degradation. Inadequate concentrations of selenium in the Chinese diet account, at least in part, for the illness called Keshan disease. Selenium deficiency occurs in the geographic areas where Balkan nephropathy appears, but there is no direct evidence that selenium deficiency contributes to the development of this chronic, progressive kidney disease. Several lines of scientific inquiry suggest that an increased risk of cancer occurs as a result of low concentrations of selenium in the diet; however, insufficient evidence exists at the present time to recommend the use of selenium supplements for the prevention of cancer. The

  8. Redox regulation of protein tyrosine phosphatase 1B by manipulation of dietary selenium affects the triglyceride concentration in rat liver.

    PubMed

    Mueller, Andreas S; Klomann, Sandra D; Wolf, Nicole M; Schneider, Sandra; Schmidt, Rupert; Spielmann, Julia; Stangl, Gabriele; Eder, Klaus; Pallauf, Josef

    2008-12-01

    Protein tyrosine phosphatase 1B (PTP1B) is a key enzyme in the counter-regulation of insulin signaling and in the stimulation of fatty acid synthesis. Selenium (Se), via the activities of glutathione peroxidase (GPx) and thioredoxin reductase (TrxR), is involved in the removal of H(2)O(2) and organic peroxides, which are critical compounds in the modulation of PTP1B activity via glutathionylation. Our study with growing rats investigated how the manipulation of dietary Se concentration influences the regulation of PTP1B and lipogenic effects mediated by PTP1B. Weanling albino rats were divided into 3 groups of 10. The negative control group (NC) was fed a Se-deficient diet for 8 wk. Rats in groups Se75 and Se150 received diets supplemented with 75 or 150 microg Se/kg. Se supplementation of the rats strongly influenced expression and activity of the selenoenzymes cytosolic GPx, plasma GPx, phospholipidhydroperoxide GPx, and cytosolic TrxR, and liver PTP1B. Liver PTP1B activity was significantly higher in groups Se75 and Se150 than in the NC group and this was attributed to a lowered inhibition of the enzyme by glutathionylation. The increased liver PTP1B activity in groups Se75 and Se150 resulted in 1.1- and 1.4-fold higher liver triglyceride concentrations than in the NC rats. The upregulation of the sterol regulatory element binding protein-1c and of fatty acid synthase, 2 PTP1B targets, provided a possible explanation for the lipogenic effect of PTP1B due to the manipulation of dietary Se. We therefore conclude that redox-regulated proteins, such as PTP1B, represent important interfaces between dietary antioxidants such as Se and the regulation of metabolic processes.

  9. Auranofin disrupts selenium metabolism in Clostridium difficile by forming a stable Au-Se adduct.

    PubMed

    Jackson-Rosario, Sarah; Cowart, Darin; Myers, Andrew; Tarrien, Rebecca; Levine, Rodney L; Scott, Robert A; Self, William Thomas

    2009-05-01

    Clostridium difficile is a nosocomial pathogen whose incidence and importance are on the rise. Previous work in our laboratory characterized the central role of selenoenzyme-dependent Stickland reactions in C. difficile metabolism. In this work we have identified, using mass spectrometry, a stable complex formed upon reaction of auranofin (a gold-containing drug) with selenide in vitro. X-ray absorption spectroscopy supports the structure that we proposed on the basis of mass-spectrometric data. Auranofin potently inhibits the growth of C. difficile but does not similarly affect other clostridia that do not utilize selenoproteins to obtain energy. Moreover, auranofin inhibits the incorporation of radioisotope selenium ((75)Se) in selenoproteins in both Escherichia coli, the prokaryotic model for selenoprotein synthesis, and C. difficile without impacting total protein synthesis. Auranofin blocks the uptake of selenium and results in the accumulation of the auranofin-selenide adduct in the culture medium. Addition of selenium in the form of selenite or L-selenocysteine to the growth medium significantly reduces the inhibitory action of auranofin on the growth of C. difficile. On the basis of these results, we propose that formation of this complex and the subsequent deficiency in available selenium for selenoprotein synthesis is the mechanism by which auranofin inhibits C. difficile growth. This study demonstrates that targeting selenium metabolism provides a new avenue for antimicrobial development against C. difficile and other selenium-dependent pathogens.

  10. Influence of dietary fat and selenium fed during initiation or promotion on the development of preneoplastic lesions in rat liver

    SciTech Connect

    Baldwin, S.; Parker, R.S.

    1986-03-05

    Aflatoxin B/sub 1/ (AFB1)-induced ..gamma..-glutamyl transpeptidase (GGT)-positive foci in rat liver were assessed in animals fed different levels of fat and selenium (Se) during either initiation (IN) or promotion (PR). Male Sprague Dawley rats (50g) were divided into 12 groups. One of six modified AIN-76 experimental diets were fed to groups 1-6 during weeks 1-4.5 (IN) and to groups 7-12 during weeks 4.5-15 (PR). During weeks 3-4, 13 rats/group received 10 daily doses of AFB1 (.4 mg/kg bwt/dose, i.g.). Two levels of corn oil (2% and 20%) were fed, each containing 3 levels of Se: < 0.02; 0.15; 2.5 (IN) or 1.9 (PR) ppm. When not fed the experimental diets rats were fed a standard AIN-76 diet. In groups 1-6, 0.03% phenobarbital was added to the standard diet. At week 15 rats were sacrificed. Compared to all low-fat groups, the high-fat diets with either < 0.02 or 0.15 ppm Se fed during IN resulted in a marked increase in mean diameter of GGT-positive foci and % liver section occupied by foci. In rats fed high-fat 2.5 ppm Se, preneoplastic development was decreased below all low-fat groups. During PR, Se status but not dietary fat level influenced foci formation. Rats fed < 0.02 ppm Se had greater mean diameter of foci and % section occupied by foci than either 0.15 or 1.9 ppm Se. Thus, an interaction was observed between dietary fat and selenium during IN, but not during PR.

  11. Structural and Spectral Features of Selenium Nanospheres Produced by Se-Respiring Bacteria

    USGS Publications Warehouse

    Oremland, R.S.; Herbel, M.J.; Blum, J.S.; Langley, S.; Beveridge, T.J.; Ajayan, P.M.; Sutto, T.; Ellis, A.V.; Curran, S.

    2004-01-01

    Certain anaerobic bacteria respire toxic selenium oxyanions and in doing so produce extracellular accumulations of elemental selenium [Se(0)]. We examined three physiologically and phylogenetically diverse species of selenate- and selenite-respiring bacteria, Sulfurospirillum barnesii, Bacillus selenitireducens, and Selenihalanaerobacter shriftii, for the occurrence of this phenomenon. When grown with selenium oxyanions as the electron acceptor, all of these organisms formed extracellular granules consisting of stable, uniform nanospheres (diameter, ???300 nm) of Se(0) having monoclinic crystalline structures. Intracellular packets of Se(0) were also noted. The number of intracellular Se(0) packets could be reduced by first growing cells with nitrate as the electron acceptor and then adding selenite ions to washed suspensions of the nitrate-grown cells. This resulted in the formation of primarily extracellular Se nanospheres. After harvesting and cleansing of cellular debris, we observed large differences in the optical properties (UV-visible absorption and Raman spectra) of purified extracellular nanospheres produced in this manner by the three different bacterial species. The spectral properties in turn differed substantially from those of amorphous Se(0) formed by chemical oxidation of H2Se and of black, vitreous Se(0) formed chemically by reduction of selenite with ascorbate. The microbial synthesis of Se(0) nanospheres results in unique, complex, compacted nanostructural arrangements of Se atoms. These arrangements probably reflect a diversity of enzymes involved in the dissimilatory reduction that are subtly different in different microbes. Remarkably, these conditions cannot be achieved by current methods of chemical synthesis.

  12. Dietary Selenium Levels Affect Selenoprotein Expression and Support the Interferon-γ and IL-6 Immune Response Pathways in Mice

    PubMed Central

    Tsuji, Petra A.; Carlson, Bradley A.; Anderson, Christine B.; Seifried, Harold E.; Hatfield, Dolph L.; Howard, Michael T.

    2015-01-01

    Selenium is an essential element that is required to support a number of cellular functions and biochemical pathways. The objective of this study was to examine the effects of reduced dietary selenium levels on gene expression to assess changes in expression of non-selenoprotein genes that may contribute to the physiological consequences of selenium deficiency. Mice were fed diets that were either deficient in selenium or supplemented with selenium in the form of sodium selenite for six weeks. Differences in liver mRNA expression and translation were measured using a combination of ribosome profiling, RNA-Seq, microarrays, and qPCR. Expression levels and translation of mRNAs encoding stress-related selenoproteins were shown to be up-regulated by increased selenium status, as were genes involved in inflammation and response to interferon-γ. Changes in serum cytokine levels were measured which confirmed that interferon-γ, as well as IL-6, were increased in selenium adequate mice. Finally, microarray and qPCR analysis of lung tissue demonstrated that the selenium effects on immune function are not limited to liver. These data are consistent with previous reports indicating that adequate selenium levels can support beneficial immune responses, and further identify the IL-6 and interferon-γ pathways as being responsive to dietary selenium intake. PMID:26258789

  13. Dietary Selenium Levels Affect Selenoprotein Expression and Support the Interferon-γ and IL-6 Immune Response Pathways in Mice.

    PubMed

    Tsuji, Petra A; Carlson, Bradley A; Anderson, Christine B; Seifried, Harold E; Hatfield, Dolph L; Howard, Michael T

    2015-08-06

    Selenium is an essential element that is required to support a number of cellular functions and biochemical pathways. The objective of this study was to examine the effects of reduced dietary selenium levels on gene expression to assess changes in expression of non-selenoprotein genes that may contribute to the physiological consequences of selenium deficiency. Mice were fed diets that were either deficient in selenium or supplemented with selenium in the form of sodium selenite for six weeks. Differences in liver mRNA expression and translation were measured using a combination of ribosome profiling, RNA-Seq, microarrays, and qPCR. Expression levels and translation of mRNAs encoding stress-related selenoproteins were shown to be up-regulated by increased selenium status, as were genes involved in inflammation and response to interferon-γ. Changes in serum cytokine levels were measured which confirmed that interferon-γ, as well as IL-6, were increased in selenium adequate mice. Finally, microarray and qPCR analysis of lung tissue demonstrated that the selenium effects on immune function are not limited to liver. These data are consistent with previous reports indicating that adequate selenium levels can support beneficial immune responses, and further identify the IL-6 and interferon-γ pathways as being responsive to dietary selenium intake.

  14. Long-term selenium biofortification in carrots and broccoli grown in soils amended with Se-enriched S. pinnata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) biofortification has been practiced in Se-deficient regions throughout the world primarily by adding inorganic sources of Se to the soil. Adding organic sources of Se could be useful as an alternative Se amendment for the production of Se-biofortified food crops needed in Se-deficient ...

  15. Opposing impacts on healthspan and longevity by limiting dietary selenium in Telomere Dysfunctional mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) is an essential trace element essential for optimal health. We investigated the role of Se in longevity and healthspan in a mouse model of healthy aging in humans with short telomeres. Telomere shortening is associated with aging, mortality and aging-related diseases. We found that whi...

  16. Regulation of Selenocysteine Content of Human Selenoprotein P by Dietary Selenium and Insertion of Cysteine in Place of Selenocysteine.

    PubMed

    Turanov, Anton A; Everley, Robert A; Hybsier, Sandra; Renko, Kostja; Schomburg, Lutz; Gygi, Steven P; Hatfield, Dolph L; Gladyshev, Vadim N

    2015-01-01

    Selenoproteins are a unique group of proteins that contain selenium in the form of selenocysteine (Sec) co-translationally inserted in response to a UGA codon with the help of cis- and trans-acting factors. Mammalian selenoproteins contain single Sec residues, with the exception of selenoprotein P (SelP) that has 7-15 Sec residues depending on species. Assessing an individual's selenium status is important under various pathological conditions, which requires a reliable selenium biomarker. Due to a key role in organismal selenium homeostasis, high Sec content, regulation by dietary selenium, and availability of robust assays in human plasma, SelP has emerged as a major biomarker of selenium status. Here, we found that Cys is present in various Sec positions in human SelP. Treatment of cells expressing SelP with thiophosphate, an analog of the selenium donor for Sec synthesis, led to a nearly complete replacement of Sec with Cys, whereas supplementation of cells with selenium supported Sec insertion. SelP isolated directly from human plasma had up to 8% Cys inserted in place of Sec, depending on the Sec position. These findings suggest that a change in selenium status may be reflected in both SelP concentration and its Sec content, and that availability of the SelP-derived selenium for selenoprotein synthesis may be overestimated under conditions of low selenium status due to replacement of Sec with Cys.

  17. Effect of dietary vitamin E or selenium on prostaglandin dehydrogenase in hyperoxic rat lung

    NASA Technical Reports Server (NTRS)

    North, L. N.; Mathias, M. M.; Schatte, C. L.

    1984-01-01

    Weanling male rats were fed semipurified diets supplemented with 0, 60, or 600 IU/kg vitamin E or 0, 100, or 1000 ppb selenium. One group was injected daily with vitamin E at a rate equivalent to consumption of 60 IU/kg. Animals from all groups were sacrificed after exposure to normobaric oxygen or air for 48 h. Lung tissue was analyzed for the combined activity of prostaglandin dehydrogenase and reductase. Using the decline in enzyme activity as an indicator of susceptibility to oxygen poisoning, protection against hyperoxia was directly related to the level of vitamin E supplementation. Selenium supplemented at 100 ppb provided significant protection when compared to 0 ppb or 1000 ppb. The latter dose may have been marginally toxic. Thus dietary supplementation of vitamin E and selenium may influence the relative susceptibility of an animal to pulmonary oxygen poisoning.

  18. Effects of Dietary Selenium and Vitamin E on Growth Performance, Meat Yield, and Selenium Content and Lipid Oxidation of Breast Meat of Broilers Reared Under Heat Stress.

    PubMed

    Habibian, Mahmood; Ghazi, Shahab; Moeini, Mohammad Mehdi

    2016-01-01

    This study was conducted using 360 broiler chickens to evaluate the effects of dietary vitamin E (0, 125, and 250 mg/kg), selenium (0, 0.5, and 1 mg/kg), or their different combinations on performance, meat yield, and selenium content and lipid oxidation of breast meat of broilers raised under either a thermoneutral (TN, 24 °C constant) or heat stress (HS, 24 to 37 °C cycling) condition. There was a reduction (P < 0.05) in body weight and feed intake and an increase (P < 0.05) in feed conversion ratio when broilers exposed to HS. In the overall period of the study (1 to 49 days), growth performance of TN broilers was not affected (P < 0.05) by vitamin E and selenium supplementation. However, under HS condition, broilers receiving 250 mg/kg vitamin E and 0.5 mg/kg selenium consumed more (P < 0.05) feed than that of broilers receiving 250 mg/kg vitamin E alone, but similar (P > 0.05) to that of broilers receiving 250 mg/kg vitamin E and 1 mg/kg selenium. The malondialdehyde (MDA) content of the breast meat was increased (P < 0.05), but its selenium content was decreased (P < 0.05) by exposure to HS. The breast meat selenium content was increased (P < 0.05) by selenium supplementation. The breast meat selenium content was decreased (P < 0.05) by supplementation of 250 mg/kg vitamin E to diet of TN birds. However, the breast meat selenium content was increased (P < 0.05) by supplementation of vitamin E under HS condition. The breast meat MDA content was not affected (P > 0.05) by dietary treatments under TN condition. However, the breast meat MDA content was decreased (P < 0.05) by both vitamin E and selenium supplementation under HS condition, and the lowest MDA content was observed in the breast meat of broilers receiving combination of 125 mg/kg vitamin E and 1 mg/kg selenium. The results showed that supplementation of selenium and vitamin E was capable of increasing the selenium content of the breast meat and could improve the lipid

  19. Is hepatic oxidative stress a main driver of dietary selenium toxicity in white sturgeon (Acipenser transmontanus)?

    PubMed

    Zee, Jenna; Patterson, Sarah; Wiseman, Steve; Hecker, Markus

    2016-11-01

    Most species of sturgeon have experienced significant population declines and poor recruitment over the past decades, leading many, including white sturgeon (Acipenser transmontanus), to be listed as endangered. Reasons for these declines are not yet fully understood but benthic lifestyle, longevity, and delayed sexual maturation likely render sturgeon particularly susceptible to factors such as habitat alteration and contaminant exposures. One contaminant of particular concern to white sturgeon is selenium (Se), especially in its more bioavailable form selenomethionine (SeMet), as it is known to efficiently bioaccumulate in prey items of this species. Studies have shown white sturgeon to be among the most sensitive species of fish to dietary SeMet as well as other pollutants such as metals, dioxin-like chemicals and endocrine disrupters. One of the primary hypothesized mechanisms of toxicity of SeMet in fish is oxidative stress; however, little is know about the specific mode by which SeMet affects the health of white sturgeon. Therefore, the aim of this study was to characterize oxidative stress and associated antioxidant responses as a molecular event of toxicity, and to link it with the pathological effects observed previously. Specifically, three-year-old white sturgeon were exposed for 72 days via their diet to 1.4, 5.6, 22.4 or 104.4µg Se per g feed (dm). Doses were chosen to range over a necessary Se intake level, current environmentally relevant intakes and an intake representing predicted increases of Se release. Lipid hydroperoxides, which are end products of lipid oxidation, were quantified as a marker of oxidative stress. Changes in gene expression of glutathione peroxidase (GPx), superoxide dismutase, catalase, glutathione S-transferase, apoptosis inducing factor and caspase 3 were quantified as markers of the response to oxidative stress. Concentrations of lipid hydroperoxides were highly variable within dose groups and no dose response was observed

  20. Selenium biofortification of broccoli and carrots grown in soil amended with Se-enriched hyperaccumulator Stanleya pinnata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Amending soils with Se-hyperaccumulator plant derived sources of selenium (Se) may be useful for increasing Se content in food crops in Se-deficient regions of the world. In this study, we evaluated total Se and the different chemical species of Se in broccoli and carrots grown in soils amended with...

  1. Selenium speciation in soil and rice: influence of water management and Se fertilization.

    PubMed

    Li, Hua-Fen; Lombi, Enzo; Stroud, Jacqueline L; McGrath, Steve P; Zhao, Fang-Jie

    2010-11-24

    Rice (Oryza sativa) is the staple food for half of the world's population, but the selenium (Se) concentrations in rice grain are low in many rice-growing regions. This study investigated the effects of water management on the Se speciation dynamics in the soil solution and Se uptake and speciation in rice in a pot experiment. A control containing no Se or 0.5 mg kg(-1) of soil of selenite or selenate was added to the soil, and plants were grown under aerobic or flooded conditions. Flooding soil increased soluble Se concentration when no Se or selenite was added to the soil, but decreased it markedly when selenate was added. Selenate was the main species in the +selenate treatment, whereas selenite and selenomethionine selenium oxide were detected in the flooded soil solutions of the control and +selenite treatments. Grain Se concentration was 49% higher in the flooded than in the aerobic treatments without Se addition. In contrast, when selenate or selenite was added, the aerobically grown rice contained 25- and 2-fold, respectively, more Se in grain than the anaerobically grown rice. Analysis of Se in rice grain using enzymatic hydrolysis followed by HPLC-ICP-MS and in situ X-ray absorption near-edge structure (XANES) showed selenomethionine to be the predominant Se species. The study showed that selenate addition to aerobic soil was the most effective way to increase Se concentration in rice grain.

  2. Simple synthesis of luminescent CdSe quantum dots from ascorbic acid and selenium dioxide.

    PubMed

    Wang, Yilin; Yu, Meihua; Yang, Kun; Lu, Jianping; Chen, Linqing

    2015-12-01

    A simple, low-cost and convenient method was developed for the synthesis of highly luminescent CdSe quantum dots (QDs) in an aqueous medium. Compared with previous methods, this synthesis was carried out in one pot using ascorbic acid (C6H8O6) to replace NaBH4 or N2H4·H2O as a reductant, and selenium dioxide to replace selenium or its other hazardous, expensive and unstable compounds as a precursor. The mechanism of CdSe QDs formation was elucidated. The influence of various experimental variables, including refluxing time, Cd/MSA and Cd/Se molar ratios, on the luminescent properties of the QDs were systematically investigated. X-Ray powder diffraction and transmission electron microscopy characterization indicated that the QDs had a pure cubic zinc-blended structure with a spherical shape.

  3. Prolonged Dietary Selenium Deficiency or Excess Does Not Globally Affect Selenoprotein Gene Expression and/or Protein Production in Various Tissues of Pigs123

    PubMed Central

    Liu, Yan; Zhao, Hua; Zhang, Qiaoshan; Tang, Jiayong; Li, Ke; Xia, Xin-Jie; Wang, Kang-Ning; Li, Kui; Lei, Xin Gen

    2012-01-01

    We previously determined the effects of dietary selenium (Se) deficiency or excess on mRNA abundance of 12 selenoprotein genes in pig tissues. In this study, we determined the effect of dietary Se on mRNA levels of the remaining porcine selenoprotein genes along with protein production of 4 selenoproteins (Gpx1, Sepp1, Selh, and Sels) and body glucose homeostasis. Weanling male pigs (n = 24) were fed a Se-deficient (<0.02 mg Se/kg), basal diet supplemented with 0, 0.3, or 3.0 mg Se/kg as Se-enriched yeast (Angel Yeast) for 16 wk. Although mRNA abundance of the 13 selenoproteins in 10 tissues responded to dietary Se in 3 patterns, there was no common regulation for any given gene across all tissues or for any given tissue across all genes. Dietary Se affected (P < 0.05) 2, 3, 3, 5, 6, 7, 7, and 8 selenoprotein genes in muscle, hypothalamus, liver, kidney, heart, spleen, thyroid, and pituitary, respectively. Protein abundance of Gpx1, Sepp1, Selh, and Sels in 6 tissues was regulated (P < 0.05) by dietary Se concentrations in 3 ways. Compared with those fed 0.3 mg Se/kg, pigs fed 3.0 mg Se/kg became hyperinsulinemic (P < 0.05) and had lower (P < 0.05) tissue levels of serine/threonine protein kinase. In conclusion, dietary Se exerted no global regulation of gene transcripts or protein levels of individual selenoproteins across porcine tissues. Pigs may be a good model for studying mechanisms related to the potential prodiabetic risk of high-Se intake in humans. PMID:22739382

  4. Graphitic Nanocarbon-Selenium Cathode with Favorable Rate Capability for Li-Se Batteries.

    PubMed

    Zhang, Shuai-Feng; Wang, Wen-Peng; Xin, Sen; Ye, Huan; Yin, Ya-Xia; Guo, Yu-Guo

    2017-03-15

    A well-organized selenium/carbon nanosheets nanocomposite(Se/CNSs) is prepared by confining chain-like Sen molecules in hierarchically micromesoporous carbon nanosheets. A unique two-dimensional morphology and high graphitization degree of carbon nanosheets benefits fast Li(+)/e(-) access to the active Se, which guarantees a high utilization of Se during the(de)lithiation process. Besides, the chain-like Se molecules confined in the carbon matrix could alleviate the shuttle effect of polyselenides and promise a stable electrochemistry. Therefore, the resultant Se/CNSs delivers a highly reversible capacity, a long cycle life and favorable rate capabilities. Furthermore, a Li-Se pouch cell built from a metallic Li anode and the as-prepared Se/CNSs cathode exhibits an excellent electrochemical performance, demonstrating the potential of Se/CNSs in serving future energy storage devices with high energy density.

  5. Selenium and selenoprotein deficiencies induce widespread pyogranuloma formation in mice, while high levels of dietary selenium decrease liver tumor size driven by TGFa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changes in dietary selenium and selenoprotein status may influence both anti- and pro-cancer pathways, making the outcome of interventions different from one study to another. To characterize such outcomes in a defined setting, we undertook a controlled hepatocarcinogenesis study involving varying l...

  6. A dietary assessment of selenium risk to aquatic birds on a coal mine affected stream in Alberta, Canada

    SciTech Connect

    Wayland, M.; Casey, R.; Woodsworth, E.

    2007-07-15

    In this article, we present the results of a dietary-based assessment of the risk that selenium may pose to two aquatic bird species, the American Dipper (Cinclus mexicanus) and the Harlequin Duck (Histrionicus histrionicus), on one of the coal mine-affected streams, the Gregg River. The study consisted of (1) a literature-based toxicity assessment, (2) simulation of selenium exposure in the diets and eggs of the two species, and (3) a risk assessment that coupled information on toxicity and exposure. Diet and egg selenium concentrations associated with a 20% hatch failure rate were 6.4 and 17 {mu} g {center_dot} g{sup -1} dry wt, respectively. Simulated dietary selenium concentrations were about 2.0-2.5 {mu} g {center_dot} g{sup -1} higher on the Gregg River than on reference streams for both species. When simulated dietary concentrations were considered, hatch failure rates on the Gregg River were predicted to average 12% higher in American Dippers and 8% higher in Harlequin Ducks than at reference streams. Corresponding values were only 3% for both species when predicted egg concentrations were used. Elevated levels of selenium in insects in some of the reference streams were unexpected and raised a question as to whether aquatic birds have evolved a higher tolerance level for dietary selenium in these areas.

  7. Thermodynamic assessment of the palladium-selenium (Pd-Se) system

    NASA Astrophysics Data System (ADS)

    Bordier, S.; Chocard, A.; Gossé, S.

    2014-08-01

    Palladium and selenium are fission products produced in the nuclear fuel under irradiation. To better understand the high temperature thermochemistry of these elements, the Pd-Se phase diagram was assessed using the Calphad method. The Pd-Se binary description was optimized using thermodynamic and phase diagram data from the literature and some DTA experiments performed in this work. The calculated phase diagram and thermodynamic properties are consistent with the experimental results in the whole Pd-Se composition range.

  8. Chromatographic separation of selenium and arsenic: A potential (72)Se/(72)As generator.

    PubMed

    Wycoff, Donald E; Gott, Matthew D; DeGraffenreid, Anthony J; Morrow, Ryan P; Sisay, Nebiat; Embree, Mary F; Ballard, Beau; Fassbender, Michael E; Cutler, Cathy S; Ketring, Alan R; Jurisson, Silvia S

    2014-05-02

    An anion exchange method was developed to separate selenium and arsenic for potential utility in a (72)Se/(72)As generator. The separation of the daughter (72)As from the (72)Se parent is based on the relative acid-base behavior of the two oxo-anions in their highest oxidation states. At pH 1.5, selenate is retained on strongly basic anion exchange resin as HSeO4(-) and SeO4(2-), while neutral arsenic acid, H3AsO4, is eluted.

  9. Chromatographic Separation of Selenium and Arsenic: A Potential 72Se/72As Generator

    PubMed Central

    Wycoff, Donald E.; Gott, Matthew D.; DeGraffenreid, Anthony J.; Morrow, Ryan P.; Sisay, Nebiat; Embree, Mary F.; Ballard, Beau; Fassbender, Michael E.; Cutler, Cathy S.; Ketring, Alan R.; Jurisson, Silvia S.

    2014-01-01

    Summary An anion exchange method was developed to separate selenium and arsenic for potential utility in a 72Se/72As generator. The separation of the daughter 72As from the 72Se parent is based on the relative acid-base behavior of the two oxo-anions in their highest oxidation states. At pH 1.5, selenate is retained on strongly basic anion exchange resin as HSeO4− and SeO42−, while neutral arsenic acid, H3AsO4, is eluted. PMID:24679827

  10. Safety evaluation of Se-methylselenocysteine as nutritional selenium supplement: acute toxicity, genotoxicity and subchronic toxicity.

    PubMed

    Yang, Hui; Jia, Xudong

    2014-12-01

    The significant toxicity of selenium emphasizes the need to assess the health risk of various selenocompounds as nutritional supplements. Se-methylselenocysteine (SeMC) was recently reported to be more bioactive but the toxicological effects have not been sufficiently characterized. This study aimed to evaluate the safety of SeMC and provide the Acceptable Daily Intake (ADI) for its use in human diet. Our results demonstrated that SeMC, with the Median Lethal Dose (LD50) of 12.6 and 9.26mg/kg BW in female and male mice, was of high potent of health hazard under acute oral exposure, but a battery of tests including Ames test, micronucleus assay and mouse sperm malformation assay suggested that SeMC was not genotoxic. The repeated dose study indicated little systemic toxicity of SeMC at supernutritional levels (0.5, 0.7, 0.9mg/kg BW/day) after 90-day oral exposure. Importantly, the 95% lower confidence value of Benchmark Dose (BMDL) was estimated as 0.34mg/kg BW/day according to the elevated relative liver weight. The ADI for human was established at 3.4μg/kg BW/day. The results suggested greater safety of SeMC as a nutritional selenium supplement, but health risk needs to be further evaluated when SeMC is applied beyond this level to achieve cancer chemoprevention.

  11. Extraordinarily High Leaf Selenium to Sulfur Ratios Define ‘Se-accumulator’ Plants

    PubMed Central

    White, Philip J.; Bowen, Helen C.; Marshall, Bruce; Broadley, Martin R.

    2007-01-01

    Background and Aims Selenium (Se) and sulfur (S) exhibit similar chemical properties. In flowering plants (angiosperms) selenate and sulfate are acquired and assimilated by common transport and metabolic pathways. It is hypothesized that most angiosperm species show little or no discrimination in the accumulation of Se and S in leaves when their roots are supplied a mixture of selenate and sulfate, but some, termed Se-accumulator plants, selectively accumulate Se in preference to S under these conditions. Methods This paper surveys Se and S accumulation in leaves of 39 angiosperm species, chosen to represent the range of plant Se accumulation phenotypes, grown hydroponically under identical conditions. Results The data show that, when supplied a mixture of selenate and sulfate: (1) plant species differ in both their leaf Se ([Se]leaf) and leaf S ([S]leaf) concentrations; (2) most angiosperms show little discrimination for the accumulation of Se and S in their leaves and, in non-accumulator plants, [Se]leaf and [S]leaf are highly correlated; (3) [Se]leaf in Se-accumulator plants is significantly greater than in other angiosperms, but [S]leaf, although high, is within the range expected for angiosperms in general; and (4) the Se/S quotient in leaves of Se-accumulator plants is significantly higher than in leaves of other angiosperms. Conclusion The traits of extraordinarily high [Se]leaf and leaf Se/S quotients define the distinct elemental composition of Se-accumulator plants. PMID:17525099

  12. Effect of dietary. beta. -carotene, vitamin A and selenium on formation of preneoplastic lesions in rat liver

    SciTech Connect

    Colford, J.; Parker, R.S.

    1986-03-05

    The effect of dietary ..beta..-carotene (BC), retinyl acetate (RA) and sodium selenite on formation of ..gamma..-glutamyltranspeptidase-positive foci in rat liver was investigated. Male Sprague-Dawley rats, 50g, were fed for 16 wks semipurified diets supplemented with either BC (500 mg/kg diet), RA (6400 IU/kg diet for wks 1-7 and 10,000 IU/kg for wks 8-16), 1.8 ppm selenium (Se) or both 1.8 ppm Se and 500 mg/kg BC. The control diet contained 0.1 ppm Se and 3200 IU RA/kg diet. During wks 3-4 rats received 10 intragastric doses of aflatoxin B/sub 1/ (0.4 mg/kg body weight/dose). Preneoplastic foci were quantitated at wk 16. Diet had no significant effect on growth rate or food consumption. None of the treatments resulted in significant differences in the number of foci per cm/sup 2/ liver section, but differences in focal size occurred. RA increased total focal area (mm/sup 2//cm/sup 2/ liver), while Se decreased focal area 5-fold. BC slightly decreased focal area. The combination of BC and Se was not as effective as Se alone. BC, RA, and BC-Se diets yielded equivalent levels of total liver retinol, which exceeded levels in control and Se rats by 30-fold. Livers from BC fed rats contained 4-5 ..mu..g BC/g liver. The different effects of dietary RA and BC on focal development may indicate a role for BC other than as a retinol precursor. The influence of each nutrient on focal size, but not number, implies they act during the post-initiation stage of focal development.

  13. Influences of intraperitoneally and dietary administered vitamin E and selenium on the lipid composition in reproductive organs of male animals.

    PubMed

    Yilmaz, O; Celik, S; Dilsiz, N

    1997-05-01

    The aim of this work was to determine the protective effect of intraperitoneally and dietary administered vitamin E and selenium (Se) on the total lipid, cholesterol, and fatty acid composition in rat and lamb testes. The level of total lipid in rat testes was significantly decreased (p < 0.001) in the combination group as compared to the control group but slightly decreased in lamb testes (p < 0.05). In addition, the level of total lipid in lamb testes was significantly decreased (p < 0.001) by the Se alone. The content of total cholesterol in rats was higher in the Se group and its level in lamb testes was higher in the vitamin E groups than in the control group (p < 0.001). In rats testes, the amounts of palmitic, oleic, arachidonic acids, the total fatty acid, total unsaturated and total omega 6 acids were higher (p < 0.001) in the Se group. The proportions of palmitic and arachidonic acids were reduced in the vitamin E group and linoleic acid, total unsaturated, and total omega 6 fatty acids were high (p < 0.05) in the vitamin E and combination groups. In lamb testis tissues, the amounts of palmitic, arachidonic, total unsaturated and total omega 6 fatty acids were decreased in the vitamin E group in comparison to the control (p < 0.05). However, the amounts of arachidonic and total omega 6 fatty acids increased (p < 0.05) in the Se group. The proportions of arachidonic acid, total unsaturated fatty acid and total omega 6 fatty acids were high (p < 0.05) in the Se and combination groups. We concluded that the level of total lipid in testis tissues was reduced by dietary and intraperitoneally administered vitamin E and Se together. In contrast, it seems that the proportions of unsaturated and essential fatty acids in examined tissues are increased by vitamin E and Se.

  14. Theory for ^77Se and ^125Te Nuclear Quadrupole Interactions in Selenium and Tellurium.

    NASA Astrophysics Data System (ADS)

    Suck-Cho, Hwa; Oh, Young-Kee; Park, Jin-Ho; Das, T. P.

    1998-03-01

    The electric field gradient(efg) tensors at ^77Se and ^125Te nuclei have been studied for the four systems involving each of these nuclei in both Selenium and Tellurium crystals utilizing the first principles Hartee-Fock Cluster procedure. Using the calculated efg for the pure systems and the experimental quadrupole coupling constants (e^2qQ), the quadrupole moments are determined to be Q(^77Se)=0.74±0,07(b) and Q(^125Te)=0.35±0.04(b). Comparison will be made with earlier values for the Q of the two nuclei. Using our values of Q and the calculated efg for ^77Se in tellurium and ^125Te in selenium, our values of e^2qQ agree within 15 per cent with that of experiment. The asymmetry parametrs η also agree reasonably well with experiment, but not as closely as the e^2qQ. Experimental results for η for ^125Te in selenium are needed to compare with theory.

  15. Selenium speciation in Lower Cambrian Se-enriched strata in South China and its geological implications

    NASA Astrophysics Data System (ADS)

    Fan, Haifeng; Wen, Hanjie; Hu, Ruizhong; Zhao, Hui

    2011-12-01

    To understand the impact of Selenium (Se) into the biogeochemical cycle and implications for palaeo-redox environment, a sequential extraction method was utilized for samples including black shales, cherts, a Ni-Mo-Se sulfide layer, K-bentonite and phosphorite from Lower Cambrian Se-enriched strata in southern China. Seven species (water-soluble, phosphate exchangeable, base-soluble, acetic acid-soluble, sulfide/selenide associated, residual Se) and different oxidation states (selenate Se(VI), selenite Se(IV), organic Se, Se (0) and mineral Se(-II)) were determinated in this study. We found that the Ni-Mo-Se sulfide layer contained a significantly greater amount of Se(-II) associated with sulfides/selenides than those in host black shales and cherts. Furthermore, a positive correlation between the degree of sulfidation of iron (DOS) and the percentage of the sulfide/selenide-associated Se(-II) was observed for samples, which suggests the proportion of sulfide/selenide-associated Se(-II) could serve as a proxy for palaeo-redox conditions. In addition, the higher percentage of Se(IV) in K-bentonite and phosphorite was found and possibly attributed to the adsorption of Se by clay minerals, iron hydroxide surfaces and organic particles. Based on the negative correlations between the percentage of Se(IV) and that of Se(-II) in samples, we propose that the K-bentonite has been altered under the acid oxic conditions, and the most of black shale (and cherts) and the Ni-Mo-Se sulfide layer formed under the anoxic and euxinic environments, respectively. Concerning Se accumulation in the Ni-Mo-Se sulfide layer, the major mechanism can be described by (1) biotic and abiotic adsorption and further dissimilatory reduction from oxidized Se(VI) and Se(IV) to Se(-II), through elemental Se, (2) contribution of hydrothermal fluid with mineral Se(-II).

  16. Effects of dietary selenium on differentiation, morphology and functions of spermatozoa of the house rat, Rattus rattus L.

    PubMed

    Kaur, R; Parshad, V R

    1994-08-01

    Ingestion of 2 ppm and 4 ppm selenium in the diet by the house rat, Rattus rattus, for 5 weeks caused a dose-dependent reduction in its body weight, testicular and cauda epididymidis weights, concentration, motility and percentage of live spermatozoa with a simultaneous increase in the percentage of their abnormal forms. Compared to 1.39% abnormal spermatozoa in cauda epididymidis in untreated control rats, 3.89% and 24.64% abnormal spermatozoa were observed in rats with 2 ppm and 4 ppm dietary selenium respectively. Ingestion of 4 ppm selenium had no significant effect on abnormalities of the head and neck regions but abnormalities of the midpiece region and multiple abnormalities increased significantly. Analysis of the various stages of differentiation of spermatids in the testis has revealed that with 4 ppm dietary selenium, the abnormalities are induced mainly in the midpiece region of the flagellum which is a site of energy production.

  17. Effects of dietary selenium exposure in captive American common eiders

    USGS Publications Warehouse

    Franson, J.C.; Hoffman, D.J.; Wells-Berlin, A. M.; Perry, M.C.; Bochsler, V.S.; Finley, D.L.; Flint, P.L.; Hollmen, T.

    2005-01-01

    We conducted two studies of Se exposure in captive common eiders (Somateria mollissima). In Study 1, eiders were fed diets with added Se (as L-selenomethionine) in concentrations increasing from 10 ppm to 80 ppm. In Study 2, eiders received control, low exposure (20 ppm Se), and high exposure (60 ppm Se) diets. One duck in the high exposure group in Study 2 died after 36 days. Remaining high exposure ducks in Study 2 and ducks in Study 1 were euthanized after losing 25-30% of their body weight, which occurred after 41 days and 60-78 days, respectively. Body weights did not differ between control and low exposure ducks in Study 2. At the end of Study 1, the mean Se concentration in blood was 32 ppm wet weight (ww). In Study 2, mean blood Se reached 14 ppm ww in the low exposure group and 17 ppm ww in high exposure ducks. Mean Se concentrations in liver were 1252 ppm dry weight (dw) in Study 1, and 351 and 735 ppm dw, respectively, in the low and high exposure groups of Study 2. Oxidative stress was evidenced by Se-associated effects on glutathione metabolism, but not entirely in the same manner as with previous laboratory studies in mallards. In plasma, activities of total and Se-dependent glutathione peroxidase increased with time. As Se concentrations in liver increased, Se-dependent glutathione peroxidase, glutathione reductase, oxidized glutathione, and the ratio of hepatic oxidized to reduced glutathione increased. Total and protein bound sulfhydryl concentrations, reduced glutathione, glutathione-S-transferase, and glucose-6-phosphate dehydrogenase in liver were negatively correlated with Se concentrations in the liver. In Study 2, spleen weights were significantly lower in ducks receiving 60 ppm Se than in those receiving 20 ppm. Gross lesions associated with high Se exposure included emaciation, absence of thymus, loss of nails from digits, and alopecia. Microscopic lesions included severe depletion of lymphoid organs, hepatopathy, and necrosis of feather

  18. Flexible one-dimensional carbon-selenium composite nanofibers with superior electrochemical performance for Li-Se/Na-Se batteries

    NASA Astrophysics Data System (ADS)

    Zeng, Linchao; Wei, Xiang; Wang, Jiaqing; Jiang, Yu; Li, Weihan; Yu, Yan

    2015-05-01

    A facile strategy is developed to synthesis selenium/carbon composites (Se@CNFs-CNT) by co-heating Se powder and electrospun Polyacrylonitrile (PAN)-CNT nanofibers at 600°Cin a sealed vessel. The Se molecules are chemically bonded and physical encapsulated by carbonized PAN-CNT composite (CNFs-CNT), which leads to prevent the dissolution of polyselenide intermediates in carbonate based electrolyte. When directly used as flexible free-standing cathode material for Li-Se batteries in low cost carbonate-based electrolyte, the Se@CNFs-CNT electrode exhibits improved cyclability (517 mAh g-1 after 500 cycles at 0.5 A g-1) and rate capability (485 mAh g-1 at 1 A g-1). Moreover, when tested as sodium batteries, it maintains a reversible capacity of 410 mAh g-1 after 240 cycles at 0.5 A g-1. The superior electrochemical performance (especially at high rates) of Se@CNFs-CNT is attributed to synergistic effect of the additive of CNT, the well confine of Se in the CNFs-CNT matrix through chemical bonding and the 3D interconnected carbon nanofibers (CNFs). This simple yet efficient process thus provides a promising route towards fabrication of a variety of high performance flexible Li-Se and Na-Se batteries.

  19. Biosynthesis of selenium rich exopolysaccharide (Se-EPS) by Pseudomonas PT-8 and characterization of its antioxidant activities.

    PubMed

    Ye, Shuhong; Zhang, Jiajia; Liu, Zhaofang; Zhang, Yu; Li, Jiang; Li, Yao Olive

    2016-05-20

    Biosynthesis of organo-selenium is achieved by submerged fermentation of selenium-tolerant Pseudomonas PT-8. The end product of metabolic process is selenium-bearing exopolysaccharide (Se-EPS), which contains a higher content of uronic acid than the exopolysaccharide (EPS) by the strain without selenium in the culture medium. Selenium content in Se-EPS reached a maximum yield of 256.7 mg/kg when using an optimized culture condition. Crude Se-EPS was purified into two fractions-a pH neutral Se-EPS-1 and an acidic Se-EPS-2. Structure and chemical composition of Se-EPS-2 were investigated by chromatographic analyses. Results showed that Se-EPS-2 was a homogenous polysaccharide with molecular weight of 7.3 kDa, consisting of monosaccharides, rhamnose, arabinose, xylose, mannose, glucose and galactose with a molar ratio of 19.58:19.28:5.97:18.99:23.70:12.48, respectively. Compared to the EPS, the content of rhamnose in Se-EPS increased and molecular weight decreased. The Se-EPS had strong scavenging actions on DPPH•, •OH and •O2(-), which is much higher than the EPS.

  20. Effect of dietary vitamin E and selenium on growth, survival and the prevalence of Renibacterium salmoninarum infection in chinook salmon (Oncorhynchus tshawytscha)

    USGS Publications Warehouse

    Thorarinsson, Ragnar; Landolt, Marsha L.; Elliott, Diane G.; Pascho, Ronald J.; Hardy, Ronald W.

    1994-01-01

    Groups of juvenile spring chinook salmon naturally infected with Renibacterium salmoninarum, the causative agent of bacterial kidney disease, were fed diets containing different levels of vitamin E and selenium for 214 days in fresh water and 110 days in seawater. The fish were fed vitamin E at concentrations of either 53±3 mg (designated e) or 299±9 mg (designated E) α-tocopheryl acetate equivalence/kg dry diet in combination with sodium selenite to give selenium concentrations of either 0.038±0.008 mg (designated s) or 2.49±0.15 mg (designated S)/kg dry diet. No mortality occurred in the group fed the SE diet, whereas mortality was 3% in the groups fed the sE and Se diets, and 31% in the group fed the se diet. At the end of the experiment, weight gain and hematocrit values were significantly greater in those fish fed the E diets compared with those fed the e diets, whereas the hepato-somatic index was significantly higher in fish fed the e diets. Glutathione peroxidase activity in blood plasma was significantly higher in fish fed the S diets compared with those fed the sdiets. No definite effect of dietary vitamin E and selenium on the prevalence and severity of natural R. salmoninarum infections was demonstrated.

  1. Dietary nano-selenium relieves hypoxia stress and, improves immunity and disease resistance in the Chinese mitten crab (Eriocheir sinensis).

    PubMed

    Qin, Fenju; Shi, Miaomiao; Yuan, Hongxia; Yuan, Linxi; Lu, Wenhao; Zhang, Jie; Tong, Jian; Song, Xuehong

    2016-07-01

    Hypoxia is a relevant physiological challenge for crab culture, and the hemolymph plays a crucial role in response to the hypoxia. In a 60 d feeding trial, Chinese mitten crabs (Eriocheir sinensis) fed a diet containing 0.2 mg/kg nano-selenium (nanoSe) showed a significantly increased weight gain rate (WGR) and a reduced feed coefficient (FC) compared to those fed diets with 0, 0.1, 0.4, 0.8, and 1.6 mg/kg nanoSe. Another 90 d feeding trial was conducted to determine the influence of dietary nanoSe on the immune response in juvenile Chinese mitten crabs kept under the condition of hypoxia. The results showed that hypoxia stress resulted in significantly increased hemocyte counts (THC, LGC, SGC, and HC), expression levels of the hemocyanin gene and protein, lactic acid level, and antioxidant capacity (T-AOC activities, SOD activities, GSH-Px and GSH content) in hemolymph supernatant. When these crabs were infected with Aeromonas hydrophila bacteria, hypoxia exposure increased mortality, but it was alleviated by a diet supplemented with 0.2 mg/kg nanoSe. The up-regulative effects of nanoSe (0.2 mg/kg) on antioxidant capacity, hemocyte counts, and hemocyanin expression under hypoxia exposure were further strengthened throughout, whereas lactic acid levels induced by hypoxia stress were restored. Thus, the observations in this study indicate that the level of dietary nanoSe is important in regulating immunity and disease resistance in crabs kept under hypoxia stress.

  2. Selenium Treatment Technologies

    EPA Science Inventory

    Selenium (Se) is a metalloid that is a dietary requirement in small quantities, but toxic at higher quantities. It also is known to bioaccumulate. In oxic environments, it exists as selenate (+6) and selenite (+4), both of which are soluble. Selenite will sorb more strongly to...

  3. Effects of dietary selenium source, storage time, and temperature on the quality of quail eggs.

    PubMed

    Baylan, Mikail; Canogullari, Sibel; Ayasan, Tugay; Copur, Gulsen

    2011-11-01

    We report the effects of time of storage, temperature, and supplementation with sodium selenite- and selenium-enriched yeast on the quality of quail eggs. For this study, 90 10-week-old female Japanese quails (Coturnix coturnix japonica) with similar body size were caged individually and randomly divided into five groups of 18 quails each. One group was fed a normal diet and served as control. A second group was supplemented with 0.2 mg/kg sodium selenite (In-Se) and three groups supplemented with 0.1, 0.2, and 0.3 mg/kg of a commercially available selenium-enriched yeast (O-Se1, O-Se2, and O-Se3, respectively). The eggs were collected at third and fourth weeks of the experiment and were stored at 4°C and 20°C for 0, 15, 30, and 45 days. Extension of the storage time to 45 days at 20°C resulted in significant deterioration of egg quality. The albumen Haugh unit (HU), pH, albumen index, yolk index, and egg weight loss were the most important parameters influenced by the nature of the selenium sources, storage time, and temperature. Storage time and temperature were also significant for egg weight loss, HU, and albumen and yolk indexes. The results show that supplementation with selenium yeast significantly affected shell weight, shell thickness, HU, albumen index, yolk index, and pH. The HU decreased with increased storage time and temperature. Higher levels of Se-yeast administration resulted in greater HU compared to the selenite and control groups.

  4. Toxicity and oxidative stress of different forms of organic selenium and dietary protein in mallard ducklings

    USGS Publications Warehouse

    Hoffman, D.J.; Heinz, G.H.; LeCaptain, L.J.; Eisemann, J.D.; Pendleton, G.W.

    1996-01-01

    Concentrations of over 100 ppm (mg/kg) selenium (Se) have been found in aquatic plants and insects associated with irrigation drainwater and toxicity to fish and wildlife. Composition of diet for wild ducklings may vary in selenium-contaminated environments. Earlier studies have compared toxicities and oxidative stress of Se as selenite to those of seleno-DL-methionine (DL) in mallards (Anas platyrhynchos). This study compares DL, seleno-L-methionine (L), selenized yeast (Y) and selenized wheat (W). Day-old mallard ducklings received an untreated diet (controls) containing 75% wheat (22% protein) or the same diet containing 15 or 30 ppm Se in the above forms except for 30 ppm Se as W. After 2 weeks blood and liver samples were collected for biochemical assays and Se analysis. All forms of selenium caused significant increases in plasma and hepatic glutathione peroxidase activities. Se as L at 30 ppm in the diet was the most toxic form, resulting in high mortality (64%) and impaired growth (>50%) in survivors and the greatest increase in ratio of oxidized to reduced hepatic glutathione (GSH). Se as both L and DL decreased the concentrations of hepatic GSH and total thiols. Se as Y accumulated the least in liver (approximately 50% of other forms) and had less effect on GSH and total thiols. In a second experiment, in which the basal diet was a commercial duck feed (22 % protein), survival was not affected by 30 ppm Se as DL, L, or Y and oxidative effects on GSH metabolism were less pronounced than with the wheat diet.

  5. Analysis of Selenium Levels in Osteosarcoma Patients and the Effects of Se-Methylselenocysteine on Osteosarcoma Cells In Vitro.

    PubMed

    Huang, Gang; Yong, Bi-cheng; Xu, Ming-hong; Li, Jing-chun; Guo, Hai-hua; Shen, Jing-nan

    2015-01-01

    The form of selenium appears to be important for preventing cancer in humans. Here, we evaluated selenium levels in the serum and bone tissue samples from osteosarcoma patients using atomic absorption spectrometry. The in vitro effects of Se-methylselenocysteine (Se-MSC) on growth, cell cycle status, and apoptosis of osteosarcoma cells were assessed using the WST-1 assay, Hoechst 33342/propidium iodide staining, and flow cytometry, respectively. In osteosarcoma cases, the mean serum selenium levels in osteosarcoma tissue and normal bone were 0.08 mg/kg and 0.03 mg/kg, respectively (P < 0.05). Serum selenium levels in osteosarcoma and non-osteosarcoma cases were 0.09 mg/L and 0.08 mg/L, respectively (P > 0.05). Se-MSC-treated MG63 cells showed altered cellular morphology, decreased viability in a time- and dose-dependent manner, and an increase in the sub-G1 cell population. Se-MSC also downregulated Bcl-2 expression and upregulated Bax. Se-MSC inhibited the proliferation of the drug-resistant osteosarcoma cell line Saos-2/MTX300 and enhanced the inhibitory effect of pirarubicin on MG63 cells. Our data demonstrate that selenium levels are significantly higher in osteosarcoma tissue than normal bone tissue in osteosarcoma patients. The results also support the anticancer effects of Se-MSC in osteosarcoma. Further development of Se-MSC as an ancillary chemotherapy agent in osteosarcoma is warranted.

  6. Environmental Selenium Transformations: Distinguishing Abiotic and Biotic Factors Influencing Se Redox Transformations

    NASA Astrophysics Data System (ADS)

    Rosenfeld, C.; Kenyon, J.; James, B. R.; Santelli, C. M.

    2014-12-01

    Worldwide, selenium (Se) is proving to be a significant environmental concern, with many anthropogenic activities (e.g. coal mining and combustion, phosphate mining and agricultural irrigation) releasing potentially hazardous concentrations into surface and subsurface ecosystems. The US EPA is currently considering aquatic Se regulations, however no guidelines exist for excess soil Se, despite its ability to act as a persistent Se source. Various abiotic and biological processes mediate Se oxidation/reduction (redox) transformations in soils, thus influencing its solubility and bioavailability. In this research we assess (1) the ability of metal-transforming fungal species to aerobically reduce Se (Se (IV and/or VI) to Se(0)), and (2) the relative contribution of biotic and abiotic pathways for aerobic Se transformation. The primary objective of this research is to determine what abiotic and biotic factors enhance or restrict Se bioavailability. Results indicate that fungal-mediated Se reduction may be quite widespread, with at least 7 out of 10 species of known Mn(II)-oxidizing fungi isolated from metal impacted environments also identified as capable of aerobically reducing Se(IV) and/or Se(VI) to Se(0). Increasing concentrations of selenite (SeO32-; Se(IV)) and selenate (SeO42-; Se(VI)) generally reduced fungal growth rates, although selenate was more likely to inhibit fungal growth than selenite. To study oxidation, Se(0) was combined with Mn(III/IV) (hydr)oxides (henceforth referred to as Mn oxides), Se-transforming fungi (Alternaria alternata), and oxalic acid to mimic Se biogeochemistry at the plant-soil interface. Increased pH in the presence of fungi (7.2 with fungi, 6.8 without fungi after 24 days) was observed. Additionally, a slight decrease in redox potential was measured for incubations without Mn oxides (236 mV with Mn oxides, 205 mV without Mn oxides after 24 days), indicating that Mn oxides may enhance Se oxidation. Elemental Se oxidation rates to

  7. Maternal selenium (Se) nutrition affects both milk Se and lipid patterns

    SciTech Connect

    Dotson, K.D.; Picciano, M.F.; Perrel, J.P.; Perkins, E.G. Univ. of Illinois, Urbana )

    1991-03-15

    In this study relationships between patterns of Se and lipid secretion in milk of women on self-selected diets were assessed. Milk samples were collected from 10 women at 4, 6 and 8 wks postpartum and blood samples at 4 to 8 wks. Milk samples were extracted and analyzed for tiacylglycerols and fatty acids. Activity of glutathione peroxidase (GSH-Px) and contents of Se in milk, plasma and erythrocytes were also measured. Two groups were found: one displaying an increase in plasma Se and the other, a decrease from 4 to 8 wks. Milk Se significantly decreased only in women whose plasma Se also decreased. Milk Se was negatively correlated with myristic and stearic acids in women whose plasma Se increased and with arachidonic, eicosapentaenoic and docosahexaenoic acids in women whose plasma Se decreased. Results of this study show that maternal Se nutrition relates not only to the quantity of Se secreted in milk but also to the quantities of individual fatty acids.

  8. Selenium Redox Reactivity on Colloidal CdSe Quantum Dot Surfaces

    PubMed Central

    2016-01-01

    Understanding the structural and compositional origins of midgap states in semiconductor nanocrystals is a longstanding challenge in nanoscience. Here, we report a broad variety of reagents useful for photochemical reduction of colloidal CdSe quantum dots, and we establish that these reactions proceed via a dark surface prereduction step prior to photoexcitation. Mechanistic studies relying on the specific properties of various reductants lead to the proposal that this surface prereduction occurs at oxidized surface selenium sites. These results demonstrate the use of small-molecule inorganic chemistries to control the physical properties of colloidal QDs and provide microscopic insights into the identities and reactivities of their localized surface species. PMID:27518320

  9. The electrical characterizations of selenium (Se) doped gallium antimony (GaSb) single crystal

    NASA Astrophysics Data System (ADS)

    Choudhari, Rashmi; Deshpande, Manisha; Maske, Dilip; Gadkari, Dattatray

    2016-05-01

    The growth of Se doped GaSb bulk crystal is carried out using Vertical directional solidification (VDS) technique. High purity Gallium and Antimony is taken as source material and selenium as doping material. From grown ingot substrate were obtained in wafer form using diamond cutter. The electrical characteristics such as Hall measurement is used to find the carrier concentration and mobility, while Van der pauw for measuring resistivity of the sample The GaSb:Se sample shows high resistivity and mobility. The grown crystal was detached from the ampoule wall with high crystal quality. The measured resistivity of GaSb:Se is 9.9×10-3ohm-cm, the mobility is 1464cm3/Vsec and carrier concentration is 5.08×1017 per cm3.

  10. A low level of dietary selenium has both beneficial and toxic effects and is protective against Cd-toxicity in the least killifish Heterandria formosa.

    PubMed

    Xie, Lingtian; Wu, Xing; Chen, Hongxing; Dong, Wu; Cazan, Alfy Morales; Klerks, Paul L

    2016-10-01

    As an essential element, selenium (Se) is beneficial at low levels yet toxic at high levels. The present study assessed the effects of dietary exposure to Se in the least killifish Heterandria formosa, and investigated how this exposure influences the effects of a subsequent exposure to cadmium (Cd). The fish were pre-exposed to an environmentally relevant concentration (2 μg g(-1) dry wt) of dietary selenite (Se(4+)) or seleno-l-methionine (Se-Met) for 10 d. The same fish were then exposed to 0.5 mg L(-1) of Cd for 5 d. Both Se(IV) and Se-Met rapidly accumulated in H. formosa. Results for the two Se species were generally similar in this study. Fish exposed to Se had lower levels of lipid peroxidation (measured as levels of thiobarbituric acid reactive substances or TBARS) and a higher catalase (CAT) activity. In contrast, their Na(+)/K(+)-ATPase activity was reduced. The Cd exposure resulted in an increase in lipid peroxidation and decreases in the activities of catalase and Na(+)/K(+)-ATPase. The Cd-exposed H. formosa that were pre-exposed to Se had lower Cd body burdens, less lipid peroxidation, and higher catalase activity, than did fish not pre-exposed to Se. The Se exposure did not have a protective effect on the Cd-induced reduction in Na(+)/K(+)-ATPase activity. These results clearly demonstrate that a Se-enriched diet reduces some (but not all) forms of Cd-toxicity and that Se can simultaneously have beneficial and detrimental effects, making it difficult to predict the net outcome of changes in dietary Se levels for fish.

  11. Selenoprotein Gene Expression in Thyroid and Pituitary of Young Pigs Is Not Affected by Dietary Selenium Deficiency or Excess1–3

    PubMed Central

    Zhou, Ji-Chang; Zhao, Hua; Li, Jun-Gang; Xia, Xin-Jie; Wang, Kang-Ning; Zhang, Ya-Jun; Liu, Yan; Zhao, Ying; Lei, Xin Gen

    2009-01-01

    Expression and function of selenoproteins in endocrine tissues remain unclear, largely due to limited sample availability. Pigs have a greater metabolic similarity and tissue size than rodents as a model of humans for that purpose. We conducted 2 experiments: 1) we cloned 5 novel porcine selenoprotein genes; and 2) we compared the effects of dietary selenium (Se) on mRNA levels of 12 selenoproteins, activities of 4 antioxidant enzymes, and Se concentrations in testis, thyroid, and pituitary with those in liver of pigs. In Experiment 1, porcine Gpx2, Sephs2, Sep15, Sepn1, and Sepp1 were cloned and demonstrated 84–94% of coding sequence homology to human genes. In Experiment 2, weanling male pigs (n = 30) were fed a Se-deficient (0.02 mg Se/kg) diet added with 0, 0.3, or 3.0 mg Se/kg as Se-enriched yeast for 8 wk. Although dietary Se resulted in dose-dependent increases (P < 0.05) in Se concentrations and GPX activities in all 4 tissues, it did not affect the mRNA levels of any selenoprotein gene in thyroid or pituitary. Testis mRNA levels of Txnrd1 and Sep15 were decreased (P < 0.05) by increasing dietary Se from 0.3 to 3.0 mg/kg. Comparatively, expressions of Gpx2, Gpx4, Dio3, and Sep15 were high in pituitary and Dio1, Sepp1, Sephs2, and Gpx1 were high in liver. In conclusion, the mRNA abundances of the 12 selenoprotein genes in thyroid and pituitary of young pigs were resistant to dietary Se deficiency or excess. PMID:19357213

  12. Effect of dietary fat on plasma glutathione peroxidase levels and intestinal absorption of /sup 75/Se-labeled sodium selenite in chicks

    SciTech Connect

    Mutanen, M.L.; Mykkaenen, H.M.

    1984-05-01

    The effect of dietary fat on the availability of selenium was investigated in chicks fed either 4 or 20% butter, olive oil, rape oil, corn oil or sunflower oil in the diet for 3 weeks after hatching. Plasma glutathione peroxidase (GSH-Px) activity was used as an indicator of the body selenium status. In addition, the intestinal absorption of sodium selenite (/sup 75/Se-labeled) was determined by using both the in vivo ligated loop procedure and oral administration of the isotope. The plasma GSH-Px levels increased with increasing proportion of the polyunsaturated fatty acids in the diet. Increasing the amount of fat from 4 to 20% significantly enhanced the GSH-Px activity in the groups receiving butter or olive oil, but had no effect in animals fed the unsaturated fats. The absorption of (/sup 75/Se)selenite from the ligated duodenal loops tended to be reduced in chicks fed corn oil or sunflower oil as compared to the animals receiving butter in their diet. On the other hand, the type of dietary fat did not appear to affect the absorption of the orally administered selenite. The present study demonstrates that the type of dietary fat can affect the plasma GSH-Px levels in chicks without altering the intestinal absorption of selenite. However, the results on the absorption of the intraduodenally injected sodium selenite suggest that dietary fat plays some role in the intestinal transport of selenium.

  13. Antidiabetic Activity of a Lotus Leaf Selenium (Se)-Polysaccharide in Rats with Gestational Diabetes Mellitus.

    PubMed

    Zeng, Zhaohui; Xu, Yun; Zhang, Bin

    2017-04-01

    A selenium (Se)-containing polysaccharide, lotus leaf selenium (Se)-polysaccharide (LLP), was isolated from a lotus leaf. The effects of LLP on antioxidant enzyme activities and insulin resistance in pregnant rats with gestational diabetes mellitus (GDM) were investigated. LLP administered orally at two doses (50 and 100 mg/kg) could significantly reverse the weight loss of pregnant rats before the delivery, fetal rats, and placentas in GDM rats (P < 0.05). Furthermore, LLP treatment induced a decrease of fasting blood glucose (FBG) and fasting blood insulin (FINS) levels in GDM rats, but an increase of hepatic glycogen content, when compared with those in GDM rats (P < 0.05). Also, oral administrations of LLP markedly improved the lipid profile of GDM rats, as evidenced by a reduction of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein (LDL) cholesterol levels except for the high-density lipoprotein (HDL) cholesterol level. Additionally, antioxidant enzyme levels, such as superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and glutathione (GSH), in liver tissues of the GDM group were lower than those of the other groups, and following treatment of LLP, these indexes in liver tissues were equivalent to those of the control group (P > 0.05). All the data indicated that LLP may be a promising drug candidate or a healthcare food for GDM therapy or protection.

