A new antipsychotic mechanism of action for cannabidiol

Totally dope! – A new antipsychotic mechanism of action for cannabidiol, by Anand Gururajan

“The pharmacological strategy for the treatment of schizophrenia has not changed in the six decades since chlorpromazine was introduced in 1952. Although several newer agents have recently gained approval, the mechanism of action of antipsychotics is still largely based on normalising dopaminergic neurotransmission which does not adequately address the symptomatology of a very complex disorder. Moreover, they cause side effects such as extrapyramidal motor symptoms and metabolic syndrome which can worsen the patient condition.

In this regard, preclinical and clinical studies since the ’90s have demonstrated the antipsychotic potential of cannabidiol (CBD), a derivative of the cannabis sativa plant which does not have the adverse psychoactive properties of tetrahydrocannabinol.

In particular, CBD has been shown to be effective in attenuating the positive symptoms of schizophrenia with a negligible side-effect profile.

Accumulating evidence implicates dysfunction of the mammalian target of rapamycin (mTOR) signaling cascade in the pathophysiology of schizophrenia. Thus, in a recent paper, Renard et al. (2016) used the amphetamine (AMPH)-sensitisation protocol in rats to investigate whether the antipsychotic effects of CBD were mediated by its effects on the mTOR cascade. Specifically, they focused on the nucleus accumbens shell (NASh) which has been implicated as a therapeutically relevant ‘hot-spot’ for antipsychotic action and is one of the brain regions targeted by CBD.

Thus, together with the fact that CBD alone had no behavioural effects, the behavioural findings reinforce the potential utility of this cannabinoid as an antipsychotic for the treatment of the positive symptoms of schizophrenia.”

http://medicalxpress.com/news/2016-08-antipsychotic-mechanism-action-cannabidiol.html

Plasma and brain pharmacokinetic profile of cannabidiol (CBD), cannabidivarine (CBDV), Δ⁹-tetrahydrocannabivarin (THCV) and cannabigerol (CBG) in rats and mice following oral and intraperitoneal administration and CBD action on obsessive-compulsive behaviour.

 

Psychopharmacology

“Phytocannabinoids are useful therapeutics for multiple applications including treatments of constipation, malaria, rheumatism, alleviation of intraocular pressure, emesis, anxiety and some neurological and neurodegenerative disorders.

Consistent with these medicinal properties, extracted cannabinoids have recently gained much interest in research, and some are currently in advanced stages of clinical testing.

Other constituents of Cannabis sativa, the hemp plant, however, remain relatively unexplored in vivo. These include cannabidiol (CBD), cannabidivarine (CBDV), Δ(9)-tetrahydrocannabivarin (Δ(9)-THCV) and cannabigerol (CBG).

RESULTS:

All phytocannabinoids readily penetrated the blood-brain barrier and solutol, despite producing moderate behavioural anomalies, led to higher brain penetration than cremophor after oral, but not intraperitoneal exposure. In mice, cremophor-based intraperitoneal administration always attained higher plasma and brain concentrations, independent of substance given. In rats, oral administration offered higher brain concentrations for CBD (120 mg/kg) and CBDV (60 mg/kg), but not for Δ(9)-THCV (30 mg/kg) and CBG (120 mg/kg), for which the intraperitoneal route was more effective. CBD inhibited obsessive-compulsive behaviour in a time-dependent manner matching its pharmacokinetic profile.

CONCLUSIONS:

These data provide important information on the brain and plasma exposure of new phytocannabinoids and guidance for the most efficacious administration route and time points for determination of drug effects under in vivo conditions.”

http://www.ncbi.nlm.nih.gov/pubmed/21796370

The therapeutic potential of the phytocannabinoid cannabidiol for Alzheimer’s disease.

“Alzheimer’s disease (AD) is the most common neurodegenerative disorder, characterized by progressive loss of cognition. Over 35 million individuals currently have AD worldwide. Unfortunately, current therapies are limited to very modest symptomatic relief.

The brains of AD patients are characterized by the deposition of amyloid-β and hyperphosphorylated forms of tau protein. AD brains also show neurodegeneration and high levels of oxidative stress and inflammation.

