Selenium is an essential trace element that exists in inorganic forms (selenite and selenates) and organic forms (selenoamino acids, seleno peptides, and selenoproteins). Selenium is known to aid in the function of the immune system for populations where human immunodeficiency virus (HIV) is endemic, as studies suggest that a lack of selenium is associated with a higher risk of mortality among those with HIV. In a recent study conducted in Zambia, adults had a median plasma selenium concentration of 0.27 μmol/L (IQR 0.14-0.43). Concentrations consistent with deficiency (<0.63 μmol/L) were found in 83% of adults. With these results, it can be clearly seen that selenium levels in Southern Africa should be investigated to ensure the good health of both livestock and humans. The recommended selenium dietary requirement of most domesticated livestock is 0.3 mg Se/kg, and in humans above 19 years, anRDA (recommended daily allowance) of 55 mcg Se/per dayisis recommended, but most of the research findings of Southern African countries have recorded low levels. With research findings showing alarming low levels of selenium in soils, humans, and raw feed materials in Southern Africa, further research will be vital in answering questions on how best to improve the selenium status of Southern African soils and plants for livestock and humans to attain sufficient quantities.

• Klíčová slova
• Southern Africa, biofortification, feed, food, humans, livestock, nutrition, selenium,
• MeSH
• dobytek MeSH
• dospělí MeSH
• HIV infekce * MeSH
• lidé MeSH
• půda MeSH
• selen * MeSH
• zvířata MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Geografické názvy
• jižní Afrika MeSH
• Zambie MeSH
• Názvy látek
• půda MeSH
• selen * MeSH

Selenium (Se) is an essential micronutrient but toxic when taken in excessive amounts. Therefore, understanding the metabolic processes related to selenium uptake and bacteria-plant interactions coupled with selenium metabolism are of high importance. We cultivated Brassica oleracea with the previously isolated heterotrophic aerobic Se(IV)-reducing Pseudomonas sp. T5-6-I strain to better understand the phenomena of bacteria-mediated Se(IV) reduction on selenium availability to the plants. B. oleracea grown on Murashige and Skoog medium (MS-salt agar) with and without of Pseudomonas sp. were amended with Se(IV)/75Se(IV), and selenium transfer into plants was studied using autoradiography and gamma spectroscopy. XANES was in addition used to study the speciation of selenium in the B. oleracea plants. In addition, the effects of Se(IV) on the protein expression in B. oleracea was studied using HPLC-SEC. TEM and confocal microscopy were used to follow the bacterial/Se-aggregate accumulation in plants and the effects of bacterial inoculation on root-hair growth. In the tests using 75Se(IV) on average 130% more selenium was translocated to the B. oleracea plants grown with Pseudomonas sp. compared to the plants grown with selenium, but without Pseudomonas sp.. In addition, these bacteria notably increased root hair density. Changes in the protein expression of B. oleracea were observed on the ∼30-58 kDa regions in the Se(IV) treated samples, probably connected e.g. to the oxidative stress induced by Se(IV) or expression of proteins connected to the Se(IV) metabolism. Based on the XANES measurements, selenium appears to accumulate in B. oleracea mainly in organic C-Se-H and C-Se-C bonds with and without bacteria inoculation. We conclude that the Pseudomonas sp. T5-6-I strain seems to contribute positively to the selenium accumulation in plants, establishing the high potential of Se0-producing bacteria in the use of phytoremediation and biofortification of selenium.

• Klíčová slova
• Bacteria, Bacteria-plant interactions, Plant uptake, Pseudomonas, Selenium,
• MeSH
• biodegradace MeSH
• Brassica metabolismus   mikrobiologie   MeSH
• Pseudomonas metabolismus   MeSH
• selen metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• selen MeSH

Selenium and iodine are essential trace elements for both humans and animals. Among other things, they have an essential role in thyroid function and the production of important hormones by the thyroid gland. Unfortunately, in many areas, soils are deficient in selenium and iodine, and their amount is insufficient to produce crops with adequate contents to cover the recommended daily intake; thus, deficiencies have an endemic character. With the introduction of iodized table salt in the food industry, the thyroid status of the population has improved, but several areas remain iodine deficient. Furthermore, due to the strong relationship between iodine and selenium in metabolic processes, selenium deficiency often compromises the desired positive impact of salt iodization efforts. Therefore, a considerable number of studies have looked for alternative methods for the simultaneous supplementation of selenium and iodine in foodstuff. In most cases, the subject of these studies is crops; recently, meat has also been a subject of interest. This paper reviews the most recent strategies in agriculture to fortify selenium and iodine in crop plants, their effect on the quality of the plant species used, and the potential impact of food processing on their stability in fortified crops.

