Cannabis hope for inflammatory bowel disease

Laboratory tests have shown that two compounds found in the cannabis plant -- the cannabinoids THC and cannabidiol -- interact with the body's system that controls gut function.

Crohn's Disease and Ulcerative Colitis, which affect about one in every 250 people in Northern Europe, are caused by both genetic and environmental factors. The researchers believe that a genetic susceptibility coupled with other triggers, such as diet, stress or bacterial imbalance, leads to a defective immune response.

Dr Karen Wright, Peel Trust Lecturer in Biomedicine at Lancaster University, presented her soon-to-be published work at The British Pharmacological Society's Winter Meeting in London.

She said: "The lining of the intestines provides a barrier against the contents of the gut but in people with Crohn's Disease this barrier leaks and bacteria can escape into the intestinal tissue leading to an inappropriate immune response.

"If we could find a way to restore barrier integrity in patients we may be able to curb the inflammatory immune response that causes these chronic conditions."

Dr Wright, working with colleagues at the School of Graduate Entry Medicine and Health in Derby, has shown that cells that react to cannabinoid compounds play an important role in normal gut function as well as the immune system's inflammatory response.

"The body produces its own cannabinoid molecules, called endocannabinoids, which we have shown increase the permeability of the epithelium during inflammation, implying that overproduction may be detrimental," said Dr Wright.

"However, we were able to reverse this process using plant-derived cannabinoids, which appeared to allow the epithelial cells to form tighter bonds with each other and restore the membrane barrier."

The research was carried out using cell cultures in a dish but, interestingly, when the team attempted to mimic the conditions of the gut by reducing the amount of oxygen in the cells' environment, much lower concentrations of cannabinoid were needed to produce the same effect.

Dr Wright added: "What is also encouraging is that while THC has psychoactive properties and is responsible for the 'high' people experience when using cannabis, cannabidiol, which has also proved effective in restoring membrane integrity, does not possess such properties."