CB2 receptor activation prevents glial-derived neurotoxic mediator production, BBB leakage and peripheral immune cell infiltration and rescues dopamine neurons in the MPTP model of Parkinson’s disease

“Parkinson’s disease (PD) is characterized by the degeneration of nigrostriatal dopamine neurons.

The endocannabinoid system consists of cannabinoid receptors, their ligands and enzymes for the synthesis and degradation of cannabinoids.

Our results suggest that targeting the cannabinoid system may be beneficial for the treatment of neurodegenerative diseases, such as PD, that are associated with glial activation, BBB disruption and peripheral immune cell infiltration.

In summary, we demonstrated that activation of the CB2 receptor inhibits BBB damage, the expression of iNOS and proinflammatory cytokines/chemokines in activated microglia, the infiltration of T cells and astroglial expression of MPO, resulting in the survival of dopamine neurons in vivo in the MPTP mouse model of PD.

Therefore, it is likely that targeting the CB2 receptor may have therapeutic value in the treatment of aspects of PD related to neuroinflammation.”

http://www.nature.com/emm/journal/v48/n1/full/emm2015100a.html

The neuroprotection of cannabidiol against MPP+-induced toxicity in PC12 cells involves trkA receptors, upregulation of axonal and synaptic proteins, neuritogenesis, and might be relevant to Parkinson’s disease.

“Cannabidiol (CBD) is a non-psychoactive constituent of Cannabis sativa with potential to treat neurodegenerative diseases.

Its neuroprotection has been mainly associated with anti-inflammatory and antioxidant events; however, other mechanisms might be involved.

We investigated the involvement of neuritogenesis, NGF receptors (trkA), NGF, and neuronal proteins in the mechanism of neuroprotection of CBD against MPP+ toxicity in PC12 cells…

This is the first study to report the involvement of neuronal proteins and trkA in the neuroprotection of CBD.

Our findings suggest that CBD has a neurorestorative potential independent of NGF that might contribute to its neuroprotection against MPP+, a neurotoxin relevant to Parkinson’s disease.”

http://www.ncbi.nlm.nih.gov/pubmed/26556726

Endocannabinoids and Neurodegenerative Disorders: Parkinson’s Disease, Huntington’s Chorea, Alzheimer’s Disease, and Others.

“This review focuses on the role of the endocannabinoid signaling system in controlling neuronal survival, an extremely important issue to be considered when developing new therapies for neurodegenerative disorders.

First, we will describe the cellular and molecular mechanisms, and the signaling pathways, underlying these neuroprotective properties, including the control of glutamate homeostasis, calcium influx, the toxicity of reactive oxygen species, glial activation and other inflammatory events; and the induction of autophagy.

We will then concentrate on the preclinical studies and the few clinical trials that have been carried out targeting endocannabinoid signaling in three important chronic progressive neurodegenerative disorders (Parkinson’s disease, Huntington’s chorea, and Alzheimer’s disease), as well as in other less well-studied disorders.

We will end by offering some ideas and proposals for future research that should be carried out to optimize endocannabinoid-based treatments for these disorders.

Such studies will strengthen the possibility that these therapies will be investigated in the clinical scenario and licensed for their use in specific disorders.”

Increasing levels of the endocannabinoid 2-AG is neuroprotective in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model of Parkinson’s disease.

“Parkinson’s disease (PD) is a common chronic neurodegenerative disorder, usually of idiopathic origin. Symptoms including tremor, bradykinesia, rigidity and postural instability are caused by the progressive loss of dopaminergic neurons in the nigrostriatal region of the brain.

Symptomatic therapies are available but no treatment slows or prevents the loss of neurons.

Neuroinflammation has been implicated in its pathogenesis.

To this end, the present study utilises the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxin to reproduce the pattern of cell death evident in PD patients.

Herein, the role of a potential regulator of an immune response, the endocannabinoid system (ECS), is investigated.

The most prevalent endocannabinoid, 2-arachidonoylglycerol (2-AG) (3 and 5mg/kg), was added exogenously and its enzymatic degradation inhibited to provide protection against MPTP-induced cell death.

