Attenuation of HIV-1 replication in macrophages by cannabinoid receptor 2 agonists.

“Previous studies showed that activation of the CB2 can attenuate inflammatory responses and affect HIV-1 infectivity in T cells and microglia. Here, we report that CB2 agonists can also act as immunomodulators on HIV-1-infected macrophages.

   We speculate that these findings indicate that prevention of viral entry is not a central mechanism for CB2-mediated suppression in viral replication.

However, CB2 may affect the HIV-1 replication machinery.

Results from a single-round infection with the pseudotyped virus revealed a marked decrease in HIV-1 LTR activation by the CB2 ligands.

Together, these results indicate that CB2 may offer a means to limit HIV-1 infection in macrophages.”

http://www.ncbi.nlm.nih.gov/pubmed/23463725

The pharmacologic and clinical effects of medical cannabis.

“Cannabis, or marijuana, has been used for medicinal purposes for many years. Several types of cannabinoid medicines are available in the United States and Canada. Dronabinol (schedule III), nabilone (schedule II), and nabiximols (not U.S. Food and Drug Administration approved) are cannabis-derived pharmaceuticals.

Medical cannabis or medical marijuana, a leafy plant cultivated for the production of its leaves and flowering tops, is a schedule I drug, but patients obtain it through cannabis dispensaries and statewide programs. The effect that cannabinoid compounds have on the cannabinoid receptors (CB(1) and CB(2) ) found in the brain can create varying pharmacologic responses based on formulation and patient characteristics. The cannabinoid Δ(9) -tetrahydrocannabinol has been determined to have the primary psychoactive effects; the effects of several other key cannabinoid compounds have yet to be fully elucidated. Dronabinol and nabilone are indicated for the treatment of nausea and vomiting associated with cancer chemotherapy and of anorexia associated with weight loss in patients with acquired immune deficiency syndrome. However, pain and muscle spasms are the most common reasons that medical cannabis is being recommended.

Studies of medical cannabis show significant improvement in various types of pain and muscle spasticity. Reported adverse effects are typically not serious, with the most common being dizziness. Safety concerns regarding cannabis include the increased risk of developing schizophrenia with adolescent use, impairments in memory and cognition, accidental pediatric ingestions, and lack of safety packaging for medical cannabis formulations. This article will describe the pharmacology of cannabis, effects of various dosage formulations, therapeutics benefits and risks of cannabis for pain and muscle spasm, and safety concerns of medical cannabis use.”

http://www.ncbi.nlm.nih.gov/pubmed/23386598

Cannabidiol Inhibits Growth and Induces Programmed Cell Death in Kaposi Sarcoma–Associated Herpesvirus-Infected Endothelium

“Kaposi sarcoma is the most common neoplasm caused by Kaposi sarcoma–associated herpesvirus (KSHV). Current treatments for Kaposi sarcoma can inhibit tumor growth but are not able to eliminate KSHV from the host. When the host’s immune system weakens, KSHV begins to replicate again, and active tumor growth ensues. New therapeutic approaches are needed.

Cannabidiol (CBD), a plant-derived cannabinoid, exhibits promising antitumor effects without inducing psychoactive side effects. CBD is emerging as a novel therapeutic for various disorders, including cancer.

In this study, we investigated the effects of CBD both on the infection of endothelial cells (ECs) by KSHV and on the growth and apoptosis of KSHV-infected ECs, an in vitro model for the transformation of normal endothelium to Kaposi sarcoma….

Cannabidiol (CBD) was first isolated in 1940. It is a major component of the plant Cannabis sativa, which is also the source of Δ9-tetrahydrocannabinol (Δ9-THC). Due to its multiple biological activities, CBD has been identified as a potential clinical agent. Moreover, CBD affects these activities without the psychoactive side effects that typify Δ9-THC. Recent studies have documented the potential antitumorigenic properties of CBD in the treatment of various neoplasms, including breast cancer, lung cancer, bladder cancer, glioblastoma,and leukemia.CBD induces these effects through a variety of mechanisms and signaling pathways

CBD has been evaluated clinically for the treatment of various conditions, including anxiety, psychosis, and pain. In contrast to other members of the cannabinoid family, CBD has a strong safety profile and induces no psychotropic effects.Therefore, it has become an attractive agent in the search for new anticancer therapies.Our current study demonstrated that CBD preferentially enhanced apoptosis and inhibited the proliferation of KSHV-infected endothelial cells. This selective targeting of KSHV-induced neoplasia suggests that CBD may have a desirable therapeutic index when used to treat cancer. Moreover, a recent study demonstrated that CBD can be delivered effectively by nasal and transdermal routes, which may be particularly valuable for the treatment of Kaposi sarcoma oral or skin lesions.”

Full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3527984/

The CB1/CB2 receptor agonist WIN-55,212-2 reduces viability of human Kaposi’s sarcoma cells in vitro.

“Kaposi’s sarcoma is a highly vascularized mesenchymal neoplasm arising with multiple lesions of the skin. Endogenous cannabinoids have been shown to inhibit proliferation of a wide spectrum of tumor cells. We studied the effects of cannabinoids on human Kaposi’s sarcoma cell proliferation in vitro.

 To do so, we first investigated the presence of the cannabinoid receptors CB(1) and CB(2) mRNAs in the human Kaposi’s sarcoma cell line KS-IMM by RT-PCR and, subsequently, the effects of the mixed CB(1)/CB(2) agonist WIN-55,212-2 (WIN) on cell proliferation in vitro. WIN showed antimitogenic effects on Kaposi’s sarcoma cells…

  In view of the antiproliferative effects of cannabinoids on KS-IMM cells, one could envision the cannabinoid system as a potential target for pharmacological treatment of Kaposi’s sarcoma”

http://www.ncbi.nlm.nih.gov/pubmed/19539619

Kaposi Sarcoma.

“Kaposi sarcoma (KS) is a low-grade vascular tumor associated with Kaposi sarcoma herpesvirus/human herpesvirus 8 (KSHV/HHV8) infection. Kaposi sarcoma lesions predominantly present at mucocutaneous sites, but may involve all organs and anatomic locations. Recognized epidemiologic-clinical forms of KS include classic, African (endemic), AIDS-associated (epidemic), and iatrogenic KS. New clinical manifestations have been described, such as antiretroviral therapy-related KS regression or flares. Kaposi sarcoma lesions evolve from early (patch stage) macules into plaques (plaque stage) that grow into larger nodules (tumor stage). Newer histologic variants include anaplastic, hyperkeratotic, lymphangioma-like, bullous, telangiectatic, ecchymotic, keloidal, pyogenic granuloma-like, micronodular, intravascular, glomeruloid and pigmented KS, as well as KS with sarcoidlike granulomas and KS with myoid nodules. Latency-associated nuclear antigen (HHV8) is the most specific immunohistochemical marker available to help distinguish KS from its mimics. Since KS remains one of the most common AIDS-defining malignancies, it is important that pathologists be able to recognize KS and its contemporary manifestations.”

http://www.ncbi.nlm.nih.gov/pubmed/23368874

Stimulation of cannabinoid receptor 2 (CB2) suppresses microglial activation

“Activated microglial cells have been implicated in a number of neurodegenerative disorders, including Alzheimer’s disease (AD), multiple sclerosis (MS), and HIV dementia. Many data reveal that cannabinoids mediate suppression of inflammation in vitro and in vivo through stimulation of cannabinoid receptor 2 (CB2).

Taken together, these results provide mechanistic insight into beneficial effects provided by cannabinoid receptor CB2 modulation in neurodegenerative diseases, particularly AD.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1352348/

Medicinal Marijuana Eases Neuropathic Pain in HIV – ABC News

“(HealthDay News) — Medicinal marijuana helps relieve neuropathic pain in people with HIV, says a University of California, San Diego, School of Medicine study.

