Development of cannabidiol as a treatment for severe childhood epilepsies

The Influence of Cannabinoids on Drosophila Behaviors, Longevity, and Traumatic Injury Responses of the Adult Nervous System

Introduction: The legalization of cannabis products has increased their usage in the United States. Among the ∼500 active compounds, this is especially true for cannabidiol (CBD)-based products, which are being used to treat a range of ailments. Research is ongoing regarding the safety, therapeutic potential, and molecular mechanism of cannabinoids. Drosophila (fruit flies) are widely used to model a range of factors that impact neural aging, stress responses, and longevity. Materials and Methods: Adult wild-type Drosophila melanogaster cohorts (w1118/+) were treated with different Δ9-tetrahydrocannabinol (THC) and CBD dosages and examined for neural protective properties using established neural aging and trauma models. The therapeutic potential of each compound was assessed using circadian and locomotor behavioral assays and longevity profiles. Changes to NF-κB pathway activation were assessed by measuring expression levels of downstream targets using quantitative real-time polymerase chain reaction analysis of neural cDNAs. Results: Flies exposed to different CBD or THC dosages showed minimal effects to sleep and circadian-based behaviors or the age-dependent decline in locomotion. The 2-week CBD (3 μM) treatment did significantly enhance longevity. Flies exposed to different CBD and THC dosages were also examined under stress conditions, using the Drosophila mild traumatic brain injury (mTBI) model (10×). Pretreatment with either compound did not alter baseline expression of key inflammatory markers (NF-κB targets), but did reduce neural mRNA profiles at a key 4-h time point following mTBI exposure. Locomotor responses were also significantly improved 1 and 2 weeks following mTBI. After mTBI (10×) exposure, the 48-h mortality rate improved for CBD (3 μM)-treated flies, as were global average longevity profiles for other CBD doses tested. While not significant, THC (0.1 μM)-treated flies show a net positive impact on acute mortality and longevity profiles following mTBI (10×) exposure. Conclusions: This study shows that the CBD and THC dosages examined had at most a modest impact on basal neural function, while demonstrating that CBD treatments had significant neural protective properties for flies following exposure to traumatic injury.

Cinnamyl-Modified Polyglycidol/Poly(ε-Caprolactone) Block Copolymer Nanocarriers for Enhanced Encapsulation and Prolonged Release of Cannabidiol

The present study describes the development of novel block copolymer nanocarriers of the phytocannabinoid cannabidiol (CBD), designed to enhance the solubility of the drug in water while achieving high encapsulation efficiency and prolonged drug release. Firstly, a well-defined amphiphilic block copolymer consisting of two outer hydrophilic polyglycidol (PG) blocks and a middle hydrophobic block of poly(ε-caprolactone) bearing pendant cinnamyl moieties (P(CyCL-co-CL)) were synthesized by the click coupling reaction of PG-monoalkyne and P(CyCL-co-CL)-diazide functional macroreagents. A non-modified polyglycidol/poly(ε-caprolactone) amphiphilic block copolymer was obtained as a referent system. Micellar carriers based on the two block copolymers were formed via the solvent evaporation method and loaded with CBD following two different protocols-loading during micelle formation and loading into preformed micelles. The key parameters/characteristics of blank and CBD-loaded micelles such as size, size distribution, zeta potential, molar mass, critical micelle concentration, morphology, and encapsulation efficiency were determined by using dynamic and static multiangle and electrophoretic light scattering, transmission electron microscopy, and atomic force microscopy. Embedding CBD into the micellar carriers affected their hydrodynamic radii to some extent, while the spherical morphology of particles was not changed. The nanoformulation based on the copolymer bearing cinnamyl moieties possessed significantly higher encapsulation efficiency and a slower rate of drug release than the non-modified copolymer. The comparative assessment of the antiproliferative effect of micellar CBD vs. the free drug against the acute myeloid leukemia-derived HL-60 cell line and Sezary Syndrome HUT-78 demonstrated that the newly developed systems have pronounced antitumor activity.

