Molecular Targets of Cannabidiol in Experimental Models of Neurological Disease

molecules-logo“Cannabidiol (CBD) is a non-psychoactive phytocannabinoid known for its beneficial effects including antioxidant and anti-inflammatory properties. Moreover, CBD is a compound with antidepressant, anxiolytic, anticonvulsant and antipsychotic effects. Thanks to all these properties, the interest of the scientific community for it has grown.

Indeed, CBD is a great candidate for the management of neurological diseases. The purpose of our review is to summarize the in vitro and in vivo studies published in the last 15 years that describe the biochemical and molecular mechanisms underlying the effects of CBD and its therapeutic application in neurological diseases.

CBD exerts its neuroprotective effects through three G protein coupled-receptors (adenosine receptor subtype 2A, serotonin receptor subtype 1A and G protein-coupled receptor 55), one ligand-gated ion channel (transient receptor potential vanilloid channel-1) and one nuclear factor (peroxisome proliferator-activated receptor γ). Moreover, the therapeutical properties of CBD are also due to GABAergic modulation.

In conclusion, CBD, through multi-target mechanisms, represents a valid therapeutic tool for the management of epilepsy, Alzheimer’s disease, multiple sclerosis and Parkinson’s disease.”

https://pubmed.ncbi.nlm.nih.gov/33171772/

https://www.mdpi.com/1420-3049/25/21/5186

The Effects of Cannabis Use on Cognitive Function in Healthy Aging: A Systematic Scoping Review

Archives of Clinical Neuropsychology“Background: Older adults (≥50 years) represent the fastest-growing population of people who use cannabis, potentially due to the increasing promotion of cannabis as medicine by dispensaries and cannabis websites. Given healthy aging and cannabis use are both associated with cognitive decline, it is important to establish the effects of cannabis on cognition in healthy aging.

Objective: This systematic scoping review used preferred reporting items for systematic reviews and meta-analyses guidelines to critically examine the extent of literature on this topic and highlight areas for future research.

Results: Six articles reported findings for older populations (three human and three rodent studies), highlighting the paucity of research in this area. Human studies revealed largely null results, likely due to several methodological limitations. Better-controlled rodent studies indicate that the relationship between ∆9-tetrahydrocannabinol (THC) and cognitive function in healthy aging depends on age and level of THC exposure. Extremely low doses of THC improved cognition in very old rodents. Somewhat higher chronic doses improved cognition in moderately aged rodents. No studies examined the effects of cannabidiol (CBD) or high-CBD cannabis on cognition.

Conclusions: This systematic scoping review provides crucial, timely direction for future research on this emerging issue. Future research that combines neuroimaging and cognitive assessment would serve to advance understanding of the effects of age and quantity of THC and CBD on cognition in healthy aging.”

https://pubmed.ncbi.nlm.nih.gov/33159510/

“THC; the main psychoactive cannabis compound; exerted pro-cognitive effects on memory and learning in older populations.”

https://academic.oup.com/acn/advance-article/doi/10.1093/arclin/acaa105/5960018

Cannabidiol (CBD) enhanced the hippocampal immune response and autophagy of APP/PS1 Alzheimer’s mice uncovered by RNA-seq

 Life Sciences“Alzheimer’s disease (AD) is a central nervous system disease characterized by dementia, which has now become a major threat to global health.

Cannabidiol (CBD) is a natural component extracted from the hemp plant and exhibits multiple mechanisms to improve the pathological process of AD in vitro and in vivo. However, its underlying molecular mechanism is still unclear.

This study attempts to reveal its common mechanism through transcriptome sequence.

This study illustrated that CBD may improve the pathological process of AD by enhancing immune system response and autophagy pathway.”

https://pubmed.ncbi.nlm.nih.gov/33096116/

https://www.sciencedirect.com/science/article/abs/pii/S0024320520313771?via%3Dihub

Attenuation of Oxidative Stress by Cannabinoids and Cannabis Extracts in Differentiated Neuronal Cells

pharmaceuticals-logo“In this proof-of-concept study, the antioxidant activity of phytocannabinoids, namely cannabidiol (CBD) and Δ9- tetrahydrocannabinol (THC), were investigated using an in vitro system of differentiated human neuronal SY-SH5Y cells.

