Navigation Links
Vitamin C injections slow tumor growth in mice
Date:8/4/2008

High-dose injections of vitamin C, also known as ascorbate or ascorbic acid, reduced tumor weight and growth rate by about 50 percent in mouse models of brain, ovarian, and pancreatic cancers, researchers from the National Institutes of Health (NIH) report in the August 5, 2008, issue of the Proceedings of the National Academy of Sciences. The researchers traced ascorbate's anti-cancer effect to the formation of hydrogen peroxide in the extracellular fluid surrounding the tumors. Normal cells were unaffected.

Natural physiologic controls precisely regulate the amount of ascorbate absorbed by the body when it is taken orally. "When you eat foods containing more than 200 milligrams of vitamin C a day--for example, 2 oranges and a serving of broccoli--your body prevents blood levels of ascorbate from exceeding a narrow range," says Mark Levine, M.D., the study's lead author and chief of the Molecular and Clinical Nutrition Section of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the NIH. To bypass these normal controls, NIH scientists injected ascorbate into the veins or abdominal cavities of rodents with aggressive brain, ovarian, and pancreatic tumors. By doing so, they were able to deliver high doses of ascorbate, up to 4 grams per kilogram of body weight daily. "At these high injected doses, we hoped to see drug-like activity that might be useful in cancer treatment," said Levine.

Vitamin C plays a critical role in health, and a prolonged deficiency leads to scurvy and eventually to death. Some proteins known as enzymes, which have vital biochemical functions, require the vitamin to work properly. Vitamin C may also act as an antioxidant, protecting cells from the damaging effects of free radicals. The NIH researchers, however, tested the idea that ascorbate, when injected at high doses, may have prooxidant instead of antioxidant activity. Prooxidants would generate free radicals and the formation of hydrogen peroxide, which, the scientists hypothesized, might kill tumor cells. In their laboratory experiments on 43 cancer and 5 normal cell lines, the researchers discovered that high concentrations of ascorbate had anticancer effects in 75 percent of cancer cell lines tested, while sparing normal cells. In their paper, the researchers also showed that these high ascorbate concentrations could be achieved in people.

The team then tested ascorbate injections in immune-deficient mice with rapidly spreading ovarian, pancreatic, and glioblastoma (brain) tumors. The ascorbate injections reduced tumor growth and weight by 41 to 53 percent. In 30 percent of glioblastoma controls, the cancer had spread to other organs, but the ascorbate-treated animals had no signs of disseminated cancer. "These pre-clinical data provide the first firm basis for advancing pharmacologic ascorbate in cancer treatment in humans," the researchers conclude.

Interest in vitamin C as a potential cancer therapy peaked about 30 years ago when case series data showed a possible benefit. In 1979 and 1985, however, other researchers reported no benefit for cancer patients taking high oral doses of vitamin C in two double-blind, placebo-controlled clinical trials.

Several observations led the NIH researchers to revisit ascorbate as a cancer therapy. "Clinical and pharmacokinetic studies conducted in the past 12 years showed that oral ascorbate levels in plasma and tissue are tightly controlled. In the case series, ascorbate was given orally and intravenously, but in the trials ascorbate was just given orally. It was not realized at the time that only injected ascorbate might deliver the concentrations needed to see an anti-tumor effect," said Levine, who noted that new clinical trials of ascorbate as a cancer treatment are in the planning stages.

Data from Levine's earlier studies of the regulation and absorption of dietary vitamin C were used in the revision of the Institute of Medicine's Recommended Dietary Allowance for the vitamin in 2000. In the current study, Levine led a team of scientists from the NIDDK and the National Cancer Institute (NCI), both components of the NIH, as well as the University of Kansas. "NIH's unique translational environment, where researchers can pursue intellectual high-risk, out-of-the-box thinking with high potential payoff, enabled us to pursue this work," he said.


'/>"/>

Contact: Joan Chamberlain
niddkmedia@mail.nih.gov
301-496-3583
NIH/National Institute of Diabetes and Digestive and Kidney Diseases
Source:Eurekalert

Related medicine news :

1. Vitalize(TM) Receives Top Multivitamin Rating
2. July 2008 Mayo Clinic Womens HealthSource Highlights Vitamin D, Savvy Use of Sunscreen and Gastrointestinal Upset and Celiac Disease
3. Moms Vitamin D Levels Affect Babys Dental Health
4. Mothers vitamin D status during pregnancy will affect her babys dental health
5. Photo: VitaminLife.com Sees Internet Sales Up 40% in Major Metro Markets as Gas Crisis Looms; Shopping Behaviors Change as People Conserve Gas
6. Low Vitamin D Could Raise Death Risk
7. Vitamin D May Promote Colon Cancer Survival
8. Study links vitamin D to colon cancer survival
9. Spotting Vitamin-D Deficiency in the Absence of Symptoms: ZRT Laboratorys New, One-of-a-Kind Blood Spot Test Answers the Call for Early Detection of Rapidly Rising D-Deficiencies
10. Low Vitamin D Levels May Boost Mens Heart Attack Risk
11. Leiner Health Products Issues Allergy Alert on Undeclared Allergens in Liquimax(R) Multivitamin
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/28/2016)... , ... May 28, 2016 , ... In a part of the city where’s it’s ... new farm-to-table Kelowna restaurants is hoping to attract diners with a taste for ... Suites officially opened the doors to Cornerstone Grill, an urban casual restaurant focusing on ...
(Date:5/27/2016)... ... 27, 2016 , ... W.S. Badger Co. Inc ., the maker of ... recognized as one of the best small businesses for new dads by Fatherly, the ... small businesses providing progressive benefits to new parents on the organization’s 2016 Best ...
(Date:5/27/2016)... ... May 27, 2016 , ... An educational campaign aimed at ... stories, courtesy of awareness-driven celebrities and thought leaders. It also provides insight to ... industry leaders such as Bioness. , As patients feel increasingly concerned about ...
(Date:5/27/2016)... NY (PRWEB) , ... May 27, 2016 , ... Aimed ... inspiring human interest stories, which come courtesy of leaders in the nursing and health ... industry, from leading advocates and associations—namely Abilene Christian University. , As the nursing ...
(Date:5/26/2016)... (PRWEB) , ... May 26, 2016 , ... There are ... Hot Dog and Sausage Council (NHDSC) suggests that Americans prefer their dogs straight off ... 63 percent say grilling is their favorite way to cook a hot dog, far ...
Breaking Medicine News(10 mins):
(Date:5/30/2016)... - DCGI grants limited approval to market ... - Stempeucel® becomes 5th off-the-shelf Stem cell product to ... - Buerger,s Disease (also known as Thromboangiitis Obliterans) is a ... Globally - Prevalence of Buerger,s Disease is estimated to ... 10,000 persons in the European Community & USA ...
(Date:5/27/2016)... , May 27, 2016 According ... of hypertension is driving ambulatory blood pressure monitoring system ... elasticity and their ability to respond to different pressure ... condition can lead to various cardiovascular disorders such as ... disease. These diseases are growing in prevalence each year. ...
(Date:5/26/2016)... , May 26, 2016 According to ... Waste Management Market - U.S. Industry Analysis, Size, Share, Growth, ... market in the U.S. was valued at US$ 5.89 Bn ... of 3.4% from 2015 to 2023 to reach US$ 7.99 ... of current and emerging needle free drug delivery devices and ...
Breaking Medicine Technology: