Sodium Selenite Supplementation Research Articles

Comparative Effects of Nano-Selenium and Sodium Selenite Supplementation on Blood Biochemical Changes in Relation to Growth Performance of Growing New Zealand White Rabbits.

The present study was conducted to compare the effect of nano-selenium (Nano-Se) and sodium selenite (SSe) on growth performance, antioxidative status and blood biochemicalof growing New Zealand White (NZW) rabbits. Total numbers of five weeks old rabbits were divided randomly into three groups (each had 24 of which a half of males and a half of females) were used. The first group was served as a placebo; in groups 2 and 3, each rabbit was intramuscularly injected once a week with 4ml solution of Nano-Se or SSe, respectively. The solution was adjusted to provide 30 µg Se/kg/live body weight. Growth trial lasted for two months. Results demonstrated that rabbits with Nano-Se treatment had showed higher significance in total gain and daily gain weight than SSe and control. Nano-Se and SSe showed low AST and ALT activities than control, with high advantage for SSe. Both Nano-Se and SSe increased significantly GR and TAC activities than the control, the upper hand recorded by Nano-Se. MDA activity was recorded similar trend using Nano-Se with significant decrement than other groups. TC, LDL, VLDL, triglycerides, and phospholipids decreased significantly due to Nano-Se group than the others. Nano-se and SSe recorded higher significantly HDL, and triglycerides and VLDL than control, respectively. T3 and T4 levels were elevated dramatically in Nano-se group, also feed efficiency, feed conversion ratio and daily gain were improved. It can be concluded that Nano-se supplementation caused positive changes in blood constituents which improved growth performance of growing NZW rabbits more than SSe.

Nano selenium treatment effects on thyroid hormones, immunity and antioxidant status in rabbits

<p>The present study was conducted to compare the effect of Nano-Selenium (Nano-Se) and sodium selenite (SSe) on antioxidant enzyme activity, immunity and thyroid activity of growing New Zealand White (NZW) rabbits. In this study, 72 male rabbits (5 wk old) were divided randomly into 3 groups (24 rabbits each). The first group served as a placebo; in groups 2 and 3, each rabbit was intramuscularly injected once a week with 4 mL solution of Nano-Se or SSe, respectively, for a 2-mo period. The solution was adjusted to provide 30 μg Se/kg/live body weight. Results showed that Nano-Se treatment significantly (<em>P</em><0.0001) increased in superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione (GSH) more than control, but decreased significantly each of glutathione disulphide (GSSG) and nitric oxide (NO) levels in serum. Likewise, supplementation of SSe increased (<em>P</em><0.0001) GPx activity and significantly decreased both malondialdehyde (MDA) and GSSG levels more than control. Nano-Se significantly enhanced serum IgG and IgM more than SSe and control groups. Serum aspartate aminotransferase increased (<em>P</em><0.0001) due to Nano-Se treatment as compared to control and SSe, although the lowest (<em>P</em><0.0001) activity of alanine aminotransferase was recorded due to SSe supplementation. Nano-Se treatment increased (<em>P</em><0.0001) both T3 and T4 concentrations more than other groups. Furthermore, administration of Nano-Se increased SOD, GPx, GSH, total antioxidant capacity (TAC) and adenosine triphosphate (ATP) in liver tissue of growing rabbits, while it decreased MDA and 8-hydroxy-2’deoxyguanosine (8-oHdG) levels in liver tissue compared with control. Also, SSe showed an increase (<em>P</em><0.0001) in GSH, and ATP, but significantly decreased TAC and MDA levels compared with control. It can be concluded that Nano-Se supplementation significantly enhanced the activity of antioxidant enzymes in both serum and liver tissues, with a greater positive influence on immunoglobulin production and thyroid activity in growing NZW rabbits than SSe.</p>

The effect of feeding inorganic and organic selenium sources on the performance and content of selenium in milk of transition dairy cows

