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Waterstradt A, Winker M, Zimmermann-Klemd AM, Devi S, Lederer AK, Huber R, Gründemann C. Silicon Resorption from Equisetum arvense Tea - A Randomized, Three-Armed Pilot Study. PLANTA MEDICA 2022; 88:1360-1368. [PMID: 34706374 DOI: 10.1055/a-1643-5493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Equisetum arvense tea (TEA) contains high concentrations of silicon and has been used in folk medicine for the treatment of inflammatory ailments. We examined the resorption of silicon after TEA consumption. Safety and immunological effects were secondary outcomes. A monocentric, randomized, three-armed pilot study was conducted with 12 voluntary, healthy, male subjects. The study is registered in the German register for clinical trials (DRKS-ID: DRKS00016628). After a low silicon diet for 36 hours, 1000 mL TEA1 with approximately 200 000 µg silicon/L, TEA2 with approximately 750 000 µg silicon/L, or Si-low-Water (approximately 10 - 10 000 µg silicon/L as a control) were ingested on three consecutive days. Blood and urine samples were collected at baseline, day 1 examining silicon kinetics, day 3 examining silicon accumulation, and day 8 (safety, immunological parameters). Si-low-Water intake did not change silicon serum (Cmax 294 µg/L) or urine (19 000 µg/24 h) concentrations compared to baseline. Cmax was 2855 µg/L for TEA1 and 2498 µg/L for TEA2; tmax was 60 and 120 min, respectively. Silicon accumulation did not occur. Urine silica within 24 h (E24 h) was higher after TEA2 compared to TEA1 ingestion (142 000 vs. 109 000 µg/24 h). Serum silicon levels at t = 120 min differed significantly after intake of TEA2 or intake of Si-low-Water (p = 0.029). The immunological parameters did not show any significant changes indicating immunosuppressive effects in volunteers. TEA1 was well tolerated, while TEA2 caused diarrhoea in 4 subjects. Our investigations show that intake of TEA1 leads to significant rise in serum silicon concentration.
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Affiliation(s)
- Aljoscha Waterstradt
- Centre for Complementary Medicine, Department of Medicine II, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Moritz Winker
- Translational Complementary Medicine, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
| | - Amy Marisa Zimmermann-Klemd
- Centre for Complementary Medicine, Department of Medicine II, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Seema Devi
- Centre for Complementary Medicine, Department of Medicine II, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Ann-Kathrin Lederer
- Centre for Complementary Medicine, Department of Medicine II, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Roman Huber
- Centre for Complementary Medicine, Department of Medicine II, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Carsten Gründemann
- Translational Complementary Medicine, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
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El-Saied FA, Salem TA, Shakdofa MM, Al-Hakimi AN. Anti-neurotoxic evaluation of synthetic and characterized metal complexes of thiosemicarbazone derivatives. Appl Organomet Chem 2018. [DOI: 10.1002/aoc.4215] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Fathy A. El-Saied
- Department of Chemistry, College of Science; Qassim University; KSA
- Department of Chemistry, Faculty of Science; El-Menoufia University; Shebin El-Kom Egypt
| | - Tarek A. Salem
- Department of Biochemistry, College of Medicine; Qassim University; Saudia Arabia
| | - Mohamad M.E. Shakdofa
- Department of Chemistry, Faculty of Sciences and Arts, Khulais; University of Jeddah; Saudi Arabia
- Inorganic Chemistry Department; National Research Centre; P.O. 12622, Elbehothe st., Dokki Cairo Egypt
| | - Ahmed N. Al-Hakimi
- Department of Chemistry, College of Science; Qassim University; KSA
- Department of Chemistry, Faculty of Science; Ibb University; Ibb Yemen
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Kupferschmidt N, Csikasz RI, Ballell L, Bengtsson T, Garcia-Bennett AE. Large pore mesoporous silica induced weight loss in obese mice. Nanomedicine (Lond) 2014; 9:1353-62. [DOI: 10.2217/nnm.13.138] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Background: There is a need for medical treatments to curb the rising rate of obesity. Weight reduction is correlated with a decrease in associated risk factors and cholesterol levels in humans. Amorphous silica particles have been found to exert a hypocholesterolemic effect in humans, making them popular dietary additives. Aim: To investigate the effect of mesoporous silica, which possess sharp pore size distributions, on: weight loss, cholesterol, triglycerides and glucose blood levels in obese mice. Materials & methods: Mesoporous silicas with differing pore size were mixed in the high-fat diet of obese mice. Results: Animals receiving large pore mesoporous silica with a high-fat diet show a significant reduction in body weight and fat composition, with no observable negative effects. Conclusion: Pore size is an important parameter for reduction of body weight and body fat composition by mesoporous silica, demonstrating promising signs for the treatment of obesity. Original submitted 30 January 2013; Revised submitted 20 June 2013
