Structural basis of signaling of cannabinoids receptors: paving a way for rational drug design in controling mutiple neurological and immune diseases

Dundee University rank & funding : Compute Scotland“Cannabinoids (CBs), analgesic drugs used for thousands of years, were first found in Cannabis sativa, and the multiple CBs used medicinally, such as tetrahydrocannabinol (THC), cannabidiol (CBD) and dozens more, have complex structures. In addition to their production by plants, CBs are naturally present in the nerves and immune systems of humans and animals.

Both exogenous and endogenous CBs carry out a variety of physiological functions by engaging with two CB receptors, the CB1 and CB2 receptors, in the human endocannabinoid system (ECS). Both CB1 and CB2 are G protein-coupled receptors that share a 7-transmembrane (7TM) topology. CB1, known as the central CB receptor, is mainly distributed in the brain, spinal cord, and peripheral nervous system. CB1 activation in the human body typically promotes the release of neurotransmitters, controls pain and memory learning, and regulates metabolism and the cardiovascular system.

Clinically, CB1 is a direct drug target for drug addiction, neurodegenerative diseases, pain, epilepsy, and obesity. Unlike the exclusive expression of CB1 in the nervous system, CB2 is mainly distributed in peripheral immune cells. Selective CB2 agonists would have therapeutic potential in the treatment of inflammation and pain and avoid side effects caused by currently used clinical drugs.

Although significant progress has been made in developing agonists toward CB receptors, efficient clinical drugs targeting CB receptors remain lacking due to their complex signaling mechanisms. The recent structural elucidation of CB receptors has greatly aided our understanding of the activation and signal transduction mechanisms of CB receptors.

Recent structural characterizations of CB receptors will greatly facilitate the design of new ligands to modulate the selective functions of CB receptors. Notably, the CBD was approved by the Food and Drug Administration (FDA) in 2018 to treat epilepsy. We now look forward to more drugs targeting these two CB receptors for clinical usage in the near future.”

https://pubmed.ncbi.nlm.nih.gov/32694501/

https://www.nature.com/articles/s41392-020-00240-5

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Report of a 6-month-old Asian infant with early infantile epileptic encephalopathy whose seizures were eliminated by cannabidiol

Epilepsy & Behavior Reports “We observed that cannabidiol supplements were highly effective in treating an infant boy with drug-resistant early infantile epileptic encephalopathy, eliminating his intractable tonic seizures.

The infant began suffering clusters of brief tonic seizures from birth at 39 weeks gestation. EEG showed burst-suppression and seizures could not be controlled by trials of phenobarbital, zonisamide, vitamin B6, clobazam, levetiracetam, topiramate, phenytoin, valproate, high-dose phenobarbital, and ACTH therapy. The boy was discharged from hospital at 130 days of age still averaging tonic seizures 20-30 times per day.

We started him on a cannabidiol supplement on day 207, increasing the dosage to 18 mg/kg/d on day 219. His seizures reduced in frequency and completely disappeared by day 234. These effects were maintained, with improved EEG background, even after his other medications were discontinued.

Cannabidiol’s effectiveness in treating drug-resistant epilepsy has been confirmed in large-scale clinical trials in Europe and the United States; however, no such trials have been run in Asia. In addition, no reports to date have documented its efficacy in an infant as young as six months of age.

This important case suggests that high-dose artisanal cannabidiol may effectively treat drug-resistant epilepsy in patients without access to pharmaceutical-grade CBD.”

https://pubmed.ncbi.nlm.nih.gov/32695984/

“CBD eliminated tonic seizures in a 6-month-old Asian infant with EIEE.  We believe him to be the youngest epilepsy patient treated with CBD in the literature. High-dose artisanal CBD may be helpful in countries without access to Epidiolex.”

https://www.sciencedirect.com/science/article/pii/S2589986420300216?via%3Dihub

Enhancing ovarian cancer conventional chemotherapy through the combination with cannabidiol loaded microparticles

 European Journal of Pharmaceutics and Biopharmaceutics“In this work, we evaluated, for the first time, the antitumor effect of cannabidiol (CBD) as monotherapy and in combination with conventional chemotherapeutics in ovarian cancer and developed PLGA-microparticles as CBD carriers to optimize its anticancer activity.

