“The isolation and identification of the discrete plant cannabinoids in marijuana revived interest in analyzing historical therapeutic claims made for cannabis in clinical case studies and anecdotes. In particular, sources as old as the 11th and 15th centuries claimed efficacy for crude marijuana extracts in the treatment of convulsive disorders, prompting a particularly active area of preclinical research into the therapeutic potential of plant cannabinoids in epilepsy. Since that time, a large body of literature has accumulated describing the effects of several of the >100 individual plant cannabinoids in preclinical models of seizures, epilepsy, epileptogenesis, and epilepsy-related neuroprotection. We surveyed the literature for relevant reports of such plant cannabinoid effects and critically reviewed their findings. We found that acute CB1R agonism in simple models of acute seizures in rodents typically produces anti-convulsant effects whereas CB1R antagonists exert converse effects in the same models. However, when the effects of such ligands are examined in more complex models of epilepsy, epileptogenesis and neuroprotection, a less simplistic narrative emerges. Here, the complex interactions between (i) brain regions involved in a given model, (ii) relative contributions of endocannabinoid signaling to modulation of synaptic transmission in such areas, (iii) multi-target effects, (iv) cannabinoid type 1 and type 2 receptor signaling interactions and, (v) timing, (vi) duration and (vii) localization of ligand administration suggest that there is both anti-epileptic therapeutic potential and a pro-epileptic risk in up- and down-regulation of endocannabinoid signaling in the central nervous system. Factors such receptor desensitization and specific pharmacology of ligands used (e.g. full vs partial agonists and neutral antagonists vs inverse agonists) also appear to play an important role in the effects reported. Furthermore, the effects of several plant cannabinoids, most notably cannabidiol (CBD) and cannabidavarin (CBDV), in models of seizures, epilepsy, epileptogenesis, and neuroprotection are less ambiguous, and consistent with reports of therapeutically beneficial effects of these compounds in clinical studies. However, continued paucity of firm information regarding the therapeutic molecular mechanism of CBD/CBDV highlights the continued need for research in this area in order to identify as yet under-exploited targets for drug development and raise our understanding of treatment-resistant epilepsies. The recent reporting of positive results for cannabidiol treatment in two Phase III clinical trials in treatment-resistant epilepsies provides pivotal evidence of clinical efficacy for one plant cannabinoid in epilepsy. Moreover, risks and/or benefits associated with the use of unlicensed Δ9-THC containing marijuana extracts in pediatric epilepsies remain poorly understood. Therefore, in light of these paradigm-changing clinical events, the present review’s findings aim to drive future drug development for newly-identified targets and indications, identify important limitations of animal models in the investigation of plant cannabinoid effects in the epilepsies, and focuses future research in this area on specific, unanswered questions regarding the complexities of endocannabinoid signaling in epilepsy.” https://www.ncbi.nlm.nih.gov/pubmed/28190698]]>
Cannabidiol: an alternative therapeutic agent for oral mucositis?
“Chemo- and radiotherapy are therapeutic modalities often used in patients with malignant neoplasms. They kill tumour cells but act on healthy tissues as well, resulting in adverse effects. Oral mucositis is especially of concern, due to the morbidity that it causes.
We reviewed the literature on the etiopathogenesis of oral mucositis and the activity of cannabidiol, to consider the possibility of its use for the prevention and treatment of oral mucositis.
The control of oxidative stress may prevent and alleviate oral mucositis. Studies have demonstrated that cannabidiol is safe to use and possesses antioxidant, anti-inflammatory and analgesic properties. The literature on the use of cannabidiol in dentistry is still scarce. Studies investigating the use of cannabidiol in oral mucositis and other oxidative stress-mediated side effects of chemotherapy and radiotherapy on the oral mucosa should be encouraged.” https://www.ncbi.nlm.nih.gov/pubmed/28191662“Review: cannabidiol may be beneficial for oral mucositis. The researchers found evidence that oxidative stress control could prevent and relieve oral mucositis. Cannabidiol was found to be safe to use and demonstrated antioxidant, anti-inflammatory, and analgesic properties,” https://medicalxpress.com/news/2017-02-cannabidiol-beneficial-oral-mucositis.html
“Cannabidiol could be beneficial for the treatment of oral mucositis, according to a review published online Feb. 12 in the Journal of Clinical Pharmacy and Therapeutics.” http://www.bioportfolio.com/news/article/3029295/Review-cannabidiol-may-be-beneficial-for-oral-mucositis.html
Bladder cancer cell growth and motility implicate cannabinoid 2 receptor-mediated modifications of sphingolipids metabolism.