We showed that THC had a high potency to combat oxidative stress in both in vitro models, while CBD did not show a remarkable antioxidant activity. The cannabis extracts also exhibited a significant antioxidant activity, which depended on the ratio of the THC and CBD. However, our results did not suggest any antagonist effect of the CBD on the antioxidant activity of THC. The effect of cannabis extracts on the cell viability of differentiated human neuronal SY-SH5Y cells was also investigated, which emphasized the differences between the bioactivity of cannabis extracts due to their composition.

Our preliminary results demonstrated that cannabis extracts and phytocannabinoids have a promising potential as antioxidants, which can be further investigated to develop novel pharmaceuticals targeting oxidative stress therapy.”

https://pubmed.ncbi.nlm.nih.gov/33105840/

https://www.mdpi.com/1424-8247/13/11/328

Cannabis: An Emerging Treatment for Common Symptoms in Older Adults

Journal of the American Geriatrics Society “Background/objectives: Use of cannabis is increasing in a variety of populations in the United States; however, few investigations about how and for what reasons cannabis is used in older populations exist.

Design: Anonymous survey.

Setting: Geriatrics clinic.

Participants: A total of 568 adults 65 years and older.

Intervention: Not applicable.

Measurements: Survey assessing characteristics of cannabis use.

Results: Approximately 15% (N = 83) of survey responders reported using cannabis within the past 3 years. Half (53%) reported using cannabis regularly on a daily or weekly basis, and reported using cannabidiol-only products (46%).

The majority (78%) used cannabis for medical purposes only, with the most common targeted conditions/symptoms being pain/arthritis (73%), sleep disturbance (29%), anxiety (24%), and depression (17%). Just over three-quarters reported cannabis “somewhat” or “extremely” helpful in managing one of these conditions, with few adverse effects.

Just over half obtained cannabis via a dispensary, and lotions (35%), tinctures (35%), and smoking (30%) were the most common administration forms. Most indicated family members (94%) knew about their cannabis use, about half reported their friends knew, and 41% reported their healthcare provider knowing. Sixty-one percent used cannabis for the first time as older adults (aged ≥61 years), and these users overall engaged in less risky use patterns (e.g., more likely to use for medical purposes, less likely to consume via smoking).

Conclusion: Most older adults in the sample initiated cannabis use after the age of 60 years and used it primarily for medical purposes to treat pain, sleep disturbance, anxiety, and/or depression. Cannabis use by older adults is likely to increase due to medical need, favorable legalization, and attitudes.”

https://pubmed.ncbi.nlm.nih.gov/33026117/

https://onlinelibrary.wiley.com/doi/10.1111/jgs.16833

“Study Finds Older Adults Using Cannabis to Treat Common Health Conditions”  https://health.ucsd.edu/news/releases/Pages/2020-10-07-study-finds-older-adults-using-cannabis-to-treat-common-health-conditions.aspx

Emerging Promise of Cannabinoids for the Management of Pain and Associated Neuropathological Alterations in Alzheimer’s Disease

Frontiers in Pharmacology (@FrontPharmacol) | Twitter “Alzheimer’s disease (AD) is an irreversible chronic neurodegenerative disorder that occurs when neurons in the brain degenerate and die. Pain frequently arises in older patients with neurodegenerative diseases including AD. However, the presence of pain in older people is usually overlooked with cognitive dysfunctions. Most of the times dementia patients experience moderate to severe pain but the development of severe cognitive dysfunctions tremendously affects their capability to express the presence of pain. Currently, there are no effective treatments against AD that emphasize the necessity for increasing research to develop novel drugs for treating or preventing the disease process. Furthermore, the prospective therapeutic use of cannabinoids in AD has been studied for the past few years. In this regard, targeting the endocannabinoid system has considered as a probable therapeutic strategy to control several associated pathological pathways, such as mitochondrial dysfunction, excitotoxicity, oxidative stress, and neuroinflammation for the management of AD. In this review, we focus on recent studies about the role of cannabinoids for the treatment of pain and related neuropathological changes in AD.”

https://pubmed.ncbi.nlm.nih.gov/32792944/

“Cannabinoids act by targeting several signaling processes, such as pain, abnormal processing of Aβ and tau, neuroinflammation, excitotoxicity, oxidative stress, and mitochondrial dysfunction, which play a pivotal role in the management of AD. Cannabinoids also ameliorate behavioral and cognitive dysfunctions. Therefore, due to these extensive medical uses of cannabinoid compounds, it can be said that targeting the endocannabinoid system can be a promising strategy to develop an effective therapy for the management of AD. Furthermore, cannabinoids may demonstrate a safe and reliable low-cost therapy, with limited side effects.”

