Organic Forms Of Selenium Research Articles

Application of the Se NPs-Chitosan molecular complex for the correction of selenium deficiency in rats model

Selenium is an integral component of vital biologically active compounds of the human body. Currently, the population of many countries is characterized by selenium deficiency. In this regard, many preparations of inorganic and organic forms of selenium have been developed. Nevertheless, it is evident that the most effective solution to the problem is to enrich the diet with bioavailable forms of selenium. Thus, this work aimed to synthesize and study the antioxidant and immunomodulatory effects of the molecular complex of selenium nanoparticles (Se NPs) and chitosan in laboratory rats with induced hyposelenosis. During the experiment with animals, we found that as a result of 70-day consumption of food with a low selenium content, rats develop an alimentary selenium deficiency state, as evidenced by a significant decrease in the content of this trace element in control group rats to 48.2 ±6.71 µg/kg versus 149.3 ±21.63 µg/kg in intact animals. Course, administration of the molecular complex Se NPs- Chitosan to rats of the experimental group, contributed to the replenishment of selenium deficiency: its concentration in the blood of animals was 96.6 ±3.57 µg/kg. Thus, in animals of the control group, there was a decrease in the total number of lymphocytes by 2.7 times, T-lymphocytes – by 1.8 times, and B-lymphocytes – by 2.3 times compared with similar data in intact animals. In the context of hyposelenosis, it is worth mentioning that there was a slight increase in the content of T-helper cells and cytotoxic T-lymphocytes. The synthesized Se NPs – Chitosan complex administration during hyposelenosis demonstrated a notable immunomodulatory effect by restoring the body's immune response indicators. Thus, the total number of lymphocytes increased by 3 times, T-lymphocytes – by 1.9 times, and B-lymphocytes – by 2 times. The number of T-helper cells and cytotoxic T-lymphocytes increased by 1.9 times compared to the group of intact animals and 1.6 times compared to selenium-deficient rats. Thus, the course introduction of the molecular complex Se NPs – Chitosan against the background of selenium deficiency was accompanied by inhibition of free radical oxidation processes, activation of the antioxidant system and restoration of the immune status of the organism of laboratory animals.

Selenium and immune function: a systematic review and meta-analysis of experimental human studies

BackgroundSelenium is an essential trace element with both beneficial and detrimental effects on health depending on dose and chemical form. Currently, there is debate on recommendations for selenium supplementation as a public health measure to improve immune function and reduce infectious disease susceptibility. ObjectivesWe performed a systematic review and meta-analysis of experimental studies assessing the effect of selenium supplementation on immunity-related outcomes in healthy people. MethodsWe undertook a search of published and unpublished studies in literature databases such as PubMed/MEDLINE, Embase, and clinicaltrials.gov up to 17 October, 2022, and performed a meta-analysis comparing the effects on immunity-related outcomes between Se-supplemented versus control arms. Whenever possible we assessed the nonlinear relation using a dose–response approach. Results9 trials were included, 5 in North America, and 4 in Europe, with a duration between 8 and 48 weeks and supplementation of both inorganic and organic selenium forms. Selenium supplementation did not substantially affect immunoglobulin or white blood cell concentrations, and the dose–response meta-analysis indicated that an increase in plasma selenium concentrations above 100 μg/L did not further increase IgA levels nor T cells. An inverted U-shaped relation emerged for NK cell count, with a lower number of these cells both below and above 120 μg/L. The only beneficial effect of selenium supplementation was the increased activity for NK lysis, but the available data did not permit dose–response analysis. Cytokine levels were substantially unaffected by selenium supplementation. ConclusionsAlthough some of the data suggested beneficial effects of selenium supplementation on immune function, the overall picture appears to be inconsistent and heterogeneous due to differences in trial duration and interventions, plus evidence of null and even detrimental effects. Overall, the evidence that we extracted from the literature in this systematic review does not support the need to supplement selenium beyond the recommended dietary intake to obtain beneficial effects on immune function.This trial was registered at PROSPERO (CRD42022312280).

Hydroxy-Selenomethionine, an Organic Selenium Source, Increases Selenoprotein Expression and Positively Modulates the Inflammatory Response of LPS-Stimulated Macrophages.

