Cannabinoids in treatment-resistant epilepsy: A review

Comparison of various doses of oral cannabidiol for treating refractory epilepsy indications: a network meta-analysis

Aim

To evaluate the comparative efficacy and safety of various doses of oral cannabidiol (CBD) in treating refractory epilepsy indications, thus providing more informative evidence for clinical decision-making.

Methods

A literature search of PubMed, Embase, the Cochrane library, and Web of Science (WoS) was performed to retrieve relevant randomized controlled trials (RCTs) that compared different doses of oral CBD with placebo or each other in refractory epilepsy indications. The search was limited from the inception of each database to January 3, 2023. Relative risk [RR] with a 95% confidence interval [CI] was used to express results. STATA/SE 14 was employed for network meta-analysis.

Results

Six RCTs involving 972 patients were included in the final data analysis. Network meta-analysis showed that, CBD10 (10 mg/kg/day) (RR: 1.77, 95%CI: 1.28 to 2.44), CBD20 (20 mg/kg/day) (RR: 1.91, 95%CI: 1.49 to 2.46), CBD25 (25 mg/kg/day) (RR: 1.61, 95%CI: 0.96 to 2.70), and CBD50 (50 mg/kg/day) (RR: 1.78, 95%CI: 1.07 to 2.94) were associated with higher antiseizure efficacy although the pooled result for CBD25 was only close to significant. In addition, in terms of the risk of treatment-emergent adverse events (TEAEs), the difference between different doses is not significant. However, CBD20 ranked first in terms of antiseizure efficacy, followed by CBD50, CBD10, and CBD25. For TEAEs, CBD25 ranked first, followed by CBD10, CBD50, CBD5, and CBD20.

Conclusion

For refractory indications, CBD20 may be optimal option for antiseizure efficacy; however, CBD25 may be best for TEAEs. Therefore, an appropriate dose of oral CBD should be selected based on the actual situation. Due to the limitations of eligible studies and the limited sample size, more studies are needed in the future to validate our findings.

Potential perioperative cardiovascular outcomes in cannabis/cannabinoid users. A call for caution

Background

Cannabis is one of the most widely used psychoactive substances. Its components act through several pathways, producing a myriad of side effects, of which cardiovascular events are the most life-threatening. However, only a limited number of studies address cannabis's perioperative impact on patients during noncardiac surgery.

Methods

Studies were identified by searching the PubMed, Medline, EMBASE, and Google Scholar databases using relevant keyword combinations pertinent to the topic.

Results

Current evidence shows that cannabis use may cause several cardiovascular events, including abnormalities in cardiac rhythm, myocardial infarction, heart failure, and cerebrovascular events. Additionally, cannabis interacts with anticoagulants and antiplatelet agents, decreasing their efficacy. Finally, the interplay of cannabis with inhalational and intravenous anesthetic agents may lead to adverse perioperative cardiovascular outcomes.

Conclusions

The use of cannabis can trigger cardiovascular events that may depend on factors such as the duration of consumption, the route of administration of the drug, and the dose consumed, which places these patients at risk of drug-drug interactions with anesthetic agents. However, large prospective randomized clinical trials are needed to further elucidate gaps in the body of knowledge regarding which patient population has a greater risk of perioperative complications after cannabis consumption.

Potential of CBD Acting on Cannabinoid Receptors CB1 and CB2 in Ischemic Stroke

Stroke is one of the leading causes of death. It not only affects adult people but also many children. It is estimated that, every year, 15 million people suffer a stroke worldwide. Among them, 5 million people die, while 5 million people are left permanently disabled. In this sense, the research to find new treatments should be accompanied with new therapies to combat neuronal death and to avoid developing cognitive impairment and dementia. Phytocannabinoids are among the compounds that have been used by mankind for the longest period of history. Their beneficial effects such as pain regulation or neuroprotection are widely known and make them possible therapeutic agents with high potential. These compounds bind cannabinoid receptors CB1 and CB2. Unfortunately, the psychoactive side effect has displaced them in the vast majority of areas. Thus, progress in the research and development of new compounds that show efficiency as neuroprotectors without this psychoactive effect is essential. On the one hand, these compounds could selectively bind the CB2 receptor that does not show psychoactive effects and, in glia, has opened new avenues in this field of research, shedding new light on the use of cannabinoid receptors as therapeutic targets to combat neurodegenerative diseases such as Alzheimer's, Parkinson's disease, or stroke. On the other hand, a new possibility lies in the formation of heteromers containing cannabinoid receptors. Heteromers are new functional units that show new properties compared to the individual protomers. Thus, they represent a new possibility that may offer the beneficial effects of cannabinoids devoid of the unwanted psychoactive effect. Nowadays, the approval of a mixture of CBD (cannabidiol) and Δ9-THC (tetrahydrocannabinol) to treat the neuropathic pain and spasticity in multiple sclerosis or purified cannabidiol to combat pediatric epilepsy have opened new therapeutic possibilities in the field of cannabinoids and returned these compounds to the front line of research to treat pathologies as relevant as stroke.

Assessment of the Novel Anti-Seizure Potential of Validamycin A Using Zebrafish Epilepsy Model

Epilepsy is a prevalent neurological disorder characterized by recurrent seizures. Validamycin A (VA) is an antibiotic fungicide that inhibits trehalase activity and is widely used for crop protection in agriculture. In this study, we identified a novel function of VA as a potential anti-seizure medication in a zebrafish epilepsy model. Electroencephalogram (EEG) analysis demonstrated that VA reduced pentylenetetrazol (PTZ)-induced seizures in the brains of larval and adult zebrafish. Moreover, VA reduced PTZ-induced irregular movement in a behavioral assessment of adult zebrafish. The developmental toxicity test showed no observable anatomical alteration when the zebrafish larvae were treated with VA up to 10 µM within the effective range. The median lethal dose of VA in adult zebrafish was > 14,000 mg/kg. These results imply that VA does not demonstrate observable toxicity in zebrafish at concentrations effective for generating anti-seizure activity in the EEG and alleviating abnormal behavior in the PTZ-induced epileptic model. Furthermore, the effectiveness of VA was comparable to that of valproic acid. These results indicate that VA may have a potentially safer anti-seizure profile than valproic acid, thus offering promising prospects for its application in agriculture and medicine.

Treating Hyperexcitability in Human Cerebral Organoids Resulting from Oxygen-Glucose Deprivation

Human cerebral organoids resemble the 3D complexity of the human brain and have the potential to augment current drug development pipelines for neurological disease. Epilepsy is a complex neurological condition characterized by recurrent seizures. A third of people with epilepsy do not respond to currently available pharmaceutical drugs, and there is not one drug that treats all subtypes; thus, better models of epilepsy are needed for drug development. Cerebral organoids may be used to address this unmet need. In the present work, human cerebral organoids are used along with electrophysiological methods to explore oxygen-glucose deprivation as a hyperexcitability agent. This activity is investigated in its response to current antiseizure drugs. Furthermore, the mechanism of action of the drug candidates is probed with qPCR and immunofluorescence. The findings demonstrate OGD-induced hyperexcitable changes in the cerebral organoid tissue, which is treated with cannabidiol and bumetanide. There is evidence for NKCC1 and KCC2 gene expression, as well as other genes and proteins involved in the complex development of GABAergic signaling. This study supports the use of organoids as a platform for modelling cerebral cortical hyperexcitability that could be extended to modelling epilepsy and used for drug discovery.

Genome-wide DNA methylation association study of recent and cumulative marijuana use in middle aged adults

Marijuana is a widely used psychoactive substance in the US and medical and recreational legalization has risen over the past decade. Despite the growing number of individuals using marijuana, studies investigating the association between epigenetic factors and recent and cumulative marijuana use remain limited. We therefore investigated the association between recent and cumulative marijuana use and DNA methylation levels. Participants from the Coronary Artery Risk Development in Young Adults Study with whole blood collected at examination years (Y) 15 and Y20 were randomly selected to undergo DNA methylation profiling at both timepoints using the Illumina MethylationEPIC BeadChip. Recent use of marijuana was queried at each examination and used to estimate cumulative marijuana use from Y0 to Y15 and Y20. At Y15 (n = 1023), we observed 22 and 31 methylation markers associated (FDR P ≤ 0.05) with recent and cumulative marijuana use and 132 and 16 methylation markers at Y20 (n = 883), respectively. We replicated 8 previously reported methylation markers associated with marijuana use. We further identified 640 cis-meQTLs and 198 DMRs associated with recent and cumulative use at Y15 and Y20. Differentially methylated genes were statistically overrepresented in pathways relating to cellular proliferation, hormone signaling, and infections as well as schizophrenia, bipolar disorder, and substance-related disorders. We identified numerous methylation markers, pathways, and diseases associated with recent and cumulative marijuana use in middle-aged adults, providing additional insight into the association between marijuana use and the epigenome. These results provide novel insights into the role marijuana has on the epigenome and related health conditions.

