Effect of fertilization on selenium content of tea and the nutritional function of Se-enriched tea in rats

The present study examined the effect of fertilization with sodium selenite on the selenium content of tea and the nutritional function of Se-enriched tea. Selenium content of tea leaves was increased up to 0.36 g g^–1 by the application of sodium selenite to soil at 0.5 and 1.0 kg Se ha^–1. Application by a Se-enriched organic manure at a rate of 0.5 kg Se ha^–1 provided a higher biological availability of selenium for plant uptake compared with a similar amount of sodium selenite. Foliar spray of sodium selenite at 50–100 g Se ha^–1 increased the selenium content to 0.32–1.45 g g^–1 in tea leaves sampled at the 8–26 days after spraying. Selenium content in the blood and liver, glutathione peroxidase activity in blood of rats were significantly enhanced by feeding of an extracted solution of Se-enriched tea leaves and sodium selenite. Glutathione peroxidase activity in liver of rats fed with Se-enriched tea was higher than that fed with sodium selenite, indicating that the selenium in Se-enriched tea leaves is a more effective Se source than sodium selenite. Increasing the Se level in food products through the application of a selenium fertilizer is a safe, effective and feasible means of increasing the selenium intake of human and animals in low selenium areas of China.     

Selenium homeostasis and induction of thioredoxin reductase during long term selenite supplementation in the rat

Selenium is a candidate treatment for liver tumour prevention in chronic liver disease. In this study, we have studied selenium uptake, distribution and accumulation in rats provided with water containing tumour-preventive doses of sodium selenite for 10 weeks. Male Fischer 344 rats were given drinking water containing 1 μg/mL or 5 μg/mL sodium selenite. Selenium levels were monitored in serum and liver tissue over the 10-week period, and the kinetics of induction of the redox-active cytosolic selenoenzyme thioredoxin reductase were followed. Selenite exposure via drinking water caused a dose-dependent increase in blood and liver selenium levels, with plateaus at 6 and 8 weeks, respectively. These plateaus were reached at the same level of selenium regardless of dose, and no further accumulation was observed. A selenium-dependent increase in the activity of TrxR1 in parallel with the increase in liver selenium levels was also seen, and the induction of TrxR1 mRNA was seen only during the first three days of treatment, when the levels of selenium in the liver were increasing. Sodium selenite at 1 and 5 μg/mL did not affect body weight or relative liver mass. We concluded that long-term treatment with selenite did not cause accumulation of selenium and that the activity of TrxR1 in the liver rose with the selenium levels. We therefore suggest that sodium selenite at doses up to 5 μg/mL could be used for long-term tumour prevention.     

Development of sensory motor reflexes in 2 G exposed rats

During gestation and early postnatal development, the animal's size and weight rapidly increase. Within that period, gravity affects sensory and motor development. We studied age-dependent modifications of several types of motor reflexes in 5 groups of rats conceived, born and reared in hypergravity (HG; 2 g). These rats were transferred to normal gravity (NG; 1 g) at various postnatal days, and their behavioral reflexes were compared with a control group which was constantly kept under NG. HG induced a retarded development of vestibular dependent reflexes. Other types of motor behavior were not delayed.     

Cellular response of <Emphasis Type="Italic">Chlorella zofingiensis</Emphasis> to exogenous selenium

An investigation of the cellular response of the freshwater microalga Chlorella zofingiensis to exogenous selenium showed that Chlorella cells can tolerate sodium selenite up to a concentration of 100 mg l⁻¹. Cells grown in such a selenium-supplemented medium accumulated boiling-stable proteins in a concentration-dependant manner. Western blot analysis revealed that three of these boiling-stable proteins cross-reacted with anti-dehydrin antibody. Selenium was also found to exert an effect on antioxidative enzymes: superoxide dismutase (Fe-SOD and Mn-SOD isoforms) accumulated in response to selenium stress of 100 mg l⁻¹ sodium selenite, as did a new form of selenium-dependent glutathione peroxidase. Upon transfer of the cells to a selenium-free medium, the boiling-stable proteins, the superoxide dismutase isoforms and the selenium-dependent glutathione peroxidase were all down regulated. The accumulation of boiling-stable proteins and the increased activities of the antioxidant enzymes in selenium-treated Chlorella cells suggest that these compounds are probably involved in the mechanism(s) of selenium tolerance of this alga.     

High dose antioxidant supplementation to MS patients. Effects on glutathione peroxidase, clinical safety, and absorption of selenium.