Furthermore, the addition of DFU (25mg/kg), a selective inhibitor of inflammatory mediator cyclooxygenase-2 (COX-2), potentiated these effects.

Levels of 2-AG were shown to be upregulated in a time- and region-specific manner following MPTP administration, indicating that the ECS represents a natural defence mechanism against inflammation, potentiation of which could provide therapeutic benefits.

The results expand the current understanding of the role that this signalling system has and its potential influence in PD.”

Cannabinoids in Neurodegenerative Disorders and Stroke/Brain Trauma: From Preclinical Models to Clinical Applications.

“Cannabinoids form a singular family of plant-derived compounds (phytocannabinoids), endogenous signaling lipids (endocannabinoids), and synthetic derivatives with multiple biological effects and therapeutic applications in the central and peripheral nervous systems.

One of these properties is the regulation of neuronal homeostasis and survival, which is the result of the combination of a myriad of effects addressed to preserve, rescue, repair, and/or replace neurons, and also glial cells against multiple insults that may potentially damage these cells.

These effects are facilitated by the location of specific targets for the action of these compounds (e.g., cannabinoid type 1 and 2 receptors, endocannabinoid inactivating enzymes, and nonendocannabinoid targets) in key cellular substrates (e.g., neurons, glial cells, and neural progenitor cells).

This potential is promising for acute and chronic neurodegenerative pathological conditions. In this review, we will collect all experimental evidence, mainly obtained at the preclinical level, supporting that different cannabinoid compounds may be neuroprotective in adult and neonatal ischemia, brain trauma, Alzheimer’s disease, Parkinson’s disease, Huntington’s chorea, and amyotrophic lateral sclerosis.

This increasing experimental evidence demands a prompt clinical validation of cannabinoid-based medicines for the treatment of all these disorders, which, at present, lack efficacious treatments for delaying/arresting disease progression…”

http://www.ncbi.nlm.nih.gov/pubmed/26260390

Cannabinoids and Tremor Induced by Motor-related Disorders: Friend or Foe?

“Tremor arises from an involuntary, rhythmic muscle contraction/relaxation cycle and is a common disabling symptom of many motor-related diseases such as Parkinson disease, multiple sclerosis, Huntington disease, and forms of ataxia.

In the wake of anecdotal, largely uncontrolled, observations claiming the amelioration of some symptoms among cannabis smokers, and the high density of cannabinoid receptors in the areas responsible for motor function, including basal ganglia and cerebellum, many researchers have pursued the question of whether cannabinoid-based compounds could be used therapeutically to alleviate tremor associated with central nervous system diseases.

In this review, we focus on possible effects of cannabinoid-based medicines, in particular on Parkinsonian and multiple sclerosis-related tremors and the common probable molecular mechanisms. While, at present, inconclusive results have been obtained, future investigations should extend preclinical studies with different cannabinoids to controlled clinical trials to determine potential benefits in tremor.”

http://www.ncbi.nlm.nih.gov/pubmed/26152606

The endocannabinoid system as a target for the treatment of neurodegenerative disease.

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“The Cannabis sativa plant has been exploited for medicinal, agricultural and spiritual purposes in diverse cultures over thousands of years.

Cannabis has been used recreationally for its psychotropic properties, while effects such as stimulation of appetite, analgesia and anti-emesis have lead to the medicinal application of cannabis.

Indeed, reports of medicinal efficacy of cannabis can been traced back as far as 2700 BC, and even at that time reports also suggested a neuroprotective effect of the cultivar.

…alterations in the endocannabinoid system have been extensively investigated in a range of neurodegenerative disorders.

In this review we examine the evidence implicating the endocannabinoid system in the cause, symptomatology or treatment of neurodegenerative disease. We examine data from human patients and compare and contrast this with evidence from animal models of these diseases. On the basis of this evidence we discuss the likely efficacy of endocannabinoid-based therapies in each disease context.

There has been anecdotal and preliminary scientific evidence of cannabis affording symptomatic relief in diverse neurodegenerative disorders. These include multiple sclerosis, Huntington’s, Parkinson’s and Alzheimer’s diseases, and amyotrophic lateral sclerosis.