Non-psychoactive Cannabidiol Prevents Osteoporosis in an Animal Model and Increases Cell Viability, Proliferation, and Osteogenic Gene Expression in Human Skeletal Stem and Progenitor Cells

Cannabidiol (CBD), the non-psychoactive component of the Cannabis sativa plant, is marketed as a potential therapeutic agent and has been studied for its roles in reducing inflammation and managing neuropathic pain. Some studies have reported that CB1 and CB2 receptor activation can attenuate and reverse bone loss in experimental animal models. Despite this, little is known about the impact of CBD on fracture healing. We investigated the effects of CBD in vitro using human osteoprogenitor cells and in vivo via murine femur fracture and osteoporosis models. In vitro mesenchymal stem cells were treated with increasing concentrations of crystalized pharmaceutical grade CBD or vehicle solution. Cell viability and proliferation were significantly increased in cells treated with CBD compared to vehicle control. Osteocalcin expression was also significantly higher in the CBD-treated human stem cells compared to vehicle control. In vivo the effect of CBD on bone mineral density and fracture healing in mice was examined using a two-phase experimental approach. Fluoxetine was used for pharmacologic induction of osteoporosis and surgical oophorectomy (OVX) was used for hormonal induction of osteoporosis. X-ray and microCT analysis showed that CBD prevented both fluoxetine- and OVX-induced osteoporosis. We found that while OVX resulted in delayed bone healing in control mice, CBD-pretreated mice exhibited normal bone healing. Collectively these in vitro and in vivo findings suggest that CBD exerts cell-specific effects which can be exploited to enhance bone metabolism. These findings also indicate that CBD usage in an osteoporotic population may positively impact bone morphology, warranting further research.

NETWORK ANALYSIS REVEALS A ROLE OF THE HIPPOCAMPUS IN ABSENCE SEIZURES: THE EFFECTS OF A CANNABINOID AGONIST

The role of the hippocampus (Hp) in absence epileptic networks and the effect of endocannabinoid system on this network remain enigmatic. Here, using adapted nonlinear Granger causality, we compared the differences in network strength in four intervals (baseline or interictal, preictal, ictal and postictal) in two hours before (Epoch 1) and six hours (epochs 2, 3 and 4) after the administration of three different doses of the endocannabinoid agonist WIN55,212-2 (WIN) or solvent. Local field potentials were recorded for eight hours in 23 WAG/Rij rats in the Frontal (FC), Parietal PC), Occipital Cortex (OC) and in the hippocampus (Hp). The four intervals were visually marked by an expert neurophysiologist and the strength of couplings between electrode pairs were calculated in both directions. Ictally, a strong decrease in coupling strength was found between Hp and FC, as well as a large increase bidirectionally between PC and FC and unidirectionally from FC and PC to OC, and from FC to Hp over all epochs. The highest dose of WIN increased the couplings strength from FC to Hp and from OC to PC during 4 and 2 hr respectively in all intervals, and decreased the FC to PC coupling strength postictally in epoch 2. A single rat showed generalized convulsive seizures after the highest dose: this rat shared not only coupling changes with the other rats in the same condition, but showed many more. WIN reduced SWD number in epoch 2 and 3, their mean duration increased in epochs 3 and 4. Conclusions:during SWDs FC and PC are strongly coupled and drive OC, while at the same time the influence of Hp to FC is diminished. The first is in agreement with the cortical focus theory, the latter demonstrates an involvement of the hippocampus in SWD occurrence and that ictally the hippocampal control of the cortico-thalamo-cortical system is lost. WIN causes dramatic network changes which have major consequences for the decrease of SWDs, the occurrence of convulsive seizures, and the normal cortico-cortical and cortico-hippocampal interactions.

The effects of cannabidiol and Δ9-tetrahydrocannabinol, alone and in combination, in the maximal electroshock seizure model

In the present study, cannabidiol (CBD), Δ9-tetrahydrocannabinol (THC), and combinations of CBD and THC, were evaluated in the mouse maximal electroshock (MES) seizure test - an animal model of generalized-onset seizures. Male CF-1 mice were injected intraperitoneally (i.p.) with either CBD, THC or a combination of CBD and THC. The MES test was conducted 2 h after the injection of CBD and 1 h after the injection of THC. A wide range of doses was tested to allow the construction of dose-response curves. Toxicity was assessed using a behavioral rating scale. It was found that: 1) the ED₅₀ for THC alone was 52 mg/kg and its therapeutic index (TI) was 1.7; 2) the ED₅₀ for CBD alone was 190 mg/kg and its TI was 2.4; and 3) the ED₅₀ for a 15:1 combination of CBD+THC was 130 mg/kg + 8.6 mg/kg (CBD + THC). Thus, CBD and THC were both effective in the MES model, and CBD was somewhat more effective in the presence of low (non-therapeutic) doses of THC. The improvement in CBD's effect, however, was less dramatic than that seen in past experiments with the amygdala-kindling model (Fallah et al., 2021). Both CBD alone and CBD+THC in combination might be useful in the treatment of generalized-onset seizures. The advantage of adding THC to CBD, however, might be less than in the treatment of focal-onset seizures.

Therapeutic and clinical foundations of cannabidiol therapy for difficult-to-treat seizures in children and adults with refractory epilepsies

Novel and effective antiseizure medications are needed to treat refractory and rare forms of epilepsy. Cannabinoids, which are obtained from the cannabis plant, have a long history of medical use, including for neurologic conditions. In 2018, the US Food and Drug Administration approved the first phytocannabinoid, cannabidiol (CBD, Epidiolex), which is now indicated for severe seizures associated with three rare forms of developmental and epileptic encephalopathy: Dravet syndrome, Lennox-Gastaut syndrome, and tuberous sclerosis complex. Compelling evidence supports the efficacy of CBD in experimental models and patients with epilepsy. In randomized clinical trials, highly-purified CBD has demonstrated efficacy with an acceptable safety profile in children and adults with difficult-to-treat seizures. Although the underlying antiseizure mechanisms of CBD in humans have not yet been elucidated, the identification of novel antiseizure targets of CBD preclinically indicates multimodal mechanisms that include non-cannabinoid pathways. In addition to antiseizure effects, CBD possesses strong anti-inflammatory and neuroprotective activities, which might contribute to protective effects in epilepsy and other conditions. This article provides a succinct overview of therapeutic approaches and clinical foundations of CBD, emphasizing the clinical utility of CBD for the treatment of seizures associated with refractory and rare epilepsies. CBD has shown to be a safe and effective antiseizure medicine, demonstrating a broad spectrum of efficacy across multiple seizure types, including those associated with severe epilepsies with childhood onset. Despite such promise, there are many perils with CBD that hampers its widespread use, including limited understanding of pharmacodynamics, limited exposure-response relationship, limited information for seizure freedom with continued use, complex pharmacokinetics with drug interactions, risk of adverse effects, and lack of expert therapeutic guidelines. These scientific issues need to be resolved by further investigations, which would decide the unique role of CBD in the management of refractory epilepsy.

Dispensary Cannabidiol (CBD): Nothing to Worry About!

Introduction: Despite US FDA approval of cannabidiol (CBD) liquid (Epidiolex®), patients with epilepsy still supplement prescription treatments with dispensary CBD. This study aimed to evaluate therapeutic effectiveness of dispensary CBD. Methods: We retrospectively collected dosage information, CBD serum levels, efficacy, and adverse effects from patient charts (children, adolescents, adults) (n = 18). Results: All 18 patients showed no clinical benefit from dispensary CBD as detectable serum levels never reached a therapeutic range of 150 ng/mL (6 patients had barely detectable levels that were below laboratory reporting thresholds). Minute levels of tetrahydrocannabinol (THC) were found in 3 patients, and moderate levels were found in 1 patient. Conclusion: Dispensary CBD failed to reach effective therapeutic levels in all of these patients. The presence of THC demonstrates the current lack of regulation of dispensary CBD. Anecdotal reports of clinical effectiveness should be considered an effect of concomitant prescription antiseizure medications and not dispensary CBD.

Use of non-medical cannabis in epilepsy: A scoping review

Objective

The use of medical cannabis among people with epilepsy (PWE) has been garnering increasing interest. In this scoping review, we aimed to summarize the literature on recreational/non-medical cannabis (NMC) use in PWE, focusing on the experience, habits, and beliefs of PWE regarding NMC.

Methods

Four databases (OVID Medline, OVID Embase, Ovid APA PsycInfo, and Web of Science) were searched for studies describing NMC use in PWE. NMC was defined as cannabis products procured from sources other than by prescription. Studies that consisted in original research and that detailed the experience, habits, and/or beliefs of PWE regarding NMC use were included in the analysis. Data pertaining to study identification, demographics, NMC use, and epilepsy characteristics were extracted. Descriptive statistical analyses and reflexive thematic analyses were performed to map these data.

Results

In total, 3,228 records were screened, and 66 were included for analysis: 45 had mainly adult samples, whereas 21 had mainly pediatric samples. Most studies were published after 2010, originated from the USA, and were cross-sectional. The median number of PWE using cannabis in these studies was 24.5 (1-37,945). No studies showcased elderly PWE, and most had predominantly Caucasian samples. The lifetime prevalence of NMC use in PWE was variable, ranging between 0.69 and 76.8%. Factors frequently associated with NMC use in PWE were male sex, younger adult age, and lower education status. Children with epilepsy took NMC primarily for seizure control, using high CBD/THC ratios, and only orally. Adults with epilepsy took NMC for various reasons including recreationally, using variable CBD/THC ratios, and predominantly through smoking. The majority of PWE across all studies perceived that NMC aided in seizure control. Other aspects pertaining to NMC use in PWE were rarely reported and often conflicting.

