Dietary selenium supplementation alleviates low salinity stress in the Pacific white shrimp Litopenaeus vannamei: growth, antioxidative capacity and hepatopancreas transcriptomic responses.

Se is an essential trace element associated with animal growth and antioxidant and metabolic processes. However, whether Se, especially organic Se with higher bioavailability, can alleviate the adverse effects of low salinity stress on marine economic crustacean species has not been investigated. Accordingly, juvenile Pacific white shrimp (Litopenaeus vannamei) were reared in two culture conditions (low and standard salinity) fed diets supplemented with increasing levels of l-selenomethionine (0·41, 0·84 and 1·14 mg/kg Se) for 56 d, resulting in four treatments: 0·41 mg/kg under standard seawater (salinity 31) and 0·41, 0·84 and 1·14 mg/kg Se under low salinity (salinity 3). The diet containing 0·84 mg/kg Se significantly improved the survival and weight gain of shrimp under low salinity stress and enhanced the antioxidant capacity of the hepatopancreas. The increased numbers of B and R cells may be a passive change in hepatopancreas histology in the 1·14 mg/kg Se group. Transcriptomic analysis found that l-selenomethionine was involved in the regulatory pathways of energy metabolism, retinol metabolism and steroid hormones. In conclusion, dietary supplementation with 0·84 mg/kg Se (twice the recommended level) effectively alleviated the effects of low salinity stress on L. vannamei by regulating antioxidant capacity, hormone regulation and energy metabolism.

Protective role of selenium on ammonia-mediated nephrotoxicity via PI3K/AKT/mTOR pathway: Crosstalk between autophagy and cytokine release.

Ammonia (NH3) is a hazardous substance to human and animal health. Selenium (Se) is an essential micronutrient with multiple health benefits. The present study aimed to verify whether and how Se supplementation has a protective role against NH3 mediated-nephrotoxicity in pigs. A Se-NH3 interaction model was established in pigs and the kidney samples were collected after a 30-day treatment period. The results showed that NH3 exposure inhibited the PI3K/AKT/mTOR pathway and enhanced the secretion of inflammatory cytokines to induce autophagy and inflammation. Se can regulate the PI3K/AKT/mTOR pathway and attenuate the secretion of inflammatory cytokines altered by NH3 to reduce autophagy and inflammation. In addition, Se co-treatment inhibited ROS production, elevated the activities of antioxidant systems, and increased the expression of 13 selenoproteins in pig kidneys caused by NH3 exposure. These results implied that L-selenomethionine can moderate NH3-induced nephrotoxicity in pigs. Our study gives new ideas for the specific mechanism of NH3 nephrotoxicity and provides a reference for comparative medicine and clinical medication.

Intestinal barrier dysfunction induced by ammonia exposure in pigs in vivo and in vitro: The protective role of L-selenomethionine.

Ammonia has been reported to have a variety of toxicity to aquatic animals, farm animals and humans. However, its potential toxicity on the intestines remains unknown. L-selenomethionine is one of the important organic selenium sources. However, the mitigating effect of L-selenomethionine on ammonia exposure toxicity is still lacking. Therefore, in this study, the mechanism of toxic action of ammonia on intestinal tract and the detoxification effect of L-selenomethionine were examined. We evaluated the intestinal toxicity of ammonia and the alleviating effect of L-selenomethionine in an in vivo model, and then verified it in vitro model by a variety of cutting-edge experimental techniques. Our results showed that ammonia exposure causes oxidative stress, necroptosis, Th1/Th2 imbalance and inflammation in the intestinal tissue and the intestinal cells, and L-selenomethionine had a significant mitigation effect on the changes of these indexes induced by ammonia. In conclusion, ammonia exposure caused oxidative stress and Th1/Th2 imbalance in the porcine small intestine and IPEC-J2 cells, and that excessive ROS accumulation-mediated necroptosis targeted inflammatory responses, resulting in the destruction of tight connections of intestinal cells, thereby causing intestinal barrier dysfunction. L-selenomethionine could effectively reduce the intestinal injury caused by ammonia exposure and antagonize the toxic effect of ammonia.

Recent evidence for toxic effects of NH3 exposure on lung injury: Protective effects of L-selenomethionine.

