Concentrations Of Sodium Selenite Research Articles

93P - Decreasing telomerase activity of adenocarcinoma cancer cell line (AGS) is associated with different concentrations of sodium selenite and cadmium chloride and selenium l methionine

93P - Decreasing telomerase activity of adenocarcinoma cancer cell line (AGS) is associated with different concentrations of sodium selenite and cadmium chloride and selenium l methionine

Selenium speciation and biological characteristics of selenium-rich Bailing mushroom, Pleurotus tuoliensis

Nowadays the study of selenium-rich mushrooms is very popular. In the present study, selenium speciation in fruiting body of Pleurotus tuoliensis was investigated in cultivation substrates with different concentrations of sodium selenite, as well as mycelia growth and mushroom development. The results showed that the P. tuoliensis mycelia appeared good tolerance to selenium at all test concentrations. A selenium concentration of 10 mg/kg promoted fruiting of P. tuoliensis; the fruiting bodies were of good quality and had a low malformation rate. HPLC–ICP-MS determined that organic seleniums enriched in stipes and caps existed mainly in the form of selenoCystine and selenoMethionine at selenium concentrations of 10-100 mg/kg. These findings suggest that P. tuoliensis could be developed as a selenium-rich mushroom product for use as a novel dietary source of bioavailable supplemental selenium.

Selenium bioaccumulation and associated nutraceutical properties in Calocybe indica mushroom cultivated on Se-enriched wheat straw

Calocybe indica was cultivated on wheat straw enriched with various concentrations of sodium selenite (Na2SeO3), (2.5-40μg/ml). The content of selenium (Se) in fruit bodies increased linearly by increasing the amount of Na2SeO3, although the biomass yield inhibited above 5μg/ml. The fruit bodies accumulated inorganic Se into organic forms by integrating the Se into proteins (56%-68%), polysaccharides (22%-29%), and nucleic acids (1.4%-2.7%). Maximum protein content (25.31g/100g) was observed in fruit bodies harvested from the substrate enriched with 10μg/ml Se. Amino acid profiling revealed the highest value of glutamic acid (4.73g/100g), followed by aspartic acid (1.80g/100g), and glycine (1.61g/100g) at 10μg/ml. The Se enrichment also enhanced the total phenol, free radical 2,2-dipheynl-1-picrylhydrazyl (DPPH) scavenging activity and ferric reducing power (FRAP) of methanolic extracts of fruiting bodies to almost double of their contents. The principle component analysis (PCA) illustrated close correlations amongst the biomass yield, polyphenols, and antioxidant activities at 5μg/ml concentrations of the Se.

Selenium Uptake and Biotransformation and Effect of Selenium Exposure on the Essential and Trace Elements Status: Comparative Evaluation of Four Edible Plants

<p>Due to the essential nature of selenium and the beneficial effects attributed to the consumption of selenized plants in human and animal health. The accumulation, metabolism in plants and the effects of this element on the nutritional quality of exposed crops is still a subject of study. The selenium plant enrichment, in addition to providing dietary supplements with organic selenium species as SeMet and MeSeCys, could be a strategy to yield functional foods that guarantee the recommended absorption of other essential minerals. To contributing to the design of biofortification/supplementation strategies to obtain selenized edible sprouts, in this work were selected four types of plants commonly consumed in Mexico (radish, alfalfa, sunflower and chard), which were exposed to different concentrations of sodium selenite (0, 0.25, 0.5, 1.0, 5.0 and 10 mg of Se L-1) for 10 days. At the end of the exposure time, the growth, uptake and biotransformation from iSe to oSe, as well as the impact of Se on the content of other essential elements were evaluated. The results obtained indicate that alfalfa could be a good candidate to produce selenized food supplement, due to its short germination time (5 days), high yield of biomass production without growth inhibition up to selenite concentration corresponding to 10 mg L-1. Using this exposure condition, tSe accumulated in biomass is high (75.0 mg g-1) with 66% of iSe transformed to oSe in plant and with enhanced uptake of important minerals, namely Cu, Mn, Mo, Ca and K.</p>

Influence of Sodium Selenite on the mRNA Expression of the Mammalian Selenocysteine-Containing Protein Genes in Testicle and Prostate Cancer Cells.

The sodium selenite concentration that reduces the viability of Du-145 human prostate adenocarcinoma cells and F-9 mouse testicular teratocarcinoma cells was determined. We investigated the effect of sodium selenite on the mRNA expression level of the genes encoding mammalian selenocysteine-containing glutathione peroxidases and thioredoxin reductases (key antioxidant enzymes involved in the regulation of intracellular thiol redox balance), endoplasmic reticulum selenoproteins, and selenoproteins located in the testes and prostate.

