Selenium (Se) is an essential trace element for organisms. Se deficiency will cause diseases such as Keshan disease and Kashin-Beck in human being, and huge loss to animal husbandry. Currently available Se supplements have such problems as low Se content, poor bioavailability, and poor safety. Chlorella pyrenoidosa can produce bioavailable and safe organic Se under suitable conditions, which is thus a promising Se supplement. Therefore, in this study, we tried to improve the Se tolerance and accumulation of C. pyrenoidosa by directional adaptation. To be specific, we gradually increased the concentration of Na₂SeO₃ in medium to domesticate C. pyrenoidosa and optimized the adapting time and concentration gradient of Na₂SeO₃ during the adaptation. The results showed that the adapted C. pyrenoidosa was more tolerant to Se and had stronger Se enrichment ability. In 5 L fermenter, the adapted strains could tolerate 40 mg/L Na₂SeO₃ and the synthesis rate of organic Se was 175.6% higher. Then, Se addition method in the 5 L fermenter was optimized. The result demonstrated that addition of Na₂SeO₃ at 40 mg/L during heterotrophic culture achieved the final dry weight of C. pyrenoidosa cells at 106.4 g/L, content of organic Se at 1 227 mg/kg, and synthesis rate of organic Se at 1.36 mg/(L·h). Compared with the reported highest cell density of 75 g/L and the highest organic Se content of 560 mg/kg, the corresponding figures in this study were 41.9% and 119.1% higher, respectively. In conclusion, directional adaptation can remarkably improve the Se tolerance and enrichment of C. pyrenoidosa.
Animals ; Humans ; Selenium/pharmacology* ; Chlorella ; Heterotrophic Processes

Orthogonal combination design was adopted in examining the Spirulina platensis (S. platensis) yield and the influence of four factors (Se content, Se-adding method, S content and NaHCO3 content) on algae growth. The results showed that Se content, Se-adding method and NaHCO3 content were key factors in cultivation conditions of Se-enriched S. platensis with the optimal combination being Se at 300 mg/L, Se-adding amount equally divided into three times and NaHCO3 at 16.8 g/L. Algae yield had a remarkable correlation with OD560 and floating rate by linear regression analysis. There was a corresponding relationship between effects of the four factors on algae yield and on OD560, floating rate too. In conclusion, OD560 and floating rate could be served as yield-forming factors.
Bicarbonates ; analysis ; Culture Media ; Cyanobacteria ; growth & development ; Selenium ; analysis ; pharmacology

OBJECTIVETo study the effects of benzene and selenium on telomerase in mouse lymphocytes in vivo and evaluate telomerase activity as an early marker of benzene effects on lymphocytes.

METHODSMale Kunming mice were divided randomly into 8 groups, including negative control group, reagent control group, 100 mg/kg benzene group, 200 mg/kg benzene group, 400 mg/kg benzene group, 200 mg/kg benzene + 0.75 mg/kg selenium group, 200 mg/kg benzene + 1.50 mg/kg selenium group and 200 mg/kg benzene + 3.00 mg/kg selenium group, 5 mice in each group. The mice in different groups were treated with different methods, once daily for 5 days. After 48 hours of the final exposure, lymphocytes were separated and the telomerase activities were detected with TRAPELISA.

RESULTSCompared with negative and reagent control groups, the telomerase activity was increased after treatment with different dose of benzene and at the dose of 100 mg/kg benzene group it was significantly increased (P < 0.01). At the dose of 200 mg/kg benzene + 0.75 mg/kg selenium group, it was significantly increased (P < 0.01). Compared with the counterpart treated with 200 mg/kg benzene group, the expression of telomerase was increased at the different concentrations after treatment with benzene combined with selenium and it was significantly increased at the dose of 200 mg/kg benzene + 0.75 mg/kg selenium group (P < 0.05).

CONCLUSIONIncreased telomerase activity in lymphocytes stimulated by benzene at different concentrations indicates activation and proliferation of these lymphocytes of mice in vivo. Telomerase activity is probably a sensitive early marker of lymphocyte proliferation by benzene. Selenium can upregulate the telomerase activity.

Animals ; Benzene ; pharmacology ; Cells, Cultured ; Lymphocytes ; drug effects ; enzymology ; Male ; Mice ; Selenium ; pharmacology ; Telomerase ; metabolism

Animals ; Codonopsis ; chemistry ; Drugs, Chinese Herbal ; pharmacology ; Myocardial Reperfusion Injury ; drug therapy ; Rats ; Selenium ; pharmacology

Animals ; Female ; Hypoxia ; prevention & control ; Ketamine ; pharmacology ; Male ; Mice ; Mice, Inbred Strains ; Selenium ; pharmacology ; Tea

