Virginia Thornley, M.D., Neurologist, Epileptologist
August 15, 2018
Using medical cannabis in medical practice, one stumbles on incidental anecdotal symptoms that are relieved including effects on the gastrointestinal tract.
With the advent of cannabinoids, more and more conditions are determined to be helped with its use. This includes the conditions affecting the digestive tract. This explores the role the endocannabinoid system has in the homeostatic activities of the gut and the use of cannabinoids in maintaining this. The endocannabinoid system appears to participate in a regulatory role including maintaining motor and sensory function, maintenance of the epithelial layer and regulate the microenvironment.
Endocannabinoid system and GI motility
It appears that CB1 activation ameliorates gastrointestinal motility under normal physiologic conditions whereas the CB2 receptor seems to modulate it under abnormal conditions such as autoimmune or anti-inflammatory conditions (1).
Endocannabinoid system and pain in the GI tract
Studies have found that there is an interconnection of the TPRV and cannabinoid receptors in affecting visceral pain from stress-related causes and from underlying pathophysiologic conditions. CB1 likely modulates the TPRV receptors causing a reduction of these receptors, whereas the CB2 receptors counteracts the pain effects of mediators of inflammation on the afferent nerves of the visceral organs (2).
Endocannabinoid system and irritable bowel syndrome
Because irritable bowel syndrome has a certain extent of inflammation, this may be a mechanism by which cannabinoids help with the process (2).
Endocannabinoid system and inflammatory conditions of the GI tract
In one study in the animal model, it was found that the endocannabinoid system has an impact the permeability of the GI tract in either a positive or negative fashion. Cannabidiol (CBD) and Tetrahydrocannabinol (THC), 2 of the most well-studied phytocannabinoids, have the capacity to reverse this permeability of the GI tract that is associated with inflammation (3).
Cannabinoids and nausea
Nausea is one of the most well-known and earliest established symptom treated with cannabinoids. Nabilone which has cannabinoids has been used in treating oncologic patients undergoing chemotherapy to ameliorate the nausea that often accompanies this treatment.
In one study of 110 pediatric patients were studied between December 2010 and August 2015 using nabilone. 20% of the patients developed somnolence, euphoria was seen in 3.6% and dizziness was seen in 10%. In 83 patients with chemotherapy causing high rates of emesis, 50% had complete resolution of chemotherapy-induced vomiting. In 23 patients with chemotherapy with moderate rates of emesis, vomiting control was achieved in 53.8% (4).
Role of cannabinoids in the liver
The endicannabinoid system comprises of the CB1 and CB2 receptors, enzymes and endocannabinoids. The CB1 receptor is found to be pro-fibrinogenic in liver cirrhosis and CB2 receptor is found to be anti-fibrinogenic (5).
1.Duncan, M., Mouihate, A., Mackie, K., Keenan, C.M., Buckley, N.E., Davison, J.S., Patel, K.D., Pittman, Q.J., Sharkey, K.A. Cannabinoid CB2 receptors in the enteric nervous system modulate gastrointesintal contractility in lipopolysaccharide-treated rats. Am J Physiol Gastrointest Liver Physiol. 2008, July, 295 (1):G78-G87
2. Pesce, M., D’Alessandro, A., Borelli, O., Gigli, S., Seguella, L., Cuomo, R., Esposito, G., Sarnelli, G. Endocannabinoid-related compounds in gastrointestinal diseases. J. Cell. Mol. Med 2018, Feb., 22(2):706-715
3. Alhamorumi, A., Wright, K.L., Larvin, M., O’Sullivan, S.E. Cannabinoids mediate opposing effects on inflammation-induced intestinal permeability. Br. J. Pharmacology. 2012, Apr. 165(8):2598-2610
4. Polito, S., MacDonald, T., Romanick, M., Jupp, J., Wiernikpwski, J., Vennetilli, A., Khanna, M., Patel, P., Nin, L., Dupuis, L.L. Safety and efficacy of nabilone for acute chemotherapy-induced vomit in pediatric patients: a multicenter, retrospective review. Pedr. Blood cancer. 2018, Jul. 26:e27374
5. Dibba, P., Li, A.A., Cholankeril, G., Iqbal, U., Gadiparthi, C., Khan, M.A., Kim, D., Ahmed, A. The role of cannabinoids in the setting of cirrhosis. Medicines (Basel). 2018, Jun 9:5(2). pii E52