The direct actions of cannabidiol and 2-arachidonoyl glycerol at GABA A receptors

Recent developments on triazole nucleus in anticonvulsant compounds: a review

Epilepsy is one of the common diseases seriously threatening life and health of human. More than 50 million people are suffering from this condition and anticonvulsant agents are the main treatment. However, side effects and intolerance, and a lack of efficacy limit the application of the current anticonvulsant agents. The search for new anticonvulsant agents with higher efficacy and lower toxicity continues to be the focus and task in medicinal chemistry. Numbers of triazole derivatives as clinical drugs or candidates have been frequently employed for the treatment of various types of diseases, which have proved the importance of this heterocyclic nucleus in drug design and discovery. Recently many endeavours were made to involve the triazole into the anticonvulsants design, which have brought lots of active compounds. This work is an attempt to systematically review the research of triazole derivatives in the design and development of anticonvulsant agents during the past two decades.

Cannabinoids and Pain: New Insights From Old Molecules

Cannabis has been used for medicinal purposes for thousands of years. The prohibition of cannabis in the middle of the 20th century has arrested cannabis research. In recent years there is a growing debate about the use of cannabis for medical purposes. The term ‘medical cannabis’ refers to physician-recommended use of the cannabis plant and its components, called cannabinoids, to treat disease or improve symptoms. Chronic pain is the most commonly cited reason for using medical cannabis. Cannabinoids act via cannabinoid receptors, but they also affect the activities of many other receptors, ion channels and enzymes. Preclinical studies in animals using both pharmacological and genetic approaches have increased our understanding of the mechanisms of cannabinoid-induced analgesia and provided therapeutical strategies for treating pain in humans. The mechanisms of the analgesic effect of cannabinoids include inhibition of the release of neurotransmitters and neuropeptides from presynaptic nerve endings, modulation of postsynaptic neuron excitability, activation of descending inhibitory pain pathways, and reduction of neural inflammation. Recent meta-analyses of clinical trials that have examined the use of medical cannabis in chronic pain present a moderate amount of evidence that cannabis/cannabinoids exhibit analgesic activity, especially in neuropathic pain. The main limitations of these studies are short treatment duration, small numbers of patients, heterogeneous patient populations, examination of different cannabinoids, different doses, the use of different efficacy endpoints, as well as modest observable effects. Adverse effects in the short-term medical use of cannabis are generally mild to moderate, well tolerated and transient. However, there are scant data regarding the long-term safety of medical cannabis use. Larger well-designed studies of longer duration are mandatory to determine the long-term efficacy and long-term safety of cannabis/cannabinoids and to provide definitive answers to physicians and patients regarding the risk and benefits of its use in the treatment of pain. In conclusion, the evidence from current research supports the use of medical cannabis in the treatment of chronic pain in adults. Careful follow-up and monitoring of patients using cannabis/cannabinoids are mandatory.

Cannabis and epilepsy

Click here to listen to the Podcast The one-third of people who do not gain seizure control through current treatment options need a revolution in epilepsy therapeutics. The general population appears to be showing a fundamental and rapid shift in its opinion regarding cannabis and cannabis-related drugs. It is quite possible that cannabidiol, licensed in the USA for treating rare genetic epilepsies, may open the door for the widespread legalisation of recreational cannabis. It is important that neurologists understand the difference between artisanal cannabidiol products available legally on the high street and the cannabidiol medications that have strong trial evidence. In the UK in 2018 there are multiple high-profile reports of the response of children taking cannabis-derived medication, meaning that neurologists are commonly asked questions about these treatments in clinic. We address what an adult neurologist needs to know now, ahead of the likely licensing of Epidiolex in the UK in 2019.

Cannabinoid-Based Therapies and Brain Development: Potential Harmful Effect of Early Modulation of the Endocannabinoid System

