Photobiomodulation Therapy Improves Acute Inflammatory Response in Mice: the Role of Cannabinoid Receptors/ATP-Sensitive K+ Channel/p38-MAPK Signalling Pathway.

Molecular Neurobiology

“Although photobiomodulation therapy (PBM) has been applied clinically for the treatment of pain and inflammation, wound healing, sports and soft tissue injuries, as well as to repair injured spinal cords and peripheral nerves, it remains unclear which molecular substrates (receptor) are implicated in the cellular mechanisms of PBM.

Here, we reported that PBM (660 nm, 30 mW, 0.06 cm2, 50 J/cm2, plantar irradiation) significantly inhibited carrageenan-induced paw oedema, but not noxious thermal response, through positive modulation to both CB1 and CB2 cannabinoid receptors. The use of CB1 antagonist AM281 or CB2 antagonist AM630 significantly reversed the anti-inflammatory effect of PBM. Analysis of signalling pathway downstream of cannabinoid receptors activation reveals that anti-inflammatory effects of PBM depend, in great extent, on its ability to activate ATP-dependent K+ channels and p38 mitogen-activated protein kinase. Moreover, PBM therapy significantly reduced the levels of pro-inflammatory cytokine IL-6 in both paw and spinal cord, and restored the reduction of the level of anti-inflammatory cytokine IL-10 in spinal cord after carrageenan injection. Unlike the potent cannabinoid receptor agonist (WIN 55212-2), PBM did not exert any CNS-mediated effects in the tetrad assay. Finally, PBM does not reduce inflammation and noxious thermal response induced by LPS and zymosan, a TLR4 and TLR2/dectin-1 ligand, respectively.

Thus, cannabinoid receptors and, possibly, the endocannabinoid system, represent an important site of action of PBM that opens the possibility of complementary and nonpsychotropic therapeutic interventions in clinical practice.”

https://www.ncbi.nlm.nih.gov/pubmed/28980210

https://link.springer.com/article/10.1007%2Fs12035-017-0792-z

Targeting fatty acid amide hydrolase as a therapeutic strategy for antitussive therapy.

“Cough is the most common reason to visit a primary care physician, yet it remains an unmet medical need. Fatty acid amide hydrolase (FAAH) is an enzyme that breaks down endocannabinoids, and inhibition of FAAH produces analgesic and anti-inflammatory effects. Cannabinoids inhibit vagal sensory nerve activation and the cough reflex, so it was hypothesised that FAAH inhibition would produce antitussive activity via elevation of endocannabinoids. Primary vagal ganglia neurons, tissue bioassay, in vivoelectrophysiology and a conscious guinea pig cough model were utilised to investigate a role for fatty acid amides in modulating sensory nerve activation in vagal afferents. FAAH inhibition produced antitussive activity in guinea pigs with concomitant plasma elevation of the fatty acid amides N-arachidonoylethanolamide (anandamide), palmitoylethanolamide, N-oleoylethanolamide and linoleoylethanolamide. Palmitoylethanolamide inhibited tussive stimulus-induced activation of guinea pig airway innervating vagal ganglia neurons, depolarisation of guinea pig and human vagus, and firing of C-fibre afferents. These effects were mediated via a cannabinoid CB2/Gi/o-coupled pathway and activation of protein phosphatase 2A, resulting in increased calcium sensitivity of calcium-activated potassium channels. These findings identify FAAH inhibition as a target for the development of novel, antitussive agents without the undesirable side-effects of direct cannabinoid receptor agonists.” https://www.ncbi.nlm.nih.gov/pubmed/28931663 http://erj.ersjournals.com/content/50/3/1700782]]>

Results of a Double-Blind, Randomized, Placebo-Controlled Study of Nabiximols Oromucosal Spray as Adjunctive Therapy in Advanced Cancer Patients With Chronic Uncontrolled Pain.

“Prior phase 2/3 studies found that cannabinoids might provide adjunctive analgesia in advanced cancer patients with uncontrolled pain. To assess adjunctive nabiximols (Sativex®), an extract of Cannabis sativa containing two potentially therapeutic cannabinoids (Δ9-tetrahydrocannabinol and cannabidiol, in advanced cancer patients with chronic pain unalleviated by optimized opioid therapy. Nabiximols was statistically superior to placebo on two of three quality-of-life instruments at week 3 and on all three at week 5. The safety profile of nabiximols was consistent with earlier studies.

Although not superior to placebo on the primary efficacy endpoint, nabiximols had benefits on multiple secondary endpoints, particularly in US patients.

Nabiximols might have utility in patients with advanced cancer who receive a lower opioid dose, such as individuals with early intolerance to opioid therapy.”

https://www.ncbi.nlm.nih.gov/pubmed/28923526 http://www.jpsmjournal.com/article/S0885-3924(17)30465-7/fulltext]]>

Re-visiting the Endocannabinoid System and Its Therapeutic Potential in Obesity and Associated Diseases.

 Current Diabetes Reports

“The purpose of the review was to revisit the possibility of the endocannabinoid system being a therapeutic target for the treatment of obesity by focusing on the peripheral roles in regulating appetite and energy metabolism.

Previous studies with the global cannabinoid receptor blocker rimonabant, which has both central and peripheral properties, showed that this drug has beneficial effects on cardiometabolic function but severe adverse psychiatric side effects. Consequently, focus has shifted to peripherally restricted cannabinoid 1 (CB1) receptor blockers as possible therapeutic agents that mitigate or eliminate the untoward effects in the central nervous system. Targeting the endocannabinoid system using novel peripheral CB1 receptor blockers with negligible penetrance across the blood-brain barrier may prove to be effective therapy for obesity and its co-morbidities. Perhaps the future of blockers targeting CB1 receptors will be tissue-specific neutral antagonists (e.g., skeletal muscle specific to treat peripheral insulin resistance, adipocyte-specific to treat fat excess, liver-specific to treat fatty liver and hepatic insulin resistance).” https://www.ncbi.nlm.nih.gov/pubmed/28913816 https://link.springer.com/article/10.1007%2Fs11892-017-0924-x
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