Ammonia (NH3) is a common air pollutant, which poses a serious threat to farm animals. L-selenomethionine is organic selenium (Se), which can inhibit intracellular ROS generation, block ROS-dependent autophagy, promote mitochondrial energy metabolism, and enhance the body's immunity. Lung, as an important organ of the respiratory system, is highly susceptible to the toxic effects of NH3. However, there were few studies on the mechanism of toxic effects of NH3 on lung tissues. The aim of this study was to investigate the effect of NH3 on the lungs in pigs and the alleviating effect of L-selenomethionine. Twenty-four Large White*Duroc*Min pigs were randomly assigned to 4 groups: control group, NH3 group, Se group, and NH3 +Se group. The results showed that exposure to NH3 caused damage and inflammation in lung tissues and significantly increased blood NH3 concentration. NH3 induced changes of oxidative stress indexes (GSH, GSH-Px, SOD, MDA, Keap1, Nrf2, and HO-1) and expressions of energy metabolism related genes (HK1, HK2, PFK, PK, LDHA, and HIF-1α). Ultrastructure showed that mitochondrial damage and autophagosome increased significantly, and the expression levels of autophagy related genes (Beclin1, ATG5, ATG7, ATG10, and p62) changed. However, the addition of L-selenomethionine alleviated the above changes, but there was still a significant difference compared with the control group (P < 0.05). This finding can provide a new evidence for mitigation of NH3 toxicity.

Ferroptosis and Apoptosis Are Involved in the Formation of L-Selenomethionine-Induced Ocular Defects in Zebrafish Embryos.

Selenium is an essential trace element for humans and other vertebrates, playing an important role in antioxidant defense, neurobiology and reproduction. However, the toxicity of excessive selenium has not been thoroughly evaluated, especially for the visual system of vertebrates. In this study, fertilized zebrafish embryos were treated with 0.5 µM L-selenomethionine to investigate how excessive selenium alters zebrafish eye development. Selenium-stressed zebrafish embryos showed microphthalmia and altered expression of genes required for retinal neurogenesis. Moreover, ectopic proliferation, disrupted mitochondrial morphology, elevated ROS-induced oxidative stress, apoptosis and ferroptosis were observed in selenium-stressed embryos. Two antioxidants-reduced glutathione (GSH) and N-acetylcysteine (NAC)-and the ferroptosis inhibitor ferrostatin (Fer-1) were unable to rescue selenium-induced eye defects, but the ferroptosis and apoptosis activator cisplatin (CDDP) was able to improve microphthalmia and the expression of retina-specific genes in selenium-stressed embryos. In summary, our results reveal that ferroptosis and apoptosis might play a key role in selenium-induced defects of embryonic eye development. The findings not only provide new insights into selenium-induced cellular damage and death, but also important implications for studying the association between excessive selenium and ocular diseases in the future.

Exposure to the environmental pollutant ammonia causes changes in gut microbiota and inflammatory markers in fattening pigs.

Ammonia (NH3) is a major pollutant in livestock houses and atmospheric environment. It has been demonstrated that NH3 can cause a series of damage to animals and human. However, toxicity evaluation of NH3 on farm animals was rarely reported, especially in the intestinal microflora. Therefore, in this study, twenty-four 125-day-old fattening pigs were randomly divided into 4 groups: control group, NH3 group (88.2 mg m-3 < NH3 concentration < 90.4 mg m-3), Se group (Se content: 0.5 mg kg-1), and NH3 + Se group (88.2 mg m-3 < NH3 concentration < 90.4 mg m-3, Se content: 0.5 mg kg-1), and the effects of NH3 and L-Selenomethionine on the microbiota composition in the jejunum and the levels of inflammatory markers in feces of fattening pigs were examined by 16S rDNA and ELISA, respectively. Our results showed that the content of Matrix metalloproteinase-9 (MMP-9), Myeloperoxidase (MPO), Lactoferrin (LTF) and Calprotectin in the ammonia group (A group) were significantly elevated compared to the control group, and the content of MMP-9, MPO, LTF and Calprotectin in the A + Se group were significantly reduced. A significant difference in microbiota composition in the phylum, class, family and genus levels was found in the A group and the NH3 + Se group. There was a negative correlation between Streptococcus and Calprotectin. Our results indicated that excessive NH3 inhalation could cause changes in inflammatory markers and beta diversity of intestinal microflora in fattening pigs. We found there was a positive correlation between MPO and Pseudomonas. In addition, we first proposed that L-Selenomethionine could improve the imbalance of microbial flora and the inflammatory injury caused by NH3. Changes in intestinal microflora and inflammatory markers can be used as important indicators to evaluate NH3 toxicity, and studying changes in intestinal microflora is also an important mechanism to reveal NH3 toxicity.

