Cannabinoids

Cannabinoids are a group of chemicals which activate the body's cannabinoid receptors. Before other types were discovered, the term referred to a unique group of secondary metabolites found in the cannabis plant, which are responsible for the plant's peculiar pharmacological effects. Currently, there are three general types of cannabinoids: herbal cannabinoids occur uniquely in the cannabis plant; endogenous cannabinoids are produced in the bodies of humans and other animals; and synthetic cannabinoids are similar compounds produced in a laboratory.

Cannabinoid receptors

Before the 1980s, it was often speculated that cannabinoids produced 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, and have been found in mammals, birds, fish, and reptiles. There are currently two known types of cannabinoid receptors, termed CB1 and CB2.

CB1 receptors are found primarily in the brain, specifically in the basal ganglia and in the limbic system, including the hippocampus. They are also found in the cerebellum and in both male and female reproductive systems. CB1 receptors are essentially absent in the medulla oblongata, the part of the brain stem that is responsible for respiratory and cardiovascular functions. Thus, there is not a risk of respiratory or cardiovascular failure as there is with many other drugs. CB1 receptors appear to be responsible for the euphoric and anticonvulsive effects of cannabis.

CB2 receptors are almost exclusively found in the immune system, with the greatest density in the spleen. CB2 receptors appear to be responsible for the anti-inflammatory and possibly other therapeutic effects of cannabis.

Synthetic & Patented Cannabinoids

Historically, laboratory synthesis of cannabinoids were often based on the structure of herbal cannabinoids and a large number of analogs have been produced and tested, especially in a group led by Roger Adams as early as 1941 and later in a group led by Raphael Mechoulam. Newer compounds are no longer related to natural cannabinoids or are based on the structure of the endogenous cannabinoids.

Synthetic cannabinoids are particularly useful in experiments to determine the relationship between the structure and activity of cannabinoid compounds, by making systematic, incremental modifications of cannabinoid molecules.

Other notable synthetic cannabinoids include:

CP-55940 Produced in 1974, this synthetic cannabinoid receptor agonist is many times more potent than THC
HU-210 2-9 times as potent as THC
SR 141716A and SR 144528 CB1 and CB2 receptor antagonists, respectively
Nabilone Used as an anti-emetic in chemotherapy
Levonantradol Used as an anti-emetic and analgesic
Marinol Used as a presription medicine for appetite stimulation
Sativex A naturally based cannabis extract that contains both THC and CBD

Miscellaneous

• delta-9-Tetrahydrocannabinol (Δ⁹-THC, THC) and delta-8-tetrahydrocannabinol (Δ⁸-THC), mimic the action of anandamide, a neurotransmitter produced naturally in the body. The THCs produce the high associated with marijuana by binding to the CB₁ cannabinoid receptors in the brain.
• Tetrahydrocannabivarin (THCV), prevalent in certain South African and Southeast Asian strains of Cannabis. It is an antagonist of THC at CB₁ receptors and attenuates the psychoactive effects of THC.[3]
• Cannabidiol (CBD), non-psychoactive and not affecting psychoactivity of THC.[4] CBD has anti-inflammatory effects. CBD is the precursor of THC and is the main cannabinoid in low-THC Cannabis strains.
• Cannabinol (CBN), a degradation product of THC, produces a depressant effect
• Cannabichromene (CBC), non-psychoactive and not affecting psychoactivity of THC,[5] a precursor of CBD and THC
• Cannabigerol (CBG), non-psychoactive

Links

• Chemical Ecology of Cannabis (J. Intl. Hemp Assn. - 1994)
• Structure Activity Relationships of the Cannabinoids (NIDA Monograph 79 - 1987)
• Marijuana and Medicine - Assessing the Science Base (Institute of Medicine - 1999)
• What Every Doctor Should Know About Cannabinoids
• Therapeutic Potential in Spotlight at Cannabinoid Researchers' Meeting
• THC (tetrahydrocannabinol) accumulation in glands of Cannabis (Cannabaceae)
• Cannabis 2002 Report (Ministry of Public Health of Belgium)
• The Health and Psychological Effects of Cannabis Use (Australia - Monograph 44 - 2001)
• House of Lords Report - Cannabis (United Kingdom - 1998)
• Inheritance of Chemical Phenotype in Cannabis Sativa (Genetics)
• Cannabis: A Health Perspective and Research Agenda (World Health Organization - 1997)
• Canadian Senate Report on Cannabis - 2002
• Medicinal marijuana laws and policies
• Erowid Compounds found in Cannabis sativa
• The Endocannabinoid System Network (ECSN) - A CME source about the Endocannabinoid System

References

• M. A. ElSohly, D. Slade. Chemical constituents of marijuana: The complex mixture of natural cannabinoids.Life Sci. 78, 539-548 (2005)
• Hanuš L. Biogenesis of cannabinoid substances in the plant. Acta Univ. Palacki. Olomuc. (Olomouc), Fac. Med. 116, 47-53 (1987)
• Hanuš L., Krejčí Z. Isolation of two new cannabinoid acids from Cannabis sativa L. of Czechoslovak origin. Acta Univ. Olomuc., Fac. Med. 74, 161-166 (1975)
• Hanuš L., Krejčí Z., Hruban L. Isolation of cannabidiolic acid from Turkish variety of cannabis cultivated for fibre. Acta Univ. Olomuc., Fac. Med. 74, 167-172 (1975)
• Turner C. E., Mole M. L., Hanuš L., ElSohly H. N. Constituents of Cannabis sativa L. XIX. Isolation and structure elucidation of cannabiglendol. A novel cannabinoid from an Indian variant. J. Nat. Prod. - Lloydia 44 (1), 27-33 (1981)
• Devane W. A., Hanuš L., Breuer A., Pertwee R. G., Stevenson L. A., Griffin G., Gibson D., Mandelbaum A., Etinger A., Mechoulam R. Isolation and structure of a brain constituent that binds to the cannabinoid receptor. Science 258, 1946-1949 (1992)
• Hanuš L., Gopher A., Almog S., Mechoulam R.: Two new unsaturated fatty acid ethanolamides in brain that bind to the cannabinoid receptor. J. Med. Chem. 36, 3032-3034 (1993)
• Mechoulam R., Ben-Shabat S., Hanuš L., Ligumsky M., Kaminski N.E., Schatz A.R., Gopher A., Almog S., Martin B.R., Compton D.R., Pertwee R.G., Griffin G., Bayewitch M., Barg J., Vogel Z. Identification of an endogenous 2-monoglyceride, present in canine gut, that binds to the peripheral cannabinoid receptors. Biochem. Pharmacol. 50(1), 83-90 (1995)
• Hanuš L., Abu-Lafi S., Fride E., Breuer A., Shalev D. E., Kustanovich, I., Vogel Z., Mechoulam R.: 2-Arachidonyl Glyceryl Ether, a Novel Endogenous Agonist of the Cannabinoid CB1 Receptor. PNAS 98 (7), 3662-3665 (2001)
• Huffman, J.W. 2000. The search for selective ligands for the CB2 receptor. Current Pharmaceutical Design 6(13): 1323-1337

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