The Major Cannabinoids

Medical Research on CannabinoidsThe cannabinoids are a family of over 60 chemical compounds found primarily in marijuana. As a family, they have remarkable medicinal properties, which have largely gone unresearched in the United States due to Federal anti-marijuana policies.

Cannabinoids mimic the chemical messengers between cells in the human brain and throughout the body, particularly in the immune system. In addition, cannabinoids appear to interact directly with cell membranes and with various enzymes.

Cannabinoids have extremely varied effects, from psychoactivity to pain and nausea relief to anti-inflammatory, cancer inhibiting and antibacterial activity. The different cannabinoids, when ingested or inhaled, interact in complex ways. Some compounds enhance or inhibit the effects of others, or help alleviate the side effects that one compound alone might cause.

THC or delta-9 tetrahydrocannabinol is the primary psychoactive component of marijuana. It is responsible for the high of marijuana, and is likely the direct or indirect cause of unwanted side effects such as anxiety, detachment and paranoia. Particularly when eaten, THC is converted by the liver into 11-hydroxy THC, which is materially more psychoactive than THC itself, and has greater effects on the immune system. THC also has anti-inflammatory properties and gives pain and nausea relief.

When marijuana is harvested, THC is primarily present in its acidic form, known as THC-A or THC-COOH, which has little psychoactive effect. As marijuana cures, a portion of the THC-A converts to THC; the conversion is accelerated as marijuana is heated during cooking or smoking.

CBD or cannabidiol is the second most prominent and studied cannabinoid, and the major cannabinoid in “hemp-type” marijuana. CBD appears to lessen many of the unwanted side effects of THC, and modifies the high of THC, making it less acute but longer lasting, with fewer effects such as sleepiness or loss of memory. On its own, CBD is a potent antioxidant, reduces anxiety and has antipsychotic effects. It has been shown to reduce spasms and has pain relief, antibacterial and anti-inflammatory effects. As with THC, CBD can also be present in its acidic form, which is converted to CBD by time and heat.

CBN or cannabinol is the breakdown product of THC; high levels indicate that the marijuana may be relatively old or has been stored at high temperatures. By itself, it has sedative and antibiotic properties.

CBG or cannabigerol is the chemical precursor of both THC and CBD is generally present at low levels, 1% or less, in mature marijuana plants. It has anti-inflammatory, analgesic, antibiotic and antifungal properties.

CBC or cannabichromene is a minor product of CBG and is present at low levels in most strains, and, like CBG, has anti-inflammatory, analgesic, antibiotic and antifungal properties.

THCV or tetrahydrocannabivarin is also generally present at low levels and has analgesic and mild psychoactive effects, and may be useful in treating migraines.

Other medicinal components of marijuana:

In addition to the cannabinoids, there are a number of other compounds in marijuana that have psychoactive or medicinal properties. However, it is unclear whether these compounds are present in marijuana in amounts large enough to have significant medical effect.

Terpenoids. The 100 or more terpene compounds in marijuana are what give it its characteristic smell.  Many, such as beta-myrcene and limonene, are found in other plants and have been extensively studied. Beta-myrcene, for example, has potent pain relief and anti-inflammatory effects. As a class, the terpenoids have analgesic, anti-inflammatory, antimutagenic and antidepressant properties.

Flavonoids. About 20 flavonoids are found in marijuana, generally at low levels. These include apinenin, which has anti-anxiety and anti-inflammatory effects and may inhibit proliferation of breast cancer cells, quercetin, a potent antioxidant and antimutagenic and cannflavin, which inhibits inflammation and pain signals.

For further reading:
McPartland and Russo, 2001, Cannabis and Cannabis Extracts: Greater than the Sum of Their Parts?
Cannabis Therapeutics in HIV/AIDS, pp103-132, Haworth Press.