Glicosamina: Diferenzas entre revisións
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| ImageNameR1 = Modelo de bólas e paus da glicosamina ((2R,6R)-6-met,-2-ol)
| IUPACName = (3''R'',4''R'',5''S'')-3-Amino-6-(hidroximetil)oxano-2,4,5-triol
| OtherNames = 2-Amino-2-desoxi-glicosa<br
Quitosamina
| Section1 = {{Chembox Identifiers
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[[Ficheiro:D-Glucosamin.svg|miniatura|dereita|α-D-glicosamina (forma de Haworth).]]
A '''glicosamina''' (C<sub>6</sub>H<sub>13</sub>NO<sub>5</sub>) é un [[aminoazucre]] formado por unha [[glicosa]] que ten o OH do carbono 2 substituído por un [[grupo amino]]. É un importante precursor na biosíntese de [[glicoproteína]]s e [[glicolípido]]s. A glicosamina e os seus derivados forman parte da estrutura dos [[polisacárido]]s [[quitosana]] (formado por glicosamina e [[N-acetilglicosamina]]) e da [[quitina]] (formada por N-acetilglicosamina), que forma parte do [[exoesqueleto]] de [[artrópodos]] e da parede celular dos [[Fungo (bioloxía)|fungos]] superiores. A glicosamina é un dos [[monosacárido]]s máis abundantes.<ref name="carb"/> Prodúcese comercialmente por [[hidrólise]] de exoesqueletos de [[crustáceos]] ou, menos frecuentemente por fermentación de cereais como o [[millo]] e o [[trigo]].<ref>{{cita web|url=http://www.devanutrition.com/easyfaq/cat/Glucosamine-Hcl/63.html|título=Vegan Glucosamine FAQ|accessdate=2010-12-08|urlarquivo=https://web.archive.org/web/20111026062312/http://www.devanutrition.com/easyfaq/cat/Glucosamine-Hcl/63.html|dataarquivo=26 de outubro de 2011|urlmorta=
== Bioquímica ==
A glicosamina está presente de forma natural nas conchas do marisco, ósos de animais e medula ósea. Tamén está presente nalgúns fungos, como ''[[Aspergillus niger]]''.<ref>{{Cita publicación periódica |title=Scientific Opinion of the Panel on Dietetic Products Nutrition and Allergies on a request from the European Commission on the safety of glucosamine hydrochloride from ''Aspergillus niger'' as food ingredient |journal=The EFSA Journal |volume=1099 |pages=1–19 |year=2009 |url=http://www.efsa.europa.eu/en/scdocs/scdoc/1099.htm}}</ref>
A glicosamina obtívoa por primeira vez en 1876 [[Georg Ledderhose]] por [[hidrólise]] da [[quitina]] con [[ácido clorhídrico]] concentrado.<ref>{{Cita publicación periódica
A D-gliucosamina prodúcese na natureza en forma de glicosamina-6-fosfato, e é o precursor bioquímico de todos os [[aminoazucre]]s.<ref>{{Cita publicación periódica | author = Roseman S | title = Reflections on glycobiology | journal = [[J Biol Chem]] | year = 2001 | volume = 276 | issue = 45 | pages = 41527–42 | pmid = 11553646 | doi = 10.1074/jbc.R100053200 | format = free full text}}</ref> Á súa vez, a glicosamina-6-fosfato sintetízase a partir de [[frutosa 6-fosfato]] e [[glutamina]]<ref>{{Cita publicación periódica | author = Ghosh S, Blumenthal HJ, Davidson E, Roseman S | title = Glucosamine metabolism. V. Enzymatic synthesis of glucosamine 6-phosphate | journal = [[J Biol Chem]] | date = 1 May 1960 | url = http://www.jbc.org/cgi/reprint/235/5/1265 | pmid = 13827775 | volume = 235 | issue = 5 | pages = 1265–73 | apelidos = | data-acceso = 24 de novembro de 2011 | data-arquivo = 26 de maio de 2009 | url-arquivo = https://web.archive.org/web/20090526062334/http://www.jbc.org/cgi/reprint/235/5/1265 | url-morta = yes }}</ref> como o primeiro paso da ruta biosintética da hexosamina.<ref>[http://www.chem.qmul.ac.uk/iubmb/enzyme/reaction/polysacc/UDPGlcN.html International Union of Biochemistry and Molecular Biology]</ref> O produto final desta vía é a [[UDP-N-acetilglicosamina]] (UDP-GlcNAc), que se utiliza despois para producir [[glicosaminoglicano]]s, [[proteoglicano]]s, e [[glicolípido]]s.
