Anxiolytic effect of cannabidiol derivatives in the elevated plus-maze.

“1.In order to assess the presence of anxiolytic properties in cannabidiol (CBD) derivatives HU-219, HU-252 and HU-261, these drugs were tested in rats submitted to the elevated plus-maze model of anxiety.

 2. Additional groups received diazepam or CBD. HU-219 (0.03-1 mg/kg) and CBD (5 mg/kg) significantly increased the percentage of open arm entries without changing the total number of entries, an anxiolytic-like effect.

 3. Both HU-252 and HU-261 increased the percentage of time spent in open arms and the total number of entries, but only at the dose of 1 mg/kg.

4. Diazepam (2.5 mg/kg) increased both the percentage of entries and time spent on open arms and the total number of entries.

5. The results confirm previous findings with CBD and indicate that its derivative HU-219 may possess a similar anxiolytic-like profile.

6. Results from HU-252 and HU-261 are less apparent and suggest that the compounds may increase general exploratory activity in a limited range of doses.”

http://www.ncbi.nlm.nih.gov/pubmed/7913072

Cannabidiol Reduces the Anxiety Induced by Simulated Public Speaking in Treatment-Naïve Social Phobia Patients

“Generalized Social Anxiety Disorder (SAD) is one of the most common anxiety conditions with impairment in social life. Cannabidiol (CBD), one major non-psychotomimetic compound of the cannabis sativa plant, has shown anxiolytic effects both in humans and in animals. This preliminary study aimed to compare the effects of a simulation public speaking test (SPST) on healthy control (HC) patients and treatment-naïve SAD patients who received a single dose of CBD or placebo…

Pretreatment with CBD significantly reduced anxiety, cognitive impairment and discomfort in their speech performance, and significantly decreased alert in their anticipatory speech. The placebo group presented higher anxiety, cognitive impairment, discomfort, and alert levels when compared with the control group…

…because of the absence of psychoactive or cognitive effects, to its safety and tolerability profiles, and to its broad pharmacological spectrum, CBD is possibly the cannabinoid that is most likely to have initial findings in anxiety translated into clinical practice…

… the effects of a single dose of CBD, observed in this study in the face of one of the main SAD’s phobic stimuli, is a promising indication of a rapid onset of therapeutic effect in patients with SAD.”

.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3079847/#bib17

Cannabidiol: an overview of some pharmacological aspects.

“Over the past few years, considerable attention has focused on cannabidiol (CBD), a major nonpsychotropic constituent of cannabis.

The authors present a review on the chemistry of CBD and discuss the anticonvulsive, antianxiety, antipsychotic, antinausea, and antirheumatoid arthritic properties of CBD.

CBD does not bind to the known cannabinoid receptors, and its mechanism of action is yet unknown. It is possible that, in part at least, its effects are due to its recently discovered inhibition of anandamide uptake and hydrolysis and to its antioxidative effect.”

http://www.ncbi.nlm.nih.gov/pubmed/12412831

Modulation of anxiety by acute blockade and genetic deletion of the CB(1) cannabinoid receptor in mice together with biogenic amine changes in the forebrain.

“The CB(1) cannabinoid receptor has been implicated in the control of fear and anxiety. We investigated the effects of genetic and pharmacological blockade of the CB(1) cannabinoid receptor on the behaviour of CD1 mice using three different ethological models of fear and anxiety…

 …in terms of anxiety our findings suggest that under physiological conditions this receptive site seems to be involved in the control of anxiolysis rather than anxiogenesis as suggested previously.”

http://www.ncbi.nlm.nih.gov/pubmed/19162082

The effects of genetic and pharmacological blockade of the CB1 cannabinoid receptor on anxiety.

“The aim of this study was to compare the effects of the genetic and pharmacological disruption of CB1 cannabinoid receptors on the elevated plus-maze test of anxiety. In the first experiment, the behaviour of CB1-knockout mice and wild-type mice was compared. In the second experiment, the cannabinoid antagonist SR141716A (0, 1, and 3 mg/kg) was administered to both CB1-knockout and wild type mice. Untreated CB1-knockout mice showed a reduced exploration of the open arms of the plus-maze apparatus, thus appearing more anxious than the wild-type animals, however no changes in locomotion were noticed. The vehicle-injected CB1-knockout mice from the second experiment also showed increased anxiety as compared with wild types. Surprisingly, the cannabinoid antagonist SR141716A reduced anxiety in both wild type and CB1 knockout mice. Locomotor behaviour was only marginally affected. Recent evidence suggests the existence of a novel cannabinoid receptor in the brain. It has also been shown that SR141716A binds to both the CB1 and the putative novel receptor. The data presented here supports these findings, as the cannabinoid receptor antagonist affected anxiety in both wild type and CB1-knockout mice.

