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Old 09-11-2007, 08:12 AM
Dross Dross is offline
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Default How vitamin C stops Cancer

Nearly 30 years after Nobel laureate Linus Pauling famously and controversially suggested that vitamin C supplements can prevent cancer, a team of Johns Hopkins scientists have shown that in mice at least, vitamin C - and potentially other antioxidants - can indeed inhibit the growth of some tumors, just not in the manner suggested by years of investigation.

The conventional wisdom of how antioxidants such as vitamin C help prevent cancer growth is that they grab up volatile oxygen free radical molecules and prevent the damage they are known to do to our delicate DNA. The Hopkins study, led by Chi Dang, M.D., Ph.D., professor of medicine and oncology and Johns Hopkins Family Professor in Oncology Research, unexpectedly found that the antioxidants actual role may be to destabilize a tumor's ability to grow under oxygen-starved conditions. Their work is detailed in Cancer Cell.

The potential anticancer benefits of antioxidants have been the driving force for many clinical and preclinical studies, says Dang. By uncovering the mechanism behind antioxidants, we are now better suited to maximize their therapeutic use.

Once again, this work demonstrates the irreplaceable value of letting researchers follow their scientific noses wherever it leads them, Dang adds.

The authors do caution that while vitamin C is still essential for good health, this study is preliminary and people should not rush out and buy bulk supplies of antioxidants as a means of cancer prevention.

The Johns Hopkins investigators discovered the surprise antioxidant mechanism while looking at mice implanted with either human lymphoma (a blood cancer) or human liver cancer cells. Both of these cancers produce high levels of free radicals that can be suppressed by feeding the mice supplements of antioxidants, either vitamin C or N-acetylcysteine (NAC).

Our cells, like everything else, are made up of chemicals. Some chemicals are very stable and can last for years (or many thousands of years) without changing. They do not interact with other things and stay just like they are. Radicals are chemicals that are unstable, they can easily interact with other chemicals, changing both of them.

Free radicals are small unstable chemicals that can be found in our cells. Because they can react with other things, they can cause damage to important cell parts. Of particular importance is the genetic material (DNA) in cells. Free radicals can be created by exposure of cells to radiation, or be formed by the breakdown of other chemicals. Cells of the immune system produce free radicals in their efforts to get rid of invading organisms (like bacteria).

Antioxidants are chemicals that can combine with free radicals, like a missile interceptor. Antioxidants can 'take the hit' for the rest of the cell, preventing damage to important proteins, and the genetic material.

Their have been several studies looking at the ability of different antioxidants to prevent cancer as well as using antioxidants along with cancer treatments. The results are not always clear and sometimes, the results have shown that antioxidants can cause problems. Examples of antioxidants include vitamin E and vitamin C.

When the Hopkins team examined cancer cells from cancer-implanted mice not fed the antioxidants, they noticed the absence of any significant DNA damage. Clearly, if DNA damage was not in play as a cause of the cancer, then whatever the antioxidants were doing to help was also not related to DNA damage, says Ping Gao, Ph.D, lead author of the paper.

That conclusion led Gao and Dang to suspect that some other mechanism was involved, such as a protein known to be dependent on free radicals called HIF-1 (hypoxia-induced factor), which was discovered over a decade ago by Hopkins researcher and co-author Gregg Semenza, M.D., Ph.D., director of the Program in Vascular Cell Engineering. Indeed, they found that while this protein was abundant in untreated cancer cells taken from the mice, it disappeared in vitamin C-treated cells taken from similar animals.

When a cell lacks oxygen, HIF-1 helps it compensate, explains Dang. HIF-1 helps an oxygen-starved cell convert sugar to energy without using oxygen and also initiates the construction of new blood vessels to bring in a fresh oxygen supply.

Some rapidly growing tumors consume enough energy to easily suck out the available oxygen in their vicinity, making HIF-1 absolutely critical for their continued survival. But HIF-1 can only operate if it has a supply of free radicals. Antioxidants remove these free radicals and stop HIF-1, and the tumor, in its tracks.

The authors confirmed the importance of this hypoxia protein by creating cancer cells with a genetic variant of HIF-1 that did not require free radicals to be stable. In these cells, antioxidants no longer had any cancer-fighting power.

Antioxidants in Cancer Therapy; Their Actions and Interactions With Oncologic Therapies

[url]http://www.medicinabiomolecular.com.br/biblioteca/pdfs/Cancer/ca-2346.pdf

Rationale for Intravenous Vitamin C in Cancer Patients

[url]http://www.orthomolecular.org/library/ivccancerpt.shtml

Last edited by gdpawel : 03-31-2013 at 09:02 PM. Reason: added url address
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Old 02-10-2014, 03:13 PM
gdpawel gdpawel is offline
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Default Vitamin C may boost chemotherapy

A new study suggests giving some cancer patients high doses of vitamin C intravenously - as opposed to orally - alongside conventional chemotherapy, may help kill cancer cells and also reduce some of its toxic side effects.

