KEY POINTS:
The compound that makes spicy food hot and generates the heat in muscle strain remedies could be the key to a new generation of cancer drugs which kill tumours with no side effects, a leading scientist said yesterday.
Capsaicin, the active component of chillis, has produced "startling" results in tests to kill a variety of tumour cells including pancreatic cancer, one of the most difficult versions of the disease to treat.
Dr Timothy Bates, who led the research at Nottingham University, said his team have discovered a potential Achilles heel for all cancers because capsaicin targets the "powerhouse" or energy source of tumour cells.
The discovery could lead to the production of drugs to cure a variety of cancers at a fraction of the £410 million cost of developing conventional medicines because capsaicin is already consumed daily by millions of people.
Capsaicin is also commonly used as an active ingredient in muscle rub creams and the treatments for psoriasis.
Dr Bates said: "This is incredibly exciting and may explain why people living in countries like Mexico and India, who traditionally eat a diet which is very spicy, tend to have lower incidences of many cancers that are prevalent in the western world.
"We appear to have discovered a fundamental weakness with all cancer cells. Capsaicin specifically targets cancerous cells, leading to the possibility that a drug based on it would kill tumours with few or no side effects for the patient."
When released onto cancer cells, capsaicin attacks the mitochondria in the cell, which is responsible for generating ATP, the major energy-producing chemical in the body.
Capsaicin specifically binds to the protein within the mitochondria of tumour cells and triggers apoptosis, the process of natural cell death.
Experiments by the Nottingham team found this took place in cancer cells without affecting surrounding healthy cells.
The team applied the compound to human lung cancer cells, considered a gold standard test for anti-cancer drugs, and produced a "startling" rate of cell death.
A similar rate was recorded on pancreatic cancer cells.
In a statement the researchers said: "These results are highly significant as pancreatic cancer is one of the most difficult cancers to treat and has a five-year survival rate of less than one per cent."
A capsaicin-based drug could be particularly effective in treating cancer in children, whose cells are already primed to die by apoptosis.
Dr Bates said the fact that capsaicin, part of a group of food compounds called vanilloids, was a common and safe part of the diet in many countries would dramatically reduce the number of regulatory hurdles that any anti-cancer drug would have to overcome.
It costs around £410 million and takes ten years for a large-scale pharmaceutical company to develop a new compound developed from scratch.
But the Nottingham team, who are also working in conjunction with Chinese scientists to develop active ingredients from herbal remedies, is looking for industrial partners to start clinical trials at a fraction of the cost.
The researchers have also found dramatic results with a common anti-depressant, chlorimipramine, in targeting tumours.
Dr Bates said: "The situation is similar to the story aspirin. A decade ago it was a headache pill but then its effects as an anticoagulant were discovered and now everyone takes it to avoid deep vein thrombosis on flights to New York.
"I am very committed to trying to bring these compounds to the next level of clinical trials. They have enormous potential in the fight against cancer."
Josephine Querido, cancer information officer at Cancer Research UK, said: "This research does not suggest that eating vast quantities of chilli pepper will help prevent or treat cancer.
"The experiments showed that pepper extracts killed cancer cells grown in the laboratory, but these have not yet been tested to see if they are safe and effective in humans. It will be interesting to see how research on capsaicin progresses.
"Cancer Research UK recommends reducing your risk of cancer by eating a healthy, balanced diet, with plenty of vegetables and fruit."
- INDEPENDENT