High-dose antioxidant supplementation has recently been recommended for multiple sclerosis (MS) patients. This study tests the clinical safety, the glutathione peroxidase (GSH-px) activity, and the absorption of selenium during such supplementation. Eighteen MS patients were given 6 tablets especially made for this study, equivalent to 6 mg sodium selenite, 2 g vitamin C, and 480 mg vitamin E a day for five wk. GSH-px, which was lower than in non-MS controls before the start of treatment, increased fivefold during 5 wk of treatment. Side effects were scarce. Ten MS patients were subjected to a 24-h selenium absorption study after ingestion of 2 active tablets, equivalent to 2 mg sodium selenite. Selenium, which was low initially, increased 24% during the first 3 h and then stabilized. It is concluded that the tested antioxidant treatment seems to be safe and that MS patients have low GSH-px, which may be increased by the tested antioxidant treatment.     

High dose antioxidant supplementation to MS patients

High-dose antioxidant supplementation has recently been recommended for multiple sclerosis (MS) patients. This study tests the clinical safety, the glutathione peroxidase (GSH-px) activity, and the absorption of selenium during such supplementation. Eighteen MS patients were given 6 tablets especially made for this study, equivalent to 6 mg sodium selenite, 2 g vitamin C, and 480 mg vitamin E a day for five wk. GSH-px, which was lower than in non-MS controls before the start of treatment, increased fivefold during 5 wk of treatment. Side effects were scarce. Ten MS patients were subjected to a 24-h selenium absorption study after ingestion of 2 active tablets, equivalent to 2 mg sodium selenite. Selenium, which was low initially, increased 24% during the first 3 h and then stabilized. It is concluded that the tested antioxidant treatment seems to be safe and that MS patients have low GSH-px, which may be increased by the tested antioxidant treatment.     

正交试验分析不同作物的产量、含硒量与土壤酸碱度、硒酸盐、亚硒酸盐含量的相关性

采用正交试验研究了碎米荠、韭菜、大豆、马铃薯的产量、含硒量与土壤酸碱度、硒酸盐、亚硒酸盐含量的关系。结果表明:影响作物含硒量最大的因素是作物品种,不同作物间差异极显著。在土壤中施用硒酸钠和亚硒酸钠均能够提高作物含硒量,用量均以1.0 mg/kg为宜;硒酸钠会使作物产量降低,用量过高使作物硒吸收总量下降;土壤pH值增加有利于植物对硒的吸收,但综合考虑作物产量、含硒量和硒摄入总量,土壤适合的pH值应在6.7～7.9之间。     

High-dose sodium selenite can induce apoptosis of lymphoma cells in adult patients with non-Hodgkin's lymphoma

The present study was undertaken to explore the effect of administration of high doses of sodium selenite on the apoptosis of lymphoma cells in patients with non-Hodgkin’s lymphoma (NHL). Forty patients with newly diagnosed NHL were randomly divided into two groups. Group I received standard chemotherapy, whereas group II received adjuvant sodium selenite 0.2 mg kg⁻¹ day⁻¹ for 7 days in addition to chemotherapy. Flow cytometry was used for monitoring of lymphoma cells apoptosis at the time of diagnosis and after therapy in the two groups. Sodium selenite administration resulted in significant increase in percentage of apoptotic lymphoma cells after therapy in group II (78.9 ± 13.3% versus 58.9 ± 18.9%, p < 0.05). In addition, patients who received sodium selenite treatment demonstrated statistically significant increase in percentage of reduction of cervical and axillary lymphadenopathy, decrease in splenic size, and decreased percentage of bone marrow infiltration. Also, we found a statistically significant decrease in cardiac ejection fraction (CEF) in group I and no reduction in CEF in patients who received sodium selenite ‘group II’, denoting the cardioprotective effect of selenium. It is concluded that sodium selenite administration at the dosage and duration chosen has synergistic effect to chemotherapy in inducing apoptosis and, consequently, could improve clinical outcome.     

