Higher Se Levels Research Articles

Combined association of early exposure to long-chain n-3 polyunsaturated fatty acids, mercury and selenium with cognitive performance in 1-year-old infants

BackgroundPrevious studies on long-chain n-3 polyunsaturated fatty acids (LCn3PUFAs) and infant neurodevelopment did not consider effect modifications of mercury (Hg) and selenium (Se). ObjectivesTo examine the joint association of prenatal LCn3PUFAs, Hg and Se with infant cognitive performance, and to explore whether DNA methylation may explain this potential association. MethodsA total of 484 newborns were enrolled from the Shanghai Birth Cohort with available data on cord blood LCn3PUFA, nail Hg and Se during 2015–2016. Cord blood LCn3PUFA concentrations were assessed by gas chromatography, and nail Hg and Se concentrations were measured using clippings collected within 6 months of birth by inductively coupled plasma mass spectrometry. Five aspects of infant neurodevelopment (communication, gross motor, fine motor, problem-solving, and personal-social skills) were assessed using the Age and Stage Questionnaire (ASQ) at ages 6 and 12 months. Multivariable-adjusted generalized estimating equations models were performed to examine the associations between cord blood LCn3PUFA concentrations and ASQ test scores, and these associations were stratified by nail Hg and Se levels. Epigenome-wide DNA methylation in cord blood was compared in a random subgroup consisting of 19 infants from the highest and 21 from the lowest decile of LCn3PUFA concentrations. ResultsLCn3PUFAs were not significantly associated with any ASQ test scores. However, in the subgroup with lower Hg (<median 0.13 ppm) and higher Se (≥median 0.87 ppm) levels, infants with higher LCn3PUFA concentrations had higher ASQ scores indicating better performance in gross motor skills [quartile 4 vs. 1: mean difference = 7.78; 95% confidence interval=(3.47, 12.09); Ptrend<0.01; Pinteraction = 0.03]. Additionally, twenty CpG sites were differentially methylated when comparing high to low LCn3PUFA groups. ConclusionThe association of prenatal LCn3PUFA concentrations with infant neurodevelopment, particularly gross motor skills, may be observed among infants with high Se and low Hg levels.

Maternal prenatal selenium levels and child risk of neurodevelopmental disorders: A prospective birth cohort study.

Selenium (Se) is an essential trace element involved in various biological processes, including neurodevelopment. Available literature indicates that both Se deficiency and excess may be detrimental to health. It is also known that Se can cross the placenta from maternal to fetal circulation. To date, the role of maternal Se status in child long-term neurodevelopment is largely unexplored. This study investigated the temporal and dose-response associations between maternal Se status and child risk of neurodevelopmental disorders including autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD). It consisted of 1550 mother-infant dyads from the Boston Birth Cohort. Maternal red blood cell (RBC) Se levels were measured in samples collected within 72 h of delivery (biomarker of third trimester Se status). Pediatric neurodevelopmental diagnoses were obtained from electronic medical records. Data analyses showed that maternal RBC Se levels were positively associated with child risk of developing ASD, with an adjusted odds ratio of 1.49 for ASD (95% CI: 1.09, 2.02) per IQR increase in Se. There was also a positive association between maternal Se and ADHD (OR: 1.29; 95% CI: 1.04, 1.56, per IQR increase in Se). These associations remained robust even after adjusting for pertinent covariables; and there was no significant interaction between Se and these covariables. Our findings suggest that prenatal exposure to high maternal Se levels may adversely affect child neurodevelopment. Our findings warrant further investigation; if confirmed, optimizing maternal prenatal Se levels may be necessary to maximize its health benefits while preventing undue risk. LAY SUMMARY: Selenium (Se) is an essential nutrient for the health of the pregnant mother and her baby. While Se can readily cross the placenta from maternal to fetal circulation, little is known about maternal Se status on her child's neurodevelopmental outcomes. We studied over 1500 mother-child dyads from birth to school age of the child. We found that babies born from mothers with high blood Se levels may be at increased risk of developing autism spectrum disorder or attention deficit hyperactivity disorder. Given this is the first study of the kind, more study is needed to confirm our findings.

Serum and Hair Trace Element and Mineral Levels in Dairy Cows in Relation to Daily Milk Yield.