  14. X-ray absorption near-edge structure of selenium in the Cu-In-Se system

    NASA Astrophysics Data System (ADS)

    Wolska, A.; Bacewicz, R.; Filipowicz, J.; Attenkofer, K.

    2001-05-01

    The x-ray absorption near edge structure (XANES) of selenium is investigated in the crystals with compositions from the pseudobinary cut line Cu2Se-In2Se3. This includes CuInSe2, indium-rich ternary compounds (Cu2In4Se7, CuIn3Se5, CuIn5Se8, CuIn7Se11) and α-In2Se3. The absorption at the K and L3/L2 edges of selenium has been measured using synchrotron radiation. Two theoretical approaches are used to the interpretation of the experimental data: the band structure calculation and the real-space multiple-scattering (RSMS) method. In the first one, the angular momentum projected densities of states at Se sites are calculated for CuInSe2 and α-In2Se3 for the energies up to 17 eV above the conduction band minimum by the LMTO-ASA method. The RSMS approach represented by the FEFF8 code is used to calculate the XANES spectra for the phases with tetragonal symmetry. Clusters up to 160 atoms are used in the calculations. The influence of different structural factors on the selenium XANES is studied.

  15. Removal of selenium from water with nanoscale zero-valent iron: mechanisms of intraparticle reduction of Se(IV).

    PubMed

    Ling, Lan; Pan, Bingcai; Zhang, Wei-xian

    2015-03-15

    Increasing evidences suggest that nanoscale zero-valent iron (nZVI) is an effective agent for treatment and removal of selenium from water. For example, 1.3 mM selenite was quickly removed from water within 3 min with 5 g/L nZVI. In this work, reaction mechanisms of selenite [Se(IV)] in a single core-shell structured nanoscale zero-valent iron (nZVI) particle were studied with the method of spherical aberration corrected scanning transmission electron microscopy (Cs-STEM) integrated with X-ray energy dispersive spectroscopy (XEDS). This method was utilized to visualize solid phase translocation and transformation of Se(IV) such as diffusion, reduction, deposition and the effect of surface defects in a single nanoparticle. Se(IV) was reduced to Se(-II) and Se(0), which then formed a 0.5 nm layer of selenium at the iron oxide-Fe(0) interface at a depth of 6 nm from the surface. The results provided near atomic-resolution proof on the intraparticle diffusion-reduction of Se(IV) induced by nZVI. The STEM mapping also discovered that defects on the surface layer accelerate the diffusion of selenium and increase the capacity of nZVI for selenium sequestration.

  16. Effects of Dietary Selenium Against Lead Toxicity Are Related to the Ion Profile in Chicken Muscle.

    PubMed

    Jin, Xi; Liu, Chun Peng; Teng, Xiao Hua; Fu, Jing

    2016-08-01

    Complex antagonistic interactions between Selenium (Se) and heavy metals have been reported in previous studies. However, little is known regarding the effects of Se on lead (Pb)-induced toxicity and the ion profile in the muscles of chickens. In this present study, we fed chickens either Se or Pb or both Se and Pb supplement and later analyzed the concentrations of 26 ions in chicken muscle tissues. We determined that a Se- and Pb-containing diets significantly affected microelements in chicken muscle. Treatment with Se increased the content of Se but resulted in a reduced concentration of Cu, As, Cd, Sn, Hg, and Ba. Treatment with Pb increased concentrations of Ni while reducing those of B, V, Cr, Fe, Co, Cu, Zn, and Mo. Moreover, Se also reduced the concentration of Pb, Zn, Co, Fe, V, and Cr, which in contrast were induced by Pb. Additionally, we also found that synergistic and antagonistic interactions existed between Se and Pb supplementation. Our findings suggested that Se can exert a negative effect on Pb in chicken muscle tissues and may be related to changes in ion profiles.

  17. Elemental selenium particles at nano-size (Nano-Se) are more toxic to Medaka (Oryzias latipes) as a consequence of hyper-accumulation of selenium: a comparison with sodium selenite.

    PubMed

    Li, Hongcheng; Zhang, Jinsong; Wang, Thanh; Luo, Wenru; Zhou, Qunfang; Jiang, Guibin

    2008-09-29

    Recent studies have shown that elemental selenium particles at nano-size (Nano-Se) exhibited comparable bioavailability and less toxicity in mice and rats when compared to sodium selenite, selenomethinine and methylselenocysteine. However, little is known about the toxicity profile of Nano-Se in aquatic animals. In the present study, toxicities of Nano-Se and selenite in selenium-sufficient Medaka fish were compared. Selenium bioaccumulation and subsequent clearance in fish livers, gills, muscles and whole bodies were examined after 10 days of exposure to Nano-Se and selenite (100 microg Se/L) and again after 7 days of depuration. Both forms of selenium exposure effectively increased selenium concentrations in the investigated tissues. Surprisingly, Nano-Se was found to be more hyper-accumulated in the liver compared to selenite with differences as high as sixfold. Selenium clearance of both Nano-Se and selenite occurred at similar ratios in whole bodies and muscles but was not rapidly cleared from livers and gills. Nano-Se exhibited strong toxicity for Medaka with an approximately fivefold difference in terms of LC(50) compared to selenite. Nano-Se also caused larger effects on oxidative stress, most likely due to more hyper-accumulation of selenium in liver. The present study suggests that toxicity of nanoparticles can largely vary between different species and concludes that the evaluation of nanotoxicology should be carried out on a case-by-case basis.

  18. Effect of dietary selenium and vitamin E on ganders' response to semen collection and ejaculate characteristics.

    PubMed

    Jerysz, Anna; Lukaszewicz, Ewa

    2013-06-01

    Compared to other domestic bird species, geese exhibit the lowest reproductive efficiency (poor semen quality, low egg production, and poor fertility and hatchability rates). From an economic perspective, it is a necessity of improve these reproductive traits. Studies have demonstrated that the essential trace element-selenium-plays key roles in testicular development and the maintenance of spermatogenesis. The aim of the present study was to determine the effect of feed supplementation with organic selenium and vitamin E on ganders' response to manual semen collection and semen quality. Sixteen 3-year-old White Koluda ganders were randomly divided into two groups. The control group was provided commercial feed while the experimental group was provided with the same commercial feed supplemented with selenium (0.3 mg/kg) and vitamin E (100 mg/kg). The response of individual ganders from both groups to manual semen collection and the quality of the semen collected were evaluated. The supplements increased (P ≤ 0.05) the frequency and decreased the time interval of a complete ejaculatory response of the ganders to manual semen collections (82.7 % supplement vs. 73.5 % control). Males from the supplemented group had significantly higher (P ≤ 0.01; P ≤ 0.05) ejaculate volumes, sperm concentrations, and percentages of viable sperm and lower percentages of immature sperm (spermatids). Lipids peroxidation, expressed in terms of the malondialdehyde concentration, was lower (P ≤ 0.01) in semen of the supplemented group (0.172 nmol/50 × 10(6)) as compared to the controls (0.320 nmol/50 × 10(6)). Moreover, the duration of the reproductive period of the ganders in the experimental group was 1 week longer. The results show that supplemental dietary selenium and vitamin E improved both the ganders' response to manual semen collection and semen quality. We conclude that such feed supplementation could lead to greater economic benefits

  19. Electronic states and spectroscopic parameters of selenium monoiodide, SeI: A theoretical contribution

    NASA Astrophysics Data System (ADS)

    Belinassi, Antonio Ricardo; Alves, Tiago Vinicius; Ornellas, Fernando R.

    2017-03-01

    A new species, selenium monoiodide (SeI), was investigated for the first time at a high level of theoretical approach, SA-CASSCF/MRCI. The overall picture of all doublet and quartet (Λ + S) states correlating with the three lowest dissociation channels and the associated Ω states provide reliable results to help understand the lack of experimental data on its transitions and to plan the investigation and determination of spectroscopic parameters. Transition probabilities were computed for the transitions X2 - X1, A1 - X1, A2 - X1, and A2 - X2, originated from the spin-forbidden 1 4Σ- - X 2Π system, and the corresponding radiative lifetimes evaluated.

  20. Urinary trimethylselenonium ion (TMSe) as an index of selenium (Se) exposure in rats

    SciTech Connect

    Morris, V.C.; Levander, O.A.

    1986-03-01

    Large doses of certain Se compounds have been suggested as cancer chemoprevention agents in humans and better techniques for assessing Se status at such intakes are needed. Others have shown that urinary TMSe excretion is a function of Se exposure in rats and an HPLC method has recently been developed for measuring TMSe in urine. In their studies, young male rats were injected i.p. with 6 to 600 ..mu..g Se as selenite or L-selenomethionine containing 3..mu..Ci /sup 75/Se as the appropriate tracer. Urine was collected for 24 hours and desalted. TMSe was separated by HPLC on a strong cation exchanger with NH/sub 4/C/sub 2/H/sub 3/O/sub 2/ (pH 5.0) as the eluting buffer. Identification of TMSe was confirmed by autoradiographic TLC vs. authentic standards. The fraction of urinary Se excreted as TMSe increased from 2 to 70% as the amount of selenite injected increased. Only 3 to 53% appeared in urine as TMSe after injection of equivalent doses of selenomethionine. There was little or no effect of crude (chow) vs. purified (casein) diet on the excretion of TMSe after selenite injection, but Se-deficient rats excreted more Se in the form of TMSe than Se-supplemented rats. Urinary TMSe is a promising tool for assessing Se exposure but more work is needed to evaluate the effect of various dietary forms of Se on the excretion of TMSe in the urine.

  1. Analytical determination of selenium in medical samples, staple food and dietary supplements by means of total reflection X-ray fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Stosnach, Hagen

    2010-09-01

    Selenium is essential for many aspects of human health and, thus, the object of intensive medical research. This demands the use of analytical techniques capable of analysing selenium at low concentrations with high accuracy in widespread matrices and sometimes smallest sample amounts. In connection with the increasing importance of selenium, there is a need for rapid and simple on-site (or near-to-site) selenium analysis in food basics like wheat at processing and production sites, as well as for the analysis of this element in dietary supplements. Common analytical techniques like electrothermal atomic absorption spectroscopy (ETAAS) and inductively-coupled plasma mass spectrometry (ICP-MS) are capable of analysing selenium in medical samples with detection limits in the range from 0.02 to 0.7 μg/l. Since in many cases less complicated and expensive analytical techniques are required, TXRF has been tested regarding its suitability for selenium analysis in different medical, food basics and dietary supplement samples applying most simple sample preparation techniques. The reported results indicate that the accurate analysis of selenium in all sample types is possible. The detection limits of TXRF are in the range from 7 to 12 μg/l for medical samples and 0.1 to 0.2 mg/kg for food basics and dietary supplements. Although this sensitivity is low compared to established techniques, it is sufficient for the physiological concentrations of selenium in the investigated samples.

  2. Effect of Dietary Selenomethionine Supplementation on Growth Performance, Tissue Se Concentration, and Blood Glutathione Peroxidase Activity in Kid Boer Goats.

    PubMed

    Song, Yu-xuan; Hou, Jin-xing; Zhang, Lei; Wang, Jian-gang; Liu, Xiao-rui; Zhou, Zhan-qin; Cao, Bin-yun

    2015-10-01

    We used 240 kid Boer goats that were divided into six groups. The control group was fed a basal diet containing 0.05 mg of selenium (Se)/kg dry matter (DM). Trial groups received the basal diet supplemented with 0.1, 0.2, 0.3, 0.4, or 0.5 mg Se/kg DM (using a commercial selenomethionine product). Trial groups showed an improvement in growth performance (P < 0.05) despite no change in average daily feed intakes (ADFIs) (P > 0.05) compared to the control group A, quadratic model showed a correlation between glutathione peroxidase activity level in whole blood and dietary Se concentration (R(2) = 0.883, P < 0.04). The best linear model showed that increasing concentrations of Se in the blood (R(2) = 0.968, P < 0.001) and muscle (R(2) = 0.942, P < 0.001) corresponded to increasing Se concentrations in feed. Accumulation of Se in different tissues and organs corresponded to increasing Se concentrations in the diet as well as to the total time goats spent feeding on supplemented diet. Kidney and muscle tissues showed the highest and lowest accumulation of Se, respectively. Thus, Se in goat meat can be increased by adding between 0.1 and 0.5 mg/kg of selenomethionine to the diet of goats.

  3. Selenium biofortification of broccoli and carrots grown in soil amended with Se-enriched hyperaccumulator Stanleya pinnata.

    PubMed

    Bañuelos, Gary S; Arroyo, Irvin; Pickering, Ingrid J; Yang, Soo In; Freeman, John L

    2015-01-01

    Amending soils with Se-hyperaccumulator plant derived sources of selenium (Se) may be useful for increasing the Se content in food crops in Se-deficient regions of the world. In this study we evaluated total Se and the different chemical species of Se in broccoli and carrots grown in soils amended with ground shoots of the Se-hyperaccumulator Stanleyapinnata. With increasing application rates of S. pinnata, total plant Se concentrations increased to nutritionally ideal levels inside edible parts. Selenium compounds in aqueous extracts were analyzed by SAX-HPLC-ICPMS and identified as a variety of mainly organic-Se forms. Together with bulk Se K-edge X-ray absorption near-edge structure (XANES) analysis performed on broccoli florets, carrot roots and shoots, dried ground S. pinnata, and the amended soil at post-plant, we demonstrate that Se-enriched S. pinnata is valuable as a soil amendment for enriching broccoli and carrots with healthful forms of organic-Se.

  4. Effect of organic selenium supplementation on growth, Se uptake, and nutrient utilization in guinea pigs.

    PubMed

    Chaudhary, Mahima; Garg, Anil Kumar; Mittal, Ganesh Kumar; Mudgal, Vishal

    2010-02-01

    Forty weaned male guinea pigs (Cavia porcellus) of 152.6 +/- 7.96 g mean body weight were divided into four equal groups and fed a common basal diet comprised of 25% ground cowpea (Vigna unguiculata) hay, 30% ground maize (Zea mays) grain, 22% ground gram (Cicer arietinum) grain, 9.5% deoiled rice (Oryza sativa) bran, 6% soybean (Glycine max) meal, 6% fish meal, 1.5% mineral mixture (without Se), and ascorbic acid at 200 mg/kg to meet their nutrient requirements along with 0, 0.1, 0.2, and 0.3 ppm of organic selenium (Se) in groups I, II, III, and IV, respectively. Experimental feeding lasted for a period of 10 weeks, during which, daily feed intake and weekly body weights were recorded. Intake and digestibility of dry matter, organic matter, ether extract, crude fiber, and nitrogen-free extract as well as uptake of calcium and phosphorus were similar (P > 0.05) among the four groups. Feed:gain ratio was also similar (P > 0.05) in the four groups. However, digestibility of crude protein was significantly (P < 0.001) higher in group II supplemented with 0.1 ppm organic Se as compared to other three group. Intake and absorption of Se was significantly (P < 0.001) higher in all the Se supplemented groups as compared to control group. Average daily gain (ADG) was significantly (P < 0.05) higher in group II (3.16 g/day) and III (3.38 g/day) as compared to group I (2.88 g/day). However, ADG in group IV (supplemented 0.3 ppm organic Se) was significantly (P < 0.05) lower (2.83 g/day) than group II and III, but comparable (P > 0.05) to group I. Findings of the present experiment suggests that Se requirements of guinea pigs are > or =0.2 ppm, as supplementation of 0.1 ppm organic Se in the diet (having 0.1 ppm Se) not only enhanced their growth rate but also improved the protein utilization.

  5. Effect of dietary selenium and cancer cell xenograft on peripheral T and B lymphocytes in adult nude mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) is known to regulate tumorigenesis and immunity at nutritional and supranutritional levels. Because the immune system provides critical defenses against cancer and the athymic, immune-deficient NU/J nude mice are known to gradually develop CD8+ and CD4+ T cells, we asked whether B and ...

  6. Characterization of a selenium-tolerant rhizosphere strain from a novel Se-hyperaccumulating plant Cardamine hupingshanesis.

    PubMed

    Tong, Xinzhao; Yuan, Linxi; Luo, Lei; Yin, Xuebin

    2014-01-01

    A novel selenium- (Se-) hyperaccumulating plant, Cardamine hupingshanesis, accumulating Se as a form of SeCys2, was discovered in Enshi, Hubei, China, which could not be explained by present selenocysteine methyltransferase (SMT) theory. However, it is interesting to investigate if rhizosphere bacteria play some roles during SeCys2 accumulation. Here, one Se-tolerant rhizosphere strain, Microbacterium oxydans, was isolated from C. hupingshanesis. Phylogenetic analysis and 16S rRNA gene sequences determined the strain as a kind of Gram positive bacillus and belonged to the family Brevibacterium frigoritolerans. Furthermore, Se tolerance test indicated the strain could grow in extreme high Se level of 15.0 mg Se L(-1). When exposed to 1.5 mg Se L(-1), SeCys2 was the predominant Se species in the bacteria, consistent with the Se species in C. hupingshanesis. This coincidence might reveal that this strain played some positive effect in SeCys2 accumulation of C. hupingshanesis. Moreover, when exposed to 1.5 mg Se L(-1) or 15.0 mg Se L(-1), As absorption diminished in the logarithmic phase. In contrast, As absorption increased when exposed to 7.5 mg Se L(-1), indicating As metabolism processes could be affected by Se on this strain. The present study provided a sight on the role of rhizosphere bacteria during Se accumulation for Se-hyperaccumulating plant.

  7. Dietary selenium and nutritional plane alter specific aspects of maternal endocrine status during pregnancy and lactation.

    PubMed

    Lemley, C O; Meyer, A M; Neville, T L; Hallford, D M; Camacho, L E; Maddock-Carlin, K R; Wilmoth, T A; Wilson, M E; Perry, G A; Redmer, D A; Reynolds, L P; Caton, J S; Vonnahme, K A

    2014-01-01

    Objectives were to examine effects of selenium (Se) supply and maternal nutritional plane during gestation on placental size at term and maternal endocrine profiles throughout gestation and early lactation. Ewe lambs (n = 84) were allocated to treatments that included Se supply of adequate Se (ASe; 11.5 μg/kg BW) or high Se (HSe; 77 μg/kg BW) initiated at breeding and nutritional plane of 60% (RES), 100% (CON), or 140% (EXC) of requirements beginning on day 40 of gestation. At parturition, lambs were removed from their dams, and ewes were transitioned to a common diet that met requirements of lactation. Blood samples were taken from a subset of ewes (n = 42) throughout gestation, during parturition, and throughout lactation to determine hormone concentrations. Cotyledon number was reduced (P = 0.03) in RES and EXC ewes compared with CON ewes. Placental delivery time tended (P = 0.08) to be shorter in HSe ewes than in ASe ewes, whereas placental delivery time was longer (P = 0.02) in RES ewes than in CON and EXC ewes. During gestation, maternal progesterone, estradiol-17β, and GH were increased (P < 0.05) in RES ewes and decreased (P < 0.05) in EXC ewes compared with CON ewes. In contrast, maternal cortisol, IGF-I, prolactin, triiodothyronine, and thyroxine were decreased in RES ewes and increased in EXC ewes compared with CON ewes during gestation. Selenium supply did not alter maternal hormone profiles during gestation. During parturition and lactation, maternal hormone concentrations were influenced by both Se and maternal nutritional plane. During the parturient process, HSe ewes tended to have greater (P = 0.06) concentrations of estradiol-17β than ASe ewes. Three hours after parturition a surge of GH was observed in ASe-RES ewes that was muted in HSe-RES ewes and not apparent in other ewes. Growth hormone area under the curve during the parturient process was increased (P < 0.05) in ASe-RES vs HSe-RES ewes. Ewes that were overfed during gestation had

  8. Size effect of elemental selenium nanoparticles (Nano-Se) at supranutritional levels on selenium accumulation and glutathione S-transferase activity.

    PubMed

    Peng, Dungeng; Zhang, Jinsong; Liu, Qingliang; Taylor, Ethan Will

    2007-10-01

    It has been shown that 36 nm Nano-Se has lower toxicity than selenite or selenomethionine, but these forms of selenium (Se) all possess similar ability to increase selenoenzyme levels. The size of nanoparticles plays an important role in their biological activity: as expected, 5-200 nm Nano-Se can directly scavenge free radicals in vitro in a size-dependent fashion. However, in Se-deficient cells and Se-deficient mice, the size effect of Nano-Se on increasing selenoenzymes and liver Se disappears unexpectedly. We hypothesize that under conditions of Se deficiency, the avidity of Se uptake mechanisms may be increased to maintain the biosynthesis of selenoenzymes, which are fundamental for redox homeostasis. This increased avidity may override the potential advantage of small size Nano-Se seen under Se-replete conditions, thereby eliminating the size effect. Once selenoenzymes have been saturated, Se uptake mechanisms may downregulate; accordingly, the size effect of Nano-Se can then reappear. To test this hypothesis, Se-deficient mice were administered either 36 or 90 nm Nano-Se at supranutritional doses, in both a short-term model and a single-dose model. Under these conditions, Nano-Se showed a size effect on Se accumulation and glutathione S-transferase (GST) activity. A size effect of Nano-Se was found in 15 out of 18 total comparisons between sizes at the same dose and time in the two models. Furthermore, the magnitude of the size effect was more prominent on Se accumulation than on GST activity. GST is strictly regulated by transcriptional and translational mechanisms, so its increase in activity normally does not exceed 3-fold. In contrast, the homeostasis of Se accumulation is not as tightly controlled. In the present experiments, GST activity had reached or was approaching saturation, but liver Se was far below saturation. Therefore, our results strongly suggest that the saturation profile of the tested biomarker has an impact on the size effect of Nano-Se

  9. Impact of selenium supply on Se-methylselenocysteine and glucosinolate accumulation in selenium-biofortified Brassica sprouts.

    PubMed

    Avila, Fabricio William; Yang, Yong; Faquin, Valdemar; Ramos, Silvio Junio; Guilherme, Luiz Roberto G; Thannhauser, Theodore W; Li, Li

    2014-12-15

    Brassica sprouts are widely marketed as functional foods. Here we examined the effects of Se treatment on the accumulation of anticancer compound Se-methylselenocysteine (SeMSCys) and glucosinolates in Brassica sprouts. Cultivars from the six most extensively consumed Brassica vegetables (broccoli, cauliflower, green cabbage, Chinese cabbage, kale, and Brussels sprouts) were used. We found that Se-biofortified Brassica sprouts all were able to synthesize significant amounts of SeMSCys. Analysis of glucosinolate profiles revealed that each Brassica crop accumulated different types and amounts of glucosinolates. Cauliflower sprouts had high total glucosinolate content. Broccoli sprouts contained high levels of glucoraphanin, a precursor for potent anticancer compound. Although studies have reported an inverse relationship between accumulation of Se and glucosinolates in mature Brassica plants, Se supply generally did not affect glucosinolate accumulation in Brassica sprouts. Thus, Brassica vegetable sprouts can be biofortified with Se for the accumulation of SeMSCys without negative effects on chemopreventive glucosinolate contents.

  10. Effects of dietary supplementation with an organic source of selenium on characteristics of semen quality and in vitro fertility in boars.

    PubMed

    Speight, S M; Estienne, M J; Harper, A F; Crawford, R J; Knight, J W; Whitaker, B D

    2012-03-01

    Semen characteristics in boars fed organic or inorganic sources of Se were assessed in 3 experiments. Crossbred boars were randomly assigned at weaning to 1 of 3 dietary treatments: I) basal diets with no supplemental Se (control), II) basal diets with 0.3 mg/kg of supplemental Se from an organic source (Sel-Plex, Alltech Inc., Nicholasville, KY), and III) basal diets supplemented with 0.3 mg/kg of supplemental Se from sodium selenite (Premium Selenium 270, North American Nutrition Co. Inc., Lewisburg, OH). For Exp. 1, semen was collected from boars (n = 10/dietary treatment) on 5 consecutive days at 15 mo of age. Effects of treatment × day were detected for the proportions of progressively motile (P = 0.02) and rapidly moving (P = 0.03) spermatozoa, and measures of sperm velocity, including path velocity of the smoothed cell path (P = 0.05) and average velocity measured in a straight line from the beginning to the end of the track (P = 0.05). Negative effects of day of semen collection on sperm motility were least pronounced in boars fed Sel-Plex. Experiment 2 was conducted when boars were 17 mo of age, and semen was collected (n = 10 boars/dietary treatment), diluted in commercially available extenders, and stored at 18°C for 9 d. Effects of treatment × day were detected for percentages of motile (P = 0.01) and static (P = 0.01) spermatozoa, amplitude of lateral head displacement (P = 0.02), frequency with which the sperm track crossed the sperm path (P = 0.04), straightness (P = 0.01), and average size of all sperm heads (P = 0.03). In general, sperm cells from boars fed Sel-Plex were better able to maintain motility during liquid storage compared with boars fed sodium selenite. For Exp. 3, semen was collected from boars (n = 6/dietary treatment) at 23 mo of age, and spermatozoa were evaluated at d 1 and 8 after semen collection using in vitro fertilization procedures. There was a tendency for an effect (P = 0.11) of dietary treatment on fertilization rate

  11. On-line pre-reduction of Se(VI) by thiourea for selenium speciation by hydride generation

    NASA Astrophysics Data System (ADS)

    Qiu, Jianhua; Wang, Qiuquan; Ma, Yuning; Yang, Limin; Huang, Benli

    2006-07-01

    In this study, thiourea (TU) was novelly developed as a reduction reagent for on-line pre-reduction of selenium(VI) before conventional hydride generation (HG) by KBH 4/NaOH-HCl. After TU on-line pre-reduction, the HG efficiency of Se(VI) has been greatly improved and because even higher than that of the same amount of Se(IV) obtained in the conventional HG system. The possible pre-reduction mechanism is discussed. The detection limit (DL) of selenate reaches 10 pg mL - 1 when using on-line TU pre-reduction followed by HG atomic fluorescence detection. When TU pre-reduction followed by HG is used as an interface between ion-pair high performance liquid chromatography and atomic fluorescence spectrometry, selenocystine, selenomethionine, selenite and selenate can be measured simultaneously and quantitatively. The DLs of these are 0.06, 0.08, 0.05 and 0.04 ng mL - 1 , respectively, and the relative standard deviations of 9 duplicate runs for all the 4 species are less than 5%. Furthermore, it was successfully applied to Se speciation analysis of cultured garlic samples, and validated by determination of total selenium and selenium species in certified reference material NIST 1946.

  12. Impact of selenium supply on se-methylselenocysteine and glucosinolates accumulation in selenium-biofortified brassica sprouts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brassica sprouts are widely marketed as functional foods. Here we examined the effects of Se treatment on the accumulation of anticancer compound Se-methylselenocysteine (SeMSCys) and glucosinolates in Brassica sprouts. Cultivars from the six most extensively consumed Brassica vegetables (broccoli, ...

  13. Effect of a dietary supplementation with linseed oil and selenium to growing rabbits on their productive performances, carcass traits and fresh and cooked meat quality.

    PubMed

    Matics, Zs; Cullere, M; Szín, M; Gerencsér, Zs; Szabó, A; Fébel, H; Odermatt, M; Radnai, I; Dalle Zotte, A; Szendrő, Zs

    2016-08-23

    The present experiment tested a dietary supplementation with linseed oil and selenium to growing rabbits. The basal diet (B) contained 3% sunflower oil, while it was substituted with 3% linseed oil in the experimental feed (S). The selenium (Se) content of the two diets was 0.10 vs. 0.46 mg/kg. Rabbits were fed with B diet from the age of 18 days. One group was fed with the B diet until 11 weeks of age (group B), whereas the experimental groups were fed with S diet for 1, 2, 3 or 4 weeks (groups S1, S2, S3 and S4, respectively), before slaughtering (11 weeks of age). Live performance and carcass traits of rabbits, fatty acid (FA) profile and selenium content of their hind leg (HL) and Longissimus thoracis et lumborum (LTL) meat were considered in this study. In addition, the effect of two different cooking methods on the nutritional value of the enriched HL meat was also assessed. The tested dietary supplementation only minimally affected the live performance and carcass traits of rabbits. The S supplementation significantly reduced the Σ n-6 FA and increased the Σ n-3 FA of the HL meat and LTL meat, compared to the B diet (p < 0.001); thus, n-6/n-3 ratio was improved (p < 0.001). In addition, HL meat and LTL meat of S fed rabbits were significantly enriched in Se reaching a twofold increase in both meat cuts (p < 0.01). Therefore, the S supplementation improved the functional value of the rabbit meat. The heat treatment affected cooking loss, Se and vitamin E contents as well as the oxidative status of the HL meat (p < 0.001), with the different cooking methods providing different results. In addition, even if the beneficial C20:5 n-3 and C22:6 n-3 decreased with cooking, the n-6/n-3 ratio remained unaffected.

  14. Simultaneous speciation of arsenic (As(III), MMA, DMA, and As(V)) and selenium (Se(IV), Se(VI), and SeCN-) in petroleum refinery aqueous streams.

    PubMed

    Tonietto, Gisele B; Godoy, José M; Oliveira, Ana Cristina; de Souza, Marcia V

    2010-07-01

    High-performance liquid chromatography (HPLC) coupled to an ICP-MS with an octapole reaction system (ORS) has been used to carry out quantitative speciation of selenium (Se) and arsenic (As) in the stream waters of a refining process. The argon dimers interfering with the (78)Se and (80)Se isotopes were suppressed by pressurizing the octapole chamber with 3.1 mL min(-1) H(2) and 0.5 mL min(-1) He. Four arsenic species arsenite--As(III), arsenate (As(V)), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA)--and three inorganic Se species--selenite Se(IV), selenate Se(VI), and selenocyanate (SeCN(-))--were separated in a single run by ion chromatography (IC) using gradient elution with 100 mmol L(-1) NH(4)NO(3), pH 8.5, adjusted by addition of NH(3), as eluent. Repeatabilities of peak position and of peak area evaluation were better than 1% and about 3%, respectively. Detection limits (as 3sigma of the baseline noise) were 81, 56, and 75 ng L(-1) for Se(IV), Se(VI), and SeCN(-), respectively, and 22, 19, 25, and 16 ng L(-1) for As(III), As(V), MMA, and DMA, respectively. Calibration curve R (2) values ranged between 0.996 and 0.999 for the arsenic and selenium species. Column recovery for ion chromatography was calculated to be 97 +/- 6% for combined arsenic species and 98 +/- 3% for combined selenium species. Because certified reference materials for As and Se speciation studies are still not commercially available, in order to check accuracy and precision the method was applied to certified reference materials, BCR 714, BCR 1714, and BCR 715 and to two different refinery samples--inlet and outlet wastewater. The method was successfully used to study the quantitative speciation of selenium and arsenic in petroleum refinery wastewaters.

  15. Selenium hyperaccumulator plants Stanleya pinnata and Astragalus bisulcatus are colonized by Se-resistant, Se-excluding wasp and beetle seed herbivores.

    PubMed

    Freeman, John L; Marcus, Matthew A; Fakra, Sirine C; Devonshire, Jean; McGrath, Steve P; Quinn, Colin F; Pilon-Smits, Elizabeth A H

    2012-01-01

    Selenium (Se) hyperaccumulator plants can concentrate the toxic element Se up to 1% of shoot (DW) which is known to protect hyperaccumulator plants from generalist herbivores. There is evidence for Se-resistant insect herbivores capable of feeding upon hyperaccumulators. In this study, resistance to Se was investigated in seed chalcids and seed beetles found consuming seeds inside pods of Se-hyperaccumulator species Astragalus bisulcatus and Stanleya pinnata. Selenium accumulation, localization and speciation were determined in seeds collected from hyperaccumulators in a seleniferous habitat and in seed herbivores. Astragalus bisulcatus seeds were consumed by seed beetle larvae (Acanthoscelides fraterculus Horn, Coleoptera: Bruchidae) and seed chalcid larvae (Bruchophagus mexicanus, Hymenoptera: Eurytomidae). Stanleya pinnata seeds were consumed by an unidentified seed chalcid larva. Micro X-ray absorption near-edge structure (µXANES) and micro-X-Ray Fluorescence mapping (µXRF) demonstrated Se was mostly organic C-Se-C forms in seeds of both hyperaccumulators, and S. pinnata seeds contained ∼24% elemental Se. Liquid chromatography-mass spectrometry of Se-compounds in S. pinnata seeds detected the C-Se-C compound seleno-cystathionine while previous studies of A. bisulcatus seeds detected the C-Se-C compounds methyl-selenocysteine and γ-glutamyl-methyl-selenocysteine. Micro-XRF and µXANES revealed Se ingested from hyperaccumulator seeds redistributed throughout seed herbivore tissues, and portions of seed C-Se-C were biotransformed into selenocysteine, selenocystine, selenodiglutathione, selenate and selenite. Astragalus bisulcatus seeds contained on average 5,750 µg Se g(-1), however adult beetles and adult chalcid wasps emerging from A. bisulcatus seed pods contained 4-6 µg Se g(-1). Stanleya pinnata seeds contained 1,329 µg Se g(-1) on average; however chalcid wasp larvae and adults emerging from S. pinnata seed pods contained 9 and 47 µg Se g(-1). The

  16. Effects of Gestational Exposure to Methylmercury and Dietary Selenium on Reinforcement Efficacy in Adulthood

    PubMed Central

    Reed, Miranda N.; Banna, Kelly M.; Donlin, Wendy D.; Newland, M. Christopher

    2008-01-01

    It has recently been demonstrated that developmental exposure to methylmercury (MeHg) is associated with perseveration on operant tasks. An understanding of the behavioral mechanisms underlying this phenomenon may improve human testing of MeHg exposures and could provide insight into clinical syndromes that include perseveration as a component. One possible mechanism is that MeHg-induced enhancement of reinforcer efficacy produces a “reinforcement trap” that inhibits change in novel situations. Rats were exposed gestationally to 0, 0.5 or 5 ppm mercury (Hg) as MeHg via maternal drinking water. They also received a diet during gestation and throughout life that was marginal (0.06 ppm) or rich (0.6 ppm) in selenium (Se), a nutrient believed to protect against MeHg's toxicity. Reinforcer efficacy was evaluated using a progressive ratio schedule of reinforcement during adulthood. Maximum ratio obtained (MRO) was determined using 20 or 60 mg sucrose pellets and with ratio requirements that increased at 5% or 20% per reinforcer. MRO was related to the rate at which the ratio increased, reinforcer magnitude, sex, and exposure regimen; MRO was increased for the 0.6 ppm Se, 5 ppm Hg group. This extends an earlier observation that developmental MeHg exposure enhances reinforcer efficacy, an effect that could be related to reports of perseveration. PMID:18096364

  17. Effect of dietary α-tocopherol + ascorbic acid, selenium, and iron on oxidative stress in sub-yearling Chinook salmon (Oncorhynchus tshawytscha Walbaum)

    USGS Publications Warehouse

    Welker, T.L.; Congleton, J.L.

    2009-01-01

    A three-variable central composite design coupled with surface-response analysis was used to examine the effects of dietary ??-tocopherol + ascorbic acid (TOCAA), selenium (Se), and iron (Fe) on indices of oxidative stress in juvenile spring Chinook salmon. Each dietary factor was tested at five levels for a total of fifteen dietary combinations (diets). Oxidative damage in liver and kidney (lipid peroxidation, protein carbonyls) and erythrocytes (erythrocyte resistance to peroxidative lysis, ERPL) was determined after feeding experimental diets for 16 (early December) and 28 (early March) weeks. Only TOCAA influenced oxidative stress in this study, with most measures of oxidative damage decreasing (liver lipid peroxidation in December and March; ERPL in December; liver protein carbonyl in March) with increasing levels of TOCAA. We also observed a TOCAA-stimulated increase in susceptibility of erythrocytes to peroxidative lysis in March at the highest levels of TOCAA. The data suggest that under most circumstances a progressive decrease in oxidative stress occurs as dietary TOCAA increases, but higher TOCAA concentrations can stimulate oxidative damage in some situations. Higher levels of TOCAA in the diet were required in March than in December to achieve comparable levels of protection against oxidative damage, which may have been due to physiological changes associated with the parr-smolt transformation. Erythrocytes appeared to be more sensitive to variation in dietary levels of TOCAA than liver and kidney tissues. Using the March ERPL assay results as a baseline, a TOCAA level of approximately 350-600 mg/kg diet would provide adequate protection against lipid peroxidation under most circumstances in juvenile Chinook salmon. ?? 2008 The Authors.

  18. Distribution of selenium in zebrafish larvae after exposure to organic and inorganic selenium forms.

    PubMed

    Dolgova, N V; Hackett, M J; MacDonald, T C; Nehzati, S; James, A K; Krone, P H; George, G N; Pickering, I J

    2016-03-01

    Selenium is an essential micronutrient for many organisms, and in vertebrates has a variety of roles associated with protection from reactive oxygen species. Over the past two decades there have been conflicting reports upon human health benefits and detriments arising from consumption of selenium dietary supplements. Thus, early studies report a decrease in the incidence of certain types of cancer, whereas subsequent studies did not observe any anti-cancer effect, and adverse effects such as increased risks for type 2 diabetes have been reported. A possible contributing factor may be that different chemical forms of selenium were used in different studies. Using larval stage zebrafish (Danio rerio) as a model organism, we report a comparison of the toxicities and tissue selenium distributions of four different chemical forms of selenium. We find that the organic forms of selenium tested (Se-methyl-l-selenocysteine and l-selenomethionine) show considerably more toxicity than inorganic forms (selenite and selenate), and that this appears to be correlated with the level of bioaccumulation. Despite differences in concentrations, the tissue specific pattern of selenium accumulation was similar for the chemical forms tested; selenium was found to be highly concentrated in pigment (melanin) containing tissues especially for the organic selenium treatments, with lower concentrations in eye lens, yolk sac and heart. These results suggest that pigmented tissues might serve as a storage reservoir for selenium.

  19. Selenium bioaccessibility in stomach, small intestine and colon: Comparison between pure Se compounds, Se-enriched food crops and food supplements.

    PubMed

    Lavu, Rama V Srikanth; Van De Wiele, Tom; Pratti, Varalakshmi L; Tack, Filip; Du Laing, Gijs

    2016-04-15

    Selenium (Se) is an essential nutrient for humans as it plays an important role in glutathione peroxidase (GPx) activity. Moreover, it may reduce cancer risks. The objective of this work was to examine in vitro the bioaccessibility of Se in three different Se-enriched food supplements and two different Se-enriched food crops, with reference to two pure Se standards, and changes in its speciation during intestinal digestion. Selenate was found to be stable throughout the entire digestion, whereas incubation of selenomethionine resulted in the chemical and microbial production of minor metabolites. The bioaccessibility of Se in Se-enriched food supplements and food crops was found to be highest in the small intestine. Compared to SelenoPrecise and Se-ACE tablets, a yoghurt-based supplement exhibited a much lower Se bioaccessibility, possibly due to the presence of nano- or microparticles of elemental Se. Colon microbiota were found to primarily affect Se bioaccessibility in the colon environment, with the presence of inactivated microbiota resulting in a higher bioaccessibility. A higher potential of Se to reach the colon and become accessible in this phase may result in beneficial effects on the colon health.

  20. Effect of dietary selenium on T cell immunity and cancer xenograft in nude mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium is known to regulate carcinogenesis and immunity at nutritional and supranutritional levels. Because the immune system provides one of the main body defenses against cancer, we asked whether T cell immunity can modulate selenium chemoprevention. Twenty-four homozygous NU/J nude mice were fe...

  1. Dietary selenium deficiency as well as excess supplementation induces multiple defects in mouse epididymal spermatozoa: understanding the role of selenium in male fertility.

    PubMed

    Shalini, Sonia; Bansal, M P

    2008-08-01

    Selenium (Se) is essential for male fertility. The present study was carried out to observe the defects associated with Se deficiency as well as excess Se supplementation by analyzing the sperm ultrastructure and chromatin organization. Different Se status mice were generated viz. Se deficient (group I), Se adequate (group II) and Se excess (group III) by feeding the respective diets for a period of 4 (group Ia, IIa and IIIa) and 8 weeks (group Ib, IIb and IIIb). Reduction in sperm concentration, motility and percentage fertility was observed in Se deficient and Se excess groups. Electron microscopy revealed mitochondrial swelling and gaps between adjacent mitochondria in mice fed Se-deficient diet for 4 weeks. At 8 weeks, several abnormalities such as loose contact of the mitochondrial helix with the plasma membrane, loss of mitochondria, retention of cytoplasmic droplet, fracturing of outer dense fibres and presence of both the midpiece and the principal piece cross-sections in a common plasma membrane were observed. In Se excess group, the predominant defect was the frequent presence of equidistant, cross-sectioned midpieces of the tail embedded in a common cytoplasm. These defects are indicative of loss of sperm motility. Spermatozoa from Se-deficient mice had incompletely condensed chromatin and indicated an increase in occurrence of DNA strand breaks. The animals fed Se excess diet also indicated increase in DNA breaks but this was significantly less than the deficient diet fed groups. Our study reveals the defects associated with Se deficiency that result in loss of reproductive ability and also reflects its possible harmful effects on spermatozoa after prolonged consumption at supranutritional level.

  2. Selenium status in Greenland Inuit.

    PubMed

    Hansen, Jens C; Deutch, Bente; Pedersen, Henning Sloth

    2004-09-20

    In Greenland, the human intake of selenium has always been relatively high and is closely connected to intake of the traditional food of marine origin. Analyses of historic and present day human and animal hair samples have indicated that the selenium level in the marine environment has been constant over time, while the levels in humans have declined corresponding to a decrease in intake of traditional food. The Inuit population in Greenland is in dietary transition where western-style food will increasingly dominate. As a consequence, the ample supply of selenium may not be sustained in the future. We report here the selenium status in three Greenlandic population groups, Ittoqqortoormiit and Tasiilaq on the east coast and Uummannaq on the west coast. Mean whole blood concentrations ranged from 178 microg/l in Tasiilaq men to 488 microg/l in Uummannaq men. Plasma concentrations ranged from 79 microg/l in Tasiilaq women to 113 microg/l in Uummannaq men. With increasing Se concentrations in whole blood, the plasma concentrations increased but tended to stabilise a level approximately 140 microg/l. Selenium blood levels were highly significantly correlated with long chain marine fatty acids. Dietary survey and food composition data from the west coast showed that whale skin, muktuk, is the main source of Se followed by birds, seal meat and organs, and fish. Terrestrial animals contributed only insignificantly to the selenium intake. In West Greenland, daily Se intake (235 microg/day) was estimated by dietary survey; it corresponded well with a calculated intake (220 microg/day) based on the mean blood concentration.

  3. Dietary advice on Inuit traditional food use needs to balance benefits and risks of mercury, selenium, and n3 fatty acids.

    PubMed

    Laird, Brian D; Goncharov, Alexey B; Egeland, Grace M; Chan, Hing Man

    2013-06-01

    Elevated concentrations of mercury (Hg) are commonly found in the traditional foods, including fish and marine mammals, of Inuit living in Canada's Arctic. As a result, Inuit often have higher dietary Hg intake and elevated Hg blood concentrations. However, these same traditional foods are excellent sources of essential nutrients. The goals of this study were 1) to identify the traditional food sources of Hg exposure for Inuit, 2) to estimate the percentage of Inuit who meet specific nutrient Dietary Reference Intakes and/or exceed the Toxicological Reference Values (TRVs), and 3) to evaluate options that maximize nutrient intake while minimizing contaminant exposure. A participatory cross-sectional survey was designed in consultation with Inuit in 3 Canadian Arctic jurisdictions (Nunatsiavut, Nunavut, and the Inuvialuit Settlement Region). Estimated intakes for EPA (20:5n3) and DHA (22:6n3) met suggested dietary targets, and estimated selenium (Se) intake fell within the Acceptable Range of Oral Intake. Estimated intakes of Hg (rs = 0.41, P < 0.001), Se (rs = 0.44, P < 0.001), EPA (rs = 0.32, P < 0.001), and DHA (rs = 0.28, P < 0.001) were correlated with their respective blood concentrations. Mean estimated Hg intake (7.9 μg · kg(-1) · wk(-1)) exceeded the TRV of 5.0 μg · kg(-1) · wk(-1), with 35% of the population above this guideline. Because the estimated intakes of each of the nutrients were strongly correlated (Se: rs = 0.92, P < 0.001; EPA: rs = 0.82, P < 0.001; DHA: rs = 0.81, P < 0.001) with estimated Hg intake, efforts to decrease Hg exposure must emphasize the overall healthfulness of traditional foods and be designed to prevent concomitant harm to the nutrient intakes of Inuit.

  4. Selenium Characterization In The Global Rice Supply Chain

    EPA Science Inventory

    For up to 1 billion people worldwide, insufficient dietary intake of selenium (Se) is a serious health constraint. Cereals are the dominant Se source for those on low protein diets, as typified by the global malnourished population. With crop Se content constrained largely by u...

  5. Proteomic analysis of liver tissue from rainbow trout (Oncorhynchus mykiss) under high rearing density after administration of dietary vitamin E and selenium nanoparticles.

    PubMed

    Naderi, Mahdi; Keyvanshokooh, Saeed; Salati, Amir Parviz; Ghaedi, Alireza

    2017-02-04

    The aim of the present study was to investigate the effects of dietary vitamin E (vit E) and selenium nanoparticles (nanoSe) on liver proteome profile of rainbow trout under high density condition. To correlate the proteome modifications with physiological aspects, growth, serum metabolites (cortisol, glucose, lactate, ALT, AST, and ALP), and liver antioxidant-related parameters (SOD, GPx, CAT, and MDA) were also examined. A total of 1275 fish (average weight of 42.6±2.3g) were stocked into 12 tanks at a density of 80kgm(-3). The fish were divided into four groups according to diet: control (basal diet), vit E (500mgkg(-)(1) vit E-supplemented diet), nanoSe (1mgkg(-1) nanoSe-supplemented diet), and combination (500mgkg(-1) vit E and 1mgkg(-1) nanoSe-supplemented diet). After 60days, the best performance and health status of fish were observed in vit E and combination groups. Supplementation with nanoSe had no significant effects on growth performance. In addition, we compared liver proteome profiles of fish fed with a basal diet (control) and diets supplemented with vit E or nanoSe. Among the identified proteins, GRP78, ATPsyn-d, and HSP70 had an increased abundance in the vit E group, while HPPD and GAPDH showed a decreased abundance. In response to nanoSe supplementation, the expression of MDH, FAA, FBPA, TPI, GRHPR, GNMT, FDH, and Enol was increased. The proteomic data indicate that vit E or nanoSe supplementation can alter the expression of proteins involved in metabolic status of rainbow trout reared under high rearing density.

  6. Metabolism of selenium (Se) in rats chronically poisoned with D- or L-selenomethionine (SeMet), selenite or selenate

    SciTech Connect

    McAdam, P.A.; Levander, O.A.

    1986-03-01

    L-SeMet is a potential cancer chemoprevention agent for humans. Little difference was seen in the acute toxicity of L vs. D-SeMet in rats. To study chronic toxicity, weanling male rats were fed purified diets containing 2.5, 5.0 or 10 ppm Se as L-SeMet, D-SeMet, Na/sub 2/SeO/sub 3/ or Na/sub 2/SeO/sub 4/ for 6 weeks. Controls received 0.1 ppm Se as selenite. All rats fed 10 ppm Se died within 29 days. Se fed as D-SeMet was retained in the tissues as strongly as L-SeMet. Rats fed D or L-SeMet deposited large amounts of Se in muscle not reflected by proportionate increases in either plasma or RBC Se. Therefore, attempts to follow increases in Se body burden in individuals supplemented with large doses of L-SeMet by monitoring plasma or whole blood Se levels should be interpreted with caution.

  7. Continued Selenium Biofortification of Carrots and Broccoli Grown in Soils Once Amended with Se-enriched S. pinnata

    PubMed Central

    Bañuelos, Gary S.; Arroyo, Irvin S.; Dangi, Sadikshya R.; Zambrano, Maria C.

    2016-01-01

    Selenium (Se) biofortification has been practiced in Se-deficient regions throughout the world primarily by adding inorganic sources of Se to the soil. Considering the use of adding organic sources of Se could be useful as an alternative Se amendment for the production of Se-biofortified food crops. In this multi-year micro-plot study, we investigate growing carrots and broccoli in soils that had been previously amended with Se-enriched Stanleya pinnata Pursh (Britton) three and 4 years prior to planting one and two, respectively. Results showed that total and extractable Se concentrations in soils (0–30 cm) were 1.65 mg kg-1 and 88 μg L-1, and 0.92 mg kg-1 and 48.6 μg L-1 at the beginning of the growing season for planting one and two, respectively. After each respective growing season, total Se concentrations in the broccoli florets and carrots ranged from 6.99 to 7.83 mg kg-1 and 3.15 to 6.25 mg kg-1 in planting one and two, respectively. In broccoli and carrot plant tissues, SeMet (selenomethionine) was the predominant selenoamino acid identified in Se aqueous extracts. In postharvest soils from planting one, phospholipid fatty acid (PLFA) analyses showed that amending the soil with S. pinnata exerted no effect on the microbial biomass, AMF (arbuscular mycorrhizal fungi), actinomycetes and Gram-positive and bacterial PLFA at both 0–5 and 0–30 cm, respectively, 3 years later. Successfully producing Se-enriched broccoli and carrots 3 and 4 years later after amending soil with Se-enriched S. pinnata clearly demonstrates its potential source as an organic Se enriched fertilizer for Se-deficient regions. PMID:27602038

  8. Continued Selenium Biofortification of Carrots and Broccoli Grown in Soils Once Amended with Se-enriched S. pinnata.

    PubMed

    Bañuelos, Gary S; Arroyo, Irvin S; Dangi, Sadikshya R; Zambrano, Maria C

    2016-01-01

    Selenium (Se) biofortification has been practiced in Se-deficient regions throughout the world primarily by adding inorganic sources of Se to the soil. Considering the use of adding organic sources of Se could be useful as an alternative Se amendment for the production of Se-biofortified food crops. In this multi-year micro-plot study, we investigate growing carrots and broccoli in soils that had been previously amended with Se-enriched Stanleya pinnata Pursh (Britton) three and 4 years prior to planting one and two, respectively. Results showed that total and extractable Se concentrations in soils (0-30 cm) were 1.65 mg kg(-1) and 88 μg L(-1), and 0.92 mg kg(-1) and 48.6 μg L(-1) at the beginning of the growing season for planting one and two, respectively. After each respective growing season, total Se concentrations in the broccoli florets and carrots ranged from 6.99 to 7.83 mg kg(-1) and 3.15 to 6.25 mg kg(-1) in planting one and two, respectively. In broccoli and carrot plant tissues, SeMet (selenomethionine) was the predominant selenoamino acid identified in Se aqueous extracts. In postharvest soils from planting one, phospholipid fatty acid (PLFA) analyses showed that amending the soil with S. pinnata exerted no effect on the microbial biomass, AMF (arbuscular mycorrhizal fungi), actinomycetes and Gram-positive and bacterial PLFA at both 0-5 and 0-30 cm, respectively, 3 years later. Successfully producing Se-enriched broccoli and carrots 3 and 4 years later after amending soil with Se-enriched S. pinnata clearly demonstrates its potential source as an organic Se enriched fertilizer for Se-deficient regions.

  9. Trace element profiles of the oxyanions of selenium in the development of murine hepatoma and the effect of Se supplementation on the essential trace element concentrations

    SciTech Connect

    Tariq, M.A.

    1992-01-01

    To determine trace quantities of selenium in tissue samples a simplified pre-concentration procedure is developed based upon sample digestion and separation of selenium from the bulk by solvent extraction and its determination by radioisotope induced x-ray fluorescence (RIXRF) spectrometry. Signal to background ratio is improved and interference from Br and As peaks is significantly reduced. Submicrogram quantities of selenium in animal tissues can be analyzed. The distribution and retention of selenate and selenite in C57L/J mice was investigated using intra-ocular injection of [sup 75]Se. The distribution and retention of species were studied during the progression of BBW756 murine hepatoma. Comparison is made with the normal distribution of selenium studied by RIXRF method. The distribution of the two oxidation states measured as activity of [sup 75]Se was almost identical but differed from the normal trace elemental profile, TEP. The excretion rates of the two selenium species in the initial phase are different with more selenate being excreted than selenite in the first two days. The whole body excretion rates followed a pure first order pattern after day two. This was not true for the individual organs of the animals. Selenium has shown both inhibiting and enhancing effects on the development of various cancer types. The effects of selenium supplementation on the development of BW7756 murine hepatoma have been monitored. Various non-lethal levels of Se are administrated in either drinking water or by intraperitoneal injection. The inhibitory effects are not specific to any stage of tumor development and the decrease in tumor growth is related to the general toxicity of the element. Supplementation of selenium at 2 [mu]g/ml level in the drinking water of the mice strongly influenced the concentration levels of Fe, Cu, Zn, Br, and Rb. The effect of selenite supplementation on the tissue levels of these elements is significantly different than that of selenate.

  10. An Overview of Selenium Uptake, Metabolism, and Toxicity in Plants

    PubMed Central

    Gupta, Meetu; Gupta, Shikha

    2017-01-01

    Selenium (Se) is an essential micronutrient for humans and animals, but lead to toxicity when taken in excessive amounts. Plants are the main source of dietary Se, but essentiality of Se for plants is still controversial. However, Se at low doses protects the plants from variety of abiotic stresses such as cold, drought, desiccation, and metal stress. In animals, Se acts as an antioxidant and helps in reproduction, immune responses, thyroid hormone metabolism. Selenium is chemically similar to sulfur, hence taken up inside the plants via sulfur transporters present inside root plasma membrane, metabolized via sulfur assimilatory pathway, and volatilized into atmosphere. Selenium induced oxidative stress, distorted protein structure and function, are the main causes of Se toxicity in plants at high doses. Plants can play vital role in overcoming Se deficiency and Se toxicity in different regions of the world, hence, detailed mechanism of Se metabolism inside the plants is necessary for designing effective Se phytoremediation and biofortification strategies. PMID:28123395

  11. UV-photochemical vapor generation of selenium for atomic absorption spectrometry: Optimization and 75Se radiotracer efficiency study

    NASA Astrophysics Data System (ADS)

    Rybínová, Marcela; Musil, Stanislav; Červený, Václav; Vobecký, Miloslav; Rychlovský, Petr

    2016-09-01

    Volatile selenium compounds were generated UV-photochemically in the continuous flow mode using four UV-photoreactors differing in the material of the reaction coil; Teflon tubing and quartz tubes with various inner diameters and wall thicknesses were tested. Atomic absorption spectrometry with an externally heated quartz furnace atomizer was employed as the detector. The relevant experimental generation parameters were optimized and the basic analytical characteristics were determined. Using formic acid as the photochemical agent, limits of detection achieved for selenium were in the range 46-102 ng L- 1 in dependence on the type of UV-photoreactor employed. When nitric acid was also added to the photochemical agent, the limits of detection were reduced to 27-44 ng L- 1. The repeatability did not exceed 2.4% (5 μg L- 1 Se(IV), n = 10). Experiments with 75Se radiotracer have been performed for the first time to quantify the efficiency of UV-photochemical vapor generation (UV-PVG) of selenium. The highest efficiency of 67 ± 1% was obtained for a UV-photoreactor containing a quartz reaction coil (2.0 mm i.d., 4.0 mm o.d.). The generation efficiency of 61 ± 1% was obtained for a Teflon reaction coil (1.0 mm i.d., 1.4 mm o.d.). Mapping of the radiotracer distribution in the individual parts of the apparatus did not reveal substantial transport losses of the analyte in the UV-PVG system.

  12. Effects of dietary selenium and vitamin E on immune response and biological blood parameters of broilers reared under thermoneutral or heat stress conditions

    NASA Astrophysics Data System (ADS)

    Habibian, Mahmood; Ghazi, Shahab; Moeini, Mohammad Mehdi; Abdolmohammadi, Alireza

    2014-07-01

    A study was conducted using 360 broiler chickens to evaluate the effects of dietary vitamin E (0, 125 and 250 mg/kg), selenium (Se, 0, 0.5 and 1 mg/kg), or their different combinations on immune response and blood biological parameters of broilers raised under either thermoneutral (TN, 23.9 °C constant) or heat stress (HS, 23.9 to 37 °C cycling) conditions. Humoral immunity was assessed by intravenous injection of 7 % sheep red blood cell (SRBC) followed by evaluation of serum for antibody titers in primary and secondary responses. Heterophil to lymphocyte (H/L) ratio also determined as an indicator of stress. Furthermore, at the end of the experiment, birds were bled for determination of some biological parameters. There was a significant reduction in body weight and feed intake, but the feed conversion ratio increased when the birds were exposed to HS ( P < 0.05). Body weight and feed intake were not influenced significantly by dietary vitamin E and Se ( P > 0.05), whereas feed conversion was improved significantly by 125 mg/kg vitamin E ( P < 0.05). The liver and lymphoid organ weights as well as IgM and IgG, antibody titers for primary and secondary antibody responses to SRBC were reduced significantly under HS ( P < 0.05). Heat stress also resulted in a significant increase in H/L ratio ( P < 0.05). Dietary vitamin E resulted in improvement of primary and secondary antibody responses both in TN and HS broilers ( P < 0.05). The HS birds also showed an improved antibody titer in secondary response with high concentration of Se ( P < 0.05). Vitamin E and Se had interactive effects on anti-SRBC titers; however, no consistent differences were found between dietary levels during the study. The H/L ratio decreased by feeding vitamin E at both levels either under HS or TN conditions ( P < 0.05). The serum concentrations of glucose, triglycerides, total cholesterol, and LDL-cholesterol were increased but serum HDL-cholesterol decreased in HS broilers ( P < 0.05).

  13. Influence of dietary selenium on the disposition of arsenate in the female B6C3F{sub 1} mouse

    SciTech Connect

    Kenyon, E.M.; Hughes, M.F.; Levander, O.A.

    1997-06-27

    Interactions between arsenic (As) and selenium (Se) at the metabolic level are multifaceted and complex. These interactions are of practical significance because populations in various parts of the world are simultaneously exposed to inorganic As in drinking water and Se mainly in the diet at varying levels. The primary goal of this study was to investigate whether differing dietary Se status would alter the profile of urinary metabolites or their time course for elimination after exposure to arsenate [As(V)]. Weanling female 86C3F, mice were maintained for 28 d on either a control diet of powdered rodent meal sufficient in Se (A 0.2 ppm) or Torula yeast-based (TYB) diets deficient (B, 0.02 ppm Se), sufficient (C, 0.2 ppm Se), or excessive (D, 2.0 ppm Se) in Se; mice then received by oral gavage 5 mg (As)/kg as sodium [{sup 73}As] arsenate. The time course for elimination of total arsenic and metabolites in urine was measured over a 48-h period, and total arsenic was determined in feces and tissues at 48 h. Mice on the Se excess diet excreted a significantly higher percentage of urinary As as inorganic As, with a significantly decreased ratio of organic to inorganic As compared to Se-sufficient mice, suggesting that As methylation was decreased. Mice on the Se-deficient diet appeared to eliminate As(V), arsenite, and dimethylarsinic acid (DMA) in urine more slowly than Se-sufficient mice; however, further studies are required to confirm this finding. Mice on the Se-sufficient meal diet (A) excreted significantly less (by percent) arsenate-derived radioactivity in urine and more in feces compared to mice on the Se-sufficient TYB diet (C), with total elimination being similar for both groups. This indicates that mice on the meal diet absorbed significantly less As(V) than mice on the TYB diet, and this may be due to more fiber or {open_quotes}bulk{close_quotes} in the meal diet. 35 refs., 6 figs., 6 tabs.

  14. Biotransformation and accumulation of selenium inside organisms in an engineered aquatic ecosystem designed for bioremediation of Se from agriculture drainage water and brine shrimp production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Excessive selenium (Se) in soils and waters present in the westside of central California was determined to be responsible for ecotoxicities observed in water fowl frequenting large bodies of water, i.e., evaporation ponds. In order to monitor the fate and potentially design an aquatic Se remediatio...

  15. Cadmium-induced alterations in the antioxidant defense system of the rat eye in relation to dietary selenium intake

    SciTech Connect

    Sinno, J.A.M.

    1989-01-01

    Studies were conducted to investigate the effects of dietary cadmium (Cd)upon enzymatic antioxidant function in the ocular tissues of the albino rat. Activity of glutathione peroxidase (GSH-Px), Se-independent GSH-Px and catalase, and concentrations of thiobarbituric acid-reactive substances (TBARS), glutathione, and the elements Se, Cd and copper (Cu) were determined in ocular tissues from each group. Feeding rats a low Se diet resulted in a significant decrease in GSH-Px activity irrespective of Cd treatment. Activity of Se-independent GSH-Px in rats maintained on the low Se diet decreased when compared to Se-adequate controls. Cd treatment of rats fed low Se resulted in increased activity when compared to low-Se controls. When comparisons were made between ocular TBARS in rats maintained at either level of dietary Se, with or without Cd treatment, decreased ocular TBARS were observed in Cd-treated groups. A significant decrease in the ocular concentration of Se occurred in rats fed 0.05 ppm Se when compared to rats supplemented with 0.10 ppm Se. Administering Cd to the low Se group increased ocular Se levels 100%. A negative correlation between ocular Se concentration and the level of TBARS was observed, suggesting a possible alternate role for Se as an antioxidant in the eye.

  16. Dietary habits and selenium, glutathione peroxidase and total antioxidant status in the serum of patients with relapsing-remitting multiple sclerosis

    PubMed Central

    2014-01-01

    Background Dietary habits and adequate dietary intake of antioxidants in the diet may be one of the most important environmental factors for the prevention of Multiple Sclerosis (MS). Objectives The aim of this study was to estimate selenium (Se) concentration, glutathione peroxidase (GSH-Px) activity and total antioxidant status (TAS) in the serum of patients with MS and the influence of dietary habits on the status. Methods 101 patients with relapsing-remitting MS (aged 18-58 years), as well as control group of 63 healthy people (aged 19-65 years) were studied. Food-frequency questionnaires were implemented to collect the dietary data. Se concentration in the serum samples was determined by atomic absorption spectrometry. GSH-Px activity and TAS in examined serum was measured using the ready-made sets of tests by Randox Laboratories Ltd., UK. Results Serum Se concentration and GSH-Px activity in the serum of patients with MS (55.2±16.2 μg/L, 6676.1±2386.4 U/L; respectively) were significantly decreased (p<0.01, p<0.05; respectively) compared with control group (79.2±20.6 μg/L, 8029.9±2650.1 U/L; respectively). A significant correlation (r=0.39, p<0.01) was observed between Se concentration and GSH-Px activity in the serum of examined patients. TAS value in the serum of patients with MS (1.03±0.37 mmol/L) was also significantly lower (p<0.01) than in healthy volunteers (1.48±0.41 mmol/L). Frequent consumption of poultry, bakery products, pulses and fish seemed to increase serum Se concentration in the group of patients; whereas frequent consumption of butter, wholegrain bread, sweet beverages and sugar was found to accompany with lower values of Se in the serum. We have observed significant decrease TAS (p<0.05, p<0.01; respectively) in the serum of smokers and those patients who received immunomodulatory drugs (0.95±0.39 mmol/L, 0.92±0.34 mmol/L; respectively) compared with no-smoking patients and not taking immunomodulators (1.14±0.33 mmol/L, 1.31±0

  17. Chemoprotective and chemosensitizing properties of selenium nanoparticle (Nano-Se) during adjuvant therapy with cyclophosphamide in tumor-bearing mice.

