In addition to the cannabinoids, there are a number of other compounds in cannabis that have psychoactive or medicinal properties.
However, it is unclear whether these compounds are present in cannabis in amounts large enough to have significant medical effect.
The cannabinoids are a family of over 80 chemical compounds that are found primarily in cannabis. 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 is the primary psychoactive component of cannabis. It is responsible for the high of cannabis, 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 cannabis is harvested, THC is primarily present in its acidic form, known as THC-A or THC-COOH, which has little psychoactive effect. As cannabis cures, a portion of the THC-A converts to THC; the conversion is accelerated as cannabis is heated during cooking or smoking.
About 20 flavonoids are found in cannabis, generally at low levels. These include apigenin, 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.
The 100 or more terpene compounds in cannabis 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.
THCV is also generally present at low levels and has analgesic and mild psychoactive effects, and may be useful in treating migraines.
CBC 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
CBG is the chemical precursor of both THC and CBD is generally present at low levels, 1% or less, in mature cannabis plants. It has anti-inflammatory, analgesic, antibiotic and antifungal properties.
CBN is the breakdown product of THC; high levels indicate that the cannabis may be relatively old or has been stored at high temperatures. By itself, it has sedative and antibiotic properties.
CBD is the second most prominent and studied cannabinoid, and the major cannabinoid in “hemp-type” cannabis. 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 cannabis in its acidic form, which is converted to CBD by time and heat.
OTHER MEDICINAL COMPONENTS OF CANNABIS
THE MAJOR CANNABINOIDS
THE GENETICS OF CANNABIS
The mix of cannabinoids in a particular strain of cannabis is largely a product of heredity. By contrast, the total level
of cannabinoids is dictated both by genetics – some strains can achieve higher levels than others – and by how well the cannabis has been grown. It appears that a single gene dictates whether a plant produces THC or CBD. A plant inherits a copy of this gene from both of its parents. If both genes are of the THC type, the plant produces almost entirely THC; if CBD type, almost all CBD, and if the plant inherits one of each, it will produce a mix of THC and CBD. There seems to be some variations in the “strength” of these genes, so the ratio of THC to CBD production varies from plant to plant depending on the exact copy of the genes the plant has inherited. Each clone of the plant will,
however, produce essentially the same ratio of THC to CBD as its “parent”.
In hemp strains, the CBD form tends to predominate, so the primary cannabinoid in hemp is CBD. By contrast, drug strains
of cannabis have been selected over centuries of breeding for the THC gene.
INDICA AND SATIVA
There is an enormous amount of contradictory and confusing information about what “indica” and “sativa” types are and what medical properties correspond to these categories. The confusion is not just among the cannabis community; the scientific community can’t agree, either. Various researchers say cannabis is one, two, or three different species; some divide cannabis into two species, indica and sativa, but then put all drug types – including those we think of as ‘indica’ and ‘sativa’ – into the indica category.
What little agreement there is: some cannabis strains are tall and skinny, with narrow, light green leaves. These are generally assigned by the medical marijuana community to the “sativa” category, and seem to originate in the hemp that grew in Europe centuries ago. Other marijuana strains are bushier, with wider, dark green leaves. These are assigned to the “indica” category and seem to have originated in India and the middle east. Indicas generally are grown indoors, have higher yields than sativas and are usually easier to grow.
Sativa drug strains appear to be a very highly bred subgroup of cannabis plants; they have been selected for generations for only the strongest versions of the THC gene, and the CBD gene has been virtually eliminated. They are the purebreds of the marijuana world; the strains have identifiable characteristics, and if you cross two plants of the same strain, the seeds will run relatively true to the parent.
Indica drug strains, by contrast, seem to have been less highly inbred; there is more genetic variation within and between strains, and the CBD gene is still present in many strains. Seeds are less likely to run true to the parents, and the results of crossbreeding are less certain (and more potentially interesting) than crosses between sativa strains. High levels of THCV are also more common among indica strains.
Finally, there are some strains reported in the literature with very high levels of THCV, CBDV or CBG, with correspondingly lower levels of THC and CBD; we have yet to encounter these varieties in our testing.
Amendment 20 to the Colorado Constitution recognizes three diagnoses that will qualify a person for medical marijuana certification: cancer, glaucoma and HIV/AIDS. In addition, it recognizes the following symptoms that may be treated with medical marijuana: cachexia (severe loss of weight and appetite); severe pain; severe nausea; seizures, including those that are characteristic of epilepsy; or persistent muscle spasms, including those that are characteristic of multiple sclerosis. The Colorado Department of Public Health and Environment is authorized to approve the use of medical marijuana for other conditions, but, as of late 2014, has chosen not to do so.
The medical literature also documents a number of other conditions and symptoms for which cannabis, THC or CBD may be effective but which are not currently approved under the Colorado medical marijuana laws. These include:
Crohn’s Disease & Ulcerative Colitis
Post-Traumatic Stress Disorder
Links to medical cannabis research
Granny Storm Crow's MMJ Reference List– a vast collection of articles from both popular and scientific literature, organized primarily by condition but also with headings for individual cannabinoids and other topics. Remarkably comprehensive.
International Association for Cannabinoid Medicines – A searchable database of clinical studies with many abstracts.