Dual-Acting Compounds Targeting Endocannabinoid and Endovanilloid Systems-A Novel Treatment Option for Chronic Pain Management.

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“Compared with acute pain that arises suddenly in response to a specific injury and is usually treatable, chronic pain persists over time, and is often resistant to medical treatment.

Because of the heterogeneity of chronic pain origins, satisfactory therapies for its treatment are lacking, leading to an urgent need for the development of new treatments.

The leading approach in drug design is selective compounds, though they are often less effective and require chronic dosing with many side effects.

Herein, we review novel approaches to drug design for the treatment of chronic pain represented by dual-acting compounds, which operate at more than one biological target.

A number of studies suggest the involvement of the cannabinoid and vanilloid receptors in pain.

Interestingly cannabinoid system is in interrelation with other systems that comprise lipid mediators: prostaglandins, produced by COX enzyme.

Therefore, in the present review, we summarize the role of dual-acting molecules (FAAH/TRPV1 and FAAH/COX-2 inhibitors) that interact with endocannabinoid and endovanillinoid systems and act as analgesics by elevating the endogenously produced endocannabinoids and dampening the production of pro-inflammatory prostaglandins.

The plasticity of the endocannabinoid system (ECS) and the ability of a single chemical entity to exert an activity on two receptor systems has been developed and extensively investigated.

Here, we review up-to-date pharmacological studies on compounds interacting with FAAH enzyme together with TRPV1 receptor or COX-2 enzyme respectively.

Multi-target pharmacological intervention for treating pain may lead to the development of original and efficient treatments.”

http://www.ncbi.nlm.nih.gov/pubmed/27582708

Endocannabinoids inhibit neurogenic inflammation in murine joints by a non-canonical cannabinoid receptor mechanism.

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“Neurogenic inflammation is a local inflammatory response that is driven by the peripheral release of neuropeptides from small diameter afferents which occurs in many organs including joints.

The knee joint has a rich endocannabinoid system which has been shown to decrease acute synovitis.

The aim of this study was to investigate the influence of joint afferents on leukocyte-endothelial interactions within the synovial microcirculation of mice and determine the role of endocannabinoids on this inflammatory response.

These results provide evidence that antidromic stimulation of the mouse saphenous nerve promotes leukocyte rolling within the synovial microcirculation, and that endocannabinoids can attenuate this neurogenic inflammatory response.”

http://www.ncbi.nlm.nih.gov/pubmed/27567396

Peripherally selective cannabinoid 1 receptor (CB1R) agonists for the treatment of neuropathic pain

 Journal of Medicinal Chemistry

“Alleviation of neuropathic pain by cannabinoids is limited by their central nervous system (CNS) side effects. Indole and indene compounds were engineered for high hCB1R affinity, peripheral selectivity, metabolic stability, and in vivo efficacy. An epithelial cell line assay identified candidates with <1% blood-brain barrier penetration for testing in a rat neuropathy induced by unilateral sciatic nerve entrapment (SNE). The SNE-induced mechanical allodynia was reversibly suppressed, partially or completely, after intraperitoneal or oral administration of several indenes. At doses that relieve neuropathy symptoms, the indenes completely lacked, while the brain-permeant CB1R agonist HU-210 (1) exhibited strong CNS side effects, in catalepsy, hypothermia, and motor incoordination assays. Pharmacokinetic findings of ~0.001 cerebrospinal fluid:plasma ratio further supported limited CNS penetration. Pretreatment with selective CB1R or CB2R blockers suggested mainly CB1R contribution to an indene’s anti-allodynic effects. Therefore, this class of CB1R agonists holds promise as a viable treatment for neuropathic pain.”

http://pubs.acs.org/doi/abs/10.1021/acs.jmedchem.6b00516

Cannabinoids in pain and inflammation.

“Cannabinoids exhibit medicinal properties including analgesic, anti-inflammatory and immunosuppressive properties. This paper reviews some of the recent findings in the study of cannabinoids in pain and inflammation. Some of the effects of cannabinoids are receptor mediated and others are receptor independent. Endocannabinoids naturally reduce pain and are cerebroprotective. Natural and synthetic cannabinoids have the potential to reduce nociception, reverse the development of allodynia and hyperalgesia, reduce inflammation and inflammatory pain and protect from secondary tissue damage in traumatic head injury.”

http://www.ncbi.nlm.nih.gov/pubmed/15265314

The future of cannabinoids as analgesic agents: a pharmacologic, pharmacokinetic, and pharmacodynamic overview.

 

“For thousands of years, physicians and their patients employed cannabis as a therapeutic agent.

