Assessing the role of serotonergic receptors in cannabidiol’s anticonvulsant efficacy.

“Cannabidiol (CBD) is a phytocannabinoid that has demonstrated anticonvulsant efficacy in several animal models of seizure. The current experiment validated CBD’s anticonvulsant effect using the acute pentylenetetrazol (PTZ) model.

While this work further confirms the anticonvulsant efficacy of CBD and supports its application in the treatment of human seizure disorders, additional research on CBD’s mechanism of action must be conducted.”

https://www.ncbi.nlm.nih.gov/pubmed/28624721

http://www.epilepsybehavior.com/article/S1525-5050(17)30122-1/fulltext

Quality of Life in Childhood Epilepsy in pediatric patients enrolled in a prospective, open-label clinical study with cannabidiol.

Epilepsia

“Recent clinical trials indicate that cannabidiol (CBD) may reduce seizure frequency in pediatric patients with certain forms of treatment-resistant epilepsy. Many of these patients experience significant impairments in quality of life (QOL) in physical, mental, and social dimensions of health. In this study, we measured the caregiver-reported Quality of Life in Childhood Epilepsy (QOLCE) in a subset of patients enrolled in a prospective, open-label clinical study of CBD. Results from caregivers of 48 patients indicated an 8.2 ± 9.9-point improvement in overall patient QOLCE (p < 0.001) following 12 weeks of CBD. Subscores with improvement included energy/fatigue, memory, control/helplessness, other cognitive functions, social interactions, behavior, and global QOL. These differences were not correlated to changes in seizure frequency or adverse events. The results suggest that CBD may have beneficial effects on patient QOL, distinct from its seizure-reducing effects; however, further studies in placebo-controlled, double-blind trials are necessary to confirm this finding.”

https://www.ncbi.nlm.nih.gov/pubmed/28617940

http://onlinelibrary.wiley.com/doi/10.1111/epi.13815/abstract

A single dose of cannabidiol reduces blood pressure in healthy volunteers in a randomized crossover study.

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“Cannabidiol (CBD) is a nonpsychoactive phytocannabinoid used in multiple sclerosis and intractable epilepsies. Preclinical studies show CBD has numerous cardiovascular benefits, including a reduced blood pressure (BP) response to stress. The aim of this study was to investigate if CBD reduces BP in humans.

CONCLUSIONS:

This data shows that acute administration of CBD reduces resting BP and the BP increase to stress in humans, associated with increased HR. These hemodynamic changes should be considered for people taking CBD. Further research is required to establish whether CBD has a role in the treatment of cardiovascular disorders.”

https://www.ncbi.nlm.nih.gov/pubmed/28614793

“Our data show that a single dose of CBD reduces resting blood pressure and the blood pressure response to stress. This may reflect the anxiolytic and analgesic effects of CBD, as well as any potential direct cardiovascular effects. CBD has multiple desirable effects on the cardiovascular system” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5470879/

https://insight.jci.org/articles/view/93760

Cannabidiol upregulates melanogenesis through CB1 dependent pathway by activating p38 MAPK and p42/44 MAPK.

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“Melanogenesis plays a critical role in the protection of skin against external stresses such as ultraviolet irradiation and oxidative stressors. This study was aimed to investigate the effects of cannabidiol on melanogenesis and its mechanisms of action in human epidermal melanocytes. We found that cannabidiol increased both melanin content and tryrosinase activity. The mRNA levels of microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein (TRP) 1, and TRP2 were increased following cannabidiol treatment. Likewise, cannabidiol increased the protein levels of MITF, TRP 1, TRP 2, and tyrosinase. Mechanistically, we found that cannabidiol regulated melanogenesis by upregulating MITF through phosphorylation of p38 mitogen-activated protein kinase (MAPK) and p42/44 MAPK, independent of cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) signaling. In addition, the melanogenic effect of cannabidiol was found to be mediated by cannabinoid CB1 receptor, not by CB2receptor. Taken together, these findings indicate that cannabidiol-induced melanogenesis is cannabinoid CB1 receptor-dependent, and cannabidiol induces melanogenesis through increasing MITF gene expression which is mediated by activation of p38 MAPK and p42/44 MAPK. Our results suggest that cannabidiol might be useful as a protective agent against external stresses.”

https://www.ncbi.nlm.nih.gov/pubmed/28601556

http://www.sciencedirect.com/science/article/pii/S0009279716304343

Regulation of human glioblastoma cell death by combined treatment of cannabidiol, γ-radiation and small molecule inhibitors of cell signaling pathways.