    PubMed

    Bhattacharjee, Arin; Basu, Abhishek; Biswas, Jaydip; Sen, Tuhinadri; Bhattacharya, Sudin

    2017-01-01

    Cyclophosphamide (CP) is one of the widely used anticancer agents; however, it has serious deleterious effects on normal host cells due to its nonspecific action. The essential trace element Selenium (Se) is suggested to have chemopreventive and chemotherapeutic efficacy and currently used in pharmaceutical formulations. Previous report had shown Nano-Se could protect CP-induced hepatotoxicity and genotoxicity in normal Swiss albino mice; however, its role in cancer management is still not clear. The aim of present study is to investigate the chemoprotective efficacy of Nano-Se against CP-induced toxicity as well as its chemoenhancing capability when used along with CP in Swiss albino mice against Ehrlich's ascites carcinoma (EAC) cells. CP was administered (25 mg/kg b.w., i.p.) and Nano-Se was given (2 mg Se/kg b.w., p.o.) in concomitant and pretreatment schedule. Increase levels of serum hepatic marker, hepatic lipid peroxidation, DNA damage, and chromosomal aberration in CP-treated mice were significantly (P < 0.05) reversed by Nano-Se. The lowered status of various antioxidant enzymes in tumor-bearing mice after CP treatment was also effectively increased by Nano-Se. Administration of Nano-Se along with CP caused a significant reduction in tumor volume, packed cell volume, viable tumor cell count, and increased the survivability of the tumor-bearing hosts. The results suggest that Nano-Se exhibits significant antitumor and antioxidant effects in EAC-bearing mice. The potential for Nano-Se to ameliorate the CP-evoked toxicity as well as to improve the chemotherapeutic effect could have beneficial implications for patients undergoing chemotherapy with CP.

  18. Selenium-tellurium sequences in binary glasses as depicted by 77Se and 125Te NMR.

    PubMed

    Bureau, Bruno; Boussard-Plédel, Catherine; LeFloch, Marie; Troles, Johann; Smektala, Frédéric; Lucas, Jacques

    2005-04-07

    Some resolved solid state (77)Se NMR spectra are presented in the Te(x)Se(1-x) vitreous system at ambient temperature. They exhibit three different kinds of Se lines assigned to the following Se atom neighborhoods: Se-Se-Se, Se-Se-Te, and Te-Se-Te. Different models were considered to describe the way the Se and Te atoms are linked into the chains: clustering process, homogeneous distribution, random distribution. Finally, thanks to the measurements of the relative intensities of the lines, it appears that Se and Te atoms are mainly randomly distributed with a small preference for heteropolar bonds. The (125)Te spectra are also shown but their resolution is too weak to be informative concerning the vitreous network.

  19. Toxicity of organic selenium in the diet to chinook salmon

    USGS Publications Warehouse

    Hamilton, Steven J.; Buhl, Kevin J.; Faerber, Neil L.; Bullard, Fern A.; Wiedmeyer, Raymond H.

    1990-01-01

    The toxicity of two organoselenium diets was evaluated in 90- to 120-d partial life cycle tests with two life stages of chinook salmon (Oncorhynchus tshawytscha Walbaum). One of the diets contained fish meal made from high-selenium mosquitofish (Gambusia affinis Baird and Girard) collected from the selenium-laden San Luis Drain, California (here termed SLD diet) and the other contained meal made from low-selenium mosquitofish (collected from a reference site) fortified with selenomethionine. A 90-d study was conducted with swim-up larvae in a water-simulating dilution of San Luis Drain water in a standardized fresh water; and a 120-d study was conducted with fingerlings 70-mm long in a water of similar quality but prepared with a standardized brackish water. After 90 d of exposure in the freshwater study, survival was reduced in fish fed ≥9.6 μg Se/g of either diet, and growth was reduced in fish fed ≥5.3 μg Se/g of SLD diet or ≥18.2 μg Se/g of selenomethionine diet. Reduced fish growth, whole-body concentrations of selenium and survival were strongly correlated to concentrations of selenium in both diets. After 120 d of exposure in the brackish-water study, survival was unaffected but growth was reduced in fish fed ≥18.2 μg Se/g of SLD diet or 35.4 μg Se/g of selenomethionine diet. After 120 d of dietary exposure, survival during a 10-d seawater challenge test was reduced in fish fed 35.4 μg Se/g of either diet. In this second dietary study, concentration—response relations were observed in both dietary treatments between the dietary concentrations of selenium and all three characteristics — fish growth, whole-body concentrations of selenium and survival in seawater.

  20. The uptake and distribution of selenium in three aquatic plants grown in Se(IV) solution.

    PubMed

    Mechora, Spela; Stibilj, Vekoslava; Germ, Mateja

    2013-03-15

    The uptake of Se(IV) by Myriophyllum spicatum, Ceratophyllum demersum and Potamogeton perfoliatus, and the effects of Se(IV) on their physiological and biochemical characteristics were studied. Plants were cultivated outdoors under semi-controlled conditions in water solution containing Na selenite (20 μg Se L(-1) and 10 mg Se L(-1)). The higher concentration of Se lowered the photochemical efficiency of PSII in all species studied, while the lower concentration had no effect on any species. The higher concentration of Se lowered respiratory potential in M. spicatum. The response of M. spicatum and C. demersum to Se(IV) regarding chlorophylls was variable, however in the majority of cases, there was a trend of increasing the amount of chlorophylls, while in P. perfoliatus the amount of chlorophyll a decreased. The concentration of Se in plants cultured in 10 mg Se(IV) L(-1) ranged from 436 to 839 μg Se g(-1) DM in M. spicatum, 319 to 988 μg Se g(-1) DM in C. demersum and 310 to 661 μg Se g(-1) DM in P. perfoliatus. The amount of soluble Se compounds in enzyme extracts of high Se treatment was 27% in M. spicatum, 41% in C. demersum and 35% in P. perfoliatus. Se compounds were determined using HPLC-ICP-MS. It was observed that the applied Se(IV) was mainly transformed to insoluble Se.

  1. Optical properties of Se2- and Se2 color centers in the red selenium ultramarine with the sodalite structure.

    PubMed

    Schlaich, H; Lindner, G G; Felmann, J; Göbel, E O; Reinen, D

    2000-06-26

    The unique optical properties of Se2- radicals located in the cages of the sodalite structure are reported. By means of luminescence, photoluminescence excitation, and absorption spectroscopy, three different centers are identified. Two of them are Se2- anions in sites with presumably a tetrahedral Na4(4+) coordination and a Na3(3+) environment with cation deficiency, respectively, giving rise to a red luminescence band with two different progressions. The third center is the intermediate Se2 molecule, created photochemically by UV laser excitation. It induces an additional blue luminescence. The electronic properties of the Se2- centers, particularly in the excited states, are significantly influenced by steric constraints imposed by the limited space in the sodalite host polyhedra. Thus, the sodalite structure can be viewed as a model system for studying effects of this kind on chromophores imbedded in the cages of the zeolite-type lattice.

  2. Effects of dietary supplementation of selenium-enriched probiotics on production performance and intestinal microbiota of weanling piglets raised under high ambient temperature.

    PubMed

    Lv, C H; Wang, T; Regmi, N; Chen, X; Huang, K; Liao, S F

    2015-12-01

    This study was designed to evaluate the efficacy of selenium-enriched probiotics (SeP) on production performance and intestinal microbiota of piglets raised under high ambient temperature. Forty-eight cross-bred weanling piglets (28 days old), randomly allotted into 12 pens (four piglets/pen) and four dietary treatments (three pens/treatment group), were fed ad libitum for 42 days a basal diet (Con) or the basal diet supplemented with probiotics (Pro), sodium selenite (ISe) or a SeP preparation. Blood and faecal samples were collected on days 0, 14, 28 and 42 post-treatment. The SeP group had higher final BW (p < 0.05), greater ADG (p < 0.05) and lower FCR (p < 0.01) than the Pro, ISe or Con group. The diarrhoea incidence rate of either SeP or Pro group was lower (p < 0.01) than the ISe or Con group. Blood Se concentration and GSH-Px activity were both higher (p < 0.01) in the SeP than in the Pro, ISe or Con group. On days 28 and 42, the serum concentrations of T3 were higher (p < 0.01) and T4 lower (p < 0.01) in the SeP than in the ISe group, and the T3 and T4 concentrations in the ISe group, in turn, were higher (p < 0.05) and lower (p < 0.01), respectively, than in the Pro or Con group. Also on days 28 and 42, the faecal counts of lactobacillus bacteria were higher (p < 0.01) while Escherichia coli lower (p < 0.01) in the SeP or Pro group as compared to the ISe or Con group. The results of RFLP showed that the faecal microbial flora in the SeP group changed the most (numerically) as compared to the Pro or ISe group. These results suggest that the SeP product may serve as a better alternative to antibiotics than the solo probiotics for using as a growth promoter for weanling piglets.

  3. Soil-type influences human selenium status and underlies widespread selenium deficiency risks in Malawi.

    PubMed

    Hurst, Rachel; Siyame, Edwin W P; Young, Scott D; Chilimba, Allan D C; Joy, Edward J M; Black, Colin R; Ander, E Louise; Watts, Michael J; Chilima, Benson; Gondwe, Jellita; Kang'ombe, Dalitso; Stein, Alexander J; Fairweather-Tait, Susan J; Gibson, Rosalind S; Kalimbira, Alexander A; Broadley, Martin R

    2013-01-01

    Selenium (Se) is an essential human micronutrient with critical roles in immune functioning and antioxidant defence. Estimates of dietary Se intakes and status are scarce for Africa although crop surveys indicate deficiency is probably widespread in Malawi. Here we show that Se deficiency is likely endemic in Malawi based on the Se status of adults consuming food from contrasting soil types. These data are consistent with food balance sheets and composition tables revealing that >80% of the Malawi population is at risk of dietary Se inadequacy. Risk of dietary Se inadequacy is >60% in seven other countries in Southern Africa, and 22% across Africa as a whole. Given that most Malawi soils cannot supply sufficient Se to crops for adequate human nutrition, the cost and benefits of interventions to alleviate Se deficiency should be determined; for example, Se-enriched nitrogen fertilisers could be adopted as in Finland.

  4. Soil-type influences human selenium status and underlies widespread selenium deficiency risks in Malawi

    PubMed Central

    Hurst, Rachel; Siyame, Edwin W. P.; Young, Scott D.; Chilimba, Allan D. C.; Joy, Edward J. M.; Black, Colin R.; Ander, E. Louise; Watts, Michael J.; Chilima, Benson; Gondwe, Jellita; Kang'ombe, Dalitso; Stein, Alexander J.; Fairweather-Tait, Susan J.; Gibson, Rosalind S.; Kalimbira, Alexander A.; Broadley, Martin R.

    2013-01-01

    Selenium (Se) is an essential human micronutrient with critical roles in immune functioning and antioxidant defence. Estimates of dietary Se intakes and status are scarce for Africa although crop surveys indicate deficiency is probably widespread in Malawi. Here we show that Se deficiency is likely endemic in Malawi based on the Se status of adults consuming food from contrasting soil types. These data are consistent with food balance sheets and composition tables revealing that >80% of the Malawi population is at risk of dietary Se inadequacy. Risk of dietary Se inadequacy is >60% in seven other countries in Southern Africa, and 22% across Africa as a whole. Given that most Malawi soils cannot supply sufficient Se to crops for adequate human nutrition, the cost and benefits of interventions to alleviate Se deficiency should be determined; for example, Se-enriched nitrogen fertilisers could be adopted as in Finland. PMID:23478344

  5. Antioxidant biomarker survey ensuing long-term selenium withdrawal in Acipenser baeri fed Se-cysteine diets.

    PubMed

    Elia, Antonia Concetta; Abete, Maria Cesarina; Pacini, Nicole; Dörr, Ambrosius Josef Martin; Scanzio, Tommaso; Prearo, Marino

    2014-05-01

    Two selenium withdrawal periods, 30 and 90 days, were considered for sturgeon fed 90 days three Se-cysteine diets (1.25, 5, 20 mgkg(-1)). Subsequently Acipenser baeri was fed the previous control diet (0.32 mgSekg(-1)) for 90 days. Levels of superoxide dismutase, catalase, glutathione peroxidases, glutathione reductase, glyoxalase-II and malondialdehyde were determined in liver and kidney. Chemical analyses were carried out for the same tissues and for muscle. A reduction of Se levels in all tissues was recorded and the metalloid concentration decreased more quickly in liver than in kidney and muscle. At the end of the withdrawal Se concentration in muscle remained high in specimens previously fed 20 mgSekg(-1) diet, and disturbance of key antioxidant enzymes was recorded in liver and kidney. Moreover, alterations in glutathione peroxidases, and glyoxalase-II activities persisted even after 90 withdrawal days and were indicative of oxidative stress induced by Se-cysteine concentrations.

  6. Effects of dietary sodium selenite and selenium yeast on antioxidant enzyme activities and oxidative stability of chicken breast meat.

    PubMed

    Ahmad, Hussain; Tian, Jinke; Wang, Jianjun; Khan, Muhammad Ammar; Wang, Yuanxiao; Zhang, Lili; Wang, Tian

    2012-07-25

    The effects of sodium selenite (SS) and selenium yeast (SY) alone and in combination (MS) on the selenium (Se) content, antioxidant enzyme activities (AEA), total antioxidant capacity (TAC), and oxidative stability of chicken breast meat were investigated. The results showed that the highest (p < 0.05) glutathione peroxidase (GSH-Px) activity was found in the SS-supplemented chicken breast meat; however, SY and MS treatments significantly increased (p < 0.05) the Se content and the activities of catalase (CAT), total superoxide dismutase (T-SOD), and TAC, but decreased (p < 0.05) the malondialdehyde (MDA) content at 42 days of age. Twelve days of storage at 4 °C decreased (p < 0.05) the activity of the GSH-Px, but CAT, T-SOD, and TAC remained stable. SY decreased the lipid oxidation more effectively in chicken breast meat. It was concluded that SY and MS are more effective than SS in increasing the AEA, TAC, and oxidative stability of chicken breast meat.

  7. Effect of Inorganic Dietary Selenium Supplementation on Selenoprotein and Lipid Metabolism Gene Expression Patterns in Liver and Loin Muscle of Growing Lambs.

    PubMed

    Juszczuk-Kubiak, Edyta; Bujko, Kamila; Cymer, Monika; Wicińska, Krystyna; Gabryszuk, Mirosław; Pierzchała, Mariusz

    2016-08-01

    Effect of selenium (Se) supplementation on the selenoprotein and lipid metabolism gene expression patterns in ruminants, especially in lambs is not yet fully understood. The aim of study was to evaluate the effect of Se supplementation on the messenger RNA (mRNA) expression patterns of selected selenoproteins and genes related to lipid metabolism in growing lambs. The experiment was conducted on 48 Polish Merino lambs divided into two groups (n = 24): control (C)-lambs fed with a basal diet (BD) with no Se supplementation, and supplemented (S)-lambs fed with a BD, supplemented with 0.5 mg Se/kg as sodium selenate for 8 weeks. Expression of 12 selenoproteins and six genes related to lipid metabolism was analyzed in the liver and longissimus dorsi (LD) muscle of growing lambs by qPCR. Significant differences were found in the expression of GPX1, GPX2, SEPM, SEPW1, SEP15, SEPGS2, and TXNRD1 in the liver, and GPX1, SEPP1, SEPN1, SEPW1, SEP15, and MSRB1 in the LD muscle between S and C lambs. Se supplementation mainly upregulated SEPW1, SEP15 (P < 0.001; P < 0.01) mRNA expression in the liver, and GPX1, SEPP1, SEPN1, SEPW1 (P < 0.001; P < 0.01) in the muscle of S group. On the other hand, significant decrease in GPX2 (P < 0.01), SEPM (P < 0.001), and SEPHS2 (P < 0.01) mRNA expression levels were observed in the liver of S group of lambs. Se supplementation did not affect PON1, LXRα, and PPARα mRNA expression levels, but a significant increase in mRNA levels of APOE and LPL in the LD muscle (P < 0.05) as well as LPL (P < 0.05) in the liver were noticed in the group of Se supplemented lambs. Our study confirmed that, in lambs, similarly to other species, mRNA expression patterns of several selenoproteins highly depend on dietary Se levels, and their expression is ruled by hierarchical principles and tissue-specific mechanisms. Moreover, the study showed that changes Se intake leads to different levels of genes expression related

  8. Formation of two-dimensional CuSe on Cu(111) at very low selenium coverage

    DOE PAGES

    Walen, Holly; Liu, Da -Jiang; Oh, Junepyo; ...

    2016-05-09

    Here, using scanning tunneling microscopy (STM), we observe that adsorption of Se on Cu(111) produces islands with (√3 x √3)R30° structure, at Se coverages far below the structure's ideal coverage of 1/3 ML. Based on density functional theory (DFT), these islands cannot form due to attractive interactions between chemisorbed Se atoms. DFT shows that incorporating Cu atoms into the √3-Se lattice stabilizes the structure, which provides a plausible explanation for the experimental observations.

  9. Selenium, Chromium, and Vitamin D: What Dietitians Need to Know Regarding Dietary Supplements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate nutrient data for dietary supplement composition are essential for determining supplements’ contribution to total dietary intake. To plan a nationwide adult multivitamin/mineral (MVM) study, the USDA Nutrient Data Laboratory (NDL) obtained prevalence information for the most common labeled...

  10. Selenium accumulation by plants

    PubMed Central

    White, Philip J.

    2016-01-01

    Background Selenium (Se) is an essential mineral element for animals and humans, which they acquire largely from plants. The Se concentration in edible plants is determined by the Se phytoavailability in soils. Selenium is not an essential element for plants, but excessive Se can be toxic. Thus, soil Se phytoavailability determines the ecology of plants. Most plants cannot grow on seleniferous soils. Most plants that grow on seleniferous soils accumulate <100 mg Se kg–1 dry matter and cannot tolerate greater tissue Se concentrations. However, some plant species have evolved tolerance to Se, and commonly accumulate tissue Se concentrations >100 mg Se kg–1 dry matter. These plants are considered to be Se accumulators. Some species can even accumulate Se concentrations of 1000–15 000 mg Se kg–1 dry matter and are called Se hyperaccumulators. Scope This article provides an overview of Se uptake, translocation and metabolism in plants and highlights the possible genetic basis of differences in these between and within plant species. The review focuses initially on adaptations allowing plants to tolerate large Se concentrations in their tissues and the evolutionary origin of species that hyperaccumulate Se. It then describes the variation in tissue Se concentrations between and within angiosperm species and identifies genes encoding enzymes limiting the rates of incorporation of Se into organic compounds and chromosomal loci that might enable the development of crops with greater Se concentrations in their edible portions. Finally, it discusses transgenic approaches enabling plants to tolerate greater Se concentrations in the rhizosphere and in their tissues. Conclusions The trait of Se hyperaccumulation has evolved several times in separate angiosperm clades. The ability to tolerate large tissue Se concentrations is primarily related to the ability to divert Se away from the accumulation of selenocysteine and selenomethionine, which might be incorporated

  11. Effect of dietary fat sources and zinc and selenium supplements on the composition and consumer acceptability of chicken meat.

    PubMed

    Bou, R; Guardiola, F; Barroeta, A C; Codony, R

    2005-07-01

    A factorial design was used to study the effect of changes in broiler feed on the composition and consumer acceptability of chicken meat. One week before slaughter, 1.25% dietary fish oil was removed from the feed and replaced by other fat sources (animal fat or linseed oil) or we continued with fish oil, and diets were supplemented with Zn (0, 300, or 600 mg/kg), and Se (0 or 1.2 mg/kg as sodium selenite or 0.2 mg/kg as Se-enriched yeast). The changes in dietary fat led to distinct fatty acid compositions of mixed raw dark and white chicken meat with skin. The fish oil diet produced meat with the highest eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) content, whereas the linseed oil diet led to meat with the highest content in total n-3 polyunsaturated acids (PUFA), especially linolenic acid. However, meat from animals on the animal fat diet was still rich in very long-chain n-3 PUFA. Se content was affected by Se and Zn supplements. Se content increased with Zn supplementation. However, only Se from the organic source led to a significant increase in this mineral in meat compared with the control. Consumer acceptability scores and TBA values of cooked dark chicken meat after 74 d or after 18 mo of frozen storage were not affected by any of the dietary factors studied.

  12. Selenium bioavailability from naturally produced high-selenium peas and oats in selenium-deficient rats.

    PubMed

    Yan, Lin; Johnson, LuAnn K

    2011-06-08

    This study determined the bioavailability of selenium (Se) from yellow peas and oats harvested from the high-Se soil of South Dakota, United States. The Se concentrations were 13.5 ± 0.2 and 2.5 ± 0.1 mg/kg (dry weight) for peas and oats, respectively. Male weanling Sprague-Dawley rats were depleted of Se by feeding them a 30% Torula yeast-based diet (4.1 μg Se/kg) for 56 days, and then they were replenished with Se for an additional 50 days by feeding them the same diet supplemented with 20, 30, or 40 μg Se/kg from peas or oats, respectively. Selenium bioavailability was determined on the basis of the restoration of Se-dependent enzyme activities and tissue Se concentrations in Se-depleted rats, comparing those responses for yellow peas and oats to those for l-selenomethionine (SeMet; used as a reference) by using a slope-ratio method. Dietary supplementation with peas or oats resulted in linear or log-linear, dose-dependent increases in glutathione peroxidase activities in blood and liver and in thioredoxin reductase activity in liver. Supplementation with peas or oats resulted in linear or log-linear, dose-dependent increases in Se concentrations of plasma, liver, gastrocnemius muscle, and kidneys. The overall bioavailability was approximately 88% for Se from yellow peas and 92% from oats, compared to SeMet. It was concluded that Se from naturally produced high-Se yellow peas or oats is highly bioavailable in this model and that these high-Se foods may be a good dietary source of Se.

  13. Effects of dietary selenium of organic form against lead toxicity on the antioxidant system in Cyprinus carpio.

    PubMed

    Özkan-Yilmaz, Ferbal; Özlüer-Hunt, Arzu; Gündüz, Suna Gül; Berköz, Mehmet; Yalin, Serap

    2014-04-01

    In this study was evaluated potential protective effect of organic selenium (Se) on heavy metal stress induced by lead (Pb) in Cyprinus carpio. For this reason, C. carpio was exposed to sublethal concentration of Pb (1.5 mg/L Pb(NO3)2) for 14 days. The fish were fed a basal (control; measured 0.55 mg/kg Se) diet or a basal diet supplemented with 2.50 mg/kg (measured 2.92 mg/kg Se) organic Se (Sel-Plex(®)) during the experiment period. The variations in glutathione peroxidase (GSH-Px), glutathione S-transferase (GST) activities, and levels of reduced glutathione (GSH) with malondialdehyde (MDA) in liver and brain tissues of C. carpio were investigated in experimental groups. GSH levels in liver and brain tissues were significantly decreased by exposure to Pb. GST activity was significantly increased (p < 0.05) in liver tissue, but decreased in brain of treated fish by exposure to Pb. Also, GSH-Px activity was significantly increased in liver tissue, but decreased in brain of Pb-treated fish. Levels of MDA were increased in liver and brain of Pb-treated fish. The organic Se treatment for Pb-intoxicated animals improved activities of GSH-Px, GST and levels of MDA within normal limits. Supplemented Se could be able to improve Pb-induced oxidative stress by decreasing lipid peroxidation and regulating antioxidant defense system in tissues.

  14. Biomimetic synthesis of selenium nanospheres by bacterial strain JS-11 and its role as a biosensor for nanotoxicity assessment: a novel se-bioassay.

    PubMed

    Dwivedi, Sourabh; Alkhedhairy, Abdulaziz A; Ahamed, Maqusood; Musarrat, Javed

    2013-01-01

    Selenium nanoparticles (Se-NPs) were synthesized by green technology using the bacterial isolate Pseudomonas aeruginosa strain JS-11. The bacteria exhibited significant tolerance to selenite (SeO3(2-)) up to 100 mM concentration with an EC50 value of 140 mM. The spent medium (culture supernatant) contains the potential of reducing soluble and colorless SeO3(2-) to insoluble red elemental selenium (Se(0)) at 37°C. Characterization of red Se° product by use of UV-Vis spectroscopy, X-ray diffraction (XRD), atomic force microscopy (AFM) and transmission electron microscopy (TEM) with energy dispersive X-ray spectrum (EDX) analysis revealed the presence of stable, predominantly monodispersed and spherical selenium nanoparticles (Se-NPs) of an average size of 21 nm. Most likely, the metabolite phenazine-1-carboxylic acid (PCA) released by strain JS-11 in culture supernatant along with the known redox agents like NADH and NADH dependent reductases are responsible for biomimetic reduction of SeO3(2-) to Se° nanospheres. Based on the bioreduction of a colorless solution of SeO3(2-) to elemental red Se(0), a high throughput colorimetric bioassay (Se-Assay) was developed for parallel detection and quantification of nanoparticles (NPs) cytotoxicity in a 96 well format. Thus, it has been concluded that the reducing power of the culture supernatant of strain JS-11 could be effectively exploited for developing a simple and environmental friendly method of Se-NPs synthesis. The results elucidated that the red colored Se° nanospheres may serve as a biosensor for nanotoxicity assessment, contemplating the inhibition of SeO3(2-) bioreduction process in NPs treated bacterial cell culture supernatant, as a toxicity end point.

  15. Biomimetic Synthesis of Selenium Nanospheres by Bacterial Strain JS-11 and Its Role as a Biosensor for Nanotoxicity Assessment: A Novel Se-Bioassay

    PubMed Central

    Dwivedi, Sourabh; AlKhedhairy, Abdulaziz A.; Ahamed, Maqusood; Musarrat, Javed

    2013-01-01

    Selenium nanoparticles (Se-NPs) were synthesized by green technology using the bacterial isolate Pseudomonas aeruginosa strain JS-11. The bacteria exhibited significant tolerance to selenite (SeO32−) up to 100 mM concentration with an EC50 value of 140 mM. The spent medium (culture supernatant) contains the potential of reducing soluble and colorless SeO32− to insoluble red elemental selenium (Se0) at 37°C. Characterization of red Se° product by use of UV-Vis spectroscopy, X-ray diffraction (XRD), atomic force microscopy (AFM) and transmission electron microscopy (TEM) with energy dispersive X-ray spectrum (EDX) analysis revealed the presence of stable, predominantly monodispersed and spherical selenium nanoparticles (Se-NPs) of an average size of 21 nm. Most likely, the metabolite phenazine-1-carboxylic acid (PCA) released by strain JS-11 in culture supernatant along with the known redox agents like NADH and NADH dependent reductases are responsible for biomimetic reduction of SeO32− to Se° nanospheres. Based on the bioreduction of a colorless solution of SeO32− to elemental red Se0, a high throughput colorimetric bioassay (Se-Assay) was developed for parallel detection and quantification of nanoparticles (NPs) cytotoxicity in a 96 well format. Thus, it has been concluded that the reducing power of the culture supernatant of strain JS-11 could be effectively exploited for developing a simple and environmental friendly method of Se-NPs synthesis. The results elucidated that the red colored Se° nanospheres may serve as a biosensor for nanotoxicity assessment, contemplating the inhibition of SeO32− bioreduction process in NPs treated bacterial cell culture supernatant, as a toxicity end point. PMID:23483909

  16. The electronic states of SeF: A reinterpretation of the chemiluminescent emission of the reaction of selenium with fluorine.

    PubMed

    Hermoso, Willian; Ornellas, Fernando R

    2010-05-21

    The low-lying doublet and quartet electronic states of the species SeF correlating with the first dissociation channel are investigated theoretically at a high-level of electronic correlation treatment, namely, the complete active space self-consistent field/multireference single and double excitations configuration interaction (CASSCF/MRSDCI) using a quintuple-zeta quality basis set including a relativistic effective core potential for the selenium atom. Potential energy curves for (Lambda+S) states and the corresponding spectroscopic properties are derived that allows for an unambiguous assignment of the only spectrum known experimentally as due to a spin-forbidden X (2)Pi-a (4) summation (-) transition, and not a A (2)Pi-X (2)Pi transition as assumed so far. For the bound excited doublets, yet unknown experimentally, this study is the first theoretical characterization of their spectroscopic properties. Also the spin-orbit coupling constant function for the X (2)Pi state is derived as well as the spin-orbit coupling matrix element between the X (2)Pi and a (4) summation (-) states. Dipole moment functions and vibrationally averaged dipole moments show SeF to be a very polar species. An overview of the lowest-lying spin-orbit (Omega) states completes this description.

  17. Dietary Selenomethionine Administration in the American Alligator (Alligator mississippiensis): Hepatic and Renal Se Accumulation and Its Effects on Growth and Body Condition.

    PubMed

    Finger, John W; Hamilton, Matthew T; Glenn, Travis C; Tuberville, Tracey D

    2017-04-01

    Selenium (Se) is an essential trace nutrient, but in excess, it can induce toxicity. Incomplete combustion of coal produces coal combustion wastes, which are enriched in Se and often disposed of in aquatic basins. While a multitude of studies have investigated Se accumulation in vertebrates, few studies have examined its effects on longer-lived top trophic carnivores, such as the American alligator (Alligator mississippiensis). In this study, alligators were fed one of three Dietary Treatments: mice injected with water (controls) or water supplemented with 1000 or 2000 ppm selenomethionine (SeMet). Dietary Treatment significantly affected Se levels in both the liver (p < 0.0001; raw mean ± SE: 1000 ppm group, 35.20 ± 6.32 ppm; 2000 ppm group, 49.97 ± 4.00 ppm) and kidney (p < 0.0001; raw mean ± SE: 1000 ppm group, 101.60 ± 8.64 ppm; 2000 ppm, 96.38 ± 5.81 ppm), which were significantly higher in alligators fed SeMet than in controls. Post-treatment head length, used to control for size variation, was negatively related to both kidney (p = 0.0142) and liver (p = 0.0010) Se concentrations. Dietary treatment with SeMet significantly reduced body condition (1000 ppm, p < 0.0029; 2000 ppm, p = 0.0075), but it significantly increased growth (1000 ppm, p < 0.0001; 2000 ppm, p = 0.0316). Body condition and growth remained unchanged in control alligators (p > 0.05). Our results demonstrate alligators are capable of accumulating high levels of Se through trophic transfer. The positive effects of accumulation on growth may demonstrate Se essentiality, whereas the negative effects on condition may demonstrate toxicity. Accumulation also was associated with mortality, further demonstrating toxicity. Future studies should further investigate the physiological effects of Se accumulation in long-lived, top-trophic carnivores.

  18. Binding and Conversion of Selenium in Candida utilis ATCC 9950 Yeasts in Bioreactor Culture.

    PubMed

    Kieliszek, Marek; Błażejak, Stanisław; Kurek, Eliza

    2017-02-25

    Selenium is considered an essential component of all living organisms. The use of yeasts as a selenium supplement in human nutrition has gained much interest over the last decade. The accumulation and biochemical transformation of selenium in yeast cells is particularly interesting to many researchers. In this article, we present the results of the determination of selenium and selenomethionine content in the biomass of feed yeast Candida utilis ATCC 9950 obtained from the culture grown in a bioreactor. The results indicated that C. utilis cells performed the biotransformation of inorganic selenium(IV) to organic derivatives (e.g., selenomethionine). Selenium introduced (20-30 mg Se(4+)∙L(-1)) to the experimental media in the form of sodium(IV) selenite (Na₂SeO₃) salt caused a significant increase in selenium content in the biomass of C. utilis,irrespective of the concentration. The highest amount of selenium (1841 μg∙gd.w.(-1)) was obtained after a 48-h culture in media containing 30 mg Se(4+)∙L(-1). The highest content of selenomethionine (238.8 μg∙gd.w.(-1)) was found after 48-h culture from the experimental medium that was supplemented with selenium at a concentration of 20 mg Se(4+)∙L(-1). Biomass cell in the cultures supplemented with selenium ranged from 1.5 to 14.1 g∙L(-1). The results of this study indicate that yeast cell biomass of C. utilis enriched mainly with the organic forms of selenium can be a valuable source of protein. It creates the possibility of obtaining selenium biocomplexes that can be used in the production of protein-selenium dietary supplements for animals and humans.

  19. Synthesis of selenium/EDTA-derived porous carbon composite as a Li-Se battery cathode

    NASA Astrophysics Data System (ADS)

    Zhao, Chenhao; Fang, Shuzhen; Hu, Zhibiao; Qiu, Sheng'en; Liu, Kaiyu

    2016-07-01

    The carbon substrate with unique 3D macroporous structure has been prepared through the immediate carbonization of ethylenediaminetetraacetic acid (EDTA) and KOH mixture. The porous carbon composed of micro- and small mesoporous (2-5 nm) structure has a BET specific surface area of 1824.8 m2 g-1. The amorphous and nanosized Se is uniformly encapsulated into the porous structure of porous carbon using melting diffusion route, and the weight content of Se in target Se/C composite can be as high as 50 %. As an Li-Se battery cathode, the Se/C composite delivers a reversible (2nd) discharge capacity of 597.4 mAh g-1 at 0.24C and retains a discharge capacity of 538.4 mAh g-1 at 0.24C after 100 cycles. Furthermore, the composite also has a stable capacity of 291.0 mAh g-1 at a high current of 4.8C. The high specific area and good porous size of EDTA-derived carbon substrate may a be responsibility for the excellent electrochemical performances of Se/C composite.

  20. JV Task - 116 Selenium's Role in the Seafood Safety Issue

    SciTech Connect

    Nicholas Ralston; Laura Raymond

    2009-03-30

    Continuing studies under these three funded projects - (JV Task 77 The Health Implications of the Mercury-Selenium Interaction, JV Task 96 Investigating the Importance of the Mercury-Selenium Interaction, and JV Task 116 Selenium's Role in the Seafood Safety Issue) - were performed to determine the effects of different levels of dietary mercury and selenium on the growth and development of test animals, and related tissue analyses, to understand the protective benefits of dietary selenium in reference to low-level exposure to mercury. Maternal exposure to methylmercury from seafood has been found to cause neurodevelopmental harm in children. However, significant nutritional benefits will be lost if fish consumption is needlessly avoided. The results of these studies support the hypothesis that intracellular Se itself is the physiologically important biomolecule and that the harm of mercury toxicity arises when Hg abundance becomes great enough to bind a significant portion of intracellular Se in vulnerable tissues such as the brain. Formation of HgSe limits bioavailability of Se for synthesis of Se-dependent enzymes, particularly in brain tissues. When production of these enzymes is impaired, the loss of their numerous essential functions results in the signs and symptoms of Hg toxicity. The finding that one mole of Se protects against many moles of Hg indicates that its beneficial effect is not due to sequestration of mercury as HgSe but rather due to the biological activity of the Se. Therefore, the selenium content of seafoods must be considered along with their methylmercury contents in evaluating the effect of dietary exposure to mercury.

  1. Synthesis of selenium nano-composite (t-Se@PS) by surface initiated atom transfer radical polymerization.

    PubMed

    Wang, Michael C P; Gates, Byron D

    2012-09-04

    Selenium nanostructures, which are otherwise susceptible to oxidative damage, were encapsulated with a thin layer of polystyrene. The thin layer of polystyrene was grafted onto the surfaces of selenium by a surface initiated atom transfer radical polymerization reaction. These encapsulated nanostructures demonstrate an enhanced resistance towards corrosion.

  2. Selenium (Se) seed priming induced growth and biochemical changes in wheat under water deficit conditions.

    PubMed

    Nawaz, Fahim; Ashraf, M Yasin; Ahmad, Rashid; Waraich, Ejaz Ahmad

    2013-02-01

    Insufficient stand establishment at early growth stages in wheat (Triticum aestivum L.) due to drought stress is a major problem that limits overall efficiency and yield of crop. Priming of seed is an effective method for raising seed performance and improving tolerance of crops to abiotic stresses especially drought. The seeds of two local wheat cultivars (Kohistan-97 and Pasban-90) were soaked in distilled water or sodium selenate solutions of 25, 50, 75, and 100 μM for 1/2 or 1 h at 25 °C and later re-dried to their original moisture levels before sowing. One-hour priming significantly increased root length stress tolerance index, dry matter stress tolerance index, and total biomass of seedlings; however, no significant effect of changing duration of Se seed priming was observed on plant height stress tolerance index and shoot/root ratio. Among cultivars, Kohistan-97 was found to be more responsive to Se seed treatment as 1 h priming at 100 μM significantly increased its total biomass by 43 % as compared to control treatment. Although biomass of seedlings was not affected with Se seed priming under normal conditions, but it increased significantly with increase in rates of Se under drought stress conditions. One-hour priming at 75 μM increased the total sugar content and total free amino acids in both wheat cultivars. A more significant decrease in soluble proteins of seedlings was observed by 1 h priming than 1/2 h priming under drought stress conditions.

  3. Dietary selenium disrupts hepatic triglyceride stores and transcriptional networks associated with growth and Notch signaling in juvenile rainbow trout.

    PubMed

    Knight, Rosalinda; Marlatt, Vicki L; Baker, Josh A; Lo, Bonnie P; deBruyn, Adrian M H; Elphick, James R; Martyniuk, Christopher J

    2016-11-01

    Dietary Se has been shown to adversely affect adult fish by altering growth rates and metabolism. To determine the underlying mechanisms associated with these observations, we measured biochemical and transcriptomic endpoints in rainbow trout following dietary Se exposures. Treatment groups of juvenile rainbow trout were fed either control Lumbriculus variegatus worms or worms cultured on selenized yeast. Selenized yeast was cultured at four nominal doses of 5, 10, 20 or 40mg/kg Se dry weight (measured dose in the worms of 7.1, 10.7, 19.5, and 31.8mg/kgSedw respectively) and fish were fed for 60days. At 60 d, hepatic triglycerides, glycogen, total glutathione, 8-isoprostane and the transcriptome response in the liver (n=8/group) were measured. Fish fed the nominal dose of 20 and 40mg/kg Se dry weight had lower body weight and a shorter length, as well as lower triglyceride in the liver compared to controls. Evidence was lacking for an oxidative stress response and there was no change in total glutathione, 8-isoprostane levels, nor relative mRNA levels for glutathione peroxidase isoforms among groups. Microarray analysis revealed that molecular networks for long-chain fatty acid transport, lipid transport, and low density lipid oxidation were increased in the liver of fish fed 40mg/kg, and this is hypothesized to be associated with the lower triglyceride levels in these fish. In addition, up-regulated gene networks in the liver of 40mg/kg Se treated fish included epidermal growth factor receptor signaling, growth hormone receptor, and insulin growth factor receptor 1 signaling pathways. These molecular changes are hypothesized to be compensatory and related to impaired growth. A gene network related to Notch signaling, which is involved in cell-cell communication and gene transcription regulation, was also increased in the liver following dietary treatments with both 20 and 40mg/kg Se. Transcriptomic data support the hypothesis that dietary Se increases the

  4. Delayed formation of zero-valent selenium nanoparticles by Bacillus mycoides SeITE01 as a consequence of selenite reduction under aerobic conditions

    PubMed Central

    2014-01-01

    Background Selenite (SeO32−) oxyanion shows severe toxicity to biota. Different bacterial strains exist that are capable of reducing SeO32− to non-toxic elemental selenium (Se0), with the formation of Se nanoparticles (SeNPs). These SeNPs might be exploited for technological applications due to their physico-chemical and biological characteristics. The present paper discusses the reduction of selenite to SeNPs by a strain of Bacillus sp., SeITE01, isolated from the rhizosphere of the Se-hyperaccumulator legume Astragalus bisulcatus. Results Use of 16S rRNA and GyrB gene sequence analysis positioned SeITE01 phylogenetically close to B. mycoides. On agarized medium, this strain showed rhizoid growth whilst, in liquid cultures, it was capable of reducing 0.5 and 2.0 mM SeO32− within 12 and 24 hours, respectively. The resultant Se0 aggregated to form nanoparticles and the amount of Se0 measured was equivalent to the amount of selenium originally added as selenite to the growth medium. A delay of more than 24 hours was observed between the depletion of SeO32 and the detection of SeNPs. Nearly spherical-shaped SeNPs were mostly found in the extracellular environment whilst rarely in the cytoplasmic compartment. Size of SeNPs ranged from 50 to 400 nm in diameter, with dimensions greatly influenced by the incubation times. Different SeITE01 protein fractions were assayed for SeO32− reductase capability, revealing that enzymatic activity was mainly associated with the membrane fraction. Reduction of SeO32− was also detected in the supernatant of bacterial cultures upon NADH addition. Conclusions The selenite reducing bacterial strain SeITE01 was attributed to the species Bacillus mycoides on the basis of phenotypic and molecular traits. Under aerobic conditions, the formation of SeNPs were observed both extracellularly or intracellullarly. Possible mechanisms of Se0 precipitation and SeNPs assembly are suggested. SeO32− is proposed to be enzimatically reduced to

  5. Induction of mitochondrial-dependent apoptosis in T24 cells by a selenium (Se)-containing polysaccharide from Ginkgo biloba L. leaves.

    PubMed

    Chen, Dong; Sun, Shaopeng; Cai, Dawei; Kong, Guangqi

    2017-03-07

    In the present study, a selenium (Se)-containing polysaccharide (Se-GBLP) was isolated and purified from the leaves of Ginkgo biloba L. Se-GBLP was further evaluated for its antitumor activity against human bladder cancer T24 cells together with the possible mechanism of action. Our results showed that treatment of T24 cells with Se-GBLP (50, 100 and 200μg/ml) for 48h significantly inhibited cell viability and induced apoptosis in a dose- dependent manner. This Se-GBLP-induced apoptosis is associated with an increased protein expression of pro-apoptotic Bax, decreased expression of anti-apoptotic Bcl-2, loss of mitochondrial membrane potential, and cleavage of caspase-9, caspase-3 and PARP, suggesting that Se-GBLP-induced apoptosis occurs through the mitochondria-dependent pathway. Se-GBLP therefore merits further investigation as a promising preventive and/or therapeutic agent against human bladder cancer.

  6. Dietary organic selenium improves growth, survival and resistance to Vibrio mimicus in cultured marron, Cherax cainii (Austin, 2002).

    PubMed

    Nugroho, Rudy Agung; Fotedar, Ravi

    2013-07-01

    To determine the effects of dietary organic selenium (OS) supplementation on the growth performance and immune competence of marron, Cherax cainii (Austin, 2002), a group of marron were fed 0.2 g kg(-1) of Sel-Plex(®) supplemented basal diet and then compared with another group (control) of marron fed basal diet without any supplementation. After 90 days of feeding, final weight, average weekly gains (AWG), relative gain rate (RGR), specific growth rate (SGR), survival, total and differential haemocyte counts (THC and DHC), were compared between the two groups. Surviving marron from each group were then divided into three sub-groups (three tanks per sub-group with seven marron per tank); (1) first sub-group was injected with 20 μL of 3.24 × 10(6) cfu Vibrio mimicus; (2) the second sub-group was injected with 20 μL normal saline and (3) the third sub-group was not subjected to injection and became the control group. THC, DHC, neutral red retention time (NRRT) and Vibrio ranks of post-injected marron were evaluated for 96 h, at every 24-h interval. The results showed that after 90 days of feeding, final weight, AWG, RGR, SGR, survival, THC, proportion of hyaline cells of OS-fed marron were significantly higher (P < 0.05) than the control group, whereas proportion of granular and semigranular cells were not affected by dietary OS. After challenging with V. mimicus, survival rate of marron without dietary OS significantly decreased (P < 0.05) as compared to the control group of marron. THC of marron in all sub-groups were significantly reduced (P < 0.05) after the challenge. However, THC and granular cells of sub-groups fed OS were higher than other sub-groups. Vibrio ranks and NRRT of marron fed OS were significantly lower and slower, respectively, than marron fed without OS. These findings demonstrated the benefits of OS inclusion in the marron diet in terms of growth, health and disease resistance.

  7. Selenium, selenoproteins and human health: a review.

    PubMed

    Brown, K M; Arthur, J R

    2001-04-01

    Selenium is of fundamental importance to human health. It is an essential component of several major metabolic pathways, including thyroid hormone metabolism, antioxidant defence systems, and immune function. The decline in blood selenium concentration in the UK and other European Union countries has therefore several potential public health implications, particularly in relation to the chronic disease prevalence of the Western world such as cancer and cardiovascular disease. Ten years have elapsed since recommended dietary intakes of selenium were introduced on the basis of blood glutathione peroxidase activity. Since then 30 new selenoproteins have been identified, of which 15 have been purified to allow characterisation of their biological function. The long term health implications in relation to declining selenium intakes have not yet been thoroughly examined, yet the implicit importance of selenium to human health is recognised universally. Selenium is incorporated as selenocysteine at the active site of a wide range of selenoproteins. The four glutathione peroxidase enzymes (classical GPx1, gastrointestinal GPx2, plasma GPx3, phospholipid hydroperoxide GPx4)) which represent a major class of functionally important selenoproteins, were the first to be characterised. Thioredoxin reductase (TR) is a recently identified seleno-cysteine containing enzyme which catalyzes the NADPH dependent reduction of thioredoxin and therefore plays a regulatory role in its metabolic activity. Approximately 60% of Se in plasma is incorporated in selenoprotein P which contains 10 Se atoms per molecule as selenocysteine, and may serve as a transport protein for Se. However, selenoprotein-P is also expressed in many tissues which suggests that although it may facilitate whole body Se distribution, this may not be its sole function. A second major class of selenoproteins are the iodothyronine deiodinase enzymes which catalyse the 5'5-mono-deiodination of the prohormone thyroxine (T4

  8. Plasma and breastmilk selenium in HIV-infected Malawian mothers are positively associated with infant selenium status but are not associated with maternal supplementations: Breastfeeding, Antiretrovirals, and Nutrition Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Low dietary selenium (Se) intake coupled with low plasma Se concentrations in HIV infection could result in inadequate breastmilk Se intake by exclusively breastfed infants of HIV-infected women. Objective: To test the effect of lipid-based nutrient supplements (LNS) containing 1.3 R...

  9. Elk (Cervus elaphus canadensis) preference for feeds varying in selenium concentration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium-accumulator plants are reputed to be unpalatable to large ungulates. Elk (Cervus elaphus canadensis) populations in south-eastern Idaho overlap with populations of Se-rich plants, but there is no information on the influence of plant Se concentration on elk dietary preferences. The objecti...

  10. Selenium-Containing Phycocyanin from Se-Enriched Spirulina platensis Reduces Inflammation in Dextran Sulfate Sodium-Induced Colitis by Inhibiting NF-κB Activation.

    PubMed

    Zhu, Chenghui; Ling, Qinjie; Cai, Zhihui; Wang, Yun; Zhang, Yibo; Hoffmann, Peter R; Zheng, Wenjie; Zhou, Tianhong; Huang, Zhi

    2016-06-22

    Selenium (Se) plays an important role in fine-tuning immune responses. Inflammatory bowel disease (IBD) involves hyperresponsive immunity of the digestive tract, and a low Se level might aggravate IBD progression; however, the beneficial effects of natural Se-enriched diets on IBD remain unknown. Previously, we developed high-yield Se-enriched Spirulina platensis (Se-SP) as an excellent organic nutritional Se source. Here we prepared Se-containing phycocyanin (Se-PC) from Se-SP and observed that Se-PC administration effectively reduced the extent of colitis in mouse induced by dextran sulfate sodium. Supplementation with Se-PC resulted in significant protective effects, including mitigation of body weight loss, bloody diarrhea, and colonic inflammatory damage. The anti-inflammatory effects of Se-PC supplementation were found to involve modulation of cytokines, including IL-6, TNF-α, MCP-1, and IL-10. Mechanistically, Se-PC inhibited the activation of macrophages by suppressing the nuclear translocation of NF-κB, which is involved in the transcription of these pro-inflammatory cytokines. These results together suggest potential benefits of Se-PC as a functional Se supplement to reduce the symptoms of IBD.

  11. Treating chronic arsenic toxicity with high selenium lentil diets

    SciTech Connect

    Sah, Shweta; Vandenberg, Albert; Smits, Judit

    2013-10-01

    Arsenic (As) toxicity causes serious health problems in humans, especially in the Indo-Gangetic plains and mountainous areas of China. Selenium (Se), an essential micronutrient is a potential mitigator of As toxicity due to its antioxidant and antagonistic properties. Selenium is seriously deficient in soils world-wide but is present at high, yet non-toxic levels in the great plains of North America. We evaluate the potential of dietary Se in counteracting chronic As toxicity in rats through serum biochemistry, blood glutathione levels, immunotoxicity (antibody response), liver peroxidative stress, thyroid response and As levels in tissues and excreta. To achieve this, we compare diets based on high-Se Saskatchewan (SK) lentils versus low-Se lentils from United States. Rats drank control (0 ppm As) or As (40 ppm As) water while consuming SK lentils (0.3 ppm Se) or northwestern USA lentils (< 0.01 ppm Se) diets for 14 weeks. Rats on high Se diets had higher glutathione levels regardless of As exposure, recovered antibody responses in As-exposed group, higher fecal and urinary As excretion and lower renal As residues. Selenium deficiency caused greater hepatic peroxidative damage in the As exposed animals. Thyroid hormones, triiodothyronine (T3) and thyroxine (T4), were not different. After 14 weeks of As exposure, health indicators in rats improved in response to the high Se lentil diets. Our results indicate that high Se lentils have a potential to mitigate As toxicity in laboratory mammals, which we hope will translate into benefits for As exposed humans. - Highlights: • We reduce chronic arsenic toxicity in rats with a whole food solution. • High selenium lentils decrease liver damage and increase blood glutathione levels. • High selenium lentil diets increase urinary and fecal arsenic excretion. • High selenium lentil diets decrease arsenic levels in kidney, the storage organ. • High selenium lentil diets reverse arsenic suppression of the B cell

  12. Influence of high dietary lead on selenium metabolism in dairy calves

    SciTech Connect

    Neathery, M.W.; Miller, W.J.; Gentry, R.P.; Crowe, C.T.; Alfaro, E.; Fielding, A.S.; Pugh, D.G.; Blackmon, D.M.

    1987-03-01

    Metabolism of orally dosed /sup 75/Se was studied in 10 intact male Holstein calves that were fed ad libitum a control diet containing no added Pb or supplemented with 1000 ppm Pb as PbSO/sub 4/ for 4 wk. Lead-supplemented calves did not exhibit any clinical signs of Pb toxicity. Voluntary feed intake was reduced by 9.5% and average daily gain by 23%. Lead content of rib, liver, and kidney increased. Serum glutamic oxaloacetate transaminase activity was increased during the last 2 wk of the experiment in calves fed Pb. In calves receiving supplemental Pb, /sup 75/Se absorption, blood concentration, and urine concentration were reduced by 26, 21, and 42%, respectively. Tissue /sup 75/Se concentrations were significantly lower in kidney, liver, testicle, pancreas, small intestine, heart, spinal cord, and muscle in calves fed Pb. There was a significant negative correlation (r = -.78) between /sup 75/Se and stable Pb concentrations in the liver. It is not clear whether the ingestion of subclinical amounts of Pb could affect the absorption and utilization of Se in dairy calves to the extent of Se deficiency when dairy calves are kept in areas known to be low in Se.

  13. Selenium accumulation in captive American kestrels (Falco sparverius) fed selenomethionine and naturally incorporated selenium

    SciTech Connect

    Yamamoto, J.T.; Wilson, B.W.; Santolo, G.M.

    1998-12-01

    Male-female pairs of kestrels were maintained for 11 weeks on diets containing 5 or 9 ppm selenium (Se) (dry weight) as seleno-L-methionine, or naturally incorporated Se in the form of mammals collected at Kesterson Reservoir, CA, USA. Selenium concentrations in blood and excreta of male and female kestrels within groups were similar. Near-maximal mean Se concentrations in blood were observed after the 5th week of treatment in the seleno-L-methionine-treated kestrels, and an approximately 1:1 ratio was observed between maximal blood concentrations and dietary concentrations. All treatment groups exhibited reduction of Se concentration in excreta, but not in blood, to baseline values 4 weeks after treatment ended. No birds were observed to exhibit signs of general illness or Se toxicity during the study.

  14. Effect of dietary selenium on biotransformation and excretion of mutagenic metabolites of N-nitrosodimethylamine and 1,1-dimethylhydrazine in the liver perfusion/cell culture system.

    PubMed

    Beije, B; Olsson, U; Onfelt, A

    1987-01-01

    The mutagenicity of N-nitrosodimethylamine (NDMA) and 1,1-dimethylhydrazine (UDMH) has been studied in an isolated liver perfusion/cell culture system. The liver donors, male Wistar rats, were either selenium (Se)-deficient or had a physiologically adequate Se status (Se-supplemented). Mutagenicity was measured in perfusate and bile with Chinese hamster V79 cells as the genetic target. Se deficiency increased the mutagenic effect of NDMA in the perfusate, whereas no mutagenicity was detected in the bile of either Se-deficient or Se-supplemented livers. No significant increase in the mutagenicity of UDMH was seen in the perfusate with Se deficiency, but the bile became mutagenic. Se deficiency thus increased the mutagenicity of both NDMA and UDMH: with NDMA, the effect was observed in the perfusate, and with UDMH, in the bile.

  15. Biomonitoring Equivalents for selenium.

    PubMed

    Hays, Sean M; Macey, Kristin; Nong, Andy; Aylward, Lesa L

    2014-10-01

    Selenium is an essential nutrient for human health with a narrow range between essentiality and toxicity. Selenium is incorporated into several proteins that perform important functions in the body. With insufficient selenium intake, the most notable effect is Keshan disease, an endemic cardiomyopathy in children. Conversely, excessive selenium intake can result in selenosis, manifested as brittle nails and hair and gastro-intestinal disorders. As such, guidance values have been established to protect against both insufficient and excessive selenium exposures. Dietary Reference Intakes (DRIs) have been established as standard reference values for nutritional adequacy in North America. To protect against selenosis resulting from exposure to excessive amounts of selenium, several government and non-governmental agencies have established a range of guidance values. Exposure to selenium is primarily through the diet, but monitoring selenium intake is difficult. Biomonitoring is a useful means of assessing and monitoring selenium status for both insufficient and excessive exposures. However, to be able to interpret selenium biomonitoring data, levels associated with both DRIs and toxicity guidance values are required. Biomonitoring Equivalents (BEs) were developed for selenium in whole blood, plasma and urine. The BEs associated with assuring adequate selenium intake (Estimated Average Requirements - EAR) are 100, 80 and 10μg/L in whole blood, plasma and urine, respectively. The BEs associated with protection against selenosis range from 400 to 480μg/L in whole blood, 180-230μg/L in plasma, and 90-110μg/L in urine. These BE values can be used by both regulatory agencies and public health officials to interpret selenium biomonitoring data in a health risk context.

  16. Effects of selenium biofortification on crop nutritional quality.

    PubMed

    Malagoli, Mario; Schiavon, Michela; dall'Acqua, Stefano; Pilon-Smits, Elizabeth A H

    2015-01-01

    Selenium (Se) at very low doses has crucial functions in humans and animals. Since plants represent the main dietary source of this element, Se-containing crops may be used as a means to deliver Se to consumers (biofortification). Several strategies have been exploited to increase plant Se content. Selenium assimilation in plants affects both sulfur (S) and nitrogen (N) metabolic pathways, which is why recent research has also focused on the effect of Se fertilization on the production of S- and N- secondary metabolites with putative health benefits. In this review we discuss the function of Se in plant and human nutrition and the progress in the genetic engineering of Se metabolism to increase the levels and bioavailability of this element in food crops. Particular attention is paid to Se biofortification and the synthesis of compounds with beneficial effects on health.

  17. Effect of selenium deficiency on gene transcription

    SciTech Connect

    Christensen, M.J.; Burgener, K.W. )

    1991-03-11

    To investigate the general effects of dietary selenium (Se) deficiency on gene transcription, weanling male Sprague-Dawley rats were fed a basal Se-deficient Torula yeast-based diet or the same diet supplemented with 0.5 ppm Se as sodium selenite for 40 days. At that time three rats in each dietary group were sacrificed. Livers were excised and divided into two portions for isolation of nuclei and for assay of cytosolic Se-glutathione peroxidase (Se-GPX) activity. Se-GPX activity was 279 {plus minus} 4 (mean {plus minus} SEM) mUnits/mg protein in Se-adequate livers, and 10 {plus minus} 2 mUnits/mg protein in Se-deficient livers. One aliquot of nuclei from each dietary group was used in a run-on transcription assay, employing {alpha}-{sup 32}P-UTP to label nascent transcripts. Equal quantities of radioactivity from these nuclei were hybridized with cDNA probes bound to nitrocellulose. Message bound to each probe was quantitated by laser densitometry of autoradiographs, and by scintillation counting of dot blotted nitrocellulose. Transcription of most genes tested, including Se-GPX, was not significantly affected by dietary Se intake. However, the amount of hybridization to a murine oncogene probe (v-fos) was increased in Se deficiency.

  18. Developing selenium-enriched animal feed and biofuel from canola planted for managing Se-laden drainage waters in the westside of central California.

    PubMed

    Bañuelos, G S; Da Roche, J; Robinson, J

    2010-03-01

    We studied the reuse of selenium (Se)-laden effluent for producing canola (Brassica napus) and subsequent bioproducts in central California. Canola was irrigated with poor quality waters [electrical conductivity (EC) of approximately 5 dS m(-1) sulfate-salinity, 5 mg B L(-1), and 0.25 mg Se L(-1)]. Typical seed yields were 2.2 metric tons ha(-1). Seeds were processed for their oil, and transesterified to produce ASTM-quality biodiesel (BD) blends. The resulting Se-enriched seed cake meal (containing approximately 2 mg Se kg(-1) DM) was used in a dairy feed trial. Seventy-two Jersey and Holstein cows, 36 respectively, were fed Se-enriched canola meal as 6.2% of their daily feed ration for five weeks. Blood and milk samples were collected weekly and analyzed for total Se. This study showed that Se-enriched canola meal did not significantly increase total blood Se content in either cow breed. Milk Se concentrations did, however, significantly increase to safe levels of 59 microg Se L(-1) and 52 microg Se L(-1) in Jersey and Holstein cows, respectively. The production of BD 20 biofuels and Se-enriched feed meal from canola irrigated with poor quality waters may help sustain similar phytomanagement strategies under Se-rich conditions.

  19. Effect of dietary vitamin E and selenium on growth, survival and the prevalence of Renibacterium salmoninarum infection in chinook salmon (Oncorhynchus tshawytscha)

    USGS Publications Warehouse

    Thorarinsson, Ragnar; Landolt, Marsha L.; Elliott, Diane G.; Pascho, Ronald J.; Hardy, Ronald W.

    1994-01-01

    Groups of juvenile spring chinook salmon naturally infected with Renibacterium salmoninarum, the causative agent of bacterial kidney disease, were fed diets containing different levels of vitamin E and selenium for 214 days in fresh water and 110 days in seawater. The fish were fed vitamin E at concentrations of either 53±3 mg (designated e) or 299±9 mg (designated E) α-tocopheryl acetate equivalence/kg dry diet in combination with sodium selenite to give selenium concentrations of either 0.038±0.008 mg (designated s) or 2.49±0.15 mg (designated S)/kg dry diet. No mortality occurred in the group fed the diet, whereas mortality was 3% in the groups fed the and diets, and 31% in the group fed the diet. At the end of the experiment, weight gain and hematocrit values were significantly greater in those fish fed the E diets compared with those fed the e diets, whereas the hepato-somatic index was significantly higher in fish fed the e diets. Glutathione peroxidase activity in blood plasma was significantly higher in fish fed the S diets compared with those fed the s diets. No definite effect of dietary vitamin E and selenium on the prevalence and severity of natural R. salmoninarum infections was demonstrated.

  20. Chemical forms of mercury and selenium in fish following digestion with simulated gastric fluid.

    PubMed

    George, Graham N; Singh, Satya P; Prince, Roger C; Pickering, Ingrid J

    2008-11-01

    Fish is a major dietary source of potentially neurotoxic methylmercury compounds for humans. It is also a rich source of essential selenium. We have used in situ mercury L(III)-edge and selenium K-edge X-ray absorption spectroscopy to chemically characterize the methylmercury and selenium in both fresh fish and fish digested with simulated gastric fluid. For the mercury, we confirm our earlier finding [ Harris et al. ( 2003 ) Science 301 , 1203 ] that the methylmercury is coordinated by a single thiolate donor, which resembles cysteine, and for the selenium, we find a mixture of organic forms that resemble selenomethionine and an aliphatic selenenyl sulfide such as Cys-S-Se-Cys. We find that local chemical environments of mercury and selenium do not change upon digestion of the fish with simulated gastric fluid. We discuss the toxicological implications for humans consuming fish.

  1. Chemical Forms of Mercury And Selenium in Fish Following Digestion With Simulated Gastric Fluid

    SciTech Connect

    George, G.N.; Singh, S.P.; Prince, R.C.; Pickering, I.J.

    2009-05-18

    Fish is a major dietary source of potentially neurotoxic methylmercury compounds for humans. It is also a rich source of essential selenium. We have used in situ mercury L{sub III}-edge and selenium K-edge X-ray absorption spectroscopy to chemically characterize the methylmercury and selenium in both fresh fish and fish digested with simulated gastric fluid. For the mercury, we confirm our earlier finding [Harris et al. (2003) Science301, 1203] that the methylmercury is coordinated by a single thiolate donor, which resembles cysteine, and for the selenium, we find a mixture of organic forms that resemble selenomethionine and an aliphatic selenenyl sulfide such as Cys-S-Se-Cys. We find that local chemical environments of mercury and selenium do not change upon digestion of the fish with simulated gastric fluid. We discuss the toxicological implications for humans consuming fish.

  2. Antagonistic Growth Effects of Mercury and Selenium in Caenorhabditis elegans Are Chemical-Species-Dependent and Do Not Depend on Internal Hg/Se Ratios.

