Cannabinoid pharmacology/therapeutics in chronic degenerative disorders affecting the central nervous system.

 Biochemical Pharmacology “The endocannabinoid system (ECS) exerts a modulatory effect of important functions such as neurotransmission, glial activation, oxidative stress, or protein homeostasis.

Dysregulation of these cellular processes is a common neuropathological hallmark in aging and in neurodegenerative diseases of the central nervous system (CNS). The broad spectrum of actions of cannabinoids allows targeting different aspects of these multifactorial diseases.

In this review, we examine the therapeutic potential of the ECS for the treatment of chronic neurodegenerative diseases of the CNS focusing on Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and amyotrophic lateral sclerosis.

First, we describe the localization of the molecular components of the ECS and how they are altered under neurodegenerative conditions, either contributing to or protecting cells from degeneration.

Second, we address recent advances in the modulation of the ECS using experimental models through different strategies including the direct targeting of cannabinoid receptors with agonists or antagonists, increasing the endocannabinoid tone by the inhibition of endocannabinoid hydrolysis, and activation of cannabinoid receptor-independent effects.

Preclinical evidence indicates that cannabinoid pharmacology is complex but supports the therapeutic potential of targeting the ECS.

Third, we review the clinical evidence and discuss the future perspectives on how to bridge human and animal studies to develop cannabinoid-based therapies for each neurodegenerative disorder.

Finally, we summarize the most relevant opportunities of cannabinoid pharmacology related to each disease and the multiple unexplored pathways in cannabinoid pharmacology that could be useful for the treatment of neurodegenerative diseases.”

https://www.ncbi.nlm.nih.gov/pubmed/30121249

https://www.sciencedirect.com/science/article/abs/pii/S000629521830337X

Emerging strategies targeting cb2 cannabinoid receptor: biased agonism and allosterism.

Biochemical Pharmacology

“During these last years, the CB2 cannabinoid receptor has emerged as a potential anti-inflammatory target in diseases such as multiple sclerosis, amyotrophic lateral sclerosis, Huntington’s disease, ischemic stroke, autoimmune diseases, osteoporosis, and cancer. However, the development of clinically useful CB2 agonists reveals to be very challenging. Allosterism and biased-signaling mechanisms at CB2 receptor may offer new avenues for the development of improved CB2 receptor-targeted therapies. Although there has been some exploration of CB1 receptor activation by new CB1 allosteric or biased-signaling ligands, the CB2 receptor is still at initial stages in this domain. In an effort to understand the molecular basis behind these pharmacological approaches, we have analyzed and summarized the structural data reported so far at CB2 receptor.”

Evidence for the use of “medical marijuana” in psychiatric and neurologic disorders.

College of Psychiatric and Neurologic Pharmacists

“Cannabis is listed as a Schedule I substance under the Controlled Substances Act of 1970, meaning the US federal government defines it as an illegal drug that has high potential for abuse and no established medical use; however, half of the states in the nation have enacted “medical marijuana” (MM) laws. Clinicians must be aware of the evidence for and against the use of MM in their patients who may consider using this substance.

RESULTS:

Publications were identified that included patients with dementia, multiple sclerosis, Parkinson disease, Huntington disease, schizophrenia, social anxiety disorder, depression, tobacco use disorder, and neuropathic pain.

DISCUSSION:

There is great variety concerning which medical conditions are approved for treatment with MM for either palliative or therapeutic benefit, depending on the state law. It is important to keep an evidence-based approach in mind, even with substances considered to be illegal under US federal law. Clinicians must weigh risks and benefits of the use of MM in their patients and should ensure that patients have tried other treatment modalities with higher levels of evidence for use when available and appropriate.”

https://www.ncbi.nlm.nih.gov/pubmed/29955495

““Medical marijuana” encompasses everything from whole-plant cannabis to synthetic cannabinoids available for commercial use approved by regulatory agencies. In determining whether MM is of clinical utility to our patients, it is important to keep in mind chemical constituents, dose, delivery, and indication. Selection of the patient appropriate for MM must be carefully considered because clinical guidelines and treatment options with stronger levels of evidence should be exhausted first in most cases. There seems to be strongest evidence for the use of MM in patients with MS and in patients with neuropathic pain; moderate evidence exists to support further research in social anxiety disorder, schizophrenia, PD, and tobacco use disorder; evidence is limited for use in patients with dementia, Huntington disease, depression, and anorexia.”

http://mhc.cpnp.org/doi/10.9740/mhc.2017.01.029?code=cpnp-site

Inhibition of endocannabinoid degradation rectifies motivational and dopaminergic deficits in the Q175 mouse model of Huntington’s disease.

