The anticonvulsant effects of cannabidiol in experimental models of epileptic seizures: From behavior and mechanisms to clinical insights

Multifaceted targets of cannabidiol in epilepsy: Modulating glutamate signaling and beyond

Cannabidiol has been reported to interact with broad-spectrum biological targets with pleiotropic pharmacology including epilepsy although a cohesive mechanism is yet to be determined. Even though some studies propose that cannabidiol may manipulate glutamatergic signals, there is insufficient evidence to support cannabidiol direct effect on glutamate signaling, which is important in intervening epilepsy. Therefore, the present study aimed to analyze the epilepsy-related targets for cannabidiol, assess the differentially expressed genes with its treatment, and identify the possible glutamatergic signaling target. In this study, the epileptic protein targets of cannabidiol were identified using the Tanimoto coefficient and similarity index-based targets fishing which were later overlapped with the altered expression, epileptic biomarkers, and genetically altered proteins in epilepsy. The common proteins were then screened for possible glutamatergic signaling targets with differentially expressed genes. Later, molecular docking and simulation were performed using AutoDock Vina and GROMACS to evaluate binding affinity, ligand-protein stability, hydrophilic interaction, protein compactness, etc. Cannabidiol identified 30 different epilepsy-related targets of multiple protein classes including G-protein coupled receptors, enzymes, ion channels, etc. Glutamate receptor 2 was identified to be genetically varied in epilepsy which was targeted by cannabidiol and its expression was increased with its treatment. More importantly, cannabidiol showed a direct binding affinity with Glutamate receptor 2 forming a stable hydrophilic interaction and comparatively lower root mean squared deviation and residual fluctuations, increasing protein compactness with broad conformational changes. Based on the cheminformatic target fishing, evaluation of differentially expressed genes, molecular docking, and simulations, it can be hypothesized that cannabidiol may possess glutamate receptor 2-mediated anti-epileptic activities.

The Development of Cannabinoids as Therapeutic Agents in the United States

Cannabis is one of the oldest and widely used substances in the world. Cannabinoids within the cannabis plant, known as phytocannabinoids, mediate cannabis' effects through interactions with the body's endogenous cannabinoid system. This endogenous system, the endocannabinoid system, has important roles in physical and mental health. These roles point to the potential to develop cannabinoids as therapeutic agents while underscoring the risks related to interfering with the endogenous system during nonmedical use. This scoping narrative review synthesizes the current evidence for both the therapeutic and adverse effects of the major (i.e., Δ9-tetrahydrocannabinol and cannabidiol) and lesser studied minor phytocannabinoids, from nonclinical to clinical research. We pay particular attention to the areas where evidence is well established, including analgesic effects after acute exposures and neurocognitive risks after acute and chronic use. In addition, drug development considerations for cannabinoids as therapeutic agents within the United States are reviewed. The proposed clinical study design considerations encourage methodological standards for greater scientific rigor and reproducibility to ultimately extend our knowledge of the risks and benefits of cannabinoids for patients and providers. SIGNIFICANCE STATEMENT: This work provides a review of prior research related to phytocannabinoids, including therapeutic potential and known risks in the context of drug development within the United States. We also provide study design considerations for future cannabinoid drug development.

Therapeutic potential of CB1R activation by Qingyangshen glycoside M1 for seizure relief

ETHNOPHARMACOLOGICAL RELEVANCE

Cynanchum otophyllum C.K.Schneid.PI.Wilson, commonly referred as ''Qingyangshen'' (QYS), is a traditional folk medicine from Yunnan, renowned for its efficacy in neurological and psychiatric disorders. Glycosides isolated from QYS have shown promise in alleviating epilepsy, however, mechanisms of action and specific molecular targets remain to be elucidated.

AIM OF THE STUDY

The study aimed to evaluate the anticonvulsant effects of Qingyangshen glycosides M1 (M1), a C21 steroidal glycoside from QYS, on pentylenetetrazol (PTZ)-induced convulsions in zebrafish (Danio rerio), and its neuroprotective effect on Glutamate (Glu)-induced damage to PC12 cells, and importantly to identify its potential molecular targets.

MATERIALS AND METHODS

To evaluate anticonvulsant activity of M1, 7 days-post-fertilization (7-dpf) animals were pretreated (by immersion) and then exposed to PTZ (10 mM) solution. Furthermore, Glu-induced PC12 cell damage was employed to investigate the neuroprotective and anti-apoptotic capacity. Cells were pretreated with various concentrations of M1 (0-10 μM) for 12 h and then co-treated with Glu (15 mM) for an additional 24 h. The cell viability, apoptosis rate and apoptosis-related proteins (p-PI3K, PI3K, Akt, p-Akt, CREB, p-CREB, BDNF, Bax and Bcl-2) were measured using CCK-8, annexin V/PI and Western blot assays. To model the expected interaction between M1 and candidate cannabinoid receptor type 1 (CB1R), ERK phosphorylation, molecular docking, and drug affinity responsive target stability (DARTS) techniques were employed. Finally, CB1R antagonist Rimonabant (Rim) was validated by co-administration in both zebrafish and cells to confirm the requirement of CB1R for M1 efficacy.

RESULTS

At a concentration of 400 μM, M1 dramatically reversed PTZ-induced convulsive-like behaviors in zebrafish, as evidenced by a significant reduction in locomotor activity. In the context of Glu-induced cytotoxicity, M1 (10 μM) demonstrated a notable increase in cell viability and suppressed apoptosis through modulation of the Bax/Bcl-2 ratio and activation of the PI3K/Akt/CREB/BDNF signaling axis. These effects were facilitated through CB1R activation. In contrast, Rim dampened the beneficial activities of M1 as a cannabinoid agonist.

CONCLUSIONS

These results demonstrated that M1 as a potential CB1R activator, exhibiting anticonvulsive effects in a PTZ-induced zebrafish model and neuroprotective properties via the PI3K/Akt/CREB/BDNF signaling axis in a Glu-induced PC12 cell injury model. Notably, the observed seizure relief attenuated by CB1R chemical antagonism.

