The cannabis plant contains dozens of active compounds called cannabinoids, found in various concentrations within a plant's flowers, leaves, and stem. The majority of cannabinoids are located in the flowers of the female plant and are concentrated in a viscous resin, which is produced in glandular structures called 'trichomes'. In addition to its wealth of cannabinoids, the resin is also rich in terpenes. Terpenes are largely responsible for cannabis' distinct odor, as well as much of the variations in physiological effects across strains.
Cannabinoids are delivered to the body via several routes, including through smoking plant material, vaporizing concentrates, ingesting plant material, and topical application. Researchers have identified over 70 unique cannabinoids within the cannabis plant. Many of these cannabinoids interact with the human endocannabinoid system via cannabinoid receptors found throughout our bodies.
Although scientists are still identifying new cannabinoid receptors, research has advanced at a rapid pace. The two main types of cannabinoid receptors in the human body are called CB1 and CB2. The CB1 receptor is expressed mainly in the brain and central nervous system, as well as the lungs, liver and kidneys. The CB2 receptor is primarily expressed in the immune system, hematopoietic cells, and throughout the gut. The affinity of an individual cannabinoid to each receptor, as well as the cannabinoid's own pharmacology, combine to determine how it will affect the human body.
The most common cannabinoids found in cannabis are the following:
TETRAHYDROCANNABINOLIC ACID (THCA)
THCA is the main constituent in raw cannabis. THCA converts to 9-THC when burned, vaporized, or heated at a certain temperature. THCA, CBDA, CBGA, and other acidic cannabinoids hold the most COX-1 and COX-2 inhibition, contributing to cannabis' anti-inflammatory effects. The cannabinoid also acts as an anti-proliferative and anti-spasmodic.
The most abundant cannabinoid present in marijuana, THC is responsible for cannabis' most well-known psychoactive effects. THC acts as a partial agonist at the CB1 and CB2 receptors. The compound is a mild analgesic, or painkiller, and cellular research has shown that it has antioxidant activity.
CANNABIDIOLIC ACID (CBDA)
CBDA, similar to THCA, is the main constituent in cannabis with elevated CBD levels. CBDA selectively inhibits the COX-2 enzyme, contributing to cannabis' anti-inflammatory effects.
CBN is a mildly psychoactive cannabinoid that is produced from the degradation of THC. There is usually very little to no CBN in a fresh plant. CBN acts as a weak agonist at both the CB1 and CB2 receptors, with greater affinity for CB2 receptors than CB1. The degradation of THC into CBN is often described as creating a sedative effect , known as a "couch lock."
A non-psychoactive cannabinoid, CBG's antibacterial effects can alter the overall effects of cannabis. CBG is known to kill or slow bacterial growth, reduce inflammation (particularly in its acidic CBGA form), inhibit cell growth in tumor/cancer cells, and promote bone growth. It acts as a low-affinity antagonist at the CB1 receptor. CBG pharmacological activity at the CB2 receptor is currently unknown.
CBC is most frequently found in tropical cannabis varieties. CBC is known to relieve pain, reduce inflammation, inhibit cell growth in tumor/cancer cells, and promote bone growth. The effects of CBC appear to be mediated through non-cannabinoid receptor interactions.
THCV is a minor cannabinoid found in only some strains of cannabis. The only structural difference between THCV and THC is the presence of a propyl (3 carbon) group, rather than a pentyl (5 carbon) group, on the molecule. Though this variation may seem subtle, it causes THCV to produce very different effects than THC. These effects include a reduction in panic attacks, suppression of appetite, and the promotion of bone growth. THCV acts as an antagonist at the CB1 receptor and a partial agonist at the CB2 receptor.
Like THCV, CBDV differs from CBD only by the substitution of a pentyl (5 carbon) for a propyl (3 carbon) sidechain. Although research on CBDV is still in its initial stages, recent studies have shown promise for its use in the management of epilepsy. This is due to its action at TRPV1 receptors and modulation of gene expression.