Cannabidiol, also known as CBD, is a cannabinoid found in Cannabis. It is a major constituent of the plant, representing up to 40% in its extracts.[1]
CBD alone is not intoxicating, but it appears to moderate the euphoric effect of tetrahydrocannabinol (THC), which is an isomer of cannabidiol and add a sedative quality.[2] Some research, however, indicates that CBD can increase alertness.[3] It may decrease the rate of THC clearance from the body, perhaps by interfering with the metabolism of THC in the liver. CBD does not appear to affect either the CB1 or CB2 receptors.[4]
In April 2005, Canadian authorities approved the marketing of Sativex, a mouth spray for multiple sclerosis to alleviate pain. Sativex contains tetrahydrocannabinol together with cannabidiol. It is marketed in Canada by GW Pharmaceuticals.
Initial research is showing that CBD has an effect in reducing schizophrenic symptoms in patients, but much more research is needed before any link is confirmed, let alone it being developed into an anti-psychotic medication.[10]
Cannabidiol has also been shown to inhibit cancer cell growth, with low potency in non-cancer cells. Although the inhibitory mechanism is not yet fully understood, Ligresti et al suggest that "cannabidiol exerts its effects on these cells through a combination of mechanisms that include either direct or indirect activation of CB2 and TRPV1 receptors, and induction of oxidative stress, all contributing to induce apoptosis."[13] In November 2007, researchers at the California Pacific Medical Center reported that CBD shows promise for controlling the spread of metastaticbreast cancer. In vitro CBD downregulates the activity of the gene Id-1 which is responsible for tumor metastasis.[7]
Chemistry
Cannabidiol is insoluble in water but soluble in organic solvents. At room temperature it is a colorless crystalline solid.[14] In strongly basic medium and the presence of air it is oxidized to a quinone.[15] Under acidic conditions it cyclizes to THC.[16] The synthesis of cannabidiol has been accomplished by several research groups.[17][18][19]
Legal Status
Cannabidiol is a Schedule I drug in the USA, despite having no psychoactive effects and no known abuse potential.
References
^ Grlie, L (1976). "A comparative study on some chemical and biological characteristics of various samples of cannabis resin". Bulletin on Narcotics14: 37–46.
^ Pickens JT (1981). "Sedative activity of cannabis in relation to its delta'-trans-tetrahydrocannabinol and cannabidiol content". Br. J. Pharmacol.72 (4): 649–56. PMID 6269680.
^ ab McAllister SD, Christian RT, Horowitz MP, Garcia A, Desprez PY (2007). "Cannabidiol as a novel inhibitor of Id-1 gene expression in aggressive breast cancer cells". Mol. Cancer Ther.6 (11): 2921–7. doi:10.1158/1535-7163.MCT-07-0371. PMID 18025276.
^ Thomas A, Baillie GL, Phillips AM, Razdan RK, Ross RA, Pertwee RG (2007). "Cannabidiol displays unexpectedly high potency as an antagonist of CB1 and CB2 receptor agonists in vitro". Br. J. Pharmacol.150 (5): 613–23. doi:10.1038/sj.bjp.0707133. PMID 17245363.
^ Ryberg E, Larsson N, Sjögren S, et al (2007). "The orphan receptor GPR55 is a novel cannabinoid receptor". British Journal of Pharmacology152: 1092. doi:10.1038/sj.bjp.0707460. PMID 17876302.
^ Ligresti A, Moriello AS, Starowicz K, et al (2006). "Antitumor activity of plant cannabinoids with emphasis on the effect of cannabidiol on human breast carcinoma". J. Pharmacol. Exp. Ther.318 (3): 1375–87. doi:10.1124/jpet.106.105247. PMID 16728591.
^ Jones PG, Falvello L, Kennard O, Sheldrick GM Mechoulam R (1977). "Cannabidiol". Acta Cryst.B33: 3211–3214. doi:10.1107/S0567740877010577.
^ Mechoulam R, Ben-Zvi Z (1968). "Hashish—XIII On the nature of the beam test". Tetrahedron24 (16): 5615–5624. doi:10.1016/0040-4020(68)88159-1.
^ Gaoni Y, Mechoulam R (1966). "Hashish—VII The isomerization of cannabidiol to tetrahydrocannabinols". Tetrahedron22 (4): 1481–1488. doi:10.1016/S0040-4020(01)99446-3.
^ Petrzilka T, Haefliger W, Sikemeier C, Ohloff G, Eschenmoser A (1967). "Synthese und Chiralität des (-)-Cannabidiols". Helv. Chim. Acta50 (2): 719–723. doi:10.1002/hlca.19670500235.
^ Gaoni Y, Mechoulam R (1985). "Boron trifluoride etherate on alumuna - a modified Lewis acid reagent. An improved synthesis of cannabidiol". Tetrahedron Letters26 (8): 1083–1086. doi:10.1016/S0040-4039(00)98518-6.
^ Kobayashi Y, Takeuchi A, Wang YG (2006). "Synthesis of cannabidiols via alkenylation of cyclohexenyl monoacetate". Org. Lett.8 (13): 2699–2702. doi:10.1021/ol060692h. PMID 16774235.