It included 28 HIV patients with neuropathic pain that wasn’t adequately controlled by opiates or other pain relievers. The researchers found that 46 percent of patients who smoked medicinal marijuana reported clinically meaningful pain relief, compared with 18 percent of those who smoked a placebo.

The study, published online Aug. 6 in Neuropsychopharmacology, was sponsored by the University of California Center for Medical Cannabis Research (CMCR).

“Neuropathy is a chronic and significant problem in HIV patients as there are few existing treatments that offer adequate pain management to sufferers,” study leader Dr. Ronald J. Ellis, an associate professor of neurosciences, said in an UCSD news release. “We found that smoked cannabis was generally well-tolerated and effective when added to the patient’s existing pain medication, resulting in increased pain relief.”

The findings are consistent with and extend other recent CMCR-sponsored research supporting the short-term effectiveness of medicinal marijuana in treating neuropathic pain.

“This study adds to a growing body of evidence that indicates that cannabis is effective, in the short-term at least, in the management of neuropathic pain,” Dr. Igor Grant, a professor of psychiatry and director of the CMCR, said in the UCSD news release.”

http://abcnews.go.com/Health/Healthday/story?id=5528635&page=1

More evidence cannabis can help in neuropathic pain.

“It’s good to see the trial of smoked cannabis in neuropathic pain reported by Ware and colleagues because smoking is the most common way in which patients try this drug. The authors should be congratulated for tackling the question of whether cannabis helps in neuropathic pain, particularly given that the regulatory hurdles for their trial must have been a nightmare. The question is worth investigating because of the ongoing publicity — which patients see, hear and read — that suggests an analgesic activity of cannabis in neuropathic pain, and because of the paucity of robust evidence for such an analgesic effect. If patients are not achieving a good response with conventional treatment of their pain, then they may, reasonably, wish to try cannabis. If medical cannabis is not available where a patient lives, then obtaining it will take the patient outside of the law, often for the first time in his or her life. Good evidence would at least buttress that decision.”

“This trial adds to the three previous studies of smoked cannabis in neuropathic pain that I could find using PubMed and reference lists…”

“Putting together the four trials of smoked cannabis, the provisional conclusions are that an analgesic effect is evident, that this effect, though not great, may be of use to some patients, and that it often carries with it some adverse effects on the central nervous system (though not obviously so in this trial). These conclusions make biological sense, given that cannabinoids taken orally have shown the same sorts of effects. Interestingly, the “moderate” analgesic effect shown here for neuropathic pain seems to hold true for nociceptive pain.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2950178/

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/

Smoked cannabis for chronic neuropathic pain: a randomized controlled trial.

“Cannabis sativa has been used to treat pain since the third millennium BC. An endogenous pain-processing system has been identified, mediated by endogenous cannabinoid ligands acting on specific cannabinoid receptors.These findings, coupled with anecdotal evidence of the analgesic effects of smoked cannabis, support a reconsideration of cannabinoid agents as analgesics.”

“Oral cannabinoids such as tetrahydrocannabinol, cannabidiol and nabilone have, alone and in combination, shown efficacy in central and peripheral neuropathic pain, rheumatoid arthritis and fibromyalgia.”

“We conducted a clinical trial using a standardized single-dose delivery system to explore further the safety and efficacy of smoked cannabis in outpatients with chronic neuropathic pain.”

“Conclusion

A single inhalation of 25 mg of 9.4% tetrahydrocannabinol herbal cannabis three times daily for five days reduced the intensity of pain, improved sleep and was well tolerated.”

“Our results support the claim that smoked cannabis reduces pain, improves mood and helps sleep. We believe that our trial provides a methodological approach that may be considered for further research. Clinical studies using inhaled delivery systems, such as vaporizers, are needed.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2950205/