Cannabis could be used to prevent cancer spreading, according to groundbreaking research conducted by British scientists.

Research carried out by a team from the University of East Anglia showed how the main psychoactive ingredient in cannabis, Tetrahydrocannabinol (THC), could be useful for shrinking tumors.

The scientists injected THC into laboratory mice bearing human cancer cells, and were able to identify for the first time two receptors in particular that were responsible for the compound’s disease-reducing effects.

Publishing the study in the Journal of Biological Chemistry, the scientists expressed their hope that a synthetic substitute for THC could be created and used to fight cancer.

Dr. Peter McCormick, from UEA’s school of Pharmacy, said “THC, the major active component of marijuana, has anti-cancer properties. This compound is known to act through a specific family of cell receptors called cannabinoid receptors.

“By identifying the receptors involved we have provided an important step towards the future development of therapeutics that can take advantage of the interactions we have discovered to reduce tumor growth.”

However, McCormick acknowledged the need for further testing, warning those undergoing cancer treatment not to self-medicate using marijuana. Similar views have been expressed by UK cancer charities, including Cancer Research UK, which told the Independent that more research on THCs needed to be conducted before being used as treatment.

Cannabis remains illegal in most countries including the UK, but is used medicinally to treat cancer and other terminal illnesses in many countries, including Germany, Canada and Israel.

While British doctors are not allowed to proscribe Cannabis to patients, a Cannabis-based product, Sativex, was legalized in 2006, but is only supplied by the National Health Service (NHS) in limited circumstances.