Selenium biofortification of rice grains and implications on macronutrients quality

Selenium is an essential element for human health but its intake is low. Accordingly, biofortified rice with this trace element can be prophylactic to consumers. In this context, this study aimed to develop an agronomic itinerary for rice biofortification with selenium, considering sodium selenite and selenate as foliar fertilizers. Since both forms of selenium fertilizers have different metabolic specificity among genotypes, the implications on sugars, fatty acids and proteins quality were also assessed. Biofortification was performed in field trials, in four target genotypes, applying both foliar fertilizers with concentrations ranging between 0 and 300 g Se ha−1. It was found that biofortification with sodium selenite caused, relatively to sodium selenate, a higher accumulation of selenium in the grain. Application of high concentrations of sodium selenite and selenate increased total lipids in all the genotypes, mostly oleic acid (C18:1), linoleic (C18:2) and palmitic acid (C16:0). Sugars (with the concentration pattern being sucrose > glucose > raffinose > fructose) and proteins showed a similar trend. It is concluded that biofortification of crops with selenium is more effective with 120–300 g Se ha−1, but macronutrients quality in the flour varies significantly within rice genotypes.

Effect of germination with sodium selenite on the isoflavones and cellular antioxidant activity of soybean (Glycine max)

Isoflavones profiles and cellular antioxidant activity (CAA) of soybeans (Glycine max) germinated for different times with several sodium selenite (Na2SeO3) concentrations were assessed. The experiments were performed using central composite design and isoflavones evaluated by HPLC–UV and HPLC-MS-TOF. Malonylated genistein and malonylated daidzein glycosides were the main isoflavones associated to the soybean sprouts. Soybeans germinated for 48 h at 20 °C with a frequent spraying of water containing less than 32 mg/L of Na2SeO3 per liter contained the optimal concentrations of selenium (Se), total isoflavones and cellular antioxidant activity. This research demonstrated that Se-enriched soybean sprouts are a good source of both dietary Se and isoflavones and potentially can be used to formulate new functional foods.

Production of Selenium-Enriched Yeast (Kluyveromyces marxianus) Biomass in a whey-based Culture Medium

Fil: Gurdo, Nicolas. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - La Plata. Instituto de Investigaciones Biotecnologicas. Instituto de Investigaciones Biotecnologicas Dr. Raul Alfonsin (sede Chascomus). Universidad Nacional de San Martin. Instituto de Investigaciones Biotecnologicas. Instituto de Investigaciones Biotecnologicas Dr. Raul Alfonsin (sede Chascomus); Argentina

DEVELOPMENT OF BIOTECHNOLOGY OF GETTING SELENIUM NANOSTRUCTURES WITH LACTOBACILLUS ACIDOPHILUS CULTURE

Selenium nanostructures are characterized with high activity and antibacterial properties. Selenium nanoparticles, received by the biotechnological method using microorganisms are not toxic and free from admixtures of other toxic elements. For getting selenium nanostructures, there was set a problem of development of the biotransfrormation technology of inorganic selenium by the culture Lactobacillus acdophilus, strain 412/307 from the museum of the Department of Biochemistry, Microbiology and Physiology of Nutrition Odessa National Academy of Food Technologies (Ukraine). Selenium nanostructures are the side product in the process of selenocysteine formation. There was realized the study of the influence of the sodium selenite concentration on the growth speed and generation duration of lactobacteria on MRS medium for determining the main technological parameters. There was determined the quantitative content of accumulated selenium at different initial concentrations of sodium selenite in the medium. The important part of the elaborated technology is destruction of cellular walls of microorganisms for removal selenium nanoparticles. There was studied the influence of different physical-chemical factors of cells’ destruction. There was offered to use the combined influence of saline acid, freezing and microwave field for destructing cellular walls of lactobacteria biomasses. There is presented the scheme of the technology of getting “Nanoselenium” and given physical-chemical parameters of the received product.

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

Corrosion Inhibition of Mg Alloy AZ31 By Selenite (SeO32-)

