Selenium Methionine Research Articles

Optimization of Selenium Inclusion Level in the Larval Diet of Labeo rohita.

The nutritional requirement of fish larvae remains a limiting factor in advanced aquaculture. Micronutrients are crucial for early development, but their dietary inclusion level in the larval feed of carps has not been standardized. The present study was executed to determine the optimum dietary inclusion level of organic and inorganic selenium in the larval feed of Rohu, Labeo rohita. A 35-day feeding trial in triplicate under semi-control conditions was conducted in 21 troughs divided into seven groups. Each trough (capacity 4.0 L) contained 200 larvae (average body weight 0.4mg). The first group (control) was reared on nano-particulate basal diet (CP 50%), while three groups Se-Na(0.5), Se-Na(1), and Se-Na(1.5) were fed basal diet supplemented with graded levels (0.5-1.5mg/kg diet) of inorganic form of Se, sodium selenite (Se-Na). The last three groups (Se-Met(0.5), Se-Met(1), and Se-Met(1.5)) were fed organic form of dietary Se, selenium methionine (Se-Met) at the same inclusion level as Se-Na. Results indicated the curvilinear relationship of dietary Se levels with body weight, activity of digestive enzymes (protease, amylase, lipases, and trypsin), and antioxidant enzymes (SOD, CAT, POD, and GSH-Px) activity, intestinal villi, width, and absorptive area. A positive correlation was observed with up to 0.5 and 1mg/kg diet of Se-Na and Se-Met, respectively; however, above these levels, a negative impact was observed. The upregulation of growth hormone mediator (IGF-1) and downregulation of heat shock protein (HSP-70) also followed a similar trend in response to Se-Na and Se-Met inclusion. Based on the results, 1mg/kg diet Se-Met could be considered the optimum level and is recommended for the early rearing of rohu larvae.

Evaluation of Selenomethionine Entrapped in Nanoparticles for Oral Supplementation Using In Vitro, Ex Vivo and In Vivo Models

Selenium methionine (SeMet) is an essential micronutrient required for normal body function and is associated with additional health benefits. However, oral administration of SeMet can be challenging due to its purported narrow therapeutic index, low oral bioavailability, and high susceptibility to oxidation. To address these issues, SeMet was entrapped in zein-coated nanoparticles made from chitosan using an ionic gelation formulation. The high stability of both the SeMet and selenomethionine nanoparticles (SeMet-NPs) was established using cultured human intestinal and liver epithelial cells, rat liver homogenates, and rat intestinal homogenates and lumen washes. Minimal cytotoxicity to Caco-2 and HepG2 cells was observed for SeMet and SeMet-NPs. Antioxidant properties of SeMet were revealed using a Reactive Oxygen Species (ROS) assay, based on the observation of a concentration-dependent reduction in the build-up of peroxides, hydroxides and hydroxyl radicals in Caco-2 cells exposed to SeMet (6.25-100 μM). The basal apparent permeability coefficient (Papp) of SeMet across isolated rat jejunal mucosae mounted in Ussing chambers was low, but the Papp was increased when presented in NP. SeMet had minimal effects on the electrogenic ion secretion of rat jejunal and colonic mucosae in Ussing chambers. Intra-jejunal injections of SeMet-NPs to rats yielded increased plasma levels of SeMet after 3 h for the SeMet-NPs compared to free SeMet. Overall, there is potential to further develop SeMet-NPs for oral supplementation due to the increased intestinal permeability, versus free SeMet, and the low potential for toxicity.

Evaluation of dietary selenium methionine levels and their effects on growth performance, antioxidant status, and meat quality of intensively reared juvenile Hypophthalmichthys molitrix.