https://www.frontiersin.org/articles/10.3389/fphar.2020.01097/full

Cannabinoid-profiled agents improve cell survival via reduction of oxidative stress and inflammation, and Nrf2 activation in a toxic model combining hyperglycemia+Aβ 1-42 peptide in rat hippocampal neurons

Neurochemistry International “Alzheimer’s disease (AD) is a multifactorial neurodegenerative disorder linked to various converging toxic mechanisms. Evidence suggests that hyperglycemia induces oxidative stress, mitochondrial dysfunction, inflammation and excitotoxicity, all of which play important roles in the onset and progression of AD pathogenesis.

The endocannabinoid system (ECS) orchestrates major physiological responses, including neuronal plasticity, neuroprotection, and redox homeostasis, to name a few. The multi-targeted effectiveness of the ECS emerges as a potential approach to treat AD.

Here we characterized the protective properties of the endocannabinoids arachidonylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG), the synthetic cannabinoids CP 55-940 and WIN 55,212-2, and the fatty acid amide hydrolase (FAAH) inhibitor URB597, on a combined hyperglycemia+oligomeric amyloid β peptide (Aβ1-42) neurotoxic model in primary hippocampal neurons which exhibit several AD features.

All agents tested preserved cell viability and stimulated mitochondrial membrane potential, while reducing all the evaluated toxic endpoints in a differential manner, with URB597 showing the highest efficacy. The neuroprotective efficacy of all cannabinoid agents, except for URB597, led to partial recruitment of specific antioxidant activity and Nrf2 pathway regulation.

Our results support the neuroprotective potential of these agents at low concentrations against the damaging effects of GLU+Aβ1-42, affording new potential modalities for the design of AD therapies.”

https://pubmed.ncbi.nlm.nih.gov/32781098/

“All cannabinoid agents prevented the GLU + Aβ1-42 toxicity in a differential manner. All cannabinoid agents recruited Nrf2 signaling to protect cells.”

https://www.sciencedirect.com/science/article/abs/pii/S0197018620302084?via%3Dihub

Phytocannabinoids: General Aspects and Pharmacological Potential in Neurodegenerative Diseases

 “In the last few years research into Cannabis and its constituent phytocannabinoids has burgeoned, particularly in the potential application of novel cannabis phytochemicals for the treatment of diverse illnesses related to neurodegeneration and dementia, including Alzheimer’s (AD), Parkinson’s (PD) and Huntington’s disease (HD). To date, these neurological diseases have mostly relied on symptomatological management. However, with an aging population globally, the search for more efficient and disease-modifying treatments that could delay or mitigate disease progression is imperative. In this context, this review aims to present a state of art in the research with cannabinoids and novel cannabinoid-based drug candidates that have been emerged as novel promising alternatives for drug development and innovation in the therapeutics of a number of diseases, especially those related to CNS-disturbance and impairment.”

https://pubmed.ncbi.nlm.nih.gov/32691712/

https://www.eurekaselect.com/183955/article

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

Use of Cannabis for Agitation in Patients With Dementia

 logo“Studies have reported changes in the endocannabinoid system in the brain of patients with Alzheimer’s disease (AD), playing a role in the pathophysiology of AD. Cannabinoids have been shown to have neuroprotective properties, reduce neuroinflammation, and enhance neurogenesis. Evidence suggests that the utilization of marijuana products containing both tetrahydrocannabinol (THC) and cannabidiol (CBD) or CBD alone have been effective and safe for use in older people with agitation associated with dementia.

A review in 2017 summarized positive findings for therapeutic benefits of cannabinoids in agitation of AD and dementia, but there was no definitive conclusion because of varying cannabinoid products. Cannabinoids were shown to be well tolerated, with few short-term side effects. This differs from first-line medications utilized for dementia behaviors, which can have unwanted side effects. Further research regarding the safety, efficacy, and variability of these products in older people is needed.”

https://pubmed.ncbi.nlm.nih.gov/32600509/

https://www.ingentaconnect.com/content/ascp/tscp/2020/00000035/00000007/art00006;jsessionid=1ivcuvrvy4g1s.x-ic-live-03