The role of 2-hydroxy-(4-methylseleno)butanoic acid (OH-SeMet), a form of organic selenium (Se), in selenoprotein synthesis and inflammatory response of THP1-derived macrophages stimulated with lipopolysaccharide (LPS) has been investigated. Glutathione peroxidase (GPX) activity, GPX1 gene expression, selenoprotein P (SELENOP) protein and gene expression, and reactive oxygen species (ROS) production were studied in Se-deprived conditions (6 and 24 h). Then, macrophages were supplemented with OH-SeMet for 72 h and GPX1 and SELENOP gene expression were determined. The protective effect of OH-SeMet against oxidative stress was studied in H2O2-stimulated macrophages, as well as the effect on GPX1 gene expression, oxidative stress, cytokine production (TNFα, IL-1β and IL-10), and phagocytic and killing capacities after LPS stimulation. Se deprivation induced a reduction in GPX activity, GPX1 gene expression, and SELENOP protein and gene expression at 24 h. OH-SeMet upregulated GPX1 and SELENOP gene expression and decreased ROS production after H2O2 treatment. In LPS-stimulated macrophages, OH-SeMet upregulated GPX1 gene expression, enhanced phagocytic and killing capacities, and reduced ROS and cytokine production. Therefore, OH-SeMet supplementation supports selenoprotein expression and controls oxidative burst and cytokine production while enhancing phagocytic and killing capacities, modulating the inflammatory response, and avoiding the potentially toxic insult produced by highly activated macrophages.

Effect of various forms and levels of selenium on milk productivity and resistance of lactating cows

The effect of two forms of selenium, inorganic and organic, was evaluated in the study. Lactating cows of the 1st control group were fed 4.9 mg/head/day of inorganic form of selenium, cows of the 2nd, 3rd and 4th experimental groups received organic form of selenium in the amounts of 2.5, 3.7 and 4.9 mg/head/day. Researches show that application of organic form of selenium permits to increase average daily milk yield by 3.3, 12.9 and 10.8% (р < 0.05), while increasing of dry matter concentration in milk by 0.57% (р < 0.05) in comparison with the 1st control group. When administering selenium in organic form 3.7 mg/head/day, there was a tendency to increase in amount of casein and decrease in amount of somatic cells in milk by 0.13% and 33.7 thousand/ cm3 respectively (р < 0.1). A dose of 4.9 mg/head/day of organic selenium contributed to a decrease in amount of somatic cells by 29.3 thousand/cm3 (р < 0.05). Feeding experimental groups with organic form of selenium in different doses had a positive effect on the immune status and antioxidant activity of blood serum. The content of free water-soluble antioxidants (TAWSA) in blood serum was higher by 39.3 and 53.5% (р < 0.001) in cows of the 3rd and 4th experimental groups fed 3.7 and 4.9 mg/head/day of organic selenium. Thus, the use of selenium in organic form is the most effective and allows to reduce the amount of used micronutrient for replenishment of animal needs.

The use of various forms of selenium in aquaculture

A study of the scientific literature on the use of nanotechnology methods for the cultivation of various aquaculture facilities has been generalized. The study was based on the addition of selenium to the diets of various shapes and origins.It is emphasized that modern scientific research on the use of nanoparticles in aquaculture emphasizes the accuracy of delivery and the appropriate number of trace elements, which in turn may reduce the cost of aquaculture products. It is pointed out that it is necessary to take into account the specifics of modern industrial aquaculture technologies, in which aquatic organisms are grown at high planting densities in pools, that means are constantly under stress, and one of the most common forms of stress leading to reduced productivity in aquaculture is oxidative stress. The review noted that selenium is one of the important micronutrients that can reduce the negative effects of oxidative stress. Studies by a number of authors on the positive effects of adding various forms of selenium to the diets of major aquaculture facilities have been analyzed. It is determined that biologically synthesized nanoselenium can be added to various commercial fish feeds to increase stress resistance and productivity of aquatic organisms, in addition, this product will meet the environmental needs of consumers. The advantage of using organic forms of selenium in aquaculture over inorganic ones has been established, as the former have higher bioavailability and better accumulation in fish tissues. A number of studies related to the determination of the toxic effects of various forms of selenium and its concentrations on aquatic organisms have been studied. It is emphasized that in aquaculture it is necessary to take into account that selenium particles must be non-toxic not only for the biological object itself, but also for other systems that are closely related to its vital activity. Key words: selenium, nanotechnology, aquaculture, fish, stress resistance, toxicity, growth rate, physiological indicators, immunological indicators.