Como a formación de glicosamina-6-fosfato é o primeiro paso para a síntese destes produtos, a glicosamina pode ser importante na regulación da súa produción; aínda que o modo en que realmente se regula a ruta de síntese da hexosamina, e se está ou non implicada en enfermidades humanas, permanece pouco claro.<ref name="Buse">{{Cita publicación periódica | author = Buse MG | title = Hexosamines, insulin resistance, and the complications of diabetes: current status | journal = [[Am. J. Physiol. Endocrinol. Metab.]] | year = 2006 | volume = 290 | issue = 1 | pages = E1–E8 | pmid = 16339923 | doi = 10.1152/ajpendo.00329.2005 | pmc = 1343508}}</ref>
== Utilización como suplemento dietario ==
A glicosamina oral é un suplemento dietario.<ref>{{Cita web |url=http://www.fda.gov/Food/DietarySupplements/ConsumerInformation/ucm110417.htm |título=Copia arquivada |data-acceso=24 de novembro de 2011 |data-arquivo=04 de xuño de 2011 |url-arquivo=https://web.archive.org/web/20110604015423/http://www.fda.gov/Food/DietarySupplements/ConsumerInformation/ucm110417.htm |url-morta=yes }}</ref> A glicosamina comercialízase para mellorar a estrutura e función das articulacións, especialmente nos casos de [[artrose]]. Xeralmente comercialízase como glicosamina sulfato e glucosamina hidrocloruro. Xeralmente véndese en combinación con outros suplementos como o [[condroitín sulfato]] e o [[metilsulfonilmetano]].
=== Efectos sobre a saúde ===
Como a glicosamina é un precursor dos [[glicosaminoglicano]]s, e estes son un dos principais compoñentes da [[cartilaxe]] das [[articulación (anatomía)|articulacións]], a suplementación con glicosamina pode axudar a previr a dexeneración da cartilaxe e a tratar a artrite. O seu uso como terapia para a artrose parece segura, pero hai probas contraditorias sobre a súa efectividade. Unha revisión sistemática encontrou que os efectos positivos da glicosamina eran maiores nos estudos financiados polas industria e menores en estudos independentes.<ref>{{Cita publicación periódica |author=Vlad SC, LaValley MP, McAlindon TE and Felson DT |title=Glucosamine for Pain in Osteoarthritis; Why Do Trial Results Differ? |journal=Arthritis & Rheumatism |volume=56 |issue=7 |pages=2267–77 |year=2007 |pmid=17599746 |doi=10.1002/art.22728}}</ref><ref>{{Cita publicación periódica |author=Towheed TE |editor1-last=Towheed |editor1-first=Tanveer |title=Glucosamine therapy for treating osteoarthritis |journal=Cochrane Database Syst Rev |issue=2 |pages=CD002946 |year=2005 |pmid=15846645 |doi=10.1002/14651858.CD002946.pub2 |author2=Maxwell L |author3=Anastassiades TP |display-authors=3 |last4=Shea |first4=B |last5=Houpt |first5=J |last6=Robinson |first6=V |last7=Hochberg |first7=MC |last8=Wells |first8=G}} [http://www.cochrane.org/reviews/en/ab002946.html Cochrane entry].</ref><ref name=AFP2008>{{Cita publicación periódica |author=Dahmer S, Schiller RM |title=Glucosamine |journal=Am Fam Physician |volume=78 |issue=4 |pages=471–6 |year=2008 |pmid=18756654 |url=http://www.aafp.org/afp/20080815/471.html |apelidos= |data-acceso=24 de novembro de 2011 |data-arquivo=30 de maio de 2020 |url-arquivo=https://web.archive.org/web/20200530080623/https://www.aafp.org/afp/2008/0815/p471.html |url-morta=yes }}</ref>