The objective of the present study was to assess hair and serum trace element and mineral levels in dairy cows in relation to daily milk yield. A total of 70 healthy 5-6-year-old Simmental cows were divided into two groups (n = 35) with high and low daily milk yield using median as a cut-off value. Hair and serum trace element and mineral content was evaluated using inductively coupled plasma mass-spectrometry. A nearly twofold difference in daily milk yield (43.8 ± 9.7 vs 21.3 ± 7.1 L/day, p < 0.001) was significantly associated with 11% lower hair Cu (p = 0.043) and 35% higher Se levels (p = 0.058) content when compared animals with lower daily milk yield. Serum trace element levels were found to be more tightly associated with milk productivity in dairy cows. Particularly, serum levels of Se and Zn were found to be 73 and 35% higher in cows with higher milk productivity in comparison to animals with lower milk production, respectively. Serum Co levels also tended to increase with higher milk productivity. Serum minerals including Ca, Mg, and P were also found to be higher in highly productive cows by 6%, 14%, and 71%, respectively. The overall regression model based on serum trace element and mineral levels accounted for 38% of daily milk production variability. Generally, improvement of essential trace element and mineral supply, as well as prevention of copper overload in dairy cows, may be considered the potential tool for modulation of milk productivity.

The Correlation Between Potential "Anti- Cancer" Trace Elements and the Risk of Breast Cancer: A Case-Control Study in a Chinese Population.

BackgroundsBreast cancer is a heterogeneous disease without clear pathogenesis and effective primary prevention. The “anti-cancer” effects of several trace elements have received increasing attention in recent years. The main purpose of current study is to explore the differences of three potential “anti-cancer” trace elements selenium (Se), molybdenum (Mo), and strontium (Sr) between patients with malignant breast tumors and healthy controls.MethodsWe conducted a case–control study in 45 patients with malignant breast tumors as cases and 95 healthy volunteers as controls from Peking University Third Hospital, Beijing, China. The serum concentrations of trace elements were evaluated by using inductively coupled plasma mass spectrometry (ICP-MS).ResultsThe cases may have a lower Se levels when compared with controls (cases: 106.22 ng/ml, SD: 20.95 ng/ml; controls: 117.02 ng/ml, IQR: 22.79 ng/ml, p = 0.014). High levels of Se were a protective factor from breast cancer after adjusting the potential confounders of age, BMI, smoking, drinking, and menopause status (OR = 0.395, 95% CI, 0.178, 0.877, p = 0.023). The levels of Sr were lower in cases with high histologic grade when compared to low histologic grade (low histologic grade: 49.83 ng/ml, IQR: 41.35–62.60 ng/ml; high histologic grade: 40.19 ng/ml, IQR: 39.24–47.16 ng/ml, p < 0.05).ConclusionsOur findings herein supported that Se has protective effects to avoid malignant breast tumors and Sr has protective effects to avoid poorly differentiated malignant breast tumors. Exploring “anti-cancer” related trace elements and their associations with breast cancer will assist for the early prevention and intervention for the disease.

Clinical Significance of Micronutrient Supplementation in Critically Ill COVID-19 Patients with Severe ARDS.

The interplay between inflammation and oxidative stress is a vicious circle, potentially resulting in organ damage. Essential micronutrients such as selenium (Se) and zinc (Zn) support anti-oxidative defense systems and are commonly depleted in severe disease. This single-center retrospective study investigated micronutrient levels under Se and Zn supplementation in critically ill patients with COVID-19 induced acute respiratory distress syndrome (ARDS) and explored potential relationships with immunological and clinical parameters. According to intensive care unit (ICU) standard operating procedures, patients received 1.0 mg of intravenous Se daily on top of artificial nutrition, which contained various amounts of Se and Zn. Micronutrients, inflammatory cytokines, lymphocyte subsets and clinical data were extracted from the patient data management system on admission and after 10 to 14 days of treatment. Forty-six patients were screened for eligibility and 22 patients were included in the study. Twenty-one patients (95%) suffered from severe ARDS and 14 patients (64%) survived to ICU discharge. On admission, the majority of patients had low Se status biomarkers and Zn levels, along with elevated inflammatory parameters. Se supplementation significantly elevated Se (p = 0.027) and selenoprotein P levels (SELENOP; p = 0.016) to normal range. Accordingly, glutathione peroxidase 3 (GPx3) activity increased over time (p = 0.021). Se biomarkers, most notably SELENOP, were inversely correlated with CRP (rs = −0.495), PCT (rs = −0.413), IL-6 (rs = −0.429), IL-1β (rs = −0.440) and IL-10 (rs = −0.461). Positive associations were found for CD8+ T cells (rs = 0.636), NK cells (rs = 0.772), total IgG (rs = 0.493) and PaO2/FiO2 ratios (rs = 0.504). In addition, survivors tended to have higher Se levels after 10 to 14 days compared to non-survivors (p = 0.075). Sufficient Se and Zn levels may potentially be of clinical significance for an adequate immune response in critically ill patients with severe COVID-19 ARDS.