Development and study of the effectiveness of a biologically active drug in the diet of sows

Many researchers note the need to improve feed additives and the search for new promising drugs for the intensification of the pig industry. We have developed a biologically active complex drug Microlact. It is used by animals as a means aimed at correcting the disturbed metabolism of sows associated with pregnancy and lactation, to activate the growth and development of piglets as well as their viability. The purpose of the work was to develop and study the effectiveness of the biologically active drug in the diet of lactating sows. The use of the drug led to the improvement of biochemical parameters of blood of pregnant sows, indicating the activation of metabolic processes in their body, which provided the increase in milk yield of sows, average daily weight gain of piglets and their livability. The live weight of piglets for weaning increased by 8,0% (P < 0,01), the livability of suckling piglets increased to 93,1%, which is a consequence of improving the quality of colostrum and milk, and consequently the positive effect of the biologically active drug containing an optimal complex of minerals, vitamin E in the composition of malt sprouts, essential amino acids and organic form of selenium. More nutritious colostrum and milk contributed to the better development of the piglets’ body and resistance to adverse factors. Immunoglobulins have been obtained by piglets with colostrum and milk increase their resistance and contribute to higher livability. The increase in the weight of suckling pigs has a positive effect on the further development and growth of animals on fattening. Thus, the administration of the biologically active drug Microlact to sows during pregnancy leads to the activation of metabolic processes, which can only be provided by a high level of functioning of the organs and systems of the body.

Suppression of lipopolysaccharide-induced activation of RAW 264.7 macrophages by Se-methylseleno-l-cysteine

Se-methylseleno-l-cysteine (l-SeMC) is a natural source of organic selenium for humans. Although it has a structure similar to that of l-Cysteine (l-Cys), its anti-inflammatory properties and possible underlying mechanisms have not been explored. Here, we compared the anti-inflammatory activities of inorganic selenium (selenite), l-Cys, and l-SeMC in lipopolysaccharide (LPS)-activated RAW 264.7 murine macrophages and focused on the related molecular and biochemical events. The results showed that, anti-inflammatory activity of l-SeMC was much stronger compared to both individual l-Cys treatment and l-Cys/selenite combinations. The organic form of selenium may play a crucial role in the effects of l-SeMC. Further study confirmed that l-SeMC suppressed the RNA expression of iNOS, TNF-α, IL-1β, IL-6, COX-2, and MMP-9, as well as the release of NO, TNF-α, IL-6, IL-12p70, COX-2, and PGE2 from LPS-activated RAW264.7 macrophages in a concentration-dependent manner. Moreover, l-SeMC prevented LPS-induced changes in cell morphology. l-SeMC concentrations between 50 and 200 μM exhibited an anti-inflammatory effect closed to that exhibited by 20 μM dexamethasone. Our results demonstrated that l-SeMC effectively inhibited the activation of RAW 264.7 macrophages induced by LPS, and suggested that l-SeMC could be a potential functional food component for the prevention or treatment of inflammatory diseases.

Form of Supplemental Selenium in Vitamin-Mineral Premixes Differentially Affects Early Luteal and Gestational Concentrations of Progesterone, and Postpartum Concentrations of Prolactin in Beef Cows.