The objective of this study was to optimize the organic selenium (Se) requirements of intensively reared silver carp (Hypophthalmichthys molitrix). A total of n = 300 juveniles silver carp 11.40±0.52 cm long, and average weighing 25.28±0.18 grams were randomly assigned to 15 aquaria (20 fish/100L aquaria) and subjected to five different dietary Se levels in a completely randomized design. The diets were pelleted supplemented with exogenous Se methionine @ 0.0, 0.3, 0.6, 0.9 and 1.2 mg/kg of the diet. The fourteen days of aquaria acclimatization was given to fish and then an 84-day feeding trial was conducted. The group supplemented with 0.9 mg/kg Se had greater feed intake, gain in length, body weight %, and specific growth rate with a better feed conversion ratio as compared to those fed on the rest of the dietary levels or control (P<0.05). The deposition of Se was greater in the liver, and kidneys of the fishes fed on diets containing 0.9 and 1.2 mg Se levels than in the rest of the treatments (P<0.05). However, dietary Se levels had no effects on the bioaccumulation of Se in muscle tissues (P>0.05). The proximate analysis showed that dry matter, crude protein, and fat contents of meat were not changed (P>0.05) by dietary treatments. Similarly, values of TBARS, RBCs, Hb, and blood glucose contents were similar (P>0.05) across the treatments. However, the concentration of WBCs, HCT, and MCHC was greater in those groups fed on 0.9 and 1.2 Se levels than in those fed on 0.6, 0.3, and 0.0 Se levels respectively (P<0.05). The activities of ALT, AST, and ALP were lowered in the 0.9 mg Se supplemented fishes compared with the rest of the treatments (P<0.05). The SOD, catalases, and GPx levels for muscle, liver, and whole body were greater (P<0.05) in the Se-supplemented groups than in the control. These outcomes indicated that up to 0.9 mg/kg inclusion of methionine-based Se in the diet of juvenile silver carp improved the growth performance, feed conversion ratio, organs Se enrichment, and antioxidant status without any compromise on meat quality.

Effects of sodium selenite, selenium methionine, and selenium yeast on growth performance, carcass composition, blood biochemistry, and antioxidant status of intensively reared Hypophthalmichthys molitrix

The current study aimed to assess the effects of various selenium(Se) sources on the growth performance, blood biochemistry, and antioxidant status of intensively reared silver carp. For this, (N = 420) fingerlings with an average body weight of 13 ± 1.5 g were randomized into 21 aquariums (20 fish/100 L aquaria) and was subjected to one of the seven dietary treatments under completely randomized design. The dietary treatments were control(C), with 0.5 mg/kg sodium selenite(N-0.5), 1 mg/kg sodium selenite(N-1), 0.5 mg/kg Se methionine(M-0.5), 1 mg/kg Se methionine(M-1), 0.5 mg/kg Se yeast(Y-0.5), and 1 mg/kg Se yeast(Y-1). The experiment was of two-weeks of fish acclimatization to ponds followed by 12-weeks of feeding trial. The source of Se influenced the growth performance and the group M-0.5supplemented diet achieved the highest(P < 0.05) final body weight (BW), final length, BW gain, and specific growth rate than others. The selenium concentration of liver, kidney, and muscle was significantly higher(P < 0.05) in methionine fed groups compared to others. However, concentrations of Se in liver, kidney and muscle were similar (P > 0.05) in fish supplemented with M-0.5 and M-1. The dry matter, fat, ash and protein contents of the fish meat were similar (P > 0.05) in all. The WBCs, HGB, HCT, and MCHC were higher (P < 0.05) in the M-0.5 supplemented group than the rest of the treatment groups. Similarly, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were also higher (P < 0.05) in the M-0.5 supplemented group compared with others. However, TBARS for liver and serum were not influenced (P > 0.05) by Se supplementation. Similarly, levels of superoxide dismutase, catalase, and peroxidase enzymes in the fish whole body, muscle, and liver were also remained unchanged (P > 0.05). From the findings, we can conclude that Se methionine is the best source, and 0.5 mg/kg dietary supplementation improved the growth performance, organs enrichment, and antioxidant status of silver carp.

The Selenium Yeast vs Selenium Methionine on Cell Viability, Selenoprotein Profile and Redox Status via JNK/ P38 Pathway in Porcine Mammary Epithelial Cells.

