First some background: Colitis specifically refers to the inflammation of the colon, the most posterior portion of the large intestine, and encompasses a broad group of medical conditions. Some of these conditions include inflammatory bowel disease (IBD), ulcerative colitis, Crohn’s disease, and pseudomembranous colitis. In addition to colonic inflammation, colitis is also usually seen with symptoms such as fever, anemia, and diarrhea; and although acute cases of colitis such as those due to bacterial infection can be easily treated, the more chronic cases of colitis may last the rest of a patient’s lifetime. It has been shown in previous studies that activation of cannabinoid receptor 1 can lead to a gradual dissipation of symptom intensity in cases of colitis.
The new information: The activation of cannabinoid receptor 2 actually protected against colitis in model organisms. The actual procedure of the experiment was to induce colitis in mice using TNBS (trinitrobenzene sulfonic acid). By studying the colons of the experimental organisms, it was also shown that mice which developed colitis showed an increase in expression of cannabinoid receptor 2 in their colons, meaning that their bodies are trying to rid themselves of colitis by increasing the effects of cannabinoids in the colon. The mice which developed colitis were then given a three-day treatment of cannabinoid agonists, which caused a large reduction in the clinical manifestations of colitis, limiting the progression of the condition.
What this means: Not only can cannabinoids lead to decreased intensity of symptoms in cases of colitis, but they can also actually protect against it, and stop the condition in its early stages. Additionally, one of the body’s natural mechanisms for protecting against the effects of colitis is to allow a greater level of access for cannabinoids to effect the colon.
Storr, M.A., et al. “Activation of cannabinoid 2 receptor (CB2) protects against experimental colitis.” Inflammatory bowel diseases. 15.11 (2009): 1678-85.