Reporting their findings in Science Translational Medicine, researchers from the University of Kansas (KU) Medical Center describe how they tested the approach in cells, animals and humans.

They found giving infused vitamin C together with carboplatin and paclitaxel - two conventional chemotherapy drugs - stopped ovarian cancer in the lab and also reduced toxic side effects of chemotherapy in ovarian cancer patients.

Since the 1970s, ascorbate - or vitamin C - has been used as an alternative therapy for cancer. It has an "outstanding safety profile," write the researchers, who also note there were anecdotal reports that it was effective if given intravenously.

However, although complementary and alternative therapy doctors continued to use it to combat cancer, conventional oncologists abandoned its use after clinical trials of orally administered vitamin C found it was ineffective against cancer.

Now, more recent studies have resurrected the possibility that intravenous vitamin C may be worth looking at again as a possible anti-cancer therapy, so the KU researchers decided to investigate.

Given intravenously, vitamin C has anti-cancer effects

And indeed, what they found was that vitamin C can be effective against cancer when given intravenously, as senior author Qi Chen, assistant professor in the Department of Pharmacology, Toxicology and Therapeutics at the KU Medical Center, explains: "What we've discovered is that, because of its pharmacokinetic differences, intravenous vitamin C, as opposed to oral vitamin C, kills some cancer cells without harming normal tissues."

For their clinical trial, the researchers recruited 27 patients who had just been diagnosed with stage 3 or stage 4 ovarian cancer.

They all underwent conventional chemotherapy with paclitaxel or carboplatin, but some also received high doses of vitamin C intravenously. They were then followed for 5 years.

The researchers found that, compared with the patients who did not receive vitamin C in addition to conventional chemotherapy, the toxic effects of the therapy tended to be less in the patients given vitamin C.

In another experiment, the researchers found vitamin C killed cancer cells in mice with ovarian cancer, but only at concentrations that can be achieved if given intravenously. They noticed no toxic effects or changes due to chemotherapy in the animals' livers, kidneys and spleens.

When they looked at what was happening at the molecular level, they found vitamin C in the fluid surrounding tumor cells acts as a "pro-oxidant," spurring formation of hydrogen peroxide, which kills cancer cells.

On further investigation of this path, the researchers found a number of mechanisms through which, acting as a pro-oxidant, vitamin C induced cell death in ovarian cancer cells, including promoting damage to their DNA, without affecting healthy tissue.

Researchers call for large clinical trials

Co-researcher Dr. Jeanne Drisko, who specializes in integrative medicine at KU, says: "We now have a better understanding of vitamin C's anti-cancer action, plus a clear safety profile, and biological and clinical plausibility with a firm foundation to proceed. Taken together, our data provide strong evidence to justify larger and robust clinical trials to definitively examine the benefit of adding vitamin C to conventional chemotherapy."

However, it may not be easy to find funding for large clinical trials of intravenous vitamin C. Pharmaceutical companies, for example, are unlikely to be interested because with vitamin C being a natural substance, they would not be able to patent it.

References: High-Dose Parenteral Ascorbate Enhanced Chemosensitivity of Ovarian Cancer and Reduced Toxicity of Chemotherapy, Qi Chen, Jeanne Drisko, et al., Sci Transl Med, published online 5 February 2014, DOI:10.1126/scitranslmed.3007154

[url]http://stm.sciencemag.org/content/6/222/222ra18

The University of Kansas Cancer Center

[url]http://www.kucancercenter.org/about-us/news/research-establishes-benefits-of-high-dosh-vitamin-c-for-ovarian-cancer-patients

Citation: Paddock, Catharine. "Vitamin C may boost chemotherapy." Medical News Today. MediLexicon, Intl., 10 Feb. 2014.
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Old 03-23-2017, 02:24 PM
gdpawel gdpawel is offline
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Default Sepsis, Cancer Patients and Intravenous vitamin C

Doctor Turns Up Possible Treatment For Deadly Sepsis

Richard Harris
NPR
March 23, 2017

It's hard not to get excited about news of a potentially effective treatment for sepsis, a condition that leads to multiple organ failure and kills more people in the hospital than any other disease.

But there have been so many false promises about this condition over the years, it's also wise to treat announcements like one published online by the journal, Chest with caution.

[url]http://www.sciencedirect.com/science/article/pii/S0012369216625643

The study, from Eastern Virginia Medical School in Norfolk, Va., reported some remarkable success in treating patients who were at high risk of sudden death.