Cannabidiol attenuates seizure susceptibility and behavioural deficits in adult CDKL5R59X knock-in mice

Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is caused by a loss-of-function mutation in CDKL5 gene, encoding a serine-threonine kinase highly expressed in the brain. CDD manifests with early-onset epilepsy, autism, motor impairment and severe intellectual disability. While there are no known treatments for CDD, the use of cannabidiol has recently been introduced into clinical practice for neurodevelopmental disorders. Given the increased clinical utilization of cannabidiol, we examined its efficacy in the CDKL5R59X knock-in (R59X) mice, a CDD model based on a human mutation that exhibits both lifelong seizure susceptibility and behavioural deficits. We found that cannabidiol pre-treatment rescued the increased seizure susceptibility in response to the chemoconvulsant pentylenetetrazol (PTZ), attenuated working memory and long-term memory impairments, and rescued social deficits in adult R59X mice. To elucidate a potential mechanism, we compared the developmental hippocampal and cortical expression of common endocannabinoid (eCB) targets in R59X mice and their wild-type littermates, including cannabinoid type 1 receptor (CB1R), transient receptor potential vanilloid type 1 (TRPV1) and 2 (TRPV2), G-coupled protein receptor 55 (GPR55) and adenosine receptor 1 (A1R). Many of these eCB targets were developmentally regulated in both R59X and wild-type mice. In addition, adult R59X mice demonstrated significantly decreased expression of CB1R and TRPV1 in the hippocampus, and TRPV2 in the cortex, while TRPV1 was increased in the cortex. These findings support the potential for dysregulation of eCB signalling as a plausible mechanism and therapeutic target in CDD, given the efficacy of cannabidiol to attenuate hyperexcitability and behavioural deficits in this disorder.

A Mutual Nexus Between Epilepsy and α-Synuclein: A Puzzle Pathway

Alpha-synuclein (α-Syn) is a specific neuronal protein that regulates neurotransmitter release and trafficking of synaptic vesicles. Exosome-associated α-Syn which is specific to the central nervous system (CNS) is involved in the pathogenesis of epilepsy. Therefore, this review aimed to elucidate the possible link between α-Syn and epilepsy, and how it affects the pathophysiology of epilepsy. A neurodegenerative protein such as α-Syn is implicated in the pathogenesis of epilepsy. Evidence from preclinical and clinical studies revealed that upregulation of α-Syn induces progressive neuronal dysfunctions through induction of oxidative stress, neuroinflammation, and inhibition of autophagy in a vicious cycle with subsequent development of severe epilepsy. In addition, accumulation of α-Syn in epilepsy could be secondary to the different cellular alterations including oxidative stress, neuroinflammation, reduction of brain-derived neurotrophic factor (BDNF) and progranulin (PGN), and failure of the autophagy pathway. However, the mechanism of α-Syn-induced-epileptogenesis is not well elucidated. Therefore, α-Syn could be a secondary consequence of epilepsy. Preclinical and clinical studies are warranted to confirm this causal relationship.

Platinum (IV) drugs with cannabidiol inducing mitochondrial dysfunction and synergistically enhancing anti-tumor effects

Chemotherapy resistance is an insurmountable problem in clinical anticancer therapy. Although Oxaliplatin is an effective chemotherapeutic agent for the treatment of colorectal cancer (CRC), it still suffers from serious toxicities as well as drug resistance. In this work, three Oxaliplatin tetravalent platinum prodrugs(O1-O3) and three novel mixed ammine/amine analogs(C1-C3) were constructed, introducing cannabidiol with anti-tumor activity in their axial position. All Pt(IV) prodrugs exhibited potent antitumor effects in a variety of tumor cell lines, especially in HCT-116 cells, where complex O3 showed strong inhibitory effects with the half maximal inhibitory concentrations (IC50) value of 6.02 ± 0.69 μM and about 2.6 times higher than that of Oxaliplatin. Further studies revealed that complex O3 decreased cellular mitochondrial membrane potential in a concentration-dependent manner and enhanced reactive oxygen species (ROS) accumulation by decreasing the expression of catalase, superoxide dismutase 2 (SOD2) and superoxide dismutase 3 (SOD3). Complex O3 induces mitochondrial dysfunction and upregulates the pro-apoptotic protein Noxa, ultimately leading to severe DNA damage. The upregulation of Phosphorylated histone protein H2AX (γ-H2AX) expression is clear evidence. In addition, O3 inhibits the expression of RAD51 protein and prevents DNA damage repair, thus overcoming drug resistance. This strategy of combining bioactive molecules cannabidiol with platinum drugs to improve therapeutic efficacy and overcome drug resistance has been proven to be very effective and deserves further investigation.

Cannabidiol and epilepsy

Cannabidiol (CBD) has been investigated as a pharmacological approach for treating a myriad of neurological and psychiatric disorders, the most successful of them being its use as an antiseizure drug (ASD). Indeed, CBD has reached the clinics for the treatment of certain epileptic syndromes. This chapter aims to overview the pharmacology of CBD and its potential mechanisms of action as an ASD. First, we give an outline of the concepts, mechanisms and pharmacology pertaining to the field of study of epilepsy and epileptic seizures. In the second section, we will summarize the effects of CBD as an ASD. Next, we will discuss its potential mechanisms of action to alleviate epileptic seizures, which seem to entail multiple neurotransmitters, receptors and intracellular pathways. Finally, we will conclude and present some limitations and perspectives for future studies.

Virus-Induced Epilepsy vs. Epilepsy Patients Acquiring Viral Infection: Unravelling the Complex Relationship for Precision Treatment

The intricate relationship between viruses and epilepsy involves a bidirectional interaction. Certain viruses can induce epilepsy by infecting the brain, leading to inflammation, damage, or abnormal electrical activity. Conversely, epilepsy patients may be more susceptible to viral infections due to factors, such as compromised immune systems, anticonvulsant drugs, or surgical interventions. Neuroinflammation, a common factor in both scenarios, exhibits onset, duration, intensity, and consequence variations. It can modulate epileptogenesis, increase seizure susceptibility, and impact anticonvulsant drug pharmacokinetics, immune system function, and brain physiology. Viral infections significantly impact the clinical management of epilepsy patients, necessitating a multidisciplinary approach encompassing diagnosis, prevention, and treatment of both conditions. We delved into the dual dynamics of viruses inducing epilepsy and epilepsy patients acquiring viruses, examining the unique features of each case. For virus-induced epilepsy, we specify virus types, elucidate mechanisms of epilepsy induction, emphasize neuroinflammation's impact, and analyze its effects on anticonvulsant drug pharmacokinetics. Conversely, in epilepsy patients acquiring viruses, we detail the acquired virus, its interaction with existing epilepsy, neuroinflammation effects, and changes in anticonvulsant drug pharmacokinetics. Understanding this interplay advances precision therapies for epilepsy during viral infections, providing mechanistic insights, identifying biomarkers and therapeutic targets, and supporting optimized dosing regimens. However, further studies are crucial to validate tools, discover new biomarkers and therapeutic targets, and evaluate targeted therapy safety and efficacy in diverse epilepsy and viral infection scenarios.

