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Designing selenium functional foods and beverages: A review. Food Res Int 2019; 120:708-725. [DOI: 10.1016/j.foodres.2018.11.029] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 10/15/2018] [Accepted: 11/15/2018] [Indexed: 02/07/2023]
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Abstract
This review was undertaken to establish what might be the maximum safe dose of selenium that could be administered to man in studies on the use of the element in cancer prevention. The early history of selenium poisoning is briefly summarized. The literature on clinical signs and toxicity data for acute and for chronic selenosis in farm and experimental animals is discussed. Several cases of acute selenosis in man are reviewed, and a number of reports on chronic selenosis in man are reviewed and evaluated. Based on these, the maximum safe single oral dose of selenite, selenate, DL-selenocysteine, or DL-selenomethionine is suggested as 0.05 mg Se/kg body weight (milligrams of selenium per kilogram of body weight). The maximum safe multiple oral dose is suggested as 5 μg Se/kg body weight.
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Affiliation(s)
- O.E. Olson
- Experiment Station Biochemistry Section Chemistry Department South Dakota State University Brookings, SD 57007
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Hinrichsen S, Planer-Friedrich B. Cytotoxic activity of selenosulfate versus selenite in tumor cells depends on cell line and presence of amino acids. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:8349-8357. [PMID: 26780055 DOI: 10.1007/s11356-015-5960-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 12/10/2015] [Indexed: 06/05/2023]
Abstract
Based on acute cytotoxicity studies, selenosulfate (SeSO3 (-)) has been suggested to possess a generally higher toxic activity in tumor cells than selenite. The reason for this difference in cytotoxic activity remained unclear. In the present study, cytotoxicity tests with human hepatoma (HepG2), malignant melanoma (A375), and urinary bladder carcinoma cells (T24) showed that the selenosulfate toxicity was very similar between all three tested cell lines (IC50 6.6-7.1 μM after 24 h). It was largely independent of exposure time and presence or absence of amino acids. What changed, however, was the toxicity of selenite, which was lower than that of selenosulfate only for HepG2 cells (IC50 > 15 μM), but similar to and higher than that of selenosulfate for A375 (IC50 4.7 μM) and T24 cells (IC50 3.5 μM), respectively. Addition of amino acids to T24 cell growth medium downregulated short-term selenite uptake (1.5 versus 12.9 ng Se/10(6) cells) and decreased its cytotoxicity (IC50 8.4 μM), rendering it less toxic than selenosulfate. The suggested mechanism is a stronger expression of the xc (-) transport system in the more sensitive T24 compared to HepG2 cells which creates a reductive extracellular microenvironment and facilitates selenite uptake by reduction. Selenosulfate is already reduced and so less affected. The cytotoxic activity of selenosulfate and selenite to tumor cells therefore depends on the sensitivity of each cell line, supplements like amino acids as well as the reductive state of the extracellular environment.
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Affiliation(s)
- Sinikka Hinrichsen
- Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BayCEER), University of Bayreuth, 95440, Bayreuth, Germany
| | - Britta Planer-Friedrich
- Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BayCEER), University of Bayreuth, 95440, Bayreuth, Germany.
