The synthetic cannabinoids attenuate allodynia and hyperalgesia in a rat model of trigeminal neuropathic pain.

 

“Trigeminal neuralgia is a disorder of paroxysmal and severely disabling facial pain and continues to be a real therapeutic challenge.

At present there are few effective drugs. Here we have evaluated the effects of the synthetic cannabinoid WIN 55,212-2 on mechanical allodynia and thermal hyperalgesia in a rat model of trigeminal neuropathic pain produced by a chronic constriction injury (CCI) of the infraorbital branch of the trigeminalnerve (ION).

Taken together, these results suggest that cannabinoids may be a useful therapeutic approach for the clinical management of trigeminal neuropathic pain disorders.”

The endocannabinoid system and Post Traumatic Stress Disorder (PTSD): From preclinical findings to innovative therapeutic approaches in clinical settings.

“Post-Traumatic Stress Disorder (PTSD) is a psychiatric chronic disease developing in individuals after the experience of an intense and life-threatening traumatic event. The post-traumatic symptomatology encompasses alterations in memory processes, mood, anxiety and arousal.

There is now consensus in considering the disease as an aberrant adaptation to traumatic stress. Pharmacological research, aimed at the discovery of new potential effective treatments, has lately directed its attention towards the “so-called” cognitive enhancers. This class of substances, by modulating cognitive processes involved in the development and/or persistence of the post-traumatic symptomatology, could be of great help in improving the outcome of psychotherapies and patients’ prognosis.

In this perspective, drugs acting on the endocannabinoid system are receiving great attention due to their dual ability to modulate memory processes on one hand, and to reduce anxiety and depression on the other.

The purpose of the present review is to offer a thorough overview of both animal and human studies investigating the effects of cannabinoids on memory processes.

First, we will briefly describe the characteristics of the endocannabinoid system and the most commonly used animal models of learning and memory. Then, studies investigating cannabinoid modulatory influences on memory consolidation, retrieval and extinction will be separately presented, and the potential benefits associated with each approach will be discussed.

In the final section, we will review literature data reporting beneficial effects of cannabinoid drugs in PTSD patients.”

http://www.ncbi.nlm.nih.gov/pubmed/27456243

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

Should we care about sativex-induced neurobehavioral effects? A 6-month follow-up study.

“Sativex® is an exclusive cannabinoid-based drug approved for the treatment of spasticity due to Multiple Sclerosis (MS).

The most common side effects include dizziness, nausea, and somnolence. However, it is still under debate whether the drug could cause negative cognitive effects.

The aim of our study was to investigate the effect of Sativex® on functional and psychological status in cannabis-naïve MS patients.

After the treatment, we did not observe any significant neurobehavioral impairment in all the patients, but one.

Our findings suggest that Sativex® treatment does not significantly affect the cognitive and neurobehavioral functions.”

http://www.ncbi.nlm.nih.gov/pubmed/27460745

Deficient Adolescent Social Behavior Following Early-Life Inflammation is Ameliorated by Augmentation of Anandamide Signaling.

“Early-life inflammation has been shown to exert profound effects on brain development and behavior, including altered emotional behavior, stress responsivity and neurochemical/neuropeptide receptor expression and function.

The current study extends this research by examining the impact of inflammation, triggered with the bacterial compound lipopolysaccharide (LPS) on postnatal day (P) 14, on social behavior during adolescence.

We investigate the role that the endocannabinoid (eCB) system plays in sociability after early-life LPS.

These data suggest that alterations in eCB signaling following postnatal inflammation contribute to impairments in social behavior during adolescence and that inhibition of FAAH could be a novel target for disorders involving social deficits such as social anxiety disorders or autism.”

http://www.ncbi.nlm.nih.gov/pubmed/27453335

Crucial Roles of the Endocannabinoid 2-Arachidonoylglycerol in the Suppression of Epileptic Seizures.

“Endocannabinoid signaling is considered to suppress excessive excitability of neural circuits and to protect the brain from seizures. However, the precise mechanisms of this effect are poorly understood.

Here, we report that 2-arachidonoylglycerol (2-AG), one of the two major endocannabinoids, is crucial for suppressing seizures.

