There is a bit of excitement about Artemisinin in osteosarcoma (the most common bone cancer) care for dogs these days, so I thought I should give you some thoughts.
Artemisinin is used for malaria infections. It is derived from the sweet wormwood, which has been used for centuries in Traditional Chinese Medicine for fever. Presumably things causing fevers (like malaria) would be killed by this herb.
Recently there is interest in artemisinin and related compounds for potential cancer care in dogs. This was started, I believe, in the late nineties due to some personal anecdotes and some science being done in Seattle by Drs Lai and Singh, at University of Washington. Discussion boards on Yahoo and the like spread the word.
It is likely that some of the initial anecdotes were from dog lovers owning dogs with osteosarcoma. This caused a stir in the osteosarcoma community, but the publications so far do not limit artemisinin’s effect to bone cancer cells. Other cancer cells have been evaluated, with some support. However, much of the evidence is from in vitro (test tube) studies, but there are some limited in vivo (in living bodies) data. More on this later.
The way this stuff is suspected to work is by oxidizing iron. Cancer cells take up more iron than normal body cells. The iron gets in through a protein channel called transferrin. The cancer cells have a higher requirement to sustain all the dividing they do.
Oxidized iron, in this form, is pretty reactive. The process turns the iron into a free radical, which reacts with parts of the cancer cell to cause injury. This is one way that artemisinin is supposed to work. Since normal body cells have much less iron, the are less affected by this damage.
It also seems to have the ability to slow the development of the growth of new blood vessels around tumors. Tumors need to be fed because they have very high metabolic demands as they grow a lot. So they cause the body to grow new arteries and veins to feed themselves. This process is called angiogenesis.
Turns out there is pretty good evidence artemisinin slows this process by shutting down the genes that create the new blood vessels. Turn off the genes, turn of the process, less cancer food supply.
We’ll look a bit more at artemisinin in the next post.