Effects of selenate applied at two growth stages on the nutrient quality of Cardamine violifolia

Cardamine violifolia is an edible selenium (Se) hyperaccumulator that is mainly distributed in Enshi, China. Here, C. violifolia treated with different selenate concentrations (i.e., 0, 1.5, 20, and 80 μmol L − 1) at the rosette and podding stages in a hydroponic experiment was carried out to investigate the effects of Se accumulation on the nutrient quality of this crop. The shoots accumulated high levels of Se at the rosette and podding stages, and the main Se forms at these stages were selenocystine and selenate. The effects of selenate on the chlorophyll, carotenoid, soluble sugar and protein, total free amino acid, and vitamin C contents of C. violifolia differed between the rosette and podding stages. Selenate treatment reduced total flavonoid and increased the total phenolic acid content at the podding stage. Total glucosinolate content decreased after selenate treatment at the rosette stage. Ten volatile compounds were found in C. violifolia shoots and the dominant volatile observed at the two stages was benzyl isothiocyanate. Selenate treatment demonstrated mixed influences on the volatile compounds. For example, at the rosette stage, selenate treatment inhibited the emission of benzyl isothiocyanate and benzyl isocyanate but promoted the generation of 12,15-octadecadiynoic acid methyl ester. Moreover, selenate treatment reduced the emission of isobutyl isothiocyanate at the podding stage of C. violifolia. These results provide us novel insights into the comprehensive effects of Se on the nutrient quality of Se hyperaccumulators.

Selenium toxicity, bioaccumulation, and distribution in earthworms (Eisenia fetida) exposed to different substrates

Selenium (Se) is an essential microelement for human or animal health. At high concentrations, it can cause Se poisoning. Human activities (such as coal burning and mining) threaten soil biota by mobilizing high levels of Se. We used the earthworm Eisenia fetida as a bio-indicator of environmental pollutants to investigate Se acute toxicity, enrichment, and distribution through exposure tests using filter paper, artificial soil and cow manure. The 24 h- and 48 h-LC50 for the filter paper contact test were 2.7 and 1.52 μg/cm2. In artificial soil test, the 14 d-LC50 and 14 d-biomass inhibition concentration (IC20) were 63.86 and 59.81 mg/kg, respectively. The cow manure resulted in a 2.2- and 2.6-fold higher LC50 and IC20 than artificial soil results, respectively. Earthworms accumulated the largest Se load (89.47 mg/kg) in artificial soil containing 80 mg Se/kg and only accumulated 90.3 mg/kg in cow manure containing 160 mg Se/kg; 46.6–60.59% of the total Se was distributed in the tail of E. fetida. The Se enrichment rate (SERSe) and bioaccumulation factor (BAFSe) scored higher in artificial soil than in cow manure with the same Se concentration exposure, and the highest SERSe was 6.21 and 6.31 mg Se/kg earthworm/d, respectively. The highest BAFSe was 1.49 in artificial soil and 0.75 in cow manure. Our results demonstrate that selenite is more toxic to earthworms living in artificial soil than in cow manure. E. fetida possesses certain Se detoxification mechanisms by distributing Se in the tail.