We found that kainate-induced seizures in mice lacking the 2-AG synthesizing enzyme, diacylglycerol lipase α, were much more severe compared with those in cannabinoid CB1 receptor knockout mice and were comparable to those in mice lacking both CB1– and CB2-receptor-mediated signaling.

In the dentate gyrus, 2-AG suppressed excitatory input around the inner and middle molecular layers through CB1 and presumably CB2 receptors, respectively.

This 2-AG-mediated suppression contributed to decreased granule cell excitability and the dampening of seizures. Furthermore, lack of 2-AG signaling enhanced kindling epileptogenesis and spontaneous seizures after kainate-induced status epilepticus.

These results highlight critical roles of 2-AG signaling in the suppression of epileptic seizures.”

http://www.ncbi.nlm.nih.gov/pubmed/27452464

Peripheral interactions between cannabinoid and opioid receptor agonists in a model of inflammatory mechanical hyperalgesia.

“Activation of opioid and cannabinoid receptors expressed in nociceptors induces effective antihyperalgesia.

In this study, we examined whether combinations of opioid and cannabinoid receptor agonists directed at the injured site would enhance therapeutic effectiveness.

Our findings showed that MOR and CB1 agonists directed at the inflamed site effectively attenuate mechanical hyperalgesia when administered individually, but exert opposing effects when administered together.

The antagonistic interactions between the two classes of drugs at the inflamed site suggest distinct mechanisms unique to peripheral nociceptors or inflamed tissue, and therefore require further studies to investigate whether the therapeutic utility of the combined drug treatments in chronic pain conditions can be optimized.”

http://www.ncbi.nlm.nih.gov/pubmed/27450703

Discovery of novel Tetrahydrobenzo[b]thiophene and pyrrole based scaffolds as potent and selective CB2 receptor ligands: The structural elements controlling binding affinity, selectivity and functionality.

“CB2-based therapeutics show strong potential in the treatment of diverse diseases such as inflammation, multiple sclerosis, pain, immune-related disorders, osteoporosis and cancer, without eliciting the typical neurobehavioral side effects of CB1 ligands.

For this reason, research activities are currently directed towards the development of CB2 selective ligands. Herein, the synthesis of novel heterocyclic-based CB2 selective compounds is reported.

The present findings thus pave the way to the design and optimization of heterocyclic-based scaffolds with lipophilic carboxamide and/or retroamide substituent that can be exploited as potential CB2 receptor activity modulators.”

http://www.ncbi.nlm.nih.gov/pubmed/27448919

Cannabinoid Modulation of Cutaneous Aδ Nociceptors During Inflammation

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“Previous studies have demonstrated that locally administered cannabinoids attenuate allodynia and hyperalgesia through activation of peripheral cannabinoid receptors (CB1 and CB2).

These results suggest that attenuation of mechanically evoked responses of Aδ nociceptors contributes to the behavioral antinociception produced by activation of peripheral CB1 receptors during inflammation.

Several studies have demonstrated that locally administered cannabinoids produce antinociception in animal models of both acute and persistent pain through peripheral mechanisms.

Taken together, our data suggest that peripherally acting cannabinoids could be a potential therapeutic treatment for chronic inflammatory pain.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2585399/

 

Complex pharmacology of natural cannabinoids: evidence for partial agonist activity of delta9-tetrahydrocannabinol and antagonist activity of cannabidiol on rat brain cannabinoid receptors.

“Delta9-tetrahydrocannabinol (delta9-THC), cannabinol and cannabidiol are three important natural cannabinoids from the Marijuana plant (Cannabis sativa).

Using [35S]GTP-gamma-S binding on rat cerebellar homogenate as an index of cannabinoid receptor activation we show that: delta9-THC does not induce the maximal effect obtained by classical cannabinoid receptor agonists such as CP55940.

Moreover at high concentration delta9-THC exhibits antagonist properties.

Cannabinol is a weak agonist on rat cerebellar cannabinoid receptors and cannabidiol behaves as an antagonist acting in the micromolar range.”

http://www.ncbi.nlm.nih.gov/pubmed/9667767