Reference: Properties of Cannabidiol, Agonistic Properties of Cannabidiol at 5-HT1a Receptors
Ethan B. Russo, Andrea Burnett, Brian Hall, and Keith K. Parker
Although cannabis and its extracts have been extensively studied, knowledge of the biochemical mechanisms of one of its major components, cannabidiol (CBD), has not been thoroughly explored (1,2). This lack of knowledge of CBD’s biochemical pharmacology is noteworthy in the context of its known potential in human therapy: for example, it has been demonstrated to have anxiolytic (3), anti-seizure (4), anti-psychotic (3), and neuroprotective properties (5,6). While previously thought to be sedating, recent clinical research has confirmed that CBD is activating, and that it counters sedative effects of THC (7). The major psychoactive component of cannabis, tetrahydrocannabinol (THC), has received extensive research attention into its biochemical pharmacology. Both THC and CBD have been pharmacologically investigated at cannabinoid receptors (CBR), which are highly conserved across animal taxa, with the major exception of insects (8–10). THC is at least 10 times more potent in binding to CB1 receptors than CB2 receptors. At CB1R, there is evidence to suggest that CBD is an antagonist or inverse agonist, although substantial debate still exits about its intrinsic activity (10,11). CBD has received little attention in other neurotransmitter systems.
Noteworthy in this regard is serotonin (5-hydroxytryptamine; 5-HT), which is known to be involved in many of the same processes important to cannabis’s actions (12,13) such as relief of anxiety, pain, the complex processes of 1 Skaggs School of Pharmacy, The University of Montana, Missoula, MT 59812-1552, USA. 2 Address reprint requests to: Keith K. Parker, Skaggs School of Pharmacy, The University of Montana, Missoula, MT 59812- 1552, USA. Tel.: +406-243-4235; Fax: +406-243-5228; E-mail: email@example.com Neurochemical Research, Vol. 30, No. 8, August 2005 ( 2005), pp. 1037–1043 DOI: 10.1007/s11064-005-6978-1 1037 0364-3190/05/0800–1037/0 2005 Springer Science+Business Media, Inc. headache (14,15), and thermoregulation. The few studies done with CBD in serotonergic systems suggest that it inhibits 5-HT re-uptake, and overall reduces 5-HT neurotransmission (2,16). There is also some experimental evidence to support CBD’s activity in other neurotransmitter systems such as dopamine, GABA, and the endogenous opioid system (2).
Properties of CannabidiolProperties of Cannabidiol