|
|
| L-ascorbic acid |
|
| CHEBI:29073 |
|
| L-ascorbic acid |
|
| The L-enantiomer of ascorbic acid and conjugate acid of L-ascorbate. |
|
This entity has been manually annotated by the ChEBI Team.
|
|
|
CHEBI:2868, CHEBI:43473, CHEBI:40892, CHEBI:17208, CHEBI:21240
|
|
| ChemicalBook:CB7853704, ChemicalBook:CB3777943, eMolecules:26405050, eMolecules:29534153, eMolecules:492402, Selleckchem:vitamin-c-ascorbic-acid, ZINC000100006770 |
|
|
Molfile
XML
SDF
|
|
|
more structures >>
|
|
call loadScript javascripts\jsmol\core\package.js call loadScript javascripts\jsmol\core\core.z.js -- required by ClazzNode call loadScript javascripts\jsmol\J\awtjs2d\WebOutputChannel.js Jmol JavaScript applet jmolApplet0_object__07878783713237691__ initializing getValue debug = null getValue logLevel = null getValue allowjavascript = null AppletRegistry.checkIn(jmolApplet0_object__07878783713237691__) call loadScript javascripts\jsmol\core\corestate.z.js viewerOptions: { "name":"jmolApplet0_object","applet":true,"documentBase":"https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:29073","platform":"J.awtjs2d.Platform","fullName":"jmolApplet0_object__07878783713237691__","display":"jmolApplet0_canvas2d","signedApplet":"true","appletReadyCallback":"Jmol._readyCallback","statusListener":"[J.appletjs.Jmol.MyStatusListener object]","codeBase":"https://www.ebi.ac.uk/chebi/javascripts/jsmol/","syncId":"07878783713237691","bgcolor":"#000" } (C) 2012 Jmol Development Jmol Version: 13.2.7 $Date: 2013-10-01 11:35:15 -0500 (Tue, 01 Oct 2013) $ java.vendor: j2s java.version: 0.0 os.name: j2s Access: ALL memory: 0.0/0.0 processors available: 1 useCommandThread: false appletId:jmolApplet0_object (signed) starting HoverWatcher_1 getValue emulate = null defaults = "Jmol" getValue boxbgcolor = null getValue bgcolor = #000 backgroundColor = "#000" getValue ANIMFRAMECallback = null getValue APPLETREADYCallback = Jmol._readyCallback APPLETREADYCallback = "Jmol._readyCallback" getValue ATOMMOVEDCallback = null getValue CLICKCallback = null getValue ECHOCallback = null getValue ERRORCallback = null getValue EVALCallback = null getValue HOVERCallback = null getValue LOADSTRUCTCallback = null getValue MEASURECallback = null getValue MESSAGECallback = null getValue MINIMIZATIONCallback = null getValue PICKCallback = null getValue RESIZECallback = null getValue SCRIPTCallback = null getValue SYNCCallback = null getValue STRUCTUREMODIFIEDCallback = null getValue doTranslate = null language=en_US getValue popupMenu = null getValue script = null Jmol applet jmolApplet0_object__07878783713237691__ ready call loadScript javascripts\jsmol\core\corescript.z.js call loadScript javascripts\jsmol\J\script\FileLoadThread.js starting QueueThread0_2 script 1 started starting HoverWatcher_3 starting HoverWatcher_4 The Resolver thinks Mol Marvin 11150514023D starting HoverWatcher_5 Time for openFile( Marvin 11150514023D 20 20 0 0 0 0 999 V2000 2.1460 -3.5372 1.5363 C 0 0 2 0 0 0 0 0 0 0 0 0 2.6985 -4.6232 2.4384 C 0 0 0 0 0 0 0 0 0 0 0 0 3.3296 -2.9255 0.9845 O 0 0 0 0 0 0 0 0 0 0 0 0 1.3154 -2.5163 2.3229 C 0 0 2 0 0 0 0 0 0 0 0 0 4.0254 -4.6232 2.3916 C 0 0 0 0 0 0 0 0 0 0 0 0 1.9452 -5.4808 3.1776 O 0 0 0 0 0 0 0 0 0 0 0 0 4.4235 -3.5701 1.4924 C 0 0 0 0 0 0 0 0 0 0 0 0 0.7728 -1.4526 1.3667 C 0 0 0 0 0 0 0 0 0 0 0 0 2.1357 -1.8974 3.3028 O 0 0 0 0 0 0 0 0 0 0 0 0 4.8550 -5.4623 3.0673 O 0 0 0 0 0 0 0 0 0 0 0 0 5.5702 -3.2940 1.2228 O 0 0 0 0 0 0 0 0 0 0 0 0 1.8561 -0.8035 0.7186 O 0 0 0 0 0 0 0 0 0 0 0 0 1.4980 -3.9285 0.7230 H 0 0 0 0 0 0 0 0 0 0 0 0 0.4941 -3.0063 2.8882 H 0 0 0 0 0 0 0 0 0 0 0 0 2.3942 -6.1861 3.7479 H 0 0 0 0 0 0 0 0 0 0 0 0 0.1922 -0.6818 1.9175 H 0 0 0 0 0 0 0 0 0 0 0 0 0.1312 -1.9115 0.5843 H 0 0 0 0 0 0 0 0 0 0 0 0 1.8966 -1.9718 4.2832 H 0 0 0 0 0 0 0 0 0 0 0 0 5.8577 -5.3772 2.9600 H 0 0 0 0 0 0 0 0 0 0 0 0 1.9270 -0.8230 -0.2907 H 0 0 0 0 0 0 0 0 0 0 0 0 1 2 1 0 0 0 0 1 3 1 0 0 0 0 1 4 1 0 0 0 0 2 5 2 0 0 0 0 2 6 1 0 0 0 0 3 7 1 0 0 0 0 4 8 1 0 0 0 0 4 9 1 0 0 0 0 5 7 1 0 0 0 0 5 10 1 0 0 0 0 7 11 2 0 0 0 0 8 12 1 0 0 0 0 13 1 1 0 0 0 0 14 4 1 0 0 0 0 15 6 1 0 0 0 0 16 8 1 0 0 0 0 17 8 1 0 0 0 0 18 9 1 0 0 0 0 19 10 1 0 0 0 0 20 12 1 0 0 0 0 M END): 19 ms reading 20 atoms ModelSet: haveSymmetry:false haveUnitcells:false haveFractionalCoord:false 1 model in this collection. Use getProperty "modelInfo" or getProperty "auxiliaryInfo" to inspect them. Default Van der Waals type for model set to Babel 20 atoms created ModelSet: not autobonding; use forceAutobond=true to force automatic bond creation Script completed Jmol script terminated
|
| Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits, berries and vegetables. It is also a generic prescription medication and in some countries is sold as a non-prescription dietary supplement. As a therapy, it is used to prevent and treat scurvy, a disease caused by vitamin C deficiency.