“The inhibitory effects demonstrated by activation of cannabinoid receptors (CB) on cancer proliferation and migration may also play critical roles in controlling bladder cancer (BC).
CB expression on human normal and BC specimens was tested by immunohistochemistry.
Human BC cells RT4 and RT112 were challenged with CB agonists and assessed for proliferation, apoptosis, and motility. Cellular sphingolipids (SL) constitution and metabolism were evaluated after metabolic labelling.
CB1-2 were detected in BC specimens, but only CB2 was more expressed in the tumour.
Both cell lines expressed similar CB2. Exposure to CB2 agonists inhibited BC growth, down-modulated Akt, induced caspase 3-activation and modified SL metabolism.
Baseline SL analysis in cell lines showed differences linked to unique migratory behaviours and cytoskeletal re-arrangements.
CB2 activation changed the SL composition of more aggressive RT112 cells by reducing (p < 0.01) Gb3 ganglioside (-50 ± 3%) and sphingosine 1-phosphate (S1P, -40 ± 4%), which ended up to reduction in cell motility (-46 ± 5%) with inhibition of p-SRC.
CB2-selective antagonists, gene silencing and an inhibitor of SL biosynthesis partially prevented CB2 agonist-induced effects on cell viability and motility.
CB2 activation led to ceramide-mediated BC cell apoptosis independently of SL constitutive composition, which instead was modulated by CB2 agonists to reduce cell motility.”
https://www.ncbi.nlm.nih.gov/pubmed/28191815
Differential Expression of Endocannabinoid System-Related Genes in the Dorsal Hippocampus following Expression and Reinstatement of Morphine Conditioned Place Preference in Mice.
“The endocannabinoid signaling plays a critical role in mediating rewarding effects to morphine. The relative stability for the expression and reinstatement of morphine conditioned place preference (CPP) suggests the involvement of differential neuroadaptations in learned associations between environmental cues and morphine. Changes in gene expression in hippocampus through the endogenous cannabinoid system (eCB) may accompany and mediate the development of such neuroadaptations to repeated morphine stimulation. To test this possibility, we systematically compared the expression of eCB-related genes in the dorsal hippocampus following the expression, extinction, and reinstatement of morphine CPP using quantitative RT-PCR analyses. These results suggest that differential regulation of the synthesis and/or degradation of the eCB system contribute to the expression and reinstatement of morphine CPP.” https://www.ncbi.nlm.nih.gov/pubmed/28192193]]>
Endocannabinoid-dependent protection against kainic acid-induced long-term alteration of brain oscillations in guinea pigs.
“Changes in rhythmic activity can serve as early biomarkers of pathological alterations, but it remains unclear how different types of rhythmic activity are altered during neurodegenerative processes. Glutamatergic neurotoxicity, evoked by kainic acid (KA), causes hyperexcitation and acute seizures that result in delayed brain damage. We employed wide frequency range (0.1-300 Hz) local field potential recordings in guinea pigs to study the oscillatory activity of the hippocampus, entorhinal cortex, medial septum, and amygdala in healthy animals for three months after KA introduction. To clarify whether the activation of endocannabinoid (eCB) system can influence toxic KA action, AM404, an eCB reuptake inhibitor, and URB597, an inhibitor of fatty acid amide hydrolase, were applied. Our results demonstrate the protective potential of the eCB system during excitotoxic influences.” https://www.ncbi.nlm.nih.gov/pubmed/28192082]]>
Potential of GPCRs to modulate MAPK and mTOR pathways in Alzheimer’s disease.
