1, 2009 (foodconsumer.org) -- Compounds extracted from green vegetables
when used along with selenium could be a potent treatment for melanoma,
a deadly skin cancer, according to a new study published in the March
2009 issue of Clinical Cancer Research.
The National Cancer Institute estimated that melanoma was found in 62,480 people in the U.S. and killed 8,420 in 2008.
study led by researchers at Penn State College of medicine showed the
treatment targeted tumors more safely and effectively than conventional
are currently no drugs to target the proteins that trigger melanoma,"
said Dr. Gavin Robertson. "We have developed drugs from naturally
occurring compounds that can inhibit the growth of tumors in mice by 50
to 60 percent with a very low dose."
previous studies, Robertson and his colleagues found targeting the Akt3
protein may potentially inhibit development of melanoma. The finding
led them to a class of compound called isothiocyanates, which are
commonly found in cruciferous vegetables such as broccoli.
have been known to have certain chemo-preventative properties. The
problem is that the potency of these compounds is too low to be used as
therapeutic agents to treat cancer.
the current study, the researchers compared the therapeutic efficacy of
isothiocyanates and isoselenocyanates in tumor-bearing mice.
Isoselenocyanate is a drug in which the sulfur bonds were replaced with
selenium, according to a press release by Penn State.
deficiency is common in cancer patients, including those diagnosed with
metastatic melanoma," explained Robertson. "Besides, selenium is known
to destabilize Akt proteins in prostate cancer cells."
the study, the researchers injected mice with 10 million cancer cells
and six days later when large tumors developed in the mice, they
treated the animals either with isothiocyanates or isoselenocyanates.
found that the selenium-enhanced compounds significantly reduced the
production of Akt3 protein and shut down its signaling network,"
In addition, isoselenocyanates also reduced the growth of tumors by 60 percent, compared to the isothiocyanates alone.
human melanoma cell lines responded to the selenium enhanced drug
differently with the efficiency ranging from 30 to 70 percent depending
on the cell lines.
mechanism behind the therapeutic effect of isoselenocyanates remains
unknown, but the researchers believe that the use of naturally
occurring compounds that target cancer-causing proteins may lead to
discovery of more effective ways to treat melanoma.
is found rich in Brazil nuts and also in shrimp, crab meat, salmon,
halibut, brown rice, chicken, port and whole wheat bread.
are found in vegetables including broccoli Brussels sprouts, cabbage,
horseradish, mustard, radish, watercress, and garden cress, Indian
cress. The common isothiocyanates include allyl isothiocyanate, benzyl
isothiocyanate, phenethyl isothiocyanate and sulforaphane, according to
the Linus Pauling Institute.