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

PubMed Central

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. PMID:28380029

Association of plasma selenium concentrations with total IGF-1 among older community-dwelling adults: the InCHIANTI study.

PubMed

Maggio, Marcello; Ceda, Gian Paolo; Lauretani, Fulvio; Bandinelli, Stefania; Dall'Aglio, Elisabetta; Guralnik, Jack M; Paolisso, Giuseppe; Semba, Richard D; Nouvenne, Antonio; Borghi, Loris; Ceresini, Graziano; Ablondi, Fabrizio; Benatti, Mario; Ferrucci, Luigi

2010-10-01

Insulin-like growth factor (IGF-1) stimulates cell proliferation and inhibits cell apoptosis. Recent studies underline its importance as anabolic hormone and nutritional marker in older individuals. IGF-1 synthesis and bioactivity are modulated by nutritional factors including selenium intake. However, whether circulating IGF-1 levels are positively influenced by plasma selenium, one of the most important human antioxidants, is still unknown. Selenium and total IGF-1 were measured in 951 men and women ≥ 65 years from the InCHIANTI study, Tuscany, Italy. Means (SD) of plasma selenium and total IGF-1 were 0.95 (0.15) μmol/L and 113.4 (31.2)ng/mL, respectively. After adjustment for age and sex, selenium levels were positively associated with total IGF-1 (β±SE: 43.76±11.2, p=0.0001). After further adjustment for total energy and alcohol intake, serum alanine aminotransferase (ALT), congestive heart failure, selenium remained significantly associated with IGF-1 (β±SE: 36.7±12.2, p=0.003). The association was still significant when IL-6 was introduced in the model (β±SE: 40.1±12.0, p=0.0008). We found an independent, positive and significant association between selenium and IGF-1 serum levels in community dwelling older adults. Copyright © 2010 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

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

USDA-ARS?s Scientific Manuscript database

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 ...

Selenium in bone health: roles in antioxidant protection and cell proliferation.

PubMed

Zeng, Huawei; Cao, Jay J; Combs, Gerald F

2013-01-10

Selenium (Se) is an essential trace element for humans and animals, and several findings suggest that dietary Se intake may be necessary for bone health. Such findings may relate to roles of Se in antioxidant protection, enhanced immune surveillance and modulation of cell proliferation. Elucidation of the mechanisms by which Se supports these cellular processes can lead to a better understanding of the role of this nutrient in normal bone metabolism. This article reviews the current knowledge concerning the molecular functions of Se relevant to bone health.

Selenium in Bone Health: Roles in Antioxidant Protection and Cell Proliferation

PubMed Central

Zeng, Huawei; Cao, Jay J.; Combs, Gerald F.

2013-01-01

Selenium (Se) is an essential trace element for humans and animals, and several findings suggest that dietary Se intake may be necessary for bone health. Such findings may relate to roles of Se in antioxidant protection, enhanced immune surveillance and modulation of cell proliferation. Elucidation of the mechanisms by which Se supports these cellular processes can lead to a better understanding of the role of this nutrient in normal bone metabolism. This article reviews the current knowledge concerning the molecular functions of Se relevant to bone health. PMID:23306191

Bio-transformation of selenium in Se-enriched bacterial strains of Lactobacillus casei.

PubMed

Kurek, Eliza; Ruszczyńska, Anna; Wojciechowski, Marcin; Łuciuk, Anna; Michalska-Kacymirow, Magdalena; Motyl, Ilona; Bulska, Ewa

Selenium is an element of very great importance for the proper functioning of the human body, mainly due to its antioxidant properties. Selenium exhibits a preventive effect in the case of cardiovascular disease, the immune system, male infertility and inhibits the toxic action of other agents. Selenium is important for Hashimoto's disease. Intake of selenium in the diet slows the aging process. The biological and toxicological effects of selenium strongly depend on its chemical form. Some organisms for example: plant, yeast, are capable of metabolizing low bioavailable selenium compounds (inorganic selenium) into its high bioavailable forms (organic selenium). The aim of this study was to investigate the bio-transformation of selenium by Lactobacillus bacteria towards the characterisation of selenium metabolites. The speciation of selenium was evaluated by high performance liquid chromatography with inductively coupled plasma mass spectrometry detector. The extraction of selenium species from lyophilized bacteria was executed with water, the mixture of lipase and protease, as well as lisozyme and sodium dodecyl sulphate. All investigated bacteria strains cultivated in the presence of Na2SeO3 effectively uptake selenium. Surprisingly, none of the applied extraction media exhibited a strong power to release the majority of the uptaken selenium compounds. Thus a maximum of 10% of the selenium was extracted from bacteria exposed to the enzymes. However, it was found that Lactobacillus bacteria are able to metabolize inorganic ions of selenium (IV) into Se-methionine, Se-methyloselenocysteine and other unidentified forms. The study confirmed the ability of probiotic bacteria to biotransform inorganic selenium into its organic derivatives. Therefore, Se-enriched bacteria can be considered as an addition to the functional food. selenium speciation, extraction procedure, Lactobacillus casei bacteria, Lactic acid bacteria (LAB), HPLC ICP-MS, functional food.

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. Copyright © 2010 Elsevier Ltd. All rights reserved.

Beneficial and paradoxical roles of selenium at nutritional levels of intake in healthspan and longevity

USDA-ARS?s Scientific Manuscript database

Accumulation of damage to the genome and macromolecules is a hallmark of aging, age-associated degeneration, and genome instability syndromes. Although the processes of aging are irreversible, they can be modulated by genome maintenance pathways and environmental factors such as diet. Selenium (Se) ...

Selenium Enrichment of Horticultural Crops.

PubMed

Puccinelli, Martina; Malorgio, Fernando; Pezzarossa, Beatrice

2017-06-04

The ability of some crops to accumulate selenium (Se) is crucial for human nutrition and health. Selenium has been identified as a cofactor of the enzyme glutathione peroxidase, which is a catalyzer in the reduction of peroxides that can damage cells and tissues, and can act as an antioxidant. Plants are the first link in the food chain, which ends with humans. Increasing the Se quantity in plant products, including leafy and fruity vegetables, and fruit crops, without exceeding the toxic threshold, is thus a good way to increase animal and human Se intake, with positive effects on long-term health. In many Se-enriched plants, most Se is in its major organic form. Given that this form is more available to humans and more efficient in increasing the selenium content than inorganic forms, the consumption of Se-enriched plants appears to be beneficial. An antioxidant effect of Se has been detected in Se-enriched vegetables and fruit crops due to an improved antioxidative status and to a reduced biosynthesis of ethylene, which is the hormone with a primary role in plant senescence and fruit ripening. This thus highlights the possible positive effect of Se in preserving a longer shelf-life and longer-lasting quality.

Treatment strategies in Alzheimer's disease: a review with focus on selenium supplementation.

PubMed

Aaseth, Jan; Alexander, Jan; Bjørklund, Geir; Hestad, Knut; Dusek, Petr; Roos, Per M; Alehagen, Urban

2016-10-01

Alzheimer's disease (AD) is a neurodegenerative disorder presenting one of the biggest healthcare challenges in developed countries. No effective treatment exists. In recent years the main focus of AD research has been on the amyloid hypothesis, which postulates that extracellular precipitates of beta amyloid (Aβ) derived from amyloid precursor protein (APP) are responsible for the cognitive impairment seen in AD. Treatment strategies have been to reduce Aβ production through inhibition of enzymes responsible for its formation, or to promote resolution of existing cerebral Aβ plaques. However, these approaches have failed to demonstrate significant cognitive improvements. Intracellular rather than extracellular events may be fundamental in AD pathogenesis. Selenate is a potent inhibitor of tau hyperphosphorylation, a critical step in the formation of neurofibrillary tangles. Some selenium (Se) compounds e.g. selenoprotein P also appear to protect APP against excessive copper and iron deposition. Selenoproteins show anti-inflammatory properties, and protect microtubules in the neuronal cytoskeleton. Optimal function of these selenoenzymes requires higher Se intake than what is common in Europe and also higher intake than traditionally recommended. Supplementary treatment with N-acetylcysteine increases levels of the antioxidative cofactor glutathione and can mediate adjuvant protection. The present review discusses the role of Se in AD treatment and suggests strategies for AD prevention by optimizing selenium intake, in accordance with the metal dysregulation hypothesis. This includes in particular secondary prevention by selenium supplementation to elderly with mild cognitive impairment.

Selenium metabolites in urine of cancer patients receiving L-selenomethionine at high doses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuehnelt, Doris; Juresa, Dijana; Francesconi, Kevin A.

2007-04-15

We investigated, with quantitative HPLC/mass spectrometry, the selenium metabolites in urine from five cancer patients receiving high doses of L-selenomethionine over an extended period (2 x 4000 {mu}g Se/day for 7 days, then 4000 {mu}g Se/day for 21 days) as an adjunct to their normal cancer chemotherapy. Urine samples were collected at day 0 (all 5 patients), and at 2-3 additional collection times ranging from 1 to 33 days. The background selenium concentrations ranged from 12 to 55 {mu}g Se/L and increased to 870 to 4420 {mu}g Se/L for the five patients during the study. All five patients had appreciablemore » levels of selenosugars in their background urine sample, and the concentrations increased dramatically after selenium intake. Trimethylselenonium ion (TMSe), on the other hand, was generally present as only a trace metabolite in background urine, and, although the concentration of TMSe increased following selenium exposure, it became a less significant proportion relative to selenosugars. These data refute the currently accepted role of TMSe as the preferred excretion metabolite when selenium exposure is high.« less

Separation and identification of selenotrisulfides in epithelial cell homogenates by LC-ICP-MS and LC-ESI-MS after incubation with selenite.

PubMed

Gabel-Jensen, Charlotte; Gammelgaard, Bente; Bendahl, Lars; Stürup, Stefan; Jøns, Ole

2006-02-01

To elucidate how selenite is metabolised in the intestine after oral intake, it was incubated with homogenized epithelial cells from pigs. When the metabolites were analysed by LC-ICP-MS, two major selenium metabolites were separated in the supernatant from the homogenate. These metabolites were formed instantly but disappeared within 15 min. No other selenium-containing compounds appeared during this time. Hence, the secondary reaction products were either volatilised or precipitated. To verify the identity of the compounds, a larger amount of selenite was incubated with epithelial cells. The presence of Cys-Se-SG and GS-Se-SG was verified by LC-ESI-MS. Selenotrisulfides were synthesized by reaction of L-cysteine and L-glutathione with sodium selenite. The reaction mixture contained three main products: selenodicysteine (Cys-Se-Cys), selenocysteine glutathione (Cys-Se-SG), and selenodiglutathione (GS-Se-SG). The two transient selenium compounds in the epithelial cell incubation mixture co-eluted with the synthesized Cys-Se-SG and GS-Se-SG, respectively. The identities of these compounds were verified by LC-ESI-MS. Hence, these selenium metabolites have now been identified by ESI-MS after isolation from epithelial cells.

Selenium content of game meat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Medeiros, L.C.; Belden, R.P.

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 ofmore » 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.« less

The potential of lentil (Lens culinaris L.) as a whole food for increased selenium, iron, and zinc intake: Preliminary results from a three year study

USDA-ARS?s Scientific Manuscript database

Micronutrient malnutrition, especially selenium (Se), iron (Fe), and zinc (Zn) deficiency, is a major global health problem. Previous attempts to prevent micronutrient malnutrition through food fortification, supplementation, and enrichment of staple crops has had limited success. Canadian grown len...

Selenium Biomarkers in Prostate Cancer Cell Lines and Influence of Selenium on Invasive Potential of PC3 Cells

PubMed Central

Hendrickx, Wouter; Decock, Julie; Mulholland, Francis; Bao, Yongping; Fairweather-Tait, Susan

2013-01-01

Dietary selenium intake has been linked to reduced cancer risk, however the underlying mechanisms are yet unknown. We question the commonly used practice of applying selenium concentrations found in human blood to in vitro studies and evaluated the utility of biomarkers, e.g., glutathione peroxidase 1 (GPx1) and thioredoxin reductase 1 (TrxR1), to determine appropriate selenium levels for in vitro work. Furthermore, we investigated the effects of Se-methylselenocysteine (SeMSC) on prostate cancer cell migration and invasion. After excluding cytotoxicity, we demonstrated that prostate cancer cell lines respond differently to selenium treatment as observed through biomarker assessment. We found that the maximum levels of GPx1 activity and TrxR1 expression were reached at lower selenium concentrations in LNCaP compared to PC3 cells, and PC3 compared to DU145 cells. Therefore the use of selenium concentrations extrapolated from human studies for in vitro work may be applicable when further informed using a readout of selenium repletion including use of selenium responsive biomarkers. No effect on PC3 migration or invasion was observed after long term SeMSC treatment; however a slight increase was found when treatment was solely administered during the assay. The opposite could be observed when cells were cultured under low serum conditions, with a significant increase in migration upon long term but not upon acute SeMSC treatment. To conclude, these findings indicate that it is imperative to study the selenium sensitivity of an in vitro model preferably using biomarkers before investigating any effects on biological processes, or before comparing models. PMID:24066278

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.

Selenium in the environment, metabolism and involvement in body functions.

PubMed

Mehdi, Youcef; Hornick, Jean-Luc; Istasse, Louis; Dufrasne, Isabelle

2013-03-13

Selenium (Se³⁴₇₉) is a metalloid which is close to sulfur (S) in terms of properties. The Se concentration in soil varies with type, texture and organic matter content of the soil and with rainfall. Its assimilation by plants is influenced by the physico-chemical properties of the soil (redox status, pH and microbial activity). The presence of Se in the atmosphere is linked to natural and anthropogenic activities. Selenoproteins, in which selenium is present as selenocysteine, present an important role in many body functions, such as antioxidant defense and the formation of thyroid hormones. Some selenoprotein metabolites play a role in cancer prevention. In the immune system, selenium stimulates antibody formation and activity of helper T cells, cytotoxic T cells and Natural Killer (NK) cells. The mechanisms of intestinal absorption of selenium differ depending on the chemical form of the element. Selenium is mainly absorbed in the duodenum and caecum by active transport through a sodium pump. The recommended daily intake of selenium varies from 60 μg/day for women, to 70 μg/day for men. In growing ruminants the requirements are estimated at 100 μg/kg dry matter and 200 μg/Kg for pregnant or lactating females. A deficiency can cause reproductive disorders in humans and animals.

Mercury and selenium in fishes from the Tapajós River in the Brazilian Amazon: An evaluation of human exposure.

PubMed

Lino, A S; Kasper, D; Guida, Y S; Thomaz, J R; Malm, O

2018-07-01

This work aimed to evaluate associated risks of fish consumption to human health, concerning mercury (Hg) and selenium (Se) concentrations in fish species largely consumed in the Tapajós River basin in the Brazilian Amazon. Total mercury (THg), methylmercury (MeHg) and Se concentrations were measured in 129 fish specimens from four sites of the Tapajós River basin. Estimated daily intake (EDI) of Hg and Se were reported regarding fish consumption. EDI were compared with the reference value of provisional tolerable daily intake proposed by the World Health Organization (WHO). Se:Hg ratios and selenium health benefit values (Se HBVs) seem to offer a more comprehensive fish safety model. THg concentrations in fishes ranged from 0.03 to 1.51 μg g -1 of wet weight (w.w.) and MeHg concentrations ranged from 0.02 to 1.44 μg g -1 (w.w.). 80% of the samples were below the value of Hg recommended by the WHO for human consumption (0.5 μg g -1 w.w.). However, Hg EDI exceeded the dose suggested by the United States Environmental Protection Agency (0.1 μg kg -1  day -1 ), due to the large level of fish consumption in that area. Se concentrations in fishes ranged from 0.02 to 0.44 μg g -1 w.w. An inverse pattern was observed between Hg and Se concentrations in the trophic chain (highest levels of Se in the lowest trophic levels). The molar ratio Se:Hg and Se HBVs were higher in iliophagous and herbivorous fishes, which is noteworthy to reduce toxic effects of Hg contamination. For planktivores, the content of Se and Hg was almost equimolar. Carnivorous fishes - with the exception of Hemisorubim platyrhynchos and Pseudoplatystoma fasciatum -, showed Se:Hg ratios <1. Thus, they do not act as a favorable source of Se in the diet. Therefore, reduced intake of carnivorous fishes with preferential consumption of iliophages, herbivores and, to some extent, even planktivores should be promoted as part of a healthier diet. Copyright © 2018 Elsevier GmbH. All rights reserved.

Responses of growing Japanese quails that received selenium from selenium enriched kale sprout (Brassica oleracea var. alboglabra L.).

PubMed

Chantiratikul, Anut; Chinrasri, Orawan; Pakmaruek, Pornpan; Chantiratikul, Piyanete; Thosaikham, Withpol; Aengwanich, Worapol

2011-12-01

The objectives of this study were to determine the effect of selenium (Se) from Se-enriched kale sprout (Brassica oleracea var. alboglabra L.) on the performance and Se concentrations in tissues of growing Japanese quails. Two hundred quails were divided into five treatments. Each treatment consisted of four replicates and each replicate contained ten quails in a completely randomize design. The experiment was conducted for 5 weeks. The treatments were T1, control diet; T2, control diet plus 0.2 mg Se/kg from sodium selenite; T3, T4, and T5, control diet plus 0.2, 0.5, and 1.0 mg Se/kg from Se-enriched kale sprout. The results revealed that Se supplementation had no impact on feed intake, performance, and carcass characteristics of quails (p > 0.05). However, Se supplementation from both sodium selenite and Se-enriched kale sprout increased (p < 0.05) Se concentrations in the heart and breast meat of quails. Se concentrations in the liver and breast meat of quails increased (p < 0.05) with increasing Se concentration from Se-enriched kale sprout. The results indicate that Se from Se-enriched kale sprout offers no advantage over Se from sodium selenite on tissue Se concentration.

Serum selenium concentration in a representative sample of the Canarian population.

PubMed

Diaz Romero, C; López Blanco, F; Henríquez Sánchez, P; Rodríguez, E; Serra Majem, L

2001-03-26

The concentration of serum selenium in 395 individuals (187 males + 218 females) living in the Canary Islands, Spain was determined by hydride generation atomic absorption spectrometry. The mean selenium concentration was 74.7 +/- 25.2 microg/l ranging between 7.86 and 182.3 microg/l. Twenty-two adults (7.2% of the total) had serum selenium concentrations under 45 microg/l. It is widely accepted that below this selenium serum concentration (45 microg/l) there is an increased risk of cardiovascular disease and cancer. Our results fall within data recently published in other Spanish and European regions and are much lower than data observed in USA or seleniferous regions. The estimated Se intakes of our population were lower than the Recommended Dietary Allowances for American people. Individuals from Lanzarote had a mean Se concentration significantly higher than individuals from the other islands. This could be attributed to differences in Se content of soil and/or differences in dietary habits of the populations. Serum selenium concentration did not vary with the sex of the subjects. Individuals younger than 14 years old had a serum selenium concentration significantly lower than the rest of the individuals. No relationship with socio-economic status, educational level, smoking habits, physical exercise or beer consumption was found. However, individuals who consume wine more than three times a week showed higher selenium concentrations than individuals with lower consumption. Also, individuals with consumption above seven units of spirit drinks a week had the highest mean selenium concentration.

The changing selenium nutritional status of Chinese residents.

PubMed

Li, Sumei; Bañuelos, Gary S; Wu, Longhua; Shi, Weiming

2014-03-14

The selenium (Se) content in human hair is useful as an indicator of human Se intake and status. In this regard, when measuring the hair Se concentrations in Chinese inhabitants across northeast to southeast China, the results indicated that generally 84% of all residents have normal hair Se content. Between the sexes, the average hair Se content of males was higher than that of females, irrespective of districts. When comparing geographical regions, the average hair Se content of southern residents was greater than that of northern residents, regardless of gender. Historically, the overall hair Se content of today's inhabitants decreased between 24% and 46% when compared with the inhabitants living in the same geographic region 20 years ago. The decrease of hair Se content may be related to the overall decrease of grain consumption and the lower Se content in the staple food rice.

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.

Toenail selenium as an indicator of environmental exposure: A cross-sectional study.

PubMed

Filippini, Tommaso; Ferrari, Angela; Michalke, Bernhard; Grill, Peter; Vescovi, Luciano; Salvia, Chiara; Malagoli, Carlotta; Malavolti, Marcella; Sieri, Sabina; Krogh, Vittorio; Bargellini, Annalisa; Martino, Antonio; Ferrante, Margherita; Vinceti, Marco

2017-05-01

The relation between toxicity and essentiality of selenium (Se) is of growing interest in human health, as the effects may widely differ depending of its different chemical species and the exposure levels. Toenail Se has been proposed as a reliable biomarker of long-term Se exposure, but few studies investigated the correlation between its toenail content and environmental determinants (i.e., dietary food intake). We aimed to determine the relation of toenail Se levels with serum Se species as well as food items. We recruited a random sample of Modena (Northern Italy) municipal residents, from whom we collected detailed personal information, dietary habits, toenail specimen for Se determination and a blood sample for serum Se speciation analysis. Toenail Se mean value was 0.96 µg/g (range, 0.47‑1.60), with slightly higher levels in females, in non-obese subjects and in Se supplements users, while it was lower in current smokers. Toenail Se positively correlated with organic Se forms, mainly selenoprotein P and selenocysteine, and inversely with the inorganic forms (selenite and selenate). Toenail Se was not associated with meat, cereals and dairy products consumption, positively correlated with fruit and slightly with vegetable intake, and negatively with fish and seafood consumption. Finally, no clear association emerged with estimated air Se exposure.

Ethanol Consumption by Wistar Rat Dams Affects Selenium Bioavailability and Antioxidant Balance in Their Progeny

PubMed Central

Ojeda, María Luisa; Vázquez, Beatriz; Nogales, Fátima; Murillo, María Luisa; Carreras, Olimpia

2009-01-01

Ethanol consumption affects maternal nutrition, the mothers’ antioxidant balance and the future health of their progeny. Selenium (Se) is a trace element cofactor of the enzyme glutathione peroxidase (GPx). We will study the effect of ethanol on Se bioavailability in dams and in their progeny. We have used three experimental groups of dams: control, chronic ethanol and pair-fed; and three groups of pups. Se levels were measured by graphite-furnace atomic absorption spectrometry. Serum and hepatic GPx activity was determined by spectrometry. We have concluded that ethanol decreased Se retention in dams, affecting their tissue Se deposits and those of their offspring, while also compromising their progeny’s weight and oxidation balance. These effects of ethanol are caused by a reduction in Se intake and a direct alcohol-generated oxidation action. PMID:19742151

[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.

Dietary Selenium Intake and Subclinical Hypothyroidism: A Cross-Sectional Analysis of the ELSA-Brasil Study.

PubMed

Andrade, Gustavo R G; Gorgulho, Bartira; Lotufo, Paulo A; Bensenor, Isabela M; Marchioni, Dirce M

2018-05-30

Selenium (Se) participates in several enzymatic reactions necessary for regulating the homeostasis of thyroid hormones. We aimed to analyze the association between dietary Se intake and subclinical hypothyroidism. Baseline data from the Longitudinal Study of Adult Health (Estudo Longitudinal de Saúde do Adulto-ELSA-Brasil) in Brazil were analyzed, with a final sample size of 14,283 employees of both sexes aged 35⁻74 years. Dietary data was collected using a previously validated food frequency questionnaire. Subclinical hypothyroidism was categorized as thyroid-stimulating hormone levels of >4.0 IU/mL and free prohormone thyroxine levels within normal limits, without administering drugs for thyroid disease. A multiple logistic regression model was used to assess the relationship between the presence of subclinical hypothyroidism and tertiles of Se consumption. The prevalence of subclinical hypothyroidism in the study sample was 5.4% (95% confidence interval [CI], 3.8⁻7.0%). Compared with the first tertile of Se intake, the second (odds ratio [OR], 0.79; 95% CI, 0.65⁻0.96%) and third (OR, 0.72; 95% CI, 0.58⁻0.90%) tertiles were inversely associated with subclinical hypothyroidism, however further research is needed to confirm the involvement of Se in subclinical hypothyroidism using more accurate methodologies of dietary assessment and nutritional status to evaluate this relationship.

Biofortification of UK food crops with selenium.

PubMed

Broadley, Martin R; White, Philip J; Bryson, Rosie J; Meacham, Mark C; Bowen, Helen C; Johnson, Sarah E; Hawkesford, Malcolm J; McGrath, Steve P; Zhao, Fang-Jie; Breward, Neil; Harriman, Miles; Tucker, Mark

2006-05-01

Se is an essential element for animals. In man low dietary Se intakes are associated with health disorders including oxidative stress-related conditions, reduced fertility and immune functions and an increased risk of cancers. Although the reference nutrient intakes for adult females and males in the UK are 60 and 75 microg Se/d respectively, dietary Se intakes in the UK have declined from >60 microg Se/d in the 1970s to 35 microg Se/d in the 1990s, with a concomitant decline in human Se status. This decline in Se intake and status has been attributed primarily to the replacement of milling wheat having high levels of grain Se and grown on high-Se soils in North America with UK-sourced wheat having low levels of grain Se and grown on low-Se soils. An immediate solution to low dietary Se intake and status is to enrich UK-grown food crops using Se fertilisers (agronomic biofortification). Such a strategy has been adopted with success in Finland. It may also be possible to enrich food crops in the longer term by selecting or breeding crop varieties with enhanced Se-accumulation characteristics (genetic biofortification). The present paper will review the potential for biofortification of UK food crops with Se.

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.

Selenium Characterization in the Global Rice Supply Chain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, Paul N.; Lombi, Enzo; Sun, Guo-Xin

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 ricemore » 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.« less

Long-Term Selenium-Deficient Diet Induces Liver Damage by Altering Hepatocyte Ultrastructure and MMP1/3 and TIMP1/3 Expression in Growing Rats.

PubMed

Han, Jing; Liang, Hua; Yi, Jianhua; Tan, Wuhong; He, Shulan; Wang, Sen; Li, Feng; Wu, Xiaofang; Ma, Jing; Shi, Xiaowei; Guo, Xiong; Bai, Chuanyi

2017-02-01

The effects of selenium (Se)-deficient diet on the liver were evaluated by using growing rats which were fed with normal and Se-deficient diets, respectively, for 109 days. The results showed that rats fed with Se-deficient diet led to a decrease in Se concentration in the liver, particularly among male rats from the low-Se group. This causes alterations to the ultrastructure of hepatocytes with condensed chromatin and swelling mitochondria observed after low Se intake. Meanwhile, pathological changes and increased fibrosis in hepatic periportal were detected by hematoxylin and eosin and Masson's trichrome staining in low-Se group. Furthermore, through immunohistochemistry (IHC) staining, higher expressions of metalloproteinases (MMP1/3) and their tissue inhibitors of metalloproteinases (TIMP1/3) were observed in the hepatic periportal of rats from the low-Se group. However, higher expressions of MMP1/3 and lower expressions of TIMP1/3 were detected in hepatic central vein and hepatic sinusoid. In addition, upregulated expressions of MMP1/3 and downregulated expressions of TIMP1/3 at the messenger RNA (mRNA) and protein levels also appeared to be relevant to low Se intake. In conclusion, Se-deficient diet could cause low Se concentration in the liver, alterations of hepatocyte ultrastructure, differential expressions of MMP1/3 and TIMP1/3 as well as fibrosis in the liver hepatic periportal.

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.

High Dietary Selenium Intake Alters Lipid Metabolism and Protein Synthesis in Liver and Muscle of Pigs123

PubMed Central

Barcus, Matthew; Kim, Jonggun; Lum, Krystal L; Mills, Courtney; Lei, Xin Gen

2016-01-01

Background: Prolonged high intakes of dietary selenium have been shown to induce gestational diabetes in rats and hyperinsulinemia in pigs. Objective: Two experiments were conducted to explore metabolic and molecular mechanisms for the diabetogenic potential of high dietary selenium intakes in pigs. Methods: In Expt. 1, 16 Yorkshire-Landrace-Hampshire crossbred pigs (3 wk old, body weight = 7.5 ± 0.81 kg, 50% males and 50% females) were fed a corn-soybean meal basal diet supplemented with 0.3 or 1.0 mg Se/kg (as selenium-enriched yeast for 6 wk). In Expt. 2, 12 pigs of the same crossbreed (6 wk old, body weight = 16.0 ± 1.8 kg) were fed a similar basal diet supplemented with 0.3 or 3.0 mg Se/kg for 11 wk. Biochemical and gene and protein expression profiles of lipid and protein metabolism and selenoproteins in plasma, liver, muscle, and adipose tissues were analyzed. Results: In Expt. 1, the 1-mg-Se/kg diet did not affect body weight or plasma concentrations of glucose and nonesterified fatty acids. In Expt. 2, the 3-mg-Se/kg diet, compared with the 0.3-mg-Se/kg diet, increased (P < 0.05) concentrations of plasma insulin (0.2 compared with 0.4 ng/mL), liver and adipose lipids (41% to 2.4-fold), and liver and muscle protein (10–14%). In liver, the 3-mg-Se/kg diet upregulated (P < 0.05) the expression, activity, or both of key factors related to gluconeogenesis [phosphoenolpyruvate carboxykinase (PEPCK); 13%], lipogenesis [sterol regulatory element binding protein 1 (SREBP1), acetyl-coenzyme A carboxylase (ACC), and fatty acid synthase (FASN); 46–90%], protein synthesis [insulin receptor (INSR), P70 ribosomal protein S6 kinase (P70), and phosphorylated ribosomal protein S6 (P-S6); 88–105%], energy metabolism [AMP-activated protein kinase (AMPK); up to 2.8-fold], and selenoprotein glutathione peroxidase 3 (GPX3; 1.4-fold) and suppressed (P < 0.05) mRNA levels of lipolysis gene cytochrome P450, family 7, subfamily A, polypeptide 1 (CYP7A1; 88%) and selenoprotein gene selenoprotein W1 (SEPW1; 46%). In muscle, the 3-mg-Se/kg diet exerted no effect on the lipid profiles but enhanced (P < 0.05) expression of P-S6 and mammalian target of rapamycin (mTOR; 42–176%; protein synthesis); selenoprotein P (SELP; 40-fold); and tumor suppressor protein 53 (P53) and peroxisome proliferator–activated receptor γ (PPARG; 52–58%; lipogenesis) and suppressed (P < 0.05) expression of INSR (59%; insulin signaling); selenoprotein S (SELS); deiodinases, iodothyronine, type I (DIO1); and thioredoxin reductase 1 (TXNRD1; 50%; selenoproteins); and ACC1 and FASN (35–51%; lipogenesis). Conclusion: Our research showed novel roles, to our best knowledge, and mechanisms of high selenium intakes in regulating the metabolism of protein, along with that of lipid, in a tissue-specific fashion in pigs. PMID:27466604

High Dietary Selenium Intake Alters Lipid Metabolism and Protein Synthesis in Liver and Muscle of Pigs.

PubMed

Zhao, Zeping; Barcus, Matthew; Kim, Jonggun; Lum, Krystal L; Mills, Courtney; Lei, Xin Gen

2016-09-01

Prolonged high intakes of dietary selenium have been shown to induce gestational diabetes in rats and hyperinsulinemia in pigs. Two experiments were conducted to explore metabolic and molecular mechanisms for the diabetogenic potential of high dietary selenium intakes in pigs. In Expt. 1, 16 Yorkshire-Landrace-Hampshire crossbred pigs (3 wk old, body weight = 7.5 ± 0.81 kg, 50% males and 50% females) were fed a corn-soybean meal basal diet supplemented with 0.3 or 1.0 mg Se/kg (as selenium-enriched yeast for 6 wk). In Expt. 2, 12 pigs of the same crossbreed (6 wk old, body weight = 16.0 ± 1.8 kg) were fed a similar basal diet supplemented with 0.3 or 3.0 mg Se/kg for 11 wk. Biochemical and gene and protein expression profiles of lipid and protein metabolism and selenoproteins in plasma, liver, muscle, and adipose tissues were analyzed. In Expt. 1, the 1-mg-Se/kg diet did not affect body weight or plasma concentrations of glucose and nonesterified fatty acids. In Expt. 2, the 3-mg-Se/kg diet, compared with the 0.3-mg-Se/kg diet, increased (P < 0.05) concentrations of plasma insulin (0.2 compared with 0.4 ng/mL), liver and adipose lipids (41% to 2.4-fold), and liver and muscle protein (10-14%). In liver, the 3-mg-Se/kg diet upregulated (P < 0.05) the expression, activity, or both of key factors related to gluconeogenesis [phosphoenolpyruvate carboxykinase (PEPCK); 13%], lipogenesis [sterol regulatory element binding protein 1 (SREBP1), acetyl-coenzyme A carboxylase (ACC), and fatty acid synthase (FASN); 46-90%], protein synthesis [insulin receptor (INSR), P70 ribosomal protein S6 kinase (P70), and phosphorylated ribosomal protein S6 (P-S6); 88-105%], energy metabolism [AMP-activated protein kinase (AMPK); up to 2.8-fold], and selenoprotein glutathione peroxidase 3 (GPX3; 1.4-fold) and suppressed (P < 0.05) mRNA levels of lipolysis gene cytochrome P450, family 7, subfamily A, polypeptide 1 (CYP7A1; 88%) and selenoprotein gene selenoprotein W1 (SEPW1; 46%). In muscle, the 3-mg-Se/kg diet exerted no effect on the lipid profiles but enhanced (P < 0.05) expression of P-S6 and mammalian target of rapamycin (mTOR; 42-176%; protein synthesis); selenoprotein P (SELP; 40-fold); and tumor suppressor protein 53 (P53) and peroxisome proliferator-activated receptor γ (PPARG; 52-58%; lipogenesis) and suppressed (P < 0.05) expression of INSR (59%; insulin signaling); selenoprotein S (SELS); deiodinases, iodothyronine, type I (DIO1); and thioredoxin reductase 1 (TXNRD1; 50%; selenoproteins); and ACC1 and FASN (35-51%; lipogenesis). Our research showed novel roles, to our best knowledge, and mechanisms of high selenium intakes in regulating the metabolism of protein, along with that of lipid, in a tissue-specific fashion in pigs. © 2016 American Society for Nutrition.

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.

Selenium-Dependent Antioxidant Enzymes: Actions and Properties of Selenoproteins

PubMed Central

Zoidis, Evangelos; Seremelis, Isidoros; Kontopoulos, Nikolaos

2018-01-01

Unlike other essential trace elements that interact with proteins in the form of cofactors, selenium (Se) becomes co-translationally incorporated into the polypeptide chain as part of 21st naturally occurring amino acid, selenocysteine (Sec), encoded by the UGA codon. Any protein that includes Sec in its polypeptide chain is defined as selenoprotein. Members of the selenoproteins family exert various functions and their synthesis depends on specific cofactors and on dietary Se. The Se intake in productive animals such as chickens affect nutrient utilization, production performances, antioxidative status and responses of the immune system. Although several functions of selenoproteins are unknown, many disorders are related to alterations in selenoprotein expression or activity. Selenium insufficiency and polymorphisms or mutations in selenoproteins’ genes and synthesis cofactors are involved in the pathophysiology of many diseases, including cardiovascular disorders, immune dysfunctions, cancer, muscle and bone disorders, endocrine functions and neurological disorders. Finally, heavy metal poisoning decreases mRNA levels of selenoproteins and increases mRNA levels of inflammatory factors, underlying the antagonistic effect of Se. This review is an update on Se dependent antioxidant enzymes, presenting the current state of the art and is focusing on results obtained mainly in chicken. PMID:29758013

Low selenium status affects arsenic metabolites in an arsenic exposed population with skin lesions.

PubMed

Huang, Zhi; Pei, Qiuling; Sun, Guifan; Zhang, Sichum; Liang, Jiang; Gao, Yi; Zhang, Xinrong

2008-01-01

The antagonistic effects between selenium (Se) and arsenic (As) suggest that low selenium status plays important roles in arsenism development. However, no study has been reported for humans suffering from chronic arsenic exposure with low selenium status. Sixty-three subjects were divided into 2 experimental groups by skin lesions (including hyperkeratosis, depigmentation, and hyperpigmentation). Total urine and serum concentrations of arsenic and selenium were determined by ICP-MS with collision/reaction cell. Arsenic species were analysed by ICP-MS coupled with HPLC. The mean concentration of As in the drinking waters was 41.5 microg/l. The selenium dietary intake for the studied population was 31.7 microg Se/d, and which for the cases and controls were 25.9 and 36.3 microg Se/d, respectively. Compared with the controls, the skin lesions cases had lower selenium concentrations in serum and urine (41.4 vs 49.6 microg/l and 71.0 vs 78.8 microg/l, respectively), higher inorganic arsenic (iAs) in serum (5.2 vs 3.4 microg/l, P<0.01), higher percentages of iAs in serum and urine (20.2) vs 16.9% and 18.3 vs 14.5%, respectively, P<0.01) but lower percentages of monomethylarsonate (MMA) in serum (15.5 vs 18.8%, P<0.01) ans dimethylarsinate acid (DMA) in urine (65.1 vs 69.8%, P<0.01). Subjects with lower selenium concentrations in serum (<50 microg/l) had a stronger tendency to the risk of skin lesions than individual having higher selenium concentrations [odd ratio (OR), 7.3; 95% confidence interval (95% CI), 1.5-35.7; P=0.014]. This OR estimation was confirmed in those subjects having higher ratios of As/Se in urine and serum, with OR as high as 10.3 and 3.8 respectively. Lower serum selenium status (<50 microg/l) is significantly correlated to the arsenic-associated skin lesions in the arsenic exposed population. The accumulation of iAs and its inhibition to be biotransformed to DMA occurred in human due to chronic exposure of low selenium status.

The levels of mercury, methylmercury and selenium and the selenium health benefit value in grey-eel catfish (Plotosus canius) and giant mudskipper (Periophthalmodon schlosseri) from the Strait of Malacca.

PubMed

Looi, Ley Juen; Aris, Ahmad Zaharin; Haris, Hazzeman; Yusoff, Fatimah Md; Hashim, Zailina

2016-06-01

The present study examined the concentrations of mercury (Hg), methylmercury (MeHg), and selenium (Se) in the multiple tissues of the Plotosus canius and Periophthalmodon schlosseri collected from the Strait of Malacca. The mean value in mg kg(-1) of Hg (P. canius: 0.34 ± 0.19; P. schlosseri: 0.32 ± 0.18) and MeHg in muscle (P. canius: 0.14 ± 0.11; P. schlosseri: 0.17 ± 0.11) were below the Codex general standard for contaminants and toxins in food and feed (CODEX STAN 193-1995), the Malaysian Food Regulation 1985 and the Japan Food Sanitation Law. For P. canius, the liver contained the highest concentrations of Hg (0.48 ± 0.07 mg kg(-1)) and MeHg (0.21 ± 0.00 mg kg(-1)), whereas for P. schlosseri, the gill contained the highest concentrations of Hg (0.36 ± 0.06 mg kg(-1)) and MeHg (0.21 ± 0.05 mg kg(-1)). The highest concentration of (80)Se (mg kg(-1)) was observed in the liver of P. canius (20.34 ± 5.68) and in the gastrointestinal tract (3.18 ± 0.42) of P. schlosseri. The selenium:mercury (Se:Hg) molar ratios were above 1 and the positive selenium health benefit value (HBVSe) suggesting the possible protective effects of Se against Hg toxicity. The estimate weekly intakes (EWIs) in μg kg(-1) body weight (bw) week(-1) of Hg (P. canius: 0.27; P. schlosseri: 0.15) and MeHg (P. canius: 0.11; P. schlosseri: 0.08) were found to be lower than the provisional tolerable weekly intake established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Based on the calculated EWIs, P. canius, and P. schlosseri were found to be unlikely to cause mercury toxicity in human consumption. Copyright © 2016 Elsevier Ltd. All rights reserved.

In vivo formation of natural HgSe nanoparticles in the liver and brain of pilot whales

NASA Astrophysics Data System (ADS)

Gajdosechova, Zuzana; Lawan, Mohammed M.; Urgast, Dagmar S.; Raab, Andrea; Scheckel, Kirk G.; Lombi, Enzo; Kopittke, Peter M.; Loeschner, Katrin; Larsen, Erik H.; Woods, Glenn; Brownlow, Andrew; Read, Fiona L.; Feldmann, Jörg; Krupp, Eva M.

2016-09-01

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 the bioavailable Se pool, a plausible driving mechanism of demonstrated neurotoxic effects of MeHg in the organism affected by its high dietary intake.

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.

Selenium protein identification and profiling by mass spectrometry: A tool to assess progression of cardiomyopathy in a whale model.

PubMed

Bryan, Colleen E; Bossart, Gregory D; Christopher, Steven J; Davis, W Clay; Kilpatrick, Lisa E; McFee, Wayne E; O'Brien, Terrence X

2017-12-01

Non-ischemic cardiomyopathy is a leading cause of congestive heart failure and sudden cardiac death in humans and in some cases the etiology of cardiomyopathy can include the downstream effects of an essential element deficiency. Of all mammal species, pygmy sperm whales (Kogia breviceps) present the greatest known prevalence of cardiomyopathy with more than half of examined individuals indicating the presence of cardiomyopathy from gross and histo-pathology. Several factors such as genetics, infectious agents, contaminants, biotoxins, and inappropriate dietary intake (vitamins, selenium, mercury, and pro-oxidants), may contribute to the development of idiopathic cardiomyopathy in K. breviceps. Due to the important role Se can play in antioxidant biochemistry and protein formation, Se protein presence and relative abundance were explored in cardiomyopathy related cases. Selenium proteins were separated and detected by multi-dimension liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS), Se protein identification was performed by liquid chromatography electrospray tandem mass spectrometry (LC-ESI-MS/MS), and Se protein profiles were examined in liver (n=30) and heart tissue (n=5) by SEC/UV/ICP-MS detection. Data collected on selenium proteins was evaluated in the context of individual animal trace element concentration, life history, and histological information. Selenium containing protein peak profiles varied in presence and intensity between animals with no pathological findings of cardiomyopathy and animals exhibiting evidence of cardiomyopathy. In particular, one class of proteins, metallothioneins, was found to be associated with Se and was in greater abundance in animals with cardiomyopathy than those with no pathological findings. Profiling Se species with SEC/ICP-MS proved to be a useful tool to identify Se protein pattern differences between heart disease stages in K. breviceps and an approach similar to this may be applied to other species to study Se protein associations with cardiomyopathy. Published by Elsevier GmbH.

Seasonal variability of iodine and selenium in surface and groundwater as a factor that may contribute to iodine isotope balance in the thyroid gland and its irradiation in case of radioiodine contamination during accidents at the NPP

NASA Astrophysics Data System (ADS)

Korobova, Elena; Kolmykova, Lyudmila; Ryzhenko, Boris; Berezkin, Viktor; Saraeva, Anastasia

2016-04-01

Radioiodine release to the environment during the accident at the Chernobyl NPP led to the increased risk of the thyroid cancer cases within the contaminated areas, the effect being aggravated in conditions of stable iodine and selenium deficiency in local food chains. Although the drinking water iodine is usually believed to contribute not more than 10% to local diet, our estimations accounting of water content in other products and several regional studies (e.g. India and Australia) proved its portion to be at least twice as much. As radioiodine isotopes are short-lived, their absorption depends greatly on stable iodine and selenium sufficiency in thyroid gland in the first few days of contamination and seasonal variation of stable iodine and selenium in local sources of drinking water may be significant as modifying the resulting thyroid irradiation in different seasons of the year. The main goal of the study was to evaluate seasonal variation of levels of iodine and selenium in natural waters of the Bryansk region as a possible factor affecting the radioiodine intake by thyroid gland of animals and humans in case of radioiodine contamination during the accident. Seasonal I and Se concentration was measured in the years of 2014 and 2015 at 14 test points characterizing surface (river and lake) and drinking groundwater. Obtained data proved considerable seasonal variation of I and Se concentration in natural waters (3,7-8,1 μg/l and 0,04-0,4 μg/l respectively) related to physico-chemical water parameters, such as pH, Eh and fluctuations in concentration of dissolved organic matter. The widest I and Se seasonal variability was observed in surface and well waters, maximum I level being found in autumn at the end of vegetation period characterized by active I leaching from the decomposed organic residues by long lasting precipitations. The content of selenium in the surface waters during summer-autumn (0,06-0,3 μg/l) was higher than in spring (0,04-0,05 μg/l). In drinking water from centralized supply pipeline low concentration of both elements was also registered in spring (3,7-4,3 μg/l (I) and 0,04-0,08 μg/l (Se)). Accounting of the fact that both the Chernobyl and Fukushima accidents took place in spring, we hypothesis that low iodine intake with water may have contributed to the risk of higher radioiodine intake by thyroid gland in the period of the accident. The work was supported the Russian Foundation for Basic Research (grant 13-05-00823).

The role of imported grain on the selenium intake of Finnish population in 1941-1981.

PubMed

Mutanen, M; Koivistoinen, P

1983-01-01

When the average intake of selenium among the Finnish population during the period 1941 to 1981 was estimated, the proportion of imported grain used for human consumption, as well as its country of origin, was taken into account as a factor increasing the total intake. The figures indicting the intake of selenium during the study period range from 21 to 56 micrograms/day, clearly exceeding the values obtained when the intake is assessed on the basis of the selenium content of Finnish grain only. The proportion of selenium derived from grain out of the total intake of selenium ranged from 10 to 67% during the study period.

Selenium extraction: development on extraction chromatographic resins compatible with Diffusive Gradient in Thin film (DGT)

NASA Astrophysics Data System (ADS)

Rad, S.; Dirks-Fandrei, C.; Happel, S. A.; Bombard, A.; Cary, L.

2016-12-01

Measurement of Selenium is of importance regarding public health as the ratio between beneficial daily intake and toxicity is rather low [1], [2]. Also from the radiological perspective, Se-79 as a long-lived fission nuclide (T1/2=2.8x105y) with high mobility in environment, is of concern regarding waste management and decommissioning [3], [4]. Due to the existence of different oxidation states Selenium has a complex speciation chemistry which makes extraction and separation schemes not straightforward. The aim of this research is to develop extraction methods for Selenium based on extraction chromatographic resins allowing for the extraction of Se(VI), as well as Se(IV), from water samples for later use on DGT (Diffusive Gradients in Thin films) devices. Extraction chromatographic resins have been tested and characterized for Se and other elements. For Se(VI) a commercially available Aliquat 336 based extraction chromatographic resin (TEVA resin[5]) was found to be most suitable, for Se(IV) a newly developed extraction chromatographic resin based on Piazselenol chemistry was found to be most effective, data on the selectivity of this resin will be presented. The extraction of Se(IV) and Se(VI) by these resins was tested on water sampled in Lille City, where a high Se spatial variability has been observed. Concentrations in groundwater can reach 30µg/L as a consequence; most Se-contaminated wells are no longer exploited by the water operators. One of the applications of this development is to be able to measure Se concentrations insitu in contaminated areas including very complex object such as hyporheic zone. [1] Cary L. et al. Applied Geochemistry 48 (2014) 70-82 [2] Chen C. et al. Biological Trace Element Research Vols. 71-72 (1999) 131-138 [3] http://www.irsn.fr/FR/Larecherche/publications-documentation/fiches-radionucleides/Documents/environnement/Selenium_Se79_v2.pdf last access 03/03/2016 [4] Uchida et al. WM2009 Conference, March 1-5, 2009, Phoenix, AZ [5] Horwitz P. et al. Analytica Chimica Acta 310 (1995) 63-78

Differences in the responses of three plasma selenium-containing proteins in relation to methylmercury-exposure through consumption of fish/whales.

PubMed

Ser, Ping Han; Omi, Sanae; Shimizu-Furusawa, Hana; Yasutake, Akira; Sakamoto, Mineshi; Hachiya, Noriyuki; Konishi, Shoko; Nakamura, Masaaki; Watanabe, Chiho

2017-02-05

Putative protective effects of selenium (Se) against methylmercury (MeHg) toxicity have been examined but no conclusion has been reached. We recently reported the lack of serious neurological symptoms in a Japanese fish-eating population with high intakes of MeHg and suggested a potential protective role for Se. Here, relationships between levels of Hg and Se in the blood and plasma samples, with a quantitative evaluation of Se-containing proteins, obtained from this population were examined. While levels of the whole-blood Hg (WB-Hg) and plasma Se (P-Se) showed a positive correlation, stratified analysis revealed that they correlated only in samples with higher (greater than the median) levels of MeHg. A food frequency questionnaire showed that consumption of fish/whales correlated with WB-Hg, but not with P-Se, suggesting that the positive correlation between WB-Hg and P-Se might not be the result of co-intake of these elements from seafood. Speciation of plasma Se revealed the differences in the responses of two plasma selenoproteins, glutathione peroxidase (GPx) and selenoprotein P (SePP), in relation to Hg exposure. In the high-Hg group, SePP showed a positive correlation with WB-Hg, but GPx did not. In the low-Hg group, neither SePP nor GPx showed any correlation with WB-Hg. These observations suggest that the increase in P-Se in the high-Hg group might be associated with an increase in SePP, which may, in turn, suggest an increased demand for one or more selenoproteins in various organs, for which SePP supplies the element. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Pig feeds rich in rapeseed products and organic selenium increased omega-3 fatty acids and selenium in pork meat and backfat.

PubMed

Gjerlaug-Enger, Eli; Haug, Anna; Gaarder, Mari; Ljøkjel, Kari; Stenseth, Ragna Sveipe; Sigfridson, Kerstin; Egelandsdal, Bjørg; Saarem, Kristin; Berg, Per

2015-03-01

The concentration of omega-3 fatty acids and selenium (Se) is generally too low in the Western diet. But as the nutrient composition of pork meat and adipose tissue is influenced by the feed given to the animals, the product can be changed to support nutrient demands. Half (297/594) the pigs were given a feed concentrate based on low-glucosinolate rapeseed products (RS), while the other half was fed a traditional concentrate (Contr): The RS feed had an omega-6/omega-3 ratio of 3.6:1, and the Contr feed had a ratio of 8.9:1, and both feeds were supplemented with 0.4 mg Se/kg (organic Se: inorganic Se, 1:1). There was a small difference in growth rate, but no differences in feed conversion ratio, lean meat percentage, carcass value, and margin per pig for the two groups. There were no differences in meat quality between the two groups, but there were differences in technological fat quality. The RS pigs contained about 2 times more alpha-linolenic acid in the backfat and 41% more in the meat (M. longissimus dorsi) compared to the controls. The concentration of EPA, DPA, and DHA were 42% and 20% higher in backfat and meat of the RS pigs compared to the control pigs respectively. The ratio between omega-6/omega-3 fatty acids were 4.7 in the meat and 4.0 in the backfat in the RS pigs, and the corresponding values were 6.6 and 8.0 in the control pigs. The selenium content was 0.3 mg/kg meat in both groups. The study showed that a portion of the present pig meat (175 g) provided the daily recommended intake of Se for men and women and about 1/6 of proposed reference intake of omega-3 LCPUFA (250 mg/day) to reduce the risk of CVD thereby providing a meat that is somewhat healthier for the consumer.

Pig feeds rich in rapeseed products and organic selenium increased omega-3 fatty acids and selenium in pork meat and backfat

PubMed Central

Gjerlaug-Enger, Eli; Haug, Anna; Gaarder, Mari; Ljøkjel, Kari; Stenseth, Ragna Sveipe; Sigfridson, Kerstin; Egelandsdal, Bjørg; Saarem, Kristin; Berg, Per

2015-01-01

The concentration of omega-3 fatty acids and selenium (Se) is generally too low in the Western diet. But as the nutrient composition of pork meat and adipose tissue is influenced by the feed given to the animals, the product can be changed to support nutrient demands. Half (297/594) the pigs were given a feed concentrate based on low-glucosinolate rapeseed products (RS), while the other half was fed a traditional concentrate (Contr): The RS feed had an omega-6/omega-3 ratio of 3.6:1, and the Contr feed had a ratio of 8.9:1, and both feeds were supplemented with 0.4 mg Se/kg (organic Se: inorganic Se, 1:1). There was a small difference in growth rate, but no differences in feed conversion ratio, lean meat percentage, carcass value, and margin per pig for the two groups. There were no differences in meat quality between the two groups, but there were differences in technological fat quality. The RS pigs contained about 2 times more alpha-linolenic acid in the backfat and 41% more in the meat (M. longissimus dorsi) compared to the controls. The concentration of EPA, DPA, and DHA were 42% and 20% higher in backfat and meat of the RS pigs compared to the control pigs respectively. The ratio between omega-6/omega-3 fatty acids were 4.7 in the meat and 4.0 in the backfat in the RS pigs, and the corresponding values were 6.6 and 8.0 in the control pigs. The selenium content was 0.3 mg/kg meat in both groups. The study showed that a portion of the present pig meat (175 g) provided the daily recommended intake of Se for men and women and about 1/6 of proposed reference intake of omega-3 LCPUFA (250 mg/day) to reduce the risk of CVD thereby providing a meat that is somewhat healthier for the consumer. PMID:25838890

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

Selenium cycling across soil-plant-atmosphere interfaces: a critical review.

PubMed

Winkel, Lenny H E; Vriens, Bas; Jones, Gerrad D; Schneider, Leila S; Pilon-Smits, Elizabeth; Bañuelos, Gary S

2015-05-29

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.

Sensitivity and toxic mode of action of dietary organic and inorganic selenium in Atlantic salmon (Salmo salar).

PubMed

Berntssen, M H G; Sundal, T K; Olsvik, P A; Amlund, H; Rasinger, J D; Sele, V; Hamre, K; Hillestad, M; Buttle, L; Ørnsrud, R

2017-11-01

Depending on its chemical form, selenium (Se) is a trace element with a narrow range between requirement and toxicity for most vertebrates. Traditional endpoints of Se toxicity include reduced growth, feed intake, and oxidative stress, while more recent finding describe disturbance in fatty acid synthesis as underlying toxic mechanism. To investigate overall metabolic mode of toxic action, with emphasis on lipid metabolism, a wide scope metabolomics pathway profiling was performed on Atlantic salmon (Salmo salar) (572±7g) that were fed organic and inorganic Se fortified diets. Atlantic salmon were fed a low natural background organic Se diet (0.35mg Se kg -1 , wet weight (WW)) fortified with inorganic sodium selenite or organic selenomethionine-yeast (SeMet-yeast) at two levels (∼1-2 or 15mgkg -1 , WW), in triplicate for 3 months. Apparent adverse effects were assessed by growth, feed intake, oxidative stress as production of thiobarbituric acid-reactive substances (TBARS) and levels of tocopherols, as well as an overall metabolomic pathway assessment. Fish fed 15mgkg -1 selenite, but not 15mgkg -1 SeMet-yeast, showed reduced feed intake, reduced growth, increased liver TBARS and reduced liver tocopherol. Main metabolic pathways significantly affected by 15mgkg -1 selenite, and to a lesser extent 15mgkg -1 SeMet-yeast, were lipid catabolism, endocannabinoids synthesis, and oxidant/glutathione metabolism. Disturbance in lipid metabolism was reflected by depressed levels of free fatty acids, monoacylglycerols and diacylglycerols as well as endocannabinoids. Specific for selenite was the significant reduction of metabolites in the S-Adenosylmethionine (SAM) pathway, indicating a use of methyl donors that could be allied with excess Se excretion. Dietary Se levels to respectively 1.1 and 2.1mgkg -1 selenite and SeMet-yeast did not affect any of the above mentioned parameters. Apparent toxic mechanisms at higher Se levels (15mgkg -1 ) included oxidative stress and altered lipid metabolism for both inorganic and organic Se, with higher toxicity for inorganic Se. Copyright © 2017 Elsevier B.V. All rights reserved.

Nutrigenetics, nutrigenomics, and selenium.

PubMed

Ferguson, Lynnette R; Karunasinghe, Nishi

2011-01-01

Selenium (Se) is an important micronutrient that, as a component of selenoproteins, influences oxidative and inflammatory processes. Its' levels vary considerably, with different ethnic and geographic population groups showing varied conditions, ranging from frank Se deficiencies to toxic effects. An optimum Se level is essential for the maintenance of homeostasis, and this optimum may vary according to life stage, general state of health, and genotype. Nutrigenetic studies of different Se levels, in the presence of genetic variants in selenoproteins, suggest that an effective dietary Se intake for one individual may be very different from that for others. However, we are just starting to learn the significance of various genes in selenoprotein pathways, functional variants in these, and how to combine such data from genes into pathways, alongside dietary intake or serum levels of Se. Advances in systems biology, genetics, and genomics technologies, including genetic/genomic, epigenetic/epigenomic, transcriptomic, proteomic, and metabolomic information, start to make it feasible to assess a comprehensive spectrum of the biological activity of Se. Such nutrigenomic approaches may prove very sensitive biomarkers of optimal Se status at the individual or population level. The premature cessation of a major human Se intervention trial has led to considerable controversy as to the value of Se supplementation at the population level. New websites provide convenient links to current information on methodologies available for nutrigenetics and nutrigenomics. These new technologies will increasingly become an essential tool in optimizing the level of Se and other micronutrients for optimal health, in individuals and in population groups. However, definitive proof of such effects will require very large collaborative studies, international agreement on study design, and innovative approaches to data analysis.

Nutrigenetics, Nutrigenomics, and Selenium

PubMed Central

Ferguson, Lynnette R.; Karunasinghe, Nishi

2011-01-01

Selenium (Se) is an important micronutrient that, as a component of selenoproteins, influences oxidative and inflammatory processes. Its’ levels vary considerably, with different ethnic and geographic population groups showing varied conditions, ranging from frank Se deficiencies to toxic effects. An optimum Se level is essential for the maintenance of homeostasis, and this optimum may vary according to life stage, general state of health, and genotype. Nutrigenetic studies of different Se levels, in the presence of genetic variants in selenoproteins, suggest that an effective dietary Se intake for one individual may be very different from that for others. However, we are just starting to learn the significance of various genes in selenoprotein pathways, functional variants in these, and how to combine such data from genes into pathways, alongside dietary intake or serum levels of Se. Advances in systems biology, genetics, and genomics technologies, including genetic/genomic, epigenetic/epigenomic, transcriptomic, proteomic, and metabolomic information, start to make it feasible to assess a comprehensive spectrum of the biological activity of Se. Such nutrigenomic approaches may prove very sensitive biomarkers of optimal Se status at the individual or population level. The premature cessation of a major human Se intervention trial has led to considerable controversy as to the value of Se supplementation at the population level. New websites provide convenient links to current information on methodologies available for nutrigenetics and nutrigenomics. These new technologies will increasingly become an essential tool in optimizing the level of Se and other micronutrients for optimal health, in individuals and in population groups. However, definitive proof of such effects will require very large collaborative studies, international agreement on study design, and innovative approaches to data analysis. PMID:22303312

Relatively high mortality risk in elderly Swedish subjects with low selenium status.

PubMed

Alehagen, U; Johansson, P; Björnstedt, M; Rosén, A; Post, C; Aaseth, J

2016-01-01

The daily dietary intake of selenium (Se), an essential trace element, is still low in Sweden in spite of decades of nutritional information campaigns and the effect of this on the public health is presently not well known. The objective of this study was to determine the serum Se levels in an elderly Swedish population and to analyze whether a low Se status had any influence on mortality. Six-hundred sixty-eight (n=668) elderly participants were invited from a municipality and evaluated in an observational study. Individuals were followed for 6.8 years and Se levels were re-evaluated in 98 individuals after 48 months. Clinical examination of all individuals included functional classification, echocardiography, electrocardiogram and serum Se measurement. All mortality was registered and endpoints of mortality were assessed by Kaplan-Meier plots, and Cox proportional hazard ratios adjusted for potential confounding factors were calculated. The mean serum Se level of the study population (n=668) was 67.1 μg/l, corresponding to relatively low Se intake. After adjustment for male gender, smoking, ischemic heart disease, diabetes, chronic obstructive pulmonary disease and impaired heart function, persons with serum Se in the lowest quartile had 43% (95% confidence interval (CI): 1.02-2.00) and 56% (95% CI: 1.03-2.36) increased risk for all-cause and cardiovascular mortality, respectively. The result was not driven by inflammatory effects on Se concentration in serum. The mean serum Se concentration in an elderly Swedish population was 67.1 μg/l, which is below the physiological saturation level for several selenoprotein enzymes. This result may suggest the value of modest Se supplementation in order to improve the health of the Swedish population.

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

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.

Dietary habits and selenium intake of residents in mountain and coastal communities in Japan.

PubMed

Miyazaki, Yukiko; Koyama, Hiroshi; Sasada, Yoko; Satoh, Hiroshi; Nojiri, Masami; Suzuki, Shosuke

2004-10-01

We used a Simple Food Frequency Questionnaire (SFFQ) in combination with other dietary approaches to estimate the selenium intake from different food groups based on the average long-term diet, in two rural communities in Japan, one in a mountain area and the other in a coastal area. The intake frequencies of rice and wheat products were significantly different in the two districts. The intake frequencies of fish, meat, and eggs, which are rich in selenium, were not significantly different. The mean dietary selenium intake, estimated from the SFFQ and the 24-h recall method, was 82.7 microg/d (n=234) (range 19.2-180.1 microg/d) in the mountain community. The mean dietary selenium intake estimated from the SFFQ and average value of the normal portion size was 118.0 microg/d (n=123) (range 22.6-255.3 microg/d) in the coastal community. These estimated mean values exceeded the Japanese RDA, although the range of daily selenium intake was large. In the mountain community, fish made the largest contribution to dietary selenium intake (48.2% of daily total), followed by eggs (24.3%), and meat (17.0%). In the coastal community, fish accounted for 57.7% of daily total selenium intake, followed by meat (17.5%), and eggs (16.1%). In both districts, the total contribution of rice and wheat products was around 10%. It was found that the contribution of fish to dietary selenium intake was high and the contribution of cereals was low among Japanese.

Selenium bioaccumulation and hazards in a fish community affected by coal fly ash effluent

USGS Publications Warehouse

Besser, John M.; Giesy, John P.; Brown, Russell W.; Buell, Julie M.; Dawson, G. A.

1996-01-01

Bioaccumulation of selenium (Se) in the fish community of Pigeon River/Pigeon Lake, which receives inputs of Se from a coal fly ash disposal facility, was studied to assess potential hazards of Se to fish, wildlife, and humans. Se concentrations in fish from sites receiving seepage and effluents from fly ash disposal ponds were significantly greater than those in fish from upstream, where Se concentrations were near background concentrations. Se concentrations differed among fish species, and interspecific variation was greatest at the most contaminated locations. Differences in Se bioaccumulation among fish species were not consistently associated with differences in trophic status. Although Se concentrations in northern pike were consistently less than those in likely prey species, large yellow perch contained Se concentrations as great as those in spottail shiners, their likely prey. Se bioaccumulation may have been influenced by differences in habitat preferences, as limnetic species generally contained greater Se concentrations than benthic species. Se concentrations in fish from the lower Pigeon River and Pigeon Lake did not exceed lowest observable adverse effect concentrations (LOAECs) for Se in tissues of fish species, but exceeded LOAECs for dietary Se exposure of sensitive species of birds and mammals. Human consumption of moderate quantities of fish from the areas studied should not result in excessive Se intake.

Effect of forms of selenium on the accumulation of selenium, sulfur, and forms of nitrogen and phosphorus in forage cowpea (Vigna sinensis)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, M.; Singh, N.

1979-05-01

The effects of forms of selenium on the accumulation of sulfur, selenium, and forms of nitrogen and phosphorus in cowpea (Vigna sinensis) were studied in pots in the greenhouse at Haryana Agricultural University, Hissar, India. The soil used was sandy, and forms of selenium added were Na/sub 2/SeO/sub 4/ 10H/sub 2/O, Na/sub 2/SeO/sub 3/ 5H/sub 2/O, H/sub 2/SeO/sub 3/, and elemental selenium at the rate of 0, 1, 2.5 and 5 ppM. Dry matter yield and sulfur content decreased with increased selenium application. This inhibition in plants, attributable to applied selenium, was in the order SeO/sub 4/ > H/sub 2/SeO/submore » 3/ > SeO/sub 3/ > elemental selenium. Plant selenium increased with increasing application of all forms of selenium. The highest plant selenium (11.58 ppM) was in the plants treated with SeO/sub 4/, followed by the plants treated with H/sub 2/SeO/sub 3/, SeO/sub 3/, and elemental selenium. The total plant phosphorus increased with increased selenium application in any form, but maximum phosphorus occurred in SeO/sub 3/-treated plants. The inorganic phosphorus increased similarly, the largest amount occurring in SeO/sub 4/-treated plants. Organic phosphorus decreased with selenium application; minimum concentration was recorded in SeO/sub 4/-treated plants. Soluble nitrogen decreased, relative to the control, with applications of 2.5 and 5 ppM selenium. This decrease was minimal for elemental selenium and maximum for SeO/sub 4/. Soluble nitrogen, in the case of SeO/sub 3/ was higher than for H/sub 2/SeO/sub 3/. Total plant nitrogen and protein also decreased. Amino N, amide N, and ammoniacal and nitrate N increased, compared to the control. The largest amount of all these forms was noted in SeO/sub 4/-treated plants. Overall, among the forms of selenium normally reported in soils, the SeO/sub 4/ form showed the highest inhibition, whereas SeO/sub 3/ showed less than both SeO/sub 4/ and H/sub 2/SeO/sub 3/.« less

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.

High hair selenium mother to fetus transfer after the Brazil nuts consumption.

PubMed

Momčilović, B; Prejac, J; Višnjević, V; Brundić, S; Skalny, A A; Mimica, N

2016-01-01

Lactating mother and her two month old healthy daughter (APGAR 10) gave their scalp hair for a multielement profile analysis; 25 elements were analyzed with the ICP MS. Mother's hair was divided into 5cm long segment proximal to the scull (Young), and the distal segment further up to the hair tip (Old). One centimeter of hair records one month of the metabolic activity of the bioelements in the body. Mother's Young hair and daughters hair have 2.70 and 9.74μgg(-1)Se, a distinctly higher Se concentrations than the Old hair of 0.87μgg(-1). The adequate hair Se concentrations in Croatia women population vary from 0.08 to 0.63μgg(-1); values below or above that range indicate deficiency or excess, respectively. Dietary recall revealed that during the last trimester of pregnancy and over a period of a week, the mother has consumed 135g of Brazil nuts (Bertholletia excelsa) (BN); BN is an exceptionally rich Se dietary source. The amount of Se in BN varies and one week consumption of 135g of BN may result in Se daily intake of 367 to 492μgg(-1)day(-1) over a period of seven consecutive days, and what is about or exceeds the Upper Limit of daily selenium intake of 400μg(-1)g(-1). The excessively high infant hair Se mirrored a natural high mother to fetus transplacental transfer of bio elements in the last trimester of pregnancy. The potential toxicological risks of such a high Se transfer remains to be elucidated. Copyright © 2015 Elsevier GmbH. All rights reserved.

Human metabolism and renal excretion of selenium compounds after oral ingestion of sodium selenite and selenized yeast dependent on the trimethylselenium ion (TMSe) status.

PubMed

Jäger, Thomas; Drexler, Hans; Göen, Thomas

2016-05-01

A human in vivo metabolism study was carried out to investigate the impact of the trimethylselenium ion (TMSe) status on metabolism and toxicokinetics of sodium selenite and selenized yeast. Nine healthy human volunteers were orally exposed to 200 µg selenium as sodium selenite and seven with selenized yeast (100 µg selenium). In each intervention group, three subjects belong to TMSe eliminators. Blood samples were withdrawn before and up to 6 h after administration. Urine samples were collected before and within 24 h after administration. Total selenium (Se) was quantified in blood plasma and urine and low molecular Se species in urine. Selenium concentration in plasma increased from 84.5 ± 13.2 µg Se/L before to 97.4 ± 13.2 µg Se/L 2-3 h after selenite supplementation and 89.5 ± 12.9 µg Se/L to 92.1 ± 13.9 µg Se/L after selenized yeast intake. The oral ingestion caused an additional Se elimination via urine of 16.9 ± 10.6 µg/24 h (TMSe elim.: 10.8 ± 6.9 µg/24 h; non-TMSe elim.: 20.0 ± 11.3 µg Se/24 h) after selenite exposure and 11.8 ± 4.1 µg/24 h (TMSe elim.: 10.8 ± 4.6 µg/24 h; non-TMSe elim.: 12.6 ± 4.2 µg Se/24 h) after selenized yeast exposure. Methyl-2-acetamido-2-deoxy-1-seleno-β-D-galactopyranoside (SeSug1) was the main metabolite in all urine samples, whereas TMSe was another main metabolite in TMSe eliminators' urine. After selenite exposure, a small amount of the dose (0.5 ± 0.2 %) was oxidized to selenate and rapidly excreted via urine. With the exception of selenite exposure in TMSe eliminators, the comparison of total Se and the sum of quantified Se species revealed a high renal portion of unidentified species. The study indicated a different metabolism of inorganic and organic Se compounds in human, but also crucial differences of Se metabolism in TMSe eliminators and non-TMSe eliminators.

Selenium distribution in the Chinese environment and its relationship with human health: A review.

PubMed

Dinh, Quang Toan; Cui, Zewei; Huang, Jie; Tran, Thi Anh Thu; Wang, Dan; Yang, Wenxiao; Zhou, Fei; Wang, Mengke; Yu, Dasong; Liang, Dongli

2018-03-01

This paper reviewed the Se in the environment (including total Se in soil, water, plants, and food), the daily Se intake and Se content in human hair were also examined to elucidate Se distribution in the environment and its effects on human health in China. Approximately 51% of China is Se deficiency in soil, compared with 72% in the survey conducted in 1989. Low Se concentrations in soil, water, plants, human diet and thus human hair were found in most areas of China. The only significant difference was observed between Se-rich and Se-excessive areas for Se contents in water, staple cereal, vegetables, fruits, and animal-based food, no remarkable contrast was found among other areas (p>0.05). This study also demonstrated that 39-61% of Chinese residents have lower daily Se intakes according to WHO/FAO recommended value (26-34μg/day). Further studies should focus on thoroughly understanding the concentration, speciation, and distribution of Se in the environment and food chain to successfully utilize Se resources, remediate Se deficiency, and assess the Se states and eco-effects on human health. Copyright © 2017 Elsevier Ltd. All rights reserved.

Health risk assessment of environmental selenium: Emerging evidence and challenges

PubMed Central

Vinceti, Marco; Filippini, Tommaso; Cilloni, Silvia; Bargellini, Annalisa; Vergoni, Anna Valeria; Tsatsakis, Aristides; Ferrante, Margherita

2017-01-01

New data have been accumulated in the scientific literature in recent years which allow a more adequate risk assessment of selenium with reference to human health. This new evidence comes from environmental studies, carried out in populations characterized by abnormally high or low selenium intakes, and from high-quality and large randomized controlled trials with selenium recently carried out in the US and in other countries. These trials have consistently shown no beneficial effect on cancer and cardiovascular risk, and have yielded indications of unexpected toxic effects of selenium exposure. Overall, these studies indicate that the minimal amount of environmental selenium which is source of risk to human health is much lower than anticipated on the basis of older studies, since toxic effects were shown at levels of intake as low as around 260 µg/day for organic selenium and around 16 µg/day for inorganic selenium. Conversely, populations with average selenium intake of less than 13–19 µg/day appear to be at risk of a severe cardiomyopathy, Keshan disease. Overall, there is the need to reconsider the selenium standards for dietary intake, drinking water, outdoor and indoor air levels, taking into account the recently discovered adverse health effects of low-dose selenium overexposure, and carefully assessing the significance of selenium-induced proteomic changes. PMID:28339083

Health risk assessment of environmental selenium: Emerging evidence and challenges (Review).

