C
Combretastin, the active ingredient in the bark, was originally isolated form the stems and branches in the 1970a by South African researcher, Dr Gordon Cragg. A massive seventy-seven kilogrammes of material was needed from the tree to produce just a few milligrams of the active ingredient. However, scientists have now been able to produce the drug synthetically. This type of manufacturing has meant that the drug can now be mass-produced and used much more widely in the treatment of cancer. Most cancers are caused by tumours, which create their own network of capillaries to supply the blood they need in order to grow. The effect of combretastin is to reduce the tumours ability to create these capillaries and thereby starve the tumour to death.
D
Combretastin appears to work very quickly, often reducing the blood flow to a tumour within four to six hours after its first application. A feature in its favour is that combretastin does not appear to affect the blood supplies to other healthy organs. But, used in isolation, a small number of cancerous cells which appear able to live off normal blood supplies, appear to remain unaffected by combretastin, and radiation therapy is required to destroy these cells and remove the threat of cancer altogether.
E
Initial trials have been carried out on twenty-five patients in the USA. These have met with a remarkable measure of success. One 55-year-old man, suffering from a particularly aggressive form of thyroid cancer before treatment, has been cancer-free for two years following a course of the new drug. It is generally held that if a cancer does not return within two years of treatment, it has been cured. So far, other patients involved in the trials since then, including those with cancer of the bowel, have also remained clear of their cancers.
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