What is a cannabinoid?
For those still learning the lingo, a cannabinoid is a compound that binds to specific types of receptors in the body and produces a variety of potential responses. CB1 receptors are primarily found in the central and peripheral nervous systems, and CB2 receptors are more prominent in the immune system. Together they make up what scientists call the endocannabinoid system (ECS).
Cannabis plants contain different types of cannabinoids, and research on the plant is responsible for much of what the scientific community knows, which is why these chemicals bear its name. Cannabinoids are not, however, exclusive to the cannabis plant. Cacao seeds, the base ingredient for chocolate, also appear to contain cannabinoids that act on the brain, while the human body itself produces natural ECS-acting chemicals. In classifying cannabinoids, plant-based compounds are commonly called phytocannabinoids, while those produced in the body are called endocannabinoids.
Researchers have identified more than 120 phytocannabinoids, and this 2016 study divided them into 11 subclasses (e.g., CBG-type, CBD-type, CBC-type) based on their chemical structure. Fresh hemp plants contain the acidic forms of several phytocannabinoids — CBGa, CBDa, CBCa and THCa — and heat, light and atmospheric oxygen produce non-enzymatic transformations that convert them into CBG, CBD, CBC and THC, respectively. Cannabinoid-based products typically feature the transformed (or decarboxylated) compounds.
As a compound that gets people high, tetrahydrocannabinol (THC) is the most famous cannabinoid, but hemp plants contain little or no THC. So what cannabinoids does hemp contain? The following are some examples.
CBG is a good place to start because it is essentially the stem cell equivalent for cannabinoids. In other words, certain cannabinoids start out as CBG and then undergo a transformative process in which they’re converted into other compounds. The “mother cannabinoid” is non-intoxicating, and studies suggest it might help manage conditions like depression and anxiety by inhibiting the reuptake of GABA and anandamide neurotransmitters. CBG might also protect brain cells, fight cancer cells and help with inflammatory conditions (e.g., IBS), glaucoma and bladder spasms. The potential is there, but studying CBG is complicated because of its transformational process. Researchers need growers to harvest plants early before CBG transforms into more profitable compounds like CBDa. The U.S. government is among the groups financing more robust CBG studies.
This cannabinoid, which actually binds better to non-ECS receptors like TRPV1 (pain, inflammation), shows promise as a therapy for chronic pain and other common conditions. An Italian study found that a combination of CBC and CBD decreased pain perception, while a U.S. study saw anti-inflammatory effects when combined with THC. Early research has focused on the analgesic effects of CBC, though some suggest there’s potential for treating mental health, acne and brain damage. More conclusive findings will take time, however, as this is one of the lesser-studied hemp compounds.
Just as CBG is the precursor to compounds like THC and CBD, others cannabinoids actually represent the aftermath of degradation. CBL, which some call cannabipinol (CBP), is one such example. The originating compound, cannabichromene (CBC), starts to decay when exposed to light, and it transforms into CBL over time. This non-psychoactive cannabinoid is primarily found in small amounts in older, poorly stored plants, and some suggest it may have anti-inflammatory effects, but there’s been very little research into CBL at present.
CBL is not the only cannabinoid that develops through degradation. CBN comes from the oxidation of the acidic precursor to THC, which means it’s also more prominent in older plants. Studies suggest CBN is a natural sedative comparable to diazepam and may have analgesic, anti-inflammatory, anti-bacterial and anti-convulsive properties. Interestingly, CBN acts indirectly on the CB1 and CB2 receptors, and binds directly to non-cannabinoid receptors like 5-HT1A (serotonin), adenosine A2A (cardiovascular, respiratory) and the aforementioned TRPV1 (pain). The amount of CBN in hemp is small, but hemp-derived isolates are available.
CBD is another cannabinoid that does not bind directly to the CB1 and CB2 receptors. Rather, it suppresses the enzyme that metabolizes certain endocannabinoids, anandamide and 2-AG, that do bind to these receptors. By increasing the presence of these endocannabinoids, CBD indirectly increases ECS receptor activity. Studies suggest that CBD may also help increase receptor density and coupling efficiency and deactivate the GPR55 receptor associated with cancer cell proliferation. CBD can help reduce seizures in children, and studies suggest it is a neuroprotectant that may help with pain, inflammation, mood disorders and heart health, among other issues.
THCv and THC have similar molecular structures, psychoactive properties and receptor targets, but THCv differs from its more famous cannabinoid cousin in that it doesn’t activate the receptors when consumed in low doses. Research suggests THCv may stimulate bone growth, reduce inflammation and pain, suppress appetite and provide neuroprotective benefits. The amount of THCv in hemp is small, but hemp-derived isolates are available.
CBDv, which some call cannabidivarol, shares an ancestry with CBD (like THCv does with THC). Like its better-known cousin, CBDv also appears to demonstrate anticonvulsant activity. GW Pharmaceuticals got the first cannabis-based CBD medication approved by the Food & Drug Administration (FDA), and now the biopharmaceutical company is testing CBDv-based therapies for reducing seizures and symptoms of autism spectrum disorder. Researchers are also exploring potential roles in helping treat Rett syndrome, Duchenne muscular dystrophy and nausea.
Endocannabinoids: Anandamide and 2-AG
As previously mentioned, endocannabinoids are compounds produced by the body that bind to receptors in the ECS. Two key endocannabinoids, anandamide and 2-arachidonoylglycerol (2-AG), might not be present in hemp plants, but CBD and CBG help increase their levels and receptor activity in the body.
Research suggests these endocannabinoids “are involved in the complex physiological functions of the cannabinoid system that include motor coordination, memory procession, control of appetite, pain modulation and neuroprotection.” They might provide “analgesia, muscle relaxation, immunosuppression, anti-inflammation, anti-allergic effects, sedation, improvement of mood, stimulation of appetite, anti-emesis, lowering of intraocular pressure, bronchodilation, neuroprotection and antineoplastic effects.”
In simpler terms, anandamide is responsible for the “runner’s high” that some people experience during intense exercise, while 2-AG is responsible for the relaxed mood that follows orgasms.