Каннабиноиды: состав, свойства и роль в организме

Compounds found in cannabis

Cannabinoids (/k//ə/'/n//æ//b//ə//n//ɔɪ//d//z//,// /'/k//æ//n//ə//b//ə//n//ɔɪ//d//z/) are several structural classes of compounds found in the cannabis plant primarily and most animal organisms (although insects lack such receptors) or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tetrahydrocannabinol (THC) (delta 9 THC), the primary psychoactive compound in cannabis. Cannabidiol (CBD) is also a major constituent of temperate cannabis plants and a minor constituent in tropical varieties. At least 113 distinct phytocannabinoids have been isolated from cannabis, although only four (i. e., THCA, CBDA, CBCA and their common precursor CBGA) have been demonstrated to have a biogenetic origin. It was reported in 2020 that phytocannabinoids can be found in other plants such as rhododendron, licorice and liverwort, and earlier in Echinacea. Phytocannabinoids are multi ring phenolic compounds structurally related to THC, but endocannabinoids are fatty acid derivatives. Nonclassical synthetic cannabinoids (cannabimimetics) include aminoalkylindoles, 1,5 diarylpyrazoles, quinolines, and arylsulfonamides as well as eicosanoids related to endocannabinoids.

Before the 1980s, cannabinoids were speculated to produce their physiological and behavioral effects via nonspecific interaction with cell membranes, instead of interacting with specific membrane bound receptors. The discovery of the first cannabinoid receptors in the 1980s helped to resolve this debate. These receptors are common in animals. Two known cannabinoid receptors are termed CB1 and CB2, with mounting evidence of more. The human brain has more cannabinoid receptors than any other G protein coupled receptor (GPCR) type. The Endocannabinoid System (ECS) regulates many functions of the human body. The ECS plays an important role in multiple aspects of neural functions, including the control of movement and motor coordination, learning and memory, emotion and motivation, addictive like behavior and pain modulation, among others.

CB2 receptors are predominantly found in the immune system, or immune derived cells with varying expression patterns. While found only in the peripheral nervous system, a report does indicate that CB2 is expressed by a subpopulation of microglia in the human cerebellum. CB2 receptors appear to be responsible for immunomodulatory The classical cannabinoids are derived from their respective 2 carboxylic acids (2 COOH) by decarboxylation (catalyzed by heat, light, or alkaline conditions).

The best studied cannabinoids include tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN).

Tetrahydrocannabinol (THC) is the primary psychoactive component of the Cannabis plant. Delta 9 tetrahydrocannabinol (Δ9 THC, THC) and delta 8 tetrahydrocannabinol (Δ8 THC), through intracellular CB1 activation, induce anandamide and 2 arachidonoylglycerol synthesis produced naturally in the body and brain. These cannabinoids produce the effects associated with cannabis by binding to the CB1 cannabinoid receptors in the brain.

Cannabidiol (CBD) is mildly psychotropic. Evidence shows that the compound counteracts cognitive impairment associated with the use of cannabis. It was found to be an antagonist at the putative new cannabinoid receptor, GPR55, a GPCR expressed in the caudate nucleus and putamen. Cannabidiol has also been shown to act as a 5 HT1A receptor agonist. CBD can interfere with the uptake of adenosine, which plays an important role in biochemical processes, such as energy transfer. It may play a role in promoting sleep and suppressing arousal. CBD shares a precursor with THC and is the main cannabinoid in CBD dominant Cannabis strains. CBD has been shown to play a role in preventing the short term memory loss associated with THC. There is tentative evidence that CBD has an anti psychotic effect, but research in this area is limited.

Cannabinol (CBN) is a mildly psychoactive cannabinoid that acts as a low affinity partial agonist at both CB1 and CB2 receptors.''''''' Through its mechanism of partial agonism at the CB1R, CBN is thought to interact with other kinds of neurotransmission (e. g., dopaminergic, serotonergic, cholinergic, and noradrenergic). CBN was the first cannabis compound to be isolated from cannabis extract in the late 1800s. Its structure and chemical synthesis were achieved by 1940', followed by some of the first pre clinical research studies to determine the effects of individual cannabis derived compounds in vivo. Although CBN shares the same mechanism of action as other more well known phytocannabinoids (e. g., delta 9 tetrahydrocannabinol or D9THC), it has a lower affinity for CB1 receptors, meaning that much higher doses of CBN are required in order to experience physiologic effects (e. g., mild sedation) associated with CB1R agonism. The best known cannabinoids that are not derived from Cannabis are the lipophilic alkamides (alkylamides) from Echinacea species, most notably the cis/trans isomers dodeca 2E,4E,8Z,10E/Z tetraenoic acid isobutylamide. In some Echinacea species, cannabinoids are found throughout the plant structure, but are most concentrated in the roots and flowers. Yangonin found in the kava plant has significant affinity to the CB1 receptor. Tea (Camellia sinensis) catechins have an affinity for human cannabinoid receptors. A widespread dietary terpene, beta caryophyllene, a component from the essential oil of cannabis and other medicinal plants, has also been identified as a selective agonist of peripheral CB2 receptors, in vivo. Black truffles contain anandamide. Perrottetinene, a moderately psychoactive cannabinoid, has been isolated from different Radula varieties. Machaeriol A and related compounds are found in plants from the Machaerium family. Most of the phytocannabinoids are nearly insoluble in water but are soluble in lipids, alcohols, and other non polar organic solvents.