Effects of Selenium and/or Arbuscular Mycorrhizal Fungal Inoculation on Strawberry Grown in Hydroponic Trial

Strawberry is considered as a fruit of high nutritional value, with appreciated benefits on human health. Arbuscular mycorrhizal fungi (AMF) are commonly used plant symbionts that affect plant growth and its effectiveness is plant species specific. Additionally, selenium (Se) projects a special interest to humans for its antioxidant specialties, and to plants, because of the potential to make them grow faster when added to the nutrient solution. Nonetheless, the performance of arbuscular mycorrhizal fungi (AMF) in Se biofortification in strawberry is unexplored. The purpose of the present study experiment was to determine whether mycorrhizal inoculation of AMF can have a positive impact on growth and quality of strawberries, and whether Se contributes in this effort or will adversely affect the plants. Four Se concentrations (0, 1, 5 and 10 mg L−1) in the nutrient solution, with or without mycorrhizal inoculation of AMF to the root system, were evaluated. Results demonstrated that Se of 10 mg L−1 negatively affected plant growth, photosynthetic rates, decreased fruit firmness and total soluble solids, induced oxidative stress in fruits and affected nutrient accumulation in different plant organs. Mycorrhizal inoculation of AMF mainly stimulated antioxidative mechanisms of the fruits and increased nutrient accumulation for plants grown at high Se levels. Based on our observations, mycorrhizal inoculation can enhance the nutritional value of strawberry fruits and strawberry plants seem to be a strong candidate for Se biofortification, allowing the rise of Se of the consumers’ intake.

Influence of Selenium on Growth, Physiology, and Antioxidant Responses in Maize Varies in a Dose-Dependent Manner

There is a very narrow margin in selenium deficiency and toxicity although it is an important element for humans, animals, and plants. Effects of selenium (Se) on the growth and physiomorphological parameters in maize were studied grown in soil spiked with sodium selenate (Na2SeO4) in 5 different concentrations (i.e., 0. 2.5, 5.0, 10.0, and 20.0 mg kg−1). The growth of plants was affected by high Se concentration. However, maximum increases in plant height and root length were observed at low Se (2.5 mg kg−1) which were 17.89 and 23.17%, respectively. At higher Se concentrations (20 mg kg−1), a considerable reduction was observed in dry matter, root length, antioxidant enzymes, and other physiological parameters. The dry matter of plants was also analyzed for nutrient (Fe and Zn) concentrations. Results indicated that Se stress inhibits plant growth. Gas exchange parameters were also found to be decreased under stress conditions, but at a lower Se level (2.5 mg kg−1), improvement in transpiration rate (63.46%), photosynthetic rate (47.47%), and stomatal conductance (54.55%) was observed. The reduction in growth attributes may be due to the high accumulation of Se in roots and the disturbance in gas exchange parameters. However, the principal component analysis revealed that higher Se levels were more hazardous for maize growth and physiological responses as compared to low Se levels.

Analysis of Bioavailability and Induction of Glutathione Peroxidase by Dietary Nanoelemental, Organic and Inorganic Selenium.

Dietary organic selenium (Se) is commonly utilized to increase formation of selenoproteins, including the major antioxidant protein, glutathione peroxidase (GPx). Inorganic Se salts, such as sodium selenite, are also incorporated into selenoproteins, and there is evidence that nanoelemental Se added to the diet may also be effective. We conducted two trials, the first investigated inorganic Se (selenite), organic Se (L-selenomethionine) and nanoelemental Se, in conventional mice. Their bioavailability and effectiveness to increase GPx activity were examined. The second trial focused on determining the mechanism by which dietary Se is incorporated into tissue, utilising both conventional and germ-free (GF) mice. Mice were fed a diet with minimal Se, 0.018 parts per million (ppm), and diets with Se supplementation, to achieve 0.07, 0.15, 0.3 and 1.7 ppm Se, for 5 weeks (first trial). Mass spectrometry, Western blotting and enzymatic assays were used to investigate bioavailability, protein levels and GPx activity in fresh frozen tissue (liver, ileum, plasma, muscle and feces) from the Se fed animals. Inorganic, organic and nanoelemental Se were all effectively incorporated into tissues. The high Se diet (1.7 ppm) resulted in the highest Se levels in all tissues and plasma, independent of the Se source. Interestingly, despite being ~11 to ~25 times less concentrated than the high Se, the lower Se diets (0.07; 0.15) resulted in comparably high Se levels in liver, ileum and plasma for all Se sources. GPx protein levels and enzyme activity were significantly increased by each diet, relative to control. We hypothesised that bacteria may be a vector for the conversion of nanoelemental Se, perhaps in exchange for S in sulphate metabolising bacteria. We therefore investigated Se incorporation from low sulphate diets and in GF mice. All forms of selenium were bioavailable and similarly significantly increased the antioxidant capability of GPx in the intestine and liver of GF mice and mice with sulphate free diets. Se from nanoelemental Se resulted in similar tissue levels to inorganic and organic sources in germ free mice. Thus, endogenous mechanisms, not dependent on bacteria, reduce nanoelemental Se to the metabolite selenide that is then converted to selenophosphate, synthesised to selenocysteine, and incorporated into selenoproteins. In particular, the similar efficacy of nanoelemental Se in comparison to organic Se in both trials is important in the view of the currently limited cheap sources of Se.

