Self-medication of a cannabinoid CB2 agonist in an animal model of neuropathic pain.

“Neuropathic pain is caused by injury to the peripheral or central nervous system (CNS)…”

“…novel approaches for identifying safe and effective analgesics with limited abuse liability are necessary.”

“Cannabinoids share the same target as the psychoactive ingredient in maijuana. Cannabinoids suppress neuropathic nociception through CB1 and CB2 mechanisms. CB1 is predominantly located within the CNS… CB2 activation is not associated with CNS side-effects linked to CB1. However, abuse potential of CB2 agonists is unknown.”

“We used a drug self-administration approach to ask whether rats with a spared nerve injury (SNI) would self-medicate with a CB2 agonist to attenuate a neuropathic pain state…”

 “Our results suggest that cannabinoid CB2 agonists may be exploited to treat neuropathic pain with limited drug abuse liability and central nervous system (CNS) side-effects. These studies validate the use of drug self-administration methods for identifying nonpsychotropic analgesics possessing limited abuse potential…”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3157548/

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/

Multiple sclerosis and extract of cannabis: results of the MUSEC trial.

“Multiple sclerosis (MS) is associated with chronic symptoms, including muscle stiffness, spasms, pain and insomnia. Here we report the results of the Multiple Sclerosis and Extract of Cannabis (MUSEC) study that aimed to substantiate the patient based findings of previous studies.”

“CONCLUSION:

The study met its primary objective to demonstrate the superiority of cannabis extract (CE) over placebo in the treatment of muscle stiffness in MS. This was supported by results for secondary efficacy variables. Adverse events in participants treated with CE were consistent with the known side effects of cannabinoids. No new safety concerns were observed.”

http://www.ncbi.nlm.nih.gov/pubmed/22791906

Cannabis eases multiple sclerosis (MS) stiffness: study

“Use of cannabis extract helps ease painful muscle stiffness among patients with multiple sclerosis (MS), according to a large trial published on Tuesday in the Journal of Neurology, Neurosurgery and Psychiatry.

The “Phase III” test — the final stage in a process to vet a new drug or medical process — took place among 22 centres in Britain.

Over 12 weeks, 144 patients were given daily tablets of tetrahydrocannabinol, which is the active ingredient in cannabis, and 135 were given a dummy pill, also called a placebo…

…They also reported improvement in sleep quality. Side effects were nervous system disorders and gut problems, but none was severe…

The trial, led by John Peter Zajicek of Britain’s Clinical Neurology Research Group, says standardized doses of cannabis extract can be useful in easing pain and spasms in this disease.

Previous Phase III trials on cannabis and MS have thrown up conflicting results, partly because of the scale by which users report any change in their symptoms, the MUSEC researchers said.”

http://articles.nydailynews.com/2012-10-10/news/34367509_1_multiple-sclerosis-cannabis-nerve-cells

Smoking Cannabis May Reduce Symptoms in Multiple Sclerosis Patients – ABC News

“Smoking marijuana may reduce certain symptoms in patients with multiple sclerosis, according to a new small study published Monday in the Canadian Medical Association Journal.

Researchers from the University of California at San Diego School of Medicine conducted a double blind, controlled clinical trial that included 30 participants who had multiple sclerosis. The scientists hoped to understand whether smoked cannabis reduces symptoms of spasticity, a common symptom of the disease that refers to stiffness and involuntary muscle spasms.

While most past trials have focused on the effects of a pill-form of cannabis, researchers wanted to see specifically whether a smoked form of the drug has a beneficial effect.

“Smoking cannabis was indeed superior to the placebo in reducing spasticity and pain…”

Read More: http://abcnews.go.com/Health/marijuana-reduce-symptoms-multiple-sclerosis-patients/story?id=16328805

Smoked cannabis for spasticity in multiple sclerosis: a randomized, placebo-controlled trial.

“Spasticity is a common and disabling symptom that remains a substantial problem for many patients with multiple sclerosis. Some patients have adverse effects from conventional antispasticity medications; for others, spasticity persists despite treatment. A report from the Institute of Medicine in the United States concluded that the active compounds of cannabis (marijuana) are potentially effective in treating neurologic conditions and “should be tested rigorously in clinical trials.” There is evidence that the cannabinoid receptors CB1 and CB2 may be involved in the control of spasticity in multiple sclerosis2 and that the endogenous ligand of CB1, anandamide, is itself an effective antispasticity agent.3 CB1 receptors are primarily presynaptic; their activation inhibits calcium influx and glutamate release, and reduces neuronal excitability by activating somatic and dendritic potassium channels.

“Although many patients with multiple sclerosis endorse smoking cannabis as therapy, evidence that it relieves spasticity is largely anecdotal, as most trials focus on orally administered cannabinoids. We sought to assess the safety and efficacy of smoked cannabis versus placebo in patients with multiple sclerosis who have treatment-resistant spasticity.”

“Smoked cannabis was superior to placebo in symptom and pain reduction in participants with treatment-resistant spasticity. Future studies should examine whether different doses can result in similar beneficial effects with less cognitive impact.”

“No serious adverse events occurred during the trial.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3394820/

Cannabis blunts prostate cancer threat: study – ABC News

“Chemicals in cannabis have been found to stop prostate cancer cells from growing in the laboratory, suggesting marijuana-based medicines could one day help fight the disease, scientists said.

After working initially with human cancer cell lines, Ines Diaz-Laviada and colleagues from the University of Alcala in Madrid also tested one compound on mice and discovered it produced a significant reduction in tumour growth.

Their research, published in the British Journal of Cancer, underlines the growing interest in the medical use of active chemicals called cannabinoids, which are found in marijuana.”