The phytocannabinoid cannabidiol (CBD) possesses neuroprotective, antioxidant and anti-inflammatory properties and reduces amyloid-β production and tau hyperphosphorylation in vitro.

CBD has also been shown to be effective in vivo making the phytocannabinoid an interesting candidate for novel therapeutic interventions in AD, especially as it lacks psychoactive or cognition-impairing properties.

CBD treatment would be in line with preventative, multimodal drug strategies targeting a combination of pathological symptoms, which might be ideal for AD therapy.

Thus, this review will present a brief introduction to AD biology and current treatment options before outlining comprehensively CBD biology and pharmacology, followed by in-vitro and in-vivo evidence for the therapeutic potential of CBD. We will also discuss the role of the endocannabinioid system in AD before commenting on the potential future of CBD for AD therapy (including safety aspects).”

http://www.ncbi.nlm.nih.gov/pubmed/27471947

Delayed treatment with cannabidiol has a cerebroprotective action via a cannabinoid receptor-independent myeloperoxidase-inhibiting mechanism.

“We examined the neuroprotective mechanism of cannabidiol, non-psychoactive component of marijuana, on the infarction in a 4 h mouse middle cerebral artery (MCA) occlusion model in comparison with Delta(9)-tetrahydrocannabinol (Delta(9)-THC).

Both pre- and post-ischemic treatment with cannabidiol resulted in potent and long-lasting neuroprotection, whereas only pre-ischemic treatment with Delta(9)-THC reduced the infarction.

Unlike Delta(9)-THC, cannabidiol did not affect the excess release of glutamate in the cortex after occlusion.

Cannabidiol suppressed the decrease in cerebral blood flow by the failure of cerebral microcirculation after reperfusion and inhibited MPO activity in neutrophils.

Furthermore, the number of MPO-immunopositive cells was reduced in the ipsilateral hemisphere in cannabidiol-treated group.

Cannabidiol provides potent and long-lasting neuroprotection through an anti-inflammatory CB(1) receptor-independent mechanism, suggesting that cannabidiol will have a palliative action and open new therapeutic possibilities for treating cerebrovascular disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/17437545

Cannabidiol prevents a post-ischemic injury progressively induced by cerebral ischemia via a high-mobility group box1-inhibiting mechanism.

“We examined the cerebroprotective mechanism of cannabidiol, the non-psychoactive component of marijuana, against infarction in a 4-h mouse middle cerebral artery (MCA) occlusion model.

Cannabidiol was intraperitoneally administrated immediately before and 3h after cerebral ischemia.

Cannabidiol significantly prevented infarction and MPO activity at 20h after reperfusion.

Cannabidiol inhibited the MPO-positive cells expressing HMGB1 and also decreased the expression level of HMGB1 in plasma.

In addition, cannabidiol decreased the number of Iba1- and GFAP-positive cells at 3 days after cerebral ischemia.

Moreover, cannabidiol improved neurological score and motor coordination on the rota-rod test.

Our results suggest that cannabidiol inhibits monocyte/macropharge expressing HMGB1 followed by preventing glial activation and neurological impairment induced by cerebral ischemia.

Cannabidiol will open new therapeutic possibilities for post-ischemic injury via HMGB1-inhibiting mechanism.”

http://www.ncbi.nlm.nih.gov/pubmed/18634812

Cannabinoids in bipolar affective disorder: a review and discussion of their therapeutic potential.

“Bipolar affective disorder is often poorly controlled by prescribed drugs.

Cannabis use is common in patients with this disorder and anecdotal reports suggest that some patients take it to alleviate symptoms of both mania and depression.

We undertook a literature review of cannabis use by patients with bipolar disorder and of the neuropharmacological properties of cannabinoids suggesting possible therapeutic effects in this condition.

No systematic studies of cannabinoids in bipolar disorder were found to exist, although some patients claim that cannabis relieves symptoms of mania and/or depression.

The cannabinoids Delta(9)-tetrahydrocannabinol (THC) and cannabidiol (CBD) may exert sedative, hypnotic, anxiolytic, antidepressant, antipsychotic and anticonvulsant effects.

Pure synthetic cannabinoids, such as dronabinol and nabilone and specific plant extracts containing THC, CBD, or a mixture of the two in known concentrations, are available and can be delivered sublingually.

