Category Archives: Parkinson’s Disease

Microglial Phenotypes and Their Relationship to the Cannabinoid System: Therapeutic Implications for Parkinson’s Disease.

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 Image result for molecules journal“Parkinson’s disease is a neurodegenerative disorder, the motor symptoms of which are associated classically with Lewy body formation and nigrostriatal degeneration.

Neuroinflammation has been implicated in the progression of this disease, by which microglia become chronically activated in response to α-synuclein pathology and dying neurons, thereby acquiring dishomeostatic phenotypes that are cytotoxic and can cause further neuronal death.

Microglia have a functional endocannabinoid signaling system, expressing the cannabinoid receptors in addition to being capable of synthesizing and degrading endocannabinoids. Alterations in the cannabinoid system-particularly an upregulation in the immunomodulatory CB2 receptor-have been demonstrated to be related to the microglial activation state and hence the microglial phenotype.

This paper will review studies that examine the relationship between the cannabinoid system and microglial activation, and how this association could be manipulated for therapeutic benefit in Parkinson’s disease.”

https://www.ncbi.nlm.nih.gov/pubmed/31973235

“Microglia activation states and cannabinoid system: Therapeutic implications.  There is accumulating evidence indicating that cannabinoids (CBs) might serve as a promising tool to modify the outcome of inflammation, especially by influencing microglial activity. Microglia has a functional endocannabinoid (eCB) signaling system, composed of cannabinoid receptors and the complete machinery for the synthesis and degradation of eCBs. These actions make CBs a promising therapeutic tool to avoid the detrimental effects of inflammation and possibly paving the way to target microglia in order to generate a reparative milieu in neurodegenerative diseases.” https://www.ncbi.nlm.nih.gov/pubmed/27373505

“These findings imply that a hypofunction or a dysregulation of the endocannabinoid system may be responsible for some of the symptoms of these diseases. Scientific evidence shows that cannabis can provide symptomatic relief in several neurodegenerative diseases.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4070159/

“Cannabinoids can have neuroprotective effects, and this can be exploited for therapeutic strategies against neurodegenerative diseases”   http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3243800/

Effects of acute cannabidiol administration on anxiety and tremors induced by a Simulated Public Speaking Test in patients with Parkinson’s disease.

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Image result for journal of psychopharmacology“Cannabidiol (CBD) is one of the main components of Cannabis sativa and has anxiolytic properties, but no study has been conducted to evaluate the effects of CBD on anxiety signs and symptoms in patients with Parkinson’s disease (PD).

This study aimed to evaluate the impacts of acute CBD administration at a dose of 300 mg on anxiety measures and tremors induced by a Simulated Public Speaking Test (SPST) in individuals with PD.

METHODS:

A randomised, double-blinded, placebo-controlled, crossover clinical trial was conducted. A total of 24 individuals with PD were included and underwent two experimental sessions within a 15-day interval. After taking CBD or a placebo, participants underwent the SPST. During the test, the following data were collected: heart rate, systemic blood pressure and tremor frequency and amplitude. In addition, the Visual Analog Mood Scales (VAMS) and Self-Statements during Public Speaking Scale were applied. Statistical analysis was performed by repeated-measures analysis of variance (ANOVA) while considering the drug, SPST phase and interactions between these variables.

RESULTS:

There were statistically significant differences in the VAMS anxiety factor for the drug; CBD attenuated the anxiety experimentally induced by the SPST. Repeated-measures ANOVA showed significant differences in the drug for the variable related to tremor amplitude as recorded by the accelerometer.

CONCLUSION:

Acute CBD administration at a dose of 300 mg decreased anxiety in patients with PD, and there was also decreased tremor amplitude in an anxiogenic situation.”

https://www.ncbi.nlm.nih.gov/pubmed/31909680

https://journals.sagepub.com/doi/abs/10.1177/0269881119895536?journalCode=jopa

Cannabinoids and the expanded endocannabinoid system in neurological disorders.

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 Related image“Anecdotal evidence that cannabis preparations have medical benefits together with the discovery of the psychotropic plant cannabinoid Δ9-tetrahydrocannabinol (THC) initiated efforts to develop cannabinoid-based therapeutics.

These efforts have been marked by disappointment, especially in relation to the unwanted central effects that result from activation of cannabinoid receptor 1 (CB1), which have limited the therapeutic use of drugs that activate or inactivate this receptor.

