Efficacy of Cannabis and its Constituents in Disease Management: Insights from Clinical Studies

There is a long history of informal use of Cannabis sativa (commonly called cannabis) for many purposes, including treating various ailments worldwide. However, the legalization of cannabis in multiple countries, specifically for medical purposes, has grabbed the researchers' attention to discover the scientific evidence regarding cannabis's beneficial effects. Among over 500 identified compounds (cannabinoids), Delta(9)-Tetrahydrocannabinol (THC) and cannabidiol (CBD) are two major active cannabinoids derived from cannabis. Cannabinoids exert their effects through cannabinoid receptors (CB1R and CB2R). In the recent past, clinical trials have shown the efficacy of cannabis and cannabinoids for various human ailments, such as cancer, neurological disorders, inflammatory bowel disease, chronic pain, and metabolic disorders. The commonly used constituents and derivatives of cannabis include CBD, THC, THCV, dronabinol, nabilone, and nabiximol. The cannabis constituents have also been used in combination with other agents, such as megestrol acetate, in some clinical trials. The common routes for the administration of cannabis are oral, sublingual, or topical. Cannabis has also been consumed through smoking, inhalation, or with food and tea. A maximum of 572 patients and a minimum of nine patients have participated in a single clinical trial. Cannabis is legalized in some countries with restrictions, such as Belize, Canada, Colombia, Costa Rica, The Czech Republic, Jamaica, Netherlands, South Africa, Spain, and Uruguay. This article provides a compilation of published studies focusing on clinal trials on the therapeutic effects of cannabis. The adverse effects of cannabis and its constituents are also discussed.