Spherical microparticles, with a mean particle size around 25 µm and high entrapment efficiency were obtained. Microparticles elaborated with a CBD:polymer ratio of 10:100 were selected due to the most suitable release profile with a zero-order CBD release (14.13±0.17 μg/day/10 mg Mps) for 40 days.

The single administration of this formulation showed an in vitro extended antitumor activity for at least 10 days and an in ovo antitumor efficacy comparable to that of CBD in solution after daily topical administration (≈1.5-fold reduction in tumor growth vs control). The use of CBD in combination with paclitaxel (PTX) was really effective.

The best treatment schedule was the pre+co-administration of CBD (10µM) with PTX. Using this protocol, the single administration of microparticles was even more effective than the daily administration of CBD in solution, achieving a ≈10- and 8- fold reduction in PTX IC50 respectively. This protocol was also effective in ovo. While PTX conducted to a 1.5-fold tumor growth inhibition, its combination with both CBD in solution (daily administered) and 10-Mps (single administration) showed a 2-fold decrease.

These results show the promising potential of CBD-Mps administered in combination with PTX for ovarian cancer treatment, since it would allow to reduce the administered dose of this antineoplastic drug maintaining the same efficacy and, as a consequence, reducing PTX adverse effects.”

https://pubmed.ncbi.nlm.nih.gov/32682943/

https://www.sciencedirect.com/science/article/abs/pii/S0939641120302113?via%3Dihub

The Pro-neurogenic Effects of Cannabidiol and Its Potential Therapeutic Implications in Psychiatric Disorders

Archive of "Frontiers in Behavioral Neuroscience". “During the last decades, researchers have investigated the functional relevance of adult hippocampal neurogenesis in normal brain function as well as in the pathogenesis of diverse psychiatric conditions.

Although the underlying mechanisms of newborn neuron differentiation and circuit integration have yet to be fully elucidated, considerable evidence suggests that the endocannabinoid system plays a pivotal role throughout the processes of adult neurogenesis. Thus, synthetic, and natural cannabinoid compounds targeting the endocannabinoid system have been utilized to modulate the proliferation and survival of neural progenitor cells and immature neurons.

Cannabidiol (CBD), a constituent of the Cannabis Sativa plant, interacts with the endocannabinoid system by inhibiting fatty acid amide hydrolase (FAAH) activity (the rate-limiting enzyme for anandamide hydrolysis), allosterically modulating CB1 and CB2 receptors, and activating components of the “extended endocannabinoid system.” Congruently, CBD has shown prominent pro-neurogenic effects, and, unlike Δ9-tetrahydrocannabinol, it has the advantage of being devoid of psychotomimetic effects.

Here, we first review pre-clinical studies supporting the facilitating effects of CBD on adult hippocampal neurogenesis and available data disclosing cannabinoid mechanisms by which CBD can induce neural proliferation and differentiation. We then review the respective implications for its neuroprotective, anxiolytic, anti-depressant, and anti-reward actions.

In conclusion, accumulating evidence reveals that, in rodents, adult neurogenesis is key to understand the behavioral manifestation of symptomatology related to different mental disorders. Hence, understanding how CBD promotes adult neurogenesis in rodents could shed light upon translational therapeutic strategies aimed to ameliorate psychiatric symptomatology dependent on hippocampal function in humans.”

https://pubmed.ncbi.nlm.nih.gov/32676014/

https://www.frontiersin.org/articles/10.3389/fnbeh.2020.00109/full

Cannabidiol attenuates methamphetamine-induced conditioned place preference via the Sigma1R/AKT/GSK-3β/CREB signaling pathway in rats

 Issue Cover“Methamphetamine (METH) is a highly addictive psychostimulant.

Cannabidiol (CBD) is an exogenous cannabinoid without psychostimulating activity, which has potential therapeutic effects on opioid addiction. However, it is unclear whether CBD has therapeutic effects on METH-induced motivational effects.

The present study examines whether CBD has a protective effect on METH-induced conditioned place preference (CPP) in rats by regulating the Sigma1R and AKT-GSK3β-CREB signaling pathway.