    PubMed

    Wyatt, Lauren H; Diringer, Sarah E; Rogers, Laura A; Hsu-Kim, Heileen; Pan, William K; Meyer, Joel N

    2016-03-15

    The relationship between mercury (Hg) and selenium (Se) toxicity is complex, with coexposure reported to reduce, increase, and have no effect on toxicity. Different interactions may be related to chemical compound, but this has not been systematically examined. Our goal was to assess the interactive effects between the two elements on growth in the nematode Caenorhabditis elegans, focusing on inorganic and organic Hg (HgCl2 and MeHgCl) and Se (selenomethionine, sodium selenite, and sodium selenate) compounds. We utilized aqueous Hg/Se dosing molar ratios that were either above, below, or equal to 1 and measured the internal nematode total Hg and Se concentrations for the highest concentrations of each Se compound. Observed interactions were complicated, differed between Se and Hg compounds, and included greater-than-additive, additive, and less-than-additive growth impacts. Biologically significant interactions were only observed when the dosing Se solution concentration was 100-25,000 times greater than the dosing Hg concentration. Mitigation of growth impacts was not predictable on the basis of internal Hg/Se molar ratio; improved growth was observed at some internal Hg/Se molar ratios both above and below 1. These findings suggest that future assessments of the Hg and Se relationship should incorporate chemical compound into the evaluation.

  3. Influence of the forms and levels of dietary selenium on antioxidant status and oxidative stress-related parameters in rainbow trout (Oncorhynchus mykiss) fry.

    PubMed

    Fontagné-Dicharry, Stéphanie; Godin, Simon; Liu, Haokun; Antony Jesu Prabhu, Philip; Bouyssière, Brice; Bueno, Maïté; Tacon, Philippe; Médale, Françoise; Kaushik, Sadasivam J

    2015-06-28

    Se is an essential micronutrient required for normal growth, development and antioxidant defence. The objective of the present study was to assess the impact of dietary Se sources and levels on the antioxidant status of rainbow trout (Oncorhynchus mykiss) fry. First-feeding fry (initial body weight: 91 mg) were fed either a plant- or fishmeal-based diet containing 0·5 or 1·2 mg Se/kg diet supplemented or not with 0·3 mg Se/kg diet supplied as Se-enriched yeast or sodium selenite for 12 weeks at 17°C. Growth and survival of rainbow trout fry were not significantly affected by dietary Se sources and levels. Whole-body Se was raised by both Se sources and to a greater extent by Se-yeast. The reduced:oxidised glutathione ratio was raised by Se-yeast, whereas other lipid peroxidation markers were not affected by dietary Se. Whole-body Se-dependent glutathione peroxidase (GPX) activity was enhanced in fish fed Se-yeast compared to fish fed sodium selenite or non-supplemented diets. Activity and gene expression of this enzyme as well as gene expression of selenoprotein P (SelP) were reduced in fish fed the non-supplemented plant-based diet. Catalase, glutamate-cysteine ligase and nuclear factor-erythroid 2-related factor 2 (Nrf2) gene expressions were reduced by Se-yeast. These results suggest the necessity to supplement plant-based diets with Se for rainbow trout fry, and highlight the superiority of organic form of Se to fulfil the dietary Se requirement and sustain the antioxidant status of fish. GPX and SelP expression proved to be good markers of Se status in fish.

  4. Dietary vitamin E (alpha-tocopherol acetate) and selenium supplementation from different sources: performance, ascites-related variables and antioxidant status in broilers reared at low and optimum temperatures.

    PubMed

    Ozkan, S; Malayoğlu, H Basmacioğlu; Yalçin, S; Karadas, F; Koçtürk, S; Cabuk, M; Oktay, G; Ozdemir, S; Ozdemir, E; Ergül, M

    2007-10-01

    1. This study compared the effect of dietary supplementation with organic or inorganic selenium (Se) sources plus control amounts or large amounts of vitamin E (alpha-tocopherol acetate) in broilers raised at control (20 to 24 degrees C) or low (14.5 to 16.8 degrees C) temperatures after 2 weeks of age. 2. The following dietary treatments were used from one day old. Diet 1, the control diet, comprised a commercial diet containing 0.15 mg/kg inorganic Se and 50 mg vitamin E/kg feed. Diet 2 was the same as diet 1, supplemented with 0.15 mg/kg inorganic Se. Diet 3 was the same as diet 2 but was supplemented with 200 mg/kg vitamin E. Diet 4 was the same as diet 1, but inorganic Se was replaced with 0.30 mg/kg organic Se. Diet 5 was the same as diet 4, supplemented with 200 mg/kg vitamin E. 3. Low temperature reduced the growth rate of broilers; however, at 6 weeks, there were no differences in the body weights of birds fed on organic Se supplemented diets housed at low or control temperature. The feed conversion ratio was significantly affected by low temperature but not by diet. The heterophil/lymphocyte ratio was higher in chicks after one week in the cold, indicating mild stress. Blood triiodothyronine levels were significantly higher in birds after 1 and 4 weeks in the cold but thyroxin was not affected. 4. Organic Se supplementation increased relative lung weight at the control temperature, which might lead to greater respiratory capacity. Relative spleen weight significantly decreased in broilers fed diets supplemented with inorganic Se under cold conditions, a possible indication of chronic oxidative stress. 5. At the low temperature, supplementation with organic Se alone, or with inorganic Se and vitamin E increased glutathione peroxidase (GSHPx) activity and glutathione (GSH) concentration in the liver of broilers, which may indicate increased activity of birds' antioxidant defence against suboptimal environments.

  5. Chicken meat nutritional value when feeding red palm oil, palm oil or rendered animal fat in combinations with linseed oil, rapeseed oil and two levels of selenium

    PubMed Central

    2013-01-01

    Chicken meat nutritional value with regard to fatty acid composition and selenium content depends on the choice of dietary oil and selenium level used in the chickens’ feed. The objective of this study was to investigate the effect of replacing commonly used rendered animal fat as a dietary source of saturated fatty acids and soybean oil as a source of unsaturated fatty acids, with palm oil and red palm oil in combinations with rapeseed oil, linseed oil and two levels of selenium enriched yeast on chicken breast meat nutritional value. The study also wished to see whether red palm oil had a cholesterol lowering effect on chicken plasma. 204 male, newly hatched broiler chickens were randomly divided into twelve dietary treatment groups, and individually fed one out of six dietary fat combinations combined with either low (0.1 mg Se /kg feed) or high (1 mg Se/kg feed) dietary selenium levels. Linseed oil, independent of accompanying dietary fat source, lead to increased levels of the n-3 EPA, DPA and DHA and reduced levels of the n-6 arachidonic acid (AA). The ratio between AA/EPA was reduced from 19/1 in the soybean oil dietary groups to 1.7/1 in the linseed oil dietary groups. Dietary red palm oil reduced total chicken plasma cholesterol levels. There were no differences between the dietary groups with regard to measured meat antioxidant capacity or sensory evaluation. Chicken meat selenium levels were clearly influenced by dietary selenium levels, but were not influenced by feed fatty acid composition. High dietary selenium level lead to marginally increased n-3 EPA and higher meat fat % in breast muscle but did not influence the other LC PUFA levels. Chicken breast meat nutritional value from the soybean oil and low selenium dietary groups may be regarded as less beneficial compared to the breast meat from the linseed oil and high selenium dietary groups. Replacing rendered animal fat with palm oil and red palm oil had no negative effects on chicken muscle

  6. Chicken meat nutritional value when feeding red palm oil, palm oil or rendered animal fat in combinations with linseed oil, rapeseed oil and two levels of selenium.

    PubMed

    Nyquist, Nicole F; Rødbotten, Rune; Thomassen, Magny; Haug, Anna

    2013-05-09

    Chicken meat nutritional value with regard to fatty acid composition and selenium content depends on the choice of dietary oil and selenium level used in the chickens' feed. The objective of this study was to investigate the effect of replacing commonly used rendered animal fat as a dietary source of saturated fatty acids and soybean oil as a source of unsaturated fatty acids, with palm oil and red palm oil in combinations with rapeseed oil, linseed oil and two levels of selenium enriched yeast on chicken breast meat nutritional value. The study also wished to see whether red palm oil had a cholesterol lowering effect on chicken plasma.204 male, newly hatched broiler chickens were randomly divided into twelve dietary treatment groups, and individually fed one out of six dietary fat combinations combined with either low (0.1 mg Se /kg feed) or high (1 mg Se/kg feed) dietary selenium levels. Linseed oil, independent of accompanying dietary fat source, lead to increased levels of the n-3 EPA, DPA and DHA and reduced levels of the n-6 arachidonic acid (AA). The ratio between AA/EPA was reduced from 19/1 in the soybean oil dietary groups to 1.7/1 in the linseed oil dietary groups. Dietary red palm oil reduced total chicken plasma cholesterol levels. There were no differences between the dietary groups with regard to measured meat antioxidant capacity or sensory evaluation. Chicken meat selenium levels were clearly influenced by dietary selenium levels, but were not influenced by feed fatty acid composition. High dietary selenium level lead to marginally increased n-3 EPA and higher meat fat % in breast muscle but did not influence the other LC PUFA levels. Chicken breast meat nutritional value from the soybean oil and low selenium dietary groups may be regarded as less beneficial compared to the breast meat from the linseed oil and high selenium dietary groups. Replacing rendered animal fat with palm oil and red palm oil had no negative effects on chicken muscle

  7. Dynamic equilibrium of endogenous selenium nanoparticles in selenite-exposed cancer cells: a deep insight into the interaction between endogenous SeNPs and proteins.

    PubMed

    Bao, Peng; Chen, Song-Can; Xiao, Ke-Qing

    2015-12-01

    Elemental selenium (Se) was recently found to exist as endogenous nanoparticles (i.e., SeNPs) in selenite-exposed cancer cells. By sequestrating critical intracellular proteins, SeNPs appear capable of giving rise to multiple cytotoxicity mechanisms including inhibition of glycolysis, glycolysis-dependent mitochondrial dysfunction, microtubule depolymerization and inhibition of autophagy. In this work, we reveal a dynamic equilibrium of endogenous SeNP assembly and disassembly in selenite-exposed H157 cells. Endogenous SeNPs are observed both in the cytoplasm and in organelles. There is an increase in endogenous SeNPs between 24 h and 36 h, and a decrease between 36 h and 72 h according to transmission electron microscopy results and UV-Vis measurements. These observations imply that elemental Se in SeNPs could be oxidized back into selenite by scavenging superoxide radicals and ultimately re-reduced into selenide; then the assembly and disassembly of SeNPs proceed simultaneously with the sequestration and release of SeNP high-affinity proteins. There is also a possibility that the reduction of elemental Se to selenide pathway may lie in selenite-exposed cancer cells, which results in the assembly and disassembly of endogenous SeNPs. Genome-wide expression analysis results show that endogenous SeNPs significantly altered the expression of 504 genes, compared to the control. The endogenous SeNPs induced mitochondrial impairment and decreasing of the annexin A2 level can lead to inhibition of cancer cell invasion and migration. This dynamic flux of endogenous SeNPs amplifies their cytotoxic potential in cancer cells, thus provide a starting point to design more efficient intracellular self-assembling systems for overcoming multidrug resistance.

  8. Effects of gestational plane of nutrition and selenium supplementation on mammary development and colostrum quality in pregnant ewe lambs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To examine effects of nutritional plane and selenium (Se) supplementation on colostrum quality and mammary development, individually fed, pregnant Rambouillet ewe lambs were allotted randomly to 1 of 6 treatments in a 2 x 3 factorial arrangement. Main effects included dietary Se level which began at...

  9. Influence of selenium evaporation temperature on the structure of Cu2ZnSnSe4 thin film deposited by a co-evaporation process

    NASA Astrophysics Data System (ADS)

    Ding, Sun; Shengzhi, Xu; Li, Zhang; Ze, Chen; Yang, Ge; Ning, Wang; Xuejiao, Liang; Changchun, Wei; Ying, Zhao; Xiaodan, Zhang

    2015-04-01

    Cu2ZnSnSe4 (CZTSe) thin film solar cells have been fabricated using a one-step co-evaporation technique. The structural properties of polycrystalline CZTSe films deposited at different selenium evaporation temperatures (TSe) have been investigated using X-ray diffraction spectra, scanning electron microscopy, and atomic force microscopy. A relationship between TSe and the secondary phases deposited in the initial stage is established to explain the experimental observations. The Se flux is not necessarily increased too much to reduce Sn loss and the consumption of Se during fabrication could also be reduced. The best solar cell, with an efficiency of 2.32%, was obtained at a medium TSe of 230 °C (active area 0.34 cm2). Project supported by the Specialized Research Fund for the PhD Program of Higher Education (No. 20120031110039).

  10. Evaluation of the inorganic selenium biotransformation in selenium-enriched yogurt by HPLC-ICP-MS.

    PubMed

    Alzate, Adriana; Cañas, Benito; Pérez-Munguía, Sandra; Hernández-Mendoza, Hector; Pérez-Conde, Concepción; Gutiérrez, Ana Maria; Cámara, Carmen

    2007-11-28

    Selenium is an essential element in the human diet. Interestingly, there has been an increased consumption of dietary supplements containing this element in the form of either inorganic or organic compounds. The effect of using selenium as a dietary supplement in yogurt has been evaluated. For this purpose, different concentrations of inorganic Se (ranging from 0.2 to 5000 microg g(-1)) have been added to milk before the fermentation process. Biotransformation of inorganic Se into organic species has been carefully evaluated by ion-exchange, reversed-phase, or size-exclusion chromatography, coupled to inductively coupled plasma mass spectrometry (ICP-MS). Yogurt fermentation in the presence of up to 2 microg g(-1) of Se(IV) produces a complete incorporation of this element into proteins as has been demonstrated applying a dialysis procedure. Analysis by SEC-ICP-MS showed that most of them have a molecular mass in the range of 30-70 kDa. Species determination after enzymatic hydrolysis has allowed the identification of Se-cystine using two different chromatographic systems. The biotransformation process that takes place during yogurt fermentation is very attractive because yogurt can act as a source of selenium supplementation.

  11. Effects of selenium source on measures of selenium status and immune function in horses.

    PubMed

    Montgomery, Julia B; Wichtel, Jeffrey J; Wichtel, Maureen G; McNiven, Mary A; McClure, J T; Markham, Fred; Horohov, David W

    2012-10-01

    The effects of selenium (Se) supplementation and source on equine immune function have not been extensively studied. This study examined the effects of oral Se supplementation and Se source on aspects of innate and adaptive immunity in horses. Fifteen horses were assigned to 1 of 3 groups (5 horses/group): control, inorganic Se (sodium selenite), organic Se (Se yeast). Immune function tests performed included: lymphocyte proliferation in response to mitogen concanavalin A, neutrophil phagocytosis, antibody production after rabies vaccination, relative cytokine gene expression in stimulated lymphocytes [interferon gamma (IFNγ), interleukin (IL)-2, IL-5, IL-10, tumor necrosis factor alpha (TNFα)], and neutrophils (IL-1, IL-6, IL-8, IL-12, TNFα). Plasma, red blood cell Se, and blood glutathione peroxidase activity were measured. Plasma and red blood cell Se were highest in horses in the organic Se group, compared with that of inorganic Se or control groups. Organic Se supplementation increased the relative lymphocyte expression of IL-5, compared with inorganic Se or no Se. Selenium supplementation increased relative neutrophil expression of IL-1 and IL-8. Other measures of immune function were unaffected. Dietary Se content and source appear to influence immune function in horses, including alterations in lymphocyte expression of IL-5, and neutrophil expression of IL-1 and IL-8.

  12. COMPARING THE RECOMMENDED DIETARY ALLOWANCE TO TOXICITY VALUES FOR ZN, SE, MN, AND MB

    EPA Science Inventory

    Certain essential nutrients can be toxic when ingested at dosages higher than the daily nutritional requirement. Research data for the essential trace elements, zinc, selenium, manganese and molybdenum have been reviewed by various government agencies for both their nutritional n...

  13. Four selenoproteins, protein biosynthesis, and Wnt signalling are particularly sensitive to limited selenium intake in mouse colon.

    PubMed

    Kipp, Anna; Banning, Antje; van Schothorst, Evert M; Méplan, Catherine; Schomburg, Lutz; Evelo, Chris; Coort, Susan; Gaj, Stan; Keijer, Jaap; Hesketh, John; Brigelius-Flohé, Regina

    2009-12-01

    Selenium is an essential micronutrient. Its recommended daily allowance is not attained by a significant proportion of the population in many countries and its intake has been suggested to affect colorectal carcinogenesis. Therefore, microarrays were used to determine how both selenoprotein and global gene expression patterns in the mouse colon were affected by marginal selenium deficiency comparable to variations in human dietary intakes. Two groups of 12 mice each were fed a selenium-deficient (0.086 mg Se/kg) or a selenium-adequate (0.15 mg Se/kg) diet. After 6 wk, plasma selenium level, liver, and colon glutathione peroxidase (GPx) activity in the deficient group was 12, 34, and 50%, respectively, of that of the adequate group. Differential gene expression was analysed with mouse 44K whole genome microarrays. Pathway analysis by GenMAPP identified the protein biosynthesis pathway as most significantly affected, followed by inflammation, Delta-Notch and Wnt pathways. Selected gene expression changes were confirmed by quantitative real-time PCR. GPx1 and the selenoproteins W, H, and M, responded significantly to selenium intake making them candidates as biomarkers for selenium status. Thus, feeding a marginal selenium-deficient diet resulted in distinct changes in global gene expression in the mouse colon. Modulation of cancer-related pathways may contribute to the higher susceptibility to colon carcinogenesis in low selenium status.

  14. Relationship of selenium concentrations in blood of calves to blood selenium of the dam and supplemental selenium

    SciTech Connect

    Kincaid, R.L.; Hodgson, A.S. )

    1989-01-01

    Selenium status of dam, injected Se, and dietary Ca on calf blood Se concentrations were determined in two trials. Blood was collected from heifer calf and dam pairs at parturition. Half of the calves were injected intramuscularly with .0825 mg Se/kg body weight at birth while the other half received no Se injection. The concentration of Se in the blood of the dam had a significant effect on blood Se of calves at wk 0, 1, and 3, whereas injected Se did not significantly affect blood Se concentrations in the calf until wk 10. In a separate trial, whole blood and plasma Se were significantly correlated at birth in calves, but plasma Se was only about one-third the concentration of whole blood. The concentration of dietary Ca in the calf starter did not significantly affect blood Se, but a quadratic relationship was suggested. Plasma Zn in calves was elevated at birth and then declined with age whereas plasma inorganic P increased with age. Early postnatal concentrations of Se in blood of calves are largely a function of the dam; thus, in areas of low Se intakes, Se supplements for the dam are important.

  15. Selenium Sulfide

    MedlinePlus

    Selenium sulfide, an anti-infective agent, relieves itching and flaking of the scalp and removes the dry, ... Selenium sulfide comes in a lotion and is usually applied as a shampoo. As a shampoo, selenium ...

  16. Selenium uptake by edible oyster mushrooms (Pleurotus sp.) from selenium-hyperaccumulated wheat straw.

    PubMed

    Bhatia, Poonam; Prakash, Ranjana; Prakash, N Tejo

    2013-01-01

    In an effort to produce selenium (Se)-fortifying edible mushrooms, five species of oyster mushroom (Pleurotus sp.), were cultivated on Se-rich wheat straw collected from a seleniferous belt of Punjab, India. Total selenium was analyzed in the selenium hyperaccumulated wheat straw and the fruiting bodies. Significantly high levels (p<0.0001) of Se uptake were observed in fruiting bodies of all mushrooms grown on Se-rich wheat straw. To the best of our knowledge, accumulation and quantification of selenium in mushrooms has hitherto not been reported with substrates naturally enriched with selenium. The results demonstrate the potential of selenium-rich agricultural residues as substrates for production of Se-enriched mushrooms and the ability of different species of oyster mushrooms to absorb and fortify selenium. The study envisages potential use of selenium-rich agricultural residues towards cultivation of Se-enriched mushrooms for application in selenium supplementation or neutraceutical preparations.

  17. Effects of vitamin E and selenium deficiencies on rat immune function.

    PubMed Central

    Eskew, M L; Scholz, R W; Reddy, C C; Todhunter, D A; Zarkower, A

    1985-01-01

    The effects of dietary restriction of vitamin E and selenium were studied in male Long-Evans hooded rats. Weanling animals were maintained for 5-6 weeks on torula yeast-based diets, with or without the addition of vitamin E (150 IU/kg) or selenium (0.5 mg/kg), to form the following dietary groups: +E, +Se; +E, -Se; -E, +Se; -E, -Se, and a fifth group pair-fed with the -E, -Se group. This latter group exhibited a decreased rate of growth similar to the -E, -Se group. Lymphocyte blastogenesis in response to mitogens was decreased in animals fed the diets deficient in either vitamin E or selenium, and also in the pair-fed group. Very marked suppression of mitogen responses was seen in the doubly deficient group, as well as a greater loss of viability during culture. Spleen cell-mediated antibody-dependent lysis of chicken erythrocytes was increased in the doubly deficient group, although this difference could be abolished by the addition of catalase, but not indomethacin, to the culture medium. Dietary deficiency of vitamin E and selenium had no discernible effects on alveolar macrophage function, as measured by cell-mediated antibody-dependent cytolysis, killing of Staphylococcus aureus or regulation of T-lymphocyte blastogenesis. PMID:3972431

  18. Selenium toxicity: cause and effects in aquatic birds.

    PubMed

    Spallholz, Julian E; Hoffman, David J

    2002-04-01

    There are several manners in which selenium may express its toxicity: (1) an important mechanism appears to involve the formation of CH(3)Se(minus sign) which either enters a redox cycle and generates superoxide and oxidative stress, or forms free radicals that bind to and inhibit important enzymes and proteins. (2) Excess selenium as selenocysteine results in inhibition of selenium methylation metabolism. As a consequence, concentrations of hydrogen selenide, an intermediate metabolite, accumulate in animals and are hepatotoxic, possibly causing other selenium-related adverse effects. (3) It is also possible that the presence of excess selenium analogs of sulfur-containing enzymes and structural proteins play a role in avian teratogenesis. L-selenomethionine is the most likely major dietary form of selenium encountered by aquatic birds, with lesser amounts of L-selenocysteine ingested from aquatic animal foods. The literature is suggestive that L-selenomethionine is not any more toxic to adult birds than other animals. L-Selenomethionine accumulates in tissue protein of adult birds and in the protein of egg white as would be expected to occur in animals. There is no suggestion from the literature that the levels of L-selenomethionine that would be expected to accumulate in eggs in the absence of environmental concentration of selenium pose harm to the developing embryo. For several species of aquatic birds, levels of Se as selenomethionine in the egg above 3 ppm on a wet weight basis result in reduced hatchability and deformed embryos. The toxicity of L-selenomethionine injected directly into eggs is greater than that found from the entry of L-selenomethionine into the egg from the normal adult diet. This suggests that there is unusual if not abnormal metabolism of L-selenomethionine in the embryo not seen when L-selenomethionine is present in egg white protein where it likely serves as a source of selenium for glutathione peroxidase synthesis in the developing

  19. Selenium toxicity: cause and effects in aquatic birds

    USGS Publications Warehouse

    Spallholz, J.E.; Hoffman, D.J.

    2002-01-01

    There are several manners in which selenium may express its toxicity: (1) an important mechanism appears to involve the formation of CH3Se- which either enters a redox cycle and generates superoxide and oxidative stress, or forms free radicals that bind to and inhibit important enzymes and proteins. (2) Excess selenium as selenocysteine results in inhibition of selenium methylation metabolism. As a consequence, concentrations of hydrogen selenide, an intermediate metabolite, accumulate in animals and are hepatotoxic, possibly causing other selenium-related adverse effects. (3) It is also possible that the presence of excess selenium analogs of sulfur-containing enzymes and structural proteins play a role in avian teratogenesis. l-selenomethionine is the most likely major dietary form of selenium encountered by aquatic birds, with lesser amounts of l-selenocysteine ingested from aquatic animal foods. The literature is suggestive that l-selenomethionine is not any more toxic to adult birds than other animals. l-Selenomethionine accumulates in tissue protein of adult birds and in the protein of egg white as would be expected to occur in animals. There is no suggestion from the literature that the levels of l-selenomethionine that would be expected to accumulate in eggs in the absence of environmental concentration of selenium pose harm to the developing embryo. For several species of aquatic birds, levels of Se as selenomethionine in the egg above 3 ppm on a wet weight basis result in reduced hatchability and deformed embryos. The toxicity of l-selenomethionine injected directly into eggs is greater than that found from the entry of l-selenomethionine into the egg from the normal adult diet. This suggests that there is unusual if not abnormal metabolism of l-selenomethionine in the embryo not seen when l-selenomethionine is present in egg white protein where it likely serves as a source of selenium for glutathione peroxidase synthesis in the developing aquatic chick.

  20. Selenium and Tellurium concentrations of ultradepleted peridotites determined by isotope dilution ICPMS: implications for Se-Te systematics of the Earth's mantle

    NASA Astrophysics Data System (ADS)

    König, S.; Luguet, A.; Lorand, J.-P.; Wombacher, F.; Lissner, M.

    2012-04-01

    As for highly siderophile elements, selenium and tellurium may constitute key tracers for planetary processes such as formation of the Earth's core and the Late Veneer composition, provided that their geochemical behaviour and abundances in the primitive upper mantle (PUM) are constrained. Within this scope, we have developed a high precision analytical method for the simultaneous determination of selenium and tellurium concentrations from a single sample aliquot and various rock matrices, including ultradepleted peridotites. The technique employs isotope dilution, thiol cotton fiber (TCF) separation and hydride generation MC-ICP-MS. A selection of international mafic and ultramafic rock reference materials BIR-1, BE-N, TDB-1, UB-N, FON B 93, BIR-1 and BHVO-2 with a range of 30 to 350 ppb Se and 0.7 to 12 ppb Te show external reproducibilities of 3 to 8% for Se and 0.4 to 11% for Te (2 relative standard deviations (r.s.d.)). We have applied this method to a suite of refractory mantle peridotites (Al2O3 <1.5 wt. %) from Lherz, previously shown to be strongly and uniformly depleted in Se, Te and incompatible elements by high degree of partial melting (20 ± 5%). In contrast to fertile lherzolites which remain at broadly chondritic values (Se/Te = 9), the ultradepleted harzburgites show highly fractionated and up to suprachondritic Se/Te (< 35) that correlate with decreasing Te concentrations. The fractionation is displayed by the depleted peridotites as well as multiple analysis of a single Lherz harzburgite sample (64-3). This shows 1) a strong sample heterogeneity effect for Te and 2) a more incompatible behaviour of Te compared to Se on the whole rock scale, once base metal sulfides are highly depleted and in some cases entirely consumed by partial melting. The marked differences in Se-Te systematics observed between fertile lherzolites and depleted harzburgites can be explained by the combined effect of i) different abundances and proportions of residual and

  1. Dietary Selenium Deficiency Partially Rescues Type 2 Diabetes–Like Phenotypes of Glutathione Peroxidase-1–Overexpressing Male Mice123

    PubMed Central

    Yan, Xi; Pepper, Matthew P.; Vatamaniuk, Marko Z.; Roneker, Carol A.; Li, Li; Lei, Xin Gen

    2012-01-01

    This study was conducted to determine whether dietary Se deficiency precluded overproduction of glutathione peroxidase-1 (GPX1) activity in mice overexpressing (OE) this gene and thus rescued their type 2 diabetes–like phenotypes. A total of 20 male OE and wild-type (WT) mice were fed an Se-deficient (<0.02 mg/kg) diet or an Se-supplemented (0.3 mg/kg as sodium selenite) diet from 1 to 5 mo of age. Dietary Se deficiency eliminated or attenuated (P < 0.05) genotype differences in concentrations of blood glucose, plasma insulin, and/or hepatic lipids, insulin sensitivity, and glucose-stimulated insulin secretion at the end of the study. Dietary Se deficiency decreased (P < 0.05) OE islet mRNA levels of 2 key transcriptional activators (Beta2 and Foxa2) and removed genotype differences in islet mRNA levels of 7 genes (Beta2, Cfos, Foxa2, Pregluc, Ins1, p53, and Sur1) related to insulin synthesis and secretion. Compared with those of the Se-adequate OE mice, the Se-deficient OE mice had lower (P < 0.05) hepatic mRNA levels of 2 key rate-limiting enzymes for lipogenesis (Acc1) and glycolysis (Gk1), along with lower (P < 0.05) activities of hepatic glucokinase and muscle phosphoenolpyruvate carboxykinase. Dietary Se deficiency also decreased (P < 0.05) blood glucose and hepatic lipid concentrations in the WT mice. In conclusion, dietary Se deficiency precluded the overproduction of GPX1 in full-fed OE mice and partially rescued their metabolic syndromes. This alleviation resulted from modulating the expression and/or function of proinsulin genes, lipogenesis rate-limiting enzyme genes, and key glycolysis and gluconeogenesis enzymes in islets, liver, and muscle. PMID:23014491

  2. Selenium in higher plants: understanding mechanisms for biofortification and phytoremediation.

    PubMed

    Zhu, Yong-Guan; Pilon-Smits, Elizabeth A H; Zhao, Fang-Jie; Williams, Paul N; Meharg, Andrew A

    2009-08-01

    Selenium (Se) is an essential micronutrient for many organisms, including plants, animals and humans. As plants are the main source of dietary Se, plant Se metabolism is therefore important for Se nutrition of humans and other animals. However, the concentration of Se in plant foods varies between areas, and too much Se can lead to toxicity. As we discuss here, plant Se uptake and metabolism can be exploited for the purposes of developing high-Se crop cultivars and for plant-mediated removal of excess Se from soil or water. Here, we review key developments in the current understanding of Se in higher plants. We also discuss recent advances in the genetic engineering of Se metabolism, particularly for biofortification and phytoremediation of Se-contaminated environments.

  3. Effect of alcohol consumption selenium bioavailability in rats

    SciTech Connect

    Cho, H.K.

    1986-01-01

    This study was done to determine the effects of alcohol consumption on selenium bioavailability in initially Se-depleted rats. Weanling male rats were fed a Se deficient basal diet for 4 weeks and then for the subsequent 4 weeks were supplemented at 0.031 mg Se/Kg or at 0.085 mg Se/Kg of diet in the form of high Se yeast. During the Se repletion period alcohol replaced medium chain triglycerides in the diet at three levels: 0%, 10% and 20% of calories. Dietary Se level significantly affected urinary Se, fecal Se, Se absorption, Se balance whole blood Se, whole blood glutathione peroxidase activity, liver Se concentration, and total liver Se content. Alcohol consumption significantly increased liver Se concentrations and total liver Se in rats fed the adequate Se diet. In rates fed the low Se diet, this pattern was not shown. There was a significant interaction between alcohol and Se level in terms of liver Se concentration and total liver Se. In the first week of Se repletion, fecal Se. Se absorption and Se balance were significantly higher in the 10% alcohol group fed the low Se repletion diet compared to rats given 0% and 20% alcohol in the same Se group. In the final week Se repletion the parameters of Se balance were not affected by alcohol consumption. Alcohol consumption did not influence whole blood Se and whole blood glutathione peroxidase activity; however alcohol consumption significantly reduced growth rate at both Se levels.

  4. Characterization of selenium-enriched mycelia of Catathelasma ventricosum and their antihyperglycemic and antioxidant properties.

    PubMed

    Liu, Yuntao; Li, Caiming; Luo, Xiaohu; Han, Guoquan; Xu, Shude; Niu, Fuge; Hu, Xinjie; Wu, Hejun; Zhang, Huimin

    2015-01-21

    This is the first report concerning the selenium enrichment of Catathelasma ventricosum mycelia. The selenium-containing proteins present in selenium-enriched mycelia (Se-MC) were identified using size-exclusion chromatography-inductively coupled plasma-mass spectrometry (SEC-ICP-MS). The selenium-containing amino acids liberated by hydrolysis of these proteins were identified using anion exchange-ICP-MS. Se-MC was found to contain selenoproteins with molecular weights ranging from 1.7 to 60.5 kDa. The main selenium-containing amino acids within them were selenomethionine and selenocysteine. Furthermore, Se-MC possessed excellent antihyperglycemic and antioxidant properties. Se-MC normalized biochemical parameters like insulin level, blood glucose level, body weight, and antioxidant enzyme activity in streptozocin-induced diabetic mice. It also inhibited the α-amylase and α-glucosidase activities present in in vitro gastric and intestinal models. In conclusion, Se-MC has the potential to serve as a dietary supplement of selenium, an antioxidant, or an ingredient for the formulation of nutraceuticals.

  5. Interaction between mercury (Hg), arsenic (As) and selenium (Se) affects the activity of glutathione S-transferase in breast milk; possible relationship with fish and sellfish intake.

    PubMed

    Gaxiola-Robles, Ramón; Labrada-Martagón, Vanessa; Celis de la Rosa, Alfredo de Jesús; Acosta-Vargas, Baudilio; Méndez-Rodríguez, Lía Celina; Zenteno-Savín, Tania

    2014-08-01

    Breast milk is regarded as an ideal source of nutrients for the growth and development of neonates, but it can also be a potential source of pollutants. Mothers can be exposed to different contaminants as a result of their lifestyle and environmental pollution. Mercury (Hg) and arsenic (As) could adversely affect the development of fetal and neonatal nervous system. Some fish and shellfish are rich in selenium (Se), an essential trace element that forms part of several enzymes related to the detoxification process, including glutathione S-transferase (GST). The goal of this study was to determine the interaction between Hg, As and Se and analyze its effect on the activity of GST in breast milk. Milk samples were collected from women between day 7 and 10 postpartum. The GST activity was determined spectrophotometrically; total Hg, As and Se concentrations were measured by atomic absorption spectrometry. To explain the possible association of Hg, As and Se concentrations with GST activity in breast milk, generalized linear models were constructed. The model explained 44% of the GST activity measured in breast milk. The GLM suggests that GST activity was positively correlated with Hg, As and Se concentrations. The activity of the enzyme was also explained by the frequency of consumption of marine fish and shellfish in the diet of the breastfeeding women.

  6. Selenium-enriched polysaccharides from Pyracantha fortuneana (Se-PFPs) inhibit the growth and invasive potential of ovarian cancer cells through inhibiting β-catenin signaling

    PubMed Central

    Wang, Changdong; Sheng, Deqiao; Li, Zhihong; Huang, Debin; Yuan, Chengfu

    2016-01-01

    Polysaccharides from medicinal plants exert antitumor activity in many cancers. Our previous study demonstrated that polysaccharides extracted from the selenium-enriched Pyracantha fortuneana (Se-PFPs) showed antiproliferative effect in breast cancer cell line. This study aimed to investigate the antitumor effect of Se-PFPs in ovarian cancer cells in vitro and in vivo. Se-PFPs could decrease cell viability, induce apoptosis, and inhibit migratory and invasive potentials in HEY and SKOV3 cells. These findings are supported by reduced expression of cyclin D1, Bcl-2 and MMP-9, enhanced cleavage of PARP and caspase-3, elevated activity of caspase-3 and caspase-9, and EMT (epithelial to mesenchymal transition) inhibition (elevated expression of E-cadherin and cytokeratin 19, and reduced expression of N-cadherin, vimentin, ZEB1 and ZEB2). Moreover, Se-PFPs inhibited xenografted tumor growth through inhibiting cell proliferation and inducing cell apoptosis. More importantly, Se-PFPs significantly reduced cytoplasmic β-catenin particularly nuclear β-catenin expression but increased β-catenin phosphorylation in a GSK-3β-dependent mechanism. Furthermore, β-catenin knockdown exerted similar effects on cell proliferation and invasion as seen in Se-PFPs-treated cells, while β-catenin overexpression neutralized the inhibitory effects of Se-PFPs on cell proliferation and invasion. Take together,Se-PFPs exert antitumor activity through inhibiting cell proliferation, migration, invasion and EMT, and inducing cell apoptosis. These effects are achieved by the inhibition of β-catenin signaling. Thus Se-PFPs can be used as potential therapeutic agents in the prevention and treatment of ovarian cancer. PMID:27058760

  7. Influence of dietary nano elemental selenium on growth performance, tissue selenium distribution, meat quality, and glutathione peroxidase activity in Guangxi Yellow chicken.

    PubMed

    Zhou, X; Wang, Y

    2011-03-01

    This experiment was designed to investigate the effect of feed supplementation with nano elemental Se (Nano-Se) on growth performance, tissue Se distribution, meat quality, and glutathione peroxidase (GSH-Px) activity in Guangxi Yellow chicken. Four treatments (control, T-1, T-2, and T-3 treatment groups) with 3 replicates of 30 chickens each were carried out. Diets for the control, T-1, T-2, and T-3 groups consisted of the basal diet supplemented with, respectively, 0.00, 0.10, 0.30, and 0.50 mg/kg of Nano-Se. Improved final BW, daily BW gain (DWG), feed conversion ratios, and survival rate (P < 0.05) were observed in the groups supplemented with Nano-Se as compared with the control groups after 90 d of feeding. The groups that received Nano-Se showed higher (P < 0.05) hepatic and muscle Se contents, drip loss percentage, inosine 5'-monophosphate content, and GSH-Px activities in the serum and liver than that did the control groups. For the T-2 and T-3 groups, a significant difference (P < 0.05) was observed in final BW, DWG, muscle Se content, breast drip loss, and GSH-Px activities in the serum and liver compared with the T-1 group. However, no significant differences were observed in final BW, DWG, and GSH-Px activities in the serum and liver between the T-2 and T-3 groups. It could be concluded from this study that supplementing diets with 0.30 mg/kg of Nano-Se for was effective in increasing the growth performance and feed conversion ratios of chickens, the Se content of tissues, and the quality of the meat.

  8. Selenium-fortified wheat: potential of microbes for biofortification of selenium and other essential nutrients.

    PubMed

    Yasin, Muhammad; El-Mehdawi, Ali Farag; Pilon-Smits, Elizabeth A H; Faisal, Muhammad

    2015-01-01

    Selenium (Se) is an essential micronutrient for humans and animals, and Se deficiency is a worldwide problem. Plants are a main dietary source of Se for humans and livestock. In this study we investigated the effect of two selenium-tolerant bacterial strains Bacillus cereus-YAP6 and Bacillus licheniformis-YAP7, on the growth and Se uptake by wheat plants. The bacteria-inoculated plants exhibited a significant increase in spike length, shoot length and dry biomass. Inoculated Se-treated plants also showed increased stem Se, S, Ca and Fe concentrations, by up to 375%, 40%, 55%, and 104%, respectively, and increased kernel Se, S, Ca and Fe concentrations by up to 154%, 85%, 60%, and 240%, respectively, compared to un-inoculated Se-treated plants. In conclusion, inoculation with strains YAP6 andYAP7 is a good Se biofortification strategy for wheat. Both strains showed resistance to other toxic elements, i.e., As, Cd, Co, Cr, Cu, Mn and Zn. Optimal growth temperature and pH for both strains were 37°C and pH7, respectively, but both strains can grow very well at different temperatures (28-45°C) and at alkaline pH. Both strains have high Se reduction potential: strains YAP6 and YAP7 converted 92% and 32% of selenite into elemental Se within 48 h, respectively.

  9. Effects of Dietary Selenium Against Lead Toxicity on mRNA Levels of 25 Selenoprotein Genes in the Cartilage Tissue of Broiler Chicken.

    PubMed

    Gao, H; Liu, C P; Song, S Q; Fu, J

    2016-07-01

    The interactions between the essential element selenium (Se) and the toxic element lead (Pb) have been reported extensively; however, little is known about the effect of Se on Pb toxicity and the expression pattern of selenoproteins in the cartilage of chicken. To investigate the effects of Se on Pb toxicity and the messenger RNA (mRNA) expressions of selenoproteins in cartilage tissue, an in vitro study was performed on 1-day-old broiler chickens (randomly allocated into four groups) with diet of different concentration of Se and Pb. After 90 days, the meniscus cartilage and sword cartilage tissue were examined for the mRNA levels of 25 selenoprotein genes. The results showed that Se and Pb influenced the expression of selenoprotein genes in the chicken cartilage tissue. In detail, Se could alleviate the downtrend of the expression of Gpx1, Gpx2, Gpx4, Txnrd2, Txnrd3, Dio1, Dio2, Seli, Selu, Sepx1, Selk, Selw, Selo, Selm, Sep15, Sepnn1, Sels, and Selt induced by Pb exposure in the meniscus cartilage. In the sword cartilage, Se alleviated the downtrend of the expression of Gpx2, Gpx3, Gpx4, Txnrd1, Txnrd2, Dio2, Dio3, Seli, Selh, SPS2, Sepx1, Selk, Selw, Selo, Selm, Sep15, Selpb, Sepn1, and Selt induced by Pb exposure. The present study provided some compensated data about the roles of Se against Pb toxicity in the regulation of selenoprotein expression.

  10. Selenium-assisted controlled growth of graphene-Bi2Se3 nanoplates hybrid Dirac materials by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Sun, Zhencui; Man, Baoyuan; Yang, Cheng; Liu, Mei; Jiang, Shouzhen; Zhang, Chao; Zhang, Jiaxin; Liu, Fuyan; Xu, Yuanyuan

    2016-03-01

    Se seed layers were used to synthesize the high-quality graphene-Bi2Se3 nanoplates hybrid Dirac materials via chemical vapor deposition (CVD) method. The morphology, crystallization and structural properties of the hybrid Dirac materials were characterized by SEM, EDS, Raman, XRD, AFM and HRTEM. The measurement results verify that the Se seed layer on the graphene surface can effectively saturate the surface dangling bonds of the graphene, which not only impel the uniform Bi2Se3 nanoplates growing along the horizontal direction but also can supply enough Se atoms to fill the Se vacancies. We also demonstrate the Se seed layer can effectively avoid the interaction of Bi2Se3 and the graphene. Further experiments testify the different Se seed layer on the graphene surface can be used to control the density of the Bi2Se3 nanoplates.

  11. Reduction of elemental selenium to selenide: Experiments with anoxic sediments and bacteria that respire Se-oxyanions

    USGS Publications Warehouse

    Herbel, M.J.; Blum, J.S.; Oremland, R.S.; Borglin, S.E.

    2003-01-01

    A selenite-respiring bacterium, Bacillus selenitireducens, produced significant levels of Se(-II) (as aqueous HSe-) when supplied with Se(O). B. selenitireducens was also able to reduce selenite [Se(IV)] through Se(O) to Se(-II). Reduction of Se(O) by B.selenitireducens was more rapid in cells grown on colloidal sulfur [S(O)] or Se(IV) as their electron acceptor than for cell lines grown on fumarate. In contrast, three cultures of selenate-respiring bacteria, Sulfurospirillum barnesii, B. arsenicoselenatis, and Selenihalanaerobacter shriftii either were unable to reduce Se(O) to Se(-II) or had only a very limited capacity to achieve this reduction. Biological reduction of Se(O) to Se(-II) was observed during incubation of estuarine sediment slurries, while no such activity was noted in formalin-killed controls. The majority of the Se(-II) produced was found in the sediments as a solid precipitate of FeSe, rather than in solution as HSe-. These results demonstrate that certain anaerobic bacteria have the capacity to reduce Se(O) to Se(-II), providing a possible biological explanation for the occurrence of the selenide species in some sedimentary rocks.

  12. A global survey of effects of genotype and environment on selenium concentration in lentils (Lens culinaris L.): Implications for nutritional fortification strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lentils (Lens culinaris L.) are an important protein and carbohydrate food, rich in essential dietary components and trace elements. Selenium (Se) is an essential micronutrient for human health. For adults, 55 µg of daily Se intake is recommended for better health and cancer prevention. Millions of ...

  13. Selenium accumulation in lettuce germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) is an essential micronutrient for animals and humans. Increasing Se content in food crops offers an effective approach to reduce the widespread selenium deficiency problem in many parts of the world. In this study, we evaluated thirty diverse accessions of lettuce (Lactuca sativa L.) f...

  14. Effect of Selenium Deficiency on Phosphorylation of the AMPK Pathway in Rats.

    PubMed

    He, Shulan; Guo, Xiong; Tan, Wuhong; Su, Xiaohui; Li, Jiangping; Pan, Wang; Qiu, Hongyan

    2016-02-01

    Selenium is an important trace element for human health. Previous studies have raised concern that dietary selenium intake may change energy metabolism. AMP-activated protein kinase (AMPK) is a sensor of energy status that controls cellular energy homeostasis. We aimed to determine the effect of selenium on the phosphorylation of AMPK pathway between Se-deficient and normal Sprague-Dawley rats. Twenty-four weaning rats were fed either a Se-deficient diet (0.02 mg Se/kg) or a standard diet (0.18 mg Se/kg). After 109 days, total serum levels of non-esterified fatty acid and total amino acids were significantly higher and the serum insulin concentration was significantly lower in Se-deficient rats than in healthy controls. Selenium concentration and the activity of glutathione peroxidase (GPx) in myocardial tissue were significantly lower in Se-deficient rats. Importantly, mRNA levels of acetyl-CoA carboxylase beta (ACACB), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), and protein levels of p-AMPKα were increased in the Se-deficient group compared to normal controls (p < 0.05). In conclusion, our results suggest that selenium deficiency induces changes in metabolic and molecular parameters involved in energy metabolism in the AMPK pathway.

  15. [Selenium and cancer: from prevention to treatment].

    PubMed

    Brozmanová, J

    2011-01-01

    Selenium (Se) is an essential dietary component for all animals, including human beings, that is regarded as a protective agent against cancer. Although the mode of its anticancer action is not yet fully understood, several mechanisms, such as antioxidant protection through selenoenzymes, stimulation of DNA repair, and apoptosis in tumor prestages have all been proposed. Despite the unsupported results of the last "SELECT" trial, the cancer-preventing activity of Se has been demonstrated in a majority of epidemiological studies. Moreover, recent studies suggest that Se has a potential to be used not only in cancer prevention but also in cancer treatment, where in combination with other anticancer drugs or radiation it may increase the efficacy of cancer therapy. In combating cancer cells, Se acts as a prooxidant rather than an antioxidant, inducing apoptosis through the generation of oxidative stress. Thus, inorganic Se compounds, having high redox potency, represent a promising option in cancer therapy.

  16. Biomarkers of selenium status

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The essential trace element selenium (Se) has multiple biological activities, which depend on the level of Se intake. Relatively low Se intakes determine the expression of selenoenzymes in which it serves as an essential constituent. Higher intakes have been shown to have anti-tumorigenic potentia...

  17. Toxicokinetics of selenium in the slider turtle, Trachemys scripta.

    PubMed

    Dyc, Christelle; Far, Johann; Gandar, Frédéric; Poulipoulis, Anastassios; Greco, Anais; Eppe, Gauthier; Das, Krishna

    2016-05-01

    Selenium (Se) is an essential element that can be harmful for wildlife. However, its toxicity in poikilothermic amniotes, including turtles, remains poorly investigated. The present study aims at identifying selenium toxicokinetics and toxicity in juvenile slider turtles (age: 7 months), Trachemys scripta, dietary exposed to selenium, as selenomethionine SeMet, for eight weeks. Non-destructive tissues (i.e. carapace, scutes, skin and blood) were further tested for their suitability to predict selenium levels in target tissues (i.e. kidney, liver and muscle) for conservation perspective. 130 juvenile yellow-bellied slider turtles were assigned in three groups of 42 individuals each (i.e. control, SeMet1 and SeMet2). These groups were subjected to a feeding trial including an eight-week supplementation period SP 8 and a following 4-week elimination period EP 4 . During the SP8, turtles fed on diet containing 1.1 ± 0.04, 22.1 ± 1.0 and 45.0 ± 2.0 µg g(-1) of selenium (control, SeMet1 and SeMet2, respectively). During the EP4, turtles fed on non-supplemented diet. At different time during the trial, six individuals per group were sacrificed and tissues collected (i.e. carapace, scutes, skin, blood, liver, kidney, muscle) for analyses. During the SP8 (Fig. 1), both SeMet1 and SeMet2 turtles efficiently accumulated selenium from a SeMet dietary source. The more selenium was concentrated in the food, the more it was in the turtle body but the less it was removed from their tissues. Moreover, SeMet was found to be the more abundant selenium species in turtles' tissues. Body condition (i.e. growth in mass and size, feeding behaviour and activity) and survival of the SeMet1 and SeMet2 turtles seemed to be unaffected by the selenium exposure. There were clear evidences that reptilian species are differently affected by and sensitive to selenium exposure but the lack of any adverse effects was quite unexpected. Fig. 1 Design of the feeding trial. T, Time of

  18. Blood glutathione peroxidase-1 mRNA levels can be used as molecular biomarkers to determine dietary selenium requirements in rats.

    PubMed

    Sunde, Roger A; Thompson, Kevin M; Evenson, Jacqueline K; Thompson, Britta M

    2009-11-01

    Transcript (mRNA) levels are increasingly being used in medicine as molecular biomarkers for disease and disease risk, including use of whole blood as a target tissue for analysis. Development of blood molecular biomarkers for nutritional status, too, has potential application that parallels opportunities in medicine, including providing solid data for individualized nutrition. We previously reported that blood glutathione peroxidase-1 (Gpx1) mRNA was expressed at levels comparable to major tissues in rats and humans. To determine the efficacy of using blood Gpx1 mRNA to assess selenium (Se) status and requirements, we fed graded levels of Se (0-0.3 microg Se/g as selenite) to weanling male rats. Se status was determined by liver Se concentration and selenoenzyme activity, and selenoprotein mRNA abundance in liver and blood was determined by ribonuclease protection analysis. Liver Se and plasma glutathione peroxidase-3 and liver Gpx1 activities indicated that minimal Se requirements were at 0.08 microg Se/g diet. When total RNA was isolated from whole blood, Gpx1 mRNA in Se-deficient rats decreased to 10% of levels in Se-adequate (0.2 microg Se/g diet) rats. With Se supplementation, blood Gpx1 mRNA levels increased sigmoidally to a plateau with a minimum Se requirement of 0.08 microg Se/g diet, whereas glutathione peroxidase-4 mRNA levels were unaffected. Similarly, Gpx1 mRNA in RNA isolated from fractionated red blood cells decreased in Se-deficient rats to 23% of Se-adequate levels, with a minimum Se requirement of 0.09 microg Se/g diet. Additional studies showed that the preponderance of whole blood Gpx1 mRNA arises from erythroid cells, most likely reticulocytes and young erythrocytes. In summary, whole blood selenoprotein mRNA levels can be used as molecular biomarkers for assessing Se requirements, illustrating that whole blood has potential as a target tissue in development of molecular biomarkers for use in nutrition as well as in medicine.

  19. Tolerance of inorganic selenium by range-type ewes during gestation and lactation.

    PubMed

    Davis, P A; McDowell, L R; Wilkinson, N S; Buergelt, C D; Van Alstyne, R; Weldon, R N; Marshall, T T

    2006-03-01

    The objectives of this 72-wk study were to evaluate and compare the effects of 6 dietary levels of inorganic Se on serum, whole blood, wool, and tissue Se concentrations and to determine the maximum tolerable level of Se for mature ewes during lamb production. Forty-one, 4-yr-old, range-type ewes (57.4 +/- 5.7 kg) were used in a completely randomized design with 6 dietary treatments. Sodium selenite was added to a corn and soybean meal-based diet to provide 0.2 (control), 4, 8, 12, 16, or 20 mg of dietary Se/kg to ewes during lamb production. Serum Se and ewe BW were measured at 4-wk intervals; whole blood Se and wool Se were measured every 12 wk; and samples of brain, diaphragm, heart, hoof, kidney, liver, and psoas major were collected at the termination of the experiment. Dietary Se did not affect ewe BW during the study (P = 0.69), and there was no treatment x time interaction. Serum Se increased linearly as dietary Se level increased (P < 0.001) and responded cubically (P = 0.02) over time. Selenium in whole blood increased linearly (P < 0.001) as supplemental Se increased. Wool Se increased linearly (P < 0.001) as dietary Se increased, and the response over time was quadratic (P < 0.001). Brain, diaphragm, heart, and psoas major Se increased (P < 0.05) linearly as dietary Se increased, liver Se responded quadratically (P < 0.05), and hoof and kidney Se increased cubicically (P < 0.05) as supplemental Se increased. In general, serum, whole blood, and tissue Se concentrations of ewes receiving 12, 16, or 20 mg of dietary Se/kg were greater (P < 0.05) than those of controls and ewes receiving less dietary Se. Although they were elevated in ewes receiving increased dietary Se, at no time did serum, whole blood, or wool Se concentrations reach levels previously reported as toxic, nor were clinical signs of Se toxicosis observed. Histopathological evaluation of liver, kidney, diaphragm, heart, and psoas major did not reveal evidence of Se toxicosis in ewes at any

  20. Effects of feeding selenium deficient diets to rhesus monkeys (Macaca Mulatta)

    SciTech Connect

    Butler, J.A.; Whanger, P.D.; Patton, N.M.

    1988-02-01

    Pregnant rhesus monkeys (Macaca mulatta) were fed either selenium (Se) deficient or Se supplemented diets with adequate vitamin E. Except for some cardiac irregularities in the first babies born to these females, no physiological disorders due to Se deficiency were seen in a subsequent offspring. Plasma and erythrocyte glutathione peroxidase activities and blood Se levels increased in the Se supplemented monkeys but decreased in the deficient ones. The data indicated that hair Se levels reflect long term exposure to this element. In a very preliminary experiment, evidence was obtained to indicate that dietary protein deficiency along with Se deficiency will generate cardiomyopathic lesions characteristic of Se deficiency. It is hypothesized that, in addition to Se deficiency, another dietary deficiency (or abnormality) is necessary to produce Se deficiency lesions in higher primates. Higher glutathione transferase (or non-Se glutathione peroxidase) activity in tissues of rhesus monkeys may account for this resistance.

  1. Influence of dietary methionine on the metabolism of selenomethionine in rats

    SciTech Connect

    Butler, J.A.; Beilstein, M.A.; Whanger, P.D. )

    1989-07-01

    To determine the influence of methionine on selenomethionine (SeMet) metabolism, weanling male rats were fed for 8 wk a basal diet marginally deficient in sulfur amino acids, containing 2.0 micrograms selenium (Se)/g as DL-SeMet and supplemented with 0, 0.3, 0.6 or 1.2% DL-methionine. Increased dietary methionine caused decreased selenium deposition in all tissues examined but increased glutathione peroxidase activity in testes, liver and lungs. A positive correlation was found between dietary methionine and the calculated percentage of selenium associated with GSHPx. In a second experiment, {sup 75}SeMet was injected into weanling male rats which had been fed the basal diet containing 2.0 micrograms selenium as DL-SeMet with or without the addition of 1.0% methionine. The selenoamino acid content of tissues and the distribution of {sup 75}Se in erythrocyte proteins were determined. In comparison to the rats fed the basal diet without added methionine, significantly more {sup 75}Se-selenocysteine was found in liver and muscle, more {sup 75}Se was found in erythrocyte GSHPx and less {sup 75}Se was found in erythrocyte hemoglobin of rats fed 1.0% methionine. These data suggest that methionine diverts SeMet from incorporation into general proteins and enhances its conversion to selenocysteine for specific selenium-requiring proteins, such as GSHPx.

  2. Selenium supplementation does not affect testicular selenium status or semen quality in North American men.

    PubMed

    Hawkes, Wayne Chris; Alkan, Zeynep; Wong, Kenneth

    2009-01-01

    Selenium (Se) is essential for sperm function and male fertility, but high Se intake has been associated with impaired semen quality. We reported previously a decrease in sperm motility in men fed high-Se foods, but we could not rule out the influence of other environmental and dietary factors. We now report on a randomized, controlled study on the potential adverse effects of Se supplementation on semen quality in 42 free-living men administered Se (300 microg/d) as high-Se yeast for 48 weeks. Semen analysis was performed 4 times before treatment began, then twice each week during treatment at 6, 12, 24, 36, and 48 weeks, and then after treatment at 72 and 96 weeks. Blood samples were collected 3 times before treatment and at each subsequent visit. Se concentration increased 61% in blood plasma and 49% in seminal plasma. However, Se supplementation had no effect on sperm Se, serum androgen concentrations, or sperm count, motility, progressive velocity, or morphology. We observed progressive decreases in serum luteinizing hormone, semen volume, and sperm Se in both the high-Se and placebo groups. Moreover, sperm straight-line velocity and percent normal morphology increased in Se-treated and placebo-treated participants. The lack of an increase in sperm Se suggests that testicular Se stores were unaffected, even though the participants' dietary Se intake was tripled and their total body Se approximately doubled by supplementation. These results are consistent with animal studies showing the Se status of testes to be unresponsive to dietary Se intake.

  3. Why Nature Chose Selenium.

    PubMed

    Reich, Hans J; Hondal, Robert J

    2016-04-15

    The authors were asked by the Editors of ACS Chemical Biology to write an article titled "Why Nature Chose Selenium" for the occasion of the upcoming bicentennial of the discovery of selenium by the Swedish chemist Jöns Jacob Berzelius in 1817 and styled after the famous work of Frank Westheimer on the biological chemistry of phosphate [Westheimer, F. H. (1987) Why Nature Chose Phosphates, Science 235, 1173-1178]. This work gives a history of the important discoveries of the biological processes that selenium participates in, and a point-by-point comparison of the chemistry of selenium with the atom it replaces in biology, sulfur. This analysis shows that redox chemistry is the largest chemical difference between the two chalcogens. This difference is very large for both one-electron and two-electron redox reactions. Much of this difference is due to the inability of selenium to form π bonds of all types. The outer valence electrons of selenium are also more loosely held than those of sulfur. As a result, selenium is a better nucleophile and will react with reactive oxygen species faster than sulfur, but the resulting lack of π-bond character in the Se-O bond means that the Se-oxide can be much more readily reduced in comparison to S-oxides. The combination of these properties means that replacement of sulfur with selenium in nature results in a selenium-containing biomolecule that resists permanent oxidation. Multiple examples of this gain of function behavior from the literature are discussed.

  4. Effects of selenium-rich yeast supplementation on the plasma progesterone levels of postpartum dairy cows

    PubMed Central

    Kamada, Hachiro

    2017-01-01

    Objective The effects of the pre- and postpartum supplementation of cows with Se on their plasma P4 concentrations after calving were investigated. Methods Thirty-four Holstein cows were used to investigate the effects of dietary selenium supplementation on the postpartum recovery of the luteal function in cows. Selenium-rich yeast (containing 300 ppm selenium) was mixed with total mixed ration fed to 17 pregnant cows from 30 days before they were due to calve (10 g yeast daily) to 100 days after calving (20 g yeast daily). The control cows (n = 17) were fed the same amount of ordinary yeast. The cows’ plasma progesterone concentrations were determined every two days using an enzyme immunoassay after calving. Results Feed intake (total digestive nutrient, crude protein), milk production, body weight and the biochemical properties of blood plasma did not differ between the two groups; however, the plasma selenium concentrations of the supplemented animals were significantly greater than those of the controls at and after calving. The postpartum plasma progesterone concentrations of the selenium-yeast-supplemented group increased earlier than those of the control group. Moreover, during the estrus cycle after the 3rd ovulation or ovulation with estrus between 60 to 80 days after calving, the selenium-supplemented cows exhibited greater progesterone concentrations than the control cows. Conclusion Selenium supplementation promotes the postpartum progesterone production of cows. PMID:27492347

  5. Selenium bioaccessibility and speciation in biofortified Pleurotus mushrooms grown on selenium-rich agricultural residues.

    PubMed

    Bhatia, Poonam; Aureli, Federica; D'Amato, Marilena; Prakash, Ranjana; Cameotra, Swaranjit Singh; Nagaraja, Tejo Prakash; Cubadda, Francesco

    2013-09-01

    Cultivation of saprophytic fungi on selenium-rich substrates can be an effective means to produce selenium-fortified food. Pleurotus florida, an edible species of oyster mushrooms, was grown on wheat straw from the seleniferous belt of Punjab (India) and its potential to mobilize and accumulate selenium from the growth substrate was studied. Selenium concentration in biofortified mushrooms was 800 times higher compared with control samples grown on wheat straw from non selenium-rich areas (141 vs 0.17 μg Se g(-1) dry weight). Seventy-five percent of the selenium was extracted after in vitro simulated gastrointestinal digestion and investigation of the selenium molecular fractions by size exclusion HPLC-ICP-MS revealed that proteins and any other high molecular weight selenium-containing molecule were hydrolyzed to peptides and low molecular weight selenocompounds. Analysis of the gastrointestinal hydrolysates by anion exchange HPLC-ICP-MS showed that the bioaccessible selenium was mainly present as selenomethionine, a good bioavailable source of selenium, which accounted for 73% of the sum of the detected species. This study demonstrates the feasibility of producing selenium-biofortified edible mushrooms using selenium-rich agricultural by-products as growth substrates. The proposed approach can be used to evaluate whether selenium-contaminated plant waste materials harvested from high-selenium areas may be used to produce selenium-biofortified edible mushrooms based on the concentration, bioaccessibility and speciation of selenium in the mushrooms.

  6. Bioavailability of selenium from veal, chicken, beef, pork, lamb, flounder, tuna, selenomethionine, and sodium selenite assessed in selenium-deficient rats.

    PubMed

    Wen, H Y; Davis, R L; Shi, B; Chen, J J; Chen, L; Boylan, M; Spallholz, J E

    1997-01-01

    The bioavailability of selenium (Se) from veal, chicken, beef, pork, lamb, flounder, tuna, selenomethionine (SeMet), and sodium selenite was assessed in Se-deficient Fischer-344 rats. Se as veal, chicken, beef, pork, lamb, flounder, tuna, SeMet, and sodium selenite was added to torula yeast (TY) basal diets to comprise Se-inadequate (0.05 mg Se/kg) diets. Se as sodium selenite was added to a TY basal diet to comprise a Se-adequate (0.10 mg Se/kg), Se-control diet. The experimental diets were fed to weanling Fischer-344 rats that had been subjected to dietary Se depletion for 6 wk. After 9 wk of the dietary Se repletion, relative activity of liver glutathione peroxidase (GSHPx) from the different dietary groups compared with control rats (100%) was: flounder 106%, tuna 101%, pork 86%, sodium selenite 81%, SeMet 80%, beef 80%, chicken 77%, veal 77%, and lamb 58%. Se from flounder was the most efficient at restoring Se concentrations in the liver and skeletal muscle. Se from sodium selenite, SeMet, beef, veal, chicken, pork, lamb, and tuna was not dietarily sufficient to restore liver and muscle Se after 9 wk of recovery following a 6-wk period of Se depletion.

