Selenium nanoparticles inhibit the formation of atherosclerosis in apolipoprotein E deficient mice by alleviating hyperlipidemia and oxidative stress.

Atherosclerosis can cause severe cardiovascular diseases, which is the most common cause of death in the world. It's of great significance to study the prevention and treatment of atherosclerosis. Selenium nanoparticles (SeNPs) has drawn more and more attention due to high biological activity, high bioavailability, strong antioxidant capacity and low toxicity, exhibiting great potential in biomedical application. Thus, this study aimed at explore the anti-atherosclerotic effect of two kinds of SeNPs, bovine serum albumin (BSA) surface-decorated SeNPs and chitosan (CS) surface-decorated SeNPs (CS-SeNPs), in apolipoprotein E deficient (ApoE-/-) mice fed with a high-cholesterol and high-fat diet, and the possible mechanisms. The results demonstrated that both BSA-SeNPs (25, 50 and 100 µg Se/kg body weight/day) and CS-SeNPs (50 µg Se/kg body weight/day) could reduce atherosclerotic lesions in ApoE-/- mice after oral administration for 12 weeks. And these effects might mainly attributed to the ability of BSA-SeNPs and CS-SeNPs to inhibit hyperlipidemia by suppressing hepatic cholesterol and fatty acid metabolism, and alleviate oxidative stress by enhancing antioxidant activity. Moreover, the benefits of BSA-SeNPs were dose-dependent and the medium dose of BSA-SeNPs (50 µg Se/kg body weight/day) was optimal. Generally, BSA-SeNPs with mean size 38.5 nm and negative surface charge showed better anti-atherosclerotic effect than CS-SeNPs with mean size 65.8 nm and positive surface charge. These results suggested that SeNPs could significantly alleviate the formation of atherosclerosis in ApoE-/- mice, possibly by inhibiting hyperlipidemia and oxidative stress, exhibiting a potential to serve as an anti-atherosclerotic agent.

The Pharmacology and Therapeutic Utility of Sodium Hydroselenide.

Metabolically active gasotransmitters (nitric oxide, carbon monoxide and hydrogen sulfide) are important signalling molecules that show therapeutic utility in oxidative pathologies. The reduced form of selenium, hydrogen selenide (HSe-/H2Se), shares some characteristics with these molecules. The simple selenide salt, sodium hydroselenide (NaHSe) showed significant metabolic activity, dose-dependently decreasing ex vivo O2 consumption (rat soleus muscle, liver) and transiently inhibiting mitochondrial cytochrome C oxidase (liver, heart). Pharmacological manipulation of selenoprotein expression in HepG2 human hepatocytes revealed that the oxidation status of selenium impacts on protein expression; reduced selenide (NaHSe) increased, whereas (oxidized) sodium selenite decreased the abundance of two ubiquitous selenoproteins. An inhibitor of endogenous sulfide production (DL-propargylglycine; PAG) also reduced selenoprotein expression; this was reversed by exogenous NaHSe, but not sodium hydrosulfide (NaHS). NaHSe also conferred cytoprotection against an oxidative challenge (H2O2), and this was associated with an increase in mitochondrial membrane potential. Anesthetized Wistar rats receiving intravenous NaHSe exhibited significant bradycardia, metabolic acidosis and hyperlactataemia. In summary, NaHSe modulates metabolism by inhibition of cytochrome C oxidase. Modification of selenoprotein expression revealed the importance of oxidation status of selenium therapies, with implications for current clinical practice. The utility of NaHSe as a research tool and putative therapeutic is discussed.

Effect of boiling and frying on the selenium content, speciation, and in vitro bioaccessibility of selenium-biofortified potato (Solanum tuberosum L.).

