Reports from cannabis users that the drug reduces the symptoms of inflammatory bowel disease (IBD) may finally be explained by new research from the University of Bath showing that cannabinoids help control and prevent intestine inflammation in mice.
This is the first time scientists have reported a biological mechanism to explain why some marijuana users have reported beneficial effects from cannabis on intestine inflammation conditions such as ulcerative colitis and Crohn’s disease.
Researchers from Bath, working with colleagues at University of Massachusetts Medical School, hope that their findings will help develop new drugs and treatments for gut disorders, which affect millions of people around the world and are caused when the body’s immune defences mistakenly attack the lining of the intestine.
The research is published in the Journal of Clinical Investigation.
The team discovered that gut inflammation is regulated by two processes, which are constantly in flux to respond to changing conditions in our intestines. Previous scientific research had identified the first process, a pathway promoting an aggressive immune response in the gut, which is useful to destroy dangerous pathogens but which can damage the lining of the intestine when immune cells attack indiscriminately.
The second process, described in this research for the first time, turns off this inflammation response, via molecules transported across the cells lining the gut into the intestine cavity.
Crucially this downregulation response requires a naturally-produced molecule called an endocannabinoid, which is very similar to cannabinoid molecules found in cannabis.
If the endocannabinoid isn’t present, inflammation isn’t kept in balance and it can flare up, as the body’s immune system cells attack the intestinal lining.
The researchers think that because cannabis use introduces cannabinoids into the body, these molecules could help relieve gut inflammation as the naturally produced endocannabinoids normally would.
Professor Randy Mrsny from the University of Bath Department of Pharmacy and Pharmacology, said: “We need to be clear that while this is a plausible explanation for why marijuana users have reported cannabis relieves symptoms of IBD we have only worked in mice and have not proven this experimentally in humans.
“However our results may provide a mechanistic explanation for anecdotal data that cannabinoid exposure benefits some colitis patients. For the first time we have identified a counterbalance to the inflammation response in the intestine and we hope that these findings will help us develop new ways to treat bowel diseases.”
Professor Beth McCormick, from the University of Massachusetts Medical School, said: “There’s been a lot of anecdotal evidence about the benefits of medical marijuana, but there hasn’t been a lot of science to back it up.
“For the first time, we have an understanding of the molecules involved in the process and how endocannabinoids and cannabinoids control inflammation. This gives clinical researchers a new drug target to explore to treat patients that suffer from inflammatory bowel diseases, and perhaps other diseases, as well.”
The global market for colitis drugs is predicted to be worth $606Bn by 2022.
The research was funded by the USA’s National Institutes of Health (NIH).