“Cannabis-based medications have been demonstrated to relieve pain.
Cannabis medications can be used in patients whose symptoms are not adequately alleviated by conventional treatment.
The clinical effect of the various cannabis-based medications rests primarily on activation of endogenous cannabinoid receptors.
Consumption of therapeutic amounts by adults does not lead to irreversible cognitive impairment.”
http://www.sciencedaily.com/releases/2012/08/120807101232.htm
“Although cannabinoids have been used for millennia for treating pain and other symptoms, their mechanisms of action remain obscure.
With the heralded identification of multiple G-protein-coupled receptors (GPCRs) mediating cannabinoid effects nearly two decades ago, the mystery of cannabinoid pharmacology was thought to be solved…
Despite the wealth of information on cannabinoid-induced peripheral antihyperalgesic and antinociceptive effects in many pain models, the molecular mechanism(s) for these actions remains unknown.
Although metabotropic cannabinoid receptors have important roles in many pharmacological actions of cannabinoids, recent studies have led to the recognition of a family of at least five ionotropic cannabinoid receptors (ICRs). The known ICRs are members of the family of transient receptor potential (TRP) channels and include TRPV1, TRPV2, TRPV4, TRPM8 and TRPA1.
Cannabinoid activation of ICRs can result in desensitization of the TRPA1 and TRPV1 channel activities, inhibition of nociceptors and antihyperalgesia and antinociception in certain pain models.
Thus, cannabinoids activate both metabotropic and ionotropic mechanisms to produce peripheral analgesic effects.”
“The cannabinoids are a group of terpenophenolic compounds present in the marijuana plant, Cannabis sativa. At present, three general types of cannabinoids have been identified: phytocannabinoids present uniquely in the cannabis plant, endogenous cannabinoids produced in humans and animals, and synthetic cannabinoids generated in a laboratory. It is worth noting that Cannabis sativa produces over 80 cannabinoids…
An accumulating body of evidence suggests that endocannabinoids and cannabinoid receptors type 1 and 2 (CB(1), CB(2)) play a significant role in physiologic and pathologic processes, including cognitive and immune functions.
…there is growing appreciation of the therapeutic potential of cannabinoids in multiple pathologic conditions involving chronic inflammation (inflammatory bowel disease, arthritis, autoimmune disorders, multiple sclerosis, HIV-1 infection, stroke, Alzheimer’sdisease to name a few), mainly mediated by CB(2) activation.
This review attempts to summarize recent advances in studies of CB(2) activation in the setting of neuroinflammation, immunomodulation and HIV-1 infection.
The full potential of CB2 agonists as therapeutic agents remains to be realized.
Despite some inadequacies of preclinical models to predict clinical efficacy in humans and differences between the signaling of human and rodent CB2 receptors, the development of selective CB2 agonists may open new avenues in therapeutic intervention.
Such interventions would aim at reducing the release of pro-inflammatory mediators particularly in chronic neuropathologic conditions such as HAND or MS.”
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3663904/
“Marijuana has been used to relieve pain for centuries. The analgesic mechanism of its constituents, the cannabinoids, was only revealed after the discovery of cannabinoid receptors (CB1 and CB2 ) two decades ago.
The subsequent identification of the endocannabinoids, anandamide and 2-arachidonoylglycerol (2-AG), and their biosynthetic and degradation enzymes discloses the therapeutic potential of compounds targeting the endocannabinoid system for pain control.
Inhibitors of the anandamide and 2-AG degradation enzymes, fatty acid amide hydrolase and monoacylglycerol lipase, respectively, may be superior to direct cannabinoid receptor ligands as endocannabinoids are synthesized on demand and rapidly degraded, focusing action at generating sites.
Recently, a promising strategy for pain relief was revealed in the periaqueductal gray (PAG). It is initiated by Gq -protein-coupled receptor (Gq PCR) activation of the phospholipase C-diacylglycerol lipase enzymatic cascade, generating 2-AG that produces inhibition of GABAergic transmission (disinhibition) in the PAG, thereby leading to analgesia.
Here, we introduce the antinociceptive properties of exogenous cannabinoids and endocannabinoids, involving their biosynthesis and degradation processes, particularly in the PAG. We also review recent studies disclosing the Gq PCR-phospholipase C-diacylglycerol lipase-2-AG retrograde disinhibition mechanism in the PAG, induced by activating several Gq PCRs, including metabotropic glutamatergic (type 5 metabotropic glutamate receptor), muscarinic acetylcholine (M1/M3), and orexin 1 receptors.
Disinhibition mediated by type 5 metabotropic glutamate receptor can be initiated by glutamate transporter inhibitors or indirectly by substance P, neurotensin, cholecystokinin and capsaicin. Finally, the putative role of 2-AG generated after activating the above neurotransmitter receptors in stress-induced analgesia is discussed.”
“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.”