Nutrient enrichment and trace element accumulation in sediments caused by waterbird colonies at a Mediterranean semiarid floodplain.

Waterfowl are vectors of nutrients, metals, and other pollutants (i.e. PCBs and microorganisms) on wetlands and other water bodies, especially when bird population density is high, e.g., in nesting, roosting or breeding periods. This work reports the effects caused by the increase in breeding pairs of herons and cormorants between 2010 and 2014 on sediments in an eutrophic Mediterranean wetland belonging to La Mancha Húmeda Biosphere Reserve. Nutrients, metals, metalloids, and isotopic composition (δ15N and δ13C) were analysed in sediments and faeces at several points in the Tablas de Daimiel National Park (TDNP), as well as in the nearby Navaseca wetland, which receives inputs from a wastewater treatment plant (WWTP). Sediments from Navaseca and from one site that is affected by heron colonies (Garcera) in the TDNP showed higher concentrations of organic matter, total organic carbon, total nitrogen, total phosphorus, Al, Co, Cu, Cr, Fe, Ni and Zn than the rest of the sampling sites. Significant correlations between these variables were found, probably suggesting that they have a common organic source. The highest δ15N values in sediments of the TDNP were registered in Guadiana, a site where there is no impact from colonies; these values might therefore be due to anthropogenic activities. Metal and metalloid content in sediments was lower than the regional reference values in soils, except for Se in the TDNP, and Zn and Cu in Navaseca. High Se level in TDNP sediment may be caused by seleniferous soils located upstream. Results showed a low impact of bird droppings compared to other sources of nutrients in the annual input in the TDNP.

Root foraging and selenium uptake in the Australian hyperaccumulator Neptunia amplexicaulis and non‐accumulator Neptunia gracilis

Background and aimsNeptunia amplexicaulis, endemic to Central Queensland (Australia), is one of the strongest selenium (Se) hyperaccumulators known globally, capable of accumulating up to 13 600 µg Se g− 1 in its leaves. This work aimed to elucidate root foraging in response to Se in N. amplexicaulis applied in two different chemical forms and concentrations compared to the sympatric non-accumulator N. gracilis.MethodsNeptunia amplexicaulis and N. gracilis seeds were germinated and transplanted into rhizotrons filled with half control and half Se-dosed soils with low (5 µg Se g− 1) or high (30 µg Se g− 1) levels of Se in soluble (Na2SeO4) or insoluble (CaSeO3) form. After 3 weeks, the root density in the two areas of the rhizotrons was measured and plants were removed from the soil to determine biomass and for chemical analysis of Se and other elements.ResultsMajor changes were observed in the low Se dosed side in Na2SeO4 form, and in the high Se dosed side in CaSeO3 form in N. amplexicaulis roots: a higher density, Se concentration, Se:S ratio, and a tendency to increase the biomass. In contrast, a reduction in the root density with 30 µg Se g− 1 in respose to the CaSeO3 form was observed in N. gracilis.ConclusionsNeptunia amplexicaulis preferentially foraged in Se soluble enriched soil, which may be beneficial for the plant given the increase in the root biomass at low Se dosed soil. In contrast, a reduction in the root density in N. gracilis indicated avoidance of soils enriched with high insoluble form of Se.