l-selenomethionine supplementation in children and adolescents with autoimmune thyroiditis: A randomized double-blind placebo-controlled clinical trial.

WHAT IS KNOWN AND OBJECTIVE: Although a beneficial effect of selenium (Se) administration has been proposed in adults with autoimmune thyroiditis (AT), there is a paucity of similar data in children and adolescents. The purpose of the study was to investigate whether administration of a high dose of organic Se (200 µg daily as l-selenomethionine) has an effect on antithyroid antibody titres in children and adolescents with AT. METHODS: Seventy-one (71) children and adolescents, with a mean age of 11.3 ± 0.3 years (range 4.5-17.8), diagnosed with AT (antibodies against thyroid peroxidase [anti-TPO] and/or thyroglobulin [anti-Tg] ≥60 IU/mL, euthyroidism or treated hypothyroidism and goitre in thyroid gland ultrasonography) were randomized to receive 200 µg l-selenomethionine or placebo daily for 6 months. Blood samples were drawn for measurement of serum fT4, TSH, anti-TPO and anti-Tg levels, and thyroid gland ultrasonography was performed at the entry to the study and after 6 months of treatment. RESULTS AND DISCUSSION: At the end of the study, a statistically significantly higher reduction in anti-Tg levels was observed in the Se group compared to the placebo group (Δ: -70.9 ± 22.1 vs -6.7 ± 60.6 IU/mL, P = 0.021). Although anti-TPO levels were also decreased in the Se group, this change was not statistically different from that of the control group (Δ: -116.2 ± 68.4 vs +262.8 ± 255.5 IU/mL, P = 0.219). No significant difference in thyroid gland volume was observed between the two study groups (P > 0.05). WHAT IS NEW AND CONCLUSION: In this original study, organic Se supplementation appears to reduce anti-Tg levels in children and adolescents with AT.

Electrochemical Oxidation of l-selenomethionine and Se-methylseleno-l-cysteine at a Thiol-Compound-Modified Gold Electrode: Its Application in a Flow-Through Voltammetric Sensor.

A flow-electrolytic cell that consists of a bare gold wire or of different thiol-compound-modified gold electrodes (such as 2,4-thiazolidinedione, 2-mercapto-5-thiazoline, 2-mercaptothiazoline, l-cysteine, thioglycolic acid) was designed to be used in a voltammetric detector to identify l-selenomethionine and Se-methylseleno-l-cysteine using high-performance liquid chromatography. Both l-selenomethionine and Se-methylseleno-l-cysteine are more efficiently electrochemically oxidized on a thiol/gold than on a bare gold electrode. For the DC mode, and for measurements with suitable experimental parameters, a linear concentration from 10 to 1600 ng·mL-1 was found. The limits of quantification for l-selenomethionine and Se-methylseleno-l-cysteine were below 10 ng·mL-1. The method can be applied to the quantitative determination of l-selenomethionine and Se-methylseleno-l-cysteine in commercial selenium-containing supplement products. Findings using high-performance liquid chromatography with a flow-through voltammetric detector and ultraviolet detector are comparable.

Absorption and initial metabolism of 75Se-l-selenomethionine: a kinetic model based on dynamic scintigraphic data.

