Since the 1990s, scientists have understood the endocannabinoid system and the process through which its CB1 and CB2 receptors interact with cannabis to produce its health-boosting effects. But a recently discovered receptor called GPR55 has many researchers considering it a possible third receptor, and it may be the key to deeper understanding of the therapeutic applications of cannabis.
GPR55 was first identified by researchers in 1999, but its function was then unknown. In 2007, however, a group of Swedish scientists published a study in the British Journal of Pharmacology revealing that GPR55 interacted with CBD and other cannabinoids.
Following studies revealed more about GPR55’s targets. In 2009, a study revealed GPR55 played a role in osteoclast function, or the formation and healing of bones. A 2015 study in Frontiers in Pharmacology found that GPR55 may have diverse targets from gastrointestinal issues to bone disorders. Because GPR55 is a metabotropic receptor, it affects different cell types differently and causes what are known of as downstream effects.
GPR55 may also play a role in CBD’s effect on seizure disorders like epilepsy. Several studies have shown that CBD may be an effective treatment for childhood seizure disorders like Dravet Syndrome, and a 2017 study found that the GPR55 receptor played a role in this treatment. These findings may encourage the scientific community to further study CBD as an epilepsy treatment option.
Other research suggests that GPR55 may also play a role in inflammatory bowel and Crohn’s disease. A study found that patients with these conditions have a higher level of GPR55, and CBD’s ability to block GPR55 activity may be one cause of CBD’s anti-inflammatory properties in this area of the body.
While more research is necessary to find out exactly how GPR55 functions differently than the CB1 and CB2 receptors, GPR55 promises to be an exciting part of cannabinoid research in the future.