Growth, physiological, biochemical, and molecular responses of Pacific white shrimp Litopenaeus vannamei fed different levels of dietary selenium

This study investigated the effects of different levels of dietary selenium (Se) on the growth, antioxidant capacity, hepatopancreas health, and transcriptional-level responses of Litopenaeus vannamei. Sodium selenite was added to basal diet formulations at 0, 0.2, 0.4, and 0.8 mg/kg, with final Se concentrations of 0.13, 0.20, 0.45, and 0.81 mg/kg, respectively. Shrimp were fed the experimental diets for 8 weeks, after which the following parameters were measured: growth performance, antioxidant enzymes activity, ALT, AST activity, endoplasmic reticulum stress and transcriptome. Shrimp fed the 0.45 and 0.81 mg/kg Se diets (P < 0.05) showed the highest weight gain, shrimp fed the 0.13 mg/kg Se diet had the highest hepatosomatic index (P < 0.05), and the endoplasmic reticulum stress related genes were down-regulated (P < 0.05) in shrimp fed the 0.45 mg/kg Se diet. Antioxidant enzyme activity (SOD, CAT, and GPx) was enhanced with the increase in the Se level. The transcriptome results showed that glycine, serine, and threonine metabolism, the pentose phosphate pathway, and ascorbate and aldarate metabolism were enriched in shrimp fed the 0.45 mg/kg Se diet, while focal adhesions, gap junctions, tight junctions, and adhesion junctions were found in shrimp fed the 0.13 and 0.81 mg/kg Se diets. Co-expression analysis showed that genes PINK1 and Innexin (among others), were involved in the influence of Se levels on shrimp. Our results suggested that Se supplementation improved the growth and antioxidant capacity of L. vannamei by promoting the biosynthesis of glutathione and enhancing the activity of antioxidant enzymes. However, high levels of dietary Se can cause endoplasmic reticulum stress and hepatopancreas tissue damage.

Organic Selenium Reaches the Central Nervous System and Downmodulates Local Inflammation: A Complementary Therapy for Multiple Sclerosis?

Multiple sclerosis (MS) is an inflammatory and demyelinating disease of the central nervous system (CNS). The persistent inflammation is being mainly attributed to local oxidative stress and inflammasome activation implicated in the ensuing demyelination and axonal damage. Since new control measures remain necessary, we evaluated the preventive and therapeutic potential of a beta-selenium-lactic acid derivative (LAD-βSe), which is a source of organic selenium under development, to control experimental autoimmune encephalomyelitis (EAE) that is an animal model for MS. Two EAE murine models: C57BL/6 and SJL/J immunized with myelin oligodendrocyte glycoprotein and proteolipid protein, respectively, and a model of neurodegeneration induced by LPS in male C57BL/6 mice were used. The preventive potential of LAD-βSe was initially tested in C57BL/6 mice, the chronic MS model, by three different protocols that were started 14 days before or 1 or 7 days after EAE induction and were extended until the acute disease phase. These three procedures were denominated preventive therapy −14 days, 1 day, and 7 days, respectively. LAD-βSe administration significantly controlled clinical EAE development without triggering overt hepatic and renal dysfunction. In addition of a tolerogenic profile in dendritic cells from the mesenteric lymph nodes, LAD-βSe also downregulated cell amount, activation status of macrophages and microglia, NLRP3 (NOD-like receptors) inflammasome activation and other pro-inflammatory parameters in the CNS. The high Se levels found in the CNS suggested that the product crossed the blood-brain barrier having a possible local effect. The hypothesis that LAD-βSe was acting locally was then confirmed by using the LPS-induced neurodegeneration model that also displayed Se accumulation and downmodulation of pro-inflammatory parameters in the CNS. Remarkably, therapy with LAD-βSe soon after the first remitting episode in SJL/J mice, also significantly downmodulated local inflammation and clinical disease severity. This study indicates that LAD-βSe, and possibly other derivatives containing Se, are able to reach the CNS and have the potential to be used as preventive and therapeutic measures in distinct clinical forms of MS.