Simple SummarySoils with inadequate levels of selenium are widespread in the northwest, northeast, and southeast USA. Therefore, dietary supplementation of forage-grazing beef cattle with additional selenium is recommended in these regions for optimal growth, immune function, and fertility. We have reported that the form of selenium provided to Angus-cross cows can affect circulating concentrations of progesterone on day 6 of the estrous cycle, a time when increased progesterone is known to promote fertility. Hence, we sought to confirm this initial finding, determine the effect of the form of selenium on peripheral concentrations of progesterone during gestation, and determine the effect of the form of selenium on circulating concentrations of prolactin during lactation. Cows were supplemented with equimolar amounts of either an inorganic form, or a 1:1 mixture of inorganic and organic forms of selenium throughout this study. We confirmed our original finding that the mixed (1:1 inorganic to organic selenium) supplement increased systemic progesterone in the early luteal phase of the estrous cycle, and determined that cows maintained on this same supplement had elevated concentrations of progesterone throughout gestation. Interestingly, these same cows revealed a treatment-induced decrease in systemic prolactin during late lactation. The form of selenium provided to cows can be manipulated to affect reproductive responses and offers a viable management tool to improve fertility in cows in regions with selenium-deficient soils.Soils with marginal to deficient levels of selenium (Se) are widespread in the northwest, northeast, and southeast US. Supplementation to the diet of forage-grazing beef cattle with a vitamin-mineral mix containing additional Se is recommended in these geographic regions. We have reported that the form of supplemental Se provided to Angus-cross beef cows can affect circulating levels of progesterone (P4) on day 6 of the estrous cycle, a time when increased P4 is known to promote fertility. The objectives of this study were to (1) confirm and expand upon our initial report that the form of Se provided to cows affects early luteal-phase concentrations of systemic P4, (2) determine the effects of the form of Se on concentrations of P4 during gestation, and (3) determine the effects of the form of Se on concentrations of prolactin (PRL) during lactation. Throughout this study, Angus-cross beef cows had ad libitum access to a vitamin-mineral mix containing 35 ppm of Se in either an inorganic form (ISe) or a 1:1 mix of inorganic and organic forms (MIX). We observed a MIX-induced increase (p = 0.006) in systemic concentrations of P4 on day 7 but not on days 4 or 10 of the estrous cycle, consistent with our earlier report. We observed a MIX-induced increase (p = 0.02) in the systemic concentration of P4 at months 1, 3, 5, and 7 of gestation, and a MIX-induced decrease (p < 0.05) in systemic concentrations of PRL at months 5 and 6 of lactation. In summary, the form of Se provided to cows can be manipulated to affect the early luteal phase and gestational concentrations of P4, and postpartum concentrations of PRL.

Changes in performance, egg quality and blood parameters of laying hens fed selenium and oregano oil

Context Organic and herbal additives in feed may lead to more healthy animal products. For this study, we hypothesised that an organic form of selenium and/or a herbal additive (oregano, Origanum vulgare L.) may improve performance of laying hens. Aims The study was designed to determine the effects of selenium source (SS, sodium selenite; or selenium yeast, SY), oregano essential oil (OEO) and a combination of Se and OEO on performance, egg quality and blood parameters of laying hens. Methods In total, 216 Lohmann LSL-Lite laying hens, 66 weeks of age, were assigned to feed on one of six diets: control group, receiving basal diet (BD); BD + 0.3 mg SS/kg; BD + 0.3 mg SY/kg; BD + 250 mg OEO/kg; BD + 250 mg OEO + 0.3 mg SS/kg; BD + 250 mg OEO + 0.3 mg SY/kg. For each treatment, there were six replicates of six hens each for 12 weeks. Key results Feed conversion ratio was higher (P &amp;lt; 0.05) with the OEO diet than in the control. The SY diet decreased egg production and the OEO diet decreased egg mass (P &amp;lt; 0.05), although this effect was reversed with the SY + OEO diet. This would illustrate a synergistic effect of OEO with SY. Highest and lowest yolk colour values were found with the SY and SS diets, respectively (P &amp;lt; 0.05). Serum uric acid was lower with diets containing Se than the control diet (P &amp;lt; 0.05). Glutathione peroxidase activity was highest with SY and SY + OEO diets and lowest with the OEO diet (P &amp;lt; 0.05). Birds fed the SS + OEO diet showed the highest total antioxidant capacity and those fed SY showed the lowest total antioxidant capacity (P &amp;lt; 0.05). Conclusions Based on the results of the current study, it can be concluded that SY diet have increasing effect on egg weight in laying hens. In addition, novel synergistic effects between OEO and SY diets on improving egg production, egg mass and feed conversion ratio have been found. In terms of oxidative status, the detected synergistic effects between OEO and SS diets on total antioxidant capacity and between OEO and SY diets on glutathione peroxidase (GPx) have not been reported before, that appreciate more clarifying investigations in future. Although, dietary supplemental SY individually and also with OEO increased GPx, adding SS to diet together with OEO showed more improving effect on GPx compared to the separate usage. Implications Dietary supplemental SY can improve egg weight in laying hens. In addition, adding SY to diet of laying hens individually and with OEO have beneficial effects on oxidative status of bird in terms of GPs activity, which in turn can ameliorate the unfavourable impressions of probable environmentally oxidative stress on productive performance.