• Klíčová slova
• biofortification, crops, deficiency, iodine, nutrition, selenium,
• MeSH
• biofortifikace MeSH
• jod * MeSH
• jodidy MeSH
• lidé MeSH
• selen * MeSH
• zemědělské plodiny MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• iodized salt MeSH Prohlížeč
• jod * MeSH
• jodidy MeSH
• selen * MeSH

In this study, we tested the ability of lactobacilli and bifidobacteria strains to accumulate and biotransform sodium selenite into various selenium species, including selenium nanoparticles (SeNPs). Selenium tolerance and cytotoxicity of selenized strains towards human adenocarcinoma Caco-2 and HT29 cells were determined for all tested strains. Furthermore, the influence of selenium enrichment on the antioxidant activity of selenized strains and hydrophobicity of the bacterial cell surfaces were evaluated. Both hydrophobicity and antioxidant activity increased significantly in the selenized L. paracasei strain and decreased significantly in the selenized L. helveticus strain. The concentrations of 5 and 10 mg/L Na2SeO3 in the growth media were safer for Caco-2 and HT29 cell growth than higher concentrations. At higher concentrations (30, 50, and 100 mg/L), the cell viability was reduced. All the tested strains showed differences in antioxidant potential and hydrophobicity after selenium enrichment. In addition to selenocystine ​​and selenomethionine, the tested bacterial strains produced significant amounts of SeNPs. Our results show that the tested bacterial strains can accumulate and biotransform inorganic selenium, which allows them to become a potential source of selenium.

• Klíčová slova
• Bioaccumulation, Cytotoxicity, Functional foods, Nanoparticles, Selenium,
• MeSH
• antioxidancia MeSH
• Caco-2 buňky MeSH
• Lactobacillus metabolismus   MeSH
• lidé MeSH
• potravní doplňky MeSH
• selen * metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antioxidancia MeSH
• selen * MeSH

The effect of an administered dose of 75Se-selenite and a previously increased selenium intake in drinking water (0.1 mg/l) on the distribution of injected selenium in rat blood was studied. In a dose range of 0.01-1.6 mg Se/kg body weight the ratio of injected selenium in blood plasma and in blood cells decreased from 3.20 in rats with increased selenium intake and 4.60 in rats without this intake, to 0.13 and 0.10, respectively. After injection of high selenite doses, 85-88% of the selenium present in the blood was localized in blood cells irrespective of increased selenium intake by drinking water. Possible relationship between accumulation of selenium in blood cells and its toxic effect in the organism is discussed. Previously increased intake of selenium had no effect on the levels of selenium in blood cells but affected significantly its plasma levels. The results indicate that the previously increased selenium intake in drinking water increases the capacity of the plasma for selenium injected in the form of selenite.

• MeSH
• časové faktory MeSH
• inbrední kmeny potkanů MeSH
• injekce intraperitoneální MeSH
• krysa rodu Rattus MeSH
• pití * MeSH
• radioizotopy selenu MeSH
• selen aplikace a dávkování   krev   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• radioizotopy selenu MeSH
• selen MeSH

Renal retention of selenium after administration of trimethylselenonium iodide (TMSeI) was studied in vivo in male and female rats during sexual maturation. The selenium level in the kidneys was found to be significantly higher in male rats than in females during the first hour after intravenous (i.v.) administration of TMSeI. The sex-linked difference, manifested already in 21-day old animals, increased markedly during the following four weeks of postnatal life. It was shown that this process may be accelerated by previously increased selenium intake. The sex-linked difference in renal retention of selenium was observed after administration of TMSeI in a wide range of doses: 0.002-10.0 mumol per animal. The size of the applied dose did not affect significantly the kinetic patterns of selenium in the kidneys during the first hour after i.v. injection. The results suggest the existence of a sex-dependent mechanism in the kidneys which may control the rate of excretion of trimethylselenonium ions in urine both under conditions of normal selenium intake and selenium intoxication.

• MeSH
• injekce intravenózní MeSH
• krysa rodu Rattus MeSH
• ledviny účinky léků   metabolismus   MeSH
• pohlavní dimorfismus MeSH
• potkani Wistar MeSH
• selen metabolismus   moč   MeSH
• sloučeniny selenu aplikace a dávkování   farmakologie   MeSH
• stárnutí MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• selen MeSH
• sloučeniny selenu MeSH
• trimethylselenonium MeSH Prohlížeč

This paper reviews the current understanding of the toxicity of selenium (Se) to terrestrial mammalian and aquatic organisms. Adverse biological effects occur in the case of Se deficiencies, associated with this element having essential biological functions and a narrow window between essentiality and toxicity. Several inorganic species of Se (-2, 0, +4, and +6) and organic species (monomethylated and dimethylated) have been reported in aquatic systems. The toxicity of Se in any given sample depends not only on its speciation and concentration, but also on the concomitant presence of other compounds that may have synergistic or antagonistic effects, affecting the target organism as well, usually spanning 2 or 3 orders of magnitude for inorganic Se species. In aquatic ecosystems, indirect toxic effects, linked to the trophic transfer of excess Se, are usually of much more concern than direct Se toxicity. Studies on the toxicity of selenium nanoparticles indicate the greater toxicity of chemically generated selenium nanoparticles relative to selenium oxyanions for fish and fish embryos while oxyanions of selenium have been found to be more highly toxic to rats as compared to nano-Se. Studies on polymer coated Cd/Se quantum dots suggest significant differences in toxicity of weathered vs. non-weathered QD's as well as a significant role for cadmium with respect to toxicity.