“After 4 millennia of more or less documented history of cannabis use, the identification of cannabinoids, and of Δ(9)-tetrahydrocannabinol in particular, occurred only during the early 1960s, and the cloning of cannabinoid CB1 and CB2 receptors, as well as the discovery of endocannabinoids and their metabolic enzymes, in the 1990s.
Despite this initial relatively slow progress of cannabinoid research, the turn of the century marked an incredible acceleration in discoveries on the “endocannabinoid signaling system,” its role in physiological and pathological conditions, and pain in particular, its pharmacological targeting with selective agonists, antagonists, and inhibitors of metabolism, and its previously unsuspected complexity.
The way researchers look at this system has thus rapidly evolved towards the idea of the “endocannabinoidome,” that is, a complex system including also several endocannabinoid-like mediators and their often redundant metabolic enzymes and “promiscuous” molecular targets.
These peculiar complications of endocannabinoid signaling have not discouraged efforts aiming at its pharmacological manipulation, which, nevertheless, now seems to require the development of multitarget drugs, or the re-visitation of naturally occurring compounds with more than one mechanism of action.
In fact, these molecules, as compared to “magic bullets,” seem to offer the advantage of modulating the “endocannabinoidome” in a safer and more therapeutically efficacious way.
This approach has provided so far promising preclinical results potentially useful for the future efficacious and safe treatment of chronic pain and inflammation.”
1942-7611/asset/olalertbanner.jpg?v=1&s=4b27d6a6bed6b58a9935efe70e4f95efc39146bd)
“Cannabis was extensively used as a medicine throughout the developed world in the nineteenth century but went into decline early in the twentieth century ahead of its emergence as the most widely used illicit recreational drug later that century. Recent advances in cannabinoid pharmacology alongside the discovery of the endocannabinoid system (ECS) have re-ignited interest in cannabis-based medicines.
The ECS has emerged as an important physiological system and plausible target for new medicines. Its receptors and endogenous ligands play a vital modulatory role in diverse functions including immune response, food intake, cognition, emotion, perception, behavioural reinforcement, motor co-ordination, body temperature, wake/sleep cycle, bone formation and resorption, and various aspects of hormonal control. In disease it may act as part of the physiological response or as a component of the underlying pathology.
In the forefront of clinical research are the cannabinoids delta-9-tetrahydrocannabinol and cannabidiol, and their contrasting pharmacology will be briefly outlined. The therapeutic potential and possible risks of drugs that inhibit the ECS will also be considered. This paper will then go on to review clinical research exploring the potential of cannabinoid medicines in the following indications: symptomatic relief in multiple sclerosis, chronic neuropathic pain, intractable nausea and vomiting, loss of appetite and weight in the context of cancer or AIDS, psychosis, epilepsy, addiction, and metabolic disorders.”
http://www.ncbi.nlm.nih.gov/pubmed/24006213
http://onlinelibrary.wiley.com/doi/10.1002/dta.1529/abstract
“The cannabinoid receptor type 2 (CB2), is a class A GPCR that was cloned in 1993 while looking for an alternate receptor that could explain the pharmacological properties of 9- tetrahydrocannabinol. CB2 was identified among cDNAs based on its similarity in amino-acid sequence to the CB1 receptor and helped provide an explanation for the established effects of cannabinoids on the immune system.
In addition to the immune system, CB2 has widespread tissue expression and has been found in brain, PNS and GI tract. Several “mixed” cannabinoid agonists are currently in clinical use primarily for controlling pain and it is believed that selective CB2 agonism may afford a superior analgesic agent devoid of the centrally mediated CB1 effects.
Thus, selective CB2 receptor agonists represent high value putative therapeutics for treating pain and other disease states. In this perspective, we seek to provide a concise update of progress in the field.”
“The transient receptor potential vanilloid type 1 channel (TRPV1) and nerve growth factor (NGF) are important mediators of inflammatory pain…
Cannabinoids, by activating CB1 G protein-coupled receptors, produce analgesia in a variety of pain models, though the exact mechanisms are not known. We tested the hypothesis that activation of the CB1 receptor by cannabinoids attenuates NGF-induced TRPV1 sensitization….
These results support the hypothesis that cannabinoids, acting through CB1 receptors, may produce analgesia in part by preventing NGF-induced sensitization of TRPV1 in afferent nociceptor nerve endings.”
“The term ‘endocannabinoid’ – originally coined in the mid-1990s after the discovery of membrane receptors for the psychoactive principle in Cannabis, Delta9-tetrahydrocannabinol and their endogenous ligands – now indicates a whole signalling system that comprises cannabinoid receptors, endogenous ligands and enzymes for ligand biosynthesis and inactivation. This system seems to be involved in an ever-increasing number of pathological conditions. With novel products already being aimed at the pharmaceutical market little more than a decade since the discovery of cannabinoid receptors, the endocannabinoid system seems to hold even more promise for the future development of therapeutic drugs. We explore the conditions under which the potential of targeting the endocannabinoid system might be realized in the years to come.” http://www.ncbi.nlm.nih.gov/pubmed/15340387