Reduction of selenium oxyanions by unicellular,polymorphic and filamentous fungi: Cellular location of reduced selenium and implications for tolerance

Summary The ability of several filamentous, polymorphic and unicellular fungi to reduce selenite to elemental selenium on solid medium was examined.Fusarium sp. andTrichoderma reeii were the only filamentous fungi, of those tested, which reduced selenite to elemental selenium on Czapek-Dox agar resulting in a red colouration of colonies. Other organisms (Aspergillus niger, Coriolus versicolor, Mucor SK, andRhizopus arrhizus) were able to reduce selenite only on malt extract agar. Several fungi were able to grow in the presence of sodium selenite but were apparently unable to reduce selenite to elemental selenium, indicating that other mechanisms of selenite tolerance were employed, such as reduced uptake and/or biomethylation to less toxic, volatile derivatives. Sodium selenate was more toxic toFusarium sp. than selenite, and the toxicity of both oxyanions was increased in sulphur-free medium, with this effect being more marked for selenate. Scanning electron microscopy ofAspergillus funiculosus andFusarium sp. incubated with sodium selenite showed the presence of needle-like crystals of elemental selenium on the surfaces of hyphae and conidia, while transmission electron microscopy ofA. funiculosus revealed the deposition of electron-dense granules in vacuoles of selenite-treated fungi. Several yeasts were able to grow on MYGP agar containing sodium selenate or sodium selenite at millimolar concentrations. Sone, notablyRhodotorula rubra andCandida lipolytica, and the polymorphic fungusAureobasidium pullulans were also effective at reducing selenite to elemental selenium, resulting in red-coloured colonies.Schizosaccharomyces pombe was able to grow at selenite concentrations up to 5 mmol L^–1 without any evidence of reduction, again indicating the operation of other tolerance mechanisms.     

Avoidance conditioning and morphometric characteristics of the sensorimotor cortex of rats exposed to social deprivation in early ontogeny

Male Wistar rats were exposed to social deprivation in the period from the 22nd to 70th days of postnatal development. The characteristics of the learning of these rats at the age 110-120 days in the passive avoidance box and during training for active avoidance of electroshock were significant lower than those of control animals. Features of motor activities of the "isolants" in learning and testing, and in the "open field" may be related to their higher anxiety level. Morfometric studies of neurons and glial cells and neocortex thickness showed that significantly lower density of neural elements may be the result of the afferent sensory input limitation produced by the social deprivation.     

Effect of dalargin on the behavior of rats subjected to intrauterine ethanol exposure

Influence was studied of dalargin--synthetic analogue of enkephalin administered in early postnatal period to young rats with intrauterine ethanol injection, on their behaviour and conditioned activity. Parameters were established of spontaneous motor activity, behaviour in the open field, acquisition and preservation of conditioned reflexes of passive and active avoidance in experimental and intact rats, injected with dalargin. A reduction of sensitivity to corasol convulsive effect was observed under the influence of dalargin.     

The metabolism of selenite and selenomethionine in mouse fibroblasts grown in tissue culture

Recent reports have provided evidence that selenium is an essential growth factor for cells grown in tissue culture. The aim of the work reported in this paper was to evaluate mouse fibroblasts as a model for the study of selenium metabolism in mammalian cells. The results showed that transformed mouse lung fibroblasts grown in media containing 9.1% bovine serum did not show a growth response to added selenium as selenite over the range of 10–1000 ng/mL. Uptake of selenium by cells was a direct function of the selenium concentration in the medium. The rate of uptake varied with the time of exposure of the cells to the selenium, and to the form of selenium in the medium. Experiments using radioactive selenium showed that⁷⁵Se from selenite was rapidly absorbed into the cell wall, but slowly incorporated into the soluble protein fraction.⁷⁵Se from selenomethionine was more slowly absorbed into the cells, but once inside, it became rapidly incorporated into soluble cytoplasmic proteins. Cell fractionation and gel filtration procedures established that⁷⁵Se from selenite was rapidly incorporated into glutathione peroxidase (GSHpx), whereas⁷⁵Se from selenomethionine was initially incorporated into a wide spectrum of proteins and only after a longer period did the⁷⁵Se peak become associated with GSHpx. These findings suggest fundamental differences exist in the manner in which mammalian cells initially absorb and metabolize different selenium compounds.     

Reduction of organic and inorganic selenium compounds by the edible medicinal basidiomycete Lentinula edodes and the accumulation of elemental selenium nanoparticles in its mycelium

We report for the first time that the medicinal basidiomycete Lentinula edodes can reduce selenium from inorganic sodium selenite (Se^IV) and the organoselenium compound 1,5-diphenyl-3-selenopentanedione-1,5 (DAPS-25) to the elemental state, forming spherical nanoparticles. Submerged cultivation of the fungus with sodium selenite or with DAPS-25 produced an intense red coloration of L. edodes mycelial hyphae, indicating accumulation of elemental selenium (Se⁰) in a red modification. Several methods, including transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), and X-ray fluorescence, were used to show that red Se⁰ accumulated intracellularly in the fungal hyphae as electron-dense nanoparticles with a diameter of 180.51±16.82 nm. Under designated cultivation conditions, shiitake did not reduce selenium from sodium selenate (Se^VI).     

