New research on mice shows that endocannabinoids help prevent -- or control -- intestinal inflammation. These findings suggest that such compounds might serve the same function in humans.
Cannabis users have long reported that the drug helps reduce the symptoms of inflammatory bowel disease (IBD). New research published by a team from the University of Massachusetts Medical School and the University of Bath explored why. Their findings reveal a novel mechanism that governs inflammation of the gut and may result in a new class of drugs to treat diseases that involve intestinal inflammation.
Pot gut
"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," said Beth A. McCormick, PhD and paper co-author.
"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."
While reports of marijuana helping alleviate gut inflammation are quite numerous, evidence to explain why aren't. This study is the first to identify a biological mechanism that underpins this effect, helping to explain why cannabis reduces intestine inflammation for conditions such as ulcerative colitis and Crohn's disease.
According to the team, gut inflammation is regulated by two distinct processes that each act in turn depending on the conditions in the intestinal environment.
The first process (which was identified in previous research) kick-starts an aggressive immune response in the intestine. This helps our bodies eliminate pathogens, but overzealous immune cells can also damage the lining of the gut by attacking cells indiscriminately.
The second process turns off this inflammation response. The response is spread by special molecules that move across the epithelial cells in the intestine (i.e. the lining) via the same channels that help flush out toxins from the gut.
The key here is that this second process involves a molecule called an endocannabinoid -- which is very similar to the cannabinoids found in cannabis. If there aren't enough endocannabinoids, inflammation won’t shut down and the body's immune cells run amok on our guts' lining.
McCormick and colleagues believe that because cannabis use introduces cannabinoids into the body, these molecules might help relieve gut inflammation as the naturally produced endocannabinoids normally would.
"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 thus far only evaluated this in mice and have not proven this experimentally in humans," she adds.
However, the team hopes that these findings will result in new drugs to help treat bowel diseases in humans.
The paper "Intestinal P-glycoprotein exports endocannabinoids to prevent inflammation and maintain homeostasis" has been published in the Journal of Clinical Investigation.