Selenium-enriched potato is a good supplement for selenium-deficient populations. This study evaluated the influence of two most common cooking methods, including boiling and frying, on selenium content, speciation, and in vitro bioaccessibility of selenium-biofortified potato tubers. After foliar application of 200 µg/mL sodium selenite, potato tubers with 1.33 µg Se/g were obtained. Peeling resulted in 53.4%-69.9% loss of selenium in tubers. The total selenium content decreased by approximately 43.3% after boiling, among which up to 38.5% of the lost selenium is found in the boiling water. Nearly 31.7% of selenium was lost via volatilization during frying. Both cooking methods significantly enhanced the bioaccessibility of Se(IV) in tubers. Whereas SeMeCys became less bioaccessible after boiling. SeMet and SeCys2 in fired tubers were not accessible after digestion. This study suggested that boiling is more appropriate for cooking selenium-enriched potatoes.

Effects of selenium combined with zinc amendment on zinc fractions and bioavailability in calcareous soil.

Selenium (Se) and zinc (Zn) are two important trace elements for human being and animals. The interaction between Se and Zn on the bioavailability of Zn in soil is still unclear. Therefore, pot experiments exposed to different dosages of zinc sulfate (ZnSO4) (0, 20, and 50 mg/kg soil) and sodium selenite (Na2SeO3) (0, 0.5, 1.0, and 2.5 mg/kg soil) were conducted to investigate the effects of selenite application on Zn bioavailability in calcareous soil and its related mechanisms. The total Zn content of different tissues (roots and shoots) of pak choi (Brassica chinensis L.) and the changes in Zn fraction distribution in soil before planting and after harvest were determined, and the mobility factor (MF) and distribution index (DI) of Zn in soils were calculated. In addition, the Pearson correlation and path analysis were conducted to clarify the relationships between Zn fractions in soil and the Zn uptake of pak choi. Results showed that Se amendment elevated soil Zn bioavailability at appropriate levels of Se and Zn. When 1.0 and 2.5 mg/kg of Se and 20 mg/kg of Zn were applied in soil, the proportion of exchangeable Zn (Ex-Zn) and Zn weakly bound to organic matter (Wbo-Zn) to the total content of Zn was significantly increased by 28.14%-82.52% compared with that of the corresponding single Zn treatment. Therefore, the Zn concentration in the shoots of pak choi was significantly increased by 27.2%-31.1%. High Zn (50 mg/kg) and Se co-amended treatments showed no significantly beneficial effect on the bioavailability of Zn. In addition, the potential available Zn content in soil (weakly bound to organic matter and carbonate bound Zn) and MF and DI values were all positively correlated with the Zn concentrations in pak choi, indicating that these indexes can be used to predict the bioavailability of Zn in soil. This study can provide a good reference for Se and Zn biofortification of plants in calcareous soil.

Physicochemical properties and bioactivities of original and Se-enriched polysaccharides with different molecular weights extracted from Pleurotus ostreatus.

Three polysaccharides (WZP1, WZP2, WZP3) and their Se-enriched products (SeWZP1, SeWZP2 and SeWZP3) were obtained from Pleurotus ostreatus using a simple, rapid method and HNO3-Na2SeO3 method, respectively. The molecular weight distribution profiles of all samples except SeWZP2 showed double peaks. The average molecular weights (Mw) of WZP1-3 were 48.6 kDa, 20.2 kDa and 11.8 kDa, respectively, and of SeWZP1-3 were 19.6 kDa, 37.7 kDa, 14.5 kDa, respectively. The complexity of monosaccharide composition of WZP1-3 was inversely proportional to the ethanol concentration used in the ethanol precipitation process. Additionally, the results of biological activity tests indicated that α-glucosidase inhibitory activity of WZP1-3 was related to the molecular weight and the monosaccharide composition complexity. The selenized modification can improve the α-glucosidase-inhibiting, hydroxyl radical-scavenging activity of P. ostreatus polysaccharides. Therefore, by improving their bioactivities by selenization, the polysaccharides of P. ostreatus could be utilized as a natural health food supplement.

Selenium attenuates apoptosis and p-AMPK expressions in fluoride-induced NRK-52E cells.