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Mohamed J, Wei WL, Husin NNA, Alwahaibi NY, Budin SB. Selenium supplementation reduced oxidative stress in diethylnitrosamine-induced hepatocellular carcinoma in rats. Pak J Biol Sci 2011; 14:1055-1060. [PMID: 22590839 DOI: 10.3923/pjbs.2011.1055.1060] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Selenium in the form of sodium selenite (SSE) is an essential micronutrient which known to possess antioxidant and anticancer properties. This study emphasizes the role of selenium on oxidative stress in experimental rats with N-diethylnitrosamine (DEN) initiated and 2-acetylaminofluorene (2-AAF) promoted multistage hepatocellular carcinogenesis (HCC). Rats were divided randomly into six groups: negative control, positive control (DEN+2-AAF), preventive group (pre-SEE 4 weeks+DEN), preventive control (respective control for preventive group), therapeutic group (DEN+post-SSE 12 weeks) and therapeutic control (respective control for therapeutic group). SSE (4 mg L(-1)) was given to animals before initiation and during promotion phase of HCC. The levels of total protein (TP), conjugated diens (CD), malondialdehyde (MDA), fluorescent pigment (FP), antioxidant activity (AOA) and DNA damage were measured. Supplementation of SSE before the initiation phase of carcinogenicity significantly increased TP and AOA level (p < 0.05) while it decreased the levels of CD, MDA, DNA damage and FP (p < 0.05). Supplementation of SSE during the promotion phase of carcinogenicity significantly decreased the DNA damage and FP level (p < 0.05) and there were negative correlation between the level of AOA and with the level of FP and CD. Thus, supplementation of SSE reduced the adverse changes which occur in liver cancer. However, the chemoprevention effect of SSE was more pronounced when it was supplemented before initiation phase of cancer when compared to promotion phase.
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Affiliation(s)
- Jamaludin Mohamed
- School of Diagnostic and Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, 50300 Kuala Lumpur, Malaysia
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Jacevic V, Jokic G, Dragojevic-Simic V, Bokonjic D, Vucinic S, Vuksa M. ACUTE TOXICITY OF SODIUM SELENITE IN RODENTS: PATHOMORPHOLOGICAL STUDY. ACTA ACUST UNITED AC 2011. [DOI: 10.31482/mmsl.2011.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Thirunavukkarasu C, Sakthisekaran D. Influence of sodium selenite on glycoprotein contents in normal and N-nitrosodiethylamine initiated and phenobarbital promoted rat liver tumors. Pharmacol Res 2003; 48:167-73. [PMID: 12798669 DOI: 10.1016/s1043-6618(03)00104-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Selenium in the form of sodium selenite is an essential micronutrient, that acts as an antioxidant/anticancer agent by its numerous macromolecules associated with them. This study emphasizes further evidence on its role as anticancer agent in experimental rats with N-nitrosodiethylamine (DEN) initiated (200 mg kg(-1) body weight) and phenobarbital (PB) promoted hepatoma. Serum, whole liver tissue (control animals, n=6), hepatoma and surrounding liver tissue samples from DEN-treated rats and rats supplemented with selenite (n=6) were collected. Total protein, albumin, globulin and albumin/globulin ratio were investigated. Hexose, hexosamine and sialic acid were also quantified. Animals treated with DEN resulted in significantly decreased levels of total protein, albumin and albumin/globulin ratio; on the other hand, globulin content was increased significantly when compared to control rats. We have also observed significant increased levels of hexose, hexosamine and sialic acid in serum, whole liver tissue (control), hepatoma and surrounding liver tissue of control and experimental animals. Supplementation of selenite (4 ppm) either before initiation, during initiation and/or during promotion stages alters the above biochemical changes significantly. Thus, supplementations of selenite in cancer bearing animals reduce the adverse changes that occur during cancer condition. However, the chemopreventive/chemotherapeutic effect of selenite is more pronounced when it was supplemented before and/or during initiation of cancer when compared to promotion stage. Our results emphasize the role of sodium selenite in cancer and strongly indicate its role as an essential micronutrient in cancer chemoprevention and therapy.
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Affiliation(s)
- C Thirunavukkarasu
- Department of Medical Biochemistry, Dr. ALM Post-Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, 600113, Chennai, India.