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Affiliation(s)
- Natalia Kupferschmidt
- Nanotechnology & Functional Materials, Department of Engineering Sciences, Uppsala University, Box 534, 751 21, Uppsala, Sweden
- Nanologica AB, Drottning Kristinasväg 62, SE 11428, Stockholm, Sweden
| | - Robert I Csikasz
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrheniusväg 20B, 106 91, Stockholm, Sweden
| | - Lluís Ballell
- Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28769 Tres Cantos, Madrid, Spain
| | - Tore Bengtsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrheniusväg 20B, 106 91, Stockholm, Sweden
| | - Alfonso E Garcia-Bennett
- Department of Materials & Environmental Chemistry, MMK, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden
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Wohl AR, Michel AR, Kalscheuer S, Macosko CW, Panyam J, Hoye TR. Silicate esters of paclitaxel and docetaxel: synthesis, hydrophobicity, hydrolytic stability, cytotoxicity, and prodrug potential. J Med Chem 2014; 57:2368-79. [PMID: 24564494 PMCID: PMC3983351 DOI: 10.1021/jm401708f] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
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We report here the synthesis and
selected properties of various
silicate ester derivatives (tetraalkoxysilanes) of the taxanes paclitaxel
(PTX) and docetaxel (DTX) [i.e., PTX-OSi(OR)3 and DTX-OSi(OR)3]. Both the hydrophobicity and hydrolytic lability of these
silicates can be (independently) controlled by choice of the alkyl
group (R). The synthesis, structural characterization, hydrolytic
reactivity, and in vitro cytotoxicity
against the MDA-MB-231 breast cancer cell line of most of these derivatives
are described. We envision that the greater hydrophobicity of these
silicates (vis-à-vis PTX or DTX itself) should be advantageous
from the perspective of preparation of stable aqueous dispersions
of amphiphilic block-copolymer-based nanoparticle formulations.
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Affiliation(s)
- Adam R Wohl
- Departments of †Chemistry, ‡Pharmaceutics, and §Chemical Engineering and Materials Science, University of Minnesota , Minneapolis, Minnesota 55455, United States
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Calcium silicate and silicon dioxide/silicic acid gel added for nutritional purposes to food supplements. EFSA J 2009. [DOI: 10.2903/j.efsa.2009.1132] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Bissé E, Epting T, Beil A, Lindinger G, Lang H, Wieland H. Reference values for serum silicon in adults. Anal Biochem 2005; 337:130-5. [PMID: 15649385 DOI: 10.1016/j.ab.2004.10.034] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2004] [Indexed: 11/25/2022]
Abstract
Silicon is an essential nutrient of fundamental importance to human biology. It has been shown that silicon is required for bone, cartilage, and connective tissue formation. However, the assessment of silicon concentration is difficult as reference values are lacking. The aim of the present study was to establish reference values for apparently healthy individuals. Silicon concentrations were determined in serum of 1325 healthy subjects 18-91 years of age using atomic absorption spectrometry. Medians for serum silicon concentrations showed a statistically significant age and sex dependency. In men 18-59 years of age the median was 9.5 micromol/L and decreased to 8.5 micromol/L at 60-74 years of age. In women there was an increase in the median from age 18-29 years (10.00 micromol/L) to 30-44 years (11.10 micromol/L) followed by a decrease in the age group of 45-59 years (9.23 micromol/L). In subjects aged over 74 years the median serum silicon values were 7.70 micromol/L for men and 8.00 micromol/L for women. The most important findings in this study are the decrease of silicon and the course of the silicon concentrations with age, especially in women. The present study is an important prerequisite for studies that aim to identify the health effects and medical implications of silicon.
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Affiliation(s)
- Emmanuel Bissé
- Department of Clinical Chemistry, University Hospital Freiburg, D-79106 Freiburg, Germany.