Cannabidiol Intervention for Muscular Tension, Pain, and Sleep Bruxism Intensity-A Randomized, Double-Blind Clinical Trial

Background: Temporomandibular disorders (TMDs) are the most prevalent non-dental pain issues in the maxillofacial region. Despite advancements, diagnosing and managing TMDs continues to pose challenges. This study aimed to assess the efficacy of cannabidiol (CBD) formulations, with different concentrations, in patients experiencing sleep bruxism and muscle-related TMDs, with a particular emphasis on their myorelaxant, pain-relieving, and bruxism-reducing properties. Methods: The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMDs) was utilized as the diagnostic framework. Sixty patients completed the study, which followed a parallel-group, three-arm, randomized, double-blind clinical trial design, with a 1:1:1 allocation ratio across three groups: 1a, 1b, and 2. Groups 1a and 1b received CBD formulations at concentrations of 10% and 5%, respectively, while Group 2 received a placebo formulation. The trial consisted of four main visits, namely screening, baseline, first follow-up after 14 days, and second follow-up after 30 days, during which surface electromyography (sEMG), the visual analogue scale (VAS) for pain assessment, and Bruxoff examinations were conducted. Results: The reduction in pain, as measured by the visual analogue scale (VAS), among patients using the 10% CBD formulation was 57.4% (p < 0.05), accompanied by a decrease in sEMG activity by 42.1% (p < 0.05). Conversely, individuals using the 5% CBD formulation experienced a 40.8% (p < 0.05) decrease in pain. Regarding the decrease in the sleep bruxism index, users of the 10% CBD formulation saw the highest reduction of 51% (p < 0.05). These findings underscore the efficacy of the proposed treatment in both experimental groups, with a notable advantage observed in Group 1a. Conversely, the outcomes of the selected variables for the control group did not exhibit significant differences throughout the study. Conclusions: The intraoral use of CBD formulations in patients with TMDs have proven to be a successful treatment for reducing pain, muscle tension, and bruxing activity in individuals with sleep bruxism and muscle-related TMDs. Specifically, a concentration of 10% CBD has demonstrated superior results compared to 5% CBD.

Cannabidiol Mediates In Vitro Attenuation of Proinflammatory Cytokine Responses in Psoriatic Disease

Background: Cannabidiol (CBD), a substance that belongs to the phytocannabinoids, appears to exert antioxidant, neuroprotective, antipsychotic, anticonvulsant, and anticancer properties. Recent evidence supports the immunoregulatory effect of CBD on autoimmune and/or inflammatory disease. Psoriasis is a chronic skin disease. The main immune cell population involved in the pathogenesis of the disease is the interleukin- (IL-) 17-producing T helper (Th) 17 subset. Other subpopulations, such as interferon-γ (IFNγ) -producing Th1 and T cytotoxic (Tc) 1, IL-17-producing Tc17, as well as natural killer (NK) and natural killer T cells (NKT) have been implicated in psoriasis development. Purpose: The aim of the present study was to evaluate the in vitro effect of CBD on the aforementioned subpopulations isolated from patients with psoriasis using flow cytometry. Methods: Cells were stimulated in the presence or absence of CBD, stained and examined using surface and intracellular markers. Results: CBD decreased IL-17 production within the CD3, Th, and NKT cell compartments and IFNγ production within the CD3 compartment in cells isolated from patients with psoriasis. Interestingly, CBD supplementation did not inhibit production of proinflammatory cytokines in cells isolated from healthy individuals. On the contrary, IFNγ-producing Th, Tc, and NK cells increased after CBD supplementation. Conclusion: CBD provides anti-inflammatory effects in T cells isolated from patients with psoriasis. Our results could be the impetus for future investigations regarding the immunomodulatory properties of CBD and its utilization for development of CBD-containing antipsoriatic agents.

Research Status, Synthesis and Clinical Application of Antiepileptic Drugs

According to the 2017 ILAE's official definition, epilepsy is a slow brain disease state characterized by recurrent episodes. Due to information released by ILAE in 2017, it can be divided into four types, including focal epilepsy, generalized epilepsy, combined generalized, and focal epilepsy, and unknown epilepsy. Since 1989, 24 new antiepileptic drugs have been approved to treat different types of epilepsy. Besides, there are a variety of antiepileptic medications under clinical monitoring. These novel antiepileptic drugs have plenty of advantages. Over the past 33 years, there have been many antiepileptic drugs on the mearket, but no one has been found that can completely cure epilepsy. In this paper, the mentioned drugs were classified according to their targets, and the essential information, and clinical studies of each drug were described. The structure-activity relationship of different chemical structures was summarized. This paper provides help for the follow-up research on epilepsy drugs.

New insights on the potential anti-epileptic effect of metformin: Mechanistic pathway

Epilepsy is a chronic neurological disease characterized by recurrent seizures. Epilepsy is observed as a well-controlled disease by anti-epileptic agents (AEAs) in about 69%. However, 30%-40% of epileptic patients fail to respond to conventional AEAs leading to an increase in the risk of brain structural injury and mortality. Therefore, adding some FDA-approved drugs that have an anti-seizure activity to the anti-epileptic regimen is logical. The anti-diabetic agent metformin has anti-seizure activity. Nevertheless, the underlying mechanism of the anti-seizure activity of metformin was not entirely clarified. Henceforward, the objective of this review was to exemplify the mechanistic role of metformin in epilepsy. Metformin has anti-seizure activity by triggering adenosine monophosphate-activated protein kinase (AMPK) signalling and inhibiting the mechanistic target of rapamycin (mTOR) pathways which are dysregulated in epilepsy. In addition, metformin improves the expression of brain-derived neurotrophic factor (BDNF) which has a neuroprotective effect. Hence, metformin via induction of BDNF can reduce seizure progression and severity. Consequently, increasing neuronal progranulin by metformin may explain the anti-seizure mechanism of metformin. Also, metformin reduces α-synuclein and increases protein phosphatase 2A (PPA2) with modulation of neuroinflammation. In conclusion, metformin might be an adjuvant with AEAs in the management of refractory epilepsy. Preclinical and clinical studies are warranted in this regard.

Effects of Oral Cannabidiol on Health and Fitness in Healthy Adults: An 8-Week Randomized Trial

BACKGROUND

There is a lack of research on the effects of cannabidiol (CBD) on health-related fitness, physical activity, cognitive health, psychological wellbeing, and concentrations of C-reactive protein (CRP) in healthy individuals. CBD has potential anti-inflammatory and neuroprotective effects.

METHODS

This study aimed to investigate the effects of 8 weeks of CBD on the above-mentioned measures in healthy individuals. Forty-eight participants were randomized into two groups receiving either oral capsules of 50 mg of CBD or a calorie-matched placebo daily. Participants completed pre- and post-intervention assessments, including blood draws, body composition, fitness, physical activity, and self-reported surveys.

RESULTS

There were no significant differences between groups regarding body composition, aerobic fitness, muscular strength, physical activity, cognitive health, psychological wellbeing, and resting CRP concentrations. However, the placebo group experienced a decline in mean peak power and relative peak power compared to the CBD group.

CONCLUSIONS

The results suggest that 8 weeks of CBD supplementation may prevent declines in anaerobic fitness over time. However, long-term CBD supplementation may not be beneficial for altering measures of health-related fitness, mental health, and inflammation in healthy individuals.

