“In the era of combined antiretroviral therapy (cART), human immunodeficiency virus type 1 (HIV-1) is considered a chronic disease that specifically targets the brain and causes HIV-1-associated neurocognitive disorders (HAND). Endocannabinoids (eCBs) elicit neuroprotective and anti-inflammatory actions in several central nervous system (CNS) disease models, but their effects in HAND remain unknown. HIV-1 does not infect neurons, but produces viral toxins, such as transactivator of transcription (Tat), that disrupt neuronal calcium equilibrium and give rise to synaptodendritic injuries and cell death, the former being highly correlated with HAND. Consequently, we tested whether the eCBs N-arachidonoyl ethanolamine (anandamide/AEA) and 2-arachidonoyl-glycerol (2-AG) offer neuroprotective actions in a neuronal culture model. Specifically, we examined the neuroprotective actions of these eCBs on Tat excitotoxicity in primary cultures of prefrontal cortex neurons (PFC), and whether cannabinoid receptors mediate this neuroprotection. Tat-induced excitotoxicity was reflected by increased intracellular calcium levels, synaptodendritic damage, neuronal excitability, and neuronal death. Further, upregulation of cannabinoid 1 receptor (CB1R) protein levels was noted in the presence of HIV-1 Tat. The direct application of AEA and 2-AG reduced excitotoxic levels of intracellular calcium and promoted neuronal survival following Tat exposure, which was prevented by the CB1R antagonist rimonabant, but not by the CB2R antagonist AM630. Overall, our findings indicate that eCBs protect PFC neurons from Tat excitotoxicity in vitro via a CB1R-related mechanism. Thus, the eCB system possesses promising targets for treatment of neurodegenerative disorders associated with HIV-1 infection.” https://www.ncbi.nlm.nih.gov/pubmed/28733129 http://www.sciencedirect.com/science/article/pii/S1044743117300830 ]]>
Category Archives: HIV/AIDS
Medicinal Uses of Marijuana and Cannabinoids
“In the past two decades, there has been increasing interest in the therapeutic potential of cannabis and single cannabinoids, mainly cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC). THC and cannabis products rich in THC exert their effects mainly through the activation of cannabinoid receptors (CB1 and CB2). Since 1975, 140 controlled clinical trials using different cannabinoids or whole-plant preparations for the treatment of a large number of disorders and symptoms have been conducted. Results have led to the approval of cannabis-based medicines [dronabinol, nabilone, and the cannabis extract nabiximols (Sativex®, THC:CBD = 1:1)] as well as cannabis flowers in several countries. Controlled clinical studies provide substantial evidence for the use of cannabinoid receptor agonists in cancer chemotherapy induced nausea and vomiting, appetite loss and cachexia in cancer and HIV patients, neuropathic and chronic pain, and in spasticity in multiple sclerosis. In addition, there is also some evidence suggesting a therapeutic potential of cannabis-based medicines in other indications including Tourette syndrome, spinal cord injury, Crohn’s disease, irritable bowel syndrome, and glaucoma. In several other indications, small uncontrolled and single-case studies reporting beneficial effects are available, for example in posttraumatic stress disorder, attention deficit hyperactivity disorder, and migraine. The most common side effects of THC and cannabis-based medicines rich in THC are sedation and dizziness (in more than 10% of patients), psychological effects, and dry mouth. Tolerance to these side effects nearly always develops within a short time. Withdrawal symptoms are hardly ever a problem in the therapeutic setting. In recent years there is an increasing interest in the medical use of CBD, which exerts no intoxicating side effects and is usually well-tolerated. Preliminary data suggest promising effects in the treatment of anxiety disorders, schizophrenia, dystonia, and some forms of epilepsy. This review gives an overview on clinical studies which have been published over the past 40 years.” http://www.tandfonline.com/doi/abs/10.1080/07352689.2016.1265360?needAccess=true&journalCode=bpts20
“Review Identifies 140 Controlled Clinical Trials Related to Cannabis” http://blog.norml.org/2017/06/04/review-identifies-140-controlled-clinical-trials-related-to-cannabis/
]]>Cannabis Use, Medication Management and Adherence Among Persons Living with HIV.