Comprehensive studies have been conducted to compare the effect of organic and inorganic selenium previously, but there is still limited knowledge about the difference between organic selenium (Se) from varied sources despite the widely use of organic Se in both animal and human being nutrient additives. In the present study, we systemically compared the effect of two different types of organic Se including selenium yeast (SeY) and selenium methionine (Sel-Met) on cell viability, selenoprotein transcriptome, and antioxidant status in porcine mammary epithelial cells (PMECs) and the results indicated that appropriate addition of SeY and Sel-Met both significantly promoted cell viability and up-regulated the mRNA expression of most selenopreoteins including DIOs, GPXs, and TrxRs family et al. (P < 0.05). Besides, two different sources of Se supplementation both greatly improved redox status with higher levels of T-AOC, SOD, and CAT (P < 0.05), while less content of MDA (P < 0.05), and reduced protein expression of cleaved-caspase-3 (P < 0.05) to mitigate cell apoptosis. Furthermore, the key proteins related to p38/JNK pathway including p38, p-p38, JNK, and p-JNK were apparently reduced in the groups with both of SeY and Sel-Met (P < 0.05). Interestingly we found that the changes induced by SeY supplementation in cell viability, selenoprotein transcriptome, antioxidative capacity, and anti-apoptosis were comprehensively greater compared with same levels addition of Sel-Met in PEMCs (P < 0.05). In conclusion, both SeY and Sel-Met promoted cell viability and attenuated cell apoptosis by regulating the selenoprotein expression and antioxidative capacity via p38/JNK signaling pathway in PMEC, but SeY has more efficient benefits than that of Sel-Met.

Persistence of the Effects of Se-Fertilization in Olive Trees over Time, Monitored with the Cytosolic Ca2+ and with the Germination of Pollen.

Selenium (Se) is an important micronutrient for living organisms, since it is involved in several physiological and metabolic processes. Biofortification with Se increases the nutritional and qualitative values of foods in Se-deficient regions and increases tolerance to oxidative stress in olive trees. Many studies have shown that Se, in addition to improving the qualitative and nutritional properties of EVO oil, also improves the plant’s response to abiotic stress. This study addressed this issue by monitoring the effects of Se on cytosolic Ca2+ and on the germination of olive pollen grains in oxidative stress. The olive trees subjected to treatment with Na-selenate in the field produced pollen with a Se content 6–8 times higher than the controls, even after 20 months from the treatment. Moreover, part of the micronutrient was organic in selenium methionine. The higher selenium content did not produce toxic effects in the pollen, rather it antagonized the undesirable effects of oxidative stress in the parameters under study. The persistence of the beneficial effects of selenium observed over time in pollens, in addition to bringing out an undisputed adaptability of olive trees to the micronutrient, suggested the opportunity to reduce the number of treatments in the field.

Analysis of the Effectiveness of Various Types of Conservative Therapy for Chronic Bacterial Prostatitis

Analysis of the Effectiveness of Various Types of Conservative Therapy for Chronic Bacterial Prostatitis

Selenium-Enriched Pollen Grains of Olea europaea L.: Ca2+ Signaling and Germination Under Oxidative Stress.

Selenium (Se) shows antioxidant properties that can be exploited in plants to combat abiotic stresses caused by reactive oxygen species produced in excess (ROS). Here, we show that the Se-fertilization of olive trees with sodium selenate effectively protects the pollen from oxidative stress. Pollen isolated from plants treated with Se or from untreated controls was incubated in vitro with H2O2 to produce an oxidative challenge. Given the impact of ROS on Ca2+ homeostasis and Ca2+-dependent signaling, cytosolic Ca2+ was measured to monitor cellular perturbations. We found that H2O2 interrupted Ca2+ homeostasis only in untreated pollen, while in samples treated in vitro with sodium selenate or selenium methionine, Ca2+ homeostasis was preserved. Furthermore, germination rates were considerably better maintained in Se-fertilized pollen compared to non-fertilized pollen (30% vs. 15%, respectively) after exposure to 1 mM H2O2. The same was observed with pollen treated in vitro with Se-methionine, which is the organic form of Se, in which part of the fertigated sodium selenate is converted in the plant. Combined, our results show a close correlation between ROS, Ca2+ homeostasis, and pollen fertility and provide clear evidence that Se-fertilization is a potential approach to preserve or improve agricultural productivity.