PubMed

Vinceti, Marco; Filippini, Tommaso; Cilloni, Silvia; Bargellini, Annalisa; Vergoni, Anna Valeria; Tsatsakis, Aristides; Ferrante, Margherita

2017-05-01

New data have been accumulated in the scientific literature in recent years which allow a more adequate risk assessment of selenium with reference to human health. This new evidence comes from environmental studies, carried out in populations characterized by abnormally high or low selenium intakes, and from high-quality and large randomized controlled trials with selenium recently carried out in the US and in other countries. These trials have consistently shown no beneficial effect on cancer and cardiovascular risk, and have yielded indications of unexpected toxic effects of selenium exposure. Overall, these studies indicate that the minimal amount of environmental selenium which is source of risk to human health is much lower than anticipated on the basis of older studies, since toxic effects were shown at levels of intake as low as around 260 µg/day for organic selenium and around 16 µg/day for inorganic selenium. Conversely, populations with average selenium intake of less than 13-19 µg/day appear to be at risk of a severe cardiomyopathy, Keshan disease. Overall, there is the need to reconsider the selenium standards for dietary intake, drinking water, outdoor and indoor air levels, taking into account the recently discovered adverse health effects of low-dose selenium overexposure, and carefully assessing the significance of selenium-induced proteomic changes.

Adverse systemic arterial function in patients with selenium deficiency.

PubMed

Chan, Y-H; Siu, C-W; Yiu, K-H; Chan, H-T; Li, S-W; Tam, S; Cheung, B M; Lau, C-P; Lam, T H; Tse, H-F

2012-01-01

Experimental studies have shown that selenium is involved in the synthesis of selenoproteins which might contribute to cardiovascular protection. However, the relationship between selenium deficiency and vascular function in clinical context remains unknown. To investigate for any relationship between selenium deficiency and systemic arterial function in patients with high risk of vascular events. Cross-sectional study. 306 consecutive patients with high risk for cardiovascular events (coronary artery disease 35%, acute/ recurrent ischemic stroke 40%, diabetes mellitus 54%) followed up at internal medicine outpatient clinics. Non-invasive brachial-ankle pulse wave velocity (PWV) was determined using vascular profiling system (VP-2000). Long-term intake of selenium was determined by a validated food frequency questionnaire. Mean daily selenium intake was 59.5 ± 52.1 mcg/day, and mean PWV was 1782.4 ± 418.4 cm/s. Patients with selenium intake <10th percentile had significantly higher PWV as compared to patients with intake ≥ 10th percentile (1968.2 ± 648.9 cm/s versus 1762.2 ± 381.6 cm/s, P=0.010). After adjusting for potential confounders including age, gender, history of hypertension, hyperlipidemia, diabetes and cardiovascular disease, smoking status, use of cardiovascular medications, waist-hip ratio, education/ financial status, physical activity, calorie intake and intake of antioxidant vitamins, deficient selenium intake <10th percentile remained independently predictive of increased PWV by +363.4 cm/s [95% CI: 68.1 to 658.6, P=0.016, relative increase 21%]. Selenium deficiency is associated with adverse arterial function in patients with high risk for vascular events.

Evaluation of the Content of Antimony, Arsenic, Bismuth, Selenium, Tellurium and Their Inorganic Forms in Commercially Baby Foods.

PubMed

Ruiz-de-Cenzano, M; Rochina-Marco, A; Cervera, M L; de la Guardia, M

2017-12-01

Baby foods, from the Spanish market and prepared from meat, fish, vegetables, cereals, legumes, and fruits, were analyzed to obtain the concentration of antimony (Sb), arsenic (As), bismuth (Bi), and tellurium (Te) as toxic elements and selenium (Se) as essential element. An analytical procedure was employed based on atomic fluorescence spectroscopy which allowed to obtain accurate data at low levels of concentration. Values of 14 commercial samples, expressed in nanograms per gram fresh weight, ranged for Sb 0.66-6.9, As 4.5-242, Te 1.35-2.94, Bi 2.18-4.79, and Se 5.4-109. Additionally, speciation studies were performed based on data from a non-chromatographic screening method. It was concluded that tellurium and bismuth were mainly present as inorganic forms and selenium as organic form, and antimony and arsenic species depend on the ingredients of each baby food. Risk assessment considerations were made by comparing dietary intake of the aforementioned elements through the consumption of one baby food portion a day and recommended or tolerable guideline values.

Selenium Biofortification in Fragaria × ananassa: Implications on Strawberry Fruits Quality, Content of Bioactive Health Beneficial Compounds and Metabolomic Profile

PubMed Central

Mimmo, Tanja; Tiziani, Raphael; Valentinuzzi, Fabio; Lucini, Luigi; Nicoletto, Carlo; Sambo, Paolo; Scampicchio, Matteo; Pii, Youry; Cesco, Stefano

2017-01-01

Selenium (Se) is an essential nutrient for humans, due to its antioxidant properties, whereas, to date, its essentiality to plants still remains to be demonstrated. Nevertheless, if added to the cultivation substrate, plants growth resulted enhanced. However, the concentration of Se in agricultural soils is very variable, ranging from 0.01 mg kg-1 up to 10 mg kg-1 in seleniferous areas. Therefore several studies have been performed aimed at bio-fortifying crops with Se and the approaches exploited were mainly based on the application of Se fertilizers. The aim of the present research was to assess the biofortification potential of Se in hydroponically grown strawberry fruits and its effects on qualitative parameters and nutraceutical compounds. The supplementation with Se did not negatively affect the growth and the yield of strawberries, and induced an accumulation of Se in fruits. Furthermore, the metabolomic analyses highlighted an increase in flavonoid and polyphenol compounds, which contributes to the organoleptic features and antioxidant capacity of fruits; in addition, an increase in the fruits sweetness also was detected in biofortified strawberries. In conclusion, based on our observations, strawberry plants seem a good target for Se biofortification, thus allowing the increase in the human intake of this essential micronutrient. PMID:29163609

Selenium Biofortification in Fragaria × ananassa: Implications on Strawberry Fruits Quality, Content of Bioactive Health Beneficial Compounds and Metabolomic Profile.

PubMed

Mimmo, Tanja; Tiziani, Raphael; Valentinuzzi, Fabio; Lucini, Luigi; Nicoletto, Carlo; Sambo, Paolo; Scampicchio, Matteo; Pii, Youry; Cesco, Stefano

2017-01-01

Selenium (Se) is an essential nutrient for humans, due to its antioxidant properties, whereas, to date, its essentiality to plants still remains to be demonstrated. Nevertheless, if added to the cultivation substrate, plants growth resulted enhanced. However, the concentration of Se in agricultural soils is very variable, ranging from 0.01 mg kg -1 up to 10 mg kg -1 in seleniferous areas. Therefore several studies have been performed aimed at bio-fortifying crops with Se and the approaches exploited were mainly based on the application of Se fertilizers. The aim of the present research was to assess the biofortification potential of Se in hydroponically grown strawberry fruits and its effects on qualitative parameters and nutraceutical compounds. The supplementation with Se did not negatively affect the growth and the yield of strawberries, and induced an accumulation of Se in fruits. Furthermore, the metabolomic analyses highlighted an increase in flavonoid and polyphenol compounds, which contributes to the organoleptic features and antioxidant capacity of fruits; in addition, an increase in the fruits sweetness also was detected in biofortified strawberries. In conclusion, based on our observations, strawberry plants seem a good target for Se biofortification, thus allowing the increase in the human intake of this essential micronutrient.

Effect of Selenium Supplementation on Redox Status of the Aortic Wall in Young Spontaneously Hypertensive Rats

PubMed Central

Ruseva, Boryana; Atanasova, Milena; Tsvetkova, Reni; Betova, Tatyana; Mollova, Margarita; Alexandrova, Margarita; Laleva, Pavlina; Dimitrova, Aneliya

2015-01-01

Selenium (Se) is an exogenous antioxidant that performs its function via the expression of selenoproteins. The aim of this study was to explore the effect of varying Se intake on the redox status of the aortic wall in young spontaneously hypertensive rats (SHR). Sixteen male Wistar Kyoto (WKY) rats and nineteen male SHR, 16-week-old, were tested after being given diets with different Se content for eight weeks. They were divided into 4 groups: control groups of WKY NSe and SHR NSe on an adequate Se diet and groups of WKY HSe and SHR HSe that received Se supplementation. The Se nutritional status was assessed by measuring whole blood glutathione peroxidase-1 (GPx-1) activity. Serum concentration of lipid hydroperoxides and serum level of antibodies against advanced glycation end products (anti-AGEs abs) were determined. Expression of GPx-1 and endothelial nitric oxide synthase (eNOS) were examined in aortic wall. Se supplementation significantly increased GPx-1 activity of whole blood and in the aortas of WKY and SHR. Decreased lipid peroxidation level, eNOS-3 expression in the aortic wall, and serum level of anti-AGEs abs were found in SHR HSe compared with SHR NSe. In conclusion, Se supplementation improved the redox status of the aortic wall in young SHR. PMID:26473024

Distribution of manganese and selenium in four different pork cuts commercially available in the Serbian market

NASA Astrophysics Data System (ADS)

Đinović-Stojanović, J.; Nikolić, D.; Janković, S.; Vranić, D.; Milijašević, M.; Babić-Milijašević, J.

2017-09-01

This study aimed to provide information on levels of Mn and Se in four different pork cuts (loin, neck, hind leg and shoulder) commercially available on the Serbian market, with a view to providing information on dietary intakes of metals associated with the consumption of these meat cuts. In total, for 50 pork cuts, the levels of Mn and Se were determined by inductively-coupled plasma mass spectrometry (ICP-MS). The following ranges of Mn and Se were found (mg kg-1) in loin 0.055-0.130 and 0.074-0.365, in neck 0.014-0.365 and 0.045-0.196, in hind leg 0.032-0.099 and 0.066-0.123, in shoulder 0.012-0.290 and 0.027-0.515, respectively. The highest mean levels were obtained for Mn (0.124 mg kg-1) in shoulder and for Se (0.209 mg kg-1) in loin. The Estimated Daily Intake (EDI) of essential elements through consumption of 114.1 g mammalian meat/person/day was below 1% of Adequate Intake (AI) for Mn and between 18.9% and 43.2% of Recommended Dietary Allowance (RDA) for Se.

Effects of supplementation of fertilizers on human selenium status in Finland.

PubMed

Aro, A; Alfthan, G; Varo, P

1995-03-01

The Se concentration of foods can be increased by supplementing fertilizers with soluble Se compounds. In Finland the availability of soil Se for plants is poor owing to the relatively low Se concentration, low pH and high iron content of the soil. Since 1984 multimineral fertilizers have been supplemented with Se (16 mg kg-1 to fertilizers for grain production and 6 mg kg-1 to those for fodder production) in the form of sodium selenate. Within two years a three-fold increase of mean Se intake was observed. The supplementation affected the Se content of all major food groups with the exception of fish. The concomitant human serum Se concentration increased by 70%. In 1990 the amount of Se that was supplemented was reduced to 6 mg kg-1 for all fertilizers. This reduced the mean Se intake by 30% and the serum Se concentration decreased by 25% from the highest levels observed in 1989. Plants take up part of the supplemented selenate and transform it into organic Se compounds, mainly selenomethionine. This affects human nutrition by increasing the Se content of foods of both animal and vegetable origin. According to data obtained in Finland, supplementation of fertilizers with Se is a safe and effective means of increasing the Se intake of both animals and humans that is feasible in countries with relatively uniform geochemical conditions. This kind of intervention requires careful monitoring of the effects on both animal and human nutrition and the environment.

Se status in normal and pathological human individuals before and after Se supplementation

NASA Astrophysics Data System (ADS)

Bellisola, G.; Cinque, G.; Galassini, S.; Guidi, G. C.; Liu, N. Q.; Moschini, G.

1996-04-01

The determination of selenium in plasma and in urine samples has been suggested for the assessment of Se status in human individuals. The kidney is of fundamental importance in Se homeostasis: with low Se intake its excretion will be decreased and with high Se intake it will be increased. In 21 patients with kidney disease (8 with normal kidney function and 13 with moderate renal failure) Se was measured in 1 ml of urine by PIXE after preconcentration of the sample. The total urine volume was measured to calculate total daily Se excretion. The same procedure was applied to 14 normal individuals for comparison. All individuals were then supplemented orally with selenite for 8 weeks (Se = 600 μg/day) and the procedure was repeated. The behaviour of the major selenoproteins was also investigated by measuring glutathione peroxidase activities in plasma, in platelets and in erythrocyte samples. For renal function, serum and urine creatinine concentrations were utilised and creatinine clearances were calculated. Results obtained were compared before and after Se treatment and between groups. Some correlation studies were carried out between Se and kidney functions and/or selenoperoxidase activities.

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 into non-functional proteins, through the synthesis of less toxic Se metabilites. There is potential to breed or select crops with greater Se concentrations in their edible tissues, which might be used to increase dietary Se intakes of animals and humans. PMID:26718221

Selenium accumulation by plants.

PubMed

White, Philip J

2016-02-01

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. 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. 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 into non-functional proteins, through the synthesis of less toxic Se metabilites. There is potential to breed or select crops with greater Se concentrations in their edible tissues, which might be used to increase dietary Se intakes of animals and humans. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Unimolecular rearrangement of the simplest compound models with a selenium-oxygen, selenium-sulphur and selenium-selenium bond: SeXH and HSeXH (X = O,S,Se)

NASA Astrophysics Data System (ADS)

Viana, Rommel B.

2017-04-01

The aim of this study was to characterise the simplest compound models with a selenium-oxygen, selenium-sulphur and selenium-selenium bond as the SeXH and HSeXH isomers (X = O,S,Se). One of the main aspects of this investigation was to provide a description on the isomerisation pathways involving 2[H,Se,X] and 1[2H,Se,X] potential energy surfaces calculated at the CCSD(T)/CBS//MP2/cc-pVTZ level. The energy difference was 13 kcal mol-1 between hydroxyselenide (SeOH) and oxoselenium (HSeO), while a gap of 3 kcal mol-1 was predicted between thiol-selenide (SeSH) and selenol-sulphide (HSeS). The SeOH→HSeO unimolecular rearrangement showed a barrier energy of 44.6 kcal mol-1, decreasing almost two times in sulphur and selenium analogous reactions. In addition, hydroxyselenide (HSeOH), thioselenenic acid (HSeSH) and diselane (HSeSeH) were the global minimum configurations in the ground state, while the energy differences among the other isomers were close to 30 kcal mol-1. The HSeXH→H2SeX and HSeXH→SeXH2 isomerisations showed barrier energies ranging from 40 to 65 kcal mol-1, while these reverse routes presented heights that were three times smaller. The kinetic rate constant of each 1,2-H shift reaction was performed here as well as an analysis of the selenium-chalcogen bonds using natural bond orbital and bond order index methodologies.

Rumen Microorganisms Decrease Bioavailability of Inorganic Selenium Supplements.

PubMed

Galbraith, M L; Vorachek, W R; Estill, C T; Whanger, P D; Bobe, G; Davis, T Z; Hall, J A

2016-06-01

Despite the availability 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 was to determine whether rumen microorganisms (RMO) alter the bioavailability of Se sources commonly used in Se supplements. Rumen microorganisms were isolated from ewes (n = 4) and incubated ex vivo with no Se (control), with inorganic Na selenite or Na selenate, or with organic selenomethionine (SeMet). Total Se incorporated into RMO and the amount of elemental Se formed were determined under equivalent conditions. Incorporation of Se from Na selenite, Na selenate, or SeMet into RMO was measured as fold change compared with control (no added Se). Incorporation of Se into microbial mass was greater for SeMet (13.2-fold greater than no-Se control) compared with inorganic Se supplements (P = 0.02); no differences were observed between inorganic Na selenate (3.3-fold greater than no-Se control) and Na selenite (3.5-fold greater than no-Se control; P = 0.97). Formation of non-bioavailable, elemental Se was less for RMO incubated with SeMet compared with inorganic Se sources (P = 0.01); no differences were observed between Na selenate and Na selenite (P = 0.09). The clinical importance of these results is that the oral bioavailability of organic SeMet should be greater compared with inorganic Se sources because of greater RMO incorporation of Se and decreased formation of elemental Se by RMO.

The effect of dietary vitamin E level on selenium status in rats.

PubMed

Fujihara, T; Orden, E A

2014-10-01

The effect of varying levels of dietary vitamin E on selenium status was determined using 40 Wistar rats with similar initial body weight. The rats were equally divided into four groups and fed the following dietary treatments (mg vitamin E/kg DM): 18 (control; C-diet), 0 (0E-diet), 9 (0.5E-diet) and 36 (2E-diet) for either 4-week (Phase 1) or 8-week (Phase 2) period. At the end of experiment, animals were slaughtered to measure vitamin E and selenium levels in the brain, liver, spleen, kidney, muscles and blood tissues. Dietary vitamin E levels did not affect feed and water intake and body weight. But whole-blood selenium concentration in rats fed 0E-diet was higher than in rats fed 2E-diet after 4 weeks. Selenium level in muscle, spleen and brain was also higher (p < 0.05) in rats fed the 0E-diet than in rats fed C-diet after 4 weeks of feeding. On the other hand, selenium level in the muscle was lower (p < 0.05) in rats fed 0.5E-diet than in those fed 0E-diet after 4 weeks of feeding, but not after 8 weeks of feeding. Increasing dietary vitamin E level directly influenced selenium content of the spleen and brain after 8 weeks of feeding 2E-diet. Moreover, the twofold increase in vitamin E intake resulted in a tendency to reduce whole-blood selenium level and total selenium in the liver and kidney after 4 and 8 weeks. The results showed that the increasing dietary vitamin E level resulted in a tendency to reduce Se contents in some vital organs of the body such as the liver and kidney, suggesting their close compensatory interrelationship. Therefore, dietary vitamin E level directly influenced selenium metabolism in the animal body. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

Bioaccumulation and toxicity of selenium compounds in the green alga Scenedesmus quadricauda

PubMed Central

Umysová, Dáša; Vítová, Milada; Doušková, Irena; Bišová, Kateřina; Hlavová, Monika; Čížková, Mária; Machát, Jiří; Doucha, Jiří; Zachleder, Vilém

2009-01-01

Background Selenium is a trace element performing important biological functions in many organisms including humans. It usually affects organisms in a strictly dosage-dependent manner being essential at low and toxic at higher concentrations. The impact of selenium on mammalian and land plant cells has been quite extensively studied. Information about algal cells is rare despite of the fact that they could produce selenium enriched biomass for biotechnology purposes. Results We studied the impact of selenium compounds on the green chlorococcal alga Scenedesmus quadricauda. Both the dose and chemical forms of Se were critical factors in the cellular response. Se toxicity increased in cultures grown under sulfur deficient conditions. We selected three strains of Scenedesmus quadricauda specifically resistant to high concentrations of inorganic selenium added as selenite (Na2SeO3) – strain SeIV, selenate (Na2SeO4) – strain SeVI or both – strain SeIV+VI. The total amount of Se and selenomethionine in biomass increased with increasing concentration of Se in the culturing media. The selenomethionine made up 30–40% of the total Se in biomass. In both the wild type and Se-resistant strains, the activity of thioredoxin reductase, increased rapidly in the presence of the form of selenium for which the given algal strain was not resistant. Conclusion The selenium effect on the green alga Scenedesmus quadricauda was not only dose dependent, but the chemical form of the element was also crucial. With sulfur deficiency, the selenium toxicity increases, indicating interference of Se with sulfur metabolism. The amount of selenium and SeMet in algal biomass was dependent on both the type of compound and its dose. The activity of thioredoxin reductase was affected by selenium treatment in dose-dependent and toxic-dependent manner. The findings implied that the increase in TR activity in algal cells was a stress response to selenium cytotoxicity. Our study provides a new insight into the impact of selenium on green algae, especially with regard to its toxicity and bioaccumulation. PMID:19445666

Selenium exposure in subjects living in areas with high selenium concentrated drinking water: results of a French integrated exposure assessment survey.

PubMed

Emmanuelle, Barron; Virginie, Migeot; Fabienne, Séby; Isabelle, Ingrand; Martine, Potin-Gautier; Bernard, Legube; Sylvie, Rabouan

2012-04-01

Selenium is an essential element which can be toxic if ingested in excessive quantities. The main human exposure is food. In addition, intake may be boosted by consumption drinking water containing unusual high selenium concentration. We measured the individual selenium level of people exposed to selenium concentration in drinking water greater than the maximum recommended limit which is 10 μg/L. We carried out a prospective cohort study on 80 adults (40 exposed subjects i.e. living in the involved area and 40 non-exposed ones i.e. living elsewhere) in western France. We used three different approaches: (1) direct measurement of ingested selenium by the duplicate portion method, (2) dietary reconstitution with a food frequency questionnaire (FFQ) and (3) evaluation of the individual selenium status by measuring the selenium content in toenail clippings. Analyses were performed by inductively coupled plasma-mass spectrometry. The association between toenail selenium concentration and area of residence was analyzed using linear regression with repeated measurements. We estimated selenium intake from FFQ at 64±14 μg/day for exposed subjects as opposed to 52±14 μg/day for the non-exposed ones. On the basis of 305 duplicate diet samples, average intake was estimated at 64±26 μg/day for exposed subjects. Area of residence (p=0.0030) and smoking (p=0.0054) were independently associated with toenail selenium concentration. Whatever method used for estimating selenium intake, the selenium level in this studied area with high selenium concentrated drinking water is much lower than in seleniferous areas. Copyright © 2011 Elsevier Ltd. All rights reserved.

Review: Selenium contamination, fate, and reactive transport in groundwater in relation to human health

NASA Astrophysics Data System (ADS)

Bailey, Ryan T.

2017-06-01

Selenium (Se) is an essential micro-nutrient for humans, but can be toxic at high levels of intake. Se deficiency and Se toxicity are linked with serious diseases, with some regions worldwide experiencing Se deficiency due to Se-poor rocks and soils and other areas dealing with Se toxicity due to the presence of Se-enriched geologic materials. In addition, Se is consumed primarily through plants that take up Se from soil and through animal products that consume these plants. Hence, the soil and groundwater system play important roles in determining the effect of Se on human health. This paper reviews current understanding of Se fate and transport in soil and groundwater systems and its relation to human health, with a focus on alluvial systems, soil systems, and the interface between alluvial systems and Cretaceous shale that release Se via oxidation processes. The review focuses first on the relation between Se and human health, followed by a summary of Se distribution in soil-aquifer systems, with an emphasis on the quantitative relationship between Se content in soil and Se concentration in underlying groundwater. The physical, chemical, and microbial processes that govern Se fate and transport in subsurface systems then are presented, followed by numerical modeling techniques used to simulate these processes in study regions and available remediation strategies for either Se-deficient or Se-toxic regions. This paper can serve as a guide to any field, laboratory or modeling study aimed at assessing Se fate and transport in groundwater systems and its relation to human health.

Preparation and characterization of a laboratory scale selenomethionine-enriched bread. Selenium bioaccessibility.

PubMed

Sánchez-Martínez, María; Pérez-Corona, Teresa; Caímara, Carmen; Madrid, Yolanda

2015-01-14

This study focuses on the preparation at lab scale of selenomethionine-enriched white and wholemeal bread. Selenium was supplemented either by adding selenite directly to the dough or by using lab-made selenium-enriched yeast. The best results were obtained when using fresh selenium-enriched yeast. The optimum incubation time for selenomethionine-enriched yeast preparation, while keeping formation of selenium byproducts to a minimum, was 96 h. Selenium content measured by isotope dilution analysis (IDA)-ICP-MS in Se-white and Se-wholemeal bread was 1.28 ± 0.02 μg g–1 and 1.16 ± 0.02 μg g–1 (expressed as mean ± SE, 3 replicates), respectively. HPLC postcolumn IDA-ICP-MS measurements revealed that selenomethionine was the main Se species found in Se-enriched bread, which accounted for ca. 80% of total selenium. In vitro gastrointestinal digestion assay provided selenium bioaccessibility values of 100 ± 3% and 40 ± 1% for white and wholemeal Se-enriched bread, respectively, being selenomethionine the main bioaccessible Se species in white bread, while in wholemeal bread this compound was undetectable.

Absorption of excess selenium and sulfur by plants and animals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayland, H.F.

1995-09-01

High concentrations of selenium (Se) and sulfur (S) often occur in over-burden soils and underlying shales associated with western coal mining areas. Knowing the role of Se and S in the soil-plant-animal system is important for proper management of mine spoil reclamation. This paper will discuss recent findings about Se and S forms in soils, their absorption and accumulation by plants, and their subsequent toxicity to grazing animals. Selenium absorbed by the accumulating plants is generally metabolized to non-protein forms, while that absorbed by the non-accumulating plants occurs predominantly as selenomethionine. Selenomethionine is readily absorbed by animals. In animals, bothmore » acute and chronic forms of selenosis are known. Death occurs when a large dose of highly-available Se is ingested. One chronic form includes symptoms of inappetence, hair loss, hardening and extension of nails and hooves, reduced weight gains, and poor reproductive performance. Beath and Rosenfield identified {open_quotes}blind staggers{close_quotes} as another from of selenosis, but this disorder; more appropriately called polioencephalomalcia (PEM), occurred only in ruminants. However; the historical association of selenosis to blind staggers has been questioned. Recent experimental evidence has shown that PEM is likely caused by excess SO{sub 4}. Cases of this disorder have been documented in the USA and Canada when ruminants have high S intake from herbage and/or drinking water. Western mine reclamation decisions should consider the potential for not only excess Se, but also excess SO{sub 4} in water, soil, and plants.« less

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

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

The response of broccoli (Brassica oleracea convar. italica) varieties on foliar application of selenium: uptake, translocation, and speciation.

PubMed

Šindelářová, Kristýna; Száková, Jiřina; Tremlová, Jana; Mestek, Oto; Praus, Lukáš; Kaňa, Antonín; Najmanová, Jana; Tlustoš, Pavel

2015-01-01

A model small-scale field experiment was set up to investigate selenium (Se) uptake by four different varieties of broccoli plants, as well as the effect of Se foliar application on the uptake of essential elements for plants calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), sulfur (S), and zinc (Zn). Foliar application of sodium selenate (Na2SeO4) was carried out at two rates (25 and 50 g Se/ha), and an untreated control variant was included. Analyses of individual parts of broccoli were performed, whereby it was found that Se in the plant accumulates mainly in the flower heads and slightly less in the leaves, stems, and roots, regardless of the Se rate and broccoli variety. In most cases, there was a statistically significant increase of Se content in all parts of the plant, while there was no confirmed systematic influence of the addition of Se on the changing intake of other monitored elements. Selenization of broccoli leads to an effective increase in the Se content at a rate of 25 g/ha, whereas the higher rate did not result in a substantial increase of Se content compared to the lower rate in all varieties. Therefore, the rate of 25 g/ha can be recommended as effective to produce broccoli with an increased Se content suitable for consumption. Moreover, Se application resulted in an adequate increase of the main organic compounds of Se, such as selenocystine (SeCys2), selenomethionine (SeMet), and Se-methylselenocysteine (Se-MeSeCys).

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.

Assessment of selenium nutritional status of school-age children from rural areas of China in 2002 and 2012.

PubMed

Liu, X; Piao, J; Li, M; Zhang, Y; Yun, C; Yang, C; Yang, X

2016-03-01

To assess the selenium nutritional status of 3458 school-age children recruited from rural areas using the China Nutrition and Health Survey 2002 and 2012 (CNHS 2002 and CNHS 2012). The serum selenium concentration was determined by high-resolution inductively coupled plasma mass spectrometry. The prevalence of dietary selenium intake insufficiency was calculated according to the formula suggested by and the estimated average requirements of the new Chinese Dietary Reference Intakes. The percentage of low selenium was based on the cutoff values with a serum selenium concentration below the threshold limit of clinical importance in coronary and cardiovascular diseases (<45 μg/l) and in abnormal physiological functions (<60 μg/l). The overall median serum selenium concentration was 64.3 μg/l in the CNHS 2002 and 74.2 μg/l in the CNHS 2012. The median calculated dietary selenium intake was 26.7 μg/day in the CNHS 2002 and 33.2 μg/day in the CNHS 2012 together with a 61.1% and 52.8% dietary selenium intake insufficiency in the CNHS 2002 and in the CNHS 2012. In addition, the percentages of low selenium (<45 μg/l and <60 μg/l) were 25.1 and 43.8% in the CNHS 2002 but 9.4 and 25.6% in the CHNS 2012. The selenium nutritional status of school-age children was significantly improved in the CNHS 2012 versus the CNHS 2002. However, the health risk for selenium malnutrition in school-age children remains a potential problem affecting children's health.

Supplementation of selenium, vitamin E, chromium and betaine above recommended levels improves lactating performance of sows over summer.

PubMed

Liu, Fan; Cottrell, Jeremy James; Collins, Cherie Louise; Henman, David James; O'Halloran, Kirrily Sharon Beatrice; Dunshea, Frank Rowland

2017-10-01

Heat stress (HS) exacerbates the body weight loss of lactating sows and reduces litter weight gain. Selenium (Se), vitamin E (VE), chromium (Cr) and betaine have been shown to ameliorate symptoms of HS, and yeast nucleotides and mannan oligosaccharides have been reported to improve lactational performance and immune response in pigs. Therefore, a combination of these nutrients may improve lactational performance of sows in summer. The effects of two nutritionally enhanced diets on lactational performance of sows in summer were investigated in two experiments. In experiment 1, we compared the effects of a nutritionally fortified diet (0.4 ppm Se, 95 IU/kg VE, 0.4 ppm Cr and 0.2% betaine; named as SVCB diet) with the NRC 2012 standard diet (0.15 ppm Se, 44 IU/kg VE) on lactational performance of sows in summer. Results showed that the SVCB diet reduced body weight loss (P = 0.039) and tended to reduce backfat loss (P = 0.075) of sows without affecting feed intake, while litter weight gain was not influenced. In experiment 2, we further enhanced the nutrients in the SVCB diet (0.8 ppm Se, 1% yeast nucleotides, and 0.1% mannan oligosaccharides; named as SNM diet). Results showed that the SNM diet did not improve feed intake of sows, farrowing performance, or litter weight gain compared with the SVCB diet, but increased body weight loss of the third parity sows (P = 0.037). Overall, a combined supplementation of Se, VE, Cr, and betaine above the NRC recommended levels can reduce mobilisation of body reserve of lactating sows in summer.

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. GPx expression was significantly increased in the low dose group indicating an induced antioxidant response. Expression of other genes were not significantly induced or suppressed. Overall, there was very little evidence of oxidative stress, and therefore, in contrast to previous reports on other species of teleost fishes, oxidative stress is not believed to be a main driver of toxicity in white sturgeon exposed to SeMet. Copyright © 2016 Elsevier Inc. All rights reserved.

Risk of chronic low-dose selenium overexposure in humans: insights from epidemiology and biochemistry.

PubMed

Vinceti, Marco; Maraldi, Tullia; Bergomi, Margherita; Malagoli, Carlotta

2009-01-01

The latest developments of epidemiologic and biochemical research suggest that current upper limits of intake for dietary selenium and for overall selenium exposure may be inadequate to protect human health. In particular, recent experimental and observational prospective studies indicate a diabetogenic effect of selenium at unexpectedly low levels of intake. Experimental evidence from laboratory studies and veterinary medicine appears to confirm previous epidemiologic observations that selenium overexposure is associated with an increased risk of amyotrophic lateral sclerosis, and a recent large trial indicated no beneficial effect in preventing prostate cancer. Moreover, the pro-oxidant properties of selenium species and the observation that the selenium-containing enzymes glutathione peroxidases are induced by oxidative stress imply that the increase in enzymatic activity induced by this metalloid may represent at least in part a compensatory response. Taken together, the data indicate that the upper safe limit of organic and inorganic selenium intake in humans may be lower than has been thought and that low-dose chronic overexposure to selenium may be considerably more widespread than supposed.

Effect of dietary selenium and omega-3 fatty acids on muscle composition and quality in broilers

PubMed Central

Haug, Anna; Eich-Greatorex, Susanne; Bernhoft, Aksel; Wold, Jens P; Hetland, Harald; Christophersen, Olav A; Sogn, Trine

2007-01-01

Background Human health may be improved if dietary intakes of selenium and omega-3 fatty acids are increased. Consumption of broiler meat is increasing, and the meat content of selenium and omega-3 fatty acids are affected by the composition of broiler feed. A two-way analyses of variance was used to study the effect of feed containing omega-3 rich plant oils and selenium enriched yeast on broiler meat composition, antioxidation- and sensory parameters. Four different wheat-based dietary treatments supplemented with 5% rapeseed oil or 4% rapeseed oil plus 1% linseed oil, and either 0.50 mg selenium or 0.84 mg selenium (organic form) per kg diet was fed to newly hatched broilers for 22 days. Results The different dietary treatments gave distinct different concentrations of selenium and fatty acids in thigh muscle; one percent linseed oil in the diet increased the concentration of the omega-3 fatty acids 18:3, 20:5 and 22:5, and 0.84 mg selenium per kg diet gave muscle selenium concentration at the same level as is in fish muscle (0.39 mg/kg muscle). The high selenium intake also resulted in increased concentration of the long-chain omega-3 fatty acids EPA (20:5), DPA (22:5) and DHA (22:6), thus it may be speculated if high dietary selenium might have a role in increasing the concentration of EPA, DPA and DHA in tissues after intake of plant oils contning omega-3 fatty acids. Conclusion Moderate modifications of broiler feed may give a healthier broiler meat, having increased content of selenium and omega-3 fatty acids. High intakes of selenium (organic form) may increase the concentration of very long-chain omega-3 fatty acids in muscle. PMID:17967172

Determination of changes in the concentration and distribution of elements within olive drupes (cv. Leccino) from Se biofortified plants, using laser ablation inductively coupled plasma mass spectrometry.

PubMed

D'Amato, Roberto; Petrelli, Maurizio; Proietti, Primo; Onofri, Andrea; Regni, Luca; Perugini, Diego; Businelli, Daniela

2018-03-25

Biofortification of food crops has been used to increase the intake of Se in the human diet, even though this may change the concentration of other elements and modify the nutritional properties of the enriched food. Selenium biofortification programs should include routine assessment of the overall mineral composition of enriched plants. Laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS) was used for the assessment of mineral composition of table olives. Olive trees were fertilized with sodium selenate before flowering. At harvest, the edible parts of drupes proved to be significantly enriched in Se, delivering 6.1 μg g -1 (39% of the RDA for five olives). Such enrichment was followed by significant changes in the concentrations of B, Mg, K, Cr, Mn, Fe and Cu in edible parts, which are discussed for their impact on food quality. The biofortification of olive plants has allowed the enrichment of fruits with selenium. Enrichment with selenium has caused an increase in the concentration of other elements, which can change the nutritional quality of the drupes. The analytical technique used well as a valuable tool for routinely determining the chemical composition of all fruit parts. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Selenium intake and metabolic syndrome: A systematic review.

PubMed

Retondario, Anabelle; Fernandes, Ricardo; Rockenbach, Gabriele; Alves, Mariane de Almeida; Bricarello, Liliana Paula; Trindade, Erasmo Benicio Santos de Moraes; Vasconcelos, Francisco de Assis Guedes de

2018-03-02

Metabolic syndrome is a multi-causal disease. Its treatment includes lifestyle changes with a focus on weight loss. This systematic review assessed the association between Selenium intake and metabolic syndrome. Data were collected mainly from four databases: PubMed, CENTRAL (Cochrane), Scopus and Web of Knowledge. Keywords related to metabolic syndrome, selenium, as well as metabolic syndrome features were searched. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. A systematic review protocol was registered at PROSPERO (n. 42016046321). Two reviewers independently screened 2957 abstracts. Six studies were included to perform data extraction with standardized spreadsheets. The risk of bias was assessed by using specific tools according to the design of the relevant studies. An assessment was carried out based on the appropriateness of the study reports accordingly to STROBE and the CONSORT-based checklist for each study design. Three studies found no association between Selenium intake and metabolic syndrome; two of them found an inverse association; and one study found a direct association between Selenium intake and metabolic syndrome. One study also showed an inverse association between Selenium intake and the prevalence of high waist circumference, high diastolic blood pressure, and hyperglycaemia in women. Overall, based on the argumentation and results of this study, it is possible to conclude that Selenium intake and metabolic syndrome are not clearly associated in adults and elderly. Copyright © 2018 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Improvement of antioxidant status after Brazil nut intake in hypertensive and dyslipidemic subjects.

PubMed

Huguenin, Grazielle V B; Oliveira, Glaucia M M; Moreira, Annie S B; Saint'Pierre, Tatiana D; Gonçalves, Rodrigo A; Pinheiro-Mulder, Alessandra R; Teodoro, Anderson J; Luiz, Ronir R; Rosa, Glorimar

2015-05-29

To investigate the effect of partially defatted Granulated Brazil nut (GBN) on biomarkers of oxidative stress and antioxidant status of hypertensive and dyslipidemic patients on nutrition and drug approaches. Ninety one hypertensive and dyslipidemic subjects of both genders (51.6 % men), mean age 62.1 ± 9.3 years, performed a randomized crossover trial, double-blind, placebo controlled. Subjects received a diet and partially defatted GBN 13 g per day (≈227.5 μg/day of selenium) or placebo for twelve weeks with four-week washout interval. Anthropometric, laboratory and clinic characteristics were investigated at baseline. Plasma selenium (Se), plasma glutathione peroxidase (GPx3) activity, total antioxidant capacity (TAC), 8-epi PGF2α and oxidized LDL were evaluated at the beginning and in the end of each intervention. GBN intake significantly increased plasma Se from 87.0 ± 16.8 to 180.6 ± 67.1 μg/L, increased GPx3 activity in 24,8% (from 112.66 ± 40.09 to 128.32 ± 38.31 nmol/min/mL, p < 0,05), and reduced 3.25% of oxidized-LDL levels (from 66.31 ± 23.59 to 60.68 ± 20.88 U/L, p < 0.05). An inverse association between GPx3 and oxidized LDL levels was observed after supplementation with GBN by simple model (β -0.232, p = 0.032) and after adjustment for gender, age, diabetes and BMI (β -0.298, p = 0.008). There wasn't association between GPx3 and 8-epi PGF2α (β -0.209, p = 0.052) by simple model. The partially defatted GBN intake has a potential benefit to increase plasma selenium, increase enzymatic antioxidant activity of GPx3 and to reduction oxidation in LDL in hypertensive and dyslipidemic patients. ClinicalTrials.gov Identifier NCT01990391; November 20, 2013.

Bioavailability of seleno-compounds in the lactating rat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, A.M.; Picciano, M.F.

Previously the authors reported an increased selenium (Se) requirement for lactating rats of at least 0.2 ppm dietary Se if provided as selenite (SEL). In the present study bioavailability of selenomethionine (SEM), Se yeast (SEY) and SEL was assessed. A casein-based diet (0.025 ppm Se) was fed to 9 groups of 8 rats each during pregnancy to produce a marginal Se deficiency. During lactation each group was fed the same diet containing either 0.1, 0.25, or 0.5 ppm Se as SEL, SEM, or SEY. On day 18 of lactation dams and pups were sacrificed and tissue Se and glutathione peroxidasemore » activities (GPx) determined. Although food intake of the dams and growth of the pups did not vary, selenium and GPx activities were dependent upon quantity and form of Se consumed. Using slope-ratio analysis linear increases in blood, tissue and milk Se content the bioavailabilities were SEM>SEY>SEL. Maximal GPx depended on the form of dietary Se with SEM>SEY>SEL. Maximal GPx occurred at 0.25 ppm dietary Se as SEM and SEY, but did not reach this activity when fed at 0.5 ppm Se as SEL. These results indicate that regardless of form, the NRC requirement for growing rats of 0.1 ppm Se, is not adequate during lactation to maintain maximum tissue GSH-Px in nursing pups. Based on higher tissue Se in dams and GPx in nursing pups the bioavailability of dietary Se to the lactating rat is greater when fed as SEM and SEY than as SEL.« less

Changing selenium nutritional status of Chinese residents

USDA-ARS?s Scientific Manuscript database

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 ...

Selenium regulates gene expression of selenoprotein W in chicken skeletal muscle system.

PubMed

Ruan, Hongfeng; Zhang, Ziwei; Wu, Qiong; Yao, Haidong; Li, Jinlong; Li, Shu; Xu, Shiwen

2012-01-01

Selenoprotein W (SelW) is abundantly expressed in skeletal muscles of mammals and necessary for the metabolism of skeletal muscles. However, its expression pattern in skeletal muscle system of birds is still uncovered. Herein, to investigate the distribution of SelW mRNA in chicken skeletal muscle system and its response to different selenium (Se) status, 1-day-old chickens were exposed to various concentrations of Se as sodium selenite in the feed for 35 days. In addition, myoblasts were treated with different concentrations of Se in the medium for 72 h. Then the levels of SelW mRNA in skeletal muscles (wing muscle, pectoral muscle, thigh muscle) and myoblasts were determined on days 1, 15, 25, and 35 and at 0, 24, 48, and 72 h, respectively. The results showed that SelW was detected in all these muscle components and it increased both along with the growth of organism and the differentiation process of myoblasts. The thigh muscle is more responsive to Se intake than the other two skeletal muscle tissues while the optimal Se supplementation for SelW mRNA expression in chicken myoblasts was 10(-7) M. In summary, Se plays important roles in the development of chicken skeletal muscles. To effect optimal SelW gene expression, Se must be provided in the diet and the media in adequate amounts and neither at excessive nor deficient levels.

Protonation of epigallocatechin-3-gallate (EGCG) results in massive aggregation and reduced oral bioavailability of EGCG-dispersed selenium nanoparticles.

PubMed

Wu, Shanshan; Sun, Kang; Wang, Xin; Wang, Dongxu; Wan, Xiaochun; Zhang, Jinsong

2013-07-31

The current results show that epigallocatechin-3-gallate (EGCG), in the form of phenolic anions at pH 8.0, can effectively disperse selenium nanoparticles. However, at gastric juice pH (1.0), the EGCG-dispersed selenium nanoparticles (referred to as E-Se) extensively aggregated, so that nano features largely disappeared. This demonstrates that deprotonated phenolic anions of EGCG play an important role in maintaining E-Se stability and suggests that E-Se would suffer from reduced oral bioavailability. To validate this conjecture, size-equivalent E-Se and bovine serum albumin (BSA)-dispersed selenium nanoparticles (B-Se), whose physicochemical properties were not altered at pH 1.0, were orally administered to selenium-deficient mice. In comparison to B-Se, the bioavailabilities of E-Se as indicated with hepatic and renal glutathione peroxidase activity and hepatic selenium levels were significantly (p < 0.01) reduced by 39, 32, and 31%, respectively. Therefore, the present study reveals that size-equivalent selenium nanoparticles prepared by different dispersers do not necessarily guarantee equivalent oral bioavailability.

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.

Effects of foliar selenite on the nutrient components of turnip (Brassica rapa var. rapa Linn.)

NASA Astrophysics Data System (ADS)

Li, Xiong; Li, Boqun; Yang, Yongping

2018-03-01

We administered foliar applications of 50, 100 and 200 mg L‑1 selenium (Se, selenite) on turnip (Brassica rapa var. rapa Linn.) and detected the changes in the main nutrient components in fleshy roots. Results showed that the foliar application of Se (Ⅳ) significantly increased the Se content in turnip, and Se (Ⅳ) positively affected the uptake of several mineral elements, including magnesium, phosphorus, iron, zinc, manganese and copper. Se (Ⅳ) treatments also improved the synthesis of protein and multiple amino acids instead of crude fat and total carbohydrate in turnip, indicating that the foliar application of Se (Ⅳ) could enhance Se biofortification in turnip and promote its nutritional value. We recommended 50–100 mg L‑1 Se treatment for foliar application on turnip based on the daily intake of Se for adults (96–139 µg person‑1 day‑1) and its favourable effects on the nutrient components of turnip.

[Effect of selenium on serum TGAb, TMAb, FT3, FT4 and TSH of rats with excessive intake of iodine].

PubMed

Chi, Haiyan; Zhou, Yuping; Li, Li

2012-07-01

To investigate the effect of selenium on the TGAb, TMAb, FT3, FT4 and TSH level of rats with excessive intake of iodine. Wistar rats were divided into three groups by random:normal control, high iodine group and high iodine plus selenium group. Rats in the high iodine plus selenium group were lavaged with sodium selenite for 10 weeks. The levels of serum TGAb, TMAb, FT3, FT4 and TSH were tested at different time of the experiment. There were no significant change on levels of FT3, FT4 and TSH (P > 0.05). The levels of TGAb and TMAb in the high iodine group were increased slowly (P < 0.05), but no significant change was observed in the high iodine plus selenium group. Excessive intake of iodine might induce goiter, and selenium might have antagonistic effect on it.

Selenium capped monolayer NbSe 2 for two-dimensional superconductivity studies

DOE PAGES

Onishi, Seita; Ugeda, Miguel M.; Zhang, Yi; ...

2016-08-01

Superconductivity in monolayer niobium diselenide (NbSe 2) on bilayer graphene is studied by electrical transport. Monolayer NbSe 2 is grown on bilayer graphene by molecular beam epitaxy and capped with a selenium film to avoid degradation in air. The selenium capped samples have T C = 1.9 K. In situ measurements down to 4 K in ultrahigh vacuum show that the effect of the selenium layer on the transport is negligible. Lastly, the superconducting transition and upper critical fields in air exposed and selenium capped samples are compared. Schematic of monolayer NbSe 2/bilayer graphene with selenium capping layer and electricalmore » contacts.« less

Selenium uptake through cystine transporter mediated by glutathione conjugation.

PubMed

Tobe, Takao; Ueda, Koji; Aoki, Akira; Okamoto, Yoshinori; Kojima, Nakao; Jinno, Hideto

2017-01-01

Selenium (Se) is an essential trace element and is regarded as a protective agent against cancer. In particular, antioxidant effects of selenoenzymes contribute to cancer prevention. Se can also produce reactive oxygen species and, thereby, exert cancer-selective cytotoxicity. Selenodiglutathione (SDG) is a primary Se metabolite conjugated to two glutathione (GSH) moieties. SDG increases intracellular Se accumulation and is more toxic than selenous acid (H 2 SeO 3 ), but the mechanisms for importing Se compounds into cells are not fully understood. Here, we propose a novel mechanism for importing Se, in the form of SDG. Cellular intake of Se compounds was assessed based on Se accumulation, as detected by ICP-MS. SDG incorporation was decreased in the presence of thiols (GSH, cysteine or their oxidized forms, GSSG and cystine), whereas H 2 SeO 3 uptake was increased by addition of GSH or cysteine. Cellular SDG uptake was decreased by pretreatment with specific inhibitors against gamma-glutamyl transpeptidase (GGT) or the cystine/glutamate antiporter (system x c - ). Furthermore, siRNA against xCT, which is the light chain component of system x c - , significantly decreased SDG incorporation. These data suggest an involvement of SDG in Se incorporation, with SDG processed at the cell surface by GGT, leading to formation of selenodicysteine which, in turn, is likely to be imported via xCT. Because GGT and xCT are highly expressed in cancer cells, these mechanisms mediated by the cystine transporter might underlie the cancer-selective toxicity of Se. In addition, the system described in our study appears to represent a physiological transport mechanism for the essential element Se.

Prostatic Response to Supranutritional Selenium Supplementation: Comparison of the Target Tissue Potency of Selenomethionine vs. Selenium-Yeast on Markers of Prostatic Homeostasis

PubMed Central

Waters, David J.; Shen, Shuren; Kengeri, Seema S.; Chiang, Emily C.; Combs, Gerald F.; Morris, J. Steven; Bostwick, David G.

2012-01-01

Prostate cancer is the product of dysregulated homeostasis within the aging prostate. Supplementation with selenium in the form of selenized yeast (Se-yeast) significantly reduced prostate cancer incidence in the Nutritional Prevention of Cancer Trial. Conversely, the Selenium and Vitamin E Cancer Prevention Trial (SELECT) showed no such cancer-protective advantage using selenomethionine (SeMet). The possibility that SeMet and Se-yeast are not equipotent in promoting homeostasis and cancer risk reduction in the aging prostate has not been adequately investigated; no direct comparison has ever been reported in man or animals. Here, we analyzed data on prostatic responses to SeMet or Se-yeast from a controlled feeding trial of 49 elderly beagle dogs—the only non-human species to frequently develop prostate cancer during aging—randomized to one of five groups: control; low-dose SeMet, low-dose Se-yeast (3 μg/kg); high-dose SeMet, high-dose Se-yeast (6 μg/kg). After seven months of supplementation, we found no significant selenium form-dependent differences in toenail or intraprostatic selenium concentration. Next, we determined whether SeMet or Se-yeast acts with different potency on six markers of prostatic homeostasis that likely contribute to prostate cancer risk reduction—intraprostatic dihydrotestosterone (DHT), testosterone (T), DHT:T, and epithelial cell DNA damage, proliferation, and apoptosis. By analyzing dogs supplemented with SeMet or Se-yeast that achieved equivalent intraprostatic selenium concentration after supplementation, we showed no significant differences in potency of either selenium form on any of the six parameters over three different ranges of target tissue selenium concentration. Our findings, which represent the first direct comparison of SeMet and Se-yeast on a suite of readouts in the aging prostate that reflect flux through multiple gene networks, do not further support the notion that the null results of SELECT are attributable to differences in prostatic consequences achievable through daily supplementation with SeMet, rather than Se-yeast. PMID:23201838

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.

Plasma Selenium Biomarkers in Low Income Black and White Americans from the Southeastern United States

PubMed Central

Hargreaves, Margaret K.; Liu, Jianguo; Buchowski, Maciej S.; Patel, Kushal A.; Larson, Celia O.; Schlundt, David G.; Kenerson, Donna M.; Hill, Kristina E.; Burk, Raymond F.; Blot, William J.

2014-01-01

Biomarkers of selenium are necessary for assessing selenium status in humans, since soil variation hinders estimation of selenium intake from foods. In this study, we measured the concentration of plasma selenium, selenoprotein P (SEPP1), and glutathione peroxidase (GPX3) activity and their interindividual differences in 383 low-income blacks and whites selected from a stratified random sample of adults aged 40–79 years, who were participating in a long-term cohort study in the southeastern United States (US). We assessed the utility of these biomarkers to determine differences in selenium status and their association with demographic, socio-economic, dietary, and other indicators. Dietary selenium intake was assessed using a validated food frequency questionnaire designed for the cohort, matched with region-specific food selenium content, and compared with the US Recommended Dietary Allowances (RDA) set at 55 µg/day. We found that SEPP1, a sensitive biomarker of selenium nutritional status, was significantly lower among blacks than whites (mean 4.4±1.1 vs. 4.7±1.0 mg/L, p = 0.006), with blacks less than half as likely to have highest vs. lowest quartile SEPP1 concentration (Odds Ratio (OR) 0.4, 95% Confidence Interval (CI) 0.2–0.8). The trend in a similar direction was observed for plasma selenium among blacks and whites, (mean 115±15.1 vs. 118±17.7 µg/L, p = 0.08), while GPX3 activity did not differ between blacks and whites (136±33.3 vs. 132±33.5 U/L, p = 0.320). Levels of the three biomarkers were not correlated with estimated dietary selenium intake, except for SEPP1 among 10% of participants with the lowest selenium intake (≤57 µg/day). The findings suggest that SEPP1 may be an effective biomarker of selenium status and disease risk in adults and that low selenium status may disproportionately affect black and white cohort participants. PMID:24465457

Ovine offspring growth and diet digestibility are influenced by maternal selenium supplementation and nutritional intake during pregnancy despite a common postnatal diet.

PubMed

Neville, T L; Caton, J S; Hammer, C J; Reed, J J; Luther, J S; Taylor, J B; Redmer, D A; Reynolds, L P; Vonnahme, K A

2010-11-01

Lambs born from feed-restricted or overfed ewes can be lighter at birth, whereas maternal Se supplementation can increase fetal size near term. We hypothesized that birth weight would be inversely related to feed efficiency and growth rates during postnatal development. To examine the effects of maternal dietary Se and nutrient restriction or excess on postnatal lamb growth, diet digestibility, and N retention, 82 ewe lambs (52.2 ± 0.8 kg) were allotted randomly to 1 of 6 treatments in a 2 × 3 factorial arrangement. Factors were dietary Se [adequate Se (9.5 μg/kg of BW; ASe) vs. high Se (Se-enriched yeast; 81.8 μg/kg of BW; HSe)] and maternal nutritional intake [60% (restricted, RES), 100% (control, CON), or 140% (high, HI) of NRC requirements]. Selenium treatments began at breeding. Nutritional treatments began on d 50 of gestation. Lambs were immediately removed from their dams at parturition, provided artificial colostrum, and fed milk replacer until weaning. After weaning, lambs were maintained using common management and on common diets until necropsy at 180 d. Male and female lambs from RES-fed ewes were lighter (P ≤ 0.03) at birth than lambs from CON-fed ewes, with lambs from HI-fed ewes being intermediate. Although maternal nutritional intake influenced (P < 0.06) BW gain before weaning on d 57, both maternal nutritional intake and sex of offspring influenced (P ≤ 0.09) BW gain from d 57 to 180. Although maternal nutritional intake did not influence (P ≥ 0.35) female lamb BW gain, male lambs from RES-fed ewes were lighter (P ≤ 0.09) than those from CON-fed ewes until d 162. By d 180, male lambs from RES- and HI-fed ewes were lighter (P ≤ 0.09) than those from CON-fed ewes. In a subset of lambs used in a feed efficiency study, namely, those born to ASe ewes, HI maternal nutritional intake decreased (P ≤ 0.09) ADG and G:F compared with lambs born to RES- and CON-fed ewes, which did not differ (P ≥ 0.60). Conversely, when lambs were born to HSe ewes, HI maternal nutritional intake increased (P ≤ 0.01) ADG and G:F compared with CON, with RES being intermediate. Moreover, lambs born to ASe-HI ewes had decreased (P < 0.01) ADG and G:F compared with lambs born to HSe-HI ewes. Furthermore, male lambs had a greater (P < 0.01) G:F than female lambs. Maternal diet did not affect (P ≥ 0.11) N retention in male lambs. These data indicate that maternal nutrition during gestation and sex of the offspring alter postnatal growth and efficiency of growth in offspring despite similar postnatal management.

Selenium and hazardous elements distribution in plant-soil-water system and human health risk assessment of Lower Cambrian, Southern Shaanxi, China.

PubMed

Du, Yajun; Luo, Kunli; Ni, Runxiang; Hussain, Rahib

2018-03-01

The natural selenium poisoning due to toxic Se levels in food chain had been observed in humans and animals in Lower Cambrian outcrop areas in Southern Shaanxi, China. To find out the distribution pattern of selenium and other hazardous elements in the plant, soil and water of Lower Cambrian in Southern Shaanxi, China, and their possible potential health risk, a total of 30 elements were analyzed and the health risk assessment of 18 elements was calculated. Results showed that the soil, plant and natural water of Lower Cambrian all had relatively high Se levels. In Lower Cambrian, the soil was enriched with Se, As, Ba, Cu, Mo, Ni, Zn, Ga, Cd and Cr (1.68 < I geo  < 4.48, I geo ; geo-accumulation index). In same plants, the contents of Se, Cd and Zn (except Cd in corn and rice, Zn in potato and corn) of Lower Cambrian were higher than that of the other strata. Ba and Ga in natural water were higher than that of the other strata, while K and Cs were opposite. The health risk assessment results showed that the people living in outcrop areas of Lower Cambrian had both high total non-carcinogenic risk of 18 elements (HI = 16.12, acceptable range: < 1) and carcinogenic risk of As (3.98E-04, acceptable range: 10 -6 -10 -4 ). High contents of Se, As, Mo and Tl of Lower Cambrian may pose a health risk to local people, and food intake was the major pathway. For minimizing potential health risk, the local inhabitants should use the mix-imported food with local growing foods.

[The selenium haemostasis during experimental anaphylaxis reaction in rats treated with reduced glutathione and selenium enriched spirulina].

PubMed

Golubkina, N A; Mazo, V K; Gmoshinskiĭ, I V; Zorin, S N; Tambiev, A Kh; Kirikova, N N

2000-01-01

The main events caused by anaphilaxis in selenium haemostasis in rats include significant increase of selenium excretion with urine (6.36 +/- 1.18 nM Se/18 h., n = 10, compared with 1.72 +/- 0.38 nM Se/18 h., n = 10) and decrease of selenium plasma/selenium erythrocytes ratio from 0.939 to 0.791. Reduced glutathione (G-SH) administration led to 1.5-fold decrease of plasma selenium level and 1.3-fold increase of selenium concentration in intestinal walls of sensitized rats (r = -0.720, P < 0.001). Chromatographic separation of plasma proteins showed that intragastric intubation of G-SH to sensibilized rats significantly decreased the protein P content and did not influence the concentration of Se-GSHPx, thus indicating the local selenium acceptor role of G-SH. G-SH administration did not influence the intestinal permeability in sensitised rats while use of complex additive: G-SH and selenium enriched spirulina--normalized the latter parameter and the ratio of protein P/Se-GSHPx in plasma.

Selenium biomineralization for biotechnological applications.

PubMed

Nancharaiah, Yarlagadda V; Lens, Piet N L

2015-06-01

Selenium (Se) is not only a strategic element in high-tech electronics and an essential trace element in living organisms, but also a potential toxin with low threshold concentrations. Environmental biotechnological applications using bacterial biomineralization have the potential not only to remove selenium from contaminated waters, but also to sequester it in a reusable form. Selenium biomineralization has been observed in phylogenetically diverse microorganisms isolated from pristine and contaminated environments, yet it is one of the most poorly understood biogeochemical processes. Microbial respiration of selenium is unique because the microbial cells are presented with both soluble (SeO(4)(2-) and SeO(3)(2-)) and insoluble (Se(0)) forms of selenium as terminal electron acceptor. Here, we highlight selenium biomineralization and the potential biotechnological uses for it in bioremediation and wastewater treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

A Novel Organic Selenium Compound Exerts Unique Regulation of Selenium Speciation, Selenogenome, and Selenoproteins in Broiler Chicks.

PubMed

Zhao, Ling; Sun, Lv-Hui; Huang, Jia-Qiang; Briens, Mickael; Qi, De-Sheng; Xu, Shi-Wen; Lei, Xin Gen

2017-05-01

Background: A new organic selenium compound, 2-hydroxy-4-methylselenobutanoic acid (SeO), displayed a greater bioavailability than sodium selenite (SeNa) or seleno-yeast (SeY) in several species. Objective: This study sought to determine the regulation of the speciation of selenium, expression of selenogenome and selenocysteine biosynthesis and degradation-related genes, and production of selenoproteins by the 3 forms of selenium in the tissues of broiler chicks. Methods: Day-old male chicks ( n = 6 cages/diet, 6 chicks/cage) were fed a selenium-deficient, corn and soy-based diet [base diet (BD), 0.05 mg Se/kg] or the BD + SeNa, SeY, or SeO at 0.2 mg Se/kg for 6 wk. Plasma, livers, and pectoral and thigh muscles were collected at weeks 3 and 6 to assay for total selenium, selenomethionine, selenocysteine, redox status, and selected genes, proteins, and enzymes. Results: Although both SeY and SeO produced greater concentrations ( P < 0.05) of total selenium (20-172%) and of selenomethionine (≤15-fold) in the liver, pectoral muscle, and thigh than those of SeNa, SeO further raised ( P < 0.05) these concentrations by 13-37% and 43-87%, respectively, compared with SeY. Compared with the BD, only SeO enhanced ( P < 0.05) the mRNA of selenoprotein ( Seleno ) s and methionine sulfoxide reductase B1 ( Msrb1 ) in the liver and thigh (62-98%) and thioredoxin reductase (TXRND) activity in the pectoral and thigh muscles (20-37%) at week 3. Furthermore, SeO increased ( P < 0.05) the expression of glutathione peroxidase ( Gpx ) 3 , GPX4, SELENOP, and SELENOU relative to the SeNa group by 26-207%, and the expression of Selenop, O-phosphoseryl-transfer RNA (tRNA):selenocysteinyl-tRNA synthase , GPX4, and SELENOP relative to the SeY group by 23-55% in various tissues. Conclusions: Compared with SeNa or SeY, SeO demonstrated a unique ability to enrich selenomethionine and total selenium depositions, to induce the early expression of Selenos and Mrsb1 mRNA and TXRND activity, and to enhance the protein production of GPX4, SELENOP, and SELENOU in the tissues of chicks. © 2017 American Society for Nutrition.

Biological effects of a nano red elemental selenium.

PubMed

Zhang, J S; Gao, X Y; Zhang, L D; Bao, Y P

2001-01-01

A novel selenium form, nano red elemental selenium (Nano-Se) was prepared by adding bovine serum albumin to the redox system of selenite and glutathione. Nano-Se has a 7-fold lower acute toxicity than sodium selenite in mice (LD(50) 113 and 15 mg Se/kg body weight respectively). In Se-deficient rat, both Nano-Se and selenite can increase tissue selenium and GPx activity. The biological activities of Nano-Se and selenite were compared in terms of cell proliferation, enzyme induction and protection against free racial-mediated damage in human hepatoma HepG2 cells. Nano-Se and selenite are similarly cell growth inhibited and stimulated synthesis of glutathione peroxidase (GPx), phospholipid hydroperoxide glutathione peroxidase (PHGPx) and thioredoxin reductase (TR). When HepG2 cells were co-treated with selenium and glutathione, Nano-Se showed less pro-oxidative effects than selenite, as measured by cell growth. These results demonstrate that Nano-Se has a similar bioavailability in the rat and antioxidant effects on cells.

Assessment of toxicity of selenium and cadmium selenium quantum dots: A review.

PubMed

Sharma, Virender K; McDonald, Thomas J; Sohn, Mary; Anquandah, George A K; Pettine, Maurizio; Zboril, Radek

2017-12-01

This paper reviews the current understanding of the toxicity of selenium (Se) to terrestrial mammalian and aquatic organisms. Adverse biological effects occur in the case of Se deficiencies, associated with this element having essential biological functions and a narrow window between essentiality and toxicity. Several inorganic species of Se (-2, 0, +4, and +6) and organic species (monomethylated and dimethylated) have been reported in aquatic systems. The toxicity of Se in any given sample depends not only on its speciation and concentration, but also on the concomitant presence of other compounds that may have synergistic or antagonistic effects, affecting the target organism as well, usually spanning 2 or 3 orders of magnitude for inorganic Se species. In aquatic ecosystems, indirect toxic effects, linked to the trophic transfer of excess Se, are usually of much more concern than direct Se toxicity. Studies on the toxicity of selenium nanoparticles indicate the greater toxicity of chemically generated selenium nanoparticles relative to selenium oxyanions for fish and fish embryos while oxyanions of selenium have been found to be more highly toxic to rats as compared to nano-Se. Studies on polymer coated Cd/Se quantum dots suggest significant differences in toxicity of weathered vs. non-weathered QD's as well as a significant role for cadmium with respect to toxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sodium selenite/selenium nanoparticles (SeNPs) protect cardiomyoblasts and zebrafish embryos against ethanol induced oxidative stress.

PubMed

Kalishwaralal, Kalimuthu; Jeyabharathi, Subhaschandrabose; Sundar, Krishnan; Muthukumaran, Azhaguchamy

2015-10-01

Alcoholic cardiomyopathy is the damage caused to the heart muscles due to high level of alcohol consumption resulting in enlargement and inflammation of the heart. Selenium is an important trace element that is beneficial to human health. Selenium protects the cells by preventing the formation of free radicals in the body. In the present study, protein mediated synthesis of SeNPs was investigated. Two different sizes of SeNPs were synthesized using BSA and keratin. The synthesized SeNPs were characterized by scanning electron microscopy (SEM) with elemental composition analysis Energy Dispersive X-ray spectroscopy(EDX) and X-ray diffraction (XRD). This study demonstrates the in vitro and in vivo antioxidative effects of sodium selenite and SeNPs. Further selenium and SeNPs were evaluated for their ability to protect against 1% ethanol induced oxidative stress in H9C2 cell line. The selenium and SeNPs were found to reduce the 1% ethanol-induced oxidative damage through scavenging intracellular reactive oxygen species. The selenium and SeNPs could also prevent pericardial edema induced ethanol treatment and reduced apoptosis and cell death in zebrafish embryos. The results indicate that selenium and SeNPs could potentially be used as an additive in alcoholic beverage industry to control the cardiomyopathy. Copyright © 2015 Elsevier GmbH. All rights reserved.

Plasma levels of selenium-containing proteins in Inuit adults from Nunavik.

PubMed

Achouba, Adel; Dumas, Pierre; Ouellet, Nathalie; Lemire, Mélanie; Ayotte, Pierre

2016-11-01

Selenium (Se) is highly abundant in marine foods traditionally consumed by Inuit of Nunavik (Northern Quebec, Canada) and accordingly, their Se intake is among the highest in the world. However, little is known regarding the biological implications of this high Se status in this Arctic indigenous population. We used a method combining affinity chromatography and inductively coupled plasma-mass spectrometry with quantification by post-column isotope dilution to determine total Se levels and concentrations of Se-containing proteins in archived plasma samples of Inuit adults who participated to the 2004 Nunavik Inuit Health Survey (N = 852). Amounts of mercury (Hg) associated with Se-containing proteins were also quantified. Results show that glutathione peroxidase 3 (GPx3), selenoprotein P (SelP) and selenoalbumin (SeAlb) represented respectively 25%, 52% and 23% of total plasma Se concentrations. In addition, small amounts of Hg co-eluted with each Se-containing protein and up to 50% of plasma Hg was associated to SelP. Total plasma Se concentrations (median = 139 μg L− 1; interquartile range (IQR) = 22.7 μg L− 1) were markedly lower and less variable than whole blood Se concentration (median = 261 μg L− 1, IQR = 166 μg L− 1). A non linear relation was observed between whole blood Se and plasma Se levels, with plasma Se concentrations leveling off at approximately 200 μg L− 1, whereas 16% and 3% of individuals exhibited whole blood concentrations higher than 500 μg L− 1 and 1000 μg L− 1, respectively. In contrast, a linear relationship was previously reported in communities consuming Brazil nuts which are rich Se, mainly present as selenomethionine. This suggests that a different selenocompound, possibly selenoneine, is present in the Arctic marine food chain and accumulates in the blood cellular fraction of Inuit.

Selenium deficiency occurs in some patients with moderate-to-severe cirrhosis and can be corrected by administration of selenate but not selenomethionine: a randomized controlled trial123

PubMed Central

Burk, Raymond F; Hill, Kristina E; Motley, Amy K; Byrne, Daniel W; Norsworthy, Brooke K

2015-01-01

Background: Selenomethionine, which is the principal dietary form of selenium, is metabolized by the liver to selenide, which is the form of the element required for the synthesis of selenoproteins. The liver synthesizes selenium-rich selenoprotein P (SEPP1) and secretes it into the plasma to supply extrahepatic tissues with selenium. Objectives: We conducted a randomized controlled trial to determine whether cirrhosis is associated with functional selenium deficiency (the lack of selenium for the process of selenoprotein synthesis even though selenium intake is not limited) and, if it is, whether the deficiency is associated with impairment of selenomethionine metabolism. Design: Patients with Child-Pugh (C-P) classes A, B, and C (mild, moderate, and severe, respectively) cirrhosis were supplemented with a placebo or supranutritional amounts of selenium as selenate (200 or 400 μg/d) or as selenomethionine (200 μg/d) for 4 wk. Plasma SEPP1 concentration and glutathione peroxidase (GPX) activity, the latter due largely to the selenoprotein GPX3 secreted by the kidneys, were measured before and after supplementation. Results: GPX activity was increased more by both doses of selenate than by the placebo in C-P class B patients. The activity was not increased more by selenomethionine supplementation than by the placebo in C-P class B patients. Plasma selenium was increased more by 400 μg Se as selenate than by the placebo in C-P class C patients. Within the groups who responded to selenate, there was a considerable variation in responses. Conclusion: These results indicate that severe cirrhosis causes mild functional selenium deficiency in some patients that is associated with impaired metabolism of selenomethionine. This trial was registered at clinicaltrials.gov as NCT00271245. PMID:26468123

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

USDA-ARS?s Scientific Manuscript database

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...

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 tissues collection in weeks. The feeding trial included a supplementation period of 8 weeks (i.e. SP8) followed by an elimination period of 4 weeks (i.e. EP4). Six turtles from each turtle group (i.e. control, SeMet1 and SeMet2) were sacrifice at each collection time, from T1 to T12. At T0, four turtles were sacrificed.

Effect of selenium-enriched organic material amendment on selenium fraction transformation and bioavailability in soil.

PubMed

Wang, Dan; Dinh, Quang Toan; Anh Thu, Tran Thi; Zhou, Fei; Yang, Wenxiao; Wang, Mengke; Song, Weiwei; Liang, Dongli

2018-05-01

To exploit the plant byproducts from selenium (Se) biofortification and reduce environmental risk of inorganic Se fertilizer, pot experiment was conducted in this study. The effects of Se-enriched wheat (Triticum aestivum L.) straw (WS + Se) and pak choi (Brassica chinensis L.) (P + Se) amendment on organo-selenium speciation transformation in soil and its bioavailability was evaluated by pak choi uptake. The Se contents of the cultivated pak choi in treatments amended with the same amount of Se-enriched wheat straw and pak choi were 1.7 and 9.7 times in the shoots and 2.3 and 6.3 times in the roots compared with control treatment. Soil respiration rate was significantly increased after all organic material amendment in soil (p < 0.05), which accelerated the mineralization of organic materials and thus resulted in soluble Se (SOL-Se), exchangeable Se (EX-Se), and fulvic acid-bound Se (FA-Se) fraction increasing by 25.2-29.2%, 9-13.8%, and 4.92-8.28%, respectively. In addition, both Pearson correlation and cluster analysis showed that EX-Se and FA-Se were better indicators for soil Se availability in organic material amendment soils. The Marquardt-Levenberg Model well described the dynamic kinetics of FA-Se content after Se-enriched organic material amendment in soil mainly because of the mineralization of organic carbon and organo-selenium. The utilization of Se in P + Se treatment was significantly higher than those in WS + Se treatment because of the different mineralization rates and the amount of FA-Se in soil. Se-enriched organic materials amendment can not only increase the availability of selenium in soil but also avoid the waste of valuable Se source. Copyright © 2018 Elsevier Ltd. All rights reserved.

The relation between amyotrophic lateral sclerosis and inorganic selenium in drinking water: a population-based case-control study

PubMed Central

2010-01-01

Background A community in northern Italy was previously reported to have an excess incidence of amyotrophic lateral sclerosis among residents exposed to high levels of inorganic selenium in their drinking water. Methods To assess the extent to which such association persisted in the decade following its initial observation, we conducted a population-based case-control study encompassing forty-one newly-diagnosed cases of amyotrophic lateral sclerosis and eighty-two age- and sex-matched controls. We measured long-term intake of inorganic selenium along with other potentially neurotoxic trace elements. Results We found that consumption of drinking water containing ≥ 1 μg/l of inorganic selenium was associated with a relative risk for amyotrophic lateral sclerosis of 5.4 (95% confidence interval 1.1-26) after adjustment for confounding factors. Greater amounts of cumulative inorganic selenium intake were associated with progressively increasing effects, with a relative risk of 2.1 (95% confidence interval 0.5-9.1) for intermediate levels of cumulative intake and 6.4 (95% confidence interval 1.3-31) for high intake. Conclusion Based on these results, coupled with other epidemiologic data and with findings from animal studies that show specific toxicity of the trace element on motor neurons, we hypothesize that dietary intake of inorganic selenium through drinking water increases the risk for amyotrophic lateral sclerosis. PMID:21134276

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

The leaching characteristics of selenium from coal fly ashes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, T.; Wang, J.; Burken, J.G.

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 formore » 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.« less

Selenium Biofortification in Rice ( Oryza sativa L.) Sprouting: Effects on Se Yield and Nutritional Traits with Focus on Phenolic Acid Profile.

