Selenium supplementation levels and sources in postlarvae Nile tilapia diet

Fish larviculture exert great influence in the subsequent phases, in which nutrition is a basic prerequisite for success. Therefore, when it is in an intensified production system, it promotes the limitation of some minerals, making it necessary to supplement selenium in diets for post-larvae. The objective of this study was to evaluate selenium levels and sources in post-larvae Nile tilapia diets on muscle performance and histology. A total of 1,260 post-larvae with an initial average weight of 0.010 g were used, distributed in a completely randomized design in a factorial scheme with four supplementation levels (0.6; 0.9; 1.2 and 1.5 mg of Se/Kg) and two sources (sodium selenite and selenium yeast), plus the negative control, with 35 post-larvae Nile tilapia used per experimental unit. The physical-chemical parameters of water quality were within those recommended for tilapia cultivation. Feed consumption (p < 0.05) and hepatosomatic index (p < 0.05) were affected by the source used. Effects of supplemented selenium levels and sources were not observed for the other performance variables. Higher values for final height, final width, specific development rate and protein efficiency rate were found (p < 0.05) when comparing the control diet with diets containing the sodium selenite source. No effects on muscle fiber morphometry were observed (p > 0.05) in the studied variables. It is concluded that 0.6 mg of selenium in the diet, regardless of the source used, met the mineral requirement for post-larvae Nile tilapia.

Combination therapy of metformin with sodium selenite reverses effects of monotherapy on nitric oxide production, IL-1β and TNF-α release, and upregulates relative expression of Bcl-2 by LPS-activated human primary monocytes in T-cell acute lymphoblastic leukemia

Objectives: We examined the influence of the ex vivo combination therapy of metformin (Met, 1,1-dimethylbiguanide hydrochloride) with sodium selenite (Ss, Na2SeO3) on the changes in the production of nitric oxide (NO) and selected cytokines by circulating monocytes (MOs) during T-cell acute lymphoblastic leukemia (T-ALL). Methods: Assays were performed on MO cell samples isolated from children with T-ALL. Results: Met+Ss combination therapy reversed the Ss effect on the upregulation of NO production. Both Met+Ss and Ss treatment alone induced a significant downregulation of extracellular calcium ions consumption (ecCa2+) levels. Additionally, Met treatment induced a significant upregulation of IL-1β and TNF-α production; such effects were significantly reversed after combination with Ss treatment. Moreover, Met+Ss induced no significant effect on the production of IL-10, IL-6 and TNF-α, but a slight increase in IFN-γ levels. Furthermore, treatment with Ss alone induced a slight increase of IFN-γ. Finally, Met+Ss induced a marked upregulation of relative Bcl-2 expression in MOs. Conclusions: Met+Ss combination therapy results in downregulation of NO production, IL-1β and TNF-α release as well as in upregulation of the relative expression levels of Bcl-2-associated survival of primary MOs in human T-ALL.

Effects of Dietary Selenium Sources on Physiological Status of Laying Hens and Production of Selenium-Enriched Eggs

Developing new sources of organic selenium (Se) has potential benefits for animal production and human nutrition via animal-based foods enriched with Se. The objective of this study was to evaluate the effects of Se-enriched insect protein (SEIP) in comparison with other sources, such as sodium selenite (SS) and selenium-enriched yeast (SEY), on performance, egg quality, selenium concentration in eggs, serum biochemical indices, immune capacity, and intestinal morphology of laying hens. Four hundred and fifty 24-week-old Hy-Line Brown laying hens with 94.0 ± 1.5% laying rate were randomly allocated to five groups with six replicates of 15 hens each. The control diet was prepared without adding exogenous selenium (calculated basal Se content of 0.08 mg/kg). The normal group was fed basal diets supplemented with 0.3 mg/kg of Se provided by sodium selenite. Three treatment groups (SS, SEY, and SEIP, respectively) were fed basal diets supplemented with 2 mg/kg of Se provided by sodium selenite, Se-enriched yeast, and SEIP, respectively. The feeding trial lasted for 12 weeks. Results revealed that dietary supplementation of 2 mg/kg of Se increased egg weight, decreased feed conversion ratio, and enhanced the antioxidant capacity of eggs in laying hens relative to the control group, whereas no significant differences were observed among SS, SEY, and SEIP treatment groups for the same. The organic source of Se provided by SEY or SEIP showed higher bio efficiency, as indicated by higher selenium content in eggs of SEY and SEIP compared with SS, although higher content was observed in SEY compared with SEIP. Also, the organic Se source significantly improved antioxidant capacity and immune functions of laying hens than the inorganic Se source. Diets supplemented with SEIP and SS significantly improved jejunal morphology of the laying hens compared with SEY, whereas SEIP was more effective than SEY to improve the oviduct health of laying hens. The results of this work evidently points the additive effect and nontoxicity of SEIP. Thus, SEIP could be used as another organic source of Se in the diet of laying hens and production of selenium-enriched eggs for humans.

Effects of sodium selenite and selenium-enriched yeast on cardiometabolic indices of patients with atherosclerosis: A double-blind randomized clinical trial study

Introduction: Atherosclerosis and related cardiovascular diseases (CVDs) are the major causes of mortality worldwide. The available reports regarding the effects of selenium (Se) supplementation in the realm of atherosclerosis have been equivocal. The present investigation is aimed to assess the effects of sodium selenite and Se-enriched yeast supplementation on metabolic parameters among atherosclerotic patients. Methods: In this double-blind placebo-controlled randomized clinical trial, 60 patients diagnosed with atherosclerosis were randomly allocated into either 200 μg/day selenite, yeast, or placebo groups for eight consecutive weeks. Serum levels of lipid profile and glycemic indices were measured at the baseline and end of the intervention. Results: There were no significant within-or between-group changes in levels of total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-c), fasting blood sugar, insulin, and homeostatic model assessment for IR throughout the study (P≥0.05). Only the low density lipoprotein cholesterol (LDL-c) levels were significantly lower in the yeast group in comparison with the placebo group (P= 0.015). Conclusion: The administration of Se-enriched yeast is significantly effective in decreasing LDL-c levels in patients with atherosclerosis. Additional clinical trial studies investigating the effect of Se administration on glucose homeostasis parameters and lipid profiles in atherosclerotic patients are suggested for a more definitive conclusion.