Conclusion

The literature on NMC use in PWE is sparse and heterogeneous, with many salient knowledge gaps. Further research is necessary to better understanding the experience, habits, and beliefs of PWE pertaining to NMC.

Differential Enantiomer-Specific Signaling of Cannabidiol at CB1 Receptors

The two main constituents of cannabis are Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). While Δ9-THC pharmacology has been studied extensively, CBD-long considered inactive-is now the subject of vigorous research related to epilepsy, pain, and inflammation and is popularly embraced as a virtual cure-all. However, our understanding of CBD pharmacology remains limited, although CBD inhibits cannabinoid CB1 receptor signaling, likely as a negative allosteric modulator. Cannabis synthesizes (-)-CBD, but CBD can also exist as an enantiomer, (+)-CBD. We enantioselectively synthesized both CBD enantiomers using established conditions and describe here a new, practical, and reliable, NMR-based method for confirming the enantiomeric purity of two CBD enantiomers. We also investigated the pharmacology of (+)-CBD in autaptic hippocampal neurons, a well-characterized neuronal model of endogenous cannabinoid signaling, and in CHO-K1 cells. We report the inhibition constant for displacing CP55,940 at CB1 by (+)-CBD, is 5-fold lower than (-)-CBD. We find that (+)-CBD is ∼10 times more potent at inhibiting depolarization-induced suppression of excitation (DSE), a form of endogenous cannabinoid-mediated retrograde synaptic plasticity. (+)-CBD also inhibits CB1 suppression of cAMP accumulation but with less potency, indicating that the signaling profiles of the enantiomers differ in a pathway-specific manner. In addition, we report that (+)-CBD stereoselectively and potently activates the sphingosine-1 phosphate (S1P) receptors, S1P1 and S1P3 These results provide an attractive method for synthesizing and distinguishing enantiomers of CBD and related phytocannabinoids and provide further evidence that these enantiomers have their own unique and interesting signaling properties. SIGNIFICANCE STATEMENT: Cannabidiol (CBD) is the subject of considerable scientific and popular interest, but we know little of the enantiomers of CBD. We find that the enantiomer (+)-CBD is substantially more potent inhibitor of cannabinoid CB1 receptors and that it activates sphingosine-1-phosphate receptors in an enantiomer-specific manner; we have additionally developed an improved method for the synthesis of enantiomers of CBD and related compounds.

Reversibility and therapeutic development for neurodevelopmental disorders, insights from genetic animal models

Neurodevelopmental Disorders (NDDs) encompass a broad spectrum of conditions resulting from atypical brain development. Over the past decades, we have had the fortune to witness enormous progress in diagnosis, etiology discovery, modeling, and mechanistic understanding of NDDs from both fundamental and clinical research. Here, we review recent neurobiological advances from experimental models of NDDs. We introduce several examples and highlight breakthroughs in reversal studies of phenotypes using genetically engineered models of NDDs. The in-depth understanding of brain pathophysiology underlying NDDs and evaluations of reversibility in animal models paves the foundation for discovering novel treatment options. We discuss how the expanding property of cutting-edge technologies, such as gene editing and AAV-mediated gene delivery, are leveraged in animal models for the therapeutic development of NDDs. We envision opportunities and challenges toward faithful modeling and fruitful clinical translation.

The Long-Term Effectiveness and Safety of Cannabidiol-Enriched Oil in Children With Drug-Resistant Epilepsy

BACKGROUND

Several retrospective studies on pediatric epilepsy reported positive effects of cannabidiol-enriched artisanal cannabis oil and pure cannabidiol oil on seizure reduction.

METHODS

This is a retrospective study of children and adolescents with refractory epilepsy caused by various etiologies who were treated with artisanal cannabis oil during January 2014 to June 2019, with at least one year follow-up.

RESULTS

Of 114 patients, 84 (73.3%) reported some improvement in seizure frequency at some point during treatment. Fifty-one (59%) of the 86 patients who continued treatment for at least one year showed >50% improvement in seizure frequency. Seizure etiology, seizure type, and patients' age and sex were not found to be associated with the response to cannabidiol-enriched cannabis oil. Side effects were minor, and positive effects beyond seizure reduction were noted.

CONCLUSIONS

Artisanal cannabidiol-enriched cannabis may be an effective and safe long-term treatment for refractory epilepsy.

Neuroplastic alterations in cannabinoid receptors type 1 (CB1) in animal models of epileptic seizures

Currently, there is an urgent need to better comprehend neuroplastic alterations in cannabinoid receptors type 1 (CB1) and to understand the biological meaning of these alterations in epileptic disorders. The present study reviewed neuroplastic changes in CB1 distribution, expression, and functionality in animal models of epileptic seizures. Neuroplastic alterations in CB1 were consistently observed in chemical, genetic, electrical, and febrile seizure models. Most studies assessed changes in hippocampal and cortical CB1, while thalamic, hypothalamic, and brainstem nuclei were rarely investigated. Additionally, the relationship between CB1 alteration and the control of brain excitability through modulation of specific neuronal networks, such as striatonigral, nigrotectal and thalamocortical pathways, and inhibitory projections to hippocampal pyramidal neurons, were all presented and discussed in the present review. Neuroplastic alterations in CB1 detected in animal models of epilepsy may reflect two different scenarios: (1) endogenous adaptations aimed to control neuronal hyperexcitability in epilepsy or (2) pathological alterations that facilitate neuronal hyperexcitability. Additionally, a better comprehension of neuroplastic and functional alterations in CB1 can improve pharmacological therapies for epilepsies and their comorbidities.

The Synthetic Cannabinoid WIN55,212-2 Can Disrupt the Golgi Apparatus Independent of Cannabinoid Receptor-1

The synthetic cannabinoid WIN55,212-2 (WIN) is widely used as a pharmacological tool to study the biologic activity of cannabinoid receptors. In contrast to many other cannabinoid agonists, however, WIN also causes broad effects outside of neurons, such as reducing inflammatory responses, causing cell cycle arrest, and reducing general protein expression. How exactly WIN causes these broad effects is not known. Here we show that WIN partially disrupts the Golgi apparatus at nanomolar concentrations and fully disperses the Golgi apparatus in neuronal and non-neuronal cells at micromolar concentrations. WIN55,212-3, the enantiomer of WIN; JWH-018, a related alkylindole; or 2-arachidonoylglycerol, an endocannabinoid, did not cause Golgi disruption, suggesting that the effect was specific to the chirality of WIN. WIN treatment also perturbed the microtubule network. Importantly, WIN disrupted the Golgi in primary cortical neurons derived from mice where cannabinoid receptor-1 (CB1) was genetically knocked out, indicating that the effects were independent of CB1 signaling. The Golgi dispersion could not be explained by WIN's action on peroxisome proliferator-activated receptors. Our results show that WIN can disrupt the Golgi apparatus independent of CB1 in cultured cells. These effects could contribute to the unique physiologic effects that WIN exhibits in neuronal behavior, as well as its role as an antiproliferative and anti-inflammatory agent. SIGNIFICANCE STATEMENT: The synthetic cannabinoid WIN55,212-2 (WIN), widely used to investigate the cannabinoid system, also shows unique broader effects at cellular and organismal levels compared to endogenous cannabinoids. Our study shows that WIN can disrupt the Golgi apparatus and the microtubule network in multiple cell types, independent of cannabinoid receptors. These results could explain how WIN reduces surface levels of proteins and contributes to the unique physiological effects observed with WIN.

Up to What Extent Does Dravet Syndrome Benefit From Neurostimulation Techniques?

Background

Dravet syndrome (DS) is a refractory developmental and epileptic encephalopathy (EE) with a variety of comorbidities, including cognitive impairment, autism-like behavior, speech dysfunction, and ataxia, which can seriously affect the quality of life of patients and impose a great burden on society and their families. Currently, the pharmacological therapy is patient dependent and may work or not. Neuromodulation techniques, including vagus nerve stimulation (VNS), deep brain stimulation (DBS), transcranial magnetic stimulation (TMS), responsive neurostimulation (RNS), and chronic subthreshold cortical stimulation (CSCS), have become common adjuvant therapies for neurological diseases, but their efficacy in the treatment of DS is unknown.

Methods

We searched Web of Science, PubMed, and SpringerLink for all published cases related to the neuromodulation techniques of DS until January 15, 2022. The systematic review was supplemented with relevant articles from the references. The results reported by each study were summarized narratively.

Results

The Web of science, PubMed and SpringerLink search yielded 258 items. A total of 16 studies published between 2016 and 2021 met the final inclusion criteria. Overall, 16 articles (109 cases) were included in this study, among which fifteen (107 patients) were involved VNS, and one (2 patients) was involved DBS. After VNS implantation, seizures were reduced to ≥50% in 60 cases (56%), seizure free were found in 8 cases (7.5%). Only two DS patients received DBS treatment, and the initial outcomes of DBS implantation were unsatisfactory. The seizures significantly improved over time for both DBS patients after the addition of antiepileptic drugs.