Vitamin C is an essential nutrient involved in the repair of tissue, the formation of collagen, and the enzymatic production of certain neurotransmitters. It is required for the functioning of several enzymes and is important for immune system function. It also functions as an antioxidant. Vitamin C may be taken by mouth or by intramuscular, subcutaneous or intravenous injection. Various health claims exist on the basis that moderate vitamin C deficiency increases disease risk, such as for the common cold, cancer or COVID-19. There are also claims of benefits from vitamin C supplementation in excess of the recommended dietary intake for people who are not considered vitamin C deficient. Vitamin C is generally well tolerated. Large doses may cause gastrointestinal discomfort, headache, trouble sleeping, and flushing of the skin. The United States Institute of Medicine recommends against consuming large amounts.: 155–165
Most animals are able to synthesize their own vitamin C. However, apes (including humans) and monkeys (but not all primates), most bats, most fish, some rodents, and certain other animals must acquire it from dietary sources because a gene for a synthesis enzyme has mutations that render it dysfunctional.
Vitamin C was discovered in 1912, isolated in 1928, and in 1933, was the first vitamin to be chemically produced. Partly for its discovery, Albert Szent-Györgyi was awarded the 1937 Nobel Prize in Physiology or Medicine. |
|
Read full article at Wikipedia
|
| InChI=1S/C6H8O6/c7-1-2(8)5-3(9)4(10)6(11)12-5/h2,5,7-10H,1H2/t2-,5+/m0/s1 |
| CIWBSHSKHKDKBQ-JLAZNSOCSA-N |
| [H][C@@]1(OC(=O)C(O)=C1O)[C@@H](O)CO |
|
|
Arabidopsis thaliana
(NCBI:txid3702)
|
See:
DOI
|
|
food antioxidant
An antioxidant that used as a food additives to help guard against food deterioration.
Bronsted acid
A molecular entity capable of donating a hydron to an acceptor (Bronsted base).
(via oxoacid )
|
|
|
coenzyme
A low-molecular-weight, non-protein organic compound participating in enzymatic reactions as dissociable acceptor or donor of chemical groups or electrons.
plant metabolite
Any eukaryotic metabolite produced during a metabolic reaction in plants, the kingdom that include flowering plants, conifers and other gymnosperms.
food colour retention agent
A food additive that intensifies, retains or stabilises the colour of a food.
cofactor
An organic molecule or ion (usually a metal ion) that is required by an enzyme for its activity. It may be attached either loosely (coenzyme) or tightly (prosthetic group).
flour treatment agent
A food additive which is added to flour or dough to improve baking quality and/or colour.
food antioxidant
An antioxidant that used as a food additives to help guard against food deterioration.
water-soluble vitamin (role)
Any vitamin that dissolves in water and readily absorbed into tissues for immediate use. Unlike the fat-soluble vitamins, they are not stored in the body and need to be replenished regularly in the diet and will rarely accumulate to toxic levels since they are quickly excreted from the body via urine.
(via vitamin C )
|
|
|
skin lightening agent
Any cosmetic used to lighten the colour of skin by reducing the concentration of melanin.
food colour retention agent
A food additive that intensifies, retains or stabilises the colour of a food.
geroprotector
Any compound that supports healthy aging, slows the biological aging process, or extends lifespan.
flour treatment agent
A food additive which is added to flour or dough to improve baking quality and/or colour.
food antioxidant
An antioxidant that used as a food additives to help guard against food deterioration.
|
|
View more via ChEBI Ontology
|
(5R)-5-[(1S)-1,2-dihydroxyethyl]-3,4-dihydroxyfuran-2(5H)-one
|
|
L-threo-hex-2-enono-1,4-lactone
|
acide ascorbique
|
ChemIDplus
|
ácido ascórbico
|
ChemIDplus
|
acidum ascorbicum
|
ChemIDplus
|
|
ascorbic acid
|
KEGG DRUG
|
|
acidum ascorbinicum
|
ChemIDplus
|
|
ASCORBIC ACID
|
PDBeChem
|
|
Ascorbic acid
|
KEGG COMPOUND
|
|
Ascorbicap
|
KEGG DRUG
|
Ascorbinsäure
|
ChEBI
|
|
E 300
|
ChEBI
|
|
E-300
|
ChEBI
|
|
E300
|
ChEBI
|
|
L-(+)-ascorbic acid
|
NIST Chemistry WebBook
|
|
L-Ascorbate
|
KEGG COMPOUND
|
|
L-Ascorbic acid
|
KEGG COMPOUND
|
|
Vitamin C
|
KEGG COMPOUND
|
|
2405
|
BPDB
|
|
4072
|
DrugCentral
|
|
ASC
|
PDBeChem
|
|
ASCORBATE
|
MetaCyc
|
|
Ascorbic_Acid
|
Wikipedia
|
|
C00001179
|
KNApSAcK
|
|
C00072
|
KEGG COMPOUND
|
|
D00018
|
KEGG DRUG
|
|
DB00126
|
DrugBank
|
|
HMDB0000044
|
HMDB
|
| View more database links |
|
4087
|
Gmelin Registry Number
|
Gmelin
|
|
50-81-7
|
CAS Registry Number
|
KEGG COMPOUND
|
|
50-81-7
|
CAS Registry Number
|
NIST Chemistry WebBook
|
|
50-81-7
|
CAS Registry Number
|
ChemIDplus
|
|
84272
|
Reaxys Registry Number
|
Reaxys
|
Roux A, Xu Y, Heilier JF, Olivier MF, Ezan E, Tabet JC, Junot C (2012)
Annotation of the human adult urinary metabolome and metabolite identification using ultra high performance liquid chromatography coupled to a linear quadrupole ion trap-Orbitrap mass spectrometer.