Duckweed (Lemna minor L.) Successfully Accumulates Selenium from Selenium-Impacted Water

The absorption of selenium (Se) from water by Lemna minor L. and the influence of different concentrations and forms of Se on its biochemical and morphological characteristics were studied. Plants were exposed to various concentrations of Se: 1 mg Se L−1, 2 mg Se L−1 and 5 mg Se L−1 in sodium selenite and sodium selenate solutions and in a combination of selenite (2 mg Se L−1) and selenate (2 mg Se L−1). When the Se was added in the form of selenate, plants accumulated higher amounts of Se compared to plants exposed to selenite. Comparisons of the combined addition of selenite and selenate (2 + 2 mg Se L−1) with their individual applications (2 and 5 mg Se L−1) showed that for the combination, the L. minor fronds accumulated more Se than in selenite alone. Plants exposed to any of the concentrations of sodium selenate or sodium selenite, or the combination of selenite and selenate, showed inferior physiological performances, and lower concentrations of photosynthetic pigments, compared to control plants. Consequently, growth was also suppressed under the stress conditions caused by higher concentrations of Se in any form. The efficient absorption of Se from the water by L. minor indicates the potential use of this species in phytoremediation processes for waters polluted with Se.

Sodium Selenite Enhances Antibiotics Sensitivity of Pseudomonas aeruginosa and Deceases Its Pathogenicity by Inducing Oxidative Stress and Inhibiting Quorum Sensing System

Pseudomonas aeruginosa, a Gram-negative opportunistic pathogen, is commonly found in clinical settings and immuno-compromised patients. It is difficult to be eradicated due to its strong antibiotic resistance, and novel inactivation strategies have yet to be developed. Selenium is an essential microelement for humans and has been widely used in dietary supplement and chemoprevention therapy. In this study, the physiological and biochemical effects of sodium selenite on P. aeruginosa PAO1 were investigated. The results showed that 0~5 mM sodium selenite did not impact the growth of PAO1, but increased the lethality rate of PAO1 with antibiotics or H2O2 treatment and the antibiotics susceptibility both in planktonic and biofilm states. In addition, sodium selenite significantly reduced the expression of quorum sensing genes and inhibited various virulence factors of this bacterium, including pyocyanin production, bacterial motilities, and the type III secretion system. Further investigation found that the content of ROS in cells was significantly increased and the expression levels of most genes involved in oxidative stress were up-regulated, which indicated that sodium selenite induced oxidative stress. The RNA-seq result confirmed the phenotypes of virulence attenuation and the expression of quorum sensing and antioxidant-related genes. The assays of Chinese cabbage and Drosophila melanogaster infection models showed that the combination of sodium selenite and antibiotics significantly alleviated the infection of PAO1. In summary, the results revealed that sodium selenite induced oxidative stress and inhibited the quorum sensing system of P. aeruginosa, which in turn enhanced the antibiotic susceptibility and decreased the pathogenicity of this bacterium. These findings suggest that sodium selenite may be used as an effective strategy for adjunct treatment of the infections caused by P. aeruginosa.

Spring wheat yield (Triticum aestivum L.) when applying selenium fertilizers in extreme growing conditions

To study the effect of sodium Selenite application different methods on the yield of spring wheat varieties, depending on the conditions of water supply, a series of vegetation experiments in accordance with the methodology were carried out. The object of the study is spring wheat of the Zlata variety (Triticum aestivum L.). It was found that the effect of selenium on the yield of wheat of the Zlata variety depended on the method of its application and the conditions of water supply. With optimal water supply, the positive effect of selenium on the yield of spring wheat plants was revealed with both methods of applying sodium selenite. It was found that in conditions of drought, the positive effect of selenium was obtained with both methods of using sodium selenite. The greatest efficiency of selenium is obtained in foliar processing of plants. The increase in grain weight in this variant was 1.4 times. The increase in the share of the agronomic significant part of the wheat crop yield to 36% is shown, which indicates the decrease in the negative effect of drought on the formation of spring wheat yield when using foliar processing of plants.

Productivity and grain quality indicators of white lupine (Lupinus albus L.) variety Degas when using sodium selenite

The aim of the research was to study the sodium selenite using various methods effect on the yield and quality of Degas variety white lupine grain. To solve these issues microfield experiment on the experimental plot of the Department of agronomic, biological chemistry and radiology of the Russian State Agrarian University - Moscow Timiryazev Agricultural Academy was carried out. Thus, it was found that the use of sodium selenite for foliar treatment of plants contributed to the greatest increase in the yield of white lupine plants. The increase in the grain yield of 27% compared to the control was obtained. The increase in the weight of the beans was revealed by almost 2 times. This indicates the influence of sodium selenite on the processes of fruit formation and the process of laying the seed productivity of lupine plants. The greatest effect of foliar treatment of plants with sodium selenite was found. In this variant, the largest increase in grain yield and the highest content of crude protein in the lupine grain were obtained. It is concluded that the use of selenium affects the formation of beans and grains in them, which determines the increase in plant yield.