Δ(9)-tetrahydrocannabinol targeting estrogen receptor signaling: the possible mechanism of action coupled with endocrine disruption.

“Δ(9)-Tetrahydrocannabinol (Δ(9)-THC), a biologically active constituent of marijuana, possesses a wide variety of pharmacological and toxicological effects (e.g., analgesia, hypotension, reduction of inflammation, and anti-cancer effects).

Among Δ(9)-THC’s biological activities, its recognized anti-estrogenic activity has been the subject of investigations.

… Δ(9)-THC is used as both a drug of abuse (marijuana) and as a preventive therapeutic to treat pain and nausea in cancer patients undergoing chemotherapy…

…important to investigate the mechanistic basis underlying the anti-estrogenic activity of Δ(9)-THC…

We have recently reported that ERβ, a second type of ER, is involved in the Δ(9)-THC abrogation of E2/ERα-mediated transcriptional activity. Here we discuss the possible mechanism(s) of the Δ(9)-THC-mediated disruption of E2/ERα signaling by presenting our recent findings as well.”

http://www.ncbi.nlm.nih.gov/pubmed/25177025

 

Nonclassical cannabinoid analgetics inhibit adenylate cyclase: development of a cannabinoid receptor model.

“Extensive structure-activity relationship studies have demonstrated that specific requirements within the cannabinoid structure are necessary to produce potent analgesia.

A three-point association between the agonist and the receptor mediating analgesia consists of: 1) the C ring hydroxyl, 2) the phenolic A ring hydroxyl, and 3) the A ring alkyl hydrophobic side chain. Potent tricyclic and bicyclic structures were synthesized as “nonclassical” cannabinoid analgetics that conform to this agonist-receptor three-point interaction model.

At the cellular level, centrally active cannabinoid drugs inhibit adenylate cyclase activity in a neuroblastoma cell line. The structure-activity relationship profile for inhibition of adenylate cyclase in vitro was consistent with this same three-point association of agonists with the receptor.

A correlation exists between the potency of drugs to produce analgesia in vivo and to inhibit adenylate cyclase in vitro.

Based on the parallels in structure-activity relationships and the enantioselective effects, it is postulated that the receptor that is associated with the regulation of adenylate cyclase in vitro may be the same receptor as that mediating analgesia in vivo.

A conceptualization of the cannabinoid analgetic receptor is presented.”

http://www.ncbi.nlm.nih.gov/pubmed/3352594

Non-psychoactive cannabinoids modulate the descending pathway of antinociception in anaesthetized rats through several mechanisms of action.

“Two non-psychoactive cannabinoids, cannabidiol (CBD) and cannabichromene (CBC), are known to modulate in vitro the activity of proteins involved in nociceptive mechanisms, including transient receptor potential (TRP) channels of vanilloid type-1 (TRPV1) and of ankyrin type-1 (TRPA1), the equilibrative nucleoside transporter and proteins facilitating endocannabinoid inactivation. Here we have tested these two cannabinoids on the activity of the descending pathway of antinociception…

CONCLUSIONS AND IMPLICATIONS:

CBD and CBC stimulated descending pathways of antinociception and caused analgesia by interacting with several target proteins involved in nociceptive control.

These compounds might represent useful therapeutic agents with multiple mechanisms of action.”

http://www.ncbi.nlm.nih.gov/pubmed/20942863

Targeting the Endocannabinoid System for Neuroprotection: A 19F-NMR Study of a Selective FAAH Inhibitor Binding with an Anandamide Carrier Protein, HSA.

“Fatty acid amide hydrolase (FAAH), the enzyme involved in the inactivation of the endocannabinoid anandamide (AEA), is being considered as a therapeutic target for analgesia and neuroprotection…
The endocannabinoid system has been implicated as a therapeutic target for analgesia, anti-emesis, and neuroprotection… These findings provide a potential new therapeutic modality for neuroprotection through dual inhibition of FAAH and anandamide carrier proteins…”

Figure 1

Endocannabinoids and exercise.

“Exercise induces changes in mental status, particularly analgesia, sedation, anxiolysis, and a sense of wellbeing. The mechanisms underlying these changes remain unknown.

Recent findings show that exercise increases serum concentrations of endocannabinoids, suggesting a possible explanation for a number of these changes…

At first glance, it appears that the runner’s high phenomenon is, at present, not a scientific problem because it is built on circumstantial evidence and lacks a plausible mechanistic explanation. However, recent data in our laboratory showed that endurance exercise activates the endocannabinoid system, suggesting a new mechanism underlying exercise induced alterations of mental status.”

http://bjsm.bmj.com/content/38/5/536.long

Exercise activates the endocannabinoid system.

“Extensive documentation exists showing that exercise induces analgesia and sedation.