The study of Mg corrosion inhibition by selenium/selenite is very limited. The first relevant work was done by Guy and Whitby in the 1930s1. That work used an acidic selenite-based coating bath to convert Mg alloy surfaces for increased corrosion resistance. It was found that the selenite can react on Mg alloys surfaces to form a protective film. After that report, there was no work reported until Kaminski showed evidence of corrosion inhibition in free corrosion exposure experiments2. The present study follows the work of Kaminski and develops a more comprehensive characterization of Mg corrosion inhibition by selenite using electrochemical and surface analytical methods. Results from these studies support the distinctive qualities of Se films and provide insights on the corrosion inhibition mechanism and inform technological approaches for using this corrosion inhibitor in practical applications. Corrosion inhibition was characterized using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) at three different concentrations of Na2SeO3, which ranged from 1 mM to 50 mM in a base solution of aerated 0.1 M NaCl. After 8 hours immersion in NaCl/inhibitor solution, anodic polarization showed that at low inhibitor concentration the corrosion current density was decreased to less than 10-6 A/cm2. EIS indicated that a low concentration of sodium selenite provided better corrosion protection, as evidenced by an increase in polarization resistance. During these characterizations, a black or red film formed on substrates after immersion tests. A red film was observed at high selenite concentrations, and some trapped transparent crystals were also noted. Several repeat experiments indicated that after three days immersion, nearly all samples were free of obvious corrosion defects. Raman spectroscopy was employed to analyze the surface chemistry. Amorphous selenium tended to form at low inhibitor concentrations, and the film formed was black. Crystallized selenium only formed at high inhibitor concentrations, and the film formed was red. Transparent insoluble crystals were trapped in the red film. Raman spectroscopy showed that these crystals were insoluble MgSeO3. Overall, the corrosion inhibition by selenite is better than that conferred by vandate, but not as good as that conferred by chromate under similar experimental conditions. Among the various film morphologies observed, the amorphous black film provided better corrosion protection than the crystallized red film, as evidenced by electrochemical testing results. In this presentation, details from electrochemical characterization and surface analysis will be discussed in the context of corrosion protection mechanism and prospects for use in a technological application.

Effect of sodium selenite on the bacteria growth, selenium accumulation, and selenium biotransformation in Pediococcus acidilactici.

In this study, the effect of low selenium concentrations on bacteria growth, selenium bioaccumulation, and selenium speciation in Pediococcus acidilactici was investigated. Six different sodium selenite (Na2SeO3) solutions with concentrations of 0, 0.5, 1, 2, 3, and 4mg/L were added in MRS broth for 24h. Then, the obtained bacterial pellets were weighed. The contents of total selenium and selenium species in the bacterial pellets were measured via optimized enzymatic hydrolysis and HPLC-ICP-MS. The maximum dried P. acidilactici biomass of 1.44g/L was achieved by utilizing 1mg/L Na2SeO3. By increasing sodium selenite concentrations, total selenium contents were significantly increased from 0.14 to 1.45mg/g dry weight (p<0.05). The findings indicated that selenium was favorably incorporated into the bacteria protein fraction and mainly formed selenocysteine. Therefore, selenium-enriched lactic acid bacterium P. acidilactici can deliver a less-toxic, more bioavailable selenium source for human and animal nutrition.

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.

Technology of production biological active additive based on selenium containing culture of bifidobacterium

The article presents data on the positive impact of essential microelement selenium on the human body. It was characterized the ability to accumulate inorganic forms of selenium (such as selenites and selenates) into the organic forms by probiotic microorganisms. The article presents data concerning sodium selenite concentration impact on biomass growth of bifidobacterium culture. It was fined optimum conditions for accumulation maximum selenium containing biomass of microorganisms. Based on experiments it was created selenium containing biologically active additive.

Evaluation of genetically modified Arabidopsis thaliana through metallomic and enzymatic approaches focusing on mass spectrometry-based platforms

This work reports the evaluation of the Arabidopsis thaliana, genetically modified or not, cultivated in the absence or in the presence of different concentrations of sodium selenite, employing mass spectrometry-based platforms and metallomics and enzymatic approaches. The genetic modification is evidenced through PCR analysis. The total selenium determination in the leaves of such culture is performed through ICP-MS. The metalloproteins are identified through LC-ICP-MS and ESI–MS/MS, which are involved in a diversity of modifications observed in the genetically and non-genetically modified plants. Additionally, some enzymes are also evaluated, which are involved in the oxidative stress such as SOD and catalase, as well as the concentrations of MDA and H2O2. Results on Se accumulation in the genetically modified is higher than non-genetically modified leaves as 130%, 19% and 17% for control, Se-low and Se-high treatments, respectively. From the results achieved in this work, it was verified that the genetic modification itself is a stressful event to the plants, once while a decreased of 32% water-soluble protein content and ca. 48% on SOD activity were observed, an increase of 69% on the H2O2 production was noted in GM leaves, when the Se was added to the culture. Additionally, the genetic modification conferred plant resistance to Se oxidative stress, due to the decrease of both water-soluble protein content (33%) and SOD activity (66%), as well as the increment on H2O2 production (19%) in control GM leaves, when compared with N-GM leaves.

Effect of sodium selenite on isoflavonoid contents and antioxidant capacity of chickpea (Cicer arietinum L.) sprouts.

