Pontifications on Poison
Being some ramblings on events associated with poisonous plants.
Sunday 25th September 2011
Earlier this month 4th I blogged about Colchicum autumnale, the autumn crocus. I mentioned the medicinal use of colchicine for treating gout and killing white blood cells, a necessary treatment for some conditions.
Yesterday, I wrote about the excellent NHS Choices ‘Behind the Headlines’ website and its clear review of newly published research. While I was looking at what it had to say about smoking in the movies, I came across another report on new research involving colchicine.
As usual, the press took a very over-stated, over-dramatic view of what the work is about. A number of papers chose to use headlines about a ‘smart bomb’ capable of ‘wiping out’ cancer or, at least, bringing ‘hope to millions’. Even the more sober media outlets referred to the effects as being ‘dramatic’.
As the NHS Choices website points out, the news reports are based, not on a full scientific paper, but on a brief presentation to the British Science Festival and a press release from the University of Bradford where the work is being carried out.
Chemotherapy, one of the most common forms of treatment for cancer is, essentially, a form of poisoning. Many people have expressed to me their amazement that the Taxus baccata, yew, can be very poisonous and yet is used to treat cancer. I always point out to them that chemotherapy is poisoning. The hope is that you can deliver enough poison to kill the cancer cells but without causing more general fatal effects. As everyone knows, the side effects of chemotherapy can be seriously unpleasant and that is because the drugs used are poisons.
The holy grail for cancer researchers is to find a drug that can be specifically targeted at cancer cells without destroying healthy cells. The work on colchicine involves modifying the substance to ‘switch off’ its toxic properties but in such a way that an enzyme only active in high levels in cancer tumours switches it back on again. In this way, the researchers hope, colchicine could be circulating harmlessly in the blood vessels but effectively kill off cancer cells by being activated by those same cells.
So far, the researchers have only experimented on mice with deliberately induced cancers of five different types but what little detail is available suggests that 70% of those cancers were cured with a single dose. The researchers say their results to date are very encouraging but there is a great deal more that needs to be done before trials in humans can be started and those trials will take some time.
As so often with press stories about cures for cancer any generally available treatment is a good number of years away and all the overblown headlines do is to give false hope to people already suffering from the disease.
Use of colchicine to treat gout comes under the heading of ‘alternative remedies’ because it is not available as a mainstream medicine for that purpose. I can’t help fearing that there will be snake oil salesmen who take this story and use it to try and con cancer sufferers into parting with a lot of money for an unproven substance.
Past experience suggests that some people would fasten on to such a remedy and turn their back on conventional treatments based on the expectation that this would terminate their disease. Such an approach could cost some of them their lives.