The aim of this study was to determine the effects of supplementing close-up and fresh dairy cows’ diets with sodium selenite or organic sources of selenium (Se) on the dry matter intake (DMI), milk production and composition. Based on their body condition score (BCS), previous lactation milk yield and expected calving date, 24 multiparous Holstein dairy cows were balanced and randomly assigned to 4 experimental treatments. Experimental treatments were: control (basal diet without Se supplementation with 0.10 and 0.15 mg of Se kg-1 DM in close-up and fresh diets, respectively), sodium selenite supplementation (0.50 mg of Se kg-1 DM; Se-S), selenium yeast supplementation (0.50 mg of Se kg-1 DM; Se-Y) and selenomethionine supplementation (0.50 mg of Se kg-1 DM; Se-M). Neither Se supplementation nor Se source affected DMI pre- and postpartum. Milk production and composition were not different across Se sources, but concentrations of Se in milk were 14 and 10% greater for cows fed Se-M and Se-Y than for those fed control, respectively. Cows fed Se–M had lower somatic cell count than control (SCC; 173.11 vs. 318.89 cells × 103 Ml-1). The changes of BW and BCS pre- and postpartum were not affected by treatments over experimental period. The results of present study showed that selenomethionine supplementation compared to other sources decreased SCC in transition cows. In addition, milk Se concentrations increased in Se-Y and Se-M groups more significantly compared to the Se-S group. This indicates that organic Se had better replace inorganic Se for transition dairy cows.

Sodium Selenite Alleviates Breast Cancer-Related Lymphedema Independent of Antioxidant Defense System.

Long-term surveillance is necessary to identify patients at risk of developing secondary lymphedema after breast cancer surgery. We assessed how sodium selenite supplementation would affect breast cancer-related lymphedema (BCRL) symptoms and parameters in association with antioxidant effects. A randomized, double-blind, controlled trial was conducted on 26 participants with clinical stage II to III BCRL. The control group (CTRL, n = 12) and selenium group (SE, n = 14) underwent five sessions of 0.9% saline and 500 μg sodium selenite (Selenase®) IV injections, respectively, within 2 weeks. All patients were educated on recommended behavior and self-administered manual lymphatic drainage. Clinical diagnosis on lymphedema by physicians, bioimpedance data, blood levels of oxidative markers, including glutathione (GSH), glutathione disulfide (GSSG), malondialdehyde (MDA), glutathione peroxidase activity (GSH-Px), and serum oxygen radical absorbance capacity (ORAC) levels, were investigated at timelines defined as baseline, 2-week, and follow-up. Sodium selenite increased whole blood selenium concentration in the SE group. Compared to the baseline, at 2 weeks, 75.0% of participants in clinical stage showed improvement, while there was no change in the CTRL group. At follow-up, 83.3% and 10.0% of the SE and CTRL, respectively, showed stage changes from III to II (p = 0.002). Extracellular water (ECW) ratios were significantly reduced at 2 weeks and follow-up, only in the SE group. Blood GSH, GSSG, GSH/GSSG ratio, MDA, and ORAC levels did not change by selenium supplementation. Sodium selenite improved diagnostic stages of BCRL along with ECW ratios, although the beneficial effect might not be related to its antioxidant activity. Selenite’s effect on lymphedema may be associated with non-antioxidant properties, such as anti-inflammation and immune function. Further mechanistic research using a larger population is needed.

ANTIOXIDANT AND IMMUNOMODULATORY EFFECTS OF NANO-SELENIUM ON RESPONSE OF BROILERS TO ND VACCINE

Trace element selenium occupies a privileged position among the natural antioxidant in addition to its ability to enhance the immune response in several species. The current challenges of supplementation of sodium selenite in poultry diets are always linked to low absorption and increased toxicity. Therefore, it is imperative to embrace new technologies like nanotechnology to get as an alternative source of traditional selenium supplementation in form of the nanoparticles with high bioavailability and low toxicity which will be positively reflected on biological activities of selenium. The present study was conducted to investigate the antioxidant and immunomodulatory effects of different concentrations of Nano-selenium on response of broilers to ND vaccination. A total of one hundred and eighty day old Cobb broilers were randomly allocated in 6 groups with each group applied to 3 replicate of 10 chicks, the first two groups were control negative groups without selenium supplementation and the remaining four groups were dietary supplemented with sodium selenite (0.15ppm) and Nano-selenium at concentration of (0.15ppm), (0.075 ppm) and (0.0375 ppm), respectively. The results showed that Nano-selenium had a superior effect compared to that of the sodium selenite either as an antioxidant or as an immunomodulatory and comparing the control negative groups. The most important results can be summarized in the following points; significant improvement in Feed conversion ratio (FCR), significant enhancement in activities of antioxidant enzymes without adverse effects on tested biochemical parameters as well as significant boosting in antibody titers against ND. In conclusion, Nano-selenium supplementation in commercial broilers diets could be an economically a promising multitask option, particularly when it comes to improving antioxidative status and boosting immune response to NDV (LaSota) vaccination in broilers.