Houbo múltiples ensaios clínicos da glicosamina como terapia médica para artrose, pero os resultados son contraditorios. As evidencias a favor e en contra da eficacia da glicosamina orixinaron un grande debate entre os médicos sobre se recomendar ou non un tratamento con glicosamina aos seus pacientes.<ref>{{Cita publicación periódica |author=Manson JJ, Rahman A |title=This house believes that we should advise our patients with osteoarthritis of the knee to take glucosamine |journal=[[Rheumatology (Oxford, England)]] |volume=43 |issue=1 |pages=100–1 |year=2004 |pmid=12867572 |doi=10.1093/rheumatology/keg458 |url=}}</ref><ref>{{Cita publicación periódica |author=Adams ME |title=Hype about glucosamine |journal=[[The Lancet|Lancet]] |volume=354 |issue=9176 |pages=353–4 |year=1999 |pmid=10437858 |doi=10.1016/S0140-6736(99)90040-5 |url=}}</ref><ref>{{Cita publicación periódica |author=McAlindon TE, LaValley MP, Gulin JP, Felson DT |title=Glucosamine and chondroitin for treatment of osteoarthritis: a systematic quality assessment and meta-analysis |journal=[[JAMA : the Journal of the American Medical Association]] |volume=283 |issue=11 |pages=1469–75 |year=2000 |pmid=10732937 |doi= 10.1001/jama.283.11.1469|url=}}</ref><ref>{{Cita publicación periódica |author=Reginster JY |title=Long-term effects of glucosamine sulphate on osteoarthritis progression: a randomised, placebo-controlled clinical trial |journal=[[The Lancet|Lancet]] |volume=357 |issue=9252 |pages=251–6 |year=2001 |pmid=11214126 |doi=10.1016/S0140-6736(00)03610-2 |author2=Deroisy R |author3=Rovati LC |display-authors=3 |last4=Lee |first4=Richard L |last5=Lejeune |first5=Eric |last6=Bruyere |first6=Olivier |last7=Giacovelli |first7=Giampaolo |last8=Henrotin |first8=Yves |last9=Dacre |first9=Jane E}}</ref><ref>{{Cita publicación periódica |author=Pavelká K, Gatterová J, Olejarová M, Machacek S, Giacovelli G, Rovati LC |title=Glucosamine sulfate use and delay of progression of knee osteoarthritis: a 3-year, randomized, placebo-controlled, double-blind study |journal=[[Archives of Internal Medicine]] |volume=162 |issue=18 |pages=2113–23 |year=2002 |pmid=12374520 |doi= 10.1001/archinte.162.18.2113|url=}}</ref><ref>{{Cita publicación periódica |author=Hughes R, Carr A |title=A randomized, double-blind, placebo-controlled trial of glucosamine sulphate as an analgesic in osteoarthritis of the knee |journal=[[Rheumatology (Oxford, England)]] |volume=41 |issue=3 |pages=279–84 |year=2002 |pmid=11934964 |doi= 10.1093/rheumatology/41.3.279|url=}}</ref><ref>{{Cita publicación periódica |author=Cibere J |title=Randomized, double-blind, placebo-controlled glucosamine discontinuation trial in knee osteoarthritis |journal=[[Arthritis and Rheumatism]] |volume=51 |issue=5 |pages=738–45 |year=2004 |pmid=15478160 |doi=10.1002/art.20697 |author2=Kopec JA |author3=Thorne A |display-authors=3 |last4=Singer |first4=Joel |last5=Canvin |first5=Janice |last6=Robinson |first6=David B. |last7=Pope |first7=Janet |last8=Hong |first8=Paul |last9=Grant |first9=Eric}}</ref><ref>{{Cita publicación periódica |author=Richy F, Bruyere O, Ethgen O, Cucherat M, Henrotin Y, Reginster JY |title=Structural and symptomatic efficacy of glucosamine and chondroitin in knee osteoarthritis: a comprehensive meta-analysis |journal=[[Archives of Internal Medicine]] |volume=163 |issue=13 |pages=1514–22 |year=2003 |pmid=12860572 |doi=10.1001/archinte.163.13.1514 |url=}}</ref>
Esta confusión levou ao [[National Institutes of Health]] nos
Os estudos e metaanálises levados a cabo en 2007, 2009 e 2010 foron tamén contraditorios e discutidos.<ref name=GUIDE2007>{{Cita publicación periódica |author=Herrero-Beaumont G |title=Glucosamine sulfate in the treatment of knee osteoarthritis symptoms: a randomized, double-blind, placebo-controlled study using acetaminophen as a side comparator |journal=Arthritis Rheum. |volume=56 |issue=2 |pages=555–67 |year=2007 |pmid=17265490 |doi=10.1002/art.22371 |author2=Ivorra JA |author3=Del Carmen Trabado M |display-authors=3 |last4=Blanco |first4=Francisco Javier |last5=Benito |first5=Pere |last6=Martín-Mola |first6=Emilio |last7=Paulino |first7=Javier |last8=Marenco |first8=José Luis |last9=Porto |first9=Armando}}</ref><ref name="pmid17599746">{{Cita publicación periódica |author=Vlad SC, LaValley MP, McAlindon TE, Felson DT |title=Glucosamine