The effect of feeding inorganic and organic selenium sources on the hematological blood parameters, reproduction and health of dairy cows in the transition period

The purpose of this study was to investigate the effects of four types of diets containing different forms of selenium on the hematological blood parameters, reproduction and health of dairy cattle during the transition period. Twenty-four close-up dry cows with a mean of 259 ± 1days of pregnancy and expected 21 ± 1days prior to parturition were selected. The cows were fed four diets: 1) basal diet without selenium supplementation (C); 2) basal diet plus 0.5ppm selenium in the form of sodium selenite (Se-S) 3) basal diet plus 0.5ppm selenium in the form of selenium yeast (Se-Y); 4) basal diet plus 0.5ppm selenium in the form of selenomethionine (Se-M). Blood samples for measuring hematological blood parameters (including lymphocyte, red blood cells, hemoglobin, and hematocrit, MCV, MCH, MCHC and RDWc) were taken at 21 and 10 days before delivery, delivery date, 10 and 21 days after delivery. There was no significant difference in hematological parameters before and after delivery in experimental and control groups. However, in the prepartum period, MCH tended to increase significantly in selenium methionine treatment (p&lt;0.05). Reproductive parameters (including distance to first estrus, insemination indexes and number of open days) and health parameters (including rectum temperature and vaginal content score) have been improved by selenium organic supplements. The results of this experiment showed that feeding organic selenium supplementation in multiparous dairy cow’s diet may improve their health and reproduction.

Supplementation with Selenium As Prevention for the Development of Mucositis in Patients Undergoing HSCT. Results of a Pilot Study

Introduction:Numerous clinical trials have been conducted in order to reduce or prevent the appearance of mucositis in patients undergoing cancer treatment and some of these have appeared in the clinical guidelines as recommendations (Keefe,DM Cancer 2007). However, to date no molecule has been shown to prevent appearance of this kind of lesions. Selenium, a trace element in the organism, cofactor of multiple biological processes, has been used previously for mucositis chemoprevention in head and neck tumors. We conducted a study to know if selenium supplementation has an impact on the development of mucositis.Objective:We aim to know the impact of Selenium in patients undergoing hematopoietic stem cell transplantation, in the presentation and duration of mucositis comparing against placebo.Methods: We performed a double blind clinical trial in a single center pilot study approved by our ethics committee. All patients candidates for autologous or allogeneic HSCT above 18 years were submitted for our study previous informed consent by our institution. Patients were randomized into one of two arms: a) selenium methionine, b) placebo.Previously randomized, patients were administered supplementation with oral selenium methionine at a dose of 400mcg/day or placebo starting 7 days prior transplantion. We determined a baseline measurement of serum and urinary selenium. Subsequent measurements were made each week for a total of 28 days. Evaluations were made with validated SMAQ questionnaires which also included scales of mucositis severity, using the WHO mucositis scale. All of them performed by an observer blinded to what supplementation were being administered to each patient.Results: We have recruited a total of 31 patients, of whom 16 were allogeneic and 15 autologous. We observed that 38.7% developed some degree of mucositis, most of them on the allogeneic arm (10 patients). Selenium consumption arm was associated with a median decrease of 32% (1.9 vs 2.8) in the WHO scale in the severity of mucositis compared to the placebo arm (p=0.046), however we didn't find difference in mucositis resolution time between groups (p=0.162). On the other hand, selenium supplementation was associated with shorter platelet engraftment time (p=0.041), without any significant difference in neutrophil engraftment time. With a follow up of 112 days, there are no difference about mortality or other analized variables.Conclusions: Supplementation with selenium was associated with a slight decrease in the severity of mucositis in comparison with placebo. Without any relevant findings in relation to mortality or other variables analized. DisclosuresGomez-Almaguer:Novartis: Consultancy; AbbVie: Consultancy. Herrera-Rojas:Janssen: Employment.