Place of therapeutic cannabis in France and safety data: A literature review

OBJECTIVES

To date, very few cannabis-based specialities are authorised on the French market despite a growing demand from patients and health professionals. The objective of this study is to review the tolerance profile and the French legislative status of the two main cannabinoids used for therapeutic purposes: tetrahydrocannabiol (THC) associated with psychoactive effects and non-psychoactive cannabidiol (CBD).

METHODS

This review is based on relevant articles retrieved by a search in Google Scholar and PubMed databases and on an assessment of the legal texts and summaries of product characteristics available in France.

RESULTS

Evidence for the tolerability of CBD during chronic use is reassuring, but a significant risk of drug interactions exists. THC use appears to be associated with a higher proportion of serious adverse effects, including neuropsychological and cardiovascular effects. Inhaled cannabis appears to be associated with greater toxicity than the oral route. These data are presented together with the pharmacokinetic and pharmacodynamic data of THC and CBD.

CONCLUSION

The literature reports several frequent but rarely serious adverse effects of CBD during chronic use as well as a significant risk of drug interactions. THC use seems to be associated with a higher proportion of serious adverse effects compared to CBD, particularly at the neuropsychological and cardiovascular levels. Health professionals should be up to date on the particularities of therapeutic cannabis in terms of efficacy, safety and drug interactions.

Scientific Validation of Cannabidiol for Management of Dog and Cat Diseases

Cannabidiol (CBD) is a non-psychotropic phytocannabinoid of the plant Cannabis sativa L. CBD is increasingly being explored as an alternative to conventional therapies to treat health disorders in dogs and cats. Mechanisms of action of CBD have been investigated mostly in rodents and in vitro and include modulation of CB1, CB2, 5-HT, GPR, and opioid receptors. In companion animals, CBD appears to have good bioavailability and safety profile with few side effects at physiological doses. Some dog studies have found CBD to improve clinical signs associated with osteoarthritis, pruritus, and epilepsy. However, further studies are needed to conclude a therapeutic action of CBD for each of these conditions, as well as for decreasing anxiety and aggression in dogs and cats. Herein, we summarize the available scientific evidence associated with the mechanisms of action of CBD, including pharmacokinetics, safety, regulation, and efficacy in ameliorating various health conditions in dogs and cats.

Cannabidiol: Bridge between Antioxidant Effect, Cellular Protection, and Cognitive and Physical Performance

The literature provides scientific evidence for the beneficial effects of cannabidiol (CBD), and these effects extend beyond epilepsy treatment (e.g., Lennox-Gastaut and Dravet syndromes), notably the influence on oxidative status, neurodegeneration, cellular protection, cognitive function, and physical performance. However, products containing CBD are not allowed to be marketed everywhere in the world, which may ultimately have a negative effect on health as a result of the uncontrolled CBD market. After the isolation of CBD follows the discovery of CB1 and CB2 receptors and the main enzymatic components (diacylglycerol lipase (DAG lipase), monoacyl glycerol lipase (MAGL), fatty acid amino hydrolase (FAAH)). At the same time, the antioxidant potential of CBD is due not only to the molecular structure but also to the fact that this compound increases the expression of the main endogenous antioxidant systems, superoxide dismutase (SOD), and glutathione peroxidase (GPx), through the nuclear complex erythroid 2-related factor (Nrf2)/Keep1. Regarding the role in the control of inflammation, this function is exercised by inhibiting (nuclear factor kappa B) NF-κB, and also the genes that encode the expression of molecules with a pro-inflammatory role (cytokines and metalloproteinases). The other effects of CBD on cognitive function and physical performance should not be excluded. In conclusion, the CBD market needs to be regulated more thoroughly, given the previously listed properties, with the mention that the safety profile is a very good one.

Cannabidiol attenuates generalized tonic-clonic and suppresses limbic seizures in the genetically epilepsy-prone rats (GEPR-3) strain

BACKGROUND

Cannabidiol (CBD) has been of rapidly growing interest in the epilepsy research field due to its antiseizure properties in preclinical models and patients with pharmacoresistant epilepsy. However, little is known about CBD effects in genetic models of epilepsies. Here we assessed CBD dose-response effects in the Genetically Epilepsy Prone Rats (GEPR-3) strain, which exhibits two types of epileptic seizures, brainstem-dependent generalized tonic-clonic seizures and limbic seizures.

METHODS

GEPR-3 s were submitted to the audiogenic seizure (AGS) protocol. Acute AGS are brainstem-dependent generalized tonic-clonic, while repeated AGS (or audiogenic kindling, AK), an epileptogenic process, leads to increased AGS severity and limbic seizure expression. Therefore, two different dose-response studies were performed, one for generalized tonic-clonic seizures and the other for limbic seizures. CBD time-course effects were assessed 2, 4, and 6 h after drug injection. GEPR-3 s were submitted to within-subject tests, receiving intraperitoneal injections of CBD (1, 10, 50, 100 mg/kg/ml) and vehicle.

RESULTS

CBD dose-dependently attenuated generalized tonic-clonic seizures in GEPR-3 s; CBD 50 and 100 mg/kg reduced brainstem-dependent seizure severity and duration. In fully kindled GEPR-3 s, CBD 10 mg/kg reduced limbic seizure severity and suppressed limbic seizure expression in 75% of animals.

CONCLUSIONS

CBD was effective against brainstem and limbic seizures in the GEPR-3 s. These results support the use of CBD treatment for epilepsies by adding new information about the pharmacological efficacy of CBD in suppressing inherited seizure susceptibility in the GEPR-3 s.

Advances and Challenges of Cannabidiol as an Anti-Seizure Strategy: Preclinical Evidence

The use of Cannabis for medicinal purposes has been documented since ancient times, where one of its principal cannabinoids extracted from Cannabis sativa, cannabidiol (CBD), has emerged over the last few years as a promising molecule with anti-seizure potential. Here, we present an overview of recent literature pointing out CBD's pharmacological profile (solubility, metabolism, drug-drug interactions, etc.,), CBD's interactions with multiple molecular targets as well as advances in preclinical research concerning its anti-seizure effect on both acute seizure models and chronic models of epilepsy. We also highlight the recent attention that has been given to other natural cannabinoids and to synthetic derivatives of CBD as possible compounds with therapeutic anti-seizure potential. All the scientific research reviewed here encourages to continue to investigate the probable therapeutic efficacy of CBD and its related compounds not only in epilepsy but also and specially in drug-resistant epilepsy, since there is a dire need for new and effective drugs to treat this disease.