The endocannabinoid retrograde signaling pathway is widely expressed in the central nervous system, where it plays major roles in regulating synaptic plasticity (excitatory and inhibitory) through long-term potentiation and long-term depression. The endocannabinoid system (ECS) components-cannabinoid receptors, endocannabinoids and synthesis/degradation enzymes-are expressed and are functional from early developmental stages and throughout adolescent cortical development, regulating progenitor cell fate, neural differentiation, migration and survival. This may potentially confer increased vulnerability to adverse outcomes from early cannabinoid exposure. Cannabidiol (CBD) is one of the most studied exogenous cannabinoids, and CBD-enriched Cannabis extracts have been widely (and successfully) used as adjuvants to treat children with refractory epilepsy, and there is even a Food and Drug Administration (FDA)-approved drug with purified CBD derived from Cannabis. However, there is insufficient information on possible long-term changes in the central nervous system caused by cannabinoid treatments during early childhood. Like the majority of cannabinoids, CBD is able to exert its effects directly and indirectly through the ECS, which can perturb the regulatory processes mediated by this system. In addition, CBD has a large number of non-endocannabinoid targets, which can explain CBD's effects. Here, we review the current knowledge about CBD-based therapies-pure and CBD-enriched Cannabis extracts-in studies with pediatric patients, their side effects, and their mechanisms of action regarding the central nervous system and neurodevelopment aspects. Since Cannabis extracts contain Δ⁹-tetrahydrocannabinol (Δ⁹-THC), we consider that pure CBD is possibly safer for young patients. Nevertheless, CBD, as well as other natural and/or synthetic cannabinoids, should be studied in more detail as a therapeutic alternative to CBD-enriched Cannabis extracts for young patients.

A Cross-Sectional Study of Cannabidiol Users

Introduction: Preclinical and clinical studies suggest that cannabidiol (CBD) found in Cannabis spp. has broad therapeutic value. CBD products can currently be purchased online, over the counter and at Cannabis-specific dispensaries throughout most of the country, despite the fact that CBD is generally deemed a Schedule I controlled substance by the U.S. Drug Enforcement Administration and renounced as a dietary supplement ingredient by the U.S. Food and Drug Administration. Consumer demand for CBD is high and growing, but few studies have examined the reasons for increasing CBD use.

Materials and Methods: A self-selected convenience sample (n = 2409) was recruited via an online survey designed to characterize whom, how, and why individuals are currently using CBD. The anonymous questionnaire was accessed from October 25, 2017 to January 25, 2018. Participants were recruited through social media.

Results: Almost 62% of CBD users reported using CBD to treat a medical condition. The top three medical conditions were pain, anxiety, and depression. Almost 36% of respondents reported that CBD treats their medical condition(s) “very well by itself,” while only 4.3% reported “not very well.” One out of every three users reported a nonserious adverse effect. The odds of using CBD to treat a medical condition were 1.44 (95% confidence interval, 1.16–1.79) times greater among nonregular users of Cannabis than among regular users.

Conclusion: Consumers are using CBD as a specific therapy for multiple diverse medical conditions—particularly pain, anxiety, depression, and sleep disorders. These data provide a compelling rationale for further research to better understand the therapeutic potential of CBD.

Current evidence of cannabinoid-based analgesia obtained in preclinical and human experimental settings

Cannabinoids have a long record of recreational and medical use and become increasingly approved for pain therapy. This development is based on preclinical and human experimental research summarized in this review. Cannabinoid CB₁ receptors are widely expressed throughout the nociceptive system. Their activation by endogenous or exogenous cannabinoids modulates the release of neurotransmitters. This is reflected in antinociceptive effects of cannabinoids in preclinical models of inflammatory, cancer and neuropathic pain, and by nociceptive hypersensitivity of cannabinoid receptor-deficient mice. Cannabis-based medications available for humans mainly comprise Δ⁹ -tetrahydrocannabinol (THC), cannabidiol (CBD) and nabilone. During the last 10 years, six controlled studies assessing analgesic effects of cannabinoid-based drugs in human experimental settings were reported. An effect on nociceptive processing could be translated to the human setting in functional magnetic resonance imaging studies that pointed at a reduced connectivity within the pain matrix of the brain. However, cannabinoid-based drugs heterogeneously influenced the perception of experimentally induced pain including a reduction in only the affective but not the sensory perception of pain, only moderate analgesic effects, or occasional hyperalgesic effects. This extends to the clinical setting. While controlled studies showed a lack of robust analgesic effects, cannabis was nearly always associated with analgesia in open-label or retrospective reports, possibly indicating an effect on well-being or mood, rather than on sensory pain. Thus, while preclinical evidence supports cannabinoid-based analgesics, human evidence presently provides only reluctant support for a broad clinical use of cannabinoid-based medications in pain therapy.

SIGNIFICANCE

Cannabinoids consistently produced antinociceptive effects in preclinical models, whereas they heterogeneously influenced the perception of experimentally induced pain in humans and did not provide robust clinical analgesia, which jeopardizes the translation of preclinical research on cannabinoid-mediated antinociception into the human setting.