Artemisinin could selectively kill cancer cells while leaving normal cells unharmed

Researchers at the University of Washington have blended the past with the present in the fight against cancer, synthesizing a promising new compound from an ancient Chinese remedy that uses cancer cells' rapacious appetite for iron to make them a target.

The leaves of Artemisia annua, the sweet wormwood tree, are the source of artemisinin. Although lethal to all known strains of malaria, the drug is produced in small quantities; extracting it from the leaves is an expensive process. Source: www.lbl.gov

The substance, artemisinin, is derived from the wormwood plant and has been used in China since ancient times to treat malaria. Earlier work by Henry Lai and Narendra Singh, both UW bioengineers, indicated that artemisinin alone could selectively kill cancer cells while leaving normal cells unharmed.

The new compound appears to vastly improve that deadly selectivity, according to a new study that appeared in a recent issue of the journal Life Sciences. In addition to Lai and Singh, co-authors include Tomikazu Sasaki and Archna Messay, both UW chemists.

"By itself, artemisinin is about 100 times more selective in killing cancer cells as opposed to normal cells," Lai said. "In this study, the new artemisinin compound was 34,000 times more potent in killing the cancer cells as opposed to their normal cousins. So the tagging process appears to have greatly increased the potency of artemisinin's cancer-killing properties."

The compound has been licensed to Chongqing Holley Holdings and Holley Pharmaceuticals, its U.S. subsidiary, to be developed for possible use in humans. Although the compound is promising, officials say, potential use for people is still years away.

In the study, researchers exposed human leukemia cells and white blood cells to the compound. While the leukemia cells quickly died, the white blood cells remained essentially unharmed.

The trick to the compound's effectiveness, according to Lai, appears to be in taking advantage of how cancer cells function.

Because they multiply so rapidly, most cancer cells need more iron than normal cells to replicate DNA. To facilitate that, cancer cells have inlets on their surface, known as transferrin receptors, in greater numbers than other cells. Those receptors allow quick transport into the cell of transferrin, an iron-carrying protein found in blood.

In creating the compound, researchers bound artemisinin to transferrin at the molecular level. The combination of the two ingredients appears to fool the cancer cell.

"We call it a Trojan horse because the cancer cell recognizes transferrin as a natural, harmless protein," Lai said. "So the cell picks up the compound without knowing that a bomb – artemisinin – is hidden inside."

Once inside the cell, the artemisinin reacts with the iron, spawning highly reactive chemicals called "free radicals." The free radicals attack other molecules and the cell membrane, breaking it apart and killing the cell.

According to Lai, that process is what initially piqued his interest in artemisinin about 10 years ago. The wormwood extract was used centuries ago in China, but the treatment became lost over time. In the 1970s, it was rediscovered as part of an ancient manuscript containing medical remedies, including a recipe that used a wormwood extract. The medical community soon discovered that the extract, artemisinin, worked well against malaria, and it is currently used for that purpose throughout Asia and Africa.

Artemisinin combats malaria because the malaria parasite collects high iron concentrations as it metabolizes hemoglobin in the blood. As science began to understand how artemisinin functioned, Lai said, he began to wonder if the process had implications for cancer treatment.

"I started thinking that maybe we could use this knowledge to selectively target cancer cells," he said. "So far, the outlook appears good."

The next step in development under the Holley licensing agreement will likely be testing in animals and, if that pans out, human trials to gauge the compound's effectiveness. The current study was funded by the Artemisinin Research Foundation and Chongqing Holley Holdings.

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  1. Skye Coe Skye Coe United States says:

    Although studies primarily were focused on breast cancer, I used artemisinin (sweet wormwood) capsules in combination with venifer (iron) while doing chemotherapy for colon cancer. I choose doing chemo because I knew that the iron and artemisinin would be delivered systemically in spite of it's poor reputation for curing cancer. After 6 chemo treatment one are of concern was returning to a walnut sized tumorous stage. After adding the artemesinin at the sixth treatment, the walnut sized tumor shrank to the size of a green pea within 3 days. Because of an adverse reaction to the chemo at the injection site, I stopped the chemo and used the opportunity to have a CT scan done which validated the change of status in the tumours. Hemorrhoids that were present until adding the artemisinin also disappeared. Comment from the amazed oncologist was 'Congratulations!! Tell all of your friends and throw a party!!". I am now awaiting the results of a final PET scan done recently. Another area of concern, a 'mass', did not disappear, so I requested a biopsy and it was determined that that area was not malignant.  If I had followed the regular protocol of using chemo and radiation at the same time, I would have received radiation treatments targeted in area not in need of such harsh treatment. Very honestly , I made quite a few lifestyles changes including adding probiotics, digestive enzymes, using the ER4YBT diet using anti-cancer ketogenic principles, but feel the success of elimination of tumors was directly related to addition of artemisinin to iron and chemo. With no harmful side effects known for short term use of artemisinin, I don't see how anyone could go wrong in trying this. My new oncologist has no interest in use of artemisin, as he considers evidence 'unempirical', but said he didn't care what I did on my own. Fortunately that's what I did and he recently changed my cancer status to 'curable' something that I knew all along. Google the info on Youtubes of work of Dr. Henry Lai and Dr Len Saputo for more specific details on how to use artemisinin. It may save your life in same way it did mine.

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News-Medical.Net.
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