Analytical chemistry 84, 6429-6437 [PubMed:22770225]
[show Abstract]
Metabolic profiles of biofluids obtained by atmospheric pressure ionization mass spectrometry-based technologies contain hundreds to thousands of features, most of them remaining unknown or at least not characterized in analytical systems. We report here on the annotation of the human adult urinary metabolome and metabolite identification from electrospray ionization mass spectrometry (ESI-MS)-based metabolomics data sets. Features of biological interest were first of all annotated using the ESI-MS database of the laboratory. They were also grouped, thanks to software tools, and annotated using public databases. Metabolite identification was achieved using two complementary approaches: (i) formal identification by matching chromatographic retention times, mass spectra, and also product ion spectra (if required) of metabolites to be characterized in biological data sets to those of reference compounds and (ii) putative identification from biological data thanks to MS/MS experiments for metabolites not available in our chemical library. By these means, 384 metabolites corresponding to 1484 annotated features (659 in negative ion mode and 825 in positive ion mode) were characterized in human urine samples. Of these metabolites, 192 and 66 were formally and putatively identified, respectively, and 54 are reported in human urine for the first time. These lists of features could be used by other laboratories to annotate their ESI-MS metabolomics data sets. | Choi HK, Gao X, Curhan G (2009)
Vitamin C intake and the risk of gout in men: a prospective study.
Archives of internal medicine 169, 502-507 [PubMed:19273781]
[show Abstract]
BackgroundSeveral metabolic studies and a recent double-blind, placebo-controlled, randomized trial have shown that higher vitamin C intake significantly reduces serum uric acid levels. Yet the relation with risk of gout is unknown.MethodsWe prospectively examined, from 1986 through 2006, the relation between vitamin C intake and risk of incident gout in 46 994 male participants with no history of gout at baseline. We used a supplementary questionnaire to ascertain the American College of Rheumatology criteria for gout. Vitamin C intake was assessed every 4 years through validated questionnaires.ResultsDuring the 20 years of follow-up, we documented 1317 confirmed incident cases of gout. Compared with men with vitamin C intake less than 250 mg/d, the multivariate relative risk (RR) of gout was 0.83 (95% confidence interval [CI], 0.71-0.97) for total vitamin C intake of 500 to 999 mg/d, 0.66 (0.52-0.86) for 1000 to 1499 mg/d, and 0.55 (0.38-0.80) for 1500 mg/d or greater (P < .001 for trend). The multivariate RR per 500-mg increase in total daily vitamin C intake was 0.83 (95% CI, 0.77-0.90). Compared with men who did not use supplemental vitamin C, the multivariate RR of gout was 0.66 (95% CI, 0.49-0.88) for supplemental vitamin C intake of 1000 to 1499 mg/d and 0.55 (0.36-0.86) for 1500 mg/d or greater (P < .001 for trend).ConclusionsHigher vitamin C intake is independently associated with a lower risk of gout. Supplemental vitamin C intake may be beneficial in the prevention of gout. | Barbosa E, Faintuch J, Machado Moreira EA, Gonçalves da Silva VR, Lopes Pereima MJ, Martins Fagundes RL, Filho DW (2009)
Supplementation of vitamin E, vitamin C, and zinc attenuates oxidative stress in burned children: a randomized, double-blind, placebo-controlled pilot study.
Journal of burn care & research : official publication of the American Burn Association 30, 859-866 [PubMed:19692922]
[show Abstract]
The aim of this study was to investigate the effect of supplementation of vitamin E, vitamin C, and zinc on the oxidative stress in burned children. In a prospective double-blind placebo controlled pilot study, 32 patients were randomized as no supplementation (n = 15) or antioxidant supplementation (n = 17) groups. Supplementation consisted of the antioxidant mixture of vitamin C (1.5 times upper intake level), vitamin E (1.35 times upper intake level), and zinc (2.0 times recommended dietary allowance) administered during 7 days starting on the second day of admittance into the hospital. Energy requirement was calculated by the Curreri equation, and protein input was 3.0 g/kg of ideal body mass index (percentile 50). Total antioxidant capacity of plasma and malondialdehyde were used to monitor oxidative stress. The time of wound healing was evaluated as the main clinical feature. Patients (age 54.2 +/- 48.9 months, 65.6% males), who exhibited 15.5 +/- 6.7% of total burn area, showed no differences in age and sex, when compared with controls. Intake of the administered antioxidants was obviously higher in treated subjects (P = .005), and serum differences were confirmed for vitamin E and C, but not for zinc (P = .180). There was a decrease in lipid peroxidation (malondialdehyde level) (P = .006) and an increase in vitamin E concentrations in the antioxidant supplementation group (P = .016). The time of wound healing was lower in the supplemented group (P < .001). The antioxidant supplementation through vitamin E and C and the mineral zinc apparently enhanced antioxidant protection against oxidative stress and allowed less time for wound healing. | Shibamura A, Ikeda T, Nishikawa Y (2009)
A method for oral administration of hydrophilic substances to Caenorhabditis elegans: Effects of oral supplementation with antioxidants on the nematode lifespan.
Mechanisms of ageing and development 130, 652-655 [PubMed:19580823]
[show Abstract]
Numerous studies using Caenorhabditis elegans have used a protocol in which chemicals are orally delivered by incorporating them into the nematode growth media or mixing them with the food bacteria. However, actual exposure levels are difficult to estimate as they are influenced by both the rates of ingestion into the intestine as well as absorption from the intestinal lumen. We used liposomes loaded with the hydrophilic fluorescent reagent uranin to test oral administration of water-soluble substances to C. elegans. Ingestion of liposomes loaded with fluorescent dye resulted in successful oral delivery of chemicals into the intestines of C. elegans. Using liposomes, oral administration of hydrophilic antioxidants (ascorbic acid, N-acetyl-cysteine, reduced glutathione, and thioproline) prolonged the lifespan of the nematodes, whereas the conventional method of delivery showed neither fluorescence nor longevity effects. Our method efficiently and quantitatively delivers solutes to nematodes. | Furuya A, Uozaki M, Yamasaki H, Arakawa T, Arita M, Koyama AH (2008)
Antiviral effects of ascorbic and dehydroascorbic acids in vitro.