  7. Distribution and speciation of selenium in the black shale of the Dogger aquifer in the Poitiers Experimental Hydrogeological Site

    NASA Astrophysics Data System (ADS)

    Bassil, Joseph; Naveau, Aude; Di Tullo, Pamela; Grasset, Laurent; Bodin, Jacques; Razack, Moumtaz; Kazpard, Véronique

    2014-05-01

    Selenium (Se) is an element having the narrowest range between dietary deficiency and toxic concentrations. In the environment, selenium has four oxidation states (-II, 0, IV and VI) and has a complex biogeochemical cycle. The European and French legislations fixed 10 µg/L as safe upper limit in drinking water. In several French regions2, selenium concentrations above the limit were detected in groundwater. This poses a problem for local authorities which are obliged to stop the exploitation of many wells. In the north flank of the "Seuil du Poitou", Selenium concentrations above 10 ppb were measured in groundwater samples collected from five wells of the Poitiers Experimental Hydrogeological Site (SEH), which investigates a 100 m carbonate aquifer (Dogger). Total rock analysis applied on samples representing all the geological facies observed in the SEH show that selenium is concentrated in the black clays that fulfill some karst cavities; these clays are thought considered as the main selenium source in the Dogger Aquifer. The main objective of this work is to study the distribution and the speciation of selenium in the geological matrix and the release mechanisms of Se in order to provide quantifiable data to numerical modeling of selenium's reactive flows across the aquifer. The distribution and the speciation of selenium in these black clays were studied by applying parallel and sequential chemical extractions and by verifying the impact of these extractions on the solid dissolution and organic matter mobilization. In all the extractions, the total dissolved selenium was quantified using ICP-MS and the selenium speciation in the aqueous phase by HPLC-ICP-MS. Verifying the impact of the extractions on the solid dissolution and on the organic matter mobilization was performed by measuring Al, Si, Fe and Ca by AAS and the Total Organic Carbon TOC and by acquisition of XRD diffractograms of the solid residues. Our results showed that most of the selenium is

  8. Changing selenium nutritional status of Chinese residents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    China has been designated as one of 40 countries deficient in selenium (Se) according to the World Health Organization. Selenium concentrations in hair are commonly used to evaluate the Se level of the human body. Moreover, hair Se concentrations are significantly correlated with Se concentrations ...

  9. Selenium toxicosis in three California sea lions (Zalophus californianus).

    PubMed

    Edwards, W C; Whitenack, D L; Alexander, J W; Solangi, M A

    1989-12-01

    Selenium poisoning occurs worldwide in nearly all domestic animals. Acute selenium poisoning is associated with feeding high levels or injecting excessive amounts of selenium and is usually fatal. The acute poisoning may cause gastrointestinal disturbance, muscle weakness, depression of the central nervous system, prostration and death (1-2). Chronic selenium poisoning in cattle, sheep and horses may result from the consumption of seleniferous plants over an extended period of time. Chronic selenium results in ataxia, incoordination, partial blindness, paralysis, loss of hair or wool, abnormal hoof growth and possibly abnormal changes in behavior (1). There is little information regarding the clinical signs and pathology of selenium toxicosis in marine mammals. Likewise, there is little information regarding normal tissue levels or toxicologically significant levels of selenium in these species. The results of these investigations in sea lions, based on clinical signs, pathologic findings and tissue levels of selenium, suggest subacute or chronic selenium poisoning was most likely from dietary fish high in selenium.

  10. Chemical Form of Selenium in Naturally Selenium-Rich Lentils (Lens Culinaris L.) From Saskatchewan

    SciTech Connect

    Thavarajah, D.; Vandenberg, A.; George, G.N.; Pickering, I.J.

    2009-06-04

    Lentils (Lens culinaris L.) are a source of many essential dietary components and trace elements for human health. In this study we show that lentils grown in the Canadian prairies are additionally enriched in selenium, an essential micronutrient needed for general well-being, including a healthy immune system and protection against cancer. Selenium K near-edge X-ray absorption spectroscopy (XAS) has been used to examine the selenium biochemistry of two lentil cultivars grown in various locations in Saskatchewan, Canada. We observe significant variations in total selenium concentration with geographic location and cultivar; however, almost all the selenium (86--95%) in these field-grown lentils is present as organic selenium modeled as selenomethionine with a small component (5--14%) as selenate. As the toxicities of certain forms of arsenic and selenium are antagonistic, selenium-rich lentils may have a pivotal role to play in alleviating the chronic arsenic poisoning in Bangladesh.

  11. Chemical form of selenium in naturally selenium-rich lentils (Lens culinaris L.) from Saskatchewan.

    PubMed

    Thavarajah, Dil; Vandenberg, Albert; George, Graham N; Pickering, Ingrid J

    2007-09-05

    Lentils (Lens culinaris L.) are a source of many essential dietary components and trace elements for human health. In this study we show that lentils grown in the Canadian prairies are additionally enriched in selenium, an essential micronutrient needed for general well-being, including a healthy immune system and protection against cancer. Selenium K near-edge X-ray absorption spectroscopy (XAS) has been used to examine the selenium biochemistry of two lentil cultivars grown in various locations in Saskatchewan, Canada. We observe significant variations in total selenium concentration with geographic location and cultivar; however, almost all the selenium (86-95%) in these field-grown lentils is present as organic selenium modeled as selenomethionine with a small component (5-14%) as selenate. As the toxicities of certain forms of arsenic and selenium are antagonistic, selenium-rich lentils may have a pivotal role to play in alleviating the chronic arsenic poisoning in Bangladesh.

  12. Effects of simultaneous low-level dietary supplementation with inorganic and organic selenium on whole-body, blood, and organ levels of toxic metals in mice.

    PubMed Central

    Andersen, O; Nielsen, J B

    1994-01-01

    Classical experiments have demonstrated that Se compounds protect against the toxicity of several toxic metals in acute experiments with simultaneous parenteral administration of high doses of Se and the toxic metal. Blood and organ levels of the toxic metals were increased, conceivably due to formation of inert Se complexes. Less is known about effects of long-term Se status on the toxicokinetics of toxic metals. Possible Se interactions in toxic metal biokinetics should therefore be studied at Se levels ranging from those just sufficient to avoid Se deficiency and up to those believed to be optimum in relation to antioxidative and other beneficial effects of Se. The toxic-metal exposure levels investigated should be similar to those occurring in human populations that are not occupationally exposed. To study interactions between Se and toxic metals at ultralow exposure levels, mice were fed semisynthetic diets containing different levels of Se. The mice were given ultralow doses of metal salts either as a single oral dose by stomach tube or as prolonged exposure in the drinking water. Diets with high or normal Se levels slightly, but nonsignificantly increased the whole-body retention (WBR) of Hg++ and CH3Hg+ compared to a diet low in Se. The dietary Se level was, however, without effect on the WBR of Cd2+ and Ag2+ in single-dose experiments. During prolonged exposure, the diets fortified with Se increased the WBR of Ag2+, had no effect on WBR of Hg2+, and reduced the WBR of CH3Hg+ and Cd2+. During prolonged exposure, the diets fortified with Se reduced blood Hg++ while organ levels were unaltered.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7843127

  13. Influence of selenium, age and dosage of 7,12-dimethylbenz(a)anthracene (DMBA) on the in vivo formation of DNA adducts in mammary tissue

    SciTech Connect

    Jinzhou Liu; Milner, J.A. )

    1991-03-15

    Diets formulated to contain selenium, as sodium selenite, 0.1 or 2 {mu}g/g were fed for 2 weeks prior to DMBA treatment. Food intake and weight gain were not influenced by Se intake. Anti- and syn-dihydrodiol epoxide adducts reached maximum binding by 24 h. Se supplementation inhibited by about 50% the appearance of both anti-and syn- DMBA-DNA adducts. Dietary selenium increased the rate of removal of the anti-dihydrodiol epoxide adduct bound to guanine, but delayed the removal of the other adducts. The occurrence of DMBA-DNA adducts correlated positively with the dosage of DMBA administered. Binding increased about 40% as the rat's age increased from 36 to 125 d. Se supplementation inhibited binding in 36, 54 and 125 d old rats. These data confirmed that dietary selenium is effective in inhibiting in vivo metabolism of DMBA.

  14. Levels of the Antioxidant Nutrients Vitamin C, Vitamin E, and Selenium in the Dietary Supplement Ingredient Database: NHANES Data Applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory evidence indicates that antioxidants may slow or possibly prevent the development of certain cancers by protecting cells from damage caused by free radicals or other mechanisms. Many dietary supplements containing antioxidant constituents (e.g., vitamin C) are available to consumers. Th...

  15. Influence of dietary selenium on the mutagenic activity of perfusate and bile from rat liver, perfused with 1,1-dimethylhydrazine.

    PubMed

    Beije, B; Onfelt, A; Olsson, U

    1984-04-01

    The mutagenic effect of 1,1-dimethylhydrazine (UDMH) was studied in the liver perfusion/cell culture system. Male Wistar rats, fed a selenium-deficient diet with or without selenium supplementation in the drinking water, were used as liver donors. UDMH caused an increased mutation frequency in Chinese hamster V79 cells exposed in the perfusate. The effect was statistically significant with both selenium-deficient and selenium-supplemented livers. With selenium-deficient livers, a significant mutagenic effect was also obtained when V79 cells were treated with bile collected after the administration of UDMH. Bile flow and bile acid excretion were not affected by UDMH treatment of selenium-deficient or selenium-supplemented livers. There was a tendency towards reduced C-oxygenation of N,N-dimethylaniline in microsomes from selenium-deficient livers perfused with UDMH. The lactate/pyruvate ratio in the perfusate was increased by UDMH, the effect being more pronounced with selenium-deficient than selenium-supplemented livers.

  16. Tracing cytotoxic effects of small organic Se species in human liver cells back to total cellular Se and Se metabolites.

    PubMed

    Marschall, T A; Kroepfl, N; Jensen, K B; Bornhorst, J; Meermann, B; Kuehnelt, D; Schwerdtle, T

    2017-02-10

    Small selenium (Se) species play a major role in the metabolism, excretion and dietary supply of the essential trace element selenium. Human cells provide a valuable tool for investigating currently unresolved issues on the cellular mechanisms of Se toxicity and metabolism. In this study, we developed two isotope dilution inductively coupled plasma tandem-mass spectrometry based methods and applied them to human hepatoma cells (HepG2) in order to quantitatively elucidate total cellular Se concentrations and cellular Se species transformations in relation to the cytotoxic effects of four small organic Se species. Species- and incubation time-dependent results were obtained: the two major urinary excretion metabolites trimethylselenonium (TMSe) and methyl-2-acetamido-2-deoxy-1-seleno-β-d-galactopyranoside (SeSugar 1) were taken up by the HepG2 cells in an unmodified manner and did not considerably contribute to the Se pool. In contrast, Se-methylselenocysteine (MeSeCys) and selenomethionine (SeMet) were taken up in higher amounts, they were largely incorporated by the cells (most likely into proteins) and metabolized to other small Se species. Two new metabolites of MeSeCys, namely γ-glutamyl-Se-methylselenocysteine and Se-methylselenoglutathione, were identified by means of HPLC-electrospray-ionization-Orbitrap-MS. They are certainly involved in the (de-)toxification modes of Se metabolism and require further investigation.

  17. Toxicity of selenium (Na sub 2 SeO sub 3 ) and mercury (HgCl sub 2 ) on the planarian Dugesia gonocephala

    SciTech Connect

    Congiu, A.M.; Casu, S.; Ugazio, G. )

    1989-10-01

    The toxicity of selenium (Na{sub 2}SeO{sub 3}) and mercury (HgCl{sub 2}) was determined by using a freshwater planarian which is particularly sensitive to pollution, and belongs to a fissiparous breed of Dugesia gonocephala. The mortality and fissiparity frequency of the subjects were studied. They were exposed to intense treatments (48 hours) or for medium to long periods of time (21 days) to either the single compounds or a combination of both, and were fed or fasting. The lethal effect of sodium selenite is correlated to the food intake, whereas the toxicity of mercurous chloride is probably the result of a fixative effect which does not depend on feeding. The 21-day treatment with the first compound has a non-negligible lethal effect which is probably due to an accumulation phenomenon. At doses where an antioxidant effect prevails, fissiparity is stimulated. On the other hand, the second compound reduces reproduction frequency to half the base values. Compared to the Paracentrotus lividus, the Dugesia gonocephala offers various advantages concerning toxicological experiments; besides being easier to handle in the laboratory, it is available all year round and is not subject to seasonal cycles. It is also more susceptible to the toxic effect of mercury, which is a common and highly toxic pollutant, than the sea urchin.

  18. Effects of different levels of dietary selenium on the proliferation of spermatogonial stem cells and antioxidant status in testis of roosters.

    PubMed

    Shi, Lei; Zhao, Hui; Ren, Youshe; Yao, Xiaolei; Song, Ruigao; Yue, Wenbin

    2014-10-01

    The objective of this study was to investigate the different levels of dietary Se (from sodium selenite) on the proliferation of SSCs (spermatogonial stem cells) in testis of roosters. Also, the antioxidant status and Se content in blood plasma and testis were evaluated. A total of eighty 12-week-old Hy-Line Variety white roosters at an averaged body weight of 1.38 ± 0.2 kg were selected and randomly divided into four experimental groups. They were fed with the basal diet (0.044 mgSe/kg DM) supplemented with 0 (control), 0.5, 1.0 or 2.0 mgSe/kg DM (from sodium selenite). After the feeding experiment, blood and testis samples were collected for analysis of the antioxidant status and Se concentration. The testis samples were also used to examine the Thy-1 and β1-integrin mRNA expression by RT-PCR and detect the population of SSCs by immunofluorescence analysis. The results show that Se concentration in blood and testis of the animals was progressively increased with the increasing Se level in diet. The highest GSH-Px (glutathione peroxidase) activity and lowest MDA content in blood and testis was obtained in the treatment of 0.5mg/kg. RT-PCR analysis showed that mRNA expression of SSCs markers were significantly lower in the control and 1.0mg/kg groups when compared with that in the treatment of 0.5mg/kg. A similar trend was observed in the population of SSCs analyzed by immunofluorescence assay. These data suggest that dietary Se can influence the population of SSCs of roosters during spermatogenesis and that oxidative stress can modulate SSCs behavior through regulating some key factors during spermatogenesis.

  19. Dietary selenium variation-induced oxidative stress modulates CDC2/cyclin B1 expression and apoptosis of germ cells in mice testis.

    PubMed

    Kaushal, Naveen; Bansal, Mohinder P

    2007-08-01

    Oxidative stress has been linked with apoptosis in germ cells and with male infertility. However, the molecular mechanism of oxidative-stress-mediated apoptosis in germ cells has not been clearly defined so far. Because of the involvement of CDC2 and cyclin B1 in cell cycle regulation and their plausible role in apoptosis, the present study aimed to investigate the possibility that selenium (Se)-induced oxidative-stress-mediated modulations of these cell cycle regulators cause DNA damage and apoptosis in germ cells. To create different Se status (deficient, adequate and excess), male Balb/c mice were fed yeast-based Se-deficient diet (Group I) and a deficient diet supplemented with Se as sodium selenite (0.2 and 1 ppm Se in Groups II and III, respectively) for a period of 8 weeks. After the completion of the diet feeding schedule, a significant decrease in Se levels and glutathione peroxidase activity was observed in the Se-deficient group (Group I), whereas the Se-excess group (Group III) demonstrated an increase in Se levels. Increased levels of lipid peroxidation were seen in both Groups I and III when compared to Group II, indicating oxidative stress. The mRNA and protein expressions of both CDC2 and cyclin B1 were found to be significantly decreased in Groups I and III. A decrease in the immunohistochemical localization of these proteins was also observed in spermatogenic cells. The mRNA expressions of apoptotic factors such as Bcl-2, Bax, caspase-3 and caspase-9 were found to be increased in Groups I and III. A decrease in CDC2 kinase activity was also seen in these groups. Increased apoptosis was observed in Group I and Group III animals by terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labeling assay indicating oxidative-stress-mediated DNA damage. These findings suggest the effect of Se-induced oxidative stress on the cell cycle regulators and apoptotic activity of germ cells, thus providing new dimensions to molecular mechanisms

  20. In vitro bioavailability of total selenium and selenium species from seafood.

    PubMed

    Moreda-Piñeiro, Jorge; Moreda-Piñeiro, Antonio; Romarís-Hortas, Vanessa; Domínguez-González, Raquel; Alonso-Rodríguez, Elia; López-Mahía, Purificación; Muniategui-Lorenzo, Soledad; Prada-Rodríguez, Darío; Bermejo-Barrera, Pilar

    2013-08-15

    In vitro bioavailability of total selenium and selenium species from different raw seafood has been assessed by using a simulated gastric and intestinal digestion/dialysis method. Inductively coupled plasma-mass spectrometry (ICP-MS) was used to assess total selenium contents after a microwave assisted acid digestion, and also to quantify total selenium in the dialyzable and non-dialyzable fractions. Selenium speciation in the dialyzates was assessed by high performance liquid chromatography (HPLC) coupled with ICP-MS detection. Major Se species (selenium methionine and oxidized selenium methionine) from dialyzate were identified and characterized by HPLC coupled to mass spectrometry (HPLC-MS). Selenocystine was detected at low concentrations while Se-(Methyl)selenocysteine and inorganic selenium species (selenite and selenate) were not detected in the dialyzate. Low bioavailability percentages for total selenium (6.69±3.39 and 5.45±2.44% for fish and mollusk samples, respectively) were obtained. Similar bioavailability percentages was achieved for total selenium as a sum of selenium species (selenocystine plus oxidized selenium methionine and selenium methionine, mainly). HPLC-MS data confirmed SeMet oxidation during the in vitro procedure.

  1. High-dose selenium for the mitigation of radiation injury: a pilot study in a rat model.

    PubMed

    Sieber, Fritz; Muir, Sarah A; Cohen, Eric P; North, Paula E; Fish, Brian L; Irving, Amy A; Mäder, Marylou; Moulder, John E

    2009-03-01

    The purpose of this study was to evaluate in an animal model the safety and efficacy of dietary supplementation with high doses of selenium for the mitigation of the type of radiation injury that might be sustained during a nuclear accident or an act of radiological terrorism. Age-matched male rats were exposed to 10 Gy (single dose) of total-body irradiation (TBI) followed by a syngeneic bone marrow transplant, then randomized to standard drinking water or drinking water supplemented with sodium selenite or seleno-l-methionine. At 21 weeks after TBI, most rats on standard drinking water had severe renal failure with a mean blood urea nitrogen (BUN) level of 124 +/- 29 mg/dl (geometric mean +/- SE) whereas rats on selenium-supplemented drinking water (100 microg/day) had a mean BUN level of 67 +/- 12 mg/dl. The mitigating effect of selenium was confirmed by histopathological analyses. None of the animals on high-dose selenium showed signs of selenium toxicity. Our results suggest that dietary supplementation with high-dose selenium may provide a safe, effective and practical way to mitigate radiation injury to kidneys.

  2. Effects of dietary selenium on tissue concentrations, pathology, oxidative stress, and immune function in common eiders (Somateria mollissima).

    PubMed

    Franson, J Christian; Hoffman, David J; Wells-Berlin, Alicia; Perry, Matthew C; Shearn-Bochsler, Valerie; Finley, Daniel L; Flint, Paul L; Hollmén, Tuula

    2007-05-15

    Common eiders (Somateria mollissima) were fed added Se (as L-selenomethionine) in concentrations increasing from 10 to 80 ppm in a pilot study (Study 1) or 20 (low exposure) and up to 60 (high exposure) ppm Se in Study 2. Body weights of Study 1 ducks and high-exposure ducks in Study 2 declined rapidly. Mean concentrations of Se in blood reached 32.4 ppm wet weight in Study 1 and 17.5 ppm wet weight in high-exposure birds in Study 2. Mean Se concentrations in liver ranged from 351 (low exposure, Study 2) to 1252 ppm dry weight (Study 1). Oxidative stress was evidenced by Se-associated effects on glutathione metabolism. As Se concentrations in liver increased, Se-dependent glutathione peroxidase activity, glutathione reductase activity, oxidized glutathione levels, and the ratio of hepatic oxidized to reduced glutathione increased. In Study 2, the T-cell-mediated immune response was adversely affected in high-exposure eiders, but ducks in the low-exposure group exhibited evidence of an enhanced antibody-mediated immune response. Gross lesions in high-exposure ducks included emaciation, absence of thymus, and loss of nails from digits. Histologic lesions included severe depletion of lymphoid organs, hepatopathy, and necrosis of feather pulp and feather epithelium. Field studies showed that apparently healthy sea ducks generally have higher levels of Se in liver than healthy fresh-water birds, but lower than concentrations found in our study. Data indicate that common eiders and probably other sea ducks possess a higher threshold, or adverse effect level, for Se in tissues than fresh-water species. However, common eiders developed signs of Se toxicity similar to those seen in fresh-water birds.

  3. Effects of dietary selenium on tissue concentrations,pathology, oxidative stress, and immune function in common eiders (Somateria mollissima)

    USGS Publications Warehouse

    Franson, J. Christian; Hoffman, David; Wells-Berlin, Alicia M.; Perry, Matthew C.; Shearn-Bochsler, Valerie I.; Finley, Daniel L.; Flint, Paul L.; Hollmén, Tuula E.

    2007-01-01

    Common eiders (Somateria mollissima) were fed added Se (as L-selenomethionine) in concentrations increasing from 10 to 80 ppm in a pilot study (Study 1) or 20 (low exposure) and up to 60 (high exposure) ppm Se in Study 2. Body weights of Study 1 ducks and high-exposure ducks in Study 2 declined rapidly. Mean concentrations of Se in blood reached 32.4 ppm wet weight in Study 1 and 17.5 ppm wet weight in high-exposure birds in Study 2. Mean Se concentrations in liver ranged from 351 (low exposure, Study 2) to 1252 ppm dry weight (Study 1). Oxidative stress was evidenced by Se-associated effects on glutathione metabolism. As Se concentrations in liver increased, Se-dependent glutathione peroxidase activity, glutathione reductase activity, oxidized glutathione levels, and the ratio of hepatic oxidized to reduced glutathione increased. In Study 2, the T-cell-mediated immune response was adversely affected in high-exposure eiders, but ducks in the low-exposure group exhibited evidence of an enhanced antibody-mediated immune response. Gross lesions in high-exposure ducks included emaciation, absence of thymus, and loss of nails from digits. Histologic lesions included severe depletion of lymphoid organs, hepatopathy, and necrosis of feather pulp and feather epithelium. Field studies showed that apparently healthy sea ducks generally have higher levels of Se in liver than healthy fresh-water birds, but lower than concentrations found in our study. Data indicate that common eiders and probably other sea ducks possess a higher threshold, or adverse effect level, for Se in tissues than fresh-water species. However, common eiders developed signs of Se toxicity similar to those seen in fresh-water birds.

  4. Tolerance of the preruminant calf for selenium in milk replacer

    SciTech Connect

    Jenkins, K.J.; Hidiroglou, M.

    1986-07-01

    Calves were fed skim milk powder-based milk replacer containing either .2, 1, 3, 5, or 10 ppm selenium (added as sodium selenate) in the dry matter from 3 to 45 d of age to estimate the lowest amount of dietary selenium that would reduce calf performance and feed utilization. Only at the highest selenium (10 ppm) did calves show reduced average daily gain and feed efficiency and lower blood packed cell volume. Apparent digestibility of dry matter, nitrogen, and lipid, and plasma creatine phosphokinase activity were not affected by any of the selenium intakes. In general, selenium in blood, bile, duodenal mucosa, liver, kidney, and muscle reflected selenium intakes with liver and kidney reaching the highest selenium concentrations. Postmortem examinations of calves revealed no gross abnormalities for any of the selenium treatments. The preruminant calf is very tolerant of high inorganic selenium concentrations in skim milk powder-based milk replacer.

  5. Dietary incorporation of feedstuffs naturally high in organic selenium for racing pigeons (Columba livia): effects on plasma antioxidant markers after a standardised simulation of a flying effort.

    PubMed

    Schoonheere, N; Dotreppe, O; Pincemail, J; Istasse, L; Hornick, J L

    2009-06-01

    Selenium is a trace element of importance for animal health. It is essential for adequate functioning of many enzymes such as, the antioxidant enzyme, glutathione peroxidase, which protects the cell against free radicals. A muscular effort induces a rise in reactive oxygen species production which, in turn, can generate an oxidative stress. Two groups of eight racing pigeons were fed respectively with a diet containing 30.3 (control group) and 195.3 (selenium group) microg selenium/kg diet. The pigeons were submitted to a standardised simulation of a flying effort during 2 h. Blood was taken before and after the effort to measure antioxidant markers and blood parameters related to muscle metabolism. Plasma selenium concentration and glutathione peroxidase activity were significantly higher in the selenium group. There were no significant differences for the other measured parameters. As a consequence of the effort, the pigeons of the selenium group showed a higher increase of glutathione peroxidase activity and a smaller increase of plasma lactate concentration. Variations because of the effort in the other markers were not significantly different between the two groups. It is concluded that the selenium status was improved with the feeding of feedstuffs high in Selenium.

  6. Selenium in soybeans: bioavailability and form

    SciTech Connect

    Mason, A.C.

    1984-01-01

    Experiments are presented which evaluate the bioavailability of different forms of selenium from intrinsically and extrinsically labeled isolated soy protein and soy flour. The bioavailability of selenium from soy and egg is compared and some characteristics of selenium are described as it exists in soybeans. The metabolism of selenium was measured by whole-body and tissue radioactivity retention and selenium excretion. Selenium-75 was well absorbed from an isolated soy protein diet by rats. Selenium-75 from isolated soy protein labeled intrinsically and extrinsically with /sup 75/Se selenate was better absorbed than from protein labeled extrinsically with /sup 75/Se selenite or /sup 75/Se selenomethionine. Bioavailability of selenium from soy flour and egg was measured by whole-body and tissue radioactivity retention and glutathione peroxidase (GSH-Px) activity regeneration. Selenium-75 from soy flour intrinsically labeled with selenite was better absorbed than /sup 75/Se from flour intrinsically labeled with selenate. GSH-Px levels in the liver, kidney, platelets and heart fell when rats were fed a selenium deficient diet, but were not significantly raised on 0.0825 ppm Se repletion diets.

  7. Selenium in ruminant nutrition: a review.

    PubMed

    Ammerman, C B; Miller, S M

    1975-10-01

    The early interest in selenium related primarily to its toxicity, but since 1957 the element has been recognized as a dietary essential. The dietary requirement for selenium by most species is about .1 ppm. Deficiencies of selenium in cattle and sheep have been confirmed under natural grazing conditions in many countries of the world. Overt signs of inadequacy such as white muscle disease (nutritional muscular dystrophy) occur primarily in young calves or lambs born to selenium deficient dams. Infertility has increased in ewes grazing pastures low in selenium. In general, signs of deficiency have not occurred in older animals such as finishing beef cattle and lactating dairy cows. Subclinical deficiencies of selenium are not determined easily, however, and thus an inadequacy of the element may be limiting maximum animal performance under certain circumstances of drylot feeding. The current nutritional status of ruminant animals in many geographical areas and involving various feeding programs with this element has not been established. The recent widespread deficiency problems with nonruminants suggest that such an assessment should be made. Concentration of selenium in tissue, particularly in the liver, has been used in establishing selenium status of the animal. With lambs glutathione peroxidase activity in certain tissues may be a more accurate indicator of selenium adequacy than is selenium content of the tissue. Supplemental sodium selenite and sodium selenate by either oral administration or parenteral injection have prevented clinical signs of selenium deficiency and animal losses in both ruminant and nonruminant animals. Heavy pellets containing elemental selenium for placement in the rumen have proved effective. In general, organic forms of selenium are absorbed more readily by animals than are inorganic compounds. The dietary requirements for selenium and its metabolism are influenced by many nutrient interrelationships, including its interactions with

  8. Selenium. Nutritional, toxicologic, and clinical aspects.

    PubMed Central

    Fan, A. M.; Kizer, K. W.

    1990-01-01

    Despite the recent findings of environmental contamination, selenium toxicosis in humans is exceedingly rare in the United States, with the few known cases resulting from industrial accidents and an episode involving the ingestion of superpotent selenium supplements. Chronic selenosis is essentially unheard of in this country because of the typical diversity of the American diet. Nonetheless, because of the growing public interest in selenium as a dietary supplement and the occurrence of environmental selenium contamination, medical practitioners should be familiar with the nutritional, toxicologic, and clinical aspects of this trace element. PMID:2219873

  9. Thioacetamide-induced cirrhosis in selenium-adequate mice displays rapid and persistent abnormity of hepatic selenoenzymes which are mute to selenium supplementation

    SciTech Connect

    Zhang Jinsong Wang Huali; Yu Hanqing

    2007-10-01

    Selenium reduction in cirrhosis is frequently reported. The known beneficial effect of selenium supplementation on cirrhosis is probably obtained from nutritionally selenium-deficient subjects. Whether selenium supplementation truly improves cirrhosis in general needs additional experimental investigation. Thioacetamide was used to induce cirrhosis in selenium-adequate and -deficient mice. Selenoenzyme activity and selenium content were measured and the influence of selenium supplementation was evaluated. In Se-adequate mice, thioacetamide-mediated rapid onset of hepatic oxidative stress resulted in an increase in thioredoxin reductase activity and a decrease in both glutathione peroxidase activity and selenium content. The inverse activity of selenoenzymes (i.e. TrxR activity goes up and GPx activity goes down) was persistent and mute to selenium supplementation during the progress of cirrhosis; accordingly, cirrhosis was not improved by selenium supplementation in any period. On the other hand, selenium supplementation to selenium-deficient mice always more efficiently increased hepatic glutathione peroxidase activity and selenium content compared with those treated with thioacetamide, indicating that thioacetamide impairs the liver bioavailability of selenium. Although thioacetamide profoundly affects hepatic selenium status in selenium-adequate mice, selenium supplementation does not modify the changes. Selenium supplementation to cirrhotic subjects with a background of nutritional selenium deficiency can improve selenium status but cannot restore hepatic glutathione peroxidase and selenium to normal levels.

  10. Iodine and selenium in natural water, their fixation on geochemical barriers in soils and rocks and explanation of I and Se behavior in water-solid phase system using thermodynamic modeling

    NASA Astrophysics Data System (ADS)

    Korobova, Elena; Ryzhenko, Boris; Cherkasova, Elena; Sedykh, Ivelina; Korsakova, Nadezhda; Berezkin, Victor; Kolmykova, Lyudmila; Danilova, Valentina; Khushvakhtova, Sabzbakhor

    2014-05-01

    Iodine and selenium are essential for normal functioning of thyroid gland. Their natural deficiency in areas subjected to radioiodine contamination during nuclear tests and accidents may increase the risk of thyroid cancer among the most sensitive groups of population. Deficiency is caused by both the low abundance of microelements in the environmental components of the local food chain and their fixation on geochemical barriers due to such processes as chemical transformation, sorption, chemisorption, complexing. The studies of iodine and selenium distribution in soils, herbs and drinking water in rural settlements of the Bryansk oblast' confirmed low level of iodine and selenium content in local soils, plants and water and revealed different character of their distribution in soils and waters formed in geochemically different conditions of water migration in areas of fluvioglacial, moraine and loess-like soil forming rocks (the polesje, moraine and opolje landscapes correspondingly). Iodine content in top horizons of the soils developed on loess-like sediments and rich in organic matter was considerably higher as compared to those formed on sandy moraine or fluvioglacial sediments. For selenium the difference was not pronounced. Iodine was noted for positive correlation with Corg and fixation in the soil profile on carbonate barrier. A negative correlation was found between selenium content in grasses and in topsoil of subordinated elementary landscapes characterized by waterlogged and reduction conditions in soils. Thermodynamic modeling performed for 47 water samples on the basis of their chemical composition helped to explain the established patterns of iodine and selenium behavior in soil-water system. It demonstrated the possibility of existence of CaI+ and MgI+ complexes in water and sedimentation of FeSe(cr) in presence of a considerable amount of Fe2+. Iodine complexation with Ca and Mg ions may explain its further fixation on carbonate barrier in soils

  11. Determination of the selenium requirement in kittens.

    PubMed

    Wedekind, K J; Howard, K A; Backus, R C; Yu, S; Morris, J G; Rogers, Q R

    2003-10-01

    The purpose of this study was to determine the selenium (Se) requirement in kittens. Thirty-six specific-pathogen-free kittens (9.8 weeks old) were utilized in a randomized complete block design to determine the Se requirement in cats with gender and weight used as blocking criteria. Kittens were fed a low Se (0.02 mg/kg Se) torula yeast-based diet for 5 weeks (pre-test) after which an amino acid-based diet (0.027 mg Se/kg diet) was fed for 8 weeks (experimental period). Six levels of Se (0, 0.05, 0.075, 0.10, 0.20 and 0.30 mg Se/kg diet) as Na2SeO3 were added to the diet and were used to construct a response curve. Response variables included Se concentrations and Se-dependent glutathione peroxidase activities (GSHpx) in plasma and red blood cells (RBC) as well as plasma total T3 (TT3) and total T4 (TT4). No significant changes in food intake, weight gain or clinical signs of Se deficiency were noted. Estimates of the kitten's Se requirement (i.e. breakpoints) were determined for RBC and plasma GSHpx (0.12 and 0.15 mg Se/kg diet, respectively), but no definitive breakpoint was determined for plasma Se. Plasma TT3 increased linearly, whereas plasma TT4 and the ratio of TT4 : TT3 decreased in a quadratic fashion to dietary Se concentration. The requirement estimate determined in this study (0.15 mg Se/kg) for kittens is in close agreement with other species. As pet foods for cats contain a high proportion of animal protein with a Se bioavailability of 30%, it is recommended that commercial diets for cats contain 0.5 mg Se/kg DM.

  12. Conventional foods, followed by dietary supplements and fortified foods, are the key sources of vitamin D, vitamin B6, and selenium intake in Dutch participants of the NU-AGE study.

    PubMed

    Berendsen, Agnes A M; van Lieshout, Lilou E L M; van den Heuvel, Ellen G H M; Matthys, Christophe; Péter, Szabolcs; de Groot, Lisette C P G M

    2016-10-01

    With aging, energy needs decrease, necessitating a more nutrient-dense diet to meet nutritional needs. To bridge this gap, the use of nutrient-dense foods, fortified foods, and dietary supplements can be important. This observational study aims to describe current micronutrient intakes of Dutch elderly and to identify the contribution of nutrient-dense foods, fortified foods, and dietary supplements to the intake of micronutrients that are often inadequately consumed in Dutch elderly. Data of 245 Dutch volunteers from the NU-AGE study aged 65 to 80 years were used. Dietary intake was assessed by means of 7-day food records, and dietary supplement use was recorded with an additional questionnaire. Information on fortified foods was obtained from the Dutch Food Composition Table 2011. Nutrient density of foods was evaluated using the Nutrient Rich Food 9.3 score. The percentages of participants not meeting their average requirement were high for vitamin D (99%), selenium (41%), and vitamin B6 (54%) based on conventional foods and also when taking into account fortified foods (98%, 41%, and 27%, respectively) and vitamin and mineral supplements (87%, 36%, and 20%, respectively). Conventional foods were the main source of vitamin D, vitamin B6, and selenium intake (42%, 45%, and 82%, respectively), followed by vitamin and mineral supplements (41%, 44%, and 18%) and fortified foods (17%, 11%, and 1%). Foods with the highest nutrient density contributed most to total vitamin B6 intake only. To optimize nutrient intakes of elderly, combinations of natural food sources, fortified foods, and dietary supplements should be considered.

  13. Platelet Indices of Selenium Status in Healthy and Selenium-Deficient Sheep: a Comparison with Selenium Indices in Plasma, Whole Blood, and Red Blood Cells.

    PubMed

    Dalir-Naghadeh, Bahram; Bahrami, Yaser; Rezaei, Siamak Asri; Anassori, Ehsan; Janalipour, Ali; Khosravi, Voria

    2015-11-01

    Several biomarkers have been used to evaluate selenium (Se) status in livestock. However, there is no report on the potential usefulness of the Se indices of platelets in diagnosis of Se deficiency in large animals. In the current study, Se concentration and glutathione peroxidase (GPx) activity in platelets of 38 healthy and 142 Se-deficient ewes were assessed, and their correlation with plasma Se concentration, plasma GPx activity, whole blood Se concentration, and erythrocyte GPx activity was determined. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff values of Se concentration and GPx activity of the platelets and to summarize the diagnostic performance of these biomarkers. In Se-deficient ewes, consistent with other indices, Se concentration and GPx activity in platelets were significantly lower than those of the healthy ewes. There was a positive significant correlation between Se concentration and GPx activity in platelets with plasma Se concentration, whole blood Se concentration, and erythrocyte GPx activity. Based on the ROC curve analysis, the best cutoff value to predict inadequate plasma selenium concentration was ≤0.0055 attogram/platelet for the platelet Se concentration, with a sensitivity of 100.0 %, specificity of 92.4 %, and AUC of 0.94. For platelet GPx activity, the cutoff value was ≤203.6 U/g protein with a sensitivity of 97.4 %, specificity of 77.7 %, and AUC of 0.90. The results of this study suggested that the platelet Se concentration and GPx activity can be considered a reliable and valid intermediate-term surrogate parameter in assessment of dietary Se intake in sheep.

  14. Bioaccumulation of organic and inorganic selenium in a laboratory food chain

    SciTech Connect

    Besser, J.M.; Canfield, T.J.; La Point, T.W. )

    1993-01-01

    Aquatic organisms accumulated selenium (Se) from inorganic and organic Se species via aqueous and food-chain exposure routes. The authors measured aqueous and food-chain Se bioaccumulation from selenate, selenite, and seleno-L-methionine in a laboratory food chain of algae (Chlamydomonas reinhardtii), daphnids (Daphnia magna), and fish (bluegill, Lepomis macrochirus). Selenium concentrations were monitored radiometrically with [sup 75]Se-labeled compounds. All three organisms concentrated Se more strongly from aqueous selenomethionine than from either inorganic Se species. Bioconcentration factors estimated from 1 [mu]g Se/L Se-methionine exposures were approximately 16,000 for algae, 200,000 for daphnids, and 5,000 for bluegills. Algae and daphnids concentrated Se more strongly from selenite than selenate whereas bluegills concentrated Se about equally from both inorganic species. Bioaccumulation of foodborne Se by daphnids and bluegills was similar in food chains dosed with different Se species. Daphnids and bluegills did not accumulate Se concentrations greater than those in their diet, except at very low dietary Se concentrations. Food-chain concentration factors (CFs) for daphnids decreased from near 1.0 to 0.5 with increases in algal Se concentrations, whereas CFs estimated from bluegill exposures averaged 0.5 over a range of foodborne Se concentrations. In exposures based on selenite, bluegills accumulated greater Se concentrations from food than from water.

  15. Biochemical Comparison of Commercial Selenium Yeast Preparations.

    PubMed

    Fagan, Sheena; Owens, Rebecca; Ward, Patrick; Connolly, Cathal; Doyle, Sean; Murphy, Richard

    2015-08-01

    The trace mineral selenium (Se) is an essential element for human and animal nutrition. The addition of Se to the diet through dietary supplements or fortified food/feed is increasingly common owing to the often sub-optimal content of standard diets of many countries. Se supplements commercially available include the inorganic mineral salts such as sodium selenite or selenate, and organic forms such as Se-enriched yeast. Today, Se yeast is produced by several manufacturers and has become the most widely used source of Se for human supplementation and is also widely employed in animal nutrition where approval in all species has been granted by regulatory bodies such as the European Food Safety Authority (EFSA). Characterisation and comparison of Se-enriched yeast products has traditionally been made by quantifying total selenomethionine (SeMet) content. A disadvantage of this approach, however, is that it does not consider the effects of Se deposition on subsequent digestive availability. In this study, an assessment was made of the water-soluble extracts of commercially available Se-enriched yeast samples for free, peptide-bound and total water-soluble SeMet. Using LC-MS/MS, a total of 62 Se-containing proteins were identified across four Se yeast products, displaying quantitative/qualitative changes in abundance relative to the certified reference material, SELM-1 (P value <0.05; fold change ≥2). Overall, the study indicates that significant differences exist between Se yeast products in terms of SeMet content, Se-containing protein abundance and associated metabolic pathways.

  16. Selenopeptides and elemental selenium in Thunbergia alata after exposure to selenite: quantification method for elemental selenium.

    PubMed

    Aborode, Fatai Adigun; Raab, Andrea; Foster, Simon; Lombi, Enzo; Maher, William; Krupp, Eva M; Feldmann, Joerg

    2015-07-01

    Three month old Thunbergia alata were exposed for 13 days to 10 μM selenite to determine the biotransformation of selenite in their roots. Selenium in formic acid extracts (80 ± 3%) was present as selenopeptides with Se-S bonds and selenium-PC complexes (selenocysteinyl-2-3-dihydroxypropionyl-glutathione, seleno-phytochelatin2, seleno-di-glutathione). An analytical method using HPLC-ICPMS to detect and quantify elemental selenium in roots of T. alata plants using sodium sulfite to quantitatively transform elemental selenium to selenosulfate was also developed. Elemental selenium was determined as 18 ± 4% of the total selenium in the roots which was equivalent to the selenium not extracted using formic acid extraction. The results are in an agreement with the XAS measurements of the exposed roots which showed no occurrence of selenite or selenate but a mixture of selenocysteine and elemental selenium.

  17. Efficacy of selenium from hydroponically produced selenium-enriched kale sprout (Brassica oleracea var. alboglabra L.) in broilers.

    PubMed

    Chantiratikul, Anut; Pakmaruek, Pornpan; Chinrasri, Orawan; Aengwanich, Worapol; Chookhampaeng, Sumalee; Maneetong, Sarunya; Chantiratikul, Piyanete

    2015-05-01

    An experiment was conducted to determine the efficacy of Se from hydroponically produced Se-enriched kale sprout (HPSeKS) on performance, carcass characteristics, tissue Se concentration, and physiological responses of broilers in comparison to that of Se from Se-enriched yeast and sodium selenite. Three hundred and sixty male broilers, 10 days of age, were assigned to 6 groups, 4 replicates of 15 broilers each, according to the completely randomized design. The dietary treatments were the following: T1: control diet; T2: control diet plus 0.3 mg Se/kg from sodium selenite; T3: control diet plus 0.3 mg Se/kg from Se-enriched yeast; and T4, T5, and T6: control diet plus 0.3, 1.0, and 2.0 mg Se/kg from HPSeKS, respectively. The results found that dietary Se supplementation did not (p > 0.05) alter performance and carcass characteristics of broilers. Se supplementation increased (p < 0.05) Se concentrations in the liver and kidney of broilers. Heart tissue Se concentration of broilers fed Se from sodium selenite was lower (p < 0.05) than that of broilers fed Se from HPSeKS and Se-enriched yeast. Selenium from HPSeKS increased higher (p < 0.05) GSH-Px activity when compared to Se from sodium selenite and Se-enriched yeast. The results indicated that the efficacy of Se from HPSeKS was comparable in increasing tissue Se concentration, but higher in improving GSH-Px activity in Rbc when compared to those of Se from Se-enriched yeast.

  18. Treating chronic arsenic toxicity with high selenium lentil diets.

    PubMed

    Sah, Shweta; Vandenberg, Albert; Smits, Judit

    2013-10-01

    Arsenic (As) toxicity causes serious health problems in humans, especially in the Indo-Gangetic plains and mountainous areas of China. Selenium (Se), an essential micronutrient is a potential mitigator of As toxicity due to its antioxidant and antagonistic properties. Selenium is seriously deficient in soils world-wide but is present at high, yet non-toxic levels in the great plains of North America. We evaluate the potential of dietary Se in counteracting chronic As toxicity in rats through serum biochemistry, blood glutathione levels, immunotoxicity (antibody response), liver peroxidative stress, thyroid response and As levels in tissues and excreta. To achieve this, we compare diets based on high-Se Saskatchewan (SK) lentils versus low-Se lentils from United States. Rats drank control (0ppm As) or As (40ppm As) water while consuming SK lentils (0.3ppm Se) or northwestern USA lentils (<0.01ppm Se) diets for 14weeks. Rats on high Se diets had higher glutathione levels regardless of As exposure, recovered antibody responses in As-exposed group, higher fecal and urinary As excretion and lower renal As residues. Selenium deficiency caused greater hepatic peroxidative damage in the As exposed animals. Thyroid hormones, triiodothyronine (T3) and thyroxine (T4), were not different. After 14weeks of As exposure, health indicators in rats improved in response to the high Se lentil diets. Our results indicate that high Se lentils have a potential to mitigate As toxicity in laboratory mammals, which we hope will translate into benefits for As exposed humans.

  19. Effects of dietary sulfur and distillers dried grains with solubles on carcass characteristics, loin quality, and tissue concentrations of sulfur, selenium, and copper in growing-finishing pigs.

    PubMed

    Kim, B G; Kil, D Y; Mahan, D C; Hill, G M; Stein, H H

    2014-10-01

    Inclusion of up to 0.38% S in diets that contain 30% distillers dried grains with solubles (DDGS) has no negative effect on growth performance of growing-finishing pigs, but there is no information about the effects of dietary S on accumulation of S in tissues in pigs. Therefore, the objective of this experiment was to determine if the concentration of S in diets containing DDGS affects carcass characteristics, loin quality, or tissue mineral concentrations in growing-finishing pigs. A total of 120 barrows (34.2 ± 2.3 kg BW) were allotted to 3 dietary treatments with 10 replicate pens and 4 pigs per pen in a randomized complete block design. Pigs were fed grower diets for 42 d and finisher diets for 42 d. At the conclusion of the experiment, the pig in each pen with the BW closest to the pen average was slaughtered. The control diet was based on corn and soybean meal and the finisher diet contained 0.14% S, 0.19 mg/kg Se, and 15.3 mg/kg Cu. The DDGS diet was formulated with corn, soybean meal, and 30% DDGS and the finisher diet with DDGS contained 0.16% S, 0.32 mg/kg Se, and 14.0 mg/kg Cu. The DDGS plus S (DDGS-S) diet was similar to the DDGS diet, except that 1.10% CaSO4 (16.2% S) was included in this diet, and the finisher diet with DDGS-S contained 0.37% S, 0.35 mg/kg Se, and 13.8 mg/kg Cu. Results indicated that organ weights and loin quality, 24-h pH, drip loss, loin subjective color, marbling, and firmness did not differ among treatments, but loin a* was greater (P < 0.05) for pigs fed the control diet than for pigs fed the DDGS-S diet. Concentrations of S in hair, liver, heart, loin, and all other tissues did not differ among treatments, but urinary S concentration was greater (P < 0.05) for pigs fed the DDGS-S diet than for pigs fed the other diets. Pigs fed the DDGS diet or the DDGS-S diet had greater (P < 0.01) concentrations of Se in hair, liver, heart, and loin than pigs fed the control diet, but liver concentrations of Cu did not differ among

  20. Influences of fiber, methionine and form of selenium on selenium hindgut targeting and tissue accumulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increased selenium (Se) status has beneficial outcomes, including decreased colorectal cancer risk, yet obesity may interfere with Se metabolism. Commensal bacteria can influence colon carcinogenesis and Se influences the microbiome, including production of volatile fatty acids by these microbes. We...

  1. Selenium as a potential protective factor against mercury developmental neurotoxicity.

    PubMed

    Choi, Anna L; Budtz-Jørgensen, Esben; Jørgensen, Poul J; Steuerwald, Ulrike; Debes, Frodi; Weihe, Pál; Grandjean, Philippe

    2008-05-01

    Experimental studies suggest that selenium (Se) may decrease methylmercury (MeHg) toxicity under certain exposure regimens. In epidemiological studies, the exposure to MeHg occurs from fish and seafood, which are also a source of beneficial nutrients such as selenium. However, little is known about the potential protective effects of dietary Se against MeHg neurotoxicity in humans. The possible interaction was assessed in two birth cohorts in the Faroe Islands, consisting of singleton term births from 1986 to 1987 (N=1,022), and 1994 to 1995 (N=182), respectively. Dietary habits in this fishing population included frequent consumption of seafood, including whale meat high in mercury. Both Hg and Se were measured in cord whole blood. Neurodevelopmental outcomes were evaluated at age 7 years in both cohorts, and the smaller cohort also included neurological assessment on several prior occasions. Each outcome was modeled as a function of Hg and Se interactions (with adjustments for potential risk factors) by expressing the effects of log10(Hg) within the lowest 25%, the middle 50%, and the highest 25% of the Se distribution. Surplus Se was present in cord blood, the average being a 10-fold molar excess above MeHg. Regression analyses failed to show consistent effects of Se, or statistically significant interaction terms between Se and MeHg. Overall, no evidence was found that Se was an important protective factor against MeHg neurotoxicity. Prevention, therefore, needs to address MeHg exposures rather than Se intakes. Because of the benefits associated with fish intake during pregnancy, consumers should be advised to maintain a high fish and seafood intake that is low in Hg contamination. Additional research is needed to determine the identity of the nutrients responsible for the beneficial effects.

  2. Effect of nano-sized, elemental selenium supplement on the proteome of chicken liver.

    PubMed

    Gulyas, G; Csosz, E; Prokisch, J; Javor, A; Mezes, M; Erdelyi, M; Balogh, K; Janaky, T; Szabo, Z; Simon, A; Czegledi, L

    2016-02-22

    The nano-sized (100-500 nm) selenium has higher bioavailability and relatively lower toxicity compared to other selenium forms. The objective of the present study was to compare liver proteome profiles of broiler chicken fed with control diet without Se supplementation and diet supplemented with nano-Se with 4.25 mg/kg DM. Differential proteome analyses were performed by two-dimensional gel electrophoresis (2D-PAGE) followed by tryptic digestion and protein identification by liquid chromatography-mass spectrometry (LC-MS). Seven hundred and eight spots were detected, and 18 protein spots showed significant difference in their intensity (p < 0.05) between the two groups. In response to nano-Se supplementation, the expression of 8 proteins was higher, and 5 proteins were lower in nano-Se supplemented group compared to control group. The functions of the differentially expressed proteins indicate that the high dose of selenium supplementation induced a dietary stress. Selenium supplementation may influence the metabolism of fatty acids and carbohydrates and antioxidant system, and increase the quantity of cytoskeletal actin and the expression of actin regulatory protein as well.

  3. Selenium and selenocysteine: roles in cancer, health, and development.

    PubMed

    Hatfield, Dolph L; Tsuji, Petra A; Carlson, Bradley A; Gladyshev, Vadim N

    2014-03-01

    The many biological and biomedical effects of selenium are relatively unknown outside the selenium field. This fascinating element, initially described as a toxin, was subsequently shown to be essential for health and development. By the mid-1990s selenium emerged as one of the most promising cancer chemopreventive agents, but subsequent human clinical trials yielded contradictory results. However, basic research on selenium continued to move at a rapid pace, elucidating its many roles in health, development, and in cancer prevention and promotion. Dietary selenium acts principally through selenoproteins, most of which are oxidoreductases involved in diverse cellular functions.

  4. Dietary selenomethionine intake increases exon-specific DNA methylation of p53 gene in rat liver and colon mucosa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The regulation of site-specific DNA methylation of tumor suppressor genes has been considered as a leading mechanism by which certain nutrients exert their anticancer property. Our previous studies suggest that dietary selenium (Se) may alter DNA methylation, and the purpose of this study was to inv...

  5. Dietary sodium selenite on host intestinal and systemic immune response and disease susceptibility to necrotic enteritis in commercial broilers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1. The present study was conducted to evaluate the supplementary effects of dietary Selenium (Se) given as sodium selenite on host immune response against necrotic enteritis (NE) in commercial broiler chickens. 2. Chickens were fed from hatch with a non-supplemented diet or diets supplemented with ...

  6. Effects of tocopherol and selenium supplementation on vitamin A evaluated by response surface analysis

    SciTech Connect

    Stoecker, B.J.; Seaborn, C.D.; Kiangura, R.K.; Hermann, J.R. )

    1991-03-15

    Sixty-six weanling male rats were fed torula-yeast based diets and deprived of selenium, vitamin A and tocopherol for five weeks. Subsequently a two-factor central composite response surface experimental design was used to determine Se and tocopherol supplementation for nine groups. Selenium, as sodium selenate, was added to the diets at concentrations between 0 and 1.0 ppm. Rats were dosed with 0.2 to 50 mg/day of dl-alpha-tocopherol. All animals were fed 100 ug beta-carotene daily. Body, liver, and spleen weights were not significantly affecteds ofdietary treatments. Dietary Se affected heart weight. Hepatic vitamin A decreased linearly with increasing tocopherol supplements. In the combinations used, tocopherol decreased total vitamin A in liver and kidney but did not interact significantly with Se.

  7. Defining the Optimal Selenium Dose for Prostate Cancer Risk Reduction: Insights from the U-Shaped Relationship Between Selenium Status, DNA Damage, and Apoptosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our work in dogs has revealed a U-shaped dose response between selenium status and prostatic DNA damage that remarkably parallels the relationship between dietary selenium and prostate cancer risk in men, suggesting that more selenium is not necessarily better. Herein, we extend this canine work to ...

  8. Selenium requirements are higher for glutathione peroxidase-1 mRNA than gpx1 activity in rat testis.

    PubMed

    Schriever, Sonja C; Barnes, Kimberly M; Evenson, Jacqueline K; Raines, Anna M; Sunde, Roger A

    2009-05-01

    Selenium (Se) plays a critical role in testis, sperm, and reproduction, and testis Se levels are remarkably maintained in Se deficiency. In most other tissues, Se levels decrease dramatically as do levels of most selenoproteins and levels of a subset of Se-regulated selenoprotein mRNAs. Because of the recent identification of key molecules in the targeted trafficking of Se to the testis, we examined the hierarchy of Se regulation in testis by determining the dietary Se regulation of the full testis selenoproteome in rats fed graded levels of Se (0 to 0.8 microg Se/g) as Na2SeO3 for 28 d. Se status did not significantly affect testis weight or glutathione peroxidase 4 (Gpx4) activity (P>0.05). qRT-PCR analysis of selenoprotein mRNA expression revealed that 21 of the 24 selenoprotein mRNAs and ApoER2 mRNA (the selenoprotein P [Sepp1] receptor) were also not regulated significantly by dietary Se status. In contrast, Gpx1 activity decreased to 28% of Se-adequate levels, and mRNA levels for Gpx1, Sepp1, and Sepw1 (selenoprotein W) decreased significantly in Se-deficient rats to 45, 46, and 55%, respectively, of Se-adequate plateau levels. Overlap of hyperbolic Gpx4 activity and Sepw1 mRNA response curves with testis Se concentration, all with minimum dietary Se requirements<0.016 microg Se/g, showed the priority for synthesis of Gpx4. Higher minimum dietary Se requirements of 0.04 microg Se/g for Gpx1 activity and Sepp1 mRNA, and the even higher minimum dietary Se requirement of 0.08 microg Se/g for Gpx1 mRNA, suggest that the hierarchy of these biomarkers reflects distinct, lower priority pools, cell types, and roles for Se within the testis.

  9. Protective role of dietary-supplemented selenium and vitamin E in heat-induced apoptosis and oxidative stress in mice testes.

    PubMed

    Kaur, S; Bansal, M P

    2015-12-01

    This study evaluated the role of selenium (0.5 ppm selenium/kg diet) and vitamin E (200 mg alpha-tocopherol/kg diet) on spermatogenesis after scrotal hyperthermia (42 °C, 30 min) in six different groups of male Balb/c mice; Control, Heat shock, Selenium, Selenium+heat shock, Vitamin E and Vitamin E+heat shock. Markers of the stress responses, hypoxia and oxidative stress, were evaluated in testis after the hyperthermic shock. Hyperthermia caused an elevated mRNA expression of hypoxia-inducible factor-1 alpha, haem oxygenase-1 (HMOX-1) and also glutathione peroxidase activity and reactive oxygen species (ROS). Apoptosis was evaluated by TUNEL assay and further by mRNA expression of Bcl-2, caspase 3, 8, 9, bid and AKT. TUNEL assay showed significant increase in apoptotic index of spermatogenic cells, whereas decrease in mRNA expression of Bcl-2, AKT and increase in caspase 3, 8, 9 and Bid in heat-shock group were observed. A significant decrease in sperm motility was also seen in heat-shock group in comparison with control group. These observations clearly indicate the development of oxidative stress and apoptosis after hyperthermia. Further analysis in Selenium+heat shock and Vitamin E+heat shock groups showed protective behaviour as compared to effects in heat-shock group which could be of therapeutic interest in future studies.

  10. Selenium Health Benefit Values: Updated Criteria for Mercury Risk Assessments.

    PubMed

    Ralston, Nicholas V C; Ralston, Carla R; Raymond, Laura J

    2016-06-01

    Selenium (Se)-dependent enzymes (selenoenzymes) protect brain tissues against oxidative damage and perform other vital functions, but their synthesis requires a steady supply of Se. High methylmercury (CH3Hg) exposures can severely diminish Se transport across the placenta and irreversibly inhibit fetal brain selenoenzymes. However, supplemental dietary Se preserves their activities and thus prevents pathological consequences. The modified Se health benefit value (HBVSe) is a risk assessment criterion based on the molar concentrations of CH3Hg and Se present in a fish or seafood. It was developed to reflect the contrasting effects of maternal CH3Hg and Se intakes on fetal brain selenoenzyme activities. However, the original equation was prone to divide-by-zero-type errors whereby the calculated values increased exponentially in samples with low CH3Hg contents. The equation was refined to provide an improved index to better reflect the risks of CH3Hg exposures and the benefits provided by dietary Se. The HBVSe provides a biochemically based perspective that confirms and supports the FDA/EPA advice for pregnant and breast-feeding women regarding seafoods that should be avoided vs. those that are beneficial to consume. Since Se can be highly variable between watersheds, further evaluation of freshwater fish is needed to identify locations where fish with negative HBVSe may arise and be consumed by vulnerable subpopulation groups.

  11. Bioaccumulation and chronic toxicity of dietary L-selenomethionine in juvenile white sturgeon (Acipenser transmontanus).

    PubMed

    Tashjian, Diran H; Teh, Swee J; Sogomonyan, Arutyun; Hung, Silas S O

    2006-10-12

    An 8-week growth trial was conducted to determine the sensitivity of white sturgeon (Acipenser transmontanus) to the toxicological effects of elevated dietary selenium (Se). Juvenile white sturgeon were fed diets supplemented with Se in the form of L-selenomethionine (SeMet), resulting in dietary concentrations of 0.4, 9.6, 20.5, 41.7, 89.8, and 191.1 microg Se/g diet on a dry weight basis. Effects of dietary SeMet on survival, swimming activity, growth, whole-body proximate composition, tissue Se concentrations, and histopathology were determined. Sturgeon survival among treatment groups did not differ significantly with a mean survival rate of 99+/-0.43% across all groups. A significant decrease (p<0.05) in swimming activity and growth rate was observed in sturgeon fed at or above 41.7 microg Se/g diet. Dietary SeMet concentrations were negatively correlated with whole-body protein and lipid content, but positively correlated with ash and moisture content. Selenium accumulated in the kidney, muscle, liver, gill, and plasma tissues in a dose-dependent manner. Histopathological alterations in the liver and kidney were observed in sturgeon fed above 20.5 microg Se/g diet. The threshold dietary Se toxicity concentration for white sturgeon was estimated to lie between 10 and 20 microg Se/g diet based on the histopathological alterations in the kidney. Research examining the consequences of elevated dietary Se concentrations on more sensitive life stages and the interactive effects of Se with other chemical or physical stressors are needed in order to determine if dietary threshold should be lowered to minimize the potential impacts of Se on white sturgeon in the San Francisco Bay-Delta.

  12. Role of selenium toxicity and oxidative stress in aquatic birds

    USGS Publications Warehouse

    Hoffman, D.J.

    2002-01-01

    Adverse effects of selenium (Se) in wild aquatic birds have been documented as a consequence of pollution of the aquatic environment by subsurface agricultural drainwater and other sources. These effects include mortality, impaired reproduction with teratogenesis, reduced growth, histopathological lesions and alterations in hepatic glutathione metabolism. A review is provided, relating adverse biological effects of Se in aquatic birds to altered glutathione metabolism and oxidative stress. Laboratory studies, mainly with an organic form of Se, selenomethionine, have revealed oxidative stress in different stages of the mallard (Anas platyrhynchos) life cycle. As dietary and tissue concentrations of Se increase, increases in plasma and hepatic GSH peroxidase activities occur, followed by dose-dependent increases in the ratio of hepatic oxidized to reduced glutathione (GSSG:GSH) and ultimately hepatic lipid peroxidation measured as an increase in thiobarbituric acid reactive substances (TBARS). One or more of these oxidative effects were associated with teratogenesis (4.6 ppm wet weight Se in eggs), reduced growth in ducklings (15 ppm Se in liver), diminished immune function (5 ppm Se in liver) and histopathological lesions (29 ppm Se in liver) in adults. Manifestations of Serelated effects on glutathione metabolism were also apparent in field studies in seven species of aquatic birds. Reduced growth and possibly immune function but increased liver:body weight and hepatic GSSG:GSH ratios were apparent in American avocet (Recurvirostra americana) hatchlings from eggs containing 9 ppm Se. In blacknecked stilts (Himantopus mexicanus), which contained somewhat lower Se concentrations, a decrease in hepatic GSH was apparent with few other effects. In adult American coots (Fulica americana), signs of Se toxicosis included emaciation, abnormal feather loss and histopathological lesions. Mean liver concentrations of 28 ppm Se (ww) in the coots were associated with elevated

  13. [Dietary reference intakes of trace elements for Japanese and problems in clinical fields].

    PubMed

    Inoue, Yoshifumi

    2016-07-01

    In the dietary reference intakes, EAR(estimated average requirement), RDA(recommended dietary allowance), AL(adequate intake), DG(tentative dietary goal for preventing life style related diseases) and UL(tolerable upper intake level) of eight types of trace elements (iron: Fe, zinc: Zn, copper: Cu, manganese: Mn, iodine: I, selenium: Se, chromium: Cr, molybdenum: Mo) have been set. However, in the meals of hospitals, only iron of which has been taken into account. The content of these trace elements in the enteral nutrient released after 2000 was determined by considering the content of dietary reference intakes of trace elements for Japanese and considered so not fall into deficiency. However, enteral nutrient must be used considering the content of Zn, Cu and the Zn/Cu ratio, the selenium content, and the route of administration, in order to avoid falling into deficiency.

  14. Effects of maternal plane of nutrition and increased dietary selenium in first-parity ewes on inflammatory response in the ovine neonatal gut.