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Terada A, Yoshida M, Seko Y, Kobayashi T, Yoshida K, Nakada M, Nakada K, Echizen H, Ogata H, Rikihisa T. Active oxygen species generation and cellular damage by additives of parenteral preparations: selenium and sulfhydryl compounds. Nutrition 1999; 15:651-5. [PMID: 10467607 DOI: 10.1016/s0899-9007(99)00119-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We investigated the relationship between active oxygen species (AOS) generation and cultured vascular endothelial cellular damage caused by simultaneous exposure to selenium compounds and sulfhydryl compounds such as cysteine (Cys) or reduced glutathione (GSH). Selenium compounds, selenite, selenate or selenomethionine (SeMet), are added to total parenteral nutrition (TPN) and intravenously administered. We confirmed by luminol dependent chemiluminescence, an indicator of AOS generation, that selenite generates AOS in the presence of clinical concentrations of sulfhydryl compounds, 0.5 mM Cys or 0.5 mM GSH, and that the amount of AOS generated reaches the maximum when their mole ratio is 1:50. However, AOS generation was not observed after simultaneous administration of various concentrations of selenate or SeMet with sulfhydryl compounds. Moreover, simultaneous exposure to 10 microM selenite and sulfhydryl compounds was found to result in significant increases in the [3H]-adenine and lactate dehydrogenase (LDH) release rates from cells, a significant decrease in the amount of cellular protein, and enhancement of cellular damage as compared with after exposure to selenite alone. However, simultaneous exposure to 10 microM selenate or 10 microM SeMet together with sulfhydryl compounds did not induce cellular damage. These findings revealed that selenite generates AOS and causes cellular damage in the presence of sulfhydryl compounds. Accordingly, it seems better to choose selenate or SeMet instead of selenite when a selenium compound is to be added to TPN.
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Affiliation(s)
- A Terada
- Department of Pharmacy, St. Marianna University School of Medicine, Kawasaki, Japan
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Stenius U, Högberg J. Re: Yang, J. and Duerksen-Hughes, P. (1998) A new approach to identifying genotoxic carcinogens: p53 induction as an indicator of genotoxic damage. Carcinogenesis, 19, 1117-1125. Carcinogenesis 1999; 20:181-2. [PMID: 9934868 DOI: 10.1093/carcin/20.1.181] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Terada A, Yoshida M, Nakada M, Nakada K, Yamate N, Kobayashi T, Yoshida K. Influence of combined use of selenious acid and SH compounds in parenteral preparations. J Trace Elem Med Biol 1997; 11:105-9. [PMID: 9285891 DOI: 10.1016/s0946-672x(97)80034-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The influence of the combined use of selenious acid and SH compounds (glutathione (GSH) and cysteine (Cys), or ascorbic acid (Asc)) on cultured venous vascular cells was investigated experimentally. When cultured human umbilical venous vascular endothelial cells were exposed to 10 microM of selenious acid combined with 0.5 mM-GSH or 0.5 mM-Cys, the release rates of [3H]-adenine and lactate dehydrogenase (LDH) from cells into the medium increased significantly as compared with after exposure to selenious acid alone, and damage to the vascular endothelial cells was found to be intensified. Addition of 1 microM of selenious acid simultaneously with 0.5 mM-GSH or 0.5 mM-Cys showed no differences in toxicity for the vascular endothelial cells as compared with the addition of selenious acid alone. On the other hand, simultaneous exposure to 10 microM of selenious acid and 1 mM-Asc induced no significant differences in the release rates of [3H]-adenine and LDH, and no damage was observed to the vascular endothelial cells. These results suggest that simultaneous addition of selenious acid together with GSH or Cys, which have the SH-group, may cause damage to the vascular endothelial cells. Therefore careful attention is warranted in total parenteral nutrition (TPN).
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Affiliation(s)
- A Terada
- Department of Pharmacy, St. Marianna University School of Medicine, Kawasaki, Japan
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Abstract
Selenium toxicity was first confirmed in 1933 to occur in livestock that consumed plants of the genus Astragalus, Xylorrhiza, Oonopsis, and Stanleya in the western regions of the United States. In 1957 selenium was identified as an essential nutrient for laboratory rats and soon thereafter for chickens and sheep. Essentiality for mammalian species was established in 1973 with the discovery that the enzyme glutathione peroxidase contained selenium. During this same period of time, human epidemiological evidence suggested that selenium possessed anticarcinogenic effects. Since the 1970s, many animal studies have confirmed the human epidemiologic evidence that selenium compounds possess carcinostatic activity. Less progress has been made in explaining why many of these compounds of selenium are toxic and why these same compounds are carcinostatic. In 1988 the observation was made that oxidation of glutathione by selenite produced superoxide, opening a new area for selenium research. This present paper, drawing information from the literature on selenium metabolism in plants and animals, selenium toxicology, selenium cytotoxicity, and selenium carcinostatic activity in animals over the last sixty years, sets forth a probable biochemical catalytic mechanism that encompasses both selenium toxicity and selenium carcinostatic activity. The thesis presented here for scrutiny is that compounds of selenium are toxic owing to their prooxidant catalytic activity to produce superoxide (O2.-), hydrogen peroxide, and very likely other cascading oxyradicals. The toxicity of selenium compounds is countered by plant and animal methylation reactions and antioxidant defenses. As carcinostasis is mostly known to occur at supranutritional levels of selenium in animals, carcinostasis appears to be directly correlated to selenium toxicity. The catalytic toxic selenium specie appears to be the metabolic selenide (RSe-) anion.