Image result for neuropsychopharmacology

“Prominent motor deficits (e.g., chorea) that typify Huntington’s disease (HD) arise following a prolonged prodromal stage characterized by psychiatric disturbances. Apathy, a disorder of motivation characterized by diminished goal-directed behavior, is one of the earliest and most common psychiatric symptoms in HD, but the underlying neurobiology is unclear and treatment options are limited.

Alterations in the endocannabinoid (eCB) and dopamine systems represent prominent pathophysiological markers in HD that-similar to motivational deficits-present early and decline across disease progression. Whether changes in dopamine and eCB systems are associated with specific behavioral impairments in HD and whether these deficits are amenable to viable treatments is unknown.

Here, we show that dopaminergic encoding of effortful drive progressively declines with age in an HD mouse model, and is restored by elevating tissue levels of the eCB 2-arachidonoylglycerol (2-AG) through targeted inhibition of its enzymatic degradation.

This work supports aberrant dopaminergic encoding of reward as a neurobiological correlate of apathy in HD, and indicates that cannabinoid receptor-based therapies may benefit neuropsychiatric care for HD.”

https://www.ncbi.nlm.nih.gov/pubmed/29925886

https://www.nature.com/articles/s41386-018-0107-8

The biomedical challenge of neurodegenerative disorders: an opportunity for cannabinoid-based therapies to improve on the poor current therapeutic outcomes.

British Journal of Pharmacology banner

“At the beginning of the 21st century, the therapeutic management of neurodegenerative disorders remains a major biomedical challenge, particularly given the worldwide aging of the population over the past 50 years that is expected to continue in the forthcoming years.

This review will focus on the promise of cannabinoid based therapies to address this challenge.

Such promise is based on the broad neuroprotective profile of cannabinoids, which may cooperate to combat excitotoxicity, oxidative stress, glia-driven inflammation and protein aggregation.

Such effects may be produced by the activity of cannabinoids through their canonical targets (e.g. cannabinoid receptors, endocannabinoid enzymes) but also, via non-canonical elements and activities in distinct cell types critical for cell survival or neuronal replacement (e.g. neurons, glia, neural precursor cells).

Ultimately, the therapeutic events driven by endocannabinoid signalling reflect the activity of an endogenous system that regulates the preservation, rescue, repair and replacement of neurons and glia.”

https://www.ncbi.nlm.nih.gov/pubmed/29856067

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.14382

Methods to Quantify Cell Signaling and GPCR Receptor Ligand Bias: Characterization of Drugs that Target the Endocannabinoid Receptors in Huntington’s Disease.

Huntington’s Disease

“G protein-coupled receptors (GPCRs) interact with multiple intracellular effector proteins such that different ligands may preferentially activate one signal pathway over others, a phenomenon known as signaling bias. Signaling bias can be quantified to optimize drug selection for preclinical research.

Here, we describe moderate-throughput methods to quantify signaling bias of known and novel compounds. In the example provided, we describe a method to define cannabinoid-signaling bias in a cell culture model of Huntington’s disease (HD).

Decreasing type 1 cannabinoid receptor (CB1) levels is correlated with chorea and cognitive deficits in HD. There is evidence that elevating CB1 levels and/or signaling may be beneficial for HD patients while decreasing CB1 levels and/or signaling may be detrimental.

Recent studies have found that Gαi/o-biased CB1 agonists activate extracellular signal-regulated kinase (ERK), increase CB1 protein levels, and improve viability of cells expressing mutant huntingtin. In contrast, CB1 agonists that are β-arrestin1-biased were found to reduce CB1 protein levels and cell viability.

Measuring agonist bias of known and novel CB1 agonists will provide important data that predict CB1-specific agonists that might be beneficial in animal models of HD and, following animal testing, in HD patients. This method can also be applied to study signaling bias for other GPCRs.”

https://www.ncbi.nlm.nih.gov/pubmed/29856035

https://link.springer.com/protocol/10.1007%2F978-1-4939-7825-0_25

Cannabinoids for Treatment of Dystonia in Huntington’s Disease.

Image result for J Huntingtons Dis

“Motor symptoms in Huntington’s disease (HD) are heterogeneous with dystonia being described as a symptom with a very high prevalence not only in juvenile cases.

OBJECTIVE:

Treatment options for dystonia are limited. Cannabinoids have been described as a potential treatment for patients with dystonia of a different origin. Here, we present early onset HD patients with a marked improvement of motor symptoms mainly due to alleviation of dystonia due to treatment with cannabinoids. In addition we review the current literature concerning the use of cannabinoids in HD.