The effect of selenium source on the oxidative status and performance of broilers reared at standard and high ambient temperatures

ABSTRACT 1. This study investigated the oxidative status of broilers fed diets containing selenium (Se) from 14 to 35 d of age and reared at two different constant temperatures. Measurements of oxidative status included blood glutathione peroxidase (GSH-Px) and plasma total antioxidant status (TAS). Other variables included feed intake (FI), weight gain (WG), feed conversion ratio (FCR), Se levels in breast and liver tissue, jejunal villus morphometry, percentage weight of organs in relation to body weight; apparent metabolisable energy adjusted for nitrogen (AMEn); dry matter retention (DMR); fat retention (FR) and nitrogen retention (NR). 2. The experiment started at 14 d of age, when 240 birds were randomly allocated to 48 pens (12 pens in four rooms). Treatments included a control diet 1 (SFC; 209.4 g/kg CP and 12.98 MJ/kg ME and no added Se containing saturated fat); diet 2 (SFSe) the control plus 12.605 mg/kg Se additive; diet 3 (USFC) was a second control diet (208.2 g/kg CP and 13.10 MJ/kg ME with no added Se containing unsaturated fat as rapeseed oil); diet 4 (USFSe) was the latter control plus 12.605 mg/kg Se additive. Two rooms were kept at a standard temperature of 20°C (ST) and two rooms were kept at high temperature of 35°C (HT). 3. A temperature x Se interaction existed for GSH-Px in birds reared at ST (P < 0.05), and these birds had the highest levels of Se in liver tissue (P < 0.05). Fat x Se interactions were evident in breast tissue with highest levels in USFSe (P < 0.05). Adding Se improved jejunal VH: CD in USFSe fed birds (P < 0.001). 4. Birds reared at ST had higher FI and WG than those reared at HT (P < 0.001), and had lower FCR than those reared at HT (P < 0.05). AMEn (MJ/kg DM) and FR were higher in birds fed USF diets, and lowest in birds fed SF (P < 0.50 and P < 0.001 respectively). NR was highest in birds raised at ST (P < 0.50). 5. Broiler growth performance was reduced by HT. Oxidative status and Se in liver tissue was improved by adding Se in both diets.

Clinical Relevance of Serum Selenium Levels and Abdominal Aortic Calcification

Selenium (Se) is an essential micronutrient with antioxidative properties, but previous studies have shown that extremely high circulating Se concentrations are associated with a higher prevalence of cardiovascular diseases (CVDs). To date, it remains unknown whether this association has connections with arterial calcification. A total of 982 participants with both serum Se concentration and abdominal aortic calcification (AAC) score data were enrolled from the 2013-2014 National Health and Nutrition Examination Survey (NHANES), a cross-sectional study of a noninstitutionalized population in the USA. Serum Se levels were determined by inductively coupled plasma-dynamic reaction cell-mass spectrometry. AAC was obtained from dual-energy X-ray absorptiometry and quantified by the Kauppila score system. Severe AAC was defined as Kauppila score ≥ 5. Among all participants, the mean serum Se level was 132.89μg/L. The average AAC score was 1.51, and 11.7% had severe AAC. Compared with those in the lowest quartile of Se (< 121.1μg/L), the highest quartile subgroup (> 143.1μg/L) was associated with a higher mean AAC score (β-coefficient 0.88; 95% CI 0.28, 1.47; p = 0.004) and greater odds of having severe AAC (odds ratio 2.19; 95% CI 1.10, 4.36; p = 0.026) after adjusting for demographic, biochemical, and clinical characteristics. The concentrations of other circulating trace elements showed no statistically significant association with the AAC score. High serum Se levels were independently associated with an increased mean AAC score and aggravated AAC severity among noninstitutionalized US adults. Serum Se might adversely affect the cardiovascular system when the serum Se concentration exceeds 143μg/L.

In vitro selenium bioaccessibility combined with in vivo bioavailability and bioactivity in Se-enriched microalga (Chlorella sorokiniana) to be used as functional food

Abstract Speciation of seleno-metabolites and selenoproteins in Se-enriched Chlorella sorokiniana microalgae, in vitro and in vivo extracts has been performed by HPLC-ICP-MS. Selenium bioaccesibility in Se-enriched Chlorela sorokiniana evaluated by in vitro gastrointestinal digestion of the selenized microalga was 81% (79% as SeMet). Mice supplemeted with Se-enriched C. sorokiniana presented increased Se concentration in kidney, reflecting a potencial mechanism of excretion by urine. In addition, selenium bioavailavility, which was in the range of 3–15% depending on the diet was 1.13-fold higher in mice fed with Se-enriched microalgae against the basal diet, but decreased with higher amounts of selenium. Regarding bioactivity (∑Se as selenoproteins in serum/total Se in serum = 76–85% depending on the diet), selenium and selenoproteins (SeP) increased in serum from animals fed high supplemental Se levels. These results showed that Se-enriched algae can be considered as an alternative selenized food for humans, due to their high Se bioavailability.