Selenomethionine supplementation reduces lesion burden, improves vessel function and modulates the inflammatory response within the setting of atherosclerosis

Atherosclerosis is a chronic inflammatory disease of the vasculature characterised by the infiltration of activated neutrophils and macrophages at sites of damage within the vessel wall, which contributes to lesion formation and plaque progression. Selenomethionine (SeMet) is an organic form of selenium (Se), an essential trace element that functions in the regulation of the immune response by both bolstering the endogenous thioredoxin and glutathione antioxidant defence systems and by directly scavenging damaging oxidant species. This study evaluated the effect of dietary SeMet supplementation within a high fat diet fed apolipoprotein E deficient (ApoE−/-) mouse model of atherosclerosis. Dietary supplementation with SeMet (2 mg/kg) increased the tissue concentration of Se, and the expression and activity of glutathione peroxidase, compared to non-supplemented controls. Supplementation with SeMet significantly reduced atherosclerotic plaque formation in mouse aortae, resulted in a more stable lesion phenotype and improved vessel function. Concurrent with these results, SeMet supplementation decreased lesion accumulation of M1 inflammatory type macrophages, and decreased the extent of extracellular trap release from phorbol myristate acetate (PMA)-stimulated mouse bone marrow-derived cells. Importantly, these latter results were replicated within ex-vivo experiments on cultured neutrophils isolated from acute coronary syndrome patients, indicating the ability of SeMet to alter the acute inflammatory response within a clinically-relevant setting. Together, these data highlight the potential beneficial effect of SeMet supplementation as a therapeutic strategy for atherosclerosis.

Production of Selenomethionine-Enriched Bifidobacterium bifidum BGN4 via Sodium Selenite Biocatalysis.

Selenium is a trace element essential for human health that has received considerable attention due to its nutritional value. Selenium’s bioactivity and toxicity are closely related to its chemical form, and several studies have suggested that the organic form of selenium (i.e., selenomethionine) is more bioavailable and less toxic than its inorganic form (i.e., sodium selenite). Probiotics, especially Bifidobacteriium and Lactobacillus spp., have received increasing attention in recent years, due to their intestinal microbial balancing effects and nutraceutical benefits. Recently, the bioconversion (a.k.a biotransformation) of various bioactive molecules (e.g., minerals, primary and secondary metabolites) using probiotics has been investigated to improve substrate biofunctional properties. However, there have been few reports of inorganic selenium conversion into its organic form using Bifidobacterium and Lactobacillus spp. Here we report that the biosynthesis of organic selenium was accomplished using the whole cell bioconversion of sodium selenite under controlled Bifidobacterium bifidum BGN4 culture conditions. The total amount of organic and inorganic selenium was quantified using an inductively coupled plasma-atomic emission spectrometer (ICP-AES). The selenium species were separated via anion-exchange chromatography and analyzed with inductively coupled plasma-mass spectrometry (ICP-MS). Our findings indicated that the maximum level of organic selenium was 207.5 µg/g in selenium-enriched B. bifidum BGN4. Selenomethionine was the main organic selenium in selenium-enriched B. bifidum BGN4 (169.6 µg/g). Considering that B. bifidum BGN4 is a commercial probiotic strain used in the functional food industry with clinically proven beneficial effects, selenium-enriched B. bifidum BGN4 has the potential to provide dual healthy functions as a daily supplement of selenium and regulator of intestinal bacteria. This is the first report on the production of organic selenium using B. bifidum spp.

Development of the biotechnology for obtaining a dietary supplement from the selenium-containing probiotic cultures Lactobacillus acidophilus 412/307 and Bifidobacterium bifidum 1