Fluoride is widely distributed in the environment, and excessive fluoride intake can induce cytotoxicity, DNA damage, and cell cycle changes in many tissues and organs, including the kidney. Accumulating evidence demonstrates that selenium (Se) administration ameliorates sodium fluoride (NaF)-induced kidney damage. However, the potentially beneficial effects of Se against NaF-induced cytotoxicity of the kidney and the underlying molecular mechanisms of this protection are not fully understood. At present, in this study, the normal rat kidney cell (NRK-52E) was used to investigate the potentially protective mechanism of Se against NaF-induced apoptosis, by using the methods of pathology, colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, and Western blot. The experiment was designed with a control group, two NaF-treated groups (NaF, 5, 20 mg/L), two sodium selenite-treated groups (Na2SeO3, 17.1, 34.2 µg/L), and four Se + NaF-treated groups (Na2SeO3, 17.1, 34.2 µg/L; NaF, 5, 20 mg/L). The results indicate that selenium can attenuate apoptosis and AMPK phosphorylation in the NRK-52E cell induced with fluoride. These results imply that selenium is capable to modulate fluoride-induced NRK-52E cell apoptosis via regulating the expression levels of the proteins involved in mitochondrial pathway and changes in p-AMPK expressions may also be a key process in preventing fluorosis.

Forms of selenium in vitamin-mineral mixes differentially affect serum alkaline phosphatase activity, and serum albumin and blood urea nitrogen concentrations, of steers grazing endophyte-infected tall fescue.

The goal of this study was to test the hypothesis that sodium selenite (ISe), SEL-PLEX (OSe), vs. a 1:1 blend (MIX) of ISe and OSe in a basal vitamin-mineral mix would differentially affect serological and hepatic parameters of growing steers grazing toxic endophyte-infected tall fescue-mixed forage pasture. Predominately Angus steers (BW = 183 ± 34 kg) were randomly selected from herds of fall-calving cows grazing endophyte-infected tall fescue-mixed pasture and consuming vitamin-mineral mixes that contained 35 ppm Se as ISe, OSe, and MIX forms. Steers were weaned, depleted of Se for 98 d, and subjected to summer-long common grazing of an endophyte-infected tall fescue-mixed pasture (0.51 ppm total ergovaline + ergovalinine; 10.1 ha). Steers were assigned (n = 8 per treatment) to the same Se form treatments upon which they were raised. Se treatments were administered by daily top-dressing 85 g of vitamin-mineral mix onto 0.23 kg soyhulls, using in-pasture Calan gates. The PROC MIXED procedure of SAS was used to assess the effect of Se form treatments on serum parameters at day 0, 22, 43, 64, and 86. After slaughter, the effect of Se treatment on hepatic alkaline phosphatase (tissue nonspecific isoform, TNALP) mRNA, protein, and albumin protein content was assessed using the PROC GLM procedure of SAS. Fisher's protected LSD procedure was used to separate treatment means. Partial correlation analysis was used to evaluate the relationship among whole blood Se concentration and serum parameters, accounting for the effect of time. Across periods, MIX steers had more (P ≤ 0.04) serum albumin than OSe and ISe steers, respectively. However, the relative hepatic bovine serum albumin protein content was not affected (P = 0.28) by Se treatments. Serum alkaline phosphatase activity was greater (P ≤ 0.01) in MIX and OSe steers. Similarly, hepatic TNALP protein content in MIX steers was greater (P = 0.01) than ISe steers. Partial correlation analysis revealed that serum albumin, blood urea nitrogen, and alkaline phosphatase activity were correlated (r ≥ 0.23, P ≤ 0.02) with whole blood Se concentration. In summary, consumption of 3 mg Se/d as OSe or MIX forms of Se in vitamin-mineral mixes increased serum albumin concentration and alkaline phosphatase activity, the reduction of which is associated with fescue toxicosis. We conclude that the organic forms of Se ameliorated the depression of 2 of known serological biomarkers of fescue toxicosis.