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“Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. The challenging problem in cancer treatment is to find a way to upregulate radiosensitivity of GBM while protecting neurons and neural stem/progenitor cells in the brain. The goal of the present study was upregulation of the cytotoxic effect of γ-irradiation in GBM by non-psychotropic and non-toxic cannabinoid, cannabidiol (CBD).

We emphasized three main aspects of signaling mechanisms induced by CBD treatment (alone or in combination with γ-irradiation) in human GBM that govern cell death: 1) CBD significantly upregulated the active (phosphorylated) JNK1/2 and MAPK p38 levels with the subsequent downregulation of the active phospho-ERK1/2 and phospho-AKT1 levels. MAPK p38 was one of the main drivers of CBD-induced cell death, while death levels after combined treatment of CBD and radiation were dependent on both MAPK p38 and JNK. Both MAPK p38 and JNK regulate the endogenous TRAIL expression. 2) NF-κB p65-P(Ser536) was not the main target of CBD treatment and this transcription factor was found at high levels in CBD-treated GBM cells. Additional suppression of p65-P(Ser536) levels using specific small molecule inhibitors significantly increased CBD-induced apoptosis. 3) CBD treatment substantially upregulated TNF/TNFR1 and TRAIL/TRAIL-R2 signaling by modulation of both ligand and receptor levels followed by apoptosis.

Our results demonstrate that radiation-induced death in GBM could be enhanced by CBD-mediated signaling in concert with its marginal effects for neural stem/progenitor cells and astrocytes. It will allow selecting efficient targets for sensitization of GBM and overcoming cancer therapy-induced severe adverse sequelae.”

Plastic and Neuroprotective Mechanisms Involved in the Therapeutic Effects of Cannabidiol in Psychiatric Disorders.

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“Beneficial effects of cannabidiol (CBD) have been described for a wide range of psychiatric disorders, including anxiety, psychosis, and depression. The mechanisms responsible for these effects, however, are still poorly understood. Similar to clinical antidepressant or atypical antipsychotic drugs, recent findings clearly indicate that CBD, either acutely or repeatedly administered, induces plastic changes. For example, CBD attenuates the decrease in hippocampal neurogenesis and dendrite spines density induced by chronic stress and prevents microglia activation and the decrease in the number of parvalbumin-positive GABA neurons in a pharmacological model of schizophrenia. More recently, it was found that CBD modulates cell fate regulatory pathways such as autophagy and others critical pathways for neuronal survival in neurodegenerative experimental models, suggesting the potential benefit of CBD treatment for psychiatric/cognitive symptoms associated with neurodegeneration. These changes and their possible association with CBD beneficial effects in psychiatric disorders are reviewed here.”

https://www.ncbi.nlm.nih.gov/pubmed/28588483

http://journal.frontiersin.org/article/10.3389/fphar.2017.00269/full

Medicinal Uses of Marijuana and Cannabinoids

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“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/

In Vivo Cannabidiol Treatment Improves Endothelium-Dependent Vasorelaxation in Mesenteric Arteries of Zucker Diabetic Fatty Rats.

 

 

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“We have shown that in vitro treatment with cannabidiol (CBD, 2 h) enhances endothelial function in arteries from Zucker diabetic fatty (ZDF) rats, partly due to a cyclooxygenase (COX)-mediated mechanism.

The aim of the present study was to determine whether treatment with CBD in vivo would also enhance endothelial function.