The relevance of creating a new dietary supplement based on the selenium-containing cultures of lacto- and bifidobacteria was proven. We have chosen the optimal source of selenium – sodium selenite (Na 2 SeO 3 ), adding which to the cultivation medium of microorganisms ensures maximum accumulation of organic forms of selenium in the examined microorganisms. We have established the effect of concentrations of sodium selenite on an increase in the biomass of lacto- and bifidobacteria. Concentrations of Na 2 SeO 3 exceeding 8 µg/cm 3 cause the inhibition of growth in the lactobacilli biomass when compared with control. The growth of biomass of bifidobacteria is inhibited under the influence of the concentration of Na 2 SeO 3 above 5 µg/cm 3 . Applying the indicators of optical density, we determined values for a specific growth rate and the duration of generation of biomass of the examined microorganisms. The dynamics of selenium accumulation by the cultures Lactobacillus acidophilus 412/307 and Bifidobacterium bifidum I was studied. A direct dependence was established between the quantitative content of inorganic selenium in the environment of cultivation and the content of organic selenium in bacterial cells. Adding the concentration of sodium selenite equal to 0.5 µg/cm 3 provides for obtaining 105 µg of organic selenium per one gram of dry biomass of lactobacilli; this indicator for bifidobacteria is 97.5 µg/g. At a concentration of Na 2 SeO 3 equal to 20 µg/cm 3 , 4,698 µg of organic selenium is biotransformed in the biomass of lactobacilli and 3,149 µg –in the biomass of bifidobacteria. Based on the data derived, we have developed a technological scheme for obtaining the dietary supplement with the quantitative content of organic selenium at 202.5±1 µg/g. The content of lactobacilli was 1.0×10 9 CFU/cm 3 ; that of bifidobacteria – 1.2×10 8 CFU/cm 3

179 - Dietary Selenomethionine Supplementation Limits Extracellular Trap Formation and Reduces Lesion Burden in a Mouse Model of Atherosclerosis

Atherosclerosis is a chronic inflammatory disease of the vasculature characterised by the infiltration of activated neutrophils and macrophages at sites of damage within the vessel wall, which contributes to lesion formation and plaque progression. This is in part due to the formation of extracellular traps (ETs) by these invading immune cells, with inhibition of ET formation previously shown to reduce lesion formation. Selenomethionine (SeMet) is the organic form of selenium (Se), an essential trace element that functions in the regulation of the immune response. The aim of this study was to evaluate the effect of dietary SeMet supplementation within normal chow and high fat diet (HFD) fed apolipoprotein E deficient (apoE-/-) mice, as a model of atherosclerosis. Dietary supplementation with 2 mg/kg SeMet (w/w) over 12 weeks resulted in the significant reduction of atherosclerotic plaque formation in aortas from mice fed SeMet compared to controls in both the normal (0.40% vs 1.26%) and HFD (4.70% vs 6.21%) fed cohorts, as assessed by Oil Red O staining of lipid content. Isolation of bone marrow derived cells from the mice and subsequent ex vivo induction of ET formation through stimulation with phorbol 12-myristate 13-acetate (PMA) resulted in markedly less ET formation within the SeMet supplementated cohorts compared to controls as assessed through SYTOX Green staining of extracellular DNA and qPCR analysis of mitochondrial and nuclear genomic DNA within culture supernatants. Together, these data support a novel role for SeMet to mitigate ET formation and reduce atherosclerotic lesion development and highlight the potential beneficial effect of SeMet supplementation as a therapeutic strategy for atherosclerosis.

Dietary supplements based on selenium containing culture of lactic acid bacteria

The article describes the role of selenium in the humankind being. The analysis based on the published data shows that the biological synthesis is a perspective way to obtain an organic form of selenium, which can be used in dietary supplements. The ability of lactic acid bacteria (Lactobacillus acidophilus 412/307)to accumulate inorganic forms of selenium (selenites, selenates), turning them into organic forms, with purposeful trace element enrichment of culture medium is described in the article. The main organic forms of selenium, which are being used in the process of biotransformation from its inorganic forms by microorganisms, have been reorganized. The relationship between the increasing of concentrations of sodium selenite in the culture medium and the growth of biomass of lactic acid bacteria was established. It was found the depressing effect of increasing concentrations of sodium selenite on optical density rate. It was estabilished the optimal conditions for the maximum accumulation of selenium containing culture of lactic acid bacteria. The influence of selenium concentration on the lactic acid bacteria biomass accumulation was determined also by changing the values of optical density. Due to the obtained data, the selenium containing dietary supplement «Selenolakt» was created. The main microbiological indicators that characterize the quality of the obtained product are given. The content of organic form of selenium in products reaches –195 ± 1 mkg/g.