Chronic Pain and Cannabidiol in Animal Models: Behavioral Pharmacology and Future Perspectives

The incidence of chronic pain is around 8% in the general population, and its impact on quality of life, mood, and sleep exceeds the burden of its causal pathology. Chronic pain is a complex and multifaceted problem with few effective and safe treatment options. It can be associated with neurological diseases, peripheral injuries or central trauma, or some maladaptation to traumatic or emotional events. In this perspective, animal models are used to assess the manifestations of neuropathy, such as allodynia and hyperalgesia, through nociceptive tests, such as von Frey, Hargreaves, hot plate, tail-flick, Randall & Selitto, and others. Cannabidiol (CBD) has been considered a promising strategy for treating chronic pain and diseases that have pain as a consequence of neuropathy. However, despite the growing body of evidence linking the efficacy of CBD on pain management in clinical and basic research, there is a lack of reviews focusing on chronic pain assessments, especially when considering pre-clinical studies, which assess chronic pain as a disease by itself or as a consequence of trauma or peripheral or central disease. Therefore, this review focused only on studies that fit our inclusion criteria: (1) used treatment with CBD extract; (2) used tests to assess mechanical or thermal nociception in at least one of the following most commonly used tests (von Frey, hot plate, acetone, Hargreaves, tail-flick, Randall & Selitto, and others); and (3) studies that assessed pain sensitivity in chronic pain induction models. The current literature points out that CBD is a well-tolerated and safe natural compound that exerts analgesic effects, decreasing hyperalgesia, and mechanical/thermal allodynia in several animal models of pain and patients. In addition, CBD presents several molecular and cellular mechanisms of action involved in its positive effects on chronic pain. In conclusion, using CBD seems to be a promising strategy to overcome the lack of efficacy of conventional treatment for chronic pain.

Role of Cannabidiol for Improvement of the Quality of Life in Cancer Patients: Potential and Challenges

There is currently a growing interest in the use of cannabidiol (CBD) to alleviate the symptoms caused by cancer, including pain, sleep disruption, and anxiety. CBD is often self-administered as an over-the-counter supplement, and patients have reported benefits from its use. However, despite the progress made, the mechanisms underlying CBD’s anti-cancer activity remain divergent and unclear. Herein, we provide a comprehensive review of molecular mechanisms to determine convergent anti-cancer actions of CBD from pre-clinical and clinical studies. In vitro studies have begun to elucidate the molecular targets of CBD and provide evidence of CBD’s anti-tumor properties in cell and mouse models of cancer. Furthermore, several clinical trials have been completed testing CBD’s efficacy in treating cancer-related pain. However, most use a mixture of CBD and the psychoactive, tetrahydrocannabinol (THC), and/or use variable dosing that is not consistent between individual patients. Despite these limitations, significant reductions in pain and opioid use have been reported in cancer patients using CBD or CBD+THC. Additionally, significant improvements in quality-of-life measures and patients’ overall satisfaction with their treatment have been reported. Thus, there is growing evidence suggesting that CBD might be useful to improve the overall quality of life of cancer patients by both alleviating cancer symptoms and by synergizing with cancer therapies to improve their efficacy. However, many questions remain unanswered regarding the use of CBD in cancer treatment, including the optimal dose, effective combinations with other drugs, and which biomarkers/clinical presentation of symptoms may guide its use.

A complex systems view on the current hypotheses of epilepsy pharmacoresistance

Drug-resistant epilepsy remains to this day as a highly prevalent condition affecting around one-third of patients with epilepsy, despite all the research and the development of several new antiseizure medications (ASMs) over the last decades. Epilepsies are multifactorial complex diseases, commonly associated with psychiatric, neurological, and somatic comorbidities. Thus, to solve the puzzling problem of pharmacoresistance, the diagnosis and modeling of epilepsy and comorbidities need to change toward a complex system approach. In this review, we have summarized the sequence of events for the definition of epilepsies and comorbidities, the search for mechanisms, and the major hypotheses of pharmacoresistance, drawing attention to some of the many converging aspects between the proposed mechanisms, their supporting evidence, and comorbidities-related alterations. The use of systems biology applied to epileptology may lead to the discovery of new targets and the development of new ASMs, as may advance our understanding of the epilepsies and their comorbidities, providing much deeper insight on multidrug pharmacoresistance.

Effects of cannabidiol on weight and fasting blood sugar with chronic and subchronic haloperidol administration

OBJECTIVES

The duration of administration (e.g., subchronic or chronic) of haloperidol may influence its adverse effects. We studied the effects of duration of administration of haloperidol on body weight and fasting blood sugar (FBS). In addition, we examined whether orally administered cannabidiol (CBD) had any putative mitigating influence on haloperidol-induced body weight changes and FBS elevation.

METHODS

Haloperidol (5 mg/kg/day) was administered for 21 days (subchronic administration), via the intraperitoneal (IP) route, or monthly (50 mg/kg monthly) for 3 months (chronic administration), via the intramuscular (IM) route, either alone or before CBD (5 mg/kg/day). Oral CBD (5 mg/kg/day) alone and distilled water alone were administered for 21 days. Weight and FBS were measured before administration of pharmacological agents (distilled water in the control group) and post-administration.

RESULTS

Group differences in average weight across time were significant. Pairwise comparisons showed that mean weight of the subchronic (IP) haloperidol alone group (Group A) and the chronic (IM) haloperidol before CBD group (Group F) increased significantly over time. Post medications, there was a significant increase in mean FBS in the subchronic (IP) haloperidol group compared to the subchronic (IP) haloperidol before CBD group. There was also a significant reduction in mean FBS from the baseline for the control group only.

CONCLUSION

We demonstrated that the duration of administration of haloperidol influenced weight and FBS in rats, suggesting that metabolic side effects, may be influenced by duration of administration. CBD ameliorated the increase in weight and FBS observed in the subchronic (IP) haloperidol groups.

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.

Hemp Seeds, Flaxseed, and Açaí Berries: Health Benefits and Nutritional Importance with Emphasis on the Lipid Content

Abstract:

Some plant seeds and berries have gained increased recognition due to their wide variety of bioactive compounds. Many of these foods are rich in lipids with high nutritional value, of which n-3 and n-6 essential fatty acids stand out. However, knowledge of the chemical composition and biological activity of these compounds and their value as a source of healthy lipids is far from being fully explored. The benefits of the intake of hemp seeds, flaxseed, and açaí berries, considered functional foods, have been compiled in this review. Likewise, their general chemical composition will be described to evaluate their relevance in a healthy diet, highlighting their lipid components and health lipid indices. The fibres and essential fatty acids of hemp seeds and flaxseed and the antioxidant properties of açaí berries provide them protective roles against several chronic non-communicable diseases and represent significant beneficial effects that add value to these healthy natural products. More research is needed to deepen the knowledge on their lipids’ molecular composition and bioactivity.

