Spicy food could provide compound to fight cancers

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 has said.

Capsaicin, the active component of chillies, 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 £410m cost of developing conventional medicines, as 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. 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."

Dr Bates said the fact that capsaicin, part of a group of food compounds called vanilloids, was a common 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 £410m and takes 10 years for a large-scale pharmaceutical company to develop a new compound 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.

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."