“Cannabis is used to relieve nausea, trigger weight gain, and reduce pain among adults living with HIV; however, the relationship between its use and medication adherence and management is unclear. Participants (N = 107) were from an ongoing cohort study of community-dwelling HIV+ adults, stratified by cannabis (CB) use: HIV+/CB+ (n = 41) and HIV+/CB- (n = 66). CB+ participants either tested positive in a urine toxicology screen for THC or had a self-reported history of regular and recent use. HIV-status was provided by physician results and/or biomarker assessment. Adherence was measured via the Morisky scale and medication management was assessed via the Medication Management Test-Revised. After adjusting for gender, we found no association between cannabis use group and adherence nor medication management. The amount of cannabis used was also not associated with measures of adherence and management. Preliminary findings suggest that cannabis use may not adversely influence medication adherence/management among adults living with HIV.”
Antihyperalgesic Activities of Endocannabinoids in a Mouse Model of Antiretroviral-Induced Neuropathic Pain.
“Nucleoside reverse transcriptase inhibitors (NRTIs) are the cornerstone of the antiretroviral therapy for human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS). However, their use is sometimes limited by the development of a painful sensory neuropathy, which does not respond well to drugs. Smoked cannabis has been reported in clinical trials to have efficacy in relieving painful HIV-associated sensory neuropathy. The aim of this study was to evaluate whether the expression of endocannabinoid system molecules is altered during NRTI-induced painful neuropathy, and also whether endocannabinoids can attenuate NRTI-induced painful neuropathy. Conclusion: These data show that ddC induces thermal hyperalgesia, which is associated with dysregulation of the mRNA expression of some endocannabinoid system molecules. The endocannabinoids AEA and 2-AG have antihyperalgesic activity, which is dependent on cannabinoid receptor and GPR55 activation. Thus, agonists of cannabinoid receptors and GPR55 could be useful therapeutic agents for the management of NRTI-induced painful sensory neuropathy.” https://www.ncbi.nlm.nih.gov/pubmed/28373843]]>
Dietary fats and pharmaceutical lipid excipients increase systemic exposure to orally administered cannabis and cannabis-based medicines
“Cannabis sativa, commonly called hemp, has thousands of years-long history of medical use. Cannabis extracts were widely used in Europe and North America for their therapeutic value as sedatives, hypnotics, analgesics, muscle relaxants, and anticonvulsant agents. However, cannabis was removed from British and American Pharmacopoeias in 20th century, partially due to politic bias. Although prohibited, many patients were nevertheless self-medicating to obtain therapeutic benefits from cannabis for various conditions, including AIDS wasting syndrome, multiple sclerosis (MS) and spinal injuries. More recently, a growing interest in the therapeutic effects of cannabis has developed following the isolation of cannabinoids, the principal chemical compounds of cannabis, as well as the discovery of endocannabinoids and their cognate receptors in humans. These advances supported legalisation and wide-spread use of cannabis for therapeutic purposes in many countries.
There has been an escalating interest in the medicinal use of Cannabis sativa in recent years. Cannabis is often administered orally with fat-containing foods, or in lipid-based pharmaceutical preparations. However, the impact of lipids on the exposure of patients to cannabis components has not been explored. Therefore, the aim of this study is to elucidate the effect of oral co-administration of lipids on the exposure to two main active cannabinoids, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). In this study, oral co-administration of lipids enhanced the systemic exposure of rats to THC and CBD by 2.5-fold and 3-fold, respectively, compared to lipid-free formulations. In vitro lipolysis was conducted to explore the effect of lipids on the intestinal solubilisation of cannabinoids. More than 30% of THC and CBD were distributed into micellar fraction following lipolysis, suggesting that at least one-third of the administered dose will be available for absorption following co-administration with lipids. Both cannabinoids showed very high affinity for artificial CM-like particles, as well as for rat and human CM, suggesting high potential for intestinal lymphatic transport. Moreover, comparable affinity of cannabinoids for rat and human CM suggests that similar increased exposure effects may be expected in humans. In conclusion, co-administration of dietary lipids or pharmaceutical lipid excipients has the potential to substantially increase the exposure to orally administered cannabis and cannabis-based medicines. The increase in patient exposure to cannabinoids is of high clinical importance as it could affect the therapeutic effect, but also toxicity, of orally administered cannabis or cannabis-based medicines.”
