Inflammatory bowel diseases (IBD) affect more than 3 million people in the western world. Advances in the therapy of IBD have been achieved with new immunosuppressive and immunomodulatory agents; however, current pharmacological treatment still relies on nonsteroidal and steroidal anti-inflammatory drugs, treatments that may cause severe side effects. With the advent of the so-called novel biologicals (e.g. tumor necrosis factor α antibodies), new hope was sparked for a more effective treatment of IBD, yet severe side effects and tolerance associated with long-term use of these drugs have dampened these outlooks. Although currently used medication can keep IBD patients in relatively long states of remission, a more effective cure with fewer side effects is a desirable aim. Cannabinoids have recently moved into the center of inflammation research. But despite the fact that Cannabis sativa has traditionally been used for centuries as an analgesic and anti-inflammatory remedy, modern pharmacological therapy of inflammation with cannabinoids is still at the beginning.
A recent article has highlighted that between 33 and 50% of people suffering from IBD have been using Cannabis to relieve IBD-related symptoms. In line with this, animal models of IBD largely suggest that cannabinoid compounds and activation of cannabinoid (CB) receptors significantly suppress the severity of colitis. In addition, non-CB receptor-mediated effects of cannabinoids can also cause improvement of experimental colitis.
In the present study, no effects of Hemp were seen following oral application of 20 mg/kg, a dose that was shown to improve pain in rats caused by chronic sciatic nerve constriction and intraplantar injection of complete Freund’s adjuvant. Whether higher doses of Hemp or application twice a day and 3 times a day would result in observable effects remains unresolved at the moment. Also, whether rectal Hemp protects against colitis by activation of local mechanisms or by systemic effects is unknown and needs to be addressed in a concomitant study. This is of additional interest as a true local effect would allow the development of e.g. slow-release formulations that may be ingested orally and then act throughout the colon, thus being helpful in patients with proximal colitis and pancolitis.
To summarize, Hemp was given via 3 different routes of delivery to mice and its effect on the severity of TNBS colitis was compared. We confirm that Hemp given intraperitoneally is protective, and we add that Hemp given per rectum also offers protective effects, suggesting that rectal application of cannabinoids for the therapy of intestinal inflammation may be a feasible option.