Cannabis plants can exhibit wide variation in the quantity and type of cannabinoids they produce. The mixture of cannabinoids produced by a plant is known as the plant's cannabinoid profile. Selective breeding has been used to control the genetics of plants and modify the cannabinoid profile. For example, strains that are used as fiber (commonly called hemp) are bred such that they are low in psychoactive chemicals like THC. Strains used in medicine are often bred for high CBD content, and strains used for recreational purposes are usually bred for high THC content or for a specific chemical balance. Quantitative analysis of a plant's cannabinoid profile is often determined by gas chromatography (GC), or more reliably by gas chromatography combined with mass spectrometry (GC/MS). Liquid chromatography (LC) techniques are also possible and, unlike GC methods, can differentiate between the acid and neutral forms of the cannabinoids. There have been systematic attempts to monitor the cannabinoid profile of cannabis over time, but their accuracy is impeded by the illegal status of the plant in many countries.

Cannabinoids can be administered by smoking, vaporizing, oral ingestion, transdermal patch, intravenous injection, sublingual absorption, or rectal suppository. Once in the body, most cannabinoids are metabolized in the liver, especially by cytochrome P450 mixed function oxidases, mainly CYP 2C9. Thus supplementing with CYP 2C9 inhibitors leads to extended intoxication. Some cannabis metabolites can be detected in the body several weeks after administration. These metabolites are the chemicals recognized by common antibody based "drug tests"; in the case of THC or others, these loads do not represent intoxication (compare to ethanol breath tests that measure instantaneous blood alcohol levels), but an integration of past consumption over an approximately month long window. This is because they are fat soluble, lipophilic molecules that accumulate in fatty tissues. Research shows the effect of cannabinoids might be modulated by aromatic compounds produced by the cannabis plant, called terpenes. This interaction would lead to the entourage effect.

Recent evidence has shown that cannabinoids play a role in the modulation of various mitochondrial processes, including intracellular calcium regulation, activation of apoptosis, impairment of electron transport chain activity, disruption of mitochondrial respiration and ATP production, and regulation of mitochondrial dynamics. These processes contribute to various aspects of cellular biology and can be modified in response to external stimuli. The interaction between cannabinoids and mitochondria is complex, and various molecular mechanisms have been proposed, including direct effects on mitochondrial membranes and receptor mediated effects. However, an integrated hypothesis of cannabinoids' actions on these processes has yet to be formulated due to conflicting data and the complexity of the pathways involved.

Nabiximols (brand name Sativex) is an aerosolized mist for oral administration containing a near 1:1 ratio of CBD and THC. Also included are minor cannabinoids and terpenoids, ethanol and propylene glycol excipients, and peppermint flavoring. The drug, made by GW Pharmaceuticals, was first approved by Canadian authorities in 2005 to alleviate pain associated with multiple sclerosis, making it the first cannabis based medicine. It is marketed by Bayer in Canada. Sativex has been approved in 25 countries; clinical trials are underway in the United States to gain FDA approval. In 2007, it was approved for treatment of cancer pain. Dronabinol (brand names Marinol and Syndros) is a delta 9 THC containing drug for treating HIV/AIDS induced anorexia and chemotherapy induced nausea and vomiting. The CBD drug Epidiolex has been approved by the Food and Drug Administration for treatment of two rare and severe forms of epilepsy, Dravet and Lennox Gastaut syndromes. Nabilone (Cesamet) is an FDA approved synthetic analog of THC, prescribed for the treatment of nausea and vomiting induced by chemotherapy treatment in people who have failed to respond adequately to conventional antiemetic treatments. Butane may be used, which evaporates extremely quickly. Supercritical solvent extraction with carbon dioxide is an alternative technique. Once extracted, isolated components can be separated using wiped film vacuum distillation or other distillation techniques. Also, techniques such as SPE or SPME are found useful in the extraction of these compounds.