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

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 Se4+∙L−1) to the experimental media in the form of sodium(IV) selenite (Na2SeO3) salt caused a significant increase in selenium content in the biomass of C. utilis, irrespective of the concentration. The highest amount of selenium (1841 μg∙gd.w.−1) was obtained after a 48-h culture in media containing 30 mg Se4+∙L−1. The highest content of selenomethionine (238.8 μg∙gd.w.−1) was found after 48-h culture from the experimental medium that was supplemented with selenium at a concentration of 20 mg Se4+∙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

Selenium and Thyroid Disease: From Pathophysiology to Treatment.

Introduction. Selenium is a micronutrient embedded in several proteins. In adults, the thyroid is the organ with the highest amount of selenium per gram of tissue. Selenium levels in the body depend on the characteristics of the population and its diet, geographic area, and soil composition. In the thyroid, selenium is required for the antioxidant function and for the metabolism of thyroid hormones. Methods. We performed a review of the literature on selenium's role in thyroid function using PubMed/MEDLINE. Results. Regarding thyroid pathology, selenium intake has been particularly associated with autoimmune disorders. The literature suggests that selenium supplementation of patients with autoimmune thyroiditis is associated with a reduction in antithyroperoxidase antibody levels, improved thyroid ultrasound features, and improved quality of life. Selenium supplementation in Graves' orbitopathy is associated with an improvement of quality of life and eye involvement, as well as delayed progression of ocular disorders. The organic form of selenium seems to be the preferable formulation for supplementation or treatment. Conclusion. Maintaining a physiological concentration of selenium is a prerequisite to prevent thyroid disease and preserve overall health. Supplementation with the organic form is more effective, and patients with autoimmune thyroiditis seem to have benefits in immunological mechanisms. Selenium supplementation proved to be clinically beneficial in patients with mild to moderate Graves' orbitopathy.

Application of X-ray absorption near edge spectroscopy to the study of the effect of sulphur on selenium uptake and assimilation in wheat seedlings

Selenium (Se) is an essential trace element for humans and animals. A hydroponic experiment was performed to study the effects of sulphur (S) on Se uptake, translocation, and assimilation in wheat (Triticum aestivum L.) seedlings. Sulphur starvation had a positive effect on selenate uptake and the form of Se supplied greatly influenced Se speciation in plants. Compared with the control plants, Se uptake by the S-starved plants was enhanced by 4.81-fold in the selenate treatment, and selenate was readily transported from roots to shoots. By contrast, S starvation had no significant effect on selenite uptake, and selenite taken up by roots was rapidly converted to organic forms and tended to accumulate in roots. X-ray absorption near edge spectroscopy (XANES) analysis showed that organic forms of selenium, including selenocystine, Se-methyl-selenocysteine (MeSeCys), and selenomethionine-Se-oxide, were dominant in the plants exposed to selenite and accounted for approximately 90 % of the total Se. Whereas selenate remained as the dominant species in the roots and shoots exposed to selenate, with little selenate converted to selenite and MeSeCys. Besides, sulphur starvation increased the proportion of inorganic Se species in the selenate-supplied plants, but had no significant effects on Se speciation in plants exposed to selenite. The present study provides important knowledge to understand the associated mechanism of Se uptake and metabolism in plants.

Evaluation of the nutritional quality of veal supplemented with organic selenium and its effect on selenium status of people

In the first stage of our research we found out a higher content of selenium in the meat of calves of experimental group (with added the organic form of selenium to the feed mixture) compared to control group (fed without organic form of selenium). In the second stage of our research we focused on monitoring the impact of selenium enriched veal meat and on selenium concentration in blood serum and the selected biochemical parameters of lipid spectrum of the experimental group of volunteers. Ten people who were participating in the research were at the age range between 29 - 56 years. All the volunteers consumed veal meat enriched with organic selenium for 4 weeks. Before starting the experiment we took venous blood of the volunteers and this blood was considered as a control sample of selenium in blood serum of the experimental group. Selenium concentration in blood serum of the examined group was determined by an average of 58.31 ±5.36 mg.L.-1 and none of them reached the optimal level of selenium. Consequently, we carried out the additional blood sampling after 2 and 4 weeks of the consumption of veal meat. There was registered a slight increasing of selenium status, whereas after the finishing the consumption, we determined the average selenium concentration in blood serum of the experimental group 60.73 ±4.05 mg.L-1. The evaluation of lipid profile of the experimental group showed (after input blood sampling) higher values of total cholesterol level and lower levels of HDL cholesterol. This fact shows the higher risk of starting the cardiovascular diseases. Reported research results didn't show statistically significant changes of blood lipid spectrum of the experimental group. We concluded that the consumption of supplemented veal meat can positively affect the level of selenium in our body and thereby increase it can increase the protective effect against the influence of free radicals.

