Capsaicin Found in Chillies Can Kill Cancer Cells Safely

15/01/07 UK scientists have shown that capsaicin, the chemical that burns your mouth when you eat chillies and an active ingredient of over the counter drugs, can kill cancer cells with little or no harmful side-effects.

The study is published in the journal Biochemical and Biophysical Research Communications.

The team that conducted the research came from the Universities of Nottingham in England and Cardiff, in Wales, and was led by Dr Timothy Bates, who is a member of the Medical Research Council (MRC) College of Experts.

The researchers believe that capsaicin, and other similar compounds, attack the mitochondria of cancerous cells, causing them to "switch off" and die (apoptosis, or cell death) without harming surrounding tissue. Mitochondria are organelles (tiny granules of tissue with their own DNA) that live inside the cells of our bodies and convert nutrients into ATP - the chemical fuel that feeds our cells with energy.

Dr Bates, who is an international expert in anti-cancer drug development and mitochondrial research in particular, said this discovery might explain the low incidence of cancer in countries where they eat a lot of chillies like Mexico and India.

From a development view this discovery is exciting for two reasons. First, because capsaicin and related compounds already exist in food that is eaten regularly, they are already safe, readily available and not unknown. Secondly, and perhaps more importantly as far as development costs and timescales go, these compounds have already been approved for use in a range of drugs such as skin ointments to treat psoriasis and neuralgia. Converting their use to treat cancer would be much cheaper and quicker compared to starting from scratch with a new compound.

Dr Bates and his colleagues tested the capsaicin on H460 human lung cancer cells, which is recognised as the "gold standard" for new anti-cancer drugs. However, they also tested similar compounds on pancreatic cancer cells and found the same effect - the tumour cells died off leaving the surrounding tissue intact. This is a very exciting result because pancreatic cancer has a five-year survival rate of less than one per cent and is currently one of the most stubborn cancers to treat.

The study that led to this discovery is the first to emerge from a newly formed Nottingham UK-China Collaboration on Complementary and Alternative Medicine (NUKCAM). The collaboration has members from the University of Nottingham and the Chinese National Academy of Sciences, for example Professor De-An Guo, who is head of the Shanghai Research Centre for the Modernization of Traditional Chinese Medicine. Prof Guo is working with Dr Bates to discover why traditional Chinese medicines are successful in treating cancer and other diseases.

Traditional Chinese Medicine (TCM) is considered an alternative medicine in the west. But in China it is an important part of the public health care system.

The last twenty or so years have seen an increasing interest on the part of the West and China to come together and explore this wealth of knowledge that dates back thousands of years. The main thrust of joint projects, like this one, is to examine the theories and uses of TCM using western scientific methods and tools.

Another important milestone in this East-West collaboration will be when The World Health Organization's (WHO) initiative to to standardize TCM nomenclature reaches conclusion. It is said to be in its final phases, and there is a paper on this by Tony Reid in the The Journal of Chinese Medicine.

As lovers of Sichuan food and dishes will know, chillies do feature prominently in the Chinese diet, and apart from adding fire and flavour are believed by local followers of Chinese medicine to help ward off the ills caused by their damp and muggy climate.