The resin of the Cannabis sativa plant, popularly named marijuana, includes a number of natural chemical compounds known as cannabinoids. They have a strong effect on the human central nervous system and are very popular recreational drugs. They provide pain relief and can change the mood or alter perception. The best known is THC, the chemical behind the psychoactive properties that make marijuana so popular. However, many other cannabinoids have been identified, which don't make people "high" but have important medical uses.

Cannabinoids are considered by researchers to be the most important chemicals in the Cannabis sativa plant. The species also includes other compounds, with various biological roles. The leaves for example are green due to the presence of chlorophyll, while the taste and smell of the plant is caused by terpenes.

The well-known popularity of marijuana as a recreational drug is solely caused by the cannabinoids in its composition. The most important chemicals responsible for the "high" effect are THC and CBD, which interact directly with some body receptors.

THC and CBD are the best known and most studied of the chemicals found in marijuana. However, a total of 113 other cannabinoids have been identified so far by scientists.

The trichomes of the marijuana plant are the area where the cannabinoids are synthetized and stored. These crystals are located on the flowers of the plant and give them a distinctive shiny surface.

Since THC is the most prized active ingredient in marijuana, most of the cultivars of the plant have a higher level than normal. This cannabinoid has strong psychoactive properties that have been known for a long time.

By contrast, CBD reduces the "high" effect and is a cannabinoid without psychoactive properties. It is known for its medical benefits that include anti-inflammatory and neuroprotective effects.

Numerous other cannabinoids found in marijuana have important health effects, even if they are not as well-known as THC or CBD. Examples of such compounds are cannabinol (CBN), cannabichromene (CBC) and cannabigerol (CBG).

Major types of cannabinoids

Cannabinoids are not only found in the marijuana plant, there is also a type that is naturally produced inside the human body. The varieties synthetized in the body are known as endocannabinoids, or endogenous cannabinoids. Exogenous cannabinoids are the ones found outside the body, in plants such as Cannabis sativa.

Since these are produced by plants, exogenous cannabinoids have the alternate name of phytocannabinoids, which comes from phyto, the ancient Greek name for plant. As a result, marijuana is a source of phytocannabinoids.

Effects of cannabinoids

Cannabinoids are able to bind to cannabinoid receptors located on the surface of cells, which explains their quick effects. CB1 and CB2 are the most important cannabinoid receptors found in the human body. Most of the receptors are located in several zones of the central nervous system.

Anandamide is a natural chemical found in the human brain that was isolated in 1992. It is very similar to a cannabinoid and has the ability to bind to CB1 receptors. It is considered the typical endocannabinoid and the first of them to be identified. Perception, pleasure and reward response are altered through the mesolimbic pathway, which also reduces pain.

How do cannabinoids work?

Cannabinoid receptors have been studied for more than 20 years. Researchers have discovered two different types of these molecules that interact with cannabinoids in the nervous system. Receptors can be compared to locks, when they come in contact with cannabinoids they open a particular "door" of the cell metabolism. This is how these bioactive chemicals interact with the human body.

The brain regions that regulate psychomotor skills, feelings of rewards, pain perception, cognition and memory include a number of cannabinoid receptors. THC and other cannabinoids cause the famous "high" effect when they come in contact with these receptors. By contrast, CBD and other cannabinoids can fight pain and reduce anxiety when they activate their specific receptors.

Scientists suspect that the presence of cannabinoids receptors show that these chemicals have a role in the human immune system. The human body produces its own compounds that bind to the cannabinoid receptors, known as endocannabinoids. This is further proof that cannabinoids are natural modulators of the immune system.

What medical problems can be treated using cannabinoids?

CBD and other cannabinoids without psychoactive effects have not been studied in depth. Scientists don't fully understand their medical benefits yet, but some properties have been identified.

These include the reduction of tumour expansion, which is a safe and natural way to make chemotherapy treatment more effective. Cannabinoids reduce anxiety, induce quality sleep, fight nausea and vomiting, destroy viruses and cure the diseases started by them, reduce weight loss, improve appetite and alleviate some symptoms of multiple sclerosis such as muscle spasms. The have strong anti-inflammatory and painkiller effects, even in cases of cancer or chronic conditions.

One of the most common of all cannabinoids is CBD. Studies have revealed that it treats anxiety, inflammation, nausea, convulsions, as well as the psychotic effects of schizophrenia. It is effective in the treatment of breast cancer and other tumours by reducing metastasis or stopping it completely. It is increasingly accepted in conventional medicine as a valuable side treatment for cancer and the associated diseases.