Neuroprotective effects of the cannabinoid agonist HU210 on retinal degeneration.

“Cannabinoids have been demonstrated to exert neuroprotective effects on different types of neuronal insults.

Here we have addressed the therapeutic potential of the synthetic cannabinoid HU210 on photoreceptor degeneration, synaptic connectivity and functional activity of the retina in the transgenic P23H rat, an animal model for autosomal dominant retinitis pigmentosa (RP)…

These data suggest that cannabinoids are potentially useful to delay retinal degeneration in RP patients.”

http://www.ncbi.nlm.nih.gov/pubmed/24495949

Anandamide in primary sensory neurons: too much of a good thing?

“The quest for possible targets for the development of novel analgesics has identified the activation of the cannabinoid type 1 (CB1) receptor outside the CNS as a potential means of providing relief from persistent pain, which currently constitutes an unmet medical need.

Increasing tissue levels of the CB1 receptor endogenous ligand N-arachidonoylethanolamine (anandamide), by inhibiting anandamide degradation through blocking the anandamide-hydrolysing enzyme fatty acid amide hydrolase, has been suggested to be used to activate the CB1 receptor.

However, recent clinical trials revealed that this approach does not deliver the expected relief from pain. Here, we discuss one of the possible reasons, the activation of the transient receptor potential vanilloid type 1 ion channel (TRPV1) on nociceptive primary sensory neurons (PSNs) by anandamide, which may compromise the beneficial effects of increased tissue levels of anandamide.

We conclude that better design such as concomitant blocking of anandamide hydrolysis and anandamide uptake into PSNs, to inhibit TRPV1 activation, could overcome these problems.”

http://www.ncbi.nlm.nih.gov/pubmed/24494681

Endocannabinoids and neuropathic pain: focus on neuron-glia and endocannabinoid-neurotrophin interactions.

“Although originally described as a signalling system encompassing the cannabinoid CB1 and CB2 receptors, their endogenous agonists (the endocannabinoids), and metabolic enzymes regulating the levels of such agonists, the endocannabinoid system is now viewed as being more complex, and including metabolically related endocannabinoid-like mediators and their molecular targets as well.

The function and dysfunction of this complex signalling system in the molecular and cellular mechanisms of pain transduction and control has been widely studied over the last two decades.

In this review article, we describe some of the latest advances in our knowledge on the role of the endocannabinoid system, in its most recent and wider conception, in pain pathways, by focusing on: (1) neuron-glia interactions; and (2) emerging data on endocannabinoid cross-talk with neurotrophins, such as nerve growth factor and brain-derived neurotrophic factor.”

http://www.ncbi.nlm.nih.gov/pubmed/24494680

Basolateral amygdala CB1 cannabinoid receptors mediate nicotine-induced place preference.

“In the present study, the effects of bilateral microinjections of cannabinoid CB1 receptor agonist and antagonist into the basolateral amygdala (intra-BLA) on nicotine-induced place preference were examined in rats.

Taken together, these findings support the possible role of endogenous cannabinoid system of the BLA in the acquisition and the expression of nicotine-induced place preference. Furthermore, it seems that there is a functional interaction between the BLA cannabinoid receptors and nicotine in producing the rewarding effects.”

http://www.ncbi.nlm.nih.gov/pubmed/24468643

Peripheral interactions between cannabinoid and opioid systems contribute to the antinociceptive effect of crotalphine.

“Crotalphine is an antinociceptive peptide… we evaluated the involvement of the peripheral cannabinoid system in the crotalphine effect and its interaction with the opioid system…

Crotalphine-induced antinociception involves peripheral CB2 cannabinoid receptors and local release of dynorphin A, which is dependent on CB2 receptor activation.

These results enhance our understanding of the mechanisms involved in the peripheral effect of crotalphine, as well as the interaction between the opioid and cannabinoid systems.”

http://www.ncbi.nlm.nih.gov/pubmed/24460677

Cannabinoid and cannabinoid-like receptors in microglia, astrocytes and astrocytomas

“…compounds targeting cannabinoid-like receptors constitute promising therapeutics to manage neuroinflammation and eradicate malignant astrocytomas.

