22 augustus 2008: De BBC meldt dat onderzoekers van Cancer research UK  - de Engelse NKI zeg maar - hebben gevonden in in vitro studies en in vivo studies bij  muizen dat intraveneus toedienen van vitamine C wel degelijk kankercellen kan doden en een goed en veilig alternatief kan betekenen voor chemo bij vele soorten van kanker. In de meest recente studie bij muizen halveerde de tumorload van de muizen met alvleesklierkanker, hersenkanker en eierstokkanker met meer dan de helft na alleen gebruik van intraveneus inspuiten van vitamine C. De BBC maakt hier melding van op hun website. Hier het bericht van BBC news en daaronder berichtgeving van intraveneus inspuiten met vitamine C uit 2005 met vergelijkbare resutlatn plus meer nuttige informatie.

 

Vitamin C 'slows cancer growth'

An injection of a high dose of vitamin C may be able to hold back the advance of cancers, US scientists claim.

The vitamin may start a destructive chain reaction within the cancer cell, they add.

The jab halved the size of brain, ovarian and pancreatic tumours in mice, reported the journal Proceedings of the National Academy of Sciences.

However, Cancer Research UK said other studies suggested large vitamin C doses may interfere with cancer treatment.

 

  This is encouraging work but it's at a very early stage because it involves cells grown in the lab and mice
Dr Alison Ross
Cancer Research UK

Earlier research by the team at the National Institutes of Health in Maryland had suggested that the vitamin, also called ascorbate, could kill cancer cells in the laboratory.

After these successful tests in mice, they are now suggesting that the treatment be considered for human use at similar levels.

The dose they employed - up to four grams per kilo of bodyweight - was far greater than any that could be achieved using diet or vitamin pills, as the digestive system does not absorb more than a fixed amount taken orally.

The mice were bred to have malfunctioning immune systems, then injected with human cancer cells, which as a result, grew quickly into large tumours. The vitamin was then injected into their abdominal cavity.

Tumour growth and weight fell by between 41% and 53%, and while in untreated mice, the disease spread rapidly to involve other body parts, no such spread was seen in the vitamin C-treated animals.

The researchers wrote: "These pre-clinical data provide the first firm basis for advancing pharmacologic ascorbate in cancer treatment in humans."

Peroxide bomb

The treatment works because a tumour cell is chemically different to a healthy cell.

The vitamin C reacts with this chemical make-up, producing enough hydrogen peroxide to kill the cell, while leaving healthy cells unscathed.

However, Dr Alison Ross, from Cancer Research UK said that much more work would have to be done to see if vitamin C could be a viable treatment.

"This is encouraging work but it's at a very early stage because it involves cells grown in the lab and mice.

"There is currently no evidence from clinical trials in humans that injecting or consuming vitamin C is an effective way to treat cancer.

"Some research even suggests that high doses of antioxidants can make cancer treatment less effective, reducing the benefits of radiotherapy and chemotherapy."

 

15 september 2005: Bron: Chemisch weekblad en website van de Proceedings of the National Academy of Sciences. Met dank aan Frank en Willem die beiden me op deze studiepublicatie wezen.

