BY KIM IRWIN
UCLA Today
There’s an untapped gold mine of herbs, plants and natural
compounds, such as shark liver oil, that may one day yield less
harmful, approved drugs that oncologists can use to fight cancer.
Funded by a $1.1-million gift, researchers at
the Jonsson Cancer Center will determine whether shark liver
oil, soy and a plant historically used by Native Americans,
among other popularly used folk remedies and alternative medicines,
can effectively fight malignancies.
Richard Pietras, associate professor of hematology/oncology,
is already working with anti-tumor agents derived from such
natural sources. He is director of the new Sue Stiles Program
in Integrative Oncology, under which squalamine, a component
of shark liver oil that has been widely used as a cancer folk
remedy, is being studied. A synthetic form of squalamine has
shown some promise in blocking the growth of blood vessels to
tumors. Early-stage clinical trials are focusing on patients
with ovarian and lung cancers.
Other herbal extracts and compounds now under
the close scrutiny of scientists include genistein from soy,
baicalein from the skullcap weed and Yerba Santa, a plant that
was often used medicinally by Native Americans in Southern California.
“I hope that we will soon be able to treat
cancer patients with less harmful and more targeted therapies
to fight their tumors and relieve their symptoms,” said
Pietras, who is both a scientist and an oncologist. “There
has been a revolution in molecular biology. We have a new understanding
of how cancer comes about at a molecular level, and that will
help us as we work to develop these new therapies.”
Turning to plants and herbs as sources for cancer-fighting
drugs is not new. Of the 92 drugs that were approved for cancer
treatment from 1983 to 1994, Pietras said, 62 were derived from
natural sources.
For example, Taxol, isolated from the bark of
the Pacific yew tree, is used to treat breast, ovarian, lung,
head and neck and bladder cancers. Topotecan, a semi-synthetic
derivative of an alkaloid extract from the bark of the Chinese
camptotheca acuminata or xi shu tree, is used to treat ovarian
and lung cancers. The periwinkle plant yields alkaloids to treat
lymphomas, leukemias and several solid tissue tumors.
But more research needs to be done. Of the 300,000
land-based plants on earth, less than 5% have been investigated
for medicinal use, said Judith C. Gasson, a scientist and the
director of the Jonsson Cancer Center.
Yet, a great number of Americans are not waiting
for scientific study to try alternative therapies. A recent
survey found that more than 70% of breast cancer patients used
some form of complementary therapy — dietary supplements,
spiritual healing practices, herbal remedies or physical therapies
like acupuncture or massage.
And about four in 10 Americans currently use
some form of alternative medicine, according to recent federal
statistics. It’s estimated that patients make more than
629 million visits annually to alternative practitioners, more
than twice the number of visits to primary care physicians each
year in the United States.
“I have no doubt that certain types of
alternative therapies will become part of our arsenal against
cancer,” Gasson said, “but we need rigorous testing
to ensure that they’re safe and effective.”
