“Twenty-eight states in the U.S have legalized medical marijuana, yet its impacts on severe health consequences such as hospitalizations remain unknown. Meanwhile, the prevalence of opioid pain reliever (OPR) use and outcomes has increased dramatically. Recent studies suggested unintended impacts of legalizing medical marijuana on OPR, but the evidence is still limited. This study examined the associations between state medical marijuana policies and hospitalizations related to marijuana and OPR.
Monthly Archives: March 2017
Cannabidiol regulation of emotion and emotional memory processing: relevance for treating anxiety-related and substance abuse disorders.
“Learning to associate cues or contexts with potential threats or rewards is adaptive and enhances survival. Both aversive and appetitive memories are therefore powerful drivers of behaviour but the inappropriate expression of conditioned responding to fear- and drug-related stimuli can develop into anxiety-related and substance abuse disorders, respectively. These disorders are associated with abnormally persistent emotional memories and inadequate treatment, often leading to symptom relapse.
Studies show that cannabidiol, the main non-psychotomimetic phytocannabinoid found in Cannabis sativa, reduces anxiety via serotonin1A and (indirect) cannabinoid receptor activation in paradigms assessing innate responses to threat.
Accumulating evidence from animal studies investigating the effects of cannabidiol on fear memory processing also indicates that it reduces learned fear in paradigms that are translationally relevant to phobias and post-traumatic stress disorder.
Cannabidiol does so by reducing fear expression acutely, and by disrupting fear memory reconsolidation and enhancing fear extinction, both of which can result in the lasting reduction of learned fear.
Recent studies have also begun to determine the effects of cannabidiol on drug memory expression using paradigms with translational relevance to addiction. Emerging evidence suggests that cannabidiol reduces the expression of drug memories acutely and by disrupting their reconsolidation.
Here we review the literature demonstrating the anxiolytic effects of cannabidiol before focusing on studies investigating its effects on various fear and drug memory processes. Understanding how cannabidiol regulates emotion and emotional memory processing may eventually lead to its use in treating anxiety-related and substance abuse disorders.”
The Ratio of 2-AG to Its Isomer 1-AG as an Intrinsic Fine Tuning Mechanism of CB1 Receptor Activation.
“Endocannabinoids are pleiotropic lipid messengers that play pro-homeostatic role in cellular physiology by strongly influencing intracellular Ca2+ concentration through the activation of cannabinoid receptors. One of the best-known endocannabinoid ‘2-AG’ is chemically unstable in aqueous solutions, thus its molecular rearrangement, resulting in the formation of 1-AG, may influence 2-AG-mediated signaling depending on the relative concentration and potency of the two isomers.
To predict whether this molecular rearrangement may be relevant in physiological processes and in experiments with 2-AG, here we studied if isomerization of 2-AG has an impact on 2-AG-induced, CB1-mediated Ca2+ signaling in vitro.
We found that the isomerization-dependent drop in effective 2-AG concentration caused only a weak diminution of Ca2+ signaling in CB1 transfected COS7 cells. We also found that 1-AG induces Ca2+transients through the activation of CB1, but its working concentration is threefold higher than that of 2-AG. Decreasing the concentration of 2-AG in parallel to the prevention of 1-AG formation by rapid preparation of 2-AG solutions, caused a significant diminution of Ca2+ signals. However, various mixtures of the two isomers in a fix total concentration – mimicking the process of isomerization over time – attenuated the drop in 2-AG potency, resulting in a minor decrease in CB1 mediated Ca2+ transients.
Our results indicate that release of 2-AG into aqueous medium is accompanied by its isomerization, resulting in a drop of 2-AG concentration and simultaneous formation of the similarly bioactive isomer 1-AG. Thus, the relative concentration of the two isomers with different potency and efficacy may influence CB1 activation and the consequent biological responses.
In addition, our results suggest that may play role in stabilizing the strength of cannabinoid signal in case of prolonged 2-AG dependent cannabinoid mechanisms.”
Does Cannabidiol Protect Against Adverse Psychological Effects of THC?
“Tetrahydrocannabinol (THC) is the main psychoactive substance in cannabis. Cannabidiol (CBD) is a cannabinoid that appears in cannabis resin but rarely in herbal cannabis. In recent years, many positive attributes have been ascribed to CBD. Is cannabis that contains CBD less harmful than cannabis without CBD? Are people who smoke cannabis resin, therefore, less susceptible to psychosis or less likely to become addicted than are people who smoke herbal marijuana?