Modulation of Gut-Specific Mechanisms by Chronic Δ9-Tetrahydrocannabinol Administration in Male Rhesus Macaques Infected with Simian Immunodeficiency Virus: A Systems Biology Analysis
“The major psychoactive cannabinoid in marijuana, Δ9-tetrahydrocannabinol (THC), exerts unique effects on the progression of simian immunodeficiency virus (SIV) infection.
Previous studies from our laboratory have shown that chronic THC administration ameliorates SIV disease progression and significantly reduces the morbidity and mortality of male SIV-infected macaques.
Our studies have demonstrated that chronic Δ9-tetrahydrocannabinol (THC) administration results in a generalized attenuation of viral load and tissue inflammation in simian immunodeficiency virus (SIV)-infected male rhesus macaques.
Gut-associated lymphoid tissue is an important site for HIV replication and inflammation that can impact disease progression.
Our results indicate that chronic THC administration modulated duodenal T cell populations, favored a pro-Th2 cytokine balance, and decreased intestinal apoptosis. These findings reveal novel mechanisms that may potentially contribute to cannabinoid-mediated disease modulation.
In summary, using a systems biology approach to understanding the impact of chronic cannabinoid treatment on gut-associated immunopathology, we identified relevant mechanisms that can potentially modulate disease progression.
Our results suggest that gut immunomodulation through changes in gene expression, cytokine profiles, and immune cell populations could potentially contribute to chronic THC modulation of SIV disease progression. Moreover, they reveal novel mechanisms that may potentially contribute to decreased morbidity and mortality.”
Cannabinoids inhibit HIV-1 Gp120-mediated insults in brain microvascular endothelial cells.
“HIV-1 infection has significant effect on the immune system as well as on the nervous system.
Breakdown of the blood-brain barrier (BBB) is frequently observed in patients with HIV-associated dementia (HAD) despite lack of productive infection of human brain microvascular endothelial cells (HBMEC).
Cellular products and viral proteins secreted by HIV-1 infected cells, such as the HIV-1 Gp120 envelope glycoprotein, play important roles in BBB impairment and HIV-associated dementia development.
HBMEC are a major component of the BBB.
Using cocultures of HBMEC and human astrocytes as a model system for human BBB as well as in vivo model, we show for the first time that cannabinoid agonists inhibited HIV-1 Gp120-induced calcium influx mediated by substance P and significantly decreased the permeability of HBMEC as well as prevented tight junction protein down-regulation of ZO-1, claudin-5, and JAM-1 in HBMEC.
Furthermore, cannabinoid agonists inhibited the transmigration of human monocytes across the BBB and blocked the BBB permeability in vivo.
These results demonstrate that cannabinoid agonists are able to restore the integrity of HBMEC and the BBB following insults by HIV-1 Gp120.
These studies may lead to better strategies for treatment modalities targeted to the BBB following HIV-1 infection of the brain based on cannabinoid pharmacotherapies.”
Marijuana use and viral suppression in persons receiving medical care for HIV-infection.
“Marijuana use is common among persons living with HIV (PLWH), but studies on its effect on HIV clinical outcomes are limited. We determined the association between marijuana use and HIV viral suppression among PLWH.
Of the 1,902 PLWH receiving antiretroviral therapy, completed an interview, and had a linked MRA, 20% reported marijuana use (13% less than daily and 7% daily use) and 73% achieved durable viral suppression. In multivariable analysis, marijuana use was not significantly associated with durable viral suppression in daily [Adjusted Odds Ratio (AOR): 0.87, 95% confidence interval (CI): 0.58, 1.33] or in less than daily [AOR: 0.83, 95% CI: 0.51, 1.37] users as compared to non-users when adjusting for sociodemographic factors, time since HIV diagnosis, depressive symptoms, alcohol, cigarette and other substance use.