Effect of inclusion of pentasulphate mixture and arsenic in diets given high level of selenium on feed intake and nutrient utilization in buffaloes

Sixteen Murrah buffalo male calves were divided into 4 groups with 4 animals in each group, based on their body weight and age. The animals were fed on rations to supply 15% less of CP requirements as per NRC (2001). Â All the animals were fed a basal diet (0.41 ppm Se) comprising of paddy straw, concentrate mixture and green maize (Control, group T1). The animals in groups T2, T3 and T4 were also supplemented with 10 ppm of Se in the form of sodium selenite after 60 d of feeding. Thereafter, animals were given supplementary arsenic (40 ppm of diet) in form of sodium arsenite and pentasulphate mixture (9 g/100 kg BW) in groups T3 and T4, respectively in addition to Se (10 ppm) being already given. After 85 days of feeding, a metabolism trial was conducted in order to determine DM intake, nutrient digestibility and balances of N and Se. DM Intake was similar in all the groups. Digestibility of nutrients (DM, OM, EE, CF, NFE, NDF) and nitrogen retention was also not affected by dietary treatments to any significant extent, however, digestibility of CP and ADF was lower (P&lt;0.05) in group T2 compared to other groups. Supplementary pentasulphate mixture and As increased excretion of Se which paved the way for its less retention (P&lt;0.01) in the body. Hence, supplementation of either pentasulphate mixture @ 9 g/100 kg BW or arsenic (40 ppm) to the diet already supplied with extra 10 ppm Se improved the digestibility of CP and ADF while reducing the Se load from the body considerably showing the positive effect of arsenic and pentasulphate supplementation in buffalo calves given high level of Se in paddy straw based rations.

Accumulation and speciation of selenium in biofortified vegetables grown under high boron and saline field conditions

Selenium (Se) biofortification, as an agronomic-based strategy, is utilized to produce Se-enriched food products for increasing Se intake in inhabitants in Se-deficient regions. This strategy can be accomplished by soil and foliar application of Se or by growing crops in soils naturally high in Se. In this study, different cruciferous vegetables were field-grown in high boron (B) and saline soils of central California containing naturally high levels of Se. We investigated whether Se biofortification occurs in salt- and B-tolerant vegetables grown in poor-quality soil. The uptake of Se and other elements occurred in all vegetables. In plant tissues, Se speciation analyses showed greatest percentages of Se-containing compounds were contained in organic Se forms (monomethylated) and as selenate in the inorganic Se forms. Selenium-enriched vegetables produced from saline soils high in B and Se can be a natural source of Se-biofortified food that can be consumed as bioactive food products.

Transcriptome analysis reveals gene expression changes of the fat body of silkworm (Bombyx mori L.) in response to selenium treatment.

A comparative transcriptome analysis was conducted to investigate the gene expression changes in the fat body of silkworm after treatment with different concentrations (50μM and 200μM) of selenium (Se). 912 differential expression genes (DEGs) (371 up-regulated and 541 down-regulated) and 1420 DEGs (1078 up-regulated and 342 down-regulated) were identified in silkworm fat body treated with 50μM and 200μM of Se, respectively. In case of 50μM group, DEGs were mainly enriched in the peroxisome pathway and fatty acid metabolism pathway, and later were associated with antioxidant defense and nutrition regulation. After 200μM Se-treatment, DEGs were mainly located in the glycerolipid metabolism and arachidonic acid metabolism pathways, which further encoded detoxification related genes. Furthermore, 32 candidate DEGs from these pathways had been selected to confirm the RNA-seq data. Among these DEGs, 14 genes were up-regulated in the 50μM Se-treated group (only three genes in the 200μM Se-treated group) which were involved in lipid metabolism and antioxidant defense, and 13 up-regulated genes (only two genes were up-regulated in the 50μM Se-treated group) were involved in detoxification of the 200μM Se-treated group. These changes showed that lower concentration of Se could regulate the nutrition and promote antioxidation pathways; whereas, high levels of Se promoted the detoxification of silkworm. These findings can be helpful to understand the possible mechanisms of Se action and detoxification in silkworm and other insects.