Selenium species determination in foods harvested in Seleniferous soils by HPLC-ICP-MS after enzymatic hydrolysis assisted by pressurization and microwave energy

Fast, green, automated, highly efficient and accurate methodology for extracting selenium species in foods samples (Brazil nut, golden berries and heart of palm) harvested in seleniferous soils by using pressurized-assisted enzymatic hydrolysis (PAEH) and microwave-assisted enzymatic hydrolysis (MAEH) were optimized. After foods defatting or drying, selenium species were released using protease XIV and enzyme activator in 7 and 12 min for PAEH and MAEHmethods, respectively. Inductively coupled plasma – mass spectrometry (ICP–MS) and high performance liquid chromatography (HPLC) coupled with ICP-MS detection were used to assess total selenium and selenium species contents in the enzymatic extracts. Analytical performances, such as limits of quantification (0.032–0.599 μg g−1 and 0.014–0.240 μg g−1 for PAEH and MAEH, respectively), repeatability (11–14.5%) and accuracy of the over-all procedures were established. Selenomethionine (SeMet) were detected in all analyzed samples and selenocystine (SeCys2) in Brazil nut; however, SeMet and SeCys2 levels were only quantified in Brazil nut. Inorganic selenium species were not detected in any sample. The presence of SeMet and SeCys2 and the absence of oxidized selenium methionine (SeOMet) in the enzymatic extracts were confirmed by Orbitrap mass spectrometry.

Preparation, characteristics and antioxidant activity of polysaccharides and proteins-capped selenium nanoparticles synthesized by Lactobacillus casei ATCC 393

Selenium (Se) is an essential element nutrient for human and animal health. Biogenic selenium nanoparticles (SeNPs) by microorganism possesses unique physical and chemical properties and biological activities compared to inorganic selenium and organic selenium. The study was conducted to establish a green, efficient and low-cost biotechnology for biogenic synthesis of SeNPs by Lactobacillus casei ATCC 393 (L. casei 393), and investigate its characteristics and antioxidant activities in vitro. The results showed that L. casei 393 transforms sodium selenite to SeNPs under anaerobic conditions. Moreover, 50–80 nm SeNPs were accumulated in the intracellular L. casei 393. The whole bacteria present distinct bright red color. SeNPs were isolated and characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), X-ray photoelectron spectroscopy (XPS), and fourier transform infrared spectroscopy (FT-IR). The results showed that the extracted SeNPs were capped by proteins and polysaccharides. Extracted biogenic SeNPs by L. casei 393 at a concentration less than 25 μg Se/mL had no cytotoxicity on the growth and proliferation of human normal epithelial cell (NCM460). The toxicity order of different selenium forms was: Sodium selenite > Selenium methionine > SeNPs synthesized by L. casei 393. Moreover, biogenic SeNPs by L. casei 393 induced HepG2 cells apoptosis via caspase cascade signaling and endocytosis of SeNPs. Moreover, SeNPs alleviated diquat or hydrogen peroxide (H2O2)-caused oxidative damage in intestinal epithelial cells, and reduced malondialdehyde (MDA) concentration and increased glutathione peroxidase (GPx) activity in culture medium. The findings suggest that biomolecules capped-SeNPs synthesized by probiotic L. casei 393 possess significant antioxidant and anticancer activities, and probiotic bacteria can provide a better alternative to synthesize biogenic elemental selenium particles with potential applications as anticancer and antioxidant agents.

PHYSIOLOGICAL RESPONSES OF BROILER CHICKENS AS INFLUENCED BY EARLY AGE HEAT CONDITIONING AND DIETARY ANTIOXIDANT SUPPLEMENTATION