Effects of different sources of selenium supplementation on antioxidant indices, biochemical parameters, thyroid hormones and Se status in transition cows

The aim of this study was to determine the effects of supplementing close-up and fresh dairy cows’ diets with sodium selenite or organic sources of selenium (Se) on the serum biochemical parameters and antioxidant indicators and Se status. Twenty-four multiparous Holstein dairy cows were balanced by body condition score (BCS), previous lactation milk yield and expected calving date and randomly assigned to 1 of 4 experimental treatments. Treatments were: control (basal diet without Se supplementation), sodium selenite supplementation (0.50 mg of Se kg -1 DM; Se-S), selenium yeast supplementation (0.50 mg of Se kg -1 DM; Se-Y) and selenomethionine supplementation (0.50 mg of Se kg -1 DM; Se-M). Serum Se concentrations were higher for cows in Se-Y (72.34 µg dL -1 ) and Se-Met (72.34 µg dL -1 ) than control (59.93µg/dl) and Se-S (64.79µg/dl). The Se supplementation and sources did not affect serum metabolites or indices of antioxidant pre and postpartum, except serum total protein and albumin concentrations. Cows in Se-M had greater serum total protein and albumin concentrations than those in control. The results of present study showed that serum Se concentrations increased in Se-Y and Se–M more effectively than Se-S, indicating that selenomethionine could replace Se-S as an effective organic Se source for transition dairy cows.

Feeding sodium selenite and nano-selenium stimulates growth and oxidation resistance in broilers

Nano-elemental selenium (nano-Se) has attracted more attention than sodium selenite (SS), owing to its low toxicity, high bioavailability, strong adsorbing ability and high catalytic efficiency. The purpose of the present study was to examine the effects of dietary supplementation with SS and nano-Se on the growth performance, digestibility, blood parameters and gene expressions related to growth and oxidation in broilers. Thirty broiler chicks at 15 days old were randomly divided into three dietary treatments, namely control (basal diet without any supplementation with selenium (Se)); SS treatment (basal diet + 1 mg SS/kg diet); and nano-Se treatment (basal diet + 0.5 mg nano-Se/kg diet). The birds were given the experimental diets from 15 to 27 days old. Bodyweight gain was enhanced in the nano-Se group, but was not influenced by SS supplementation. Breast muscle and thigh muscle weights were higher in dietary supplementation of nano-Se. Although muscle fat and Se content were significantly higher in dietary supplementation of SS and nano-Se in comparison with control, muscle thiobarbituric acid reactive substance (TBARS) and α-tocopherol concentrations were not influenced. Moreover, by feeding SS or nano-Se, glutathione peroxidase (GPx) and superoxide dismutase (SOD) mRNA expressions in muscles were higher than in the control group. Plasma total cholesterol and triglyceride concentrations were significantly lower in the nano-Se group than in the other groups, while, plasma high-density lipoprotein (HDL) cholesterol, serum aspartate aminotransferase (AST) and triiodothyronine (T 3 ) were not significantly affected. However, mRNAs levels in muscle tissue, namely insulin-like growth factor-I (IGF-I), insulin receptor (IR) and glucose transporters (Glut-8) were significantly higher; while atrogin-1 was not significantly affected by dietary Se supplementation. It could be concluded that dietary SS and nano-Se might be involved in improving growth performance, muscle Se content and antioxidative properties in broilers. Keywords: Antioxidative status, growth, digestibility, gene expressions

Effects of selenium supplementation on growth performance, selenium content and gene expression in pigeon squabs

A feeding experiment was carried out to examine the effect of dietary sodium selenite (SS) supplementation on pigeon squabs. A total of 864 paired pigeons were randomly and equally distributed into four groups with three replicates. Each group was given a basal diet either unsupplemented (T1) or supplemented with 0.5, 1.0, or 1.5 mg/kg of SS in feed (T2–T4). Diet had no significant effect on the final body weight of squabs (P > 0.05). However, during days 8–14, body weight gain (BWG) in SS supplemented groups was lower than the control group (P < 0.05), while BWG was higher than controls from days 15–21 (P < 0.05). Squabs fed the basal diet without SS supplementation displayed lower selenium content in chest and leg muscle (P < 0.05). Glutathione peroxidase 4 (GPx4) mRNA levels were lower in liver, ovary and testis tissue in controls (P < 0.05), while growth hormone (GH) mRNA levels in liver were higher in controls (P < 0.05). These results suggest dietary SS supplementation had potential effect on growth performance during the later growth period (days 15–21). Furthermore, dietary SS supplementation increased the selenium content in muscle and affected the expression of GPx4 and GH.HighlightsThe dietary selenium supplementation affected the body weight gain of the squabs.Increasing selenium supplementation in diet improved the selenium content in muscle.Increasing selenium supplementation in diet affected the expression of GPx4 and GH.