Hoge dosis vitamine C. intraveneus toegediend in de bloedstroom bewijst kankercellen te doden en gezonde cellen ongemoeid te laten in laboratorium proeven. De dosis is hoog maar volgens de onderzoekers gemakkelijk en veilig intraveneus in te brengen in de bloedstroom zodat er geen gevaar lijkt voor de patiënt. Vitamine C. doodt door middel van vorming van waterstofperoxide in de cel en leidt tot apoptosis = zelfmoord van de kankercel. Er ontstaat dan wel necrotisch weefsel. Wat, mits dit erg veel is, een gevaar kan betekenen omdat dan teveel kankercellen in een keer worden gedood en het lichaam de opruiming daarvan niet aankan. Het is dus uitermate raadzaam om als u hiermee aan de slag wilt dit te doen onder goede deskundige begeleiding van een arts die ervaring heeft met intraveneus toedienen van hoge dosis vitamine C.. Zie onder adressen van Nederlandse artsen die IAAA toepassen. Overigens wij hebben geen enkele commerciële of andere binding met een van de genoemde artsen. Het is puur een extra service aan onze OPS leden.
Wie onderstaande berichtgeving leest ziet dat dit een hele belangrijke studie kan zijn omdat hiermee in feite bewezen wordt wat al jaren wordt beweerd door vele complimentair werkende artsen in binnen- en butienalnd en vooral door prof. dr. Linus C. Pauling als dè complimentaire of zelfs mon behandeling voor kanker werd genoemd. Waarom tot nu toe vitamine C. niet echt is doorgebroken in een behandeling van kanker is volgens deze onderzoekers omdat in bijna alle studies er te lage concentraties vitamine C zijn gebruikt en ook nog oraal werden toegediend. Maar hier onder deze artikelenreeks is meer te lezen over intraveneus toedienen van hoge dosis vitamine C. Hieronder een artikel uit het Chemisch Weekblad van deze week over deze studie en het originele abstract van de onderzoekers uit het National Institutes of Health in Bethesda en een artikel van BBC news, ook over deze studie.

Véél vitamine C helpt tegen kanker

Ascorbaat, het zout van ascorbinezuur oftewel vitamine C, kan selectief kankercellen doden. Mits je er genoeg van toedient, zo stellen onderzoekers van de National Institutes of Health in Bethesda, Maryland, op de website van de Proceedings of the National Academy of Sciences.
De onderzoekers stelden diverse celculturen in het lab bloot aan ascorbaat. Gezonde cellen bleken van 20 millimolair ascorbaat geen last te hebben. Maar bij vijf van de tien kankercelkweekjes was een concentratie van 4 mM of minder al voldoende om binnen een uur de helft van de cellen te laten afsterven. Volgens de onderzoekers is deze concentratie in bloed gemakkelijk te bereiken wanneer je het ascorbaat via een infuus toedient.
De cellen gingen dood door apoptose of necrose. De onderzoekers schrijven het effect volledig toe aan de vorming van waterstofperoxide, veroorzaakt door het ascorbaat.
Dat vitamine C kankercellen doodt is al eerder beweerd. Alternatieve genezers werken er wel vaker mee. Tot nu toe wees alles er op dat zo’n behandeling niet helpt, maar het lijkt er op dat de serieuze wetenschap tot nu toe alleen met veel lagere concentraties heeft geëxperimenteerd.
bron: BBC News Online, 13 september 2005

Published online before print September 12, 2005
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0506390102

Pharmacologic ascorbic acid concentrations selectively kill cancer cells: Action as a pro-drug to deliver hydrogen peroxide to tissues

( cell death | ascorbate radical )

Qi Chen *, Michael Graham Espey , Murali C. Krishna , James B. Mitchell , Christopher P. Corpe *, Garry R. Buettner , Emily Shacter , and Mark Levine *¶ *Molecular and Clinical Nutrition Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892; Radiation Biology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892; Free Radical and Radiation Biology Program, University of Iowa, Iowa City, IA 52242-1101; and Laboratory of Biochemistry, Center for Drug Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892

Communicated by J. E. Rall, National Institutes of Health, Bethesda, MD, August 2, 2005 (received for review June 1, 2005)

