Endogenous Cannabinoids and the Role of the Endocannabinoid System | Curatio
Let's face it. The stresses of life can at times be overwhelming. If you've ever wondered how your body copes with it all and keeps you in balance from day to day, you can thank the endocannabinoid system (ECS). It's constantly on the watch and working for you from within.
The ECS is a complex combination of cell receptors, endogenous cannabinoids or endocannabinoids (ECBs) that bind to them, along with enzymes and compounds that regulate them. The ECS manages critical functions in the human body, such as appetite, sleep, memory, mood, nerve regulation, bone remodeling, reproduction and fertility. It is involved in energy production and lipid metabolism. When you add it all up, the basic role of the ECS is to help you cope. It maintains homeostasis by regulating your metabolism.
ECBs have molecular structures that resemble cannabinoids in plants. The two best-known ECBs are anandamide (AEA) and 2-arachidonoylglyerol (2-AG), which scientists discovered in the 1990s. The human body produces ECBs in amounts as needed. However, normal levels are difficult to ascertain. These compounds signal the ECS to act by binding to cell receptors. This process is halted when specific enzymes degrade the ECBs. This means ECB receptors can be turned on and off, as necessary.
CB1 and CB2
There are two main receptors in the ECS, referred to as CB1 and CB2. They exist to interact with endogenous, rather than exogenous cannabinoids. But whichever the source, these cannabinoids compete for the same receptors, though their effects are not necessarily the same. CB1 receptors — located primarily within brain cells, adipose tissue and visceral organs — are the most common receptor type. CB2 receptors are located primarily in the peripheral nervous system and immune system.
The ECS is abundant within the body. In evolutionary terms, it is an ancient system with an internal influence that is profound and widespread. But scientists did not discover the existence of ECB receptors and ECBs until the 1990's. Other researchers had first identified plant cannabinoids which compete for the same receptors and can mimic many actions of ECBs. The result is that we know much less about the full role of the ECS compared to other human systems. At first, scientists thought it existed only in the brain and nerves, but recent research has revealed it is present throughout the body.
Effects in the Body
The ECS controls energy balance by regulating food intake mechanisms within the brain. These higher centers govern appetite and satiety. The ECS also acts peripherally, in the pancreas, liver, skeletal muscle and fat cells, affecting lipid synthesis and glucose metabolism. Not surprisingly, the ECS has attracted the attention of researchers trying to develop safe and effective drugs to treat chronic diseases. Controlling weight with drugs has proved to be an especially elusive goal. Efforts to target the CB1 receptor with drug therapy has resulted in adverse effects, including nausea, anxiety and serious depression.
The actions of the ECS involve and overlap with other systems in the body. It's difficult to study them separately or treat them separately without causing unintended effects, as scientists have discovered. Metabolic processes and homeostasis are complex, with many players involved. Though we know that the ECS is a vital component, we have yet to fully comprehend its role.
Plant-based cannabinoids have become an active area of research for their therapeutic potential, once scientists concluded ECB deficiency may be involved in chronic diseases. Cannabidiol (CBD) in hemp is an especially attractive cannabinoid for medication because it is well-tolerated and not psychoactive. In addition, hemp-derived CBD is also legal to use in the U.S., whether in oral or topical form. But with the explosion of cannabinoid products in the commercial market, the challenge for consumers is to find effective, science-based remedies at a good value.
Lexa W. Lee is a former family physician, research fellow in immunology, lecturer and medical journalist. She also writes about consumer health issues.