Two hundred and forty 1-d old commercial broiler chicks (Cobb) were allotted to two groups of 120 chicks. The first group was the control(Non heat conditioning). The second one was exposed to 40±1°C for 24h at 5 DOA, (early age heat conditioning). Each group was further subdivided into 4 sub-groups of 30 birds each, the first sub-group was control group, the second was fed basal diet supplemented with 200 IU/kg diet vitamin E and 0.8 mg/kg diet chromium methionine, the third was fed basal diet supplemented with 200 IU/kg diet vitamin E and 0.3 mg/kg diet selenium methionine and the fourth was fed basal diet supplemented with 200 IU/kg diet vitamin E, 0.8 mg/kg diet chromium methionine and 0.3 mg/kg diet selenium methionine, to investigate the effects of early age of heat conditioning and some antioxidants supplementation on somephysiological changes. Results showed that Chicks exposed to early age heat conditioning recorded significantly higher (P< 0.05) BW, BWG, FI and FCR compared with non heat conditioning chicks at 21and 42 DOA. There were significant (P<0.05) effects of dietary supplements on BW, BWG, FI and FCR at 21 and 42 DOA, and also by the interaction between early age heat conditioning and dietary supplements. Early age heat conditioning had significant (P< 0.05) effect on Hb, HT, RBC´S, MCHC and MCV levels at 21 DOA, but MCH values was insignificantly influenced. Significant (P< 0.05) effects of early age heat conditioning significant (P< 0.05) effects on Hb, HT, and RBC´S levels of broiler chicks at 42 DOA, however, MCH, MCHC and MCV levels were not affected. Dietary supplements (regardless early age heat conditioning) significantly increased Hb, HT, RBC´S, MCH, MCHC and MCV levels at 21 DOA and at 42 DOA except MCH, MCHC and MCV which were not significant. The interaction between early age heat conditioning and dietary supplements was significant for most of the hematological parameters studied either at 21 or 42 DOA. Early age heat conditioning had a significant (P< 0.05) effect on H/L ratio, but the effect of dietary supplements alone was not significant at 21 and 42 DOA. Based on the results of the present study it is concluded that early age heat conditioning of broiler chicks and dietary supplements by Vit.E; organic chromium or organic selenium in combination could be recommended for alleviating the negative effects of heat stress during the summer season, on broiler chicks performance.

Final report for CCQM-K107: total elements and selenomethionine in human serum

Routine tests that measure the concentration of electrolytes in serum are needed for diagnosis and management of renal, endocrine, acid-base, water balance and other conditions such as screening D- and A-vitamin disorders, kidney insufficiency, bone diseases and leukaemia. The diagnostic concentration ranges for many such markers are narrow, requiring reference methods with small uncertainty. Serum concentration of total selenium (Se) is important in health studies but there is increasing interest in the speciation of selenium compounds in clinical samples such as serum and individual Se- Species are bio-indicators of Se status.The last CCQM IAWG key comparison for elements in the clinical area (CCQM-K14: Ca in human serum) was organized in 2003 and the previous key comparison (CCQM-K60) for Se and Se species used a wheat flour sample. Therefore, the CCQM IAWG agreed that CCQM-K107 and a parallel pilot study CCQM-P146 should be carried out. The candidate human serum sample used for both CCQM-K107 and P146 is of high complexity and contains approximately 1000-fold lower concentrations of selenium methionine (SeMet) than those encountered in the CCQM-K60 wheat flour. This significantly broadens the scope and degree of difficulty of earlier measurements in this field.A total of eleven institutes participated in CCQM-K107 (11 participants for total elements and 7 for SeMet). The performance of the majority of the K107 participants for all the measurands was very good, illustrating their ability to obtain accurate results for analytes such as electrolytes at mg kg-1 level, essential elements at µg kg-1 level and selenium species at µg kg-1 level in a complex biological fluid. The range of agreement between participants was within the interval of ± 0.1% for Ca and up to ± 1.8% for Fe.CMC claims based on total elements in this study may include other elements with similar core competencies (e.g. Se, Cu, Zn) in a wide range of biological materials (including liquids and solids) at a similar level of performance using the same measurement technique applied in CCQM-K107 provided that there are no additional factors (e.g. blank or dissolution issues). CMC claims based on SeMet measurements in this study may be applied to other biological matrices (e.g., tissues) provided that the concentration range is similar and due diligence is taken to ensure an appropriate extraction process is achieved and species specific spikes are available for quantitation by isotope dilution. Indeed, having accepted such conditions, application to quantitation of other organometallic species and other elements in similar matrices should be possible with the same level of performance.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Selenium supplementation shows protective effects against patulin-induced brain damage in mice via increases in GSH-related enzyme activity and expression

