By
Carolanne Wright Contributing Writer for
Wake Up World
The same herb frequently eaten as salad
in Asia has been shown to destroy cancer cells — without harming healthy
tissue. Researchers at the University of Washington have created a
compound based on traditional Chinese medicine that is 1,200 times more
effective in killing malignant cells than chemotherapy drugs. Combined
with iron, the herb selectively targets cancerous cells and has proven
to be a powerful tool in combating the disease. Tomikazu Sasaki, senior
author of the study and chemistry professor at the University of
Washington, describes the compound as “… a special agent planting a bomb
inside the [cancer] cell.”
Since
traditional chemotherapy is rife with severe side-effects
and kills healthy cells, researchers are encouraged by the findings.
Standard chemotherapy destroys as many as 1 normal cell for every
5 cancer cells. The compound developed by Sasaki and his team is far
more specific, killing 12,000 cancer cells for each healthy cell
affected, which minimizes adverse side-effects. Because of this, the
effectiveness of the treatment is increased as higher doses can be
tolerated.
Portrait of a 2,000-Year-Old Medicinal Treasure
Sweet wormwood (Artemisia annua L.)
has been used for over two millennia in traditional Chinese medicine
for a variety of complaints — from skin disorders to high blood pressure
and malaria. Native to Asia, the plant is rich in the following
beneficial compounds:
Artemisia
annua contains sesquiterpenes, flavonoids, coumarins, essential oil,
palmitic acid, stigmasterol, B-sitosterol, aurantiamide acetate,
annuadiepoxide, B-glucosidase III, etc. And sesquiterpenes contains
arteannuin, artemisinin A (qinghaosu I), artemisinin B (qinghaosu II),
deoxyartemisinin (qinghaosu III), qinghaosu IV, qinghaosu V, qinghaosu
VI, arteannuin C, artemisinic acid (qinghao acid), methyl artemisinate,
artemisinol, annulide, friedelin, friedelan-3B-ol, etc. Flavonoids
include chrysosplenol D, artemetin, casticin, cirsilineol, axillarin,
cirsiliol, tamarixetin, rhamnetin, cirsimaritin, rhamnocitrin,
chrysoeriol, kaempferol, quercetin, luteolin, patuletin, etc. Coumarins
include scopoletin, coumarin, 6-methoxy-7-hydroxycoumarin, scoparone,
etc. Wormwood oil includes camphor, B-caryophyllene, iso-artemisia
ketone, B-pinene, bornyl acetate, carveol, benzyl isovalerate,
B-farnesene, copaene, y-muurolene, fenchone, linalool, isoborneol,
a-terpineol, borneol, camphene, myrcene, limonene, y-terpineol, etc. [source]
Of particular interest in the treatment of disease, especially cancer, are the compounds
limonene (
anti-inflammatory, anti-cancer, anti-bacterial, anti-viral, antioxidant),
B-pinene (
antibacterial, anti-inflammatory, anti-proliferative, antioxidant) and
quercetin (
anti-inflammatory ,
anti-proliferative, supports immune function).
Artemisinin is the active
component found in sweet wormwood, which has been used successfully
to treat malaria and has saved millions of lives worldwide. Now
researchers are turning their attention towards applying the herb to
cancer.
Iron as a Trojan Horse
Artemisinin on its own will destroy 100
cancer cells for every normal cell. To improve the results, researchers
added an iron chemical tag into the mix. Since cancer cells need large
amounts of iron to maintain rapid tumor growth, they will readily engulf
the artemisinin-iron tag compound. As explained by UW Today,
“Once inside the cell, the iron reacts with artemisinin to release
poisonous molecules called free radicals. When enough of these free
radicals accumulate, the cell dies.”
Henry Lai, a University of
Washington bioengineering professor and co-author of the study, said the
compound is like a Trojan horse in gaining access to cancerous cells.
Artemisinin is extremely toxic when combined with iron, but harmless
otherwise.
Cancer cells are also not as efficient
as healthy cells in cleaning-up free-floating iron, making the malignant
cells more sensitive to the herb. Because cancer cells are already
under stress from high iron levels, artemisinin pushes the cells over
the edge. Due to this mechanism, researchers believe the compound can be
used successfully for almost any type of cancer. Currently, the
artemisinin-iron tag duo has been tested on human breast and prostate
cancers in vitro, and has safely killed breast cancer in rats.
To establish artemisinin’s
effectiveness, the team saturated normal breast cells and
radiation-resistant cancerous tissue with holotransferrin — a compound
found within the body that carries iron into the cells. Next, the cells
were dosed with artemisinin. Within 16 hours, all the cancer cells
exposed to holotransferrin died and only a few normal cells were
affected. Lai notes that a breast cancer cell contains up to 15 times
more iron receptors than other cells, therefore making it more
susceptible to artemisinin’s assault.
“Most currently available drugs are
targeted to specific cancers,” Lai said. “This compound works on a
general property of cancer cells, their high iron content.”
The research team hopes that since
artemisinin is already widely available, a compound to treat cancer can
be manufactured inexpensively to help those who are ill in developing
countries.
The Washington Technology Center and the Witmer Foundation provided funding for the study.