Delta-9-tetrahydrocannabinol (THC) is the main psychoactive constituent of cannabis, and most, if not all, of the effects associated with the use of cannabis are caused by THC. Recent studies have suggested a possible protective effect of another cannabinoid, cannabidiol (CBD).
Most recreational users will never be faced with persistent mental illness, but in some individuals cannabis use leads to undesirable effects: cognitive impairment, anxiety, paranoia, and increased risks of developing chronic psychosis or drug addiction.
Studies examining the protective effects of CBD have shown that CBD can counteract the negative effects of THC.
Few or no adverse effects of CBD have been proffered, and where CBD has been found to have an effect, it is usually in a “positive” (i.e., salubrious) direction. The evidence favoring a beneficial effect of CBD therefore merits further investigation in studies in which the amounts and ratios of CBD and THC correspond to the daily practices of recreational cannabis use.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3797438/
“Studies examining the protective effects of CBD have shown that CBD can counteract the negative effects of THC.” https://www.ncbi.nlm.nih.gov/pubmed/24137134
“CBD may also potentiate some of Δ9-THC’s beneficial effects as it reduces Δ9-THC’s psychoactivity to enhance its tolerability and widen its therapeutic window.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4707667/
Can we make cannabis safer?
“Cannabis use and related problems are on the rise globally alongside an increase in the potency of cannabis sold on both black and legal markets. Additionally, there has been a shift towards abandoning prohibition for a less punitive and more permissive legal stance on cannabis, such as decriminalisation and legalisation. It is therefore crucial that we explore new and innovative ways to reduce harm.
Research has found cannabis with high concentrations of its main active ingredient, δ-9-tetrahydrocannabinol (THC), to be more harmful (in terms of causing the main risks associated with cannabis use, such as addiction, psychosis, and cognitive impairment) than cannabis with lower concentrations of THC. By contrast, cannabidiol, which is a non-intoxicating and potentially therapeutic component of cannabis, has been found to reduce the negative effects of cannabis use.
Here, we briefly review findings from studies investigating various types of cannabis and discuss how future research can help to better understand and reduce the risks of cannabis use.” https://www.ncbi.nlm.nih.gov/pubmed/28259650
“Studies examining the protective effects of CBD have shown that CBD can counteract the negative effects of THC.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3797438/
“CBD may also potentiate some of Δ9-THC’s beneficial effects as it reduces Δ9-THC’s psychoactivity to enhance its tolerability and widen its therapeutic window.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4707667/
Cannabinoid signaling in health and disease.
“Cannabis sativa has long been used for medicinal purposes.
To improve safety and efficacy, compounds from C. sativa were purified or synthesized and named under an umbrella group as cannabinoids.
Currently, several cannabinoids may be prescribed in Canada for a variety of indications such as nausea and pain.
More recently, an increasing number of reports suggest other salutary effects associated with endogenous cannabinoid signaling including cardioprotection.
The therapeutic potential of cannabinoids is therefore extended; however, evidence is limited and mechanisms remain unclear.
In addition, the use of cannabinoids clinically has been hindered due to pronounced psychoactive side effects.
This review provides an overview on the endocannabinoid system, including known physiological roles, and conditions in which cannabinoid receptor signaling has been implicated.”
Cell-Autonomous Excitation of Midbrain Dopamine Neurons by Endocannabinoid-Dependent Lipid Signaling.
“The major endocannabinoid in the mammalian brain is the bioactive lipid 2-arachidonoylglycerol (2-AG). The best-known effects of 2-AG are mediated by G-protein-coupled cannabinoid receptors. In principle, 2-AG could modify neuronal excitability by acting directly on ion channels, but such mechanisms are poorly understood.
Using a preparation of dissociated mouse midbrain dopamine neurons to isolate effects on intrinsic excitability, we found that 100 nM 2-AG accelerated pacemaking and steepened the frequency-current relationship for burst-like firing. In voltage-clamp experiments, 2-AG reduced A-type potassium current (IA) through a cannabinoid receptor-independent mechanism mimicked by arachidonic acid, which has no activity on cannabinoid receptors. Activation of orexin, neurotensin, and metabotropic glutamate Gq/11-linked receptors mimicked the effects of exogenous 2-AG and their actions were prevented by inhibiting the 2-AG-synthesizing enzyme diacylglycerol lipase α.