Selenomethionine (SeMet) is an important organic nutritional source of Se, but the uptake and metabolism of SeMet are poorly characterised in humans. Dynamic gamma camera images of the abdominal region were acquired from eight healthy young men after the ingestion of radioactive 75Se-l-SeMet (75Se-SeMet). Scanning started simultaneously to the ingestion of 75Se-SeMet and lasted 120 min. We generated time-activity curves from two-dimensional regions of interest in the stomach, small intestine and liver. During scanning, blood samples were collected at 10-min intervals to generate plasma time-activity curves. A four-compartment model, augmented with a delay between the liver and plasma, was fitted to individual participants' data. The mean rate constant for 75Se-SeMet transport was 2·63 h-1 from the stomach to the small intestine, 13·2 h-1 from the small intestine to the liver, 0·261 h-1 from the liver to the plasma and 0·267 h-1 from the stomach to the plasma. The delay in the liver was 0·714 h. Gamma camera imaging provides data for use in compartmental modelling of 75Se-SeMet absorption and metabolism in humans. In clinical settings, the obtained rate constants and the delay in the liver may be useful variables for quantifying reduced intestinal absorption capacity or liver function.

Organic Selenium Alleviates Ammonia-Mediated Abnormal Autophagy by Regulating Inflammatory Pathways and the Keap1/Nrf2 Axis in the Hypothalamus of Finishing Pigs.

Ammonia is a significant pollutant in the livestock houses and the atmospheric environment, and excessive ammonia would harm the health of livestock and breeders. Previous studies have shown that ammonia exposure could damage the tissue structure of the nervous system, but the molecular mechanism of ammonia-induced hypothalamus damage was still unclear. The purpose of this study was to determine the role of excessive ammonia in abnormal autophagy of pig hypothalamus and whether selenomethionine would have a mitigating effect on ammonia toxicity. Twenty-four 18-week pigs were randomly divided into four groups: the control group (C group), the selenium group (Se group), the ammonia + selenium group (A + Se group), and the ammonia group (A group). In our study, the expression levels of NF-κB, IL-1ß, iNOS, TNF-α, IKK-α, p-IKK-α, Nrf2, ATG5, ATG 10, ATG 12, LC3 I/II, HSP60, HSP70, and HSP90 were increased after ammonia exposure; meanwhile, IFN-γ, IKB-α, p-IKB-α, Keap1, P62, mTOR, AKT, p-AKT, PI3K, SQSTM, and Beclin1 showed decreasing trends. The results indicated that excessive ammonia inhalation inhibited the AKT/mTOR pathway to acclerated autophagy through oxidative stress-mediated inflammation in the porcine hypothalamus. L-selenomethionine could alleviate hypothalamus injury induced by ammonia exposure.

Selenium Alleviates Ammonia-Induced Splenic Cell Apoptosis and Inflammation by Regulating the Interleukin Family/Death Receptor Axis and Nrf2 Signaling Pathway.

Ammonia (NH3) is a harmful gas in livestock houses. So far, many researchers have demonstrated that NH3 is detrimental to animal and human organs. Selenium (Se) is one of the essential trace elements in the body and has a good antioxidant effect. However, there was little conclusive evidence that Se alleviated NH3 poisoning. To investigate the toxic mechanism of NH3 on pig spleen and the antagonistic effect of L-selenomethionine, a porcine NH3-poisoning model and an L-selenomethionine intervention model were established in this study. Our results showed that NH3 exposure increased the apoptosis rate, while L-selenomethionine supplementation alleviated the process of excessive apoptosis. Immunofluorescence staining, real-time quantitative polymerase chain reaction (qRT-PCR), and western blot results confirmed that exposure to NH3 changed the expression levels of interleukin family factors, apoptosis, death receptor, and oxidative stress factors. Our study further confirmed that excessive NH3 induced inflammatory response and mediated necroptosis leading to cell apoptosis by activating the Nrf2 signaling pathway. Excessive NH3 could mediate spleen injury through oxidative stress-induced mitochondrial dynamics disorder. L-Selenomethionine could alleviate inflammation and abnormal apoptosis by inhibiting the IL-17/TNF-α/FADD axis. Our study would pave the way for comparative medicine and environmental toxicology.

