Category Archives: Endocannabinoid System

The effects of endocannabinoid receptor agonist anandamide and antagonist rimonabant on opioid analgesia and tolerance in rats.

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“The role of the cannabinoid (CB) system in the tolerance to analgesic effect of opioid remains obscure. The aim of the present study was to evaluate the effects of the endocannabinoid nonselective receptor agonist anandamide (AEA) and CB1 receptor antagonist rimonabant (SR141716) on morphine analgesia and tolerance in rats.

The findings suggested that AEA in combination with morphine produced a significant increase in expression of analgesic tolerance to morphine.

Conversely, cannabinoid receptor antagonist SR141716 attenuated morphine analgesic tolerance.

In addition, administration of AEA with morphine increased morphine analgesia.

In conclusion, we observed that the cannabinoid receptor agonist anandamide and CB1 receptor antagonist SR141716 plays a significant role in the opioid analgesia and tolerance.”

http://www.ncbi.nlm.nih.gov/pubmed/26374993

New insights on the role of the endocannabinoid system in the regulation of energy balance.

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“Within the last 15 years, the endocannabinoid system (ECS) has emerged as a lipid signaling system critically involved in the regulation of energy balance, since it exerts a regulatory control on every aspect related to the search, the intake, the metabolism and the storage of calories.

An overactive endocannabinoid-cannabinoid type 1 (CB1) receptor signaling promotes the development of obesity, insulin resistance and dyslipidemia, representing a valuable pharmacotherapeutic target for obesity and metabolic disorders.

However, due to psychiatric side effects, the first generation of brain-penetrant CB1 receptor blockers developed as anti-obesity treatment was removed from the European market in late 2008.

Since then, recent studies have identified new mechanisms of action of the ECS in energy balance and metabolism, as well as novel ways of targeting the system that may be efficacious for the treatment of obesity and metabolic disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26374449

Abnormalities in neuroendocrine stress response in psychosis: the role of endocannabinoids.

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“The aim of this article is to summarize current evidence regarding alterations in the neuroendocrine stress response system and endocannabinoid system and their relationship in psychotic disorders such as schizophrenia.

Exposure to stress is linked to the development of a number of psychiatric disorders including psychosis.

However, the precise role of stress in the development of psychosis and the possible mechanisms that might underlie this are not well understood. Recently the cannabinoid hypothesis of schizophrenia has emerged as a potential line of enquiry.

Endocannabinoid levels are increased in patients with psychosis compared with healthy volunteers; furthermore, they increase in response to stress, which suggests another potential mechanism for how stress might be a causal factor in the development of psychosis.

However, research regarding the links between stress and the endocannabinoid system is in its infancy.

Evidence summarized here points to an alteration in the baseline tone and reactivity of the hypothalamic-pituitary-adrenal (HPA) axis as well as in various components of the endocannabinoid system in patients with psychosis.

Moreover, the precise nature of the inter-relationship between these two systems is unclear in man, especially their biological relevance in the context of psychosis.

Future studies need to simultaneously investigate HPA axis and endocannabinoid alterations both at baseline and following experimental perturbation in healthy individuals and those with psychosis to understand how they interact with each other in health and disease and obtain mechanistic insight as to their relevance to the pathophysiology of schizophrenia.”

Potential Therapeutic Value of a Novel FAAH Inhibitor for the Treatment of Anxiety.

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“Anxiety disorders are among the most prevalent psychiatric diseases with high personal costs and a remarkable socio-economic burden. However, current treatment of anxiety is far from satisfactory.

Novel pharmacological targets have emerged in the recent years, and attention has focused on the endocannabinoid (eCB) system, given the increasing evidence that supports its central role in emotion, coping with stress and anxiety.

In the management of anxiety disorders, drug development strategies have left apart the direct activation of type-1 cannabinoid receptors to indirectly enhance eCB signalling through the inhibition of eCB deactivation, that is, the inhibition of the fatty acid amide hydrolase (FAAH) enzyme.