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Reffitt DM, Jugdaohsingh R, Thompson RP, Powell JJ. Silicic acid: its gastrointestinal uptake and urinary excretion in man and effects on aluminium excretion. J Inorg Biochem 1999; 76:141-7. [PMID: 10612067 DOI: 10.1016/s0162-0134(99)00126-9] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Silicon (Si), as silicic acid, is suggested to be the natural antidote to aluminium (Al) toxicity, and was recently shown to promote the urinary excretion of Al from body stores. The metabolism of Si in man, however, remains poorly investigated. Here we report on the pharmacokinetics and metabolism of Si in healthy volunteers following ingestion of orthosilicic acid (27-55 mg/l Si) in water. We also investigated whether orthosilicic acid promotes the urinary excretion of endogenous Al. Minimum, median uptake of Si from the ingested dose was 50.3% (range: 21.9-74.7%, n = 8) based on urinary analysis following dosing. Significant correlations were observed between creatinine clearance and Si levels in serum or urine (r = 0.95 and 0.99, respectively). Renal clearance of Si was 82-96 ml/min suggesting high renal filterability. These results suggest that orthosilicic acid is readily absorbed from the gastrointestinal tract of man and then readily excreted in urine. There was no significant increase in Al excretion, over 32 h, following ingestion of the orthosilicic acid dose (P = 0.5; n = 5).
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Affiliation(s)
- D M Reffitt
- Gastrointestinal Laboratory, Rayne Institute, St Thomas' Hospital, London, UK.
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Popplewell JF, King SJ, Day JP, Ackrill P, Fifield LK, Cresswell RG, di Tada ML, Liu K. Kinetics of uptake and elimination of silicic acid by a human subject: a novel application of 32Si and accelerator mass spectrometry. J Inorg Biochem 1998; 69:177-80. [PMID: 9629677 DOI: 10.1016/s0162-0134(97)10016-2] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Silicon is possibly important in human physiology in protecting against the toxic effects of aluminium, but the kinetics of uptake and excretion of silicic acid, the bioavailable form, are not well characterised. We have used 32Si as a tracer in a human uptake experiment to determine a gastrointestinal uptake factor for silicic acid, and to elucidate the kinetics of renal elimination. Urine collections were made for extending intervals from 2 to 12 h over 2 days following ingestion by a single human subject of a neutral silicic acid solution containing tracer levels of 32Si (t1/2 approximately 150 y). Silicon was isolated as SiO2 and the 32Si content determined by accelerator mass spectrometry (AMS), using a gas-filled magnet technique to eliminate a prolific isobaric interference from 32S. Silicon uptake appears to have been essentially complete within 2 h of ingestion. Elimination occurred by two simultaneous first-order processes with half-lives of 2.7 and 11.3 h, representing around 90% and 10%, respectively, of the total output. The rapidly eliminated 32Si was probably retained in the extracellular fluid volume, whilst the slower component may represent intracellular uptake and release. Elimination of absorbed 32Si was essentially complete after 48 h and was equivalent to 36% of the ingested dose. This establishes only a lower limit for gastrointestinal absorption as, although there was no evidence for longer term retention of additional 32Si, the possibility could not be excluded by these results.
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Gregorini G, Tira P, Frizza J, D'Haese PC, Elseviers MM, Nuyts G, Maiorca R, De Broe ME. ANCA-associated diseases and silica exposure. Clin Rev Allergy Immunol 1997; 15:21-40. [PMID: 9209799 DOI: 10.1007/bf02828275] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- G Gregorini
- Department of Nephrology, Spedali Civili, University of Brescia, Italy
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Bellia JP, Newton K, Davenport A, Birchall JD, Roberts NB. Silicon and aluminium and their inter-relationship in serum and urine after renal transplantation. Eur J Clin Invest 1994; 24:703-10. [PMID: 7851472 DOI: 10.1111/j.1365-2362.1994.tb01064.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The present study was undertaken to establish the relationship between serum and urine silicon and improve renal function and examine whether the increased urinary excretion of aluminium observed after successful renal transplantation was associated with silicon. The changes in silicon and aluminium concentrations in serum and urine were measured in 15 patients for a period of up to 17 days following a first renal transplant. Serum silicon, unlike aluminium, progressively decreased with improving renal function and was significantly positively correlated with serum aluminium but not with the silicon excretion. The urine excretion of aluminium peaked between 4-8 days post-transplantation and was highly significantly positively correlated with urine silicon. The individual patient fractional excretion profiles of aluminium and silicon were variable but in general gave significant positive correlations suggesting that the elements may be cleared by the kidney through a common mechanism or as a chemical species, possibly an hydroxyaluminosilicate. If soluble silicon can chemically interact with aluminium in vivo it may, as in the biosphere, be important in the control of aluminium toxicity and eventual detoxification. Thus, elevated serum silicon concentrations may help to alleviate aluminium toxicity in end-stage renal disease and assist in the rapid clearance of aluminium seen after kidney transplantation.
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Affiliation(s)
- J P Bellia
- Department of Clinical Chemistry, Royal Liverpool University Hospital, UK
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