Effects of Different Selenium Sources on Laying Performance, Egg Selenium Concentration, and Antioxidant Capacity in Laying Hens.

Supplementation of selenium (Se) is a common practice in the poultry industry via sodium selenite (SS) and selenium yeast (SY), while the effects of nano-selenium (NS) on laying hens are poorly known. This study aimed to compare the effects of NS, SS, and SY on productivity; selenium (Se) deposition in eggs; and antioxidant capacity in laying hens. A total of 288 30-week-old Brown Hy-line laying hens were randomly assigned into four dietary treatments, which included corn-soybean meal basal diet (Con) without Se sources and basal diets supplemented with 0.3mg Se/kg as SS, SY, or NS, respectively. The results exhibited that Se-supplemented treatments achieved greater egg production, egg weight, and daily egg mass, also better feed conversion ratio than Con group (p < 0.05). Se supplementation significant increased egg Se concentration and decreased the egg Se deposition efficiency (p <0.05), while SY or NS supplementation had higher Se deposition efficiency than SS group at 35days (p < 0.05). Moreover, serum glutathione peroxidase (GSH-Px) activity increased in SS or NS group compared to Con group (p < 0.05). The glutathione peroxidase 4 (GPX-4) mRNA levels in liver were significantly higher (p < 0.05) in SS or SY group than in NS group, and mRNA levels of the methionine (Met) metabolism gene glycine N-methyltranserfase (GNMT) were markedly upregulated (p < 0.05) in SY group compared to SS or NS group. Taken together, the results revealed Se from SY is deposited into eggs more efficiently than Se from NS or SS, probably via enhancing the route of Met metabolism. Meanwhile, it might be concluded that SS or SY supplementation directly regulated GSH-Px activity via enhancing GPx4 level, whereas NS via GPx1, thus affecting body oxidation and development.

Comparison of dynamic change of egg selenium deposition after feeding sodium selenite or selenium-enriched yeast.

The aim of this study was to compare the dynamic change of egg selenium (Se) deposition after sodium selenite (SS) or selenium-enriched yeast (SY) supplementation for 1, 3, 5, 7, 14, 21, 28, 56, and 84 d. A total of 576 32-wk-old Hy-Line Brown laying hens were randomly assigned to 3 groups (192 laying hens per group) with 6 replicates, and fed a basal diet (without Se supplementation) or basal diets with 0.3mg/kg of Se from SS or 0.3mg/kg of Se from SY, respectively. The results showed that the Se concentrations in the eggs from hens fed a SY-supplemented diet were significantly higher (P < 0.001) than those from hens fed a SS-supplemented diet or a basal diet after 3 d. And the Se concentrations in the eggs from hens fed a SS-supplemented diet were significantly higher (P < 0.001) than those from hens fed a basal diet after 14 d. There was a positive linear and quadratic correlation between Se concentrations in the eggs from hens fed a SY-supplemented diet (r2 = 0.782, P < 0.001; r2 = 0.837, P < 0.001) or SS-supplemented diet (r2 = 0.355, P < 0.001; r2 = 0.413, P < 0.001) and number of feeding days. The Se concentrations in the breasts from hens fed a SY-supplemented diet were 126.98% higher (P < 0.001) than those from hens fed a SS-supplemented diet, and were 299.44% higher (P < 0.001) than those from hens fed a basal diet after the 84-d feeding period. In conclusion, the dietary Se was gradually transferred into eggs with the extension of the experimental duration. The deposition rate of Se in the eggs from hens fed a SY-supplemented diet was much more rapid than that from hens fed a SS-supplemented diet, and the organic Se from SY had higher bioavailability as compared to inorganic Se from SS.

