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1. Introduction (Beginner Level) :
CBG, or cannabigerol, is one of several active compounds found in the cannabis plant. Less known than its counterpart, CBD, CBG is quickly gaining popularity due to its therapeutic potential. Unlike THC, CBG is not psychotropic, meaning it does not cause a "high."
As a reminder, a psychotropic effect refers to all the modifications in perceptions, sensations, mood, consciousness or behavior induced by the ingestion or administration of a substance. Substances with a psychotropic effect can temporarily alter brain function and influence the way a person thinks, feels, or perceives the world around them. These substances include, among others, psychiatric medications, recreational drugs, certain prescription medications and even certain plants and mushrooms. It should be noted that the term "psychotropic" is often used in medical and legal contexts to refer to medications or substances that affect the mind or behavior.
2. Chemistry of CBG (Expert Level) :
Chemically, CBG is a non-acidic cannabinoid that is formed when acidic cannabigerol (CBGA) is decarboxylated, usually through exposure to heat or ultraviolet light. CBGA is often referred to as a "precursor" because it is the starting point for the formation of several major cannabinoids, such as THC, CBD and CBC. Enzymes in the cannabis plant convert CBGA into one of these final cannabinoids, with the remainder transformed into CBG.
The conversion of CBGA (cannabigerolic acid) into CBDA (cannabidiolic acid) or THCA (tetrahydrocannabinolic acid) is catalyzed by specific enzymes.
These enzymes are:
- For the conversion of CBGA into CBDA: CBDA synthase .
- For the conversion of CBGA to THCA: THCA synthase .
These enzymes are specific to each biosynthetic pathway and determine which major cannabinoid will be primarily produced by a particular cannabis plant.
3. Potential benefits of CBG (Beginner Level):
CBG has attracted great interest for its potential medicinal properties.
Neuroprotective properties : A study published in the journal "Neurotherapeutics" in 2015 suggested that CBG may have neuroprotective properties, particularly relevant to neurodegenerative diseases.
Reference : Valdeolivas, S., et al. (2015). Neurotherapeutics, 12(1), 185-195.
Antibacterial effect : CBG has demonstrated antibacterial activity against drug-resistant bacteria. A 2008 study found that CBG had effective activity against methicillin-resistant Staphylococcus aureus (MRSA).
Reduction of inflammation : CBG has demonstrated anti-inflammatory potential, particularly in the context of inflammatory bowel disease. A study in animal models, published in 2013, found that CBG reduced inflammation in mice with colitis.
4. Therapeutic benefits and studies (Expert Level) :
Preclinical studies have shown that CBG may be particularly effective in treating glaucoma because it reduces intraocular pressure.
As a reminder, glaucoma is an eye disease characterized by an increase in intraocular pressure which can damage the optic nerve, leading to progressive loss of vision. If left untreated, this condition can lead to blindness.
A 1990 study found that CBG and other cannabinoids could improve the condition of glaucoma patients (Colasanti, Craig & Allara, 1990).
5. Mechanisms of action (Expert Level) :
CBG interacts with our body's endocannabinoid system, specifically the CB1 and CB2 receptors. However, unlike THC, it does not act directly on these receptors, but influences other chemicals in the brain.
The pathways of action of CBG (cannabigerol) on FAAH (Fatty Acid Amide Hydrolase) and COX-2 (Cyclooxygenase-2) are particularly interesting aspects of cannabis research. Here's a more in-depth explanation:
Action on the FAAH :
- FAAH is an enzyme responsible for the breakdown of anandamide, an endocannabinoid naturally present in the body. Anandamide plays a key role in regulating pain, mood, appetite, and other functions.
- Certain cannabinoids, like CBD and potentially CBG, can inhibit the action of FAAH, leading to increased anandamide levels in the body. By preventing FAAH from breaking down anandamide, CBG could thus amplify some of the positive effects of anandamide, such as reducing pain and inflammation, and potentially have anxiolytic effects.
Action on COX-2 :
- COX-2 is an enzyme involved in the formation of pro-inflammatory mediators. It is targeted by nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce inflammation and pain.
- CBG, like other cannabinoids, could selectively inhibit COX-2 without affecting COX-1, which is a similar enzyme but plays a critical role in protecting the stomach lining. This selectivity is essential because non-selective inhibition of COX-1 and COX-2 by some NSAIDs can result in gastrointestinal side effects.
- By inhibiting COX-2, CBG could potentially reduce inflammation and pain without causing gastric side effects associated with some anti-inflammatory medications.
Action on the α2-adrenergic receptor :
Adrenergic receptors are a class of G protein-coupled receptors (GPCRs) that respond to catecholamines, including adrenaline and norepinephrine. There are several types of adrenergic receptors, including the α1, α2, β1, β2, and β3 subtypes.
The α2-adrenergic receptor in particular plays a crucial role in regulating the release of neurotransmitters. When these receptors are activated, they typically inhibit the release of certain neurotransmitters, which has varying effects on the body. For example, they may contribute to vasoconstriction (narrowing of blood vessels) or decreased insulin release in the pancreas.
CBG may act on these receptors, although the exact mechanism and implications of this interaction are still under investigation. Activation or inhibition of these receptors could contribute to the anti-inflammatory, analgesic, or other potential therapeutic effects of CBG.
Action on voltage-activated ion channels :
Voltage-gated ion channels are transmembrane proteins that allow the selective passage of ions (such as Na+, K+, Ca2+) across the cell membrane in response to changes in electrical voltage. These channels play essential roles in cellular physiology, particularly in the transmission of electrical signals in neurons.
CBG can interact with some of these channels, thereby modulating how ions move across the cell membrane. This may affect how neurons send signals, which could potentially explain some of the neuroprotective or other effects of CBG.
For example, the interaction of CBG with ion channels could affect neuronal excitability, which could have implications in conditions such as epilepsy or neuropathic pain.
6. Conclusion (Beginner Level) :
CBG is a promising cannabinoid with significant therapeutic potential. Although it is less studied than THC or CBD, emerging research suggests that CBG could play a key role in the medical field in the future.