Studies on an ancient Chinese remedy for malaria are now
underway to see if this same herb will be as effective for cancer. Seattle
scientists have discovered that a compound, called artemisinin, extracted from
the wormwood plant killed virtually all human breast cancer cells exposed to it
in the test tube within 16 hours, while leaving healthy cells alone.
Part of these experiments included a dog with a bone cancer
known as osteosarcoma. Before treatment the dog could not walk across the room.
Within five days of receiving treatment, x-rays showed the animals tumor had
disappeared and the dog enjoyed a full recovery. Henry Lai, a bioengineering
researcher at the University of Washington, said that he believes the dog is
still alive two years later.
How it Works
It seems that the malaria parasite and cancer cells have one
thing in common. They both like iron. When artemisinin comes into contact with
iron, a chemical reaction occurs causing free radicals. In the case of
malaria, these free radicals attack and bind with the membranes of the
single-celled parasite, effectively killing it.
In the case of breast cancer, these cells have five to 15
times more transferrin receptors (cellular pathways that
allow iron to enter) on their surface than normal breast
cells. That's because cells need iron to replicate DNA when they divide. Since
cancer is characterized by out-of-control cell division, cancer cells have much
higher iron concentrations than normal cells --
about three times more, according to Ralph Moss, author of "Healing
The Basic Strategy
The basic strategy, according to Lai, is to pump up cancer
cells with as much iron as they can hold and then introduce artemisinin to
selectively kill them... kind of like a Trojan Horse. In his laboratory tests,
Lai uses a compound called holotransferrin to open up the receptors and allow
more iron to enter both cancer and normal cells. He then exposes each to a
water-soluble form of artemisinin.
After only eight hours, 75% of the cancer cells were
obliterated. Sixteen hours later, nearly 100% of the cancer cells were dead but
the vast majority of normal breast cells did not die. The success is
particularly noteworthy in that breast cancer cells that were resistant
to radiation were utilized in the experiment, Lai adds. "So that means this
approach might work for cancer resistant to conventional therapy."
As might be expected, more aggressive cancers such as
pancreatic and acute leukemia, which are characterized by more rapid cell
division and thus higher iron concentrations, respond even better, Lai says. In
a separate study, the therapy eliminated leukemia cells in the test tube within
Of course further animal testing followed by human trials is
necessary before this treatment will be available. That could take years. But if
this therapy lives up to its early promise, treatment would consist of the
patient being given iron supplements to raise iron concentrations in the cancer
cells, and then the compound would be given in pill form.
Henry Lai's work appears in the November, 2001, issue of the Journal Life
Sciences. The last I heard he was working in Department of Bioengineering at the
University of Washington (206) 685-2000, Fax: