Cannabinoids and gastrointestinal motility: animal and human studies

Area of Science:

• Gastroenterology
• Neurogastroenterology
• Pharmacology

Background:

• Cannabis has a long history of use for gastrointestinal ailments such as emesis, diarrhea, and pain.
• The endogenous cannabinoid system, involving CB1 and CB2 receptors and ligands like anandamide and 2-AG, is functional in the gut.
• CB1 receptors are on neurons in the enteric nervous system, modulating neurotransmission, while CB2 receptors are involved in immune responses.

Purpose of the Study:

• To review the role of the endogenous cannabinoid system in regulating gastrointestinal function and motility.
• To explore the therapeutic potential of modulating this system for gastrointestinal disorders.

Main Methods:

• Review of anatomical and functional evidence for cannabinoid receptors in the gastrointestinal tract.
• Analysis of in vivo studies in rodents and human clinical trials on cannabinoid effects on gut motility.
• Examination of the roles of CB1 and CB2 receptors in normal and pathophysiological states.

Main Results:

• CB1 receptor activation by cannabinoids reduces excitatory enteric transmission, primarily cholinergic, in the gut.
• In vivo studies demonstrate that cannabinoids decrease gastrointestinal transit via CB1 receptor activation.
• Both CB1 and CB2 receptors may mitigate inflammatory increases in intestinal motility, and cannabinoids reduce motility in clinical trials.

Conclusions:

• The endogenous cannabinoid system in the gut plays a significant role in regulating motility.
• Targeting the gut's cannabinoid system offers a promising therapeutic strategy for motility disorders.
• Cannabinoids demonstrate efficacy in reducing gastrointestinal motility, supported by preclinical and clinical data.