Channelopathy of Dravet Syndrome and Potential Neuroprotective Effects of Cannabidiol

Dravet syndrome (DS) is a channelopathy, neurodevelopmental, epileptic encephalopathy characterized by seizures, developmental delay, and cognitive impairment that includes susceptibility to thermally induced seizures, spontaneous seizures, ataxia, circadian rhythm and sleep disorders, autistic-like behaviors, and premature death. More than 80% of DS cases are linked to mutations in genes which encode voltage-gated sodium channel subunits, SCN1A and SCN1B, which encode the Nav1.1α subunit and Nav1.1β1 subunit, respectively. There are other gene mutations encoding potassium, calcium, and hyperpolarization-activated cyclic nucleotide-gated (HCN) channels related to DS. One-third of patients have pharmacoresistance epilepsy. DS is unresponsive to standard therapy. Cannabidiol (CBD), a non-psychoactive phytocannabinoid present in Cannabis, has been introduced for treating DS because of its anticonvulsant properties in animal models and humans, especially in pharmacoresistant patients. However, the etiological channelopathiological mechanism of DS and action mechanism of CBD on the channels are unclear. In this review, we summarize evidence of the direct and indirect action mechanism of sodium, potassium, calcium, and HCN channels in DS, especially sodium subunits. Some channels' loss-of-function or gain-of-function in inhibitory or excitatory neurons determine the balance of excitatory and inhibitory are associated with DS. A great variety of mechanisms of CBD anticonvulsant effects are focused on modulating these channels, especially sodium, calcium, and potassium channels, which will shed light on ionic channelopathy of DS and the precise molecular treatment of DS in the future.

Combined Antiseizure Efficacy of Cannabidiol and Clonazepam in a Conditional Mouse Model of Dravet Syndrome

Dravet Syndrome (DS) is a severe childhood epilepsy caused by heterozygous loss-of-function mutations in the SCN1A gene encoding brain type-I voltage-gated sodium channel Na_v1.1. DS is a devastating disease that typically begins at six to nine months of age. Symptoms include recurrent intractable seizures and premature death with severe neuropsychiatric comorbidities, including hyperactivity, sleep disorder, anxiety-like behaviors, impaired social interactions, and cognitive deficits. There is an urgent unmet need for therapeutic approaches that control and cure DS, as available therapeutic interventions have poor efficacy, intolerance, or other side effects. Here we investigated the therapeutic potential of combining the benzodiazepine clonazepam (CLZ) with the nonpsychotropic phytocannabinoid cannabidiol (CBD) against thermally induced febrile seizures in a conditional mouse model of DS. Our results show that a low dose of CLZ alone or combined with CBD elevated the threshold temperature for the thermal induction of seizures. Combination of CLZ with CBD significantly reduced seizure duration compared to the vehicle or CLZ alone, but did not affect seizure severity, indicating potential additive actions of CLZ and CBD on the duration of seizures. Our findings provide preclinical evidence supporting combination therapy of CLZ and CBD for treatment of febrile seizures in 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.

The Impact of Cannabidiol on the Induction of Isoflurane Anesthesia and Recovery in Wistar Rats

Background: Beside others, neuroinhibitory and sedative effects of CBD were documented. Aim and Methods: The aim of the study was to assess the dose-related effects of CBD premedication on the course of isoflurane anesthesia. Wistar rats were pretreated with different doses of CBD 1 h before isoflurane anesthesia. In the pretreatment, animals were given CBD at doses of 100, 20, 10, or 2 mg kg^-1. Before the fifth (control) anesthesia, the animals were given only mid-chain triglyceride oil, which served as a solvent in the CBD formulation. The induction time was determined, and on awakening, the time to appearance of the flexion reflex and the recovery from anesthesia were determined. Results: Statistical analysis showed a significantly shorter induction time if animals were pretreated with 20 mg kg^-1 CBD. In addition, pretreatment with 100 mg kg^-1 CBD resulted in a prolonged induction time, while on awakening, delayed appearance of reflexes and prolonged recovery from anesthesia compared to pretreatment with 20 mg kg^-1 CBD were observed. Conclusions: The results indicate that the influence of CBD on the course of isoflurane anesthesia depends on the dose and can reduce the induction time. Although this study was performed in laboratory rats, in clinical practice, these data should be considered when CBD-treated patients undergo isoflurane anesthesia.

The (Poly)Pharmacology of Cannabidiol in Neurological and Neuropsychiatric Disorders: Molecular Mechanisms and Targets

Cannabidiol (CBD), the major nonpsychoactive Cannabis constituent, has been proposed for the treatment of a wide panel of neurological and neuropsychiatric disorders, including anxiety, schizophrenia, epilepsy and drug addiction due to the ability of its versatile scaffold to interact with diverse molecular targets that are not restricted to the endocannabinoid system. Albeit the molecular mechanisms responsible for the therapeutic effects of CBD have yet to be fully elucidated, many efforts have been devoted in the last decades to shed light on its complex pharmacological profile. In particular, an ever-increasing number of molecular targets linked to those disorders have been identified for this phytocannabinoid, along with the modulatory effects of CBD on their cascade signaling. In this view, here we will try to provide a comprehensive and up-to-date overview of the molecular basis underlying the therapeutic effects of CBD involved in the treatment of neurological and neuropsychiatric disorders.

Cannabidiol in Neurological and Neoplastic Diseases: Latest Developments on the Molecular Mechanism of Action

As the major nonpsychotropic constituent of Cannabis sativa, cannabidiol (CBD) is regarded as one of the most promising therapeutic agents due to its proven effectiveness in clinical trials for many human diseases. Due to the urgent need for more efficient pharmacological treatments for several chronic diseases, in this review, we discuss the potential beneficial effects of CBD for Alzheimer's disease, epilepsy, multiple sclerosis, and neurological cancers. Due to its wide range of pharmacological activities (e.g., antioxidant, anti-inflammatory, and neuroprotective properties), CBD is considered a multimodal drug for the treatment of a range of neurodegenerative disorders, and various cancer types, including neoplasms of the neural system. The different mechanisms of action of CBD are here disclosed, together with recent progress in the use of this cannabis-derived constituent as a new therapeutic approach.

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.

Cannabinoids in Audiogenic Seizures: From Neuronal Networks to Future Perspectives for Epilepsy Treatment

Cannabinoids and Cannabis-derived compounds have been receiving especial attention in the epilepsy research scenario. Pharmacological modulation of endocannabinoid system's components, like cannabinoid type 1 receptors (CB1R) and their bindings, are associated with seizures in preclinical models. CB1R expression and functionality were altered in humans and preclinical models of seizures. Additionally, Cannabis-derived compounds, like cannabidiol (CBD), present anticonvulsant activity in humans and in a great variety of animal models. Audiogenic seizures (AS) are induced in genetically susceptible animals by high-intensity sound stimulation. Audiogenic strains, like the Genetically Epilepsy Prone Rats, Wistar Audiogenic Rats, and Krushinsky-Molodkina, are useful tools to study epilepsy. In audiogenic susceptible animals, acute acoustic stimulation induces brainstem-dependent wild running and tonic-clonic seizures. However, during the chronic protocol of AS, the audiogenic kindling (AuK), limbic and cortical structures are recruited, and the initially brainstem-dependent seizures give rise to limbic seizures. The present study reviewed the effects of pharmacological modulation of the endocannabinoid system in audiogenic seizure susceptibility and expression. The effects of Cannabis-derived compounds in audiogenic seizures were also reviewed, with especial attention to CBD. CB1R activation, as well Cannabis-derived compounds, induced anticonvulsant effects against audiogenic seizures, but the effects of cannabinoids modulation and Cannabis-derived compounds still need to be verified in chronic audiogenic seizures. The effects of cannabinoids and Cannabis-derived compounds should be further investigated not only in audiogenic seizures, but also in epilepsy related comorbidities present in audiogenic strains, like anxiety, and depression.