CONCLUSION:

Improvement of motor symptoms, mainly dystonia, led to several relevant improvements from a global clinical perspective such as improvement of care, gait and fine motor skills and weight gain. Moreover, we observed changes in behavior with less irritability and apathy, as well as less hypersalivation in some cases.”

https://www.ncbi.nlm.nih.gov/pubmed/29562549

https://content.iospress.com/articles/journal-of-huntingtons-disease/jhd170283

Endocannabinoid system and cannabinoids in neurogenesis – new opportunities for neurological treatment? Reports from experimental studies.

“Neurogenesis is one of the most important phenomenona affecting human life. This process consists of proliferation, migration and differentiation of neuroblasts and synaptic integrations of newborn neurons.
Proliferation of new cells continues into old age, also in humans, although the most extensive process of cell formation occurs during the prenatal period. It is possible to distinguish two regions in the brain responsible for neurogenesis: the dentate gyrus (DG) of the hippocampus and the sub-ventricular zone (SVZ). Hippocampal neurogenesis is very sensitive to various physiological and pathological stimuli.
The functional integration of the newly-born dentate granule cells into hippocampal circuitry, and their ability to mediate long-term potentiation in DG, has led to the hypothesis that neurogenesis in the adult brain may play a key role in learning and memory function, as well as cognitive dysfunction in some diseases.
Brain disorders, such as neurodegenerative diseases or traumatic brain injuries, significantly affect migration, proliferation and differentiation of neural cells. In searching for the best neurological drugs protecting neuronal cells, stimulating neurogenesis, while also developing no side-effects, endocannabinoids proved to be a strong group of substances having many beneficial properties.
Therefore, the latest data is reviewed of the various experimental studies concerning the analysis of the most commonly studied cannabinoids and their impact on neurogenesis.”

Novel insights into mitochondrial molecular targets of iron-induced neurodegeneration: reversal by cannabidiol.

Image result for Brain Res Bull.

“Evidence has demonstrated iron accumulation in specific brain regions of patients suffering from neurodegenerative disorders, and this metal has been recognized as a contributing factor for neurodegeneration.

Using an experimental model of brain iron accumulation, we have shown that iron induces severe memory deficits that are accompanied by oxidative stress, increased apoptotic markers, and decreased synaptophysin in the hippocampus of rats.

The present study aims to characterize iron loading effects as well as to determine the molecular targets of cannabidiol (CBD), the main non-psychomimetic compound of Cannabis sativa, on mitochondria.

Rats received iron in the neonatal period and CBD for 14 days in adulthood. Iron induced mitochondrial DNA (mtDNA) deletions, decreased epigenetic modulation of mtDNA, mitochondrial ferritin levels, and succinate dehydrogenase activity.

CBD rescued mitochondrial ferritin and epigenetic modulation of mtDNA, and restored succinate dehydrogenase activity in iron-treated rats.

These findings provide new insights into molecular targets of iron neurotoxicity and give support for the use of CBD as a disease modifying agent in the treatment of neurodegenerative diseases.”

https://www.ncbi.nlm.nih.gov/pubmed/29374603

A Systematic Review of the Effectiveness of Medical Cannabis for Psychiatric, Movement and Neurodegenerative Disorders.

“The discovery of endocannabinoid’s role within the central nervous system and its potential therapeutic benefits have brought forth rising interest in the use of cannabis for medical purposes. The present review aimed to synthesize and evaluate the available evidences on the efficacy of cannabis and its derivatives for psychiatric, neurodegenerative and movement disorders. A systematic search of randomized controlled trials of cannabis and its derivatives were conducted via databases (PubMed, Embase and the Cochrane Central Register of Controlled Trials). A total of 24 reports that evaluated the use of medical cannabis for Alzheimer’s disease, anorexia nervosa, anxiety, dementia, dystonia, Huntington’s disease, Parkinson’s disease, post-traumatic stress disorder (PTSD), psychosis and Tourette syndrome were included in this review. Trial quality was assessed with the Cochrane risk of bias tool. There is a lack of evidence on the therapeutic effects of cannabinoids for amyotrophic lateral sclerosis and dystonia. Although trials with positive findings were identified for anorexia nervosa, anxiety, PTSD, psychotic symptoms, agitation in Alzheimer’s disease and dementia, Huntington’s disease, and Tourette syndrome, and dyskinesia in Parkinson’s disease, definitive conclusion on its efficacy could not be drawn. Evaluation of these low-quality trials, as rated on the Cochrane risk of bias tools, was challenged by methodological issues such as inadequate description of allocation concealment, blinding and underpowered sample size. More adequately powered controlled trials that examine the long and short term efficacy, safety and tolerability of cannabis for medical use, and the mechanisms underpinning the therapeutic potential are warranted.”

https://www.ncbi.nlm.nih.gov/pubmed/29073741

http://www.cpn.or.kr/journal/view.html?doi=10.9758/cpn.2017.15.4.301