The present study found that METH can induce CPP in rats. When a pretreatment of CBD is applied, the CBD can weaken CPP in METH-induced rats by regulating the SigmaR1/AKT/GSK-3β/CREB signaling pathway.

The results of this study indicate that CBD has a potential therapeutic effect on METH-induced rewarding effects.”

https://pubmed.ncbi.nlm.nih.gov/32670551/

https://academic.oup.com/toxres/article-abstract/9/3/202/5831937?redirectedFrom=fulltext

Understanding the basics of cannabidiol from cannabis to apply to therapeutics in epilepsy

Page Header“The compounds present in cannabis have been in use for both recreational and medicinal purposes for many centuries. Changes in the legislation in South Africa have led to an increase in the number of people interested in using these compounds for self-medication. Many of them may approach their general practitioner as the first source of information about possible therapeutic effects. It is important that medical professionals are able to give patients the correct information. Cannabidiol (CBD) is one of the main compounds in cannabis plants, and there is evidence that it can successfully treat certain patients with epilepsy. This review looks at the most recent evidence on the use of CBD in the treatment of epilepsy and explores the mechanisms behind these beneficial effects.”

https://pubmed.ncbi.nlm.nih.gov/32657678/

http://www.samj.org.za/index.php/samj/article/view/12839

Cannabidiol induces osteoblast differentiation via angiopoietin1 and p38 MAPK

Publication cover image“In this study, we report the potential of cannabidiol, one of the major cannabis constituents, for enhancing osteoblastic differentiation in U2OS and MG-63 cells.

Cannabidiol increased the expression of Angiopoietin1 and the enzyme activity of alkaline phosphatase in U2OS and MG-63. Invasion and migration assay results indicated that the cell mobility was activated by cannabidiol in U2OS and MG-63. Western blotting analysis showed that the expression of tight junction related proteins such as Claudin1, Claudin4, Occuludin1, and ZO1 was increased by cannabidiol in U2OS and MG-63.

Alizarin Red S staining analysis showed that calcium deposition and mineralization was enhanced by cannabidiol in U2OS and MG-63. Western blotting analysis indicated that the expression of osteoblast differentiation related proteins such as distal-less homeobox 5, bone sialoprotein, osteocalcin, type I collagen, Runt-related transcription factor 2 (RUNX2), osterix (OSX), and alkaline phosphatase was time dependently upregulated by cannabidiol in U2OS and MG-63. Mechanistically, cannabidiol-regulated osteoblastic differentiation in U2OS and MG-63 by strengthen the protein-protein interaction among RUNX2, OSX, or the phosphorylated p38 mitogen-activated protein kinase (MAPK).

In conclusion, cannabidiol increased Angiopoietin1 expression and p38 MAPK activation for osteoblastic differentiation in U2OS and MG-63 suggesting that cannabidiol might provide a novel therapeutic option for the bone regeneration.”

https://pubmed.ncbi.nlm.nih.gov/32656944/

https://onlinelibrary.wiley.com/doi/abs/10.1002/tox.22996

Anticonvulsive Properties of Cannabidiol in a Model of Generalized Seizure Are Transient Receptor Potential Vanilloid 1 Dependent

View details for Cannabis and Cannabinoid Research cover image“Highly purified cannabidiol (CBD) (approved as Epidiolex® in the United States) has demonstrated efficacy with an acceptable safety profile in patients with Lennox-Gastaut or Dravet syndrome in four randomized controlled trials. CBD possesses affinity for many target classes with functional effects relevant to the pathophysiology of many disease types, including epilepsy.

Although the mechanism of action of CBD underlying the reduction of seizures in humans is unknown, transient receptor potential vanilloid 1 (TRPV1) represents a plausible target because (1) CBD activates and then desensitizes TRPV1, (2) TRPV1 is overexpressed in models of temporal lobe epilepsy and patients with epilepsy, (3) and TRPV1 modulates neuronal excitability.

Methods: To investigate a potential role of TRPV1 in the anticonvulsive effects of CBD, the effect of CBD on seizure threshold was assessed using a mouse maximal electroshock threshold model of generalized seizure in TRPV1 knockout and wildtype mice. The dose dependence of the CBD effect was determined and compared with that of the positive comparator diazepam and vehicle.