Modification of the terms of authorisation of zinc-l-selenomethionine as a feed additive for all animal species (Zinpro Animal Nutrition (Europe), Inc.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a new preparation of zinc-l-selenomethionine, with selenium content of 4%, as a nutritional feed additive for all animal species. Zinc-l-selenomethionine is already authorised for use in all animal species (3b818). Current authorisation defines the additive as 'Solid preparation of zinc-l-selenomethionine with a selenium content of 1-2 g/kg'. The applicant developed a new preparation of zinc-l-selenomethionine containing a minimum of 40 g Se/kg and seeks to modify the current authorisation. The FEEDAP Panel concluded that the newly proposed preparation is considered safe for all animal species. The FEEDAP Panel recommends adding, to the currently existing authorisation, a new preparation (40-46 g Se/kg) and not the range proposed by the applicant (1-46 g Se/kg), since no characterisation data on the intermediate preparation range (from 2 to 40 g Se/kg) have been provided. The use of the new preparation (minimum 40 g Se/kg) of zinc-l-selenomethionine in animal nutrition is of no concern for consumer safety. The newly proposed preparation presents a risk by inhalation; it is not irritant to eyes or skin. No conclusion can be reached regarding dermal sensitisation. The previous conclusion by the Panel on the safety for the environment remains unchanged. The Panel concluded that the modification request has no impact on efficacy.

Evaluation of L-Selenomethionine on Ameliorating Cardiac Injury Induced by Environmental Ammonia.

L-Selenomethionine is one of the important organic selenium sources. The supplementation of L-selenomethionine in diets is significant to improve the health of pigs. Ammonia is a major pollutant in the atmosphere and piggery, posing a threat to human and animal health. Although ammonia exposure can damage the heart, the mechanism of cardiac toxicity by ammonia is still unknown. In this study, we investigated the mechanism of cardiac injury induced by ammonia exposure in pigs and the protective effect of L-selenomethionine on its cardiotoxicity. The results showed that the blood ammonia content of pig increased significantly in ammonia group, the expressions of energy metabolism-related genes (LDHA, PDK4, HK2, and CPTIB) and the oxidative stress indexes were significantly changed (P < 0.05), the AMPK/PPAR-γ/NF-κB signaling pathways were activated, the chromatin edge aggregation and nuclear pyknosis were observed in ultrastructure, the apoptotic cells were significantly increased (P < 0.05), and the mRNA and protein expressions of apoptosis-related genes (Bcl-2, Bax, Cyt-c, caspase-3, and caspase-9) were significantly affected (P < 0.05). The above changes were significantly alleviated in ammonia + L-selenomethionine group, but there were still significant differences compared with the C group (P < 0.05). Our results indicated that ammonia exposure could cause energy metabolism disorder and oxidative stress and induce apoptosis of cardiomyocytes through AMPK/PPAR-γ/NF-κB pathways, which could lead to cardiac injury and affect cardiac function. L-Selenomethionine could effectively alleviate the cardiac damage caused by ammonia and antagonize the cardiotoxicity of ammonia.

Beneficial antioxidant status of piglets from sows fed selenomethionine compared with piglets from sows fed sodium selenite.