International journal of molecular medicine 22, 541-545 [PubMed:18813862]
[show Abstract]
In the present study, ascorbic acid weakly inhibited the multiplication of viruses of three different families: herpes simplex virus type 1 (HSV-1), influenza virus type A and poliovirus type 1. Dehydroascorbic acid, an oxidized form of ascorbic acid and hence without reducing ability, showed much stronger antiviral activity than ascorbic acid, indicating that the antiviral activity of ascorbic acid is due to factors other than an antioxidant mechanism. Moreover, addition of 1 mM Fe3+, which oxidizes ascorbic acid to dehydroascorbic acid and also enhances the formation of hydroxyl radicals by ascorbic acid in the culture media, strongly enhanced the antiviral activity of ascorbic acid to a level significantly stronger than that of dehydroascorbic acid. Although both ascorbic acid and dehydroascorbic acid showed some cytotoxicity, the degree of cytotoxicity of the former was 10-fold higher than the latter, suggesting that the observed antiviral activity of ascorbic acid with and without ferric ion is, at least in part, a secondary result of the cytotoxic effect of the reagent, most likely due to the free radicals. However, the possibility that oxidation of ascorbic acid also contributed to the antiviral effects of ascorbic acid exists, in particular in the presence of ferric ion, since dehydroascorbic acid exhibited a very strong antiviral activity. Characterization of the mode of antiviral action of dehydroascorbic acid revealed that the addition of the reagent even at 11 h post infection almost completely inhibited the formation of progeny infectious virus in the infected cells, indicating that the reagent inhibits HSV-1 multiplication probably at the assembly process of progeny virus particles after the completion of viral DNA replication. | Rai B, Kharb S, Jain R, Anand SC (2007)
Salivary vitamins E and C in oral cancer.
Redox report : communications in free radical research 12, 163-164 [PubMed:17623524]
[show Abstract]
Lipid peroxidation may be involved in cancer and essential nutrients that can scavenge free radicals, such as vitamins E and C, operate in concert. Levels of antioxidant vitamins E and C were estimated in 50 patients with oral cancer and 24 healthy persons served as control. Significantly lower levels of vitamins E and C were observed in oral cancer patients as compared to controls (P < 0.011). Antioxidant nutrients may be utilized to a greater extent in oral cancer patients to counteract free radical-mediated cell disturbances, resulting in a reduction in salivary antioxidant levels. | Hemilä H, Louhiala P (2007)
Vitamin C for preventing and treating pneumonia.
The Cochrane database of systematic reviewsCD005532 [PubMed:17253561]
[show Abstract]
BackgroundPneumonia is one of the most common serious infections, causing two million deaths annually among young children in developing countries. In developed countries pneumonia is most significantly a problem of the elderly.ObjectivesTo assess the prophylactic and therapeutic effects of vitamin C on pneumonia.Search strategyWe searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 1), OLD MEDLINE (1950 TO 1965), MEDLINE (1966 to February Week 2, 2006), EMBASE (1974 to March 2006), Web of Science (1945 to February 2006) and reference lists of reviews and articles.Selection criteriaTo assess the therapeutic effects of vitamin C, we selected placebo-controlled trials. To assess prophylactic effects, we selected controlled trials with or without a placebo.Data collection and analysisTwo review authors independently read the trial reports and extracted data.Main resultsWe identified three prophylactic trials which recorded 37 cases of pneumonia in 2,335 people. Only one was satisfactorily randomised, double-blind and placebo-controlled. Two trials examined military recruits and the third studied boys from "lower wage-earning classes" attending a boarding school in the UK during World War II. Each of these trials found a statistically significant (80% or greater) reduction in pneumonia incidence in the vitamin C group. We identified two therapeutic trials involving 197 pneumonia patients. Only one was satisfactorily randomised, double-blind and placebo-controlled. One studied elderly patients in the UK which found lower mortality and reduced respiratory symptom scores in the vitamin C group; however, the benefit was restricted to the most ill patients. The other studied adults (with a wide age range) in the former Soviet Union and found a dose-dependent reduction in the time to recovery with two vitamin C doses.Authors' conclusionsThe prophylactic use of vitamin C to prevent pneumonia should be further investigated in populations who have high incidence of pneumonia, especially if dietary vitamin C intake is low. Similarly, the therapeutic effects of vitamin C should be studied especially in patients with low plasma vitamin C levels. The current evidence is too weak to advocate widespread prophylactic use of vitamin C to prevent pneumonia in the general population. However, therapeutic vitamin C supplementation may be reasonable for pneumonia patients who have low vitamin C plasma levels because its cost and risks are low. | Douglas RM, Hemilä H, Chalker E, Treacy B (2007)
Vitamin C for preventing and treating the common cold.