Extracellular Synthesis of Selenium Nanoparticles from an Actinomycetes Streptomyces griseoruber and Evaluation of its Cytotoxicity on HT-29 Cell Line.

BACKGROUND: Selenium nanoparticles (SeNPs) have gained significant importance because of its bioavailability, least toxicity, its interaction with proteins and its biocompatibility. OBJECTIVE: In the present study, the extracellular synthesis of SeNPs was carried out by using culture supernatant of Streptomyces griseoruber, an Actinomycetes member isolated from the soil and cytotoxicity was tested on HT-29 cell line. METHODS: Culture supernatant was mixed with 1mM sodium selenite for the biosynthesis of SeNPs. Characterisation of the synthesised SeNPs was done by UV-Visible spectrophotometer, FTIR, XRD, DLS and HR-TEM. The cytotoxicity of nanoparticles on HT-29 cell line was studied by MTT assay and with different staining procedure. RESULTS: Bioreduction of SeNPs was confirmed by UV-Visible spectrophotometer that showed the peak at 575 nm. Size and distribution of the biosynthesised SeNPs were analysed by HR-TEM that showed the formation of particle size in the range of 100-250nm. The synthesised SeNPs showed good cytotoxic activity against HT-29 cell line with 40.5%, 33% and 23.7% of cell viability at 2µg/ ml, 4µg/ml and 30µg/ml concentration respectively. CONCLUSION: The present study reports the simple and eco-friendly synthesis of SeNPs that showed good cytotoxic activity against HT-29 cell line suggesting that biogenic SeNPs could be a potential chemotherapeutic agent.

Aerobic biogenesis of selenium nanoparticles by Enterobacter cloacae Z0206 as a consequence of fumarate reductase mediated selenite reduction.

In the present study, we examined the ability of Enterobacter cloacae Z0206 to reduce toxic sodium selenite and mechanism of this process. E. cloacae Z0206 was found to completely reduce up to 10 mM selenite to elemental selenium (Se°) and form selenium nanoparticles (SeNPs) under aerobic conditions. The selenite reducing effector of E. cloacae Z0206 cell was to be a membrane-localized enzyme. iTRAQ proteomic analysis revealed that selenite induced a significant increase in the expression of fumarate reductase. Furthermore, the addition of fumarate to the broth and knockout of fumarate reductase (frd) both significantly decreased the selenite reduction rate, which revealed a previously unrecognized role of E. cloacae Z0206 fumarate reductase in selenite reduction. In contrast, glutathione-mediated Painter-type reactions were not the main pathway of selenite reducing. In conclusion, E. cloacae Z0206 effectively reduced selenite to Se° using fumarate reductase and formed SeNPs; this capability may be employed to develop a bioreactor for treating Se pollution and for the biosynthesis of SeNPs in the future.

Effects of selenium biofortification of hayfields on measures of selenium status in cows and calves consuming these forages.