BACKGROUND: Studies in mammals proved dietary organic selenium (Se) being superior to inorganic Se regarding effects on growth performance, antioxidative status, immune response, and Se homeostasis. However, the picture of possible effects of different Se sources and - levels can be expanded. The present field study evaluated the effects on weight gain, hematological and selected biochemical variables as well as plasma concentrations of vitamin E (vitE), total Se and selenobiomolecules in piglets throughout the suckling period. METHODS: Piglets were monitored from birth to 38 days of age (d). The mother sows' diets were enriched with l-selenomethionine (SeMet-0.26 and -0.43 mg Se/kg feed) or sodium selenite (NaSe-0.40 and -0.60 mg Se/kg feed) from 1 month prior to farrowing until the end of lactation period. Piglets received pelleted feed supplemented with Se similarly to the sows' diets from one week of age. Selenite at 0.40 mg Se/kg (NaSe-0.40) represents a common Se source and -level in pig feed and served as control diet. RESULTS: From 24d, piglets in SeMet-groups had higher mean body weight (BW) compared with piglets from sows fed NaSe-0.40. Furthermore, from five-d and above, piglets from sows fed NaSe-0.60 had significantly higher BW than offspring from sows fed NaSe-0.40. Neonatal piglets in group SeMet-0.43 had significantly lower red blood cell counts (RBC), hemoglobin (Hgb) and hematocrit (Hct) concentrations compared with piglets from sows fed with NaSe-0.40. Neonatal and 5d-old piglets in group SeMet-0.26 showed higher gamma-glutamyl transferase activity than piglets in group NaSe-0.40. From five d and above, group NaSe-0.60 excelled with increased specific hematological variables culminating at age 38d with increased Hct, mean corpuscular volume (MCV), and MC hemoglobin (MCH) as well as increased activities of aspartate transaminase and lactate dehydrogenase compared with the other groups. Generally, offspring in the SeMet groups had higher total Se-concentrations in plasma than those from sows fed selenite, and showed a dose-response effect on plasma Se-concentrations. Furthermore, SeMet-fed piglets had higher plasma levels of the selenoproteins (Sel) glutathione peroxidase 3 (GPx3) and SelP as well as selenoalbumin. Plasma vitE levels were significantly negatively correlated with RBC throughout trial period. CONCLUSIONS: Maternal supplementation with SeMet during gestation influenced hematology and clinical biochemistry in neonatal piglets in a different way than in offspring from sows receiving selenite enriched diets. Growth performance was positively influenced by both dietary Se source and Se level. Higher plasma levels of GPx3 observed in piglets receiving SeMet probably improved the protection against birth or growth related oxidative stress. These might prime the piglets for demanding situations as indicated by higher weight gain in offspring from sows fed with SeMet-supplemented diets. Our results on some enzyme activities might indicate that piglets fed NaSe-0.60 had to cope with increased levels of oxidative stress compared with those originating from sows fed SeMet or lower dietary levels of selenite. We assume that combining inorganic and organic Se sources in complete feed for breeding sows might be beneficial fro reproduction and the offspring's performance.

Selenium supplementation in the management of thyroid autoimmunity during pregnancy: results of the "SERENA study", a randomized, double-blind, placebo-controlled trial.

PURPOSE: Selenium is frequently in nutraceuticals for pregnancy, given its role on fertility and thyroid metabolism. However, most evidence rise from non-controlled studies. We aimed to evaluate the protective effect of selenium against thyroid autoimmunity during and after pregnancy. METHODS: A multicenter, randomized, double-blind, placebo-controlled trial was performed and promoted by the Young Italian Endocrinologists Group (EnGioI)-Italian Society of Endocrinology. Forty-five women with thyroiditis in pregnancy were enrolled and randomly assigned to L-selenomethionine (L-Se-Met) 83 mcg/day or placebo (PLB) and evaluated at 10 ± 2 (T1), 36 ± 2 weeks of gestation (T2) and 6 months after delivery (postpartum, PP). RESULTS: We measured a significant reduction of autoantibodies after pregnancy in L-Se-Met group [at PP: TgAb 19.86 (11.59-52.60), p < 0.01; TPOAb 255.00 (79.00-292.00), p < 0.01], and an antibodies titer's rebound in PLB group (TgAb 151.03 ± 182.9, p < 0.01; TPOAb 441.28 ± 512.18, p < 0.01). A significant increase in selenemia was measured in L-Se-Met group at T2 (91.33 ± 25.49; p < 0.01) and PP (93.55 ± 23.53; p = 0.02). Two miscarriage occurred in PLB. No differences were found in thyroid volume, echogenicity, quality of life, maternal/fetal complications. CONCLUSIONS: SERENA study demonstrated a beneficial effect of L-Se-Met supplementation on autoantibody titer during pregnancy and on postpartum thyroiditis recurrence.

Effect of sub-chronic dietary L-selenomethionine exposure on reproductive performance of Red Swamp Crayfish, (Procambarus clarkii).

