Cannabinoid Receptors: CB1 and CB2
Summary
Cannabinoid receptors are the primary targets of the endocannabinoid system, bound by lipid signaling molecules called endocannabinoids.
CB2 to the Rescue: Understanding CB1 and CB2 Receptors
The endocannabinoid system (ECS) is a relatively unknown system of the body with a considerable influence on human health and well-being. The ECS is composed of cannabinoid receptors, endocannabinoids, and metabolic enzymes, playing a crucial role in the human body: maintenance of homeostasis via various physiological and regulatory mechanisms.
A “receptor” is typically defined as an intracellular protein molecule that receives and responds to extracellular chemical signals, ultimately producing a cellular cascade of events. Cannabinoid receptors (CBs) are the primary targets of the ECS, bound by lipid signaling molecules called endocannabinoids (eCBs) that are produced on demand in response to elevated intracellular calcium levels in neurons. After eCBs bind a receptor to inhibit the release of neurotransmitters and exert a particular effect on the body, they are degraded via metabolic enzymes in a process called hydrolysis.
While eCBs are endogenous to the human body, there are two other types of cannabinoids that can bind CBs: phytocannabinoids (plant-based chemicals) and synthetic cannabinoids (designed specifically to interact with the ECS). Two of the most-studied eCBs include N-archidonylethanolamide (anandamide, AEA) and sn-z-archidonoylglycerol (2-AG).
There are two main types of CBs, which vary in their chemical structure and thus perform different functions in terms of diet, lifestyle, and nutrition:
Cannabinoid Receptor 1 (CB1) is associated with psychoactive, neuromodulatory, and analgesic effects due to its activation by a lipid called tetrahydrocannabinol (THC). CB1 is mostly expressed in the brain, adipocytes (fat cells), hepatocytes (liver cells), and musculoskeletal tissues.
Cannabinoid Receptor 2 (CB2) is associated with anti-inflammatory and immunomodulatory effects but no psychoactive effects. CB2 is expressed in body cells controlling immune function and (potentially) the central nervous system (CNS). Additionally, research suggests that secondary metabolites from phytonutrients in plant-based foods enhance the activity of CB2 receptors and confer healthy inflammatory responses.
Hemp, also known as the fiber and seeds from the Cannabis sativa L. plant species, contains a negligible amount of THC. Instead, the phytocannabinoids found in hemp largely activate CB2, thus exerting positive, non-psychoactive effects on the human body. However, a balance of targets and specific receptor activators is more beneficial than non-selective activation.
Read more about CB2, hemp, and nutrients supporting the endocannabinoid system.