Results: At 50 and 100 mg/kg, CBD significantly (p<0.0001) increased seizure threshold in wildtype mice compared with TRPV1 knockout and vehicle controls. This effect was observed only at 100 mg/kg in TRPV1 knockout mice compared with knockout vehicle mice, in which gene deletion partially attenuated the CBD-increased seizure threshold. The effect of high-dose CBD in wildtype mice was nevertheless significantly different from vehicle-treated TRPV1 knockout mice (p<0.0001). Bioanalysis confirmed that genotype-specific differential brain exposure to CBD was not responsible for the observed effect on seizure threshold.

Conclusion: These data strongly implicate TRPV1 in the potential mechanisms of action for the anticonvulsive effects of CBD. The partial inhibition of the anticonvulsive effect of high-dose CBD in TRPV1 knockout mice may indicate the involvement of targets other than TRPV1. Further characterization of TRPV1 in the anticonvulsive effect of CBD in validated models of seizure is warranted, as is pharmacological investigation of the molecular interaction between CBD and TRPV1.”

https://pubmed.ncbi.nlm.nih.gov/32656346/

https://www.liebertpub.com/doi/10.1089/can.2019.0028

Impact of Cannabis-Based Medicine on Alzheimer’s Disease by Focusing on the Amyloid β- Modifications: A Systematic Study

 “Deposition of amyloid-beta (Aβ) peptide in the brain is the leading source of the onset and progression of Alzheimer’s disease (AD). Recent studies have suggested that anti-amyloidogenic agents may be a suitable therapeutic strategy for AD.

Aim: The current review was proposed to address the beneficial effects of cannabis-based drugs for the treatment of AD, focusing primarily on Aβ modifications.

Result: A total of 17 studies were identified based on the inclusion criteria; however, nine studies qualified for this systematic review. The maximum and minimum cannabis dosages, mostly CBD and THC in animal studies, were 0.75 and 50 mg/kg, respectively. Cannabis (CBD and THC) was injected for 10 to 21 days. The findings of the 9 articles indicated that cannabis-based drugs might modulate Aβ modifications in several AD models.

Conclusion: Our findings establish that cannabis-based drugs inhibited the progression of AD by modulating Aβ modifications.”

https://pubmed.ncbi.nlm.nih.gov/32640965/

https://www.eurekaselect.com/183559/article

Evaluation of the Potential Use of Cannabidiol in the Treatment of Cocaine Use Disorder: A Systematic Review

 Pharmacology Biochemistry and Behavior“Cannabinoids may have an important therapeutic potential for the treatment of dependence on crack cocaine.

Cannabidiol (CBD), in particular, has anxiolytic, antipsychotic and anticonvulsant properties and plays a role in regulating motivation circuitry and controlling sleep disorders. Several studies were performed evaluating CBD in experimental models for cocaine.

This systematic review aims evaluate the potential use of CBD in the treatment of cocaine use disorder.

Major findings: Fifty-one studies were analyzed, and 14 were selected. No studies conducted with humans were found; only one clinical trial was ongoing. The results were grouped into the following categories: cocaine self-administration, brain-stimulation reward, conditioned place preference, neuronal proliferation, anxiety, hepatic protection, anticonvulsant effect and locomotor sensitization response Only four studies had a low risk of bias. CBD promotes reduction on cocaine self-administration. Also, it interferes in cocaine induce brain reward stimulation and dopamine release. CBD promotes alteration in contextual memory associated with cocaine and in the neuroadaptations, hepatotoxicity and seizures induced by cocaine.

Conclusion: The evidence indicates that CBD is a promising adjunct therapy for the treatment of cocaine dependence due to its effect on: cocaine reward effects, cocaine consumption, behavioral responses, anxiety, neuronal proliferation, hepatic protection and safety. Moreover, clinical trials are strongly required to determine whether the findings in animal models occur in humans diagnosed for cocaine or crack cocaine use disorder.”

https://pubmed.ncbi.nlm.nih.gov/32645315/

“CBD is a promising adjunct therapy for the treatment of cocaine dependence. CBD promotes reduction on cocaine self-administration.”

https://www.sciencedirect.com/science/article/pii/S0091305720300307?via%3Dihub