The story began in January, 2015, when Dr. Paul Marik was running the intensive care unit at Sentara Norfolk General Hospital. A 48-year-old woman came in with a severe case of sepsis inflammation frequently triggered by an overwhelming infection.

"Her kidneys weren't working. Her lungs weren't working. She was going to die," Marik said. "In a situation like this, you start thinking out of the box."

Marik had recently read a study by researchers at Virginia Commonwealth University in Richmond. Dr. Berry Fowler and his colleagues had shown some moderate success in treating people who had sepsis with intravenous vitamin C.

Marik decided to give it a try. He added in a low dose of corticosteroids, which are sometimes used to treat sepsis, along with a bit of another vitamin, thiamine. His desperately ill patient got an infusion of this mixture.

[url]https://www.ncbi.nlm.nih.gov/pubmed/27379022

"I was expecting the next morning when I came to work she would be dead," Marik said."But when I walked in the next morning, I got the shock of my life."

The patient was well on the road to recovery.

Marik tried this treatment with the next two sepsis patients he encountered, and was similarly surprised. So he started treating his sepsis patients regularly with the vitamin and steroid infusion.

[url]http://www.evms.edu/about_evms/administrative_offices/marketing_communications/publications/issue_9_4/sepsis.php#medical-professional

After he'd treated 50 patients, he decided to write up his results. As he described it in Chest, only four of those 47 patients died in the hospital and all the deaths were from their underlying diseases, not from sepsis. For comparison, he looked back at 47 patients the hospital had treated before he tried the vitamin C infusion and found that 19 had died in the hospital.

This is not the standard way to evaluate a potential new treatment. Ordinarily, the potential treatment would be tested head to head with a placebo or standard treatment, and neither the doctors nor the patients would know who in the study was getting the new therapy.

But the results were so stunning, Marik decided that from that point on he would treat all his sepsis patients with the vitamin C infusion. So far, he's treated about 150 patients, and only one has died of sepsis, he said.

That's a phenomenal claim, considering that of the million Americans a year who get sepsis, about 300,000 die.

"So that's the equivalent of three jumbo jets crashing every single day," Marik said.

An effective treatment for sepsis would be a really big deal.

"If it turns out in further studies that this is true, and we can validate it, then this will be an unbelievably huge deal," said Dr. Craig Coopersmith, a surgery professor at Emory University School of Medicine. "But right now we should treat it as a preliminary deal that needs to be validated."

Coopersmith, a top sepsis researcher, is cautious for a reason. There have been hundreds of exciting results from sepsis studies that failed in follow-up research.

A result "can look really exciting when you do it on a group in one hospital with one set of clinicians, and then when you try to validate with a larger group in multiple centers thus far we've been unsuccessful with anything," Coopersmith said.

Marik may face extra skepticism because the main ingredient is vitamin C, which has attracted a great deal of skepticism over the years. Fowler at VCU was concerned about that when he wanted to launch a study about the role of vitamin C in sepsis.

"Honestly, when we submitted the grant to the NIH, I was fully expecting them to say 'vitamin C? Really?' " Fowler tells Shots.

But he'd made the case that vitamin C wasn't simply a once-trendy antioxidant. When the vitamin is injected, as opposed to taken orally, it can influence the immune system's response to inflammation, he told Shots.

The NIH gave him a $3.2 million grant to run a carefully controlled study of vitamin C to treat sepsis, with all the usual conditions: It includes placebos; the scientists don't know who's getting the active drug; and it's being conducted at several universities.

[url]https://clinicaltrials.gov/ct2/show/NCT02106975?term=fowler+AND+sepsis&rank=2

That study could wrap up later this year. Fowler says some patients in the trial will probably have been given corticosteroids, as Marik's patients were, but that's not a formal part of the study.

Coopersmith said the extraordinary results reported from Norfolk clearly need that kind of careful scrutiny. Marik said he agrees, though he's obviously not waiting for those results to emerge.

Taxpayers and drug companies have spent billions of dollars searching for an effective treatment for sepsis. Drug companies could reap billions in profits if they can develop a successful treatment for this common and often fatal disease.

But profit is not the motive here, Marik says. The ingredients cost about as much as a single dose of antibiotics.

"I obviously have no vested interest," he says. "Nobody's going to make money from this so this is a very anti-capitalistic thing!"

Citation: Doctor Turns Up Possible Treatment For Deadly Sepsis NPR Health News March 23, 2017

Why Are People with Cancer at High Risk for Sepsis?

[url]http://www.sepsis.org/sepsis-and/cancer/
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Last edited by gdpawel : 03-23-2017 at 02:38 PM.
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