Conclusion

More than half of the DS patients benefited from VNS, and VNS may be effective in the treatment of DS. However, it is important to note that VNS does not guarantee improvement of seizures, and there is a risk of infection and subsequent device failure. Although DBS is a safe and effective strategy for the treatment of refractory epilepsy, the role of DBS in DS needs further study, as the sample size was small. Thus far, there is no strong evidence for the role of DBS in DS.

Observational study of medical marijuana as a treatment for treatment-resistant epilepsies

Objectives

Medical cannabis formulations with cannabidiol (CBD) and delta‐9‐tetrahydrocannabinol (THC) are widely used to treat epilepsy. We studied the safety and efficacy of two formulations.

Methods

We prospectively observed 29 subjects (12 to 46 years old) with treatment‐resistant epilepsies (11 Lennox–Gastaut syndrome; 15 with focal or multifocal epilepsy; three generalized epilepsy) were treated with medical cannabis (1THC:20CBD and/or 1THC:50CBD; maximum of 6 mg THC/day) for ≥24 weeks. The primary outcome was change in convulsive seizure frequency from the pre‐treatment baseline to the stable optimal dose phase.

Results

There were no significant differences during treatment on stable maximal doses for convulsive seizure frequency, seizure duration, postictal duration, or use of rescue medications compared to baseline. No benefits were seen for behavioral disorders or sleep duration; there was a trend for more frequent bowel movements compared to baseline. Ten adverse events occurred in 6/29 patients, all were transient and most unrelated to study medication. No serious adverse events were related to study medication.

Interpretation

Our prospective observational study of two high‐CBD/low‐THC formulations found no evidence of efficacy in reducing seizures, seizure duration, postictal duration, or rescue medication use. Behavioral disorders or sleep duration was unchanged. Study medication was generally well tolerated. The doses of CBD used were lower than prior studies. Randomized trials with larger cohorts are needed, but we found no evidence of efficacy for two CBD:THC products in treating epilepsy, sleep, or behavior in our population.

Effects of Epidiolex® (Cannabidiol) on seizure-related emergency department visits and hospital admissions: A retrospective cohort study

AIM

The aim of this study was to evaluate the potential impact of cannabidiol (CBD) on healthcare resource utilization and determine the effect of CBD on seizure-related emergency departments (ED) and hospital admissions in patients with epilepsy.

METHODS

This single-center, retrospective longitudinal cohort study included patients ≥1 year on CBD, excluding participants in CBD clinical trials or on <6 months of CBD therapy. Demographics, antiseizure medications (ASM), ED and hospital admissions were collected from the electronic medical record. Co-primary outcomes included change in seizure-related ED and hospital admissions. Secondary outcomes included change in ASMs and total ED or hospital admissions. Co-primary outcomes were assessed using generalized linear modeling. Descriptive statistics were used to analyze all other variables.

RESULTS

In the one-hundred total patients, there was no difference in either seizure-related ED visits (0.012 vs 0.011, p = 0.85) or hospital admissions per month (0.019 vs 0.021, p = 0.7). However, given the low percentage of the total cohort (n = 100) with either a seizure-related ED visits and hospital admissions (9% and 18%, respectively), a subgroup analysis was conducted. Those with seizure-related hospital admissions prior to CBD (n = 18) had significantly less seizure-related hospital admissions after initiation of CBD (23 admissions [0.104 per month] vs 15 admissions [0.055 per month], p = 0.007).

CONCLUSION

Despite the lack of statistically significant difference in primary outcomes for the total cohort, CBD may have a potential for a clinically beneficial impact in real-world settings on those patients with prior seizure-related admissions, who are the highest utilizers of healthcare resources.

Staff awareness of the use of cannabidiol (CBD): a trust-wide survey study in the UK

INTRODUCTION

Cannabidiol (CBD) is now a legal substance in Europe and is available in 'high street shops', usually as CBD oil. However, in the United Kingdom (UK), there is no clear consensus among healthcare professionals and organisations over how to manage CBD use in their patients. This is an important issue as CBD is a constituent of 'medicinal and recreational cannabis' and is gaining support in the scientific literature and lay media for use in physical and mental health problems. Given the aforementioned, this study is an exploration of healthcare professionals' beliefs and attitudes with regard to CBD.

METHODS

In July 2018, we sent requests by email to approximately 2000 clinical staff (including 319 physicians) at a mental health trust in South West London to answer 8 questions in a single survey using Surveyplanet.com , about their beliefs regarding CBD. There was no specific method of choosing the staff, and the aim was to get the email request sent to as many staff as possible on each service line. We did an analysis to see how the attitudes and beliefs of different staff member groups compared. We also gave them space to offer free text responses to illustrate their ideas and concerns. We used chi-squared tests for comparison across groups and used odds ratio for pairwise group comparisons.

RESULTS

One hundred ninety surveys were received in response, and of these, 180 were included in the final sample. The physician response rate was 17.2% (55/319); the response rate for non-physicians could not be estimated as their total number was not known at outset. 32.2% of the responders had the right to prescribe (58/180) and 52.8% had an experience of working in addiction services (95/180). We found that staff members who can prescribe were 1.99 times as likely to believe CBD has potential therapeutic properties compared to those who do not (OR = 1.99, CI = 1.03, 3.82; p = 0.038) and 2.94 times less likely to think it had dangerous side effects (OR = 0.34, CI = 0.15, 0.75; p = 0.006). Prescribing healthcare professionals were 2.3 times as likely to believe that CBD reduces the likelihood of psychosis (OR = 2.30, CI = 1.10, 4.78; p = 0.024). However, prescribing healthcare professionals with the ability to prescribe were 2.12 times as likely to believe that CBD should be prescription only (OR = 2.12, CI = 1.12, 4.01; p = 0.02). Individuals experienced in addiction services were 2.22 times as likely to be associated with a belief that CBD has therapeutic properties (OR = 2.22, CI = 1.22, 4.04; p = 0.009). Staff in general reported a lack of knowledge about CBD in their free text responses.

CONCLUSIONS

With almost 95% of prescribers being physicians, they appear to demonstrate awareness of potential therapeutic benefit, reduced likelihood of psychosis and seeming lack of dangerous side effects with CBD. However, their higher stringency about the need for prescription implies an attitude of caution. There was also a suggestion that biases about cannabis were influencing responses to questions as well. The external validity of this study could be diminished by sampling bias and limitation to a single mental health trust. Nonetheless, some of the results drew a reasonable comparison with similar studies.

Palmitoylethanolamide: A Potential Alternative to Cannabidiol

The endocannabinoid system (ECS) is a widespread cell signaling network that maintains homeostasis in response to endogenous and exogenous stressors. This has made the ECS an attractive therapeutic target for various disease states. The ECS is a well-known target of exogenous phytocannabinoids derived from cannabis plants, the most well characterized being Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD). However, the therapeutic efficacy of cannabis products comes with a risk of toxicity and high abuse potential due to the psychoactivity of THC. CBD, on the other hand, is reported to have beneficial medicinal properties including analgesic, neuroprotective, anxiolytic, anticonvulsant, and antipsychotic activities, while apparently lacking the toxicity of THC. Nevertheless, not only is the currently available scientific data concerning CBD's efficacy insufficient, there is also ambiguity surrounding its regulatory status and safety in humans that brings inherent risks to manufacturers. There is a demand for alternative compounds combining similar effects with a robust safety profile and regulatory approval. Palmitoylethanolamide (PEA) is an endocannabinoid-like lipid mediator, primarily known for its anti-inflammatory, analgesic and neuroprotective properties. It appears to have a multi-modal mechanism of action, by primarily activating the nuclear receptor PPAR-α while also potentially working through the ECS, thus targeting similar pathways as CBD. With proven efficacy in several therapeutic areas, its safety and tolerability profile and the development of formulations that maximize its bioavailability, PEA is a promising alternative to CBD.

Headache in people with epilepsy

Epidemiological estimates indicate that individuals with epilepsy are more likely to experience headaches, including migraine, than individuals without epilepsy. Headaches can be temporally unrelated to seizures, or can occur before, during or after an episode; seizures and migraine attacks are mostly not temporally linked. The pathophysiological links between headaches (including migraine) and epilepsy are complex and have not yet been fully elucidated. Correct diagnoses and appropriate treatment of headaches in individuals with epilepsy is essential, as headaches can contribute substantially to disease burden. Here, we review the insights that have been made into the associations between headache and epilepsy over the past 5 years, including information on the pathophysiological mechanisms and genetic variants that link the two disorders. We also discuss the current best practice for the management of headaches co-occurring with epilepsy and highlight future challenges for this area of research.