Read more: http://www.abc.net.au/news/2009-08-19/cannabis-blunts-prostate-cancer-threat-study/1396346

Cannabinoid Receptor as a Novel Target for the Treatment of Prostate Cancer

“Because prostate cancer has become the most common cancer diagnosed in men, developing novel targets and mechanism-based agents for its treatment has become a challenging issue. In recent years cannabinoids, the active components of Cannabis sativa Linnaeus (marijuana) and their derivatives have drawn renewed attention because of their diverse pharmacologic activities such as cell growth inhibition, anti-inflammatory effects, and tumor regression . Cannabinoids have been shown to induce apoptosis in gliomas, PC-12 pheochromocytoma, CHP 100 neuroblastoma, and hippocampal neurons in vitro, and most interestingly, regression of C6-cell gliomas in vivo. Further interest in cannabinoid research came from the discovery of specific cannabinoid systems and the cloning of specific cannabinoid receptors. These diversified effects of cannabinoids are now known to be mediated by the activation of specific G protein-coupled receptors that are normally bound by a family of endogenous ligands, the endocannabinoids. Two different cannabinoid receptors have been characterized and cloned from mammalian tissues: the “central” CB1 receptor, and the “peripheral” CB2 receptor.”

“In the present study, we show for the first time that expression levels of both cannabinoid receptors, CB1 and CB2, are higher in human prostate cancer cells than in normal cells. Importantly, we also show that WIN-55,212-2 (CB1/CB2 agonist) treatment with androgen-responsive LNCaP cells results in a dose- and time-dependent inhibition of cell growth with a concomitant induction of apoptosis, decrease in protein and mRNA expression of androgen receptor and prostate-specific antigen (PSA), decrease in secreted PSA levels, protein expression of proliferating cell nuclear antigen (PCNA), and vascular endothelial growth factor (VEGF). We suggest that cannabinoid receptor agonists may be useful in the treatment of human prostate cancer.”

“…non–habit-forming cannabinoid receptor agonists could be developed as novel therapeutic agents for the treatment of prostate cancer.”

“We conclude that cannabinoids should be considered as agents for the management of prostate cancer.”

.http://cancerres.aacrjournals.org/content/65/5/1635.long

Cannabinoid Receptor Agonist-induced Apoptosis of Human Prostate Cancer Cells LNCaP Proceeds through Sustained Activation of ERK1/2 Leading to G1 Cell Cycle Arrest

“Prostate cancer (CaP)2 ranks as the most common noncutaneous malignancy and the second leading cause of cancer-related deaths in American males, with similar trends in many Western countries…The major cause of mortality from this disease is metastasis of hormone refractory cancer cells that fail to respond to hormone ablation therapy. Because surgery and current treatment options have proven to be inadequate in treating and controlling CaP, the search for novel targets and mechanism-based agents for prevention and treatment of this disease has become a priority.”

“In recent years, cannabinoids the active components of Cannabis sativa linnaeus (marijuana) and their derivatives are drawing renewed attention because of their diverse pharmacological activities such as cell growth inhibition, anti-inflammatory effects, and tumor regression. Further interest in cannabinoid research came from the discovery of the cannabinoid system and the cloning of specific cannabinoid receptors. Two cannabinoid receptors have been identified: the “central” CB1 and the “peripheral” CB2 receptor. In a recent study, we have shown that WIN 55,212-2 a mixed CB1/CB2 receptor agonist imparts cell growth inhibitory effects in LNCaP cells via an induction of apoptosis. An important observation of this study was that WIN 55,212-2 treatment did not result in apoptosis of the normal prostate epithelial cell at similar doses.”

“Cannabinoids and their derivatives are drawing considerable attention in the treatment of cancer because of their diverse activities such as cell growth inhibition, anti-inflammatory effects, and tumor regression. Accumulated evidence indicates that cannabinoid receptor(s) could be an important target for the treatment of cancer. We have earlier shown that WIN-55,212-2 induced apoptosis of prostate cancer LNCaP cells is mediated through CB1 and CB2 receptors and suggested that these receptors could be an important targets for the treatment of prostate cancer…”

“Hence, we conclude that cannabinoid receptor agonist should be considered as an effective agent for the treatment of prostate cancer. If our hypothesis is supported by in vivo experiments, the long term implications of our study could be to develop nonhabit-forming cannabinoid agonist (s) for the management of prostate cancer.”

http://www.jbc.org/content/281/51/39480.long

Delta9-tetrahydrocannabinol induces apoptosis in human prostate PC-3 cells via a receptor-independent mechanism.

Abstract

“The effect of delta9-tetrahydrocannabinol (THC), the major psycho-active component of marijuana, in human prostate cancer cells PC-3 was investigated. THC caused apoptosis in a dose-dependent manner. Morphological and biochemical changes induced by THC in prostate PC-3 cells shared the characteristics of an apoptotic phenomenon. First, loss of plasma membrane asymmetry determined by fluorescent anexin V binding. Second, presence of apoptotic bodies and nuclear fragmentation observed by DNA staining with 4′,6-diamino-2-phenylindole (DAPI). Third, presence of typical ‘ladder-patterned’ DNA fragmentation. Central cannabinoid receptor expression was observed in PC-3 cells by immunofluorescence studies. However, several results indicated that the apoptotic effect was cannabinoid receptor-independent, such as lack of an effect of the potent cannabinoid agonist WIN 55,212-2, inability of cannabinoid antagonist AM 251 to prevent cellular death caused by THC and absence of an effect of pertussis toxin pre-treatment.”

http://www.ncbi.nlm.nih.gov/pubmed/10570948