The results show that 2-AG and related lipid signaling molecules can directly tune neuronal excitability in a cell-autonomous manner by modulating IA.”
Inflammatory Regulation by Driving Microglial M2 Polarization: Neuroprotective Effects of Cannabinoid Receptor-2 Activation in Intracerebral Hemorrhage.
“The cannabinoid receptor-2 (CB2R) was initially thought to be the “peripheral cannabinoid receptor.” Recent studies, however, have documented CB2R expression in the brain in both glial and neuronal cells, and increasing evidence suggests an important role for CB2R in the central nervous system inflammatory response.
Intracerebral hemorrhage (ICH), which occurs when a diseased cerebral vessel ruptures, accounts for 10-15% of all strokes. Although surgical techniques have significantly advanced in the past two decades, ICH continues to have a high mortality rate.
The aim of this study was to investigate the therapeutic effects of CB2R stimulation in acute phase after experimental ICH in rats and its related mechanisms.
These findings demonstrated that CB2R stimulation significantly protected the brain damage and suppressed neuroinflammation by promoting the acquisition of microglial M2 phenotype in acute stage after ICH.
Taken together, this study provided mechanism insight into neuroprotective effects by CB2R stimulation after ICH.”
Endocannabinoids: A Promising Impact for Traumatic Brain Injury.
“The endogenous cannabinoid (endocannabinoid) system regulates a diverse array of physiological processes and unsurprisingly possesses considerable potential targets for the potential treatment of numerous disease states, including two receptors (i.e., CB1 and CB2 receptors) and enzymes regulating their endogenous ligands N-arachidonoylethanolamine (anandamide) and 2-arachidonyl glycerol (2-AG).
Increases in brain levels of endocannabinoids to pathogenic events suggest this system plays a role in compensatory repair mechanisms.
Traumatic brain injury (TBI) pathology remains mostly refractory to currently available drugs, perhaps due to its heterogeneous nature in etiology, clinical presentation, and severity. Here, we review pre-clinical studies assessing the therapeutic potential of cannabinoids and manipulations of the endocannabinoid system to ameliorate TBI pathology.
Specifically, manipulations of endocannabinoid degradative enzymes (e.g., fatty acid amide hydrolase, monoacylglycerol lipase, and α/β-hydrolase domain-6), CB1and CB2 receptors, and their endogenous ligands have shown promise in modulating cellular and molecular hallmarks of TBI pathology such as; cell death, excitotoxicity, neuroinflammation, cerebrovascular breakdown, and cell structure and remodeling.
TBI-induced behavioral deficits, such as learning and memory, neurological motor impairments, post-traumatic convulsions or seizures, and anxiety also respond to manipulations of the endocannabinoid system.
As such, the endocannabinoid system possesses potential drugable receptor and enzyme targets for the treatment of diverse TBI pathology.
Yet, full characterization of TBI-induced changes in endocannabinoid ligands, enzymes, and receptor populations will be important to understand that role this system plays in TBI pathology.
Promising classes of compounds, such as the plant-derived phytocannabinoids, synthetic cannabinoids, and endocannabinoids, as well as their non-cannabinoid receptor targets, such as TRPV1 receptors, represent important areas of basic research and potential therapeutic interest to treat TBI.”
EFFECTS OF CANNABIDIOL IN HUNTINGTON’S DISEASE
“Cannabidiol (CBD) is a major nonpsychoactive cannabinoid of marijuana.
Based on reports indicating possible efficacy of CBD in dystonic movements, we tried CBD in three patients with Huntington’s disease (HD).
The patients;, aged 30 to 56, had HD of 7 to 12 years’ duration. Their condition has been slowly progressive and unresponsive to prior therapy with neuroleptics. Orally administered CBD was initiated at 300 mg/d and increased 1 week later to 600 mg/d for the next 3 weeks.
Mild improvement ( 5 to 15%) in the choreic movements was documented using the tongueprotrusion test and a chorea severity evaluation scale after the first week. Further improvement (20 to 40%) was noticed after the second week of CBD, and this remained stable for the following 2 weeks.
Except for transient, mild hypotension, no side effects were recorded, and laboratory tests were normal. Withdrawal of CBD after 48 hours resulted in return of choreic movements to the pre-CBD state.”
http://www.druglibrary.org/schaffer/hemp/medical/hunting1.htm