Comparative effects of selenite and selenite on the glutathione-related enzymes activity in pig blood platelets

The effects of inorganic selenium (Se) compounds (sodium selenite and selenate) on the activities of glutathione-related enzymes (glutathione peroxidase, glutathione-S-transferase [GST] and glutathione reductase [GR]) in pig blood platelets were investigated in vitro. GST activity in blood platelets treated with 10⁻⁴ M of selenite was reduced to 50%, whereas no decrease GST activity was observed after the treatment of platelets with the same dose of selenate. In platelets incubated with physiological doses (10⁻⁷, and 10⁻⁶ M) of Se compounds, the activity of glutathione peroxidase (GSH-Px) was enhanced (about 20%). GR activity after the exposure of platelets to tested Se compounds was unaffected.     

Gender-dependent effects of selenite on the perfused rat heart

Gender differences are related to the manner in which the heart responds to chronic and acute stress conditions of physiological and pathological nature. Depending on dose, sodium selenite acts as an antioxidant proven to have beneficial effects in several pathological conditions G. Drasch, J. Schopfer, and G. N. Schrauzer, Selenium/cadmium ratios in human prostates: indicators of prostate cancer risk of smokers and non-smokers, and relevance to the cancer protective effects of selenium,Biol. Trace Element Res. 103(2), 103–107 (2005); R. G. Kasseroller and G. N. Schrauzer, Treatment of secondary lymphedema of the arm with physical decongestive therapy and sodium selenite: a review,Am. J. Ther. 7(4), 273–279 (2000); G. N. Schrauzer, Anticarcinogenic effects of selenium,Cell. Mol. Life Sci. 57(13–14), 1864–1873 (2000); I. S. Palmer and O. E. Olson, Relative toxicities of selenite and selenate in the drinking water of rats,J. Nutr. 104(3), 306–314 (1974). To date, little is known about the gender-dependent direct effects of toxic doses of selenite on electrophysiology of the cardiovascular system H. A. Schroeder and M. Mitchener, Selenium and tellurium in rats: effect on growth, survival and tumors,J. Nutr. 101(11), 1531–1540 (1971); G. N. Schrauzer, The nutritional significance, metabolism and toxicology of selenomethionine,Adv. Food Nutr. Res. 47, 73–112 (2003). In the present study, the effects of in vitro toxic concentrations of sodium selenite ranging from 10^-6 M to 10^-3 M were tested on both male and female rat heart preparations. The toxic effects seen in an electrocardiogram and left ventricular pressure were dose and sex dependent at most of the tested concentrations. The present study clearly shows that at toxic doses, stress conditions are induced by selenite, resulting in gender-dependent modifications of the heart function. This modification is more pronounced in the contraction cascade of female rats. Males, on the other hand, had been much more affected in excitation-related parameters.     

Intravenous Administration of Achyranthes Bidentata Polypeptides Supports Recovery from Experimental Ischemic Stroke in Vivo

Background

Achyranthes bidentata Blume (A. bidentata) is a commonly prescribed Chinese medicinal herb. A. bidentata polypeptides (ABPP) is an active composite constituent, separated from the aqueous extract of A. bidentata. Our previous studies have found that ABPP have the neuroprotective function in vitro and in rat middle cerebral artery occlusion (MCAO) model in attenuating the brain infract area induced by focal ischemia-reperfusion. However, the ultimate goal of the stroke treatment is the restoration of behavioral function. Identifying behavioral deficits and therapeutic treatments in animal models of ischemic stroke is essential for potential translational applications.

Methodology and Principal Findings

The effect of ABPP on motor, sensory, and cognitive function in an ischemic stroke model with MCAO was investigated up to day 30. The function recovery monitored by the neurological deficit score, grip test, body asymmetry, beam-balancing task, and the Morris Water Maze. In this study, systemic administration of ABPP by i.v after MCAO decreased the neurological deficit score, ameliorated the forepaw muscle strength, and diminished the motor and sensory asymmetry on 7^th and 30^th day after MCAO. MCAO has been observed to cause prolonged disturbance of spatial learning and memory in rats using the MWM, and ABPP treatment could improve the spatial learning and memory function, which is impaired by MCAO in rats, on 30^th day after MCAO. Then, the viable cells in CA1 region of hippocampus were counted by Nissl staining, and the neuronal cell death were significantly suppressed in the ABPP treated group.