Antagonistic effects of different selenium sources on growth inhibition, oxidative damage, and apoptosis induced by fluorine in broilers

Fluorosis can induce oxidative stress through leading to reactive oxygen species (ROS) generation. Selenium (Se) can eliminate ROS by direct and indirect manners. In this study, therefore, we investigated the possible protective effects of sodium selenite (SS) and selenomethionine (Se-Met) on fluorine (F)-induced oxidative stress in broilers. A total of 720 1-day-old Lingnan Yellow broilers were allotted to 4 groups (6 replicates of 30 birds each group) and fed with basal diet (control group), 800mg/kg F (high F group), 800mg/kg F+0.15mg Se/kg as SS (SS group), or Se-Met (Se-Met group), respectively. The experiment lasted 50 d. High F group significantly decreased (P < 0.05) the average daily gain (ADG) and feed efficiency (FE) in comparison with control group. The contents of ROS, malondialdehyde, 8-hydroxydeoxyguanosine, protein carbonyl, and cysteinyl aspartate specific proteinases 3 in serum, liver, and kidney were higher (P < 0.05) in high F group than those in control group. Compared with control group, the decreased (P < 0.05) activities of glutathione peroxidase (GSH-Px) and cytoplasmic thioredoxin reductase (TrxR1) as well as contents of selenoprotein P (SelP), total protein (TP), and B-cell lymphoma-2 in serum and tissues were observed in high F group. Moreover, the pathological lesions of liver and kidney in high F group were more than those in control group. However, supplementation with SS and Se-Met could improve ADG and FE, increase SelP and TP concentrations, elevate GSH-Px and TrxR1 activities, minimize the changes of oxidative stress and apoptosis parameters as well as ultrastructure of liver and kidney, whereas the effects of Se-Met were better than those of SS. The results indicated that excess F could result in growth inhibition of broilers through inducing oxidative stress and subsequently caused oxidative damage to biological macromolecules and soft tissues as well as apoptosis, whereas dietary SS and Se-Met supplementation could antagonize high F induced growth retardation by inhibiting oxidative stress and a mechanism of apoptosis regulation and the impact was more with Se-Met.

Rationale and Design for the Peripartum Cardiomyopathy in Nigeria (PEACE) Registry

Background: Nigeria probably has the highest burden of Peripartum Cardiomyopathy (PPCM) in the world. The primary objective is to describe the burden, ventricular remodelling and outcomes (rehospitalisation rate, cardio-embolic events and survival) of PPCM in Nigeria. In the sub-studies, we aim to describe the relationship between selenium deficiency, oxidative stress and PPCM, the impact of sodium selenite supplementation on cardiac function in PPCM, and the prevalence of selenium deficiency and its relationship with cardiac function in apparently healthy pregnant women.Methods: The main Registry and the first sub-study are prospective longitudinal studies, while the second sub-study is an open-label randomised trial. 36 study centres across Nigeria have been registered and 10 of them are already recruiting subjects. Patients will be recruited from June to December 2017 and followed up till December 2018. Serum selenium and glutathione peroxidase will be assayed at recruitment for consecutive PPCM patients with LV ejection fraction (LVEF) &lt;45% at 6 months postpartum. 200 subjects with selenium deficiency will be randomised into treatment (Selenium Selenite 200µg tablets daily for 3 months) and control arms. In the second sub-study, 120 apparently healthy pregnant women will be recruited at 28-38 weeks of gestation and reviewed at 6-8 weeks postpartum, and their serum selenium and GPO levels will be measured at recruitment.Conclusion: This will be the largest systematic evaluation of PPCM in Nigeria, and it is hoped that the information will assist in developing locally applicable treatment guidelines and policies for the disease.

Selenium (Na2SeO3) Upregulates Expression of Immune Genes and Blood-Testis Barrier Constituent Proteins of Bovine Sertoli Cell In Vitro.

Sertoli cells were isolated from newborn calves and cultured in a medium supplemented with 0, 0.25, 0.50, 0.75, and 1.00mg/L of sodium selenite to study their immune stimulatory effect, influence on cell's viability, and expression of blood-testis barrier proteins (occludin, connexin-43, zonula occluden, E-cadherin) using quantitative PCR and western blot analyses. Results showed that medium supplemented with 0.50mg/L of selenium significantly (P < 0.05) promoted cell viability, upregulated toll-like receptor gene (TLR4), anti-inflammatory cytokines (IL-4, IL-10, TGFβ1), and expressions of blood-testis barrier proteins, and modulated expressions of pro-inflammatory cytokines (TNF-α, IL-1β, IFN-γ). Sertoli cells grown in culture medium supplemented with 0.25mg/L of selenium significantly upregulated TLR4, IL-4, IL-10, TGFβ1, and blood-testis barrier proteins compared to the control group. Sodium selenite supplementation at 0.75 and 1.00mg/L levels was cytotoxic and temporarily downregulated the expression of blood-testis barrier protein within 24h after culture; however, commencing from 72h post culture, increased cell viability and upregulation of expression of blood-testis barrier proteins were observed. In conclusion, the results of this study showed that selenium supplementation in the culture medium up to 0.50mg/L concentration upregulates immune genes and blood-testis barrier constituent proteins of bovine Sertoli cells.