Isoflavonoid compositions, phenylalanine ammonia lyase (PAL) activity and antioxidant capacity were evaluated in chickpea (Cicer arietinum L.) sprouts germinated after soaking with different sodium selenite (Na2SeO3) concentrations (0, 1 and 2mg/100g seeds). Chickpea seeds were germinated during four days at 24°C and the isoflavonoid profiles and concentrations evaluated by HPLC-UV daily during four days of germination. Eleven isoflavones and two pterocarpan phytoalexins forms were identified in sprouts, being malonylated formononetin glycoside, formononetin, isoformononetin glycoside and malonylated biochanin A glycoside the major compounds. Compared to untreated sprouts, total isoflavonoid, PAL activity and antioxidant capacity showed a remarkable increase of 83%, 56%, and 33%, respectively in chickpea sprouts that were treated with a high sodium selenite content (2mg/100g seeds). Results suggest that Se-enriched chickpea sprouts could represent a good source of dietary Se and as an upgraded source of isoflavonoids.

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.

Probiotic and antioxidant properties of selenium-enriched Lactobacillus brevis LSe isolated from an Iranian traditional dairy product

The present study was designed to isolate a highly selenium-tolerant lactobacillus strain from an Iranian traditional dairy product named as Spar. Different criteria such as tolerance to the low pH, simulated gastric juice (SGJ), simulated intestinal juice (SIJ) and bile salts tolerance as well as Caco-2 cell adhesion assay were examined to evaluate the probiotic potentials of the selected isolate. Furthermore, the antioxidant properties of the isolate cultivated in medium containing and free of SeO32− ions were evaluated using DPPH scavenging and reducing power assays. The isolate was identified using conventional identification and 16S rDNA gene sequencing methods as Lactobacillus brevis LSe. The obtained results showed that the isolate was able to tolerate high concentration of sodium selenite (3.16mM). By decreasing the pH of the SGJ from 6 to 3, the survival percent of L. brevis LSe was not significantly changed over the time (p>0.05). In addition, the survival percent of the isolate in the SIJ (pH 6 and pH 8) was not statistically altered after 3h, 6h and 24h of incubation (p>0.05). In the presence of bile salts (0.3% and 0.6%) the survival rate of L. brevis LSe was not significantly decreased (p>0.05).L. brevis LSe also demonstrated the satisfactory ability to adhere to Caco-2 cells which were similar to that of the reference strain L. plantarum. The obtained results of antioxidant evaluation showed that L. brevis LSe containing elemental Se exhibited significantly higher radical scavenging ability (36.5±1.31%) and reducing power (OD700, 0.14) than L. brevis LSe cultured in selenite-free medium (p<0.05). To sum up, further investigations should be conducted to merit the probable potential health benefit of Se-enriched L. brevis LSe and its application as Se-containing supplements or fermented foods.

Biosynthesis of selenium nanoparticles using Enterococcus faecalis and evaluation of their antibacterial activities

Microorganisms are capable of synthesizing metal nanoparticles, and specifically Enterococcus faecalis bacteria were tested for its ability to synthesize selenium nanoparticles (Se-NPs) from sodium selenite. The biosynthesized Se-NPs were spherical in shape with the size range of 29–195nm. Also, the TEM microscopy showed the accumulation of nano-structures as extracellular deposits. The ability of the bacteria to tolerate high levels of toxic selenite was studied by changing with different concentrations of sodium selenite (0.19mM–2.97mM). Also, the effect of Se-NPs was studied on the growth profile of number of pathogenic Gram-positive and -negative bacteria. High concentrations of sodium selenite in the medium led to the production of small amounts of selenium nanostructures by bacteria. In addition, Se-NPs can be used as an anti-staphylococcal element to effectively prevent and treat S. aureus infections.

Can a Low-Dose Selenium (Se) Additive Reduce Environmental Risks of Mercury (Hg) and Arsenic (As) in Old Gold Mine Tailings?

Selenium (Se) has long been known as an effective antagonist for counteracting mercury (Hg) and arsenic (As) toxicity in many animal and plant species. This study is the first to assess a low-dose Se additive as an in situ remediation tool for As- and Hg-contaminated gold mine tailing material. Mine tailing material from an 1860s gold mine stamp mill site was treated with different concentrations of sodium selenite (0, 0.5, 1, 3, 8, and 15 mg Se/kg). Reclamation grass seeds planted in each treatment showed significantly decreased plant toxicity with increasing [Se], as measured by increases in biomass, % emergence, and root lengths. Leachate was collected from each pot after the grass was harvested. The lowest Hg and As concentrations measured in the leachate were associated with the 1 mg Se/kg treatment (94 and 71 % lower than concentrations in leachate from untreated tailing material) and increased with lower and higher Se treatments. Finally, earthworms (Eisenia andrei) were introduced to the experimental treatments. Earthworm [Hg] decreased with increasing [Se], but this effect was confounded by differing [Hg] in the tailing material. Earthworm [As] decreased with [Se] up to 3 mg Se/kg, then earthworm [As] increased with tailing [Se]. This experiment confirms that low-dose selenium additions (up to 3 mg Se/kg tailing material) can have beneficial effects by limiting toxicity and mobility of As and Hg from the tailing material for both grass and earthworms.