“Despite efforts to understand the mechanism of neuronal cell death, finding effective therapies for neurodegenerative diseases is still a challenge. Cognitive deficits are often associated with neurodegenerative diseases.
Remarkably, in the absence of consensus biomarkers, diagnosis of diseases such as Alzheimer’s still relies on cognitive tests. Unfortunately, all efforts to translate findings in animal models to the patients have been unsuccessful. Alzheimer’s disease may be addressed from two different points of view, neuroprotection or cognitive enhancement.
Based on recent data, the mammalian target of rapamycin (mTOR) pathway arises as a versatile player whose modulation may impact on mechanisms of both neuroprotection and cognition. Whereas direct targeting of mTOR does not seem to constitute a convenient approach in drug discovery, its indirect modulation by other signaling pathways seems promising.
In fact, G-protein-coupled receptors (GPCRs) remain the most common ‘druggable’ targets and as such pharmacological manipulation of GPCRs with selective ligands may modulate phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K), mitogen-activated protein (MAP) kinase and mTOR signaling pathways.
Thus, GPCRs become important targets for potential drug treatments in different neurodegenerative disorders including, but not limited to, Alzheimer’s disease. GPCR-mediated modulation of mTOR may take advantage of different GPRCs coupled to different G-dependent and G-independent signal transduction routes, of functional selectivity and/or of biased agonism. Signals mediated by GPCRs may act as coincidence detectors to achieve different benefits in different stages of the neurodegenerative disease.”
Potential of GPCRs to modulate MAPK and mTOR pathways in Alzheimer's disease.
“Despite efforts to understand the mechanism of neuronal cell death, finding effective therapies for neurodegenerative diseases is still a challenge. Cognitive deficits are often associated with neurodegenerative diseases. Remarkably, in the absence of consensus biomarkers, diagnosis of diseases such as Alzheimer’s still relies on cognitive tests. Unfortunately, all efforts to translate findings in animal models to the patients have been unsuccessful. Alzheimer’s disease may be addressed from two different points of view, neuroprotection or cognitive enhancement. Based on recent data, the mammalian target of rapamycin (mTOR) pathway arises as a versatile player whose modulation may impact on mechanisms of both neuroprotection and cognition. Whereas direct targeting of mTOR does not seem to constitute a convenient approach in drug discovery, its indirect modulation by other signaling pathways seems promising. In fact, G-protein-coupled receptors (GPCRs) remain the most common ‘druggable’ targets and as such pharmacological manipulation of GPCRs with selective ligands may modulate phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K), mitogen-activated protein (MAP) kinase and mTOR signaling pathways. Thus, GPCRs become important targets for potential drug treatments in different neurodegenerative disorders including, but not limited to, Alzheimer’s disease. GPCR-mediated modulation of mTOR may take advantage of different GPRCs coupled to different G-dependent and G-independent signal transduction routes, of functional selectivity and/or of biased agonism. Signals mediated by GPCRs may act as coincidence detectors to achieve different benefits in different stages of the neurodegenerative disease.” https://www.ncbi.nlm.nih.gov/pubmed/28189739]]>
Effects on Spasticity and Neuropathic Pain of an Oral Formulation of Δ9-Tetrahydrocannabinol in Patients With Progressive Multiple Sclerosis
“The aim of the present study was to evaluate the efficacy of an oral formulation of Δ9-tetrahydrocannabinol (ECP002A) in patients with progressive multiple sclerosis (MS). Pain was significantly reduced when measured directly after administration of ECP002A in the clinic but not when measured in a daily diary. A similar pattern was observed in subjective muscle spasticity. Other clinical outcomes were not significantly different between active treatment and placebo. Cognitive testing indicated that there was no decline in cognition after 2 or 4 weeks of treatment attributable to ECP002A compared with placebo. Implications This study specifically underlines the added value of thorough investigation of pharmacokinetic and pharmacodynamic associations in the target population. Despite the complex interplay of psychoactive effects and analgesia, the current oral formulation of Δ9-tetrahydrocannabinol may play a role in the treatment of spasticity and pain associated with MS because it was well tolerated and had a stable pharmacokinetic profile.” https://www.ncbi.nlm.nih.gov/pubmed/28189366]]>
Cannabinoids in treatment-resistant epilepsy: A review.