Selenium supplementation during invitro maturation enhances meiosis and developmental capacity of yak oocytes.

The objectives of the present study were to investigate the effects of selenium (Se) supplementation during invitro maturation (IVM) on the developmental capacity of yak (Bos grunniens) oocytes. Nuclear maturation, DNA integrity, glutathione peroxidase (GSH-Px) activity, subsequent embryonic development, and gene expression after invitro fertilization (IVF) were evaluated. The Se concentrations in yak plasma and follicular fluid were 0.142 and 0.069μg/mL, respectively. The DNA damage in cumulus cells decreased significantly with 2 and 4μg/mL supplementation of sodium selenite to IVM medium (P<0.05). Total GSH-Px activity in oocytes increased in all Se supplementation groups, and the 2 and 4μg/mL groups were significantly higher than the control group (0μg/mL). However, the cleavage rate was not significantly different after Se supplementation (P>0.05). The IVF blastocyst formation rates of 0, 1 and 4μg/mL sodium selenite groups were 47.7%, 51.2% and 58.9%, respectively. The 2μg/mL sodium selenite group had the highest blastocyst formation rate (60.5%). Gene expression analysis revealed that the quantity of transcripts associated with selenoprotein and protein synthesis were high in the 2 and 4μg/mL groups. In conclusion, both GSH-Px activity of oocytes and DNA integrity of cumulus cells significantly increased with supplemental Se during oocyte IVM. Considering that embryonic development is responsive to Se supplementation, we inferred that appropriate Se concentrations during IVM were beneficial for yak oocyte maturation and subsequent development.

Hydroxy-selenomethionine: A novel organic selenium source that improves antioxidant status and selenium concentrations in milk and plasma of mid-lactation dairy cows

This study aimed to evaluate the effect of hydroxy-selenomethionine (HMSeBA), a novel organic selenium (Se) source, on milk performance, antioxidative status, and Se concentrations in the milk and plasma of mid-lactation dairy cows compared with that of sodium selenite (SS). Fifty mid-lactation dairy cows with similar days in milk, milk yield, and parity received the same basal diet containing 0.06 mg of Se/kg of DM. They were assigned to 1 of 5 treatments according to a randomized complete block design: negative control (without Se supplementation), SS supplementation (0.3 mg of Se/kg of DM; SS-0.3) or HMSeBA supplementation (0.1, 0.3, or 0.5 mg of Se/kg of DM: SO-0.1, SO-0.3, and SO-0.5, respectively). The experiment lasted for 10 wk, including a pretrial period of 2 wk. The results indicated that neither Se supplementation nor Se source affected dry matter intake, milk yield, milk composition, or blood biochemical parameters, except for milk fat percentage. Simultaneously, milk fat percentage and milk fat yield increased linearly as the quantity of HMSeBA supplementation was increased. Production of 4% FCM and ECM was elevated linearly as dietary HMSeBA increased. The SO-0.3 group showed higher serum activity of glutathione peroxidase, total antioxidant capacity, and superoxide dismutase than the SS-0.3 group, but malondialdehyde content was not affected by Se source. Furthermore, HMSeBA supplementation linearly increased the activities of serum glutathione peroxidase and superoxide dismutase, but decreased malondialdehyde content. Compared with the SS-0.3 group, the SO-0.3 group showed augmented concentrations of total Se in milk and plasma, and total Se milk-to-plasma concentration ratio. In addition, increasing doses of HMSeBA linearly increased the concentrations of total Se in the milk and plasma. This study demonstrates that HMSeBA improves antioxidant status and increases milk and plasma Se concentrations more effectively than SS, indicating that HMSeBA could replace SS as an effective organic Se source for lactating dairy cows.

Efficient Expression of Glutathione Peroxidase with Chimeric tRNA in Amber-less Escherichia coli.