Human pharmacokinetics data indicate that i.v. ascorbic acid (ascorbate) in pharmacologic concentrations could have an unanticipated role in cancer treatment. Our goals here were to test whether ascorbate killed cancer cells selectively, and if so, to determine mechanisms, using clinically relevant conditions. Cell death in 10 cancer and 4 normal cell types was measured by using 1-h exposures. Normal cells were unaffected by 20 mM ascorbate, whereas 5 cancer lines had EC50 values of <4 mM, a concentration easily achievable i.v. Human lymphoma cells were studied in detail because of their sensitivity to ascorbate (EC50 of 0.5 mM) and suitability for addressing mechanisms. Extracellular but not intracellular ascorbate mediated cell death, which occurred by apoptosis and pyknosis/necrosis. Cell death was independent of metal chelators and absolutely dependent on H2O2 formation. Cell death from H2O2 added to cells was identical to that found when H2O2 was generated by ascorbate treatment. H2O2 generation was dependent on ascorbate concentration, incubation time, and the presence of 0.5-10% serum, and displayed a linear relationship with ascorbate radical formation. Although ascorbate addition to medium generated H2O2, ascorbate addition to blood generated no detectable H2O2 and only trace detectable ascorbate radical. Taken together, these data indicate that ascorbate at concentrations achieved only by i.v. administration may be a pro-drug for formation of H2O2, and that blood can be a delivery system of the pro-drug to tissues. These findings give plausibility to i.v. ascorbic acid in cancer treatment, and have unexpected implications for treatment of infections where H2O2 may be beneficial.

--------------------------------------------------------------------------------
Author contributions: Q.C., M.G.E., M.C.K., J.B.M., C.P.C., G.R.B., E.S., and M.L. designed research; Q.C., M.G.E., J.B.M., C.P.C., E.S., and M.L. performed research; M.G.E., M.C.K., J.B.M., C.P.C., G.R.B., and E.S. contributed new reagents/analytic tools; Q.C., M.G.E., M.C.K., G.R.B., E.S., and M.L. analyzed data; and Q.C. and M.L. wrote the paper.

¶To whom correspondence should be addressed at: Molecular and Clinical Nutrition Section, National Institutes of Health, Building 10, Room 4D52, MSC-1372, Bethesda, MD 20892-1372.

Mark Levine, E-mail: markl@mail.nih.gov
PNAS website

Injected vitamin C. may fight cancer

High doses of vitamin C injected into the bloodstream may be effective at combating cancer, new research suggests. Scientists found that vitamin C in the form of ascorbate killed cancer cells in the laboratory - but the effective dose was so high it could only be delivered to patients by infusion into the bloodstream. The findings appear to contradict earlier studies showing no cancer benefit from vitamin C. However the researchers point out that those trials only investigated orally taken vitamins. Earlier work in the 1970s which used both intravenous and oral ascorbate had hinted at an anti-cancer effect. In the latest study a US team led by Dr Mark Levine, from the National Institutes of Health in Bethesda, Maryland, conducted laboratory experiments which simulated clinical infusions of vitamin C. Cultures of a range of nine cancer and four normal cell types were studied by exposing them to high doses of ascorbate. In five of the cancer lines, there was a 50% decrease in cell survival, while normal cells were unaffected. A more detailed look at lymphoma cells - which were especially sensitive to ascorbate - showed they were either destroyed directly or induced to commit "cell suicide". Further tests revealed that the growth of cells exposed to vitamin C was reduced by at least 99%. The effective dose was less than four millimoles, a concentration much higher than an oral dose but easily achievable by intravenous infusion. Ascorbate treatment led to the formation of hydrogen peroxide (H2O2), a chemical known to be toxic to cells. Why it killed cancer cells but not normal cells was unknown, said the researchers. It was possible the hydrogen peroxide caused damage that was repaired in normal cells but not in sensitive cancer cells.


Plaats een reactie ...

Reageer op "Intraveneus toedienen van hoge dosis vitamine C - ascorbinezuur - bewijst in laboratorium proeven en dierproeven dat het kankercellen doodt en gezonde cellen ongemoeid laat."


Gerelateerde artikelen
 

Gerelateerde artikelen

Het effect van intraveneuze >> Vitamine C: een man met hairycell >> Twee patiënten met uitgezaaide >> Intraveneus toedienen van >> Nederlandse artsen die intraveneus >> Intraveneus toedienen van >> Het effect van ascorbinezuur >> IAA - Intraveneuze injecties >>