for pain in osteoarthritis: why do trial results differ? |journal=[[Arthritis and Rheumatism]] |volume=56 |issue=7 |pages=2267–77 |year=2007 |pmid=17599746 |doi=10.1002/art.22728 |url=}}</ref><ref name=Reginster2007>{{Cita publicación periódica |author=Reginster JY |title=The efficacy of glucosamine sulfate in osteoarthritis: financial and nonfinancial conflict of interest |journal=[[Arthritis and Rheumatism]] |volume=56 |issue=7 |pages=2105–10 |year=2007 |pmid=17599727 |doi=10.1002/art.22852 |url=}}</ref><ref>{{Cita publicación periódica |journal=J Orthop Surg (Hong Kong) |date=2009 Apr |volume=17 |issue=1 |pages=72–6 |title=Review article: Glucosamine |author=Kirkham SG, Samarasinghe RK |pmid=19398798 |issn=1022-5536}}</ref><ref>Vangsness Jr, C.; Spiker, W.; Erickson, J. (2009). "A review of evidence-based medicine for glucosamine and chondroitin sulfate use in knee osteoarthritis". Arthroscopy 25 (1): 86–94. doi:10.1016/j.arthro.2008.07.020. PMID 19111223.</ref><ref>{{Cita publicación periódica |author=Wandel S, Jüni P, Tendal B, Nüesch E, Villiger PM, Welton NJ, Trelle S| title=Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis |journal=British Medical Journal| year=2010| volume=341 |issue=sep16 2| pages=c4675 |url=http://www.bmj.com/content/341/bmj.c4675.full.pdf | doi=10.1136/bmj.c4675 |quote=Compared with placebo, glucosamine, chondroitin, and their combination do not reduce joint pain or have an impact on narrowing of joint space.}}</ref>
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Os estudos clínicos indicaron de forma sólida que a glicosamina é segura. Porén, un estudo recente da [[Universidade Laval]] mostra que a xente que toma glicosamina tende a tomala en exceso con respecto ás prescricións, e tomada en exceso pode producir danos pancreáticos, e incrementa o risco de [[diabetes]].<ref>{{Cita publicación periódica |author=Lafontaine-Lacasse M, Dore M, Picard, F |title=Hexosamines stimulate apoptosis by altering Sirt1 action and levelsin rodent pancreatic β-cells |journal=[[Journal of Endocrinology]] |pmid=20923823 |doi= 10.1677/JOE-10-0243 |volume=208 |issue=1 |year=2011 |pages=41–9}}</ref>
Os efectos secundarios da glicosamina son de pouca importancia e infrecuentes, e inclúen trastornos estomacais, problemas intestinais, dor de cabeza e erupcións cutáneas.<ref name="ARC report">{{cita libro|autor=McFarlane Gary J|título=Complementary and alternative medicines for the treatment of reheumatoid arthritis, osteoarthritis and fibromyalgia|editor=ARC|páxinas=44–46|isbn=9781901815139|url=http://www.arthritisresearchuk.org/Files/Complementary%20and%20alternative%20medicines_11012010154331.pdf|accessdate=29 April 2010|urlarquivo=https://web.archive.org/web/20100702112932/http://www.arthritisresearchuk.org/Files/Complementary%20and%20alternative%20medicines_11012010154331.pdf|dataarquivo=02 de xullo de 2010|urlmorta=
Considérase que non produce alerxia ás persoas alérxicas ao marisco.<ref>{{Cita publicación periódica |author=Gray HC, Hutcheson PS, Slavin RG |title=Is glucosamine safe in patients with seafood allergy? |url=https://archive.org/details/sim_journal-of-allergy-and-clinical-immunology_2004-08_114_2/page/459 |journal=[[The Journal of Allergy and Clinical Immunology]] |volume=114 |issue=2 |pages=459–60 |year=2004 |pmid=15341031 |doi= 10.1016/j.jaci.2004.05.050}}</ref>
