Ginkgo biloba reduces aggressive cancer risk in animal experiments

Discussion in 'Food and nutrition' started by Roman Bystrianyk, Feb 28, 2006.

  1. "Ginkgo biloba reduces aggressive cancer risk in animal experiments",
    news-medical.net, February 27, 2006,
    Link: http://www.news-medical.net/?id=16245

    Researchers at Georgetown University Medical Center say they now have a
    clearer picture of how an extract from the leaves of the Ginkgo biloba
    tree reduces the risk of aggressive cancer in animal experiments.

    In the January-February issue of the journal Anticancer Research, the
    investigators reported that treating mice with an extract of leaves of
    Ginkgo biloba both before and after implanting human breast or brain
    (glioma) tumors decreased expression of a cell receptor associated with
    invasive cancer. This decreased expression slowed the growth of the
    breast tumors by 80 percent as long as the extract was used, compared
    to untreated mice, and also reduced the size of the brain tumors, but
    temporarily, and to a lesser extent.

    Ginkgo biloba extract is a popular supplement that comes from the
    leaves of the Gingko tree, which is indigenous to Japan, Korea and
    China but can be found all over the world. Many believe it enhances
    memory, and is being currently being tested as a treatment for
    Alzheimer's disease.

    "It is very encouraging that Ginkgo biloba appeared to reduce the
    aggressiveness of these cancers, because it suggests that the leaves
    could be useful in some early stage diseases to prevent them from
    becoming invasive, or spreading," said the study's senior author,
    Vassilios Papadopoulos, DPharm, PhD, Director, Biomedical Graduate
    Research Organization and Associate Vice President of Georgetown
    University Medical Center.

    "But I must stress that this is a study in mice, and so we cannot say
    what anticancer effects, if any, Gingko biloba might offer humans," he
    said.

    Papadopoulos and his research team became interested in Gingko biloba
    because their research suggested that it might interact with the
    peripheral-type benzodiazepine receptor (PBR), a molecule they have
    been studying for the last 20 years. For example, they have determined
    that this protein (discovered by accident when researchers looked at
    how the anti-anxiety drug diazepam, better known as Valium., worked) is
    involved in bringing cholesterol into a cell's mitochondria.

    In some cells the mitochondria uses cholesterol to produce steroids,
    which are regulatory hormones that, among other functions, help a cell
    grow, Papadopoulos said. "In fact, we have found that most life forms,
    including plants, insects, and animals, have receptors like these that
    help regulate growth."

    So they looked at whether cancer cells -- with their need to
    proliferate -- produce more of these cholesterol-bearing receptors, and
    found that some highly invasive cancers do, indeed, over-express PBR.
    "Accelerated growth requires production of new cell membranes, and one
    of the main components of membranes is cholesterol," Papadopoulos said.

    The researchers also knew that steroids help regulate brain function,
    and they found over-expression of PBR is also associated with a variety
    of neurological disorders. Because the leaf of Ginkgo biloba is an
    ancient Chinese treatment for dementia that is still widely used -- and
    which is now being tested in the U.S. to treat Alzheimer's disease
    patients -- Papadopoulos decided to look at the effect of Ginkgo biloba
    on PBR production.

    He selected breast cancer cells that over-expressed PBR, implanted them
    in mice, and treated the mice with a standardized extract of Ginkgo
    biloba leaves. After 30 days, tumor size was reduced by 35 percent,
    compared to untreated mice. That research was published in 2000.

    One aim of this new study, then, was to find whether other cancer cell
    lines also over-express PBR. They found that, in addition to one form
    of aggressive breast cancer (invasive estrogen-receptor negative),
    certain brain, colon, and prostate cancers also show higher than normal
    levels of PBR.

    The other part of the research was to see if Ginkgo biloba would show
    any anticancer effects on these cancer cell lines, and concluded that
    the extract did nothing to cancers that were not invasive, but
    significantly slowed the growth of aggressive cancer cells.

    Papadopoulos and his team then studied whether a non-commercial
    injectable form of a standardized extract of Ginkgo biloba leaves might
    have any preventive effects, and selected the aggressive breast cancer
    and brain glioma to study in mice. The researchers pretreated the
    animals with this pharmaceutical preparation of Ginkgo biloba, then
    implanted the tumors. The Ginkgo biloba extract inhibited growth of the
    breast tumors by more than 80 percent, but glioma tumors did not
    respond as strongly, and the benefit was maintained for only 50 days
    despite continuous treatment. Tumors implanted in mice that did not
    over-express PBR did not respond to the extract.

    Papadopoulos now plans to examine the notion that a cancer diagnosis
    might increase production of stress steroids such as corticosteroids
    through PBR over-expression, and it is this stress that, in effect,
    pushes a tumor to become invasive. "Ginkgo biloba could possibly reduce
    this stress by tamping down PBR," he said.

    http://gumc.georgetown.edu
     
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  2. Roman Bystrianyk wrote:
    > "Ginkgo biloba reduces aggressive cancer risk in animal experiments",
    > news-medical.net, February 27, 2006,
    > Link: http://www.news-medical.net/?id=16245
    >
    > Researchers at Georgetown University Medical Center say they now have a
    > clearer picture of how an extract from the leaves of the Ginkgo biloba
    > tree reduces the risk of aggressive cancer in animal experiments.


    Yeah, but is it a whole-grain?
     
  3. On 28 Feb 2006 14:36:07 -0800, "Mr-Natural-Health"
    <[email protected]> wrote:

    >Yeah, but is it a whole-grain?


    anything in the entry pointing to whole-grains except your mind is
    still in whole-grain mode ??
     
  4. Alf Christophersen wrote:
    > On 28 Feb 2006 14:36:07 -0800, "Mr-Natural-Health"
    > <[email protected]> wrote:
    >
    > >Yeah, but is it a whole-grain?

    >
    > anything in the entry pointing to whole-grains except your mind is
    > still in whole-grain mode ??


    Whole-grains are a good thing!

    Bonded antioxidants naturally found in whole-grains are a good thing.
    They are a natural form of timereleased antioxidants thoughtfully
    provided by mother nature.

    Just thought that you might want to know that whole-grains are a good
    thing.
     
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