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Affiliation(s)
- J E Spallholz
- College of Human Sciences, Texas Tech University, Lubbock
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Ishikawa T, Ali-Osman F. Glutathione-associated cis-diamminedichloroplatinum(II) metabolism and ATP-dependent efflux from leukemia cells. Molecular characterization of glutathione-platinum complex and its biological significance. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(20)80702-9] [Citation(s) in RCA: 182] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Abstract
Selenium is an essential trace element at lower concentrations and toxic at higher concentration. Animals can metabolize both inorganic and organic forms and convert non methylated Se to mono--or di--or tri--methylated forms, of which, mono-methylated forms are most toxic. Glutathione reductase converts selenoglutathione to H2S in liver and erythrocytes and is ultimately excreted. Se effects the toxicities of xenobiotic agents, provides antagonistic effect to Sulphur and co-administration with Zn increase Se retention in certain organs. At its toxic level (4-8 ppm) it increases Cu contents of heart, liver and kidney and has detoxifying or protecting effect against Cd and Hg. It is a prosthetic group of several seleno metalloenzymes. The concentration of the element is decreased in serum/plasma or erythrocytes of patients of AIDS, trisomy-21, Crohn's and Down's syndrome, phenylketonurea, Keshan's disease and cancer. Rather, the element has antiproliferative and cancer protecting effect. Se content of testes increases considerably during pubertal maturation and, during Se deficiency, the supply to the testes has priority over the other tissues. The element is localized in the mitochondrial capsule protein (MCP) and is involved in biosynthesis of testosterone. Neither the age of mother nor the concentration of Se during pregnancy has any effect on weight of baby or the length of pregnancy. Se levels in human milk is affected by maternal intake and its requirements by infants and young children are higher for their rapid growth. Clinical symptoms of its toxicity include severe irritations of respiratory system, metallic taste in mouth, formication of nose, signs of rhinitis, lung edema and brancho-pneumonia. The typical garlic odour of breath and sweat is due to dimethyl-selenide.
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Affiliation(s)
- R S Bedwal
- Department of Zoology, University of Rajasthan, Jaipur, India
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Matsumura H, Takahata R, Hayaishi O. Inhibition of sleep in rats by inorganic selenium compounds, inhibitors of prostaglandin D synthase. Proc Natl Acad Sci U S A 1991; 88:9046-50. [PMID: 1924366 PMCID: PMC52648 DOI: 10.1073/pnas.88.20.9046] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Prostaglandin (PG) D2 has been postulated to be an endogenous sleep-promoting factor in rats, and SeCl4 and Na2SeO3 recently have been shown to inhibit the PGD synthase (prostaglandin-H2 D-isomerase, EC 5.3.99.2) activity of rat brain. The effect of these selenium compounds on sleep-wake activities was examined in freely moving rats along with their effects on brain temperature, food and water intake, and behavior. Test substances were administered for 6 hr into the third ventricle of rats, using a microdialysis technique. SeCl4, time- and dose-dependently, inhibited sleep at perfusion rates of 60 pmol/0.2 microliter per min and higher, and the inhibition was almost complete at rates greater than 200 pmol/0.2 microliter per min. The effect was reversible and was followed by a rebound. Na2SeO3 exhibited similar effects, but Na2SO3 did not show any effect on sleep. Simultaneous administration of dithiothreitol eliminated the sleep-inhibiting effects of these selenium compounds. These findings indicate that the decrease in sleep is due to inhibition of the PGD synthase activity in the brain by SeCl4 as well as Na2SeO3. During the inhibition of sleep, the rats in general showed an activation of behavior with moderate elevation of brain temperature and a detectable increase in food and water intake, suggesting that the sleep-inhibited state of the rats was similar to the physiological state of wakefulness and that the inhibitory effect was not due to the general toxicity of selenium.