AimsThis study was designed to investigate the protective effects of selenium supplementation on patulin-induced neurotoxicity. Main methodsMice were subjected to patulin for 8weeks. Sodium selenite (Na2SeO3) and selenium–methionine (Se–Met) were supplemented with the diet, and we investigated the effects of selenium on patulin-induced neurotoxicity. The animals were randomly divided into 4 groups containing 6–8 mice each. The first group was used as a control, and only physiological saline (0.9%) was injected. The second group was treated with patulin (1mg/kg) intraperitoneally. The third group was treated with patulin (1mg/kg) along with a dietary supplementation of Na2SeO3 (0.2mg Se/kg of diet). The fourth group was treated with patulin (1mg/kg) plus Se–Met (0.2mg Se/kg of diet). Key findingsPatulin treatment increased oxidative damage in the brain, as evidenced by a decrease in non-protein thiol and total thiol groups, along with significant increases in GSSG, reactive oxygen species, thiobarbituric acid reactive substances and protein carbonyl levels. Moreover, the activities of glutathione peroxidase (GPx) and glutathione reductase were inhibited with patulin treatment. Selenium supplementation significantly ameliorated these biological parameter changes. In addition, selenium treatments significantly increased the mRNA levels of GPx-1, GPx-4 and thioredoxin reductase. SignificanceOur data show that selenium supplementation increases the activity and expression of glutathione-related enzymes and offers significant protection against brain damage induced by patulin.

Molecular mechanisms involved in the protective effect of selenocystine against methylmercury-induced cell death in human HepG2 cells

Methylmercury (MeHg) has been recognized as a very toxic contaminant present in certain foodstuffs that adversely affects health and impairs the normal function of different organs. Experimental studies have shown that selenocompounds play an important role as cellular detoxificant and protective agents against the harmful effects of mercury. The present study examined the potential preventive activities of organic selenocompounds, focused on selenocystine (SeCys), against MeHg-induced toxicity in human HepG2 cells. Combined treatment of SeCys and MeHg protected HepG2 cells against MeHg-induced cell damage, showing this selenocompound a more relevant effect than those of selenium methylselenocysteine and selenium methionine. Co-treatment with SeCys exerted a protective effect against MeHg by restraining ROS generation and glutathione decrease, and through the modulation of antioxidant enzymes activities. In addition, SeCys delayed MeHg-induced apoptosis and prevented extracellular regulated kinases (ERKs) deactivation, as well as p38 and c-Jun N-terminal kinase (JNK) stimulations in comparison to MeHg-treated cells. ERK, JNK and p38 involvement on the protective effect of SeCys against MeHg-induced cell damage was confirmed by using selective inhibitors. All these results indicate that SeCys protects against MeHg-induced cell damage by modulating the redox status and key proteins related to cell stress and survival/proliferation pathways.

In vitro bioavailability of total selenium and selenium species from seafood

In vitro bioavailability of total selenium and selenium species from different raw seafood has been assessed by using a simulated gastric and intestinal digestion/dialysis method. Inductively coupled plasma-mass spectrometry (ICP-MS) was used to assess total selenium contents after a microwave assisted acid digestion, and also to quantify total selenium in the dialyzable and non-dialyzable fractions. Selenium speciation in the dialyzates was assessed by high performance liquid chromatography (HPLC) coupled with ICP-MS detection. Major Se species (selenium methionine and oxidized selenium methionine) from dialyzate were identified and characterized by HPLC coupled to mass spectrometry (HPLC–MS). Selenocystine was detected at low concentrations while Se-(Methyl)selenocysteine and inorganic selenium species (selenite and selenate) were not detected in the dialyzate. Low bioavailability percentages for total selenium (6.69±3.39 and 5.45±2.44% for fish and mollusk samples, respectively) were obtained. Similar bioavailability percentages was achieved for total selenium as a sum of selenium species (selenocystine plus oxidized selenium methionine and selenium methionine, mainly). HPLC–MS data confirmed SeMet oxidation during the in vitro procedure.

Age related changes in the activity of selenoenzymes in mice—Interaction with chalcogen metalloids selenium and tellurium

