Cannabinoid Science 101: What Is Cannabidiol (CBD)?

CBD is a non-psychoactive component of cannabis. CBD gained popularity much later than psychoactive THC, but was isolated more than 20 years earlier. Currently CBD is being thoroughly studied and investigated for its medicinal applications in treating numerous ailments. As it stands CBD now tops THC as the most well-understood cannabinoid in cannabis plants.

Cannabidiol (CBD) is one of the better-known and intensively studied phytocannabinoids. Acting as a mediator for the effects of THC, it is widely considered to be non-psychoactive in nature. However, research has indicated that CBD has a sedative effect. This may partly explain why cannabis strains high in CBD are known for their ‘stoned’ (relaxed and calm) effect rather than their ‘high’ (uplifted and energized).

If you follow the latest advances in dietary supplements for health and wellbeing you may already have heard of CBD products, even if you’ve never seen a cannabis plant. There is increasing and compelling evidence that adding CBD nutritional supplements to your diet can potentially alleviate and protect against a variety of conditions.

Chemical properties of the cannabidiol molecule

CBD has the same chemical formula and molar mass as THC (C21H30O2, 314.46 g/mol), although the molecular structure differs slightly. Like THC and most other lipids, CBD is hydrophobic and lipophilic, meaning that it does not dissolve or emulsify readily in water, but will dissolve in fat (as well as most organic solvents, such as butane and alcohol).

In acidic conditions, CBD cyclises (forms a new carbon ring) to become THC. In alkaline conditions (when water is present) CBD oxidises to become cannabidiol-hydroxyquinone, which is as yet poorly-studied, but may exert an inhibitory effect on the hepatic (liver) enzymes that are vital in the metabolism of ingested drugs.

The THC and CBD molecules, showing their extremely close resemblance

Cannabidiol in the endocannabinoid system

Although widely considered to have no affinity for the cannabinoid receptors, CBD has been shown in an at least one study to act as an inverse agonist of the CB2-receptor. An inverse agonist is a receptor ligand that induces an opposite response to an agonist. While THC increases the level of receptor activity above the intrinsic level found in the absence of any ligand, CBD reduces the level below this baseline. An antagonist, on the other hand, binds to a receptor and remains inactive, blocking the actions of nearby agonists.

The speculative new cannabinoid receptor, GPR55, may be influenced by the action of CBD. This receptor has been shown to respond to both CBD and THC, as well as the endocannabinoids 2-AG, anandamide, and noladin ether (also known as 2-AG ether). It has even been postulated as the CB3-receptor itself.

It is also thought that while CBD has little direct affinity for the cannabinoid receptors, it may have various indirect effects. For example, CBD inhibits the degradation of the endocannabinoid anandamide, by inhibiting the enzyme responsible for breaking it down. This increases anandamide’s endogenous levels and bioactivity. CBD may also act on receptors that are not part of the endocannabinoid system but work in combination with it.

CBD’s effect on non-endocannabinoid receptors

CBD is a full, but weak agonist of the transient receptor potential vanilloid type 1 (TRPV1), which plays an important role in the response to heat and noxious stimuli. TRPV1 is a nociceptor: when sufficient excitation of the receptor occurs, signals are sent to the brain, triggering a set of automatic responses including the sensation of pain.

Various cannabinoids including the endocannabinoids anandamide and N-Arachidonoyl dopamine (a CB1-receptor agonist) affect the TRPV1 receptor. Conversely, several vanilloids affect cannabinoid receptors, including olvanil and pseudocapsaicin, but not including capsaicin itself. The close chemical similarity between many vanilloids and cannabinoids has led researchers to conclude that there is great therapeutic potential in researching vanilloid cannabimimetics (substances that mimic cannabinoids).

CBD has also been demonstrated to act as a 5-HT1a receptor agonist. This receptor regulates the expression of serotonin (5-HT) in the central nervous system, and may explain many of CBD’s anxiety- and depression-relieving properties. Further, CBD’s modulatory effects on the Mu and Delta opioid receptors, which are involved in the analgesic and euphoric response, may add to the overall effect experienced by the cannabis user.

The dominant cannabinoid found in industrial hemp is CBD

Cannabidiol and its potential for medicinal application

CBD has been described as being of even greater medical importance than THC. It is non-psychoactive, and can therefore be used safely without fear of intoxication. Beyond this, it has numerous known beneficial properties, and no doubt many that are yet to be discovered.

CBD has an analgesic, antidepressant and anxiolytic (anti-anxiety) effect, and is also being explored for its neuroprotective properties. Neuroprotection, in which the structures of the brain and central nervous system are protected against damage (including further damage, in the case of degenerative illnesses such as Parkinson’s), is a growing area of medicine which is of huge importance.

Perhaps most excitingly, CBD has been shown to have an inhibitory effect on the proliferation of cancer cells. It is thought that CBD’s effect on the CB2- and TRPV1 -receptors may play a role here, through the induction of oxidative stress. Systemic biological functions produce reactive oxygen species (ROS) such as peroxides, oxygen ions and free radicals, which must usually be detoxified to mitigate damage to the cells.

The most studied medicinal application of cannabidiol is in the treatment of epilepsy. The case of Charlotte Figi, whose parents successfully used medicinal cannabis to reduce the seizures she suffered due to Dravet Syndrome, led to the development of the Charlotte’s Web cannabis strain.

As more children were treated with this low THC, high CBD variety, scientists began investigating the remedial effects CBD could have on seizure incidence and seizure cessation. The ability of CBD to treat epilepsy has been investigated in multiple high quality, placebo controlled adjunctive-therapy trials. It is one of CBD’s only medicinal applications that has hard evidence as to its medicinal validity. Research into all the others continues apace.

  • Disclaimer:

    This article is not a substitute for professional medical advice, diagnosis, or treatment. Always consult with your doctor or other licensed medical professional. Do not delay seeking medical advice or disregard medical advice due to something you have read on this website.

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