PubMed

D'Amato, Roberto; Fontanella, Maria Chiara; Falcinelli, Beatrice; Beone, Gian Maria; Bravi, Elisabetta; Marconi, Ombretta; Benincasa, Paolo; Businelli, Daniela

2018-04-25

The contents of total Se and of inorganic and organic Se species, as well as the contents of proteins, chlorophylls, carotenoids, and phenolic acids, were measured in 10-day old sprouts of rice ( Oryza sativa L.) obtained with increasing levels (15, 45, 135, and 405 mg Se L -1 ) of sodium selenite and sodium selenate and with distilled water as control. Increasing Se levels increased organic and inorganic Se contents of sprouts, as well as the content of phenolic acids, especially in their soluble conjugated forms. Moderate levels of sodium selenite (i.e., not higher that 45 mg L -1 ) appeared the best compromise to obtain high Se and phenolic acid yields together with high proportion of organic Se while limiting residual Se in the germination substrate waste. Se biofortification of rice sprouts appears a feasible and efficient way to promote Se and phenolic acid intake in human diet, with well-known health benefits.

Selenium(IV) and (VI) sorption by soils surrounding fly ash management facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hyun, S.; Burns, P.E.; Murarka, I.

2006-11-15

Leachate derived from unlined coal ash disposal facilities is one of the most significant anthropogenic sources of selenium to the environment. To establish a practical framework for predicting transport of selenium in ash leachate, sorption of Se(IV) and Se(VI) from 1 mM CaSO{sub 4} was measured for 18 soils obtained down-gradient from three ash landfill sites and evaluated with respect to several soil properties. Furthermore, soil attenuation from lab-generated ash leachate and the effect of Ca{sup 2+} and SO{sub 4}{sup 2-} concentrations as well as pH on both Se(IV) and Se(VI) was quantified for a subset of soils. For bothmore » Se(IV) and Se(VI), pH combined with either percentage clay or dithionite-citrate-bicarbonate (DCB)-extractable Fe described {gt} 80% of the differences in sorption across all soils, yielding an easy approach for making initial predictions regarding site-specific selenium transport to sensitive water bodies. Se(IV) consistently exhibited an order of magnitude greater sorption than Se(VI). Selenium sorption was highest at lower pH values, with Se(IV) sorption decreasing at pH values above 6, whereas Se(VI) decreased over the entire pH range (2.5-10). Using these pH adsorption envelopes, the likely effect of ash leachate-induced changes in soil pore water pH with time on selenium attenuation by down gradient soils can be predicted. Selenium sorption increased with increasing Ca{sup 2+} concentrations while SO{sub 4}2- suppressed sorption well above enhancements by Ca{sup 2+}. Soil attenuation of selenium from ash leachates agreed well with sorption measured from 1 mM CaSO{sub 4}, indicating that 1 mM CaSO{sub 4} is a reasonable synthetic leachate for assessing selenium behavior at ash landfill sites.« less

Ionic liquids improved reversed-phase HPLC on-line coupled with ICP-MS for selenium speciation.

PubMed

Chen, Beibei; He, Man; Mao, Xiangju; Cui, Ran; Pang, Daiwen; Hu, Bin

2011-01-15

Room-temperature ionic liquids (RTILs) improved reversed-phase high performance liquid chromatography (RP-HPLC) on-line combined with inductively coupled plasma mass spectrometry (ICP-MS) was developed for selenium speciation. The different parameters affecting the retention behaviors of six target selenium species especially the effect of RTILs as mobile phase additives have been studied, it was found that the mobile phase consisting of 0.4% (v/v) 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), 0.4% (v/v) 1-butyl-2,3-dimethylimidazolium tetrafluroborate ([BMMIM]BF(4)) and 99.2% (v/v) water has effectively improved the peak profile and six target selenium species including Na(2)SeO(3) (Se(IV)), Na(2)SeO(4) (Se(VI)), L-selenocystine (SeCys(2)), D,L-selenomethionine (SeMet), Se-methylseleno-l-cysteine (MeSeCys), seleno-D,L-ethionine (SeEt) were separated in 8 min. In order to validate the accuracy of the method, a Certified Reference Material of SELM-1 yeast sample was analyzed and the results obtained were in good agreement with the certified values. The developed method was also successfully applied to the speciation of selenium in Se-enriched yeasts and clover. For fresh Se-enriched yeast cells, it was found that the spiked SeCys(2) in living yeast cells could be transformed into SeMet. Compared with other ion-pair RP-HPLC-ICP-MS approaches for selenium speciation, the proposed method possessed the advantages including ability to regulate the retention time of the target selenium species by selecting the suitable RTILs and their concentration, simplicity, rapidness and low injection volume, thus providing wide potential applications for elemental speciation in biological systems. Copyright © 2010 Elsevier B.V. All rights reserved.

Mushroom and dietary selenium intakes in relation to fasting glucose levels in a free-living Italian adult population: the Moli-sani Project.

PubMed

Pounis, G; Costanzo, S; Persichillo, M; de Curtis, A; Sieri, S; Vinceti, M; Zito, F; Di Castelnuovo, A F; Donati, M B; de Gaetano, G; Iacoviello, L

2014-02-01

Mushrooms are known to be a major food source of selenium, a mineral associated with diabetes prevalence. This study aimed to evaluate the relationship between mushroom and dietary selenium intakes and blood glucose levels in a free-living adult Italian population. A total of 6879 men and 6891 women (aged 53.1±11.0years) with neither diabetes nor on special diets were analyzed from the population randomly recruited for the Moli-sani study. The European Prospective Investigation into Cancer and Nutrition (EPIC) food frequency questionnaire was used for dietary assessment. Fasting blood glucose (FBG) levels were measured from fasting serum samples, and diabetes prevalence was determined according to American Diabetes Association diagnostic criteria. In men, an increase of one (30-g) portion/week in mushroom consumption was associated with a 0.43-0.55mmol/L increase in FBG at different levels of adjustment (P<0.05). In both men and women, dietary selenium was positively associated with blood glucose in both unadjusted and fully adjusted models (P<0.05 for all). Both mushroom and dietary selenium intakes were independently associated with blood glucose on multivariate analyses. In addition, high intakes of both were associated with higher diabetes prevalence in men and women (OR>1, P<0.05). The association of mushroom and selenium intakes with FBG suggests that mushroom and selenium might each independently increase the risk of diabetes. However, prospective studies are now necessary to confirm this hypothesis. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

The Association between Selenium and Other Micronutrients and Thyroid Cancer Incidence in the NIH-AARP Diet and Health Study

PubMed Central

O’Grady, Thomas J.; Kitahara, Cari M.; DiRienzo, A. Gregory; Gates, Margaret A.

2014-01-01

Background Selenium is an essential trace element that is important for thyroid hormone metabolism and has antioxidant properties which protect the thyroid gland from oxidative stress. The association of selenium, as well as intake of other micronutrients, with thyroid cancer is unclear. Methods We evaluated associations of dietary selenium, beta-carotene, calcium, vitamin D, vitamin C, vitamin E, folate, magnesium, and zinc intake with thyroid cancer risk in the National Institutes of Health – American Association of Retired Persons Diet and Health Study, a large prospective cohort of 566,398 men and women aged 50–71 years in 1995–1996. Multivariable-adjusted Cox proportional hazards regression was used to examine associations between dietary intake of micronutrients, assessed using a food frequency questionnaire, and thyroid cancer cases, ascertained by linkage to state cancer registries and the National Death Index. Results With the exception of vitamin C, which was associated with an increased risk of thyroid cancer (HRQ5 vs Q1, 1.34; 95% CI, 1.02–1.76; Ptrend, <0.01), we observed no evidence of an association between quintile of selenium (HRQ5 vs Q1, 1.23; 95% CI, 0.92–1.65; Ptrend, 0.26) or other micronutrient intake and thyroid cancer. Conclusion Our study does not suggest strong evidence for an association between dietary intake of selenium or other micronutrients and thyroid cancer risk. More studies are needed to clarify the role of selenium and other micronutrients in thyroid carcinogenesis. PMID:25329812

Uptake and speciation of selenium in garlic cultivated in soil amended with symbiotic fungi (mycorrhiza) and selenate.

PubMed

Larsen, Erik H; Lobinski, Ryszard; Burger-Meÿer, Karin; Hansen, Marianne; Ruzik, Rafal; Mazurowska, Lena; Rasmussen, Peter Have; Sloth, Jens J; Scholten, Olga; Kik, Chris

2006-07-01

The scope of the work was to investigate the influence of selenate fertilisation and the addition of symbiotic fungi (mycorrhiza) to soil on selenium and selenium species concentrations in garlic. The selenium species were extracted from garlic cultivated in experimental plots by proteolytic enzymes, which ensured liberation of selenium species contained in peptides or proteins. Separate extractions using an aqueous solution of enzyme-deactivating hydroxylamine hydrochloride counteracted the possible degradation of labile selenium species by enzymes (such as alliinase) that occur naturally in garlic. The selenium content in garlic, which was analysed by ICP-MS, showed that addition of mycorrhiza to the natural soil increased the selenium uptake by garlic tenfold to 15 microg g(-1) (dry mass). Fertilisation with selenate and addition of mycorrhiza strongly increased the selenium content in garlic to around one part per thousand. The parallel analysis of the sample extracts by cation exchange and reversed-phase HPLC with ICP-MS detection showed that gamma-glutamyl-Se-methyl-selenocysteine amounted to 2/3, whereas methylselenocysteine, selenomethionine and selenate each amounted to a few percent of the total chromatographed selenium in all garlic samples. Se-allyl-selenocysteine and Se-propyl-selenocysteine, which are selenium analogues of biologically active sulfur-containing amino acids known to occur in garlic, were searched for but not detected in any of the extracts. The amendment of soil by mycorrhiza and/or by selenate increased the content of selenium but not the distribution of detected selenium species in garlic. Finally, the use of two-dimensional HPLC (size exclusion followed by reversed-phase) allowed the structural characterisation of gamma-glutamyl-Se-methyl-selenocysteine and gamma-glutamyl-Se-methyl-selenomethionine in isolated chromatographic fractions by quadrupole time-of-flight mass spectrometry.

Plasma and breastmilk selenium in HIV-infected Malawian mothers is positively associated with infant selenium status at 2 or 6 and 24 weeks post-partum but is not associated with supplementation

USDA-ARS?s Scientific Manuscript database

Selenium (Se) levels are typically low in HIV-infected individuals, but have been increased by supplementation in previous studies. In HIV-infected populations, the effect of Se supplementation on breastmilk Se and, consequently, plasma Se levels in exclusively breastfed infants is unknown. HIV-inf...

Investigation of biotransformation of selenium in plants using spectrometric methods

NASA Astrophysics Data System (ADS)

Ruszczyńska, Anna; Konopka, Anna; Kurek, Eliza; Torres Elguera, Julio Cesar; Bulska, Ewa

2017-04-01

The aim of this research was to study the processes of biotransformation of selenium in plants such as garlic, radish sprouts and sunflower sprouts via identification of selenium-containing compounds as metabolites of inorganic selenium using mass spectrometry. Speciation analysis of selenium in extracts from plant samples was performed with the use of hyphenated high performance liquid chromatography and inductively coupled plasma mass spectrometry (HPLC-ICP-MS) method. Matching the retention times of sample compounds with standards allowed identification of Se-methyl-selenocysteine, selenomethionine, γ-glutamyl-Se-methylselenocysteine and inorganic SeO32 -. However, registered chromatograms included additional 82Se signals which couldn't be identified due to the lack of standards. Qualitative analysis of unknown compounds was achieved using high-resolution mass spectrometer equipped with mass analyzer Orbitrap coupled to high performance liquid chromatography. Since selenium has six stable isotopes of different abundance in nature, mass spectra of have a very characteristic isotopic pattern. In order to elucidate the structure of unknown Se compounds, selected ions were subjected to the fragmentation. Following selenocompounds were identified an inorganic selenium metabolites in garlic, sunflower sprouts and/or radish sprouts: selenohomolanthionine, Se-methyl-selenocysteine, selenomethionine, selenomethionine oxide, deaminohydroxy-selenohomolanthionine, N-acetylcysteine-selenomethionine, γ-glutamyl-Se-methyl-selenocysteine, methylseleno-Se-pentose-hexose, Se-methyl-selenoglutathione, 2,3-dihydroxy-propionyl-selenocysteine-cysteine, methyltio-selenoglutathione, 2,3-dihydroxypropionyl-selenolanthionine and two Se-containing compounds with proposed molecular formula C10H18N2O6Se and C10H13N5O3Se. Moreover, the structure was proposed for one selenocompound found in sunflower sprouts which has not been reported so far.

Selenium in edible mushrooms.

PubMed

Falandysz, Jerzy

2008-01-01

Selenium is vital to human health. This article is a compendium of virtually all the published data on total selenium concentrations, its distribution in fruitbody, bioconcentration factors, and chemical forms in wild-grown, cultivated, and selenium-enriched mushrooms worldwide. Of the 190 species reviewed (belonging to 21 families and 56 genera), most are considered edible, and a few selected data relate to inedible mushrooms. Most of edible mushroom species examined until now are selenium-poor (< 1 microg Se/g dry weight). The fruitbody of some species of wild-grown edible mushrooms is naturally rich in selenium; their occurrence data are reviewed, along with information on their suitability as a dietary source of selenium for humans, the impact of cooking and possible leaching out, the significance of traditional mushroom dishes, and the element's absorption rates and co-occurrence with some potentially problematic elements. The Goat's Foot (Albatrellus pes-caprae) with approximately 200 microg Se/g dw on average (maximum up to 370 microg/g dw) is the richest one in this element among the species surveyed. Several other representatives of the genus Albatrellus are also abundant in selenium. Of the most popular edible wild-grown mushrooms, the King Bolete (Boletus edulis) is considered abundant in selenium as well; on average, it contains approximately 20 microg Se/g dw (maximum up to 70 microg/g dw). Some species of the genus Boletus, such as B. pinicola, B. aereus, B. aestivalis, B. erythropus, and B. appendiculus, can also accumulate considerable amounts of selenium. Some other relatively rich sources of selenium include the European Pine Cone Lepidella (Amanita strobiliformis), which contains, on average, approximately 20 microg Se/g dw (up to 37 microg/g dw); the Macrolepiota spp., with an average range of approximately 5 to < 10 microg/g dw (an exception is M. rhacodes with < 10 microg/g dw); and the Lycoperdon spp., with an average of approximately 5 microg Se/g dw. For several wild-grown species of the genus Agaricus, the selenium content ( approximately 5 microg/g dw) is much greater than that from cultivated Champignon Mushroom; these include A. bisporus, A. bitorquis, A. campestris, A. cesarea, A. campestris, A. edulis, A. macrosporus, and A. silvaticus. A particularly rich source of selenium could be obtained from selenium-enriched mushrooms that are cultivated on a substrate fortified with selenium (as inorganic salt or selenized-yeast). The Se-enriched Champignon Mushroom could contain up to 30 or 110 microg Se/g dw, while the Varnished Polypore (Ganoderma lucidum) could contain up to 72 microg Se/g dw. An increasingly growing database on chemical forms of selenium of mushrooms indicates that the seleno-compounds identified in carpophore include selenocysteine, selenomethionine, Se-methylselenocysteine, selenite, and several unidentified seleno-compounds; their proportions vary widely. Some aspects of environmental selenium occurrence and human body pharmacokinetics and nutritional needs will also be briefly discussed in this review.

Selenium hyperaccumulation - Astragalus bisulcatus, Cardamine hupingshanensis and Stanleya pinnata - may be useful for agromining selenium-rich soils

USDA-ARS?s Scientific Manuscript database

Selenium hyperaccumulator plants like Stanleya pinnata, Astragalus bisulcatus and the newly discovered Se-accumulator Cardamine hupingshanensis may play an important role in the Se cycle from soil to plant to human in China. Se-hyperaccumulators can be used for agromining or for phytoremediation of ...

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.

Modeling the impact of soil aggregate size on selenium immobilization

NASA Astrophysics Data System (ADS)

Kausch, M. F.; Pallud, C. E.

2013-03-01

Soil aggregates are mm- to cm-sized microporous structures separated by macropores. Whereas fast advective transport prevails in macropores, advection is inhibited by the low permeability of intra-aggregate micropores. This can lead to mass transfer limitations and the formation of aggregate scale concentration gradients affecting the distribution and transport of redox sensitive elements. Selenium (Se) mobilized through irrigation of seleniferous soils has emerged as a major aquatic contaminant. In the absence of oxygen, the bioavailable oxyanions selenate, Se(VI), and selenite, Se(IV), can be microbially reduced to solid, elemental Se, Se(0), and anoxic microzones within soil aggregates are thought to promote this process in otherwise well-aerated soils. To evaluate the impact of soil aggregate size on selenium retention, we developed a dynamic 2-D reactive transport model of selenium cycling in a single idealized aggregate surrounded by a macropore. The model was developed based on flow-through-reactor experiments involving artificial soil aggregates (diameter: 2.5 cm) made of sand and containing Enterobacter cloacae SLD1a-1 that reduces Se(VI) via Se(IV) to Se(0). Aggregates were surrounded by a constant flow providing Se(VI) and pyruvate under oxic or anoxic conditions. In the model, reactions were implemented with double-Monod rate equations coupled to the transport of pyruvate, O2, and Se species. The spatial and temporal dynamics of the model were validated with data from experiments, and predictive simulations were performed covering aggregate sizes 1-2.5 cm in diameter. Simulations predict that selenium retention scales with aggregate size. Depending on O2, Se(VI), and pyruvate concentrations, selenium retention was 4-23 times higher in 2.5 cm aggregates compared to 1 cm aggregates. Under oxic conditions, aggregate size and pyruvate concentrations were found to have a positive synergistic effect on selenium retention. Promoting soil aggregation on seleniferous agricultural soils, through organic matter amendments and conservation tillage, may thus help decrease the impacts of selenium contaminated drainage water on downstream aquatic ecosystems.

Modeling the impact of soil aggregate size on selenium immobilization

NASA Astrophysics Data System (ADS)

Kausch, M. F.; Pallud, C. E.

2012-09-01

Soil aggregates are mm- to cm-sized microporous structures separated by macropores. Whereas fast advective transport prevails in macropores, advection is inhibited by the low permeability of intra-aggregate micropores. This can lead to mass transfer limitations and the formation of aggregate-scale concentration gradients affecting the distribution and transport of redox sensitive elements. Selenium (Se) mobilized through irrigation of seleniferous soils has emerged as a major aquatic contaminant. In the absence of oxygen, the bioavailable oxyanions selenate, Se(VI), and selenite, Se(IV), can be microbially reduced to solid, elemental Se, Se(0), and anoxic microzones within soil aggregates are thought to promote this process in otherwise well aerated soils. To evaluate the impact of soil aggregate size on selenium retention, we developed a dynamic 2-D reactive transport model of selenium cycling in a single idealized aggregate surrounded by a macropore. The model was developed based on flow-through-reactor experiments involving artificial soil aggregates (diameter: 2.5 cm) made of sand and containing Enterobacter cloacae SLD1a-1 that reduces Se(VI) via Se(IV) to Se(0). Aggregates were surrounded by a constant flow providing Se(VI) and pyruvate under oxic or anoxic conditions. In the model, reactions were implemented with double-Monod rate equations coupled to the transport of pyruvate, O2, and Se-species. The spatial and temporal dynamics of the model were validated with data from experiments and predictive simulations were performed covering aggregate sizes between 1 and 2.5 cm diameter. Simulations predict that selenium retention scales with aggregate size. Depending on O2, Se(VI), and pyruvate concentrations, selenium retention was 4-23 times higher in 2.5-cm-aggregates compared to 1-cm-aggregates. Under oxic conditions, aggregate size and pyruvate-concentrations were found to have a positive synergistic effect on selenium retention. Promoting soil aggregation on seleniferous agricultural soils, through organic matter amendments and conservation tillage, may thus help decrease the impacts of selenium contaminated drainage water on downstream aquatic ecosystems.

The contribution of dairy products to micronutrient intake in the Netherlands.

PubMed

Vissers, Pauline A J; Streppel, Martinette T; Feskens, Edith J M; de Groot, Lisette C P G M

2011-10-01

To assess the contribution of dairy products to the intake of various vitamins and minerals in several life stages in the Dutch population. Data from 3 Dutch Food Consumption Surveys and the Leiden Longevity Study were used to estimate the contribution of dairy products--as percentage of total intake--to the intake of iron, copper, selenium, zinc, calcium, folic acid, vitamin D, vitamin C, and vitamin B(12). In young children, dairy products contributed substantially to the intake of calcium (73%), selenium (21%), iron (8%), zinc (39%), copper (12%), folic acid (24%), vitamin C (18%), vitamin D (16%), and vitamin B(12) (58%). Of all dairy products, milk contributed the most to the intake of these nutrients. In adults and elderly subjects, the contribution of dairy products to total micronutrient intake was 65%-68% for calcium, 18%-19% for selenium, 3%-4% for iron, 28%-31% for zinc, 6%-7% for copper, 17%-19% for folic acid, 10%-14% for vitamin C, 11%-16% for vitamin D, and 44%-46% for vitamin B(12). Milk as well as cheese contributed the most to the intake of these nutrients. Dairy products are an important source of vitamins and minerals in the Dutch population. Dairy products, especially milk and cheese, contribute substantially to the intake of calcium, selenium, zinc, and vitamin B(12).

Comparative oral dose toxicokinetics of selenium compounds commonly found in selenium accumulator plants

USDA-ARS?s Scientific Manuscript database

Consumption of Se accumulator plants by livestock can result in Se intoxication. Recent research indicates that the Se forms most common in Se accumulator plants are selenate and Se-methylselenocysteine (MeSeCys). In this study the absorption, distribution, and elimination kinetics of Se in serum ...

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. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Elucidating the selenium and arsenic metabolic pathways following exposure to the non-hyperaccumulating Chlorophytum comosum, spider plant

PubMed Central

Afton, Scott E.; Catron, Brittany; Caruso, Joseph A.

2009-01-01

Although many studies have investigated the metabolism of selenium and arsenic in hyperaccumulating plants for phytoremediation purposes, few have explored non-hyperaccumulating plants as a model for general contaminant exposure to plants. In addition, the result of simultaneous supplementation with selenium and arsenic has not been investigated in plants. In this study, Chlorophytum comosum, commonly known as the spider plant, was used to investigate the metabolism of selenium and arsenic after single and simultaneous supplementation. Size exclusion and ion-pairing reversed phase liquid chromatography were coupled to an inductively coupled plasma mass spectrometer to obtain putative metabolic information of the selenium and arsenic species in C. comosum after a mild aqueous extraction. The chromatographic results depict that selenium and arsenic species were sequestered in the roots and generally conserved upon translocation to the leaves. The data suggest that selenium was directly absorbed by C. comosum roots when supplemented with SeVI, but a combination of passive and direct absorption occurred when supplemented with SeIV due to the partial oxidation of SeIV to SeVI in the rhizosphere. Higher molecular weight selenium species were more prevalent in the roots of plants supplemented with SeIV, but in the leaves of plants supplemented with SeVI due to an increased translocation rate. When supplemented as AsIII, arsenic is proposed to be passively absorbed as AsIII and partially oxidized to AsV in the plant root. Although total elemental analysis demonstrates a selenium and arsenic antagonism, a compound containing selenium and arsenic was not present in the general aqueous extract of the plant. PMID:19273464

The Effect on Selenium Concentrations of a Randomized Intervention with Fish and Mussels in a Population with Relatively Low Habitual Dietary Selenium Intake

PubMed Central

Outzen, Malene; Tjønneland, Anne; Larsen, Erik H.; Andersen, Klaus K.; Christensen, Jane; Overvad, Kim; Olsen, Anja

2015-01-01

Selenium status of the Danish population is below that assumed optimal for the suggested protective effects against chronic diseases, including certain cancers. Fish and shellfish are important dietary sources of selenium in Denmark. We investigated the effect of increased fish and mussel intake on selenium blood concentrations in a population with relatively low habitual dietary selenium intake. We randomly assigned 102 healthy men and women (all non-smokers) aged 48–76 years to an intervention group (n = 51) or a control group (n = 51). Intervention participants received 1000 g fish and mussels/week for 26 weeks (~50 μg selenium/day). Controls received no intervention. Non-fasting blood samples were taken and whole blood selenium was determined using inductively coupled plasma-mass spectrometry (ICP-MS), and plasma selenoprotein P (SelP) was determined by high performance liquid chromatography coupled to ICP-MS. All available observations were included in linear multiple regression analysis to evaluate the effect of the intervention. The difference in mean change for intervention compared with control persons was 14.9 ng/mL (95% CI: 10.2, 19.7) for whole blood selenium, and 7.0 ng/mL (95% CI: 3.1, 10.9) for plasma SelP (Weeks 0–26). Selenium concentrations were significantly increased after 26 weeks of intervention, albeit to a lower degree than expected. PMID:25599275

Toxic effects of trace elements on newborns and their birth outcomes.

PubMed

Tang, Mengling; Xu, Chenye; Lin, Nan; Yin, Shanshan; Zhang, Yongli; Yu, Xinwei; Liu, Weiping

2016-04-15

Some trace elements are essential for newborns, their deficiency may cause abnormal biological functions, whereas excessive intakes due to environmental contamination may create adverse health effects. This study was conducted to measure the levels of selected trace elements in Chinese fish consumers by assessing their essentiality and toxicity via colostrum intake in newborns, and evaluated the effects of these trace elements on birth outcomes. Trace elements in umbilical cord serum and colostrum of the studied population were relatively high compared with other populations. The geometric means (GM) of estimated daily intake (EDI, mgday(-1)) of the trace elements were in the safe ranges for infant Dietary Reference Intakes (DRIs) recommended by the United States Food and Drug Administration (FDA). When using total dietary intake (TDI, mgkg(-1)bwday(-1)), zinc (Zn) (0.880mgkg(-1)bwday(-1)) and selenium (Se) (6.39×10(-3)mgkg(-1)bwday(-1)) were above the Reference Doses (RfD), set by the United States Environmental Protection Agency (EPA). Multivariable linear regression analyses showed that Se was negatively correlated with birth outcomes. Our findings suggested that overloading of trace elements due to environmental contamination may contribute to negative birth outcomes. Copyright © 2016 Elsevier B.V. All rights reserved.

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.

Selenium and selenium-sulfur cathode materials for high-energy rechargeable magnesium batteries

NASA Astrophysics Data System (ADS)

Zhao-Karger, Zhirong; Lin, Xiu-Mei; Bonatto Minella, Christian; Wang, Di; Diemant, Thomas; Behm, R. Jürgen; Fichtner, Maximilian

2016-08-01

Magnesium (Mg) is an attractive metallic anode material for next-generation batteries owing to its inherent dendrite-free electrodeposition, high capacity and low cost. Here we report a new class of Mg batteries based on both elemental selenium (Se) and selenium-sulfur solid solution (SeS2) cathode materials. Elemental Se confined into a mesoporous carbon was used as a cathode material. Coupling the Se cathode with a metallic Mg anode in a non-nucleophilic electrolyte, the Se cathode delivered a high initial volumetric discharge capacity of 1689 mA h cm-3 and a reversible capacity of 480 mA h cm-3 was retained after 50 cycles at a high current density of 2 C. The mechanistic insights into the electrochemical conversion in Mg-Se batteries were investigated by microscopic and spectroscopic methods. The structural transformation of cyclic Se8 into chainlike Sen upon battery cycling was revealed by ex-situ Raman spectroscopy. In addition, the promising battery performance with a SeS2 cathode envisages the perspective of a series of SeSn cathode materials combining the benefits of both selenium and sulfur for high energy Mg batteries.

Insights for Setting of Nutrient Requirements, Gleaned by Comparison of Selenium Status Biomarkers in Turkeys and Chickens versus Rats, Mice, and Lambs12

PubMed Central

Sunde, Roger A; Li, Jin-Long; Taylor, Rachel M

2016-01-01

To gain insights into nutrient biomarkers and setting of dietary nutrient requirements, selenium biomarker levels and requirements in response to multiple graded levels of dietary selenium were compared between day-old turkeys and chickens versus weanling rats and mice and 2-d-old lambs supplemented with sodium selenite. In rodents, there was no significant effect of dietary selenium on growth, indicating that the minimum selenium requirement was <0.007 μg Se/g diet. In contrast, there was a significant effect in turkeys, chicks, and lambs, which showed selenium requirements for growth of 0.05, 0.025, and 0.05 μg Se/g diet, respectively. Liver glutathione peroxidase (GPX) 1 activity fell in all species to <4% of selenium-adequate levels, plasma GPX3 activity fell to <3% in all species except for mice, and liver GPX4 activity fell to <10% in avians but only to ∼50% of selenium-adequate levels in rodents. Selenium-response curves for these biomarkers reached well-defined plateaus with increasing selenium supplementation in all species, collectively indicating minimum selenium requirements of 0.06–0.10 μg Se/g for rats, mice, and lambs but 0.10–0.13 μg Se/g for chicks and 0.23–0.33 μg Se/g for turkeys. In contrast, increasing dietary selenium did not result in well-defined plateaus for erythrocyte GPX1 activity and liver selenium in most species. Selenium-response curves for GPX1 mRNA for rodents and avians had well-defined plateaus and similar breakpoints. GPX4 mRNA was not significantly regulated by dietary selenium in rodents, but GPX4 mRNA in avians decreased in selenium deficiency to ∼35% of selenium-adequate plateau levels. Notably, no selenoprotein activities or mRNA were effective biomarkers for supernutritional selenium status. Robust biomarkers, such as liver GPX1 and plasma GPX3 activity for selenium, should be specific for the nutrient, fall dramatically in deficiency, and reach well-defined plateaus. Differences in biomarker-response curves may help researchers better understand nutrient metabolism and targeting of tissues in deficiency, thus to better characterize requirements. PMID:28140330

Insights for Setting of Nutrient Requirements, Gleaned by Comparison of Selenium Status Biomarkers in Turkeys and Chickens versus Rats, Mice, and Lambs.

PubMed

Sunde, Roger A; Li, Jin-Long; Taylor, Rachel M

2016-11-01

To gain insights into nutrient biomarkers and setting of dietary nutrient requirements, selenium biomarker levels and requirements in response to multiple graded levels of dietary selenium were compared between day-old turkeys and chickens versus weanling rats and mice and 2-d-old lambs supplemented with sodium selenite. In rodents, there was no significant effect of dietary selenium on growth, indicating that the minimum selenium requirement was <0.007 μg Se/g diet. In contrast, there was a significant effect in turkeys, chicks, and lambs, which showed selenium requirements for growth of 0.05, 0.025, and 0.05 μg Se/g diet, respectively. Liver glutathione peroxidase (GPX) 1 activity fell in all species to <4% of selenium-adequate levels, plasma GPX3 activity fell to <3% in all species except for mice, and liver GPX4 activity fell to <10% in avians but only to ∼50% of selenium-adequate levels in rodents. Selenium-response curves for these biomarkers reached well-defined plateaus with increasing selenium supplementation in all species, collectively indicating minimum selenium requirements of 0.06-0.10 μg Se/g for rats, mice, and lambs but 0.10-0.13 μg Se/g for chicks and 0.23-0.33 μg Se/g for turkeys. In contrast, increasing dietary selenium did not result in well-defined plateaus for erythrocyte GPX1 activity and liver selenium in most species. Selenium-response curves for GPX1 mRNA for rodents and avians had well-defined plateaus and similar breakpoints. GPX4 mRNA was not significantly regulated by dietary selenium in rodents, but GPX4 mRNA in avians decreased in selenium deficiency to ∼35% of selenium-adequate plateau levels. Notably, no selenoprotein activities or mRNA were effective biomarkers for supernutritional selenium status. Robust biomarkers, such as liver GPX1 and plasma GPX3 activity for selenium, should be specific for the nutrient, fall dramatically in deficiency, and reach well-defined plateaus. Differences in biomarker-response curves may help researchers better understand nutrient metabolism and targeting of tissues in deficiency, thus to better characterize requirements. © 2016 American Society for Nutrition.

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

Continued selenium biofortification of carrots and broccoli grown in soils once amended with Se-enriched S. pinnata

USDA-ARS?s Scientific Manuscript database

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 ...

The Impact of Phosphorus Supply on Selenium Uptake During Hydroponics Experiment of Winter Wheat (Triticum aestivum) in China.

PubMed

Liu, Hongen; Shi, Zhiwei; Li, Jinfeng; Zhao, Peng; Qin, Shiyu; Nie, Zhaojun

2018-01-01

Selenium (Se) is a necessary trace element for humans and animals, and Se fertilization is an efficient way to increase Se concentration in the edible parts of crops, thus enhance the beneficiary effects of Se in human and animal health. Due to the similarity of physical and chemical properties between phosphate () and selenite (), phosphorus (P) supply often significantly impacts the absorption of Se in plants, but little is known about how P supply influences the subcellular distribution and chemical forms of Se. In this study, the effects of P supply on subcellular distribution and chemical forms of Se in winter wheat were investigated in a hydroponic trial with medium Se level (0.1 mg Se L -1 ). P was applied with three concentrations (0.31, 3.1, and 31 mg P L -1 ) in the experiment. The results showed that increasing P supply significantly decreased the concentration and accumulation of Se in the roots, stems, and leaves of winter wheat. An increase in P supply significantly inhibited Se accumulation in the root cell wall, but enhanced Se distribution in the organelles and soluble fraction of root cells. These findings suggest that increased P supply inhibited the root-to-shoot transport of Se. An increase in P supply enhanced Se accumulation in the cell wall of plant stems (both apical and axillary stem) and cell organelles of plants leaves, but inhibited Se distribution in the soluble fraction of stems and leaves. This suggests that P supply enhances Se transportation across the cell membrane in shoots of winter wheat. In addition, increased P supply also altered the chemical forms of Se in tissues of winter wheat. These findings will help in understanding of the regulation grain Se accumulation and provide a practical way to enhance Se intake for humans inform Se-enriched grains.

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∙g d.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∙g d.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.

Selenomethionine protects against neuronal degeneration by methylmercury in the developing rat cerebrum.

PubMed

Sakamoto, Mineshi; Yasutake, Akira; Kakita, Akiyoshi; Ryufuku, Masae; Chan, Hing Man; Yamamoto, Megumi; Oumi, Sanae; Kobayashi, Sayaka; Watanabe, Chiho

2013-03-19

Although many experimental studies have shown that selenium protects against methylmercury (MeHg) toxicity at different end points, the direct interactive effects of selenium and MeHg on neurons in the brain remain unknown. Our goal is to confirm the protective effects of selenium against neuronal degeneration induced by MeHg in the developing postnatal rat brain using a postnatal rat model that is suitable for extrapolating the effects of MeHg to the fetal brain of humans. As an exposure source of selenium, we used selenomethionine (SeMet), a food-originated selenium. Wistar rats of postnatal days 14 were orally administered with vehicle (control), MeHg (8 mg Hg/kg/day), SeMet (2 mg Se/kg/day), or MeHg plus SeMet coexposure for 10 consecutive days. Neuronal degeneration and reactive astrocytosis were observed in the cerebral cortex of the MeHg-group but the symptoms were prevented by coexposure to SeMet. These findings serve as a proof that dietary selenium can directly protect neurons against MeHg toxicity in the mammalian brain, especially in the developing cerebrum.

Speciation of selenium and arsenic compounds by capillary electrophoresis with hydrodynamically modified electroosmotic flow and on-line reduction of selenium(VI) to selenium(IV) with hydride generation inductively coupled plasma mass spectrometric detection.

PubMed

Magnuson, M L; Creed, J T; Brockhoff, C A

1997-10-01

Capillary electrophoresis (CE) with hydride generation inductively coupled plasma mass spectrometry was used to determine four arsenicals and two selenium species. Selenate (SeVI) was reduced on-line to selenite (SeIV) by mixing the CE effluent with concentrated HCl. A microporous PTFE tube was used as a gas-liquid separator to eliminate the 40Ar37Cl and 40Ar35Cl interference from 77Se and 75As, respectively. The direction of the electroosmotic flow during CE was reversed with hydrodynamic pressure, which allowed increased freedom of buffer choice. For conventional pressure injection, method detection limits for SeIV and SeVI based on seven replicate injections were 10 and 24 pg, respectively. Recoveries of SeIV and SeVI in drinking water were measured.

The selenium content of SEPP1 versus selenium requirements in vertebrates

PubMed Central

Hamre, Kristin; Ellingsen, Ståle

2015-01-01

Selenoprotein P (SEPP1) distributes selenium (Se) throughout the body via the circulatory system. For vertebrates, the Se content of SEPP1 varies from 7 to 18 Se atoms depending on the species, but the reason for this variation remains unclear. Herein we provide evidence that vertebrate SEPP1 Sec content correlates positively with Se requirements. As the Se content of full length SEPP1 is genetically determined, this presents a unique case where a nutrient requirement can be predicted based on genomic sequence information. PMID:26734501

Selenium-induced toxicity is counteracted by sulfur in broccoli (Brassica oleracea L. var. italic)

USDA-ARS?s Scientific Manuscript database

Selenium (Se) is an essential micronutrient for humans. Increasing Se content in food crops offers an effective approach to enhance the consumption of Se in human diets. A thoroughly understanding of the effects of Se on plant growth is important for Se biofortification in food crops. Given that Se ...

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

USDA-ARS?s Scientific Manuscript database

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...

Treating chronic arsenic toxicity with high selenium lentil diets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sah, Shweta; Vandenberg, Albert; Smits, Judit, E-mail: judit.smits@ucalgary.ca

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 comparemore » 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 response.« less

Acute selenium toxicosis induced in baby pigs by parenteral administration of selenium-vitamin E preparations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Vleet, J.F.; Meyer, K.B.; Olander, H.J.

1974-09-15

Acute selenium (Se) toxicosis was induced in baby pigs by intramuscular (IM) injection of Se, as selenite, using commercially available selenium-vitamin E (Se-E) preparations. Graded amounts of Se were given to 26 pigs from a herd that had not experienced losses from Se-E deficiency and to 136 pigs from a herd that had continual losses from Se-E deficiency. Of the 2 groups of pigs, those from the Se-E-deficient herd were more susceptible to acute Se toxicosis. Clinical signs of toxicosis were vomiting, anorexia, depression, dyspnea, weakness, and coma, with death occurring 24 to 48 hours after injection. Pathologic alterations observedmore » grossly and histologically included pulmonary edema, skeletal myodegeneration, hepatic degeneration and necrosis, transudation into body cavities, and widespread circulatory disturbances. Mean tissue Se concentrations in 20 pigs with acute toxicosis 24 to 48 hours after injection were 12.44 ppm in liver, 1.31 ppm in kidney, and 0.32 ppm in skeletal muscle.« less

Comparison of the metabolism of inorganic and organic selenium species between two selenium accumulator plants, garlic and Indian mustard.

PubMed

Ogra, Yasumitsu; Ogihara, Yurie; Anan, Yasumi

2017-01-25

The metabolism of selenomethionine (SeMet) in two major selenium (Se) accumulator plants, garlic and Indian mustard, was compared to that of stable isotope labeled selenate. Indian mustard more efficiently transported Se from roots to leaves than garlic. In addition, Indian mustard accumulated larger amounts of Se than garlic. γ-Glutamyl-Se-methylselenocysteine (γ-GluMeSeCys) and Se-methylselenocysteine (MeSeCys) were the common metabolites of selenate and SeMet in garlic and Indian mustard. Indian mustard had a specific metabolic pathway to selenohomolanthionine (SeHLan) from both inorganic and organic Se species. SeMet was a more effective fertilizer for cultivating Se-enriched plants than selenate in terms of the production of selenoamino acids.

Selenium accumulation in lettuce germplasm

USDA-ARS?s Scientific Manuscript database

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...

Deficient selenium status of a healthy adult Spanish population.

PubMed

Millán Adame, E; Florea, D; Sáez Pérez, L; Molina López, J; López-González, B; Pérez de la Cruz, A; Planells del Pozo, E

2012-01-01

Selenium is an essential micronutrient for human health, being a cofactor for enzymes with antioxidant activity that protect the organism from oxidative damage. An inadequate intake of this mineral has been associated with the onset and progression of chronic diseases such as hypertension, diabetes, coronary diseases, asthma, and cancer. For this reason, knowledge of the plasma and erythrocyte selenium levels of a population makes a relevant contribution to assessment of its nutritional status. The objective of the present study was to determine the nutritional status of selenium and risk of selenium deficiency in a healthy adult population in Spain by examining food and nutrient intake and analyzing biochemical parameters related to selenium metabolism, including plasma and erythrocyte levels and selenium-dependent glutathione peroxidase (GPx) enzymatic activity. We studied 84 healthy adults (31 males and 53 females) from the province of Granada, determining their plasma and erythrocyte selenium concentrations and the association of these levels with the enzymatic activity of glutathione peroxidase (GPx) and with life style factors. We also gathered data on their food and nutrient intake and the results of biochemical analyses. Correlations were studied among all of these variables. The mean plasma selenium concentration was 76.6 ± 17.3 μg/L (87.3 ± 17.4 μg/L in males, 67.3 ± 10.7 μg/L in females), whereas the mean erythrocyte selenium concentration was 104.6 μg/L (107.9 ± 26.1 μg/L in males and 101.7 ± 21.7 μg/L in females). The nutritional status of selenium was defined by the plasma concentration required to reach maximum GPx activity, establishing 90 μg/L as reference value. According to this criterion, 50% of the men and 53% of the women were selenium deficient. Selenium is subjected to multiple regulation mechanisms. Erythrocyte selenium is a good marker of longer term selenium status, while plasma selenium appears to be a marker of short-term nutritional status. The present findings indicate a positive correlation between plasma selenium concentration and the practice of physical activity. Bioavailability studies are required to establish appropriate reference levels of this mineral for the Spanish population.

SPECIATION OF SELENIUM AND ARSENIC COMPOUNDS BY CAPILLARY ELECTROPHORESIS WITH HYDRODYNAMICALLY MODIFIED ELECTROOSMOTIC FLOW AND ON-LINE REDUCTION OF SELENIUM(VI) TO SELENIUM(IV) WITH HYDRIDE GENERATION INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRIC DETECTION

EPA Science Inventory

Capillary electrophoresis (CE) with hydride generation inductively coupled plasma mass spectrometry was used to determine four arsenicals and two selenium species. Selenate (SeVI) was reduced on-line to selenite (SeIV') by mixing the CE effluent with concentrated HCl. A microporo...

Influence of processing in mercury and selenium vapor on the electrical properties of Cd /SUB x/ Hg /SUB 1-x/ Se, Zn /SUB x/ Hg /SUB 1-x/ Se solid solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gavaleshko, N.P.; Khomyak, V.V.; Makogonenko, V.N.

1985-12-01

In order to determine the predominant intrinsic point defects in Cd /SUB x/ Hg /SUB 1-x/ Se and Zn /SUB x/ Hg /SUB 1-x/ Se solid solutions, the authors study the influence of annealing in mercury and selenium vapor on the carrier concentration and mobility. When the specimens are annealed in selenium vapor the electron concentration at first increases and then becomes constant. A theoretical analysis of the results obtained indicate that selenium vacancies are the predominant point defects in the solutions, and that the process of defect formation itself is quasiepitaxial.

Synthesis and thermal stability of selenium-doped hydroxyapatite with different substitutions

NASA Astrophysics Data System (ADS)

Liu, Yonghui; Ma, Jun; Zhang, Shengmin

2015-12-01

Selenium (Se) plays a specific role in human health, especially for its antitumor effect. Incorporation of selenium into biocompatible hydroxyapatite (HAP) may endow the materials with novel characteristics. In the current work, a series of seleniumdoped hydroxyapatite (Se-HAP) nanoparticles with different Se/P ratios were synthesized by a modified chemical precipitation. It was revealed that the powders with/without heattreatment were nano-sized needle-like HAP while the heat-treated samples have high crystallinity. The addition of selenium decreases the crystallinity of the synthesized apatite, and also takes a negative effect on the thermal stability of the as-prepared powders. The Se-HAP nanoparticles with Se/P molar ratio not more than 5% sintered at 900°C can achieve good crystallinity and thermal stability.

Effects of Interaction between Cadmium (Cd) and Selenium (Se) on Grain Yield and Cd and Se Accumulation in a Hybrid Rice (Oryza sativa) System.

PubMed

Huang, Baifei; Xin, Junliang; Dai, Hongwen; Zhou, Wenjing

2017-11-01

A pot experiment was conducted to investigate the interactive effects of cadmium (Cd) and selenium (Se) on their accumulation in three rice cultivars, which remains unclear. The results showed that Se reduced Cd-induced growth inhibition, and increased and decreased Se and Cd concentrations in brown rice, respectively. Cadmium concentrations in all tissues of the hybrid were similar to those in its male parent yet significantly lower than those in its female parent. Selenium reduced Cd accumulation in rice when Cd concentration exceeded 2.0 mg kg -1 ; however Se accumulation depended on the levels of Cd exposure. Finally, Cd had minimal effect on Se translocation within the three cultivars. We concluded that Cd concentration in brown rice is a heritable trait, making crossbreeding a feasible method for cultivating high-yield, low-Cd rice cultivars. Selenium effectively decreased the toxicity and accumulation of Cd, and Cd affected Se uptake but not translocation.

Alcohol, gestation and breastfeeding: selenium as an antioxidant therapy.

PubMed

Ojeda, Ma Luisa; Nogales, Fatima; Vázquez, Beatriz; Delgado, Ma José; Murillo, Ma Luisa; Carreras, Olimpia

2009-01-01

The aim of this paper is to study the relationship between alcohol, selenium and oxidative stress in breastfeeding rat pups exposed to ethanol during gestation and lactation. We have also studied how a Se-supplemented diet among mothers could prevent different oxidative liver disorders in the pups. Pups of 21 days were randomized into four groups: control group (C), alcohol group (A), alcohol selenium group (AS) and control selenium group (CS). Alcohol was supplied to their mothers for 13 weeks (induction, reproduction, gestation and lactation periods). The selenium-supplemented diet contained 0.5 ppm as selenite. We determined serum and liver selenium by graphite-furnace atomic absorption spectrometry. We measured antioxidant enzyme activities: glutathione peroxidase (GPx), glutathione reductase (GR), catalase (CAT) and superoxide dismutase (SOD); and lipid peroxidation (TBARS) and protein carbonyl (PC) by a spectrophotometric method in the liver. In the liver of pups, exposure to ethanol provoked a decrease in selenium and GPx activity and an increase in GR and CAT activity, as well as in carbonyl groups in protein. A pups had higher Se levels and GPx activity in serum than C pups. Administering Se with alcohol balances the activities of scavenging enzymes and reduces peroxidation protein products. These results suggest that selenium could be effective in neutralizing the damage of ethanol consumption during gestation and lactation in pups since it repairs selenium levels in liver as well as the activity of scavenging enzymes and peroxidation protein products. In serum, Se also recovers GPx activity and increases the levels of Se that are available to other organs.

Reported Dietary Intake and Food Sources of Zinc, Selenium, and Vitamins A, E and C in the Spanish Population: Findings from the ANIBES Study.

PubMed

Olza, Josune; Aranceta-Bartrina, Javier; González-Gross, Marcela; Ortega, Rosa M; Serra-Majem, Lluis; Varela-Moreiras, Gregorio; Gil, Ángel

2017-07-06

Zinc, selenium, and the vitamins A, E and C, all have specific biological functions that are involved mainly in the antioxidant defence system, which has important implications for the development of chronic diseases. We aimed to assess the reported intake of those six nutrients, as well as the food that contributes to their sources of intakes. Data were obtained from the Spanish ANIBES ("Anthropometry, Intake and Energy Balance in Spain") study, n = 2009 (9-75 years old). The analyses were performed in the whole population and in the plausible energy reporters after a misreporting analysis according to the European Food and Safety Authority (EFSA) protocol. A validated, photo-based three-day food record was used to collect the data. Mean (max-min) reported intake for the whole population of zinc was 8.1 ± 0.1 mg/day, (2.3-27.3 mg/day), selenium 75 ± 1 µg/day, (14-265 µg/day), vitamin A 668 µg RE/day (2-11,017 µg RE/day), retinol 364 ± 18 µg/day (0-10,881 µg/day), carotenes 1735 ± 35 µg/day (13-13,962 µg/day), vitamin E 7.0 ± 0.1 mg α-TE/day (0.7-55.2 mg α-TE/day) and vitamin C 84.4 ± 1.4 mg/day (5.0-802.7 mg/day). The main source intakes for zinc were meat and meat products, for selenium cereals and grains, for vitamin E oils and fat, and for vitamin A and C vegetables. There is an elevated percentage of the Spanish ANIBES population not meeting the EFSA recommended intakes for all analysed micronutrients: zinc (83%), vitamin A (60%), vitamin E (80%), vitamin C (36%) and selenium (25%).

Selenium-methionine and chromium-methionine supplementation of sheep around parturition: impacts on dam and offspring performance.

PubMed

Mousaie, Amir; Valizadeh, Reza; Chamsaz, Mahmoud

2017-04-01

To examine the effects of maternal energy restriction along with selenium-methionine (Se-Met) and chromium-methionine (Cr-Met) supplementation on performance of pregnant sheep and their offspring, the following treatments were allotted randomly to 40 multiparous Baluchi ewes (53.9 ± 1.15 kg of body weight [BW]) from 5 weeks prior to 5 weeks after parturition: (1) Control diet (60% and 100% of NRC energy requirements in pre- and post-partum, respectively); (2) Control diet plus 5 mg Se-Met/kg dry matter (DM); (3) Control diet plus 3 mg Cr-Met/kg DM and (4) Control diet plus 5 mg Se-Met and 3 mg Cr-Met/kg DM (Se-Cr-Met) of concentrate diet. The results indicated that Cr-Met alone or in combination with Se-Met increased average DM intake of ewes. In addition, Group Cr-Met had higher average BW than the Control (p < 0.05). Se-Met and/or Cr-Met supplementation led to decreased average serum cholesterol of the ewes (p < 0.05). Groups Cr-Met and Se-Cr-Met displayed decreased average serum malondialdehyde compared to the Control (p < 0.05). At 24 h post-partum, Group Se-Cr-Met had a greater serum Se content than the Control (p = 0.006). Compared with the Control, the Se concentration in milk was significantly increased from 30 to 138 µg/l and 197 µg/l in Groups Se-Met and Se-Cr-Met, respectively (p < 0.01), which proved that Se-Met supplementation can increase the Se concentration of ewe milk. Furthermore, feeding Cr-Met may attenuate BW loss post-partum and Se-Met and/or Cr-Met supplements may ameliorate oxidative stress condition in ewes around parturition.

Blood Selenium Concentration and Blood Cystatin C Concentration in a Randomly Selected Population of Healthy Children Environmentally Exposed to Lead and Cadmium.

PubMed

Gać, Paweł; Pawlas, Natalia; Wylężek, Paweł; Poręba, Rafał; Poręba, Małgorzata; Pawlas, Krystyna

2017-01-01

This study aimed at evaluation of a relationship between blood selenium concentration (Se-B) and blood cystatin C concentration (CST) in a randomly selected population of healthy children, environmentally exposed to lead and cadmium. The studies were conducted on 172 randomly selected children (7.98 ± 0.97 years). Among participants, the subgroups were distinguished, manifesting marginally low blood selenium concentration (Se-B 40-59 μg/l), suboptimal blood selenium concentration (Se-B: 60-79 μg/l) or optimal blood selenium concentration (Se-B ≥ 80 μg/l). At the subsequent stage, analogous subgroups of participants were selected separately in groups of children with BMI below median value (BMI <16.48 kg/m 2 ) and in children with BMI ≥ median value (BMI ≥16.48 kg/m 2 ). In all participants, values of Se-B and CST were estimated. In the entire group of examined children no significant differences in mean CST values were detected between groups distinguished on the base of normative Se-B values. Among children with BMI below 16.48 kg/m 2 , children with marginally low Se-B manifested significantly higher mean CST values, as compared to children with optimum Se-B (0.95 ± 0.07 vs. 0.82 ± 0.15 mg/l, p < 0.05). In summary, in a randomly selected population of healthy children no relationships could be detected between blood selenium concentration and blood cystatin C concentration. On the other hand, in children with low body mass index, a negative non-linear relationship was present between blood selenium concentration and blood cystatin C concentration.

Selenium Levels in the Whole Blood of Children and Teenagers from Two Riparian Communities at the Madeira River Basin in the Western Brazilian Amazon.

PubMed

Vega, Claudia M; Godoy, José M; Barrocas, Paulo R G; Gonçalves, Rodrigo A; De Oliveira, Beatriz F A; Jacobson, Ludmilla V; Mourão, Dennys S; Hacon, Sandra S

2017-01-01

Selenium (Se) is an essential micronutrient that exerts multiple functions in the organism, and both its deficiency and excess can cause health impairments. Thus, it is important to monitor its levels in the population, especially in vulnerable groups, such as children from the Brazilian Amazon region, where there is a lack of information in this regard. The aim of this research was to study Se levels in the whole blood of children and teenagers (5-16 years old) from two riparian communities at the Madeira River (Cuniã RESEX and Belmont). Se level variations related to the communities' location, seasonality, diet, and body mass index (BMI) were assessed. Blood samples were collected in both communities for Se determinations, using ICP-MS and hemogram analyses, during May and September of 2011. Food frequency questionnaires were applied to assess consumption rates of specific food items. Non-parametric tests and linear multiple regressions were applied in the data analyses. Median Se levels were significantly higher during May (Cuniã RESEX 149 μg L -1 ; Belmont 85 μg L -1 ) compared to September (Cuniã RESEX 79 μg L -1 ; Belmont 53 μg L -1 ). No significant differences were found between the communities regarding BMI measurements and anemia prevalence. However, Se blood levels were significantly higher at the Cuniã RESEX compared to Belmont. In addition, the former showed higher fish and Brazil nut intakes, which may be the main Se sources for this community. These results contribute to a better understanding of Se reference levels for children and teenagers of Western Amazon riparian communities.

Extracellular polymeric substances govern the surface charge of biogenic elemental selenium nanoparticles.

PubMed

Jain, Rohan; Jordan, Norbert; Weiss, Stephan; Foerstendorf, Harald; Heim, Karsten; Kacker, Rohit; Hübner, René; Kramer, Herman; van Hullebusch, Eric D; Farges, François; Lens, Piet N L

2015-02-03

The origin of the organic layer covering colloidal biogenic elemental selenium nanoparticles (BioSeNPs) is not known, particularly in the case when they are synthesized by complex microbial communities. This study investigated the presence of extracellular polymeric substances (EPS) on BioSeNPs. The role of EPS in capping the extracellularly available BioSeNPs was also examined. Fourier transform infrared (FT-IR) spectroscopy and colorimetric measurements confirmed the presence of functional groups characteristic of proteins and carbohydrates on the BioSeNPs, suggesting the presence of EPS. Chemical synthesis of elemental selenium nanoparticles in the presence of EPS, extracted from selenite fed anaerobic granular sludge, yielded stable colloidal spherical selenium nanoparticles. Furthermore, extracted EPS, BioSeNPs, and chemically synthesized EPS-capped selenium nanoparticles had similar surface properties, as shown by ζ-potential versus pH profiles and isoelectric point measurements. This study shows that the EPS of anaerobic granular sludge form the organic layer present on the BioSeNPs synthesized by these granules. The EPS also govern the surface charge of these BioSeNPs, thereby contributing to their colloidal properties, hence affecting their fate in the environment and the efficiency of bioremediation technologies.

Reduction of Selenite to Red Elemental Selenium by Rhodopseudomonas palustris Strain N

PubMed Central

Li, Baozhen; Liu, Na; Li, Yongquan; Jing, Weixin; Fan, Jinhua; Li, Dan; Zhang, Longyan; Zhang, Xiaofeng; Zhang, Zhaoming; Wang, Lan

2014-01-01

The trace metal selenium is in demand for health supplements to human and animal nutrition. We studied the reduction of selenite (SeO3 −2) to red elemental selenium by Rhodopseudomonas palustris strain N. This strain was cultured in a medium containing SeO3 −2 and the particles obtained from cultures were analyzed using transmission electron microscopy (TEM), energy dispersive microanalysis (EDX) and X ray diffraction analysis (XRD). Our results showed the strain N could reduce SeO3 −2 to red elemental selenium. The diameters of particles were 80–200 nm. The bacteria exhibited significant tolerance to SeO3 −2 up to 8.0 m mol/L concentration with an EC50 value of 2.4 m mol/L. After 9 d of cultivation, the presence of SeO3 2− up to 1.0 m mol/L resulted in 99.9% reduction of selenite, whereas 82.0% (p<0.05), 31.7% (p<0.05) and 2.4% (p<0.05) reduction of SeO3 −2 was observed at 2.0, 4.0 and 8.0 m mol/L SeO3 2− concentrations, respectively. This study indicated that red elemental selenium was synthesized by green technology using Rhodopseudomonas palustris strain N. This strain also indicated a high tolerance to SeO3 −2. The finding of this work will contribute to the application of selenium to human health. PMID:24759917

Assessment of selenium bioavailability from naturally produced high-selenium soy foods in selenium-deficient rats.

PubMed

Yan, Lin; Reeves, Philip G; Johnson, LuAnn K

2010-10-01

We assessed the bioavailability of selenium (Se) from a protein isolate and tofu (bean curd) prepared from naturally produced high-Se soybeans. The Se concentrations of the soybeans, the protein isolate and tofu were 5.2±0.2, 11.4±0.1 and 7.4±0.1mg/kg, respectively. Male weanling Sprague-Dawley rats were depleted of Se by feeding them a 30% Torula yeast-based diet (4.1μg Se/kg) for 56 days, and then they were replenished with Se for an additional 50 days by feeding them the same diet containing 14, 24 or 30 μg Se/kg from the protein isolate or 13, 23 or 31 μg Se/kg from tofu, respectively. l-Selenomethionine (SeMet) was used as a reference. 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 the protein isolate and tofu to those for SeMet by using a slope-ratio method. Dietary supplementation with the protein isolate or tofu resulted in linear or log-linear, dose-dependent increases in glutathione peroxidase activities in blood and liver and in thioredoxin reductase activity in liver. Furthermore, supplementation with the protein isolate or tofu resulted in linear or log-linear, dose-dependent increases in the Se concentrations of plasma, liver, muscle and kidneys. These results indicated an overall bioavailability of approximately 101% for Se from the protein isolate and 94% from tofu, relative to SeMet. We conclude that Se from naturally produced high-Se soybeans is highly bioavailable in this model and that high-Se soybeans may be a good dietary source of Se. Published by Elsevier GmbH.

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

Fish, mercury, selenium and cardiovascular risk: current evidence and unanswered questions.

PubMed

Mozaffarian, Dariush

2009-06-01

Controversy has arisen among the public and in the media regarding the health effects of fish intake in adults. Substantial evidence indicates that fish consumption reduces coronary heart disease mortality, the leading cause of death in developed and most developing nations. Conversely, concerns have grown regarding potential effects of exposure to mercury found in some fish. Seafood species are also rich in selenium, an essential trace element that may protect against both cardiovascular disease and toxic effects of mercury. Such protective effects would have direct implications for recommendations regarding optimal selenium intake and for assessing the potential impact of mercury exposure from fish intake in different populations. Because fish consumption appears to have important health benefits in adults, elucidating the relationships between fish intake, mercury and selenium exposure, and health risk is of considerable scientific and public health relevance. The evidence for health effects of fish consumption in adults is reviewed, focusing on the strength and consistency of evidence and relative magnitudes of effects of omega-3 fatty acids, mercury, and selenium. Given the preponderance of evidence, the focus is on cardiovascular effects, but other potential health effects, as well as potential effects of polychlorinated biphenyls and dioxins in fish, are also briefly reviewed. The relevant current unanswered questions and directions of further research are summarized.

Nutritional and supranutritional levels of selenate differentially suppress prostate tumor growth in adult but not young nude mice.

PubMed

Holmstrom, Alexandra; Wu, Ryan T Y; Zeng, Huawei; Lei, K Y; Cheng, Wen-Hsing

2012-09-01

The inhibitory effect of oral methylseleninic acid or methylselenocysteine administration on cancer cell xenograft development in nude mice is well characterized; however, less is known about the efficacy of selenate and age on selenium chemoprevention. In this study, we tested whether selenate and duration on diets would regulate prostate cancer xenograft in nude mice. Thirty-nine homozygous NU/J nude mice were fed a selenium-deficient, Torula yeast basal diet alone (Se-) or supplemented with 0.15 (Se) or 1.0 (Se+) mg selenium/kg (as Na₂SeO₄) for 6 months in Experiment 1 and for 4 weeks in Experiment 2, followed by a 47-day PC-3 prostate cancer cell xenograft on the designated diet. In Experiment 1, the Se- diet enhanced the initial tumor development on days 11-17, whereas the Se+ diet suppressed tumor growth on days 35-47 in adult nude mice. Tumors grown in Se- mice were loosely packed and showed increased necrosis and inflammation as compared to those in Se and Se+ mice. In Experiment 2, dietary selenium did not affect tumor development or histopathology throughout the time course. In both experiments, postmortem plasma selenium concentrations in Se and Se+ mice were comparable and were twofold greater than those in Se- mice. Taken together, dietary selenate at nutritional and supranutritional levels differentially inhibit tumor development in adult, but not young, nude mice engrafted with PC-3 prostate cancer cells. Copyright © 2012 Elsevier Inc. All rights reserved.

Management of bile acid malabsorption using low-fat dietary interventions: a useful strategy applicable to some patients with diarrhoea-predominant irritable bowel syndrome?

PubMed

Watson, Lorraine; Lalji, Amyn; Bodla, Shankar; Muls, Ann; Andreyev, H Jervoise N; Shaw, Clare

2015-12-01

This study evaluates the efficacy of low-fat dietary interventions in the management of gastrointestinal (GI) symptoms due to bile acid malabsorption. In total, 40 patients with GI symptoms and a 7-day (75)selenium homocholic acid taurine (SeHCAT) scan result of <20%, were prospectively recruited and then advised regarding a low-fat dietary intervention. Before and after dietary intervention, patients rated their GI symptoms using a 10-point numerical scale, and recorded their intake in 7-day dietary diaries. After dietary intervention, the median scores for all GI symptoms decreased, with a significant reduction for urgency, bloating, lack of control, bowel frequency (p ≥: 0.01). Mean dietary fat intake reduced to 42 g fat after intervention (p ≥: 0.01). Low-fat dietary interventions in patients with a SeHCAT scan result of <20% leads to clinically important improvement in GI symptoms and should be widely used. © Royal College of Physicians 2015. All rights reserved.

Interactions of climate, socio-economics, and global mercury pollution in the North Water.

PubMed

Dietz, Rune; Mosbech, Anders; Flora, Janne; Eulaers, Igor

2018-04-01

Despite the remoteness of the North Water, Northwest Greenland, the local Inughuit population is affected by global anthropogenic pollution and climate change. Using a cross-disciplinary approach combining Mercury (Hg) analysis, catch information, and historical and anthropological perspectives, this article elucidates how the traditional diet is compromised by Hg pollution originating from lower latitudes. In a new approach we here show how the Inughuits in Avanersuaq are subject to high Hg exposure from the hunted traditional food, consisting of mainly marine seabirds and mammals. Violation of the provisional tolerably yearly intake of Hg, on average by a factor of 11 (range 7-15) over the last 20 years as well as the provisional tolerably monthly intake by a factor of 6 (range 2-16), raises health concerns. The surplus of Selenium (Se) in wildlife tissues including narwhals showed Se:Hg molar ratios of 1.5, 2.3, and 16.7 in muscle, liver, and mattak, respectively, likely to provide some protection against the high Hg exposure.

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

USDA-ARS?s Scientific Manuscript database

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, ...

Overview and prospects of selenium phytoremediation approaches

USDA-ARS?s Scientific Manuscript database

Evidence is lacking on whether selenium (Se) is essential for vegetation growth, but plants can absorb, assimilate, and accumulate Se in leaves and roots. The capability of plants to take up substantial amount of Se is now being utilized to remove excess Se from contaminated soils. This process has ...

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 baselinemore » values 4 weeks after treatment ended. No birds were observed to exhibit signs of general illness or Se toxicity during the study.« less

A subchronic toxicity study of elemental Nano-Se in Sprague-Dawley rats.

PubMed

Jia, X; Li, N; Chen, J

2005-03-11

The subchronic toxicity of Nano-Se was compared with selenite and high-selenium protein in rats. Groups of Sprague-Dawley rats (12 males and 12 females per group) were fed diets containing Nano-Se, selenite and high-selenium protein at concentrations of 0, 2, 3, 4 and 5 ppm Se, respectively, for 13 weeks. Clinical observations were made and body weight and food consumption were recorded weekly. At the end of the study, the rats were subjected to a full necropsy, blood samples were collected for hematology and clinical chemistry determination. Histopathological examination was performed on selected tissues. At the two higher doses (4 and 5 ppm Se), significant abnormal changes were found in body weight, hematology, clinical chemistry, relative organ weights and histopathology parameters. However, the toxicity was more pronounced in the selenite and high-selenium protein groups than the Nano-Se group. At the dose of 3 ppm Se, significant growth inhibition and degeneration of liver cells were found in the selenite and high-selenium protein groups. No changes attributable to administration of Nano-Se at the dose of 3 ppm Se were found. Taken together, the no-observed-adverse-effect level (NOAEL) of Nano-Se in male and female rats was considered to be 3 ppm Se, equivalent to 0.22 mg/kg bw/day for males and 0.33 mg/kg bw/day for females. On the other hand, the NOAELs of selenite and high-selenium protein in males and females were considered to be 2 ppm Se, equivalent to 0.14 mg/kg bw/day for males and 0.20 mg/kg bw/day for females. In addition, studies have shown that Nano-Se has a similar bioavailability in rat, and much less acute toxicity in mice compared with selenite. In conclusion, Nano-Se is less toxic than selenite and high-selenium protein in the 13-week rat study.

[Studies of bioavailability of different food sources of selenium in experiment].

PubMed

Egorova, E A; Gmoshinskiĭ, I V; Zorin, S I; Mazo, V K

2006-01-01

The selenium bioavailability in selenium enriched Spirulina (Arthrospira platensis), phycocyanin containing (Se-PC) protein isolate, separated from this micro algae and in sodium selenite was studied and compared in rats. The daily dose of selenium per one animal was 5 microgram in all experimental groups. The average selenium levels in blood serum and liver of animals that received sodium selenite during 14 days were the highest. The average selenium level in blood serum of animals fed with selenium enriched Spirulina platensis after 14 days of receiving was the same with the control group, but the average concentration of selenium in their liver was rather high and close to this parameter of sodium selenite animal group. The animals which were fed with Se-PC showed better results. Their average selenium level in blood serum was higher than in Spirulina group, but lower than in sodium selenite group. The average concentration of selenium in the liver of these animals was the same with sodium selenite animal group. As regards to animals that were fed with selenium enriched Spirulina, Se-PC and sodium selenite for 21 days, the average selenium levels ratio in their blood serum and liver was higher than in control group, but these results were not significantly different among each other. The concentrations of selenium in seminal glands in all groups of animals including control group both after 14 and 21 days feeding were close to each other.

Inverse association between gluthathione peroxidase activity and both selenium-binding protein 1 levels and gleason score in human prostate tissue

USDA-ARS?s Scientific Manuscript database

BACKGROUND. Data from human epidemiological studies, cultured mammalian cells, and animal models have supported a potentially beneficial role of selenium (Se) in prostate cancer prevention. In addition, Se-containing proteins including members of the gutathione peroxidase (GPx) family and Selenium-B...

Vitamin E and selenium supplementation and risk of prostate cancer in the Vitamins and lifestyle (VITAL) study cohort.

PubMed

Peters, Ulrike; Littman, Alyson J; Kristal, Alan R; Patterson, Ruth E; Potter, John D; White, Emily

2008-02-01

Vitamin E and selenium are promising nutrients for the prevention of prostate cancer, and both are currently being tested in a large randomized trial for prostate cancer. However, results are not expected for at least 6 years. We aimed to investigate the association of vitamin E and selenium supplementation with prostate cancer in the VITamins And Lifestyle (VITAL) study, a cohort study specifically designed to examine supplement use and future cancer risk. In a prospective design, 35,242 men recruited between 2000 and 2002 from western Washington State completed a questionnaire, including detailed questions about vitamin E and selenium supplement intake during the past 10 years from brand-specific multivitamins and single supplements. Using linkage to the western Washington SEER cancer registry, we documented 830 new cases of prostate cancer from baseline through December 2004. A 10-year average intake of supplemental vitamin E was not associated with a reduced prostate cancer risk overall [hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.65-1.1 for > or =400 IU/day vs. non-use, p for trend 0.36]; however, risk for advanced prostate cancer (regionally invasive or distant metastatic, n = 123) decreased significantly with greater intake of supplemental vitamin E (HR 0.43, 95% CI 0.19-1.0 for 10-year average intake > or =400 IU/day vs. non-use, p for trend 0.03). There was no association between selenium supplementation and prostate cancer risk (HR 0.90, 95% CI 0.62-1.3 for 10-year average intake >50 microg/day vs. non-use, p for trend 0.97). In this prospective cohort, long-term supplemental intake of vitamin E and selenium were not associated with prostate cancer risk overall; however, risk of clinically relevant advanced disease was reduced with greater long-term vitamin E supplementation.

Chemical characterisation and speciation of organic selenium in cultivated selenium-enriched Agaricus bisporus.

PubMed

Maseko, Tebo; Callahan, Damien L; Dunshea, Frank R; Doronila, Augustine; Kolev, Spas D; Ng, Ken

2013-12-15

The selenium concentration in Agaricus bisporus cultivated in growth compost irrigated with sodium selenite solution increased by 28- and 43-fold compared to the control mushroom irrigated solely with water. Selenium contents of mushroom proteins increased from 13.8 to 60.1 and 14.1 to 137 μgSe/g in caps and stalks from control and selenised mushrooms, respectively. Selenocystine (SeCys; detected as [SeCys]2 dimer), selenomethionine (SeMet), and methyl-selenocysteine (MeSeCys) were separated, identified and quantified by liquid chromatography-electrospray ionisation-mass spectrometry from water solubilised and acetone precipitated proteins, and significant increases were observed for the selenised mushrooms. The maximum selenoamino acids concentration in caps and stalks of control/selenised mushrooms was 4.16/9.65 μg/g dried weight (DW) for SeCys, 0.08/0.58 μg/g DW for SeMet, and 0.031/0.10 μg/g DW for MeSeCys, respectively. The most notable result was the much higher levels of SeCys accumulated by A. bisporus compared to SeMet and MeSeCys, for both control and selenised A. bisporus. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Multispecies Biofilms Transform Selenium Oxyanions into Elemental Selenium Particles: Studies Using Combined Synchrotron X-ray Fluorescence Imaging and Scanning Transmission X-ray Microscopy.

PubMed

Yang, Soo In; George, Graham N; Lawrence, John R; Kaminskyj, Susan G W; Dynes, James J; Lai, Barry; Pickering, Ingrid J

2016-10-04

Selenium (Se) is an element of growing environmental concern, because low aqueous concentrations can lead to biomagnification through the aquatic food web. Biofilms, naturally occurring microbial consortia, play numerous important roles in the environment, especially in biogeochemical cycling of toxic elements in aquatic systems. The complexity of naturally forming multispecies biofilms presents challenges for characterization because conventional microscopic techniques require chemical and physical modifications of the sample. Here, multispecies biofilms biotransforming selenium oxyanions were characterized using X-ray fluorescence imaging (XFI) and scanning transmission X-ray microscopy (STXM). These complementary synchrotron techniques required minimal sample preparation and were applied correlatively to the same biofilm areas. Sub-micrometer XFI showed distributions of Se and endogenous metals, while Se K-edge X-ray absorption spectroscopy indicated the presence of elemental Se (Se 0 ). Nanoscale carbon K-edge STXM revealed the distributions of microbial cells, extracellular polymeric substances (EPS), and lipids using the protein, saccharide, and lipid signatures, respectively, together with highly localized Se 0 using the Se L III edge. Transmission electron microscopy showed the electron-dense particle diameter to be 50-700 nm, suggesting Se 0 nanoparticles. The intimate association of Se 0 particles with protein and polysaccharide biofilm components has implications for the bioavailability of selenium in the environment.