Anandamide was the first such compound identified as arachidonoyl ethanolamine. The name is derived from ananda, the Sanskrit word for bliss. It has a pharmacology similar to THC, although its structure is quite different. Anandamide binds to the central (CB1) and, to a lesser extent, peripheral (CB2) cannabinoid receptors, where it acts as a partial agonist. Anandamide is about as potent as THC at the CB1 receptor. Anandamide is found in nearly all tissues in a wide range of animals. Anandamide has also been found in plants, including small amounts in chocolate. Two analogs of anandamide, 7,10,13,16 docosatetraenoylethanolamide and homo γ linolenoylethanolamine, have similar pharmacology. All of these compounds are members of a family of signalling lipids called N acylethanolamines, which also includes the noncannabimimetic palmitoylethanolamide and oleoylethanolamide, which possess anti inflammatory and anorexigenic effects, respectively. Many N acylethanolamines have also been identified in plant seeds and in molluscs.

Another endocannabinoid, 2 arachidonoylglycerol, binds to both the CB1 and CB2 receptors with similar affinity, acting as a full agonist at both. and there is some controversy over whether 2 AG rather than anandamide is chiefly responsible for endocannabinoid signalling in vivo.

In 2001, a third, ether type endocannabinoid, 2 arachidonyl glyceryl ether (noladin ether), was isolated from porcine brain. Prior to this discovery, it had been synthesized as a stable analog of 2 AG; indeed, some controversy remains over its classification as an endocannabinoid, as another group failed to detect the substance at "any appreciable amount" in the brains of several different mammalian species. It binds to the CB1 cannabinoid receptor (Ki = 21.2 nmol/L) and causes sedation, hypothermia, intestinal immobility, and mild antinociception in mice. It binds primarily to the CB1 receptor, and only weakly to the CB2 receptor. Like anandamide, NADA is also an agonist for the vanilloid receptor subtype 1 (TRPV1), a member of the vanilloid receptor family.

A fifth endocannabinoid, virodhamine, or O arachidonoyl ethanolamine (OAE), was discovered in June 2002. Although it is a full agonist at CB2 and a partial agonist at CB1, it behaves as a CB1 antagonist in vivo. In rats, virodhamine was found to be present at comparable or slightly lower concentrations than anandamide in the brain, but 2 to 9 fold higher concentrations peripherally.

Lysophosphatidylinositol is the endogenous ligand to novel endocannabinoid receptor GPR55, making it a strong contender as the sixth endocannabinoid.

Endocannabinoids serve as intercellular 'lipid messengers', signaling molecules that are released from one cell and activating the cannabinoid receptors present on other nearby cells. Although in this intercellular signaling role they are similar to the well known monoamine neurotransmitters such as dopamine, endocannabinoids differ in numerous ways from them. For instance, they are used in retrograde signaling between neurons. Furthermore, endocannabinoids are lipophilic molecules that are not very soluble in water. They are not stored in vesicles and exist as integral constituents of the membrane bilayers that make up cells. They are believed to be synthesized 'on demand' rather than made and stored for later use. As hydrophobic molecules, endocannabinoids cannot travel unaided for long distances in the aqueous medium surrounding the cells from which they are released and therefore act locally on nearby target cells. Hence, although emanating diffusely from their source cells, they have much more restricted spheres of influence than do hormones, which can affect cells throughout the body. The mechanisms and enzymes underlying the biosynthesis of endocannabinoids remain elusive and continue to be an area of active research. The endocannabinoid 2 AG has been found in bovine and human maternal milk. A review by Matties et al. (1994) summed up the phenomenon of gustatory enhancement by certain cannabinoids. The sweet receptor (Tlc1) is stimulated by indirectly increasing its expression and suppressing the activity of leptin, the Tlc1 antagonist. It is proposed that the competition of leptin and cannabinoids for Tlc1 is implicated in energy homeostasis.

Conventional neurotransmitters are released from a ‘presynaptic’ cell and activate appropriate receptors on a ‘postsynaptic’ cell, where presynaptic and postsynaptic designate the sending and receiving sides of a synapse, respectively. Endocannabinoids, on the other hand, are described as retrograde transmitters because they most commonly travel ‘backward’ against the usual synaptic transmitter flow. They are, in effect, released from the postsynaptic cell and act on the presynaptic cell, where the target receptors are densely concentrated on axonal terminals in the zones from which conventional neurotransmitters are released. Activation of cannabinoid receptors temporarily reduces the amount of conventional neurotransmitter released. This endocannabinoid mediated system permits the postsynaptic cell to control its own incoming synaptic traffic. The ultimate effect on the endocannabinoid releasing cell depends on the nature of the conventional transmitter being controlled. For instance, when the release of the inhibitory transmitter GABA is reduced, the net effect is an increase in the excitability of the endocannabinoid releasing cell. On the converse, when release of the excitatory neurotransmitter glutamate is reduced, the net effect is a decrease in the excitability of the endocannabinoid releasing cell.

The runner's high, the feeling of euphoria that sometimes accompanies aerobic exercise, has often been attributed to the release of endorphins, but newer research suggests that it might be due to endocannabinoids instead.