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Islam F, Watanabe Y, Morii H, Hayaishi O. Inhibition of rat brain prostaglandin D synthase by inorganic selenocompounds. Arch Biochem Biophys 1991; 289:161-6. [PMID: 1910313 DOI: 10.1016/0003-9861(91)90456-s] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Various inorganic selenocompounds dose-dependently inhibited the rat brain prostaglandin (PG) D synthase, both in the purified enzyme preparation and in the crude brain supernatant. All of the quadrivalent selenium compounds tested had a very limited range of IC50 values in the purified enzyme (11-12 microM) and in the brain supernatant (9-15 microM). A divalent selenium compound was also inhibitory, but a hexavalent selenium compound was ineffective. In contrast, organic selenocompounds such as selenomethionine and selenourea had no effect on the PGD synthase activity. Furthermore, sodium sulfate and sodium sulfite up to 10 mM did not inhibit the activity. The inhibition by selenium required the preincubation of the metal with sulfhydryl compounds such as dithiothreitol (DTT), indicating that the formation of selenotrisulfide or some other adduct(s) is essential for the inhibition. Furthermore, the inhibition was reversed by an excess amount of dithiothreitol, suggesting that the selenotrisulfide derivative of DTT binds to the SH group of the PGD synthase. The kinetic analysis revealed the inhibition by selenite to be noncompetitive with a Ki value of 10.1 microM. On the other hand, glutathione-dependent PGD synthase from rat spleen was much less inhibited, and PGF synthase and PGD2 11-ketoreductase activities were not inhibited by the selenium compound.
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Affiliation(s)
- F Islam
- Department of Neuroscience, Osaka Bioscience Institute, Japan
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Vernie LN, De Vries M, Karreman L, Topp RJ, Bont WS. Inhibition of amino acid incorporation in a cell-free system and inhibition of protein synthesis in cultured cells by reaction products of selenite and thiols. BIOCHIMICA ET BIOPHYSICA ACTA 1983; 739:1-7. [PMID: 6403034 DOI: 10.1016/0167-4781(83)90037-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Reaction products of selenite with thiols were tested for an inhibitory effect on amino acid incorporation in a cell-free system derived from rat liver and on protein synthesis in intact P815 and L1210 cells. In the cell-free system maximum inhibition, up to 96%, was reached at about 10 microM selenium. In intact cells inhibitory effect varied depending on which reaction product or cell line was used. Maximum inhibition was obtained after 30 min of incubation with selenium concentrations ranging from 0.25 microM to over 7 microM. Selenite itself also inhibited protein synthesis of L1210 cells, but only after 90 min of incubation and starting at selenium concentrations of 2 microM. Inhibition of protein synthesis in intact cells was followed by cell death. Pre-incubation of the reaction products of a monothiol (2-propanethiol) and of a vicinal dithiol (2,3-dimercapto-1-propanol) in culture medium showed a rapid decrease of the inhibitory capability of the product from the monothiol, but not of the product from the dithiol. The results indicate that selenite and a thiol react to form products which have differential toxic effects to cells in vitro.