The discovery of CB2 and of endogenous cannabinoid receptor ligands (endocannabinoids) raised new possibilities for safe targeting of this endocannabinoid system. However, clinical success has been limited, complicated by the discovery of an expanded endocannabinoid system – known as the endocannabinoidome – that includes several mediators that are biochemically related to the endocannabinoids, and their receptors and metabolic enzymes.

The approvals of nabiximols, a mixture of THC and the non-psychotropic cannabinoid cannabidiol, for the treatment of spasticity and neuropathic pain in multiple sclerosis, and of purified botanical cannabidiol for the treatment of otherwise untreatable forms of paediatric epilepsy, have brought the therapeutic use of cannabinoids and endocannabinoids in neurological diseases into the limelight.

In this Review, we provide an overview of the endocannabinoid system and the endocannabinoidome before discussing their involvement in and clinical relevance to a variety of neurological disorders, including Parkinson disease, Alzheimer disease, Huntington disease, multiple sclerosis, amyotrophic lateral sclerosis, traumatic brain injury, stroke, epilepsy and glioblastoma.”

https://www.ncbi.nlm.nih.gov/pubmed/31831863

“The existence of the endocannabinoidome explains in part why some non-euphoric cannabinoids, which affect several endocannabinoidome proteins, are useful for the treatment of neurological disorders, such as multiple sclerosis and epilepsy.”

https://www.nature.com/articles/s41582-019-0284-z

Cannabidiol increases the nociceptive threshold in a preclinical model of Parkinson’s disease.

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Neuropharmacology

“Medications that improve pain threshold can be useful in the pharmacotherapy of Parkinson’s disease (PD). Pain is a prevalent PD’s non-motor symptom with a higher prevalence of analgesic drugs prescription for patients. However, specific therapy for PD-related pain are not available.

Since the endocannabinoid system is expressed extensively in different levels of pain pathway, drugs designed to target this system have promising therapeutic potential in the modulation of pain. Thus, we examined the effects of the 6-hydroxydopamine- induced PD on nociceptive responses of mice and the influence of cannabidiol (CBD) on 6-hydroxydopamine-induced nociception.

Further, we investigated the pathway involved in the analgesic effect of the CBD through the co-administration with a fatty acid amide hydrolase (FAAH) inhibitor, increasing the endogenous anandamide levels, and possible targets from anandamide, i.e., the cannabinoid receptors subtype 1 and 2 (CB1 and CB2) and the transient receptor potential vanilloid type 1 (TRPV1).

We report that 6-hydroxydopamine- induced parkinsonism decreases the thermal and mechanical nociceptive threshold, whereas CBD (acute and chronic treatment) reduces this hyperalgesia and allodynia evoked by 6-hydroxydopamine. Moreover, ineffective doses of either FAAH inhibitor or TRPV1 receptor antagonist potentialized the CBD-evoked antinociception while an inverse agonist of the CB1 and CB2 receptor prevented the antinociceptive effect of the CBD.

Altogether, these results indicate that CBD can be a useful drug to prevent the parkinsonism-induced nociceptive threshold reduction. They also suggest that CB1 and TRPV1 receptors are important for CBD-induced analgesia and that CBD could produce these analgesic effects increasing endogenous anandamide levels.”

https://www.ncbi.nlm.nih.gov/pubmed/31706993

“The CBD treatment decreases hyperalgesia and allodynia in experimental parkinsonism.”

https://www.sciencedirect.com/science/article/pii/S0028390819303703?via%3Dihub

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Potential new therapies against a toxic relationship: neuroinflammation and Parkinson’s disease.

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 Image result for ovid journal“Parkinson’s disease (PD) is a neurodegenerative disorder classically associated with motor symptoms, but several nonmotor disturbances appear decades before the clinical diagnosis of the disease.

A variety of hypotheses exist to explain the onset of PD, and neuroinflammation is one of the most investigated processes. In fact, strong evidence suggests that PD begins with an inflammatory process; currently, however, no anti-inflammatory therapy is clinically employed to alleviate the typical motor and the prodromal disturbances such as olfactory loss, cognitive impairments, depression and anxiety, sleep disturbances, and autonomic disorders.

In fact, the classical dopaminergic therapies are not effective in alleviating these symptoms and there is no other specific therapy for these outcomes. Therefore, in this review, we will discuss novel potential pharmacological therapeutic strategies focusing on cannabinoids, caffeine, melatonin, and dietary compounds, which could act as adjuvants to regular PD therapy.

