Green Tea and gold to treat prostate cancer?
21 July BBC
A combination of gold and green tea compounds may be the future of
prostate cancer treatments, according to a new mouse study published in
the Proceedings of the National Academy of Sciences.Researchers from the
University of Missouri found that a combination of a compound found in
green tea leaves radioactive gold nanoparticles were able to destroy the
tumor cells. The tea compound, which was attracted to the cancerous
cells, helped to deliver the gold nanoparticles, which killed the cancer
cells.
Researchers said large doses of chemotherapy, which sometimes have
toxic side effects, are currently used to treat a variety of cancers,
but the new treatment would require doses that are "thousands of times"
lower than that of chemotherapy.
The particles are small enough to destroy the diseased cells, but
leave the healthy surrounding tissue and cells intact.
"By combining a natural component in green tea that has an affinity
for prostate tumor cells, we have formed gold nanoparticles that have a
high uptake in tumor cells," said Dr. Cathy Cutler, research professor
at the MU Research Reactor and co-author of the study. "This formulation
of gold nanoparticles, which has shown such tumor cell death at such a
low dose in a model of aggressive human prostate cancer indicates it
could be effective for aggressive prostate cancer."
The green tea compound used in the study, known as
epigallocatechin-gallate, or EGCg, is an antioxidant that has been shown
in prior research to have cancer-fighting properties.According to the
Centers Disease Control and Prevention, more than 200,000 men in the
United States were diagnosed with prostate cancer, and more than 28,000
died of the disease in 2008. There is currently no treatment for
aggressive prostate cancer, which is the second leading cause of cancer
deaths in men.
In less aggressive forms of the disease, physicians inject hundreds
of radioactive "seeds" into the prostate to treat the cancer, but the
seeds have limited tissue penetration, so it is a treatment best used
for early stages of the cancer that is contained in the prostate.
Dr. David Crawford, professor of surgery and radiation oncology at
the University of Colorado Health Sciences Center, said the use of
nanoparticles for a number of areas in medicine to deliver therapy is
"exciting," and, while early in development, still promising.
But Dr. Derek Raghavan, president of Levine Cancer Institute at
Carolinas HealthCare System, called the study "headline hunting" and
noted the gap between data and clinical application is "vast." He said
there are years of research needed to ensure the safety and efficacy of
the treatment.
"I wish people working in basic labs would stop making these types of
promises at such an early stage," Raghavan said. "They secure brief
fame, but it is so disruptive to patients who are fighting for their
lives. It also adds confusion when real progress is actually being
made."
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