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Yamamoto R, Suzuki T. Effects of methylmercury and selenite on osmolarity and electrolytes in blood of mice. Toxicol Lett 1982; 13:17-21. [PMID: 7179304 DOI: 10.1016/0378-4274(82)90133-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Female IVCS mice were fed methylmercury at a low dose (10 nmol/g feed) with each of the doses of selenite (0, 8, 20 and 50 nmol/ml of drinking water) for 2 weeks. Mice fed methylmercury alone showed increased osmolarity of plasma: coadministration of selenite produced no change even at the lowest dose. Selenite alone did not change the osmolarity. Both concentrations of Na+ and total protein in plasma increased due to administration of methylmercury alone without change of K+ and Cl- levels. Coadministered selenite abolished this effect of methylmercury on the electrolytes and total protein of plasma.
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Ankerst J, Sjögren HO. Effect of selenium on the induction of breast fibroadenomas by adenovirus type 9 and 1,2-dimethylhydrazine-induced bowel carcinogenesis in rats. Int J Cancer 1982; 29:707-10. [PMID: 7107071 DOI: 10.1002/ijc.2910290618] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Selenium in its organic and inorganic forms has been shown to inhibit the development of chemically induced, spontaneous and transplanted tumors. The present investigation was performed to study the effect of selenium (4 micrograms per ml of drinking water) on tumorigenesis of adenovirus-type-9-induced breast fibroadenomas and on 1,2-dimethylhydrazine-induced bowel carcinogenesis in WF rats. It was found that identical treatment with Se under identical conditions and with no obvious toxic effects on the rats (1) resulted in inhibition of DMH-induced large-bowel carcinogenesis; (2) facilitated induction of small-bowel cancer by the same carcinogen in the same animals, and (3) greatly facilitated induction of breast fibroadenoma by adenovirus type 9 in the same strain of rats. The effect of Se treatment on DMH-induced large-bowel carcinogenesis confirms previous findings and proves that the opposite effect on fibroadenoma development is not due to differences in e.g. effective dose, animal strains or condition of the animals. It is not yet clear through which mechanisms Se exerts these effects.
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Vernie L, Homburg C, Bont W. Inhibition of the growth of malignant mouse lymphoid cells by selenodiglutathione and selenodicysteine. Cancer Lett 1981. [DOI: 10.1016/0304-3835(81)90159-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Snodgrass W, Rumack BH, Sullivan JB, Peterson RG, Chase HP, Cotton EK, Sokol R. Selenium: childhood poisoning and cystic fibrosis. Clin Toxicol (Phila) 1981; 18:211-20. [PMID: 7226733 DOI: 10.3109/15563658108990027] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Two cases of selenium ingestion in children are described; one child with severe cystic fibrosis died. Both children had cystic fibrosis and both had low serum chloride in association with selenium usage. Neither child was exposed to excessive heat or cold weather, factors known to salt-deplete children were cystic fibrosis, although one child was dehydrated during a summer month on initial presentation. One child had protein-calorie malnutrition, a condition known to enhance selenium toxicity in animals. We conclude that selenium is a potential hazard in its use as a health food fad for children with cystic fibrosis and in overdose ingestions. Thus selenium supplementation may have contributed to the morbidity and mortality reported here.
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Safer B, Jagus R, Crouch D. Indirect inactivation of eukaryotic initiation factor 2 in reticulocyte lysate by selenite. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(18)43661-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Vernie LN, Ginjaar HB, Wilders IT, Bont WS. Amino acid incorporation in a cell-free system derived from rat liver studied with the aid of selenodiglutathione. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 518:507-17. [PMID: 656431 DOI: 10.1016/0005-2787(78)90168-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Selenodiglutathione (GSSeSG), a potent inhibitor of elongation factor 2 (EF2) has been used to study amino acid incorporation in a rat liver cell-free system. While translocation of the ribosomes was inhibited by GSSeSG, ribosomes with a free acceptor site were still capable of incorporating one amino acid residue. From this the average number of amino acids incorporated per ribosomes was calculated to be 2--5. In this respect virtually no difference has been observed between ribosomes present on small or large aggregates. The time required for one translocation by all active ribosomes, and the time required for the incorporation of one amino acid (starting with aminoacyl-tRNA or amino acids) has also been determined. By incubation under conditions for amino acid incorporation, part of the ribosomes were completely inactivated whereas the rest remained as active as at the start of the incubation.