The Cochrane database of systematic reviewsCD000980 [PubMed:17636648]
[show Abstract]
BackgroundThe role of vitamin C (ascorbic acid) in the prevention and treatment of the common cold has been a subject of controversy for 60 years, but is widely sold and used as both a preventive and therapeutic agent.ObjectivesTo discover whether oral doses of 0.2 g or more daily of vitamin C reduces the incidence, duration or severity of the common cold when used either as continuous prophylaxis or after the onset of symptoms.Search strategyWe searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2006); MEDLINE (1966 to December 2006); and EMBASE (1990 to December 2006).Selection criteriaPapers were excluded if a dose less than 0.2 g per day of vitamin C was used, or if there was no placebo comparison.Data collection and analysisTwo review authors independently extracted data and assessed trial quality. 'Incidence' of colds during prophylaxis was assessed as the proportion of participants experiencing one or more colds during the study period. 'Duration' was the mean days of illness of cold episodes.Main resultsThirty trial comparisons involving 11,350 study participants contributed to the meta-analysis on the relative risk (RR) of developing a cold whilst taking prophylactic vitamin C. The pooled RR was 0.96 (95% confidence intervals (CI) 0.92 to 1.00). A subgroup of six trials involving a total of 642 marathon runners, skiers, and soldiers on sub-arctic exercises reported a pooled RR of 0.50 (95% CI 0.38 to 0.66). Thirty comparisons involving 9676 respiratory episodes contributed to a meta-analysis on common cold duration during prophylaxis. A consistent benefit was observed, representing a reduction in cold duration of 8% (95% CI 3% to 13%) for adults and 13.6% (95% CI 5% to 22%) for children. Seven trial comparisons involving 3294 respiratory episodes contributed to the meta-analysis of cold duration during therapy with vitamin C initiated after the onset of symptoms. No significant differences from placebo were seen. Four trial comparisons involving 2753 respiratory episodes contributed to the meta-analysis of cold severity during therapy and no significant differences from placebo were seen.Authors' conclusionsThe failure of vitamin C supplementation to reduce the incidence of colds in the normal population indicates that routine mega-dose prophylaxis is not rationally justified for community use. But evidence suggests that it could be justified in people exposed to brief periods of severe physical exercise or cold environments. | Huang J, May JM (2006)
Ascorbic acid protects SH-SY5Y neuroblastoma cells from apoptosis and death induced by beta-amyloid.
Brain research 1097, 52-58 [PubMed:16725131]
[show Abstract]
beta-Amyloid causes apoptosis and death in cultured neurons that may be mediated by generation of reactive oxygen species. Since ascorbic acid concentrations are relatively high in brain, we tested whether and how this antioxidant might protect cultured SH-SY5Y neuroblastoma cells from apoptotic cell death. SH-SY5Y cells did not contain ascorbate in culture but readily took it up to achieve intracellular concentrations several-fold those of GSH. Treatment of cells with 2-10 microM beta-amyloid(25-35) decreased both intracellular ascorbate and GSH without affecting rates of ascorbate transport, which suggests that the peptide induces an oxidant stress in the cells. Overnight culture of cells with 10-20 microM beta-amyloid(25-35) induced apoptosis in SH-SY5Y cells when measured as externalization of phosphatidylserine by annexin V binding, as DNA fragmentation in the TUNEL assay, and as caspase-3 activity in cell lysates. Pre-loading cells with ascorbate substantially prevented apoptosis measured by these assays as well as cell death. In addition to preventing apoptosis, ascorbate loading of SH-SY5Y cells also decreased basal rates of generation of endogenous beta-amyloid. Together, these results support the notion that beta-amyloid induces apoptosis and death in neurons due to oxidant stress and suggest that intracellular ascorbate effectively prevents this toxicity. | Wannamethee SG, Lowe GD, Rumley A, Bruckdorfer KR, Whincup PH (2006)
Associations of vitamin C status, fruit and vegetable intakes, and markers of inflammation and hemostasis.
The American journal of clinical nutrition 83, 567-74; quiz 726-7 [PubMed:16522902]
[show Abstract]
BackgroundIt has been suggested that a high dietary intake and high circulating concentrations of vitamin C may protect against ischemic heart disease.ObjectivesThe objective was to examine the associations between dietary and plasma vitamin C concentrations, fruit and vegetable intakes, and markers of inflammation and hemostasis associated with cardiovascular disease in older men free of cardiovascular disease.DesignThis cross-sectional study examined 3258 men aged 60-79 y with no physician diagnosis of myocardial infarction, stroke, or diabetes and who were drawn from general practices in 24 British towns. Fruit and vegetable intakes and dietary vitamin C were assessed by using a food-frequency questionnaire.ResultsPlasma vitamin C, fruit intake, and dietary vitamin C intake were significantly and inversely associated with mean concentrations of C-reactive protein, an acute phase reactant, and tissue plasminogen activator (t-PA) antigen, a marker of endothelial dysfunction, even after adjustment for confounders. Vegetable intake was correlated significantly (inversely) only with t-PA. For plasma vitamin C (highest versus lowest quartile), the adjusted odds of elevated C-reactive protein and t-PA (highest tertile versus lowest tertile) were 0.56 (95% CI: 0.44, 0.71) and 0.79 (0.62, 1.00); for fruit intake, the corresponding odds ratios were 0.76 (0.60, 0.95) and 0.76 (0.61, 0.95). Plasma (but not dietary) vitamin C also showed inverse associations with both fibrinogen concentrations and blood viscosity. No associations were seen with von Willebrand factor or factor VIII.ConclusionThe findings suggest that vitamin C has antiinflammatory effects and is associated with lower endothelial dysfunction in men with no history of cardiovascular disease or diabetes. | Close GL, Ashton T, Cable T, Doran D, Holloway C, McArdle F, MacLaren DP (2006)
Ascorbic acid supplementation does not attenuate post-exercise muscle soreness following muscle-damaging exercise but may delay the recovery process.
The British journal of nutrition 95, 976-981 [PubMed:16611389]
[show Abstract]
Exercise involving lengthening muscle actions, such as downhill running, results in delayed onset muscle soreness (DOMS), which may be attributable to reactive oxygen species (ROS). Although exercise causes oxidative stress, any link between ROS and DOMS remains speculative. There is emerging evidence to suggest that ROS play an important physiological role, assisting in the recovery process and protecting the cell from future damage; however, this has not been fully established. Despite this uncertainty as to the precise role of ROS, attempts to prevent post-exercise ROS production through antioxidant intervention are still common. The study investigated the effects of ascorbic acid supplementation on ROS production and DOMS following downhill running. Subjects were assigned to two groups. The ascorbic acid group (group AA) received 1 g ascorbic acid 2 h pre-, and for 14 d post-downhill running, whilst the placebo group (Pl group) received a placebo. Blood samples were drawn pre-supplement, pre- and post-exercise, and then 1, 2, 3, 4, 7 and 14 d post-exercise for analysis of ascorbate, malonaldehyde and total glutathione. DOMS was assessed using a visual analogue scale and pressure algometry. Muscle function was assessed using isokinetic dynamometry. Plasma ascorbate was elevated throughout in group AA compared with the Pl group. Downhill running resulted in DOMS in both groups. Muscle function was impaired post-exercise in both groups, although a delayed recovery was noted in group AA. Malonaldehyde increased 4 d post-exercise in the Pl group only. Ascorbic acid supplementation attenuates ROS production following downhill running, without affecting DOMS. Furthermore, ascorbic acid supplementation may inhibit the recovery of muscle function. | Khonsari H, Grandière-Perez L, Caumes E (2005)
[Scurvy, a re-emerging disease].