Two experiments were conducted to evaluate the Se status of weaned calves (Exp. 1) and pregnant cows and newborn calves (Exp. 2) consuming bermudagrass [ (L.) Pers.] fertilized with Se. Sodium selenate was dissolved into water (8.8 g/L) and sprayed onto hayfields. Selenium-fertilized forage had greater ( ≤ 0.001) Se concentration compared with the control forage without Se fertilization (7.7 ± 1.81 vs. 0.1 ± 0.04 mg Se/kg DM and 10.8 vs. 0.1 mg Se/kg DM for Exp. 1 and Exp. 2, respectively). In Exp. 1, beef calves ( = 32; 176 ± 8.7 kg initial BW) were stratified by BW and randomly assigned to pens (16 pens; 2 calves/pen). Treatments were randomly assigned to pens, including control (no supplemental Se), Se hay, or sodium selenite ( = 2, 7, and 7 pens, respectively). A 42-d pair-feeding design was used, wherein each pen receiving Se hay was paired to a pen receiving sodium selenite. Blood and liver samples were collected on d 0, 21, and 42. Liver Se concentrations were greatest ( ≤ 0.005) on d 42 for calves provided Se hay compared with calves provided sodium selenite or control. This difference was attributed only to paired-feeding groups consuming <3 mg Se daily. In Exp. 2, mature, late-pregnancy cows were randomly assigned to 3 treatments: Se hay ( = 12), sodium selenite ( = 9), or control (no supplemental Se; = 6). Cows assigned to the sodium selenite and Se hay treatments were provided 2.5 mg of supplemental Se daily. Upon enrollment, cows were moved into individual feeding areas at an estimated 30 d prior to calving. Following calving, cotyledon and colostrum samples were collected from cows. Four days later, liver and blood samples were collected from both cows and calves. Selenium-supplemented cows had greater ( ≤ 0.001) liver, cotyledon, plasma, and whole blood Se concentrations compared with cows not receiving supplemental Se. Furthermore, cows provided Se hay tended ( = 0.11) to have greater liver Se concentrations compared with cows provided sodium selenite. Calves born to Se-supplemented cows had greater ( = 0.001) plasma Se concentrations than calves born to cows receiving no supplemental Se. Furthermore, calves born to cows provided Se hay tended ( = 0.06) to have greater plasma Se concentrations compared with calves born to cows provided sodium selenite. These data imply that Se biofortification of hayfields is an effective method to increase Se concentration of forage. Consumption of these forages result in increased Se status of weaned calves, periparturient cows, and their calves.

Supplementation of organic and inorganic selenium to late gestation and early lactation beef cows effect on cow and preweaning calf performance.

Angus × Simmental cows ( = 48; BW = 595 ± 17.4 kg, BCS = 5.26 ± 0.05, and age = 2.3 ± 0.07 yr), pregnant with male fetuses, were used to determine the effect of Se source during the last 80 d of gestation and first 108 d of lactation on cow and calf performance. At 203 d in gestation, cows were blocked by BW, breed composition, age, and calf sire and randomly allotted to organic Se, inorganic Se, or no Se treatments. Diets contained corn silage, corn stover, haylage, dried distillers' grains with solubles, and minerals and were formulated to contain 10.4% CP and 0.90 Mcal/kg NEg during gestation and 12.1% CP and 1.01 Mcal/kg NEg during lactation. Diets were fed daily as a total mixed ration and none, 3 mg/d Se as sodium selenite, or 3 mg/d Se as Sel-Plex were top-dressed daily. At 68 d postpartum (DPP), milk production was calculated using the weigh-suckle-weigh procedure and a milk sample was collected to determine composition. At 108 DPP, cow-calf pairs were commingled until weaning at 210 DPP. Cow BW and BCS ( ≥ 0.56) did not differ between treatments at any time point during the study. Milk production, milk fat, and total solids ( ≥ 0.38) did not differ among treatments. Milk protein tended to increase in cows fed inorganic Se compared with cows fed organic Se ( = 0.07) and milk lactose tended to be greatest in cows fed organic Se ( = 0.10). Conception to AI and overall pregnancy rates did not differ between treatments ( ≥ 0.39). Calf weights and ADG did not differ through 108 DPP ( ≥ 0.77) or for the preweaning period ( ≥ 0.33). Plasma Se concentration was adequate for all cows and did not differ among treatments for cows ( ≥ 0.37) or calves ( ≥ 0.90). Liver Se concentrations in cows fed inorganic or organic Se were greater than in control cows ( < 0.01). Longissimus muscles biopsies taken from progeny at 108 DPP also did not differ between treatments ( = 0.45). In conclusion, dietary Se source did not affect cow performance, milk production, or reproductive efficiency. Organic Se decreased milk protein and increased milk lactose but did not alter preweaning performance of progeny from Se-adequate cows.

[Sodium Selenite Regulates Growth and Uptake of Se,As and Heavy Metals of Trillium tschonoskii].

