Scientists in the UK have now traced marijuana's ability to prevent the growth and spread of cancer to specific pathways found in tumor cells, known as cannabinoid receptors.

Dr. Peter McCormick of the University of East Anglia (UEA)'s School of Pharmacy explained the findings to Medical News Today:

"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."

The study, published last month in the Journal of Biological Chemistry, showed that injecting THC into mice with implanted tumors caused the cells to kill themselves — a process known as autophagy.

It also slowed the growth of tumors in breast and brain cancer cell lines.

While anecdotal reports have suggested that marijuana can fight cancer in some patients, Dr. McCormick notes that pharmaceutical companies have focused on developing synthetics and that the actual mechanisms remain "poorly understood."

But Dr. McCormick hopes his team's discovery will help speed along the development of new cancer treatments.

"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."

Previous research had already linked the anti-cancer effects of THC to the CB1 receptor, which is the most common cannabinoid pathway found in the body. CB1 receptors, when activated by THC, are also responsible for the marijuana high.

However, the group showed for the first time that CB2 receptors and GPR55 receptors are also involved, lending further evidence that marijuana can treat various cancers by acting through more than one pathway.

Still, Dr. McCormick believes patients shouldn't treat themselves with marijuana just yet.

"Cancer patients should not use cannabis to self-medicate, but I hope that our research will lead to a safe synthetic equivalent being available in the future."

It may not be only THC in the plant that fights cancer, though.

A 2013 study by a team at St. George's, University of London identified six different compounds in cannabis with anti-tumor properties including cannabidiol (CBD), cannabigerol (CBG) and cannabigevarin (CBGV).

Source: LeafScience