SNP in Potentially Defunct Tetrahydrocannabinolic Acid Synthase Is a Marker for Cannabigerolic Acid Dominance in Cannabis sativa L

The regulation of cannabinoid synthesis in Cannabis sativa is of increasing research interest as restrictions around the globe loosen to allow the plant's legal cultivation. Of the major cannabinoids, the regulation of cannabigerolic acid (CBGA) production is the least understood. The purpose of this study was to elucidate the inheritance of CBGA dominance in C. sativa and describe a marker related to this chemotype. We produced two crossing populations, one between a CBGA dominant cultivar and a tetrahydrocannabinolic acid (THCA) dominant cultivar, and one between a CBGA dominant cultivar and a cannabidiolic acid (CBDA) cultivar. Chemical and genotyping analyses confirmed that CBGA dominance is inherited as a single recessive gene, potentially governed by a non-functioning allelic variant of the THCA synthase. The "null" THCAS synthase contains a single nucleotide polymorphism (SNP) that may render the synthase unable to convert CBGA to THCA leading to the accumulation of CBGA. This SNP can be reliably used as a molecular marker for CBGA dominance in the selection and breeding of C. sativa.

Is Cannabidiol During Neurodevelopment a Promising Therapy for Schizophrenia and Autism Spectrum Disorders?

Schizophrenia and autism spectrum disorders (ASD) are psychiatric neurodevelopmental disorders that cause high levels of functional disabilities. Also, the currently available therapies for these disorders are limited. Therefore, the search for treatments that could be beneficial for the altered course of the neurodevelopment associated with these disorders is paramount. Preclinical and clinical evidence points to cannabidiol (CBD) as a promising strategy. In this review, we discuss clinical and preclinical studies on schizophrenia and ASD investigating the behavioral, molecular, and functional effects of chronic treatment with CBD (and with cannabidivarin for ASD) during neurodevelopment. In summary, the results point to CBD's beneficial potential for the progression of these disorders supporting further investigations to strengthen its use.

Behavioral and Molecular Effects Induced by Cannabidiol and Valproate Administration in the GASH/Sal Model of Acute Audiogenic Seizures

Despite evidence that supports cannabidiol (CBD) as an anticonvulsant agent, there remains controversy over the antiseizure efficacy, possible adverse effects, and synergistic interactions with classic antiepileptics such as valproate (VPA). The genetic audiogenic seizure hamster from the University of Salamanca (GASH/Sal) is a reliable experimental model of generalized tonic–clonic seizures in response to intense sound stimulation. The present study examines the behavioral and molecular effects of acute and chronic intraperitoneal administrations of VPA (300 mg/kg) and CBD (100 mg/kg) on the GASH/Sal audiogenic seizures, as well as the coadministration of both drugs. The GASH/Sal animals were examined prior to and after the corresponding treatment at 45 min, 7 days, and 14 days for seizure severity and neuroethology, open-field behaviors, body weight variations, and various hematological and biochemical parameters. Furthermore, the brain tissue containing the inferior colliculus (so-called epileptogenic nucleus) was processed for reverse transcription–quantitative polymerase chain reaction analysis to determine the treatment effects on the gene expression of neuronal receptors associated with drug actions and ictogenesis. Our results indicated that single dose of VPA helps prevent the animals from getting convulsions, showing complete elimination of seizures, whereas 7 days of chronic VPA treatment had few effects in seizure behaviors. Acute CBD administration showed subtle attenuation of seizure behaviors, increasing seizure latency and decreasing the duration of the convulsion phase, but without entirely seizure abolition. Chronic CBD treatments had no significant effects on sound-induced seizures, although some animals slightly improved seizure severity. Acute and chronic CBD treatments have no significant adverse effects on body weight, hematological parameters, and liver function, although locomotor activity was reduced. The combination of VPA and CBD did not alter the therapeutic outcome of the VPA monotherapy, showing no apparent synergistic effects. As compared to sham animals, chronic treatments with CBD caused abnormal mRNA expression levels for Trpv1, Adora1, Slc29a1, and Cnr1 genes, whereas no differences in gene expression were found for Htr1a and Sigmar1. Our study shed light on the behavioral and molecular effects of CBD and VPA on the GASH/Sal model and constituted the basis to develop further studies on the pharmacological effects of CBD and its interactions with other anticonvulsants.

Cannabidiol in the treatment of epilepsy: Current evidence and perspectives for further research

The therapeutic potential of cannabidiol (CBD) in seizure disorders has been known for many years, but it is only in the last decade that major progress has been made in characterizing its preclinical and clinical properties as an antiseizure medication. The mechanisms responsible for protection against seizures are not fully understood, but they are likely to be multifactorial and to include, among others, antagonism of G protein-coupled receptor, desensitization of transient receptor potential vanilloid type 1 channels, potentiation of adenosine-mediated signaling, and enhancement of GABAergic transmission. CBD has a low and highly variable oral bioavailability, and can be a victim and perpetrator of many drug-drug interactions. A pharmaceutical-grade formulation of purified CBD derived from Cannabis sativa has been evaluated in several randomized placebo-controlled adjunctive-therapy trials, which resulted in its regulatory approval for the treatment of seizures associated with Dravet syndrome, Lennox-Gastaut syndrome and tuberous sclerosis complex. Interpretation of results of these trials, however, has been complicated by the occurrence of an interaction with clobazam, which leads to a prominent increase in the plasma concentration of the active metabolite N-desmethylclobazam in CBD-treated patients. Despite impressive advances, significant gaps in knowledge still remain. Areas that require further investigation include the mechanisms underlying the antiseizure activity of CBD in different syndromes, its pharmacokinetic profile in infants and children, potential relationships between plasma drug concentration and clinical response, interactions with other co-administered medications, potential efficacy in other epilepsy syndromes, and magnitude of antiseizure effects independent from interactions with clobazam. This article is part of the special issue on 'Cannabinoids'.