La Revue de medecine interne 26, 885-890 [PubMed:15949874]
[show Abstract]
BackgroundScurvy is the clinical manifestation of vitamin C deficiency. It is historically linked to the era of great maritime expeditions. But it is remerging in Western countries as in France.SituationNowadays, scurvy mainly affects homeless populations of large occidental cities and the isolated and malnourished inhabitants of developing countries. The clinical presentations of scurvy are numerous and often misleading and its evolution without treatment is always lethal. After years of wanderings and research, the physiopathological mechanisms of scurvy were finally understood, due to the will of outstanding personalities who took the risk to brave the established superstitions in order to apply a strict medical approach.PerspectivesScurvy must still be prevented in at risk-populations. Indeed a pocket meal enriched with vitamin C is distributed to homeless people in Paris. | Berndt SI, Carter HB, Landis PK, Hallfrisch J, Rohrmann S, Metter EJ, Platz EA (2005)
Prediagnostic plasma vitamin C levels and the subsequent risk of prostate cancer.
Nutrition (Burbank, Los Angeles County, Calif.) 21, 686-690 [PubMed:15925292]
[show Abstract]
ObjectiveAntioxidants, such as vitamin C, are hypothesized to prevent prostate carcinogenesis by protecting the DNA from oxidative damage. We assessed whether higher prediagnostic plasma concentrations of vitamin C were associated with a lower risk of prostate cancer in a well-nourished cohort of men.MethodsPlasma concentrations of ascorbic acid (vitamin C) were previously determined in blood specimens collected between 1984 and 1990 in men participating in the Baltimore Longitudinal Study of Aging. Total plasma ascorbic acid (L-ascorbic acid plus dehydro-L-ascorbic acid) levels were measured by using a modification of the 2,4-dinitrophenylhydrazine method. Among the 498 male participants with measured plasma vitamin C levels, 62 men were subsequently diagnosed with prostate cancer during their lifetime. Cox proportional hazards regression models were used to estimate relative risks and 95% confidence intervals for prostate cancer.ResultsThe median plasma concentration of vitamin C for the cohort was 1.17 mg/dL, which is in the normal to high range for older men. The age-adjusted relative risk of prostate cancer for the highest quartile (median = 1.47 mg/dL, range = 1.36-2.58) compared with the lowest quartile (median = 0.83 mg/dL, range = 0.15-0.98) of plasma vitamin C concentration was 1.31 (95% confidence interval 0.63 to 2.70, P for trend = 0.29). Adjustment for cigarette smoking status, body mass index, or plasma cholesterol concentration did not attenuate the results.ConclusionsThis small but prospective study suggests that higher plasma vitamin C concentrations within the normal physiologic range are not associated with a lower risk of prostate cancer in well-nourished men. | Wolters M, Hickstein M, Flintermann A, Tewes U, Hahn A (2005)
Cognitive performance in relation to vitamin status in healthy elderly German women-the effect of 6-month multivitamin supplementation.
Preventive medicine 41, 253-259 [PubMed:15917019]
[show Abstract]
BackgroundPrior investigations have reported a link between poor status of antioxidants, folate, and cobalamin resulting in elevated total plasma homocysteine (tHcy) and methylmalonic acid (MMA) concentrations with an increased risk for reduced cognitive performance. The aim of the study was to evaluate the effect of a 6-month multivitamin supplementation on the cognitive performance of female seniors and to assess cognitive functioning in relation to vitamin status, tHcy, and MMA values at baseline.MethodsThe study was performed as a randomized placebo-controlled double-blind trial. 220 healthy, free-living women (aged 60-91 years) were included. Blood drawings and cognitive tests were performed at the Institute of Food Science of the University of Hanover, Germany. Vitamin and cognitive status have been evaluated prior to and 6 months after supplementation. Plasma ascorbic acid, serum concentrations of alpha-tocopherol, beta-carotene, and coenzyme Q10, serum and erythrocyte folate as well as serum cobalamin, serum MMA, and plasma tHcy concentrations were measured. Activity coefficient of erythrocyte alpha aspartic aminotransferase was used as functional index for vitamin B(6) status. The cognitive performance was assessed by the Symbol Search test, a subtest of the Wechsler Adult Intelligence Scale (WAIS-III) and the pattern-recognition test. Intelligence as assessed by the 'Kurztest für Allgemeine Intelligenz' (KAI) was a further variable.ResultsNo significant differences in pattern-recognition and intelligence score were observed between vitamin and placebo group prior to and after multivitamin supplementation. In the Symbol Search test, the vitamin group exhibited better test results than the placebo group at both measure points. One-way ANOVA showed a marginally significant linear trend between the baseline tHcy concentration and the pattern-recognition score (P = 0.051) in the total sample. Multiple backward regression revealed only a significant influence of the school graduation on baseline cognitive function test results. A general linear model showed that the changes in cognitive function scores could not be explained by the type of treatment or blood parameters.ConclusionsOur data indicate that 6 months supplementation of physiological dosages of antioxidants and B vitamins have no effect on cognitive performance in presumedly healthy and well-nourished female seniors. An intervention period of only 6 months may be too short for improving cognitive performance in well-educated elderly women without dementia. | Dudek H, Farbiszewski R, Rydzewska M, Michno T, Kozłowski A (2005)
[Concentration of glutathione (GSH), ascorbic acid (vitamin C) and substances reacting with thiobarbituric acid (TBA-rs) in single human brain metastases].