Cannabidiol reduces lesion volume and restores vestibulomotor and cognitive function following moderately severe traumatic brain injury

Despite the high incidence of traumatic brain injury (TBI), there is no universal treatment to safely treat patients. Blunt brain injuries destroy primary neural tissue that results in impaired perfusion, excessive release of glutamate, inflammation, excitotoxicity, and progressive secondary neuronal cell death. We hypothesized that administration of cannabidiol (CBD) directly to a brain contusion site, will optimize delivery to the injured tissue which will reduce local neural excitation and inflammation to spare neural tissue and improve neurological outcome following TBI. CBD was infused into a gelfoam matrix forming an implant (CBDi), then applied over the dura at the contusion site as well as delivered systemically by injection (CBD.IP). Post-injury administration of CBDi+IP greatly reduced defecation scores, lesion volume, the loss of neurons in the ipsilateral hippocampus, the number of injured neurons of the contralateral hippocampus, and reversed TBI-induced glial fibrillary acidic protein (GFAP) upregulation which was superior to either CBD.IP or CBDi treatment alone. Vestibulomotor performance on the beam-balance test was restored by 12 days post-TBI and sustained through 28 days. CBDi+IP treated rats exhibited preinjury levels of spontaneous alternation on the spontaneous alternation T-maze. In the object recognition test, they had greater mobility and exploration of novel objects compared to contusion or implant alone consistent with reduced anxiety and restored cognitive function. These results suggest that dual therapy by targeting the site of injury internally with a CBD-infused medical carrier followed by systemic supplementation may offer a more effective countermeasure than systemic or implant treatment alone for the deleterious effects of penetrating head wounds.

Enantioselective Organocatalytic Synthesis of Bicyclic Resorcinols via an Intramolecular Friedel-Crafts-Type 1,4-Addition: Access to Cannabidiol Analogues

The organocatalytic transformation of resorcinols is extremely rare. In this article, we report a highly enantioselective, organocatalytic intramolecular cyclization of these systems by a Friedel-Crafts-type 1,4-addition using a Jørgensen-Hayashi-like organocatalyst with a large silyl protecting group, and show that heat improves reaction yield with virtually no detriment to enantioselectivity. A variety of bicyclic resorcinols were obtained with excellent enantioselectivities (up to 94%). To show the utility of these constructs, and as part of a wider project involving the synthesis of cannabinoid-like compounds, the resorcinol formed was used to generate both 'normal' and 'abnormal' cannabidiol (CBD) derivatives which were shown to have anticonvulsant activity.

CB2R induces a protective response against epileptic seizures through ERK and p38 signaling pathways

BACKGROUND AND PURPOSE

Epilepsy is a pivotal neurological disorder characterized by the synchronous discharging of neurons to induce momentary brain dysfunction. Temporal lobe epilepsy is the most common type of epilepsy, with seizures originating from the mesial temporal lobe. The hippocampus forms part of the mesial temporal lobe and plays a significant role in epileptogenesis; it also has a vital influence on the mental development of children. In this study, we aimed to explore the effects of CB2 receptor (CB2R) activation on ERK and p38 signaling in nerve cells of a rat epilepsy model.

MATERIALS AND METHODS

We treated Sprague-Dawley rats with pilocarpine to induce an epilepsy model and treated such animals with a CB2R agonist (JWH133) alone or with a CB2R antagonist (AM630). Nissl's stain showed the neuron conditon in different groups. Western blot analyzed the level of p-ERK and p-p38.

RESULTS

JWH133 can increase the latent period of first seizure attack and decrease the Grades IV-V magnitude ratio after the termination of SE. Nissl's stain showed JWH133 protected neurons in the hippocampus while AM630 inhibited the functioning of CB2R in neurons. Western blot analysis showed that JWH133 decreased levels of p-ERK and p-p38, which is found at increased levels in the hippocampus of our epilepsy model. In contrast, AM630 inhibited the protective function of JWH133 and also enhanced levels of p-ERK and p-p38.

CONCLUSIONS

CB2R activation can induce neurons proliferation and survival through activation of ERK and p38 signaling pathways.

Phytocannabinoids - An Overview of the Analytical Methodologies for Detection and Quantification of Therapeutically and Recreationally Relevant Cannabis Compounds

The legalization of the cultivation of low Δ9-tetrahydrocannabinol (Δ9-THC) and high cannabidiol (CBD) Cannabis Sativa plants is gaining momentum around the world due to increasing demand for CBD-containing products. In many countries where CBD oils, extracts and CBD-infused foods and beverages are being sold in health shops and supermarkets, appropriate testing of these products is a legal requirement. Normally this involves determining the total Δ9-THC and CBD and their precursor tetrahydrocannabinolic acids (THCA) and cannabidiolic acid (CBDA). As our knowledge of the other relevant cannabinoids expands, it is likely so too will the demand for them as additives in many consumer products ensuring a necessity for quantification methods and protocols for their identification. This paper discusses therapeutically relevant cannabinoids found in Cannabis plant, the applicability and efficiency of existing extraction and analytical techniques as well as the legal requirements for these analyses.

Pharmacological potential of JWH133, a cannabinoid type 2 receptor agonist in neurodegenerative, neurodevelopmental and neuropsychiatric diseases

The pharmacological activation of cannabinoid type 2 receptors (CB2R) gained attention due to its ability to mitigate neuroinflammatory events without eliciting psychotropic actions, a limiting factor for the drugs targeting cannabinoid type 1 receptors (CB1R). Therefore, ligands activating CB2R are receiving enormous importance for therapeutic targeting in numerous neurological diseases including neurodegenerative, neuropsychiatric and neurodevelopmental disorders as well as traumatic injuries and neuropathic pain where neuroinflammation is a common accompaniment. Since the characterization of CB2R, many CB2R selective synthetic ligands have been developed with high selectivity and functional activity. Among numerous ligands, JWH133 has been found one of the compounds with high selectivity for CB2R. JWH133 has been reported to exhibit numerous pharmacological activities including antioxidant, anti-inflammatory, anticancer, cardioprotective, hepatoprotective, gastroprotective, nephroprotective, and immunomodulatory. Recent studies have shown that JWH133 possesses potent neuroprotective properties in several neurological disorders, including neuropathic pain, anxiety, epilepsy, depression, alcoholism, psychosis, stroke, and neurodegeneration. Additionally, JWH133 showed to protect neurons from oxidative damage and inflammation, promote neuronal survival and neurogenesis, and serve as an immunomodulatory agent. The present review comprehensively examined neuropharmacological activities of JWH133 in neurological disorders including neurodegenerative, neurodevelopmental and neuropsychiatric using synoptic tables and elucidated pharmacological mechanisms based on reported observations. Considering the cumulative data, JWH133 appears to be a promising CB2R agonist molecule for further evaluation and it can be a prototype agent in drug discovery and development for a unique class of agents in neurotherapeutics. Further, regulatory toxicology and pharmacokinetic studies are required to determine safety and proceed for clinical evaluation.

Motor Dysfunction of Autonomic Nervous System Based on Resting State Functional Magnetic Resonance Imaging

Epilepsy is caused by highly synchronized abnormal discharges of neurons in the brain. Resting State FMRI is widely used as a non-invasive checking method, clinical and basic research in the field of epilepsy has a huge influence, to study the plant nerve system movement function of brain activity and the neural network function of the complex contact provides broad prospects, greatly promote the development of clinical neurology and imaging. Therefore, this paper studies the functional connection and cognitive function of verbal working memory (VWM) in patients with epilepsy by applying resting state FMRI. The experimental results showed that VWM and cognitive functions of epileptic patients showed a trend of decline or even disappearance, to realize the detection of autonomic nervous system motor dysfunction of patients.

Antisense oligonucleotides increase Scn1a expression and reduce seizures and SUDEP incidence in a mouse model of Dravet syndrome

Dravet syndrome (DS) is an intractable developmental and epileptic encephalopathy caused largely by de novo variants in the SCN1A gene, resulting in haploinsufficiency of the voltage-gated sodium channel α subunit Na_V1.1. Here, we used Targeted Augmentation of Nuclear Gene Output (TANGO) technology, which modulates naturally occurring, nonproductive splicing events to increase target gene and protein expression and ameliorate disease phenotype in a mouse model. We identified antisense oligonucleotides (ASOs) that specifically increase the expression of productive Scn1a transcript in human cell lines, as well as in mouse brain. We show that a single intracerebroventricular dose of a lead ASO at postnatal day 2 or 14 reduced the incidence of electrographic seizures and sudden unexpected death in epilepsy (SUDEP) in the F1:129S-Scn1a ^+/- × C57BL/6J mouse model of DS. Increased expression of productive Scn1a transcript and Na_V1.1 protein was confirmed in brains of treated mice. Our results suggest that TANGO may provide a unique, gene-specific approach for the treatment of DS.

Chronic cannabidiol (CBD) administration induces anticonvulsant and antiepileptogenic effects in a genetic model of epilepsy

Cannabidiol (CBD) is a marijuana compound implicated in epilepsy treatment in animal models and pharmacoresistant patients. However, little is known about chronic CBD administration's effects in chronic models of seizures, especially regarding its potential antiepileptogenic effects. In the present study, we combined a genetic model of epilepsy (the Wistar Audiogenic Rat strain - WARs), a chronic protocol of seizures (the audiogenic kindling - AuK), quantitative and sequential behavioral analysis (neuroethology), and microscopy imaging to analyze the effects of chronic CBD administration in a genetic model of epilepsy. The acute audiogenic seizure is characterized by tonic-clonic seizures and intense brainstem activity. However, during the AuK WARs can develop limbic seizures associated with the recruitment of forebrain and limbic structures. Here, chronic CBD administration, twice a day, attenuated brainstem, tonic-clonic seizures, prevented limbic recruitment, and suppressed limbic (kindled) seizures, suggesting CBD antiepileptogenic effects. Additionally, CBD prevented chronic neuronal hyperactivity, suppressing FosB immunostaining in the brainstem (inferior colliculus and periaqueductal gray matter) and forebrain (basolateral amygdala nucleus and piriform cortex), structures associated with tonic-clonic and limbic seizures, respectively. Chronic seizures increased cannabinoid receptors type 1 (CB1R) immunostaining in the hippocampus and the BLA, while CBD administration prevented changes in CB1R expression induced by the AuK. The neuroethological analysis provided details about CBD's protective effects against brainstem and limbic seizures associated with FosB expression. Our results strongly suggest chronic CBD anticonvulsant and antiepileptogenic effects associated with reduced chronic neuronal activity and modulation of CB1R expression. We also support the chronic use of CBD for epilepsies treatments.