These described chemicals have been extensively investigated as anti-inflammatory agents possibly promoting beneficial effects on nonmotor symptoms of PD. The investigation of the inflammatory process at different stages of PD progression should give us a better view of the therapeutic scenario and could improve our understanding of the mechanisms of this disease.”

https://www.ncbi.nlm.nih.gov/pubmed/31703030

https://insights.ovid.com/crossref?an=00008877-201912000-00008

Inhibition of tremulous jaw movements in rats by memantine-Δ9 -tetrahydrocannabinol combination: neuroanatomical correlates.

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British Journal of Pharmacology banner“Memantine and marijuana smoking have been previously found to inhibit tremor in parkinsonian patients, however, the observed effects were relatively weak. The tremorolytic efficacy of memantine and cannabinoid co-administration is unstudied.

This work aimed to evaluate antitremor activity of memantine-Δ9 -tetrahydrocannabinol combination; additionally, the involvement of some neuroanatomical structures in the regulation of the combination effect was evaluated.

EXPERIMENTAL APPROACH:

Haloperidol-induced tremulous jaw movements in rats were used as a model of parkinsonian-like tremor. To evaluate the role of central receptor systems in the drug effect, receptor-targeting agents were administered locally into certain brain areas.

KEY RESULTS:

Memantine and Δ9 -tetrahydrocannabinol alone were without effect, however, co-administration of the drugs significantly decreased number of haloperidol-induced jaw movements. The antitremor activity of the combination was antagonized (i) by injections of L-glutamate into the dorsal striatum, entopeduncular nucleus, substantia nigra pars reticulata, globus pallidus, supratrigeminal and trigeminal motor nuclei but not into the subthalamic and cuneiform nuclei; (ii) by injections of CGS 21680 into the ventrolateral striatum; (iii) by injections of bicuculline into the rostral part of the parvicellular reticular nucleus.

CONCLUSION AND IMPLICATIONS:

Memantine and Δ9 -tetrahydrocannabinol supra-additively inhibit haloperidol-induced tremulous jaw movements. Apparently, the co-administration of the drugs might be a new approach to the treatment of tremor. The presented results identify brain areas influencing parkinsonian-like tremor in rats; these data can help advance the development of novel treatments for repetitive involuntary movements.”

https://www.ncbi.nlm.nih.gov/pubmed/31696510

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.14914

“Memantine is a prescription drug used to treat moderate to severe confusion (dementia) related to Alzheimer’s disease. Memantine is available under the following different brand names: Namenda XR, and Namenda.”  https://www.rxlist.com/consumer_memantine_namenda/drugs-condition.htm

Targeting the cannabinoid receptor CB2 in a mouse model of l-dopa induced dyskinesia.

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Neurobiology of Disease“L-dopa induced dyskinesia (LID) is a debilitating side-effect of the primary treatment used in Parkinson’s disease (PD), l-dopa. Here we investigate the effect of HU-308, a cannabinoid CB2 receptor agonist, on LIDs.

Utilizing a mouse model of PD and LIDs, induced by 6-OHDA and subsequent l-dopa treatment, we show that HU-308 reduced LIDs as effectively as amantadine, the current frontline treatment. Furthermore, treatment with HU-308 plus amantadine resulted in a greater anti-dyskinetic effect than maximally achieved with HU-308 alone, potentially suggesting a synergistic effect of these two treatments. Lastly, we demonstrated that treatment with HU-308 and amantadine either alone, or in combination, decreased striatal neuroinflammation, a mechanism which has been suggested to contribute to LIDs.

Taken together, our results suggest pharmacological treatments with CB2 agonists merit further investigation as therapies for LIDs in PD patients. Furthermore, since CB2 receptors are thought to be primarily expressed on, and signal through, glia, our data provide weight to suggestion that neuroinflammation, or more specifically, altered glial function, plays a role in development of LIDs.”

https://www.ncbi.nlm.nih.gov/pubmed/31669673

“Collectively, our findings suggest CB2 agonists offer a putative target to treat LIDs, with efficacy comparable to the frontline treatment amantadine. Our study suggests that targeting glial function may be an important strategy for developing therapies for treating LIDs, a major unmet need for PD patients.”

https://www.sciencedirect.com/science/article/pii/S0969996119303213?via%3Dihub

Cannabidiol and Cannabinoid Compounds as Potential Strategies for Treating Parkinson’s Disease and L-DOPA-Induced Dyskinesia.

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 “Parkinson’s disease (PD) and L-DOPA-induced dyskinesia (LID) are motor disorders with significant impact on the patient’s quality of life. Unfortunately, pharmacological treatments that improve these disorders without causing severe side effects are not yet available. Delay in initiating L-DOPA is no longer recommended as LID development is a function of disease duration rather than cumulative L-DOPA exposure.