Controlled trials of these cannabinoids as adjunctive medication in bipolar disorder are now indicated.”

http://www.ncbi.nlm.nih.gov/pubmed/15888515

Cannabidiol inhibitory effect on marble-burying behaviour: involvement of CB1 receptors.

“Cannabidiol (CBD) is a major non-psychotomimetic component of Cannabis sativa that has been shown to have an anxiolytic effect in human and animal models.

Earlier studies suggest that these effects involve facilitation of serotonin, a neurotransmitter that has also been related to obsessive-compulsive disorder.

On the basis of this evidence, this study investigated the effects of CBD in C57BL/6J mice submitted to the marble-burying test (MBT), an animal model proposed to reflect compulsive behaviour.

CBD induced a significant decrease in the number of buried marbles compared with controls.

These results indicated that CBD and paroxetine decrease the number of buried marbles in the MBT through distinct pharmacological mechanisms.

They also suggest a potential role of drugs acting on the cannabinoid system in modulating compulsive behaviour.”

http://www.ncbi.nlm.nih.gov/pubmed/20695034

Study: Non-Psychoactive Cannabis Could Treat OCD

Leaf Science

“A non-psychoactive chemical in marijuana may be able to control symptoms of obsessive-compulsive disorder, according to new research out of Brazil.

Cannabidiol (CBD) is one of the major compounds found in marijuana, but lacks the high caused by THC.

Previous studies suggest that it can be used to combat anxiety and other obsessive-compulsive behaviors.

While research has mostly involved simple animal models, a team led by Dr. Francisco Guimarães of the University of Sao Paulo’s School of Medicine decided to test cannabidiol in rats that were given mCPP – a drug that blocks the effects of traditional OCD treatments.

Interestingly, even at low doses, CBD was able to reverse the obsessive-compulsive behavior caused by mCPP. Published in the journal Fundamental & Clinical Pharmacology, the authors conclude that the study adds support to “a possible anti-compulsive effect of CBD.””

http://www.leafscience.com/2013/10/22/study-non-psychoactive-cannabis-treat-ocd/

“Cannabidiol reverses the mCPP-induced increase in marble-burying behavior.”  http://www.ncbi.nlm.nih.gov/pubmed/24118015

Cannabidiol reverses the mCPP-induced increase in marble-burying behavior

Fundamental & Clinical Pharmacology

“Cannabidiol (CBD), one of the main components of Cannabis sp., presents clinical and preclinical anxiolytic properties.

Recent results using the marble-burying test (MBT) suggest that CBD can also induce anticompulsive-like effects.

The results, in addition to reinforcing a possible anticompulsive effect of CBD, also suggest that mCPP-induced repetitive burying could be a useful test for the screening of compounds with presumed anticompulsive properties.”

http://onlinelibrary.wiley.com/doi/10.1111/fcp.12051/abstract

Refractory trigeminal neuralgia responsive to nabiximols in a patient with multiple sclerosis.

“Nabiximols is a cannabinoid compound approved for the treatment of multiple sclerosis (MS)-related spasticity.

However, additional symptoms, such as pain, urinary urgency and sleep disturbance, may benefit from treatment.

CASE REPORT:

The present report describes a patient with secondary progressive MS and severe lower limbs spasticity who was started on treatment with nabiximols. The patient also suffered from trigeminal neuralgia, which he was not treating due to inefficacy or side effects of all previously tried medications. After nabiximols initiation the patient experienced a marked benefit on trigeminal neuralgia, which completely resolved, while spasticity responded only partially to treatment.

CONCLUSION:

Nabiximols mechanism of action is based on the interaction with CB1 and CB2 receptors, which are expressed by central nervous system neurons and are known to modulate pain among other effects. The present case indicates that nabiximols and other cannabinoids need to be further tested for the treatment of trigeminal neuralgia.”

http://www.ncbi.nlm.nih.gov/pubmed/27456876

“Therapeutic potential of cannabinoids in trigeminal neuralgia. Considering the pronounced antinociceptive effects produced by cannabinoids, they may be a promising therapeutic approach for the clinical management of trigeminal neuralgia.”  http://www.ncbi.nlm.nih.gov/pubmed/15578967