This evidence implied that hypofunction or dysregulation of the endocannabinoid system may be responsible for some of the symptomatology of these diseases.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2931550/

Differential upregulation of the cannabinoid CB2 receptor in neurotoxic and inflammation-driven rat models of Parkinson’s disease.

“The cannabinoid CB2 receptor has recently emerged as a potential anti-inflammatory target to break the self-sustaining cycle of neuroinflammation and neurodegeneration that is associated with neurodegenerative diseases.

…the aim of this study was to investigate and compare the changes that occur in the endocannabinoid system in neurotoxic and inflammation-driven models of Parkinson’s disease.

…this study has shown that the endocannabinoid system is dysregulated in animal models of Parkinson’s disease, and has also revealed significant differences in the level of dysregulation between the models themselves.

This study indicates that targeting the CB2 receptor may represent a viable target for anti-inflammatory disease modification in Parkinson’s disease.”

 http://www.ncbi.nlm.nih.gov/pubmed/25895887

http://www.thctotalhealthcare.com/category/parkinsons-disease/

Promising cannabinoid-based therapies for Parkinson’s disease: motor symptoms to neuroprotection.

“Parkinson’s disease (PD) is a slow insidious neurological disorder characterized by a loss of dopaminergic neurons in the midbrain. Although several recent preclinical advances have proposed to treat PD, there is hardly any clinically proved new therapeutic for its cure.

Increasing evidence suggests a prominent modulatory function of the cannabinoid signaling system in the basal ganglia. Hence, use of cannabinoids as a new therapeutic target has been recommended as a promising therapy for PD.

The elements of the endocannabinoid system are highly expressed in the neural circuit of basal ganglia wherein they bidirectionally interact with dopaminergic, glutamatergic, and GABAergic signaling systems.

As the cannabinoid signaling system undergoes a biphasic pattern of change during progression of PD, it explains the motor inhibition typically observed in patients with PD.

Cannabinoid agonists such as WIN-55,212-2 have been demonstrated experimentally as neuroprotective agents in PD, with respect to their ability to suppress excitotoxicity, glial activation, and oxidative injury that causes degeneration of dopaminergic neurons.

Additional benefits provided by cannabinoid related compounds including CE-178253, oleoylethanolamide, nabilone and HU-210 have been reported to possess efficacy against bradykinesia and levodopa-induced dyskinesia in PD.

Despite promising preclinical studies for PD, use of cannabinoids has not been studied extensively at the clinical level. In this review, we reassess the existing evidence suggesting involvement of the endocannabinoid system in the cause, symptomatology, and treatment of PD. We will try to identify future threads of research that will help in the understanding of the potential therapeutic benefits of the cannabinoid system for treating PD.”

http://www.ncbi.nlm.nih.gov/pubmed/25888232

“To conclude, development of safe, effective cannabis-based medicines targeting different mechanisms may have a significant impact in PD therapy.”

Full-text: http://www.molecularneurodegeneration.com/content/10/1/17

http://www.thctotalhealthcare.com/category/parkinsons-disease/

The role of cannabinoids and leptin in neurological diseases.

“Cannabinoids exert a neuroprotective influence on some neurological diseases, including Alzheimer’s, Parkinson’s, Huntington’s, multiple sclerosis and epilepsy.

Synthetic cannabinoid receptor agonists/antagonists or compounds can provide symptom relief or control the progression of neurological diseases. However, the molecular mechanism and the effectiveness of these agents in controlling the progression of most of these diseases remain unclear.

Cannabinoids may exert effects via a number of mechanisms and interactions with neurotransmitters, neurotropic factors and neuropeptides.

Leptin is a peptide hormone involved in the regulation of food intake and energy balance via its actions on specific hypothalamic nuclei. Leptin receptors are widely expressed throughout the brain, especially in the hippocampus, basal ganglia, cortex and cerebellum. Leptin has also shown neuroprotective properties in a number of neurological disorders, such as Parkinson’s and Alzheimer’s.

Therefore, cannabinoid and leptin hold therapeutic potential for neurological diseases.

Further elucidation of the molecular mechanisms underlying the effects on these agents may lead to the development of new therapeutic strategies for the treatment of neurological disorders.”