Cannabidiol Modulates Mitochondrial Redox and Dynamics in MCF7 Cancer Cells: A Study Using Fluorescence Lifetime Imaging Microscopy of NAD(P)H

The cannabinoid, cannabidiol (CBD), is part of the plant's natural defense system that when given to animals has many useful medicinal properties, including activity against cancer cells, modulation of the immune system, and efficacy in epilepsy. Although there is no consensus on its precise mode of action as it affects many cellular targets, CBD does appear to influence mitochondrial function. This would suggest that there is a cross-kingdom ability to modulate stress resistance systems that enhance homeostasis. As NAD(P)H autofluorescence can be used as both a metabolic sensor and mitochondrial imaging modality, we assessed the potential of this technique to study the in vitro effects of CBD using 2-photon excitation and fluorescence lifetime imaging microscopy (2P-FLIM) of NAD(P)H against more traditional markers of mitochondrial morphology and cellular stress in MCF7 breast cancer cells. 2P-FLIM analysis revealed that the addition of CBD induced a dose-dependent decrease in bound NAD(P)H, with 20 µM treatments significantly decreased the contribution of bound NAD(P)H by 14.6% relative to the control (p < 0.001). CBD also increased mitochondrial concentrations of reactive oxygen species (ROS) (160 ± 53 vs. 97.6 ± 4.8%, 20 µM CBD vs. control, respectively, p < 0.001) and Ca2+ (187 ± 78 vs. 105 ± 10%, 20 µM CBD vs. the control, respectively, p < 0.001); this was associated with a significantly decreased mitochondrial branch length and increased fission. These are all suggestive of mitochondrial stress. Our results support the use of NAD(P)H autofluorescence as an investigative tool and provide further evidence that CBD can modulate mitochondrial function and morphology in a dose-dependent manner, with clear evidence of it inducing oxidative stress at higher concentrations. This continues to support emerging data in the literature and may provide further insight into its overall mode of action, not only in cancer, but potentially its function in the plant and why it can act as a medicine.

Efficacy of Phytocannabinoids in Epilepsy Treatment: Novel Approaches and Recent Advances

Epilepsy is a neurological disorder mainly characterised by recurrent seizures that affect the entire population diagnosed with the condition. Currently, there is no cure for the disease and a significant proportion of patients have been deemed to have treatment-resistant epilepsy (TRE). A patient is deemed to have TRE if two or more antiepileptic drugs (AEDs) fail to bring about seizure remission. This inefficacy of traditional AEDs, coupled with their undesirable side effect profile, has led to researchers considering alternative forms of treatment. Phytocannabinoids have long served as therapeutics with delta-9-THC (Δ⁹-THC) receiving extensive focus to determine its therapeutic potential. This focus on Δ⁹-THC has been to the detriment of analysing the plethora of other phytocannabinoids found in the cannabis plant. The overall aim of this review is to explore other novel phytocannabinoids and their place in epilepsy treatment. The current review intends to achieve this aim via an exploration of the molecular targets underlying the anticonvulsant capabilities of cannabidiol (CBD), cannabidavarin (CBDV), delta-9-tetrahydrocannabivarin (Δ⁹-THCV) and cannabigerol (CBG). Further, this review will provide an exploration of current pre-clinical and clinical data as it relates to the aforementioned phytocannabinoids and the treatment of epilepsy symptoms. With specific reference to epilepsy in young adult and adolescent populations, the exploration of CBD, CBDV, Δ⁹-THCV and CBG in both preclinical and clinical environments can guide future research and aid in the further understanding of the role of phytocannabinoids in epilepsy treatment. Currently, much more research is warranted in this area to be conclusive.

Recent advances in Cannabis sativa genomics research

Cannabis (Cannabis sativa L.) is one of the oldest cultivated plants purported to have unique medicinal properties. However, scientific research of cannabis has been restricted by the Single Convention on Narcotic Drugs of 1961, an international treaty that prohibits the production and supply of narcotic drugs except under license. Legislation governing cannabis cultivation for research, medicinal and even recreational purposes has been relaxed recently in certain jurisdictions. As a result, there is now potential to accelerate cultivar development of this multi-use and potentially medically useful plant species by application of modern genomics technologies. Whilst genomics has been pivotal to our understanding of the basic biology and molecular mechanisms controlling key traits in several crop species, much work is needed for cannabis. In this review we provide a comprehensive summary of key cannabis genomics resources and their applications. We also discuss prospective applications of existing and emerging genomics technologies for accelerating the genetic improvement of cannabis.

Distribution of the Cannabinoid Receptor Type 1 in the Brain of the Genetically Audiogenic Seizure-Prone Hamster GASH/Sal

The endocannabinoid system modulates epileptic seizures by regulating neuronal excitability. It has become clear that agonist activation of central type I cannabinoid receptors (CB1R) reduces epileptogenesis in pre-clinical animal models of epilepsy. The audiogenic seizure-prone hamster GASH/Sal is a reliable experimental model of generalized tonic-clonic seizures in response to intense sound stimulation. However, no studies hitherto had investigated CB1R in the GASH/Sal. Although the distribution of CB1R has been extensively studied in mammalian brains, their distribution in the Syrian golden hamster brain also remains unknown. The objective of this research is to determine by immunohistochemistry the differential distribution of CB1R in the brains of GASH/Sal animals under seizure-free conditions, by comparing the results with wild-type Syrian hamsters as controls. CB1R in the GASH/Sal showed a wide distribution in many nuclei of the central nervous system. These patterns of CB1R-immunolabeling are practically identical between the GASH/Sal model and control animals, varying in the intensity of immunostaining in certain regions, being slightly weaker in the GASH/Sal than in the control, mainly in brain regions associated with epileptic networks. The RT-qPCR analysis confirms these results. In summary, our study provides an anatomical basis for further investigating CB1R in acute and kindling audiogenic seizure protocols in the GASH/Sal model as well as exploring CB1R activation via exogenously administered cannabinoid compounds.

An assessment of the potency related to Cannabis-based products in the South African market

It was the aim of this study to analyse a portion of the South African cannabis-based products market and provide a detailed overview of their THC and CBD profiles. To date, no data of this kind exists in South Africa. Samples were submitted to a contract laboratory. A total of 840 samples were analysed in duplicate (1680 datapoints in total) and reported in an anonymous format. Samples were categorised into 7 different types: Edible, Extract, Infusion, Liquid, Other, Plant material, and Solid. Each category was divided into the following weight by percentage concentration levels:<0.1 wt.-%, 0.1 wt.-% to 1 wt.-% and finally>1 wt.-%. Both HPLC-UV, as well as, GC-MS was employed for analysis with the datasets combined. The results indicated that high amounts of THC are present in most of the cannabis-based products in South Africa. This is of concern due to the health implications of these products, and the current South African legislation related to CBD and THC. Medicines and controlled substance regulators as well as the South African public will be informed about the current state of cannabis-based products in South Africa.

The role of new medical treatments for the management of developmental and epileptic encephalopathies: Novel concepts and results

Developmental and epileptic encephalopathies (DEEs) are among the most challenging of all epilepsies to manage, given the exceedingly frequent and often severe seizure types, pharmacoresistance to conventional antiseizure medications, and numerous comorbidities. During the past decade, efforts have focused on development of new treatment options for DEEs, with several recently approved in the United States or Europe, including cannabidiol as an orphan drug in Dravet and Lennox-Gastaut syndromes and everolimus as a possible antiepileptogenic and precision drug for tuberous sclerosis complex, with its impact on the mammalian target of rapamycin pathway. Furthermore, fenfluramine, an old drug, was repurposed as a novel therapy in the treatment of Dravet syndrome. The evolution of new insights into pathophysiological processes of various DEEs provides possibilities to investigate novel and repurposed drugs and to place them into the context of their role in future management of these patients. The purpose of this review is to provide an overview of these new medical treatment options for the DEEs and to discuss the clinical implications of these results for improved treatment.

The Clinical Significance of miR-135b-5p and Its Role in the Proliferation and Apoptosis of Hippocampus Neurons in Children with Temporal Lobe Epilepsy

Temporal lobe epilepsy (TLE) is the most familiar localized epilepsy in children. MicroRNAs (miRNAs) are essential for the inhibition or promotion of numerous diseases. This study aimed to detect the expression of miR-135b-5p and primarily uncover its underlying function and mechanism in children with TLE. Quantitative real-time polymerase chain reaction was used to evaluate the expression of miR-135b-5p in children with TLE and in a rat model of epilepsy. MTT assay and flow cytometric apoptosis assay were conducted to evaluate the effects of miR-135b-5p on cell viability and apoptosis. Additionally, the dual luciferase reporter assay was performed to confirm the direct target of miR-135b-5p. Our data showed that the expression of miR-135b-5p was significantly decreased in children with TLE and in the epileptic rat neuron model. The dysregulation of miR-135b-5p could serve as a promising diagnostic biomarker for children with TLE. The overexpression of miR-135b-5p moderated the adverse influence on cell viability and apoptosis induced by magnesium-free medium. SIRT1 was identified as a target gene of miR-135b-5p. These results proved that miR-135b-5p might serve as a potential diagnostic biomarker in children with TLE. Overexpression of miR-135b-5p alleviates the postepileptic influence on cell viability and apoptosis by targeting SIRT1.