This study was designed to investigate the protective effects of selenium supplementation on patulin-induced neurotoxicity.Mice were subjected to patulin for 8 weeks. Sodium selenite (Na2SeO3) and selenium–methionine (Se–Met) were supplemented with the diet, and we investigated the effects of selenium on patulin-induced neurotoxicity. The animals were randomly divided into 4 groups containing 6–8 mice each. The first group was used as a control, and only physiological saline (0.9%) was injected. The second group was treated with patulin (1 mg/kg) intraperitoneally. The third group was treated with patulin (1 mg/kg) along with a dietary supplementation of Na2SeO3 (0.2 mg Se/kg of diet). The fourth group was treated with patulin (1 mg/kg) plus Se–Met (0.2 mg Se/kg of diet).Patulin treatment increased oxidative damage in the brain, as evidenced by a decrease in non-protein thiol and total thiol groups, along with significant increases in GSSG, reactive oxygen species, thiobarbituric acid reactive substances and protein carbonyl levels. Moreover, the activities of glutathione peroxidase (GPx) and glutathione reductase were inhibited with patulin treatment. Selenium supplementation significantly ameliorated these biological parameter changes. In addition, selenium treatments significantly increased the mRNA levels of GPx-1, GPx-4 and thioredoxin reductase.Our data show that selenium supplementation increases the activity and expression of glutathione-related enzymes and offers significant protection against brain damage induced by patulin.

Effect of selenium methionine on rumen fermentation and purine derivatives in Simmental steer

选用4头平均体重420 kg、年龄2.5岁装有永久性瘤胃瘘管的西门塔尔牛阉牛，采用4×4拉丁方设计，以混合精料和风干玉米秸秆为基础日粮，以蛋氨酸硒为硒源，在基础日粮中分别添加硒0 mg·kg^-1、0.3 mg·kg^-1、0.6 mg·kg^-1和0.9 mg·kg^-1，研究蛋氨酸硒对西门塔尔牛瘤胃pH、氨态氮、VFA、营养物质降解率及尿嘌呤衍生物浓度的影响。结果表明：不同浓度硒处理间西门塔尔牛瘤胃pH、挥发性脂肪酸(VFA)和乙酸/丙酸无显著差异(<i>P</i> >0.05)，氨态氮浓度显著低于对照(<i>P</i><0.05)；0.6 mg·kg^-1硒处理组西门塔尔牛玉米秸秆干物质(DM)、有机物质(OM)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和豆粕DM、OM、粗蛋白质(CP)有效降解率均显著高于对照(<i>P</i><0.05)；0.6 mg·kg^-1和0.9 mg·kg^-1硒处理组西门塔尔牛尿囊素和尿嘌呤衍生物浓度显著高于0.3 mg·kg^-1组和对照组(<i>P</i><0.05)；西门塔尔牛日粮以蛋氨酸硒为硒源时，硒的适宜添加浓度为0.6 mg·kg^-1。

Inhibition of invasion and induction of apoptosis by selenium in human malignant brain tumour cells in vitro

Selenium is considered to be one of the most promising micronutrients for cancer prevention and therapy, based on evidence from epidemiological studies, laboratory-based research and clinical trial intervention. There are ample reports of selenium methionine and sodium selenite's ability to induce apoptosis in various cancers in vitro. There are a few reports in the literature on the effects of selenium on established glioma cell lines but none on biopsy-derived short-term brain tumour cultures. In this in vitro study the effects of a range of concentrations (2-10 microg/ml) of sodium selenite were investigated in one low-passage culture of biopsy-derived glioma cells (IPSB-18, an anaplastic astrocytoma, P 18-22) and a normal human brain cell culture (CC2565, P11). Results from 2 viability assays, 3[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and sulphorodamine B (SRB) consistently showed that the IC50 for selenium in the astrocytoma was approximately 5 microg/ml whilst the normal brain cells were unaffected by selenium in the range of concentrations studied. Time-lapse video microscopy revealed that, while at 4 microg/ml selenium, the time taken to achieve 100% cell death was 17 h, with increasing concentrations of selenium from 6 to 8 microg/ml and finally at 10 microg/ml the IPSB-18 cells rounded up and died much more quickly. The time taken to achieve 100% cell death was 7 h, 7 h and 6 h, respectively, suggesting that the effect was similar at higher concentrations. Flow cytometry indicated that cell death was by apoptosis. RT-PCR results showed downregulation of the gene expression of 6 matrix metalloproteases (MMP2, 9, 14, 15, 16, 24), their inhibitors, TIMPs and epidermal growth factor receptor, in IPSB-18 cells treated with 2, 4 and 8 microg/ml of selenium. Collectively, the data in this study suggests that selenium, not only induces tumour cell-specific apoptosis but also has anti-invasive potential.