Multispecies Biofilms Transform Selenium Oxyanions into Elemental Selenium Particles: Studies Using Combined Synchrotron X-ray Fluorescence Imaging and Scanning Transmission X-ray Microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Soo In; George, Graham N.; Lawrence, John R.

2016-10-04

Selenium (Se) is an element of growing environmental concern, because low aqueous concentrations can lead to biomagnification through the aquatic food web. Biofilms, naturally occurring microbial consortia, play numerous important roles in the environment, especially in biogeochemical cycling of toxic elements in aquatic systems. The complexity of naturally forming multispecies biofilms presents challenges for characterization because conventional microscopic techniques require chemical and physical modifications of the sample. Here, multispecies biofilms biotransforming selenium oxyanions were characterized using X-ray fluorescence imaging (XFI) and scanning transmission X-ray microscopy (STXM). These complementary synchrotron techniques required minimal sample preparation and were applied correlatively to themore » same biofilm areas. Sub-micrometer XFI showed distributions of Se and endogenous metals, while Se K-edge X-ray absorption spectroscopy indicated the presence of elemental Se (Se0). Nanoscale carbon K-edge STXM revealed the distributions of microbial cells, extracellular polymeric substances (EPS), and lipids using the protein, saccharide, and lipid signatures, respectively, together with highly localized Se0 using the Se LIII edge. Transmission electron microscopy showed the electron-dense particle diameter to be 50–700 nm, suggesting Se0 nanoparticles. The intimate association of Se0 particles with protein and polysaccharide biofilm components has implications for the bioavailability of selenium in the environment.« less

In vitro antioxidant and antiproliferative activities of selenium-containing phycocyanin from selenium-enriched Spirulina platensis.

PubMed

Chen, Tianfeng; Wong, Yum-Shing

2008-06-25

Both selenium and phycocyanin have been reported to show potent cancer chemopreventive activities. In this study, we investigated the in vitro antioxidant and antiproliferative activities of selenium-containing phycocyanin (Se-PC) purified from selenium-enriched Spirulina platensis. The antioxidant activity of Se-PC was evaluated by using four different free radical scavenging assays, namely, the 2,2'-azinobis-3-ethylbenzothiazolin-6-sulfonic acid (ABTS) assay, 1,1-diphenyl-2-picryhydrazyl (DPPH) assay, superoxide anion scavenging assay, and erythrocyte hemolysis assay. The results indicated that Se-PC exhibited stronger antioxidant activity than phycocyanin by scavenging ABTS, DPPH, superoxide anion, and 2,2'-azobis-(2-amidinopropane)dihydrochloride free radicals. Se-PC also showed dose-dependent protective effects on erythrocytes against H 2O 2-induced oxidative DNA damage as evaluated by the Comet assay. Moreover, Se-PC was identified as a potent antiproliferative agent against human melanoma A375 cells and human breast adenocarcinoma MCF-7 cells. Induction of apoptosis in both A375 and MCF-7 cells by Se-PC was evidenced by accumulation of sub-G1 cell populations, DNA fragmentation, and nuclear condensation. Further investigation on intracellular mechanisms indicated that depletion of mitochondrial membrane potential (DeltaPsi m) was involved in Se-PC-induced cell apoptosis. Our findings suggest that Se-PC is a promising organic Se species with potential applications in cancer chemoprevention.

Antioxidant Actions of Selenium in Orbital Fibroblasts: A Basis for the Effects of Selenium in Graves' Orbitopathy.

PubMed

Rotondo Dottore, Giovanna; Leo, Marenza; Casini, Giamberto; Latrofa, Francesco; Cestari, Luca; Sellari-Franceschini, Stefano; Nardi, Marco; Vitti, Paolo; Marcocci, Claudio; Marinò, Michele

2017-02-01

A recent clinical trial has shown a beneficial effect of the antioxidant agent selenium in Graves' orbitopathy (GO). In order to shed light on the cellular mechanisms on which selenium may act, this study investigated its effects in cultured orbital fibroblasts. Primary cultures of orbital fibroblasts from six GO patients and six control subjects were established. Cells were treated with H 2 O 2 to induce oxidative stress, after pre-incubation with selenium-(methyl)selenocysteine (SeMCys). The following assays were performed: glutathione disulfide (GSSG), as a measure of oxidative stress, glutathione peroxidase (GPX) activity, cell proliferation, hyaluronic acid (HA), and pro-inflammatory cytokines. H 2 O 2 induced an increase in cell GSSG and fibroblast proliferation, which were reduced by SeMCys. Incubation of H 2 O 2 -treated cells with SeMCys was followed by an increase in glutathione peroxidase activity, one of the antioxidant enzymes into which selenium is incorporated. At the concentrations used (5 μM), H 2 O 2 did not significantly affect HA release, but it was reduced by SeMCys. H 2 O 2 determined an increase in endogenous cytokines involved in the response to oxidative stress and GO pathogenesis, namely tumor necrosis factor alpha, interleukin 1 beta, and interferon gamma. The increases in tumor necrosis factor alpha and interferon gamma were blocked by SeMCys. While the effects of SeMCys on oxidative stress and cytokines were similar in GO and control fibroblasts, they were exclusive to GO fibroblasts in terms of inhibiting proliferation and HA secretion. Selenium, in the form of SeMCys, abolishes some of the effects of oxidative stress in orbital fibroblasts, namely increased proliferation and secretion of pro-inflammatory cytokines. SeMCys reduces HA release in GO fibroblasts in a manner that seems at least in part independent from H 2 O 2 -induced oxidative stress. Some effects of SeMCys are specific for GO fibroblasts. These findings reveal some cellular mechanisms by which selenium may act in patients with GO.

Selenium status in adult cats and dogs fed high levels of dietary inorganic and organic selenium.

PubMed

Todd, S E; Thomas, D G; Bosch, G; Hendriks, W H

2012-08-01

Cats (Felis catus) maintain greater blood Se concentrations compared with dogs (Canis familiaris) and, unlike dogs, show no signs of chronic Se toxicity (selenosis) when fed dietary organic Se (selenomethionine) concentrations of 10 μg/g DM. This study investigated the response of cats and dogs to high dietary concentrations of sodium selenite and organic Se to determine differences in metabolism between both species. In 2 consecutive studies, 18 adult cats and 18 adult dogs of with equal numbers of each sex were fed a control diet (0.6 μg Se/g DM) or the control diet supplemented to 8 to 10 μg Se/g DM from Na(2)SeO(3) or organic Se for 3 wk. All animals were fed the control diet 1 mo before the start of the study and blood samples were taken on d 0 and 21. The Se balance was assessed during the final week and a liver biopsy was obtained on the final day of the study. Measurements included plasma Se concentrations, plasma glutathione peroxidise (GPx) activities, plasma Se clearance, Se intake, and urinary Se excretion. No clinical signs of selenosis were observed in the cats or dogs, and apart from Se clearance, form of Se had no effect on any of the measurements. Apparent fecal Se absorption was greater in the dogs fed both forms of Se, while greater plasma Se concentrations were observed in the cats on both the control and supplemented diet (P = 0.034). Cats fed the supplemented diets had lower hepatic Se concentrations (P < 0.001) and excreted more Se in urine (P < 0.001) compared with dogs. Furthermore, cats fed the Na(2)SeO(3) supplement had greater Se clearance rates than dogs (P < 0.001). There was no effect of species on plasma GPx activity. We conclude that cats can tolerate greater dietary Se concentrations as they are more efficient at excreting excess Se in the urine and storing less Se in the liver.

Dynamics of the phase formation process upon the low temperature selenization of Cu/In-multilayer stacks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oertel, M., E-mail: michael.oertel@uni-jena.de; Ronning, C.

2015-03-14

Phase reactions occurring during a low temperature selenization of thin In/Cu-multilayer stacks were investigated by ex-situ x-ray diffraction (XRD) and energy dispersive x-ray spectroscopy (EDS). Therefore, dc-sputtered In/Cu-multilayers onto molybdenum coated soda lime glass were selenized in a high vacuum system at temperatures between 260 and 340 °C with different dwell times and selenium supply. The combination of the results of the phase analysis by XRD and the measurements of the in-depth elemental distribution by EDS allowed a conclusion on the occurring reactions within the layer depth. We found two CuInSe{sub 2} formation processes depending on the applied temperature. Already, atmore » a heater temperature of 260 °C, the CuInSe{sub 2} formation can occur by the reaction of Cu{sub 2−x}Se with In{sub 4}Se{sub 3} and Se. At 340 °C, CuInSe{sub 2} is formed by the reaction of Cu{sub 2−x}Se with InSe and Se. Because both reactions need additional selenium, the selenium supply during the selenization can shift the reaction equilibria either to the metal binaries side or to the CuInSe{sub 2} side. Interestingly, a lower selenium supply shifts the equilibrium to the CuInSe{sub 2} side, because the amount of selenium incorporated into the metallic layer is higher for a lower selenium supply. Most likely, a larger number of grain boundaries are the reason for the stronger selenium incorporation. The results of the phase formation studies were used to design a two stage selenization process to get a defined structure of an indium selenide- and a copper selenide-layer at low temperatures as the origin for a controlled interdiffusion to form the CuInSe{sub 2}-absorber-layer at higher temperatures. The approach delivers a CuInSe{sub 2} absorber which reach total area efficiencies of 11.8% (13.0% active area) in a CuInSe{sub 2}-thin-film solar cell. A finished formation of CuInSe{sub 2} at low temperature was not observed in our experiments but is probably possible for longer dwell times.« less

Protective Effect of Selenium Against Cisplatin-Induced Ototoxicity in an Experimental Design.

PubMed

Doğan, Sedat; Yazici, Hasmet; Yalçinkaya, Esin; Erdoğdu, Halil Ibrahim; Tokgöz, Sibel Alicura; Sarici, Furkan; Namuslu, Mehmet; Sarikaya, Yasin

2016-10-01

Cisplatin is an effective chemotherapeutic agent in the treatment of several types of malignant solid tumors but its clinical use is associated with ototoxicity. In the present study, we investigated the effect of selenium administration on lipid peroxidation (malondialdehyde [MDA]) and cisplatin-induced ototoxicity in rats. Healthy wistar albino rats (n = 21) were randomly divided into 3 groups: control (C), cisplatin (Cis), cisplatin and selenium (Cis+Se). Cisplatin was administered for 3 days to Cis and Cis+Se groups. Cis+Se group received selenium 5 days before cisplatin injection and continued for 11 consecutive days. Hearing thresholds and lipid peroxidation (MDA) levels of the rats were recorded before injections and at the end of experimental protocol. The cochleas of animals were harvested for histologic and immunuhistochemical examinations. In biochemichal analyses, pretreatment with selenium prevented the elevation of MDA levels in Cis+Se group rats. Moreover, animals in Cis+Se group had better hearing threshold levels than animals in cis group. Samples obtained from the animals in Cis group revealed extensive loss of the normal microarchitecture of the organ of Corti. On the other hand, animals in Cis+Se group exhibited a preservation of the morphology of the organ of Corti and outer hair cells. In the immunohistochemical examinations of cochlear tissues stained with anti-caspase-3, a higher degree of immunopositivity was found in the Cis group. When Cis+Se group and Cis group were compared, significantly less immunopositivity occurred in the Cis+Se group (P < 0.05). Thus, it appears that pretreatment with selenium may reduce cisplatin-induced ototoxicity in rats.

[Studies of immunomodulation caused by selenium-enriched phycocyanin].

PubMed

Egorova, E A; Gmoshinskiĭ, I V; Zorin, S N; Mazo, V K

2006-01-01

An influense was studied in rats of selenium enriched phycocyanin (Se-PC) from food microalgae Spirulina on anaphylactic reaction severity and circulating antibody response against model allergen--hen's egg white ovalbumin. Se-PC was introduced into diet in form of protein isolate precipitated with ammonia sulphate. Se-PC dosage made up to 450 mcg per rat daily that corresponded to 5 mcg of selenium. There were no differences revealed between experimental and control group that received standard diet in severity of anaphylactic reaction. Nevertheless rats receiving Se-PC demonstrated significantly increased specific IgG response. The probable immunomodulating properties of Se-PC included into food are discussed.

Preparation and antioxidant properties of selenium nanoparticles-loaded chitosan microspheres.

PubMed

Bai, Kaikai; Hong, Bihong; He, Jianlin; Hong, Zhuan; Tan, Ran

2017-01-01

Selenium nanoparticles (SeNPs), as a special form of selenium (Se) supplement, have attracted worldwide attention due to their favorable properties and unique bioactivities. Herein, an eco-friendly and economic way to prepare stable SeNPs is introduced. SeNPs were synthesized in aqueous chitosan (CTS) and then embedded into CTS microspheres by spray-drying, forming selenium nanoparticles-loaded chitosan microspheres (SeNPs-M). The physicochemical properties including morphology, elemental state, size distribution and surface potential were investigated. Institute of Cancer Research mice were used as model animal to evaluate the bioactivities of SeNPs-M. Trigonal-phase SeNPs of ~35 nm were synthesized, and SeNPs-M physically embedding those SeNPs were successfully prepared. Amazingly, acute toxicity test indicated that SeNPs-M were much safer than selenite in terms of Se dose, with a LD 50 of around 18-fold of that of selenite. In addition, SeNPs-M possessed powerful antioxidant activities, as evidenced by a dramatic increase of both Se retention and the levels of glutathione peroxidase, superoxide dismutase and catalase. The design of SeNPs-M can offer a new way for further development of SeNPs with a higher efficacy and better biosafety. Thus, SeNPs-M may be a potential candidate for further evaluation as an Se supplement with antioxidant properties and be used against Se deficiency in animals and human beings.

Preparation and antioxidant properties of selenium nanoparticles-loaded chitosan microspheres

PubMed Central

Bai, Kaikai; Hong, Bihong; He, Jianlin; Hong, Zhuan; Tan, Ran

2017-01-01

Selenium nanoparticles (SeNPs), as a special form of selenium (Se) supplement, have attracted worldwide attention due to their favorable properties and unique bioactivities. Herein, an eco-friendly and economic way to prepare stable SeNPs is introduced. SeNPs were synthesized in aqueous chitosan (CTS) and then embedded into CTS microspheres by spray-drying, forming selenium nanoparticles-loaded chitosan microspheres (SeNPs-M). The physicochemical properties including morphology, elemental state, size distribution and surface potential were investigated. Institute of Cancer Research mice were used as model animal to evaluate the bioactivities of SeNPs-M. Trigonal-phase SeNPs of ~35 nm were synthesized, and SeNPs-M physically embedding those SeNPs were successfully prepared. Amazingly, acute toxicity test indicated that SeNPs-M were much safer than selenite in terms of Se dose, with a LD50 of around 18-fold of that of selenite. In addition, SeNPs-M possessed powerful antioxidant activities, as evidenced by a dramatic increase of both Se retention and the levels of glutathione peroxidase, superoxide dismutase and catalase. The design of SeNPs-M can offer a new way for further development of SeNPs with a higher efficacy and better biosafety. Thus, SeNPs-M may be a potential candidate for further evaluation as an Se supplement with antioxidant properties and be used against Se deficiency in animals and human beings. PMID:28684913

How might selenium moderate the toxic effects of mercury in stream fish of the Western USA?

EPA Science Inventory

The ability of selenium (Se) to moderate mercury (Hg) toxicity is well established in the literature. Mercury exposures that might otherwise produce toxic effects are counteracted by Se, particularly when Se:Hg molar ratios approach or exceed 1. We analyzed whole body Se and Hg c...

How might selenium moderate the toxic effects of mercury in stream fish of the Western USA? - abstract

EPA Science Inventory

The ability of selenium (Se) to moderate mercury (Hg) toxicity is well established in the literature. Mercury exposures that might otherwise produce toxic effects are counteracted by Se, particularly when Se:Hg molar ratios approach or exceed 1. We analyzed whole body Se and Hg c...

The Insufficiency Intake of Dietary Micronutrients Associated with Malnutrition-Inflammation Score in Hemodialysis Population

PubMed Central

Xiao, Long; Yuan, Zhimin; Chen, Jianping; Wang, Zhiyu; Wang, Jingfeng; Huang, Hui

2013-01-01

The relations between dietary micronutrient, nutritional status and inflammation in hemodialysis patients are still unclear. A cross-sectional study was performed in hemodialysis population. 75 hemodialysis patients from South China participated in the dietary and nutritional assessment. Clinical and dietary data were collected. Nutritional status was assessed by Malnutrition-Inflammation Score (MIS) in addition to related anthropometric measurements. And according to the MIS score, the whole hemodialysis patients were divided into normal nutrition group and malnutrition group. The results showed that mid arm circumference (MAC) negatively correlated with MIS (r = −0.425; P = 0.002). The area under the ROC curve (AUC) for MAC was 0.737 (0.614–0.859). Comparing with the normal nutritional group, lower dietary selenium (Se), copper (Cu), iodine (I) and manganese (Mn) intake were observed among patients with malnutrition (P<0.05). While no significant differences of diverse vitamins were found. In conclusion, MAC was effective indicator for assessing nutritional and inflammatory status (P<0.05). The reduction of dietary Se, Cu, I and Mn intake level may be alarming markers for malnutrition and inflammatory status in hemodialysis patients. PMID:23825573

Chemical Kinetic and Molecular Genetic Study of Selenium Oxyanion Reduction by Enterobactor cloacae SLD1a-1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma,J.; Kobayashi, D.; Yee, N.

2007-01-01

Microbial processes play an important role in the redox transformations of toxic selenium oxyanions. In this study, we employed chemical kinetic and molecular genetic techniques to investigate the mechanisms of Se(IV) and Se(VI) reduction by the facultative anaerobe Enterobacter cloacae SLD1a-1. The rates of microbial selenium oxyanion reduction were measured as a function of initial selenium oxyanion concentration (0-1.0 mM) and temperature (10-40 C), and mutagenesis studies were performed to identify the genes involved in the selenium oxyanion reduction pathway. The results indicate that Se(IV) reduction is significantly more rapid than the reduction of Se(VI). The kinetics of the reductionmore » reactions were successfully quantified using the Michaelis-Menten kinetic equation. Both the rates of Se(VI) and Se(IV) reduction displayed strong temperature-dependence with Ea values of 121 and 71.2 kJ/mol, respectively. X-ray absorption near-edge spectra collected for the precipitates formed by Se(VI) and Se(IV) reduction confirmed the formation of Se(0). A miniTn5 transposon mutant of E. cloacae SLD1a-1 was isolated that had lost the ability to reduce Se(VI) but was not affected in Se(IV) reduction activity. Nucleotide sequence analysis revealed the transposon was inserted within a tatC gene, which encodes for a central protein in the twin arginine translocation system. Complementation by the wild-type tatC sequence restored the ability of mutant strains to reduce Se(VI). The results suggest that Se(VI) reduction activity is dependent on enzyme export across the cytoplasmic membrane and that reduction of Se(VI) and Se(IV) are catalyzed by different enzymatic systems.« less

Mitochondria-Mediated Protein Regulation Mechanism of Polymorphs-Dependent Inhibition of Nanoselenium on Cancer Cells

NASA Astrophysics Data System (ADS)

Wang, Ge; Guo, Yuming; Yang, Gai; Yang, Lin; Ma, Xiaoming; Wang, Kui; Zhu, Lin; Sun, Jiaojiao; Wang, Xiaobing; Zhang, Hua

2016-08-01

The present study was (i) to prepare two types of selenium nanoparticles, namely an amorphous form of selenium quantum dots (A-SeQDs) and a crystalline form of selenium quantum dots (C-SeQDs); and (ii) to investigate the nano-bio interactions of A-SeQDs and C-SeQDs in MCF-7, HepG2, HeLa, NIH/3T3, L929 cells and BRL-3A cells. It was found that A-SeQDs could induce the mitochondria-mediated apoptosis, necrosis and death of cells, while C-SeQDs had much weaker effects. This polymorphs-dependent anti-proliferative activity of nano-selenium was scarcely reported. Further investigation demonstrated that A-SeQDs could differentially regulate 61 proteins and several pathways related to stress response, protein synthesis, cell migration and cell cycle, including “p38 MAPK Signaling”, “p53 Signaling”, “14-3-3-mediated Signaling”, “p70S6K Signaling” and “Protein Ubiquitination Pathway”. This was the first report to demonstrate the involvement of protein synthesis and post-translational modification pathways in the anti-proliferative activity associated with NMs. Compared with previously fragmentary studies, this study use a nanomics approach combining bioinformatics and proteomics to systematically investigate the nano-bio interactions of selenium nanoparticles in cancer cells.

Distribution and bioaccumulation of selenium in aquatic microcosms

USGS Publications Warehouse

Besser, John M.; Huckins, James N.; Little, Edward E.; La Point, Thomas W.

1989-01-01

Closed-system microcosms were used to study factors affecting the fate of selenium (Se) in aquatic systems. Distribution and bioaccumulation of Se varied among sediment types and Se species. A mixture of dissolved 75Se species (selenate, selenite and selenomethionine) was sorbed more rapidly to fine-textured, highly organic pond sediments than to sandy riverine sediments. Sulfate did not affect the distribution and bioaccumulation of 75Se over the range 80–180 mg SO4 liter−1. When each Se species was labeled separately, selenomethionine was lost from the water column more rapidly than selenate or selenite. Selenium lost from the water column accumulated primarily in sediments, but volatilization was also an important pathway for loss of Se added as selenomethionine. Loss rates of dissolved Se residues were more rapid than rates reported from mesocosm and field studies, suggesting that sediment: water interactions are more important in microcosms than in larger test systems. Daphnids accumulated highest concentrations of Se, followed by periphyton and macrophytes. Selenium added as selenomethionine was bioaccumulated preferentially compared to that added as selenite or selenate. Organoselenium compounds such as selenomethione may thus contribute disproportionately to Se bioaccumulation and toxicity in aquatic organisms.

Selenium-containing allophycocyanin purified from selenium-enriched Spirulina platensis attenuates AAPH-induced oxidative stress in human erythrocytes through inhibition of ROS generation.

PubMed

Zhang, Haobin; Chen, Tianfeng; Jiang, Jie; Wong, Yum-Shing; Yang, Fang; Zheng, Wenjie

2011-08-24

Both selenium and allophycocyanin (APC) have been reported to show novel antioxidant activities. In this study, a fast protein liquid chromatographic method for purification of selenium-containing allophycocyanin (Se-APC) from selenium-enriched Spirulina platensis and the protective effect of Se-APC on 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative stress have been described. After fractionation by ammonium sulfate precipitation, and separation by DEAE-Sepharose ion-exchange and Sephacryl S-300 size exclusion chromatography, Se-APC with purity ratio (A652/A280) of 5.30 and Se concentration of 343.02 μg g(-1) protein was obtained. Se-APC exhibited stronger antioxidant activity than APC by scavenging ABTS (2,2'-azinobis-3-ethylbenzothiazolin-6-sulfonic acid) and AAPH free radicals. The oxidative hemolysis and morphological changes induced by AAPH in human erythrocytes were effectively reversed by coincubation with Se-APC. Lipid oxidation induced by the pro-oxidant agent cupric chloride in human plasma, as evaluated by formation of conjugated diene, was blocked by Se-APC. The accumulation of malondialdehyde, loss of reduced glutathione, and increase in enzyme activities of glutathione peroxidase and reductase induced by AAPH in human erythrocytes were effectively suppressed by Se-APC. Furthermore, Se-APC significantly prevented AAPH-induced intracellular reactive oxygen species (ROS) generation. Taken together, our results suggest that Se-APC demonstrates application potential in treatment of diseases in which excess production of ROS acts as a casual or contributory factor.

Distribution and reuse of {sup 76}Se-selenosugar in selenium-deficient rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suzuki, Kazuo T.; Somekawa, Layla; Suzuki, Noriyuki

2006-10-15

Nutritional selenium compounds are transformed to the common intermediate selenide and then utilized for selenoprotein synthesis or excreted in urine mostly as 1{beta}-methylseleno-N-acetyl-DD-galactosamine (selenosugar). Since the biological significance of selenosugar formation is unknown, we investigated their role in the formation of selenoenzymes in selenium deficiency. Rats were depleted of endogenous natural abundance selenium with a single stable isotope ({sup 82}Se) and then made Se-deficient. {sup 76}Se-Selenosugar was administered intravenously to the rats and their urine, serum, liver, kidneys and testes were subjected to speciation analysis with HPLC inductively coupled argon plasma mass spectrometry. Most {sup 76}Se was recovered in itsmore » intact form (approximately 80% of dose) in urine within 1 h. Speciation analysis revealed that residual endogenous natural abundance selenium estimated by {sup 77}Se and {sup 78}Se was negligible and distinct distributions of the labeled {sup 76}Se were detected in the body fluids and organs without interference from the endogenous natural abundance stable isotope. Namely, intact {sup 76}Se-selenosugar was distributed to organs after the injection, and {sup 76}Se was used for selenoprotein synthesis. Oxidation to methylseleninic acid and/or hydrolysis of the selenoacetal group to methylselenol were proposed to the transformation of selenosugar for the reuse. Effective use of an enriched stable isotope as an absolute label in hosts depleted of natural abundance isotopes was discussed for application in tracer experiments.« less

Selenium and Zinc Status in Chronic Myofascial Pain: Serum and Erythrocyte Concentrations and Food Intake

PubMed Central

Barros-Neto, João Araújo; Souza-Machado, Adelmir; Kraychete, Durval Campos; de Jesus, Rosangela Passos; Cortes, Matheus Lopes; Lima, Michele dos Santos; Freitas, Mariana Carvalho; Santos, Tascya Morganna de Morais; Viana, Gustavo Freitas de Sousa; Menezes-Filho, José Antonio

2016-01-01

Introduction Nutritional disorders have been reported to be important causal factors that can intensify or cause a painful response in individuals with chronic musculoskeletal pain. Aim To assess the habitual intake of and the serum and erythrocyte levels of selenium and zinc in patients with chronic myofascial pain. Materials and Methods A case-control study of 31 patients with chronic myofascial pain (group I) and 31 subjects without pain (group II). Dietary record in five days for assessing food intake were used. The serum and erythrocyte concentrations of selenium and zinc were analyzed using an atomic absorption spectrophotometry. Pain intensity was assessed using a visual analog scale. Results The group of patients with chronic myofascial pain, compared with the control group, showed a lower erythrocyte concentration of selenium (79.46 ± 19.79 μg/L vs. 90.80 ± 23.12 μg/L; p = 0.041) and zinc (30.56 ± 7.74 μgZn/gHb vs. 38.48 ± 14.86 μgZn/gHb, respectively; p = 0.004). In this study, a compromised food intake of zinc was observed in the majority of the subjects in both groups. The selenium intake was considered to be safe in 80% of the subjects in both groups; however, the likelihood of inadequate intake of this mineral was twice as high in group I (49.5% vs. 24.4%, respectively). In the logistic regression analysis, the erythrocyte concentration of zinc was associated with the presence of pain. In each additional 1 mg of Zn2+ per gram of hemoglobin, a reduction of 12.5% was observed in the risk of the individual having chronic myofascial pain (B = -0.133; adjusted OR = 0.875, 95% CI = 0.803 to 0.954, Wald = 9.187, standard error = 0.044, p = 0.002). Physical inactivity and obesity were noted more commonly in group I compared with the control group. Conclusion In this study, patients with chronic myofascial pain showed lower intracellular stores of zinc and selenium and inadequate food intake of these nutrients. PMID:27755562

Competition between the Brain and Testes under Selenium-Compromised Conditions: Insight into Sex Differences in Selenium Metabolism and Risk of Neurodevelopmental Disease.

PubMed

Pitts, Matthew W; Kremer, Penny M; Hashimoto, Ann C; Torres, Daniel J; Byrns, China N; Williams, Christopher S; Berry, Marla J

2015-11-18

Selenium (Se) is essential for both brain development and male fertility. Male mice lacking two key genes involved in Se metabolism (Scly(-/-)Sepp1(-/-) mice), selenoprotein P (Sepp1) and Sec lyase (Scly), develop severe neurological dysfunction, neurodegeneration, and audiogenic seizures that manifest beginning in early adulthood. We demonstrate that prepubescent castration of Scly(-/-)Sepp1(-/-) mice prevents behavioral deficits, attenuates neurodegeneration, rescues maturation of GABAergic inhibition, and increases brain selenoprotein levels. Moreover, castration also yields similar neuroprotective benefits to Sepp1(-/-) and wild-type mice challenged with Se-deficient diets. Our data show that, under Se-compromised conditions, the brain and testes compete for Se utilization, with concomitant effects on neurodevelopment and neurodegeneration. Selenium is an essential trace element that promotes male fertility and brain function. Herein, we report that prepubescent castration provides neuroprotection by increasing selenium-dependent antioxidant activity in the brain, revealing a competition between the brain and testes for selenium utilization. These findings provide novel insight into the interaction of sex and oxidative stress upon the developing brain and have potentially significant implications for the prevention of neurodevelopmental disorders characterized by aberrant excitatory/inhibitory balance, such as schizophrenia and epilepsy. Copyright © 2015 the authors 0270-6474/15/3515326-13$15.00/0.

Modulation of nano-selenium on tetrodotoxin-sensitive voltage-gated sodium currents in rat dorsal root ganglion neurons.

PubMed

Yuan, Huijun; Lan, Tonghan; Lin, Jiarui

2005-01-01

Nano-Selenium, a novel Nano technology production, was demonstrated to be useful in medical and scientific researches. Here, we investigated the effects of Nano-Selenium on tetrodotoxin-sensitive (TTX-S) voltage-dependent Na⁺channels in isolated rat dorsal root ganglion neurons, using whole-cell patch-clamp method. Nano-Selenium irreversibly decreased TTX-S Na⁺current (INa) in a concentration-dependent manner and shifted the maximum of the current/voltage relationship from -67mV to -52mV, without modifying the threshold potential of the current. Nano-Selenium shifted the steady-state activation and inactivation curves to the left. In the contrast of Na2SeO3, the inhibition effect of 1nM Nano-Se was much stronger. The cell treated with 1nM Na2SeO3firstly, still respond to futher addition of 1nM Nano-Selenium. These results prove Nano-Selenium to be a novel antiagonist, acted within the channel pore, not on or near the exterior surface of the channel protein where it would experience the membrane electric field, which possesses a distinct binding site from Na2SeO3.

Status of selenium in cancer prevention

USDA-ARS?s Scientific Manuscript database

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...

Selecting Lentil Accessions for Global Selenium Biofortification

USDA-ARS?s Scientific Manuscript database

Biofortification of lentil (Lens culinaris Medikus.) has the potential to provide adequate daily selenium (Se) to human diets. The objectives of this study were to (1) determine how low dose Se fertilizer application at germination affects seedling biomass, antioxidant activity, and Se uptake of 26 ...

Naphthalene-1,2,3-dithiazolyl and its selenium-containing variants.

PubMed

Oakley, Richard T; Reed, Robert W; Robertson, Craig M; Richardson, John F

2005-03-21

Synthetic routes to salts of the 3H-naphtho[1,2-d][1,2,3]dithiazolylium cation and its three selenium-containing variants (SSeN, SeSN, and SeSeN) are described. The most efficient and general method involves the intermediacy of bis-acetylated aminothiolates and aminoselenolates. These reagents react smoothly with sulfur and selenium halides to afford the desired ring closure products. Electrochemical reduction of the four cations indicates that corresponding radicals (SSN, SSeN, SeSN, and SeSeN) are stable in solution. The EPR spectra of all four have been recorded, and experimental spin distributions have been cross-matched with those obtained from DFT calculations. The selenium-containing radicals are thermally unstable at or slightly above room temperature, but the all-sulfur species has been isolated and characterized crystallographically. In the solid state, the radicals are associated into cofacial dimers which are closely linked to other dimers by intermolecular S---S, S---N, and C-H---aromatic ring interactions.

Selenium mass balance in the Great Salt Lake, Utah

USGS Publications Warehouse

Diaz, X.; Johnson, W.P.; Naftz, D.L.

2009-01-01

A mass balance for Se in the south arm of the Great Salt Lake was developed for September 2006 to August 2007 of monitoring for Se loads and removal flows. The combined removal flows (sedimentation and volatilization) totaled to a geometric mean value of 2079??kg Se/yr, with the estimated low value being 1255??kg Se/yr, and an estimated high value of 3143??kg Se/yr at the 68% confidence level. The total (particulates + dissolved) loads (via runoff) were about 1560??kg Se/yr, for which the error is expected to be ?? 15% for the measured loads. Comparison of volatilization to sedimentation flux demonstrates that volatilization rather than sedimentation is likely the major mechanism of selenium removal from the Great Salt Lake. The measured loss flows balance (within the range of uncertainties), and possibly surpass, the measured annual loads. Concentration histories were modeled using a simple mass balance, which indicated that no significant change in Se concentration was expected during the period of study. Surprisingly, the measured total Se concentration increased during the period of the study, indicating that the removal processes operate at their low estimated rates, and/or there are unmeasured selenium loads entering the lake. The selenium concentration trajectories were compared to those of other trace metals to assess the significance of selenium concentration trends. ?? 2008 Elsevier B.V.

Bioaccessibility of selenium after human ingestion in relation to its chemical species and compartmentalization in maize.

PubMed

Mombo, Stéphane; Schreck, Eva; Dumat, Camille; Laplanche, Christophe; Pierart, Antoine; Longchamp, Mélanie; Besson, Philippe; Castrec-Rouelle, Maryse

2016-06-01

Selenium is a micronutrient needed by all living organisms including humans, but often present in low concentration in food with possible deficiency. From another side, at higher concentrations in soils as observed in seleniferous regions of the world, and in function of its chemical species, Se can also induce (eco)toxicity. Root Se uptake was therefore studied in function of its initial form for maize (Zea mays L.), a plant widely cultivated for human and animal food over the world. Se phytotoxicity and compartmentalization were studied in different aerial plant tissues. For the first time, Se oral human bioaccessibility after ingestion was assessed for the main Se species (Se(IV) and Se(VI)) with the BARGE ex vivo test in maize seeds (consumed by humans), and in stems and leaves consumed by animals. Corn seedlings were cultivated in hydroponic conditions supplemented with 1 mg L(-1) of selenium (Se(IV), Se(VI), Control) for 4 months. Biomass, Se concentration, and bioaccessibility were measured on harvested plants. A reduction in plant biomass was observed under Se treatments compared to control, suggesting its phytotoxicity. This plant biomass reduction was higher for selenite species than selenate, and seed was the main affected compartment compared to control. Selenium compartmentalization study showed that for selenate species, a preferential accumulation was observed in leaves, whereas selenite translocation was very limited toward maize aerial parts, except in the seeds where selenite concentrations are generally high. Selenium oral bioaccessibility after ingestion fluctuated from 49 to 89 % according to the considered plant tissue and Se species. Whatever the tissue, selenate appeared as the most human bioaccessible form. A potential Se toxicity was highlighted for people living in seleniferous regions, this risk being enhanced by the high Se bioaccessibility.

Oxidation Mechanism of Copper Selenide

NASA Astrophysics Data System (ADS)

Taskinen, Pekka; Patana, Sonja; Kobylin, Petri; Latostenmaa, Petri

2014-09-01

The oxidation mechanism of copper selenide was investigated at deselenization temperatures of copper refining anode slimes. The isothermal roasting of synthetic, massive copper selenide in flowing oxygen and oxygen - 20% sulfur dioxide mixtures at 450-550 °C indicate that in both atmospheres the mass of Cu2Se increases as a function of time, due to formation of copper selenite as an intermediate product. Copper selenide oxidises to copper oxides without formation of thick copper selenite scales, and a significant fraction of selenium is vaporized as SeO2(g). The oxidation product scales on Cu2Se are porous which allows transport of atmospheric oxygen to the reaction zone and selenium dioxide vapor to the surrounding gas. Predominance area diagrams of the copper-selenium system, constructed for selenium roasting conditions, indicate that the stable phase of copper in a selenium roaster gas with SO2 is the sulfate CuSO4. The cuprous oxide formed in decomposition of Cu2Se is further sulfated to CuSO4.

Feasibility of measuring selenium in humans using in vivo neutron activation analysis.

PubMed

Tahir, S N A; Chettle, D R; Byun, S H; Prestwich, W V

2015-11-01

Selenium (Se) is an element that, in trace quantities, plays an important role in the normal function of a number of biological processes in humans. Many studies have demonstrated that selenium deficiency in the body may contribute to an increased risk for certain neoplastic, cardiovascular, osseous, and nervous system diseases including retardation of bone formation. However, at higher concentrations Se is cytotoxic. For these reasons it is desirable to have a means of monitoring selenium concentration in humans.This paper presents the outcome of a feasibility study carried out for measuring selenium in humans using in vivo neutron activation analysis (IVNAA). In this technique a small dose of neutrons is delivered to the organ of interest, the neutrons are readily captured by the target nuclei, and the γ-rays given off are detected outside of the body. For the present study, human hand (bone) tissue equivalent phantoms were prepared with varying amounts of Se. These were irradiated by a low energy fast neutron beam produced by the (7)Li(p,n)(7)Be reaction employing the high beam current Tandetron accelerator. The counting data saved using a 4π NaI(TI) detection system were analyzed. The selenium was detected via the neutron capture reaction, (76)Se(n,γ)(77 m)Se, whereas calcium was detected through the (48)Ca(n,γ)(49)Ca reaction for the purpose of normalization of the Se signals to the calcium signals. From the calibration lines drawn between Se/Ca concentrations and Se/Ca counts ratio, the minimum detection limits (MDLs) were computed for two sets of phantoms irradiated under different irradiation parameters.In this study the optimized MDL value was determined to be 81 ng g(-1) (Se/phantom mass) for an equivalent dose of 188 mSv to the phantom. This MDL was found at least 10 times lower than the reported data on Se concentration measured in bone tissues. It was concluded that the NAA technique would be a feasible means of performing in vivo measurements of selenium in humans. Currently the data on in vivo measurement of selenium in humans are limited; the results of the present study would greatly contribute to the present data.

Managing selenium-contaminated agricultural drainage water by the integrated on-farm drainage management system: role of selenium volatilization.

PubMed

Lin, Z Q; Cervinka, V; Pickering, I J; Zayed, A; Terry, N

2002-07-01

The Integrated on-Farm Drainage Management (IFDM) system was designed to dispose of selenium (Se)-contaminated agricultural irrigation drainage water through the sequential reuse of saline drainage water to grow crops having different salt tolerance. This study quantified the extent of biological volatilization in Se removal from the IFDM system located in the western San Joaquin Valley, California. Selenium volatilization from selected treatment areas, including pickleweed (Salicornia bigelovii Torr.), saltgrass (Distichlis spicata L.), bare soil, and the solar evaporator, was monitored biweekly using an open-flow sampling chamber system during the pickleweed growing season from February to September 1997, and monthly from September 1997 to January 1998. Biological volatilization from the pickleweed section removed 62.0 +/- 3.6 mg Se m(-2) y(-1) to the atmosphere, which was 5.5-fold greater than the Se accumulated in pickleweed tissues (i.e., phytoextraction). The total Se removed by volatilization from the bare soil, saltgrass, and the solar evaporator was 16.7 +/- 1.1, 4.8 +/- 0.3, and 4.3 +/- 0.9mg Se m(-2) y(-1), respectively. Selenium removal by volatilization accounted for 6.5% of the annual total Se input (957.7mg Sem(-2) y(-1)) in the pickleweed field, and about 1% of the total Se input (432.7 mg Se m(-2) y(-1)) in the solar evaporator. We concluded that Se volatilization under naturally occurring field conditions represented a relatively minor, but environmentally important pathway of Se removal from the IFDM system.

Selenium biofortification

USDA-ARS?s Scientific Manuscript database

Plant foods are the major dietary sources of selenium (Se) in most countries around the world, followed by meats and seafood. For this reason, it is vital to increase Se uptake by plants and to produce crops with higher Se concentrations and bioavailability in their edible tissues. One of the most p...

Conditional effect of selenium on the mammalian hind gut microbiota

USDA-ARS?s Scientific Manuscript database

Selenium (Se) status is linked to cancer risk in humans and other mammals. Because Se is used by certain microbial species which contain selenoproteins, and because hind gut microfloral composition is linked to cancer development, we proposed that supranutritional Se could reduce tumorigenisis by af...

Insights into selenite reduction and biogenesis of elemental selenium nanoparticles by two environmental isolates of Burkholderia fungorum.

PubMed

Khoei, Nazanin Seyed; Lampis, Silvia; Zonaro, Emanuele; Yrjälä, Kim; Bernardi, Paolo; Vallini, Giovanni

2017-01-25

Microorganisms capable of transforming toxic selenium oxyanions into non-toxic elemental selenium (Se°) may be considered as biocatalysts for the production of selenium nanoparticles (SeNPs), eventually exploitable in different biotechnological applications. Two Burkholderia fungorum strains (B. fungorum DBT1 and B. fungorum 95) were monitored during their growth for both capacity and efficiency of selenite (SeO 3 2- ) reduction and elemental selenium formation. Both strains are environmental isolates in origin: B. fungorum DBT1 was previously isolated from an oil refinery drainage, while B. fungorum 95 has been enriched from inner tissues of hybrid poplars grown in a soil contaminated by polycyclic aromatic hydrocarbons. Our results showed that B. fungorum DBT1 is able to reduce 0.5mM SeO 3 2- to Se° when cultured aerobically in liquid medium at 27°C, while B. fungorum 95 can reduce more than 1mM SeO 3 2- to Se° within 96h under the same growth conditions, with the appearance of SeNPs in cultures of both bacterial strains. Biogenic SeNPs were spherical, with pH-dependent charge and an average hydrodynamic diameter of 170nm and 200nm depending on whether they were produced by B. fungorum 95 or B. fungorum DBT1, respectively. Electron microscopy analyses evidenced that Se nanoparticles occurred intracellularly and extracellularly. The mechanism of SeNPs formation can be tentatively attributed to cytoplasmic enzymatic activation mediated by electron donors. Biogenic nanoparticles were then probably released outside the bacterial cells as a consequence of a secretory process or cell lysis. Nevertheless, formation of elemental selenium nanoparticles under aerobic conditions by B. fungorum DBT1 and B. fungorum 95 is likely due to intracellular reduction mechanisms. Biomedical and other high tech sectors might exploit these biogenic nanoparticles in the near future, once fully characterized and tested for their multiple properties. Copyright © 2016 Elsevier B.V. All rights reserved.

Prediagnostic selenium status and hepatobiliary cancer risk in the European Prospective Investigation into Cancer and Nutrition cohort.

PubMed

Hughes, David J; Duarte-Salles, Talita; Hybsier, Sandra; Trichopoulou, Antonia; Stepien, Magdalena; Aleksandrova, Krasimira; Overvad, Kim; Tjønneland, Anne; Olsen, Anja; Affret, Aurélie; Fagherazzi, Guy; Boutron-Ruault, Marie-Christine; Katzke, Verena; Kaaks, Rudolf; Boeing, Heiner; Bamia, Christina; Lagiou, Pagona; Peppa, Eleni; Palli, Domenico; Krogh, Vittorio; Panico, Salvatore; Tumino, Rosario; Sacerdote, Carlotta; Bueno-de-Mesquita, Hendrik Bastiaan; Peeters, Petra H; Engeset, Dagrun; Weiderpass, Elisabete; Lasheras, Cristina; Agudo, Antonio; Sánchez, Maria-José; Navarro, Carmen; Ardanaz, Eva; Dorronsoro, Miren; Hemmingsson, Oskar; Wareham, Nicholas J; Khaw, Kay-Tee; Bradbury, Kathryn E; Cross, Amanda J; Gunter, Marc; Riboli, Elio; Romieu, Isabelle; Schomburg, Lutz; Jenab, Mazda

2016-08-01

Selenium status is suboptimal in many Europeans and may be a risk factor for the development of various cancers, including those of the liver and biliary tract. We wished to examine whether selenium status in advance of cancer onset is associated with hepatobiliary cancers in the EPIC (European Prospective Investigation into Cancer and Nutrition) study. We assessed prediagnostic selenium status by measuring serum concentrations of selenium and selenoprotein P (SePP; the major circulating selenium transfer protein) and examined the association with hepatocellular carcinoma (HCC; n = 121), gallbladder and biliary tract cancers (GBTCs; n = 100), and intrahepatic bile duct cancer (IHBC; n = 40) risk in a nested case-control design within the EPIC study. Selenium was measured by total reflection X-ray fluorescence, and SePP was determined by a colorimetric sandwich ELISA. Multivariable ORs and 95% CIs were calculated by using conditional logistic regression. HCC and GBTC cases, but not IHBC cases, showed significantly lower circulating selenium and SePP concentrations than their matched controls. Higher circulating selenium was associated with a significantly lower HCC risk (OR per 20-μg/L increase: 0.41; 95% CI: 0.23, 0.72) but not with the risk of GBTC or IHBC. Similarly, higher SePP concentrations were associated with lowered HCC risk only in both the categorical and continuous analyses (HCC: P-trend ≤ 0.0001; OR per 1.5-mg/L increase: 0.37; 95% CI: 0.21, 0.63). These findings from a large prospective cohort provide evidence that suboptimal selenium status in Europeans may be associated with an appreciably increased risk of HCC development. © 2016 American Society for Nutrition.

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.

Photodynamic effect and mechanism study of selenium-enriched phycocyanin from Spirulina platensis against liver tumours.

PubMed

Liu, Zijian; Fu, Xiang; Huang, Wei; Li, Chunxia; Wang, Xinyan; Huang, Bei

2018-03-01

Selenium-containing phycocyanin (Se-PC) has been proved to have many biological effects, including anti-inflammatory and antioxidant. In this study, we investigated the photodynamic therapy (PDT) effects of Se-PC against liver tumour in vitro and in vivo experiment. Our results demonstrated that the half lethal dose of Se-PC PDT on HepG2 cells was 100μg/ml PC containing 20% selenium. Se-PC location migration from lysosomes to mitochondria was time dependent. In in vivo experiments, the tumour inhibition rate was 75.4% in the Se-PC PDT group, compared to 52.6% in PC PDT group. Histological observations revealed that the tumour cells outside the tissue showed cellular necrosis, and those inside the tissue exhibited apoptotic nuclei and digested vacuoles in the cytoplasm after Se-PC PDT treatment. Antioxidant enzyme analysis indicated that GSH-Px activity was linked to the selenium content of Se-PC, and SOD activity was affected by PC PDT. Therefore, Se-PC PDT could induce cell death through free radical production of PDT in tumours and enhance the activity of antioxidant enzymes with selenium in vivo. The mechanism of Se-PC PDT against liver tumour involves hematocyte damage and mitochondria-mediated apoptosis accompanied with autophagy inhibition during early stage of tumour development, which displayed new prospect and offered relatively safe way for cancer therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

Selenium nanoparticles as a nutritional supplement.

PubMed

Skalickova, Sylvie; Milosavljevic, Vedran; Cihalova, Kristyna; Horky, Pavel; Richtera, Lukas; Adam, Vojtech

2017-01-01

Selenium is an essential trace element in the diet, required for maintenance of health and growth; however, its toxicity could cause serious damage depending on dose and chemical form. Selenium nanoparticles (SeNPs) represent what we believe to be a novel prospect for nutritional supplementation because of their lower toxicity and ability to gradually release selenium after ingestion. In this review, we discuss various forms and types of SeNPs, as well as the way they are synthesized. We also discuss absorption and bioavailability of nanoparticles within the organism. SeNPs demonstrate anticancer and antimicrobial properties that may contribute to human health, not only as dietary supplements, but also as therapeutic agents. Copyright © 2016 Elsevier Inc. All rights reserved.

Pressure-Stabilized Tin Selenide Phase with an Unexpected Stoichiometry and a Predicted Superconducting State at Low Temperatures

NASA Astrophysics Data System (ADS)

Yu, Hulei; Lao, Wenxin; Wang, Lijuan; Li, Kuo; Chen, Yue

2017-03-01

Tin-selenium binary compounds are important semiconductors that have attracted much interest for thermoelectric and photovoltaic applications. As tin has a +2 or +4 oxidation state and selenium has an oxidation number of -2 , only SnSe and SnSe2 have been observed. In this work, we show that the chemical bonding between tin and selenium becomes counterintuitive under pressures. Combining evolutionary algorithms and density functional theory, a novel cubic tin-selenium compound with an unexpected stoichiometry 3 ∶4 has been predicted and further synthesized in laser-heated diamond anvil cell experiments. Different from the conventional SnSe and SnSe2 semiconductors, Sn3 Se4 is predicted to be metallic and exhibit a superconducting transition at low temperatures. Based on electron density and Bader charge analysis, we show that Sn3 Se4 has a mixed nature of chemical bonds. The successful synthesis of Sn3 Se4 paves the way for the discovery of other IV-VI compounds with nonconventional stoichiometries and novel properties.

Pressure-Stabilized Tin Selenide Phase with an Unexpected Stoichiometry and a Predicted Superconducting State at Low Temperatures.

PubMed

Yu, Hulei; Lao, Wenxin; Wang, Lijuan; Li, Kuo; Chen, Yue

2017-03-31

Tin-selenium binary compounds are important semiconductors that have attracted much interest for thermoelectric and photovoltaic applications. As tin has a +2 or +4 oxidation state and selenium has an oxidation number of -2, only SnSe and SnSe_{2} have been observed. In this work, we show that the chemical bonding between tin and selenium becomes counterintuitive under pressures. Combining evolutionary algorithms and density functional theory, a novel cubic tin-selenium compound with an unexpected stoichiometry 3∶4 has been predicted and further synthesized in laser-heated diamond anvil cell experiments. Different from the conventional SnSe and SnSe_{2} semiconductors, Sn_{3}Se_{4} is predicted to be metallic and exhibit a superconducting transition at low temperatures. Based on electron density and Bader charge analysis, we show that Sn_{3}Se_{4} has a mixed nature of chemical bonds. The successful synthesis of Sn_{3}Se_{4} paves the way for the discovery of other IV-VI compounds with nonconventional stoichiometries and novel properties.

Facile Synthesis and Optical Properties of Small Selenium Nanocrystals and Nanorods

NASA Astrophysics Data System (ADS)

Jiang, Fengrui; Cai, Weiquan; Tan, Guolong

2017-06-01

Selenium is an important element for human's health, small size is very helpful for Se nanoparticles to be absorbed by human's body. Here, we present a facile approach to fabrication of small selenium nanoparticles (Nano-Se) as well as nanorods by dissolving sodium selenite (Na2SeO3) in glycerin and using glucose as the reduction agent. The as-prepared selenium nanoparticles have been characterized by X-ray diffraction (XRD), UV-Vis absorption spectroscopy and high resolution transmission electron microscope (HRTEM). The morphology of small Se nanoparticles and nanorods have been demonstrated in the TEM images. A small amount of 3-mercaptoproprionic acid (MPA) and glycerin play a key role on controlling the particle size and stabilize the dispersion of Nano-Se in the glycerin solution. In this way, we obtained very small and uniform Se nanoparticles; whose size ranges from 2 to 6 nm. This dimension is much smaller than the best value (>20 nm) ever reported in the literatures. Strong quantum confinement effect has been observed upon the size-dependent optical spectrum of these Se nanoparticles.

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.

Effects of Copper and Selenium Supplementation on Performance and Lipid Metabolism in Confined Brangus Bulls

PubMed Central

Netto, Arlindo Saran; Zanetti, Marcus Antônio; Claro, Gustavo Ribeiro Del; de Melo, Mariza Pires; Vilela, Flávio Garcia; Correa, Lisia Bertonha

2014-01-01

Twenty-eight Brangus cattle were used to determine the effect of copper and selenium supplementation on performance, feed efficiency, composition of fatty acids in Longissimus dorsi (LD) muscle, and cholesterol concentration in serum and in LD muscle and enzymes activities, reduced glutathione (GSH) and oxidized glutathione (GSSG). The treatments were: i) Control, without copper (Cu) and selenium (Se) supplementation; ii) Se, 2 mg Se/kg of dry matter such as sodium selenite; iii) Cu, 40 mg Cu/kg of dry matter such as copper sulfate; iv) Se/Cu, 2 mg Se/kg of dry matter such as sodium selenite and 40 mg Cu/kg of dry matter such as copper sulfate. LD muscle fatty acid composition was not influenced by the treatments (p>0.05). The serum concentration of cholesterol was not influenced by the treatments (p>0.05), however, the concentration of cholesterol in LD was lower in cattle supplemented with copper and selenium (p<0.05). Oxidized glutathione and reduced glutathione increased (p<0.05) with Cu, Se and Se/Cu supplementation. The supplementation of copper (40 mg/kg DM) and selenium (2 mg/kg DM) altered the metabolism of lipids in confined Brangus cattle, through a decrease in cholesterol deposition in the LD, possibly by changing the ratio between reduced glutathione/oxidized glutathione. Copper and selenium supplementation improved animal performance and feed efficiency (p<0.05) when compared to the control group, providing advantages in the production system, while also benefiting consumers by reducing cholesterol concentration in the meat. PMID:25049978

Comparative study of selenium and selenium nanoparticles with reference to acute toxicity, biochemical attributes, and histopathological response in fish.

PubMed

Kumar, Neeraj; Krishnani, Kishore Kumar; Singh, Narendra Pratap

2018-03-01

Recent studies have demonstrated that selenium (Se) and selenium nanoparticles (Se-NPs) exhibited toxicity at a higher concentration. The lethal concentration of Se and Se-NPs was estimated as 5.29 and 3.97 mg/L at 96 h in Pangasius hypophthalmus. However, the effect of different definite concentration of Se (4.5, 5.0, 5.5, and 6.0 mg/L) and Se-NPs (2.5, 3.0, 3.5, and 4.0 mg/L) was decided for acute experiment. Selenium and Se-NPs alter the biochemical attributes such as anti-oxidative status [catalase (CAT), superoxide dismutase (SOD), and glutathione-S-transferase (GST) activities], neurotransmitter enzyme, cellular metabolic enzymes, stress marker, and histopathology of P. hypophthalmus in a dose- and time-dependent manner. CAT, SOD, and GST were significantly elevated (p < 0.01) when exposed to Se and Se-NPs, and similarly, a neurotransmitter enzyme (acetylcholine esterase (AChE)) was significantly inhibited in a time- and dose-dependent manner. Further, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and malate hydrogenase were noticeably (p < 0.01) affected by Se and Se-NPs from higher concentration to lower concentration. Stress markers such as cortisol and HSP 70 were drastically enhanced by exposure to Se and Se-NPs. All the cellular metabolic and stress marker parameters were elevated which might be due to hyperaccumulation of Se and Se-NPs in the vital organ and target tissues. The histopathology of liver and gill was also altered such as large vacuole, cloudy swelling, focal necrosis, interstitial edema, necrosis in liver, and thickening of primary lamellae epithelium and curling of secondary lamellae due to Se and Se-NP exposure. The study suggested that essential trace element in both forms (inorganic and nano) at higher concentration in acute exposure of Se and Se-NPs led to pronounced deleterious alteration on histopathology and cellular and metabolic activities of P. hypophthalmus.

Homeostasis of chosen bioelements in organs of rats receiving lithium and/or selenium.

PubMed

Kiełczykowska, Małgorzata; Musik, Irena; Żelazowska, Renata; Lewandowska, Anna; Kurzepa, Jacek; Kocot, Joanna

2016-10-01

Lithium is an essential trace element, widely used in medicine and its application is often long-term. Despite beneficial effects, its administration can lead to severe side effects including hyperparathyroidism, renal and thyroid disorders. The aim of the current study was to evaluate the influence of lithium and/or selenium treatment on magnesium, calcium and silicon levels in rats' organs as well as the possibility of using selenium as an adjuvant in lithium therapy. The study was performed on rats divided into four groups (six animals each): control-treated with saline; Li-treated with Li2CO3 (2.7 mg Li/kg b.w.); Se-treated with Na2SeO3·H2O (0.5 mg Se/kg b.w.); Se + Li-treated simultaneously with Li2CO3 and Na2SeO3·H2O (2.7 mg Li/kg b.w. and of 0.5 mg Se/kg b.w., respectively). The administration was performed in form of water solutions by stomach tube once a day for 3 weeks. In the organs (liver, kidney, brain, spleen, heart, lung and femoral muscle) the concentrations of magnesium, calcium and silicon were determined. Magnesium was increased in liver of Se and Se + Li given rats. Lithium decreased tissue Ca and co-administration of selenium reversed this effect. Silicon was not affected by any treatment. The beneficial effect of selenium on disturbances of calcium homeostasis let suggest that further research on selenium application as an adjuvant in lithium therapy is worth being performed.

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. Published by Elsevier Ltd.

Photon-induced selenium migration in TiSe 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lioi, David B.; Gosztola, David J.; Wiederrecht, Gary P.

2017-02-20

TiSe 2 is a member of the transition metal dichalcogenide family of layered van der Waals materials which exhibits some distinct electronic and optical properties. Here, we perform Raman spectroscopy and microscopy studies on single crystal TiSe 2 to investigate thermal and photon-induced defects associated with diffusion of selenium to the surface. Additional phonon peaks near 250 cm -1 are observed in the laser- irradiated regions that are consistent with formation of amorphous and nanocrys- talline selenium on the surface. Temperature dependent studies of the threshold temperature and laser intensity necessary to initiate selenium migration to the surface show anmore » activation barrier for the process of 1.55 eV. The impact of these results on the properties of strongly correlated electron states in TiSe 2 are discussed« less

Selenium and breast cancer risk: A prospective nested case-control study on serum selenium levels, smoking habits and overweight.

PubMed

Sandsveden, Malte; Manjer, Jonas

2017-11-01

Previous research has not been conclusive regarding the association between selenium (Se) and breast cancer. This study was conducted to clarify if there is an association between prediagnostic serum Se levels and breast cancer risk. A population based cohort, the Malmö Diet and Cancer Study, was used and linked with the Swedish cancer registry up to 31 December 2013. Our study included 1,186 women with breast cancer and an equal number of controls. Selenium levels were analysed from stored serum samples. The included individuals were divided into quartiles based on Se value and we compared breast cancer cases with controls using logistic regression yielding odds ratios (OR) with 95% confidence intervals. Serum Se was also analysed as a continuous variable regarding breast cancer risk. The analyses were adjusted for established risk factors and stratified on smoking status and body mass index (BMI). When comparing the highest Se quartile with the lowest, the adjusted OR for breast cancer was 0.98 (0.75-1.26). With selenium as a continuous variable the adjusted OR was 1.00 (1.00-1.01) per 10 ng/ml. When comparing the highest with the lowest Se quartile in women with BMI > 25 kg/m 2 the adjusted OR was 0.77 (0.53-1.14). We conclude that it is unlikely that prediagnostic serum selenium is overall associated with breast cancer risk and no modifying effect from BMI or smoking was seen. © 2017 UICC.

Weaned beef calves fed selenium-biofortified alfalfa hay have an enriched nasal microbiota compared with healthy controls.

PubMed

Hall, Jean A; Isaiah, Anitha; Estill, Charles T; Pirelli, Gene J; Suchodolski, Jan S

2017-01-01

Selenium (Se) is an essential trace mineral important for immune function and overall health of cattle. The nasopharyngeal microbiota in cattle plays an important role in overall respiratory health, especially when stresses associated with weaning, transport, and adaptation to a feedlot affect the normal respiratory defenses. Recent evidence suggests that cattle diagnosed with bovine respiratory disease complex have significantly less bacterial diversity. The objective of this study was to determine whether feeding weaned beef calves Se-enriched alfalfa (Medicago sativa) hay for 9 weeks in a preconditioning program prior to entering the feedlot alters nasal microbiota. Recently weaned beef calves (n = 45) were blocked by sex and body weight, randomly assigned to 3 treatment groups with 3 pens of 5 calves per treatment group, and fed an alfalfa hay based diet for 9 weeks. Alfalfa hay was harvested from fields fertilized with sodium selenate at a rate of 0, 45.0 or 89.9 g Se/ha. Blood samples were collected biweekly and analyzed for whole-blood Se concentrations. Nasal swabs were collected during week 9 from one or two calves from each pen (total n = 16). Calculated Se intake from dietary sources was 3.0, 15.6, and 32.2 mg Se/head/day for calves consuming alfalfa hay with Se concentrations of 0.34 to 2.42 and 5.17 mg Se/kg dry matter, respectively. Whole-blood Se concentrations after 8 weeks of feeding Se-fertilized alfalfa hay were dependent upon Se-application rates (0, 45.0, or 89.9 g Se/ha) and were 155, 345, and 504 ng/mL (PLinear < 0.0001). Microbial DNA was extracted from nasal swabs and amplified and sequenced. Alpha rarefaction curves comparing the species richness (observed OTUs) and overall diversity (Chao1, Observed OTU, and Shannon index) between calves fed selenium-biofortified alfalfa hay compared with control calves showed that Se-supplementation tended to be associated with an enriched nasal microbiota. ANOSIM of unweighted UniFrac distances showed that calves fed high Se-biofortified alfalfa hay clustered separately when compared with control calves in the PCoA plot (R = 0.216, P = 0.04). The bacterial orders Lactobacillales and Flavobacteriales were increased in healthy control calves compared with Clostridiales and Bacteroidales being increased in calves fed Se-biofortified alfalfa hay. Although there were strong trends, no significant differences were noted for any of the bacterial taxa. Based upon these findings, we suggest that weaned beef calves fed Se-biofortified hay tend to have an enriched nasal microbiota. Feeding Se-biofortified alfalfa hay to weaned beef calves prior to entering the feedlot is a strategy for increasing nasopharyngeal microbial diversity.

Comparative effects of two different forms of selenium on oxidative stress biomarkers in healthy men: a randomized clinical trial.

PubMed

Richie, John P; Das, Arun; Calcagnotto, Ana M; Sinha, Raghu; Neidig, Wanda; Liao, Jiangang; Lengerich, Eugene J; Berg, Arthur; Hartman, Terryl J; Ciccarella, Amy; Baker, Aaron; Kaag, Matthew G; Goodin, Susan; DiPaola, Robert S; El-Bayoumy, Karam

2014-08-01

Epidemiologic and laboratory studies indicate that dietary selenium protects against prostate cancer. Results from clinical trials suggest that selenium-enriched yeast (SY) but not selenomethionine (SeMet) may be effective at reducing prostate cancer risk. Our objectives were to directly compare for the first time the effects of SeMet and SY on prostate cancer relevant biomarkers in men. We performed a randomized double blind, placebo-controlled trial of SY (200 or 285 μg/day) and SeMet (200 μg/day) administered for 9 months in 69 healthy men. Primary endpoints included blood levels of selenium-containing compounds and oxidative stress biomarkers [urine 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-iso-prostaglandin-F2α (8-iso-PGF2α) and blood glutathione (GSH)]. Secondary endpoints included plasma glucose and PSA levels. Compliance was high in all groups (>95%). Plasma selenium levels were increased 93%, 54%, and 86% after 9 months in SeMet and low- and high-dose SY groups, respectively, and returned to baseline levels after a 3-month washout (P < 0.05). Levels of 8-OHdG and 8-iso-PGF2α were decreased 34% and 28%, respectively, after 9 months in the high-dose SY group (P < 0.05). These decreases were greatest in individuals with low baseline plasma levels of selenium (<127 ng/mL). No changes in serum PSA or blood glucose and GSH were observed. Overall, we showed for the first time, reductions in biomarkers of oxidative stress following supplementation with SY but not SeMet in healthy men. These findings suggest that selenium-containing compounds other than SeMet may account for the decrease in oxidative stress. ©2014 American Association for Cancer Research.

Comparative effects of two different forms of selenium on oxidative stress biomarkers in healthy men: a randomized clinical trial

PubMed Central

Richie, John P.; Das, Arun; Calcagnotto, Ana M.; Sinha, Raghu; Neidig, Wanda; Liao, Jiangang; Lengerich, Eugene J.; Berg, Arthur; Hartman, Terryl J.; Ciccarella, Amy; Baker, Aaron; Kaag, Matthew G.; Goodin, Susan; DiPaola, Robert S.; El-Bayoumy, Karam

2014-01-01

Epidemiological and laboratory studies indicate that dietary selenium protects against prostate cancer. Results from clinical trials suggest that selenium-enriched yeast (SY) but not selenomethionine (SeMet) may be effective at reducing prostate cancer risk. Our objectives were to directly compare for the first time the effects of SeMet and SY on prostate cancer relevant biomarkers in men. We performed a randomized double blind, placebo-controlled trial of SY (200 or 285 µg/day) and SeMet (200 µg/day) administered for 9 months in 69 healthy men. Primary endpoints included blood levels of selenium-containing compounds and oxidative stress biomarkers (urine 8-hydroxy-2’-deoxyguanosine [8-OHdG] and 8-iso-prostaglandin-F2α [8-iso-PGF2α] and blood glutathione [GSH]). Secondary endpoints included plasma glucose and PSA levels. Compliance was high in all groups (>95%). Plasma selenium levels were increased 93%, 54%, and 86% after 9 months in SeMet and low and high dose SY groups, respectively, and returned to baseline levels after a 3 month washout (P<0.05). Levels of 8-OHdG and 8-iso-PGF2α, were decreased 34% and 28%, respectively, after 9 months in the high dose SY group (P<0.05). These decreases were greatest in individuals with low baseline plasma levels of selenium (<127 ng/ml). No changes in serum PSA or blood glucose and GSH were observed. Overall, we showed for the first time, reductions in biomarkers of oxidative stress following supplementation with SY but not SeMet in healthy men. These findings suggest that selenium-containing compounds other than SeMet may account for the decrease in oxidative stress. PMID:24938534

Fabrication and physicochemical characterization of porous composite microgranules with selenium oxyanions and risedronate sodium for potential applications in bone tumors.

PubMed

Kolmas, Joanna; Pajor, Kamil; Pajchel, Lukasz; Przekora, Agata; Ginalska, Grażyna; Oledzka, Ewa; Sobczak, Marcin

2017-01-01

Nanocrystalline hydroxyapatite containing selenite ions (SeHA; 9.6 wt.% of selenium) was synthesized using wet method and subject to careful physicochemical analysis by powder X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, solid-state nuclear magnetic resonance, wavelength dispersive X-ray fluorescence, and inductively coupled plasma optical emission spectrometry. SeHA was then used to develop the selenium-containing hydroxyapatite/alginate (SeHA/ALG) composite granules. Risedronate sodium (RIS) was introduced to the obtained spherical microgranules of a size of about 1.1-1.5 mm in 2 ways: during the granules' preparation (RIS solution added to a suspension of ALG and SeHA), and as a result of SeHA/ALG granules soaking in aqueous RIS solution. The analysis made using 13 C and 31 P cross-polarization magic angle spinning nuclear magnetic resonance confirmed the presence of RIS and its interaction with calcium ions. Then, the release of selenium (inductively coupled plasma optical emission spectrometry) and RIS (high-performance liquid chromatography) from microgranules was examined. Moreover, cytotoxicity of fabricated granules was assessed by MTT test. Selenium release was biphasic: the first stage was short and ascribed to a "burst release" probably from a hydrated surface layer of SeHA crystals, while the next stage was significantly longer and ascribed to a sustained release of selenium from the crystals' interior. The study showed that the method of obtaining microgranules containing RIS significantly affects its release profile. Performed cytotoxicity test revealed that fabricated granules had high antitumor activity against osteosarcoma cells. However, because of the "burst release" of selenium during the first 10 h, the granules significantly reduced viability of normal osteoblasts as well.

Fabrication and physicochemical characterization of porous composite microgranules with selenium oxyanions and risedronate sodium for potential applications in bone tumors

PubMed Central

Kolmas, Joanna; Pajor, Kamil; Pajchel, Lukasz; Przekora, Agata; Ginalska, Grażyna; Oledzka, Ewa; Sobczak, Marcin

2017-01-01

Nanocrystalline hydroxyapatite containing selenite ions (SeHA; 9.6 wt.% of selenium) was synthesized using wet method and subject to careful physicochemical analysis by powder X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, solid-state nuclear magnetic resonance, wavelength dispersive X-ray fluorescence, and inductively coupled plasma optical emission spectrometry. SeHA was then used to develop the selenium-containing hydroxyapatite/alginate (SeHA/ALG) composite granules. Risedronate sodium (RIS) was introduced to the obtained spherical microgranules of a size of about 1.1–1.5 mm in 2 ways: during the granules’ preparation (RIS solution added to a suspension of ALG and SeHA), and as a result of SeHA/ALG granules soaking in aqueous RIS solution. The analysis made using 13C and 31P cross-polarization magic angle spinning nuclear magnetic resonance confirmed the presence of RIS and its interaction with calcium ions. Then, the release of selenium (inductively coupled plasma optical emission spectrometry) and RIS (high-performance liquid chromatography) from microgranules was examined. Moreover, cytotoxicity of fabricated granules was assessed by MTT test. Selenium release was biphasic: the first stage was short and ascribed to a “burst release” probably from a hydrated surface layer of SeHA crystals, while the next stage was significantly longer and ascribed to a sustained release of selenium from the crystals’ interior. The study showed that the method of obtaining microgranules containing RIS significantly affects its release profile. Performed cytotoxicity test revealed that fabricated granules had high antitumor activity against osteosarcoma cells. However, because of the “burst release” of selenium during the first 10 h, the granules significantly reduced viability of normal osteoblasts as well. PMID:28848343

Toxicokinetics and pathology of plant-associated acute selenium toxicosis in steers

USDA-ARS?s Scientific Manuscript database

Sixteen of about 500 yearling steers died of acute selenium (Se) toxicosis after grazing Se contaminated range for only a few days. Field studies and chemical analyses identified the predominant toxic plant as western aster (Aster ascendens), which contained over 4,000 ppm Se. Several dead animals...

A novel one-pot green synthesis of selenium nanoparticles and evaluation of its toxicity in zebrafish embryos.

PubMed

Kalishwaralal, Kalimuthu; Jeyabharathi, Subhaschandrabose; Sundar, Krishnan; Muthukumaran, Azhaguchamy

2016-01-01

Over the last 50 years, compelling evidence has accumulated on the beneficial role of selenium in human health. In the present study, different proteins were evaluated as reducing agents for the eco-friendly synthesis of selenium nanoparticles from an aqueous solution of sodium selenite. This method is a simple, low cost green synthesis alternative to chemical synthesis. The high conversion of selenium ions to selenium nanoparticles (SeNPs) was achieved by a reaction mixture of 0.1 g bovine serum albumin and 0.1 g sodium selenite at a reaction temperature of 121°C for 20 min duration. The selenium nanoparticles were characterized by fourier transform infrared (FTIR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy. The FTIR spectral bands were sharp with strong absorption peaks at 1649 and 1551 cm(-1). SEM analysis of the synthesized selenium nanoparticles clearly showed the spherical shape with an average size ranging from 500 to 600 nm. The toxicity of SeNPs was evaluated using zebrafish embryos as a model system. SeNPs induced malformations in zebrafish embryos in a concentration-dependent manner. Selenium nanoparticles at 15-25 μg/ml concentration caused pericardial edema, tail malformation and decrease in heart rate in zebrafish embryos. Treatments with lower concentrations did not alter the heart rate or display any heart abnormalities. This study underlines the importance of identifying optimal SeNP concentration that could have potential therapeutic applications.

Dietary antioxidants and the biochemical response to oxidant inhalation. II. Influence of dietary selenium on the biochemical effects of ozone exposure in mouse lung

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elsayed, N.M.; Hacker, A.D.; Kuehn, K.