Cannabidiol: pharmacology and therapeutic targets

RATIONALE

Cannabidiol (CBD) products lacking regulatory approval are being used to self-treat a myriad of conditions and for their unsubstantiated health benefits. The scientific evidence supporting these claims largely arises not from controlled clinical trials, but from the recognition that CBD has numerous biological targets. Yet, CBD is commonly consumed and often in over-the-counter products that are unapproved and of unknown composition. Epidiolex® is the only product that has undergone rigorous pharmacokinetic assessment and testing in clinical trials; it was approved as a non-scheduled drug by the U.S. Food and Drug Administration for the treatment of intractable childhood-onset seizures. However, studies investigating CBD for other medical conditions are limited in number and often lack the scientific rigor, controls, or sample sizes required to draw clinically meaningful conclusions. Although Epidiolex® is safe for human consumption, recent changes in regulation of commercially available CBD products have resulted in limited quality control and products marketed with unknown CBD bioavailability. Even scientifically rigorous studies have used different sources of CBD and different suspension vehicles for administration, making it difficult to compare results among studies and resolve mixed outcomes.

OBJECTIVES

This paper reviews the molecular targets, pharmacokinetics, and safety and abuse liability of CBD; additionally, the extant evidence on its potential therapeutic effects for neurological disorders, pain, inflammation, conditions related to immune function, psychiatric disorders, and substance use are described.

A survey of Δ9-THC and relevant cannabinoids in products from the Italian market: A study by LC-MS/MS of food, beverages and feed

In 2016, the European Commission recommended the Member States to monitor the content of Δ⁹-tetrahydrocannabinol and other cannabinoids in food and feed derived from hemp and in food of animal origin for possible transfer from feed. Thus, the Italian Ministry of Health implemented a monitoring plan. To this aim, nine cannabinoids in beverages and food for human consumption and in feed were determined. The method applied, based on rapid clean-up and LC-MS/MS determination, was previously developed and in-house validated, evaluating the analytical performance in the concentration ranges 2-50 µg/L for beverages, 0.020-0.500 mg/kg for food and 0.100-10.0 mg/kg for feed. Then, it was applied to determine the cannabinoids in 78 food, 16 beverage and 6 feed samples, collected from the Italian market since 2017. The results are herein reported, for evaluation of both product characteristics and compliance to national maximum limits. Some study cases are also described.

Cannabinoid Receptor Type 1 (CB1R) Expression in Limbic Brain Structures After Acute and Chronic Seizures in a Genetic Model of Epilepsy

The endocannabinoid system (ECS) is related to several physiological processes, associated to the modulation of brain excitability, with impact in the expression of susceptibility and control of epileptic seizures. The cannabinoid receptor type 1 (CB1R) is widely expressed in the brain, especially in forebrain limbic structures. Changes in CB1R expression are associated with epileptic seizures in animal models and humans. The Wistar Audiogenic Rat (WAR) strain is a genetic model of epilepsy capable of mimicking tonic-clonic and limbic seizures in response to intense sound stimulation. The WAR strain presents several behavioral and physiological alterations associated with seizure susceptibility, but the ECS has never been explored in this strain. Therefore, the aim of the present study was to characterize CB1R expression in forebrain limbic structures important to limbic seizure expression in WARs. We used a detailed anatomical analysis to assess the effects of acute and chronic audiogenic seizures on CB1R expression in several layers and regions of hippocampus and amygdala. WARs showed increased CB1R immunostaining in the inner molecular layer of the hippocampus, when compared to control Wistar rats. Acute and chronic audiogenic seizures increased CB1R immunostaining in several regions of the dorsal hippocampus and amygdala of WARs. Also, changes in CB1R expression in the amygdala, but not in the hippocampus, were associated with limbic recruitment and limbic seizure severity in WARs. Our results suggest that endogenous alterations in CB1R immunostaining in WARs could be associated with genetic susceptibility to audiogenic seizures. We also demonstrated CB1R neuroplastic changes associated with acute and chronic seizures in the amygdala and hippocampus. Moreover, the present study brings important information regarding CB1R and seizure susceptibility in a genetic model of seizures and supports the relationship between ECS and epilepsy.

Cannabidiol reduces soman-induced lethality and seizure severity in female plasma carboxylesterase knockout mice treated with midazolam

Cannabidiol, approved for treatment of pediatric refractory epilepsy, has anti-seizure effects in various animal seizure models. Chemical warfare nerve agents, including soman, are organophosphorus chemicals that can induce seizure and death if untreated or if treatment is delayed. Our objective was to evaluate whether cannabidiol would ameliorate soman-induced toxicity using a mouse model that similar to humans lacks plasma carboxylesterase. In the present study, adult female plasma carboxylesterase knockout (Es1-/-) mice were pre-treated with cannabidiol (20-150 mg/kg) or vehicle 1 h prior to exposure to a seizure-inducing dose of soman and evaluated for survival and seizure activity. The muscarinic antagonist atropine sulfate and the oxime HI-6 were administered at 1 min after exposure, and the benzodiazepine midazolam was administered at 30 min after seizure onset. Cannabidiol (150 mg/kg) pre-treatment led to a robust increase in survival rate and attenuated body weight loss in soman-exposed mice treated with medical countermeasures, compared to mice pre-treated with vehicle. In addition, mice pretreated with cannabidiol (150 mg/kg) had a modest reduction in seizure severity after midazolam treatment compared to vehicle-pretreated. These findings of improved outcome with cannabidiol administration in a severe seizure model of soman exposure provide additional pre-clinical support for the benefits of cannabidiol against exposure to seizure-inducing chemical agents and suggest cannabidiol may augment the anti-seizure effects of midazolam.

Cannabidiol Treatment for Refractory Epilepsies in Pediatrics

Cannabis extracts in oil are becoming increasingly available, and, during the last years, there has been growing public and scientific interest about therapeutic properties of these compounds for the treatment of several neurologic diseases, not just epilepsy. The discovered role of the endocannabinoid system in epileptogenesis has provided the basis to investigate the pharmacological use of exogenously produced cannabinoids, to treat epilepsy. Although, physicians show reluctance to recommend Cannabis extracts given the lack of high-quality safety available data, from literature data cannabidiol (CBD) results to be a promising and safe anticonvulsant drug with low side-effect. In particular, according to early studies, CBD can reduce the frequency of seizures and lead to improvements in quality of life in children affected by refractory epilepsy. So, for these reasons, the detailed study of the interactions between CBD and anticonvulsant drugs (AEDs) administered simultaneously in polytherapy, is arousing increasing interest, to clarify and to assess the incidence of adverse effects and the relation between dose escalation and quality of life measures. To date, in pediatric age, CBD efficacy and safety is not supported by well-designed trials and strong scientific evidence are not available. These studies are either retrospective or small-scale observational and only during the last years Class I evidence data for a pure form of CBD have been available, as demonstrated in placebo-controlled RCTs for patients affected by Lennox-Gastaut syndrome and Dravet syndrome. It is necessary to investigate CBD safety, pharmacokinetics and interaction with other AEDs alongside performing double-blinded placebo-controlled trials to obtain conclusive data on its efficacy and safety in the most frequent epilepsies in children, not just in the epileptic encephalopathy. This review was aimed to revise the available data to describe the scientific evidence for CBD in Pediatric Epilepsies.