    PubMed

    Wang, H; Zhao, J; Huang, Y; Yan, X; Meyer, A M; Du, M; Vonnahme, K A; Reynolds, L P; Caton, J S; Zhu, M J

    2012-01-01

    Many areas of the western United States have soils that have increased Se content, and ruminants grazing these rangelands may ingest increased quantities of Se. In addition, high-energy diets or increased Se intake may induce gut inflammation. The objective of this study was to evaluate the effects of maternal plane of nutrition and increased dietary Se during gestation on inflammatory responses in neonatal lamb ileal tissue, a major immune organ. Rambouillet ewes (age = 240 ± 17 d; initial BW = 52.1 ± 6.2 kg) were allocated to 4 treatments arranged in a 2 × 2 factorial. Factors included Se [adequate Se (ASe, 11.5 µg/kg of BW) or high Se (HSe, 77.0 µg/kg of BW)] initiated at breeding, and nutritional plane [100% (CON) or 140% (HIH) of requirements] initiated at d 40 of gestation. Ewes were fed individually from d 40, and lambs were removed at parturition and fed artificial colostrum and milk replacer. Lambs were necropsied at 20 d of age, and ileal tissues were sampled for immunoblotting and real-time quantitative reverse-transcription PCR analyses. The ASe-HIH and HSe-CON treatments had no effect (P = 0.179) on inflammatory signaling compared with ASe-CON. However, greater inflammatory signaling was detected in the HSe-HIH group, as shown by increased (P < 0.05) mRNA expression of tumor necrosis factor-α and chemotaxis IL-8. Consistently, phosphorylation of c-Jun N-terminal kinase, a primary inflammatory signaling mediator, was greater (P < 0.05) in the HSe-HIH group compared with other treatments. Consistent with cytokine expression, mast cell density was less in the HSe-CON group than in other treatments. The expression of transforming growth factor β mRNA was greater (P < 0.05) in the HSe-HIH group; consistently, collagen content was increased in the HSe-HIH group compared with the ASe-CON group (P < 0.05). In conclusion, independently, neither HSe nor HIH had major effects on inflammation, but in combination, these maternal treatments induced an

  15. Selenium and mercury have a synergistic negative effect on fish reproduction.

    PubMed

    Penglase, S; Hamre, K; Ellingsen, S

    2014-04-01

    Selenium (Se) can reduce the negative impacts of mercury (Hg) toxicity on growth and survival, but little is known about how these two elements interact in reproduction. In the following study we explored the effects of organic Hg and Se on the growth, survival and reproduction of female zebrafish (Danio rerio). Fish were fed one of four diets from 73 until 226 dpf in a 2 × 2 factorial design, using selenomethionine (SeMet) and methylmercury (MeHg) as the Se and Hg sources, respectively. Each diet contained Se at either requirement (0.7 mg Se/kg DM) or elevated levels (10 mg Se/kgDM), and Hg at either low (0.05 mg Hg/kg DM) or elevated (12 mg Hg/kg DM) levels. Between 151 and 206 dpf the female fish were pairwise crossed against untreated male fish and the mating success, fecundity, embryo survival, and subsequent overall reproductive success were measured. Elevated dietary Se reduced Hg levels in both the adult fish and their eggs. Elevated dietary Hg and Se increased egg Se levels to a greater extent than when dietary Se was elevated alone. At elevated maternal intake levels, egg concentrations of Se and Hg reflected the maternal dietary levels and not the body burdens of the adult fish. Elevated dietary Hg reduced the growth and survival of female fish, but these effects were largely prevented with elevated dietary Se. Elevated dietary Se alone did not affect fish growth or survival. Compared to other treatments, elevated dietary Hg alone increased both mating and overall reproductive success with <100 days of exposure, but decreased these parameters with >100 days exposure. Elevated dietary Se decreased fecundity, embryo survival, and overall reproductive success. The combination of elevated Se and Hg had a synergistic negative effect on all aspects of fish reproduction compared to those groups fed elevated levels of either Se or Hg. Overall the data demonstrate that while increased dietary Se may reduce adverse effects of Hg on the growth and survival in

  16. [The effect of an increased dietary intake of organic selenium on the resistance of rats to ionizing radiation, aflatoxin B1 and infection].

    PubMed

    Knizhnikov, V A; Komleva, V A; Tutel'ian, V A; Novoselova, G P; Golubkina, N A; Trushina, E N; Kumpulaĭnen, I; Edelman, K

    1991-01-01

    Varying concentrations of the selenium biological compound "Selena" were tested in animals subjected to the action of extremal factors simulating those that affected the population at the territories radiocontaminated as a result of the catastrophe at the Chernobyl NPS (131I and external irradiation in falling down doses). The death rate in the group of animals that were not given "Selena" comprised 30% during 6 months after irradiation, their body mass was 120 g lower as compared to the animals in the group of biological control; among the animals given 0.03 mg of selenium/day the death rate was 4 times lower.

  17. Natural selenium-rich feeds manage selenium deficiency in Oregon sheep

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A natural selenium-rich feed product (SePR) was developed by the USDA, ARS, U.S. Sheep Experiment Station for the purposes of enhancing the long-term selenium status of grazing livestock. In cooperation with Intermountain Farmers Association (Salt Lake City, UT), a bulk amount of SePR was manufactur...

  18. Selenium semiconductor core optical fibers

    SciTech Connect

    Tang, G. W.; Qian, Q. Peng, K. L.; Wen, X.; Zhou, G. X.; Sun, M.; Chen, X. D.; Yang, Z. M.

    2015-02-15

    Phosphate glass-clad optical fibers containing selenium (Se) semiconductor core were fabricated using a molten core method. The cores were found to be amorphous as evidenced by X-ray diffraction and corroborated by Micro-Raman spectrum. Elemental analysis across the core/clad interface suggests that there is some diffusion of about 3 wt % oxygen in the core region. Phosphate glass-clad crystalline selenium core optical fibers were obtained by a postdrawing annealing process. A two-cm-long crystalline selenium semiconductor core optical fibers, electrically contacted to external circuitry through the fiber end facets, exhibit a three times change in conductivity between dark and illuminated states. Such crystalline selenium semiconductor core optical fibers have promising utility in optical switch and photoconductivity of optical fiber array.

  19. Distribution and translocation of selenium from soil to grain and its speciation in paddy rice (Oryza sativa L.).

    PubMed

    Sun, Guo-Xin; Liu, Xiao; Williams, Paul N; Zhu, Yong-Guan

    2010-09-01

    Selenium, an essential micronutrient for humans, is insufficient in dietary intake for millions of people worldwide. Rice as the most popular staple food in the world is one of the dominant selenium (Se) sources for people. The distribution and translocation of Se from soil to grain were investigated in a Se-rich environment in this study. The Se levels in soils ranged widely from 0.5 to 47.7 mg kg(-1). Selenium concentration in rice bran was 1.94 times higher than that in corresponding polished rice. The total Se concentrations in the rice fractions were in the following order: straw>bran>whole grain>polished rice>husk. Significant linear relationships between different rice fractions were observed with each other, and Se in the soil has a linear relationship with different rice fractions as well. Se concentration in rice can easily be predicted by soil Se concentrations or any rice fractions and vice versa according to their linear relationships. In all rice samples for Se speciation, SeMet was the major Se species, followed by MeSeCys and SeCys. The average percentage for SeMet (82.9%) and MeSeCys (6.2%) was similar in the range of total Se from 2.2 to 8.4 mg kg(-1) tested. The percentage of SeCys decreased from 6.3 to 2.8%, although its concentration elevated with the increase in total Se in rice. This could be due to the fact that SeCys is the precursor for the formation of other organic Se compounds. The information obtained may have considerable significance for assessing translocation and accumulation of Se in plant.

  20. Producing selenium-enriched eggs and meat to improve the selenium status of the general population.

    PubMed

    Fisinin, Vladimir I; Papazyan, Tigran T; Surai, Peter F

    2009-01-01

    The role of selenium (Se) in human health and diseases has been discussed in detail in several recent reviews, with the main conclusion being that selenium deficiency is recognised as a global problem which urgently needs resolution. Since selenium content in plant-based food depends on its availability from soil, the level of this element in food and feeds varies among regions. In general, eggs and meat are considered to be good sources of selenium in human diet. When considering ways to improve human selenium intake, there are several potential options. These include direct supplementation, soil fertilisation and supplementation of food staples such as flour, and production of functional foods. Analysing recent publications related to functional food production, it is evident that selenium-enriched eggs can be used as an important delivery system of this trace mineral for humans. In particular, developments and commercialisation of organic forms of selenium have initiated a new era in the availability of selenium-enriched products. It has been shown that egg selenium content can easily be manipulated to give increased levels, especially when organic selenium is included in hens' diet at levels that provide 0.3-0.5 mg/kg selenium in the feed. As a result, technology for the production of eggs delivering approximately 50% (30-35 microg) of the human selenium RDA have been developed and successfully tested. Currently companies all over the world market selenium-enriched eggs including the UK, Ireland, Mexico, Columbia, Malaysia, Thailand, Australia, Turkey, Russia and the Ukraine. Prices for enriched eggs vary from country to country, typically being similar to free-range eggs. Selenium-enriched chicken, pork and beef can also be produced when using organic selenium in the diet of poultry and farm animals. The scientific, technological and other advantages and limitations of producing designer/modified eggs as functional foods are discussed in this review.

  1. Erythrocyte selenium and breast cancer risk: brief reports

    SciTech Connect

    Meyer, F.; Verreault, R.

    1987-05-01

    Animal experiments and ecologic studies suggest that low dietary selenium intake is associated with an increased risk of some types of cancer. However, studies assessing the relation of indicators of selenium intake in subjects to site-specific cancer incidence are few. This paper reports the results of a case-control study of erythrocyte selenium in relation to breast carcinoma in premenopausal women. 1 figure, 1 table.

  2. Toxicity of organic and inorganic selenium to mallard ducklings

    USGS Publications Warehouse

    Heinz, G.H.; Hoffman, D.J.; Gold, L.G.

    1988-01-01

    The toxicity of selenomethionine and sodium selenite to mallard ducklings (Anas platyrhynchos) was measured by feeding each form from hatching to six weeks of age at dietary concentrations of 0, 10, 20, 40, and 80 ppm selenium. At 80 ppm selenium, sodium selenite caused 97.5% mortality by six weeks and selenomethionine caused 100% mortality. At 40 ppm, these two forms of selenium caused 25 and 12.5% mortality. No mortality occurred at 10 or 20 ppm. Diets containing 20, 40, or 80 ppm selenium in both forms caused decreases in food consumption and growth. The only statistically significant effect of 10 ppm selenium was with sodium selenite, which resulted in larger livers than controls. Selenomethionine was more readily stored in the liver than sodium selenite at levels above 10 ppm selenium in the diet. Based on comparisons of residues of selenium in livers of surviving and dead ducklings, concentrations in the liver were not diagnostic of death due to selenium poisoning. Because both forms of selenium resulted in severe reductions in food consumption, selenium-induced starvation may have been related to duckling mortality. It was not clear whether either form of selenium at 10 ppm in the diet resulted in a leveling off of selenium concentrations in the liver within six weeks.

  3. Revised reference values for selenium intake.

    PubMed

    Kipp, A P; Strohm, D; Brigelius-Flohé, R; Schomburg, L; Bechthold, A; Leschik-Bonnet, E; Heseker, H

    2015-10-01

    The German, Austrian and Swiss nutrition societies are the joint editors of the 'reference values for nutrient intake'. They have revised the reference values for the intake of selenium and published them in February 2015. The saturation of selenoprotein P (SePP) in plasma is used as a criterion for the derivation of reference values for selenium intake in adults. For persons from selenium-deficient regions (China) SePP saturation was achieved with a daily intake of 49μg of selenium. When using the reference body weights the D-A-CH reference values are based upon, the resulting estimated value for selenium intake is 70μg/day for men and 60μg/day for women. The estimated value for selenium intake for children and adolescents is extrapolated using the estimated value for adults in relation to body weight. For infants aged 0 to under 4 months the estimated value of 10μg/day was derived from the basis of selenium intake via breast milk. For infants aged 4 to under 12 months this estimated value was used and taking into account the differences regarding body weight an estimated value of 15μg/day was derived. For lactating women compared to non-lactating women a higher reference value of 75μg/day is indicated due to the release of selenium with breast milk. The additional selenium requirement for pregnant women is negligible, so that no increased reference value is indicated.

  4. A concise review of Hashimoto thyroiditis (HT) and the importance of iodine, selenium, vitamin D and gluten on the autoimmunity and dietary management of HT patients.Points that need more investigation.

    PubMed

    Liontiris, Michael I; Mazokopakis, Elias E

    2017-03-20

    Hashimoto's thyroiditis (HT) is a chronic autoimmune thyroid disease caused by an interaction between genetic factors and environmental conditions, both of which are yet to be fully understood. The management of HT depends on its clinical manifestations, commonly including diffuse or nodular goiter with euthyroidism, subclinical hypothyroidism and permanent hypothyroidism. However, in most cases of patients with HT, lifelong levothyroxine substitution is required. The additional role of diet for the management of HT is usually overlooked. A literature search regarding the importance and the influence of iodine, selenium, vitamin D and gluten on HT was conducted. In HT careful supplementation of possible deficiencies is recommended for the dietary management of these patients. The use of a diet low in gluten among HT patients with or without celiac disease (CD) is discussed.

  5. High potential for selenium biofortification of lentils ( Lens culinaris L.).

    PubMed

    Thavarajah, Dil; Ruszkowski, Jamie; Vandenberg, Albert

    2008-11-26

    Beneficial forms of selenium (Se) and their impact on human health are a global topic of interest in public health. We are studying the genetic potential for Se biofortification of pulse crops to improve human nutrition. Lentils ( Lens culinaris L.) are an important protein and carbohydrate food and are a valuable source of essential dietary components and trace elements. We analyzed the total Se concentration of 19 lentil genotypes grown at eight locations for two years in Saskatchewan, Canada. We observed significant genotypic and environmental variation in total Se concentration in lentils and that total Se concentration in lentils ranged between 425 and 673 microg kg(-1), providing 77-122% of the recommended daily intake in 100 g of dry lentils. Over 70% of the Se was present as selenomethionine (SeMet) with a smaller fraction (<20%) as inorganic Se and very small amounts as selenocysteine (SeCys). We found that soils from the locations where the lentils were grown were rich in Se (37-301 microg kg(-1)) and that lentils grown in Saskatchewan have the potential to provide an excellent natural source of this essential element. Our analyses gave us a preliminary understanding of the genetic basis of Se uptake in lentil and indicated that any potential strategy for micronutrient biofortification in lentil will require choice of field locations that minimize the spatial variability of soil Se content.

  6. Supplementation of organic and inorganic selenium to diets using grains grown in various regions of the United States with differing natural Se concentrations and fed to grower-finisher swine.

    PubMed

    Mahan, D C; Azain, M; Crenshaw, T D; Cromwell, G L; Dove, C R; Kim, S W; Lindemann, M D; Miller, P S; Pettigrew, J E; Stein, H H; van Heugten, E

    2014-11-01

    Grains grown in various regions of the United States vary in their innate or natural Se contents. A regional study evaluated the effects of adding inorganic Se (sodium selenite) or organic Se (Se yeast) to diets with differing innate Se contents. A 2 × 2 + 1 factorial experiment evaluating 2 Se sources (organic or inorganic) at 2 Se levels (0.15 or 0.30 mg/kg) in 18 total replicates (n = 360 total pigs). A basal diet was fed without supplemental Se and served as the negative (basal) control. The study was conducted as a randomized complete block design in 9 states (Georgia, Illinois, Kentucky, Nebraska, North Carolina, Ohio, South Dakota, Texas, and Wisconsin) with each station conducting 2 replicates. Pigs were fed from 25 to approximately 115 kg BW. Similar dietary formulations were used at each station, incorporating a common source of trace mineral and Se premixes. Three pigs per treatment in 16 replicates (n = 240) were bled at 55, 85, and 115 kg BW and serum Se and glutathione peroxidase (GSH-Px) activities were determined. Three pigs (n = 260) from each treatment pen were killed at 115 kg BW and issues (liver, loin, and hair) were analyzed for Se. The corn Se content from the various states ranged from 0.026 to 0.283 mg Se/kg while the soybean meal Se content ranged from 0.086 to 0.798 mg Se/kg. Tissue and serum Se concentrations were greater (P < 0.01) when supplemental organic Se was fed, whereas serum GSH-Px was greater (P < 0.01) as Se level increased. There were linear increases (P < 0.01) in loin and quadratic increases (P < 0.01) in liver and hair Se concentrations as dietary Se level increased within each state. There was a source × level interaction (P < 0.01) for each tissue resulting in a greater increase when organic Se was fed. Serum Se and GSH-Px activity increased (P < 0.01) when both Se sources were fed and plateaued at each state at 0.15 mg Se/kg. There was a high and significant correlation between each tissue Se, serum Se, and GSH

  7. Syntheses, crystal structures and optical properties of the first strontium selenium(IV) and tellurium(IV) oxychlorides: Sr{sub 3}(SeO{sub 3})(Se{sub 2}O{sub 5})Cl{sub 2} and Sr{sub 4}(Te{sub 3}O{sub 8})Cl{sub 4}

    SciTech Connect

    Jiang Hailong; Mao Jianggao

    2008-02-15

    Two new quaternary strontium selenium(IV) and tellurium(IV) oxychlorides, namely, Sr{sub 3}(SeO{sub 3})(Se{sub 2}O{sub 5})Cl{sub 2} and Sr{sub 4}(Te{sub 3}O{sub 8})Cl{sub 4}, have been prepared by solid-state reaction. Sr{sub 3}(SeO{sub 3})(Se{sub 2}O{sub 5})Cl{sub 2} features a three-dimensional (3D) network structure constructed from strontium(II) interconnected by Cl{sup -}, SeO{sub 3}{sup 2-} as well as Se{sub 2}O{sub 5}{sup 2-} anions. The structure of Sr{sub 4}(Te{sub 3}O{sub 8})Cl{sub 4} features a 3D network in which the strontium tellurium oxide slabs are interconnected by bridging Cl{sup -} anions. The diffuse reflectance spectrum measurements and results of the electronic band structure calculations indicate that both compounds are wide band-gap semiconductors. - Graphical abstract: Solid-state reactions of SrO, SrCl{sub 2}, and SeO{sub 2} or TeO{sub 2} in different molar ratios and under different temperatures lead to two new strontium selenium(IV) or tellurium(IV) oxychlorides with two different types of structures, namely, Sr{sub 3}(SeO{sub 3})(Se{sub 2}O{sub 5})Cl{sub 2} and Sr{sub 4}(Te{sub 3}O{sub 8})Cl{sub 4}. Both compounds are wide band-gap semiconductors based on the diffuse reflectance spectra and the electronic band structures.

  8. Effects of nano-selenium on performance, meat quality, immune function, oxidation resistance, and tissue selenium content in broilers.

    PubMed

    Cai, S J; Wu, C X; Gong, L M; Song, T; Wu, H; Zhang, L Y

    2012-10-01

    This study was conducted to investigate the effect of nano-selenium (nano-Se) on performance, meat quality, immune function, oxidation resistance, and tissue selenium content in broilers. A total of five hundred forty 1-d-old male Arbor Acres broilers were randomly allotted to 1 of 5 treatments with each treatment being applied to 6 replicates of 18 chicks. The 5 treatments consisted of corn-soybean meal-based diets supplemented with 0.0, 0.3, 0.5, 1.0, or 2.0 mg/kg of nano-Se. The selenium content of the unsupplemented control diet was 0.09 mg/kg for the starter phase (0 to 21 d) and 0.08 mg/kg for the grower phase (22 to 42 d). There were no significant differences (P > 0.05) in performance, meat color, or immune organ index (thymus, bursa, and spleen) due to supplementation with nano-Se. On d 42, a significant quadratic effect of nano-Se was observed on glutathione peroxidase activity, free radical inhibition, contents of IgM, glutathione, and malondialdehyde in serum, on glutathione peroxidase activity, free radical inhibition in liver, and on glutathione peroxidase activity in muscle, with birds fed 0.30 mg/kg of nano-Se exhibiting the best effect and birds fed 2.0 mg/kg of nano-Se showing the worst effect on these parameters. Liver and muscle selenium content increased linearly and quadratically as the dietary nano-Se level increased (P < 0.01), and reached the highest value when 2.0 mg/kg of nano-Se was fed. Based on a consideration of all experiment indexes, 0.3 to 0.5 mg/kg is suggested to be the optimum level of supplementation of nano-Se, and the maximum supplementation of nano-Se could not be more than 1.0 mg/kg in broilers.

  9. The Outcome of Selenium and Vitamin E Cancer Prevention Trial (SELECT) reveals the need for better understanding of selenium biology.

    PubMed

    Hatfield, Dolph L; Gladyshev, Vadim N

    2009-02-01

    The recently completed Selenium and Vitamin E Cancer Prevention Trial (SELECT) was one of the largest human cancer prevention trials ever undertaken. Its purpose was to assess the role of selenium and vitamin E in prostate cancer prevention, but SELECT found no decline in prostate cancer. Comparison of this study to other clinical trials involving selenium and to the results of animal studies suggests that the source of the selenium supplement, L-selenomethionine, and the relatively high initial levels of selenium in the enrolled men may have contributed to this outcome. Further analysis of the clinical and animal data highlights the need for mechanistic studies to better understand selenium biology in order to target dietary selenium to appropriate subsets of the human population: those individuals most likely to benefit from this micronutrient.

  10. Selenium: environmental significance, pollution, and biological treatment technologies.

    PubMed

    Tan, Lea Chua; Nancharaiah, Yarlagadda V; van Hullebusch, Eric D; Lens, Piet N L

    2016-01-01

    Selenium is an essential trace element needed for all living organisms. Despite its essentiality, selenium is a potential toxic element to natural ecosystems due to its bioaccumulation potential. Though selenium is found naturally in the earth's crust, especially in carbonate rocks and volcanic and sedimentary soils, about 40% of the selenium emissions to atmospheric and aquatic environments are caused by various industrial activities such as mining-related operations. In recent years, advances in water quality and pollution monitoring have shown that selenium is a contaminant of potential environmental concern. This has practical implications on industry to achieve the stringent selenium regulatory discharge limit of 5μgSeL(-1) for selenium containing wastewaters set by the United States Environmental Protection Agency. Over the last few decades, various technologies have been developed for the treatment of selenium-containing wastewaters. Biological selenium reduction has emerged as the leading technology for removing selenium from wastewaters since it offers a cheaper alternative compared to physico-chemical treatments and is suitable for treating dilute and variable selenium-laden wastewaters. Moreover, biological treatment has the advantage of forming elemental selenium nanospheres which exhibit unique optical and spectral properties for various industrial applications, i.e. medical, electrical, and manufacturing processes. However, despite the advances in biotechnology employing selenium reduction, there are still several challenges, particularly in achieving stringent discharge limits, the long-term stability of biogenic selenium and predicting the fate of bioreduced selenium in the environment. This review highlights the significance of selenium in the environment, health, and industry and biotechnological advances made in the treatment of selenium contaminated wastewaters. The challenges and future perspectives are overviewed considering recent

  11. Main and interactive effects of arsenic and selenium on mallard reproduction and duckling growth and survival

    USGS Publications Warehouse

    Stanley, T.R.; Spann, J.W.; Smith, G.J.; Rosscoe, R.

    1994-01-01

    Arsenic (As) and selenium (Se) occur together in high concentrations in the environment and can accumulate in aquatic plants and invertebrates consumed by waterfowl. Ninety-nine pairs of breeding mallards (Anas platyrhynchos) were fed diets supplemented with As (sodium arsenate) at 0, 25, 100, or 400 ug/g, in combination with Se (seleno-DL-methionine) at 0 or 10 ug/g, in a replicated factorial experiment. Ducklings produced were placed on the same treatment combination as their parents. Arsenic accumulated in adult liver and egg, reduced adult weight gain and liver weight, delayed the onset of egg laying, decreased whole egg weight, and caused eggshell thinning. Arsenic did not affect hatching success and was not teratogenic. In ducklings, As accumulated in the liver and reduced body weight, growth, and liver weight. Arsenic did not increase duckling mortality, but it did decrease overall duckling production. Selenium accumulated in adult liver and egg, was teratogenic, and decreased hatching success. Selenium did not affect adult weight, liver weight, survival, onset of egg laying, egg fertility, egg weight, or eggshell thickness. In ducklings, Se accumulated in the liver and reduced body weight and growth, and increased liver weight. Selenium increased duckling mortality and decreased overall duckling production. Antagonistic interactions between As and Se occurred whereby As reduced Se accumulation in liver and egg, and alleviated the effects of Se on hatching success and embryo deformities. It was demonstrated that As and Se, in the chemical forms and at the dietary levels administered in this study, can adversely affect mallard reproduction and duckling growth and survival, and that As can alleviate toxic effects of Se.

  12. Urinary trimethylselenonium excretion by the rat: effect of level and source of selenium-75

    SciTech Connect

    Nahapetian, A.T.; Janghorbani, M.; Young, V.R.

    1983-02-01

    The purpose of this study was to explore in rats the urinary metabolites of selenium (Se), by using (/sup 75/Se)selenomethionine, (/sup 75/Se)selenocystine, and (/sup 75/Se)selenite, and to assess the effects of low and high levels of Se intake on trimethylselenonium ion (TMSe) excretion in urine. Male adult rats were adapted for 6 weeks to a commercial rat laboratory stock diet (0.25 ppm Se). They were then starved for 24 hours and given an oral dose of either low (16 micrograms Se/kg body weight) or high (1500 micrograms Se/kg body weight) Se as the test Se compounds. Appearance of radioactivity in TMSe and non-TMSe Se metabolites in urine was monitored for 48 hours. About 40% of the /sup 75/Se dose was excreted in urine. TMSe was the major urinary Se metabolite at high, and a minor urinary Se metabolite at low dose levels of Se and for all three Se test compounds. At least 80% of urinary /sup 75/Se and 26-42% of the orally administered /sup 75/Se were excreted as non-TMSe Se metabolites in urine under the latter condition. It is hypothesized that at a requirement intake of Se either a trace or no TMSe is excreted in urine, and it becomes a major excretory metabolite of Se when the dietary trace mineral intake exceeds a requirement level, probably serving as a means of detoxification.

  13. Light dependence of selenium uptake by phytoplankton and implications for predicting selenium incorporation into food webs

    USGS Publications Warehouse

    Baines, S.B.; Fisher, N.S.; Doblin, M.A.; Cutter, G.A.; Cutter, L.S.; Cole, B.

    2004-01-01

    The potentially toxic element selenium is first concentrated from solution to a large but highly variable degree by algae and bacteria before being passed on to consumers. The large loads of abiotic and detrital suspended particles often present in rivers and estuaries may obscure spatial and temporal patterns in Se concentrations at the base of the food web. We used radiotracers to estimate uptake of both selenite (Se(IV)) and C by intact plankton communities at two sites in the Sacramento/San Joaquin River Delta. Our goals were to determine (1) whether C and Se(IV) uptake were coupled, (2) the role of bacteria in Se(IV) uptake, and (3) the Se:C uptake ratio of newly produced organic material. Se(IV) uptake, like C uptake, was strongly related to irradiance. The shapes of both relationships were very similar except that at least 42-56% of Se(IV) uptake occurred in the dark, whereas C uptake in the dark was negligible. Of this dark Se(IV) uptake, 34-67% occurred in the 0.2-1.0-??m size fraction, indicating significant uptake by bacteria. In addition to dark uptake, total Se(IV) uptake consisted of a light-driven component that was in fixed proportion to C uptake. Our estimates of daily areal Se(IV):C uptake ratios agreed very well with particulate Se:C measured at a site dominated by phytoplankton biomass. Estimates of bacterial Se:C were 2.4-13 times higher than for the phytoplankton, suggesting that bacteriovores may be exposed to higher dietary Se concentrations than herbivores.

  14. Selenium Characterization in the Global Rice Supply Chain

    SciTech Connect

    Williams, Paul N.; Lombi, Enzo; Sun, Guo-Xin; Scheckel, Kirk; Zhu, Yong-Guan; Feng, Xinbin; Zhu, Jianming; Carey, Anne-Marie; Adomako, Eureka; Lawgali, Youseff; Deacon, Claire; Meharg, Andrew A.

    2009-08-13

    For up to 1 billion people worldwide, insufficient dietary intake of selenium (Se) is a serious health constraint. Cereals are the dominant Se source for those on low protein diets, as typified by the global malnourished population. With crop Se content constrained largely by underlying geology, regional soil Se variations are often mirrored by their locally grown staples. Despite this, the Se concentrations of much of the world's rice, the mainstay of so many, is poorly characterized, for both total Se content and Se speciation. In this study, 1092 samples of market sourced polished rice were obtained. The sampled rice encompassed dominant rice producing and exporting countries. Rice from the U.S. and India were found to be the most enriched, while mean average levels were lowest in Egyptian rice: {approx}32-fold less than their North American equivalents. By weighting country averages by contribution to either global production or export, modeled baseline values for both were produced. Based on a daily rice consumption of 300 g day{sup -1}, around 75% of the grains from the production and export pools would fail to provide 70% of daily recommended Se intakes. Furthermore, Se localization and speciation characterization using X-ray fluorescence ({mu}-XRF) and X-ray absorption near edge structure ({mu}-XANES) techniques were investigated in a Se-rich sample. The results revealed that the large majority of Se in the endosperm was present in organic forms.

  15. Selenium sulfide

    Integrated Risk Information System (IRIS)

    Selenium sulfide ; CASRN 7446 - 34 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  16. Preparation of selenium yeasts I. Preparation of selenium-enriched Saccharomyces cerevisiae.

    PubMed

    Suhajda, A; Hegóczki, J; Janzsó, B; Pais, I; Vereczkey, G

    2000-04-01

    Selenium (Se) is an essential micronutrient for human and animal organisms. Organic selenium complexes and selenium-containing amino acids are considered the most bioavailable. Under appropriate conditions yeasts are capable of accumulating large amounts of trace elements, such as selenium, and incorporating them into organic compounds. It has been found that introduction of water-soluble selenium salt as a component of the culture medium for yeasts produced by conventional batch processing results in a substantial amount of selenium being absorbed by the yeast. Using a culture medium supplemented with 30 microg/mL sodium-selenite added during the exponential growth phase results in selenium-accumulation in the range of 1200-1400 microg/g dried baker's yeast (Saccharomyces cerevisiae) measured by ICP-AES method. In our previous studies it was shown that higher amounts of sodium-selenite in the culture medium have a strong inhibitory effect on the growth of this yeast. As a consequence of variations in cultivation conditions we obtained selenium yeast with different inorganic selenium content. The most important parameters influencing incorporated forms of selenium are pH value and dissolved oxygen level in the culture medium, and depending on these the selenium consumption rate of the yeast. A 0.40-0.50 mg/g h-1 specific selenium consumption rate was found to be appropriate to obtain selenium-enriched bakers' yeast of a high quality. Under suitable conditions the undesirable inorganic selenium content of the yeast could be suppressed to as low as 5-6% at the expense, however, of approximately a 20% decrease in the final biomass.

  17. Selenium in Cattle: A Review.

    PubMed

    Mehdi, Youcef; Dufrasne, Isabelle

    2016-04-23

    This review article examines the role of selenium (Se) and the effects of Se supplementation especially in the bovine species. Selenium is an important trace element in cattle. Some of its roles include the participation in the antioxidant defense the cattle farms. The nutritional requirements of Se in cattle are estimated at 100 μg/kg DM (dry matter) for beef cattle and at 300 μg/kg DM for dairy cows. The rations high in fermentable carbohydrates, nitrates, sulfates, calcium or hydrogen cyanide negatively influence the organism's use of the selenium contained in the diet. The Se supplementation may reduce the incidence of metritis and ovarian cysts during the postpartum period. The increase in fertility when adding Se is attributed to the reduction of the embryonic death during the first month of gestation. A use of organic Se in feed would provide a better transfer of Se in calves relative to mineral Se supplementation. The addition of Se yeasts in the foodstuffs of cows significantly increases the Se content and the percentage of polyunsaturated fatty acids (PUFA) in milk compared to the addition of sodium selenite. The enzyme 5-iodothyronine deiodinase is a seleno-dependent selenoprotein. It is one of the last proteins to be affected in the event of Se deficiency. This delay in response could explain the fact that several studies did not show the effect of Se supplementation on growth and weight gain of calves. Enrichment of Se in the diet did not significantly affect the slaughter weight and carcass yield of bulls. The impact and results of Se supplementation in cattle depend on physiological stage, Se status of animals, type and content of Se and types of Se administration. Further studies in Se supplementation should investigate the speciation of Se in food and yeasts, as well as understanding their metabolism and absorption. This constitute a path to exploit in order to explain certain different effects of Se.

  18. Selenium Digestibility and Bioactivity in Dogs: What the Can Can, the Kibble Can’t

    PubMed Central

    van Zelst, Mariëlle; Hesta, Myriam; Gray, Kerry; Beech, Karen; Cools, An; Alexander, Lucille G.; Du Laing, Gijs; Janssens, Geert P. J.

    2016-01-01

    There is a growing concern for the long-term health effects of selenium (Se) over- or underfeeding. The efficiency of utilization of dietary Se is subject to many factors. Our study in dogs evaluated the effect of diet type (canned versus kibble) and dietary protein concentration on Se digestibility and bioactivity. Canned and kibble diets are commonly used formats of dog food, widely ranging in protein concentration. Twenty-four Labrador retrievers were used and four canned and four kibble diets were selected with crude protein concentrations ranging from 10.1 to 27.5 g/MJ. Crude protein concentration had no influence on the digestibility of Se in either canned or kibble diets, but a lower Se digestibility was observed in canned compared to kibble diets. However, the biological activity of Se, as measured by whole blood glutathione peroxidase, was higher in dogs fed the canned diets than in dogs fed the kibble diets and decreased with increasing crude protein intake. These results indicate that selenium recommendations in dog foods need to take diet type into account. PMID:27043433

  19. Determination of the need for selenium by chicks fed practical diets adequate in vitamin E

    SciTech Connect

    Combs, G.F. Jr.; Su, Q.; Liu, C.H.; Sinisalo, M.; Combs, S.B.

    1986-03-01

    Experiments were conducted to compare the dietary needs for selenium (Se) by chicks fed either purified (amino acid-based) or practical (corn- and soy-based) diets that were adequate with respect to vitamin E (i.e., contained 100 IU/kg) and all other known nutrients with the single exception of Se (i.e., contained only 0.10 ppm Se). Studies were conducted in Ithaca using Single Comb White Leghorn chicks fed the purified basal diet and in Beijing using chicks of the same breed fed either the same purified basal diet or the practical diet formulated to be similar to that used in poultry production in some parts of China and the US. Results showed that each basal diet produced severe depletion of Se-dependent glutathione peroxidase (SeGSHpx) in plasma, liver and pancreas according to the same time-course, but that other consequences of severe uncomplicated Se deficiency were much more severe among chicks fed the purified diet (e.g., growth depression, pancreatic dysfunction as indicated by elevated plasma amylase and abnormal pancreatic histology). Chicks fed the practical Se-deficient diet showed reduced pancreas levels of copper, zinc and molybdenum and elevated plasma levels of iron; they required ca. 0.10 ppm dietary Se to sustain normal SeGSHpx in several tissues and to prevent elevated amylase in plasma. The dietary Se requirement of the chick is, therefore, estimated to be 0.10 ppm.

  20. Selenium hyperaccumulators harbor a diverse endophytic bacterial community characterized by high selenium resistance and plant growth promoting properties

    PubMed Central

    Sura-de Jong, Martina; Reynolds, Ray J. B.; Richterova, Klara; Musilova, Lucie; Staicu, Lucian C.; Chocholata, Iva; Cappa, Jennifer J.; Taghavi, Safiyh; van der Lelie, Daniel; Frantik, Tomas; Dolinova, Iva; Strejcek, Michal; Cochran, Alyssa T.; Lovecka, Petra; Pilon-Smits, Elizabeth A. H.

    2015-01-01

    Selenium (Se)-rich plants may be used to provide dietary Se to humans and livestock, and also to clean up Se-polluted soils or waters. This study focused on endophytic bacteria of plants that hyperaccumulate selenium (Se) to 0.5–1% of dry weight. Terminal restriction fragment length polymorphism (T-RFLP) analysis was used to compare the diversity of endophytic bacteria of hyperaccumulators Stanleya pinnata (Brassicaceae) and Astragalus bisulcatus (Fabaceae) with those from related non-accumulators Physaria bellii (Brassicaceae) and Medicago sativa (Fabaceae) collected on the same, seleniferous site. Hyperaccumulators and non-accumulators showed equal T-RF diversity. Parsimony analysis showed that T-RFs from individuals of the same species were more similar to each other than to those from other species, regardless of plant Se content or spatial proximity. Cultivable endophytes from hyperaccumulators S. pinnata and A. bisulcatus were further identified and characterized. The 66 bacterial morphotypes were shown by MS MALDI-TOF Biotyper analysis and 16S rRNA gene sequencing to include strains of Bacillus, Pseudomonas, Pantoea, Staphylococcus, Paenibacillus, Advenella, Arthrobacter, and Variovorax. Most isolates were highly resistant to selenate and selenite (up to 200 mM) and all could reduce selenite to red elemental Se, reduce nitrite and produce siderophores. Seven isolates were selected for plant inoculation and found to have plant growth promoting properties, both in pure culture and when co-cultivated with crop species Brassica juncea (Brassicaceae) or M. sativa. There were no effects on plant Se accumulation. We conclude that Se hyperaccumulators harbor an endophytic bacterial community in their natural seleniferous habitat that is equally diverse to that of comparable non-accumulators. The hyperaccumulator endophytes are characterized by high Se resistance, capacity to produce elemental Se and plant growth promoting properties. PMID:25784919

  1. Selenium deficiency risk predicted to increase under future climate change.

    PubMed

    Jones, Gerrad D; Droz, Boris; Greve, Peter; Gottschalk, Pia; Poffet, Deyan; McGrath, Steve P; Seneviratne, Sonia I; Smith, Pete; Winkel, Lenny H E

    2017-03-14

    Deficiencies of micronutrients, including essential trace elements, affect up to 3 billion people worldwide. The dietary availability of trace elements is determined largely by their soil concentrations. Until now, the mechanisms governing soil concentrations have been evaluated in small-scale studies, which identify soil physicochemical properties as governing variables. However, global concentrations of trace elements and the factors controlling their distributions are virtually unknown. We used 33,241 soil data points to model recent (1980-1999) global distributions of Selenium (Se), an essential trace element that is required for humans. Worldwide, up to one in seven people have been estimated to have low dietary Se intake. Contrary to small-scale studies, soil Se concentrations were dominated by climate-soil interactions. Using moderate climate-change scenarios for 2080-2099, we predicted that changes in climate and soil organic carbon content will lead to overall decreased soil Se concentrations, particularly in agricultural areas; these decreases could increase the prevalence of Se deficiency. The importance of climate-soil interactions to Se distributions suggests that other trace elements with similar retention mechanisms will be similarly affected by climate change.

  2. Role of selenium in male reproduction - a review.

    PubMed

    Ahsan, U; Kamran, Z; Raza, I; Ahmad, S; Babar, W; Riaz, M H; Iqbal, Z

    2014-04-01

    The role of Se and various selenoproteins in male reproductive performance is reviewed. Development of male reproductive tissue requires an optimal level of Se in testis, and a small deviation, either deficiency or excess, leads to abnormal development. Selenium is a constituent of selenoproteins including GPx1, GPx3, mGPx4, cGPx4, and GPx5 that protect against oxidative damage to spermatozoa throughout the process of sperm maturation, whereas selenoproteins, such as mGPx4 and snGPx4, serve as structural components of mature spermatozoa. Thus Se and selenoproteins ensure viability of spermatozoa as well as providing protection against reactive oxygen species. Gene knock-out studies of selenoproteins revealed that their absence during spermatogenesis results in abnormal spermatozoa, which in turn affects semen quality and fertility. Deviation from the optimal quantities of dietary Se, both above or below, may cause multiple abnormalities of spermatozoa and affect motility and fertility. Libido may also be increased by Se. Dietary Se should be in optimal quantity to maintain reproductive function in males and to avoid infertility.

  3. Selenium deficiency risk predicted to increase under future climate change

    PubMed Central

    Jones, Gerrad D.; Droz, Boris; Greve, Peter; Gottschalk, Pia; Poffet, Deyan; McGrath, Steve P.; Seneviratne, Sonia I.; Smith, Pete; Winkel, Lenny H. E.

    2017-01-01

    Deficiencies of micronutrients, including essential trace elements, affect up to 3 billion people worldwide. The dietary availability of trace elements is determined largely by their soil concentrations. Until now, the mechanisms governing soil concentrations have been evaluated in small-scale studies, which identify soil physicochemical properties as governing variables. However, global concentrations of trace elements and the factors controlling their distributions are virtually unknown. We used 33,241 soil data points to model recent (1980–1999) global distributions of Selenium (Se), an essential trace element that is required for humans. Worldwide, up to one in seven people have been estimated to have low dietary Se intake. Contrary to small-scale studies, soil Se concentrations were dominated by climate–soil interactions. Using moderate climate-change scenarios for 2080–2099, we predicted that changes in climate and soil organic carbon content will lead to overall decreased soil Se concentrations, particularly in agricultural areas; these decreases could increase the prevalence of Se deficiency. The importance of climate–soil interactions to Se distributions suggests that other trace elements with similar retention mechanisms will be similarly affected by climate change. PMID:28223487

  4. Bioactivity of selenium from Brazil nut for cancer prevention and selenoenzyme maintenance.

    PubMed

    Ip, C; Lisk, D J

    1994-01-01

    Brazil nut (Bertholletia excelsa) is one of very few consumable products with exceptionally high levels of selenium. The mean selenium concentrations of two shipments of Brazil nut used in the present study were determined to be 16 and 30 micrograms/g. In contrast, most common foods contain much less selenium, from 0.01 to 1 micrograms/g. Previous research on selenium cancer chemoprevention invariably used a pure compound, whereas little information is available on the efficacy of selenium delivered naturally in a food form. This paper reports the results of two mammary cancer prevention experiments in the rat dimethylbenz[a]anthracene model by continuous feeding of selenium-rich Brazil nut (processed to a smooth-textured nut material for mixing in the diet). A dose-dependent inhibitory response was observed at dietary selenium concentrations of 1-3 micrograms/g. Interestingly, Brazil nut was found to be just as powerful as sodium selenite, if not more so, at similar levels of dietary selenium intake. Mammary cancer protection gland, and plasma. The magnitude of tissue selenium accumulation was proportional to the amount of Brazil nut added to the diet. The nutritional biopotency of selenium in Brazil nut was also evaluated by the repletion of two selenoenzymes, glutathione peroxidase and type I 5'-deiodinase, in selenium-deficient rats. Supplementation with Brazil nut as the sole source of selenium produced an efficient gradient of enzyme restoration at 0.05-0.2 microgram/g of dietary selenium. A parallel comparison with sodium selenite indicated that the selenium in Brazil nut and selenite selenium were equally bioactive. Although at this point it can only be inferred that the above biologic effects are likely to be attributable to the high selenium content of Brazil nut, there is persuasive evidence to suggest that the models under investigation are responding to the selenium rather than to the other components of Brazil nut.

  5. JV Task 77 - Health Implications of Mercury - Selenium Interactions

    SciTech Connect

    Nicholas Ralstion; Laura Raymond

    2007-12-15

    Exposure to mercury (Hg) commonly results from eating fish containing bioaccumulated methylmercury (MeHg). However, conflicting observations and conclusions have arisen from the ongoing human studies of MeHg exposure from fish consumption. Resolving these uncertainties has important implications for human health since significant nutritional benefits will be lost if fish consumption is needlessly avoided. Selenium (Se), an important nutrient that is abundant in ocean fish, has a potent protective effect against Hg toxicity. This protective effect was thought to be due to the high binding affinities between Hg and Se resulting in Se sequestration of Hg to prevent its harmful effects. However, it is imperative to consider the opposing effect of Hg on Se physiology. Crucial proteins that require Se normally protect the brain and hormone-producing glands from oxidative damage. MeHg is able to cross all biological barriers and enter cells in these tissues, where its high Se affinity results in Se sequestration. Sequestration in association with Hg prevents Se from participating in proteins that perform essential antioxidant activities. Supplemental dietary Se is able to replace Se sequestered by Hg and maintain normal antioxidant protection of brain and glands. The goal of this research project was to assess the potency of normal dietary levels of Se in protection against MeHg toxicity. Results from this project indicate that MeHg toxicity is only evident in situations resulting in Hg occurring in high molar excess of Se. Additionally, the common method of MeHg risk assessments using measurements of toenail and blood levels of Hg was shown to provide an accurate reflection of Hg exposure but did not accurately indicate risk of toxicity resulting from that exposure. Instead, Hg:Se molar ratios are proposed as a superior means of assessing risks associated with MeHg exposure.

  6. Biofortification and phytoremediation of selenium in China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biofortification is an agricultural process that increases the uptake and accumulation of specific nutrients, e.g. selenium (Se), in agricultural food products through plant breeding, genetic engineering, and manipulation of agronomic practices. The development and uses of biofortified agricultural ...

  7. High-resolution imaging of selenium in kidneys: a localized selenium pool associated with glutathione peroxidase 3

    SciTech Connect

    Malinouski, M.; Kehr, S.; Finney, L.; Vogt, S.; Carlson, B.A.; Seravalli, J.; Jin, R.; Handy, D.E.; Park, T.J.; Loscalzo, J.; Hatfield, D.L.; Gladyshev, V.N.

    2012-04-17

    Recent advances in quantitative methods and sensitive imaging techniques of trace elements provide opportunities to uncover and explain their biological roles. In particular, the distribution of selenium in tissues and cells under both physiological and pathological conditions remains unknown. In this work, we applied high-resolution synchrotron X-ray fluorescence microscopy (XFM) to map selenium distribution in mouse liver and kidney. Liver showed a uniform selenium distribution that was dependent on selenocysteine tRNA{sup [Ser]Sec} and dietary selenium. In contrast, kidney selenium had both uniformly distributed and highly localized components, the latter visualized as thin circular structures surrounding proximal tubules. Other parts of the kidney, such as glomeruli and distal tubules, only manifested the uniformly distributed selenium pattern that co-localized with sulfur. We found that proximal tubule selenium localized to the basement membrane. It was preserved in Selenoprotein P knockout mice, but was completely eliminated in glutathione peroxidase 3 (GPx3) knockout mice, indicating that this selenium represented GPx3. We further imaged kidneys of another model organism, the naked mole rat, which showed a diminished uniformly distributed selenium pool, but preserved the circular proximal tubule signal. We applied XFM to image selenium in mammalian tissues and identified a highly localized pool of this trace element at the basement membrane of kidneys that was associated with GPx3. XFM allowed us to define and explain the tissue topography of selenium in mammalian kidneys at submicron resolution.

  8. Selenium regulates gene expression for estrogen sulfotransferase and alpha 2U-globulin in rat liver.

    PubMed

    Yang, Q; Christensen, M J

    1998-03-01

    Dietary intake of the essential trace element selenium (Se) regulates expression of genes for selenoproteins and certain non-Se-containing proteins. However, these proteins do not account for all of Se's biological effects. The objective of this work was to identify additional genes whose expression is regulated by Se. Identification of these genes may reveal new functions for Se or define mechanisms for its biological effects. Weanling male Sprague-Dawley rats were fed a Torula yeast-based Se-deficient basal diet or the same diet supplemented with 0.5 mg Se/kg diet as sodium selenite for 13 weeks. Total RNA was used as template for RNA fingerprinting. Two differentially expressed cDNA fragments were identified and cloned. The first had 99% nucleotide identity with rat liver estrogen sulfotransferase (EST) isoform-6. The second had 99% nucleotide sequence identity with rat liver alpha 2u-globulin. The mRNA levels for both were markedly reduced in Se deficiency. Laser densitometry showed that EST mRNA in Se deficiency was 7.3% of that in Se-adequate rat liver. The level of alpha 2u-globulin mRNA in Se-deficient rat liver was only 12.6% of that in Se-adequate rat liver. These results indicate that dietary Se may play a role in steroid hormone metabolism in rat liver.

  9. RNA adducts with Na 2SeO 4 and Na 2SeO 3 - Stability and structural features

    NASA Astrophysics Data System (ADS)

    Nafisi, Shohreh; Manouchehri, Firouzeh; Montazeri, Maryam

    2011-12-01

    Selenium compounds are widely available in dietary supplements and have been extensively studied for their antioxidant and anticancer properties. Low blood Se levels were found to be associated with an increased incidence and mortality from various types of cancers. Although many in vivo and clinical trials have been conducted using these compounds, their biochemical and chemical mechanisms of efficacy are the focus of much current research. This study was designed to examine the interaction of Na 2SeO 4 and Na 2SeO 3 with RNA in aqueous solution at physiological conditions, using a constant RNA concentration (6.25 mM) and various sodium selenate and sodium selenite/polynucleotide (phosphate) ratios of 1/80, 1/40, 1/20, 1/10, 1/5, 1/2 and 1/1. Fourier transform infrared, UV-Visible spectroscopic methods were used to determine the drug binding modes, the binding constants, and the stability of Na 2SeO 4 and Na 2SeO 3-RNA complexes in aqueous solution. Spectroscopic evidence showed that Na 2SeO 4 and Na 2SeO 3 bind to the major and minor grooves of RNA ( via G, A and U bases) with some degree of the Se-phosphate (PO 2) interaction for both compounds with overall binding constants of K(Na 2SeO 4-RNA) = 8.34 × 10 3 and K(Na 2SeO 3-RNA) = 4.57 × 10 3 M -1. The order of selenium salts-biopolymer stability was Na 2SeO 4-RNA > Na 2SeO 3-RNA. RNA aggregations occurred at higher selenium concentrations. No biopolymer conformational changes were observed upon Na 2SeO 4 and Na 2SeO 3 interactions, while RNA remains in the A-family structure.

  10. Organic and inorganic selenium in Aseel chicken diets: Effect on hatching traits.

    PubMed

    Khan, M T; Mahmud, A; Zahoor, I; Javed, K

    2016-11-11

    A study was conducted to evaluate the effect of dietary selenium (Se) sources (organic and inorganic Se at 0.30 ppm and basal diet at 0 ppm level of supplemented Se) on hatching traits in four varieties of Aseel chicken, Lakha, Mushki, Peshawari, and Mianwali. In total, 84 adult molted hens (50 wk old), 21 from each variety, were randomly assigned to 12 treatment groups in a 3 (Se diets) × 4 (Aseel varieties) factorial arrangement under a randomized complete block design. Each treatment was replicated 7 times with individual hens in each. Settable egg, fertility, hatch of fertile eggs, hatchability, A-grade chick, and embryonic mortality parameters were evaluated. The results indicated that the birds fed an organic Se supplemented diet had greater (P < 0.05) settable eggs, fertility, hatch of fertile eggs, hatchability, and A-grade chicks and reduced embryonic mortality than those fed inorganic or no Se. Among varieties, Mushki had lower (P < 0.05) fertility, hatch of fertile eggs, hatchability, and A-grade chicks than rest of three varieties. Interaction of Se sources and varieties indicated that dietary organic Se supplementation improved (P < 0.05) hatch of fertile eggs in Peshawari and Mianwali, whereas hatchability only in Peshawari variety and reduced embryonic mortality in Mianwali. It was concluded that dietary supplementation of organic Se could be used to improve hatching traits as well as reduce embryonic mortality in native Aseel chicken.

  11. Selenium impacts on razorback sucker, Colorado: Colorado River: III. Larvae

    USGS Publications Warehouse

    Hamilton, S.J.; Holley, K.M.; Buhl, K.J.; Bullard, F.A.

    2005-01-01

    Razorback sucker (Xyrauchen texanus) larvae from adults exposed to selenium at three sites near Grand Junction, Colorado, for 9 months were used in a 30-day waterborne and dietary selenium study. Selenium concentrations in water averaged <1.6 ??g/L from 24-Road, 0.9 ??g/L from Horsethief, 5.5 ??g/L from Adobe Creek, and 10.7 ??g/L from the North Pond. Selenium in dietary items averaged 2.7 ??g/g in brine shrimp, 5.6 ??g/g in zooplankton from Horsethief east wetland, 20 ??g/g in zooplankton from Adobe Creek, and 39 ??g/g in zooplankton from North Pond. The lowest survival occurred in larvae fed zooplankton rather than brine shrimp. Survival of larvae at Adobe Creek and North Pond was lower in site water than in reference water. Survival of brood stock larvae was higher than Horsethief larvae even though they received the same water and dietary treatments. Arsenic concentrations in brine shrimp may have resulted in an antagonistic interaction with selenium and reduced adverse effects in larvae. Deformities in larvae from North Pond were similar to those reported for selenium-induced teratogenic deformities in other fish species. Selenium concentrations of ???4.6 ??g/g in food resulted in rapid mortality of larvae from Horsethief, Adobe Creek, and North Pond, and suggested that selenium toxicity in the Colorado River could limit recovery of this endangered fish.

  12. Selenium impacts on razorback sucker, Colorado: Colorado River III. Larvae.

    PubMed

    Hamilton, Steven J; Holley, Kathy M; Buhl, Kevin J; Bullard, Fern A

    2005-06-01

    Razorback sucker (Xyrauchen texanus) larvae from adults exposed to selenium at three sites near Grand Junction, Colorado, for 9 months were used in a 30-day waterborne and dietary selenium study. Selenium concentrations in water averaged <1.6 microg/L from 24-Road, 0.9 microg/L from Horsethief, 5.5 microg/L from Adobe Creek, and 10.7 microg/L from the North Pond. Selenium in dietary items averaged 2.7 microg/g in brine shrimp, 5.6 microg/g in zooplankton from Horsethief east wetland, 20 microg/g in zooplankton from Adobe Creek, and 39 microg/g in zooplankton from North Pond. The lowest survival occurred in larvae fed zooplankton rather than brine shrimp. Survival of larvae at Adobe Creek and North Pond was lower in site water than in reference water. Survival of brood stock larvae was higher than Horsethief larvae even though they received the same water and dietary treatments. Arsenic concentrations in brine shrimp may have resulted in an antagonistic interaction with selenium and reduced adverse effects in larvae. Deformities in larvae from North Pond were similar to those reported for selenium-induced teratogenic deformities in other fish species. Selenium concentrations of 4.6 microg/g in food resulted in rapid mortality of larvae from Horsethief, Adobe Creek, and North Pond, and suggested that selenium toxicity in the Colorado River could limit recovery of this endangered fish.

  13. Investigation of electrical noise in selenium-immersed thermistor bolometers

    NASA Technical Reports Server (NTRS)

    Tarpley, J. L.; Sarmiento, P. D.

    1980-01-01

    The selenium immersed, thermistor bolometer, IR detector failed due to spurious and escalating electrical noise outburst as a function of time at elevated temperatures during routine ground based testing in a space simulated environment. Spectrographic analysis of failed bolometers revealed selenium pure zones in the insulating selenium arsenic (Se-As) glass film which surrounds the active sintered Mn, Ni, Co oxide flake. The selenium pure film was identified as a potentially serious failure mechanism. Significant changes were instituted in the manufacturing techniques along with more stringent process controls which eliminated the selenium pure film and successfully produced 22study bolometers.

  14. Synthesis and stabilization of selenium nanoparticles on cellulose nanocrystal

    SciTech Connect

    Shin, Yongsoon; Blackwood, Jade M.; Bae, In-Tae; Arey, Bruce W.; Exarhos, Gregory J.

    2007-08-01

    Selenium nanoparticles of 10-20 nm in diameter have been prepared using cellulose nanocrystal (CNXL) as a reducing and structure-directing agent under hydrothermal conditions. Na2SeO3 was reduced to form elemental selenium nanoparticles under hydrothermal conditions. During the hydrothermal process (120-160 oC), CNXL rods were mainly maintained and selenium nanoparticles were interfacially bound to CNXL surface. The reaction temperature affects the sizes of interfacially bound selenium nanoparticles. X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), and transmission electron microscope (TEM) were employed to characterize interfacially bound selenium nanoparticles on CNXL surface.

  15. Biomarkers of Selenium Status

    PubMed Central

    Combs, Gerald F.

    2015-01-01

    The essential trace element, selenium (Se), has multiple biological activities, which depend on the level of Se intake. Relatively low Se intakes determine the expression of selenoenzymes in which it serves as an essential constituent. Higher intakes have been shown to have anti-tumorigenic potential; and very high Se intakes can produce adverse effects. This hierarchy of biological activities calls for biomarkers informative at different levels of Se exposure. Some Se-biomarkers, such as the selenoproteins and particularly GPX3 and SEPP1, provide information about function directly and are of value in identifying nutritional Se deficiency and tracking responses of deficient individuals to Se-treatment. They are useful under conditions of Se intake within the range of regulated selenoprotein expression, e.g., for humans <55 μg/day and for animals <20 μg/kg diet. Other Se-biomarkers provide information indirectly through inferences based on Se levels of foods, tissues, urine or feces. They can indicate the likelihood of deficiency or adverse effects, but they do not provide direct evidence of either condition. Their value is in providing information about Se status over a wide range of Se intake, particularly from food forms. There is need for additional Se biomarkers particularly for assessing Se status in non-deficient individuals for whom the prospects of cancer risk reduction and adverse effects risk are the primary health considerations. This would include determining whether supranutritional intakes of Se may be required for maximal selenoprotein expression in immune surveillance cells. It would also include developing methods to determine low molecular weight Se-metabolites, i.e., selenoamino acids and methylated Se-metabolites, which to date have not been detectable in biological specimens. Recent analytical advances using tandem liquid chromatography-mass spectrometry suggest prospects for detecting these metabolites. PMID:25835046

  16. Selenium in mammalian spermiogenesis.

    PubMed

    Flohé, Leopold

    2007-10-01

    The role of selenium in male fertility is reviewed with special emphasis on selenoprotein P and phospholipid hydroperoxide glutathione peroxidase (GPx4) in spermiogenesis. Inverse genetics reveal that selenoprotein P is required for selenium supply to the testis. GPx4 is abundantly synthesized in spermatids. As a moonlighting protein it is transformed in the later stages of spermiogenesis from an active selenoperoxidase into a structural protein that becomes a constituent of the mitochondrial sheath of spermatozoa. The transformation is paralleled by loss of glutathione. Mechanistically, the process is an alternate substrate inactivation of GPx4 resulting from reactions of its selenenic form with thiols of GPx4 itself and other proteins. Circumstantial evidence and ongoing experimental genetics indicate that the mitochondrially expressed form of the GPx4 gene is the most relevant one in spermiogenesis, with the nuclear form being dispensable for fertility and the role of cytosolic GPx4 remaining unclear. Clinical data reveal a strong association of low sperm GPx4 with infertility. Thus, impaired GPx4 biosynthesis, due to selenium deficiency or to genetic defects in gpx4 itself or in proteins involved in Se distribution and selenoprotein biosynthesis, causes male infertility, but can also be an epiphenomenon due to any perturbation of testicular function.

  17. Variations in the distribution of selenium between erythrocyte glutathione peroxidase and hemoglobin in different human populations

    SciTech Connect

    Whanger, P.D.; Robinson, M.F.; Feldman, E.B.; Beilstein, M.A.; Butler, J.A.

    1986-03-01

    The majority of erythrocyte (RBC) selenium (Se) is associated with glutathione peroxidase (GPx) in animals, but most of it is with hemoglobin (Hb) in human RBCs. Dietary forms of Se may influence this distribution since a rat study showed that selenite promoted the deposition of Se in GPx but selenomethionine (SeMet) resulted in greater amounts with Hb. Three different populations of people were chosen to investigate some possible reasons for the Se distribution in human RBC proteins. An average of 12% of the RBC Se (0.71 ng Se/mg Hb) was associated with GPx in people living in Oregon, but nearly 30% of the Se was associated with GPx in RBC (0.26 ng Se/mg Hb) from New Zealanders. Georgia residents with low RBC Se levels (0.35 ng Se/mg Hb) had 38% of the Se associated with GPx as compared to 29% for those with higher RBC levels (0.56 ng Se/mg Hb). In a third group of people the amount of Se tended to be higher in RBC GPx from non-vegetarian OSU students than from vegetarians. The predominant form of Se in meat appears to be selenocysteine, which is metabolized similarly to selenite, and presumably contributes to this difference since many plant foods contain Se as SeMet. These are examples of many possible factors affecting the relative distribution of Se in human RBC proteins.

  18. Selenium supplementation in radiotherapy patients: do we need to measure selenium levels in serum or blood regularly prior radiotherapy?

    PubMed

    Muecke, Ralph; Micke, Oliver; Schomburg, Lutz; Kisters, Klaus; Buentzel, Jens; Huebner, Jutta; Kriz, Jan

    2014-12-16

    Considering the review by Puspitasari and colleagues, an additional discussion of the endpoints of the Se supplementation studies described would be helpful. In our view, selenium can safely be given to selenium-deficient cancer patients prior to and during radiotherapy. Therefore, in order to help the radiation oncologist in decision making, we strongly advocate to determine the selenium status prior to and during a potential adjuvant selenium supplementation, e.g. when trying to ease the side-effects of radiation treatment or in the aftercare situation when the selenium status may become insufficient.

  19. Effects of Different Forms of Selenium Fertilizers on Se Accumulation, Distribution, and Residual Effect in Winter Wheat-Summer Maize Rotation System.

    PubMed

    Wang, Qi; Yu, Yao; Li, Jixiang; Wan, Yanan; Huang, Qingqing; Guo, Yanbin; Li, Huafen

    2017-02-15

    Foliar Se fertilizers were applied to investigate the effects of Se forms on Se accumulation and distribution in the wheat-maize rotation system and residual concentration of Se in subsequent crops. Sodium selenite, sodium selenate, selenomethionine, chemical nano-Se, humic acid + sodium selenite, and compound fertilizer + sodium selenite were applied once at the flowering stage of wheat (30 g ha(-1)) and at the bell stage of maize (60 g ha(-1)). Compared with the control treatment, foliar Se applications significant increased the grain Se concentration of wheat and maize by 0.02-0.31 and 0.07-1.09 mg kg(-1), respectively. Wheat and maize grain Se recoveries were 3.0-10.4 and 4.1-18.5%, respectively. However, Se concentrations in the grain of subsequent wheat and maize significantly decreased by 77.9 and 91.2%, respectively. The change of Se concentration in soil was a dynamic process with Se depletion after harvest of maize.