Considérase que a glicosamina non interfire coa regulación da ruta de síntese da hexosamina.<ref name="Buse"/><ref>{{Cita publicación periódica |author=Scroggie DA, Albright A, Harris MD |title=The effect of glucosamine-chondroitin supplementation on glycosylated hemoglobin levels in patients with type 2 diabetes mellitus: a placebo-controlled, double-blinded, randomized clinical trial |journal=[[Archives of Internal Medicine]] |volume=163 |issue=13 |pages=1587–90 |year=2003 |pmid=12860582 |doi=10.1001/archinte.163.13.1587}}</ref><ref>{{Cita publicación periódica |author=Tannis AJ, Barban J, Conquer JA |title=Effect of glucosamine supplementation on fasting and non-fasting plasma glucose and serum insulin concentrations in healthy individuals |journal=[[Osteoarthritis and Cartilage / OARS, Osteoarthritis Research Society]] |volume=12 |issue=6 |pages=506–11 |year=2004 |pmid=15135147 |doi=10.1016/j.joca.2004.03.001}}</ref><ref>{{Cita publicación periódica |author=Monauni T |title=Effects of glucosamine infusion on insulin secretion and insulin action in humans |url=https://archive.org/details/sim_diabetes_2000-06_49_6/page/926 |journal=[[Diabetes (journal)|Diabetes]] |volume=49 |issue=6 |pages=926–35 |year=2000 |pmid=10866044 |doi= 10.2337/diabetes.49.6.926 |author2=Zenti MG |author3=Cretti A |display-authors=3 |last4=Daniels |first4=M. C. |last5=Targher |first5=G. |last6=Caruso |first6=B. |last7=Caputo |first7=M. |last8=McClain |first8=D. |last9=Del Prato |first9=S.}}</ref><ref>{{Cita publicación periódica |author=Anderson JW, Nicolosi RJ, Borzelleca JF |title=Glucosamine effects in humans: a review of effects on glucose metabolism, side effects, safety considerations and efficacy |journal=[[Food and Chemical Toxicology]] |volume=43 |issue=2 |pages=187–201 |year=2005 |pmid=15621331 |doi=10.1016/j.fct.2004.11.006}}</ref><ref>{{Cita publicación periódica |author=Muniyappa R |title=Oral glucosamine for 6 weeks at standard doses does not cause or worsen insulin resistance or endothelial dysfunction in lean or obese subjects |url=https://archive.org/details/sim_diabetes_2006-11_55_11/page/3142 |journal=[[Diabetes (journal)|Diabetes]] |volume=55 |issue=11 |pages=3142–50 |year=2006 |pmid=17065354 |doi=10.2337/db06-0714 |author2=Karne RJ |author3=Hall G |display-authors=3 |last4=Crandon |first4=S. K. |last5=Bronstein |first5=J. A. |last6=Ver |first6=M. R. |last7=Hortin |first7=G. L. |last8=Quon |first8=M. J.}}</ref><ref>{{Cita publicación periódica |author=Pouwels MJ, Jacobs JR, Span PN, Lutterman JA, Smits P, Tack CJ |title=Short-term glucosamine infusion does not affect insulin sensitivity in humans |journal=[[The Journal of Clinical Endocrinology and Metabolism]] |volume=86 |issue=5 |pages=2099–103 |year=2001 |pmid=11344213 |doi= 10.1210/jc.86.5.2099}}</ref><ref>{{Cita publicación periódica |author=Biggee BA, Blinn CM, Nuite M, Silbert JE, McAlindon TE |title=Effects of oral glucosamine sulphate on serum glucose and insulin during an oral glucose tolerance test of subjects with osteoarthritis |journal=[[Annals of the Rheumatic Diseases]] |volume=66 |issue=2 |pages=260–2 |year=2007 |pmid=16818461 |pmc=1798503 |doi=10.1136/ard.2006.058222}}</ref>
== Status legal ==
Liña 98:
=== Nos Estados Unidos ===
Nos Estados Unidos a glicosamina non está aprobada pola FDA ([[Food and Drug Administration]]) para uso médico en humanos. Como a glicosamina está clasificada como un suplemento dietario nos
== Notas ==
Liña 116:
* "[http://www.clinicaltrials.gov/show/NCT00032890 Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT)]," ClinicalTrials.gov registration and information.
* "[http://www.clinicaltrials.gov/ct/show/NCT00065377 Effects of Oral Glucosamine on Insulin and Blood Vessel Activity in Normal and Obese People]," ClinicalTrials.gov information.
* "[http://www.nih.gov/news/pr/feb2006/nccam-22.htm NIH News: Efficacy of Glucosamine and Chondroitin Sulfate May Depend on Level of Osteoarthritis Pain]," Wednesday,
* "[http://www.quackwatch.org/01QuackeryRelatedTopics/DSH/glucosamine.html Glucosamine and Chondroitin for Arthritis: Benefit is Unlikely]," Summary of and commentary on research findings, including GAIT.
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