Objective: To study the influence of different concentrations of selenium on the growth and absorbing of Se,Cd,Pb,Hg and As in Trillium tschonoskii. Methods: Trillium tschonoskii was treated with different concentrations of exogenous selenium, arsenic and heavy metals,and then the mass growth, leaf area,root number and other indicators reflecting its growth rule were calculated. Atomic fluorescence method was used to measure the absorption contents of Se,Cd,Pb,Hg and As. Results: The relative mass growth,leaf area and root number of Trillium tschonoskii increased at first and then decreased with the increasing of exogenous selenium concentrations. When the concentration of selenium was 25 mg / kg,the relative mass growth,leaf area and root number of Trillium tschonoskii reached a maximum. When selenium concentrations was over than 30 mg / kg,it inhibited the growth and development of Trillium tschonoskii. Trillium tschonoskii absorbing Cd,Pb,Hg and As had a regular of first decreasing then increasing and last decreasing. It reached the lowest when selenium concentrations at the range of 10 ~ 15 mg / kg. . Conclusion: Selenium had both stimulating effect and inhibiting effect on the growth and development of Trillium tschonoskii. Different selenium concentrations have different effects in absorbing Cd,Pb,Hg and As of Trillium tschonoskii

Optimization of selenizing conditions for Seleno-Lentinan and its characteristics.

Lentinan was successfully modified with nitric acid-sodium selenite method based on L9(3(4)) orthogonal experiments. The optimum selenizing conditions were obtained according to selenium conversion rate as follows: Lentinan of 1.0g, pH of 4.5, temperature of 70°C and sodium selenite of 1.50g. The antioxidant activity assays in vitro (DPPH, reducing power, superoxide radicals and hydroxyl radicals) proved that Lentinan had stronger antioxidant activity after selenizing. The elevations of serum alanine aminotransferase and aspartate aminotransferase, as well as the abnormal hepatic architecture, verified that oral administration of Seleno-Lentinan (SL2-1) markedly alleviated oxidative damage in the liver of mice induced by D-gal. In addition, SL2-1 significantly increased total antioxidant capacity, activities and protein expressions of catalase and glutathione peroxidase and lowered malondialdehyde levels in serum and liver. Fourier transform infrared spectroscopy analysis indicated that selenium of SL2-1 was mostly existed as the formations of OSeO, SeO and SeOC. Scanning electron microscope coupled with energy dispersive X-ray spectroscopy analysis revealed that the surface structure and elemental components of Lentinan significantly changed after selenizing. The results are instructive for the development of organic selenium-supplement resource.

Chokeberry (Aronia melanocarpa (Michx.) Elliot) concentrate inhibits NF-κB and synergizes with selenium to inhibit the release of pro-inflammatory mediators in macrophages.

Black chokeberry has been known to play a protective role in human health due to its high polyphenolic content including anthocyanins and caffeic acid derivatives. In the present study, we first characterized the polyphenolic content of a commercial chokeberry concentrate and investigated its effect on LPS-induced NF-κB activation and release of pro-inflammatory mediators in macrophages in the presence or the absence of sodium selenite. Examination of the phytochemical profile of the juice concentrate revealed high content of polyphenols (3.3%), including anthocyanins, proanthocyanidins, phenolic acids, and flavonoids. Among them, cyanidin-3-O-galactoside and caffeoylquinic acids were identified as the major compounds. Data indicated that chokeberry concentrate inhibited both the release of TNFα, IL-6 and IL-8 in human peripheral monocytes and the activation of the NF-κB pathway in RAW 264.7 macrophage cells. Furthermore, chokeberry synergizes with sodium selenite to inhibit NF-κB activation, cytokine release and PGE2 synthesis. These findings suggest that selenium added to chokeberry juice enhances significantly its anti-inflammatory activity, thus revealing a sound approach in order to tune the use of traditional herbals by combining them with micronutrients.

Effects of selenium-chitosan on blood selenium concentration, antioxidation status, and cellular and humoral immunity in mice.