From an Alternative Medicine to a New Treatment for Refractory Epilepsies: Can Cannabidiol Follow the Same Path to Treat Neuropsychiatric Disorders?

Although cannabis has been known for ages as an "alternative medicine" to provide relief from seizures, pain, anxiety, and inflammation, there had always been a limited scientific review to prove and establish its use in clinics. Early studies carried out by Carlini's group in Brazil suggested that cannabidiol (CBD), a non-psychotropic phytocannabinoid present in Cannabis sativa, has anticonvulsant properties in animal models and reduced seizure frequency in limited human trials. Over the past few years, the potential use of cannabis extract in refractory epilepsy, including childhood epilepsies such as Dravet's syndrome and Lennox-Gastaut Syndrome, has opened a new era of treating epileptic patients. Thus, a considerable number of pre-clinical and clinical studies have provided strong evidence that phytocannabinoids has anticonvulsant properties, as well as being promising in the treatment of different neuropsychiatric disorders, such as depression, anxiety, post-traumatic stress disorder (PTSD), addiction, neurodegenerative disorders and autism spectrum disorder (ASD). Given the advances of cannabinoids, especially CBD, in the treatment of epilepsy, would the same expectation regarding the treatment of other neuropsychiatric disorders be possible? The present review highlights some contributions from Brazilian researchers and other studies reported elsewhere on the history, pre-clinical and clinical data underlying the use of cannabinoids for the already widespread treatment of refractory epilepsies and the possibility of use in the treatment of some neuropsychiatric disorders.

Cannabis sativa L. as a Natural Drug Meeting the Criteria of a Multitarget Approach to Treatment

Cannabis sativa L. turned out to be a valuable source of chemical compounds of various structures, showing pharmacological activity. The most important groups of compounds include phytocannabinoids and terpenes. The pharmacological activity of Cannabis (in epilepsy, sclerosis multiplex (SM), vomiting and nausea, pain, appetite loss, inflammatory bowel diseases (IBDs), Parkinson's disease, Tourette's syndrome, schizophrenia, glaucoma, and coronavirus disease 2019 (COVID-19)), which has been proven so far, results from the affinity of these compounds predominantly for the receptors of the endocannabinoid system (the cannabinoid receptor type 1 (CB1), type two (CB2), and the G protein-coupled receptor 55 (GPR55)) but, also, for peroxisome proliferator-activated receptor (PPAR), glycine receptors, serotonin receptors (5-HT), transient receptor potential channels (TRP), and GPR, opioid receptors. The synergism of action of phytochemicals present in Cannabis sp. raw material is also expressed in their increased bioavailability and penetration through the blood-brain barrier. This review provides an overview of phytochemistry and pharmacology of compounds present in Cannabis extracts in the context of the current knowledge about their synergistic actions and the implications of clinical use in the treatment of selected diseases.

Development of Stimuli-Responsive Chitosan/ZnO NPs Transdermal Systems for Controlled Cannabidiol Delivery

One of the most common neurological diseases is epilepsy, which not only negatively affects the quality of people's life but also may lead to life-threatening situations when its symptoms such as seizures cannot be controlled medically. A very serious problem to be overcame is the untreatable form of this disease, which cannot be cured by any currently available medicines. Cannabidiol, which is a natural product obtained from Cannabis Sativa, brings a new hope to people suffering from drug-resistant epilepsy. However, the hydrophobic character of this compound significantly lowers its clinical efficiency. One of the promising methods of this substance bioactivity increase is delivery through the skin tissue. In this article, a new type of advanced transdermal systems based on chitosan and ZnO nanoparticles (NPs) has been developed according to Sustained Development principles. The chemical modification of the biopolymer confirmed by FT-IR method resulted in the preparation of the material with great swelling abilities and appropriate water vapor permeability. Obtained nanoparticles were investigated over their crystalline structure and morphology and their positive impact on drug loading capacity and cannabidiol controlled release was proved. The novel biomaterials were confirmed to have conductive properties and not be cytotoxic to L929 mouse fibroblasts.

Clinical Pharmacokinetics of Cannabinoids and Potential Drug-Drug Interactions

Over the past few years, considerable attention has focused on cannabidiol (CBD) and Δ⁹-tetrahydrocannabinol (THC), the two major constituents of Cannabis sativa, mainly due to the promising potential medical uses they have shown. However, more information on the fate of these cannabinoids in human subjects is still needed and there is limited research on the pharmacokinetic drug-drug interactions that can occur in the clinical setting and their prevalence. As the use of cannabinoids is substantially increasing for many indications and they are not the first-line therapy in any treatment, health care professionals must be aware of drug-drug interactions during their use as serious adverse events can happen related with toxic or ineffective outcomes. The present chapter overview summarizes our current knowledge on the pharmacokinetics and metabolic fate of CBD and THC in humans and discusses relevant drug-drug interactions, giving a plausible explanation to facilitate further research in the area.

Cannabidiol-enriched oil in children and adults with treatment-resistant epilepsy-does tolerance exist?

AIM

To evaluate the long-term effectiveness of cannabidiol (CBD)-enriched oil for the treatment of refractory epilepsy and to assess the development of tolerance to its anti-seizure effect.

METHODS

A prospective study of 92 consecutive patients (age 1-37 years, mean-11.8 years) with treatment resistant epilepsy who were treated with cannabis oil extract (CBD/tetrahydrocannabinol [THC] ratio of 20:1). Mean monthly seizure frequency was reported by the patients/their parents during monthly clinic visits. Tolerance was defined as either the need to increase the dose by ≥30% due to reduced treatment efficacy or as an increase of ≥30% in mean monthly seizure frequency in patients treated for at least 3 months with no change in other anti-seizure medications.

RESULTS

Mean follow-up time was 19.8 ± 12.5 months (range 3-45). Mean CBD dose was 11.3 (4-38) mg/kg/day. Twenty-nine (31%) patients discontinued treatment due to lack of effect or adverse reactions, which were reported in 51% (47/87) of the patients. Overall responder rate (>50% seizures reduction) was 54%, whereas 8 patients (9%) became seizure-free. Eighty-four patients were included in the tolerance analysis. Tolerance was observed in 21 (25%) patients after a mean duration of 7.3 ± 5.4 months of CBD-enriched oil treatment. There was a negative correlation between epilepsy duration and tolerance development (p = 0.038).

CONCLUSIONS

We report for the first time the plausible appearance of tolerance to cannabidiol-enriched oil. This may limit treatment efficacy in the long-term clinical management of refractory epilepsy in both pediatric and adult population. Further studies are needed to investigate potential mechanisms.

Cognitive and behavioral effects of cannabidiol in patients with treatment-resistant epilepsy

PURPOSE

Therapeutic use of cannabidiol (CBD) in intractable epilepsies has increased considerably over the last ten years. As more evidence for the potentially beneficial effects of CBD on different epilepsy types is emerging, it is important to monitor potential cognitive and behavioral side effects. So far, studies including standardized neuropsychological data in the context of treatment with CBD in epilepsy patients are sparse. The present open-label study examines cognitive and behavioral effects of CBD in children and adults with treatment resistant epilepsy.

METHOD

Thirty-nine patients with treatment-resistant epilepsy completed the study protocol, i.e. they were tested at baseline (T0) and after three months of CBD treatment (T1). Patients completed standardized neuropsychological tests on memory, executive functions and attention if they were capable. For cognitively impaired patients who could not complete cognitive tests, caregiver interviews were conducted and caregiver questionnaires completed.

RESULTS

Significant cognitive decline from T0 to T1 was observed on none of the included measures. There was a significant improvement on a measure of selective attention and on a caregiver-rated behavioral measure. More than 89% of all individual test results remained stable or showed reliable improvement from T0 to T1. Cognitive and behavioral changes from T0 to T1 were not significantly correlated with CBD dose. Improvements in short-term/working memory were significantly related to better therapy response.

CONCLUSION

No adverse group-level effects of CBD treatment were detected. On an individual level, most test results remained stable or were improved. Cognitive change was not related to CBD dose. The present results show that, from a cognitive and behavioral point of view, CBD seems to have an encouraging side-effect profile. The results need to be replicated with larger samples.