…we report here the first evidence that exercise of moderate intensity activates the endocannabinoid system, suggesting a new mechanism for exercise-induced analgesia and possibly other physiological and psychological adaptations to exercise.”

http://www.ncbi.nlm.nih.gov/pubmed/14625449

Involvement of cannabinoid receptors in peripheral and spinal morphine analgesia.

“The interactions between the cannabinoid and opioid systems for pain modulation are reciprocal. However, the role and the importance of the cannabinoid system in the antinociceptive effects of opioids remain uncertain. We studied these interactions with the goal of highlighting the involvement of the cannabinoid system in morphine-induced analgesia.

In both phases of the formalin test, intra paw and intrathecal morphine produced similar antinociceptive effects in C57BL/6, cannabinoid type 1 and type 2 receptor wildtype (respectively cnr1WT and cnr2WT) mice. In cnr1 and cnr2 knockout (KO) mice, at the dose used the antinociceptive effect of intra paw morphine in the inflammatory phase of the formalin test was decreased by 87% and 76%, respectively. Similarly, the antinociceptive effect of 0.1 μg spinal morphine in the inflammatory phase was abolished in cnr1KO mice and decreased by 90% in cnr2KO mice. Interestingly, the antinociceptive effect of morphine in the acute phase of the formalin test was only reduced in cnr1KO mice. Notably, systemic morphine administration produced similar analgesia in all genotypes, in both the formalin and the hot water immersion tail flick tests.

Because the pattern of expression of the mu opioid receptor (MOP), its binding properties and its G protein coupling remained unchanged across genotypes, it is unlikely that the loss of morphine analgesia in the cnr1KO and cnr2KO mice is the consequence of MOP malfunction or downregulation due to the absence of its heterodimerization with either the CB1 or the CB2 receptors, at least at the level of the spinal cord.”

http://www.ncbi.nlm.nih.gov/pubmed/24365460

CB1 Cannabinoid Receptor Agonist Prevents NGF-Induced Sensitization of TRPV1 in Sensory Neurons.

“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.”

http://www.ncbi.nlm.nih.gov/pubmed/23850608

Marijuana May Be Effective For Neuropathic Pain.

“The growing body of evidence that marijuana (cannabis) may be effective as a pain reliever has been expanded with publication of a new study in The Journal of Pain reporting that patients with nerve pain showed reduced pain intensity from smoking marijuana.

Researchers at University of California Davis examined whether marijuana produces analgesia for patients with neuropathic pain. Thirty-eight patients were examined. They were given either high-dose (7%), low-dose (3.5%) or placebo cannabis.

The authors reported that identical levels of analgesia were produced at each cumulative dose level by both concentrations of the agent. As with opioids, cannabis does not rely on a relaxing or tranquilizing effect, but reduces the core component of nociception and the emotional aspect of the pain experience to an equal degree. There were undesirable consequences observed from cannabis smoking, such as feeing high or impaired, but they did not inhibit tolerability or cause anyone to withdraw from the study. In general, side effects and mood changes were inconsequential.

It was noted by the authors that since high and low dose cannabis produced equal analgesic efficacy, a case could be made for testing lower concentrations to determine if the analgesic profile can be maintained while reducing potential cognitive decline.

In addition, the authors said further research could probe whether adding the lowest effective dose of cannabis to another analgesic drug might lead to more effective neuropathic pain treatment for patients who otherwise are treatment-resistant.”

http://www.sciencedaily.com/releases/2008/06/080626150628.htm

Smoked Medicinal Cannabis for Neuropathic Pain in HIV: A Randomized, Crossover Clinical Trial.

“In 1999, a report of the United States Institute of Medicine recommended further investigations of the possible benefits of cannabis (marijuana) as a medicinal agent for a variety of conditions, including neuropathic pain due to HIV distal sensory polyneuropathy (DSPN). The most abundant active ingredient in cannabis, tetrahydro-cannabinol (THC), and its synthetic derivatives, produce effective analgesia in most animal models of pain. The antinociceptive effects of THC are mediated through cannabinoid receptors (CB1, CB2) in the central and peripheral nervous systems, which in turn interact with noradrenergic and κ-opioid systems in the spinal cord to modulate the perception of painful stimuli. The endogenous ligand of CB1, anandamide, itself is an effective antinociceptive agent. In open-label clinical trials and one recent controlled trial, medicinal cannabis has shown preliminary efficacy in relieving neuropathic pain.”

“We conducted a clinical trial to assess the impact of smoked cannabis on neuropathic pain in HIV. This was a phase II, double-blind, placebo-controlled, crossover trial of analgesia with smoked cannabis in HIV-associated distal sensory predominant polyneuropathy (DSPN).”

 “…pain relief was greater with cannabis than placebo…”

 “Smoked cannabis was generally well tolerated and effective when added to concomitant analgesic therapy in patients with medically refractory pain due to HIV DSPN.”

“Our findings suggest that cannabinoid therapy may be an effective option for pain relief in patients with medically intractable pain due to HIV-associated DSPN.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3066045/