  20. Factors affecting the selenium intake of people in Transbaikalian Russia.

    PubMed

    Aro, A; Kumpulainen, J; Alfthan, G; Voshchenko, A V; Ivanov, V N

    1994-03-01

    The selenium concentration in foods grown and consumed and in plasma, red blood cells, and toenails of people living in the district of Chita in the transbaikalian part of Russia were studied in August 1991. Preliminary results from the area have suggested low selenium intakes and the possible occurrence of cardiomyopathy (Keshan disease) in the population. A low selenium concentration in foods grown locally was found: mean selenium concentration in wheat grains was 1, 5, and 28 micrograms/kg, respectively, in three villages studied, that of oats was between 3-6 micrograms/kg, and of cow's milk 10-27 micrograms/kg dry matter. The selenium concentration of bread was considerably higher, between 87-337 micrograms/kg dry wt, presumably because wheat imported from the US had been used for baking. Occasional samples of pork, beef, and mutton contained between 32-218 micrograms selenium/kg dry wt. Low selenium concentrations were observed in samples of soil and river water. The mean plasma selenium concentration of 52 persons was 1.02 mumol/L, including 33 children and 19 adult subjects. The selenium concentrations in red blood cells and toenails were 1.95 mumol/L and 0.61 mg/kg, respectively. No symptoms of heart disease caused by selenium deficiency were observed. It is concluded that the selenium status of people was fairly good thanks to the contribution to dietary intake of imported wheat with a high selenium content. As the selenium concentration was very low in foods grown in the area, the selenium intake of the population will be reduced to a very low level if only locally produced foods are consumed.

  1. Arsenic and selenium in microbial metabolism

    USGS Publications Warehouse

    Stolz, John F.; Basu, Partha; Santini, Joanne M.; Oremland, Ronald S.

    2006-01-01

    Arsenic and selenium are readily metabolized by prokaryotes, participating in a full range of metabolic functions including assimilation, methylation, detoxification, and anaerobic respiration. Arsenic speciation and mobility is affected by microbes through oxidation/reduction reactions as part of resistance and respiratory processes. A robust arsenic cycle has been demonstrated in diverse environments. Respiratory arsenate reductases, arsenic methyltransferases, and new components in arsenic resistance have been recently described. The requirement for selenium stems primarily from its incorporation into selenocysteine and its function in selenoenzymes. Selenium oxyanions can serve as an electron acceptor in anaerobic respiration, forming distinct nanoparticles of elemental selenium that may be enriched in (76)Se. The biogenesis of selenoproteins has been elucidated, and selenium methyltransferases and a respiratory selenate reductase have also been described. This review highlights recent advances in ecology, biochemistry, and molecular biology and provides a prelude to the impact of genomics studies.

  2. Quantification, localization, and speciation of selenium in seeds of canola and two mustard species compared to seed-meals produced by hydraulic press.

    PubMed

    Bañuelos, Gary S; Walse, Spencer S; Yang, Soo In; Pickering, Ingrid J; Fakra, Sirine C; Marcus, Matthew A; Freeman, John L

    2012-07-17

    Brassica plants accumulate selenium (Se) especially in seeds when grown in soils laden with Se. We report a chemical analysis of Se in Brassica seeds (canola, Indian mustard, and white mustard) and in their hydraulically pressed seed meals, which are used as a Se supplement in livestock animal feeds. Complementary techniques were used to measure total Se concentrations, to map the localization of Se, and to quantify different Se forms. Seeds and hydraulically pressed seed meals contained an average of 1.8 and 2.0 μg Se g(-1) DW, respectively. Selenium was primarily located in cotyledons and roots of seed embryos. Microfocused Se K-edge XANES and bulk XANES showed that seeds contained 90% of Se as C-Se-C forms. Hydraulically pressing seeds for oil caused changes in the forms of Se as follows: 40-55% C-Se-C forms, 33-42% selenocystine, 5-12% selenocysteine, and 11-14% trimethylselenonium ion. Aqueous extracts of seed and seed meals were also analyzed by SAX-HPLC/ICPMS and found to contain mainly the C-Se-C form SeMet, but also another C-Se-C form MeSeCys, which is of dietary pharmacological interest for cancer inhibition. In addition, SAX-HPLC/ICPMS also detected selenocystine and selenocysteine, further confirming the results obtained by XANES analyses.

  3. In vivo and in vitro testing for selenium and selenium compounds bioavailability assessment in foodstuff.

    PubMed

    Moreda-Piñeiro, Jorge; Moreda-Piñeiro, Antonio; Bermejo-Barrera, Pilar

    2017-03-04

    The assessment of selenium and selenium species bioavailability in foodstuff is of special concern on the context of human nutrition. In vivo (human and animal), and in vitro tests are important approaches for estimating the bioavailability of toxic and essential compounds to humans. An overview on in vivo and in vitro bioavailability assays for releasing selenium and selenium species in foodstuffs is summarized. Se and Se species content in a foodstuff critically influence Se bioavailability and bioactivity to humans and animals. Se bioavailability is affected by foodstuff-matrix major composition and minor components. Foodstuffs processing and/or treatments could enhancement or decrease Se bioavailability. Experimental conditions such as the selection of healthy status of examined people (in in vivo humans approaches), the selection of animal model (in vivo animals approaches), or the selection of GI conditions (in in vitro tests) could determines the results. Thus, international standardized protocol for in vivo and in vitro approaches assessment is mandatory.

  4. Selenium and immune responses

    SciTech Connect

    Kiremidjian-Schumacher, L.; Stotzky, G.

    1987-04-01

    Selenium (Se) affects all components of the immune system, i.e., the development and expression of nonspecific, humoral, and cell-mediated responses. In general, a deficiency in Se appears to result in immunosuppression, whereas supplementation with low doses of Se appears to result in augmentation and/or restoration of immunologic functions. A deficiency of Se has been shown to inhibit (1) resistance to microbial and viral infections, (2) neutrophil function, (3) antibody production, (4) proliferation of T and B lymphocytes in response to mitogens, and (5) cytodestruction by T lymphocytes and NK cells. Supplementation with Se has been shown to stimulate (1) the function of neutrophils, (2) production of antibodies, (3) proliferation of T and B lymphocytes in response to mitogens, (4) production of lymphokines, (5) NK cell-mediated cytodestruction, (6) delayed-type hypersensitivity reactions and allograft rejection, and (7) the ability of a host to reject transplanted malignant tumors. The mechanism(s) whereby Se affects the immune system is speculative. The effects of Se on the function of glutathione peroxidase and on the cellular levels of reduced glutathione and H/sub 2/Se, as well as the ability of Se to interact with cell membranes, probably represent only a few of many regulatory mechanisms. The manipulation of cellular levels of Se may be significant for the maintenance of general health and for the control of immunodeficiency disorders and the chemoprevention of cancer.

  5. Selenium Cycling Across Soil-Plant-Atmosphere Interfaces: A Critical Review

    PubMed Central

    Winkel, Lenny H.E.; Vriens, Bas; Jones, Gerrad D.; Schneider, Leila S.; Pilon-Smits, Elizabeth; Bañuelos, Gary S.

    2015-01-01

    Selenium (Se) is an essential element for humans and animals, which occurs ubiquitously in the environment. It is present in trace amounts in both organic and inorganic forms in marine and freshwater systems, soils, biomass and in the atmosphere. Low Se levels in certain terrestrial environments have resulted in Se deficiency in humans, while elevated Se levels in waters and soils can be toxic and result in the death of aquatic wildlife and other animals. Human dietary Se intake is largely governed by Se concentrations in plants, which are controlled by root uptake of Se as a function of soil Se concentrations, speciation and bioavailability. In addition, plants and microorganisms can biomethylate Se, which can result in a loss of Se to the atmosphere. The mobilization of Se across soil-plant-atmosphere interfaces is thus of crucial importance for human Se status. This review gives an overview of current knowledge on Se cycling with a specific focus on soil-plant-atmosphere interfaces. Sources, speciation and mobility of Se in soils and plants will be discussed as well as Se hyperaccumulation by plants, biofortification and biomethylation. Future research on Se cycling in the environment is essential to minimize the adverse health effects associated with unsafe environmental Se levels. PMID:26035246

  6. Palladacycle containing nitrogen and selenium: highly active pre-catalyst for the Suzuki-Miyaura coupling reaction and unprecedented conversion into nano-sized Pd17Se15.

    PubMed

    Rao, Gyandshwar Kumar; Kumar, Arun; Ahmed, Jahangeer; Singh, Ajai Kumar

    2010-08-28

    Newly synthesized, air and moisture insensitive palladacycle [PdCl(L-H)] (L = (C(6)H(5))(2-HOC(6)H(4))CHNH(CH(2))(3)SePh; a (N, Se, C(-)) ligand) shows high catalytic activity for the Suzuki-Miyaura coupling reaction of phenylboronic acid with aryl/heteroaryl chlorides/bromides (TON for aryl chlorides up to 9200) and is converted to approximately 8 nm size particles of Pd(17)Se(15) (probably the real catalyst).

  7. Mitochondrial Protein Profile in Mice with Low or Excessive Selenium Diets

    PubMed Central

    Hu, Lianmei; Wang, Congcong; Zhang, Qin; Yan, Hao; Li, Ying; Pan, Jiaqiang; Tang, Zhaoxin

    2016-01-01

    Dietary selenium putatively prevents oxidative damage, whereas excessive selenium may lead to animal disorder. In this study, we investigated the effects of low and excessive levels of dietary selenium on oxidative stress and mitochondrial proteins in mouse liver. Six to eight week old mice were fed a diet with low, excessive, or moderate (control) levels of selenium (sodium selenite). The selenium concentration and oxidative stress-related parameters in hepatic mitochondria were evaluated. Two-dimensional electrophoresis and mass spectrometry were applied to identify the differentially-expressed proteins associated with dietary selenium. The selenium content of the livers in mice with the low selenium diet was significantly lower than that of the control, while that of mice fed excessive levels was significantly higher. In both groups oxidative stress in hepatic mitochondria was found; accompanied by lower superoxide dismutase (SOD) and glutathione peroxidase (GPX) levels and higher malondialdehyde (MDA) content, compared with the control group. Furthermore, ten proteins in the hepatic mitochondria of the selenium-low or -excessive groups with more than two-fold differences in abundance compared with the control group were identified. The differentially-expressed proteins in hepatic mitochondria may be associated with dietary (low or excessive) selenium-induced oxidative stress. PMID:27428959

  8. Mitochondrial Protein Profile in Mice with Low or Excessive Selenium Diets.

    PubMed

    Hu, Lianmei; Wang, Congcong; Zhang, Qin; Yan, Hao; Li, Ying; Pan, Jiaqiang; Tang, Zhaoxin

    2016-07-15

    Dietary selenium putatively prevents oxidative damage, whereas excessive selenium may lead to animal disorder. In this study, we investigated the effects of low and excessive levels of dietary selenium on oxidative stress and mitochondrial proteins in mouse liver. Six to eight week old mice were fed a diet with low, excessive, or moderate (control) levels of selenium (sodium selenite). The selenium concentration and oxidative stress-related parameters in hepatic mitochondria were evaluated. Two-dimensional electrophoresis and mass spectrometry were applied to identify the differentially-expressed proteins associated with dietary selenium. The selenium content of the livers in mice with the low selenium diet was significantly lower than that of the control, while that of mice fed excessive levels was significantly higher. In both groups oxidative stress in hepatic mitochondria was found; accompanied by lower superoxide dismutase (SOD) and glutathione peroxidase (GPX) levels and higher malondialdehyde (MDA) content, compared with the control group. Furthermore, ten proteins in the hepatic mitochondria of the selenium-low or -excessive groups with more than two-fold differences in abundance compared with the control group were identified. The differentially-expressed proteins in hepatic mitochondria may be associated with dietary (low or excessive) selenium-induced oxidative stress.

  9. Geological evolution of the marine selenium cycle: Insights from the bulk shale δ82/76Se record and isotope mass balance modeling

    NASA Astrophysics Data System (ADS)

    Mitchell, Kristen; Mansoor, Sannan Z.; Mason, Paul R. D.; Johnson, Thomas M.; Van Cappellen, Philippe

    2016-05-01

    Bulk δ82/76Se values of representative marine shales from the Paleoarchean to the present day vary between approximately -3 and + 3 ‰ with only local deviations beyond this range. This muted Se isotope variability in the shale record contrasts with the relatively large fractionations associated with abiotic and microbial Se oxyanion reduction seen in experimental studies. Long-term temporal trends in the bulk shale data do not directly correlate with changes in redox conditions of the global ocean, although a minor but significant shift towards more negative formation-averaged δ82/76Se values appears to track oxygenation of the deep ocean at the end of the Proterozoic. We hypothesize that extensive δ82/76Se variability in the shale data was suppressed due to the early emergence of biological assimilatory uptake and the resulting persistence of low seawater Se concentrations, coupled with small authigenic Se outputs throughout most of geological time. In the modern ocean, Se is an essential micronutrient with a relatively short residence time of about 11,500 yrs. The marine Se cycle is dominated by assimilation into biomass and subsequent recycling in the water column and surface sediments, i.e. processes that result in only minimal isotopic fractionation. We suggest that similar processes dominated back through the geological record to Archean times. Our model shows that paleoceanographic information could in principle be extracted from proxy data on the Se isotopic composition of seawater, once isotopic differences can be readily discerned between individual sedimentary Se pools.

  10. Influence of different sulfur to selenium ratios on the structural and electronic properties of Cu(In,Ga)(S,Se){sub 2} thin films and solar cells formed by the stacked elemental layer process

    SciTech Connect

    Mueller, B. J.; Zimmermann, C.; Haug, V. Koehler, T.; Zweigart, S.; Hergert, F.; Herr, U.

    2014-11-07

    In this study, we investigate the effect of different elemental selenium to elemental sulfur ratios on the chalcopyrite phase formation in Cu(In,Ga)(S,Se){sub 2} thin films. The films are formed by the stacked elemental layer process. The structural and electronic properties of the thin films and solar cells are analyzed by means of scanning electron microscopy, glow discharge optical emission spectrometry, X-ray diffraction, X-ray fluorescence, Raman spectroscopy, spectral photoluminescence as well as current-voltage, and quantum efficiency measurements. The influence of different S/(S+Se) ratios on the anion incorporation and on the Ga/In distribution is investigated. We find a homogenous sulfur concentration profile inside the film from the top surface to the bottom. External quantum efficiency measurements show that the band edge of the solar cell device is shifted to shorter wavelength, which enhances the open-circuit voltages. The relative increase of the open-circuit voltage with S/(S+Se) ratio is lower than expected from the band gap energy trend, which is attributed to the presence of S-induced defects. We also observe a linear decrease of the short-circuit current density with increasing S/(S+Se) ratio which can be explained by a reduced absorption. Above a critical S/(S+Se) ratio of around 0.61, the fill factor drops drastically, which is accompanied by a strong series resistance increase which may be attributed to changes in the back contact or p-n junction properties.

  11. Developing selenium-enriched animal feed and biofuel from canola planted for managing Se-laden drainage waters in the Westside of Central California.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Identifying alternative crops for planting in Se-containing agricultural soils of western central California will depend upon the plants’ ability to tolerate high salt and boron (B) conditions. Multi-year field studies were conducted on Se-laden soils with different cactus clones (Opuntia-ficus indi...

  12. The leaching characteristics of selenium from coal fly ashes

    SciTech Connect

    Wang, T.; Wang, J.; Burken, J.G.; Ban, H.; Ladwig, K.

    2007-11-15

    The leaching characteristics of selenium from several bituminous and subbituminous coal fly ashes under different pH conditions were investigated using batch methods. Results indicated that pH had a significant effect on selenium leaching from bituminous coal ash. The minimum selenium leaching occurred in the pH range between 3 and 4, while the maximum selenium leaching occurred at pH 12. The release of selenium from subbituminous coal ashes was very low for the entire experimental pH range, possibly due to the high content of calcium which can form hydration or precipitation products as a sink for selenium. The adsorption results for different selenium species indicated that Se(VI) was hardly adsorbable on either bituminous coal ashes or subbitumminous coal ashes at any pH. However, Se(I) was highly adsorbed by bituminous coal ashes under acidic pH conditions and was mostly removed by subbitumminous coal ashes across the entire pH range. This result suggests that the majority of selenium released from the tested fly ashes was Se(IV). A speciation-based model was developed to simulate the adsorption of Se(IV) on bituminous coal fly ash, and the pH-independent adsorption constants of HSeO{sup 3-} and SeO{sub 3}{sup 2-} were determined. The modeling approach is useful for understanding and predicting the release process of selenium from fly ash.

  13. Status of selenium in cancer prevention

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An abundance of data indicate that selenium (Se) can be antitumorigenic. Those data, mostly from controlled studies using animal tumor models and some from clinical studies in free-living people, indicate that treatment with Se in the absence of nutritional Se-deficiency, can reduce cancer risk. T...

  14. Selenium in Oklahoma ground water and soil

    SciTech Connect

    Atalay, A.; Vir Maggon, D.

    1991-03-30

    Selenium with a consumption of 2 liters per day (5). The objectives of this study are: (1) to determine the concentrations of Se in Oklahoma ground water and soil samples. (2) to map the geographical distribution of Se species in Oklahoma. (3) to relate groundwater depth, pH and geology with concentration of Se.

  15. 21 CFR 101.36 - Nutrition labeling of dietary supplements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., total calories, calories from fat, total fat, saturated fat, trans fat, cholesterol, sodium, total..., saturated fat, cholesterol, total carbohydrate, dietary fiber, vitamin K, selenium, manganese, chromium... fat, saturated fat, cholesterol, sodium, potassium, total carbohydrate, and dietary fiber,...

  16. Assessment of two nonnative poeciliid fishes for monitoring selenium exposure in the endangered desert pupfish

    USGS Publications Warehouse

    Saiki, Michael K.; Martin, Barbara A.; May, Thomas W.; Brumbaugh, William G.

    2012-01-01

    We assessed the suitability of two nonnative poeciliid fishes—western mosquitofish (Gambusia affinis) and sailfin mollies (Poecilia latipinna)—for monitoring selenium exposure in desert pupfish (Cyprinodon macularius). Our investigation was prompted by a need to avoid lethal take of an endangered species (pupfish) when sampling fish for chemical analysis. Total selenium (SeTot) concentrations in both poeciliids were highly correlated with SeTot concentrations in pupfish. However, mean SeTot concentrations varied among fish species, with higher concentrations measured in mosquitofish than in mollies and pupfish from one of three sampled agricultural drains. Moreover, regression equations describing the relationship of selenomethionine to SeTot differed between mosquitofish and pupfish, but not between mollies and pupfish. Because selenium accumulates in animals primarily through dietary exposure, we examined fish trophic relationships by measuring stable isotopes (δ13C and δ15N) and gut contents. According to δ13C measurements, the trophic pathway leading to mosquitofish was more carbon-depleted than trophic pathways leading to mollies and pupfish, suggesting that energy flow to mosquitofish originated from allochthonous sources (terrestrial vegetation, emergent macrophytes, or both), whereas energy flow to mollies and pupfish originated from autochthonous sources (filamentous algae, submerged macrophytes, or both). The δ15N measurements indicated that mosquitofish and mollies occupied similar trophic levels, whereas pupfish occupied a slightly higher trophic level. Analysis of gut contents showed that mosquitofish consumed mostly winged insects (an indication of terrestrial taxa), whereas mollies and pupfish consumed mostly organic detritus. Judging from our results, only mollies (not mosquitofish) are suitable for monitoring selenium exposure in pupfish.

  17. Biofortification and phytoremediation of selenium in China.

    PubMed

    Wu, Zhilin; Bañuelos, Gary S; Lin, Zhi-Qing; Liu, Ying; Yuan, Linxi; Yin, Xuebin; Li, Miao

    2015-01-01

    Selenium (Se) is an essential trace element for humans and animals but at high concentrations, Se becomes toxic to organisms due to Se replacing sulfur in proteins. Selenium biofortification is an agricultural process that increases the accumulation of Se in crops, through plant breeding, genetic engineering, or use of Se fertilizers. Selenium phytoremediation is a green biotechnology to clean up Se-contaminated environments, primarily through phytoextraction and phytovolatilization. By integrating Se phytoremediation and biofortification technologies, Se-enriched plant materials harvested from Se phytoremediation can be used as Se-enriched green manures or other supplementary sources of Se for producing Se-biofortified agricultural products. Earlier studies primarily aimed at enhancing efficacy of phytoremediation and biofortification of Se based on natural variation in progenitor or identification of unique plant species. In this review, we discuss promising approaches to improve biofortification and phytoremediation of Se using knowledge acquired from model crops. We also explored the feasibility of applying biotechnologies such as inoculation of microbial strains for improving the efficiency of biofortification and phytoremediation of Se. The key research and practical challenges that remain in improving biofortification and phytoremediation of Se have been highlighted, and the future development and uses of Se-biofortified agricultural products in China has also been discussed.

  18. Biofortification and phytoremediation of selenium in China

    PubMed Central

    Wu, Zhilin; Bañuelos, Gary S.; Lin, Zhi-Qing; Liu, Ying; Yuan, Linxi; Yin, Xuebin; Li, Miao

    2015-01-01

    Selenium (Se) is an essential trace element for humans and animals but at high concentrations, Se becomes toxic to organisms due to Se replacing sulfur in proteins. Selenium biofortification is an agricultural process that increases the accumulation of Se in crops, through plant breeding, genetic engineering, or use of Se fertilizers. Selenium phytoremediation is a green biotechnology to clean up Se-contaminated environments, primarily through phytoextraction and phytovolatilization. By integrating Se phytoremediation and biofortification technologies, Se-enriched plant materials harvested from Se phytoremediation can be used as Se-enriched green manures or other supplementary sources of Se for producing Se-biofortified agricultural products. Earlier studies primarily aimed at enhancing efficacy of phytoremediation and biofortification of Se based on natural variation in progenitor or identification of unique plant species. In this review, we discuss promising approaches to improve biofortification and phytoremediation of Se using knowledge acquired from model crops. We also explored the feasibility of applying biotechnologies such as inoculation of microbial strains for improving the efficiency of biofortification and phytoremediation of Se. The key research and practical challenges that remain in improving biofortification and phytoremediation of Se have been highlighted, and the future development and uses of Se-biofortified agricultural products in China has also been discussed. PMID:25852703

  19. Effects of nationwide addition of selenium to fertilizers on foods, and animal and human health in Finland: From deficiency to optimal selenium status of the population.

    PubMed

    Alfthan, Georg; Eurola, Merja; Ekholm, Päivi; Venäläinen, Eija-Riitta; Root, Tarja; Korkalainen, Katja; Hartikainen, Helinä; Salminen, Pirjo; Hietaniemi, Veli; Aspila, Pentti; Aro, Antti

    2015-01-01

    Despite different geological features the Nordic countries are generally selenium-poor areas. In each country various factors such as food importation and life-style determine the selenium (Se) intake. Due to an extremely low Se intake in the 1970s in Finland, 0.025 mg/day, an official decision was made in 1984 to supplement multinutrient fertilizers with Se in the chemical form of sodium selenate. Almost all fertilizers used in Finland since 1985 have contained Se. Currently all crop fertilizers contain 15 mg Se/kg. Finland is still the only country to take this country-wide measure. In a national monitoring programme, sampling of cereals, basic foodstuffs, feeds, fertilizers, soils, and human tissues has been carried out annually since 1985 by four governmental research organizations. Sampling of foods has been done four times per year and human blood has been obtained annually from the same (n=60) adults. The accuracy of analyses has been verified by annual interlaboratory quality control. During this programme the selenium concentration of spring cereals has increased on average 15-fold compared with the level before the Se fertilization. The mean increase in the Se concentration in beef, pork and milk was 6-, 2- and 3-fold. In terms of Se, organically grown foods of plant origin are generally comparable to products produced before the Se supplementation of fertilizers. Milk from organically fed cows is 50% lower in Se than the usual milk. The average dietary human intake increased from 0.04 mg Se/day/10 MJ in 1985 to a present plateau of 0.08 mg Se/day/10 MJ, which is well above the current nutrition recommendations. Foods of animal origin contribute over 70% of the total daily Se intake. The mean human plasma Se concentration increased from 0.89 μmol/L to a general level of 1.40 μmol/L that can be considered to be an optimal status. The absence of Se deficiency diseases and a reference population have made conclusions on the impact on human health difficult

  20. Ecology and Biotechnology of Selenium-Respiring Bacteria

    PubMed Central

    2015-01-01

    SUMMARY In nature, selenium is actively cycled between oxic and anoxic habitats, and this cycle plays an important role in carbon and nitrogen mineralization through bacterial anaerobic respiration. Selenium-respiring bacteria (SeRB) are found in geographically diverse, pristine or contaminated environments and play a pivotal role in the selenium cycle. Unlike its structural analogues oxygen and sulfur, the chalcogen selenium and its microbial cycling have received much less attention by the scientific community. This review focuses on microorganisms that use selenate and selenite as terminal electron acceptors, in parallel to the well-studied sulfate-reducing bacteria. It overviews the significant advancements made in recent years on the role of SeRB in the biological selenium cycle and their ecological role, phylogenetic characterization, and metabolism, as well as selenium biomineralization mechanisms and environmental biotechnological applications. PMID:25631289

  1. Spatial variability in selenium and mercury interactions in a key recreational fish species: implications for human health and environmental monitoring.

    PubMed

    Jones, H J; Butler, E C V; Macleod, C K

    2013-09-15

    Selenium's (Se) protective effects against mercury (Hg) toxicity have been demonstrated; however, this is seldom considered in health assessments, where dietary exposure is still evaluated by Hg concentration alone. Se:Hg ratios and selenium health benefit values (Se HBVs) offer a more comprehensive seafood safety model. Here we describe total mercury (THg), methylmercury (MeHg) and Se concentrations in fish from a Hg-polluted estuary. Spatial variation in THg, MeHg and Se was evident, though all regions maintained Se:Hg ratio values >1. Se HBV varied between regions and in one region mean negative values (-5.17) were evident. This study provides the first evidence that quoting a single all-encompassing Se HBV is not appropriate when species demonstrate strong site fidelity. It highlights the need for research into Se-Hg relationships in environments with established Hg pollution and reinforces the assertion that Se concentration be considered in assessments of human health risk to Hg exposure.

  2. Toxicology of selenium in a freshwater reservoir: implications for environmental hazard evaluation and safety.

    PubMed

    Lemly, A D

    1985-12-01

    A study was conducted to document patterns of accumulation and toxicity of selenium to organisms in a power plant cooling reservoir in North Carolina. Selenium entered the reservoir by way of effluent from the coal ash disposal basin, which contained 100-200 micrograms Se/liter. Concentrations of selenium in the lake water averaged 10 micrograms/liter, but were accumulated from 519 times (periphyton) to 3975 times (visceral tissue, largemouth bass) in the biota. The pattern and degree of accumulation was essentially complete within 2 years after the initial operation of the power plant, and persisted throughout the remainder of the study: fishes greater than insects greater than annelids greater than molluscs greater than crustaceans greater than plankton greater than periphyton. The plantonic and detrital food pathways exposed fishes to potential dietary concentrations of selenium that were some 770 and 519-1395 times the waterborne exposure, respectively. Of the 20 species of fish originally present in the reservoir, 16 were entirely eliminated, 2 were rendered sterile but persisted as adults, 1 was eliminated but managed to recolonize from a relatively uncontaminated headwater area as sterile adults, and 1 was unaffected. Two nonnative fish species were accidentally introduced and established reproducing populations. Abundance and diversity of biota other than fishes was not affected. Relative to control habitats, the contaminated reservoir had concentrations of waterborne selenium that were 20-30 times background levels; the flora and fauna contained about 10-15 times background. The results show that selenium can accumulate and be biologically magnified to toxic levels in a reservoir even though waterborne concentrations are in the low microgram per liter range. This study also provides data which indicate that current toxicological information is neither accurate when used to predict the relative sensitivity of individual fish species to selenium, nor is it

  3. Selenium content of game meat

    SciTech Connect

    Medeiros, L.C.; Belden, R.P. Univ. of Wyoming, Laramie )

    1991-03-11

    Selenium (Se) content of elk, deer, bison and beef were measured and compared. Samples were obtained from animals grazed on soil known to contain high, but variable amounts of Se. Beef were feedlot grazed and elk, deer, and bison were from captive or semi-captive herds. Selenium content was determined by graphite furnace after high pressure wet microwave digestion of samples. Deer and bison contained more Se than elk or beef. On a dry weight basis, deer contained more Se than bison. Game species contained more Se than beef. Within samples from male elk and deer and elk and bison of both genders, there were interactions between specie and muscle effects. Muscle and gender did not significantly influence Se content. The animals from which these samples were taken were supplemented with feeds grown on high Se containing soils, which was reflected in all values. Se values were twofold higher than those previously reported for meat. Those consuming large quantities of game from areas with high Se soil may need to monitor Se intake to avoid consuming excessive quantities.

  4. Toxicologic evaluation of a high-selenium hay diet in captive pronghorn antelope (Antilocapra americana).

    PubMed

    Raisbeck, M F; O'Toole, D; Schamber, R A; Belden, E L; Robinson, L J

    1996-01-01

    Five captive-raised pronghorn antelope (Antilocapra americana) were fed an alfalfa-grass hay diet containing 15 ppm total dietary selenium (Se) for 164 days. Four additional captive-raised pronghorns fed a similar diet containing approximately 0.3 ppm total dietary Se served as controls. None of the pronghorns had clinical signs attributable to the high Se hay. Plasma Se increased more rapidly than blood Se concentrations, from baseline concentrations (< 0.15 g/ml) to > 0.40 g/ml within the first 50 days on the high selenium diet, but thereafter declined to approximately 0.30 microgram/ml. Mean primary antibody response to hen egg albumin was less in pronghorn on Se hay. No significant gross or histological lesions attributable to selenosis were found, nor was there any evidence of dystrophic hoof growth. The greatest Se tissue concentrations were found in liver and kidney (5.67 to 10.4 micrograms/g and 2.36 to 3.14 micrograms/g, respectively) from experimental animals; liver and kidney from the controls contained considerably less (< or = 0.52 microgram/g and < or = 0.61 microgram/g, respectively). Exposure of pronghorns for more than 5 mo to a diet containing 15 ppm Se caused significant increases in plasma, liver and kidney Se concentrations, in the absence of clinical disease or pathologic lesions due to selenosis. Based on these results, we propose that pronghorns are less susceptible to selenosis than previously reported and that diagnostic criteria for the disease should be modified.

  5. Access to B=S and B=Se double bonds via sulfur and selenium insertion into a B-H bond and hydrogen migration.

    PubMed

    Wang, Hao; Zhang, Jianying; Hu, Hongfan; Cui, Chunming

    2010-08-18

    Stable compounds with a boron-chalcogen (S or Se) valence double bond have been prepared via sequences involving insertion of the chalcogen into a B-H bond and subsequent hydrogen migration. X-ray diffraction studies and density functional theory calculations on the resulting compounds provide convincing evidence for the boron-chalcogen multiple bonding.

  6. Characterization of selenium-enriched wheat by agronomic biofortification.

    PubMed

    Galinha, Catarina; Sánchez-Martínez, María; Pacheco, Adriano M G; Freitas, Maria do Carmo; Coutinho, José; Maçãs, Benvindo; Almeida, Ana Sofia; Pérez-Corona, María Teresa; Madrid, Yolanda; Wolterbeek, Hubert T

    2015-07-01

    Agronomic biofortification of staple crops is an effective way to enhance their contents in essential nutrients up the food chain, with a view to correcting for their deficiencies in animal or human status. Selenium (Se) is one such case, for its uneven distribution in the continental crust and, therefore, in agricultural lands easily translates into substantial variation in nutritional intakes. Cereals are far from being the main sources of Se on a content basis, but they are likely the major contributors to intake on a dietary basis. To assess their potential to assimilate and biotransform Se, bread and durum wheat were enriched with Se through foliar and soil addition at an equivalent field rate of 100 g of Se per hectare (ha), using sodium selenate and sodium selenite as Se-supplementation matrices, in actual field conditions throughout. Biotransformation of inorganic Se was evaluated by using HPLC-ICP-MS after enzymatic hydrolysis for Se-species extraction in the resulting mature wheat grains. Selenomethionine and Se(VI) were identified and quantified: the former was the predominant species, representing 70-100 % of the total Se in samples; the maximum amount of inorganic Se was below 5 %. These results were similar for both supplementation methods and for both wheat varieties. Judging from the present results, one can conclude that agronomic biofortification of wheat may improve the nutritional quality of wheat grains with significant amounts of selenomethionine, which is an attractive option for increasing the Se status in human diets through Se-enriched, wheat-based foodstuff.

  7. Selenium: a double-edged sword for defense and offence in cancer.

    PubMed

    Brozmanová, Jela; Mániková, Dominika; Vlčková, Viera; Chovanec, Miroslav

    2010-12-01

    Selenium (Se) is an essential dietary component for animals including humans and is regarded as a protective agent against cancer. Although the mode of anticancer action of Se is not fully understood yet, several mechanisms, such as antioxidant protection by selenoenzymes, specific inhibition of tumor cell growth by Se metabolites, modulation of cell cycle and apoptosis, and effect on DNA repair have all been proposed. Despite the unsupported results of the last SELECT trial, the cancer-preventing activity of Se was demonstrated in majority of the epidemiological studies. Moreover, recent studies suggest that Se has a potential to be used not only in cancer prevention but also in cancer treatment where in combination with other anticancer drugs or radiation, it can increase efficacy of cancer therapy. In combating cancer cells, Se acts as pro-oxidant rather than antioxidant, inducing apoptosis through the generation of oxidative stress. Thus, the inorganic Se compound, sodium selenite (SeL), due to its prooxidant character, represents a promising alternative for cancer therapy. However, this Se compound is highly toxic compared to organic Se forms. Thus, the unregulated intake of dietary or pharmacological Se supplements mainly in the form of SeL has a potential to expose the body tissues to the toxic levels of Se with subsequent negative consequences on DNA integrity. Hence, due to a broad interest to exploit the positive effects of Se on human health and cancer therapy, studies investigating the negative effects such as toxicity and DNA damage induction resulting from high Se intake are also highly required. Here, we review a role of Se in cancer prevention and cancer therapy, as well as mechanisms underlying Se-induced toxicity and DNA injury. Since Saccharomyces cerevisiae has proven a powerful tool for addressing some important questions regarding Se biology, a part of this review is devoted to this model system.

  8. Selenium concentration in the milk of breast-feeding mothers and its geographic distribution.

    PubMed Central

    Zachara, B A; Pilecki, A

    2000-01-01

    A total of 905 human milk samples collected in all provinces of Poland, between 12 and 75 days of lactation, were analyzed for selenium concentration. The distribution of Se levels in milk between the provinces was narrow and varied from 8.81 to 11.58 ng/mL, with the mean value (+/- SD) of 10.24 +/- 2.82 ng/mL. The regions with lower levels of Se were in the central and eastern part of Poland; the areas with higher values were in the northern, western, and southern parts of Poland. No significant correlations were found between Se levels in milk and the age of lactating mothers or between Se levels and the postpartum period. The calculated daily Se intakes by breast-fed infants varied from 6.46 to 8.50 microg/day, with the mean value of 7.52 microg/day. This amount does not meet the recommended dietary allowances for infants between 0 and 6 months of age. Based on Se levels in human milk, we present a selenium map of Poland. PMID:11102294

  9. Synthesis, characterization and antioxidant activity of selenium polysaccharide from Cordyceps militaris.

    PubMed

    Zhu, Zhen-Yuan; Liu, Fei; Gao, Hui; Sun, Huiqing; Meng, Meng; Zhang, Yong-Min

    2016-12-01

    A purified selenium-containing derivatives of Cordyceps militaris polysaccharide synthesized using H2SeO3/HNO3 and BaCl2 as a catalyst was investigated in this paper. The reaction condition was optimized by selecting different reaction temperature and period. Afterward, the one with the highest Se content was purified by ultra-filtration device with a molecular cut off size of 10KDa. Followed by its structural characterizations. Results of IFR and (13)C NMR spectroscopy indicated that C-6 substitution was predominant in selenized polysaccharide. The modified polysaccharide with molecular weight of 1998 KDa was mainly consisted of mannose, glucose and galactose in the mole ratios of with the mole ratios of 1:28.63:1.41. Thermogravimetric and morphological analyses of the samples were carried out by AFS, SEM and AFM. In addition, the in vitro antioxidant results suggested that selenium-containing polysaccharide should be applied as a novel selenium source in dietary supplements, with potent antioxidant properties.

  10. [Correction of selenium deficiency in patients with pneumonia].

    PubMed

    Bakulin, I G; Novozhenov, V G; Orlov, A M; Gmoshinskiĭ, I V; Mazo, V K

    2004-01-01

    The estimation of selenium (Se) safety in patients with pneumonia is important for evaluation of antioxidant defense system capacity and the immune status of the patients. The research has been carried out on the serum Se levels in patients with pneumonia at standard treatment and at treatment with the usage of selenium enriched food supplement (Se-spirulina). The results of research have shown that application of additional selenium in amount providing physiological requirement leads to full varnishing its deficiency cases and to restoration in the majority of patients the suboptimum Se level.

  11. Molecular cloning and expression study of pi-class glutathione S-transferase (pi-GST) and selenium-dependent glutathione peroxidase (Se-GPx) transcripts in the freshwater bivalve Dreissena polymorpha.

    PubMed

    Doyen, Périne; Bigot, Aurélie; Vasseur, Paule; Rodius, François

    2008-01-01

    Glutathione S-transferases (GST) and glutathione peroxidases (GPx) are essential components of cellular detoxification systems. We identified GST and GPx transcripts in the freshwater bivalve Dreissena polymorpha, their full-length coding sequences were obtained by reverse-transcription PCR using degenerated primers followed by 5' and 3' RACE-PCR (rapid amplification of cDNA ends-PCR). The cDNA identified encoded proteins of 205 and 243 amino acids corresponding respectively to a pi-class GST and a selenium-dependent GPx. The comparison of the deduced amino acid sequences with GST and GPx from other species showed that the residues essential to the enzymatic function of these two proteins are highly conserved. We studied their expression pattern in the digestive gland, the gills and the excretory system of D. polymorpha. The results showed that pi-GST mRNA expression is higher in the digestive gland than in the gills or the excretory system. Se-GPx transcripts are expressed at high, medium and very low levels in the digestive gland, the excretory system and the gills, respectively.

  12. Microbial Transformations of Selenium Species of Relevance to Bioremediation

    PubMed Central

    Eswayah, Abdurrahman S.; Smith, Thomas J.

    2016-01-01

    Selenium species, particularly the oxyanions selenite (SeO32−) and selenate (SeO42−), are significant pollutants in the environment that leach from rocks and are released by anthropogenic activities. Selenium is also an essential micronutrient for organisms across the tree of life, including microorganisms and human beings, particularly because of its presence in the 21st genetically encoded amino acid, selenocysteine. Environmental microorganisms are known to be capable of a range of transformations of selenium species, including reduction, methylation, oxidation, and demethylation. Assimilatory reduction of selenium species is necessary for the synthesis of selenoproteins. Dissimilatory reduction of selenate is known to support the anaerobic respiration of a number of microorganisms, and the dissimilatory reduction of soluble selenate and selenite to nanoparticulate elemental selenium greatly reduces the toxicity and bioavailability of selenium and has a major role in bioremediation and potentially in the production of selenium nanospheres for technological applications. Also, microbial methylation after reduction of Se oxyanions is another potentially effective detoxification process if limitations with low reaction rates and capture of the volatile methylated selenium species can be overcome. This review discusses microbial transformations of different forms of Se in an environmental context, with special emphasis on bioremediation of Se pollution. PMID:27260359

  13. [Selenium deficiency in pregnancy?].

    PubMed

    Lechner, W; Jenewein, I; Ritzberger, G; Sölder, E; Waitz-Penz, A; Schirmer, M; Abfalter, E

    1990-07-15

    Selenium content was investigated by atomic absorbtion spectroscopy in 32 normal pregnant women in the 38th-42, week of pregnancy. In congruence with other investigations from middle and northern Europe, selenium deficiency was stated in all of the patients.

  14. Selenium in diet

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002414.htm Selenium in diet To use the sharing features on this page, please enable JavaScript. Selenium is an essential trace mineral. This means your ...

  15. Selenium: Poison and Preventive.

    ERIC Educational Resources Information Center

    Marmion Howe, Sister

    1978-01-01

    Selenium is an essential nutrient to the human body, but it can reach toxic levels causing a disease called selenosis. This article discusses selenium, its geographical distribution, toxicity, nutritional role, and carcinogenicity. (MA)

  16. Selenium: Element of Contrasts

    ERIC Educational Resources Information Center

    Goldsmith, Robert H.; And Others

    1978-01-01

    Reports on recent findings concerning the impact of selenium on human and animal health. In its various oxidation states, different concentrations of selenium may be helpful or detrimental to human health. (CP)

  17. A mutual protective effect of mercury and selenium in Japanese quail.

    PubMed

    El-Begearmi, M M; Sunde, M L; Ganther, H E

    1977-01-01

    Dietary interactions between methylmercury (Ch3Hg) and sodium selenite (Na2SeO3) were studied in Japanese quail. Addition of 0.35-6 p.p.m. Se to diets containing toxic levels of Hg (5-30 p.p.m. Hg) reduced the toxicity of methylmercury and increased the survival of Japanese quail. The survival increased with increasing levels of Se in the diet. Selenium as 6 p.p.m. did not cause any mortality in males and caused only relatively low mortality in females. However, 12 p.p.m. Se depressed the survival of quail, especially females. No consistent effect of Hg, Se or both was observed on body weight or feed consumption. High levels of Hg reduced egg production, fertility and hatchability, and the addition of Se lessened these effects of Hg. Selenium in the diet alone (6 or 12 p.p.m.) generally produced lower hatchability and a high percentage of deformed embryos, and 12 p.p.m. Se also depressed egg production. Addition of 5-15 p.p.m. Hg to such Se diets overcame these effects and reduced the percentage of abnormal embryos more than 50%. Analysis of tissues for total Hg showed that Hg was distributed in a pattern typical for alkyl mercurials. Hg levels in Se-protected birds equaled or exceeded the levels in those fed Hg without Se. Se levels in tissues were generally elevated by feeding Hg, especially in brain. Extremely high brain Hg levels, up to 58 p.p.m., were observed in birds fed 15 p.p.m. Hg plus 6 p.p.m. Se for 20 weeks prior to sacrifice. The levels of Se in the brain of these birds was elevated (4 p.p.m.), but not equimolar to Hg.

  18. Selenium in oncology: from chemistry to clinics.

    PubMed

    Micke, Oliver; Schomburg, Lutz; Buentzel, Jens; Kisters, Klaus; Muecke, Ralph

    2009-10-12

    The essential trace element selenium, which is a crucial cofactor in the most important endogenous antioxidative systems of the human body, is attracting more and more the attention of both laypersons and expert groups. The interest of oncologists mainly focuses in the following clinical aspects: radioprotection of normal tissues, radiosensitizing in malignant tumors, antiedematous effect, prognostic impact of selenium, and effects in primary and secondary cancer prevention. Selenium is a constituent of the small group of selenocysteine-containing selenoproteins and elicits important structural and enzymatic functions. Selenium deficiency has been linked to increased infection risk and adverse mood states. It has been shown to possess cancer-preventive and cytoprotective activities in both animal models and humans. It is well established that Se has a key role in redox regulation and antioxidant function, and hence in membrane integrity, energy metabolism and protection against DNA damage. Recent clinical trials have shown the importance of selenium in clinical oncology. Our own clinical study involving 48 patients suggest that selenium has a positive effect on radiation-associated secondary lymphedema in patients with limb edemas, as well as in the head and neck region, including endolaryngeal edema. Another randomized phase III study of our group was performed to examine the cytoprotective properties of selenium in radiation oncology. The aim was to evaluate whether sodium selenite is able to compensate a preexisting selenium deficiency and to prevent radiation induced diarrhea in adjuvant radiotherapy for pelvic gynecologic malignancies. Through this study, the significant benefits of sodium selenite supplementation with regards to selenium deficiency and radiotherapy induced diarrhea in patients with cervical and uterine cancer has been shown for the first time in a prospective randomized trial. Survival data imply that supplementation with selenium does not

  19. Synergy between broccoli sprout extract and selenium in the upregulation of thioredoxin reductase in human hepatocytes.

    PubMed

    Li, Dan; Wu, Kun; Howie, A Forbes; Beckett, Geoffrey J; Wang, Wei; Bao, Yongping

    2008-09-01

    Dietary isothiocyanates and selenium (Se) can up-regulate thioredoxin reductase 1 (TR1) in cultured human HepG2 and MCF-7 cells [Zhang et al. (2003). Synergy between sulforaphane and selenium in the induction of thioredoxin reductase 1 requires both transcriptional and translational modulation. Carcinogenesis, 24, 497-503; Wang et al. (2005). Sulforaphane, erucin and iberin up-regulate thioredoxin reductase expression in human MCF-7 cells. Journal of Agricultural and Food Chemistry, 53, 1417-1421] at both the protein and mRNA levels. In this study, broccoli sprout extract (a rich source of the isothiocyanates sulforaphane and iberin) and Se interacted synergistically to induce TR1 in immortalised human hepatocytes. Broccoli sprout extracts containing 1.6, 4 and 8μM isothiocyanates were tested for their ability to induce TR1 at the protein and mRNA level. Although induction of TR1 mRNA by broccoli sprout extract (1.6-8μM) was only 1.7-2.2-fold, co-treatment with Se (0.2-1μM) enhanced the expression of TR1 mRNA (3.0-3.3-fold). Moreover, broccoli sprout extract induced the cellular concentration of TR1 and TR enzymatic activity, an induction that was augmented by Se addition. Thus, broccoli sprout extract (8μM) and Se induced cellular TR1 concentration and enzymatic activity 3.7- and 5-fold respectively, whereas, Se or broccoli sprout extract alone produced an induction of only approximately 2-fold. These data suggest that dietary isothiocyanates from broccoli sprouts and Se are important agents in the regulation of redox status in human liver cells. The synergistic effect between isothiocyanates and Se at physiologically-relevant concentrations on the induction of TR1 may play an important role in protection against oxidative stress.

  20. Selenium and vitamin E inhibit radiogenic and chemically induced transformation in vitro via different mechanisms

    SciTech Connect

    Borek, C.; Ong, A.; Mason, H.; Donahue, L.; Biaglow, J.E.

    1986-03-01

    Results from in vivo and in vitro studies showing that antioxidants may act as anticarcinogens support the role of active oxygen in carcinogenesis and provide impetus for exploring the functions of dietary antioxidants in cancer prevention by using in vitro models. The authors examined the single and combined effects of selenium, a component of glutathione peroxidase, and vitamin E, a known antioxidant, on cell transformation induced in C3H/10T-1/2 cells by x-rays, benzo(a)pyrene, or tryptophan pyrolysate and on the levels of cellular scavenging systems peroxide destruction. Incubation of C3H/10T-1/2 cells with 2.5 ..mu..M Na/sup 2/SeO/sup 3/ (selenium) or with 7 ..mu..M ..cap alpha..-tocopherol succinate (vitamin E) 24 hr prior to exposure to x-rays or the chemical carcinogens resulted in an inhibition of transformation by each of the antioxidants with an additive-inhibitory action when the two nutrients were combined. Cellular pretreatment with selenium resulted in increased levels of cellular glutathione peroxidase, catalase, and nonprotein thiols (glutathione) and in an enhanced destruction of peroxide. The results support our earlier studies showing that free radical-mediated events play a role in radiation and chemically induced transformation. They indicate that selenium and vitamin E act alone and in additive fashion as radioprotecting and chemopreventing agents. The results further suggest that selenium confers protection in part by inducing or activating cellular free-radical scavenging systems and by enhancing peroxide breakdown while vitamin E appears to confer its protection by and alternate complementary mechanism.

  1. Selenium in bovine spermatozoa.

    PubMed

    Niemi, S M; Kuzan, F B; Senger, P L

    1981-05-01

    This study investigated the association of selenium with ejaculated bovine spermatozoa. Over 75% of the radioactive spermatozoa. Over 75% of the radioactive selenium-75 was released after 30 min of incubation in 2 X 10(-3) dithiothreitol. Of the selenium-75 released by dithiothreitol, 85% was associated with spermatozoal protein. Protein containing selenium-75 was found predominantly in a single band after polyacrylamide gel electrophoresis. Molecular weight was approximately 21,500 daltons.

  2. Biological and chemical investigation of Allium cepa L. response to selenium inorganic compounds.

    PubMed

    Michalska-Kacymirow, M; Kurek, E; Smolis, A; Wierzbicka, M; Bulska, E

    2014-06-01

    The aim of this study was to evaluate the biological and chemical response of Allium cepa L. exposed to inorganic selenium compounds. Besides the investigation of the total content of selenium as well as its chemical speciation, the Allium test was used to evaluate the growth of onion roots and mitotic activity in the roots' meristem. The total content of selenium was determined by inductively coupled plasma mass spectrometry (ICP MS). High-performance liquid chromatography (HPLC), coupled to ICP MS, was used for the selenium chemical speciation. Results indicated that A. cepa plants are able to biotransform inorganic selenium compounds into their organic derivatives, e.g., Se-methylselenocysteine from the Se(IV) inorganic precursor. Although the differences in the biotransformation of selenium are due mainly to the oxidation state of selenium, the experiment has also shown a fine effect of counter ions (H(+), Na(+), NH4 (+)) on the response of plants and on the specific metabolism of selenium.

  3. WE-G-204-04: Focal Spot Deblurring For High Resolution Amorphous Selenium (aSe) Complementary Metal Oxide Semiconductor (CMOS) X-Ray Detector

    SciTech Connect

    Nagesh, S Setlur; Rana, R; Russ, M; Ionita, C; Bednarek, D; Rudin, S

    2015-06-15

    Purpose: CMOS-based aSe detectors compared to CsI-TFT-based flat panels have the advantages of higher spatial sampling due to smaller pixel size and decreased blurring characteristic of direct rather than indirect detection. For systems with such detectors, the limiting factor degrading image resolution then becomes the focal-spot geometric unsharpness. This effect can seriously limit the use of such detectors in areas such as cone beam computed tomography, clinical fluoroscopy and angiography. In this work a technique to remove the effect of focal-spot blur is presented for a simulated aSe detector. Method: To simulate images from an aSe detector affected with focal-spot blur, first a set of high-resolution images of a stent (FRED from Microvention, Inc.) were acquired using a 75µm pixel size Dexela-Perkin-Elmer detector and averaged to reduce quantum noise. Then the averaged image was blurred with a known Gaussian blur at two different magnifications to simulate an idealized focal spot. The blurred images were then deconvolved with a set of different Gaussian blurs to remove the effect of focal-spot blurring using a threshold-based, inverse-filtering method. Results: The blur was removed by deconvolving the images using a set of Gaussian functions for both magnifications. Selecting the correct function resulted in an image close to the original; however, selection of too wide a function would cause severe artifacts. Conclusion: Experimentally, focal-spot blur at different magnifications can be measured using a pin hole with a high resolution detector. This spread function can be used to deblur the input images that are acquired at corresponding magnifications to correct for the focal spot blur. For CBCT applications, the magnification of specific objects can be obtained using initial reconstructions then corrected for focal-spot blurring to improve resolution. Similarly, if object magnification can be determined such correction may be applied in fluoroscopy and

  4. Review - Selenium - Its metabolism and relation to exercise.

    PubMed

    Baltaci, Abdulkerim Kasim; Mogulkoc, Rasim; Akil, Mustafa; Bicer, Mursel

    2016-09-01

    Selenium (Se), which is commonly found in nature, is one of the essential trace elements necessary for the normal development of human and animal organisms. Selenium was first defined in 1818 by the Swedish chemist Berzelius in sulfuric acid residues. At the end of 1960s, the role of selenium in human health began to attract attention and human diseases that resembled animal diseases responding to selenium was started to be investigated. Selenium, which is highly important for human health, is necessary for a variety of metabolic processes, including thyroid hormone metabolism, protection against oxidative stress and immunity functions. Selenium is a molecule that activates glutathione peroxidase, and thus, it is involved in the antioxidant mechanisms that prevent oxidant damage. Exhaustive physical exercise is known to cause oxidant damage, probably by promoting free radical production in many tissues, including muscle, liver, heart and lungs in animals. The increase in oxidative stress during exercise and recognition of selenium's stimulation of antioxidant activity inevitably suggest a relation between selenium and exercise. The present review aims to provide information on selenium metabolism and the relation between selenium and exercise.

  5. A prospective study of selenium status and breast cancer risk

    SciTech Connect

    Hunter, D.J.; Stampfer, M.J.; Colditz, G.A.; Speizer, F.E.; Willett, W.C. ); Morris, J.S. )

    1990-09-05

    Low dietary intake of selenium has been proposed as a risk factor for breast cancer. To address this hypothesis, the authors collected toenail clippings from 62,641 women in the Nurses' Health Study cohort who were free from cancer in 1982 and 1983. The selenium concentration in nails has been shown to reflect dietary intake of selenium. During 53 months of follow-up, 434 cases of breast cancer were diagnosed among women who had submitted a set of toenail clippings, and they matched one control free from breast and other cancers to each case. The mean selenium level in toenails in the cases was almost identical to that of the controls. After controlling for known breast cancer risk factors, the relative risk for women in the highest quintile of selenium as compared with the lowest quintile was 1.10 and there was not trend across quintiles. Results were similar for both premenopausal and postmenopausal women. Although these data do not exclude a possible influence of selenium intake before adulthood on subsequent risk of breast cancer, selenium intake later in life is not likely to be an important factor in the etiology of breast cancer.

  6. Effect of dietary selenomethionine on growth performance, tissue burden, and histopathology in green and white sturgeon.

    PubMed

    De Riu, Nicola; Lee, Jang-Won; Huang, Susie S Y; Moniello, Giuseppe; Hung, Silas S O

    2014-03-01

    A comparative examination of potential differences in selenium (Se) sensitivity was conducted on two sturgeon species indigenous to the San Francisco Bay-Delta. Juvenile green (Acipenser medirostris), recently given a federally threatened status, and white sturgeon (Acipenser transmontanus) were exposed to one of four nominal concentrations of dietary l-selenomethionine (SeMet) (0 (control), 50, 100, or 200 mg SeMet/kg diet) for 8 weeks. Mortality, growth performance, whole body composition, histopathology, and Se burdens of the whole body, liver, kidneys, gills, heart, and white muscle were determined every 2 to 4 weeks. Significant (p<0.05) mortality was observed in green sturgeon fed the highest SeMet diet after 2 weeks, whereas no mortality was observed in white sturgeon. Growth rates were significantly reduced in both species; however, green sturgeon was more adversely affected by the treatment. Dietary SeMet significantly affected whole body composition and most noticeably, in the decline of lipid contents in green sturgeon. Selenium accumulated significantly in all tissues relative to the control groups. After 4 and 8 weeks of exposure, marked abnormalities were observed in the kidneys and liver of both sturgeon species; however, green sturgeon was more susceptible to SeMet than white sturgeon at all dietary SeMet levels. Our results showed that a dietary Se concentration at 19.7 ± 0.6 mg Se/kg, which is in range with the reported Se concentrations of the benthic macro-vertebrate community of the San Francisco Bay, had adverse effects on both sturgeon species. However, the exposure had a more severe pathological effect on green sturgeon, suggesting that when implementing conservation measures, this federally listed threatened species should be monitored and managed independently from white sturgeon.

  7. Elk (Cervus Canadensis) preference for feeds varying in selenium concentration.

    PubMed

    Pfister, J A; Davis, T Z; Hall, J O; Stegelmeier, B L; Panter, K E

    2015-07-01

    Selenium-accumulator plants are reputed to be unpalatable to large ungulates. Elk (Cervus canadensis) populations in southeastern Idaho overlap with populations of Se-rich plants, but there is no information on the influence of plant Se concentration on elk dietary preferences. The objective of this study was to determine, under controlled conditions, the preference of elk for feeds varying in Se concentrations. Seven yearling female elk (128 ± 5 kg) were purchased from a commercial elk farm in southeastern Idaho and adapted to low-Se alfalfa pellets. Three feeding trials using pellets with predetermined Se concentrations were conducted. Alfalfa pellets were commercially made with the addition of Symphyotrichum ascendens (western aster) so that the pellets contained 0.4, 5, 20, 50, or 100 mg/kg (DM basis) Se. In trial 1, 5 Se-containing alfalfa pellets (0.4, 5, 20, 50, and 100 mg/kg Se) were offered for 10 d; trial 2 used 4 Se-containing alfalfa pellet choices (0.4, 20, 50, and 100 mg/kg), and trial 3 used 3 pellet choices (0.4, 50, and 100 mg/kg) for 6 d. In trial 1, consumption of the control pellets by elk was greater than each of the other pellet choices (P < 0.001). Similarly, consumption of the 5-mg/kg Se pellet differed from control pellet and all other Se-containing pellets (P < 0.0001). There were no differences (P > 0.50) in consumption of the 20-, 50-, or 100-mg/kg Se pellets. In trial 2, elk consumed more (P < 0.0001) of the control pellet than the 20-, 50-, and 100-mg/kg Se pellets. Similarly, elk consumed more (P < 0.0001) of the 20-mg/kg Se pellet than the 50- and 100-mg/kg Se pellets. There were no differences (P > 0.99) in elk consumption of the 50- and 100-mg/kg Se pellets. In trial 3, elk consumption of the control and 50- and 100-mg/kg Se pellets differed (P ≤ 0.03) from one another each day except that on d 1 and 2, where elk consumption of the 50- and 100-mg/kg Se pellets did not differ (P ≥ 0.32). Elk clearly discriminated against

  8. Plasma selenium concentrations are sufficient and associated with protease inhibitor use in treated HIV-infected adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Selenium (Se) is an essential constituent of selenoproteins which play significant roles in antioxidant defense and inflammatory cascades. Selenium deficiency is associated with disease states characterized by inflammation including cardiovascular disease (CVD). While HIV infection has b...

  9. Selenium toxicity to aquatic life: An argument for sediment-based water quality criteria

    SciTech Connect

    Canton, S.P.; Van Derveer, W.D.

    1997-06-01

    A number of streams in Colorado were found to contain waterborne selenium concentrations that consistently exceeded the current US EPA chronic criterion of 5 {micro}g/L and often exceeded the acute criterion of 210 {micro}g/L. Despite these elevated concentrations, no biological impact was observed. These findings led to a review of selenium exposure pathways in freshwater. The literature strongly indicates that chronic selenium toxicity can result from accumulation of selenium in the sediment, movement into the food chain, and resulting dietary uptake. Chronic toxicity does not appear to be strictly a result of waterborne selenium concentrations. In fact, dissolved selenium concentrations are a poor predictor of potential chronic toxicity to freshwater organisms, when evaluated with Hill`s criteria for causal association. To develop a more reliable chronic waterborne criterion, a sediment-based method is needed to describe accurately potential chronic toxicity of selenium on a site-specific basis.

  10. Selenium cytotoxicity in cancer.

    PubMed

    Wallenberg, Marita; Misra, Sougat; Björnstedt, Mikael

    2014-05-01

    Selenium is an essential trace element with growth-modulating properties. Decades of research clearly demonstrate that selenium compounds inhibit the growth of malignant cells in diverse experimental model systems. However, the growth-modulating and cytotoxic mechanisms are diverse and far from clear. Lately, a remarkable tumour selective cytotoxicity of selenium compounds has been shown, indicating the potential of selenium in the treatment of cancer. Of particular interest are the redox-active selenium compounds exhibiting cytotoxic potential to tumour cells. These selenium compounds elicit complex patterns of pharmacodynamics and pharmacokinetics, leading to cell death pathways that differ among compounds. Modern oncology often focuses on targeted ligand-based therapeutic strategies that are specific to their molecular targets. These drugs are initially efficient, but the tumour cells often rapidly develop resistance against these drugs. In contrast, certain redox-active selenium compounds induce complex cascades of pro-death signalling at pharmacological concentrations with superior tumour specificity. The target molecules are often the ones that are important for the survival of cancer cells and often implicated in drug resistance. Therefore, the chemotherapeutic applications of selenium offer great possibilities of multi-target attacks on tumour cells. This MiniReview focuses on the tumour-specific cytotoxic effects of selenium, with special emphasis on cascades of cellular events induced by the major groups of pharmacologically active selenium compounds. Furthermore, the great pharmacological potential of selenium in the treatment of resistant cancers is discussed.

  11. Selenium as an antidote in the treatment of mercury intoxication.

    PubMed

    Bjørklund, Geir

    2015-08-01

    Selenium (Se) is an essential trace element for humans. It is found in the enzyme glutathione peroxidase. This enzyme protects the organism against certain types of damage. Some data suggest that Se plays a role in the body's metabolism of mercury (Hg). Selenium has in some studies been found to reduce the toxicity of Hg salts. Selenium and Hg bind in the body to each other. It is not totally clear what impact the amount of Se has in the human body on the metabolism and toxicity of prolonged Hg exposure.

  12. Long-term organic selenium supplementation overcomes the trade-off between immune and antioxidant systems in pacu (Piaractus mesopotamicus).

    PubMed

    Takahashi, Leonardo Susumu; Biller-Takahashi, Jaqueline Dalbello; Mansano, Cleber Fernando Menegasso; Urbinati, Elisabeth Criscuolo; Gimbo, Rodrigo Yukihiro; Saita, Marcos Vinícius

    2017-01-01

    Selenium (Se) is an essential nutrient for antioxidant defenses in fish because of its role in preventing immunosuppression caused by oxidative stress. In this study it was demonstrated the relation between the oxidative stress and immune status after a long Se supplementation period, as a result of the evaluation of immunological, hematological and antioxidant responses, as well as growth performance of pacu fed diets supplemented with different concentrations of organic selenium (0, 0.3, 0.6, 0.9, and 1.8 mg Se-yeast/kg, but the final analyzed selenium concentrations were 0.72, 0.94, 1.15, 1.57 and 2.51 mg/kg, respectively) for 65 days. Dietary Se supplementation at 1.15 mg Se-yeast/kg (analyzed value) restored the production of antioxidant enzymes (glutathione peroxidase (GPx) and glutathione S-transferase (GST)), and consequently allowed the increased of some immunological parameters (leukocyte respiratory burst activity and lysozyme activity), hematological parameters (red blood cell count (RBC), hematocrit (HTC), mean corpuscular volume (MCV), and white blood cell count (WBC)). Se supplementation in pacu diets at 1.15 mg Se-yeast/kg for 65 days improved immune response and antioxidant defenses, suggesting that oxidative stress impairs immune system response to prevent excessive reactive oxygen species in cells and indicating the occurrence of a physiological trade-off between immune and antioxidant systems. Higher Se levels, such as 1.57 mg Se-yeast/kg increased the leukocyte respiratory burst activity, the WBC and thrombocyte counts, the RBC and HTC, and the GST and GPx enzymes. However, 2.51 mg Se-yeast/kg decreased the lysozyme levels, the WBC and thrombocyte counts, the RBC, HTC and MCV, and the GST and GPx enzymes. Those findings are important to future studies because showed the negative effect of oxidative stress on immunity, and may help to prevent any inhibition of the expected immune response after immunomodulators administration and

  13. Strategic Selenium Management: Natural Biofortification of Grazing Livestock with Selenium to Avert Selenium Deficiency and Enhance the Nutritional Value of Food Products.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    : Efficient and effective management of Se deficiency is required to sustain profitability of grazing-based livestock operations. Selenium deficiency increases morbidity and mortality rates, reduces reproduction rates, and reduces yield and quality of marketable products. Therefore, producers must p...