Manipulation of the endocannabinoid system could be a promising therapy to control PD and LID symptoms.

In this way, phytocannabinoids and synthetic cannabinoids, such as cannabidiol (CBD), the principal non-psychotomimetic constituent of the Cannabis sativa plant, have received considerable attention in the last decade.

In this review, we present clinical and preclinical evidence suggesting CBD and other cannabinoids have therapeutic effects in PD and LID. Here, we discuss CBD pharmacology, as well as its neuroprotective effects and those of other cannabinoids.

Finally, we discuss the modulation of several pro- or anti-inflammatory factors as possible mechanisms responsible for the therapeutic/neuroprotective potential of Cannabis-derived/cannabinoid synthetic compounds in motor disorders.”

https://www.ncbi.nlm.nih.gov/pubmed/31637586

https://link.springer.com/article/10.1007%2Fs12640-019-00109-8

Effects of cannabidiol (CBD) in neuropsychiatric disorders: A review of pre-clinical and clinical findings.

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Progress in Molecular Biology and Translational Science“Cannabis sativa (cannabis) is one of the oldest plants cultivated by men. Cannabidiol (CBD) is the major non-psychomimetic compound derived from cannabis. It has been proposed to have a therapeutic potential over a wide range of neuropsychiatric disorders.

In this narrative review, we have summarized a selected number of pre-clinical and clinical studies, examining the effects of CBD in neuropsychiatric disorders. In some pre-clinical studies, CBD was demonstrated to potentially exhibit anti-epileptic, anti-oxidant, anti-inflammatory anti-psychotic, anxiolytic and anti-depressant properties. Moreover, CBD was shown to reduce addictive effects of some drugs of abuse.

In clinical studies, CBD was shown to be safe, well-tolerated and efficacious in mitigating the symptoms associated with several types of seizure disorders and childhood epilepsies.

Given that treatment with CBD alone was insufficient at managing choreic movements in patients with Huntington’s disease, other cannabis-derived treatments are currently being investigated. Patients with Parkinson’s disease (PD) have reported improvements in sleep and better quality of life with CBD; however, to fully elucidate the therapeutic potential of CBD on the symptoms of PD-associated movement disorders, larger scale, randomized, placebo-controlled studies still need to be conducted in the future.

Currently, there are no human studies that investigated the effects of CBD in either Alzheimer’s disease or unipolar depression, warranting further investigation in this area, considering that CBD was shown to have effects in pre-clinical studies.

Although, anxiolytic properties of CBD were reported in the Social Anxiety Disorder, antipsychotic effects in schizophrenia and anti-addictive qualities in alcohol and drug addictions, here too, larger, randomized, placebo-controlled trials are needed to evaluate the therapeutic potential of CBD.”

https://www.ncbi.nlm.nih.gov/pubmed/31601406

https://www.sciencedirect.com/science/article/pii/S187711731930095X?via%3Dihub

The therapeutic role of cannabinoid receptors and its agonists or antagonists in Parkinson’s disease.

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Progress in Neuro-Psychopharmacology and Biological Psychiatry“Parkinson’s disease (PD) is a neurodegenerative disease and its characteristic is the progressive degeneration of dopaminergic neurons within the substantia nigra (SN) of the midbrain. There is hardly any clinically proven efficient therapeutics for its cure in several recent preclinical advances proposed to treat PD.

Recent studies have found that the endocannabinoid signaling system in particular the comprised two receptors, CB1 and CB2 receptors, has a significant regulatory function in basal ganglia and is involved in the pathogenesis of PD. Therefore, adding new insights into the biochemical interactions between cannabinoids and other signaling pathways may help develop new pharmacological strategies.

Factors of the endocannabinoid system (ECS) are abundantly expressed in the neural circuits of basal ganglia, where they interact interactively with glutamatergic, γ-aminobutyric acid-ergic (GABAergic), and dopaminergic signaling systems. Although preclinical studies on PD are promising, the use of cannabinoids at the clinical level has not been thoroughly studied.

In this review, we evaluated the available evidence and reviewed the involvement of ECS in etiologies, symptoms and treatments related to PD. Since CB1 and CB2 receptors are the two main receptors of endocannabinoids, we primarily put the focus on the therapeutic role of CB1 and CB2 receptors in PD. We will try to determine future research clues that will help understand the potential therapeutic benefits of the ECS in the treatment of PD, aiming to open up new strategies and ideas for the treatment of PD.”

https://www.ncbi.nlm.nih.gov/pubmed/31442553

https://www.sciencedirect.com/science/article/pii/S0278584619302210?via%3Dihub