How does cannabis work (pharmacology)
Cannabis has a clear and obvious effect on the human body. But how does that actually work, and where in the body do these effects originate? Over the last decade, scientists have learned a lot about the mechanisms of action of cannabis.
Why do cannabinoids from the cannabis plant have an effect on the human body? The surprising answer is that our body produces a group of ‘cannabis-like’ chemicals called endogenous cannabinoids, or endocannabinoids. Together, the endocannabinoids regulate many bodily functions, as widely diverse as sleep, blood pressure, immune responses, and bone growth, among others. When the different endocannabinoids work together in a proper way, they help to keep us balanced and therefore, healthy. Conversely, it is becoming increasingly clear that an unbalance in endocannabinoid activity is involved in many medical conditions.
Endocannabinoids exert their biological effects by binding to the cannabinoid receptors, which act like switches to changes bodily functions such as blood pressure, pain responses or appetite. It is now known that cannabinoid receptors can be found in most parts of the brain, as well as in the immune system and a variety of other organs. Endocannabinoids and their receptors together are called the . This system can be found even in very primitive organisms, indicating it has a very fundamental and important role in basic physiology.
Plant cannabinoids meet endocannabinoids
Some of the plant-derived cannabinoids bind to the endocannabinoid receptors, and can therefore induce responses that are normally regulated by the endocannabinoids. The specific distribution of cannabinoid receptors in the human body seems to explain many of the observed effects of Cannabis consumption. But cannabinoids can also have effects that are independent from binding to the receptors. For example, some cannabinoids are known to be potent anti-oxidants. Other cannabinoids do not bind directly to receptors, but can influence the way other cannabinoids (such as THC) bind.
Because cannabinoid receptors are mainly found in the nervous system and immune system, it may be easy to understand why the use of cannabis materials may have an effect on medical conditions where the nervous system (MS, pain of neurologic origin) or the immune system (auto-immune disease like rheumatism, inflammation) is involved. However, this does not necessarily mean it is easy for scientists to translate these effects into the development of a viable medicine.
Someone who uses cannabis as a recreational drug deliberately unbalances his body, and enjoys the effect as a pleasurable experience (intoxication). But it is also possible to look at this the other way round: under certain medical conditions, where the body is already out of balance, the use of cannabinoids may (partly) restore balance again. By looking at it this way, it is easy to see the difference between recreational and medicinal use of cannabis.