The influence of dietary selenium (Se) on the pulmonary biochemical response to ozone (O/sub 3/) exposure was examined. For 11 weeks, weanling female strain A/St mice were fed a test diet containing Se either at 0 ppm (-Se) or 1 ppm (+Se). Each diet contained 55 ppm vitamin E (vit E). Mice from each dietary group were exposed to 0.8 +/- 0.05 ppm (1568 +/- 98 micrograms/m3) O/sub 3/ continuously for 5 days. After O/sub 3/ exposure, they were killed along with a matched number of unexposed controls, and their lungs were analyzed for various biochemical parameters. The Se contentsmore » of lung tissue and whole blood were determined, and the levels were seven- to eightfold higher in +Se mice than in -Se mice, reflecting the Se intake of the animals. In unexposed control mice, Se deficiency caused a decline in glutathione peroxidase (GP) activity relative to +Se group. After O/sub 3/ exposure, the GP activity in the -Se group was associated with a lack of stimulation of glutathione reductase (GR) activity and the pentose phosphate cycle (PPC) as assessed by measuring glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) activities. In contrast, the +Se group after O/sub 3/ exposure exhibited increases in all four enzyme activities. Other parameters, e.g., lung weight, total lung protein, DNA and nonprotein sulfhydryl contents, and O/sub 2/ consumption, were not affected by dietary Se in the presence or absence of O/sub 3/ exposure. The data indicate that dietary Se alters the GP activity, which in turn influences the GR and PPC activities in the lung evidently through a reduced demand for NADPH. The level of vit E in the lung was found to be twofold higher in the -Se group than in the +Se group, suggesting a compensatory relationship between Se and vit E in the lung. With O3 exposure, both Se and vit E contents further increased in the lungs of each dietary group.« less

Fractionation of selenium isotopes during bacterial respiratory reduction of selenium oxyanions

USGS Publications Warehouse

Herbel, M.J.; Johnson, T.M.; Oremland, R.S.; Bullen, T.D.

2000-01-01

Reduction of selenium oxyanions by microorganisms is an important process in the biogeochemical cycling of selenium. Numerous bacteria can reduce Se oxyanions, which are used as electron acceptors during the oxidation of organic matter in anoxic environments. In this study, we used a double spike (82Se and 74Se) thermal ionization mass spectrometry technique to quantify the isotopic fractionation achieved by three different species of anaerobic bacteria capable of accomplishing growth by respiratory reduction of selenate [SeO42- or Se(VI)] or selenite [SeO32- or Se(IV)] to Se(IV) or elemental selenium [Se(0)] coupled with the oxidation of lactate. Isotopic discrimination in these closed system experiments was evaluated by Rayleigh fractionation equations and numerical models. Growing cultures of Bacillus selenitireducens, a haloalkaliphile capable of growth using Se(IV) as an electron acceptor, induced a 80Se/76Se fractionation of -8.0 ?? 0.4??? (instantaneous ?? value) during reduction of Se(IV) to Se(0). With Bacillus arsenicoselenatis, a haloalkaliphile capable of growth using Se(VI) as an electron acceptor, fractionations of -5.0 ?? 0.5??? and -6.0 ?? 1.0??? were observed for reduction of Se(VI) to Se(IV) and reduction of Se(IV) to Se(0), respectively. In growing cultures of Sulfurospirillum barnesii, a freshwater species capable of growth using Se(VI), fractionation was small initially, but near the end of the log growth phase, it increased to -4.0 ?? 1.0??? and -8.4 ?? 0.4??? for reduction of Se(VI) to Se(IV) and reduction of Se(IV) to Se(O), respectively. Washed cell suspensions of S. barnesii induced fractionations of -1.1 ?? 0.4??? during Se(VI) reduction, and -9.1 ?? 0.5% for Se(IV) reduction, with some evidence for smaller values (e.g., -1.7???) in the earliest-formed Se(0) results. These results demonstrate that dissimilatory reduction of selenate or selenite induces significant isotopic fractionation, and suggest that significant Se isotope ratio variation will be found in nature. Copyright (C) 2000 Elsevier Science Ltd.

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.

Anticancer activity of biostabilized selenium nanorods synthesized by Streptomyces bikiniensis strain Ess_amA-1

PubMed Central

Ahmad, Maged Sayed; Yasser, Manal Mohamed; Sholkamy, Essam Nageh; Ali, Ali Mohamed; Mehanni, Magda Mohamed

2015-01-01

Selenium is an important component of human diet and a number of studies have declared its chemopreventive and therapeutic properties against cancer. However, very limited studies have been conducted about the properties of selenium nanostructured materials in comparison to other well-studied selenospecies. Here, we have shown that the anticancer property of biostabilized selenium nanorods (SeNrs) synthesized by applying a novel strain Ess_amA-1 of Streptomyces bikiniensis. The strain was grown aerobically with selenium dioxide and produced stable SeNrs with average particle size of 17 nm. The optical, structural, morphological, elemental, and functional characterizations of the SeNrs were carried out using techniques such as UV-vis spectrophotometry, transmission electron microscopy, energy dispersive X-ray spectrometry, and Fourier transform infrared spectrophotometry, respectively. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay revealed that the biosynthesized SeNrs induces cell death of Hep-G2 and MCF-7 human cancer cells. The lethal dose (LD50%) of SeNrs on Hep-G2 and MCF-7 cells was recorded at 75.96 μg/mL and 61.86 μg/mL, respectively. It can be concluded that S. bikiniensis strain Ess_amA-1 could be used as renewable bioresources of biosynthesis of anticancer SeNrs. A hypothetical mechanism for anticancer activity of SeNrs is also proposed. PMID:26005349

Anticancer activity of biostabilized selenium nanorods synthesized by Streptomyces bikiniensis strain Ess_amA-1.

PubMed

Ahmad, Maged Sayed; Yasser, Manal Mohamed; Sholkamy, Essam Nageh; Ali, Ali Mohamed; Mehanni, Magda Mohamed

2015-01-01

Selenium is an important component of human diet and a number of studies have declared its chemopreventive and therapeutic properties against cancer. However, very limited studies have been conducted about the properties of selenium nanostructured materials in comparison to other well-studied selenospecies. Here, we have shown that the anticancer property of biostabilized selenium nanorods (SeNrs) synthesized by applying a novel strain Ess_amA-1 of Streptomyces bikiniensis. The strain was grown aerobically with selenium dioxide and produced stable SeNrs with average particle size of 17 nm. The optical, structural, morphological, elemental, and functional characterizations of the SeNrs were carried out using techniques such as UV-vis spectrophotometry, transmission electron microscopy, energy dispersive X-ray spectrometry, and Fourier transform infrared spectrophotometry, respectively. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay revealed that the biosynthesized SeNrs induces cell death of Hep-G2 and MCF-7 human cancer cells. The lethal dose (LD50%) of SeNrs on Hep-G2 and MCF-7 cells was recorded at 75.96 μg/mL and 61.86 μg/mL, respectively. It can be concluded that S. bikiniensis strain Ess_amA-1 could be used as renewable bioresources of biosynthesis of anticancer SeNrs. A hypothetical mechanism for anticancer activity of SeNrs is also proposed.

Comparing immune and anti-oxidant effects of selenium sources by in ovo treatment on post-hatch experimental avian necrotic enteritis

USDA-ARS?s Scientific Manuscript database

This study was conducted to investigate the effects of in ovo injection of selenium (Se) from 3 different sources on modulating the immune and antioxidant responses in broiler chickens in experimental necrotic enteritis (NE). SE contents of Sodium selenite (Na2SeO3 [SS]), Se-enriched yeast (YS), and...

Chemical Form and Distribution of Selenium and Sulfur in the Selenium Hyperaccumulator Astragalus bisulcatus1

PubMed Central

Pickering, Ingrid J.; Wright, Carrie; Bubner, Ben; Ellis, Danielle; Persans, Michael W.; Yu, Eileen Y.; George, Graham N.; Prince, Roger C.; Salt, David E.

2003-01-01

In its natural habitat, Astragalus bisulcatus can accumulate up to 0.65% (w/w) selenium (Se) in its shoot dry weight. X-ray absorption spectroscopy has been used to examine the selenium biochemistry of A. bisulcatus. High concentrations of the nonprotein amino acid Se-methylseleno-cysteine (Cys) are present in young leaves of A. bisulcatus, but in more mature leaves, the Se-methylseleno-Cys concentration is lower, and selenate predominates. Seleno-Cys methyltransferase is the enzyme responsible for the biosynthesis of Se-methylseleno-Cys from seleno-Cys and S-methyl-methionine. Seleno-Cys methyltransferase is found to be expressed in A. bisulcatus leaves of all ages, and thus the biosynthesis of Se-methylseleno-Cys in older leaves is limited earlier in the metabolic pathway, probably by an inability to chemically reduce selenate. A comparative study of sulfur (S) and Se in A. bisulcatus using x-ray absorption spectroscopy indicates similar trends for oxidized and reduced Se and S species, but also indicates that the proportions of these differ significantly. These results also indicate that sulfate and selenate reduction are developmentally correlated, and they suggest important differences between S and Se biochemistries. PMID:12644695

XAS Studies of Se Speciation in Selenite-Fed Rats

PubMed Central

Weekley, Claire M.; Aitken, Jade B.; Witting, Paul K.; Harris, Hugh H.

2014-01-01

The biological activity of selenium is dependent on its chemical form. Therefore, knowledge of Se chemistry in vivo is required for efficacious use of selenium compounds in disease prevention and treatment. Using X-ray absorption spectroscopy, Se speciation in the kidney, liver, heart, spleen, testis and red blood cells of rats fed control (~0.3 ppm Se) or selenite-supplemented (1 ppm or 5 ppm Se) diets for 3 or 6 weeks, was investigated. X-ray absorption spectroscopy revealed the presence of Se–Se and Se–C species in the kidney and liver, and Se–S species in the kidney, but not the liver. X-ray absorption near edge structure (XANES) spectra showed that there was variation in speciation in the liver and kidneys, but Se speciation was much more uniform in the remaining organs. Using principal component analysis (PCA) to interpret the Se K-edge X-ray absorption spectra, we were able to directly compare the speciation of Se in two different models of selenite metabolism – human lung cancer cells and rat tissues. The effects of Se dose, tissue type and duration of diet on selenium speciation in rat tissues were investigated, and a relationship between the duration of the diet (3 weeks versus 6 weeks) and selenium speciation was observed. PMID:25363824

Selenium modification of β-lactoglobulin (β-Lg) and its biological activity.

PubMed

Zheng, GuoQiang; Liu, HaoYu; Zhu, ZhenYuan; Zheng, Jie; Liu, AnJun

2016-08-01

β-Lg is a major whey protein in cow's milk. This study was aimed to find a new kind of organic selenium compound synthesized with β-Lg and selenium dioxide as raw materials under the conditions of vacuum and low temperature. Fourier transformed infrared spectroscopy revealed that seleno-β-lactoglobulin (Se-β-Lg) displayed a strong band at 878cm(-1), belonging to SeO. Circular dichroism spectra results indicated that the conformation of Se-β-Lg was transformed and α-helical, and unordered structures were increased by 9% and 11.2%, respectively, while β-sheet and β-turn were reduced by 14.2% and 6%, respectively. Electrophoresis and matrix-assisted laser desorption/ionization time of flight mass spectrometry results showed that there were two protein bands (1-Seβ-Lg and 2-Seβ-Lg) in Se-β-Lg, only one β-Lg connected with selenate in 1-Seβ-Lg, but two β-Lgs, connected to each other, and with selenate, in 2-Seβ-Lg. Morphological observation and hematoxylin and eosin staining indicated that Se-β-lg could induce K562 cell apoptosis. These results indicated that Se-β-Lg could be synthesized by selenium conjugating β-Lg and it had antitumor activity. Copyright © 2016. Published by Elsevier Ltd.

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.

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

Ecology and biotechnology of selenium-respiring bacteria.

PubMed

Nancharaiah, Y V; Lens, P N L

2015-03-01

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. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Elemental selenium at nano size possesses lower toxicity without compromising the fundamental effect on selenoenzymes: comparison with selenomethionine in mice.

PubMed

Wang, Huali; Zhang, Jinsong; Yu, Hanqing

2007-05-15

Glutathione peroxidase and thioredoxin reductase are major selenoenzymes through which selenium exerts powerful antioxidant effects. Selenium also elicits pro-oxidant effects at toxic levels. The antioxidant and pro-oxidant effects, or bioavailability and toxicity, of selenium depend on its chemical form. Selenomethionine is considered to be the most appropriate supplemental form due to its excellent bioavailability and lower toxicity compared to various selenium compounds. The present studies reveal that, compared with selenomethionine, elemental selenium at nano size (Nano-Se) possesses equal efficacy in increasing the activities of glutathione peroxidase and thioredoxin reductase but has much lower toxicity as indicated by median lethal dose, acute liver injury, and short-term toxicity. Our results suggest that Nano-Se can serve as an antioxidant with reduced risk of selenium toxicity.

Trace Mineral Micronutrients and Chronic Periodontitis-a Review.

PubMed

Gaur, Sumit; Agnihotri, Rupali

2017-04-01

Trace mineral micronutrients are imperative for optimum host response. Populations worldwide are prone to their insufficiency owing to lifestyle changes or poor nutritional intake. Balanced levels of trace minerals like iron (Fe), zinc (Zn), selenium (Se) and copper (Cu) are essential to prevent progression of chronic conditions like periodontitis. Their excess as well as deficiency is detrimental to periodontal health. This is specifically true in relation to Fe. Furthermore, some trace elements, e.g. Se, Zn and Cu are integral components of antioxidant enzymes and prevent reactive oxygen species induced destruction of tissues. Their deficiency can worsen periodontitis associated with systemic conditions like diabetes mellitus. With this background, the present review first focusses on the role of four trace minerals, namely, Fe, Zn, Se and Cu in periodontal health followed by an appraisal of the data from case control studies related to their association with chronic periodontitis.

Selenium status in U.K. pregnant women and its relationship with hypertensive conditions of pregnancy.

PubMed

Rayman, Margaret P; Bath, Sarah C; Westaway, Jacob; Williams, Peter; Mao, Jinyuan; Vanderlelie, Jessica J; Perkins, Anthony V; Redman, Christopher W G

2015-01-28

Dietary intake/status of the trace mineral Se may affect the risk of developing hypertensive conditions of pregnancy, i.e. pre-eclampsia and pregnancy-induced hypertension (PE/PIH). In the present study, we evaluated Se status in U.K. pregnant women to establish whether pre-pregnant Se status or Se supplementation affected the risk of developing PE/PIH. The samples originated from the SPRINT (Selenium in PRegnancy INTervention) study that randomised 230 U.K. primiparous women to treatment with Se (60 μg/d) or placebo from 12 weeks of gestation. Whole-blood Se concentration was measured at 12 and 35 weeks, toenail Se concentration at 16 weeks, plasma selenoprotein P (SEPP1) concentration at 35 weeks and plasma glutathione peroxidase (GPx3) activity at 12, 20 and 35 weeks. Demographic data were collected at baseline. Participants completed a FFQ. U.K. pregnant women had whole-blood Se concentration lower than the mid-range of other populations, toenail Se concentration considerably lower than U.S. women, GPx3 activity considerably lower than U.S. and Australian pregnant women, and low baseline SEPP1 concentration (median 3.00, range 0.90-5.80 mg/l). Maternal age, education and social class were positively associated with Se status. After adjustment, whole-blood Se concentration was higher in women consuming Brazil nuts (P= 0.040) and in those consuming more than two seafood portions per week (P= 0.054). A stepwise logistic regression model revealed that among the Se-related risk factors, only toenail Se (OR 0.38, 95% CI 0.17, 0.87, P= 0.021) significantly affected the OR for PE/PIH. On excluding non-compliers with Se treatment, Se supplementation also significantly reduced the OR for PE/PIH (OR 0.30, 95% CI 0.09, 1.00, P= 0.049). In conclusion, U.K. women have low Se status that increases their risk of developing PE/PIH. Therefore, U.K. women of childbearing age need to improve their Se status.

Tracking Se Assimilation and Speciation through the Rice Plant – Nutrient Competition, Toxicity and Distribution

PubMed Central

Eiche, Elisabeth; Riemann, Michael; Nick, Peter; Winkel, Lenny H. E.; Göttlicher, Jörg; Steininger, Ralph; Brendel, Rita; von Brasch, Matthias; Konrad, Gabriele; Neumann, Thomas

2016-01-01

Up to 1 billion people are affected by low intakes of the essential nutrient selenium (Se) due to low concentrations in crops. Biofortification of this micronutrient in plants is an attractive way of increasing dietary Se levels. We investigated a promising method of Se biofortification of rice seedlings, as rice is the primary staple for 3 billion people, but naturally contains low Se concentrations. We studied hydroponic Se uptake for 0–2500 ppb Se, potential phyto-toxicological effects of Se and the speciation of Se along the shoots and roots as a function of added Se species, concentrations and other nutrients supplied. We found that rice germinating directly in a Se environment increased plant-Se by factor 2–16, but that nutrient supplementation is required to prevent phyto-toxicity. XANES data showed that selenite uptake mainly resulted in the accumulation of organic Se in roots, but that selenate uptake resulted in accumulation of selenate in the higher part of the shoot, which is an essential requirement for Se to be transported to the grain. The amount of organic Se in the plant was positively correlated with applied Se concentration. Our results indicate that biofortification of seedlings with selenate is a successful method to increase Se levels in rice. PMID:27116220

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.

Rapid, room-temperature synthesis of amorphous selenium/protein composites using Capsicum annuum L extract

NASA Astrophysics Data System (ADS)

Li, Shikuo; Shen, Yuhua; Xie, Anjian; Yu, Xuerong; Zhang, Xiuzhen; Yang, Liangbao; Li, Chuanhao

2007-10-01

We describe the formation of amorphous selenium (α-Se)/protein composites using Capsicum annuum L extract to reduce selenium ions (SeO32-) at room temperature. The reaction occurs rapidly and the process is simple and easy to handle. A protein with a molecular weight of 30 kDa extracted from Capsicum annuum L not only reduces the SeO32- ions to Se0, but also controls the nucleation and growth of Se0, and even participates in the formation of α-Se/protein composites. The size and shell thickness of the α-Se/protein composites increases with high Capsicum annuum L extract concentration, and decreases with low reaction solution pH. The results suggest that this eco-friendly, biogenic synthesis strategy could be widely used for preparing inorganic/organic biocomposites. In addition, we also discuss the possible mechanism of the reduction of SeO32- ions by Capsicum annuum L extract.

Selenium accumulation and metabolism in algae.

PubMed

Schiavon, Michela; Ertani, Andrea; Parrasia, Sofia; Vecchia, Francesca Dalla

2017-08-01

Selenium (Se) is an intriguing element because it is metabolically required by a variety of organisms, but it may induce toxicity at high doses. Algae primarily absorb selenium in the form of selenate or selenite using mechanisms similar to those reported in plants. However, while Se is needed by several species of microalgae, the essentiality of this element for plants has not been established yet. The study of Se uptake and accumulation strategies in micro- and macro-algae is of pivotal importance, as they represent potential vectors for Se movement in aquatic environments and Se at high levels may affect their growth causing a reduction in primary production. Some microalgae exhibit the capacity of efficiently converting Se to less harmful volatile compounds as a strategy to cope with Se toxicity. Therefore, they play a crucial role in Se-cycling through the ecosystem. On the other side, micro- or macro-algae enriched in Se may be used in Se biofortification programs aimed to improve Se content in human diet via supplementation of valuable food. Indeed, some organic forms of selenium (selenomethionine and methylselenocysteine) are known to act as anticarcinogenic compounds and exert a broad spectrum of beneficial effects in humans and other mammals. Here, we want to give an overview of the developments in the current understanding of Se uptake, accumulation and metabolism in algae, discussing potential ecotoxicological implications and nutritional aspects. Copyright © 2017 Elsevier B.V. All rights reserved.

Biocompatibility selenium nanoparticles with an intrinsic oxidase-like activity

NASA Astrophysics Data System (ADS)

Guo, Leilei; Huang, Kaixun; Liu, Hongmei

2016-03-01

Selenium nanoparticles (SeNPs) are considered to be the new selenium supplement forms with high biological activity and low toxicity; however, the molecular mechanism by which SeNPs exert the biological function is unclear. Here, we reported that biocompatibility SeNPs possessed intrinsic oxidase-like activity. Using Na2SeO3 as a precursor and glutathione as a reductant, biocompatibility SeNPs were synthesized by the wet chemical reduction method in the presence of bovine serum albumin (BSA). The results of structure characterization revealed that synthesized SeNPs were amorphous red elementary selenium with spherical morphology, and ranged in size from 25 to 70 nm size with a narrow distribution (41.4 ± 6.7 nm). The oxidase-like activity of the as-synthesized SeNPs was tested with 3,3',5,5'-tetramethylbenzidine (TMB) as a substrate. The results indicated that SeNPs could catalyze the oxidization of TMB by dissolved oxygen. These SeNPs showed an optimum catalytic activity at pH 4 and 30 °C, and the oxidase-like activity was higher as the concentration of SeNPs increased and the size of SeNPs decreased. The Michaelis constant ( K m) values and maximal reaction velocity ( V max) of the SeNPs for TMB oxidation were 0.0083 mol/L and 3.042 μmol/L min, respectively.

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

USDA-ARS?s Scientific Manuscript database

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...

Selenium promotes sulfur accumulation and plant growth in wheat (Triticum aestivum)

USDA-ARS?s Scientific Manuscript database

Selenium (Se) is an essential micronutrient for animals and humans and a target for biofortification in crops. Sulfur (S) is a crucial nutrient for plant growth. To gain better understanding of Se and S nutrition and interaction in plants, the effects of Se dosages and forms on plant growth as well ...

Selenium as an Essential Micronutrient: Roles in Cell Cycle and Apoptosis

USDA-ARS?s Scientific Manuscript database

Selenium (Se) is an anticancer nutrient, and the essential role of Se in growth of most mammalian cells is well recognized but certain cancer cells appear to have acquired a survival advantage under conditions of Se-deficiency. The objective of the present study is to understand the molecular basis ...

Dietary Selenium Deficiency or Excess Reduces Sperm Quality and Testicular mRNA Abundance of Nuclear Glutathione Peroxidase 4 in Rats.

PubMed

Zhou, Ji-Chang; Zheng, Shijie; Mo, Junluan; Liang, Xiongshun; Xu, Yuanfei; Zhang, Huimin; Gong, Chunmei; Liu, Xiao-Li; Lei, Xin Gen

2017-10-01

Background: Glutathione peroxidase (GPX) 4 and selenoprotein P (SELENOP) are abundant, and several variants are expressed in the testis. Objective: We determined the effects of dietary selenium deficiency or excess on sperm quality and expressions of GPX4 and SELENOP variants in rat testis and liver. Methods: After weaning, male Sprague-Dawley rats were fed a Se-deficient basal diet (BD) for 5 wk until they were 9 wk old [mean ± SEM body weight (BW) = 256 ± 5 g]. They were then fed the BD diet alone (deficient) or with 0.25 (adequate), 3 (excess), or 5 (excess) mg Se/kg for 4 wk. Testis, liver, blood, and semen were collected to assay for selenoprotein mRNA and protein abundances, selenium concentration, GPX activity, 8-hydroxy-deoxyguanosine concentration, and sperm quality. Results: Dietary selenium supplementations elevated ( P < 0.05) tissue selenium concentrations and GPX activities. Compared with those fed BD + 0.25 mg Se/kg, rats fed BD showed lower ( P < 0.05) BW gain (86%) and sperm density (57%) but higher ( P < 0.05) plasma 8-hydroxy-deoxyguanosine concentrations (189%), and nonprogressive sperm motility (4.4-fold). Likewise, rats fed BD + 5 mg Se/kg had ( P = 0.06) lower BW gain and higher (1.9-fold) sperm deformity rates than those in the selenium-adequate group. Compared with the selenium-adequate group, dietary selenium deficiency (BD) or excess (BD + 3 or 5 mg Se/kg) resulted in 45-77% lower ( P < 0.05) nuclear Gpx4 ( nGpx4 ) mRNA abundance in the testis. Rats fed BD had lower ( P < 0.05) mRNA levels of 2 Selenop variants in both testis and liver than those in the other groups. Testicular SELENOP was 155-170% higher ( P < 0.05) in rats fed BD + 5 mg Se/kg and hepatic c/mGPX4 was 13-15% lower ( P < 0.05) in rats fed BD than in the other groups. Conclusions: The mRNA abundance of rat testicular nGPX4 responded to dietary selenium concentrations in similar ways to sperm parameters and may be used as a sensitive marker to assess appropriate Se status for male function. © 2017 American Society for Nutrition.

Selenium and 17 other largely essential and toxic metals in muscle and organ meats of Red Deer (Cervus elaphus)--consequences to human health.

PubMed

Jarzyńska, Grażyna; Falandysz, Jerzy

2011-07-01

Concentrations, composition and interrelationships of selenium and metallic elements (Ag, Ba, Cd, Co, Cr, Cs, Cu, Ga, Mn, Mo, Pb, Rb, Sb, Sr, Tl, V and Zn) have been examined in muscle and organ meats of Red Deer hunted in Poland. The analytical data obtained were also discussed in terms of Se supplementation and deficit to Deer as well as the benefits and risk to humans associated with the essential and toxic metals intake resulting from consumption of Deer meat and products. These elements were determined in 20 adult animals of both sexes that were obtained in the 2000/2001 hunting season from Warmia and Mazury in the north-eastern part of Poland. The whole kidneys contained Ba, Cd, Cr, Ga, Pb, Se, Sr and Tl at statistically greater concentrations than liver or muscle tissue from the same animal. Liver showed statistically greater concentrations of Ag, Co, Cu, Mn and Mo than kidneys or muscle tissue, and muscle tissue was richer in Zn, when compared to the kidneys or liver. Cs and Rb were similarly distributed between all three tissue types, while V was less abundant in liver than kidneys or muscle tissue. There were significant associations between some metallic elements retained in Red Deer demonstrated by Principal Component Analysis (PCA) of the data set. In organ and muscle meats (kidneys, liver and muscle tissue considered together) the first principal component (PC1) was strongly influenced by positively correlated variables describing Se, Ba and Cd and negatively correlated variables describing Ag, Co, Cs, Mn, Pb, Tl and V; PC2, respectively, by Cu, Mn and Mo (+) and Zn (-); PC3 by Ga (+) and PC4 by Sb (+). Selenium occurred in muscle tissue, liver and kidneys at median concentrations of 0.13, 0.19 and 4.0mg/g dry weight, respectively. These values can be defined as marginally deficient (< 0.6mg Se/kg liver dw) or satisfactory (≤ 3.0mg Se/kg kidneys dw) for the amount required to maintain the Deer's body condition and health, depending on the criterion for supplementation used. In terms of human nutritional needs, a relatively high selenium content of kidneys can be beneficial. The muscle meat, liver and kidneys of Red Deer can be considered as a very good source of essential Co, Cr, Cu, Mo, Mn, Se and Zn in the human diet. Lead is generally considered as toxic, and the concentrations found in Red Deer (via the food chain intake) were well below the European Union tolerance limit. Pb from the lead bullets can always create food hygienic problem, if not well recognized during sanitary inspection, and this was noted for one muscle meat sample in this study (5% surveyed). There is no tolerance limit of Cd in game animal meats. The median values of Cd noted in fresh muscle tissue, liver and whole kidneys were 0.07, 0.18, and 3.3mg/kg wet weight, respectively. Cd exists as a chemical element present at trace levels in plants and mushrooms in Deer's food chain in background (uncontaminated) areas. When these are consumed by the Deer, the amount of Cd sequestered with metallothioneins and retained in the organ and muscle meat in this study is low enough to be considered safe for human consumption. Copyright © 2011 Elsevier Ltd. All rights reserved.

Does boiling affect the bioaccessibility of selenium from cabbage?

PubMed

Funes-Collado, Virginia; Rubio, Roser; López-Sánchez, J Fermín

2015-08-15

The bioaccessible selenium species from cabbage were studied using an in vitro physiologically-based extraction test (PBET) which establishes conditions that simulate the gastric and gastrointestinal phases of human digestion. Samples of cabbage (Brassica oleracea) grown in peat fortified with different concentrations of Se(IV) and Se(VI) were analysed, and several enzymes (pepsin, pancreatin and amylase) were used in the PBET. The effect of boiling before extraction was also assayed. Selenium speciation in the PBET extracts was determined using anionic exchange and LC-ICP/MS. The selenocompounds in the extracts were Se(IV), SeMet and, mostly, Se(VI) species. The results show that the activity of the enzymes increased the concentration of the selenocompounds slightly, although the use of amylase had no effect on the results. The PBET showed the concentration of inorganic selenium in the extracts from boiled cabbage decreased as much as 4-fold while the release of SeMet and its concentration increased (up to 6-fold), with respect to raw cabbage. Copyright © 2015 Elsevier Ltd. All rights reserved.

Selenium in foods produced and consumed in Greece

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bratakos, M.S.; Zafiropoulos, T.F.; Siskos, P.A.

The total selenium within a wide variety (315 food items) of Greek foods was determined fluorimetrically. Rich selenium sources were the proteinaceous foods such as fish, meat, bread, and spaghetti. Butter, oils, vegetables, and fruits were poor sources. The selenium content of Greek foods was lower than that of many other countries and resembled more closely that of British foods. From available food consumption data and values in this study, it was estimated that the daily selenium intake of Greeks was 110 {mu}g.

[Effect of lead and selenium on learning and memory ability in rats].

PubMed

Han, Xiaojie; Hu, Xiaoxia; Wei, Qing; Chen, Yilin; Yu, De'e; Hu, Qiansheng

2013-11-01

To study the effect of lead and (or) selenium on learning and memory ability in rats. SPF Wistar rats, after weaning, were divided into six groups, control group, Pb group (respectively Pb exposed), Se group (respectively Se added), Pb-Se group (added Se after Pb exposure), Se-Pb group (added Se before Pb exposure) and Pb + Se group (Pb and Se exposed simultaneously). After intervention for six weeks in rats, the spatial learning and memory of each group rats were measured by Morris water maze assay. Rats in Pb group had significantly longer latency, less site crossings, less percentage of time and distance spent in the target quadrant, and bigger first bearing compared with control group (P < 0.05). Rats in Pb and Se joint exposure groups had significantly shorter latency, more site crossings, less percentage of time and distance spent in the target quadrant, and smaller first bearing compared with Pb group (P < 0.05). There were no significant differences in the indexes of spatial learning and memory ability between the groups of lead and selenium joint exposure groups (P > 0.05). Lead damaged the ability of learning and memory in rats and organic selenium had protective effects on Pb-induced spatial learning and memory deficits in rats.

Efficient interface for online coupling of capillary electrophoresis with inductively coupled plasma-mass spectrometry and its application in simultaneous speciation analysis of arsenic and selenium.

PubMed

Liu, Lihong; Yun, Zhaojun; He, Bin; Jiang, Guibin

2014-08-19

A simple and highly efficient online system coupling of capillary electrophoresis to inductively coupled plasma-mass spectrometry (CE-ICP-MS) for simultaneous separation and determination of arsenic and selenium compounds was developed. CE was coupled to an ICP-MS system by a sprayer with a novel direct-injection high-efficiency nebulizer (DIHEN) chamber as the interface. By using this interface, six arsenic species, including arsenite (As(III), arsenate (As(V)), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AsB), and arsenocholine (AsC) and five selenium species (such as sodium selenite (Se(IV)), sodium selenate (Se(VI)), selenocysteine (SeCys), selenomethionine (SeMet), and Se-methylselenocysteine (MeSeCys)) were baseline-separated and determined in a single run within 9 min under the optimized conditions. Minimum dead volume, low and steady sheath flow liquid, high nebulization efficiency, and high sample transport efficiency were obtained by using this interface. Detection limits were in the range of 0.11-0.37 μg L(-1) for the six arsenic compounds (determined as (75)As at m/z 75) and 1.33-2.31 μg L(-1) for the five selenium species (determined as (82)Se at m/z 82). Repeatability expressed as the relative standard deviations (RSD, n = 6) of both migration time and peak area were better than 2.68% for arsenic compounds and 3.28% for selenium compounds, respectively. The proposed method had been successfully applied for the determination of arsenic and selenium species in the certified reference materials DORM-3, water, urine, and fish samples.

Modeling selenium bioaccumulation through arthropod food webs in San Francisco Bay, California, USA.

PubMed

Schlekat, Christian E; Purkerson, David G; Luoma, Samuel N

2004-12-01

Trophic transfer is the main process by which upper trophic level wildlife are exposed to selenium. Transfers through lower levels of a predator's food web thus can be instrumental in determining the threat of selenium in an ecosystem. Little is known about Se transfer through pelagic, zooplankton-based food webs in San Francisco Bay ([SFB], CA, USA), which serve as an energy source for important predators such as striped bass: A dynamic multipathway bioaccumulation model was used to model Se transfer from phytoplankton to pelagic copepods to carnivorous mysids (Neomysis mercedis). Uptake rates of dissolved Se, depuration rates, and assimilation efficiencies (AE) for the model were determined for copepods and mysids in the laboratory. Small (73-250 microm) and large (250-500 microm) herbivorous zooplankton collected from SFB (Oithona/Limnoithona and Acartia sp.) assimilated Se with similar efficiencies (41-52%) from phytoplankton. Mysids assimilated 73% of Se from small herbivorous zooplankton; Se AE was significantly lower (61%) than larger herbivorous zooplankton. Selenium depuration rates were high for both zooplankton and mysids (12-25% d(-1)), especially compared to bivalves (2-3% d(-1)). The model predicted steady state Se concentrations in mysids similar to those observed in the field. The predicted concentration range (1.5-5.4 microg g(-1)) was lower than concentrations of 4.5 to 24 microg g(-1) observed in bivalves from the bay. Differences in efflux between mysids and bivalves were the best explanation for the differences in uptake. The results suggest that the risk of selenium toxicity to predators feeding on N. mercedis would be less than the risk to predators feeding on bivalves. Management of selenium contamination should include food webs analyses to focus on the most important exposure pathways identified for a given watershed.

Modeling selenium bioaccumulation through arthropod food webs in San Francisco Bay, California, USA

USGS Publications Warehouse

Schlekat, C.E.; Purkerson, D.G.; Luoma, S.N.

2004-01-01

Trophic transfer is the main process by which upper trophic level wildlife are exposed to selenium. Transfers through lower levels of a predator's food web thus can be instrumental in determining the threat of selenium in an ecosystem. Little is known about Se transfer through pelagic, zooplankton-based food webs in San Francisco Bay ([SFB], CA, USA), which serve as an energy source for important predators such as striped bass. A dynamic multipathway bioaccumulation model was used to model Se transfer from phytoplankton to pelagic copepods to carnivorous mysids (Neomysis mercedis). Uptake rates of dissolved Se, depuration rates, and assimilation efficiencies (AE) for the model were determined for copepods and mysids in the laboratory. Small (73-250 ??m) and large (250-500 ??m) herbivorous zooplankton collected from SFB (Oithona/Limnoithona and Acartia sp.) assimilated Se with similar efficiencies (41-52%) from phytoplankton. Mysids assimilated 73% of Se from small herbivorous zooplankton; Se AE was significantly lower (61%) than larger herbivorous zooplankton. Selenium depuration rates were high for both zooplankton and mysids (12-25% d-1), especially compared to bivalves (2-3% d-1). The model predicted steady state Se concentrations in mysids similar to those observed in the field. The predicted concentration range (1.5-5.4 ??g g -1) was lower than concentrations of 4.5 to 24 ??g g-1 observed in bivalves from the bay. Differences in efflux between mysids and bivalves were the best explanation for the differences in uptake. The results suggest that the risk of selenium toxicity to predators feeding on N. mercedis would be less than the risk to predators feeding on bivalves. Management of selenium contamination should include food webs analyses to focus on the most important exposure pathways identified for a given watershed.

Reduction of selenite by Azospirillum brasilense with the formation of selenium nanoparticles.

PubMed

Tugarova, Anna V; Vetchinkina, Elena P; Loshchinina, Ekaterina A; Burov, Andrei M; Nikitina, Valentina E; Kamnev, Alexander A

2014-10-01

The ability to reduce selenite (SeO(3)(2-)) ions with the formation of selenium nanoparticles was demonstrated in Azospirillum brasilense for the first time. The influence of selenite ions on the growth of A. brasilense Sp7 and Sp245, two widely studied wild-type strains, was investigated. Growth of cultures on both liquid and solid (2 % agar) media in the presence of SeO(3)(2-) was found to be accompanied by the appearance of the typical red colouration. By means of transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS) and X-ray fluorescence analysis (XFA), intracellular accumulation of elementary selenium in the form of nanoparticles (50 to 400 nm in diameter) was demonstrated for both strains. The proposed mechanism of selenite-to-selenium (0) reduction could involve SeO(3)(2-) in the denitrification process, which has been well studied in azospirilla, rather than a selenite detoxification strategy. The results obtained point to the possibility of using Azospirillum strains as endophytic or rhizospheric bacteria to assist phytoremediation of, and cereal cultivation on, selenium-contaminated soils. The ability of A. brasilense to synthesise selenium nanoparticles may be of interest to nanobiotechnology for "green synthesis" of bioavailable amorphous red selenium nanostructures.

Selenium Partitioning and Removal Across a Wet FGD Scrubber at a Coal-Fired Power Plant.

PubMed

Senior, Constance L; Tyree, Corey A; Meeks, Noah D; Acharya, Chethan; McCain, Joseph D; Cushing, Kenneth M

2015-12-15

Selenium has unique fate and transport through a coal-fired power plant because of high vapor pressures of oxide (SeO2) in flue gas. This study was done at full-scale on a 900 MW coal-fired power plant with electrostatic precipitator (ESP) and wet flue gas desulfurization (FGD) scrubber. The first objective was to quantify the partitioning of selenium between gas and condensed phases at the scrubber inlet and outlet. The second objective was to determine the effect of scrubber operation conditions (pH, mass transfer, SO2 removal) on Se removal in both particulate and vapor phases. During part of the testing, hydrated lime (calcium hydroxide) was injected upstream of the scrubber. Gas-phase selenium and particulate-bound selenium were measured as a function of particle size at the inlet and outlet of the scrubber. The total (both phases) removal of Se across the scrubber averaged 61%, and was enhanced when hydrated lime sorbent was injected. There was evidence of gas-to-particle conversion of selenium across the scrubber, based on the dependence of selenium concentration on particle diameter downstream of the scrubber and on thermodynamic calculations.

Synergistic Effects of SAM and Selenium Compounds on Proliferation, Migration and Adhesion of HeLa Cells.

PubMed

Sun, Licui; Zhang, Jianxin; Yang, Qiu; Si, Yang; Liu, Yiqun; Wang, Qin; Han, Feng; Huang, Zhenwu

2017-08-01

To determine the antitumor activities and molecular mechanism of selenium compounds in HeLa cells. Western blotting was used to detect ERK and AKT activation in HeLa cells induced by selenium compounds selenomethionine (SeMet), methylselenocysteine (MeSeCys) and methylseleninic acids (MeSeA). Using MTT, wound-healing and Matrigel adhesion assays, the antitumor effects of SAM and selenium compounds were evaluated in HeLa cells. MeSeA inhibited ERK and AKT signaling pathways and suppressed the proliferation (p<0.05 vs. HeLa control), migration (p<0.05 vs. HeLa control) and adhesion (p<0.01 vs. HeLa control) of HeLa cells. MeSeCys and SeMet inhibited AKT signaling pathways and the migration (p<0.05 vs. HeLa control) and adhesion (p<0.01 vs. HeLa control) of HeLa cells. The synergistic action of MeSeA with SAM led to a statistically significant inhibition of proliferation, migration and adhesion of HeLa cells. MeSeA, MeSeCys and SeMet exert different antitumor activities by inhibiting ERK and AKT signaling pathways. The combination of MeSeA and SAM exhibited better antitumor effects compared to the other treatments. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Covalent Incorporation of Selenium into Oligonucleotides for X-ray Crystal Structure Determination via MAD: Proof of Principle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teplova, M.; Wilds, C.J.; Wawrzak, Z.

2010-03-08

Selenium was incorporated into an oligodeoxynucleotide in the form of 2'-methylseleno-uridine (U{sub Se}). The X-ray crystal structure of the duplex d(GCGTA)U{sub Se}d(ACGC){sub 2} was determined by the multiwavelength anomalous dispersion (MAD) technique and refined to a resolution of 1.3 {angstrom}, demonstrating that selenium can selectively substitute oxygen in DNA and that the resulting compounds are chemically stable. Since derivatization at the 2'-{alpha}-position with selenium does not affect the preference of the sugar for the C3'-endo conformation, this strategy is suitable for incorporating selenium into RNA. The availability of selenium-containing nucleic acids for crystallographic phasing offers an attractive alternative to themore » commonly used halogenated pyrimidines.« less

Temporal variations in dissolved selenium in Lake Kinneret (Israel)

USGS Publications Warehouse

Nishri, A.; Brenner, I.B.; Hall, G.E.M.; Taylor, Howard E.

1999-01-01

Selenium is an essential micronutrient for the growth of the dinoflagellate Peridinium gatunense that dominates the spring algal bloom in Lake Kinneret (LK). The relationship between the levels of dissolved selenium species and the occurance of algal blooms in this lake was studied. During algal blooms of P. gatunense in spring and of the blue-green Aphanizomenon ovalisporum in fall (in 1994) the concentration of epilimnetic dissolved organic Se (Se(org)) increased whereas that of selenite (SeIV) decreased, to levels below the limit of detection: 5 ng/l. The disappearance of SeIV during these blooms is attributed to algal uptake and it is suggested that the growth of both algae may have depended on Se(org) regeneration. A budget performed for selenate (SeVI) suggests that this species is also consumed by algae but to a lesser extent than SeIV (in 1994 ~40% of the epilimnetic load). During the stratification period the hypolimnion of Lake Kinneret becomes anoxic, with high levels of dissolved sulfide. The affects of this environment on the distribution of Se oxy-anions, selenite (SeIV) and selenate(SeVI), were also studied. At the onset of thermal stratification (March) about 35% of the lake inventory of both Se oxidized species are entrapped in the hypolimnion. During stages of oxygen depletion and H2S accumulation, SeIV is completely and SeVI partially removed from this layer. The removal is attributed to reduction followed by formation of particulate reduced products, such as elemental selenium Se(o). The ratio between SeVI to total dissolved selenium (SE(T)) in water sources to the lake is ~0.84, about twice the corresponding ratio in the lake (~0.44, during holomixis). In the lake about 75% of annual SeVI inflow from external sources undergoes reduction to selenide (Se-II) and Se(o) through epilimnetic algal assimilation and hypolimnetic anoxic reduction, respectively. It is suggested that the latter oxidation of the dissolved organic selenide released from biogenic particles and of Se(o) only to the tetravalent species is the cause for the lower ratio of SeVI/Se(T) in the lake.

Microbial Selenite Reduction and the Selenium Biogeochemical Cycle

NASA Astrophysics Data System (ADS)

Stolz, J. F.; Wells, M.

2016-12-01

Selenium is an essential trace element utilized by many species in the three domains of life. In most Bacteria and Archaea, selenium is primarily assimilated to form selenocysteine, the 21st amino acid (Sec). Additionally selenium can be methylated, demethylated, or used as a terminal electron acceptor in dissimilatory selenate or selenite reduction. Although progress has been made on elucidating the synthesis of selenoproteins, less is known of their occurrence, diversity, and functionality, primarily due to poor genome annotation (e.g., failure to recognize UGA as a Sec and not a stop codon) and proteomics analysis (e.g., failure to detect Sec in LC/MS-MS). Furthermore important parts of the selenium biogeochemical cycle remain to be fully explored, in particular the reduction of Se(IV) to Se(O). We have examined the selenoproteome of a selenate respiring bacterium Sulfurospirillum barnesii strain SES-3, which reduces Se(VI) to Se(0) and the dissimilatory selenite reducing bacterium, Bacillus selenitireducens, strain MLS-10, which reduces Se(IV) to Se(0). Candidate selenoproteins including D-proline reductase, formate dehydrogenase, and methionine-S sulfoxide reductase have been identified in the genomes. A putative dissimilatory selenate reducase (Ser) was found in the genome of S. barnesii. More significant was the discovery of a candidate for the respiratory selenite reductase in B. selenitireducens as determined by in gel assays and LC/MS-MS. The latter has provided a hint at the potential diversity of DSiR bacteria and the development of molecular probes for investigating DSiR in the selenium biogeochemical cycle.

Purification and characterization of selenium-containing phycocyanin from selenium-enriched Spirulina platensis.

PubMed

Chen, Tianfeng; Wong, Yum-Shing; Zheng, Wenjie

2006-11-01

A fast protein liquid chromatographic method for purification of selenium-containing phycocyanin (Se-PC) from selenium-enriched Spirulina platensis was described in this study. The purification procedures involved fractionation by ammonium sulfate precipitation, DEAE-Sepharose ion-exchange chromatography and Sephacry S-300 size exclusion chromatography. The purity ratio (A620/A280) and the separation factor (A620/A655) of the purified Se-PC were 5.12 and 7.92, respectively. The Se concentration of purified Se-PC was 496.5 microg g(-1) protein, as determined by ICP-AES analysis. The purity of the Se-PC was further characterized by UV-VIS and fluorescence spectrometry, SDS-PAGE, RP-HPLC and gel filtration HPLC. The apparent molecular mass of the native Se-PC determined by gel filtration HPLC was 109 kDa, indicating that the protein existed as a trimer. SDS-PAGE of the purified Se-PC yielded two major bands corresponding to the alpha and beta subunits. A better separation of these two subunits was obtained by RP-HPLC. Identification of the alpha and beta subunits separated by SDS-PAGE and RP-HPLC was achieved by peptide mass fingerprinting (PMF) using MALDI-TOF-TOF mass spectrometry.

Selenoproteins in human body: focus on thyroid pathophysiology.

PubMed

Valea, Ana; Georgescu, Carmen Emanuela

2018-06-05

Selenium (Se) has a multilevel, complex and dynamic effect on the human body as a major component of selenocysteine, incorporated into selenoproteins, which include the selenocysteine-containing enzymes iodothyronine deiodinases. At the thyroid level, these proteins play an essential role in antioxidant protection and hormone metabolism. This is a narrative review based on PubMed/Medline database research regarding thyroid physiology and conditions with Se and Se-protein interferences. In humans, Se-dependent enzyme functions are best expressed through optimal Se intake, although there is gap in our knowledge concerning the precise mechanisms underlying the interrelation. There is a good level of evidence linking low serum Se to autoimmune thyroid diseases and, to a lesser extent, differentiated thyroid cancer. However, when it comes to routine supplementation, the results are heterogeneous, except in the case of mild Graves' orbitopathy. Autoimmune hypothyroidism is associated with a state of higher oxidative stress, but not all studies found an improvement of thyroid function after Se was introduced as antioxidant support. Meanwhile, no routine supplementation is recommended. Low Se intake is correlated with an increased risk of developing antithyroid antibodies, its supplementation decreasing their titres; there is also a potential reduction in levothyroxine replacement dose required for hypothyroidism and/or the possibility that it prevents progression of subclinical hypothyroidism, although not all studies agree. In thyroid-associated orbitopathy, euthyroidism is more rapidly achieved if the micronutrient is added to traditional drugs, while controls appear to benefit from the microelement only if they are deficient; thus, a basal assay of Se appears advisable to better select patients who need substitution. Clearly, further Se status biomarkers are required. Future introduction of individual supplementation algorithms based on baseline micronutrient levels, underlying or at-risk clinical conditions, and perhaps selenoprotein gene polymorphisms is envisaged.

Selenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California.

PubMed

Saiki, Michael K; Martin, Barbara A; May, Thomas W

2012-09-01

Resource managers are concerned that water conservation practices in irrigated farmlands along the southern border of the Salton Sea, Imperial County, California, could increase selenium concentrations in agricultural drainwater and harm the desert pupfish (Cyprinodon macularius), a federally protected endangered species. As part of a broader attempt to address this concern, we conducted a 3-year investigation to collect baseline information on selenium concentrations in seven agricultural drains inhabited by pupfish. We collected water, sediment, selected aquatic food-chain taxa (particulate organic detritus, filamentous algae, net plankton, and midge [Chironomidae] larvae), and two poeciliid fishes (western mosquitofish Gambusia affinis and sailfin molly Poecilia latipinna) for selenium determinations. The two fish species served as ecological surrogates for pupfish, which we were not permitted to sacrifice. Dissolved selenium ranged from 0.70 to 32.8 μg/L, with selenate as the major constituent. Total selenium concentrations in other environmental matrices varied widely among drains, with one drain (Trifolium 18) exhibiting especially high concentrations in detritus, 5.98-58.0 μg Se/g; midge larvae, 12.7-50.6 μg Se/g; mosquitofish, 13.2-20.2 μg Se/g; and mollies, 12.8-30.4 μg Se/g (all tissue concentrations are based on dry weights). Although toxic thresholds for selenium in fishes from the Salton Sea are still poorly understood, available evidence suggests that ambient concentrations of this element may not be sufficiently elevated to adversely affect reproductive success and survival in selenium-tolerant poeciliids and pupfish.

Selenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California

USGS Publications Warehouse

Saiki, Michael K.; Martin, Barbara A.; May, Thomas W.

2012-01-01

Resource managers are concerned that water conservation practices in irrigated farmlands along the southern border of the Salton Sea, Imperial County, California, could increase selenium concentrations in agricultural drainwater and harm the desert pupfish (Cyprinodon macularius), a federally protected endangered species. As part of a broader attempt to address this concern, we conducted a 3-year investigation to collect baseline information on selenium concentrations in seven agricultural drains inhabited by pupfish. We collected water, sediment, selected aquatic food-chain taxa (particulate organic detritus, filamentous algae, net plankton, and midge [Chironomidae] larvae), and two poeciliid fishes (western mosquitofish Gambusia affinis and sailfin molly Poecilia latipinna) for selenium determinations. The two fish species served as ecological surrogates for pupfish, which we were not permitted to sacrifice. Dissolved selenium ranged from 0.70 to 32.8 μg/L, with selenate as the major constituent. Total selenium concentrations in other environmental matrices varied widely among drains, with one drain (Trifolium 18) exhibiting especially high concentrations in detritus, 5.98–58.0 μg Se/g; midge larvae, 12.7–50.6 μg Se/g; mosquitofish, 13.2–20.2 μg Se/g; and mollies, 12.8–30.4 μg Se/g (all tissue concentrations are based on dry weights). Although toxic thresholds for selenium in fishes from the Salton Sea are still poorly understood, available evidence suggests that ambient concentrations of this element may not be sufficiently elevated to adversely affect reproductive success and survival in selenium-tolerant poeciliids and pupfish.

Combined effect of selenium and ascorbic acid on alcohol induced hyperlipidemia in male guinea pigs.

PubMed

Asha, G S; Indira, M

2004-02-01

Alcoholics usually suffer from malnutrition and are especially deficient in micronutrients like vitamin C, selenium and Zn. In the present study, combined effects of selenium and ascorbic acid on alcohol-induced hyperlipidemia were studied in guinea pigs. Four groups of male guinea pigs were maintained for 45 days as follows: control (1 mg ascorbate (AA)/100 g body mass/day), ethanol (900 mg ethanol/100 g body mass + 1 mg AA/100 g body mass/day), selenium+ascorbic acid [(25 mg AA + 0.05 mg Se)/100 g body mass/day], ethanol+selenium+ascorbic acid [(25 mg AA + 0.05 mg Se + 900 mg ethanol)/100 g body mass/day]. Co-administration of selenium and ascorbic acid along with alcohol reduced the concentration of all lipids, as also evidenced from the decreased activities of hydroxymethylglutaryl-CoA reductase and enhanced activities of plasma lecithin cholesterol acyl transferase and lipoprotein lipase. Concentrations of bile acids were increased. We conclude that the supplementation of Se and ascorbic acid reduced alcohol induced hyperlipidemia, by decreased synthesis and increased catabolism.

Distribution of soil selenium in China is potentially controlled by deposition and volatilization?

PubMed Central

Sun, Guo-Xin; Meharg, Andrew A.; Li, Gang; Chen, Zheng; Yang, Lei; Chen, Song-Can; Zhu, Yong-Guan

2016-01-01

Elucidating the environmental drivers of selenium (Se) spatial distribution in soils at a continental scale is essential to better understand it’s biogeochemical cycling to improve Se transfer into diets. Through modelling Se biogeochemistry in China we found that deposition and volatilization are key factors controlling distribution in surface soil, rather than bedrock-derived Se (<0.1 mg/kg). Wet deposition associated with the East Asian summer monsoon, and dry deposition associated with the East Asian winter monsoon, are responsible for dominant Se inputs into northwest and southeast China, respectively. In Central China the rate of soil Se volatilization is similar to that of Se deposition, suggesting that Se volatilization offsets it’s deposition, resulting in negligible net Se input in soil. Selenium in surface soil at Central China is roughly equal to low petrogenic Se, which is the main reason for the presence of the Se poor belt. We suggest that both deposition and volatilization of Se could play a key role in Se balance in other terrestrial environments worldwide. PMID:26883576

Effects of various doses of selenite on stinging nettle (Urtica dioica L.).

PubMed

Krystofova, Olga; Adam, Vojtech; Babula, Petr; Zehnalek, Josef; Beklova, Miroslava; Havel, Ladislav; Kizek, Rene

2010-10-01

The aim of this study was to investigate the effects of selenium (Se) on the growth, accumulation and possible mechanisms of Se transport in certain parts (roots, leaves, stamp and apex) of nettle (Urtica dioica L.) plants. Se was supplemented by one-shot and two repeated doses to the soil (2.0 and 4.0 mg Se per kg of substrate). Selenium content in roots increased linearly with dose and was significantly higher compared to other plant parts of interest. However, growth of the above-ground parts of plant as well as roots was slightly inhibited with increasing selenium concentration in comparison to the untreated plants. The content of phytochelatin2, a low molecular mass peptide containing a sulfhydryl group, correlated well with the Se content. This suggests a possible stimulation of synthesis of this plant peptide by Se.

Studies on the origin and transformation of selenium and its chemical species along the process of petroleum refining

NASA Astrophysics Data System (ADS)

Stivanin de Almeida, Cibele M.; Ribeiro, Anderson S.; Saint'Pierre, Tatiana D.; Miekeley, Norbert

2009-06-01

Inductively coupled plasma optical emission spectrometry and mass spectrometry (ICPMS), the latter hyphenated to flow injection hydride generation, electrothermal vaporization or ion chromatography, have been applied to the chemical characterization of crude oil, aqueous process stream samples and wastewaters from a petroleum refinery, in order to get information on the behavior of selenium and its chemical species along effluent generation and treatment. Multielemental characterization of these effluents by ICPMS revealed a complex composition of most of them, with high salinity and potential spectral and non-spectral interferents present. For this reason, a critical re-assessment of the analytical techniques for the determination of total selenium and its species was performed. Methane was employed as gas in dynamic reaction cell ICPMS and cell parameters were optimized for a simulated brine matrix and for diluted aqueous solutions to match the expected process and treated wastewaters samples. The signal-to-background ratios for 78Se and 80Se were used as criteria in optimization, the first isotope resulting in better detection limits for the simulated brine matrix ( 78Se: 0.07 μg L - 1 , 80Se: 0.31 μg L - 1 ). A large variability in the concentration of selenium (from < 10 μg kg - 1 up to 960 μg kg - 1 ) was observed in 16 of the most frequently processed crude oil samples in the refinery here investigated, which may explain the pronounced concentrations changes of this element measured in aqueous process stream and wastewater samples. Highest concentrations of total selenium were analyzed in samples from the hydrotreater (up to about 1800 μg L - 1 ). The predominance of selenocyanate (SeCN -) was observed in most of the wastewaters so far investigated, but also other species were detected with retention times different from Se(IV), Se(VI) and SeCN -. Colloidal selenium (Se 0) was the only Se-species observed in samples from the atmospheric distillation unit, but was also identified in other samples, most probably formed by the decomposition of SeCN - or other unstable species.

Monodispersed spherical shaped selenium nanoparticles (SeNPs) synthesized by Bacillus subtilis and its toxicity evaluation in zebrafish embryos

NASA Astrophysics Data System (ADS)

Chandramohan, Subburaman; Sundar, Krishnan; Muthukumaran, Azhaguchamy

2018-02-01

Selenium is one of the essential elements involved in antioxidative and antiinflammatory effects in human body. By naturally, selenium ions are metabolised and converted into nano selenium. Now a days there is an increasing attention on applications of nanoparticles in therapeutic field. In the present study Bacillus subtilis was used to convert sodium selenite to SeNPs. The synthesized SeNPs were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X ray spectroscopy (EDX). The presence of SeNPs was confirmed by the formation of red colour. The bands were sharp with broad absorption peaks at 3562 cm-1 and 1678-1 cm in FTIR which showed that the bacterial proteins were responsible for the reduction of sodium selenite to SeNPs. The average size of the SeNPs was 334 nm and were spherical in shape with uniform distribution. The XRD data confirmed that SeNPs were of amorphous in nature. The zeta potential of SeNPs was negative in charge which indicated high stability. In the present study zebrafish embryos were used to study the toxicity of SeNPs and the results showed that the concentration beyond 10 μg ml-1 leads to toxic effects in embryos/hatchlings. The lesser concentration of SeNPs can be useful in various biomedical applications.

Selenium retention in tissues of swine fed carcasses of pigs grown on diets containing sodium selenite or high selenium white sweet clover grown on fly ash

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mandisodza, K.T.; Pond, W.G.; Lisk, D.J.

1980-04-01

Growing pigs were fed diets containing 5 or 10% white sweet clover, and 0, 3.5 or 7.0 ppM selenium (Se) supplied as sodium selenite (Na/sub 2/SeO/sub 3/) or occurring naturally in white sweet clover harvested from a coal fly ash dump. Ground carcasses of these pigs were included in corn meal diets at 23% and fed back to pigs. Compared to the pigs fed the high Se, fly ash-grown clover diets, the pigs fed Na/sub 2/SeO/sub 3/ diets had higher blood Se levels but lower Se concentrations in kidney, liver and skeletal muscle. Tissues of the pigs which were fedmore » carcasses of the high Se clover-fed pigs had higher Se concentrations than those of the pigs fed carcasses of the Na/sub 2/SeO/sub 3/ - fed pigs.« less

Production of selenium nanoparticles in Pseudomonas putida KT2440.

PubMed

Avendaño, Roberto; Chaves, Nefertiti; Fuentes, Paola; Sánchez, Ethel; Jiménez, Jose I; Chavarría, Max

2016-11-15

Selenium (Se) is an essential element for the cell that has multiple applications in medicine and technology; microorganisms play an important role in Se transformations in the environment. Here we report the previously unidentified ability of the soil bacterium Pseudomonas putida KT2440 to synthesize nanoparticles of elemental selenium (nano-Se) from selenite. Our results show that P. putida is able to reduce selenite aerobically, but not selenate, to nano-Se. Kinetic analysis indicates that, in LB medium supplemented with selenite (1 mM), reduction to nano-Se occurs at a rate of 0.444 mmol L -1 h -1 beginning in the middle-exponential phase and with a final conversion yield of 89%. Measurements with a transmission electron microscope (TEM) show that nano-Se particles synthesized by P. putida have a size range of 100 to 500 nm and that they are located in the surrounding medium or bound to the cell membrane. Experiments involving dynamic light scattering (DLS) show that, in aqueous solution, recovered nano-Se particles have a size range of 70 to 360 nm. The rapid kinetics of conversion, easy retrieval of nano-Se and the metabolic versatility of P. putida offer the opportunity to use this model organism as a microbial factory for production of selenium nanoparticles.

Production of selenium nanoparticles in Pseudomonas putida KT2440

PubMed Central

Avendaño, Roberto; Chaves, Nefertiti; Fuentes, Paola; Sánchez, Ethel; Jiménez, Jose I.; Chavarría, Max

2016-01-01

Selenium (Se) is an essential element for the cell that has multiple applications in medicine and technology; microorganisms play an important role in Se transformations in the environment. Here we report the previously unidentified ability of the soil bacterium Pseudomonas putida KT2440 to synthesize nanoparticles of elemental selenium (nano-Se) from selenite. Our results show that P. putida is able to reduce selenite aerobically, but not selenate, to nano-Se. Kinetic analysis indicates that, in LB medium supplemented with selenite (1 mM), reduction to nano-Se occurs at a rate of 0.444 mmol L−1 h−1 beginning in the middle-exponential phase and with a final conversion yield of 89%. Measurements with a transmission electron microscope (TEM) show that nano-Se particles synthesized by P. putida have a size range of 100 to 500 nm and that they are located in the surrounding medium or bound to the cell membrane. Experiments involving dynamic light scattering (DLS) show that, in aqueous solution, recovered nano-Se particles have a size range of 70 to 360 nm. The rapid kinetics of conversion, easy retrieval of nano-Se and the metabolic versatility of P. putida offer the opportunity to use this model organism as a microbial factory for production of selenium nanoparticles. PMID:27845437

Biochemical and biophysical characterization of the selenium-binding and reducing site in Arabidopsis thaliana homologue to mammals selenium-binding protein 1.

PubMed

Schild, Florie; Kieffer-Jaquinod, Sylvie; Palencia, Andrés; Cobessi, David; Sarret, Géraldine; Zubieta, Chloé; Jourdain, Agnès; Dumas, Renaud; Forge, Vincent; Testemale, Denis; Bourguignon, Jacques; Hugouvieux, Véronique

2014-11-14

The function of selenium-binding protein 1 (SBP1), present in almost all organisms, has not yet been established. In mammals, SBP1 is known to bind the essential element selenium but the binding site has not been identified. In addition, the SBP family has numerous potential metal-binding sites that may play a role in detoxification pathways in plants. In Arabidopsis thaliana, AtSBP1 over-expression increases tolerance to two toxic compounds for plants, selenium and cadmium, often found as soil pollutants. For a better understanding of AtSBP1 function in detoxification mechanisms, we investigated the chelating properties of the protein toward different ligands with a focus on selenium using biochemical and biophysical techniques. Thermal shift assays together with inductively coupled plasma mass spectrometry revealed that AtSBP1 binds selenium after incubation with selenite (SeO3(2-)) with a ligand to protein molar ratio of 1:1. Isothermal titration calorimetry confirmed the 1:1 stoichiometry and revealed an unexpectedly large value of binding enthalpy suggesting a covalent bond between selenium and AtSBP1. Titration of reduced Cys residues and comparative mass spectrometry on AtSBP1 and the purified selenium-AtSBP1 complex identified Cys(21) and Cys(22) as being responsible for the binding of one selenium. These results were validated by site-directed mutagenesis. Selenium K-edge x-ray absorption near edge spectroscopy performed on the selenium-AtSBP1 complex demonstrated that AtSBP1 reduced SeO3(2-) to form a R-S-Se(II)-S-R-type complex. The capacity of AtSBP1 to bind different metals and selenium is discussed with respect to the potential function of AtSBP1 in detoxification mechanisms and selenium metabolism. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Biochemical and Biophysical Characterization of the Selenium-binding and Reducing Site in Arabidopsis thaliana Homologue to Mammals Selenium-binding Protein 1*

PubMed Central

Schild, Florie; Kieffer-Jaquinod, Sylvie; Palencia, Andrés; Cobessi, David; Sarret, Géraldine; Zubieta, Chloé; Jourdain, Agnès; Dumas, Renaud; Forge, Vincent; Testemale, Denis; Bourguignon, Jacques; Hugouvieux, Véronique

2014-01-01

The function of selenium-binding protein 1 (SBP1), present in almost all organisms, has not yet been established. In mammals, SBP1 is known to bind the essential element selenium but the binding site has not been identified. In addition, the SBP family has numerous potential metal-binding sites that may play a role in detoxification pathways in plants. In Arabidopsis thaliana, AtSBP1 over-expression increases tolerance to two toxic compounds for plants, selenium and cadmium, often found as soil pollutants. For a better understanding of AtSBP1 function in detoxification mechanisms, we investigated the chelating properties of the protein toward different ligands with a focus on selenium using biochemical and biophysical techniques. Thermal shift assays together with inductively coupled plasma mass spectrometry revealed that AtSBP1 binds selenium after incubation with selenite (SeO32−) with a ligand to protein molar ratio of 1:1. Isothermal titration calorimetry confirmed the 1:1 stoichiometry and revealed an unexpectedly large value of binding enthalpy suggesting a covalent bond between selenium and AtSBP1. Titration of reduced Cys residues and comparative mass spectrometry on AtSBP1 and the purified selenium-AtSBP1 complex identified Cys21 and Cys22 as being responsible for the binding of one selenium. These results were validated by site-directed mutagenesis. Selenium K-edge x-ray absorption near edge spectroscopy performed on the selenium-AtSBP1 complex demonstrated that AtSBP1 reduced SeO32− to form a R-S-Se(II)-S-R-type complex. The capacity of AtSBP1 to bind different metals and selenium is discussed with respect to the potential function of AtSBP1 in detoxification mechanisms and selenium metabolism. PMID:25274629

Novel selenium-doped hydroxyapatite coatings for biomedical applications.

PubMed

Rodríguez-Valencia, C; López-Álvarez, M; Cochón-Cores, B; Pereiro, I; Serra, J; González, P

2013-03-01

Nowadays there is a short-term need of investigating in orthopedic implants with a greater functionality, including an improved osseointegration and also antibacterial properties. The coating of metallic implants with hydroxyapatite (HA) remains to be the main proposal, but superior quality HA coatings with compositions closer to natural bone apatites, including carbonates, trace elements are required. Selenium is an essential nutrient in biological tissues and, at the same time, it also presents antibacterial properties. A pioneering study on the fabrication of selenium-doped carbonated hydroxyapatite (iHA:Se) coatings by Pulsed Laser Deposition (PLD) is presented. Different proportions of selenium were incorporated to obtain the iHA:Se coatings. Their physicochemical characterization, performed by SEM/EDS, FTIR, FT-Raman, Interferometric Profilometry and XPS, revealed typical columnar growth of HA in globular aggregates and the efficient incorporation of selenium into the HA coatings by the, most probably, substitution of SeO(3)(2-) groups in the CO(3)(2-) sites. Biological evaluation illustrated the absence of cytotoxicity when an amount of 0.6 at.% of Se was added to the iHA:Se coatings and excellent proliferation of the MC3T3-E1 preosteoblasts. Antibacterial properties were also proved with the inhibition of P. aeruginosa and S. aureus from establishing bacterial biofilms. Copyright © 2012 Wiley Periodicals, Inc.

Selenium and its relationship with selenoprotein P and glutathione peroxidase in children and adolescents with Hashimoto's thyroiditis and hypothyroidism.

PubMed

Nourbakhsh, Mitra; Ahmadpour, Fatemeh; Chahardoli, Behnam; Malekpour-Dehkordi, Zahra; Nourbakhsh, Mona; Hosseini-Fard, Seyed Reza; Doustimotlagh, Amirhossein; Golestani, Abolfazl; Razzaghy-Azar, Maryam

2016-03-01

The essential trace element selenium (Se) is required for thyroid hormone synthesis and metabolism. Selenoproteins contain selenocysteine and are responsible for biological functions of selenium. Glutathione peroxidase (GPx) is one of the major selenoproteins which protects the thyroid cells from oxidative damage. Selenoprotein P (SePP) is considered as the plasma selenium transporter to tissues. The aim of this study was to evaluate serum Se and SePP levels, and GPx activity in erythrocytes of children and adolescents with treated Hashimoto's thyroiditis, hypothyroidism, and normal subjects. Blood samples were collected from 32 patients with Hashimoto's thyroiditis, 20 with hypothyroidism, and 25 matched normal subjects. All the patients were under treatment with levothyroxine and at the time of analysis all of the thyroid function tests were normal. GPx enzyme activity was measured by spectrophotometry at 340 nm. Serum selenium levels were measured by high-resolution continuum source graphite furnace atomic absorption. SePP, TPOAb (anti-thyroid peroxidase antibody), and TgAb (anti-thyroglobulin antibody) were determined by ELISA kits. T4, T3, T3 uptake and TSH were also measured. Neither GPx activity nor SePP levels were significantly different in patients with Hashimoto's thyroiditis or hypothyroidism compared to normal subjects. Although GPx and SePP were both lower in patients with hypothyroidism compared to those with Hashimoto's thyroiditis and normal subjects but the difference was not significant. Serum Se levels also did not differ significantly in patients and normal subjects. We did not find any correlation between GPx or SePP with TPOAb or TgAb but SePP was significantly correlated with Se. Results show that in patients with Hashimoto's thyroiditis or hypothyroidism who have been under treatment with levothyroxine and have normal thyroid function tests, the GPx, SePP and Se levels are not significantly different. Copyright © 2015 Elsevier GmbH. All rights reserved.

Comparative study of a new organic selenium source v. seleno-yeast and mineral selenium sources on muscle selenium enrichment and selenium digestibility in broiler chickens.

PubMed

Briens, Mickaël; Mercier, Yves; Rouffineau, Friedrich; Vacchina, Veronique; Geraert, Pierre-André

2013-08-01

Two experiments were conducted on broiler chickens to compare the effect of a new organic Se source, 2-hydroxy-4-methylselenobutanoic acid (HMSeBA; SO), with two practical Se additives, sodium selenite (SS) and Se yeast (SY). The relative bioavailability of the different Se sources was compared on muscle (pectoralis major) total Se, selenomethionine (SeMet) and selenocysteine (SeCys) concentrations and apparent digestibility of total Se (ADSe). In the first experiment, from day (d) 0 to d21, Se sources were tested at different supplied levels and compared with an unsupplemented diet (NC). No significant effects were observed on growth performance during the experimental period. However, the different Se sources and levels improved muscle Se concentration compared with the NC, with a significant source effect in the following order: SS < SY < SO (P<0·05). Seleno-amino acids speciation results for NC, SY and SO at 0·3 mg Se/kg feed indicated that muscle Se was only present as SeMet or SeCys, showing a full conversion of Se by the bird. The second experiment (d0-d24) compared SS, SY or SO at 0·3 mg Se/kg feed. The ADSe measurements carried out between d20 and d23 were 24, 46 and 49% for SS, SY and SO, respectively, with significant differences between the organic and mineral Se sources (P<0·05). These results confirmed the higher bioavailability of organic Se sources compared with the mineral source and demonstrated a significantly better efficiency of HMSeBA compared with SY for muscle Se enrichment.

Biogenic selenium nanoparticles: current status and future prospects.

PubMed

Wadhwani, Sweety A; Shedbalkar, Utkarsha U; Singh, Richa; Chopade, Balu A

2016-03-01

Selenium nanoparticles (SeNPs) are gaining importance in the field of medicine owing to their antibacterial and anticancer properties. SeNPs are biocompatible and non-toxic compared to the counterparts, selenite (SeO3 (-2)) and selenate (SeO4 (-2)). They can be synthesized by physical, chemical, and biological methods and have distinct bright orange-red color. Biogenic SeNPs are stable and do not aggregate owing to natural coating of the biomolecules. Various hypotheses have been proposed to describe the mechanism of microbial synthesis of SeNPs. It is primarily a two-step reduction process from SeO4 (-2) to SeO3 (-2) to insoluble elemental selenium (Se(0)) catalyzed by selenate and selenite reductases. Phenazine-1-carboxylic acid and glutathione are involved in selenite reduction. Se factor A (SefA) and metalloid reductase Rar A present on the surface of SeNPs confer stability to the nanoparticles. SeNPs act as potent chemopreventive and chemotherapeutic agents. Conjugation with antibiotics enhances their anticancer efficacy. These also have applications in nanobiosensors and environmental remediation.

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.

Effect of sodium selenite on chosen anti- and pro-oxidative parameters in rats treated with lithium: A pilot study.