Importantly, the selective targeting of cannabinoid-like receptors should provide therapeutic relieve without inducing the typical psychotropic effects and possible addictive properties…

 Taken together, the studies outlined in this review suggest that stereotactic injection of high concentrations of CBD could constitute a useful regimen for neurosurgeons to use in the treatment of malignant astrocytomas and of excessive/chronic neuroinflammation.

Such a treatment could provide therapeutic effects both directly, by killing the astrocytoma and limiting its propagation, and indirectly, by reducing the accumulation of activated microglia or invading peripheral immune cells.

The fact that non-psychotropic cannabinoids acting through CB-like receptors affect such fundamental processes involved in microglial cell activation and astrocytoma propagation constitutes, in my opinion, one of the most exciting areas of research in our search for new chemotherapeutic agents to treat malignant brain tumors and new anti-inflammatory agents to temper the damage linked to chronic neuroinflammation.

Furthermore, the curative properties of cannabinoids do not overlap with currently available medicines, and therefore cannabinoid-based treatments constitute a new therapeutic platform.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2919281/

5-Lipoxygenase and anandamide hydrolase (FAAH) mediate the antitumor activity of cannabidiol, a non-psychoactive cannabinoid.

“It has been recently reported that cannabidiol (CBD), a non-psychoactive cannabinoid, is able to kill glioma cells, both in vivo and in vitro, independently of cannabinoid receptor stimulation.

…the present investigation indicates that CBD exerts its antitumoral effects through modulation of the LOX pathway and of the endocannabinoid system…”

http://www.ncbi.nlm.nih.gov/pubmed/18028339

Effects of cannabinoid receptor type 2 on endogenous myocardial regeneration by activating cardiac progenitor cells in mouse infarcted heart.

“Cannabinoid receptor type 2 (CB2) activation is recently reported to promote proliferation of some types of resident stem cells (e.g., hematopoietic stem/progenitor cell or neural progenitor cell).

Resident cardiac progenitor cell (CPC) activation and proliferation are crucial for endogenous cardiac regeneration and cardiac repair after myocardial infarction (MI). This study aims to explore the role and possible mechanisms of CB2 receptor activation in enhancing myocardial repair…

In conclusion, AM1241 could induce myocardial regeneration and improve cardiac function, which might be associated with PI3K/Akt/Nrf2 signaling pathway activation.

Our findings may provide a promising strategy for cardiac endogenous regeneration after MI.”

http://www.ncbi.nlm.nih.gov/pubmed/24430557

The Novel Endocannabinoid Receptor GPR18 is Expressed in the Rostral Ventrolateral Medulla and Exerts Tonic Restraining Influence on Blood Pressure.

“Systemic administration of the GPR18 agonist abnormal cannabidiol (Abn CBD) lowers blood pressure (BP).

These findings are the first to demonstrate GPR18 expression in the RVLM, and to suggest sympathoinhibitory role for this receptor. The findings yield new insight into the role of a novel cannabinoid receptor (GPR18) in central BP control.”

http://www.ncbi.nlm.nih.gov/pubmed/24431468PR

A double-blind, randomized, placebo-controlled, parallel group study of THC/CBD spray in peripheral neuropathic pain treatment.

“Peripheral neuropathic pain (PNP) associated with allodynia poses a significant clinical challenge. The efficacy of Δ9 -tetrahydrocannabinol/cannabidiol (THC/CBD) oromucosal spray, a novel cannabinoid formulation, was investigated in this 15-week randomized, double-blind, placebo-controlled parallel group study…

These findings demonstrate that, in a meaningful proportion of otherwise treatment-resistant patients, clinically important improvements in pain, sleep quality and SGIC of the severity of their condition are obtained with THC/CBD spray. THC/CBD spray was well tolerated and no new safety concerns were identified.”

http://www.ncbi.nlm.nih.gov/pubmed/24420962