In the present study, we provide evidence for the anxiolytic-like properties of a novel, potent and selective reversible inhibitor of FAAH, ST4070, orally administered to rodents.

Altogether, ST4070 offers a promising anxiolytic-like profile in preclinical studies, although further studies are warranted to clearly demonstrate its efficacy in the clinic management of anxiety disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26360704

Anandamide mediates cognitive judgement bias in rats.

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“In the present study, we investigated the effects of acute pharmacological manipulation of the endocannabinoid (EC) system on the valence of cognitive judgement bias of rats in the ambiguous-cue interpretation (ACI) paradigm.

Our findings suggest involvement of the endocannabinoid system in the mediation of optimistic judgement bias.”

http://www.ncbi.nlm.nih.gov/pubmed/26363193

Endocannabinoid regulation of amyloid-induced neuroinflammation.

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“The modulation of endocannabinoid (EC) levels and the activation of cannabinoid receptors are seen as promising therapeutic strategies in a variety of diseases, including Alzheimer’s disease (AD).

These data reinforce the notion of a role for the EC system in neuroinflammation and open new perspectives on the relevance of modulating EC levels in the inflammed brain.”

http://www.ncbi.nlm.nih.gov/pubmed/26362942

Cannabidiol and sodium nitroprusside: two novel neuromodulatory pharmacological interventions to treat and prevent psychosis.

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“Since most patients with schizophrenia do not respond properly to treatment, scientific effort has been driven to the development of new compounds acting on pharmacological targets beyond the dopaminergic system.

Therefore, the aim is to review basic and clinical research findings from studies evaluating the effects of cannabidiol (CBD), an inhibitor of the reuptake and metabolism of anandamide and several other effects on nervous system, and sodium nitroprusside, a nitric oxide donor, on the prevention and treatment of psychosis.

Animal and human research supports that CBD and sodium nitroprusside might be effective in the prevention and treatment of psychosis in general and especially in schizophrenia.

The evidence available to date shows that CBD and sodium nitroprusside act in pathways associated with psychotic symptoms and that they may be important agents in the management of prodromal psychotic states and psychosis.

This underscores the relevance of further research on the effects of these agents and others that mediate the activity of the cannabinoid system and of nitric oxide, as well as comparative studies of their antipsychotic effects and those of other antipsychotic drugs currently used to treat schizophrenia.”

http://www.ncbi.nlm.nih.gov/pubmed/26350340

Cannabinoid-based drugs targeting CB1 and TRPV1, the sympathetic nervous system, and arthritis.

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“Chronic inflammation in rheumatoid arthritis (RA) is accompanied by activation of the sympathetic nervous system, which can support the immune system to perpetuate inflammation. Several animal models of arthritis already demonstrated a profound influence of adrenergic signaling on the course of RA.

Peripheral norepinephrine release from sympathetic terminals is controlled by cannabinoid receptor type 1 (CB1), which is activated by two major endocannabinoids (ECs), arachidonylethanolamine (anandamide) and 2-arachidonylglycerol.

These ECs also modulate function of transient receptor potential channels (TRPs) located on sensory nerve fibers, which are abundant in arthritic synovial tissue. TRPs not only induce the sensation of pain but also support inflammation via secretion of pro-inflammatory neuropeptides.

In addition, many cell types in synovial tissue express CB1 and TRPs.

In this review, we focus on CB1 and transient receptor potential vanilloid 1 (TRPV1)-mediated effects on RA since most anti-inflammatory mechanisms induced by cannabinoids are attributed to cannabinoid receptor type 2 (CB2) activation.

We demonstrate how CB1 agonism or antagonism can modulate arthritic disease.

The concept of functional antagonism with continuous CB1 activation is discussed.

Since fatty acid amide hydrolase (FAAH) is a major EC-degrading enzyme, the therapeutic possibility of FAAH inhibition is studied.