One hundred and eighty Kunming mice were allotted to three groups in a randomized complete block design, including two treatments and one control. Mice in group 1 were fed a basal diet as control, while mice in groups 2 and 3 were fed the basal diet supplemented with 0.2 mg/kg selenium as sodium selenite (SS) or selenium-chitosan (SC), respectively. On day 28 of the experiment, blood selenium concentration, glutathione peroxidase (GPx) activity, plasma superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, and Con A-induced splenocyte proliferation were determined, and plasma interleukin-2 (IL-2) and interferon-γ (IFN-γ) concentrations, splenic plaque-forming cell (PFC) responses, serum hemolysis level (HC50), and delayed-type hypersensitivity (DTH) responses were determined on day 15 of the experiment. The results showed that blood selenium concentration, GPx activity, splenic PFC response, and plasma IL-2 and IFN-γ concentrations in SC group were higher than those in the control and SS groups (P < 0.01 or P < 0.05), respectively. Plasma SOD activity, Serum hemolysis level, DTH responses, and Con A-induced splenocyte proliferation in SC group were higher than those in control (P < 0.01 or P < 0.05). Plasma SOD activity, serum hemolysis level, DTH responses, and Con A-induced splenocyte proliferation in SC group were also higher than those in SS group, while there was no significant difference between SC and SS groups (P > 0.05). Plasma MDA content in SC group was lower than those in the control and SS groups (P < 0.01 or P < 0.05). It is concluded that SC supplement can increase blood selenium concentration, antioxidation status, and cellular and humoral immunity, and SC has better biological activity than SS in mice.

Optimization of selenylation conditions for lycium barbarum polysaccharide based on antioxidant activity.

Lycium barbarum polysaccharide (LBP) was modified by HNO3-Na2SeO3 method according to L9(3(4)) orthogonal design to obtain nine selenizing LBPs (sLBPs), sLBP1-sLBP9. Their antioxidant activities in vitro were compared by free radical-scavenging test. sLBP6, sLBP8 and sLBP9 presented stronger activity. In vivo test, 14-day-old chickens were injected respectively with sLBP6, sLBP8 and sLBP9 taking LBP as control, and serum GSH-Px and SOD activities and MDA content were determined. The results showed that three sLBPs could significantly enhance GSH-Px and SOD activities and decrease MDA content. The actions of sLBPs were significantly stronger than that of unmodified LBP. These results indicated that selenylation modification could significantly enhance the antioxidant activities of LBP, sLBP6 possessed the best efficacy and could be exploited into an antioxidant. The optimal modification conditions were 400mg of sodium selenite for 500 mg of LBP, reaction temperature of 70 °C and reaction time of 6h.

Effect of different selenium sources on production performance and biochemical parameters of broilers.

Selenium (Se) is an essential trace element for animal and human. Supplementation of Se usually in livestock diet has been proved as effective element. This study was conducted to investigate the effect of different sources of selenium on growth performance, slaughter performance, immune trait, oxidation resistance, meat quality and selenium content in tissue of broilers to comprehensively evaluate the effect of selenium. A total of 324 1-day-old AA broilers were selected and randomly allocated to three treatments of six replicates with 18 broilers each. The trial period was 42 days and was divided into two periods. Our results showed that effect of different sources of selenium on growth performance, slaughter performance, the immune status, drip loss and flesh had not significant difference (p > 0.05); while the activities of serum glutathione peroxidase (GSH-Px), total superoxide dismutase (T-SOD), the abilities to inhibit hydroxyl radical (OH˙) and total antioxidant capacity (T-AOC) were significantly higher in selenium yeast than sodium selenite groups, and the contents of MDA of selenium yeast groups were significantly lower than that of sodium selenite. This study demonstrated that the different sources of selenium had no obvious effect on production performance of broilers, but significantly influenced the broiler oxidation resistance.

Microencapsulated sodium selenite supplementation in dairy cows: effects on selenium status.