The effect of selenium (Se) on the reproductive system has been investigated in both humans and vertebrates, but few studies of female fertility and reproduction in invertebrate have been reported. This study is aimed to investigate the effect of SeMet on growth performance and reproductive system after crayfish were fed with graded levels of dietary SeMet (0, 1.49, 3.29, 10.02, 30.27 or 59.8 µg Se/g dry weight) for 60 days. Crayfish treated with the high levels of SeMet (10.02, 30.27 and 59.76 µg Se/g) exhibited decreasing FW and CL in both male and female. Interestingly, Se accumulation was higher in ovary than in other tissues, suggesting that ovary may serve as a target organ for Se accumulation. We found that dietary Se concentration of 10.02 µg Se/g significantly improved the spawning rate, promoted the synchronized spawning, and up-regulated the expressions of mRNA of cdc2 and vitellogenin, with significantly increased E2 and VTG concentrations in hemolymph of female crayfish. However, a marked decrease of the E2 contents and spawning rate was observed in the groups treated with 30.27 and 59.76 µg Se/g diets. In conclusion, the results of this study indicated that the Se had maximum accumulation in ovary, affecting the reproductive capacity by intervening the expression of cdc2 and vitellogenin in the reproductive system. The LOAEL to induce FW was observed in crayfish fed with 10.02 µg Se/g diet, and its value can cause toxicity within the range of natural concentration, so the addition of Se in the feed should be within 10.02 µg Se/g.

Effects of sodium selenite and L-selenomethionine on feed intake, clinically relevant blood parameters and selenium species in plasma, colostrum and milk from high-yielding sows.

A field study in periparturient sows fed different dietary concentrations of either sodium selenite or L-selenomethionine (SeMet) was conducted to evaluate feed intake, haematological and biochemical parameters as well as to describe some key selenium (Se) species, namely selenoprotein P (SelP), selenoalbumin (SeAlb) and selenomethionine (SeMet) as well as total Se in plasma, colostrum and milk. Thirty-two sows were allotted to four treatments from 30 days (d) prepartum throughout on average a 32 d lactation period. Sodium selenite supplemented diets contained 0.40 and 0.60 mg Se/kg feed, while SeMet supplemented feed contained 0.26 and 0.43 mg Se/kg feed. Concentrations of sodium selenite and SeMet in complete feed exceeded the upper limits for total dietary Se and added organic Se, respectively, according to the European Union legislation. Blood samples were collected at initiation of the study, at farrowing and at weaning. Colostrum samples were collected at farrowing and milk samples at weaning. Se species were subjected to liquid chromatography, and total Se and Se species were determined using inductively coupled plasma mass spectrometry. The SeMet supplemented diets resulted in higher feed intake and in higher levels of total Se, SelP, SeAlb and SeMet in colostrum compared with sows fed sodium selenite. Similar results were obtained for levels of total Se and SeMet in milk at weaning. The higher dietary sodium selenite concentration in sows' feed did not increase the Se transfer into colostrum or milk when compared with those receiving the lower level of sodium selenite. However, the increase in serum-Zn from initiation until farrowing, observed in sows fed SeMet as well as the higher glutamate dehydrogenase activity in sodium selenite supplemented sows in this period might indicate a higher requirement of antioxidant defence in sodium selenite-supplemented sows. To our knowledge, the present data on Se species in plasma, colostrum and milk of sows represent the most complete investigation of Se in sows conducted to date. A higher amount of the above-mentioned Se species in the colostrum of sows supplemented with SeMet might strengthen the piglets' antioxidative system and passive immunity as well as improve their average daily weight gain. The higher feed intake in sows fed diets supplemented with SeMet is an interesting finding that warrants further investigation.

Effects of Different Forms and Levels of Selenomethionine on Productive Performance and Antioxidant Status of Broiler Breeders and Its Offspring.