• Klíčová slova
• Biological selenium, Metals, Nanoparticles, Organisms, Quantum dots, Toxicity,
• MeSH
• ekosystém MeSH
• krysa rodu Rattus MeSH
• kvantové tečky toxicita   MeSH
• látky znečišťující životní prostředí toxicita   MeSH
• lidé MeSH
• organoselenové sloučeniny toxicita   MeSH
• skot MeSH
• sloučeniny kadmia toxicita   MeSH
• sloučeniny selenu toxicita   MeSH
• synergismus léků MeSH
• vodní organismy účinky léků   růst a vývoj   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• cadmium selenide MeSH Prohlížeč
• látky znečišťující životní prostředí MeSH
• organoselenové sloučeniny MeSH
• sloučeniny kadmia MeSH
• sloučeniny selenu MeSH

Utilization of selenium was examined in slow-growing laying-type chickens (SG) and in fast-growing broiler hybrids (FG) fed ad libitum on a diet with 265 microg of selenium/kg, including 128 microg of selenium added as sodium selenite. To 40 d of age, coefficients of selenium retention increased (P < 0.05) daily in the SG and FG groups by 0.76 and 0.61%, respectively. From 40 to 100 d, the regression coefficients were not significant. Coefficients of selenium retention and retention per unit of body gain were higher in SG chickens. The influence of age on selenium content in BW gain of birds was evident (P < 0.01). From 5 to 40 d, allometric coefficients were 1.444 and 1.070 for SG and FG, respectively, and from d 40 to 100 the corresponding values were 1.282 and 1.081, respectively.

• MeSH
• kur domácí genetika   růst a vývoj   metabolismus   MeSH
• selen metabolismus   MeSH
• stárnutí metabolismus   MeSH
• stravovací zvyklosti MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• selen MeSH

INTRODUCTION: Placental oxidative stress has been implicated in pregnancy complications and previous work has shown that selenium can protect trophoblast mitochondria from oxidative stress. This report examines mitochondrial function and content in trophoblasts supplemented with selenium. METHODS: Swan-71, JEG-3 and BeWo cells and placental tissue were incubated with sodium selenite or selenomethionine. Mitochondrial function was examined in a respirometer. Mitochondrial content was determined using RT-PCR. The levels of the mitochondrial biogenesis markers selenoprotein H, PGC-1α and NRF-1 was examined by western blotting. RESULTS: Mitochondrial respiration was significantly enhanced post selenium supplementation in cells and tissues. Selenium supplementation increased mitochondrial content and up-regulated mitochondrial biogenesis mediators in cells. DISCUSSION: These results emphasise the importance of selenium in mitochondrial regeneration in trophoblasts.

• Klíčová slova
• Antioxidant, Mitochondrial biogenesis, Reactive oxygen species, Selenium, Trophoblast,
• MeSH
• biogeneze organel * MeSH
• buněčné linie MeSH
• DNA vazebné proteiny metabolismus   MeSH
• faktor 1 související s NF-E2 metabolismus   MeSH
• lidé MeSH
• mitochondrie účinky léků   metabolismus   MeSH
• placenta účinky léků   metabolismus   MeSH
• PPARGC1A MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• selen aplikace a dávkování   MeSH
• selenoproteiny metabolismus   MeSH
• těhotenství MeSH
• transkripční faktory metabolismus   MeSH
• trofoblasty účinky léků   metabolismus   MeSH
• upregulace účinky léků   MeSH
• Check Tag
• lidé MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA vazebné proteiny MeSH
• faktor 1 související s NF-E2 MeSH
• PPARGC1A protein, human MeSH Prohlížeč
• PPARGC1A MeSH
• reaktivní formy kyslíku MeSH
• selen MeSH
• selenoprotein H, human MeSH Prohlížeč
• selenoproteiny MeSH
• transkripční faktory MeSH

Selenium is an essential trace element important for many physiological processes, especially for the functions of immune and reproductive systems, metabolism of thyroid hormones, as well as antioxidant defense. Selenium deficiency is usually manifested by an increased incidence of retention of placenta, metritis, mastitis, aborts, lowering fertility and increased susceptibility to infections. In calves, lambs and kids, the selenium deficiency demonstrates by WMD (white muscle disease), in foals and donkey foals, it is associated with incidence of WMD and yellow fat disease, and in pigs it causes VESD (vitamin E/selenium deficiency) syndrome. The prevention of these health disorders can be achieved by an adequate selenium supplementation to the diet. The review summarizes the survey of knowledge on selenium, its biological significance in the organism, the impact of its deficiency in mammalian livestock (comparison of ruminants vs. non-ruminants, herbivore vs. omnivore) and possibilities of its peroral administration. The databases employed were as follows: Web of Science, PubMed, MEDLINE and Google Scholar.

• Klíčová slova
• antioxidant, donkeys, horses, metallomics, oxidative stress, ruminants, selenium,
• MeSH
• lidé MeSH
• potravní doplňky MeSH
• savci metabolismus   MeSH
• selen nedostatek   metabolismus   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• selen MeSH