http://www.sciencedaily.com/releases/2004/05/040526065457.htm

Source: University Of Virginia Health System

Date: 2004-05-28

Researchers Discover That A Protein In Grape Skins Can Kill Cancer Cells
CHARLOTTESVILLE, Va., May 25 – It's well known that drinking red wine in
moderation can have some health benefits, mainly attributed to a compound
called resveratrol. Now, scientists at the University of Virginia Health System
have discovered how.

They found how resveratrol helps to starve cancer cells by inhibiting the
action of a key protein that feeds them. The protein, called nuclear factor-
kappa B (NF-kB), is found in the nucleus of all cells and activates genes
responsible for cell survival. "We used physiologically-relevant doses of
resveratrol and found dramatic effects on human cancer cells," said Marty Mayo,
assistant professor of biochemistry and molecular genetics at U.Va.

Mayo said that the resveratrol in one glasses of wine three or four times a
week is the right amount to block the protein from feeding cancer cells.
Drinking much more than that, however, could stop this affect and, in fact,
lead to a greater risk of cancer, he said.

The findings, discovered by Fan Yeung, a postdoctoral fellow at U.Va., are
published in the May 20 online edition of the Journal of the European Molecular
Biology Organization (EMBO) found at: http://embojournal.npgjournals.com/.

Resveratrol is an antioxidant found in a number of plants, including grape
skins, raspberries, mulberries and peanuts. Its job in nature is to fight
fungus during the rainy season, and it is especially prevalent in grapes used
in making red wine. Resveratrol is also sold over-the-counter in the U.S. as a
nutritional supplement.

For a number of years, scientists have known that resveratrol acts as an
anti-cancer agent, but its role has not been well understood. Mayo and his team
demonstrated that cancer cells treated with resveratrol died because they
became sensitive to a compound called Tumor Necrosis Factor alpha (TNFa). The
U.Va. Health System researchers found that resveratrol initiated a reaction in
the NF-kB molecule that caused the cancer cells essentially to self-destruct in
a process called apoptosis.

The use of NF-kB inhibitors like resveratrol also has important implications
for increasing the effectiveness of cancer therapy. "Researchers are always
looking for ways to improve cancer therapy," Mayo said. "Current studies are
using compounds similar to TNFa in conjunction with resveratrol to kill cancer
cells." Clinical trials using this approach in patients are showing encouraging
results, Mayo said, and this research may explain why this combined therapy is
effective.

Previous studies have also shown that resveratrol can help control
atherosclerosis, heart disease, arthritis, and autoimmune disorders. Mayo
believes the inhibition of NF-kB may be responsible in those disorders, as
well, since NF-kB can control inflammatory responses.

Mayo's research on resveratrol was funded by grants from the National Cancer
Institute and the Paul Mellon Prostate Cancer Institute.

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Resveratrol protected Parkinson’s-like nerve cells against iron-enhanced
oxidative damage. This is encouraging because in Parkinson’s disease areas
around the nerves become abnormally enriched with iron. This in turn makes the
nerves more susceptible to oxidative damage.3

http://www.sabinsa.com/news/nlr0700.htm

Our data show that, like flavonoids, resveratrol protects LDL against
peroxidative degradation by both chelating and free radical scavenging
mechanisms.

PMID: 9214696 [PubMed - indexed for MEDLINE]

Previous Story | Related Stories | Next Story

Source:
American Chemical Society
Date:
12/13/2002

Too Much Grape Juice Could Cause Iron Deficiency
The same antioxidant compounds in dark grape juice that are noted for their
health benefits in fighting heart disease may have a downside, according to new
research in the Journal of Agricultural and Food Chemistry. In cell studies,
scientists with the U.S. Department of Agriculture and Cornell University found
that polyphenols in purple (also called red) grape juice can inhibit the uptake
of iron, which could increase the risk of iron-deficiency anemia.

The findings still need to be confirmed in human studies, cautions the study's
lead author, Raymond P. Glahn, Ph.D., a physiologist/nutritionist with the
USDA's Plant, Soil and Nutrition Laboratory, located on the Cornell campus in
Ithaca, N.Y. The study, which appears in the Nov. 6 issue of the journal, is
the first comparative analysis among juices for iron uptake ability. The
journal is published by the American Chemical Society, the world's largest
scientific society.

While reducing iron can be beneficial for adults with certain medical
conditions that involve excess iron, the same isn't necessarily true for young
children. Iron-deficiency anemia can lead to mental, physical and behavioral
impairment, particularly in infants and toddlers, say the researchers.

While iron-deficiency anemia is a major problem among children worldwide,
youngsters in the United States are largely spared this problem by iron
fortification of cereals, formulas and other foods, according to nutrition
experts. Many children in this country, however, still do not get enough iron,
notes Glahn.

Nonetheless, Glahn does not advocate removing dark grape juice from children's
diets. Instead, he suggests limiting the amount.

"Since we don't know how much grape juice you have to drink to have an effect,
I recommend alternating between dark and light juices. Don't just drink dark
juices all the time," Glahn says.

"We're not saying, 'Don't drink grape juice,'" Glahn emphasizes. "We're saying,
'Here are some conditions that inhibit iron availability.'"

The study looked at the effect of various juices — red grape, white grape,
prune, pear, orange, apple and grapefruit — on the ability of intestinal
cells to absorb iron.

Using a novel laboratory model comprised of human intestinal cells, the
researchers simulated conditions of digestion (including digestive enzymes and
acidity) to compare the juices.

Dark grape juice reduced iron availability by 67 percent, while prune juice
produced a 31 percent reduction. Light-colored juices, on the other hand,
actually had the opposite effect; they increased iron uptake. Pear juice
produced the highest uptake levels, followed by apple, orange, grapefruit and
white grape juices.

Getting proper amounts of iron is particularly important for infants and
children, as the mineral is essential for normal physical and mental
development, whereas adult males and post-menopausal women generally get
sufficient amounts of iron. Insufficient amounts of dietary iron, the number
one nutritional disorder in the world, can lead to iron-deficiency anemia. This
condition is characterized by excessive tiredness, decreased work and school
performance, and decreased immune function, among others.

Iron metabolism differs among individuals. For the best advice on addressing
the specific nutritional needs of children and adults, see a doctor or
nutritionist.

The USDA funded this study.

Editor's Note: The original news release can be found here.

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Note: This story has been adapted from a news release issued for journalists
and other members of the public. If you wish to quote any part of this story,
please credit American Chemical Society as the original source. You may also
wish to include the following link in any citation:

http://www.sciencedaily.com/releases/2002/12/021213062321.htm

Who loves ya.
Tom