Effect of Supplementing Organic Forms of Zinc, Selenium and Chromium on Performance, Anti-Oxidant and Immune Responses in Broiler Chicken Reared in Tropical Summer

Two experiments were conducted to study the effect of supplementing organic forms of zinc (Zn), selenium (Se) and chromium (Cr) on performance, anti-oxidant activities and immune responses in broiler chickens from 1 to 21days of age, which were reared in cyclic heat-stressed condition under tropical summer in open-sided poultry house. A total of 200 (experiment I) and 450-day-old (experiment II) broiler male chicks (Cobb 400) were randomly distributed in stainless steel battery brooders (610mm × 762mm × 475mm) at the rate of five birds per pen. A maize-soybean meal-based control diet (CD) containing recommended (Vencobb 400, Broiler Management Guide) concentrations of inorganic trace minerals and other nutrients was prepared. The CD was supplemented individually with organic form of selenium (Se, 0.30mg/kg), chromium (Cr, 2mg/kg) and zinc (Zn, 40mg/kg) in experiment I. In experiment II, two concentrations of each Zn (20 and 40mg/kg), Se (0.15 and 0.30mg/kg) and Cr (1 and 2mg/kg) were supplemented to the basal diet in 2 × 2 × 2 factorial design. A group without supplementing inorganic trace minerals was maintained as control group in both experiments. Each diet was allotted randomly to ten replicates in both experiments and fed ad libitum from 1 to 21days of age. At 19th day of age, blood samples were collected for estimation of anti-oxidant and immune responses. Supplementation of Se, Cr and Zn increased (P < 0.05) body mass gain (BMG) and feed intake compared to those fed the CD in experiment I. The feed efficiency (FE) in Cr-fed group was higher (P < 0.05) compared to the CD-fed group. Se or Cr supplementation reduced lipid peroxidation (LP) compared to broilers fed the CD. In experiment II, BMG was not affected (P > 0.05) by the interaction between levels of Zn, Se and Cr in broiler diet. The FE improved (P < 0.05) with supplementation of the trace minerals tested at both concentrations except in group fed 40mg Zn, 0.5mg Se and 1mg Cr/kg. Reduction in lipid peroxidation (LP, P < 0.05) and increased (P < 0.05) activity of superoxide dismutase were observed in broiler fed organic Zn, Se and Cr compared to the CD-fed group. The dietary concentrations of Zn, Se and Cr did not influence (P > 0.05) the immune responses (Newcastle disease titre and cell-mediated immune response to phytohaemagglutinin-P) in both the experiments. Based on the results, it is concluded that supplementation of organic form of Se, Cr and Zn (0.30, 2 and 40mg/kg, respectively) either alone or in combination significantly improved performance and anti-oxidant responses (reduced LP and increased superoxide dismutase) in commercial broiler chicks (21days of age) reared in cyclic heat stress conditions in open-sided poultry house during summer.

Effect of dietary organic and inorganic selenium supplementation on chemical, mineral and fatty acid composition of ostrich meat

This study evaluated the effect of dietary organic and inorganic selenium supplementation on chemical, mineral and fatty acid composition of ostrich meat. Forty ostriches were raised in two groups (OSe and IOSe, diets supplemented with an organic form and an inorganic form of selenium, respectively). The form of selenium had no influence on chemical composition of ostrich muscle. Although, there were no significant differences in total content of SFA, MUFA and PUFA, the content of LA and EPA was higher in the muscles of ostriches which were put on a diet supplemented with an organic form of selenium, what resulted in lower n-6/n-3 fatty acids ratio in OSe group (9.99) in comparison to IOSe group (11.70). The results of the study indicate that dietary organic selenium supplementation improves the quality of the ostrich meat as related to the health promoting properties (LA, EPA and selenium content) of meat.