Conclusion and implications: Short-term in vivo treatment with CBD improves ex vivo endothelium-dependent vasorelaxation in mesenteric arteries from ZDF rats due to COX- or NO-mediated mechanisms, and leads to improvements in serum biomarkers.”  https://www.ncbi.nlm.nih.gov/pubmed/28572770

“In conclusion, this study has shown that a short in vivo treatment protocol with CBD was associated with improvements in endothelium-dependent vasorelaxation in mesenteric arteries, and an improvement in the profile of cardiovascular and metabolic parameters. The current study supports the growing evidence that CBD may be beneficial against a number of problems associated with diabetes including inflammation, endothelial dysfunction, cardiomyopathy, retinal function, and neuropathic pain.”  http://journal.frontiersin.org/article/10.3389/fphar.2017.00248/full

GPR3 and GPR6, novel molecular targets for cannabidiol.

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“GPR3 and GPR6 are members of a family of constitutively active, Gs protein-coupled receptors. Previously, it has been reported that GPR3 is involved in Alzheimer’s disease whereas GPR6 plays potential roles in Parkinson’s disease.

GPR3 and GPR6 are considered orphan receptors because there are no confirmed endogenous agonists for them. However, GPR3 and GPR6 are phylogenetically related to the cannabinoid receptors.

In this study, the activities of endocannabinoids and phytocannabinoids were tested on GPR3 and GPR6 using a β-arrestin2 recruitment assay. Among the variety of cannabinoids tested, cannabidiol (CBD), the major non-psychoactive component of marijuana, significantly reduced β-arrestin2 recruitment to both GPR3 and GPR6. In addition, the inhibitory effects of CBD on β-arrestin2 recruitment were concentration-dependent for both GPR3 and GPR6, with a higher potency for GPR6.

These data show that CBD acts as an inverse agonist at both GPR3 and GPR6 receptors. These results demonstrate for the first time that both GPR3 and GPR6 are novel molecular targets for CBD.

Our discovery that CBD acts as a novel inverse agonist on both GPR3 and GPR6 indicates that some of the potential therapeutic effects of CBD (e.g. treatment of Alzheimer’s disease and Parkinson’s disease) may be mediated through these important receptors.”

https://www.ncbi.nlm.nih.gov/pubmed/28571738

http://www.sciencedirect.com/science/article/pii/S0006291X17310744

Anticancer effects of phytocannabinoids used with chemotherapy in leukaemia cells can be improved by altering the sequence of their administration.

Journal Cover

“Phytocannabinoids possess anticancer activity when used alone, and a number have also been shown to combine favourably with each other in vitro in leukaemia cells to generate improved activity.

We have investigated the effect of pairing cannabinoids and assessed their anticancer activity in cell line models. Those most effective were then used with the common anti-leukaemia drugs cytarabine and vincristine, and the effects of this combination therapy on cell death studied in vitro.

Results show a number of cannabinoids could be paired together to generate an effect superior to that achieved if the components were used individually.

For example, in HL60 cells, the IC50 values at 48 h for cannabidiol (CBD) and tetrahydrocannabinol (THC) when used alone were 8 and 13 µM, respectively; however, if used together, it was 4 µM. Median-effect analysis confirmed the benefit of using cannabinoids in pairs, with calculated combination indices being <1 in a number of cases.

The most efficacious cannabinoid-pairs subsequently synergised further when combined with the chemotherapy agents, and were also able to sensitise leukaemia cells to their cytotoxic effects.

The sequence of administration of these drugs was important though; using cannabinoids after chemotherapy resulted in greater induction of apoptosis, whilst this was the opposite when the schedule of administration was reversed.

Our results suggest that when certain cannabinoids are paired together, the resulting product can be combined synergistically with common anti-leukaemia drugs allowing the dose of the cytotoxic agents to be dramatically reduced yet still remain efficacious. Nevertheless, the sequence of drug administration is crucial to the success of these triple combinations and should be considered when planning such treatments.”