Wiadomosci lekarskie (Warsaw, Poland : 1960) 58, 379-381 [PubMed:16425787]
[show Abstract]
The aim of the study was to estimate the concentration of glutathione (GSH), ascorbic acid (vitamin C) and thiobarbituric acid (TBA-rs) in single human brain metastases and histologically unchanged nerve tissue. The research was conducted on fragments of neoplasmatic tissue collected from 45 patients undergoing surgery in the Department of Neurosurgery, Medical University of Białystok in years 1996-2002. Concentration of GSH was evaluated using the GSH-400 method, vitamin C using the method of Kyaw and TBA-rs using the method of Salaris and Babs. It has been found that there is a decrease of concentration of GSH and vitamin C and a considerable increase (p < 0.05) of concentration of TBA-rs in investigated single brain human metastasis in correlation to the concentration of the mentioned above substances in unchanged nerve tissue. | Padayatty SJ, Katz A, Wang Y, Eck P, Kwon O, Lee JH, Chen S, Corpe C, Dutta A, Dutta SK, Levine M (2003)
Vitamin C as an antioxidant: evaluation of its role in disease prevention.
Journal of the American College of Nutrition 22, 18-35 [PubMed:12569111]
[show Abstract]
Vitamin C in humans must be ingested for survival. Vitamin C is an electron donor, and this property accounts for all its known functions. As an electron donor, vitamin C is a potent water-soluble antioxidant in humans. Antioxidant effects of vitamin C have been demonstrated in many experiments in vitro. Human diseases such as atherosclerosis and cancer might occur in part from oxidant damage to tissues. Oxidation of lipids, proteins and DNA results in specific oxidation products that can be measured in the laboratory. While these biomarkers of oxidation have been measured in humans, such assays have not yet been validated or standardized, and the relationship of oxidant markers to human disease conditions is not clear. Epidemiological studies show that diets high in fruits and vegetables are associated with lower risk of cardiovascular disease, stroke and cancer, and with increased longevity. Whether these protective effects are directly attributable to vitamin C is not known. Intervention studies with vitamin C have shown no change in markers of oxidation or clinical benefit. Dose concentration studies of vitamin C in healthy people showed a sigmoidal relationship between oral dose and plasma and tissue vitamin C concentrations. Hence, optimal dosing is critical to intervention studies using vitamin C. Ideally, future studies of antioxidant actions of vitamin C should target selected patient groups. These groups should be known to have increased oxidative damage as assessed by a reliable biomarker or should have high morbidity and mortality due to diseases thought to be caused or exacerbated by oxidant damage. | Trommer H, Böttcher R, Pöppl A, Hoentsch J, Wartewig S, Neubert RH (2002)
Role of ascorbic acid in stratum corneum lipid models exposed to UV irradiation.
Pharmaceutical research 19, 982-990 [PubMed:12180551]
[show Abstract]
PurposeThe effects of ascorbic acid on Stratum corneum lipid models following ultraviolet irradiation were studied adding iron ions as transition metal catalysts.MethodsLipid peroxidation was quantified by the thiobarbituric acid assay. The qualitative changes were studied on a molecular level by mass spectrometry. To elucidate the nature of free radical involvement we carried out electron paramagnetic resonance studies. The influence of ascorbic acid on the concentration of hydroxyl radicals was examined using the spin trapping technique. Moreover, we checked the vitamin's ability to react with stable radicals.ResultsAscorbic acid was found to have prooxidative effects in all lipid systems in a concentration dependent manner. The degradation products of ascorbic acid after its prooxidative action were detected. The concentration of the hydroxyl radicals in the Fenton assay was decreased by ascorbic acid. The quantification assay of 2,2-diphenyl-1-picrylhydrazyl hydrate showed reduced concentration levels of the stable radical caused by ascorbic acid.ConclusionsConsidering human skin and its constant exposure to UV light and oxygen, an increased pool of iron ions in irradiated skin and the depletion of co-antioxidants, the administration of ascorbic acid in cosmetic formulations or in sunscreens could unfold adverse effects among the Stratum corneum lipids. | Padayatty SJ, Levine M (2000)
Vitamin C and myocardial infarction: the heart of the matter.
The American journal of clinical nutrition 71, 1027-1028 [PubMed:10799361] | Shamsi FA, Partal A, Sady C, Glomb MA, Nagaraj RH (1998)
Immunological evidence for methylglyoxal-derived modifications in vivo. Determination of antigenic epitopes.
The Journal of biological chemistry 273, 6928-6936 [PubMed:9506998]
[show Abstract]
The Maillard reaction, a non-enzymatic reaction of ketones and aldehydes with amino groups of proteins, contributes to the aging of proteins and to complications associated with diabetes. Methylglyoxal (MG) is a 2-oxoaldehyde derived from glycolytic intermediates and produced during the Maillard reaction. We reported previously the formation of a lysine-lysine protein cross-linking structure (imidazolysine) and a fluorescent arginine modification (argpyrimidine) from the Maillard reaction of MG. Here we show that rabbit antibodies to MG-modified ribonuclease A identify proteins modified by the Maillard reaction of glucose, fructose, ribose, glyceraldehyde, glyoxal, ascorbate, and ascorbate oxidation products (dehydroascorbate, 2,3-diketogulonate, L-xylosone, and L-threose) in addition to those modified by MG. The antibody recognized imidazolysine and argpyrimidine and a glyoxal-derived lysine-lysine cross-link. It did not react with Nepsilon-carboxymethyllysine. Incubations with amino acids revealed strongest reactivity with Nalpha-t-butoxycarbonylarginine and MG, and we identified argpyrimidine as one of the epitopes from this incubation mixture. Serum proteins from human diabetics reacted more strongly with the antibody than those from normal individuals, and the levels correlated with glycemic control. Collagen from human corneas contained MG-derived modifications, with those from older subjects containing higher levels of modified proteins than those from younger ones. An immunoaffinity-purified antibody showed higher reactivity with old corneas than with younger ones and localized the antigens primarily within the stromal region of the cornea. These results confirm reported MG-derived modifications in tissue proteins and show that dicarbonyl-mediated protein modification occurs during Maillard reactions in vivo. | Kodama M, Inoue F, Kodama T, Kodama M (1996)
Intraperitoneal administration of ascorbic acid delays the turnover of 3H-labelled cortisol in the plasma of an ODS rat, but not in the Wistar rat. Evidence in support of the cardinal role of vitamin C in the progression of glucocorticoid synthesis.
