Traditional Medicine
Reveals Its Cancer-Fighting Secret
LONDON (Agence France Presse) - A Chinese traditional remedy derived from plants, which has shown itself to be effective in treating certain forms of leukemia, has revealed its secrets to French molecular biologists, according to a report in the May issue of the monthly Nature Cell Biology.
The scientists found that indirubin, which is a component of the ancient Chinese remedy, blocks the multiplication or the division of the cancerous cells.
Chinese herbal remedies, in use for centuries, are generally a mixture of several plants and it is often difficult to isolate the active ingredients and determine how they work.
In their study of the remedy Danggui Longhui Wan, which is a mixture of 11 plants, the team of Laurent Meijer of the CNRS cellular cycle laboratory in Roscoff, Brittany, used the resources of molecular biology.
Indirubin, which is the red relative of indigo blue, the first dye used by man, had been regarded for some time as the active ingredient of the Danggui Longhui Wan potion, which is used to treat chronic myeloid leukemia.
The French team, working in collaborating with British and German scientists, found that indirubin interacted with a class of proteins called cyclin dependent kinases (CDK). These enzymes play a role in the process which commands cell division, the report said.
"When indirubin binds to these kinases, it blocks their activity and hence halts cell division," the report said.
"Meijer's group have also determined the molecular structure of a complex molecule comprised of CDKs bound to indirubin. This structure sheds light on how exactly indirubin is able to specifically impede the function of these enzymes but not others like them.
"It is hoped that these insights into the way indirubin - and indeed Danggui Longhui Wan - works may feed into the search for better anti-cancer drugs," the report said.
Future development of "powerful and selective inhibitors" of CDK enzymes "offers hope for future application in the treatment of various diseases," the scientists said in a complementary report published in the Franco-Quebec review Medicine-Sciences.