“Treatment-resistant epilepsy (TRE) affects 30% of epilepsy patients and is associated with severe morbidity and increased mortality. Cannabis-based therapies have been used to treat epilepsy for millennia, but only in the last few years have we begun to collect data from adequately powered placebo-controlled, randomized trials (RCTs) with cannabidiol (CBD), a cannabis derivative. Previously, information was limited to case reports, small series, and surveys reporting on the use of CBD and diverse medical marijuana (MMJ) preparations containing: tetrahydrocannabinol (THC), CBD, and many other cannabinoids in differing combinations. These RCTs have studied the safety and explored the potential efficacy of CBD use in children with Dravet Syndrome (DS) and Lennox-Gastaut Syndrome (LGS). The role of the placebo response is of paramount importance in studying medical cannabis products given the intense social and traditional media attention, as well as the strong beliefs held by many parents and patients that a natural product is safer and more effective than FDA-approved pharmaceutical agents. We lack valid data on the safety, efficacy, and dosing of artisanal preparations available from dispensaries in the 25 states and District of Columbia with MMJ programs and online sources of CBD and other cannabinoids. On the other hand, open-label studies with 100mg/ml CBD (Epidiolex®, GW Pharmaceuticals) have provided additional evidence of its efficacy along with an adequate safety profile (including certain drug interactions) in children and young adults with a spectrum of TREs. Further, Phase 3 RCTs with Epidiolex support efficacy and adequate safety profiles for children with DS and LGS at doses of 10- and 20-mg/kg/day. This article is part of a Special Issue titled “Cannabinoids and Epilepsy”.” https://www.ncbi.nlm.nih.gov/pubmed/28188044]]>
Cannabinoids activate monoaminergic signaling to modulate key C. elegans behaviors.
“Cannabis or marijuana, a popular recreational drug, alters sensory perception and exerts a range of potential medicinal benefits. The present study demonstrates that the endogenous cannabinoid receptor agonists, 2-arachidonoylglycerol (2-AG) and anandamide (AEA) activate a canonical cannabinoid receptor in C. elegans and also modulate monoaminergic signaling at multiple levels. 2-AG or AEA inhibit nociception and feeding through a pathway requiring the cannabinoid-like receptor, NPR-19. 2-AG or AEA activate NPR-19 directly and cannabinoid-dependent inhibition can be rescued in npr-19 null animals by the expression of a human cannabinoid receptor, CB1, highlighting the orthology of the receptors. Cannabinoids also modulate nociception and locomotion through an NPR-19-independent pathway requiring an α2A-adrenergic-like octopamine receptor, OCTR-1, and a 5-HT1A-like receptor, SER-4, that involves a complex interaction among cannabinoid, octopaminergic and serotonergic signaling. 2-AG activates OCTR-1 directly. In contrast, 2-AG does not activate SER-4 directly, but appears to enhance SER-4-dependent serotonergic signaling by increasing endogenous 5-HT. This study defines a conserved cannabinoid signaling system in C. elegans, demonstrates the cannabinoid-dependent activation of monoaminergic signaling and highlights the advantages of studying cannabinoid signaling in a genetically-tractable whole animal model. SIGNIFICANCE STATEMENTCannabis sativa causes euphoria and exerts a wide range of medicinal benefits. For years, cannabinoids have been studied at the cellular level using tissue explants with conflicting results. To better understand cannabinoid signaling, we have used the C. elegans model to examine the effects of cannabinoids on behavior. The present study demonstrates that mammalian cannabinoid receptor ligands activate a conserved cannabinoid signaling system in C. elegans and also modulate monoaminergic signaling, potentially impacting an array of disorders, including anxiety and depression. This study highlights the potential role of cannabinoids in modulating monoaminergic signaling, and the advantages of studying cannabinoid signaling in a genetically-tractable, whole-animal model.” https://www.ncbi.nlm.nih.gov/pubmed/28188220]]>