CONCLUSION:
In this sample of PLWH receiving medical care in Florida, there was no statistically significant association between marijuana use and viral suppression. However, as the limits of the confidence intervals include effects that may be considered to be clinically important, there is a need for additional evidence from other samples and settings that include more marijuana users.”
Pharmacologic and non-pharmacologic treatments for chronic pain in individuals with HIV: a systematic review.
“Chronic pain occurs in as many as 85% of individuals with HIV and is associated with substantial functional impairment. Little guidance is available for HIV providers seeking to address their patients’ chronic pain. We conducted a systematic review to identify clinical trials and observational studies that examined the impact of pharmacologic or non-pharmacologic interventions on pain and/or functional outcomes among HIV-infected individuals with chronic pain in high-development countries. Eleven studies met inclusion criteria and were mostly low or very low quality. Seven examined pharmacologic interventions (gabapentin, pregabalin, capsaicin, analgesics including opioids) and four examined non-pharmacologic interventions (cognitive behavioral therapy, self-hypnosis, smoked cannabis). The only controlled studies with positive results were of capsaicin and cannabis, and had short-term follow-up (≤12 weeks). Among the seven studies of pharmacologic interventions, five had substantial pharmaceutical industry sponsorship. These findings highlight several important gaps in the HIV/chronic pain literature that require further research.”
ENDOCANNABINOID SYSTEM: A multi-facet therapeutic target.
“Cannabis sativa is also popularly known as marijuana. It is being cultivated and used by man for recreational and medicinal purposes from many centuries.
Study of cannabinoids was at bay for very long time and its therapeutic value could not be adequately harnessed due to its legal status as proscribed drug in most of the countries.
The research of drugs acting on endocannabinoid system has seen many ups and down in recent past. Presently, it is known that endocannabinoids has role in pathology of many disorders and they also serve “protective role” in many medical conditions.
Several diseases like emesis, pain, inflammation, multiple sclerosis, anorexia, epilepsy, glaucoma, schizophrenia, cardiovascular disorders, cancer, obesity, metabolic syndrome related diseases, Parkinson’s disease, Huntington’s disease, Alzheimer’s disease and Tourette’s syndrome could possibly be treated by drugs modulating endocannabinoid system.
Presently, cannabinoid receptor agonists like nabilone and dronabinol are used for reducing the chemotherapy induced vomiting. Sativex (cannabidiol and THC combination) is approved in the UK, Spain and New Zealand to treat spasticity due to multiple sclerosis. In US it is under investigation for cancer pain, another drug Epidiolex (cannabidiol) is also under investigation in US for childhood seizures. Rimonabant, CB1 receptor antagonist appeared as a promising anti-obesity drug during clinical trials but it also exhibited remarkable psychiatric side effect profile. Due to which the US Food and Drug Administration did not approve Rimonabant in US. It sale was also suspended across the EU in 2008.
Recent discontinuation of clinical trial related to FAAH inhibitor due to occurrence of serious adverse events in the participating subjects could be discouraging for the research fraternity. Despite of some mishaps in clinical trials related to drugs acting on endocannabinoid system, still lot of research is being carried out to explore and establish the therapeutic targets for both cannabinoid receptor agonists and antagonists.
One challenge is to develop drugs that target only cannabinoid receptors in a particular tissue and another is to invent drugs that acts selectively on cannabinoid receptors located outside the blood brain barrier. Besides this, development of the suitable dosage forms with maximum efficacy and minimum adverse effects is also warranted.
Another angle to be introspected for therapeutic abilities of this group of drugs is non-CB1 and non-CB2 receptor targets for cannabinoids.
In order to successfully exploit the therapeutic potential of endocannabinoid system, it is imperative to further characterize the endocannabinoid system in terms of identification of the exact cellular location of cannabinoid receptors and their role as “protective” and “disease inducing substance”, time-dependent changes in the expression of cannabinoid receptors.”