Natural compounds in tea, coffee, chocolate and cola could one day be dispensed as drugs to fight heart disease and cancer.
Peter Shepherd and colleagues at the University College London report in the Journal of Biological Chemistry today that because caffeine and theophylline block the function of a key enzyme in the body they might also block cell growth and blood clotting.
The discovery could help explain why theophylline, already used in asthma treatment, is an effective anti-inflammatory.
The researchers homed in on an enzyme called PI-3 kinase, thought to have a role in the signalling machinery which determines cell growth and death. One particular form of the enzyme, targeted by caffeine, also plays a role in the body's response to infection and could be linked to the development of irritable bowel disease.
The team tested the effect of caffeine and other compounds on the enzyme in genetically engineered insect tissue. They confirmed that caffeine and theophylline played an unexpected role in blocking enzymes which in turn were critical to a range of cell functions.
"Alongside possible advances in cancer treatment, this research suggests that caffeine type drugs could be used to treat heart disease and inflammatory illnesses," said Prof Shepherd.
"But the message to the public is not to overdose on chocolate or coffee. The study relied on using high concentrations of caffeine that would be unhealthy for human use. Caffeine has well known side effects that make it inappropriate for drug use."
The research is the latest discovery of potential pharmacy from the dinner table. In separate earlier studies tea has been linked with protection against certain cancers, and chocolate has repeatedly been shown - in moderation - to have valuable anti-oxidant properties.
The UCL team has been able to watch caffeine and theophylline at work deep in the heart of the cell. "The next stage of our research will be to develop compounds which mimic the structure of caffeine but without its negative effects," said Prof Shepherd.