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Abstract
Injection of 0.48 or 0.72 mg of selenium/100 g body weight (as Na2SeO3) into 3-week-old chicks depressed hepatic activity of fatty acid synthetase compared with saline-injected controls. In in vitro experiments with fatty acid synthetase purified to homogeneity, Na2SeO3 was a competitive inhibitor (Ki = ca. 70 micronM). Dithiothreitol (DTT) at low concentrations increased the inhibition of the enzyme by Na2SeO3. At higher DTT concentrations the potentiating effect of DTT on selenium inhibition of the enzyme disappeared. At still higher DTT concentrations, selenium inhibition of fatty acid synthetase was partically relieved. If DTT and Na2SeO3 (2 : 1 molar ratio, respectively) in inhibitory concentrations, were reacted together prior to addition to enzyme and substrate, no inhibition was observed. Potentiation of selenium inhibition of fatty acid synthetase was observed with 2-mercaptoethanol but not with ascorbate. Several organic seleno-compounds were not inhibitory. The data suggest that selenium inhibits fatty acid synthetase by reversible bonding to the sulfhydryl (SH) groups (possibly at the active sites for acetyl-CoA and/or malonyl-CoA binding) of the enzyme. Selenotrisulfide formation involving selenium and the SH groups from the enzyme and thiol compounds is advanced as a possible explanation for the interaction among Se, DTT and enzyme observed in these experiments.
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Rhead WJ, Schneider JA. Effect of selenium compounds on selenium content, growth and 35S-cystine metabolism of skin fibroblasts from normal and cystinotic individuals. BIOINORGANIC CHEMISTRY 1976; 6:187-202. [PMID: 1053514 DOI: 10.1016/s0006-3061(00)80226-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Kidney samples from children with the inborn metabolic disease cystinosis contain 4 times more selenium (Se) than do kidney samples from normal individuals (p = 0.1). However, when cultured skin fibroblasts from cystinotic patients and normal control individuals are incubated in Se-D,L-methionine, Se-D,L-cystine, Se-cystamine X HCl, Se-urea, selenite or in medium without added selenium, only the cystinotic fibroblasts grown in Se-urea or selenite (SeO3=) contain more selenium than do the corresponding normal cells (p less than 0.05). In both types of cultured fibroblasts, the order of descending toxicity per ppm selenium is: Se-urea greater than Se-cystamine greater than Se-cystine greater than or equal to SeO3= much greater than Se-methionine. High (apparently toxic) concentrations of Se-urea and Se-cystamine lower the elevated intracellular free (nonprotein) cystine content of cystinotic fibroblasts to less than 60% of control values; at lower concentrations, these compounds raise the cystine content of these cells to over 140% of control values. Appropriate concentrations of SeO3=, Se-cystine and Se-methionine also elevate the free cystine content of the cystinotic cells. During a 75 minute incubation in 35S-cystine, the incorporation of 35S into the acid precipitable (protein) fraction of both cell types is significantly inhibited by Se-cystamine (approximately 55% control; p less than 0.05). The incorporation of 35S-cystine into glutathione is inhibited by Se-cystine (approximately 40% control) in both fibroblast types (p less than 0.05). In cystinotic cells, Se-cystamine significantly reduces incorporation of 35S-cystine into the cystine pool (40% control) as does SeO3= (67% control; p less than 0.05). Protein and glutathione synthesis in cystinotic fibroblasts are more strongly inhibited by Se-cystine and SeO3=, respectively, than in normal fibroblasts (p less than 0.05). These studies demonstrate that selenium compounds exhibit a different sequence of toxicity in fibroblasts than in the intact animal and that some previously unreported metabolic effects (i.e. inhibition of glutathione synthesis) may contribute to their toxicity.