The active center of selenium-containing glutathione peroxidase (GPx) is selenocysteine (Sec), which is is biosynthesized on its tRNA in organisms. The decoding of Sec depends on a specific elongation factor and a Sec Insertion Sequence (SECIS) to suppress the UGA codon. The expression of mammalian GPx is extremely difficult with traditional recombinant DNA technology. Recently, a chimeric tRNA (tRNAUTu) that is compatible with elongation factor Tu (EF-Tu) has made selenoprotein expression easier. In this study, human glutathione peroxidase (hGPx) was expressed in amber-less Escherichia coli C321.ΔA.exp using tRNAUTu and seven chimeric tRNAs that were constructed on the basis of tRNAUTu. We found that chimeric tRNAUTu2, which substitutes the acceptor stem and T-stem of tRNAUTu with those from tRNASec, enabled the expression of reactive hGPx with high yields. We also found that chimeric tRNAUTuT6, which has a single base change (A59C) compared to tRNAUTu, mediated the highest reactive expression of hGPx1. The hGPx1 expressed exists as a tetramer and reacts with positive cooperativity. The SDS-PAGE analysis of hGPx2 produced by tRNAUTuT6 with or without sodium selenite supplementation showed that the incorporation of Sec is nearly 90%. Our approach enables efficient selenoprotein expression in amber-less Escherichia coli and should enable further characterization of selenoproteins in vitro.

Effect of selenium supplementation on pigeon reproductive performance, selenium concentration and antioxidant status

The effects of dietary supplementation of sodium selenite (SS) on the reproductive performance and the concentration of selenium, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and malondialdehyde (MDA) were determined, and expression of glutathione peroxidase 4 (GPx4) and bone morphogenic protein 15 (BMP15) was evaluated. Paired pigeons (n = 864) were fed: T1 received no SS, while T2, T3, and T4 received 0.5, 1.0, and 1.5 mg of SS/kg of dry matter (DM), respectively. Treatments were performed in triplicate with 72 pairs in each replicate. The results showed that selenium supplementation significantly affected pigeon reproductive performance. Birds fed 1.0 mg of SS/kg displayed higher egg production (P > 0.05), higher birth rate, and lower dead sperm rate than the control group (P < 0.05). Selenium and biochemical analyses revealed a higher selenium concentration in the 1.5 mg of SS/kg group than in the control group (P < 0.05), while GSH-Px was higher in the 0.5 mg of SS/kg group than in the control group (P < 0.05). Neither the MDA nor the SOD content were affected significantly in liver, chest muscle, or leg muscle (P > 0.05); however, in plasma, MDA was lower in the control group (P < 0.05), while SOD was higher in the control group (P < 0.05). qRT-PCR results revealed up-regulation of GPx4 in hypothalamus, pituitary and testis tissues in supplemented groups (P < 0.05). However, expression in ovary differed; GPx4 mRNA levels were lower in the 1.5 mg of SS/kg and control groups than in the 1.0 or 0.5 mg of SS/kg groups (P < 0.05). Expression of BMP15 in the hypothalamus, pituitary, and testis tissues was unaffected (P > 0.05), while in ovary, BMP15 was down-regulated in the 1.5 mg of SS/kg group (P < 0.05). These results suggest pigeons supplemented with SS up-regulated GPx4, 1.0 mg of SS/kg exhibited superior reproductive performance, while 1.5 mg of SS/kg increased the selenium concentration, and 0.5 mg of SS/kg up-regulated GSH-Px activity.

Effect of high-dose sodium selenite in cardiac surgery patients: A randomized controlled bi-center trial

Cardiac surgery is accompanied by oxidative stress and systemic inflammatory response, which may be associated with organ dysfunction and increased mortality. Selenium and selenoenzymes are important constituents of anti-oxidative defense. We hypothesized that high-dose sodium selenite supplementation can attenuate the postoperative inflammation and might, therefore, improve clinical outcome. Randomized, placebo-controlled, double-blinded, bi-center study on 411 adult patients undergoing elective cardiac surgery. Patients received an intravenous bolus of 4000μg selenium (in the form of sodium selenite) or placebo after induction of anesthesia and 1000μg/d selenium or placebo during their intensive care unit (ICU) stay. Primary outcome measure was the Sequential Organ Failure Assessment (SOFA) score on the second postoperative day. Secondary endpoints included the change in perioperative selenium levels, change of inflammatory and cardiac markers, use of vasoactive medication, incidence of acute kidney injury, ICU and hospital length of stay, and mortality. The perioperative administration of high-dose sodium selenite prevented the postoperative drop of blood and serum selenium levels, reduced the number of patients depending on postoperative vasoactive support but failed to reduce the postoperative SOFA score and its related organ-specific scores compared to placebo. Except for an increase of postoperative procalcitonin and bilirubin levels in the sodium selenite group, other inflammatory markers, organ function variables and clinical endpoints remained unchanged. The perioperative administration of high-dose sodium selenite in cardiac surgery patients prevented the postoperative fall of blood selenium levels and reduced the need for postoperative vasoactive support by a yet unknown mechanism. Registered under ClinicalTrials.gov Identifier no. NCT01141556.

