Introduction To Phytocannabinoids

Summary

Phytocannabinoids are naturally occurring molecules within the cannabis family of plants. Cannabis plants can be classified in different ways-such as their strains or trade names. However, the most accurate terminology is the term chemovars, which classifies cannabis plants on their chemical composition. Cannabis plants contain over 120 different types of phytocannabinoids along with multiple other compounds. The most prevalent ones are delta-9-tetrahydrocannabinol (Δ9-THC or THC), cannabidiol (CBD) and cannabichromene (CBC). These substances are associated with unique therapeutic effects and can be found in different quantities in each plant variety. Phytocannabinoids are now utilized for managing various symptoms and conditions based on their broad therapeutic potential.

What are phytocannabinoids and where do they come from?

Phytocannabinoids are molecules produced by tiny hair-like protrusions called trichomes that are distributed along the cannabis plant, but are mainly concentrated in the flowers. In addition to producing more than 120 different types of phytocannabinoids, cannabis plants produce over 18 distinct compound classes such as enzymes, terpenes and flavonoids.

Cannabis is a flowering plant that comes from the family Cannabaceae and grows in tropical and temperate climates. The two most well-known species of this plant are C. sativa and C. indica, which can be crossbred to produce other hybrid varieties. 

What are the differences between C. sativa and C. indica?

C. Sativa and C. Indica are the two most common cultivated varieties or cultivars of the cannabis plant and are often incorrectly referred to as ‘strains’. In the past, C. Sativa and C. Indica were classified according to their phenotype (physical characteristics). However, centuries of breeding and selection between the Sativa and Indica phenotypes have resulted in numerous cultivars and hybrids.

Cross-breeding and selection has now made it difficult to identify cannabis varieties purely by their physical characteristics. A more reliable method for distinguishing cannabis varieties is by their chemical composition, as chemical variants or chemovars. Classifying plants into chemovars may allow for a better understanding of the psychological and physiological effects by considering the complex interactions of their chemical components. For example, the relative amounts of THC and CBD between chemovars can produce different health effects and should be carefully considered when cannabinoids are authorized for medical purposes.

The cultivar classification system has become less relevant as it does not reflect the pertinent differences in chemical composition between plants. In fact, healthcare practitioners rely primarily on the amounts of THC and CBD when authorizing medical cannabinoids rather than relying on cultivar types to determine what would be most appropriate for each individual. 

THC Molecule

What is THC?

THC directly binds to cannabinoid (CB₁ and CB₂) receptors. It is the cannabinoid that may provide benefits for pain, sleep, muscle spasms, nausea and stimulating appetite and is also responsible for the ‘intoxicating’ feeling that some people feel when they absorb cannabinoids. The amount of THC in the cannabis plant varies from less than 1% to as high as 30%.

What is CBD?

CBD indirectly binds to cannabinoid (CB₁ and CB₂) receptors. It does not cause the intoxicating effects that THC does. The effects of CBD include helping to reduce inflammation (anti- inflammatory), lowering pain, helping for nausea and vomiting, reducing anxiety and lowering seizures in people with epilepsy.

What are the main phytocannabinoids in the cannabis plant?

The main phytocannabinoids produced by the cannabis plant are delta-9-tetrahydrocannabinol (Δ9-THC or THC), cannabidiol (CBD) and cannabichromene (CBC). Other phytocannabinoids found in the plant include cannabigerol (CBG) and tetrahydrocannabivarin (THCV).

These phytocannabinoids can be found in different quantities in each plant, depending on factors such as:

  • Cannabis plant variety
  • Soil and climate conditions
  • Cultivation techniques

Among all the phytocannabinoids, THC has been studied the most and is responsible for many of the physical and psychotropic effects associated with cannabinoids (e.g. euphoria or intoxication). Compared to THC, other phytocannabinoids (e.g. CBD, CBC, CBG) are less abundant in the cannabis plant and have little to no intoxicating properties.

What is phytotherapy?

Phytotherapy, also known as phyto-therapeutics, is a practice of using medicinal plants and their related products (e.g. cannabis and cannabis extracts) to manage a range of conditions or symptoms. This practice involves extensive clinical research, assessment of traditional plant uses, and clinical evaluations to gain a better understanding of potential therapeutic applications.

With the help of modern scientific and technological innovations, the clinical potential of plants (such as cannabis) is being identified. Phytotherapy is now slowly gaining global recognition as an alternative or complement to pharmaceutical medicine.

Phytocannabinoids have been studied, explored and used in phytotherapy for centuries due to their therapeutic potential, particularly when they interact with the endocannabinoid system (ECS). Click here to learn more about the ECS.

What is the difference between phytocannabinoids and synthetic cannabinoids?

Cannabinoids produced by plants, such as cannabis, are called phytocannabinoids (e.g. THC and CBD) while synthetic cannabinoids, such as nabilone (Cesamet®) and dronabinol (Marinol®), are chemicals manufactured in laboratories aimed to mimic natural cannabinoid behavior.

How do cannabinoids interact with the endocannabinoid system (ECS)?

The endocannabinoid system (ECS) has two principle cannabinoid receptors, called CB₁ and CB₂. Cannabinoids, such as THC, CBD and CBC, bind to receptors by a lock-and-key mechanism. Once activated, receptors produce unique effects, including: 

  • When THC interacts with the cannabinoid receptors, CB₁ and CB₂, it primarily produces psychotropic effects (i.e. euphoria, intoxication). THC may also stimulate appetite and reduce pain and spasms.
  • Unlike THC, CBD does not bind directly to the CB₁ or CB₂ receptors and does not cause intoxication. CBD holds potential as an anti-inflammatory, analgesic and anti-nausea agent and may have anti-intoxicating effects.
  • CBC is an anti-inflammatory agent and has analgesic effects.
Reference

1. Health Canada. Information for Health Care Professionals: Cannabis (marihuana, marijuana) and the cannabinoids. aem. https://www.canada.ca/en/health-canada/services/drugs-medication/cannabis/information-medical-practitioners/information-health-care-professionals-cannabis-cannabinoids.html