Despite this extensive historical usage, in the Western world, cannabis fell into disfavor among medical professionals because the technology available in the 1800s and early 1900s did not permit reliable, standardized preparations to be developed.

However, since the discovery and cloning of cannabinoid receptors (CB1 and CB2) in the 1990s, scientific interest in the area has burgeoned, and the complexities of this fascinating receptor system, and its endogenous ligands, have been actively explored.

Recent studies reveal that cannabinoids have a rich pharmacology and may interact with a number of other receptor systems-as well as with other cannabinoids-to produce potential synergies.

Cannabinoids-endocannabinoids, phytocannabinoids, and synthetic cannabinoids-affect numerous bodily functions and have indicated efficacy of varying degrees in a number of serious medical conditions.

Cannabinoid receptor agonists and/or molecules that affect the modulation of endocannabinoid synthesis, metabolism, and transport may, in the future, offer extremely valuable tools for the treatment of a number of currently intractable disorders.”

 http://www.ncbi.nlm.nih.gov/pubmed/17890938

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

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/

 

Cannabimimetic Drugs: Recent Patents in Central Nervous System Disorders.

“Agents acting via cannabinoid receptors have been widely developed; starting from the chemical structure of phytocannabinoids isolated from cannabis sativa plant, specific and selective compounds of these receptors have been produced ranging from partial to full agonists and /or antagonists endowed with different potency.

The enhanced interest on developing such classes of drugs is due to the beneficial properties widely reported by both anecdotal reports and scientific studies describing the potential medicinal use of cannabinoids and their derivatives in numerous pathological conditions in both in vitro and in vivo models.

The use of these drugs has been found to be of benefit in a wide number of neurological and neuropsychiatric disorders, and in many other diseases ranging from cancer, atherosclerosis, stroke, hypertension, inflammatory related disorders, and autoimmune diseases, just to mention some.

In particular, being the cannabinoid CB1 receptor a central receptor expressed by neurons of the central nervous system, the attention for the treatment of neurological diseases has been mainly focused on compounds acting via this receptor, however some of these compounds has been showed to act by alternative pathways in some cases unrelated to CB1 receptors.

Nonetheless, endocannabinoids are potent regulators of the synaptic function in the central nervous system and their levels are modulated in neurological diseases.

In this study, we focused on endocannabinoid mechanism of action in neuronal signaling and on cannabimimetic drug potential application in neurological disorders.

Finally, novel patents on cannabis-based drugs with applicability in central nervous system disorders are highlighted, to suggest future potential therapeutic utility of derivatives of this ancient plant.”

http://www.ncbi.nlm.nih.gov/pubmed/27334611

[MEDICAL CANNABIS].

“The cannabis plant has been known to humanity for centuries as a remedy for pain, diarrhea and inflammation.

Current research is inspecting the use of cannabis for many diseases, including multiple sclerosis, epilepsy, dystonia, and chronic pain.

In inflammatory conditions cannabinoids improve pain in rheumatoid arthritis and: pain and diarrhea in Crohn’s disease.

Despite their therapeutic potential, cannabinoids are not free of side effects including psychosis, anxiety, paranoia, dependence and abuse.

Controlled clinical studies investigating the therapeutic potential of cannabis are few and small, whereas pressure for expanding cannabis use is increasing.

Currently, as long as cannabis is classified as an illicit drug and until further controlled studies are performed, the use of medical cannabis should be limited to patients who failed conventional better established treatment.”

http://www.ncbi.nlm.nih.gov/pubmed/27215115

The synthetic cannabinoid WIN55,212-2 mesylate decreases the production of inflammatory mediators in rheumatoid arthritis synovial fibroblasts by activating CB2, TRPV1, TRPA1 and yet unidentified receptor targets

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“Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by joint inflammation and cartilage destruction.

In this study we assessed the ability of WIN to modulate cytokine and MMP-3 production in SFs over a wide concentration range and identified specific receptor targets that mediate the effects of this synthetic cannabinoid.

The synthetic cannabinoid WIN in low concentrations exhibits anti-inflammatory effects in synovial fibroblasts independent of CB1 and CB2 while CB2 and yet unidentified receptor targets are responsible for WIN effects in micromolar concentrations.

Our results indicate a TRPV1/TRPA1 dependent mechanism of SF regulation that might be coupled to cellular energy status and calcium content.

In this report we demonstrated anti-inflammatory effects of the synthetic cannabinoid WIN in low and high concentrations.

Furthermore, this study demonstrated anti-inflammatory effects via modulation of TRP channels by WIN. Together, inactivation of TRPs and activation of cannabinoid receptors might also reduce the sensation of pain, which further underlines the potential of WIN in the treatment of chronic inflammation.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4858820/