Effect of Low-Dose Selenium Supplementation on the Genotoxicity, Tissue Injury and Survival of Mice Exposed to Acute Whole-Body Irradiation.

The aim of the present study is to evaluate the radioprotective effect of low-dose selenium supplementation (multiple administrations) on radiation toxicities and mortality induced by lethal dose of whole-body irradiation (WBI). For this, BALB/c mice received sodium selenite (4μg/kg body wt) intraperitoneally for five consecutive days and subjected to WBI at an absorbed dose of 8Gy (60Co, 1Gy/min). Administration of sodium selenite was continued even during the post irradiation days three times a week till the end of the experiment. The radioprotective effect was evaluated in terms of the improvement in 30days post irradiation survival, protection from DNA damage, and biochemical and histological changes in radiosensitive organs. The results indicated that low-dose sodium selenite administration did not protect the mice from radiation-induced hematopoietic and gastrointestinal injuries and subsequent mortality. However, it significantly prevented the radiation-induced genotoxicity or DNA damage in peripheral leukocytes. Further sodium selenite administration modulated the messenger RNA (mRNA) expression of GPx1, GPx2, and GPx4 in the spleen and intestine differentially and led to a significant increase in GPx activity (∼1.5 to 2-folds) in these organs. In line with this observation, sodium selenite administration reduced the level of lipid peroxidation in the intestine. In conclusion, our study shows that low-dose sodium selenite supplementation can be an effective strategy to prevent WBI-induced genotoxicity but may not have an advantage against mortality sustained during nuclear emergencies.

Protective effects of sodium selenite supplementation against irradiation-induced damage in non-cancerous human esophageal cells.

The administration of radioprotective compounds is one approach to preventing radiation damage in non-cancerous tissues. Therefore, radioprotective compounds are crucial in clinical radiotherapy. Selenium is a radioprotective compound that has been used in previous clinical studies of radiotherapy. However, evidence regarding the effectiveness of selenium in radiotherapy and the mechanisms underlying the selenium-induced reduction of the side effects of radiotherapy remains insufficient. To further investigate the effectiveness of selenium in radiotherapy, the present study examined the protective effects of sodium selenite supplementation administered prior to X-ray radiation treatment in CHEK-1 non-cancerous human esophageal cells. Sodium selenite supplementation increased glutathione peroxidase 1 (GPx-1) activity in a dose- and time-dependent manner. The sodium selenite dose that induced the highest GPx-1 activity was determined to be 50 nM for 72 h prior to radiotherapy. The half-maximal inhibitory concentration of sodium selenite in CHEK-1 cells was 3.6 µM. Sodium selenite supplementation increased the survival rate of the cells in a dose-dependent manner and enhanced the degree of cell viability at 72 h post-irradiation (P<0.05). Combined treatment with 50 nM sodium selenite and 2 gray (Gy) X-ray irradiation decreased the number of sub-G1 cells from 5.9 to 4.2% (P<0.05) and increased the proportion of G1 cells from 58.8 to 62.1%, compared with 2 Gy X-ray irradiation alone; however, this difference was not statistically significant (P=1.00). Western blot analysis revealed that treatment with 2 Gy X-ray irradiation significantly increased the expression levels of cleaved poly (ADP-ribose) polymerase (PARP; P<0.05). In addition, combined treatment with 50 nM sodium selenite and 2 Gy X-ray irradiation reduced the expression levels of cleaved PARP protein, compared with 2 Gy X-ray irradiation alone; however, this reduction was not statistically significant (P=0.423). These results suggest that 50 nM sodium selenite supplementation administered for 72 h prior to irradiation may protect CHEK-1 cells from irradiation-induced damage by inhibiting irradiation-induced apoptosis. Therefore, sodium selenite is a potential radioprotective compound for non-cancerous cells in clinical radiotherapy.