In recent years, selenium nanoparticles (SeNPs) have been widely used in many fields such as nanotechnology, biomedicine and environmental remediation due to their good electrical conductivity, photothermal properties and anticancer properties. In this study, the cell-free supernatant, whole cell and the cell-free extracts of the strain Cupriavidus sp. SHE were used to synthesize SeNPs, and several methods were applied to analyze the crystal structure and surface functional groups of the nanoparticles. Finally, Pseudomonas sp. PI1 (G⁺) and Escherichia coli BL21 (G⁻) were selected to investigate the antibacterial properties of SeNPs. Cell-free supernatant, whole cell and cell-free extracts of the strain could synthesize SeNPs. As for the cell-free supernatant, selenite concentration of 5 mmol/L and pH=7 were favorable for the synthesis of SeNPs. TEM images show that the average size of nanospheres synthesized by the supernatant was 196 nm. XRD analysis indicates the hexagonal crystals structure of SeNPs. FTIR and SDS-PAGE confirmed the proteins bound to the surfaces of SeNPs. SeNPs synthesized by cell-free supernatant showed no antimicrobial activities against Pseudomonas sp. PI1 and Escherichia coli BL21 (DE3). These results suggest that proteins played an important role in biotransformation of SeNPs in an eco-friendly process, and SeNPs synthesized in this study were non-toxic and biologically compatible, which might be applied in other fields in the future.
Anti-Bacterial Agents ; pharmacology ; Bacteria ; drug effects ; Cupriavidus ; metabolism ; Nanoparticles ; Selenious Acid ; analysis ; Selenium ; chemistry ; pharmacology

Alkaloids ; pharmacology ; Animals ; Liver Neoplasms, Experimental ; enzymology ; prevention & control ; Quinolizines ; pharmacology ; Rats ; Selenium ; pharmacology ; Telomerase ; metabolism ; Yeast, Dried ; pharmacology

OBJECTIVETo study the factors influencing the activity of fibrinolytic enzymes from earthworm and to obtain the better way to extract fibrinolytic enzymes as well as keep its optimum activity.

METHOD75% alcohol, 0.9% NaCl and 10% saccharose was used to extract the crude fibrinolytic enzymes from earthworm, the method of urokinase gelose-fibrin plate was used to measure the activity of fibrinolytic enzymes from earthworm. and the method of 3,3'-diaminobezidine tetrahydrochloride colorimetry to was used measure the content of selenium. The method use ts of measuring the content of arsenic was silver diethyldithiocarbamate colorimetry.

RESULTThe fibrinolytin of earthworms reared with cattle soils had higher activity than that reared with garbage. The arsenic in the earthworm's body could improve the activity of earthworm's fibrinolytin. However, the selenium had litter influence on it. Among the three methods of extraction, the 75% alcohol one was the most efficient, the 0.9% NaCl was next, and the 10% saccharose was the lowest. The influence of dialysis on the activity of fibrinolytin was less than that of ultrafiltration, when the earthworm's fibrinolytin enzyme was further sublimated.

CONCLUSIONThe activity of the earthworm's fibrinolytin will be increased earthworm is reared with the fitting baits and when appropriate methods, of extraction and purification are used.

Animal Feed ; Animals ; Endopeptidases ; isolation & purification ; metabolism ; Oligochaeta ; chemistry ; Selenium ; pharmacology

This study determined the effects of selenium on the growth of Fusarium strains and the effects of products extracted from the fungal cultures on relevant indicators of chondrocytes injury. The results showed that selenium supplementation resulted in differential effects on the mycelial growth of the strains. Levels of the chondrocyte injury indicators, including cell viability, proteoglycan and type II collagen contents and their mRNA expressions, were all reduced to varying degrees when the chondrocytes were incubated with fermentation extracts, the inhibitory effect varied depending on selenium content supplemented to fungal culture media. The results indicated that certain chain relations existed between the content of selenium in the environment, the production of some metabolites by fungi, and the occurrence of chondrocyte damage. The extent of this relationship and the role it plays in Kaschin-Beck disease pathogenesis merit further study.
Animals ; Cell Survival ; Cells, Cultured ; Chondrocytes ; pathology ; Fermentation ; Fusarium ; drug effects ; physiology ; Rabbits ; Selenium ; pharmacology

The Protective effect of vitamin E and selenium against peroxidative damage in white blood cells was studied. Forty-eight male rats (~100g BW) were divided into four groups and were fed with a torula yeast based diet deficient in Vit.E and Se. Vit.E (100IU/Kg diet) and Se (0.3ppm) supplementation increased the total peritoneal cell (P.C) population and cell survival rate. Selenium supplementation decreased the hydrogen peroxide generation (half of the control) significantly and Vit.E supplementation reduced the malonaldehyde production during phagocytosis in vitro. However, superoxide generation was not affected by the supplementation of Vit.E or Se. There were no significant differences in catalase activity between groups but glutathione peroxidase activity was increased about twofold by Se supplementation with no effect of Vit.E. In a separate experiment, activated alveolar macrophages were obtained from BCG infected rabbits fed a diet supplemented with Vit.E (100 IU/Kg diet) or Se (0.3 ppm). Se supplementation increased glutathione peroxidase in cells, and both Vit.E and Se increased the cell survival rate during phagocytosis as compared to the control. Both Vit.E and Se are necessary to protect host cells from peroxidative damage during phagocytosis.
Animal ; Macrophages/drug effects ; Macrophages/physiology* ; Male ; Peroxides/metabolism* ; Phagocytosis/drug effects* ; Rats ; Selenium/pharmacology* ; Vitamin E/pharmacology*