In vivo (Athens, Greece) 10, 97-102 [PubMed:8726814]
[show Abstract]
The purpose of this investigation was to reproduce in rats the enhancing effect of vitamin C on adrenal glucocorticoid production, a phenomenon that has been repeatedly observed in our human experiments. Here, we tried to assess the impact of vitamin C pretreatment on the turnover of exogenous 3H-labelled cortisol tracer in rats. 500 mg ascobic acid in 15 ml isotonic liquid per rat was administered intraperitoneally into rats of the experimental group, and 15 ml physiological saline per rat was similarly introduced into rats of the control group. At various times after the loading of either vitamin C or saline, 3H-labelled cortisol, 20 muc/0.5 ml saline/rat, was injected subcutaneously into rats of both the experimental and control groups. Thirty minutes later, all rats were sacrificed by exsanguination, and the radioactivity content was measured in the lipophilic fractions as well as in the purified corticosteroid compounds of blood, adrenal, testis and liver samples. To test the specificity of vitamin C action, experimental results from scurvy-prone ODS rats were compared with those of scurvy-resistant Wistar rats. Results obtained are as follows: a) the practice of vitamin C loading markedly delayed the turnover of 3H-cortisol in both the plasma lipophilic fraction and the plasma cortisol fraction, a finding which indicates that the above vitamin C pretreatment enhanced the release of endogenous glucocorticoid in such as to delay the turnover of the tracer cortisol in plasma. b) The above "dilution" effect of endogenous glucocorticoid surge was very distinct in both the lipophilic fraction and the cortisol fraction of ODS rats, and was less distinct (lipophilic fraction) or insignificant (cortisol fraction) in Wistar rats, a finding to indicate that the observed effect of vitamin C was of physiological significance. c) The responses of the adrenal glands, testes and liver to vitamin C pretreatment were generally more distinct in ODS rats than in Wistar rats, but varied from one organ to another. The significance of the functional linkage between vitamin C and adrenal glucocorticoid, which has been confirmed both in both the humans and rats in our laboratory, was discussed in the light of the historical development of vitamino-endocrinology. | Luck MR, Jeyaseelan I, Scholes RA (1995)
Ascorbic acid and fertility.
Biology of reproduction 52, 262-266 [PubMed:7711198]
[show Abstract]
Ascorbic acid has long been associated with fertility, but no consistent study of its mechanism of action in reproductive tissues has been made. This article considers how three of ascorbic acid's principal functions, namely its promotion of collagen synthesis, its role in hormone production, and its ability to protect cells from free radicals, may explain its reproductive actions. Data relating to both ovary and testis are reviewed since ascorbate accumulates in both tissues. Both gonads exhibit cycles of tissue remodeling and of peptide and steroid secretion that can be assumed to be ascorbate-dependent. Ascorbic acid may also prevent gametes from damage by free radicals during production and fertilization. Preliminary data on the concentrations of ascorbic acid in serum and follicular fluid from women undergoing in vitro fertilization are presented. They suggest that the supply of ascorbic acid to the ovary might be a limiting factor in the ability of the preovulatory follicle to grow in response to gonadotropin stimulation. It is concluded that ascorbic acid is a key compound in gonadal physiology on which further research is needed and that a reappraisal of its potential clinical value in the treatment of various types of male and female infertility would be timely. | Grünewald RA (1993)
Ascorbic acid in the brain.
Brain research. Brain research reviews 18, 123-133 [PubMed:8467348]
[show Abstract]
Ascorbic acid is highly concentrated in the central nervous system. Measurement of the extracellular concentration of ascorbate in animals, mainly by the technique of voltammetry in vivo, has demonstrated fluctuation in release from neuropil, both spontaneously and in response to physical stimulation of the animal and to certain drugs. Although in the adrenal medulla ascorbate is co-released with catecholamines, release of ascorbate from brain cells is associated principally with the activity of glutamatergic neurones, mainly by glutamate-ascorbate heteroexchange across cell membranes of neurones or glia. This phenomenon is discussed in relation to a possible role of ascorbate as a neuromodulator or neuroprotective agent in the brain. | Englard S, Seifter S (1986)
The biochemical functions of ascorbic acid.
Annual review of nutrition 6, 365-406 [PubMed:3015170] | Stone I (1979)
Homo sapiens ascorbicus, a biochemically corrected robust human mutant.
Medical hypotheses 5, 711-721 [PubMed:491997]
[show Abstract]
Homo sapiens' gene pool contains a defective gene for the synthesis of the active enzyme protein, L-gulonolactone oxidase(GLO). The absence of GLO in the human liver blocks the normal mammalian conversion of blood sugar into ascorbate, leading to the potentially-fatal "inborn error of carbohydrate metabolism", the genetic disease, Hypoascorbemia (in the older nomenclature- scurvy). To survive, humans need exogenous sources of daily ascorbate. Most mammals have the intact gene for GLO synthesis and produce generous daily amounts of the liver metabolite, ascorbate; for instance, an unstressed 70 Kg goat is capable of producing over 13 grams of ascorbate daily and much more under stress. The recommended dietary allowance of 45 milligrams of ascorbate a day for human adults, now proposed and used by nutritionists, is grossly inadequate to restore Homo sapiens to a normal mammalian ascorbate physiology. To correct fully this human genetic defect and banish epidemic chronic subclinical scurvy requires daily intakes of ascorbate equivalent to, at least, the amounts synthesized by the other mammals. Humans kept on a long term regime of full correction of this birth defect show great salutary benefits in health maintenance, disease therapy and slowing of the aging process. This can be regarded as the creation of a new and more robust, longer-living, tough human sub-species, Homo sapiens ascorbicus, by the biochemical reversal of a primate mutation occurring some 60 million years ago. Some of the practical benefits and pathways of future clinical research are discussed. | Proctor P (1970)
Similar functions of uric acid and ascorbate in man?
Nature 228, 868 [PubMed:5477017] |
|
2011-03-23