Cannabidiol counters the effects of a dominant-negative pathogenic Kv7.2 variant

Epilepsy and neurodevelopmental disorders can arise from pathogenic variants of KCNQ (Kv7) channels. A patient with developmental and epileptic encephalopathy exhibited an in-frame deletion of histidine 260 on Kv7.2. Coexpression of Kv7.2 mutant (mut) subunits with Kv7.3 invoked a decrease in current density, a depolarizing shift in voltage for activation, and a decrease in membrane conductance. Biotinylation revealed an increased level of surface Kv7.2mut compared to Kv7.3 with no change in total membrane protein expression. Super-resolution and FRET imaging confirmed heteromeric channel formation and a higher expression density of Kv7.2mut. Cannabidiol (1 μM) offset the effects of Kv7.2mut by inducing a hyperpolarizing shift in voltage for activation independent of CB1 or CB2 receptors. These data reveal that the ability for cannabidiol to reduce the effects of a pathogenic Kv7.2 variant supports its use as a potential therapeutic to reduce seizure activity.

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A patient with epileptic encephalopathy exhibits a Kv7.2 deletion at H260 (Kv7.2mut)

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Kv7.2mut shows increased expression at the membrane compared to Kv7.3

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Kv7.2mut acts in a dominant-negative manner to reduce Kv7 conductance

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Cannabidiol acts on Kv7.x activation voltage to offset the effects of Kv7.2mut

Cannabidiol activates neuronal Kv7 channels

Cannabidiol (CBD), a chemical found in the Cannabis sativa plant, is a clinically effective antiepileptic drug whose mechanism of action is unknown. Using a fluorescence-based thallium flux assay, we performed a large-scale screen and found enhancement of flux through heterologously expressed human Kv7.2/7.3 channels by CBD. Patch-clamp recordings showed that CBD acts at submicromolar concentrations to shift the voltage dependence of Kv7.2/7.3 channels in the hyperpolarizing direction, producing a dramatic enhancement of current at voltages near –50 mV. CBD enhanced native M-current in mouse superior cervical ganglion starting at concentrations of 30 nM and also enhanced M-current in rat hippocampal neurons. The potent enhancement of Kv2/7.3 channels by CBD may contribute to its effectiveness as an antiepileptic drug by reducing neuronal hyperexcitability.

The value of real world evidence: The case of medical cannabis

Randomised controlled trials (RCTs) have long been considered the gold standard of medical evidence. In relation to cannabis based medicinal products (CBMPs), this focus on RCTs has led to very restrictive guidelines in the UK, which are limiting patient access. There is general agreement that RCT evidence in relation to CBPMs is insufficient at present. As well as commercial reasons, a major problem is that RCTs do not lend themselves well to the study of whole plant medicines. One solution to this challenge is the use of real world evidence (RWE) with patient reported outcomes (PROs) to widen the evidence base. Such data increasingly highlights the positive impact medical cannabis can have on patients' lives. This paper outlines the value of this approach which involves the study of interventions and patients longitudinally under medical care. In relation to CBMPs, RWE has a broad range of advantages. These include the study of larger groups of patients, the use of a broader range and ratio of components of CBMPs, and the inclusion of more and rarer medical conditions. Importantly, and in contrast to RCTs, patients with significant comorbidities-and from a wider demographic profile-can also be studied, so providing higher ecological validity and increasing patient numbers, whilst offering significant cost savings. We conclude by outlining 12 key recommendations of the value of RWE in relation to medical cannabis. We hope that this paper will help policymakers and prescribers understand the importance of RWE in relation to medical cannabis and help them develop approaches to overcome the current situation which is detrimental to patients.

Development of cannabidiol as a treatment for severe childhood epilepsies

In recent years, there has been a growing appreciation by regulatory authorities that cannabis-based medicines can play a useful role in disease therapy. Although often conflagrated by proponents of recreational use, the legislative rescheduling of cannabis-derived compounds, such as cannabidiol (CBD), has been associated with the steady increase in the pursuit of use of medicinal cannabis. One key driver in this interest has been the scientific demonstration of efficacy and safety of CBD in randomised, placebo-controlled clinical trials in children and young adults with difficult-to-treat epilepsies, which has encouraged increasing numbers of human trials of CBD for other indications and in other populations. The introduction of CBD as the medicine Epidiolex in the United States (in 2018) and as Epidyolex in the European Union (in 2019) as the first cannabis-derived therapeutic for the treatment of seizures was underpinned by preclinical research performed at the University of Reading. This work was awarded the British Pharmacological Society Sir James Black Award for Contributions to Drug Discovery 2019 and is discussed in the following review article.