Conclusion

ABPP could improve the recovery of sensory, motor and coordination, and cognitive function in MCAO-induced ischemic rats. And this recovery had a good correlation to the less of neuronal injury in brain.     

Influence of sodium selenite on203Hg absorption,distribution, and elimination in male mice exposed to methyl203Hg

To study the effects of long-term selenium supplementation on absorption, distribution, and elimination of methylmercury (MeHg) in mice, three groups of male mice (Balb/c CA) were exposed for 7 wk to 0, 0.6, and 3 ppm sodium selenite in tap water. They were then given a single oral dose of Me²⁰³Hg (2 μmol/kg) by gastric intubation, and elimination of²⁰³Hg was followed by whole-body counting for 49 d at the same Se exposure as previously. Twenty-four hours and 49 d after dosage, 6–7 animals/group were sampled for analysis of²⁰³Hg distribution in the body. Glutathione peroxidase (GSH-PX) activity in blood and selenium levels in the liver were used as measures of selenium status. Gastrointestinal absorption of Me²⁰³Hg was not influenced by the Se status of the animals. Selenium supplementation of MeHg-exposed mice caused an enhanced whole-body elimination of Hg, but selenium-supplemented animals did not have lower Hg levels in the brain and kidney than nonsupplemented animals. The effect of selenium on the accumulation, of Hg in the brain was dose-dependent, a high dose (3 ppm Se) causing a higher initial accumulation of Hg. The intracellular distribution of²⁰³Hg in the liver and kidney was not affected by Se. The results indicate that selenium treatment of MeHg-exposed mice may have a positive effection the health of the animals by decreasing the total body burden of MeHg.     

Fluctuations in Fe,Cu, Zn,Br, As,Se, and Rb concentrations in C57L/J mice bearing BW7756 murine hepatoma using radioisotope-induced X-ray fluorescence

The effects of selenite or selenate supplementation on the concentration and distribution of Fe, Cu, Zn, As, Br, and Rb are investigated using the radioisotope-induced X-ray fluorescence, RIXRF. These effects are studied in the animals bearing BW7756 murine hepatoma and healthy animals for both of the oxidation states. Selenite and selenate induce different effects on the distribution of selenium, zinc, copper, bromine, and rubidium. The differences may be attributed to the differences in the inter element interaction after absorption into the bloodstream as well as to the mode of their intestinal absorption. Simultaneous supplementation of copper with selenite or selenate at the described levels has a profound influence on the concentration levels of other elements in the normal as well as in the diseased mice. The administration of selenium (0.67 μg/g body wt sodium selenite or sodium selenate, daily) and selenium and copper (0.67 and 1.35 μ/g body wt, respectively) has no effect on the incidence rate of hepatoma development.     

Influence of Dietary Sodium Selenite on Tissue Selenium Levels of Growing Pigs

Twenty Norwegian Landrace pigs were divided into 5 groups and fed a basal diet consisting of a mixture of dried skim milk and whey powder together with ground barley. The diet was supplemented with 0, 0.2, 0.8, 1.2 and 2.2 μg selenium as sodium selenite and was fed for 12 weeks. The muscle selenium level was increased by a factor of about 4 and the liver selenium by a factor of about 12 when the dietary selenium supplement was increased from zero to 2.2 μg/g. There was a significant linear correlation between dietary selenium and selenium concentrations in tissues. Possible benefit for humans consuming meat from animals having received the selenium doses used in this experiment are discussed. dietary selenium; tissue levels; pigs.     

培养方式对富硒产朊假丝酵母性能的影响

在摇瓶和5 L发酵罐水平上分别考察亚硒酸钠浓度及其添加方式对高性能(高有机硒含量和高谷胱甘肽含量)富硒产朊假丝酵母制备的影响.结果表明:亚硒酸钠添加质量浓度为15 mg/L时,产朊假丝酵母具有较好的富硒效果,但一次性添加对酵母细胞有较大的毒害作用.采用分批次添加亚硒酸钠的方法获得了较好的制备高性能富硒产朊假丝酵母的培养方式:发酵起始添加L-蛋氨酸10 mmol/L,并在发酵过程的12和15 h分别添加亚硒酸钠10和5 mg/L.在此培养方式下,产朊假丝酵母胞内谷胱甘肽和有机硒含量分别达到172.3 mg/L和1194 μg/g.