The objective of this study was to compare the efficiency of transfer of selenium (Se) to plasma and milk from inorganic sodium selenite, either free or microencapsulated, and from selenized yeast in dairy cows. The study consisted of an in situ-nylon bags incubation, and in an in vivo experiment to compare the Se status of cows supplemented with either sodium selenite, microencapsulated sodium selenite, or Se yeast. Thirty dairy cows, divided in five groups, were fed the following diets: the control group (CTR) received a total mixed ration supplemented with sodium selenite in order to have 0.3 mg/kg DM of total Se; 0.3M and 0.5M groups received the same control diet supplemented with lipid microencapsulated sodium selenite to provide 0.3 and 0.5 mg/kg DM of total Se, respectively; 0.3Y and 0.5Y groups received selenized yeast to provide 0.3 and 0.5 mg/kg of total Se, respectively. Cows were fed the supplements for 56 days during which milk, blood, and fecal samples were collected weekly to conduct analysis of Se and glutathione peroxidase (GSH-px) activity. Se concentration in the nylon bags was assessed to 72%, 64%, and 40% of the initial value (time 0) after 4, 8, and 24 h of incubation, respectively. In vivo, cows supplemented with 0.3 mg/kg of microencapsulated Se had higher milk Se concentration compared to CTR. The increment was more pronounced at the highest inclusion rate (0.5 mg/kg, 0.5M group). GSH-px activity was not significantly affected by treatments. The results indicate that lipid microencapsulation has the potential to protect nutrients from complete rumen reduction and that Se from microencapsulated selenite is incorporated in milk more efficiently than the free form. Microencapsulated sodium selenite was shown to be comparable to Se-yeast in terms of availability and incorporation in milk when fed at 0.3 mg/kg DM, whereas the inclusion in the diet at 0.5 mg/kg DM resulted in higher plasma and milk concentrations than selenized yeast.

Optimization of selenylation conditions for Chinese angelica polysaccharide based on immune-enhancing activity.

Chinese angelica polysaccharide (CAP) was extracted by water decoction and ethanol precipitation, purified through eliminating protein by Sevage method and column chromatography of Sephadex G-200, then selenizingly modified by nitric acid-sodium selenite method according to L(9)(3(4)) orthogonal design of three-factors, the usage amount of sodium selenite, reaction temperature and reaction time, at three level to obtain nine selenizing CAPs, sCAP(1)-sCAP(9). Their effects on chicken peripheral lymphocytes proliferation in vitro were compared by MTT assay taking the non-modified CAP as control. The results showed that selenylation modification could significantly enhance the immune-enhancing activity of CAP, sCAP(2) presented best effect and the optimal modification conditions were 200mg of sodium selenite for 500 mg of CAP, the reaction temperature of 70 °C and the reaction time of 6 h.

Influence of trace elements on stabilization of aqueous solutions of ascorbic acid.

Together with vitamin C, zinc, selenium, manganese, and magnesium play a vital role in the preservation of organs scheduled for transplantation. In the present study, it is shown that addition of 1 mg/l of these elements influences the stability of 0.3 mM ascorbic acid solutions. The solution's stability was estimated using an accelerated stability test. The concentration of vitamin C was measured using a validated spectrophotometric method, which uses the reduction of 2,6-dichlorophenoloindophenol by ascorbic acid. Elevated temperatures, the factor accelerating substances' decomposition reaction rate, were used in the tests. The research was conducted at two temperatures at intervals of 10 °C: 80 ± 0.1 and 90 ± 0.1 °C. It was stated that the studied substances' decomposition occurred in accordance with the equation for first-order reactions. The function of the logarithmic concentration (log%C) over time was revealed to be rectilinear. This dependence was used to determine the kinetics of decomposition reaction rate parameters. The stabilization of vitamin C solutions was measured as the time in which 10 % of the substance decomposed at 20 and 0 °C. Addition of Se(IV) or Mg(II) ions significantly increase the stability of ascorbic acid solution (∼34 and ∼16 %, respectively), but Zn(II) causes a significant decrease in stability by ∼23 %. Addition of Mn(II) has no significant influence on vitamin C stability.