Tentatively, it may be suggested that the discrepancy between the effects of the genetic and pharmacological blockade of the CB1 receptor suggests that the novel receptor plays a role in anxiety.”

http://www.ncbi.nlm.nih.gov/pubmed/12405999

Endocannabinoid system and stress and anxiety responses.

“Cannabinoid agonists induce complex and often contradictory effects on anxiety in humans and experimental animals. The data from animal tests provide evidence of dose-dependent bidirectional modulation of anxiety by the cannabinoid system and the importance of environmental context. The mechanisms mediating the effects of cannabinoids on anxiety-related responses appear to involve CB1 and non-CB1 cannabinoid receptors. In addition, the CRH, GABA(A), cholecystokinin, opioid and serotonergic systems have also been implicated. Brain regions such as the amygdala, hippocampus and cortex, directly involved in the regulation of emotional behavior, contain high densities of CB1 receptors. Mutant mice lacking CB1 receptors show anxiogenic-like and depressive-like phenotypes in several tests, as well as profound alterations in their adrenocortical activity. Pharmacological blockade of CB1 receptors induces anxiety in rats, and inhibition of anandamide metabolism produces anxiolytic-like effects.

Thus, the endocannabinoid system appears to play a pivotal role in the regulation of emotional states and may constitute a novel pharmacological target for anti-anxiety therapy.”

http://www.ncbi.nlm.nih.gov/pubmed/15927244

Overexpression of CB2 cannabinoid receptors decreased vulnerability to anxiety and impaired anxiolytic action of alprazolam in mice.

“Overexpression of CB2r reduced anxiety-like behaviours in… mice…

 Our findings revealed that increased expression of CB2r significantly reduced anxiogenic-related behaviours, modified the response to stress and impaired the action of anxiolytic drugs.”

http://www.ncbi.nlm.nih.gov/pubmed/20837564

Pharmacological and pharmacokinetic characterization of the cannabinoid receptor 2 agonist, GW405833, utilizing rodent models of acute and chronic pain, anxiety, ataxia and catalepsy.

“To date, two cannabinoid receptors have been identified, CB1 and CB2. Activation of these receptors with non-selective cannabinoid receptor agonists reduces pain sensitivity in animals and humans. However, activation of CB1 receptors is also associated with central side effects… More recently, a role for selective CB2 agonists in pain modification has been demonstrated…a selective CB2 agonist, was recently reported to partially reverse the inflammation and hyperalgesia in a rat model of acute inflammation. In the current report, we extend the characterization and therapeutic potential of this compound…

 These data support the tenet that selective CB2 receptor agonists have the potential to treat pain without eliciting the centrally-mediated side effects associated with non-selective cannabinoid agonists…”

http://www.ncbi.nlm.nih.gov/pubmed/15814101

Role of endocannabinoid system in mental diseases.

“In the last decade, a large number of studies using Delta9-tetrahydrocannabinol (THC), the main active principle derivative of the marijuana plant, or cannabinoid synthetic derivatives have substantially contributed to advance the understanding of the pharmacology and neurobiological mechanisms produced by cannabinoid receptor activation.

 Cannabis has been historically used to relieve some of the symptoms associated with central nervous system disorders. Nowadays, there are anecdotal evidences for the use of cannabis in many patients suffering from multiple sclerosis or chronic pain. Following the historical reports of the use of cannabis for medicinal purposes, recent research has highlighted the potential of cannabinoids to treat a wide variety of clinical disorders. Some of these disorders that are being investigated are pain, motor dysfunctions or psychiatric illness…

 Considering that cannabis or cannabinoid pharmaceutical preparations may no longer be exclusively recreational drugs but may also present potential therapeutic uses, it has become of great interest to analyze the neurobiological and behavioral consequences of their administration. This review attempts to link current understanding of the basic neurobiology of the endocannabinoid system to novel opportunities for therapeutic intervention and its effects on the central nervous system.”

http://www.ncbi.nlm.nih.gov/pubmed/15325960

Facilitation of contextual fear memory extinction and anti-anxiogenic effects of AM404 and cannabidiol in conditioned rats.

“The present study investigated the central effects of the eCB uptake/metabolism inhibitor AM404 and the phytocannabinoid cannabidiol (CBD) on the extinction of contextual fear memories in rats…

… In conclusion, CBD, a non-psychoactive phytocannabinoid could be an interesting pharmacological approach to reduce the anxiogenic effects of stress and promote the extinction of fear memories.”

http://www.ncbi.nlm.nih.gov/pubmed/18706790