This study was conducted to investigate the effects of different selenomethionine (SM) forms and levels on productive performance and antioxidant status of broiler breeders and its offspring. Four hundred eighty 48-week-old Lingnan Yellow broiler breeders were randomly divided into four groups, provided basal diet with 0.15 or 0.30 mg/kg Se coming from two SM forms of DL-SM and L-SM. The experiment included a 4-week pretreatment period and an 8-week trial period. During the trial period, eggs were incubated once a week under standard conditions. The broiler breeders were slaughtered after the trial period. At the same time, 15 1-day-old chicks were selected at random per replicate and killed. The results showed that different SM forms and levels had no significant differences in average egg weight, feed intake, and feed-to-egg ration. The DL-SM group in contrast to the L-SM group induced a notable elevation of glutathione peroxidase (GPx) activity in serum (P < 0.01) and liver (P < 0.05), and the 0.15 mg/kg group had higher GPx activity than 0.30 mg/kg in serum (P < 0.01) and pancreas (P < 0.05). Different SM forms showed no significant differences in total antioxidant capability (T-AOC). Diets with 0.15 mg/kg Se exhibited a higher level of T-AOC in serum (P < 0.01) and some tissues. Besides, malondialdehyde (MDA) concentrations in serum, liver, and kidney significantly decreased due to the supplementation of DL-SM. Supplemental 0.15 mg/kg Se reduced MDA concentrations in kidney and muscle. The offspring of broiler breeders fed on DL-SM had higher GPx activity in liver and kidney than L-SM treatment. Supplemental 0.15 mg/kg Se also improved GPx activity in kidney and muscle and T-AOC in kidney of 1-day-old chicks. In summary, our study demonstrated that compared with L-SM, DL-SM was more effective for enhancing the antioxidant status of broiler breeders and its offspring. Moreover, the recommended level of Se supplementation was 0.15 mg/kg Se in Lingnan Yellow broiler breeder diets.

Specificity of Biogenic Selenium Nanoparticles for Prostate Cancer Therapy With Reduced Risk of Toxicity: An in vitro and in vivo Study.

Selenium deficiency is associated with many physiological disorders including the high risk of cancer. The rehabilitation of selenium with different selenium supplements, however, fails due to their low therapeutic index. Therefore, it is advantageous to have a less toxic form of selenium for supplementation with potentially high anticancer activity. Here we show Bacillus licheniformis derived biogenic selenium nanoparticles at a minimal concentration of 2 µg Se/ml induce necroptosis in LNCaP-FGC cells, without affecting the RBC integrity. Real-time gene expression analysis indicated the overexpression of tumor necrotic factor (TNF) and interferon regulatory factor (IRF1) and decreased expression of androgen receptor (AR) and prostate-specific antigen (PSA). Furthermore, histopathological analysis showed the subsequent oral administrations of 10 times higher concentration of these endotoxin free selenium nanoparticles in C3H/HeJ mice (50 mg Se/kg of body weight), induce significantly lower toxicity compared to the L-selenomethionine (5 mg Se/kg). Our study suggested that the biogenic SeNP could emerge as the safest form of selenium supplementation with potent anticancer activity.

N-ϒ-(l-Glutamyl)-l-Selenomethionine Inhibits Fat Storage via the Stearoyl-CoA Desaturases FAT-6 and FAT-7 and the Selenoprotein TRXR-1 in Caenorhabditis elegans.

SCOPE: Selenium is an important nutrient for human health. The influence of dietary selenium on lipid metabolism remains largely unknown. N-γ-(l-glutamyl)-l-selenomethionine (Glu-SeMet) on inhibition of fat accumulation and its underlying mechanisms in the nematode Caenorhabditis elegans are investigated. METHODS AND RESULTS: Triacylglyceride quantification and post-fixed Nile red staining methods are conducted to evaluate fat accumulation in wild-type N2 worms in normal or high-glucose diet. Glu-SeMet (0.01 µm) treatment effectively reduces fat storage in wild-type N2 C. elegans in both a normal and high-glucose diet. Further evidence shows that Glu-SeMet (0.01 µm) decreases the ratio of oleic acid/stearic acid (C18:1Δ9/C18:0) using gas chromatography-mass spectrometry analysis. The mRNA levels of fatty acid stearoyl-CoA desaturases, FAT-6 and FAT-7, and the mediator-15 (MDT-15) are downregulated while the wild-type N2 worms are co-treated with high glucose and Glu-SeMet (0.01 µm). The effect of reduced fat accumulation is absent in fat-6, fat-7, and trxr-1 mutant worms under high glucose and Glu-SeMet (0.01 µm) co-treatment. CONCLUSIONS: This study demonstrates that Glu-SeMet inhibiting fat accumulation may be associated with FAT-6 and FAT-7 and the selenoprotein TRXR-1 in C. elegans. This study implies a potential for Glu-SeMet as a new treatment for obesity or its complications.