PubMed

Musik, Irena; Kocot, Joanna; Kiełczykowska, Małgorzata

2015-06-01

Selenium is an essential element of antioxidant properties. Lithium is widely used in medicine but its administration can cause numerous side effects including oxidative stress. The present study aimed at evaluating if sodium selenite could influence chosen anti- and pro-oxidant parameters in rats treated with lithium. The experiment was performed on four groups of Wistar rats: I (control) - treated with saline; II (Li) - treated with lithium (2.7 mgLi/kg b.w. as Li2CO3), III (Se) - treated with selenium (0.5 mgSe/kg b.w. as Na2SeO3), IV (Li+Se) - treated with Li2CO3 and Na2SeO3 together at the same doses as in group II and III, respectively. All treatments were performed by stomach tube for three weeks in form of water solutions. The following anti- and pro-oxidant parameters: total antioxidant status (TAS) value, catalase (CAT) activity, concentrations of ascorbic acid (AA) and malonyldialdehyde (MDA) in plasma as well as whole blood superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were measured. Selenium given alone markedly enhanced whole blood GPx and diminished plasma CAT vs. Lithium significantly decreased plasma CAT and slightly increased AA vs. Selenium co-administration restored these parameters to the values observed in control animals. Furthermore, selenium co-administration significantly increased GPx in Li-treated rats. All other parameters (TAS, SOD and MDA) were not affected by lithium and/or selenium. Further research seems to be warranted to decide if application of selenium as an adjuvant in lithium therapy is worth considering. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Adaptive dysfunction of selenoproteins from the perspective of the triage theory: why modest selenium deficiency may increase risk of diseases of aging.

PubMed

McCann, Joyce C; Ames, Bruce N

2011-06-01

The triage theory proposes that modest deficiency of any vitamin or mineral (V/M) could increase age-related diseases. V/M-dependent proteins required for short-term survival and/or reproduction (i.e., "essential") are predicted to be protected on V/M deficiency over other "nonessential" V/M-dependent proteins needed only for long-term health. The result is accumulation of insidious damage, increasing disease risk. We successfully tested the theory against published evidence on vitamin K. Here, we review about half of the 25 known mammalian selenoproteins; all of those with mouse knockout or human mutant phenotypes that could be used as criteria for a classification of essential or nonessential. Five selenoproteins (Gpx4, Txnrd1, Txnrd2, Dio3, and Sepp1) were classified as essential and 7 (Gpx1, Gpx 2, Gpx 3, Dio1, Dio2, Msrb1, and SelN) nonessential. On modest selenium (Se) deficiency, nonessential selenoprotein activities and concentrations are preferentially lost, with one exception (Dio1 in the thyroid, which we predict is conditionally essential). Mechanisms include the requirement of a special form of tRNA sensitive to Se deficiency for translation of nonessential selenoprotein mRNAs except Dio1. The same set of age-related diseases and conditions, including cancer, heart disease, and immune dysfunction, are prospectively associated with modest Se deficiency and also with genetic dysfunction of nonessential selenoproteins, suggesting that Se deficiency could be a causal factor, a possibility strengthened by mechanistic evidence. Modest Se deficiency is common in many parts of the world; optimal intake could prevent future disease.

Exposure to polycyclic aromatic hydrocarbons, arsenic and environmental tobacco smoke, nutrient intake, and oxidative stress in Japanese preschool children.

PubMed

Mori, Takuya; Yoshinaga, Jun; Suzuki, Kei; Mizoi, Miho; Adachi, Shu-Ichi; Tao, Hiroaki; Nakazato, Tetsuya; Li, Yun-Shan; Kawai, Kazuaki; Kasai, Hiroshi

2011-07-01

The association between oxidative stress and exposure to environmental chemicals was assessed in a group of Japanese preschool children. The concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG), 1-hydroxypyrene (1-OHP), inorganic arsenic (iAs) and monomethylarsonic acid (MMA), and cotinine in spot urine samples, collected from 134 children (3-6 yrs) from a kindergarten in Kanagawa, Japan, were measured as biomarkers of oxidative stress or exposure to environmental chemicals. For 76 subjects of the 134, intakes of anti-oxidant nutrients (vitamins A, C, and E, manganese, copper, zinc and selenium (Se)) were estimated from a food consumption survey carried out 2-4 weeks after urine sampling and by urine analysis (Se). The median (min-max) creatinine-corrected concentrations of urinary biomarkers were 4.45 (1.98-12.3), 0.127 (0.04-2.41), 4.78 (1.18-12.7), and 0.62 (<0.6-19.0) μg/g cre for 8-OHdG, 1-OHP, iAs+MMA, and cotinine, respectively. Multiple regression analysis was carried out using 8-OHdG concentration as a dependent variable and urinary biomarkers of exposure and Se intake, intakes of vitamins and biological attributes of the subjects as independent variables. To explain 8-OHdG concentrations, intake of vitamin A and age were significant variables with negative coefficients, while 1-OHP concentration had a positive coefficient. These results indicated that oxidative stress of children is affected by chemical exposure at environmental levels, by nutrient intake and by physiological factors in a complex manner. On the other hand, unstable statistical results due to sub-grouping of subject, based on the availability of food consumption data, were found: the present results should further be validated by future studies with suitable research design. Copyright © 2011 Elsevier B.V. All rights reserved.

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

PubMed

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).

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).

SPECIATION OF SELENIUM AND ARSENIC COMPOUNDS BY CAPILLARY...

EPA Science Inventory

Capillary electrophoresis (CE) with hydride generation inductively coupled plasma mass spectrometry was used to determine four arsenicals and two selenium species. Selenate (SeVI) was reduced on-line to selenite (SeIV) by mixing the CE effluent with concentrated HCl. A microporou...

Bioaccessibility of selenium, selenomethionine and selenocysteine from foods and influence of heat processing on the same.

PubMed

Khanam, Anjum; Platel, Kalpana

2016-03-01

Selenium (Se) is an essential nutrient with diverse physiological functions. The selenium content of commonly consumed cereals, pulses and green leafy vegetables (GLV) was determined. Bioaccessibility of Se, and its organic forms selenomethionine (SeMet), and selenocysteine (SeCys2) was also examined, and the effect of heat processing on the same was studied. The bioaccessibility of Se in cereals ranged from 10% to 24%, that of pulses was between 12% and 29%, and of GLV, 10-31%. The concentration of SeMet in the dialysates of the cereals, pulses and GLV ranged from 5.15 to 28.7, 2.7 to 36.2, and 0.03 to 5ngg(-1), respectively. The concentration of SeCys2 in the dialysates of the foods examined was negligible. Heat processing significantly decreased the bioaccessibility of Se, SeMet and SeCys2. This is the first report on the bioaccessibility of Se and its major organic forms from commonly consumed staples, and the effect of heat processing on the same. Copyright © 2015 Elsevier Ltd. All rights reserved.

The behavior of dissolved inorganic selenium in the Changjiang Estuary

NASA Astrophysics Data System (ADS)

Chang, Yan; Zhang, Jing; Qu, Jianguo; Zhang, Guosen; Zhang, Anyu; Zhang, Ruifeng

2016-02-01

To investigate the behavior of inorganic selenium species in the Changjiang Estuary, samples were taken during summer (July 2011) and winter (March 2012). Dissolved inorganic selenium (DISe) concentrations averaged 1.79 nmol/L in summer and 1.24 nmol/L in winter; the average selenite [Se(IV)] to selenate [Se(VI)] ratio [Se(IV)/Se(VI)] was 0.42 in summer and 0.61 in winter. The data show that Se(IV) and Se(VI) concentrations in the estuary behaved strictly conservatively during winter but non-conservatively during summer due to adsorption by suspended particulate matter (SPM) and assimilation by phytoplankton. In addition, the Se concentration distributions in the Changjiang Estuary were controlled by three water masses, each with a specific Se(IV)/Se(VI) ratio "signature": the Changjiang Water input, the Taiwan Warm Current, and the Yellow Sea Coastal Current. The Se(IV) concentrations were related to the nitrate, silicate, and phosphate concentrations in the estuary. The DISe and Se(IV) concentrations were comparable to those found in other coastal regions and estuaries, which were considered to be natural levels.

Antioxidant Intake and Pancreatic Cancer Risk: the VITamins And Lifestyle (VITAL) Study

PubMed Central

Han, Xuesong; Li, Jingjing; Brasky, Theodore M.; Xun, Pengcheng; Stevens, June; White, Emily; Gammon, Marilie D.; He, Ka

2012-01-01

Background Oxidative stress causes damage to many components of human cells (i.e., proteins, lipids, and DNA) and is involved in carcinogenesis. Nutrients with antioxidant properties may protect against oxidative stress. We examined intake of antioxidants from diet and supplements in relation to pancreatic cancer risk among participants of the VITamins And Lifestyle (VITAL) Study. Methods Participants were 77,446 men and women, ages 50–76 years, who were residents of western Washington State and completed a baseline questionnaire between 2000 and 2002. Participants reported usual diet over the past year and use of supplements over the past 10 years, in addition to demographic and lifestyle factors. During a median follow-up of 7.1 years, 184 participants developed pancreatic adenocarcinoma. Cox regression models were used to estimate multivariable-adjusted hazard ratios (HR) and 95% confidence intervals (CI) for seven antioxidants: β-carotene, lutein and zeaxanthin, lycopene, vitamin C, vitamin E, selenium and zinc. Results We observed an inverse association between dietary selenium and pancreatic cancer risk (medium vs. low intake: HR 0.58, 95% CI 0.35–0.94; high vs. low intake: HR 0.44, 95% CI 0.23–0.85; p-trend = 0.01); however, when supplemental and dietary exposures were combined, the association was no longer statistically significant. Conclusions Dietary selenium intake is inversely associated with risk of pancreatic cancer and the observed association is attenuated by selenium supplementation. PMID:23280534

The investigation of the possible protective influence of selenium on antioxidant barrier in heart of rats exposed to lithium.

PubMed

Musik, Irena; Kocot, Joanna; Lewandowska, Anna; Żelazowska, Renata; Kiełczykowska, Małgorzata

2015-07-01

Selenium is an essential element possessing antioxidant properties and the treatment with it has displayed protective effects against toxicity of different substances occurring in the environment and food as well as against the side effects of some drugs. Lithium is used in medicine although numerous side effects can occur during therapy, including disturbances of the heart. For these reasons studies to find protective adjuvants have been performed. In the current study the possibility of selenium (as sodium selenite) application as a protective adjuvant in lithium treatment was studied. Male Wistar rats were treated: control - with saline; Li-group - with Li2CO3 (2.7 mg Li/kg b.w.); Se-group - with Na2SeO3 (0.5 mg Se/kg b.w.); Li+Se-group simultaneously with Li2CO3 and Na2SeO3 (2.7 mg Li/kg b.w. and 0.5 mg Se/kg b.w., respectively) by a stomach tube for a period of three weeks, once a day. In heart homogenate activities of antioxidant enzymes - catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx), concentrations of low-molecular-weight antioxidants - ascorbic acid (AA) and reduced glutathione (GSH) as well as total antioxidant status (TAS) values were determined. GPx/SOD and CAT/SOD ratios were evaluated. In comparison with control selenium caused no significant changes of the studied parameters except for GPx, whereas lithium slightly disturbed TAS and markedly GPx, CAT and CAT/SOD ratio. In Li-treated rats co-administration of selenium displayed tendency towards restoring the impaired parameters. The results suggest that research on selenium application as an adjuvant in lithium therapy is worthy to be continued. Copyright © 2015 Elsevier Inc. All rights reserved.

Cytotoxicity and therapeutic effect of irinotecan combined with selenium nanoparticles.

PubMed

Gao, Fuping; Yuan, Qing; Gao, Liang; Cai, Pengju; Zhu, Huarui; Liu, Ru; Wang, Yaling; Wei, Yueteng; Huang, Guodong; Liang, Jian; Gao, Xueyun

2014-10-01

Although chemotherapeutic drugs are widely applied for clinic tumor treatment, severe toxicity restricts their therapeutic efficacy. In this study, we reported a new form of selenium, selenium nanoparticles (Nano Se) which have significant lower toxicity and acceptable bioavailability. We investigated Nano Se as chemotherapy preventive agent to protect against toxicities of anticancer drug irinotecan and synergistically enhance the anti-tumor treatment effect in vitro and in vivo. The underlying mechanisms were also investigated. The combination of Nano Se and irinotecan showed increased cytotoxic effect with HCT-8 tumor cells likely by p53 mediated apoptosis. Nano Se inhibited growth of HCT-8 tumor cells partially through caspases mediated apoptosis. In vivo experiment showed Nano Se at a dose of 4 mg/kg/day significantly alleviated adverse effects induced by irinotecan (60 mg/kg) treatment. Nano Se alone treatment did not induce any toxic manifestations. The combination of Nano Se and irinotecan dramatically inhibited tumor growth and significantly induced apoptosis of tumor cells in HCT-8 cells xenografted tumor. Tumor inhibition rate was about 17.2%, 48.6% and 62.1% for Nano Se, irinotecan and the combination of Nano Se and irinotecan, respectively. The beneficial effects of Nano Se for tumor therapy were mainly ascribed to selectively regulating Nrf2-ARE (antioxidant responsive elements) pathway in tumor tissues and normal tissues. Our results suggest Nano Se is a promising selenium species with potential application in cancer treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

Se(VI) Reduction and the Precipitation of Se(0) Precipitation by the Facultative Bacterium Enterobacter Cloacae SLD1a-1 is Regulated by FNR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yee,N.; Ma, J.; Dalia, A.

2007-01-01

The fate of selenium in the environment is controlled, in part, by microbial selenium oxyanion reduction and Se(0) precipitation. In this study, we identified a genetic regulator that controls selenate reductase activity in the Se-reducing bacterium Enterobacter cloacae SLD1a-1. Heterologous expression of the global anaerobic regulatory gene fnr (fumarate nitrate reduction regulator) from E. cloacae in the non-Se-reducing strain Escherichia coli S17-1 activated the ability to reduce Se(VI) and precipitate insoluble Se(0) particles. Se(VI) reduction by E. coli S17-1 containing the fnr gene occurred at rates similar to those for E. cloacae, with first-order reaction constants of k = 2.07more » x 10{sup -2} h{sup -1} and k = 3.36 x 10{sup -2} h{sup -1}, respectively, and produced elemental selenium particles with identical morphologies and short-range atomic orders. Mutation of the fnr gene in E. cloacae SLD1a-1 resulted in derivative strains that were deficient in selenate reductase activity and unable to precipitate elemental selenium. Complementation by the wild-type fnr sequence restored the ability of mutant strains to reduce Se(VI). Our findings suggest that Se(VI) reduction and the precipitation of Se(0) by facultative anaerobes are regulated by oxygen-sensing transcription factors and occur under suboxic conditions.« less

Chemical form of selenium affects its uptake, transport and glutathione peroxidase activity in the human intestinal Caco-2 cell model

USDA-ARS?s Scientific Manuscript database

Determining the effect of selenium (Se) chemical form on uptake and transport in human intestinal cells is critical to assess Se bioavailability. In the present study, we measured the uptake and transport of various Se compounds in the human intestinal Caco-2 cell model. We found that two sources...

Selenoprotein W depletion induces a p53- and p21-dependent delay in cell cycle progression in RWPE-1 prostate epithelial cells

USDA-ARS?s Scientific Manuscript database

The anticancer activity of selenium (Se) has been demonstrated in myriad animal and in vitro studies, yet the mechanisms remain obscure. The relative importance of small selenium compounds versus selenoproteins in the cancer-protective activity of Se is unresolved, but the main form of Se in animal ...

Effects of Various Doses of Selenite on Stinging Nettle (Urtica dioica L.)

PubMed Central

Krystofova, Olga; Adam, Vojtech; Babula, Petr; Zehnalek, Josef; Beklova, Miroslava; Havel, Ladislav; Kizek, Rene

2010-01-01

The aim of this study was to investigate the effects of selenium (Se) on the growth, accumulation and possible mechanisms of Se transport in certain parts (roots, leaves, stamp and apex) of nettle (Urtica dioica L.) plants. Se was supplemented by one-shot and two repeated doses to the soil (2.0 and 4.0 mg Se per kg of substrate). Selenium content in roots increased linearly with dose and was significantly higher compared to other plant parts of interest. However, growth of the above-ground parts of plant as well as roots was slightly inhibited with increasing selenium concentration in comparison to the untreated plants. The content of phytochelatin2, a low molecular mass peptide containing a sulfhydryl group, correlated well with the Se content. This suggests a possible stimulation of synthesis of this plant peptide by Se. PMID:21139861

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

2017-06-01

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. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

Anti-biofilm activity of biogenic selenium nanoparticles and selenium dioxide against clinical isolates of Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis.

PubMed

Shakibaie, Mojtaba; Forootanfar, Hamid; Golkari, Yaser; Mohammadi-Khorsand, Tayebe; Shakibaie, Mohammad Reza

2015-01-01

The aim of the present study was to investigate the anti-biofilm activity of biologically synthesized selenium nanoparticles (Se NPs) against the biofilm produced by clinically isolated bacterial strains compared to that of selenium dioxide. Thirty strains of Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis were isolated from various specimens of the patients hospitalized in different hospitals (Kerman, Iran). Quantification of the biofilm using microtiter plate assay method introduced 30% of S. aureus, 13% of P. aeruginosa and 17% of P. mirabilis isolates as severely adherent strains. Transmission electron micrograph (TEM) of the purified Se NPs (produced by Bacillus sp. MSh-1) showed individual and spherical nano-structure in the size range of 80-220nm. Obtained results of the biofilm formation revealed that selenium nanoparticles inhibited the biofilm of S. aureus, P. aeruginosa, and P. mirabilis by 42%, 34.3%, and 53.4%, respectively, compared to that of the non-treated samples. Effect of temperature and pH on the biofilm formation in the presence of Se NPs and SeO2 was also evaluated. Copyright © 2014 Elsevier GmbH. All rights reserved.

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.

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. Published by Elsevier Ltd.

Evaluation of selenium in dietary supplements using elemental speciation

PubMed Central

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

2016-01-01

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. PMID:27719915

Enhancing nutritiousness of lamb meat and preventing selenium deficiency.

USDA-ARS?s Scientific Manuscript database

Lamb meat is a naturally flavorful and nutritious product. Our research indicates that feeding a specific wheat-milling coproduct will enhance the nutritiousness of lamb, potentially add monetary value to lamb, and prevent Se deficiency. Selenium is an essential micromineral, and Se supplementation ...

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.

Selenium isotope ratios as indicators of selenium sources and oxyanion reduction

USGS Publications Warehouse

Johnson, T.M.; Herbel, M.J.; Bullen, T.D.; Zawislanski, P.T.

1999-01-01

Selenium stable isotope ratio measurements should serve as indicators of sources and biogeochemical transformations of Se. We report measurements of Se isotope fractionation during selenate reduction, selenite sorption, oxidation of reduced Se in soils, and Se volatilization by algae and soil samples. These results, combined with previous work with Se isotopes, indicate that reduction of soluble oxyanions is the dominant cause of Se isotope fractionation. Accordingly, Se isotope ratios should be useful as indicators of oxyanion reduction, which can transform mobile species to forms that are less mobile and less bioavailable. Additional investigations of Se isotope fractionation are needed to confirm this preliminary assessment. We have developed a new method for measurement of natural Se isotope ratio variation which requires less than 500 ng Se per analysis and yields ??0.2??? precision on 80Se/76Se. A double isotope spike technique corrects for isotopic fractionation during sample preparation and mass spectrometry. The small minimum sample size is important, as Se concentrations are often below 1 ppm in solids and 1 ??g/L in fluids. The Se purification process is rapid and compatible with various sample matrices, including acidic rock or sediment digests.

Selenium isotope ratios as indicators of selenium sources and oxyanion reduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, T.M.; Herbel, M.J.; Bullen, T.D.

1999-09-01

Selenium stable isotope ratio measurements should serve as indicators of sources and biogeochemical transformations of Se. The authors report measurements of Se isotope fractionation during selenate reduction, selenite sorption, oxidation of reduced Se in soils, and Se volatilization by algae and soil samples. These results, combined with previous work with Se isotopes, indicate that reduction of soluble oxyanions is the dominant cause of Se isotope fractionation. Accordingly, Se isotope ratios should be useful as indicators of oxyanion reduction, which can transform mobile species to forms that are less mobile and less bioavailable. Additional investigations of Se isotope fractionation are neededmore » to confirm this preliminary assessment. The authors have developed a new method for measurement of natural Se isotope ratio variation which requires less than 500 ng Se per analysis and yields {+-}0.2% precision on {sup 80}Se/{sup 76}Se. A double isotope spike technique corrects for isotopic fractionation during sample preparation and mass spectrometry. The small minimum sample size is important, as Se concentrations are often below 1 ppm in solids and 1 {micro}g/L in fluids. The Se purification process is rapid and compatible with various sample matrices, including acidic rock or sediment digests.« less

[The selenium content of food products and the blood of inhabitants of Norilsk].

PubMed

Golubkina, N A; Shagova, M V; Spirichev, V B; Khristenko, P P; Alftan, D; Laaksonen, P; Muratov, Iu M; Vachaeva, N N

1992-01-01

The intake of trace element selenium by Norilsk citizens was assessed by its levels in the serum, food and soil. It was found that soil and food made in the Norilsk region are rich in selenium, its serum concentration in the population is normal (102 micrograms/l). References to such values for the Moscow and Zaporoje (Ukraine) regions are made. Low selenium levels in the serum may be indicative of pulmonary diseases.

No-carrier-added labeling of the neuroprotective Ebselen with selenium-73 and selenium-75.

PubMed

Helfer, Andreas; Ermert, Johannes; Humpert, Sven; Coenen, Heinz H

2015-03-01

Selenium-73 is a positron emitting non-standard radionuclide, which is suitable for positron emission tomography. A copper-catalyzed reaction allowed no-carrier-added labeling of the anti-inflammatory seleno-organic compound Ebselen with (73) Se and (75) Se under addition of sulfur carrier in a one-step reaction. The new authentically labeled radioselenium molecule is thus available for preclinical evaluation and positron emission tomography studies. Copyright © 2015 John Wiley & Sons, Ltd.

Electrochemical vapor generation of selenium species after online photolysis and reduction by UV-irradiation under nano TiO2 photocatalysis and its application to selenium speciation by HPLC coupled with atomic fluorescence spectrometry.

PubMed

Liang, Jing; Wang, Qiuquan; Huang, Benli

2005-01-01

An online UV photolysis and UV/TiO2 photocatalysis reduction device (UV-UV/TiO2 PCRD) and an electrochemical vapor generation (ECVG) cell have been used for the first time as an interface between high-performance liquid chromatography (HPLC) and atomic fluorescence spectrometry (AFS) for selenium speciation. The newly designed ECVG cell of approximately 115 microL dead volume consists of a carbon fiber cathode and a platinum loop anode; the atomic hydrogen generated on the cathode was used to reduce selenium to vapor species for AFS determination. The noise was greatly reduced compared with that obtained by use of the UV-UV/TiO2 PCRD-KBH4-acid interface. The detection limits obtained for seleno-DL: -cystine (SeCys), selenite (Se(IV)), seleno-DL: -methionine (SeMet), and selenate (Se(VI)) were 2.1, 2.9, 4.3, and 3.5 ng mL(-1), respectively. The proposed method was successfully applied to the speciation of selenium in water-soluble extracts of garlic shoots cultured with different selenium species. The results obtained suggested that UV-UV/TiO2 PCRD-ECVG should be an effective interface between HPLC and AFS for the speciation of elements amenable to vapor generation, and is superior to methods involving KBH4.

Synthesis, purification, and structural characterization of the dimethyldiselenoarsinate anion.

PubMed

Gailer, Jürgen; George, Graham N; Harris, Hugh H; Pickering, Ingrid J; Prince, Roger C; Somogyi, Arpad; Buttigieg, Gavin A; Glass, Richard S; Denton, M Bonner

2002-10-21

A novel arsenic-selenium solution species was synthesized by reacting equimolar sodium selenite and sodium dimethylarsinate with 10 mol equiv of glutathione (pH 7.5) in aqueous solution. The solution species showed a single (77)Se NMR resonance at 112.8 ppm. Size-exclusion chromatography (SEC) using an inductively coupled plasma atomic emission spectrometer (ICP-AES) as the simultaneous arsenic-, selenium-, sulfur-, and carbon-specific detector revealed an arsenic-selenium moiety with an As:Se molar ratio of 1:2. Electrospray ionization mass spectrometry (ESI-MS) of the chromatographically purified compound showed a molecular mass peak at m/z 263 in the negative ion mode. Fragmentation of the parent ion (ESI-MS-MS) produced (CH(3))(2)As(-) and Se(2)(-) fragments. Arsenic and selenium extended X-ray absorption fine structure spectroscopy (EXAFS) of the purified species revealed two As-C interactions at 1.943 A and two As-Se interactions at 2.279 A. On the basis of these results this novel solution species is identified as the dimethyldiselenoarsinate anion.

Selenium inhibits the phytotoxicity of mercury in garlic (Allium sativum).

PubMed

Zhao, Jiating; Gao, Yuxi; Li, Yu-Feng; Hu, Yi; Peng, Xiaomin; Dong, Yuanxing; Li, Bai; Chen, Chunying; Chai, Zhifang

2013-08-01

To investigate the influence of selenium on mercury phytotoxicity, the levels of selenium and mercury were analyzed with inductively coupled plasma-mass spectrometry (ICP-MS) in garlic tissues upon exposure to different dosages of inorganic mercury (Hg(2+)) and selenite (SeO3(2-)) or selenate (SeO4(2-)). The distributions of selenium and mercury were examined with micro-synchrotron radiation X-ray fluorescence (μ-SRXRF), and the mercury speciation was investigated with micro-X-ray absorption near edge structure (μ-XANES). The results show that Se at higher exposure levels (>1mg/L of SeO3(2-) or SeO4(2-)) would significantly inhibit the absorption and transportation of Hg when Hg(2+) levels are higher than 1mg/L in culture media. SeO3(2-) and SeO4(2-) were found to be equally effective in reducing Hg accumulation in garlic. The inhibition of Hg uptake by Se correlates well with the influence of Se on Hg phytotoxicity as indicated by the growth inhibition factor. Elemental imaging using μ-SRXRF also shows that Se could inhibit the accumulation and translocation of Hg in garlic. μ-XANES analysis shows that Hg is mainly present in the forms of Hg-S bonding as Hg(GSH)2 and Hg(Met)2. Se exposure elicited decrease of Hg-S bonding in the form of Hg(GSH)2, together with Se-mediated alteration of Hg absorption, transportation and accumulation, may account for attenuated Hg phytotoxicity by Se in garlic. Copyright © 2013 Elsevier Inc. All rights reserved.

Graphene-Selenium Hybrid Microballs as Cathode Materials for High-performance Lithium-Selenium Secondary Battery Applications.

PubMed

Youn, Hee-Chang; Jeong, Jun Hui; Roh, Kwang Chul; Kim, Kwang-Bum

2016-08-02

In this study, graphene-selenium hybrid microballs (G-SeHMs) are prepared in one step by aerosol microdroplet drying using a commercial spray dryer, which represents a simple, scalable continuous process, and the potential of the G-SeHMs thus prepared is investigated for use as cathode material in applications of lithium-selenium secondary batteries. These morphologically unique graphene microballs filled with Se particles exhibited good electrochemical properties, such as high initial specific capacity (642 mA h g(-1) at 0.1 C, corresponding to Se electrochemical utilisation as high as 95.1%), good cycling stability (544 mA h g(-1) after 100 cycles at 0.1 C; 84.5% retention) and high rate capability (specific capacity of 301 mA h g(-1) at 5 C). These electrochemical properties are attributed to the fact that the G-SeHM structure acts as a confinement matrix for suppressing the dissolution of polyselenides in the organic electrolyte, as well as an electron conduction path for increasing the transport rate of electrons for electrochemical reactions. Notably, based on the weight of hybrid materials, electrochemical performance is considerably better than that of previously reported Se-based cathode materials, attributed to the high Se loading content (80 wt%) in hybrid materials.

Field evidence of selenium bioreduction in a uranium-contaminated aquifer.

PubMed

Williams, Kenneth H; Wilkins, Michael J; N'Guessan, A Lucie; Arey, Bruce; Dodova, Elena; Dohnalkova, Alice; Holmes, Dawn; Lovley, Derek R; Long, Philip E

2013-06-01

Removal of selenium from groundwater was documented during injection of acetate into a uranium-contaminated aquifer near Rifle, Colorado (USA). Bioreduction of aqueous selenium to its elemental form (Se0) concentrated it within mineralized biofilms affixed to tubing used to circulate acetate-amended groundwater. Scanning and transmission electron microscopy revealed close association between Se0 precipitates and cell surfaces, with Se0 aggregates having a diameter of 50-60 nm. Accumulation of Se0 within biofilms occurred over a three-week interval at a rate of c. 9 mg Se0 m(-2) tubing day(-1). Removal was inferred to result from the activity of a mixed microbial community within the biofilms capable of coupling acetate oxidation to the reduction of oxygen, nitrate and selenate. Phylogenetic analysis of the biofilm revealed a community dominated by strains of Dechloromonas sp. and Thauera sp., with isolates exhibiting genetic similarity to the latter known to reduce selenate to Se0. Enrichment cultures of selenate-respiring microorganisms were readily established using Rifle site groundwater and acetate, with cultures dominated by strains closely related to D. aromatica (96-99% similarity). Predominance of Dechloromonas sp. in recovered biofilms and enrichments suggests this microorganism may play a role in the removal of selenium oxyanions present in Se-impacted groundwaters and sediments.

Field evidence of selenium bioreduction in a uranium-contaminated aquifer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams , K. H.; Wilkins, Michael J.; N'Guessan, A. Lucie

2013-06-01

Removal of selenium from groundwater was documented during injection of acetate into a uraniumcontaminated aquifer near Rifle, Colorado (USA). Bioreduction of aqueous selenium to its elemental form (Se0) concentrated it within mineralized biofilms affixed to tubing used to circulate acetate-amended groundwater. Scanning and transmission electron microscopy revealed close association between Se0 precipitates and cell surfaces, with Se0 aggregates having a diameter of 50-60 nm. Accumulation of Se0 within biofilms occurred over a three-week interval at a rate of c. 9 mg Se0m-2 tubing day-1. Removal was inferred to result from the activity of a mixed microbial community within the biofilmsmore » capable of coupling acetate oxidation to the reduction of oxygen, nitrate and selenate. Phylogenetic analysis of the biofilm revealed a community dominated by strains of Dechloromonas sp. and Thauera sp., with isolates exhibiting genetic similarity to the latter known to reduce selenate to Se0. Enrichment cultures of selenate-respiring microorganisms were readily established using Rifle site groundwater and acetate, with cultures dominated by strains closely related to D. aromatica (96-99% similarity). Predominance of Dechloromonas sp. in recovered biofilms and enrichments suggests this microorganism may play a role in the removal of selenium oxyanions present in Se-impacted groundwaters and sediments.« less

Selenium speciation in radix puerariae using ultrasonic assisted extraction combined with reversed phase high performance liquid chromatography-inductively coupled plasma-mass spectrometry after magnetic solid-phase extraction with 5-sulfosalicylic acid functionalized magnetic nanoparticles

NASA Astrophysics Data System (ADS)

Cao, Yupin; Yan, Lizhen; Huang, Hongli; Deng, Biyang

2016-08-01

A new method for determination of selenium species in radix puerariae was described. The method consists of sample enrichment with 5-sulfosalicylic acid (SSA)-functionalized silica-coated magnetic nanoparticles (SMNPs), high performance liquid chromatography (HPLC) separation, and online detection using inductively coupled plasma mass spectrometry (ICP-MS). The selenium species were extracted using ultrasonic extraction system with a mixture of protease K and lipase. The SSA-SMNPs were used to enrich trace amounts of selenite [Se(IV)], selenate [Se(VI)], selenomethionine (SeMet), and selenocystine (SeCys2) from lower selenium containing samples. Under the optimal conditions, the limits of detection (3σ) for SeCys2, Se(IV), SeMet and Se(VI) were observed as 0.0023, 0.0015, 0.0043, and 0.0016 ng mL- 1, respectively. The RSD values (n = 6) of method for intraday were observed between 0.5% and 0.9%. The RSD values of method for interday were less than 1.3%. The linear concentration ranges for SeCys2, Se(IV), SeMet and Se(VI) were 0.008-1000, 0.005-200, 0.015-500 and 0.006-200 ng mL- 1, respectively. The detection limits of this method were improved by 10 times due to the enrichment with the SSA-SMNP extraction. The contents of SeCys2, Se(IV), SeMet, and Se(VI) in radix puerariae were determined as 0.0140, 0.171, 0.0178, and 0.0344 μg g- 1, respectively. The recoveries were in the range of 95.6%-99.4% and the RSDs (n = 6) of recoveries were less than 1.5%.

Selenium deposition kinetics of different selenium sources in muscle and feathers of broilers.

PubMed

Couloigner, Florian; Jlali, Maamer; Briens, Mickael; Rouffineau, Friedrich; Geraert, Pierre-André; Mercier, Yves

2015-11-01

The objective of this study was to determine selenium (Se) deposition kinetics in muscles and feathers of broilers in order to develop a rapid method to compare bioavailability of selenium sources. Different Se sources such as 2-hydroxy-4-methylselenobutanoic acid (HMSeBA, SO), sodium selenite (SS) and seleno-yeast (SY) were compared for their kinetics on Se deposition in muscles and feathers in broiler chicks from 0 to 21 d of age. A total of 576 day-old broilers were divided into four treatments with 8 replicates of 18 birds per pen. The diets used in the experiment were a negative control (NC) not supplemented with Se and 3 diets supplemented with 0.2 mg Se/kg as SS, SY or SO. Total Se content in breast muscle and feathers were assessed on days 0, 7, 14 and 21. At 7 d of age, SO increased muscle Se content compared to D0 (P < 0.05), whereas with the other treatments, muscle Se concentration decreased (P < 0.05). After 21 days, organic Se sources maintained (SY) or increased (SO) (P < 0.05) breast muscle Se concentration compared to hatch value whereas inorganic source (SS) or non-supplemented group (NC) showed a significant decrease in tissue Se concentration (P < 0.05). At D21, Se contents of muscle and feathers were highly correlated (R(2) = 0.927; P < 0.0001). To conclude, these results indicate that efficiency of different Se sources can be discriminated through a 7 d using muscle Se content in broiler chickens. Muscle and feathers Se contents were highly correlated after 21 days. Also feather sampling at 21 days of age represents a reliable and non-invasive procedure for Se bioefficacy comparison. © 2015 Poultry Science Association Inc.

Urinary excretion of platinum, arsenic and selenium of cancer patients from the Antofagasta region in Chile treated with platinum-based drugs

PubMed Central

2012-01-01

Background Arsenic exposure increases the risk of non-cancerous and cancerous diseases. In the Antofagasta region in Chile, an established relationship exists between arsenic exposure and the risk of cancer of the bladder, lung and skin. Platinum-based drugs are first-line treatments, and many works recognise selenium as a cancer-fighting nutrient. We characterised the short-term urinary excretion amounts of arsenic, selenium and platinum in 24-h urine samples from patients with lung cancer and those with cancer other than lung treated with cisplatin or/and carboplatin. As - Se - Pt inter-element relationships were also investigated. Results The amounts of platinum excreted in urine were not significantly different between patients with lung cancer and those with other cancers treated with cisplatin, despite the significant variation in platinum amounts supplied from platinum-based drugs. In general, the analytical amounts of excreted selenium were greater than those for arsenic, which could imply that platinum favours the excretion of selenium. For other types of cancers treated with drugs without platinum, excretion of selenium was also greater than that of arsenic, suggesting an antagonist selenium-anti-cancer drug relationship. Conclusions Regards the baseline status of patients, the analytical amounts of excreted Se is greater than those for As, particularly, for cisplatin chemotherapy. This finding could imply that for over the As displacement Pt favours the excretion of Se. The analytical amounts of excreted Se were greater than those for As, either with and without Pt-containing drugs, suggesting an antagonist Se-anti-cancer drug relationship. However, it seemed that differences existed between As - Se - Pt inter-element associations in patients treated for lung cancer in comparison with those treated for cancer other than lung. Therefore, knowledge obtained in this work, can contribute to understanding the arsenic cancer mechanism and the As - Se - Pt inter-element association for lung cancer and other types of cancer, which in some cases respond at a linear mathematical model. PMID:22546077

Selenium accumulation in plants--phytotechnological applications and ecological implications.

PubMed

Valdez Barillas, José Rodolfo; Quinn, Colin F; Pilon-Smits, Elizabeth A H

2011-01-01

Selenium (Se) is an essential trace element for many organisms including humans, yet toxic at higher levels. Both Se deficiency and toxicity are problems worldwide. Since plants readily accumulate and volatilize Se, they may be used both as a source of dietary Se and for removing excess Se from the environment. Plant species differ in their capacity to metabolize and accumulate Se, from non-Se accumulators (< 100 mg Se/kg DW), to Se-accumulators (100-1000 mg Se/kg DW) to Se hyperaccumulators (> 1,000 mg Se/kg DW). Here we review plant mechanisms of Se metabolism in these various plant types. We also summarize results from genetic engineering that have led to enhanced plant Se accumulation, volatilization, and/or tolerance, including field studies. Before using Se-accumulating plants at a large scale we need to evaluate the ecological implications. Research so far indicates that plant Se accumulation significantly affects the plant's ecological interactions below and above ground. Selenium canprotect plants from fungal pathogens and from a variety of invertebrate and vertebrate herbivores, due to both deterrence and toxicity. However, specialist (Se-tolerant herbivores), detritivores and endophytes appear to utilize Se hyperaccumulator plants as a resource. These findings are relevant for managing phytoremediation of Se and similar elements.

Ameliorative effect of selenium in cisplatin-induced testicular damage in rats.

PubMed

Simsek, Nejdet; Koc, Akif; Karadeniz, Ali; Yildirim, Mehmet Erol; Celik, Hüseyin Tuğrul; Sari, Erhan; Kara, Adem

2016-04-01

In this study, we investigated the protective effect of selenium (Se) on cisplatin (Cis) induced testicular damage using histopathological, immunohistochemical and biochemical approaches. Twenty-one male Wistar rats were equally divided into three groups of seven rats each: control (C), Cis, and Cis+Se. Cis and Cis+Se group rats received Cis at a dose of 12mg/kg b.w./day, intraperitoneally for 3 consecutive days. Cis+Se group rats received selenium via oral gavage 3mg/kg/day (twice-a day as 1.5mg/kg) until 11th consecutive days starting at 5 days before cisplatin injection. C group received only 0.9% NaCl intraperitoneally and orally at same time and at equal volume. After the treatment, the histopathological, immunohistochemical and biochemical examinations were performed. In seminiferous tubules of Cis treated rats were observed the most consistent findings characterized with vacuolization, desquamation, disorganization, and also was a considerable reduction in elongated spermatids, however the Cis+Se group exhibited improved histopathologic changes. In the immunohistochemical examinations, caspase-3 immunopositive cells displayed higher in the Cis group according to C and Cis+Se groups. Bcl-2 and NF-κB staining revealed a moderate number in the C group and significantly fewer in the Cis group compared to the Cis+Se groups. Additionally, MDA levels were also significantly increased in the Cis group in comparison to Control group, but pretreatment with selenium prevented elevation of MDA levels significantly in Cis+Se group rats. This study indicates that Cis-treatment induced testicular apoptosis and lipid peroxidation, and combined treatment with selenium prevented severity of the toxicity in rats. Copyright © 2016 Elsevier GmbH. All rights reserved.

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.

Spectrophotometric evaluation of selenium binding by Saccharomyces cerevisiae ATCC MYA-2200 and Candida utilis ATCC 9950 yeast.

PubMed

Kieliszek, Marek; Błażejak, Stanisław; Płaczek, Maciej

2016-05-01

In this study, the ability of selenium binding the biomas of Saccharomyces cerevisiae ATCC MYA-2200 and Candida utilis ATCC 9950 was investigated. Sodium selenite(IV) salts were added to the experimental media at concentrations of 10, 20, 40, and 60 mg Se(4+) L(-1). In the tested concentration range, one concentration reported a significant reduction in the biomass yield of both yeast strains. Intense growth was observed for C. utilis yeast, which reached the highest biomass yield of 15 gd.w.L(-1) after 24h cultivation in the presence of 10mg Se(4+) L(-1). Based on the use of spectrophotometric method for the determination of selenium content by using Variamine Blue as a chromogenic agent, efficient accumulation of this element in the biomass of the investigated yeast was observed. The highest amount of selenium, that is, 5.64 mg Se(4+)gd.w.(-1), was bound from the environment by S. cerevisiae ATCC MYA-2200 cultured in the presence of 60 mg Se(4+) L(-1) medium 72h Slightly less amount, 5.47 mg Se(4+) gd.w.(-1), was absorbed by C. utilis ATCC 9950 during similar cultural conditions. Based on the results of the biomass yield and the use of selenium from the medium, it can be observed that yeasts of the genus Candida are more efficient in binding this element, and this property finds practical application in the production of selenium-enriched yeast. Copyright © 2016 Elsevier GmbH. All rights reserved.

Effect of Phosphine-Free Selenium Precursor Reactivity on The Optical and Vibrational properties of Colloidal CdSe Nanocrystals

NASA Astrophysics Data System (ADS)

Thi, L. A.; Lieu, N. T. T.; Hoa, N. M.; Tran, N.; Binh, N. T.; Quang, V. X.; Nghia, N. X.

2018-03-01

Phosphine-free selenium precursor solutions have been prepared by heating at temperatures ranging from 160 °C to 240 °C and studied by means of infrared absorption spectroscopy. The colloidal CdSe nanocrystals (NCs) synthesized from all those solutions by the wet chemical method. The influence of heating temperature on the chemical reactivity of selenium precursor and its role on the optical and vibrational properties of CdSe NCs are discussed in details. Their morphology, particle size, structural, optical and vibrational properties were investigated using transmission electron microscopy, X-ray diffraction, UV-Vis, fluorescence and Raman spectroscopy, respectively.

Selenium in San Francisco Bay zooplankton: Potential effects of hydrodynamics and food web interactions

USGS Publications Warehouse

Purkerson, D.G.; Doblin, M.A.; Bollens, S.M.; Luoma, S.N.; Cutter, G.A.

2003-01-01

The potential toxicity of elevated selenium (Se) concentrations in aquatic ecosystems has stimulated efforts to measure Se concentrations in benthos, nekton, and waterfowl in San Francisco Bay (SF Bay). In September 1998, we initiated a 14 mo field study to determine the concentration of Se in SF Bay zooplankton, which play a major role in the Bay food web, but which have not previously been studied with respect to Se. Monthly vertical plankton tows were collected at several stations throughout SF Bay, and zooplankton were separated into two operationally defined size classes for Se analyses: 73-2,000 ??m, and ???2,000 ??m. Selenium values ranged 1.02-6.07 ??g Se g-1 dry weight. No spatial differences in zooplankton Se concentrations were found. However, there were inter- and intra-annual differences. Zooplankton Se concentrations were enriched in the North Bay in Fall 1999 when compared to other seasons and locations within and outside SF Bay. The abundance and biovolume of the zooplankton community varied spatially between stations, but not seasonally within each station. Smaller herbivorous-omnivorous zooplankton had higher Se concentrations than larger omnivorous-carnivorous zooplankton. Selenium concentrations in zooplankton were negatively correlated with the proportion of total copepod biovolume comprising the large carnivorous copepod Tortanus dextrilobatus, but positively correlated with the proportion of copepod biovolume comprising smaller copepods of the family Oithonidae, suggesting an important role of trophic level and size in regulating zooplankton Se concentrations.

Grain Accumulation of Selenium Species in Rice (Oryza sativa L.)

EPA Science Inventory

Selenium (Se) is an essential micronutrient in which up to 1 billion people worldwide are deficient, causing a range of health disorders and potentially an increased risk of certain cancers. Consequently, there is much interest in Se biofortification of rice, the staple food for...

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.

Nanometer-sized alumina packed microcolumn solid-phase extraction combined with field-amplified sample stacking-capillary electrophoresis for the speciation analysis of inorganic selenium in environmental water samples.

PubMed

Duan, Jiankuan; Hu, Bin; He, Man

2012-10-01

In this paper, a new method of nanometer-sized alumina packed microcolumn SPE combined with field-amplified sample stacking (FASS)-CE-UV detection was developed for the speciation analysis of inorganic selenium in environmental water samples. Self-synthesized nanometer-sized alumina was packed in a microcolumn as the SPE adsorbent to retain Se(IV) and Se(VI) simultaneously at pH 6 and the retained inorganic selenium was eluted by concentrated ammonia. The eluent was used for FASS-CE-UV analysis after NH₃ evaporation. The factors affecting the preconcentration of both Se(IV) and Se(VI) by SPE and FASS were studied and the optimal CE separation conditions for Se(IV) and Se(VI) were obtained. Under the optimal conditions, the LODs of 57 ng L⁻¹ (Se(IV)) and 71 ng L⁻¹ (Se(VI)) were obtained, respectively. The developed method was validated by the analysis of a certified reference material of GBW(E)080395 environmental water and the determined value was in a good agreement with the certified value. It was also successfully applied to the speciation analysis of inorganic selenium in environmental water samples, including Yangtze River water, spring water, and tap water. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

USDA-ARS?s Scientific Manuscript database

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...

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 adult fish, it can negatively affect fish reproductive potential, and the effect on reproduction is enhanced in the presence of elevated Hg. Copyright © 2014 Elsevier B.V. All rights reserved.

Dietary selenium requirements based on tissue selenium concentration and glutathione peroxidase activities in old female rats.

PubMed

Sunde, Roger A; Thompson, Kevin M

2009-01-01

Dietary nutrient requirements for older animals have been studied far less than have requirements for young growing animals. To determine dietary selenium (Se) requirements in old rats, we fed female weanling rats a Se-deficient diet (0.007 microg Se/g) or supplemented rats with graded levels of dietary Se (0-0.3 microg Se/g) as Na(2)SeO(3) for 52 weeks. At no point did Se deficiency or level of Se supplementation have a significant effect (P>0.05) on growth. To determine Se requirements, Se response curves were determined for 7 Se-dependent parameters. We found that minimum dietary Se requirements in year-old female rats were at or below 0.05 microg Se/g diet based on liver Se, red blood cell glutathione peroxidase (Gpx1) activity, plasma Gpx3 activity, liver and kidney Gpx1 activity, and liver and kidney Gpx4 activity. In conclusion, this study found that dietary Se requirements in old female rats were decreased at least 50% relative to requirements found in young, rapidly growing female rats. Collectively, this indicates that the homeostatic mechanisms related to retention and maintenance of Se status are still fully functional in old female rats.

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

USDA-ARS?s Scientific Manuscript database

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...

Selenium deficiency decreases antioxidative capacity and is detrimental to bone microarchitecture in mice

USDA-ARS?s Scientific Manuscript database

Selenium (Se), a chemical component of selenoproteins (such as glutathione peroxidases and thioredoxin reductase), plays a major role in cellular redox status and may have beneficial effects on bone health. The deficiency of Se has been linked to increased oxidative stress with increased levels of r...

Selenium speciation analysis of Misgurnus anguillicaudatus selenoprotein by HPLC-ICP-MS and HPLC-ESI-MS/MS

USDA-ARS?s Scientific Manuscript database

Analytical methods for selenium (Se) speciation were developed using high performance liquid chromatography (HPLC) coupled to either inductively coupled plasma mass spectrometry (ICP-MS) or electrospray ionization tandem mass spectrometry (ESI-MS/MS). Separations of selenomethionine (Se-Met) and sel...

Selenium cycling across soil-plant atmosphere interfaces: a critical review

USDA-ARS?s Scientific Manuscript database

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 ha...

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.

Protection of methamphetamine nigrostriatal toxicity by dietary selenium.

PubMed

Kim, H C; Jhoo, W K; Choi, D Y; Im, D H; Shin, E J; Suh, J H; Floyd, R A; Bing, G

1999-12-18

Multiple dose administration of methamphetamine (MA) results in long-lasting toxic effects in the nigrostriatal dopaminergic system. These effects are considered to be primarily due to oxidative damage mediated by increased production of hydrogen peroxide or other reactive oxygen species in the dopaminergic system. The present study was designed to determine the protective effects of dietary antioxidant selenium on MA-induced neurotoxicity in the nigrostriatal dopaminergic system. Male C57BL/6J mice were fed either selenium-deficient (< 0.01 ppm Se) or selenium-replete (0.2 ppm Se) diets for 90 days. MA treatment decreased the dopamine (DA) levels in the striatum and substantia nigra (SN) of both Se-replete and Se-deficient animals. However, in Se-replete animals, this DA depletion was significantly attenuated in both the striatum and SN. A novel observation is that MA administration resulted in increased activity of Cu,Zn-SOD in the brains of both Se-deficient and Se-replete animals. However, MA administration to Se-deficient animals exhibited a higher Cu,Zn-SOD activity in the nigrostriatal system than the control animals. Elevated malondialdehyde (MDA) levels in the striatum and SN were also observed in Se-deficient MA-treated animals. Se repletion significantly increased the glutathione peroxidase (GPx) activity and the ratio of reduced glutathione (GSH)/oxidized glutathione (GSSG) in the MA-treated animals. In conclusion, we have shown that dietary Se attenuated methamphetamine neurotoxicity and that this protection involves GPx-mediated antioxidant mechanisms. Even though Cu,Zn-SOD activity was significantly elevated by MA treatment, the role of this enzyme in MA-mediated neurotoxicity is not yet clear.

Effects of a low-fat vegan diet and a Step II diet on macro- and micronutrient intakes in overweight postmenopausal women.

PubMed

Turner-McGrievy, Gabrielle M; Barnard, Neal D; Scialli, Anthony R; Lanou, Amy J

2004-09-01

This study investigated the nutrient intake of overweight postmenopausal women assigned to a low-fat vegan diet or a Step II diet. Fifty-nine overweight (body mass index, 26 to 44 kg/m2) postmenopausal women were randomly assigned to a self-selected low-fat vegan or a National Cholesterol Education Program Step II diet in a 14-wk controlled trial on weight loss and metabolism. Nutrient intake, which was measured per 1000 kcal, was the main outcome measure. Statistical analyses included within-group and between-group t tests examining changes associated with each diet. Consumption of a low-fat vegan diet was associated with greater decreases in fat, saturated fat, protein, and cholesterol intakes and greater increases in carbohydrate, fiber, beta-carotene, and total vitamin A intakes than was a Step II diet. The low-fat vegan group also increased thiamin, vitamin B6, and magnesium intakes more than the Step II group, and both groups increased folic acid, vitamin C, and potassium intakes. If considering only food sources of micronutrients, the low-fat vegan group decreased vitamin D, vitamin B12, calcium, selenium, phosphorous, and zinc intakes compared with baseline. However, with incidental supplements included, decreases were evident only in phosphorous and selenium intakes. No micronutrient decreases were found in the Step II group. Individuals on a low-fat vegan or Step II diet should take steps to meet the recommended intakes of vitamin D, vitamin K, folic acid, calcium, magnesium, and zinc. Individuals on a low-fat vegan diet should also ensure adequate intakes of vitamin B12, phosphorous, and selenium.

Dietary Micronutrient Intake and Micronutrient Status in Patients With Chronic Stable Heart Failure: An Observational Study.

PubMed

McKeag, Nicholas A; McKinley, Michelle C; Harbinson, Mark T; McGinty, Ann; Neville, Charlotte E; Woodside, Jayne V; McKeown, Pascal P

Observational studies suggest that patients with heart failure have a tendency to a reduced status of a number of micronutrients and that this may be associated with an adverse prognosis. A small number of studies also suggest that patients with heart failure may have reduced dietary intake of micronutrients, a possible mechanism for reduced status. The aims of this study were to assess dietary micronutrient intake and micronutrient status in a group of patients with heart failure. Dietary intake was assessed in 79 outpatients with chronic stable heart failure with a reduced ejection fraction using a validated food frequency questionnaire. Blood concentrations of a number of micronutrients, including vitamin D, were measured in fasting blood samples, drawn at the time of food frequency questionnaire completion. More than 20% of patients reported intakes less than the reference nutrient intake or recommended intake for riboflavin, vitamin D, vitamin A, calcium, magnesium, potassium, zinc, copper, selenium, and iodine. More than 5% of patients reported intakes less than the lower reference nutrient intake or minimum recommended intake for riboflavin, vitamin D, vitamin A, calcium, magnesium, potassium, zinc, selenium, and iodine. Vitamin D deficiency (plasma total 25-hydroxy-vitamin D concentration <50 nmol/L) was observed in 75.6% of patients. Vitamin D deficiency was common in this group of patients with heart failure. Based on self-reported dietary intake, a substantial number of individuals may not have been consuming enough vitamin D and a modest number of individuals may not have been consuming enough riboflavin, vitamin A, calcium, magnesium, potassium, zinc, copper, selenium, or iodine to meet their dietary needs.

Identification of selenium-containing proteins in HEK 293 kidney cells using multiple chromatographies, LC-ICPMS and nano-LC-ESIMS.

PubMed

Chitta, Karnakar R; Landero-Figueroa, Julio A; Kodali, Phanichand; Caruso, Joseph A; Merino, Edward J

2013-09-30

Our previous studies using HeLa and HEK 293 cells demonstrated that selenomethionine, SeMet, exerts more of an antagonistic effect on arsenic than other selenium species. These studies attributed the antagonistic effect of SeMet to decreased levels of reactive oxygen species, ROS, changes in protein phosphorylation and possible incorporation of SeMet into proteins. The present study employs a metallomics approach to identify the selenium-containing proteins in HEK 293 cells raised with SeMet. The proteins were screened and separated using two dimensional high performance liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICPMS), size exclusion chromatography (SEC) and reversed-phase chromatography (RPC). The Se-containing proteins were identified by peptide mapping using nano-HPLC-Chip-electrospray ionization mass spectrometry (ESIMS). Copyright © 2013 Elsevier B.V. All rights reserved.

Geochemistry of selenium.

PubMed

Kabata-Pendias, A

1998-01-01

Selenium (Se) is one of the most peculiar chemical elements in the geo- and biospheres. It partly resembles sulfur and tellurium; however, its behavior in the geosphere and its functions in the biosphere are very specific. Despite a relatively large database, its cycling in both the natural environment and in that modified by human activities requires further study. Selenium is rather concentrated in the geospheric cycle and is also bioconcentrated. The values of its accumulation ratios are: 5 for soil/sandstone, 2 for animal tissues/sandstone, and 5 for animal tissues/grain. For a specific plant/soil system, the bioconcentration factor for plants always has to be estimated because some plants can absorb extremely high concentrations of Se. Their ability to accumulate and tolerate high Se levels is related to different Se metabolisms. These plants play a significant role in geochemical prospecting and animal nutrition. This paper presents some geochemical observations toward a better understanding of the environmental properties of Se.

Selenium adsorption to aluminum-based water treatment residuals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ippolito, James A.; Scheckel, Kirk G.; Barbarick, Ken A.

2009-09-02

Aluminum-based water treatment residuals (WTR) can adsorb water- and soil-borne P, As(V), As(III), and perchlorate, and may be able to adsorb excess environmental selenium. WTR, clay minerals, and amorphous aluminum hydroxide were shaken for 24 h in selenate or selenite solutions at pH values of 5-9, and then analyzed for selenium content. Selenate and selenite adsorption edges were unaffected across the pH range studied. Selenate adsorbed on to WTR, reference mineral phases, and amorphous aluminum hydroxide occurred as outer sphere complexes (relatively loosely bound), while selenite adsorption was identified as inner-sphere complexation (relatively tightly bound). Selenite sorption to WTR inmore » an anoxic environment reduced Se(IV) to Se(0), and oxidation of Se(0) or Se(IV) appeared irreversible once sorbed to WTR. Al-based WTR could play a favorable role in sequestering excess Se in affected water sources.« less

Selenium and Anticarcinogenesis: Underlying Mechanisms

USDA-ARS?s Scientific Manuscript database

The manuscript discusses recent research related to anticarcinogenic mechanisms of selenium (Se) action in light of the underlying chemical/biochemical functions of the selenium species likely to be executors of those effects. Recent studies in a variety of model systems have increased understanding...

[Effect of selenium on the uptake and translocation of manganese, iron, phosphorus and selenium in rice (Oryza sativa L.)].

PubMed

Hu, Ying; Huang, Yi-Zong; Huang, Yan-Chao; Liu, Yun-Xia; Liang, Jian-Hong

2013-10-01

A pot experiment was conducted to clarify the effect of selenium on the uptake and translocation of manganese (Mn), iron (Fe) , phosphorus (P) and selenium (Se) in rice ( Oryza sativa L.). The results showed that addition of Se led to the significant increase of Se concentration in iron plaque on the root surface, root, shoot, husk and brown rice, and significant decrease of Mn concentration in shoot, husk and brown rice. At the Se concentrations of 0.5 and 1.0 mg.kg-1 in soil, Mn concentrations in rice shoot decreased by 32. 2% and 35.0% respectively, in husk 22.0% and 42.6% , in brown rice 27.5% and 28.5% , compared with the Se-free treatment. There was no significant effect of Se on the P and Fe concentrations in every parts of rice, except for Fe concentrations in husk. The translocation of P and Fe from iron plaque, root, shoot and husk to brown rice was not significantly affected by Se addition, but Mn translocation from iron plaque and root to brown rice was significantly inhibited by Se addition. Addition of 1.0 mg.kg-1. Se resulted in the decrease of translocation factor from iron plaque and root to brown rice by 38.9% and 37.9%, respectively, compared with the control treatment. The distribution ratios of Mn, Fe, P and Se in iron plaque, root, shoot, husk and brown rice were also affected by Se addition. The results indicated that Mn uptake, accumulation and translocation in rice could be decreased by the addition of Se in soil, therefore, Se addition could reduce the Mn harm to human health through food chain.

Selenium stable isotope ratios in California agricultural drainage water management systems

USGS Publications Warehouse

Herbel, M.J.; Johnson, T.M.; Tanji, K.K.; Gao, S.; Bullen, T.D.

2002-01-01

Selenium stable isotope ratios are known to shift in predictable ways during various microbial, chemical, and biological processes, and can be used to better understand Se cycling in contaminated environments. In this study we used Se stable isotopes to discern the mechanisms controlling the transformation of oxidized, aqueous forms of Se to reduced, insoluble forms in sediments of Se-affected environments. We measured 80Se/76Se in surface waters, shallow ground waters, evaporites, digested plants and sediments, and sequential extracts from several sites where agricultural drainage water is processed in the San Joaquin Valley of California. Selenium isotope analyses of samples obtained from the Tulare Lake Drainage District flow-through wetland reveal small isotopic contrasts (mean difference 0.7%o) between surface water and reduced Se species in the underlying sediments. Selenium in aquatic macrophytes was very similar isotopically to the NaOH and Na2SO3 sediment extracts designed to recover soluble organic Se and Se(O), respectively. For the integrated on-farm drainage management sites, evaporite salts were slightly (approximately 0.6%o) enriched in the heavier isotope relative to the inferred parent waters, whereas surface soils were slightly (approximately 1.4%o) depleted. Bacterial or chemical reduction of Se(VI) or Se(IV) may be occurring at these sites, but the small isotopic contrasts suggest that other, less isotopically fractionating mechanisms are responsible for accumulation of reduced forms in the sediments. These findings provide evidence that Se assimilation by plants and algae followed by deposition and mineralization is the dominant transformation pathway responsible for accumulation of reduced forms of Se in the wetland sediments.

Biogenic selenium nanoparticles induce ROS-mediated necroptosis in PC-3 cancer cells through TNF activation.

PubMed

Sonkusre, Praveen; Cameotra, Swaranjit Singh

2017-06-07

Selenium is well documented to inhibit cancer at higher doses; however, the mechanism behind this inhibition varies widely depending on the cell type and selenium species. Previously, we have demonstrated that Bacillus licheniformis JS2 derived biogenic selenium nanoparticles (SeNPs) induce non-apoptotic cell death in prostate adenocarcinoma cell line, PC-3, at a minimal concentration of 2 µg Se/ml, without causing toxicity to the primary cells. However, the mechanism behind its anticancer activity was elusive. Our results have shown that these SeNPs at a concentration of 2 µg Se/ml were able to induce reactive oxygen species (ROS) mediated necroptosis in PC-3 cells by gaining cellular internalization. Real-time qPCR analysis showed increased expression of necroptosis associated tumor necrotic factor (TNF) and interferon regulatory factor 1 (IRF1). An increased expression of RIP1 protein was also observed at the translational level upon SeNP treatment. Moreover, the cell viability was significantly increased in the presence of necroptosis inhibitor, Necrostatin-1. Data suggest that our biogenic SeNPs induce cell death in PC-3 cells by the ROS-mediated activation of necroptosis, independent to RIP3 and MLKL, regulated by a RIP1 kinase.

In vivo synthesis of selenium nanoparticles by Halococcus salifodinae BK18 and their anti-proliferative properties against HeLa cell line.

PubMed

Srivastava, Pallavee; Braganca, Judith M; Kowshik, Meenal

2014-01-01

Nanoparticles synthesis by bacteria and yeasts has been widely reported, however, synthesis using halophilic archaea is still in a nascent stage. This study aimed at the intracellular synthesis of selenium nanoparticles (SeNPs) by the haloarchaeon Halococcus salifodinae BK18 when grown in the presence of sodium selenite. Crystallographic characterization of SeNPs by X-ray diffraction, Selected area electron diffraction, and transmission electron microscopy exhibited rod shaped nanoparticles with hexagonal crystal lattice, a crystallite domain size of 28 nm and an aspect ratio (length:diameter) of 13:1. Energy disruptive analysis of X-ray analysis confirmed the presence of selenium in the nano-preparation. The nitrate reductase enzyme assay and the inhibitor studies indicated the involvement of NADH-dependent nitrate reductase in SeNPs synthesis and metal tolerance. The SeNPs exhibited good anti-proliferative properties against HeLa cell lines while being non-cytotoxic to normal cell line model HaCat, suggesting the use of these SeNPs as cancer chemotherapeutic agent. This is the first study on selenium nanoparticles synthesis by haloarchaea. © 2014 American Institute of Chemical Engineers.

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.

Biogenesis of Selenium Nanoparticles Using Green Chemistry.

PubMed

Shoeibi, Sara; Mozdziak, Paul; Golkar-Narenji, Afsaneh

2017-11-09

Selenium binds some enzymes such as glutathione peroxidase and thioredoxin reductase, which may be activated in biological infections and oxidative stress. Chemical and physical methods for synthesizing nanoparticles, apart from being expensive, have their own particular risks. However, nanoparticle synthesis through green chemistry is a safe procedure that different biological sources such as bacteria, fungi, yeasts, algae and plants can be the catalyst bed for processing. Synthesis of selenium nanoparticles (SeNPs) by macro/microorganisms causes variation in morphology and shape of the particles is due to diversity of reduction enzymes in organisms. Reducing enzymes of microorganisms by changing the status of redox convert metal ions (Se 2- ) to SeNPs without charge (Se 0 ). Biological activity of SeNPs includes their protective role against DNA oxidation. Because of the biological and industrial properties, SeNPs have wide applications in the fields of medicine, microelectronic, agriculture and animal husbandry. SeNPs can show strong antimicrobial effects on the growth and proliferation of microorganisms in a dose-dependent manner. The objective of this review is to consider SeNPs applications to various organisms.

Aerobic and anaerobic biosynthesis of nano-selenium for remediation of mercury contaminated soil.

PubMed

Wang, Xiaonan; Zhang, Daoyong; Pan, Xiangliang; Lee, Duu-Jong; Al-Misned, Fahad A; Mortuza, M Golam; Gadd, Geoffrey Michael

2017-03-01

Selenium (Se) nanoparticles are often synthesized by anaerobes. However, anaerobic bacteria cannot be directly applied for bioremediation of contaminated top soil which is generally aerobic. In this study, a selenite-reducing bacterium, Citrobacter freundii Y9, demonstrated high selenite reducing power and produced elemental nano-selenium nanoparticles (nano-Se 0 ) under both aerobic and anaerobic conditions. The biogenic nano-Se 0 converted 45.8-57.1% and 39.1-48.6% of elemental mercury (Hg 0 ) in the contaminated soil to insoluble mercuric selenide (HgSe) under anaerobic and aerobic conditions, respectively. Addition of sodium dodecyl sulfonate enhanced Hg 0 remediation, probably owing to the release of intracellular nano-Se 0 from the bacterial cells for Hg fixation. The reaction product after remediation was identified as non-reactive HgSe that was formed by amalgamation of nano-Se 0 and Hg 0 . Biosynthesis of nano-Se 0 both aerobically and anaerobically therefore provides a versatile and cost-effective remediation approach for Hg 0 -contaminated surface and subsurface soils, where the redox potential often changes dramatically. Copyright © 2016. Published by Elsevier Ltd.

Glassy selenium at high pressure: Le Chatelier's principle still works

NASA Astrophysics Data System (ADS)

Brazhkin, V. V.; Tsiok, O. B.

2017-10-01

Selenium is the only easily vitrified elementary substance. Numerous experimental studies of glassy Se (g -Se) at high pressures show a large spread in the data on the compressibility and electrical resistivity of g -Se. Furthermore, H. Liu et al. [Proc. Natl. Acad. Sci. USA 105, 13229 (2008), 10.1073/pnas.0806857105] have arrived at the surprising conclusion that the volume of glass increases during pressure-induced crystallization. We have performed high-precision measurements of the specific volume and electrical resistivity of glassy selenium (g -Se) at high hydrostatic pressures up to 9 GPa. The measured bulk modulus at normal pressure is B =(9.0 5 ±0.15 ) GPa and its pressure derivative is BP'=6.4 ±0.2 . In the pressure range P <3 GPa, glassy selenium has an anomalously large negative second derivative of the bulk modulus. The electrical resistivity of g -Se decreases almost exponentially with increasing pressure and reaches 20 Ω cm at a pressure of 8.75 GPa. The inelastic behavior and weak relaxation of the volume for g -Se begin at pressures above 3.5 GPa; the volume and logarithm of the electrical resistivity relax significantly (logarithmically with the time) at pressures above 8 GPa. Bulk measurements certainly indicate that the volume of g -Se glass in the crystallization pressure range is larger than the volumes of both appearing crystalline phases (by 2% and 4%). Therefore, the "volume expansion phenomenon" suggested in [H. Liu et al., Proc. Natl. Acad. Sci. USA 105, 13229 (2008), 10.1073/pnas.0806857105] is not observed, and the pressure-induced crystallization of glassy selenium is consistent with the laws of thermodynamics.

Accumulation and distribution of selenium in mussel and shrimp tissues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fowler, S.W.; Benayoun, G.

1976-09-01

The tissue distribution of selenium in mussels and shrimp was examined and the bioaccumulation kinetics in the various tissues was elucidated with the aid of radio selenium. Mussels (Mytilus galloprovincialis) and shrimp (Lysmata seticaudata) collected near the Monaco port, were apportioned into several groups. One group of mussels and shrimp was maintained in sea water containing 0.8 ..mu..Ci/liter high specific activity Se-75. Three to four individuals were dissected and their tissues monitored for Se-75 content periodically. Another group of shrimp, maintained in flowing sea water, were fed ad libitum mussels that had previously accumulated Se-75 from sea water for severalmore » days. Shrimp were periodically dissected to follow tissue accumulation of ingested selenium. The highest concentrations of selenium were found in the exoskeleton, presumably due, in part, to the relatively large amount of isotope sorbed to its outer surface. Molts, cast by shrimp at various times throughout uptake, contained from 60 to 90% of the total Se-75 body burden. Direct uptake of water led to initially small fractions in internal tissues such as muscle and viscera compared to the relatively large fraction associated with the exoskeleton. With time percentages in internal tissues gradually increased relative to that in the exoskeleton. When Se-75 was accumulated through the food chain an opposite trend was noted with the Se-75 fraction in exoskeleton slowly increasing and that in viscera decreasing during the course of the experiment. All tissues examined readily accumulated the isotope and, in general, did not appear to have reached a steady state concentration after 63 days. The highest Se-75 concentrations were found in the visceral mass with lesser amounts in gills, muscle and mantle, in that order.« less

Effect of high-dose nano-selenium and selenium-yeast on feed digestibility, rumen fermentation, and purine derivatives in sheep.

PubMed

Xun, Wenjuan; Shi, Liguang; Yue, Wenbin; Zhang, Chunxiang; Ren, Youshe; Liu, Qiang

2012-12-01

The aim of this study was to evaluate the effect of nano-selenium (NS) and yeast-selenium (YS) supplementation on feed digestibility, rumen fermentation, and urinary purine derivatives in sheep. Six male ruminally cannulated sheep, average 43.32 ± 4.8 kg of BW, were used in a replicated 3 × 3 Latin square experiment. The treatments were control (without NS and YS), NS with 4 g nano-Se (provide 4 mg Se), and YS with 4 g Se-yeast (provide 4 mg Se) per kilogram of diet dry matter (DM), respectively. Experimental periods were 25 days with 15 days of adaptation and 10 days of sampling. Ruminal pH, ammonia N concentration, molar proportion of propionate, and ratio of acetate to propionate were decreased (P < 0.01), and total ruminal VFA concentration was increased with NS and YS supplementation (P < 0.01). In situ ruminal neutral detergent fiber (aNDF) degradation of Leymus chinensis (P < 0.01) and crude protein (CP) of soybean meal (P < 0.01) were significantly improved by Se supplementation. Digestibilities of DM, organic matter, crude protein, ether extract, aNDF, and ADF in the total tract and urinary excretion of purine derivatives were also affected by feeding Se supplementation diets (P < 0.01). Ruminal fermentation was improved by feeding NS, and feed conversion efficiency was also increased compared with YS (P < 0.01). We concluded that nano-Se can be used as a preferentially available selenium source in ruminant nutrition.

Selenium speciation in malt, wort, and beer made from selenium-biofortified two-rowed barley grain.

PubMed

Rodrigo, Sara; Santamaria, Oscar; Chen, Yi; McGrath, Steve P; Poblaciones, Maria J

2014-06-25

Selenium (Se) biofortification of barley is a suitable strategy to increase the Se concentration in grain. In the present paper, the suitability of this Se-biofortified grain for making Se-enriched beer is analyzed. The aim of the present study was to evaluate the effect of different Se fertilizer doses (0, 10, and 20 g of Se ha(-1)) and forms (sodium selenate or sodium selenite) on the Se loss during the malting and brewing processes and Se speciation in grain, malt, wort, and beer. Samples were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS) and high-performance liquid chromatography (HPLC)-ICP-MS for total Se and speciation. Mashing-lautering was the process with the greatest Se loss (83.8%). After malting and brewing, only 7.3% of the initial Se was retained in beer, mainly in selenite form. Even so, the fertilizer application of sodium selenate at 20 g ha(-1) increased the total Se concentration almost 6-fold in the final beer in comparison to the use of grain derived from unfertilized barley. The present paper provides evidence that the use of Se-biofortified barley grain as a raw material to produce Se-enriched beer is possible, and the results are comparable to other methods in terms of efficiency.

Species richness and selenium accumulation of plants in soils with elevated concentration of selenium and salinity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Z.Z.; Wu, L.