Cannabidiol Therapy for Refractory Epilepsy and Seizure Disorders

Cannabis-derived cannabinoids have neuroactive properties. Recently, there has been emerging interest in the use of cannabidiol (CBD)-enriched products for treatment of drug-resistant epilepsy. In 2018, the FDA approved the use of CBD-rich Epidiolex for two severe forms of epilepsy in children (Lennox-Gastaut and Dravet syndromes). Experimental research supports the use of CBD in many CNS disorders, though the mechanisms underlying its anticonvulsant and neuroprotective effects remain unclear. CBD has been shown to reduce inflammation, protect against neuronal loss, normalize neurogenesis, and act as an antioxidant. These actions appear to be due to the multimodal mechanism of action of CBD in the brain. This chapter briefly describes the current information on cannabis pharmacology with an emphasis on the clinical utility of CBD in the treatment of refractory epilepsies and other related seizure conditions. Clinical trials are ongoing for other forms of epilepsy and refractory seizures associated with infantile spasms, tuberous sclerosis, and Rett syndrome. Overall, adjunct CBD has been found to be generally safe and effective for treatment-resistant seizures in children with severe early-onset epilepsy. Whether an add-on CBD is efficacious for the long-term treatment of various epilepsy and seizure types in adults being tested in various clinical trials.

Cannabidiol for Treating Lennox-Gastaut Syndrome and Dravet Syndrome in Korea

BACKGROUND

For the first time in Korea, we aimed to study the efficacy and safety of cannabidiol (CBD), which is emerging as a new alternative in treating epileptic encephalopathies.

METHODS

This study was conducted retrospectively with patients between the ages of 2-18 years diagnosed with Lennox-Gastaut syndrome (LGS) or Dravet syndrome (DS) were enrolled from March to October 2019, who visited outpatient unit at 3 and 6 months to evaluate medication efficacy and safety based on caregiver reporting. Additional evaluations, such as electroencephalogram and blood tests, were conducted at each period also. CBD was administered orally at a starting dose of 5 mg/kg/day, and was maintained at 10 mg/kg/day.

RESULTS

We analyzed 34 patients in the LGS group and 10 patients in the DS group between the ages of 1.2-15.8 years. In the 3-month evaluation, the overall reduction of seizure frequency in the LGS group was 52.9% (>50% reduction in 32.3% of the cases), and 29.4% in the 6-month evaluation (more than 50% reduction in 20.6%). In DS group, the reduction of seizure frequency by more than 50% was 30% and 20% in the 3-month and 6-month evaluation, respectively. Good outcomes were defined as the reduction of seizure frequency by more than 50% and similar results were observed in both LGS and DS groups. Adverse events were reported in 36.3% of total patients of which most common adverse events were gastrointestinal problems. However, no life-threatening adverse event was reported in both LGS and DS during the observation period.

CONCLUSION

In this first Korean study, CBD was safe and tolerable for use and could be expected to potentially reduce the seizure frequency in pediatric patients with LGS or DS.

A validated method for the simultaneous quantification of cannabidiol, Δ9 -tetrahydrocannabinol, and their metabolites in human plasma and application to plasma samples from an oral cannabidiol open-label trial

Cannabidiol (CBD) and Δ⁹ -tetrahydrocannabinol (THC) are the two best known and most extensively studied phytocannabinoids within Cannabis sativa. An increasing number of preclinical studies and clinical trials have been conducted with one or both compounds, often probing their therapeutic effects in conditions such as paediatric epilepsy, anxiety disorders or chronic pain. Accurate monitoring of THC and CBD and their metabolites is essential for tracking treatment adherence and pharmacokinetics. However, fully validated methods for the comprehensive analysis of major Phase I CBD metabolites are yet to be developed due to a historical lack of commercially available reference material. In the present study, we developed, optimised and validated a method for the simultaneous quantification of CBD, THC and their major Phase I metabolites 6-hydroxy-CBD (6-OH-CBD), 7-hydroxy-CBD (7-OH-CBD), 7-carboxy-CBD (7-COOH-CBD), 11-hydroxy-tetrahydrocannabinol (11-OH-THC) and 11-carboxy-tetrahydrocannabinol (11-COOH-THC) as per Food and Drug Administration (FDA) guidelines for bioanalytical method validation. The method is accurate, reproducible, sensitive and can be carried out in high-throughput 96-well formats, ideal for larger scale clinical trials. Deuterated internal standards for each analyte were crucial to account for variable matrix effects between plasma lots. The application of the method to plasma samples, taken from people who had been administered oral CBD as part of an open-label trial of CBD effects in anxiety disorders, demonstrated its immediate utility in ongoing and upcoming clinical trials. The method will prove useful for future studies involving CBD and/or THC and can likely accommodate the inclusion of additional metabolites as analytical reference materials become commercially available.

A phase I trial of the safety, tolerability and pharmacokinetics of cannabidiol administered as single-dose oil solution and single and multiple doses of a sublingual wafer in healthy volunteers

AIMS

This study investigated the safety, tolerability and pharmacokinetics after administration of a specific Cannabis sativa cultivar extract, standardised to cannabidiol (CBD) content as sublingual wafer or oil formulation compared to nabiximols oromucosal spray.

METHODS

For the single-dose study, the design was an open-label, 4-way crossover in 12 healthy volunteers randomised to receive a sequence of 4 different single doses of CBD as a sublingual wafer (25 or 50 mg CBD), oil solution (50 mg CBD), or nabiximols oromucosal spray (20 mg CBD, 21.6 mg tetrahydrocannabinol). For the multiple-dose study, sublingual wafer (50 mg CBD) was administered twice a day for 5 days.

RESULTS

The extract was generally well tolerated by participants when administered in either wafer or oil form, with some adverse events, including mild or moderate somnolence, sedation and altered mood. The relative bioavailability of CBD after administration as a sublingual wafer was comparable with that of oil solution with 90% confidence interval of 83-131%. The median maximum concentrations of CBD after administration of oil solution and wafer was 9.4 and 11.9 ng mL^-1 , respectively. Maximum concentrations of CBD occurred 4 hours after administration, with an estimated terminal elimination half-life of 6 hours. There was no statistically significant difference between the AUC_0-τ of CBD after administration of oil solution or wafer compared with nabiximols oromucosal spray.

CONCLUSION

Oil solution and sublingual wafer formulations of the extract standardised with CBD were well tolerated and achieved equivalent concentrations of CBD when compared to an available commercial nabiximols formulation.

Bench to bedside: Multiple facets of cannabinoid control in epilepsy

Epilepsy is a neurological disease recognized as the consequence of excessive neuronal excitability. Endocannabinoid system, the critical regulator of synaptic inhibition in brain, was supposed to be closely involved in epilepsy. Cannabinoid receptors mostly locate on presynaptic terminals of both excitatory and inhibitory neurons, but with characteristic distribution varying in different brain areas and synapses. Endocannabinoids are synthesized in postsynaptic neurons and retrogradely act on presynaptic cannabinoid receptors. Accumulating evidence suggest that the expression of cannabinoid receptors and synthesis or breakdown of endocannabinoids were cell-type specifically altered and spatiotemporally regulated in seizures, and intervention of the expression of cannabinoid receptors or the level of endocannabinoids could affect seizure actions. Further in clinic, cannabidiol as an add-on treatment could reduce seizures in patients with treatment-resistant epilepsy, but the underlying mechanisms are still unclear and independent of the endocannabinoid system. Therefore, we review recent advances from bench to bedside, to address the cannabinoid control on seizures, discuss the existing confusion in current studies and provide directions for further research, which may be clinically important for the design of cannabinoid-based precise therapeutic interventions for epilepsy.

Cannabidiol normalizes resting-state functional connectivity in treatment-resistant epilepsy

OBJECTIVE

Resting-state (rs) network dysfunction is a contributing factor to treatment resistance in epilepsy. In treatment-resistant epilepsy (TRE), pharmacological and nonpharmacological therapies have been shown to improve such dysfunction. In this study, our goal was to prospectively evaluate the effect of highly purified plant-derived cannabidiol (CBD; Epidiolex®) on rs functional magnetic resonance imaging (fMRI) functional connectivity (rs-FC). We hypothesized that CBD would change and potentially normalize the rs-FC in TRE.

METHODS

Twenty-two of 27 participants with TRE completed all study procedures including longitudinal pre-/on-CBD rs-fMRI (8M/14F, mean age = 36.2 ± 15.9 years, TRE duration = 18.3 ± 12.6 years); there were no differences in age (p = 0.99) or sex (p = 0.15) between groups. Assessments collected included seizure frequency (SF), Chalfont Seizure Severity Scale (CSSS), Columbia Suicide Severity Rating Scale (C-SSRS), Adverse Events Profile (AEP), and Profile of Mood States (POMS). Twenty-three healthy controls (HCs) received rs-fMRI and POMS once.

RESULTS

Participants with TRE showed average decrease of 71.7% in SF (p < 0.0001) and improved CSSS, AEP, and POMS confusion, depression, and fatigue subscores (all p < 0.05) on-CBD with POMS scores becoming similar to those of HCs. Paired t-tests showed significant pre-/on-CBD changes in rs-FC in cerebellum, frontal areas, temporal areas, hippocampus, and amygdala with some of them correlating with improvement in behavioral measures. Significant differences in rs-FC between pre-CBD and HCs were found in cerebellum, frontal, and occipital regions. After controlling for changes in SF with CBD, these differences were no longer present when comparing on-CBD to HCs.

SIGNIFICANCE

This study indicates that highly purified CBD modulates and potentially normalizes rs-FC in the epileptic brain. This effect may underlie its efficacy. This study provides Class III evidence for CBD's normalizing effect on rs-FC in TRE.