  14. Effects of commercial selenium products on glutathione peroxidase activity and semen quality in stud boars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study was to determine how dietary supplementation of inorganic and organic selenium affects selenium concentration and glutathione peroxidase activity in blood and sperm of sexually mature stud boars. Twenty-four boars of the Large White, Landrace, Pietrain, and Duroc breeds of opt...

  15. Selenium in Pig Nutrition and Reproduction: Boars and Semen Quality—A Review

    PubMed Central

    Surai, Peter F.; Fisinin, Vladimir I.

    2015-01-01

    Selenium plays an important role in boar nutrition via participating in selenoprotein synthesis. It seems likely that selenoproteins are central for antioxidant system regulation in the body. Se-dependent enzyme glutathione peroxidase (GSH-Px) is the most studied selenoprotein in swine production. However, roles of other selenoproteins in boar semen production and maintenance of semen quality also need to be studied. Boar semen is characterised by a high proportion of easily oxidized long chain polyunsaturated fatty acids and requires an effective antioxidant defense. The requirement of swine for selenium varies depending on many environmental and other conditions and, in general, is considered to be 0.15 to 0.30 mg/kg feed. It seems likely that reproducing sows and boars are especially sensitive to Se deficiency, and meeting their requirements is an important challenge for pig nutritionists. In fact, in many countries there are legal limits as to how much Se may be included into the diet and this restricts flexibility in terms of addressing the Se needs of the developing and reproducing swine. The analysis of data of various boar trials with different Se sources indicates that in some cases when background Se levels were low, there were advantages of Se dietary supplementation. It is necessary to take into account that only an optimal Se status of animals is associated with the best antioxidant protection and could have positive effects on boar semen production and its quality. However, in many cases, background Se levels were not determined and therefore, it is difficult to judge if the basic diets were deficient in Se. It can also be suggested that, because of higher efficacy of assimilation from the diet, and possibilities of building Se reserves in the body, organic selenium in the form of selenomethionine (SeMet) provided by a range of products, including Se-Yeast and SeMet preparations is an important source of Se to better meet the needs of modern pig

  16. Effect of dietary selenium and vitamin E on the ultrastructure and ATP concentration of boar spermatozoa, and the efficacy of added sodium selenite in extended semen on sperm motility.

    PubMed

    Marin-Guzman, J; Mahan, D C; Whitmoyer, R

    2000-06-01

    Three experiments evaluated the effects of dietary Se and vitamin E on the ultrastructure of spermatozoa, ATP concentration of spermatozoa, and the effects of adding sodium selenite to semen extenders on subsequent sperm motility. The experiment was a 2 x 2 arrangement of treatments in a randomized complete block design. A total of 10 mature boars were fed from weaning to 18 mo of age diets fortified with two levels of supplemental Se (0 or .5 ppm) or vitamin E (0 or 220 IU/kg diet). The nonfortified diets contained .06 ppm Se and 4.4 IU vitamin E/kg. In Exp. 1, the spermatozoa from all boars were examined by electron microscopy. Vitamin E had no effect on structural abnormalities in the spermatozoa. When the low-Se diet was fed the acrosome or nuclei of the spermatozoa was unaffected, but the mitochondria in the tail midpiece were more oval with wider gaps between organelles. The plasma membrane connection to the tail midpiece was not tightly bound as when boars were fed Se. Immature spermatozoa with cytoplasmic droplets were more numerous when boars were fed the low-Se diet, but the occurrence of midpiece abnormalities occurred in boars fed diets with or without Se or vitamin E. Our results suggest that Se may enhance spermatozoa maturation in the epididymis and may reduce the number of sperm with cytoplasmic droplets. In Exp. 2, the concentration of ATP in the spermatozoa was evaluated in the semen of all treatment boars. When the low-Se diet was fed, ATP concentration was lower (P < .01), whereas vitamin E had no effect on ATP concentration. Experiment 3 investigated the effect of diluting boar semen with a semen extender with sodium selenite added at 0, .3, .6, or .9 ppm Se. Three ejaculates from each boar were used to evaluate these effects on sperm motility to 48 h after dilution. Sperm motility declined (P < .01) when Se was added to the extender, and this decline was exacerbated as the concentration of added Se increased (P < .01). The added Se was

  17. Selenium and endocrine systems.

    PubMed

    Beckett, Geoffrey J; Arthur, John R

    2005-03-01

    The trace element selenium (Se) is capable of exerting multiple actions on endocrine systems by modifying the expression of at least 30 selenoproteins, many of which have clearly defined functions. Well-characterized selenoenzymes are the families of glutathione peroxidases (GPXs), thioredoxin reductases (TRs) and iodothyronine deiodinases (Ds). These selenoenzymes are capable of modifying cell function by acting as antioxidants and modifying redox status and thyroid hormone metabolism. Se is also involved in cell growth, apoptosis and modifying the action of cell signalling systems and transcription factors. During thyroid hormone synthesis GPX1, GPX3 and TR1 are up-regulated, providing the thyrocytes with considerable protection from peroxidative damage. Thyroidal D1 in rats and both D1 and D2 in humans are also up-regulated to increase the production of bioactive 3,5,3'-tri-iodothyronine (T3). In the basal state, GPX3 is secreted into the follicular lumen where it may down-regulate thyroid hormone synthesis by decreasing hydrogen peroxide concentrations. The deiodinases are present in most tissues and provide a mechanism whereby individual tissues may control their exposure to T3. Se is also able to modify the immune response in patients with autoimmune thyroiditis. Low sperm production and poor sperm quality are consistent features of Se-deficient animals. The pivotal link between Se, sperm quality and male fertility is GPX4 since the enzyme is essential to allow the production of the correct architecture of the midpiece of spermatozoa. Se also has insulin-mimetic properties, an effect that is probably brought about by stimulating the tyrosine kinases involved in the insulin signalling cascade. Furthermore, in the diabetic rat, Se not only restores glycaemic control but it also prevents or alleviates the adverse effects that diabetes has on cardiac, renal and platelet function.

  18. Radioprotection by metals: Selenium

    NASA Astrophysics Data System (ADS)

    Weiss, J. F.; Srinivasan, V.; Kumar, K. S.; Landauer, M. R.

    The need exists for compounds that will protect individuals from high-dose acute radiation exposure in space and for agents that might be less protective but less toxic and longer acting. Metals and metal derivatives provide a small degree of radioprotection (dose reduction factor <= 1.2 for animal survival after whole-body irradiation). Emphasis is placed here on the radioprotective potential of selenium (Se). Both the inorganic salt, sodium selenite, and the organic Se compound, selenomethionine, enhance the survival of irradiated mice (60Co, 0.2 Gy/min) when injected IP either before (-24 hr and -1 hr) or shortly after (+15 min) radiation exposure. When administered at equitoxic doses (one-fourth LD10; selenomethionine = 4.0 mg/kg Se, sodium selenite = 0.8 mg/kg Se), both drugs enhanced the 30-day survival of mice irradiated at 9 Gy. Survival after 10-Gy exposure was significantly increased only after selenomethionine treatment. An advantage of selenomethionine is lower lethal and behavioral toxicity (locomotor activity depression) compared to sodium selenite, when they are administered at equivalent doses of Se. Sodium selenite administered in combination with WR-2721, S-2-(3-aminopropylamino)ethylphosphorothioic acid, enhances the radioprotective effect and reduces the lethal toxicity, but not the behavioral toxicity, of WR-2721. Other studies on radioprotection and protection against chemical carcinogens by different forms of Se are reviewed. As additional animal data and results from human chemoprevention trials become available, consideration also can be given to prolonged administration of Se compounds for protection against long-term radiation effects in space.

  19. Intestinal nematodes affect selenium bioaccumulation, oxidative stress biomarkers, and health parameters in juvenile rainbow trout (Oncorhynchus mykiss).

    PubMed

    Hursky, Olesya; Pietrock, Michael

    2015-02-17

    In environmental studies, parasites are often seen as a product of enhanced host susceptibility due to exposure to one or several stressors, whereas potential consequences of infections on host responses are often overlooked. Therefore, the present study focused on effects of parasitism on bioaccumulation of selenium (Se) in rainbow trout (Oncorhynchus mykiss). Joint effects of biological (parasite) and chemical (Se) stressors on biomarkers of oxidative stress (glutathione-S-transferase (GST), superoxide dismutase (SOD)), and fish health (condition factor (K), hepatosomatic index (HSI), gross energy) were also examined. Fish of the control group received uncontaminated food, while test fish, either experimentally infected with the nematode Raphidascaris acus or not, were exposed to dietary selenomethionine (Se-Met) at an environmentally relevant dose over 7 weeks. Selenium bioaccumulation by the parasite was low relative to its host, and parasitized trout showed slowed Se accumulation in the muscle as compared to uninfected fish. Furthermore, GST and SOD activities of trout exposed to both Se-Met and parasites were generally significantly lower than in fish exposed to Se-Met alone. Gross energy concentrations, but not K or HSI, were reduced in fish exposed to both Se-Met and R. acus. Together the experiment strongly calls for consideration of parasites when interpreting effects of pollutants on aquatic organisms in field investigations.

  20. The role of selenium in inflammation and immunity: from molecular mechanisms to therapeutic opportunities.

    PubMed

    Huang, Zhi; Rose, Aaron H; Hoffmann, Peter R

    2012-04-01

    Dietary selenium (]Se), mainly through its incorporation into selenoproteins, plays an important role in inflammation and immunity. Adequate levels of Se are important for initiating immunity, but they are also involved in regulating excessive immune responses and chronic inflammation. Evidence has emerged regarding roles for individual selenoproteins in regulating inflammation and immunity, and this has provided important insight into mechanisms by which Se influences these processes. Se deficiency has long been recognized to negatively impact immune cells during activation, differentiation, and proliferation. This is related to increased oxidative stress, but additional functions such as protein folding and calcium flux may also be impaired in immune cells under Se deficient conditions. Supplementing diets with above-adequate levels of Se can also impinge on immune cell function, with some types of inflammation and immunity particularly affected and sexually dimorphic effects of Se levels in some cases. In this comprehensive article, the roles of Se and individual selenoproteins in regulating immune cell signaling and function are discussed. Particular emphasis is given to how Se and selenoproteins are linked to redox signaling, oxidative burst, calcium flux, and the subsequent effector functions of immune cells. Data obtained from cell culture and animal models are reviewed and compared with those involving human physiology and pathophysiology, including the effects of Se levels on inflammatory or immune-related diseases including anti-viral immunity, autoimmunity, sepsis, allergic asthma, and chronic inflammatory disorders. Finally, the benefits and potential adverse effects of intervention with Se supplementation for various inflammatory or immune disorders are discussed.

  1. Urinary selenium excretion in patients with cervical uterine cancer.

    PubMed

    Navarrete, M; Gaudry, A; Revel, G; Martínez, T; Cabrera, L

    2001-02-01

    In this work, we report on a relationship between urinary selenium and the development of cervical uterine cancer. A simple chemical method was developed to concentrate trace amounts of selenium from relatively large urine samples by use of small activated carbon filters. When these filters are irradiated with thermal neutrons, selenium can be determined either by 77mSe (t1/2 = 17.5 s) or 75Se (t1/2 = 120 d). In this article, we report the results for 82 urine samples from women with cervical uterine cancer in several stages of development and from healthy controls. These results show a statistically significant increase of selenium excretion in cancer patients as compared to controls. Urinary selenium excretion is highest for patients in the intermediate stages of the disease.

  2. Effect of exogenous selenium on nicotine induced hyperlipidemia in rats.

    PubMed

    Sreekala, S; Indira, M

    2008-01-01

    The effect of two different doses (1 microg Se/Kg and 50 microg Se/Kg Body wt) of selenium on nicotine induced hyperlipidemia was investigated in rats. Results revealed that nicotine intake caused an increase in concentration of cholesterol, triglycerides, free fatty acids, phospholipids and low density lipoprotein compared to control group. Coadministration of selenium along with nicotine reduced the levels of lipids compared to nicotine group. This reduction was due to reduction in the biosynthesis of lipids as evidenced by the reduced activity of HMGCoA reductase and lipogenic enzymes. Nicotine intake also reduced the absorption of selenium in the intestine. Histopathological studies revealed that selenium at a dose of 1 microg was more effective in reducing lipid levels and higher dose of selenium was toxic.

  3. Removal of arsenic and selenium from wastewaters - a review

    SciTech Connect

    Mirza, A.H.; Ramachandran, V.

    1996-12-31

    Arsenic and selenium are found in low quantities together with other metals in several nonferrous metallurgical process streams such as scrubber blowdown solution, acid plant wastewater, gas cleaning plant water, etc. Normally, the other metals in these streams are present as cations and can be precipitated by conventional lime treatment and sulfide polishing. However, arsenic and selenium are invariably present as anions, AsO{sub 3}{sup 3-} and AsO{sub 4}{sup 3-} in the case of arsenic and SeO{sub 3}{sup 2-} and SeO{sub 4}{sup 2-} for selenium. Conventional lime treatment removes most of the arsenic, but it does not remove selenium. The present paper reviews the processes and technologies developed to date on the removal of arsenic and selenium from metallurgical process streams. 58 refs., 4 figs., 1 tab.

  4. Selenium quantum dots: Preparation, structure, and properties

    NASA Astrophysics Data System (ADS)

    Qian, Fuli; Li, Xueming; Tang, Libin; Lai, Sin Ki; Lu, Chaoyu; Lau, Shu Ping

    2017-01-01

    An interesting class of low-dimensional nanomaterials, namely, selenium quantum dots (SeQDs), which are composed of nano-sized selenium particles, is reported in this study. The SeQDs possess a hexagonal crystal structure. They can be synthesized in large quantity by ultrasound liquid-phase exfoliation using NbSe2 powders as the source material and N-Methyl-2-pyrrolidone (NMP) as the dispersant. During sonication, the Nb-Se bonds dissociate; the SeQDs are formed, while niobium is separated by centrifugation. The SeQDs have a narrow diameter distribution from 1.9 to 4.6 nm and can be dispersed with high stability in NMP without the need for passivating agents. They exhibit photoluminescence properties that are expected to find useful applications in bioimaging, optoelectronics, as well as nanocomposites.

  5. Selenium in blood, semen, seminal plasma and spermatozoa of stallions and its relationship to sperm quality.

    PubMed

    Bertelsmann, H; Keppler, S; Höltershinken, M; Bollwein, H; Behne, D; Alber, D; Bukalis, G; Kyriakopoulos, A; Sieme, H

    2010-01-01

    The essential trace element selenium is indispensable for male fertility in mammals. Until now, little data existed regarding the relationship between selenium and sperm quality in the stallion. Selenium, or selenium-dependent glutathione peroxidase activity, was determined in red blood cells, semen, seminal plasma and spermatozoa, and the percentages of spermatozoa with progressive motility (PMS), intact membranes (PMI), altered (positive) acrosomal status (PAS) and detectable DNA damage, determined by the sperm chromatin structure assay, were evaluated in 41 healthy stallions (three samples each). The pregnancy rate per oestrus cycle (PRC) served as an estimation of fertility. An adverse effect on stallion fertility caused by low dietary selenium intake was excluded, as all stallions had sufficient selenium levels in their blood. Interestingly, no significant correlations (P > 0.05) between the selenium level in blood and the selenium level in seminal plasma or spermatozoa were found, suggesting that the selenium level in blood is no indicator of an adequate selenium supply for spermatogenesis. The selenium level in spermatozoa (nmol billion(-1)) was correlated with PMI, PMS and PAS (r = 0.40, r = 0.31 and r = -0.42, respectively; P selenium concentration in spermatozoa (nmol g(-1)) was correlated with PRC (r = 0.40, P < 0.03). The results of the present study show that the determination of an adequate selenium status for the male equine reproduction requires the analysis of selenium in spermatozoa. Furthermore, selenium is associated with improved sperm quality and fertility in the stallion.

  6. Effects of copper and selenium on beta-carotene conversion and bone strength in rats

    SciTech Connect

    Seaborn, C.D.; Kiangura, R.K.; Brusewitz, G.H.; Stoecker, B.J. )

    1991-03-15

    Thirty-four weanling male rats were depleted of vitamin A and selenium for 5 wk, randomly assigned to groups in a 2 {times} 2 factorial design, and fed a torula yeast diet without vitamin A for 4 wks. The diets contained either 20 ppb Se ({minus}Se) or 510 ppb Se as sodium selenate (+Se) and 1 ppm Cu ({minus}Cu) or 6 ppm Cu (+Cu). Rats were fed 100 ug of beta-carotene daily. Force to break tibias was measured with a three point bending fixture in an Instron universal testing machine. Bone weights and kg force to break bones were increased by +Cu diets. Animals fed the {minus}Cu diets had depressed body and organ weights. An interaction between Cu and Se affected hepatic and kidney vitamin A after feeding carotene. Total hepatic vitamin A was 26.8, 44.2, 45.1 and 32.5 ug for the {minus}Cu{minus}Se, {minus}Cu+Se, +Cu{minus}Se, and +Cu+Se groups, respectively. Total kidney vitamin A was 8.7, 3.9, 7.1 and 13.5 ug for the same groups. Beta-carotene dioxygenase activity was not significantly affected by treatment. The findings indicate that dietary Cu and Se affect the metabolism of vitamin A.

  7. Effects of selenium-enriched probiotics on heat shock protein mRNA levels in piglet under heat stress conditions.

    PubMed

    Gan, Fang; Ren, Fei; Chen, Xingxiang; Lv, Chenhui; Pan, Cuiling; Ye, Gengping; Shi, Jun; Shi, Xiuli; Zhou, Hong; Shituleni, Shituleni Andreas; Huang, Kehe

    2013-03-13

    The effects of selenium-enriched probiotics (SP) on tissue selenium (Se) deposition, glutathione peroxidase-1 (GPx1) activity and mRNA level, and heat shock protein (Hsp) mRNA levels of piglets under heat stress conditions were investigated. A total of 48 crossbred ([Landrace × Yorkshire] × Duroc) piglets were randomly divided into 4 groups and fed a basal diet (Con, 0.16 mg Se/kg) or basal diets with added probiotics (P, 0.16 mg Se/kg), sodium selenite (SS, 0.46 mg Se/kg), or SP (0.46 mg Se/kg), respectively, for 42 days. Three piglets were randomly selected from each group for blood sample collection at days 0, 14, 28, and 42 and for liver, kidney, and spleen sample collection at day 42. The results showed that P, SS, and SP could significantly down-regulate the average mRNA levels of Hsp70 (17.3, 23.7, and 40.1%) and Hsp27 (22.4, 24.4, and 44.7%) of the tissues, respectively (P < 0.05), whereas SS and SP could significantly elevate Se concentration, GPx1 activity and mRNA level (P < 0.05). The maximal effects of these parameters were observed in SP. It was concluded that SP is a feasible dietary supplementation of piglets under heat stress conditions during the summer season.

  8. Assessment of serum selenium levels in 2-month-old sucking calves using total reflection X-ray fluorescence technique

    NASA Astrophysics Data System (ADS)

    Buoso, M. C.; Ceccato, D.; Moschini, G.; Bernardini, D.; Testoni, S.; Torboli, A.; Valdes, M.

    2001-11-01

    The assessment of selenium status of livestock plays an important role in the production of medicine since low serum Se levels influence disease resistance in ruminants. It has been proved that Se deficiency may cause muscular dystrophy, cardiomyopathy and even death. Serum level has been widely used to evaluate the Se short-term status in animals since there is a good association between serum Se level and the dietary intake of the element over a wide range. The purpose of this work was to determine the Se serum concentration in a population of 78 sucking 2-month-old calves, in order to corroborate a clinical diagnosis of severe deficiency status. The samples were analyzed by total reflection X-ray fluorescence (TXRF) at the ITAL STRUCTURES Research Laboratory. The results obtained from the serum samples presented Se concentrations varying from 10 to 66 ng/ml. The comparison between the obtained values and the expected serum selenium values (60-80 ng/ml), confirmed a mild to severe deficiency status in the investigated population.

  9. Rumen microorganisms decrease bioavailability of inorganic selenium supplements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite the availaility of selenium (Se)-enriched trace mineral supplements, we have observed low Se status in cattle and sheep offered traditional inorganic Se supplements. Reasons for this may include inadequate intake or low bioavailability of inorganic Se sources. The objective of this study w...

  10. Selenium and human health.

    PubMed

    Rayman, Margaret P

    2012-03-31

    Selenium is incorporated into selenoproteins that have a wide range of pleiotropic effects, ranging from antioxidant and anti-inflammatory effects to the production of active thyroid hormone. In the past 10 years, the discovery of disease-associated polymorphisms in selenoprotein genes has drawn attention to the relevance of selenoproteins to health. Low selenium status has been associated with increased risk of mortality, poor immune function, and cognitive decline. Higher selenium status or selenium supplementation has antiviral effects, is essential for successful male and female reproduction, and reduces the risk of autoimmune thyroid disease. Prospective studies have generally shown some benefit of higher selenium status on the risk of prostate, lung, colorectal, and bladder cancers, but findings from trials have been mixed, which probably emphasises the fact that supplementation will confer benefit only if intake of a nutrient is inadequate. Supplementation of people who already have adequate intake with additional selenium might increase their risk of type-2 diabetes. The crucial factor that needs to be emphasised with regard to the health effects of selenium is the inextricable U-shaped link with status; whereas additional selenium intake may benefit people with low status, those with adequate-to-high status might be affected adversely and should not take selenium supplements.

  11. An accurate determination of the surface energy of solid selenium

    NASA Astrophysics Data System (ADS)

    Guisbiers, G.; Arscott, S.; Snyders, R.

    2012-12-01

    Selenium is currently a key element for developing nano and micro-technologies. Nevertheless, the surface energy of solid seleniumSe) reported in the literature is still questionable. In this work, we have measured γSe = 0.291 ± 0.025 J/m2 at 293 K using the sessile drop technique with different probe liquids, namely ethylene glycol, de-ionized water, mercury, and gallium. This value is in excellent agreement with theoretical predictions.

  12. Abnormality of epiphyseal plate induced by selenium deficiency diet in two generation DA rats.

    PubMed

    Min, Zixin; Zhao, Wenxiang; Zhong, Nannan; Guo, Yuanxu; Sun, Mengyao; Wang, Quancheng; Zhang, Rui; Yan, Jidong; Tian, Lifang; Zhang, Fujun; Han, Yan; Ning, Qilan; Meng, Liesu; Sun, Jian; Lu, Shemin

    2015-08-01

    This study aimed to observe the effects of Se deficiency on epiphyseal plates of two generation DA rats fed with artificial total synthetic low Se diet. All F0 and F1 DA rats were fed with synthetic low Se diet (SeD group) and low Se diet supplied with Se (SeS group). The levels of selenium and enzyme activities of GPx were detected in plasma of the rats. General growth of bone and articular cartilage was measured macroscopically and microscopically. The epiphyseal plate of femur heads or tibia were obtained to histological and immunohistochemical examinations. The cartilage from left knee joints and femur heads was used to detect the gene expression of collagens, ADAMTSs and several selenoproteins by RT-qPCR. Two generation SeD rats showed Se insufficiency status. The thicknesses of the femur and tibial epiphyseal plates in both F0 and F1 SeD rats were significantly less than that of SeS rats. In F1 generation, SeD rats showed much fewer proliferative chondrocyte layers than SeS ones. Importantly, two generation SeD rats both showed significantly more serious pathological changes of epiphyseal plates. In two generation rats, gene expressions of COL II, GPx1 and GPx4 were significantly down-regulated in SeD rats than SeS ones; meanwhile ADAMTS-4 showed an up-regulated expression in cartilage. Dietary Se deficiency can apparently cause epiphyseal plate lesion and decrease cartilage type II collagen production and GPx1 activity in two generation DA rats fed with the artificial total synthesis low Se diet.

  13. Effects of selenium status and supplementary seleno-chemical sources on mouse T-cell mitogenesis.

    PubMed

    Ueno, Hitoshi; Hasegawa, Gohki; Ido, Ryoko; Okuno, Tomofumi; Nakamuro, Katsuhiko

    2008-01-01

    Although selenium is thought to be essential for various immune responses, the excess supplementation may have an adverse effect on certain immunological functions. The present study was designed to determine the effective chemical forms of selenium and their optimal levels on T-cell mitogenesis with splenic cells from mice given a selenium-deficient diet for 8 weeks to avoid effects of cellular selenium sources. Although selenium in tissues, except for spleen and thymus, was almost depleted by feeding selenium-deficient diet, the lymphoid organs still contained low levels of selenium. Both activities of cellular glutathione peroxidase (cGPx) and thioredoxin reductase (TR) in liver and splenic cells showed a tendency to decrease by selenium deficiency. However, splenic cells were tolerant against decrease of the selenoenzyme activities, and TR was also more tolerant than cGPx. T-cell proliferation of the selenium-insufficient splenic cells induced by concanavalin A was increased by addition of Na2SeO3, Na2SeO4, Na2Se, seleno-DL-cystine, seleno-L-methionine and selenocystamine. Their promoting action was observed at levels lower than 0.1 micromol/L and was completely suppressed at the highest concentration (1 micromol/L), except for selenocystamine. Na2SeO3 was one of the efficient selenocompounds for the mitogenesis, which was concomitant with the significant induction of cGPx and TR. However, recovery of cGPx activity in the selenium-insufficient cells by supplementary Na2SeO3 was only partial,while TR activity was readily recovered from selenium deficiency. These results therefore indicate that only low levels of selenium is essential for T-cell mitogenesis even in selenium-insufficient splenic cells, and TR, which is readily recovered by Na2SeO3, may be the critical enzyme.

  14. Iodine and Selenium Intakes of Postmenopausal Women in New Zealand.

    PubMed

    Brough, Louise; Gunn, Caroline A; Weber, Janet L; Coad, Jane; Jin, Ying; Thomson, Jasmine S; Mauze, Mathilde; Kruger, Marlena C

    2017-03-09

    Iodine and selenium are required for thyroid function. This study investigated iodine and selenium intakes in healthy, women aged 50-70 years (n = 97) from three cities in the North Island of New Zealand, after mandatory fortification of bread with iodised salt. Iodine and selenium concentrations were determined in 24-h urine samples; daily intakes were extrapolated from amounts in urine (90% and 55% of daily intake, respectively). Three day diet diaries (3DDD) also estimated selenium and iodine (excluding iodised salt) intake. Median urinary iodine concentration (UIC) was 57 (41, 78) µg/L, indicating mild iodine deficiency. Estimated median iodine intake based on urine was 138 (100, 172) µg/day, below Recommended Dietary Intake (RDI) (150 µg/day) with 25% below Estimated Average Requirement (EAR) (100 µg/day). Estimated median selenium intake was 50 (36, 71) µg/day based on urine and 45 (36, 68) µg/day using 3DDD, below RDI (60 µg/day) with 49%-55% below EAR (50 µg/day). Median bread intakes were low at 1.8 (1.1, 2.7) serves/day; 25% consumed ≤1 serve/day. Although population iodine intakes improved following mandatory fortification, some had low intakes. Selenium intakes remain low. Further research should investigate thyroid function of low consumers of iodine fortified bread and/or selenium in New Zealand.

  15. Iodine and Selenium Intakes of Postmenopausal Women in New Zealand

    PubMed Central

    Brough, Louise; Gunn, Caroline A.; Weber, Janet L.; Coad, Jane; Jin, Ying; Thomson, Jasmine S.; Mauze, Mathilde; Kruger, Marlena C.

    2017-01-01

    Iodine and selenium are required for thyroid function. This study investigated iodine and selenium intakes in healthy, women aged 50–70 years (n = 97) from three cities in the North Island of New Zealand, after mandatory fortification of bread with iodised salt. Iodine and selenium concentrations were determined in 24-h urine samples; daily intakes were extrapolated from amounts in urine (90% and 55% of daily intake, respectively). Three day diet diaries (3DDD) also estimated selenium and iodine (excluding iodised salt) intake. Median urinary iodine concentration (UIC) was 57 (41, 78) µg/L, indicating mild iodine deficiency. Estimated median iodine intake based on urine was 138 (100, 172) µg/day, below Recommended Dietary Intake (RDI) (150 µg/day) with 25% below Estimated Average Requirement (EAR) (100 µg/day). Estimated median selenium intake was 50 (36, 71) µg/day based on urine and 45 (36, 68) µg/day using 3DDD, below RDI (60 µg/day) with 49%–55% below EAR (50 µg/day). Median bread intakes were low at 1.8 (1.1, 2.7) serves/day; 25% consumed ≤1 serve/day. Although population iodine intakes improved following mandatory fortification, some had low intakes. Selenium intakes remain low. Further research should investigate thyroid function of low consumers of iodine fortified bread and/or selenium in New Zealand. PMID:28282932

  16. JV Task 96 - Phase 2 - Investigating the Importance of the Mercury-Selenium Interaction

    SciTech Connect

    Nicholas Ralston; Laura Raymond

    2008-03-01

    In order to improve the understanding of the mercury issue, it is vital to study mercury's effects on selenium physiology. While mercury present in the environment or food sources may pose health risks, the protective effects of selenium have not been adequately considered in establishing regulatory policy. Numerous studies report that vulnerability to mercury toxicity is inversely proportional to selenium status or level. However, selenium status has not been considered in the development of the reference dosage levels for mercury exposure. Experimental animals fed low-selenium diets are far more vulnerable to mercury toxicity than animals fed normal selenium, and animals fed selenium-rich diets are even more resistant. Selenium-dependent enzymes in brain and endocrine tissues can be impaired by excessive mercury exposure, apparently because mercury has an extremely high binding affinity for selenium. When selenium becomes bound to mercury, it is unable to participate in the metabolic cycling of selenoprotein synthesis. Because of mercury-dependent impairments of selenoprotein synthesis, various antioxidant and regulatory functions in brain biochemistry are compromised. This report details a 2-year multiclient-funded research program designed to examine the interactions between mercury and selenium in animal models. The studies explored the effects of dietary intakes of toxic amounts of methylmercury and the protective effects of the normal dietary range of selenium in counteracting mercury toxicity. This study finds that the amounts of selenium present in ocean fish are sufficient to protect against far larger quantities of methylmercury than those present in typical seafoods. Toxic effects of methylmercury exposure were not directly proportional to mercury concentrations in blood, brain, or any other tissues. Instead, mercury toxicity was proportional to molar ratios of mercury relative to selenium. In order to accurately assess risk associated with

  17. Chapter 6: Selenium Toxicity to Aquatic Organisms

    EPA Science Inventory

    This chapter addresses the characteristics and nature of organic selenium (Se) toxicity to aquatic organisms, based on the most current state of scientific knowledge. As such, the information contained in this chapter relates to the 'toxicity assessment' phase of aquatic ecologi...

  18. Choice feeding of selenium-deficient laying hens affects diet selection, selenium intake and body weight.

    PubMed

    Zuberbuehler, Christine A; Messikommer, Ruth E; Wenk, Caspar

    2002-11-01

    Inadequate selenium (Se) supply often in combination with low vitamin E status causes deficiency symptoms in many species. It is likely that a vague discomfort or sickness is perceived before clear deficiency signs become apparent. We investigated whether Se-deficient hens reduce their Se deficit by selecting a diet containing more selenium when offered two diets with different Se concentrations. A Low-Se diet (0.07 mg Se/kg) was supplemented with Se-enriched yeast (Sel-Plex 50) to produce Medium-Se (0.20 mg Se/kg) and High-Se (1.50 mg Se/kg) diets. Each of two consecutive study parts (I and II) with the same hens and treatments began with a 6-wk baseline period (Medium-Se diet), subsequently followed a 9-wk depletion period (Low-Se diet or Medium-Se diet), then a 6-wk choice feeding period in which two diets with different Se concentrations (Low-Se and Medium-Se, Medium-Se and High-Se, or Low-Se and High-Se) were offered. A control group received the Medium-Se diet throughout the study. Daily Se intake, calculated from daily feed intake, followed similar patterns in both parts of the study, but Se-deficient hens preferred (P < 0.05) the High-Se diet to the Low-Se diet during the first 3 wk of choice feeding only in part I. We conclude that young Se-deficient laying hens reduce their Se deficit if they have a choice between a Low-Se and a High-Se diet by preferentially selecting the High-Se diet, possibly based on learned place preference and/or learned taste aversion to the Low-Se diet, presumably in response to discomfort due to Se-deficiency.

  19. Dietary CdSe/ZnS quantum dot exposure in estuarine fish: bioavailability, oxidative stress responses, reproduction, and maternal transfer.

    PubMed

    Blickley, T Michelle; Matson, Cole W; Vreeland, Wyatt N; Rittschof, Daniel; Di Giulio, Richard T; McClellan-Green, Patricia D

    2014-03-01

    Continued development, use, and disposal of quantum dots (QDs) ensure their entrance into aquatic environments where they could pose a risk to biological organisms as whole nanoparticles or as degraded metal constituents. Reproductive Fundulus heteroclitus were fed a control diet with lecithin, diets containing 1 or 10 μg of lecithin-encapsulated CdSe/ZnS QD/day, or a diet containing 5.9 μg CdCl2/day for 85 days. Cadmium concentrations in liver, intestine, and eggs were quantified with inductively coupled plasma mass spectrometry. In fish fed 10 μg QD/day, QDs or their degradation products traversed the intestinal epithelia and accumulated in the liver. Less than 0.01% of the QD's cadmium was retained in the liver or intestinal tissues. This compares to 0.9% and 0.5% of the cadmium in the intestine and liver, respectively of fish fed a CdCl2 diet. Cadmium was also detected in the eggs from parents fed 10 μg QD/day. No significant changes in hepatic total glutathione, lipid peroxidation, or expression of genes involved in metal metabolism or oxidative stress were observed. While QDs in the diet are minimally bioavailable, unusual levels of vitellogenin transcription in male fish as well as declining fecundity require further investigation to determine if endocrine disruption is of environmental concern.

  20. Effects of boron and selenium on mallard reproduction and duckling growth and survival

    USGS Publications Warehouse

    Stanley, T.R.; Smith, G.J.; Hoffman, D.J.; Heinz, G.H.; Rosscoe, R.

    1996-01-01

    Boron (B) and selenium (Se) sometimes occur together in high concentrations in the environment and can accumulate in plants and invertebrates consumed by waterfowl. One hundred twenty-six pairs of breeding mallards (Anas platyrhynchos) were fed diets supplemented with B (as boric acid) at 0, 450, or 900 ppm, in combination with Se (as seleno-DL-methionine) at 0, 3.5, or 7 ppm, in a replicated factorial experiment. Ducklings produced received the same treatment combination as their parents. Boron and Se accumulated in adult liver, egg, and duckling liver. In adults, B and Se caused weight loss, and B decreased hemoglobin concentration, egg weight, and egg fertility. Both B and Se reduced hatching success and duckling weight, and B reduced duckling growth and duckling production, and caused several alterations in duckling liver biochemistry. Duckling survival was not reduced by B or Se, and neither B nor Se had histopathologic effects on adult or duckling liver, kidney, or spleen. There was little evidence of interaction between B and Se. This study demonstrated that B and Se, in the chemical forms and at the dietary levels administered in this study, can adversely affect mallard reproduction and duckling growth.

  1. Evaluation of selenium species in selenium-enriched pakchoi (Brassica chinensis Jusl var parachinensis (Bailey) Tsen & Lee) using mixed ion-pair reversed phase HPLC-ICP-MS.

    PubMed

    Thosaikham, Witphon; Jitmanee, Kritsana; Sittipout, Rossukon; Maneetong, Sarunya; Chantiratikul, Anut; Chantiratikul, Piyanete

    2014-02-15

    HPLC-ICP-MS based on ion-paired reversed phase chromatography for the selenium speciation using the mixture of 1-butanesulfonic acid (BA) and trifluoroacetic acid (TFA) as the mixed ion-pairing reagents was developed and applied to selenium-enriched pakchoi (Brassica chinensis Jusl var parachinensis (Bailey) Tsen & Lee). Several conditions of ion-paired reversed phase HPLC-ICP-MS, such as pH of the mobile phase, concentration of ion pairing reagents, types and length of analytical column, and flow rate of the mobile phase, were optimised for five selenium species; selenate (Se(VI)), Selenite (se(IV)), selenocysteine (SeC), Se-methylselenocysteine (SeMC) and selenomethionine (SeM). The results showed that the optimum conditions for pH, BA and TFA condition, type of separating column and flow rate, were 4.5, 8mM, 4mM, C18 (250 mm length × 4.6mm I.D) and 1.2 mL min(-1), respectively. These conditions archived separation of the organic selenium species. The limits of detection (LOD) and quantitation (LOQ) of each selenium species were lower than 5 and 16 ng Se mL(-1), respectively. Furthermore, the recoveries of most selenium species were good, except for SeC. In this research, selenium-enriched pakchoi was cultivated by supplementing inorganic selenium from selenate into sand. The result showed that inorganic selenium, SeMC, SeM and several unknown species were found in selenium-enriched pakchoi sprouts by using the proposed method. Thereby, the biotransformation of selenate in pakchoi was similar to other Brassicaceae plants such as kale and broccoli.

  2. Redox-Active Selenium Compounds—From Toxicity and Cell Death to Cancer Treatment

    PubMed Central

    Misra, Sougat; Boylan, Mallory; Selvam, Arun; Spallholz, Julian E.; Björnstedt, Mikael

    2015-01-01

    Selenium is generally known as an antioxidant due to its presence in selenoproteins as selenocysteine, but it is also toxic. The toxic effects of selenium are, however, strictly concentration and chemical species dependent. One class of selenium compounds is a potent inhibitor of cell growth with remarkable tumor specificity. These redox active compounds are pro-oxidative and highly cytotoxic to tumor cells and are promising candidates to be used in chemotherapy against cancer. Herein we elaborate upon the major forms of dietary selenium compounds, their metabolic pathways, and their antioxidant and pro-oxidant potentials with emphasis on cytotoxic mechanisms. Relative cytotoxicity of inorganic selenite and organic selenocystine compounds to different cancer cells are presented as evidence to our perspective. Furthermore, new novel classes of selenium compounds specifically designed to target tumor cells are presented and the potential of selenium in modern oncology is extensively discussed. PMID:25984742

  3. Effect of chemical form of selenium on tissue glutathione peroxidase activity in developing rats

    NASA Technical Reports Server (NTRS)

    Lane, Helen W.; Strength, Ralph; Johnson, Janet; White, Marguerite T.

    1991-01-01

    The hypothesis that the stage of development of rats may affect the availability of various forms of selenium for the activity of glutathione peroxidase (GSHPx) in the rat was experimentally investigated. One experiment evaluated the availability of selenium as selenite or selenomethionine for GSPHx activity during three developmental states in rats: fetus and 7-day old and 14-day old nursing pups. In all tissues studied, GSHPx activity was highest in the 14-day-old pups whose dams were in the selenomethionine group. Rat pups given intraperitoneal selenite had higher liver and kidney GSHPx activity than pups given the same amount of selenium as intraperitoneal selenomethionine. In a second experiment, all dams were fed the same basal diet and pups were weaned to diets containing one of two levels of selenium and one of three forms of selenium (selenite, selenomethionine, or selenocystine). The results also supported the hypothesis these dietary forms of selenium are differentially available for GSHPx activity.

  4. Correlation of mercury and selenium in the human kidney.

    PubMed

    Drasch, G; Wanghofer, E; Roider, G; Strobach, S

    1996-12-01

    The total mercury (Hg) and selenium (Se) concentrations were determined in kidney cortex samples of 195 deceased, non-occupationally burdened individuals. Mercury was determined by means of Cold-vapour Atomic Absorption Spectrometry (CV-AAS) and selenium by Graphite-Furnace Atomic Absorption Spectrometry (GF-AAS). The molar Se/Hg ratio is high (up to (a) 300) in cases with relatively low mercury concentrations [Hg]. The ratio decreases with increasing [Hg]. At [Hg] of 700-1000 ng/g it reaches unity, where it remains constant even at larger [Hg]. Since in vitro mercury and selenium form relatively stable adducts, our results suggest the formation of a 1:1 Hg-Se compound that may explain mercury detoxification by selenium. This effect also results in the trapping of available selenium by mercury, too. Decreasing the reserve of free (i.e. not Hg-bound) selenium. The effect of this decrease of free selenium is under further investigation.

  5. Metabolism of manganese, iron, copper, and selenium in calves

    SciTech Connect

    Ho, S.Y.

    1981-01-01

    Sixteen male Holstein calves were used to study manganese and iron metabolism. The calves were fed one of the following diets for 18 days: control, control + iron, control + manganese, and control + iron and manganese. All calves were dosed orally with manganese-54. Tissue concentrations of manganese, iron and manganese-54 were determined. Small intestinal iron was lower in calves fed the high manganese diet than in controls. Tissue manganese-54 was lower in calves fed a high manganese diet. Fecal manganese content increased in calves fed both high manganese and high manganese-high iron diets. Serum total iron was not affected by the dietary treatments. To study the effects of high dietary levels of copper and selenium on the intracellular distributions of these two elements in liver and kidney cytosol, calves were fed one of four diets for 15 days. These were 0 and 100 ppM supplemental copper and 0 and 1 ppM added selenium. The control diet containing 0.1 ppM of selenium and 15 ppM of copper. All calves were orally dosed 48 hrs prior to sacrifice with selenium-75. A high copper diet increased copper concentrations in all intracellular liver fractions and most kidney fractions. Only the effects in the liver were significant. Less copper was found in the mitochondria fractions in liver and kidney of calves fed a high selenium diet. Three major copper-binding protein peaks were separated from the soluble fractions of calf liver and kidney. Peak 1 appeared to be the major copper-binding protein in liver and kidney cytosol of copper-loaded animals. Added selenium alone or in combination with copper accentuated the copper accumulation in this peak. Most of selenium-75 was recovered in the same peak as the copper. The results of this experiment indicated that the large molecular proteins in liver and kidney cytosol of calves play an important role in copper and selenium-75 metabolism. (ERB)

  6. Epigenetic effects of selenium and their implications for health.

    PubMed

    Speckmann, Bodo; Grune, Tilman

    2015-01-01

    Alterations of epigenetic marks are linked to normal development and cellular differentiation as well as to the progression of common chronic diseases. The plasticity of these marks provides potential for disease therapies and prevention strategies. Macro- and micro-nutrients have been shown to modulate disease risk in part via effects on the epigenome. The essential micronutrient selenium affects human health outcomes, e.g., cancers, cardiovascular and autoimmune diseases, via selenoproteins and through a range of biologically active dietary selenocompounds and metabolism products thereof. This review provides an assessment of the current literature regarding epigenetic effects of dietary and synthetic selenocompounds, which include the modulation of marks and editors of epigenetic information and interference with one-carbon metabolism, which provides the methyl donor for DNA methylation. The relevance of a selenium-epigenome interaction for human health is discussed, and we also indicate where future studies will be helpful to gain a deeper understanding of epigenetic effects elicited by selenium.

  7. Se metallomics during lactic fermentation of Se-enriched yogurt.

    PubMed

    Palomo, María; Gutiérrez, Ana M; Pérez-Conde, M Concepción; Cámara, Carmen; Madrid, Yolanda

    2014-12-01

    Selenium biotransformation by lactic acid bacteria during the preparation of Se-enriched yogurt was evaluated. The study focused on the distribution of selenium in the aqueous soluble protein fraction and the detection of selenoamino acids. Screening of selenium in Tris-buffer-urea soluble fraction was carried out by sodium dodecyl sulphate polyacrylamide gel electrophoresis after pre-fractionating with asymmetric field flow fractionation using inductively coupled plasma-mass spectrometry as the detector. Selenium-containing fractions were identified by peptide mapping using nano LC-ESI/LTQMS. Proteins such as thioredoxin, glutaredoxin, albumin, β-lactoglobulin, and lactoperoxidase were identified in the selenium-containing fraction. All these proteins were detected in both the control and the selenium-enriched yogurt except chaperones, which were only detected in the control samples. Chaperones are heat-shock proteins expressed in response to elevated temperature or other cellular stresses. Selenium may have an effect on chaperones expression in Lactobacillus. For the amino acids analysis, selenocysteine was the primary seleno-containing species.

  8. Prostate cancer risk and DNA damage: translational significance of selenium supplementation in a canine model.

    PubMed

    Waters, David J; Shen, Shuren; Glickman, Lawrence T; Cooley, Dawn M; Bostwick, David G; Qian, Junqi; Combs, Gerald F; Morris, J Steven

    2005-07-01

    Daily supplementation with the essential trace mineral selenium significantly reduced prostate cancer risk in men in the Nutritional Prevention of Cancer Trial. However, the optimal intake of selenium for prostate cancer prevention is unknown. We hypothesized that selenium significantly regulates the extent of genotoxic damage within the aging prostate and that the relationship between dietary selenium intake and DNA damage is non-linear, i.e. more selenium is not necessarily better. To test this hypothesis, we conducted a randomized feeding trial in which 49 elderly beagle dogs (physiologically equivalent to 62-69-year-old men) received nutritionally adequate or supranutritional levels of selenium for 7 months, in order to mimic the range of dietary selenium intake of men in the United States. Our results demonstrate an intriguing U-shaped dose-response relationship between selenium status (toenail selenium concentration) and the extent of DNA damage (alkaline Comet assay) within the prostate. Further, we demonstrate that the concentration of selenium that minimizes DNA damage in the aging dog prostate remarkably parallels the selenium concentration in men that minimizes prostate cancer risk. By studying elderly dogs, the only non-human animal model of spontaneous prostate cancer, we have established a new approach to bridge the gap between laboratory and human studies that can be used to select the appropriate dose of anticancer agents for large-scale human cancer prevention trials. From the U-shaped dose-response, it follows that not all men will necessarily benefit from increasing their selenium intake and that measurement of baseline nutrient status should be required for all individuals in prevention trials to avoid oversupplementation.

  9. Selenium recovery from kiln powder of cement manufacturing by chemical leaching and bioreduction.

    PubMed

    Soda, S; Hasegawa, A; Kuroda, M; Hanada, A; Yamashita, M; Ike, M

    2015-01-01

    A novel process by using chemical leaching followed by bacterial reductive precipitation was proposed for selenium recovery from kiln powder as a byproduct of cement manufacturing. The kiln powder at a slurry concentration of 10 w/v% with 0.25 M Na2CO3 at 28°C produced wastewater containing about 30 mg-Se/L selenium. The wastewater was diluted four-fold and adjusted to pH 8.0 as preconditioning for bioreduction. A bacterial strain Pseudomonas stutzeri NT-I, capable of reducing selenate and selenite into insoluble elemental selenium, could recover about 90% selenium from the preconditioned wastewater containing selenium of 5 mg-Se/L when supplemented with lactate or glycerol. The selenium concentrations in the treated wastewater were low around the regulated effluent concentration of 0.1 mg-Se/L in Japan.

  10. Dietary mineral supplies in Africa

    PubMed Central

    Joy, Edward J M; Ander, E Louise; Young, Scott D; Black, Colin R; Watts, Michael J; Chilimba, Allan D C; Chilima, Benson; Siyame, Edwin W P; Kalimbira, Alexander A; Hurst, Rachel; Fairweather-Tait, Susan J; Stein, Alexander J; Gibson, Rosalind S; White, Philip J; Broadley, Martin R

    2014-01-01

    Dietary micronutrient deficiencies (MNDs) are widespread, yet their prevalence can be difficult to assess. Here, we estimate MND risks due to inadequate intakes for seven minerals in Africa using food supply and composition data, and consider the potential of food-based and agricultural interventions. Food Balance Sheets (FBSs) for 46 countries were integrated with food composition data to estimate per capita supply of calcium (Ca), copper (Cu), iron (Fe), iodine (I), magnesium (Mg), selenium (Se) and zinc (Zn), and also phytate. Deficiency risks were quantified using an estimated average requirement (EAR) ‘cut-point’ approach. Deficiency risks are highest for Ca (54% of the population), followed by Zn (40%), Se (28%) and I (19%, after accounting for iodized salt consumption). The risk of Cu (1%) and Mg (<1%) deficiency are low. Deficiency risks are generally lower in the north and west of Africa. Multiple MND risks are high in many countries. The population-weighted mean phytate supply is 2770 mg capita−1 day−1. Deficiency risks for Fe are lower than expected (5%). However, ‘cut-point’ approaches for Fe are sensitive to assumptions regarding requirements; e.g. estimates of Fe deficiency risks are 43% under very low bioavailability scenarios consistent with high-phytate, low-animal protein diets. Fertilization and breeding strategies could greatly reduce certain MNDs. For example, meeting harvestplus breeding targets for Zn would reduce dietary Zn deficiency risk by 90% based on supply data. Dietary diversification or direct fortification is likely to be needed to address Ca deficiency risks. PMID:24524331

  11. In vivo formation of natural HgSe nanoparticles in the liver and ...

    EPA Pesticide Factsheets

    To understand the biochemistry of methylmercury (MeHg) that leads to the formation of mercury-selenium (Hg-Se) clusters is a long outstanding challenge that promises to deepen our knowledge of MeHg detoxification and the role SE plays in this process. Here, we show that mercury selenide (HgSe) nanoparticles in the liver and brain of long-finned pilot whales are attached to Se-rich structures and possibly act as a nucleation point for the formation of large Se-Hg clusters, which can grow with age to over 5 µm in size. The detoxification mechanism is fully developed from the early age of the animals, with particulate Hg found already in juvenile tissues. As a consequence of MeHg detoxification, Se-methionine, the selenium pool in the system is depleted in the efforts to maintain essential levels of Se-cysteine. This study provides evidence of so far unreported depletion of bioavailable Se pool, a plausible driving mechanism of demonstrated neurotoxic effects of MeHg in the organism affected by its high dietary intake. We investigated in vivo formation of natural HgSe particles in a pod of stranded long-finned pilot whales (Globicephala melas), with age of the animal and the potency of the environmentally relevant dose of dietary MeHg to disrupt the Se-proteins synthesis. This has been previously investigated despite the substantial indications of the interaction between Hg and Se, and therefore we conducted a multi-method analytical approach on brain and liv

  12. Selenium proteins in ovine tissues: III. Distribution of selenium and glutathione peroxidases in tissue cytosols.

    PubMed

    Black, R S; Tripp, M J; Whanger, P D; Weswig, P H

    1978-01-01

    Three 6 week-old lambs were injected with carrier-free selenium-75 as sodium selenite initially and again after 6 days. One lamb received no further injections whereas the other two received injections of either vitamin E or unlabeled Na2SeO3 when the first selenium-75 injection was given. Selected tissues were removed at autopsy 10 days after the first injection. The cytosol from homogenates of these tissues was subjected to gel chromatography, and the elution profiles determined for radioactivity, protein content, and glutathione peroxidase activity using either hydrogen peroxide or cumene hydroperoxide as substrates. The selenium-75 was found to be distributed mainly between 2 different MW peaks. The larger MW seleno-peak (90,000) possessed both glutathione:hydrogen peroxide oxidoreductase, and glutathione:cumene hydroperoxide oxidoreductase activities, but the smaller MW seleno-peak (about 10,000) possessed no glutathione peroxidase activity. A peak of about 60,000 daltons containing only glutathione:cumene hydroperoxide oxidoreductase activity and no selenium-75 was found primarily in the liver and kidney. Vitamin E had no effect on the elution profiles. Selenium status of the animal had only a minor effect on the selenium-75 distribution in the cytosol, but had a marked effect on the absolute amount of the label taken up by tissues.

  13. Selenium Accumulating Leafy Vegetables Are a Potential Source of Functional Foods

    PubMed Central

    Mabeyo, Petro E.; Manoko, Mkabwa L. K.; Gruhonjic, Amra; Fitzpatrick, Paul A.; Landberg, Göran; Erdélyi, Máté; Nyandoro, Stephen S.

    2015-01-01

    Selenium deficiency in humans has been associated with various diseases, the risks of which can be reduced through dietary supplementation. Selenium accumulating plants may provide a beneficial nutrient for avoiding such illnesses. Thus, leafy vegetables such as Amaranthus hybridus, Amaranthus sp., Cucurbita maxima, Ipomoea batatas, Solanum villosum, Solanum scabrum, and Vigna unguiculata were explored for their capabilities to accumulate selenium when grown on selenium enriched soil and for use as a potential source of selenium enriched functional foods. Their selenium contents were determined by spectrophotometry using the complex of 3,3′-diaminobenzidine hydrochloride (DABH) as a chromogen. The mean concentrations in the leaves were found to range from 7.90 ± 0.40 to 1.95 ± 0.12 μg/g dry weight (DW), with C. maxima accumulating the most selenium. In stems, the accumulated selenium content ranged from 1.12 ± 0.10 μg/g in Amaranthus sp. to 5.35 ± 0.78 μg/g DW in C. maxima and was hence significantly different (P < 0.01). The cancer cell line MDA-MB-231 was used in cytotoxicity assays to determine the anticancer potential of these extracts. With exception of S. scabrum and S. villosum, no cytotoxicity was detected for the selenium enriched vegetable extracts up to 100 μg/mL concentration. Hence, following careful evaluation the studied vegetables may be considered as selenium enriched functional foods. PMID:26955635

  14. Selenium Accumulating Leafy Vegetables Are a Potential Source of Functional Foods.

    PubMed

    Mabeyo, Petro E; Manoko, Mkabwa L K; Gruhonjic, Amra; Fitzpatrick, Paul A; Landberg, Göran; Erdélyi, Máté; Nyandoro, Stephen S

    2015-01-01

    Selenium deficiency in humans has been associated with various diseases, the risks of which can be reduced through dietary supplementation. Selenium accumulating plants may provide a beneficial nutrient for avoiding such illnesses. Thus, leafy vegetables such as Amaranthus hybridus, Amaranthus sp., Cucurbita maxima, Ipomoea batatas, Solanum villosum, Solanum scabrum, and Vigna unguiculata were explored for their capabilities to accumulate selenium when grown on selenium enriched soil and for use as a potential source of selenium enriched functional foods. Their selenium contents were determined by spectrophotometry using the complex of 3,3'-diaminobenzidine hydrochloride (DABH) as a chromogen. The mean concentrations in the leaves were found to range from 7.90 ± 0.40 to 1.95 ± 0.12 μg/g dry weight (DW), with C. maxima accumulating the most selenium. In stems, the accumulated selenium content ranged from 1.12 ± 0.10 μg/g in Amaranthus sp. to 5.35 ± 0.78 μg/g DW in C. maxima and was hence significantly different (P < 0.01). The cancer cell line MDA-MB-231 was used in cytotoxicity assays to determine the anticancer potential of these extracts. With exception of S. scabrum and S. villosum, no cytotoxicity was detected for the selenium enriched vegetable extracts up to 100 μg/mL concentration. Hence, following careful evaluation the studied vegetables may be considered as selenium enriched functional foods.

  15. Selenium in Camel – A Review

    PubMed Central

    Faye, Bernard; Seboussi, Rabiha

    2009-01-01

    Requirements for trace minerals in camels, particularly selenium, are not well-known. Selenium supplementation using a pharmaceutical form or commercial mineral mixture is common practice in camels to address the cardiomyopathy often attributed to selenium deficiency. This supplementation is often empirical and based on estimated needs for cattle. Nowadays the use of selenium in animal foodstuffs is commonplace and further investigation of its metabolism (ingestion, dynamic of storage-destocking, excretion) in camels is warranted. The present review aimed to synthesize all the experimental research (comparative selenium status in cow and camel, response to different levels of supplementation at different physiological stages, excretion maternal transfer, experimental toxicosis) and field observations (deficiency, supplementation practices) undertaken in camels. The results underline the particularity of the unique metabolic profile of the camel and lead to practical recommendations for supplementation in camels, highlighting its relative sensitivity to excess Se intake at lower levels than in cattle. The maximal tolerable dose is 8 mg and the recommended doses range from 2 to 4 mg. PMID:22253966

  16. Effect of atmospheric mercury deposition on selenium accumulation in rice (Oryza sativa L.) at a mercury mining region in southwestern China.

    PubMed

    Zhang, Chao; Qiu, Guangle; Anderson, Christopher W N; Zhang, Hua; Meng, Bo; Liang, Liang; Feng, Xinbin

    2015-03-17

    Selenium (Se) is an important trace element for human nutrition and has an interactive effect on mercury (Hg) uptake by plants and Hg toxicity in animals. Rice (Oryza sativa L.) is the dominant source of dietary Se in China, however the effect of soil Hg contamination on the Se concentration in rice is unknown. We collected 29 whole rice plant samples and corresponding soils from an active artisanal mercury mining area and an abandoned commercial mercury mining area. The soil Se concentration was similar across the two mining areas and greater than the background concentration for China. However, the Se concentration in rice grain was dramatically different (artisanal area 51±3 ng g(-1); abandoned area 235±99 ng g(-1)). The total gaseous mercury (TGM) concentration in ambient air at the artisanal mining site was significantly greater than at the abandoned area (231 and 34 ng m(-3), respectively) and we found a negative correlation between TGM and the Se concentration in grain for the artisanal area. Principal component analysis indicated that the source of Se in rice was the atmosphere for the artisanal area (no contribution from soil), and both the atmosphere and soil for the abandoned area. We propose that TGM falls to soil and reacts with Se, inhibiting the translocation of Se to rice grain. Our data suggest that Se intake by the artisanal mining community is insufficient to meet Se dietary requirements, predisposing this community to greater risk from Hg poisoning.

  17. Selenium metabolism in cancer cells: the combined application of XAS and XFM techniques to the problem of selenium speciation in biological systems.

    PubMed

    Weekley, Claire M; Aitken, Jade B; Finney, Lydia; Vogt, Stefan; Witting, Paul K; Harris, Hugh H

    2013-05-21

    Determining the speciation of selenium in vivo is crucial to understanding the biological activity of this essential element, which is a popular dietary supplement due to its anti-cancer properties. Hyphenated techniques that combine separation and detection methods are traditionally and effectively used in selenium speciation analysis, but require extensive sample preparation that may affect speciation. Synchrotron-based X-ray absorption and fluorescence techniques offer an alternative approach to selenium speciation analysis that requires minimal sample preparation. We present a brief summary of some key HPLC-ICP-MS and ESI-MS/MS studies of the speciation of selenium in cells and rat tissues. We review the results of a top-down approach to selenium speciation in human lung cancer cells that aims to link the speciation and distribution of selenium to its biological activity using a combination of X-ray absorption spectroscopy (XAS) and X-ray fluorescence microscopy (XFM). The results of this approach highlight the distinct fates of selenomethionine, methylselenocysteine and selenite in terms of their speciation and distribution within cells: organic selenium metabolites were widely distributed throughout the cells, whereas inorganic selenium metabolites were compartmentalized and associated with copper. New data from the XFM mapping of electrophoretically-separated cell lysates show the distribution of selenium in the proteins of selenomethionine-treated cells. Future applications of this top-down approach are discussed.

  18. Comparison of 3 methods of selenium assessment in cattle.

    PubMed Central

    Waldner, C; Campbell, J; Jim, G K; Guichon, P T; Booker, C

    1998-01-01

    Three tests are routinely done to assess blood status of selenium in cattle: serum selenium, whole blood selenium, and glutathione peroxidase. The objective of this study was to compare the various analytical methods for determining blood selenium status in groups of mature cows and beef calves. Twenty to 30 blood samples per herd were collected from 8 beef herds in central Alberta and 1 dairy in Alberta herd twice a year from the spring of 1992 through the fall of 1995, and once from 185 spring calves in 2 beef herds in Saskatchewan. Serum and whole blood samples were submitted to 1 laboratory and whole blood samples were submitted to a 2nd laboratory. Samples for glutathione peroxidase determinations were submitted to a 3rd laboratory. Pearson's correlation coefficients and Cohen's kappa were calculated for each possible comparison among the different measures. The best agreement was observed between serum and whole blood analysis within Laboratory A. The remaining comparisons reflected poor agreement. Comparison of herd-level assessment resulted in better agreement than comparison of individual sample results among laboratories and procedures for all combinations tested. Serum selenium analysis was the only laboratory procedure for which external reference material was utilized. Serum selenium, whole blood selenium, and glutathione peroxidase measure different compartments of the blood selenium pool. The time frame of interest, supplementation practices, and the stability of recent dietary intake determine the optimum assessment method for individual animals or herds. Determination of the serum status or of blood selenium is more consistently measured at the herd-level than for individual samples. PMID:9559213

  19. Selenium uptake, tolerance and reduction in Flammulina velutipes supplied with selenite

    PubMed Central

    Zhang, Dan

    2016-01-01

    Recently, selenium (Se) enriched mushrooms have been exploited as dietary Se supplements, but our knowledge of the metabolic process during the Se enrichment process is far from complete. In this study, the uptake, tolerance and reduction of selenite in a widely cultivated mushroom, Flammulina velutipes, was investigated. The results showed that pH variation (from 5.5–7.5), metabolic inhibitor (0.1 mM 2,4-DNP) and P or S starvation led to 11–26% decreases in the selenite uptake rate of F. velutipes. This indicates that a minor portion of the selenite uptake was metabolism dependent, whereas a carrier-facilitated passive transport may be crucial. Growth inhibition of F. velutipes initiated at 0.1 mM selenite (11% decrease in the growth rate) and complete growth inhibition occurred at 3 mM selenite. A selenite concentration of 0.03–0.1 mM was recommended to maintain the balance between mycelium production and Se enrichment. F. velutipes was capable of reducing selenite to elemental Se [Se(0)] including Se(0) nanoparticles, possibly as a detoxification mechanism. This process depended on both selenite concentration and metabolism activity. Overall, the data obtained provided some basic information for the cultivation of the selenized F. velutipes, and highlighted the opportunity of using mushrooms for the production of Se(0) nanoparticles. PMID:27547513

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