1991-12-01

Field studies were conducted in soils with elevated concentrations of Se and salinity at Kesterson, California. Biomass distribution, species richness, and selenium accumulation of plants were examined for two sites where 15 cm of surface soil was removed and replaced with fill dirt in the fall of 1989, and two sites were native soil cover. The Se concentrations in the top 15 cm of fill dirt ranged from undetectable to 36 ng g-1. For the native soil sites, Se levels ranged from 75 to 550 ng g-1. Soil Se concentrations below 15 cm ranged from 300 to 700 ng g-1more » and were comparable between the fill dirt and the native soil sites. At least 20 different plant species were brought into the two fill dirt sites with the top soil. Avena fatua L., Bassia hyssopifolia Kuntze Rev. Gen. Pl., Centaurea solstitialis L., Erysimum officianale L., Franseria acanthicarpa Cav. Icon., and Melilotus indica (L.) All. contributed over 60% of the total biomass. Only 5 species were found in the native soil sites, and salt grass (Distichlis spicata L.) was the predominant species and accounted for over 80% of the total biomass. Between 1989 and 1990, two years after the surface soil replacement, the two fill dirt sites had a 70% reduction in species richness. Plant tissue selenium concentrations were found to be quite variable between plant species and between sites of sampling. At the fill dirt sites, the plant species with deep root systems accumulated greater amounts of selenium than the shallow-rooted species. The soil selenium concentration of the field soil had no negative effect on pollen fertility, seed set, and seed germination for the plant species examined. However, seedling growth was impaired by the soil selenium concentrations. This suggests that a selection pressure of soil Se concentration may have been imposed on plant species such as M. indica in an early stage of its life cycle.« less

A Solid-State NMR Study of Selenium Substitution into Nanocrystalline Hydroxyapatite

PubMed Central

Kolmas, Joanna; Kuras, Marzena; Oledzka, Ewa; Sobczak, Marcin

2015-01-01

The substitution of selenium oxyanions in the hydroxyapatite structure was examined using multinuclear solid-state resonance spectroscopy (ssNMR). The study was supported by powder X-ray diffractometry (PXRD) and wavelength dispersion X-ray fluorescence (WD-XRF). Samples of pure hydroxyapatite (HA300) and selenate (HA300-1.2SeO4) or selenite (HA300-1.2SeO3) substituted hydroxyapatites were synthesized using the standard wet method and heated at 300 °C to remove loosely bonded water. PXRD data showed that all samples are single-phase, nanocrystalline hydroxyapatite. The incorporation of selenite and selenate ions affected the lattice constants. In selenium-containing samples the concentration of Se was very similar and amounted to 9.55% and 9.64%, for HA300-1.2SeO4 and HA300-1.2SeO3, respectively. PXRD and ssNMR data showed that the selenite doping significantly decreases the crystallite size and crystallinity degree. 31P and 1H NMR experiments demonstrated the developed surface hydrated layer in all samples, especially in HA300-1.2SeO3. 1H NMR studies showed the dehydroxylation of HA during the selenium oxyanions substitution and the existence of hydrogen bonding in structural hydroxyl group channels. 1H→77Se cross polarization NMR experiments indicated that selenites and selenates are located in the crystal lattice and on the crystal surface. PMID:25997001

Subacute toxicity of nano-selenium compared to other selenium species in mice.

PubMed

Benko, Ilona; Nagy, Gabor; Tanczos, Bence; Ungvari, Eva; Sztrik, Attila; Eszenyi, Peter; Prokisch, Jozsef; Banfalvi, Gaspar

2012-12-01

Sixteen groups of mice were fed diets containing different selenium species to compare their toxicity. Inorganic sodium selenate and sodium hydroselenite, elementary nanoSe, organic Sel-Plex, and Lacto-MicroSelenium were administered for 14 d at concentrations of 0.5, 5, and 50 ppm Se, equivalent to 0.5, 5, and 50 mg Se/kg food, corresponding to an estimated 4, 40, and 400 µg/kg body weight/d Se uptake, respectively. At the end of the treatment, body, liver, spleen, kidney, heart, and brain weights were measured, mice were subjected to necropsy, and histological examinations were performed on the liver. At lower Se doses (0.5 and 5 ppm) a moderate reduction was observed in the number of bone marrow and white blood cells and in granulocyte-macrophage colony-forming units (GM-CFUs) relative to the untreated control group of mice. A comparison of lowest toxic doses of sodium selenite in mice (0.5 ppm) and mallard (10 ppm) indicates that birds are more resistant to Se than rodents. In mice, a small but measurable weight loss was observed after 5 ppm selenate and LactoMicroSe treatment. The most significant changes took place after 50-ppm administration in body and spleen weight, hematology, and liver histology. Toxicity was more pronounced when inorganic Se was applied than after subacute application of Sel-Plex, nanoSe, or LactoMicroSe. To summarize the effects, the authors' 14-d murine subacute toxicity study showed that the toxicity of Se species decreased in the following order: selenate > selenite > nanoSe > Sel-Plex > LactoMicroSe. Copyright © 2012 SETAC.

Comparison of the redox chemistry of sulfur- and selenium-containing analogs of uracil.

PubMed

Payne, N Connor; Geissler, Andrew; Button, Aileen; Sasuclark, Alexandru R; Schroll, Alayne L; Ruggles, Erik L; Gladyshev, Vadim N; Hondal, Robert J

2017-03-01

Selenium is present in proteins in the form of selenocysteine, where this amino acid serves catalytic oxidoreductase functions. The use of selenocysteine in nature is strongly associated with redox catalysis. However, selenium is also found in a 2-selenouridine moiety at the wobble position of tRNA Glu , tRNA Gln and tRNA Lys . It is thought that the modifications of the wobble position of the tRNA improves the selectivity of the codon-anticodon pair as a result of the physico-chemical changes that result from substitution of sulfur and selenium for oxygen. Both selenocysteine and 2-selenouridine have widespread analogs, cysteine and thiouridine, where sulfur is used instead. To examine the role of selenium in 2-selenouridine, we comparatively analyzed the oxidation reactions of sulfur-containing 2-thiouracil-5-carboxylic acid (s 2 c 5 Ura) and its selenium analog 2-selenouracil-5-carboxylic acid (se 2 c 5 Ura) using 1 H-NMR spectroscopy, 77 Se-NMR spectroscopy, and liquid chromatography-mass spectrometry. Treatment of s 2 c 5 Ura with hydrogen peroxide led to oxidized intermediates, followed by irreversible desulfurization to form uracil-5-carboxylic acid (c 5 Ura). In contrast, se 2 c 5 Ura oxidation resulted in a diselenide intermediate, followed by conversion to the seleninic acid, both of which could be readily reduced by ascorbate and glutathione. Glutathione and ascorbate only minimally prevented desulfurization of s 2 c 5 Ura, whereas very little deselenization of se 2 c 5 Ura occurred in the presence of the same antioxidants. In addition, se 2 c 5 Ura but not s 2 c 5 Ura showed glutathione peroxidase activity, further suggesting that oxidation of se 2 c 5 Ura is readily reversible, while oxidation of s 2 c 5 Ura is not. The results of the study of these model nucleobases suggest that the use of 2-selenouridine is related to resistance to oxidative inactivation that otherwise characterizes 2-thiouridine. As the use of selenocysteine in proteins also confers resistance to oxidation, our findings suggest a common mechanism for the use of selenium in biology. Copyright © 2017. Published by Elsevier Inc.

Comparison of the redox chemistry of sulfur- and selenium-containing analogs of uracil✰

PubMed Central

Payne, N. Connor; Geissler, Andrew; Button, Aileen; Sasuclark, Alexandru R.; Schroll, Alayne L.; Ruggles, Erik L.; Gladyshev, Vadim N.; Hondal, Robert J.

2017-01-01

Selenium is present in proteins in the form of selenocysteine, where this amino acid serves catalytic oxidoreductase functions. The use of selenocysteine in nature is strongly associated with redox catalysis. However, selenium is also found in a 2-selenouridine moiety at the wobble position of tRNAGlu, tRNAGln and tRNALys. It is thought that the modifications of the wobble position of the tRNA improves the selectivity of the codon-anticodon pair as a result of the physico-chemical changes that result from substitution of sulfur and selenium for oxygen. Both selenocysteine and 2-selenouridine have widespread analogs, cysteine and thiouridine, where sulfur is used instead. To examine the role of selenium in 2-selenouridine, we comparatively analyzed the oxidation reactions of sulfur-containing 2-thiouracil-5-carboxylic acid (s2c5Ura) and its selenium analog 2-selenouracil-5-carboxylic acid (se2c5Ura) using 1H-NMR spectroscopy, 77Se-NMR spectroscopy, and liquid chromatography-mass spectrometry. Treatment of s2c5Ura with hydrogen peroxide led to oxidized intermediates, followed by irreversible desulfurization to form uracil-5-carboxylic acid (c5Ura). In contrast, se2c5Ura oxidation resulted in a diselenide intermediate, followed by conversion to the seleninic acid, both of which could be readily reduced by ascorbate and glutathione. Glutathione and ascorbate only minimally prevented desulfurization of s2c5Ura, whereas very little deselenization of se2c5Ura occurred in the presence of the same antioxidants. In addition, se2c5Ura but not s2c5Ura showed glutathione peroxidase activity, further suggesting that oxidation of se2c5Ura is readily reversible, while oxidation of s2c5Ura is not. The results of the study of these model nucleobases suggest that the use of 2-selenouridine is related to resistance to oxidative inactivation that otherwise characterizes 2-thiouridine. As the use of selenocysteine in proteins also confers resistance to oxidation, our findings suggest a common mechanism for the use of selenium in biology. PMID:28108278

TRANSPORT OF CHROMIUM AND SELENIUM IN A PRISTINE SAND AND GRAVEL AQUIFER: ROLE OF ADSORPTION PROCESSES

EPA Science Inventory

Field transport experiments were conducted in an oxic sand and gravel aquifer using Br (bromide ion), Cr (chromium, injected as Cr(VI)), Se (selenium, injected as Se(VI)), and other tracers. The aquifer has mildly acidic pH values and low concentrations of dissolved salts. Within...

Dietary selenium supplementation and whole blood gene expression in healthy North American men

USDA-ARS?s Scientific Manuscript database

Selenium (Se) is a trace nutrient required in microgram amounts by all animals, with a recommended dietary allowance of 55 µg/d in humans. The biological functions of Se are performed by a group of 25 selenoproteins containing the unusual amino acid selenocysteine at their active sites. The selenopr...

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

USDA-ARS?s Scientific Manuscript database

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...

Cathodic electrodeposition of amorphous elemental selenium from an air- and water-stable ionic liquid.

PubMed

Redman, Daniel W; Murugesan, Sankaran; Stevenson, Keith J

2014-01-14

Electrodeposition of selenium from 1-propyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide is reported. In situ UV-vis spectroelectrochemistry was used to investigate the reduction of diethyl selenite to form elemental selenium thin films from an ionic liquid-acetonitrile medium. Three reduction peaks of diethyl selenite were observed via cyclic voltammetry and are attributed to the stepwise reduction of the selenium precursor adsorbed on the electrode. The electrodeposition mechanism is influenced by both potential and time. Electrodeposition at -1.7 V vs Pt QRE resulted in the deposition of elemental selenium nanoparticles that with time coalesced to form a continuous film. At reduction potentials more negative than -1.7 V the morphology of the deposit changed significantly due to the reduction of elemental Se to Se(2-). In addition, p-type photoconductivity of the films was observed during the spectroelectrochemical measurements. X-ray diffraction and Raman spectroscopy confirmed that the deposited selenium films were amorphous. X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy confirm the films consisted of pure selenium with minor residual contamination from the precursor and ionic liquid.

Dietary supplementation of organic selenium could improve performance, antibody response, and yolk oxidative stability in laying hens fed on diets containing oxidized fat.

PubMed

Laika, M; Jahanian, R

2015-06-01

The present study was carried out to investigate the effect of dietary supplementation of organic selenium (Se) on performance, egg quality indices, and yolk oxidative stability in laying hens fed diets with different fat sources. A total of 270 Hy-line W-36 Leghorn hens of 47 weeks of age were randomly distributed into the 5 replicate cages of 9 dietary treatments. Experimental diets consisted of a 3 × 3 factorial arrangement of treatments with three different fat sources (soybean oil, SO; yellow grease, YG; and palm fat powder, PFP) and three different levels of supplemental Se (0, 0.2, and 0.4 mg/kg of diet) as supplied by zinc-L-selenomethionine (ZnSeMet) complex, which fed during a 77-day feeding trial including 7 days for adaptation and 70 days as the main recording period. Results showed that the highest (P < 0.05) egg weights assigned to the hens fed on SO-supplemented diets. Hen-day egg production was affected by both dietary fat source (P < 0.01) and Se level (P < 0.05) throughout the trial period. Regardless of dietary fat source, dietary supplementation of ZnSeMet improved (P < 0.05) egg mass during all trial periods. Moreover, the significant (P < 0.05) fat  source× Se interactions were observed for egg mass, so that dietary supplementation with 0.4 mg/kg Se was more effective in diets supplemented with YG. Although feed intake was not affected by experimental diets during the first 35-day period, dietary inclusion of PFP reduced feed intake during both second 35-day (P < 0.01) and entire trial period (P < 0.05). The best (P < 0.01) feed conversion ratio during the first 35-day period was assigned to the birds fed on SO-diets, followed by those fed YG-diets. Dietary supplementation of ZnSeMet improved (P < 0.05) feed efficiency during the first 35-day period. Supplementation of ZnSeMet into the diets increased yolk index, with more impact in hens fed on YG-diets. The highest concentration of yolk malondialdehyde was observed in YG-fed groups, and ZnSeMet supplementation of diets decreased (P < 0.05) yolk malondialdehyde. The highest (P<0.01) glutathione peroxidase activity was observed for hens fed on diets supplemented by YG, followed by those on SO-diets. Although different fat sources had no effect on antibody titer against Newcastle disease virus, supplemental ZnSeMet improved (P < 0.05) antibody response. The present findings indicate that dietary supplementation of ZnSeMet could improve performance parameters and egg oxidative stability in laying hens, with the highest impact in diets containing oxidized (high peroxide values) fat sources.

Selenium as an essential micronutrient: roles in cell cycle and apoptosis.

PubMed

Zeng, Huawei

2009-03-23

Selenium is an essential trace element for humans and animals, and selenium deficiency is associated with several disease conditions such as immune impairment. In addition, selenium intakes that are greater than the recommended daily allowance (RDA) appear to protect against certain types of cancers. In humans and animals, cell proliferation and death must be regulated to maintain tissue homeostasis, and it has been well documented that numerous human diseases are directly related to the control of cell cycle progression and apoptosis. Thus, the elucidation of the mechanisms by which selenium regulates the cell cycle and apoptosis can lead to a better understanding of the nature of selenium's essentiality and its role in disease prevention. This article reviews the status of knowledge concerning the effect of selenium on cell cycle and apoptosis.

Systems and methods for solar cells with CIS and CIGS films made by reacting evaporated copper chlorides with selenium

DOEpatents

Albin, David S.; Noufi, Rommel

2015-06-09

Systems and methods for solar cells with CIS and CIGS films made by reacting evaporated copper chlorides with selenium are provided. In one embodiment, a method for fabricating a thin film device comprises: providing a semiconductor film comprising indium (In) and selenium (Se) upon a substrate; heating the substrate and the semiconductor film to a desired temperature; and performing a mass transport through vapor transport of a copper chloride vapor and se vapor to the semiconductor film within a reaction chamber.

Exploring the structural basis for selenium/mercury antagonism in Allium fistulosum

DOE Office of Scientific and Technical Information (OSTI.GOV)

McNear, Jr., David H.; Afton, Scott E.; Caruso, Joseph A.

While continuing efforts are devoted to studying the mutually protective effect of mercury and selenium in mammals, few studies have investigated the mercury-selenium antagonism in plants. In this study, we report the metabolic fate of mercury and selenium in Allium fistulosum (green onion) after supplementation with sodium selenite and mercuric chloride. Analysis of homogenized root extracts via capillary reversed phase chromatography coupled with inductively coupled plasma mass spectrometry (capRPLC-ICP-MS) suggests the formation of a mercury-selenium containing compound. Micro-focused synchrotron X-ray fluorescence mapping of freshly excised roots show Hg sequestered on the root surface and outlining individual root cells, while Semore » is more evenly distributed throughout the root. There are also discrete Hg-only, Se-only regions and an overall strong correlation between Hg and Se throughout the root. Analysis of the X-ray absorption near edge structure (XANES) spectra show a 'background' of methylselenocysteine within the root with discrete spots of SeO{sub 3}{sup 2-}, Se{sup 0} and solid HgSe on the root surface. Mercury outlining individual root cells is possibly binding to sulfhydryl groups or plasma membrane or cell wall proteins, and in some places reacting with reduced selenium in the rhizosphere to form a mercury(II) selenide species. Together with the formation of the root-bound mercury(II) selenide species, we also report on the formation of cinnabar (HgS) and Hg{sup 0} in the rhizosphere. The results presented herein shed light on the intricate chemical and biological processes occurring within the rhizosphere that influence Hg and Se bioavailability and will be instrumental in predicting the fate and assisting in the remediation of these metals in the environment and informing whether or not fruit and vegetable food selection from aerial plant compartments or roots from plants grown in Hg contaminated soils, are safe for consumption.« less

Simultaneous removal of SO2 and trace SeO2 from flue gas: effect of SO2 on selenium capture and kinetics study.

PubMed

Li, Yuzhong; Tong, Huiling; Zhuo, Yuqun; Wang, Shujuan; Xu, Xuchang

2006-12-15

Sulfur dioxide (SO2) and trace elements are all pollutants derived from coal combustion. This study relates to the simultaneous removal of SO2 and trace selenium dioxide (SeO2) from flue gas by calcium oxide (CaO) adsorption in the moderate temperature range, especially the effect of SO2 presence on selenium capture. Experiments performed on a thermogravimetric analyzer (TGA) can reach the following conclusions. When the CaO conversion is relatively low and the reaction rate is controlled by chemical kinetics, the SO2 presence does not affect the selenium capture. When the CaO conversion is very high and the reaction rate is controlled by product layer diffusion, the SO2 presence and the product layer diffusion resistance jointly reduce the selenium capture. On the basis of the kinetics study, a method to estimate the trace selenium removal efficiency using kinetic parameters and the sulfur removal efficiency is developed.

Metabolic and immune response of young turkeys originating from parent flocks fed diets with inorganic or organic selenium.

PubMed

Jankowski, J; Zduńczyk, Z; Sartowska, K; Tykałowski, B; Stenzel, T; Wróblewska, M; Koncicki, A

2011-01-01

The aim of this study was to verify the hypothesis that the health and growth of turkey poults may be improved by supplementing diets fed to parent flocks with available selenium. Experimental poults originated from parent flocks fed with diets containing 0.3 mg/kg inorganic selenium (control group Se(M)) and organic selenium (experimental group Se(O)). Egg yolk selenium content was comparable in both flocks (0.72 and 0.70 mg/kg d.m., respectively). Eggs from the Se(O) flock had a significantly lower content of thiobarbituric acid reactive substances - TBARS (31.13 vs. 53.10 nmol/g, p > 0.001). Se(O) group poults were characterized by higher activity of glutathione peroxidase (7.54 vs. 5.92 U/mL, P = 0.001) and superoxide dismutase (89.30 vs. 79.23 U/mL, P = 0.026). The thigh muscles of Se(O) group birds had significantly higher selenium concentrations (0.74 vs. 0.57, p = 0.045) and a significantly lower TBARS content (38.42 vs. 65.01, p = 0.001). No differences were found between the groups with respect to the content of total protein, albumins and uric acid, and the activites of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (DLH) in day-old poults. On day 28, groups Se(O) and Se(M) differed in the activity of ALT (20.50 vs. 26.33, p = 0.05) and SOD (87.29 vs. 100.02 U/mL, p = 0.035). There were no differences between the groups regarding the percentages of T lymphocyte subpopulations CD4+, CD8+, CD4+CD8+ and B lymphocyte subpopulations (IgM+) at 1 and 28 days of age. Over the experimental period, mortality rates were similar in both groups (7.32 and 8.87%), and so were the final body weights of birds (1108 vs. 1135 g). The results of the study show that the dietary supplementation of organic selenium in turkey parent flocks reduces the rate of oxidation processes in the egg and in the tissues of newly-hatched poults, yet it has no effect on the analyzed parameters of cell-mediated immunity and the growth performance of birds during the first five weeks of their life.

Selenium concentrations and enzyme activities of glutathione metabolism in wild long-tailed ducks and common eiders

USGS Publications Warehouse

Franson, J. Christian; Hoffman, David J.; Flint, Paul L.

2011-01-01

The relationships of selenium (Se) concentrations in whole blood with plasma activities of total glutathione peroxidase, Se-dependent glutathione peroxidase, and glutathione reductase were studied in long-tailed ducks (Clangula hyemalis) and common eiders (Somateria mollissima) sampled along the Beaufort Sea coast of Alaska, USA. Blood Se concentrations were >8 μg/g wet weight in both species. Linear regression revealed that the activities of total and Se-dependent glutathione peroxidase were significantly related to Se concentrations only in long-tailed ducks, raising the possibility that these birds were experiencing early oxidative stress.

Effects of selenium on biological and physiological properties of the duckweed Landoltia punctata.

PubMed

Zhong, Y; Cheng, J J

2016-09-01

Duckweed can be used for bioremediation of selenium (Se) polluted water because of its capability of absorbing minerals from growing media. However, the presence of Se in the media may affect the growth of the duckweed. Landoltia punctata 7449 has been studied for its changes in chemical and biological properties with the presence of Se in the media. The duckweed was cultivated over a 12-day period at different initial concentrations of selenite (Na2 SeO3 ) from 0 to 80 μmol·l(-1) . The growth rate, the organic and total Se contents, the activity of antioxidant enzymes, the photosynthetic pigment contents, the chlorophyll a fluorescence OJIP transient, and the ultrastructure of the duckweed were monitored during the experiment. The results have shown that Se at low concentrations of ≤20 μmol·l(-1) promoted the growth of the L. punctata and inhibited lipid peroxidation. Substantial increases in duckweed growth rate and organic Se content in the duckweed were observed at low Se concentrations. The anti-oxidative effect occurred likely with the increases in guaiacol peroxidase, catalase and superoxide dismutase activities as well as the amount of photosynthetic pigments. However, negative impact to the duckweed was observed when the L. punctata was exposed to high Se concentrations (≥40 μmol·l(-1) ), in which the duckweed growth was inhibited by the selenium. The results indicate that L. punctata 7449 can be used for bioremediation of selenium (Se) polluted water when the Se concentration is ≤20 μmol·l(-1) . © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

Defect-induced magnetism in two-dimensional NbSe2

NASA Astrophysics Data System (ADS)

Manchanda, P.; Skomski, R.

2017-01-01

The energetics and magnetism of perfect and vacancy-containing two-dimensional NbSe2 monolayers is investigated by first-principle calculations. It has been found the single Se vacancy has the lowest formation energy. Perfect NbSe2 monolayers, as well as monolayers containing single-selenium and double-selenium vacancies, are nonmagnetic metallic. However, Nb vacancies create a magnetic moment of 1.5 μB per vacancy. The moment is highly localized, confined nearly exclusively on the Se atoms adjacent to the vacancy, and mainly originates from the Se 4p electrons. The moment distribution indicates strongly anisotropic exchange bonds between vacancy moments.

A stable lithiated silicon-chalcogen battery via synergetic chemical coupling between silicon and selenium.

PubMed

Eom, KwangSup; Lee, Jung Tae; Oschatz, Martin; Wu, Feixiang; Kaskel, Stefan; Yushin, Gleb; Fuller, Thomas F

2017-01-05

Li-ion batteries dominate portable energy storage due to their exceptional power and energy characteristics. Yet, various consumer devices and electric vehicles demand higher specific energy and power with longer cycle life. Here we report a full-cell battery that contains a lithiated Si/graphene anode paired with a selenium disulfide (SeS 2 ) cathode with high capacity and long-term stability. Selenium, which dissolves from the SeS 2 cathode, was found to become a component of the anode solid electrolyte interphase (SEI), leading to a significant increase of the SEI conductivity and stability. Moreover, the replacement of lithium metal anode impedes unwanted side reactions between the dissolved intermediate products from the SeS 2 cathode and lithium metal and eliminates lithium dendrite formation. As a result, the capacity retention of the lithiated silicon/graphene-SeS 2 full cell is 81% after 1,500 cycles at 268 mA g SeS2 -1 . The achieved cathode capacity is 403 mAh g SeS2 -1 (1,209 mAh cm SeS2 -3 ).

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. Copyright © 2013 Elsevier Inc. All rights reserved.

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.

Selenite reduction by the obligate aerobic bacterium Comamonas testosteroni S44 isolated from a metal-contaminated soil

PubMed Central

2014-01-01

Background Selenium (Se) is an essential trace element in most organisms but has to be carefully handled since there is a thin line between beneficial and toxic concentrations. Many bacteria have the ability to reduce selenite (Se(IV)) and (or) selenate (Se(VI)) to red elemental selenium that is less toxic. Results A strictly aerobic bacterium, Comamonas testosteroni S44, previously isolated from metal(loid)-contaminated soil in southern China, reduced Se(IV) to red selenium nanoparticles (SeNPs) with sizes ranging from 100 to 200 nm. Both energy dispersive X-ray Spectroscopy (EDX or EDS) and EDS Elemental Mapping showed no element Se and SeNPs were produced inside cells whereas Se(IV) was reduced to red-colored selenium in the cytoplasmic fraction in presence of NADPH. Tungstate inhibited Se(VI) but not Se(IV) reduction, indicating the Se(IV)-reducing determinant does not contain molybdenum as co-factor. Strain S44 was resistant to multiple heavy and transition metal(loid)s such as Se(IV), As(III), Cu(II), and Cd(II) with minimal inhibitory concentrations (MIC) of 100 mM, 20 mM, 4 mM, and 0.5 mM, respectively. Disruption of iscR encoding a transcriptional regulator negatively impacted cellular growth and subsequent resistance to multiple heavy metal(loid)s. Conclusions C. testosteroni S44 could be very useful for bioremediation in heavy metal(loid) polluted soils due to the ability to both reduce toxic Se(VI) and Se(IV) to non-toxic Se (0) under aerobic conditions and to tolerate multiple heavy and transition metals. IscR appears to be an activator to regulate genes involved in resistance to heavy or transition metal(loid)s but not for genes responsible for Se(IV) reduction. PMID:25098921

Selenium inhibits the phytotoxicity of mercury in garlic (Allium sativum)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Jiating; Gao, Yuxi, E-mail: gaoyx@ihep.ac.cn; Li, Yu-Feng

2013-08-15

To investigate the influence of selenium on mercury phytotoxicity, the levels of selenium and mercury were analyzed with inductively coupled plasma-mass spectrometry (ICP-MS) in garlic tissues upon exposure to different dosages of inorganic mercury (Hg{sup 2+}) and selenite (SeO{sub 3}{sup 2−}) or selenate (SeO{sub 4}{sup 2−}). The distributions of selenium and mercury were examined with micro-synchrotron radiation X-ray fluorescence (μ-SRXRF), and the mercury speciation was investigated with micro-X-ray absorption near edge structure (μ-XANES). The results show that Se at higher exposure levels (>1 mg/L of SeO{sub 3}{sup 2−} or SeO{sub 4}{sup 2−}) would significantly inhibit the absorption and transportation ofmore » Hg when Hg{sup 2+} levels are higher than 1 mg/L in culture media. SeO{sub 3}{sup 2−} and SeO{sub 4}{sup 2−} were found to be equally effective in reducing Hg accumulation in garlic. The inhibition of Hg uptake by Se correlates well with the influence of Se on Hg phytotoxicity as indicated by the growth inhibition factor. Elemental imaging using μ-SRXRF also shows that Se could inhibit the accumulation and translocation of Hg in garlic. μ-XANES analysis shows that Hg is mainly present in the forms of Hg–S bonding as Hg(GSH){sub 2} and Hg(Met){sub 2}. Se exposure elicited decrease of Hg–S bonding in the form of Hg(GSH){sub 2}, together with Se-mediated alteration of Hg absorption, transportation and accumulation, may account for attenuated Hg phytotoxicity by Se in garlic. -- Highlights: ► Hg phytotoxicity can be mitigated by Se supplement in garlic growth. ► Se can inhibit the accumulation and transportation of Hg in garlic tissues. ► Localization and speciation of Hg in garlic can be modified by Se.« less

Plasma selenium concentrations are sufficient and associated with protease inhibitor use in treated HIV-infected adults

USDA-ARS?s Scientific Manuscript database

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...

Selenate reduction to elemental selenium by anaerobic bacteria in sediments and culture: biogeochemical significance of a novel, sulfate-independent respiration

USGS Publications Warehouse

Oremland, Ronald S.; Hollibaugh, James T.; Maest, Ann S.; Presser, Theresa S.; Miller, Laurence G.; Culbertson, Charles W.

1989-01-01

Interstitial water profiles of SeO42−, SeO32−, SO42−, and Cl− in anoxic sediments indicated removal of the seleno-oxyanions by a near-surface process unrelated to sulfate reduction. In sediment slurry experiments, a complete reductive removal of SeO42− occurred under anaerobic conditions, was more rapid with H2 or acetate, and was inhibited by O2, NO3−, MnO2, or autoclaving but not by SO42− or FeOOH. Oxidation of acetate in sediments could be coupled to selenate but not to molybdate. Reduction of selenate to elemental selenium was determined to be the mechanism for loss from solution. Selenate reduction was inhibited by tungstate and chromate but not by molybdate. A small quantity of the elemental selenium precipitated into sediments from solution could be resolublized by oxidation with either nitrate or FeOOH, but not with MnO2. A bacterium isolated from estuarine sediments demonstrated selenate-dependent growth on acetate, forming elemental selenium and carbon dioxide as respiratory end products. These results indicate that dissimilatory selenate reduction to elemental selenium is the major sink for selenium oxyanions in anoxic sediments. In addition, they suggest application as a treatment process for removing selenium oxyanions from wastewaters and also offer an explanation for the presence of selenite in oxic waters.

Characterization of the nutritional components in fruit and cladode of selenium-enriched nutraceutical cactus pear fruit varieties grown on agricultural sediment

USDA-ARS?s Scientific Manuscript database

Different accessions of different colored cactus pear (Opuntia ficus Indica) were grown in soils high in salts, boron and selenium (Se) located in the Westside of central California. The changes in the nutritional status and biological transformation of the absorbed inorganic Se from the soils into ...

Nanocrystalline hydroxyapatite doped with selenium oxyanions: a new material for potential biomedical applications.

PubMed

Kolmas, Joanna; Oledzka, Ewa; Sobczak, Marcin; Nałęcz-Jawecki, Grzegorz

2014-06-01

Selenium-substituted hydroxyapatites containing selenate SeO4(2-) or selenite SeO3(2-) ions were synthesized using a wet precipitation method. The selenium content was determined by atomic absorbance spectrometry. The raw, unsintered powders were also characterized using powder X-ray diffraction, middle-range FT-IR spectroscopy and transmission electron microscopy with energy-dispersive X-ray spectroscopic microanalysis. The synthesized apatites were found to be pure and nanocrystalline with a crystal size similar to that in bone mineral. The incorporation of selenium oxyanions into the crystal lattice was confirmed. The toxicity of hydroxyapatites containing selenite or selenate ions was evaluated with a protozoan assay and bacterial luminescence test. Copyright © 2014 Elsevier B.V. All rights reserved.

Molybdenum accumulation, tolerance and molybdenum-selenium-sulfur interactions in Astragalus selenium hyperaccumulator and nonaccumulator species.

PubMed

DeTar, Rachael Ann; Alford, Élan R; Pilon-Smits, Elizabeth A H

2015-07-01

Some species hyperaccumulate selenium (Se) upwards of 0.1% of dry weight. This study addressed whether Se hyperaccumulators also accumulate and tolerate more molybdenum (Mo). A field survey revealed on average 2-fold higher Mo levels in three hyperaccumulator Astragali compared to three nonaccumulator Astragali, which were not significantly different. Next, a controlled study was performed where hyperaccumulators Astragalus racemosus and Astragalus bisulcatus were compared with nonaccumulators Astragalus drummondii and Astragalus convallarius for Mo accumulation and tolerance, alone or in the presence of Se. When grown on agar media with 0, 12, 24 or 48 mg L(-1) molybdate and/or 0, 1.6 or 3.2 mg L(-1) selenate, all species decreased in biomass with increasing Mo supply. Selenium did not impact biomass at the supplied levels. All Astragali accumulated Mo upwards of 0.1% of dry weight. Selenium levels were up to 0.08% in Astragalus racemosus and 0.04% Se in the other species. Overall, there was no correlation between Se hyperaccumulation and Mo accumulation capacity. However, the hyperaccumulators and nonaccumulators differed in some respects. While none of the species had a higher tissue Mo to sulfur (S) ratio than the growth medium, nonaccumulators had a higher Mo/S ratio than hyperaccumulators. Also, while molybdate and selenate reduced S accumulation in nonaccumulators, it did not in hyperaccumulators. Furthermore, A. racemosus had a higher Se/S ratio than its medium, while the other species did not. Additionally, Mo and Se treatment affected S levels in nonaccumulators, but not in hyperaccumulators. In conclusion, there is no evidence of a link between Se and Mo accumulation and tolerance in Astragalus. Sulfate transporters in hyperaccumulating Astragali appear to have higher sulfate specificity over other oxyanions, compared to nonaccumulators, and A. racemosus may have a transporter with enhanced selenate specificity relative to sulfate or molybdate. Copyright © 2015 Elsevier GmbH. All rights reserved.

Natural establishment and selenium accumulation of herbaceous plant species in soils with elevated concentrations of selenium and salinity under irrigation and tillage practices.

PubMed

Wu, L; Enberg, A; Tanji, K K

1993-04-01

The effects of irrigation and tillage practices were studied on species richness, biomass, and selenium accumulation of naturally established herbaceous plants in soils with elevated levels of selenium (Se) and salinity at Kesterson Reservoir, Merced County, California. The four different irrigation-tillage practice combinations were (1) no irrigation, no tillage; (2) irrigation, no tillage; (3) no irrigation, tillage; and (4) irrigation, tillage. The fields were allowed to become colonized naturally by herbaceous plant species. For the Mediterranean climate in the study site, irrigation was conducted biweekly through the summer months, and tillage was done in 3-month intervals. Biomass and Se accumulation of Atriplex patula L, Bassia hyssopifolia Kuntze, Rev. Gen. Pl., Melilotus indica (L.) All., and Salsola kali L. were substantially affected by irrigation. The degree and direction of the effects were found to be species dependent. The field plots which were tilled at 3-month intervals remained bare throughout the experiment. The total soil Se concentrations in the top 15 cm soil horizon were found to be in the range of 40 to 70 mg kg-1 dry wt. Soil Se concentrations below 25 cm soil depth were much lower and within a range of 2 to 4 mg kg-1. Less than 1/10th of the total soil Se inventory in the top soil horizon was water extractable, and the distribution of the Se inventory did not change significantly over the period of 1990 and 1991 despite the irrigation and tillage practices suggesting that a large portion of the Se inventory was not remobilized. The water-extractable soil Se concentration was found to be significantly lower in soils with the greatest biomass production suggesting an effective bioextraction of soil selenium by the native herbaceous plants.

Toxicity of Selenium, Weathered and Aged in Soil, to the Collembolan Folsomia candida

DTIC Science & Technology

2016-07-01

TOXICITY OF SELENIUM, WEATHERED AND AGED IN SOIL , TO THE COLLEMBOLAN FOLSOMIA CANDIDA ECBC-TR-1404...2006 4. TITLE AND SUBTITLE Toxicity of Selenium, Weathered and Aged in Soil , to the Collembolan Folsomia candida 5a. CONTRACT NUMBER 5b. GRANT...selenium (Se) to the soil invertebrate Folsomia candida using the Folsomia Reproduction Test (ISO 11267:1999). Studies were designed to generate

Safety of long-term restrictive diets for peroxisomal disorders: vitamin and trace element status of patients treated for Adult Refsum Disease.

PubMed

Baldwin, E J; Harrington, D J; Sampson, B; Feher, M D; Wierzbicki, A S

2016-03-01

Adult Refsum's Disease (ARD) is caused by defects in the pathway for alpha-oxidation of phytanic acid (PA). Treatment involves restricting the dietary intake of phytanic acid by reducing the intake of dairy-derived fat. The adequacy of micronutrient intake in patients with ARD is unknown. Patients established on the Chelsea low-PA diet had general diet macronutrients, vitamins and trace elements assessed using 7-day-weighed intakes and serial 24-h recalls. Intakes were compared with biochemical assessments of nutritional status for haematinics (ferritin), trace elements (copper, zinc, iron, selenium), water- (vitamin B6 , B12 and folate) and fat-soluble vitamins (A, D, E and K). Eleven subjects (four women, seven men) were studied. Body mass index was 27 ± 5 kg/m(2) (range 19-38). All subjects had high sodium intakes (range 1873-4828 mg). Fat-soluble vitamin insufficiencies occurred in some individuals (vitamin A, n = 2; vitamin D, n = 6; vitamin E, n = 3; vitamin K, n = 10) but were not coincident. Vitamin B6 levels were normal or elevated (n = 6). Folate and 5-methyltetrahydrofolate concentrations were normal. Metabolic vitamin B12 insufficiency was suspected in four subjects based on elevated methylmalonic acid concentrations. Low copper and selenium intakes were noted in some subjects (n = 7, n = 2) but plasma levels were adequate. Iron, ferritin and zinc intakes and concentrations were normal. Subjects with ARD can be safely managed on the Chelsea low PA without routine micronutrient supplementation. Sodium intake should be monitored and reduced. Periodic nutritional screening may be necessary for fat-soluble vitamins, vitamin B12 , copper or selenium. © 2016 John Wiley & Sons Ltd.

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 (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 (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 SeO3 2− to Se° nanospheres. Based on the bioreduction of a colorless solution of SeO3 2− 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 SeO3 2− bioreduction process in NPs treated bacterial cell culture supernatant, as a toxicity end point. PMID:23483909

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 amore » 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.« less

Protective effect of Selenium nanoparticle against cyclophosphamide induced hepatotoxicity and genotoxicity in Swiss albino mice.

PubMed

Bhattacharjee, Arin; Basu, Abhishek; Ghosh, Prosenjit; Biswas, Jaydip; Bhattacharya, Sudin

2014-08-01

Cyclophosphamide (CP) is the most commonly used chemotherapeutic drug for various types of cancer. However, its use causes severe cytotoxicity to normal cells in human. It is well known that the undesirable side effects are caused due to the formation of reactive oxygen species. Selenium is an essential micronutrient for both animals and humans and has antioxidant and membrane stabilizing property, but selenium is also toxic above certain level. Nano selenium has been well proved to be less toxic than inorganic selenium as well as certain organoselenium compounds. The objective of the study is to evaluate the protective role of Nano-Se against CP-induced hepatotoxicity and genotoxicity in Swiss albino mice. CP was administered intraperitoneally (25 mg/kg b.w.) and Nano-Se was given by oral gavages (2 mg Se/kg b.w.) in concomitant and pretreatment scheme. Intraperitoneal administration of CP induced hepatic damage as indicated by the serum marker enzymes aspartate and alanine transaminases and increased the malonaldehyde level, depleted the glutathione content and antioxidant enzyme activity (glutathione peroxidase, glutathione-s-transferase, superoxide dismutase and catalase), and induced DNA damage and chromosomal aberration. Oral administration of Nano-Se caused a significant reduction in malonaldehyde, ROS level and glutathione levels, restoration of antioxidant enzyme activity, reduction in chromosomal aberration in bone marrow, and DNA damage in lymphocytes and also in bone marrow. Moreover, the chemoprotective efficiency of Nano-Se against CP induced toxicity was confirmed by histopathological evaluation. The results support the protective effect of Nano-Se against CP-induced hepatotoxicity and genotoxicity. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Pseudomonas moraviensis subsp. stanleyae, a bacterial endophyte of hyperaccumulator Stanleya pinnata, is capable of efficient selenite reduction to elemental selenium under aerobic conditions.

PubMed

Staicu, L C; Ackerson, C J; Cornelis, P; Ye, L; Berendsen, R L; Hunter, W J; Noblitt, S D; Henry, C S; Cappa, J J; Montenieri, R L; Wong, A O; Musilova, L; Sura-de Jong, M; van Hullebusch, E D; Lens, P N L; Reynolds, R J B; Pilon-Smits, E A H

2015-08-01

To identify bacteria with high selenium tolerance and reduction capacity for bioremediation of wastewater and nanoselenium particle production. A bacterial endophyte was isolated from the selenium hyperaccumulator Stanleya pinnata (Brassicaceae) growing on seleniferous soils in Colorado, USA. Based on fatty acid methyl ester analysis and multi-locus sequence analysis (MLSA) using 16S rRNA, gyrB, rpoB and rpoD genes, the isolate was identified as a subspecies of Pseudomonas moraviensis (97.3% nucleotide identity) and named P. moraviensis stanleyae. The isolate exhibited extreme tolerance to SeO3(2-) (up to 120 mmol l(-1)) and SeO4(2-) (>150 mmol l(-1)). Selenium oxyanion removal from growth medium was measured by microchip capillary electrophoresis (detection limit 95 nmol l(-1) for SeO3(2-) and 13 nmol l(-1) for SeO4(2-)). Within 48 h, P. moraviensis stanleyae aerobically reduced SeO3(2-) to red Se(0) from 10 mmol l(-1) to below the detection limit (removal rate 0.27 mmol h(-1) at 30 °C); anaerobic SeO3(2-) removal was slower. No SeO4(2-) removal was observed. Pseudomonas moraviensis stanleyae stimulated the growth of crop species Brassica juncea by 70% with no significant effect on Se accumulation. Pseudomonas moraviensis stanleyae can tolerate extreme levels of selenate and selenite and can deplete high levels of selenite under aerobic and anaerobic conditions. Pseudomonas moraviensis subsp. stanleyae may be useful for stimulating plant growth and for the treatment of Se-laden wastewater. © 2015 The Society for Applied Microbiology.

Antioxidant effects of selenium on lung injury in paraquat intoxicated rats

USGS Publications Warehouse

Kim, K.S.; Suh, G.J.; Kwon, W.Y.; Kwak, Y.H.; Lee, Kenneth; Lee, H.J.; Jeong, K.Y.; Lee, M.W.

2012-01-01

CONTEXT: Paraquat (PQ) causes lethal intoxication by inducing oxidant injury to the lung. Selenium is a cofactor for glutathione peroxidase (GPx), which is one of the major endogenous antioxidant enzymes. OBJECTIVE: To determine whether selenium post-treatment activates GPx, decreases lung injury, and improves survival in PQ intoxicated rats. MATERIALS AND METHODS: Male Spraque-Dawley rats were categorized into three groups: sham (n = 6), PQ (n = 12), and PQ + Se (n = 12). In the PQ and PQ + Se groups, 50 mg/kg of PQ was administered intraperitoneally. After 10 minutes, 60 μg/kg of Se (PQ + Se) or saline (PQ) was administered via the tail vein. Six rats per group were euthanized 6 hours or 24 hours later. Lung tissues were harvested for the measurement of GPx activity, reduced glutathione (GSH), glutathione disulfide (GSSG) and malondialdehyde (MDA) and for histological analysis. Using separated set of rats, survival of PQ (n = 10) and PQ + Se (n = 10) were observed for 72 hours. RESULTS: GPx activity in the PQ group at the 6-hour and 24-hour time points was lower than in the sham group (p CONCLUSION: Single dose of selenium post-treatment activates GPx and attenuates lipid peroxidation and lung injury early after paraquat intoxication, but does not improve 72 hours of survival.

Selenium Derivatization of Nucleic Acids for Crystallography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang,J.; Sheng, J.; Carrasco, N.

2007-01-01

The high-resolution structure of the DNA (5'-GTGTACA-C-3') with the selenium derivatization at the 2'-position of T2 was determined via MAD and SAD phasing. The selenium-derivatized structure (1.28 {angstrom} resolution) with the 2'-Se modification in the minor groove is isomorphorous to the native structure (2.0 {angstrom}). To directly compare with the conventional bromine derivatization, we incorporated bromine into the 5-postion of T4, determined the bromine-derivatized DNA structure at 1.5 {angstrom} resolution, and found that the local backbone torsion angles and solvent hydration patterns were altered in the structure with the Br incorporation in the major groove. Furthermore, while the native andmore » Br-derivatized DNAs needed over a week to form reasonable-size crystals, we observed that the Se-derivatized DNAs grew crystals overnight with high-diffraction quality, suggesting that the Se derivatization facilitated the crystal formation. In addition, the Se-derivatized DNA sequences crystallized under a broader range of buffer conditions, and generally had a faster crystal growth rate. Our experimental results indicate that the selenium derivatization of DNAs may facilitate the determination of nucleic acid X-ray crystal structures in phasing and high-quality crystal growth. In addition, our results suggest that the Se derivatization can be an alternative to the conventional Br derivatization.« less

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.

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 vaccination. Also it was possible to meet the dietary selenium requirement of pacu, that was estimated to be 1.56 mg/kg. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biosynthesis of Se-methyl-seleno-l-cysteine in Basidiomycetes fungus Lentinula edodes (Berk.) Pegler.

PubMed

Klimaszewska, M; Górska, S; Dawidowski, M; Podsadni, P; Turło, J

2016-01-01

The aim of the current study was to investigate whether the Basidiomycetes fungus Lentinula edodes can biosynthesize Se-methyl-seleno-l-cysteine, a seleno-amino acid with strong anticancer activity, and to optimize the culture conditions for its biosynthesis. We hypothesize that preparations obtained from Se-methyl-seleno-l-cysteine-enriched mycelia from this medicinal mushroom would possess stronger cancer-preventive properties than current preparations. By optimizing the concentration of selenium in the culture medium, we increased the mycelial concentration of Se-methyl-seleno-l-cysteine from essentially non-detectable levels to 120 µg/g dry weight. Significantly elevated levels of this amino acid also correlated with significant (twofold) inhibition of mycelial growth. Increases in the concentration of mycelial Se-methyl-seleno-l-cysteine appeared to be highly correlated with the enhanced biosynthesis of selenomethionine and total selenium content in mycelium. We have demonstrated that in L. edodes, enhanced biosynthesis of this non-protein amino acid eliminates excess selenium.

Supplementation with Selenium and Coenzyme Q10 Reduces Cardiovascular Mortality in Elderly with Low Selenium Status. A Secondary Analysis of a Randomised Clinical Trial

PubMed Central

Alexander, Jan; Aaseth, Jan

2016-01-01

Background Selenium is needed by all living cells in order to ensure the optimal function of several enzyme systems. However, the selenium content in the soil in Europe is generally low. Previous reports indicate that a dietary supplement of selenium could reduce cardiovascular disease but mainly in populations in low selenium areas. The objective of this secondary analysis of a previous randomised double-blind placebo-controlled trial from our group was to determine whether the effects on cardiovascular mortality of supplementation with a fixed dose of selenium and coenzyme Q10 combined during a four-year intervention were dependent on the basal level of selenium. Methods In 668 healthy elderly individuals from a municipality in Sweden, serum selenium concentration was measured. Of these, 219 individuals received daily supplementation with selenium (200 μg Se as selenized yeast) and coenzyme Q10 (200 mg) combined for four years. The remaining participants (n = 449) received either placebo (n = 222) or no treatment (n = 227). All cardiovascular mortality was registered. No participant was lost during a median follow-up of 5.2 years. Based on death certificates and autopsy results, all mortality was registered. Findings The mean serum selenium concentration among participants at baseline was low, 67.1 μg/L. Based on the distribution of selenium concentration at baseline, the supplemented group was divided into three groups; <65 μg/L, 65–85 μg/L, and >85 μg/L (45 and 90 percentiles) and the remaining participants were distributed accordingly. Among the non-treated participants, lower cardiovascular mortality was found in the high selenium group as compared with the low selenium group (13.0% vs. 24.1%; P = 0.04). In the group with the lowest selenium basal concentration, those receiving placebo or no supplementation had a mortality of 24.1%, while mortality was 12.1% in the group receiving the active substance, which was an absolute risk reduction of 12%. In the middle selenium concentration group a mortality of 14.0% in the non-treated group, and 6.0% in the actively treated group could be demonstrated; thus, there was an absolute risk reduction of 8.0%. In the group with a serum concentration of >85 μg/L, a cardiovascular mortality of 17.5% in the non-treated group, and 13.0% in the actively treated group was observed. No significant risk reduction by supplementation could thus be found in this group. Conclusions In this evaluation of healthy elderly Swedish municipality members, two important results could be reported. Firstly, a low mean serum selenium concentration, 67 μg/L, was found among the participants, and the cardiovascular mortality was higher in the subgroup with the lower selenium concentrations <65 μg/L in comparison with those having a selenium concentration >85 μg/L. Secondly, supplementation was cardio-protective in those with a low selenium concentration, ≤85 at inclusion. In those with serum selenium>85 μg/L and no apparent deficiency, there was no effect of supplementation. This is a small study, but it presents interesting data, and more research on the impact of lower selenium intake than recommended is therefore warranted. Trial Registration Clinicaltrials.gov NCT01443780 PMID:27367855

Understanding reduced inorganic mercury accumulation in rice following selenium application: Selenium application routes, speciation and doses.

PubMed

Tang, Wenli; Dang, Fei; Evans, Douglas; Zhong, Huan; Xiao, Lin

2017-02-01

Selenium (Se) has recently been demonstrated to reduce inorganic mercury (IHg) accumulation in rice plants, while its mechanism is far from clear. Here, we aimed at exploring the potential effects of Se application routes (soil or foliar application with Se), speciation (selenite and selenate), and doses on IHg-Se antagonistic interactions in soil-rice systems. Results of our pot experiments indicated that soil application but not foliar application could evidently reduce tissue IHg concentrations (root: 0-48%, straw: 15-58%, and brown rice: 26-74%), although both application routes resulted in comparable Se accumulation in aboveground tissues. Meanwhile, IHg distribution in root generally increased with amended Se doses in soil, suggesting antagonistic interactions between IHg and Se in root. These results provided initial evidence that IHg-Se interactions in the rhizosphere (i.e., soil or rice root), instead of those in the aboveground tissues, could probably be more responsible for the reduced IHg bioaccumulation following Se application. Furthermore, Se dose rather than Se speciation was found to be more important in controlling IHg accumulation in rice. Our findings regarding the importance of IHg-Se interactions in the rhizosphere, together with the systematic investigation of key factors affecting IHg-Se antagonism and IHg bioaccumulation, advance our understanding of Hg dynamics in soil-rice systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Selenium emission control at high temperatures with mineral sorbents. Final report, September 1, 1994--February 29, 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh-Dastidar, A.; Mahuli, S.; Agnihotri, R.

1996-03-01

The focus of this project is on toxic metal removal by sorbent injection in the upper furnace and economizer sections of a coal- fired boiler. Selenium was chosen as the candidate heavy metal to be studied because of its high volatility and associated difficulties in removal. A thorough mechanistic investigation of the SeO{sub 2}-Ca(OH){sub 2} interaction at both medium and high temperatures has been conducted in this project. Experiments were performed in the two temperature ranges in the presence and absence of O{sub 2}; desorption studies were conducted to characterize the nature of interaction; and XRD/XPS and Ion Chromatography studiesmore » were performed for species identification. It was inferred from these findings that the selenium capture was significantly more in the medium temperature range (450-650{degrees}C) than in high temperature range (800-1000{degrees}C) and the captured selenium species in the medium temperature range is in the form of calcium selenite (CaSeO{sub 3}) and a reaction scheme was proposed for the CaO/SeO{sub 2} interaction: CaO (s) + SeO{sub 2} (g) = CaSeO{sub 3} (s). This reaction process does not require the participation of oxygen, as was confirmed by various analytical techniques and supported by the experimental evidence. Results of the high-temperature studies indicate much reduced capture at these temperatures with negligible selenium sorption above 900{degrees}C. This behavior was attributed to the decomposition of calcium selenite at higher temperatures.« less

Determination of the distribution and speciation of selenium in an argillaceous sample using chemical extractions and post-extractions analyses: application to the hydrogeological experimental site of Poitiers.

PubMed

Bassil, Joseph; Naveau, Aude; Bueno, Maïté; Di Tullo, Pamela; Grasset, Laurent; Kazpard, Véronique; Razack, Moumtaz

2016-05-01

To better understand selenium's dynamics in environmental systems, the present study aims to investigate selenium speciation and distribution in black argillaceous sediments, partially fulfilling karstic cavities into the Hydrogeological Experimental Site of Poitiers. These sediments are suspected to be responsible for selenium concentrations exceeding the European Framework Directive's drinking water limit value (10 μg L(-1)) in some specific wells. A combination of a sequential extractions scheme and single parallel extractions was thus applied on a representative argillaceous sample. Impacts of the extractions on mineral dissolution and organic matter mobilization were followed by quantifying major cations and total organic carbon (TOC) in the aqueous extracts. The nature of the released organic matter was characterized using thermochemolysis coupled with gas chromatography-mass spectrometry (GC-MS). About 10 % of selenium from the black argillaceous studied matrix could be defined as 'easily mobilizable' when the majority (around 70 %) revealed associated with the aliphatic and alkaline-soluble organic matter's fraction (about 20 %). In these fractions, selenium speciation was moreover dominated by oxidized species including a mixture of Se(VI) (20-30 %) and Se(IV) (70-80 %) in the 'easily mobilizable' fraction, while only Se(IV) was detected in alkaline-soluble organic matter fraction.

Anomalous antibacterial activity and dye degradation by selenium doped ZnO nanoparticles.

PubMed

Dutta, Raj Kumar; Nenavathu, Bhavani Prasad; Talukdar, Soumita

2014-02-01

Selenium doped ZnO nanoparticles synthesized by mechanochemical method were spherically shaped of size distribution of 10.2±3.4 nm measured by transmission electron microscopy. Diffused reflectance spectroscopy revealed increase in the band gap, ranging between 3.47 eV and 3.63 eV due to Se doping in ZnO nanoparticles. The antibacterial activity of pristine and Se doped ZnO nanoparticles was attributed to ROS (reactive oxygen species) generation in culture media confirmed by TBARS assay. Compared to complete inhibition of growth by 0.45 mg/mL of pristine ZnO nanoparticles, the batches of 0.45 mg/mL of selenium doped ZnO nanoparticles exhibited only 51% inhibition of growth of Escherichia coli. The reduced antibacterial activity of selenium doped ZnO nanoparticles was attributed to two opposing factors, e.g., ROS generation for inhibition of growth, countered by sustaining growth of E. coli due to availability of Se micronutrients in culture media, confirmed by inductively coupled plasma mass spectrometer measurement. Higher ROS generation by selenium doped ZnO nanoparticles was attributed to creation of oxygen vacancies, confirmed from green emission peak observed at 565 nm. The impact of higher ROS generation by selenium doped ZnO nanoparticles was evident from enhanced photocatalytic degradation of trypan blue dye, than pristine ZnO nanoparticles. Copyright © 2013 Elsevier B.V. All rights reserved.

Combination of Lewis Basic Selenium Catalysis and Redox Selenium Chemistry: Synthesis of Trifluoromethylthiolated Tertiary Alcohols with Alkenes.

PubMed

Zhu, Zechen; Luo, Jie; Zhao, Xiaodan

2017-09-15

A new and efficient method for diaryl selenide catalyzed vicinal CF 3 S hydroxylation of 1,1-multisubstitued alkenes has been developed. Various trifluoromethylthiolated tertiary alcohols could be readily synthesized under mild conditions. This method is also effective for the intramolecular cyclization of alkenes tethered by carboxylic acid, hydroxy, sulfamide, or ester groups and is associated with the introduction of a CF 3 S group. Mechanistic studies have revealed that the pathway involves a redox cycle between Se(II) and Se(IV) and Lewis basic selenium catalysis.

Addition of high concentration of inorganic selenium in orchardgrass (Dactylis glomerata L.) hay diet does not interfere with microbial fermentation in mixed ruminal microorganisms in continuous cultures

USDA-ARS?s Scientific Manuscript database

The current literature lacks information on ruminal microbial metabolism in response to high selenium (Se) concentration in the diet. We investigated changes in ruminal fermentation when high concentration of Se was administered in mixed ruminal cultures in fermentors. Two mature beef cows, 'tted wi...

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.

Solution-processed air-stable mesoscopic selenium solar cells

DOE PAGES

Zhu, Menghua; Hao, Feng; Ma, Lin; ...

2016-07-28

Crystalline selenium (c-Se) is a direct band gap semiconductor and has been developed for detector applications for more than 30 years. While most advances have been made using vacuum deposition processes, it remains a challenge to prepare efficient c-Se devices directly from solution. We demonstrate a simple solution process leading to uniform and high-crystallinity selenium films under ambient conditions. A combination of ethylenediamine (EDA) and hydrazine solvents was found to be effective in dissolving selenium powder and forming highly concentrated solutions. These can be used to infiltrate a mesoporous titanium dioxide layer and form a smooth and pinhole-free capping overlayer.more » Efficient light-induced charge injection from the crystalline selenium to TiO 2 was observed using transient absorption spectroscopy. A small amount of EDA addition in the hydrazine solution was found to improve the film coverage significantly, and on the basis of the finding, we are able to achieve up to 3.52% power conversion efficiency solar cells with a fill factor of 57%. Lastly, these results provide a method to control the crystalline selenium film and represent significant progress in developing low-cost selenium-based solar cells.« less

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.

FTIR spectroscopic studies of selenite reduction by cells of the rhizobacterium Azospirillum brasilense Sp7 and the formation of selenium nanoparticles

NASA Astrophysics Data System (ADS)

Kamnev, Alexander A.; Mamchenkova, Polina V.; Dyatlova, Yulia A.; Tugarova, Anna V.

2017-07-01

Microbially driven reduction of selenium oxyanions to elementary selenium, often in the form of nanoparticles (NPs), is widespread in nature. A diversity of possible applications of such biogenic NPs, including those in nanobiotechnology, as well as the specificity of methodologies and mechanisms of their formation via ;green synthesis; are very attractive features justifying further studies of the processes of selenium oxyanion bioreduction and the resulting Se0 nanostructures. In this study, live biomass of the rhizobacterium Azospirillum brasilense Sp7 (harvested after the logarithmic growth phase and washed from culture medium components) was used to obtain extracellular Se NPs relatively homogeneous in size (with average diameters within 50-100 nm) in the process of selenite reduction. Both the control cultures of A. brasilense Sp7 and those incubated with SeO32- (producing Se NPs), as well as the resulting separated Se NPs were studied using Fourier transform infrared (FTIR) spectroscopy in the transmission mode (measured as dried layers on a ZnSe disc), in addition to transmission electron microscopy (TEM), to compare metabolic changes in cells and the bioorganic layers associated with the Se NPs. In the control culture (stored for 24 h in physiological saline), FTIR spectroscopic signs of poly-3-hydroxybutyrate (a 'reserve' biopolyester) were observed as a response to the lack of nutrients (trophic stress), whereas they were virtually absent in cells incubated for 24 h in physiological saline with 10 mM SeO32- (toxicity stress). FTIR spectra of Se NPs separated from bacterial cells showed bands typical of proteins, polysaccharides and lipids associated with the particles (in line with their TEM images showing a thin layer over the NPs), in addition to strong carboxylate bands, which evidently stabilise the NP structure and morphology.

Optimised selenium enrichment of Artemia sp. feed to improve red drum (Sciaenops ocellatus) larvae rearing.

PubMed

Juhász, Péter; Lengyel, Szvetlana; Udvari, Zsolt; Sándor, Alex Nagy; Stündl, László

2017-09-01

Selenium is an essential microelement for the normal functioning of life processes. Moreover, it is a component of enzymes with antioxidant effects. However, it has the smallest window of any micronutrient between requirement and toxicity. Selenium is a regularly used element in fish feeds; moreover, enriching zooplankton with selenium to rear larvae is also a well-known technology. It is accepted that the most common starter foods of fish larvae, natural rotifers contain the smallest dosage of selenium, but providing selenium enriched Artemia sp. instead could increase survival and growth rate of fish. However, no such references are available for the red drum (Sciaenops ocellatus) larvae. Therefore, in this study, Artemia sp. was enriched with nano-selenium of verified low toxicity and easy availability in 5 treatments (1, 5, 10, 50, 100 mg/l Se), and then, fish larvae were fed with four of these enriched Artemia stocks (1, 5, 10, 50 mg/l Se) and a control group. At the end of the 9-day-long experiment, survival rate (S) and growth parameters (SL, W, K-factor, SGR) of fish larvae were calculated as well as their selenium retention and glutathione peroxidase enzyme activity were analysed. It was revealed that a moderate level of selenium enrichment (~4 mg/kg dry matter) of Artemia sp. positively influences the rearing efficiency (i.e. survival and growth) of fish larvae, but higher dosages of selenium could cause adverse effects.

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.

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.

Reaction-diffusion-induced explosive crystallization in a metal-selenium nanometer film structure

NASA Astrophysics Data System (ADS)

Kogai, V. Ya.

2016-03-01

Experimental data for reaction-diffusion-induced explosive crystallization in a nanodimensional metal (Cu, Ag)/selenium structure are presented. It is found that after the metal layer has completely diffused into the amorphous Se film, the electrical potential rises from 0.14 to 1.21 V in the Cu(30 nm)/Se(140 nm) heterolayer and from 0.01 to 1.17 V in the Ag(30 nm)/Se(140 nm) heterolayer. The metals diffusing into the amorphous Se layer interact with Se, forming nuclei of a new phase (CuSe or Ag2Se). The intense growth of the CuSe and Ag2Se crystallization centers results in a considerable liberation of latent energy in the form of phase transformation heat and in explosive growth of CuSe and Ag2Se nanocrystalline particles. The mean size of CuSe and Ag2Se crystallites equals 25 and 50 nm, respectively.

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.

Selenium fertilization on lentil (Lens culinaris Medikus) grain yield, seed selenium concentration, and antioxidant activity

USDA-ARS?s Scientific Manuscript database

Selenium (Se) is an essential element for mammals but has not been considered as an essential element for higher plants. Lentil (Lens culinaris Medik.) is a cool season food legume rich in protein and a range of micronutrients including minerals (iron and zinc), folates, and carotenoids. The objecti...

Solid phase extraction for the speciation and preconcentration of inorganic selenium in water samples: a review.

PubMed

Herrero Latorre, C; Barciela García, J; García Martín, S; Peña Crecente, R M

2013-12-04

Selenium is an essential element for the normal cellular function of living organisms. However, selenium is toxic at concentrations of only three to five times higher than the essential concentration. The inorganic forms (mainly selenite and selenate) present in environmental water generally exhibit higher toxicity (up to 40 times) than organic forms. Therefore, the determination of low levels of different inorganic selenium species in water is an analytical challenge. Solid-phase extraction has been used as a separation and/or preconcentration technique prior to the determination of selenium species due to the need for accurate measurements for Se species in water at extremely low levels. The present paper provides a critical review of the published methods for inorganic selenium speciation in water samples using solid phase extraction as a preconcentration procedure. On the basis of more than 75 references, the different speciation strategies used for this task have been highlighted and classified. The solid-phase extraction sorbents and the performance and analytical characteristics of the developed methods for Se speciation are also discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

Selenium and Selenium–Sulfur Chemistry for Rechargeable Lithium Batteries: Interplay of Cathode Structures, Electrolytes, and Interfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Gui-Liang; Liu, Jianzhao; Amine, Rachid

2017-02-09

In the search for a transformative new energy storage system, the rechargeable Li/sulfur battery is considered as one of the promising candidates due to its much higher energy density and lower cost than state-of-the-art lithium-ion batteries. However, the insulating nature of sulfur and the dissolution of intermediary polysulfides into the electrolyte significantly hinder its practical application. Very recently, selenium and selenium-sulfur systems have received considerable attention as cathode materials for rechargeable batteries owing to the high electronic conductivity (20 orders of magnitude higher than sulfur) and high volumetric capacity (3254 mAh/cm3 ) of selenium. In this perspective, we present anmore » overview of the implications of employing selenium and selenium-sulfur systems with different structures and compositions as electroactive materials for rechargeable lithium batteries. We also show how the cathode structures, electrolytes, and electrode-electrolyte interfaces affect the electrochemistry of Se and Se-S based cathodes. Furthermore, suggestions are provided on paths for future development of these cathodes.« less

Bacterial reduction of selenium in coal mine tailings pond sediment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siddique, T.; Arocena, J.M.; Thring, R.W.

2007-05-15

Sediment from a storage facility for coal tailings solids was assessed for its capacity to reduce selenium (Se) by native bacterial community. One Se{sup 6+}-reducing bacterium Enterobacter hormaechei (Tar11) and four Se{sup 4+}-reducing bacteria, Klebsiella pneumoniae (Tar1), Pseudomonasfluorescens (Tar3), Stenotrophomonas maltophilia (Tar6), and Enterobacter amnigenus (Tar8) were isolated from the sediment. Enterobacter horinaechei removed 96% of the added Se{sup 6+} (0.92 mg L{sup -1} from the effluents when Se6+ was determined after 5 d of incubation. Analysis of the red precipitates showed that Se{sup 6+} reduction resulted in the formation of spherical particles ({lt}1.0 {mu} m) of Se 0 asmore » observed under scanning electron microscope (SEM) and confirmed by EDAX. Selenium speciation was performed to examine the fate of the added Se{sup 6+} in the sediment with or without addition of Enterobacter hormaechei cells. More than 99% of the added Se{sup 6+} (about 2.5 mg L{sup -1}) was transformed in the nonsterilized sediment (without Enterobacter hormaechei cells) as well as in the sterilized (heat-killed) sediment (with Enterobacter hormaechei cells). The results of this study suggest that the lagoon sediments at the mine site harbor Se{sup 6+}- and Se{sup 4+} -reducing bacteria and may be important sinks for soluble Se (Se{sup 6+} and Se{sup 4+}). Enterobacter hormaechei isolated from metal-contaminated sediment may have potential application in removing Se from industrial effluents.« less

Selenium stable isotope investigation into selenium biogeochemical cycling in a lacustrine environment: Sweitzer Lake, Colorado.

PubMed

Clark, Scott K; Johnson, Thomas M

2010-01-01

We present a comprehensive set of Se concentration and isotope ratio data collected over a 3-yr period from dissolved, sediment-hosted, and organically bound Se in a Se-contaminated lake and littoral wetland. Median isotope ratios of these various pools of Se spanned a narrow isotopic range (delta80/76Se(SRM-3149)) = 1.14-2.40 per thousand). Selenium (VI) reduction in the sediments is an important process in this system, but its isotopic impact is muted by the lack of direct contact between surface waters and reduction sites within sediments. This indicates that using Se isotope data as an indicator of microbial or abiotic Se oxyanion reduction is not effective in this or other similar systems. Isotopic data suggest that most Se(IV) in the lake originates from oxidation of organically bound Se rather than directly through Se(VI) reduction. Mobilization of Se(VI) from bedrock involves only a slight isotopic shift. Temporally constant isotopic differences observed in Se(VI) from two catchment areas suggest the potential for tracing Se(VI) from different source areas. Phytoplankton isotope ratios are close to those of the water, with a small depletion in heavy isotopes (0.56 per thousand). Fish tissues nearly match the phytoplankton, being only slightly depleted in the heavier isotopes. This suggests the potential for Se isotopes as migration indicators. Volatile, presumably methylated Se was isotopically very close to median values for phytoplankton and macrophytes, indicating a lack of isotopic fractionation during methylation.

Mechanism of Selenium Loss in Copper Slag

NASA Astrophysics Data System (ADS)

Desai, Bhavin; Tathavadkar, Vilas; Basu, Somnath

2018-03-01

During smelting of copper sulfide concentrate, selenium is distributed between silica-saturated iron-silicate slag and copper-iron sulfide matte. The recovery coefficients of selenium between slag and matte were determined as a function of the initial concentration of selenium at 1523 K (1250 °C) under an inert atmosphere in a vertical tubular furnace. The initial concentration of selenium was varied by the addition of metallic selenium as well as selenium dioxide to the mixture of slag and matte. Analysis of the results indicated high affinity of selenium for matte. The apparent loss of selenium with the slag was attributed to the presence of selenium-enriched matte particles entrapped in the slag, rather than dissolved SeO2. The mechanisms proposed by previous investigators were discussed and also compared with the results of the present investigation.

Mechanism of Selenium Loss in Copper Slag

NASA Astrophysics Data System (ADS)

Desai, Bhavin; Tathavadkar, Vilas; Basu, Somnath

2018-06-01

During smelting of copper sulfide concentrate, selenium is distributed between silica-saturated iron-silicate slag and copper-iron sulfide matte. The recovery coefficients of selenium between slag and matte were determined as a function of the initial concentration of selenium at 1523 K (1250 °C) under an inert atmosphere in a vertical tubular furnace. The initial concentration of selenium was varied by the addition of metallic selenium as well as selenium dioxide to the mixture of slag and matte. Analysis of the results indicated high affinity of selenium for matte. The apparent loss of selenium with the slag was attributed to the presence of selenium-enriched matte particles entrapped in the slag, rather than dissolved SeO2. The mechanisms proposed by previous investigators were discussed and also compared with the results of the present investigation.

A stable lithiated silicon–chalcogen battery via synergetic chemical coupling between silicon and selenium

PubMed Central

Eom, KwangSup; Lee, Jung Tae; Oschatz, Martin; Wu, Feixiang; Kaskel, Stefan; Yushin, Gleb; Fuller, Thomas F.

2017-01-01

Li-ion batteries dominate portable energy storage due to their exceptional power and energy characteristics. Yet, various consumer devices and electric vehicles demand higher specific energy and power with longer cycle life. Here we report a full-cell battery that contains a lithiated Si/graphene anode paired with a selenium disulfide (SeS2) cathode with high capacity and long-term stability. Selenium, which dissolves from the SeS2 cathode, was found to become a component of the anode solid electrolyte interphase (SEI), leading to a significant increase of the SEI conductivity and stability. Moreover, the replacement of lithium metal anode impedes unwanted side reactions between the dissolved intermediate products from the SeS2 cathode and lithium metal and eliminates lithium dendrite formation. As a result, the capacity retention of the lithiated silicon/graphene—SeS2 full cell is 81% after 1,500 cycles at 268 mA gSeS2−1. The achieved cathode capacity is 403 mAh gSeS2−1 (1,209 mAh cmSeS2−3). PMID:28054543

Using Sulfur Stable Isotopes to Understand Feeding Behavior and Selenium Concentrations in Yellow Perch (Perca flavescens).

PubMed

Ponton, Dominic E; Hare, Landis

2015-07-07

We measured selenium (Se) concentrations in yellow perch (Perca flavescens) muscle and their prey collected from four Se-contaminated lakes located near metal smelters in the eastern Canadian cities of Sudbury and Rouyn-Noranda. Yellow perch Se concentrations were related to their weight in two of the four lakes. Measurements of sulfur stable isotopes (δ(34)S) in yellow perch muscle and stomach contents showed that larger fish tended to feed less on zooplankton and more on benthic invertebrates than did smaller fish. Because Se concentrations are lower and δ(34)S signatures are higher in zooplankton than in sediment-feeding invertebrates, there was an inverse relationship between animal Se concentrations and δ(34)S signatures in all of our study lakes. δ(34)S signatures were highly effective in characterizing these food web relationships. Selenium concentrations in yellow perch were 1.6 times those of its prey, which indicates that Se is biomagnified by this fish in our study lakes. Estimated Se concentrations in yellow perch gonads suggest that in two of our study lakes one-third of fish are at risk of reproductive toxicity.

Quantification of low molecular weight selenium metabolites in human plasma after treatment with selenite in pharmacological doses by LC-ICP-MS.

PubMed

Flouda, Konstantina; Dersch, Julie Maria; Gabel-Jensen, Charlotte; Stürup, Stefan; Misra, Sougat; Björnstedt, Mikael; Gammelgaard, Bente

2016-03-01

The paper presents an analytical method for quantification of low molecular weight (LMW) selenium compounds in human plasma based on liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS) and post column isotope dilution-based quantification. Prior to analysis, samples were ultrafiltrated using a cut-off value of 3000 Da. The method was validated in aqueous solution as well as plasma using standards of selenomethionine (SeMet), Se-methylselenocysteine (MeSeCys), selenite, and the selenosugar Se-methylseleno-N-acetylgalactosamine (SeGal) for linearity, precision, recoveries, and limits of detection and quantitation with satisfactory results. The method was applied for analysis of a set of plasma samples from cancer patients receiving selenite treatment in a clinical trial. Three LMW selenium compounds were observed. The main compounds, SeGal and selenite were tentatively identified by retention time matching with standards in different chromatographic systems, while the third minor compound was not identified. The identity of the selenosugar was verified by ESI-MS-MS product ion scanning, while selenite was identified indirectly as the glutathione (GSH) reaction product, GS-Se-SG.