Finally, the therapeutic potential of ECs is examined since they interact with cannabinoid receptors and TRPs but do not produce central side effects.”

http://www.ncbi.nlm.nih.gov/pubmed/26343051

High Times for Painful Blues: The Endocannabinoid System in Pain-Depression Comorbidity.

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“Depression and pain are two of the most debilitating disorders worldwide and have an estimated cooccurrence of up to 80%. Comorbidity of these disorders is more difficult to treat, associated with significant disability and impaired health-related quality of life than either condition alone, resulting in enormous social and economic cost.

Several neural substrates have been identified as potential mediators in the association between depression and pain, including neuroanatomical reorganization, monoamine and neurotrophin depletion, dysregulation of the hypothalamo-pituitary-adrenal axis, and neuroinflammation.

However, the past decade has seen mounting evidence supporting a role for the endogenous cannabinoid (endocannabinoid) system in affective and nociceptive processing, and thus, alterations in this system may play a key role in reciprocal interactions between depression and pain.

This review will provide an overview of the preclinical evidence supporting an interaction between depression and pain and the evidence supporting a role for the endocannabinoid system in this interaction.”

http://www.ncbi.nlm.nih.gov/pubmed/26342110

“The plant Cannabis sativa has been used as a medicine throughout the world for several thousand years, with reports of its use in treating painful symptoms appearing as early as 2600 BC. The principal psychoactive ingredient of Cannabis sativa, delta-9-tetrahydrocannabinol (Δ9-THC), was first identified in 1964, and subsequent studies to understand its mechanism of action led to the discovery of the endogenous cannabinoid (endocannabinoid) system… Because of the distribution of the endocannabinoid system throughout spinal and supraspinal regions, it is in a prime position to regulate neurophysiological activities such as affective and nociceptive processing… evidence suggests a prominent role for the endocannabinoid system in the interaction between depression and pain,” http://ijnp.oxfordjournals.org/content/early/2015/09/04/ijnp.pyv095.long

Cannabinoids in the Treatment of Neurological Disorders

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“The force of the recent explosion of largely unproven and unregulated cannabis-based preparations on medical therapeutics may have its greatest impact in the field of neurology.

Paradoxically, for 10 millennia this plant has been an integral part of human cultivation, where it was used for its fibers long before its pharmacological properties.

With regard to the latter, cannabis was well known to healers from China and India thousands of years ago; Greek and Roman doctors during classic times; Arab doctors during the Middle Ages; Victorian and Continental physicians in the nineteenth century; American doctors during the early twentieth century; and English doctors until 1971 when a variety of nonevidence-based remedies were removed from the British Pharmaceutical Codex.

The clinical data on cannabis therapeutics are meager and the vast majority are formed by surveys or small studies that are underpowered and/or suffer from multiple methodological flaws, often by virtue of limited research funding for nonaddiction-focused studies. Thus, we know relatively little about the clinical efficacy of cannabinoids for the various neurological disorders for which historical nonscientific and medical literature have advocated its use.

The relative scarcity of proven cannabis-based therapies is not due to data that show that cannabinoids are ineffective or unsafe, but rather reflects a poverty of medical interest and a failure by pharmaceutical companies arising from regulatory restrictions compounded by limits for patent rights on plant cannabinoid-containing preparations that have been used medicinally for millennia, as is the case for most natural products.

We are pleased to have gathered many of the world’s experts together on the basic biology of cannabinoids, as well as their potential role in treating neurologic and psychiatric disorders…

We hope that this issue of Neurotherapeutics will serve to mark the bounds of verifiable scientific knowledge of cannabinoids in the treatment of neuropsychiatric and neurological disorders. At the same time, our contributors have also helped identify areas for future research, as well as the strategies needed to move our base of knowledge forward.

We hope that this volume will help to accelerate the pace of the appropriately focused and productive research and double-blind placebo-controlled randomized trials to the point at which the care of patients is informed by valid data and not just anecdote.”

http://link.springer.com/article/10.1007/s13311-015-0388-0/fulltext.html