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Vernie LN, Bont WS, Ginjaar HB, Emmelot P. Elongation factor 2 as the target of the reaction product between sodium selenite and glutathione (GSSeSG) in the inhibiting of amino acid incorporation in vitro. BIOCHIMICA ET BIOPHYSICA ACTA 1975; 414:283-92. [PMID: 1203259 DOI: 10.1016/0005-2787(75)90167-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The product of the reaction between sodium selenite and glutathione, designated as selenodiglutathione (GSSeSG), nearly completely inhibits amino acid incorporation from [14C]leucyl-tRNA by free polyribosomes isolated from rat liver. The mechanism of this inhibition was studied on the basis of the following three findings. Glutathione decomposes GSSeSG to harmless products; GSSeSG acts instantaneously on some component of the complete incubation system during preparation of the incubation vessels (at 0 degrees C); once GSSeSG has reacted its inhibitory effect cannot be reversed by glutathione. Accordingly, the effect of GSSeSG on the various steps of the amino acid incorporation process was studied by varying the sequence of additions of the reaction components, GSSeSG and GSH. The results of these and other experiments showed elongation factor 2 to be target of GSSeSG. The GSSeSG-B blocked factor could be regenerated by reduction with glutathione reductase and NADPH.
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Sandy JD, Davies RC, Neuberger A. Control of 5-aminolaevulinate synthetase activity in Rhodopseudomonas spheroides a role for trisulphides. Biochem J 1975; 150:245-57. [PMID: 1080999 PMCID: PMC1165732 DOI: 10.1042/bj1500245] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
1. The aminolaevulinate synthetase activator of fresh extracts of semi-anaerobically grown Rhodopseudomonas spheroids was resolved into two fractions by ion-exchange chromatography. One fraction was identified as cystine trisulphide (CySSSCy). Analysis of the other fraction indicated the presence of about equal amounts of glutathione trisulphide (GSSSG) and the mixed trisulphide of glutathione and cystine (GSSSCy). 2. Four further fractions with activator activity were observed on ion-exchange chromatography of extracts prepared by methods similar to those described earlier [Neuberger et al. (1973)Biochem. J. 136,491-499]. These activators were generated by the extraction procedure. Two of them have been identified as trisulphanedisulphonate (S5O62-) and additional cystine trisulphide. 3. For the series of polysulphanedisulphonates (-O3S-Sn-SO3-, n greater than or equal to 1), activator activity at muM concentrations was exhibited only by compounds with n greater than 3. This, together with the results described above, indicates that for a compound R-Sn-R' (where R and R' are organic or inorganic groups) the only structural requirement for activity is n greater than or equal to 3. 4. Oxygenation of a semipanaerobic culture of R. spheroids for 1.5h before harvesting the cells produced a decrease of more than 90% in the cellular content of cystine trisulphide and glutathione trisulphides. 5. Chromatography on DEAE-Sephadex confirmed the presence of multiple forms of aminolaevulinate synthetase in extracts of R. spheroides [Tuboi et al. (1970) Arch.Biochem. Biophys. 138,147-154]. Oxygenation of a semi-anaerobic culture resulted in the disappearance of high-activity enzyme (a-form) and the accumulation of low-activity enzyme (b-form) in the cell. Spontaneous activation [Marriott et al. (1969) Biochem. J. 111,385-394] And activation by cystine trisulphide both resulted in the almost complete conversion of the b-form into the a-form.
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Cannella C, Pecci L, Finazzi Agro A, Federici G, Pensa B, Cavallini D. Selenium binding to beef-kidney rhodanese. EUROPEAN JOURNAL OF BIOCHEMISTRY 1975; 55:285-9. [PMID: 1236798 DOI: 10.1111/j.1432-1033.1975.tb02161.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The reaction of beef kidney rhodanese with selenosulfate was studied. The selenium-treated enzyme shows an absorption spectrum with a maximum at 375 nm attributable to a sulfoselenide group. This absorption is bleached by addition of cyanide. After cyanide treatment stoichiometric amount of selenocyanate can be found. The intrinsic fluorescence of rhodanese is quenched by addition of stoichiometric selenosulfate. This effect can be reversed by cyanide or sulfite but not by selenite or glutathione. By comparison with model complexes the selenium-rhodanese intermediate was identified as a cysteinyl-selenium derivative.
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