Selenium hyperaccumulation by Astragalus (Fabaceae) does not inhibit root nodule symbiosis.

PubMed

Alford, Elan R; Pilon-Smits, Elizabeth A H; Fakra, Sirine C; Paschke, Mark W

2012-12-01

A survey of the root-nodule symbiosis in Astragalus and its interaction with selenium (Se) has not been conducted before. Such studies can provide insight into how edaphic conditions modify symbiotic interactions and influence partner coevolution. In this paper plant-organ Se concentration ([Se]) was investigated to assess potential Se exposure to endophytes. • Selenium distribution and molecular speciation of root nodules from Se-hyperaccumulators Astragalus bisulcatus, A. praelongus, and A. racemosus was determined by Se K-edge x-ray absorption spectroscopy. A series of greenhouse experiments were conducted to characterize the response of root-nodule symbiosis in Se-hyperaccumulators and nonhyperaccumulators. • Nodules in three Se-hyperaccumulators (Astragalus crotalariae, A. praelongus, and A. preussii) are reported for the first time. Leaves, flowers, and fruits from Se-hyperaccumulators were routinely above the hyperaccumulator threshold (1,000 µg Se g(-1) DW), but root samples rarely contained that amount, and nodules never exceeded 110 µg Se g(-1) DW. Nodules from A. bisulcatus, A. praelongus, and A. racemosus had Se throughout, with a majority stored in C-Se-C form. Finally, an evaluation of nodulation in Se-hyperaccumulators and nonhyperaccumulators indicated that there was no nodulation inhibition because of plant Se tolerance. Rather, we found that in Se-hyperaccumulators higher levels of Se treatment (up to 100 µM Se) corresponded with higher nodule counts, indicating a potential role for dinitrogen fixation in Se-hyperaccumulation. The effect was not found in nonhyperaccumulators. • As the evolution of Se hyperaccumulation in Astragalus developed, root-nodule symbiosis may have played an integral role.

Trace element supplementation in hemodialysis patients: a randomized controlled trial.

PubMed

Tonelli, Marcello; Wiebe, Natasha; Thompson, Stephanie; Kinniburgh, David; Klarenbach, Scott W; Walsh, Michael; Bello, Aminu K; Faruque, Labib; Field, Catherine; Manns, Braden J; Hemmelgarn, Brenda R

2015-04-11

People with kidney failure are often deficient in zinc and selenium, but little is known about the optimal way to correct such deficiency. We did a double-blind randomized trial evaluating the effects of zinc (Zn), selenium (Se) and vitamin E added to the standard oral renal vitamin supplement (B and C vitamins) among hemodialysis patients in Alberta, Canada. We evaluated the effect of two daily doses of the new supplement (medium dose: 50 mg Zn, 75 mcg Se, 250 IU vitamin E; low dose: 25 mg Zn, 50 mcg Se, 250 IU vitamin E) compared to the standard supplement on blood concentrations of Se and Zn at 90 days (primary outcome) and 180 days (secondary outcome) as well as safety outcomes. We enrolled 150 participants. The proportion of participants with low zinc status (blood level <815 ug/L) did not differ between the control group and the two intervention groups at 90 days (control 23.9% vs combined intervention groups 23.9%, P > 0.99) or 180 days (18.6% vs 28.2%, P = 0.24). The proportion with low selenium status (blood level <121 ug/L) was similar for controls and the combined intervention groups at 90 days (32.6 vs 19.6%, P = 0.09) and 180 days (34.9% vs 23.5%, P = 0.17). There were no significant differences in the risk of adverse events between the groups. Supplementation with low or medium doses of zinc and selenium did not correct low zinc or selenium status in hemodialysis patients. Future studies should consider higher doses of zinc (≥75 mg/d) and selenium (≥100 mcg/d) with the standard supplement. Registered with ClinicalTrials.gov (NCT01473914).

Study of Highly Selective and Efficient Thiol Derivatization using Selenium Reagents by Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Kehua; Zhang, Yun W.; Tang, Bo

2010-08-15

Biological thiols are critical physiological components and their detection often involves derivatization. This paper reports a systemic mass spectrometry (MS) investigation of the cleavage of Se-N bond by thiol to form a new Se-S bond, the new selenium chemistry for thiol labeling. Our data shows that the reaction is highly selective, rapid, reversible and efficient. For instance, among twenty amino acids, only cysteine was found to be reactive with Se-N containing reagents and the reaction takes place in seconds. By adding dithiothreitol (DTT), the newly formed Se-S bond of peptides/proteins can be reduced back to free thiol. The high selectivitymore » and excellent reversibility of the reaction provide potential of using this chemistry for selective identification of thiol compounds or enriching and purifying thiol peptides/proteins. In addition, the derivatized thiol peptides have interesting dissociation behavior, which is tunable using different selenium reagents. For example, by introducing an adjacent nucleophilic group into the selenium reagent in the case of using ebselen, the reaction product of ebselen with glutathione (GSH) is easy to lose the selenium tag upon collision-induced dissociation (CID), which is useful to "fish out" those peptides containing free cysteine residues by precursor ion scan. By contrast, the selenium tag of N-(phenylseleno) phthalimide reagent can be stable and survive in CID process, which would be of value in pinpointing thiol location using a top-down proteomic approach. Also, the high conversion yield of the reaction allows the counting of total number of thiol in proteins. We believe that ebselen or N-(phenylseleno) phthalimide as tagging thiol-protein reagents will have important applications in both qualitative and quantitative analysis of different thiol-proteins derived from living cells by MS method.« less

Pathway of cytotoxicity induced by folic acid modified selenium nanoparticles in MCF-7 cells.

PubMed

Pi, Jiang; Jin, Hua; Liu, Ruiying; Song, Bing; Wu, Qing; Liu, Li; Jiang, Jinhuan; Yang, Fen; Cai, Huaihong; Cai, Jiye

2013-02-01

Selenium nanoparticles (Se NPs) have been recognized as promising materials for biomedical applications. To prepare Se NPs which contained cancer targeting methods and to clarify the cellular localization and cytotoxicity mechanisms of these Se NPs against cancer cells, folic acid protected/modified selenium nanoparticles (FA-Se NPs) were first prepared by a one-step method. Some morphologic and spectroscopic methods were obtained to prove the successfully formation of FA-Se NPs while free folate competitive inhibition assay, microscope, and several biological methods were used to determine the in vitro uptake, subcellular localization, and cytotoxicity mechanism of FA-Se NPs in MCF-7 cells. The results indicated that the 70-nm FA-Se NPs were internalized by MCF-7 cells through folate receptor-mediated endocytosis and targeted to mitochondria located regions through endocytic vesicles transporting. Then, the FA-Se NPs entered into mitochondria; triggered the mitochondria-dependent apoptosis of MCF-7 cells which involved oxidative stress, Ca(2)+ stress changes, and mitochondrial dysfunction; and finally caused the damage of mitochondria. FA-Se NPs released from broken mitochondria were transported into nucleus and further into nucleolus which then induced MCF-7 cell cycle arrest. In addition, FA-Se NPs could induce cytoskeleton disorganization and induce MCF-7 cell membrane morphology alterations. These results collectively suggested that FA-Se NPs could be served as potential therapeutic agents and organelle-targeted drug carriers in cancer therapy.

Phytoremediation of selenium by two helophyte species in subsurface flow constructed wetland.

PubMed

Shardendu; Salhani, N; Boulyga, S F; Stengel, E

2003-03-01

The phytoremediation of selenium by two different wetland species was investigated. Selenium (20.4 microg/l) was supplied continuously to subsurface flow constructed wetlands, one vegetated with Typha latifolia L. and the other with Phragmites australis (Cav.) Trin. ex Steud. The beds of both species had same hydraulic loading rate (0.079 m(3)/m(2)/d) and water retention time (24 h). However, the mass loading rate was 1.27 mg Se/m(2)/d for Phragmites and 1.35 mg Se/m(2)/d for Typha. In the Typha bed Se migrated faster than in the Phragmites bed. After 25 d of Se supplementation in the Typha bed about 54% of the Se inlet concentration remained in the outlet water. In the Phragmites bed Se was removed completely from the water after passing through 3/4 of the bed length. After 65 d of Se supplementation the highest amount of Se (2.8 microg/g dry matter) was determined in the organic material of the Typha bed. Roots and rhizomes accumulated 2.2 and 1.8 microg/g dry matter respectively. Phragmites accumulated Se in the leaves and stems, but not in the rhizomes. The accumulation in the leaves (1.8 microg Se/g dry matter) was three times higher than in the stems (0.6 microg Se/g dry matter). Copyright 2002 Elsevier Science Ltd.

Selenium and its supplementation in cardiovascular disease--what do we know?

PubMed

Benstoem, Carina; Goetzenich, Andreas; Kraemer, Sandra; Borosch, Sebastian; Manzanares, William; Hardy, Gil; Stoppe, Christian

2015-04-27

The trace element selenium is of high importance for many of the body's regulatory and metabolic functions. Balanced selenium levels are essential, whereas dysregulation can cause harm. A rapidly increasing number of studies characterizes the wide range of selenium dependent functions in the human body and elucidates the complex and multiple physiological and pathophysiological interactions of selenium and selenoproteins. For the majority of selenium dependent enzymes, several biological functions have already been identified, like regulation of the inflammatory response, antioxidant properties and the proliferation/differentiation of immune cells. Although the potential role of selenium in the development and progression of cardiovascular disease has been investigated for decades, both observational and interventional studies of selenium supplementation remain inconclusive and are considered in this review. This review covers current knowledge of the role of selenium and selenoproteins in the human body and its functional role in the cardiovascular system. The relationships between selenium intake/status and various health outcomes, in particular cardiomyopathy, myocardial ischemia/infarction and reperfusion injury are reviewed. We describe, in depth, selenium as a biomarker in coronary heart disease and highlight the significance of selenium supplementation for patients undergoing cardiac surgery.

Selenium and Its Supplementation in Cardiovascular Disease—What do We Know?

PubMed Central

Benstoem, Carina; Goetzenich, Andreas; Kraemer, Sandra; Borosch, Sebastian; Manzanares, William; Hardy, Gil; Stoppe, Christian

2015-01-01

The trace element selenium is of high importance for many of the body’s regulatory and metabolic functions. Balanced selenium levels are essential, whereas dysregulation can cause harm. A rapidly increasing number of studies characterizes the wide range of selenium dependent functions in the human body and elucidates the complex and multiple physiological and pathophysiological interactions of selenium and selenoproteins. For the majority of selenium dependent enzymes, several biological functions have already been identified, like regulation of the inflammatory response, antioxidant properties and the proliferation/differentiation of immune cells. Although the potential role of selenium in the development and progression of cardiovascular disease has been investigated for decades, both observational and interventional studies of selenium supplementation remain inconclusive and are considered in this review. This review covers current knowledge of the role of selenium and selenoproteins in the human body and its functional role in the cardiovascular system. The relationships between selenium intake/status and various health outcomes, in particular cardiomyopathy, myocardial ischemia/infarction and reperfusion injury are reviewed. We describe, in depth, selenium as a biomarker in coronary heart disease and highlight the significance of selenium supplementation for patients undergoing cardiac surgery. PMID:25923656

Significant changes in circulating microRNA by dietary supplementation of selenium and coenzyme Q10 in healthy elderly males. A subgroup analysis of a prospective randomized double-blind placebo-controlled trial among elderly Swedish citizens.

PubMed

Alehagen, Urban; Johansson, Peter; Aaseth, Jan; Alexander, Jan; Wågsäter, Dick

2017-01-01

Selenium and coenzyme Q10 is essential for important cellular functions. A low selenium intake is reported from many European countries, and the endogenous coenzyme Q10 production is decreasing in the body with increasing age. Supplementation with selenium and coenzyme Q10 in elderly have shown reduced cardiovascular mortality and reduced levels of markers of inflammation. However, microRNA analyses could give important information on the mechanisms behind the clinical effects of supplementation. Out of the 443 healthy elderly participants that were given supplementation with 200 μg Se/day as organic selenium yeast tablets, and 200 mg/day of coenzyme Q10 capsules, or placebo for 4 years, 25 participants from each group were randomized and evaluated regarding levels of microRNA. Isolation of RNA from plasma samples and quantitative PCR analysis were performed. Volcano- and principal component analyses (PCA)-plots were used to illustrate the differences in microRNA expression between the intervention, and the placebo groups. Serum selenium concentrations were measured before intervention. On average 145 different microRNAs out of 172 were detected per sample. In the PCA plots two clusters could be identified indicating significant difference in microRNA expression between the two groups. The pre-treatment expression of the microRNAs did not differ between active treatment and the placebo groups. When comparing the post-treatment microRNAs in the active and the placebo groups, 70 microRNAs exhibited significant differences in expression, also after adjustment for multiple measurements. For the 20 microRNAs with the greatest difference in expression the difference was up to more than 4 fold and with a P-value that were less than 4.4e-8. Significant differences were found in expression of more than 100 different microRNAs with up to 4 fold differences as a result of the intervention of selenium and coenzyme Q10 combined. The changes in microRNA could be a part of mechanisms underlying the clinical effects earlier reported that reduced cardiovascular mortality, gave better cardiac function, and showed less signs of inflammation and oxdative stress following the intervention. However, more research is needed to understand biological mechanisms of the protective effects of selenium and Q10 supplementation.

Dietary factors associated with subclinical inflammation among girls.

PubMed

Del Mar Bibiloni, M; Maffeis, C; Llompart, I; Pons, A; Tur, J A

2013-12-01

Dietary patterns and biomarkers of inflammation have been scarcely associated. The aim was to assess dietary factors associated with subclinical inflammation among girls. Fasting blood samples were collected from 12- to 17-year old girls (n=219) to measure adiponectin, leptin, tumor necrosis factor-alpha, plasminogen activator inhibitor 1 (PAI-1), interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hs-CRP) levels. Body mass index (BMI) and waist-to-height ratio (WHtR), and food intake were also measured. Western (WDP) and Mediterranean (MDP) dietary patterns were identified. BMI and WHtR were associated with adiponectin, leptin and hs-CRP (the last, only associated with BMI). Intakes of β-carotene equivalents and vitamin C were associated with adiponectin; saturated fatty acids (SFA), vitamin A, manganese and selenium with leptin; linoleic acid with PAI-1; and oleic acid and vitamin E with IL-6. Selenium was inversely associated with adiponectin, whereas magnesium was positively associated with IL-6. MDP was associated with higher plasma concentrations of adiponectin (β=0.174, P<0.05); after adjustment for BMI, associations were not significant (β=0.144, P=0.076). WDP was negatively associated with adiponectin (β=-0.177, P<0.05) and positively with IL-6 (β=0.183, P<0.05). Subclinical inflammation is detectable with increasing BMI and also WHtR. Measures of adiposity (BMI and WHtR) are significant predictors of adiponectin, leptin and hs-CRP. Dietary patterns per se have a small role in affecting inflammatory markers among adolescents.

Long-term dietary supplementation of organic selenium modulates gene expression profiles in leukocytes of adult pigs.

PubMed

Song, Ki-Duk; Dowd, Scott E; Lee, Hak-Kyo; Kim, Sung Woo

2013-03-01

Seventy-two pigs at 34.4 kg body weight (BW) were allotted to two treatments with six replicates/treatment and six pigs/pen: the CON (negative control, no added selenium (Se)) and the OS (0.36 mg/kg added selenium from selenium-enriched yeast). Pigs were fed until 130 kg BW. The CON diet contained 0.18 mg/kg indigenous Se whereas the OS diet contained 0.54 mg/kg Se. Blood samples were collected at 130 kg BW and further processed for microarray analysis, prepared with 885 genes related to immune function of pigs. Among those, 28 genes related to improved immune status and innate immunity were up-regulated (P < 0.05) in leukocytes from Se-fed pigs and those include major histocompatibility class I (> 1.66), arginase I (> 1.27), integrin beta-1-subunit (> 1.20), toll like receptor 2 (> 1.12) and double-stranded RNA-dependent protein kinase. However, 24 genes including tissue factor (< 4.70), serum amyloid A-2 protein (< 3.11) and p27Kip1 (< 1.42) were down-regulated (P < 0.05) in leukocytes from Se-fed pigs. Expression of four selected genes was validated using quantitative PCR (qPCR) showing significant correlation between mircroarray analysis and qPCR analysis. This study indicates that a long- term dietary supplementation (0.3%) of organic Se improves the expression of genes that are related to enhanced immunity of pigs. © 2012 Japanese Society of Animal Science.

Effects of Selenium Supplementation on the Diabetic Condition Depend on the Baseline Selenium Status in KKAy Mice.

PubMed

Febiyanto, Novian; Yamazaki, Chiho; Kameo, Satomi; Sari, Dian K; Puspitasari, Irma M; Sunjaya, Deni K; Herawati, Dewi M D; Nugraha, Gaga I; Fukuda, Toshio; Koyama, Hiroshi

2018-01-01

Oxidative stress in obesity leads to insulin resistance in type 2 diabetes. Some selenoproteins possess antioxidant properties, suggesting that selenium (Se) may protect against type 2 diabetes; however, evidence from epidemiological studies is contradictory. We hypothesized that Se status before supplementation (baseline) contributes to the supplementation outcome. This study aimed to clarify the influence of baseline Se status on the effect of Se supplementation on the diabetic condition. Six-week-old KKAy mice were fed a diet without supplemental Se or with 0.1 ppm Se in the form of L-selenomethionine (SeM) for 2 weeks to create low-Se and sufficient-Se baseline statuses, respectively. For the next 4 weeks, low-Se mice were given a SeM (0.5 ppm Se)-supplemented diet, and sufficient-Se mice were given either a SeM (0.5 ppm Se)- or sodium selenite (0.5 ppm Se)-supplemented diet; control groups continued on baseline diets. Serum Se concentrations, glutathione peroxidase (GPx) activities, adiponectin levels, glucose tolerance, and insulin sensitivity were analyzed. All mice became diabetic during the 2-week baseline induction period. At the end of the supplementation period, Se-receiving groups demonstrated significantly higher Se concentrations and GPx activities than their respective controls. Sufficient-Se mice receiving SeM had lower blood glucose levels and better insulin sensitivity than control and sodium selenite-receiving mice, whereas low-Se mice receiving SeM showed no such improvements compared with their controls. Our results suggest that Se supplementation in the form of SeM may help prevent type 2 diabetes aggravation in people taking the 55 μg/day Se recommended dietary allowance.

Formation and Characterization of Gold Nanoparticles

DTIC Science & Technology

2013-09-01

nanowires are useful because they can be grown almost dislocation free, due to their nano dimension. The quality of crystalline materials is diminished by...real substrate temperature was obtained from the calibration based on the melting points of indium (In), selenium (Se), cadmium (Cd), and zinc (Zn...hydrogen fluoride In indium MBE molecular beam epitaxy NH3OH ammonium hydroxide RHEED reflection high-energy electron diffraction Se selenium SEM

Influence of inorganic and organic selenium on number of living mycelial cells and their ultrastructure in culture of Hericium erinaceum (Bull.: Fr. Pers.).

PubMed

Slusarczyk, Joanna; Malinowska, Eliza; Krzyczkowski, W; Kuraś, M

2013-03-01

Mycelium of the white-rot fungus (Hericium erinaceum (Bull.: Fr. Pers.) produces polysaccharides showing anticancer and immunostimulating activity. In our previous works, we have shown that organic selenitetriglycerides (Selol) contribute to the increase of biosynthesis of exopolysaccharides (EPS) having antioxidative properties and containing large amounts of selenium. The present work is a study of influence of inorganic and organic form of selenium on viability of H. erinaceum mycelium and on ultrastructural changes taking place during its development in submerged culture. The mycelium was grown on media containing sodium selenite (Na2SeO3), a mixture of Na2SeO3 + Selol2% and on control medium (no selenium added). It was shown that mycelium cultured for 3 days in control conditions on standard media contained almost 100% of living cells, with over 80% after 24 days. Treatment with 100 ppm of Na2SeO3 lowered the number of viable cells to 11.8% and 9.1% after 3 and 24 days, respectively. The addition of 2% Selol caused the amounts of living cells to remain at ca 90%. Apparently, Selol helped the cells to cope with the toxic activity of inorganic selenium ions. The addition of sodium selenite induced degradative changes in cell organelles. Such changes were not observed in the case of Na2SeO3 + Selol mixture, in which case cells contained numerous ribosomes and small lipid bodies.

Maternal hair selenium levels as a possible long-term nutritional indicator of recurrent pregnancy loss

PubMed Central

2013-01-01

Background Approximately 1% of all couples trying to conceive will suffer from recurrent pregnancy loss (RPL). Nutritional deficiencies have been postulated as a possible cause of RPL and in particular, selenium deficiency has been associated with reproductive failure in animal studies and more recently, in some human studies. This study was undertaken to assess the maternal hair selenium levels in women with RPL without an identified cause and to compare these results with those of women with successful reproductive histories. Methods Twenty four patients with RPL and twenty four control subjects with at least one successful pregnancy and no pregnancy failures, who were matched for age and ethnicity, were recruited. A questionnaire was completed, which included demographic and social information and a dietary history. Hair samples were collected and analyzed for selenium content by inductively coupled plasma mass spectrometry. Results The control subjects had a higher mean income and had completed more years of education compared with the RPL patients. There was no significant difference in the intake of selenium rich foods between the 2 groups. The patients, however, consumed significantly more fruit, cheese, potatoes and chocolate than the controls. The median (range) selenium content was 0.80 ppm (0.19-4.15) and 0.68 ppm (0.43-3.76) in patients and controls respectively (Mann Whitney U test 209.5 p = 0.74). Conclusions While there were significant differences in the 2 groups with regard to resources, education and diet our results show that hair selenium concentrations and dietary selenium intake, were similar in the two groups. Both groups had low levels of this important element. PMID:24148900

Mercury-Selenium Relationships in Liver of Guiana Dolphin: The Possible Role of Kupffer Cells in the Detoxification Process by Tiemannite Formation

PubMed Central

Lailson-Brito, José; Dorneles, Paulo Renato; Andrade, Leonardo; Azevedo, Alexandre de Freitas; Fragoso, Ana Bernadete; Vidal, Lara Gama; Costa, Marianna Badini; Bisi, Tatiana Lemos; Almeida, Ronaldo; Carvalho, Dario Pires; Bastos, Wanderley Rodrigues; Malm, Olaf

2012-01-01

Top marine predators present high mercury concentrations in their tissues as consequence of biomagnification of the most toxic form of this metal, methylmercury (MeHg). The present study concerns mercury accumulation by Guiana dolphins (Sotalia guianensis), highlighting the selenium-mediated methylmercury detoxification process. Liver samples from 19 dolphins incidentally captured within Guanabara Bay (Rio de Janeiro State, Brazil) from 1994 to 2006 were analyzed for total mercury (THg), methylmercury (MeHg), total organic mercury (TOrgHg) and selenium (Se). X-ray microanalyses were also performed. The specimens, including from fetuses to 30-year-old dolphins, comprising 8 females and 11 males, presented high THg (0.53–132 µg/g wet wt.) and Se concentrations (0.17–74.8 µg/g wet wt.). Correlations between THg, MeHg, TOrgHg and Se were verified with age (p<0.05), as well as a high and positive correlation was observed between molar concentrations of Hg and Se (p<0.05). Negative correlations were observed between THg and the percentage of MeHg contribution to THg (p<0.05), which represents a consequence of the selenium-mediated methylmercury detoxification process. Accumulation of Se-Hg amorphous crystals in Kupffer Cells was demonstrated through ultra-structural analysis, which shows that Guiana dolphin is capable of carrying out the demethylation process via mercury selenide formation. PMID:22860072

Simultaneous speciation analysis of inorganic arsenic, chromium and selenium in environmental waters by 3-(2-aminoethylamino) propyltrimethoxysilane modified multi-wall carbon nanotubes packed microcolumn solid phase extraction and ICP-MS.

PubMed

Peng, Hanyong; Zhang, Nan; He, Man; Chen, Beibei; Hu, Bin

2015-01-01

Speciation analysis of inorganic arsenic, chromium and selenium in environmental waters is of great significance for the monitoring of environmental pollution. In this work, 3-(2-aminoethylamino) propyltrimethoxysilane (AAPTS) functionalized multi-wall carbon nanotubes (MWCNTs) were synthesized and employed as the adsorbent for simultaneous speciation analysis of inorganic arsenic, chromium and selenium in environmental waters by microcolumn solid-phase extraction (SPE)-inductively coupled plasma mass spectrometry (ICP-MS). It was found that As(V), Cr(VI) and Se(VI) could be selectively adsorbed on the microcolumn packed with AAPTS-MWCNTs adsorbent at pH around 2.2, while As(III), Cr(III) and Se(IV) could not be retained at this pH and passed through the microcolumn directly. Total inorganic arsenic, chromium and selenium was determined after the oxidation of As(III), Cr(III) and Se(IV) to As(V), Cr(VI) and Se(VI) with 10.0 μmol L(-1) KMnO4. The assay of As(III), Cr(III) and Se(IV) was based on subtracting As(V), Cr(VI) and Se(VI) from the total As, Cr and Se, respectively. Under the optimized conditions, the detection limits of 15, 38 and 16 ng L(-1) with the relative standard deviations (RSDs) of 7.4, 2.4 and 6.2% (c=1 µg L(-1), n=7) were obtained for As(V), Cr(VI) and Se(VI), respectively. The developed method was validated by analyzing four Certified Reference Materials, rainwater, Yangtze River and East Lake waters. Copyright © 2014 Elsevier B.V. All rights reserved.

Embryotoxic and teratogenic effects of selenium in the diet of mallards

USGS Publications Warehouse

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

1988-01-01

Mallards (Anas platyrhynchos) were fed a control diet, diets containing 1, 5, 10, or 25 ppm Se as sodium selenite, or a diet containing 10 ppm Se as seleno-DL-methionine in the first of two experiments. Selenium at 10 ppm as selenomethionine or 25 ppm as sodium selenite caused a 40-44% decrease in the total number of eggs that hatched compared to controls. Selenium at 25 ppm (sodium selenite) resulted in a 19% decrease in mean embryonic weight at 18 d of incubation, accompanied by a 6% decrease in crown-rump length. Ten parts per million Se as selenomethionine was more teratogenic than sodium selenite at 25 ppm. Selenomethionine (10 ppm Se) resulted in an incidence of 13.1% malformations that were often multiple, whereas sodium selenite (10 and 25 ppm Se) resulted in 3.6 and 4.2% malformations. The teratogenicity of selenomethionine was confirmed in a second experiment in which mallards received 1, 2, 4, 8, or 16 ppm Se as selenomethionine, resulting in 0.9, 0.5, 1.4, 6.8, and 67.9% malformations, respectively. These malformations included hydrocephaly, microphthalmia, lower bill defects, and foot defects with ectrodactyly. Both forms of selenium increased the incidence of edema and stunted embryonic growth. Selenomethionine (10 ppm Se) resulted in a significant increase of approximately 40% in plasma glutathione peroxidase activity and a 70% increase in sorbitol dehydrogenase activity (indicative of hepatotoxicity) in hatchlings. Sodium selenite (25 ppm Se) resulted in fourfold elevation in plasma uric acid concentration, indicative of renal alteration. Selenomethionine accumulated much better in eggs than did sodium selenite. These findings indicate that selenomethionine is considerably more teratogenic and generally more embryotoxic than sodium selenite, probably due to higher uptake of selenomethionine.

The effect of selenium on spoil suitability as root zone material at Navajo Mine, New Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lane, J.R.; Buchanan, B.A.; Ramsey, T.C.

1995-09-01

The root zone suitability limits for spoil Se at Navajo Mine in northwest New Mexico are currently 0.8 ppm total Se and 0.15 ppm hot-water soluble Se. These criteria were largely developed by the Office of Surface Mining using data from the Northern Great Plains. Applying these values, approximately 23% of the spoil volume and 47% of the spoil area sampled at Navajo Mine from 1985 to December 1993 were determined to be unsuitable as root zone material. Secondary Se accumulator plants (Atriplex canescens) growing in both undisturbed and reclaimed areas were randomly sampled for selenium from 1985 to Decembermore » 1993. In most cases the undisturbed soil and reclaimed spoil at these plant sampling sites were sampled for both total and hot-water soluble Se. Selenium values for Atriplex canescens samples collected on the undisturbed sites averaged 0.64 ppm and ranged from 0.20 ppm to 2.5 ppm. Selenium values for the plants growing on spoil ranged from 0.02 ppm to 7.75 ppm and averaged 1.07 ppm. Total and hot-water Se values for spoil averaged 0.66 ppm and 0.06 ppm respectively, and ranged from 0.0 to 14.2 for total Se and 0.0 ppm to 0.72 ppm for hot-water soluble Se. The plant Se values were poorly correlated to both total and hot-water soluble Se values for both soil and spoil. Therefore, predicting suitable guidelines using normal regression techniques was ineffective. Based on background Se levels in native soils, and levels found on reclaimed areas with Atriplex canescens, it is suggested that a total Se level of 2.0 ppm and a hot-water soluble Se level of 0.25 ppm should be used to represent the suitability limits for Se at Navajo Mine. If these Se values are used, it is estimated that less than 1% of the spoil volume would be unsuitable. This volume of spoil seems to be a more accurate estimate of the amount of spoil with unsuitable levels of Se than the estimated 23% using the current guidelines.« less

Selenium species-dependent toxicity, bioavailability and metabolic transformations in Caenorhabditis elegans.

PubMed

Rohn, Isabelle; Marschall, Talke Anu; Kroepfl, Nina; Jensen, Kenneth Bendix; Aschner, Michael; Tuck, Simon; Kuehnelt, Doris; Schwerdtle, Tanja; Bornhorst, Julia

2018-05-17

The essential micronutrient selenium (Se) is required for various systemic functions, but its beneficial range is narrow and overexposure may result in adverse health effects. Additionally, the chemical form of the ingested selenium contributes crucially to its health effects. While small Se species play a major role in Se metabolism, their toxicological effects, bioavailability and metabolic transformations following elevated uptake are poorly understood. Utilizing the tractable invertebrate Caenorhabditis elegans allowed for an alternative approach to study species-specific characteristics of organic and inorganic Se forms in vivo, revealing remarkable species-dependent differences in the toxicity and bioavailability of selenite, selenomethionine (SeMet) and Se-methylselenocysteine (MeSeCys). An inverse relationship was found between toxicity and bioavailability of the Se species, with the organic species displaying a higher bioavailability than the inorganic form, yet being less toxic. Quantitative Se speciation analysis with HPLC/mass spectrometry revealed a partial metabolism of SeMet and MeSeCys. In SeMet exposed worms, identified metabolites were Se-adenosylselenomethionine (AdoSeMet) and Se-adenosylselenohomocysteine (AdoSeHcy), while worms exposed to MeSeCys produced Se-methylselenoglutathione (MeSeGSH) and γ-glutamyl-MeSeCys (γ-Glu-MeSeCys). Moreover, the possible role of the sole selenoprotein in the nematode, thioredoxin reductase-1 (TrxR-1), was studied comparing wildtype and trxr-1 deletion mutants. Although a lower basal Se level was detected in trxr-1 mutants, Se toxicity and bioavailability following acute exposure was indistinguishable from wildtype worms. Altogether, the current study demonstrates the suitability of C. elegans as a model for Se species dependent toxicity and metabolism, while further research is needed to elucidate TrxR-1 function in the nematode.

Toxicity of nutritionally available selenium compounds in primary and transformed hepatocytes.

PubMed

Weiller, Markus; Latta, Markus; Kresse, Matthias; Lucas, Rudolf; Wendel, Albrecht

2004-09-01

The essential trace element selenium is also toxic at low doses. Since supplementation of selenium is discussed as cancer prophylaxis, we investigated whether or not bioavailable selenium compounds are selectively toxic on malignant cells by comparing primary and transformed liver cells as to the extent and mode of cell death. Sodium selenite and selenate exclusively induced necrosis in a concentration-dependent manner in all cell types investigated. In primary murine hepatocytes, the EC50 was 20 microM for selenite, 270 microM for selenate, and 30 microM for Se-methionine. In the human carcinoma cell line HepG2, the EC50 for selenite was 40 microM, and for selenate 1.1 mM, whereas Se-methionine was essentially non-toxic up to 10 mM. Similar results were found in murine Hepa1-6 cells. Exposure of primary murine cells to selenate or selenite resulted in increased lipid peroxidation. Toxicity was inhibited by superoxide dismutase plus catalase, indicating an important role for reactive oxygen intermediates. In primary hepatocytes, metabolical depletion of intracellular ATP by the ketohexose tagatose, significantly decreased the cytotoxicity of Se-methionine, while the one of selenite was increased. These data do not provide any in vitro evidence that bioavailable selenium compounds induce preferentially apoptotic cell death or selectively kill transformed hepatocytes.

Preparation of cuxinygazsen precursor films and powders by electroless deposition

DOEpatents

Bhattacharya, Raghu N.; Batchelor, Wendi Kay; Wiesner, Holm; Ramanathan, Kannan; Noufi, Rommel

1999-01-01

A method for electroless deposition of Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3) precursor films and powders onto a metallic substrate comprising: preparing an aqueous bath solution of compounds selected from the group consisting of: I) a copper compound, a selenium compound, an indium compound and gallium compound; II) a copper compound, a selenium compound and an indium compound; III) a selenium compound, and indium compound and a gallium compound; IV) a selenium compound and a indium compound; and V) a copper compound and selenium compound; each compound being present in sufficient quantity to react with each other to produce Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3); adjusting the pH of the aqueous bath solution to an acidic value by the addition of a dilute acid; and initiating an electroless reaction with an oxidizing counterelectrode for a sufficient time to cause a deposit of Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3) from the aqueous bath solution onto a metallic substrate.

Toxic effects of selenium and copper on the planarian, Dugesia dorotocephala

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rauscher, J.D.

1988-01-01

Aquatic toxicologists have become increasingly concerned with the effects of sublethal concentrations of toxicants on aquatic organisms. Sublethal effects of toxicants on freshwater invertebrates were reviewed. Selenium (Se) and copper (Cu) are both essential trace elements and toxicants. Se has been reported to alter the toxicity of heavy metals. Planarians, Dugesia dorotocephala, were used as test animals. The objectives of this study were to determine: (1) acute toxicity of Se on planarians and the effect of the number of planarians per test chamber, (2) interaction of the acute toxicity of Se and Cu on planarians, and (3) sublethal effects ofmore » Se and Cu on planarians.« less

Low temperature co-pyrolysis of hexabenzylditinsulfide and selenium. An alternate route to Sn(S{sub x}Se{sub 1{minus}x})

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boudjouk, P.; Remington, M.P. Jr.; Seidler, D.J.

1999-12-01

Benzyl-substituted tin chalcogenides (Bn{sub 3}Sn){sub 2}S (1) and (Bn{sub 3}Sn){sub 2}Se (2) yield polycrystalline-phase pure SnS and SnSe in good ceramic yields when pyrolyzed with S and Se, respectively, at 275 C. Heating mixtures of (1) and elemental selenium produce solid solutions of the formula Sn(S{sub x}Se{sub 1{minus}x}). Combustion analysis showed less than 1% residual carbon in all ceramic products. This methodology allows the complete conversion of tin-to-tin chalcogenides and eliminates the need to synthesize organosulfur and organoselenium intermediates.

Selenium supplementation to chronic kidney disease patients on hemodialysis does not induce the synthesis of plasma glutathione peroxidase.

PubMed

Zachara, Bronislaw A; Gromadzinska, Jolanta; Zbrog, Zbigniew; Swiech, Rafal; Wasowicz, Wojciech; Twardowska, Ewa; Jablonska, Ewa; Sobala, Wojciech

2009-01-01

Numerous authors have shown that selenium (Se) concentration and glutathione peroxidase (GSH-Px) activity in plasma of chronic kidney disease (CKD) patients are lower than in healthy subjects, but there are only few publications on the level of GSH-Px protein in those patients and no reports on the effect of Se supplementation to HD patients on the level of this enzyme. Se concentration and GSH-Px protein level in plasma were measured in a group of 30 CKD patients on hemodialysis (HD) supplemented with 200 microg Se/day for 3 months, and 28 patients on HD administered with placebo. Se concentration was measured by graphite furnace atomic absorption spectrometry and plasma GSH-Px protein level by the sandwich ELISA method using polyclonal antibody specific for human plasma GSH-Px. Se concentration in patients on placebo did not change throughout the 3-month study period, but increased significantly in Se supplemented group. Se supplementation to CKD patients on HD had no effect on the level of GSH-Px protein. The lack of GSH-Px protein in CKD patients on HD is not linked to Se deficiency since the level of this element increased after Se supplementation while enzyme protein level did not change. The damaged kidney of HD patients is unable to synthesize GSH-Px, even after induction with selenium.

Derivatization of DNAs with Selenium at 6-Position of Guanine for Function and Crystal Structure Studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salon, J.; Jiang, J; Sheng, J

2008-01-01

To investigate nucleic acid base pairing and stacking via atom-specific mutagenesis and crystallography, we have synthesized for the first time the 6-Se-deoxyguanosine phosphoramidite and incorporated it into DNAs via solid-phase synthesis with a coupling yield over 97%. We found that the UV absorption of the Se-DNAs red-shifts over 100 nm to 360 nm ({Epsilon} = 2.3 x 10{sup 4} M{sup -1} cm{sup -1}), the Se-DNAs are yellow colored, and this Se modification is relatively stable in water and at elevated temperature. Moreover, we successfully crystallized a ternary complex of the Se-G-DNA, RNA and RNase H. The crystal structure determination andmore » analysis reveal that the overall structures of the native and Se-modified nucleic acid duplexes are very similar, the selenium atom participates in a Se-mediated hydrogen bond (Se H-N), and the {sup Se}G and C form a base pair similar to the natural G-C pair though the Se-modification causes the base-pair to shift (approximately 0.3 {angstrom}). Our biophysical and structural studies provide new insights into the nucleic acid flexibility, duplex recognition and stability. Furthermore, this novel selenium modification of nucleic acids can be used to investigate chemogenetics and structure of nucleic acids and their protein complexes.« less

Productivity and selenium concentrations in egg and tissue of laying quails fed selenium from hydroponically produced selenium-enriched kale sprout (Brassica oleracea var. alboglabra L.).

PubMed

Chinrasri, Orawan; Chantiratikul, Piyanete; Maneetong, Sarunya; Chookhampaeng, Sumalee; Chantiratikul, Anut

2013-12-01

This study aimed to determine the effectiveness of Se from hydroponically produced Se-enriched kale sprout (HPSeKS) on productive performance, egg quality, and Se concentrations in egg and tissue of laying quails. Two-hundred quails, 63 days of age, were divided into four groups. Each group consisted of five replicates and each replicate had ten birds, according to a completely randomized design. The experiment lasted for 6 weeks. The dietary treatments were T1 (control diet), T2 (control diet plus 0.2 mg Se/kg from sodium selenite), T3 (control diet plus 0.2 mg Se/kg from Se-enriched yeast), T4 (control diet plus 0.2 mg Se/kg from HPSeKS). The findings revealed that productive performance and egg quality of quails were not altered (p > 0.05) by Se sources. Whole egg Se concentrations of quails fed Se from HPSeKS and Se-enriched yeast were higher (p < 0.05) than that of quails fed the control diet. Breast muscle Se concentrations in quails fed Se from HPSeKS were higher (p < 0.05) than that of quails fed Se from sodium selenite and Se-enriched yeast. Heart tissue Se concentrations of quails fed Se from Se-enriched yeast and HPSeKS were similar (p > 0.05), but higher (p < 0.05) than that of quails fed Se from sodium selenite. The results reveal that Se from HPSeKS did not change the performance and egg quality of quails. The effectiveness of Se from HPSeKS was comparable to that of Se-enriched yeast, which was higher than that of Se from sodium selenite.

Effects of selenium supplementation in cattle on aquatic ecosystems in northern California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norman, B.; Nader, G.; Oliver, M.

1992-09-15

The potential impact on aquatic ecosystems of supplementing the diets of beef cattle with selenium (Se) was studied on 4 northern California ranches. All study sites included an area of concentrated use by cattle that had diets supplemented with Se. In each case, a stream flowed through the site and provided a control sampling area upstream and a treated sampling area downstream. Specimens of water, sediment, algae, aquatic plants, aquatic invertebrates, and fish were analyzed fluorometrically for total Se content. Significant differences in Se concentration were not found between specimens from upstream control areas and those from downstream areas subjectedmore » to use by Se-treated cattle. Evidence was not found that Se supplementation in cattle at maximal permitted concentrations caused Se accumulation in associated aquatic ecosystems.« less

A selenium-deficient Caco-2 cell model for assessing differential incorporation of chemical or food selenium into glutathione peroxidase.

PubMed

Zeng, Huawei; Botnen, James H; Johnson, Luann K

2008-01-01

Assessing the ability of a selenium (Se) sample to induce cellular glutathione peroxidase (GPx) activity in Se-deficient animals is the most commonly used method to determine Se bioavailability. Our goal is to establish a Se-deficient cell culture model with differential incorporation of Se chemical forms into GPx, which may complement the in vivo studies. In the present study, we developed a Se-deficient Caco-2 cell model with a serum gradual reduction method. It is well recognized that selenomethionine (SeMet) is the major nutritional source of Se; therefore, SeMet, selenite, or methylselenocysteine (SeMSC) was added to cell culture media with different concentrations and treatment time points. We found that selenite and SeMSC induced GPx more rapidly than SeMet. However, SeMet was better retained as it is incorporated into proteins in place of methionine; compared with 8-, 24-, or 48-h treatment, 72-h Se treatment was a more sensitive time point to measure the potential of GPx induction in all tested concentrations. Based on induction of GPx activity, the cellular bioavailability of Se from an extract of selenobroccoli after a simulated gastrointestinal digestion was comparable with that of SeMSC and SeMet. These in vitro data are, for the first time, consistent with previous published data regarding selenite and SeMet bioavailability in animal models and Se chemical speciation studies with broccoli. Thus, Se-deficient Caco-2 cell model with differential incorporation of chemical or food forms of Se into GPx provides a new tool to study the cellular mechanisms of Se bioavailability.

Controlling morphology and crystallite size of Cu(In{sub 0.7}Ga{sub 0.3})Se{sub 2} nano-crystals synthesized using a heating-up method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsu, Wei-Hsiang; Hsiang, Hsing-I, E-mail: hsingi@mail.ncku.edu.tw; Chia, Chih-Ta

2013-12-15

CuIn{sub 0.7}Ga{sub 0.3}Se{sub 2}(CIGS) nano-crystals were successfully synthesized via a heating-up process. The non-coordinating solvent (1-octadecene) and selenium/cations ratio effects on the crystalline phase and crystallite size of CIGS nano-crystallites were investigated. It was observed that the CIGS nano-crystallite morphology changed from sheet into spherical shape as the amount of 1-octadecene addition was increased. CIGS nano-crystals were obtained in 9–20 nm sizes as the selenium/cations ratio increased. These results suggest that the monomer reactivity in the solution can be adjusted by changing the solvent type and selenium/cations ratio, hence affecting the crystallite size and distribution. - Graphical abstract: CuIn{sub 0.7}Ga{submore » 0.3}Se{sub 2}(CIGS) nano-crystals were successfully synthesized via a heating-up process in this study. The super-saturation in the solution can be adjusted by changing the OLA/ODE ratio and selenium/cation ratio.« less

Ultrasound-assisted ionic liquid dispersive liquid-liquid microextraction combined with graphite furnace atomic absorption spectrometric for selenium speciation in foods and beverages.

PubMed

Tuzen, Mustafa; Pekiner, Ozlem Zeynep

2015-12-01

A rapid and environmentally friendly ultrasound assisted ionic liquid dispersive liquid liquid microextraction (USA-IL-DLLME) was developed for the speciation of inorganic selenium in beverages and total selenium in food samples by using graphite furnace atomic absorption spectrometry. Some analytical parameters including pH, amount of complexing agent, extraction time, volume of ionic liquid, sample volume, etc. were optimized. Matrix effects were also investigated. Enhancement factor (EF) and limit of detection (LOD) for Se(IV) were found to be 150 and 12 ng L(-1), respectively. The relative standard deviation (RSD) was found 4.2%. The accuracy of the method was confirmed with analysis of LGC 6010 Hard drinking water and NIST SRM 1573a Tomato leaves standard reference materials. Optimized method was applied to ice tea, soda and mineral water for the speciation of Se(IV) and Se(VI) and some food samples including beer, cow's milk, red wine, mixed fruit juice, date, apple, orange, grapefruit, egg and honey for the determination of total selenium. Copyright © 2015 Elsevier Ltd. All rights reserved.

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 genotypes in commercial conditions of intensive pig production. PMID:25924964

Comparative study of the effects of organic selenium on hen performance and productivity of broiler breeders.

PubMed

Rajashree, K; Muthukumar, T; Karthikeyan, N

2014-01-01

1. A 10-week experiment was conducted with Ross 308 broiler breeder chickens in cages to evaluate the influence of organic and inorganic sources of selenium (Se) supplementation. A total of 600 birds at 29 weeks of age were divided at random into 4 groups and fed on a maize-soya basal diet supplemented with different forms of Se. 2. The first (control) group was given the basal diet without Se supplementation, whereas the second, third and fourth groups were given, respectively, the basal diet with 0.3 mg/kg of inorganic Se in the form of sodium selenite or 0.3 and 0.5 mg/kg of organic Se in the form of Se enriched yeast (Se-yeast). 3. The experiment was carried out for 10 weeks to compare and evaluate the influence of Se supplementation on breeder performance, egg production, hatchability and the quality of eggs. Samples were collected for analysis at weeks 0, 5 and 10 of the experimental period. 4. At the end of the experiment (39 weeks), there was a reduction in mortality in breeders given diets supplemented with 0.5 mg/kg of Se-yeast. Supplementation of feed with 0.5 mg/kg organic Se increased egg production, percentage of settable eggs and hatchability. 5. Selenium supplementation increased egg weight and specific gravity compared to the control diet. However, no significant variation was found in albumen or yolk protein content at the end of week 10. 6. Selenium accumulation and glutathione peroxidase (GSHPx) activity were lower in the egg albumen and yolk of control compared with Se-supplemented treatments. Se accumulation and GSHPx activity were higher in the group given 0.3 mg/kg organic compared to 0.3 mg/kg of inorganic Se. 7. The results favour the use of Se-yeast at the dose of 0.5 mg/kg in broiler breeder diets for better productivity of eggs, settable eggs, hatchability and higher Se accumulation and antioxidant status in eggs.

Biological activity of selenium: Revisited.

PubMed

Wrobel, Jagoda K; Power, Ronan; Toborek, Michal

2016-02-01

Selenium (Se) is an essential micronutrient that exerts multiple and complex effects on human health. Se is essential for human well-being largely due to its potent antioxidant, anti-inflammatory, and antiviral properties. The physiological functions of Se are carried out by selenoproteins, in which Se is specifically incorporated as the amino acid, selenocysteine. Importantly, both beneficial and toxic effects of Se have been reported suggesting that the mode of action of Se is strictly chemical form and concentration dependent. Additionally, there is a relatively narrow window between Se deficiency and toxicity and growing evidence suggests that Se health effects depend greatly on the baseline level of this micronutrient. Thus, Se supplementation is not an easy task and requires an individualized approach. It is essential that we continue to explore and better characterize Se containing compounds and mechanisms of action, which could be crucial for disease prevention and treatment. © 2015 International Union of Biochemistry and Molecular Biology.

Selenium Nanoparticles Formed by Modulation of Carrageenan Enhance Osteogenic Differentiation of Mesenchymal Stem Cells.

PubMed

Kim, Jin; Lee, Ki-Young; Lee, Chang-Moon

2016-03-01

Fabrication of nano-sized selenium (Se) particles may help to expend the applications of Se. In this study, we focused on the preparation and characterization of Se nanoparticles (Se NPs) modulated with carrageenan (CA). Furthermore, their influence on osteoblast cell growth was investigated in vitro. Spherical Se-NPs, of 100-200 nm diameter, were prepared simply by adding κ-, ι-, and λ-CA, which has sulfate groups, hydroxyl groups, and carboxyl groups. CA-modulated Se NPs (CA-Se NPs) were readily suspended in liquid medium with no precipitation over long time periods. In particular, it was found through Alizarin Red S staining that the growth of osteoblast D1 cells treated with λ-CA-Se NPs was improved significantly. These results suggest that Se NPs can be prepared simply, using CA, have good suspension stability in liquid medium, and λ-CA-Se NPs may induce the growth of osteoblast cells.

Acute selenium selenite exposure effects on oxidative stress biomarkers and essential metals and trace-elements in the model organism zebrafish (Danio rerio).

PubMed

Hauser-Davis, R A; Silva, J A N; Rocha, Rafael C C; Saint'Pierre, Tatiana; Ziolli, R L; Arruda, M A Z

2016-01-01

Selenium (Se) is an essential trace-element that becomes toxic when present at high concentrations. Little is known regarding Se effects on parameters such as oxidative stress biomarkers. The aim of the present study was to investigate the effects of acute selenium exposure on oxidative stress biomarkers in a model organism, zebrafish (Danio rerio). Fish were exposed to selenium selenite at 1mgL(-1). Reduced glutathione (GSH), and metallothionein (MT) concentrations were determined in liver, kidney and brain, with MT also being determined in bile. Essential metals and trace-elements were also determined by inductively coupled mass spectrometry (ICP-MS) in order to verify possible metal homeostasis alterations. GSH concentrations in liver, kidney and brain increased significantly (1.05±0.03μmolg(-1) ww, 1.42±0.03μmolg(-1) ww and 1.64±0.03μmolg(-1) ww, respectively) in the Se-exposed group when compared to the controls (0.88±0.05μmolg(-1) ww, 0.80±0.04μmolg(-1) ww and 0.89±0.03μmolg(-1) ww for liver, kidney and brain, respectively). MT levels in Se-exposed liver (0.52±0.03μmolg(-1) ww) decreased significantly in comparison to the control group (0.64±0.02μmolg(-1) ww), while levels in bile increased, albeit non-significantly. This is in accordance with previous studies that indicate efficient biliary MT action, leading to a rapid metabolism and elimination of contaminants from the body. Levels in the brain increased significantly after Se-exposure (0.57±0.01μmolg(-1) ww) when compared to the control group (0.35±0.03μmolg(-1) ww) since this organ does not present a detoxification route as quick as the liver-gallbladder route. Several metal and trace-elements were altered with Se-exposure, indicating that excess of selenium results in metal dyshomeostasis. This is the first report on metal dyshomeostasis due to Se-exposure, which may be the first step in the mechanism of action of selenium toxicity, as is postulated to occur in certain major human pathophysiologies. Copyright © 2015 Elsevier GmbH. All rights reserved.

Selenium-fertilized forage as a way to supplement lactating dairy cows.

PubMed

Séboussi, R; Tremblay, G F; Ouellet, V; Chouinard, P Y; Chorfi, Y; Bélanger, G; Charbonneau, É

2016-07-01

Fertilization with Se improves forage organic Se concentration, but comparisons with other forms of Se supplementation in feeding lactating dairy cows are scarce. Our objective was to compare the effect of Se-enriched forages to dietary sources of inorganic and organic Se. Digestibility, retention, and balance were assessed by measuring Se concentrations in feces, urine, milk, and blood. The resulting effect on antioxidant status and lactation performance of dairy cows was also determined. High-Se silages [1.72 mg of Se/kg of dry matter (DM)] were produced following a spring application of 2.5 kg/ha of Selcote Ultra, whereas low-Se silages (0.05 mg of Se/kg of DM) were produced in the Se-unfertilized portion of the same fields. After a 77±17 d period of Se depletion, 33 late-lactation primiparous Holstein cows were blocked and randomly assigned for 43 d to 1 of 4 experimental total mixed rations fed for ad libitum intake in an unbalanced randomized block design. Treatments consisted of 4 diets: control with low-Se silages, without Se supplement (0.12±0.04 mg of Se/kg of DM); ISe with low-Se silages and inorganic Se (0.80±0.14 mg of Se/kg of DM); YSe with low-Se silages and organic Se from yeast (0.70±0.11 mg of Se/kg of DM); and FSe with high-Se silages, without Se supplement (0.79±0.14 mg of Se/kg of DM). Organic Se, either as YSe or FSe, was more available and more effective to increase blood and milk Se concentrations than ISe. Moreover, FSe was more available than YSe, as cows fed FSe excreted 16 and 22% less Se (as percentage of intake) in feces and urine, respectively, had higher Se apparent absorption (17%), retention (37%), and balance (45%), and had greater concentration of Se in serum (16%) and milk (11%) than cows fed YSe. Antioxidant status (whole blood and plasma glutathione peroxidase, and milk thioredoxin reductase and malondialdehyde) was not affected by treatments. Dry matter intake, yield of actual, energy-corrected, and fat-corrected milk, as well as milk fat and lactose concentrations, were not affected by the dietary treatments. Cows fed ISe had lower milk protein concentration (3.44%) than cows fed YSe (3.58%) or FSe (3.51%). Cows fed Se-supplemented diets had a lower milk somatic cell count than cows fed the control diet. Results from the current study showed that the production of Se-enriched forages is an effective method to supplement dairy cows in Se as it was more available than YSe, and did not alter antioxidant status and performances of lactating dairy cows. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Influence of methane addition on selenium isotope sensitivity and their spectral interferences.

PubMed

Floor, Geerke H; Millot, Romain; Iglesias, Mónica; Négrel, Philippe

2011-02-01

The measurements of stable selenium (Se) isotopic signatures by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) are very challenging, due to the presence of spectral interferences and the low abundance of Se in environmental samples. We systematically investigated the effect of methane addition on the signal of Se isotopes and their interferences. It is the first time that the effect of methane addition has been assessed for all Se isotopes and its potential interferences using hydride generator multi-collector inductively coupled plasma mass spectrometry (HG-MC-ICP-MS). Our results show that a small methane addition increases the sensitivity. However, the response differs between a hydride generator and a standard introduction system, which might be related to differences in the ionization processes. Both argon and hydrogen-based interferences, the most common spectral interferences on selenium isotopes in HG-MC-ICP-MS, decrease with increasing methane addition. Therefore, analyte-interference ratios and precision are improved. Methane addition has thus a high potential for the application to stable Se isotopes ratios by HG-MC-ICP-MS. Copyright © 2011 John Wiley & Sons, Ltd.

[Assessment of efficiency of use of the developed supplement containing selenium on laboratory animals].

PubMed

Bazhenova, B A; Aslaliev, A D; Danilov, M B; Badmaeva, T M; Vtorushina, I A

2015-01-01

The article presents the results of a study of the effectiveness of wheat flour containing selenium in organic form. The organic form of trace element was achieved by transformation of selenium in selenium-methionine (Se-Met) at germination of wheat grains, moistened with a solution of sodium selenite. To determine the effectiveness of selenium- containing supplements experimental investigations were carried out on Long white rats with initial body weight 50 ± 2 g. The duration of the experiment was 30 days. The research model included four groups of animals: control group--animals were fed a complete vivarium diet; group 1--a model of selenium deficiency, which was achieved by feeding selenium-deficient food (grain growh in the Chita region of the Trans-Baikal Territory Zabaikalsky Krai); group 2--animals were administered selenium supplement in the form of enriched flour (0.025 µg Se per 50 g body weight of the animal) on the background of selenium-deficient diet; group 3--animals were treated with a high dose of selenium in the form of a solution of sodium selenite intragastrically through a tube (0.15 µg Se per 50 g body weight). Selenium-containing additive on the background of selenium-deficient diet had a positive impact on the appearance and behavior of animals, the body weight gain per head after 10 days in group 2 amounted to 47.9 g that was 4 fold larger than in rats of group 1. The study of selenium content showed that in the blood, liver, lungs and heart of rats treated with the additive on the background of selenium-deficient diet (group 2), selenium level did not differ from those in the control group and was within physiological norms. The experiment showed that selenium deficiency and rich in selenium rich diet has a significantly different effect on the studied parameters of oxidative-antioxidative status. The activity of blood glutathione peroxidase in animals of group 2 (did not differ from that in group 3) was almost 2 fold higher than in blood of control animals and was seven fold higher than that in blood of animals kept on selenium deficient diet (35.57 ± 3.36 µmol/g per 1 min) A similar dependence was established when studying the activity of glutathione reductase. It has been revealed thatthe oxidative-antioxidative status of animals from experimental groups 1 and 3 was lower than from control group and group 2. Thus, blood antioxidant activity in animals receiving diet with selenium deficiency and high dose of this trace element, was less than in the control group by 43.1 and 25.4%, respectively. Liver MDA level in animals kept on a diet with selenium deficiency exceeded the value of this indicator in the group 2 more than 1.5 fold (110.5 ± 10.70 vs. 72.5 ± 4.30 nmol/mg). When using selenium-containing supplement, this parameter decreased to the control level. In blood plasma of the animals of group 2 total antioxidant activity increased by about five times as compared with the indicators of animals kept on selenium-deficient diet, and was 25% higher than in control. Thus, the introduction of a selenium supplements in the deficient diet contributes to the development of endogenous antioxidants that suppress lipid oxidation. High biological effectiveness of supplements containing organic form of selenium has been proved.

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. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Bioaccumulation of organic and inorganic selenium in a laboratory food chain

USGS Publications Warehouse

Besser, John M.; Canfield, Timothy J.; La Point, Thomas W.

1993-01-01

Aquatic organisms accumulated selenium (Se) from inorganic and organic Se species via aqueous and food-chain exposure routes. We 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 75Se-labeled compounds. All three organisms concentrated Se more strongly from aqueous selenomethionine than from either inorganic Se species. Bioconcentration factors (BCFs) estimated from 1 μg 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 (BCFs = 220–3,600) than selenate (BCFs = 65–500) whereas bluegills concenrated Se about equally from both inorganic species (estimated BCFs = 13 to 106). 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. Aqueous and food-chain Se uptakes were approximately additive, and depuration rates were similar in aqueous, food-chain, and combined exposures. Our results suggest that bluegills in Secontaminated habitats accumulate inorganic Se species primarily via food-chain uptake, although organoselenium compounds such as Se-methionine may contribute significantly to Se bioaccumulation by bluegills via both aqueous and food-chain uptake.

Biosynthesis of selenium nanoparticles using Enterococcus faecalis and evaluation of their antibacterial activities.

PubMed

Shoeibi, Sara; Mashreghi, Mohammad

2017-01-01

Microorganisms are capable of synthesizing metal nanoparticles, and specifically Enterococcus faecalis bacteria were tested for its ability to synthesize selenium nanoparticles (Se-NPs) from sodium selenite. The biosynthesized Se-NPs were spherical in shape with the size range of 29-195nm. Also, the TEM microscopy showed the accumulation of nano-structures as extracellular deposits. The ability of the bacteria to tolerate high levels of toxic selenite was studied by changing with different concentrations of sodium selenite (0.19mM-2.97mM). Also, the effect of Se-NPs was studied on the growth profile of number of pathogenic Gram-positive and -negative bacteria. High concentrations of sodium selenite in the medium led to the production of small amounts of selenium nanostructures by bacteria. In addition, Se-NPs can be used as an anti-staphylococcal element to effectively prevent and treat S. aureus infections. Copyright © 2016 Elsevier GmbH. All rights reserved.

Hydrological and geochemical investigations of selenium behavior at Kesterson Reservoir

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zawislanski, P.T.; Tokunaga, T.K.; Benson, S.M.

1995-05-01

This report describes research relevant to selenium specification, fractionation, physical redistribution, reduction and oxidation, and spatial distribution as related to Kesterson Reservoir. The work was carried out by scientists and engineers from the Earth Sciences Division of the Lawrence Berkeley Laboratory over a two year period from October 1992 to September 1994. Much of the focus of these efforts was on the effects of two above-average rainfall years (1991/1992 and 1992/1993). These events marked a departure from the previous six years of drought conditions, under which oxidation of Se in the soil profile led to a marked increase in solublemore » Se. Evidence from the last two years show that much of the re-oxidized Se was once more reduced due to increased soil moisture content. Also, in areas of high hydraulic conductivity, major vertical displacement of selenium and other solutes due to rainfall infiltration was observed. Such observations underscore the dependence of the future of Se speciation and distribution on environmental conditions.« less

The role of selenium in protecting plants against prairie dog herbivory: implications for the evolution of selenium hyperaccumulation.

PubMed

Quinn, Colin F; Freeman, John L; Galeas, Miriam L; Klamper, Erin M; Pilon-Smits, Elizabeth A H

2008-03-01

Some plants can hyperaccumulate the element selenium (Se) up to 10,000 mg Se kg(-1) dry weight. Hyperaccumulation has been hypothesized to defend against herbivory. In laboratory studies high Se levels protect plants from invertebrate herbivores and pathogens. However, field studies and mammalian herbivore studies that link Se accumulation to herbivory protection are lacking. In this study a combination of field surveys and manipulative field studies were carried out to determine whether plant Se accumulation in the field deters herbivory by black-tailed prairie dogs (Cynomys ludovicianus). The Se hyperaccumulator Astragalus bisulcatus (two-grooved milkvetch) occurs naturally on seleniferous soils in the Western USA, often on prairie dog colonies. Field surveys have shown that this Se hyperaccumulator is relatively abundant on some prairie dog colonies and suffers less herbivory than other forb species. This protection was likely owing to Se accumulation, as judged from subsequent manipulative field experiments. When given a choice between pairs of plants of the Se hyperaccumulator Stanleya pinnata (prince's plume) that were pretreated with or without Se, prairie dogs preferred to feed on the plants with low Se; the same results were obtained for the non-hyperaccumulator Brassica juncea (Indian mustard). Plants containing as little as 38 mg Se kg(-1) DW were protected from herbivory. Taken together these results shed light on the functional significance of Se hyperaccumulation and the possible selection pressures driving its evolution. They also have implications for the use of plants in Se phytoremediation, or as Se-fortified crops.

Selenium Biofortification in Radish Enhances Nutritional Quality via Accumulation of Methyl-Selenocysteine and Promotion of Transcripts and Metabolites Related to Glucosinolates, Phenolics, and Amino Acids.

PubMed

Schiavon, Michela; Berto, Chiara; Malagoli, Mario; Trentin, Annarita; Sambo, Paolo; Dall'Acqua, Stefano; Pilon-Smits, Elizabeth A H

2016-01-01

Two selenium (Se) fertilization methods were tested for their effects on levels of anticarcinogenic selenocompounds in radish (Raphanus sativus), as well as other nutraceuticals. First, radish was grown on soil and foliar selenate applied 7 days before harvest at 0, 5, 10, and 20 mg Se per plant. Selenium levels were up to 1200 mg Se/kg DW in leaves and 120 mg Se/kg DW in roots. The thiols cysteine and glutathione were present at 2-3-fold higher levels in roots of Se treated plants, and total glucosinolate levels were 35% higher, due to increases in glucoraphanin. The only seleno-aminoacid detected in Se treated plants was Se-methyl-SeCys (100 mg/kg FW in leaves, 33 mg/kg FW in roots). The levels of phenolic aminoacids increased with selenate treatment, as did root total nitrogen and protein content, while the level of several polyphenols decreased. Second, radish was grown in hydroponics and supplied with 0, 5, 10, 20, or 40 μM selenate for 1 week. Selenate treatment led to a 20-30% increase in biomass. Selenium concentration was 242 mg Se/kg DW in leaves and 85 mg Se/kg DW in roots. Cysteine levels decreased with Se in leaves but increased in roots; glutatione levels decreased in both. Total glucosinolate levels in leaves decreased with Se treatment due to repression of genes involved in glucosinolates metabolism. Se-methyl-SeCys concentration ranged from 7-15 mg/kg FW. Aminoacid concentration increased with Se treatment in leaves but decreased in roots. Roots of Se treated plants contained elevated transcript levels of sulfate transporters (Sultr) and ATP sulfurylase, a key enzyme of S/Se assimilation. No effects on polyphenols were observed. In conclusion, Se biofortification of radish roots may be achieved via foliar spray or hydroponic supply. One to ten radishes could fulfill the daily human requirement (70 μg) after a single foliar spray of 5 mg selenate per plant or 1 week of 5-10 μM selenate supply in hydroponics. The radishes metabolized selenate to the anticarcinogenic compound Se-methyl-selenocysteine. Selenate treatment enhanced levels of other nutraceuticals in radish roots, including glucoraphanin. Therefore, Se biofortification can produce plants with superior health benefits.

Selenium Biofortification in Radish Enhances Nutritional Quality via Accumulation of Methyl-Selenocysteine and Promotion of Transcripts and Metabolites Related to Glucosinolates, Phenolics, and Amino Acids

PubMed Central

Schiavon, Michela; Berto, Chiara; Malagoli, Mario; Trentin, Annarita; Sambo, Paolo; Dall'Acqua, Stefano; Pilon-Smits, Elizabeth A. H.

2016-01-01

Two selenium (Se) fertilization methods were tested for their effects on levels of anticarcinogenic selenocompounds in radish (Raphanus sativus), as well as other nutraceuticals. First, radish was grown on soil and foliar selenate applied 7 days before harvest at 0, 5, 10, and 20 mg Se per plant. Selenium levels were up to 1200 mg Se/kg DW in leaves and 120 mg Se/kg DW in roots. The thiols cysteine and glutathione were present at 2–3-fold higher levels in roots of Se treated plants, and total glucosinolate levels were 35% higher, due to increases in glucoraphanin. The only seleno-aminoacid detected in Se treated plants was Se-methyl-SeCys (100 mg/kg FW in leaves, 33 mg/kg FW in roots). The levels of phenolic aminoacids increased with selenate treatment, as did root total nitrogen and protein content, while the level of several polyphenols decreased. Second, radish was grown in hydroponics and supplied with 0, 5, 10, 20, or 40 μM selenate for 1 week. Selenate treatment led to a 20–30% increase in biomass. Selenium concentration was 242 mg Se/kg DW in leaves and 85 mg Se/kg DW in roots. Cysteine levels decreased with Se in leaves but increased in roots; glutatione levels decreased in both. Total glucosinolate levels in leaves decreased with Se treatment due to repression of genes involved in glucosinolates metabolism. Se-methyl-SeCys concentration ranged from 7–15 mg/kg FW. Aminoacid concentration increased with Se treatment in leaves but decreased in roots. Roots of Se treated plants contained elevated transcript levels of sulfate transporters (Sultr) and ATP sulfurylase, a key enzyme of S/Se assimilation. No effects on polyphenols were observed. In conclusion, Se biofortification of radish roots may be achieved via foliar spray or hydroponic supply. One to ten radishes could fulfill the daily human requirement (70 μg) after a single foliar spray of 5 mg selenate per plant or 1 week of 5–10 μM selenate supply in hydroponics. The radishes metabolized selenate to the anticarcinogenic compound Se-methyl-selenocysteine. Selenate treatment enhanced levels of other nutraceuticals in radish roots, including glucoraphanin. Therefore, Se biofortification can produce plants with superior health benefits. PMID:27683583

Plants and microbes assisted selenium nanoparticles: characterization and application

PubMed Central

2014-01-01

Selenium is an essential trace element and is an essential component of many enzymes without which they become inactive. The Se nanoparticles of varying shape and size may be synthesized from Se salts especially selenite and selenates in presence of reducing agents such as proteins, phenols, alcohols and amines. These biomolecules can be used to reduce Se salts in vitro but the byproducts released in the environment may be hazardous to flora and fauna. In this review, therefore, we analysed in depth, the biogenic synthesis of Se nanoparticles, their characterization and transformation into t- Se, m-Se, Se-nanoballs, Se-nanowires and Se-hollow spheres in an innocuous way preventing the environment from pollution. Their shape, size, FTIR, UV–vis, Raman spectra, SEM, TEM images and XRD pattern have been analysed. The weak forces involved in aggregation and transformation of one nano structure into the other have been carefully resolved. PMID:25128031

Plants and microbes assisted selenium nanoparticles: characterization and application.

PubMed

Husen, Azamal; Siddiqi, Khwaja Salahuddin

2014-08-16

Selenium is an essential trace element and is an essential component of many enzymes without which they become inactive. The Se nanoparticles of varying shape and size may be synthesized from Se salts especially selenite and selenates in presence of reducing agents such as proteins, phenols, alcohols and amines. These biomolecules can be used to reduce Se salts in vitro but the byproducts released in the environment may be hazardous to flora and fauna. In this review, therefore, we analysed in depth, the biogenic synthesis of Se nanoparticles, their characterization and transformation into t- Se, m-Se, Se-nanoballs, Se-nanowires and Se-hollow spheres in an innocuous way preventing the environment from pollution. Their shape, size, FTIR, UV-vis, Raman spectra, SEM, TEM images and XRD pattern have been analysed. The weak forces involved in aggregation and transformation of one nano structure into the other have been carefully resolved.

Selenoproteins and maternal nutrition.

PubMed

Pappas, A C; Zoidis, E; Surai, P F; Zervas, G

2008-12-01

Selenium (Se) is an essential trace element of fundamental importance to health due to its antioxidant, anti-inflammatory and chemopreventive properties attributed to its presence within at least 25 selenoproteins (Sel). Sel include but not limited to glutathione peroxidases (GPx1-GPx6), thioredoxin reductases (TrxR1-TrxR3), iodothyronine deiodinases (ID1-ID3), selenophosphate synthetase 2 (SPS2), 15-kDa Sel (Sel15), SelH, SelI, SelK, SelM, SelN, SelO, SelP, SelR, SelS, SelT, SelV, SelW, as well as the 15-kDa Sel (Fep15), SelJ and SelU found in fish. In this review, we describe some of the recent progress in our understanding of the mechanisms of Sel synthesis. The impact of maternal Se intake on offspring is also discussed. The key regulatory point of Sel synthesis is Se itself, which acts predominantly at post-transcriptional levels, although recent findings indicate transcriptional and redox regulation. Maternal nutrition affects the performance and health of the progeny. Both maternal and offspring Se supplementations are essential for the antioxidant protection of the offspring. Prenatal Se supplementation provides an effective antioxidant system that is already in place at the time of birth while, postnatal Se supplementation becomes the main determinant of progeny Se status after the first few days of progeny life.

RED MEAT, MICRONUTRIENTS AND ORAL SQUAMOUS CELL CARCINOMA OF ARGENTINE ADULT PATIENTS.

PubMed

Secchi, Dante Gustavo; Aballay, Laura Rosana; Galíndez, María Fernanda; Piccini, Daniel; Lanfranchi, Héctor; Brunotto, Mabel

2015-09-01

the identification of risk group of oral cancer allows reducing the typical morbidity and mortality rates of this pathology. it was analyzed the role of red meat, macronutrients and micronutrients on Oral Squamous Cell carcinoma (OSCC) in a case-control study carried out in Cordoba, Argentina. case-control study 3:1, both genders, aged 24-80 years. Dietary information was collected using a quali-quantitative food frequency questionnaire. The logistic regression was applied for assessing the association among case/control status and daily red meat/macronutrient/ micronutrients/energy intake. micronutrients and minerals in the diet that showed high significant median values of common consumption in cases relative to controls were iron, phosphorus, vitamins B1, B5, B6, E and K and selenium. The association measurement estimated by logistic regression was showed that a significant association between red meat, fat, daily energy, phosphorous, vitamin B5, vitamin E, and selenium intake and OSCC presence. a high intake of fats, phosphorus, vitamin B5, vitamin E, and selenium intake and red meat appears to be related to the presence OSCC in Cordoba, Argentina. In relation to red meat consumption and risk of OSCC, the future research should center of attention on reducing the complexity of diet and disease relationships and reducing variability in intake data by standardizing of criteria in order to implement simple strategies in public health for recognizing risk groups of OSCC. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.