Cannabinoids and Neurogenesis: The Promised Solution for Neurodegeneration?

molecules-logo“The concept of neurons as irreplaceable cells does not hold true today. Experiments and evidence of neurogenesis, also, in the adult brain give hope that some compounds or drugs can enhance this process, helping to reverse the outcomes of diseases or traumas that once were thought to be everlasting.

Cannabinoids, both from natural and artificial origins, already proved to have several beneficial effects (e.g., anti-inflammatory, anti-oxidants and analgesic action), but also capacity to increase neuronal population, by replacing the cells that were lost and/or regenerate a damaged nerve cell.

Neurogenesis is a process which is not highly represented in literature as neuroprotection, though it is as important as prevention of nervous system damage, because it can represent a possible solution when neuronal death is already present, such as in neurodegenerative diseases.

The aim of this review is to resume the experimental evidence of phyto- and synthetic cannabinoids effects on neurogenesis, both in vitro and in vivo, in order to elucidate if they possess also neurogenetic and neurorepairing properties.”

https://pubmed.ncbi.nlm.nih.gov/34684894/

“The current results of cannabinoids effects on neurogenesis are encouraging, and it is expectable that the amount of evidence continues to increase in the future with other experiments.”

https://www.mdpi.com/1420-3049/26/20/6313/htm

Inducing Effects of Illegal Drugs to Improve Mental Health by Self-Regulation Therapy: A Pilot Study

ijerph-logo“This study consists of a brief psychological intervention, which uses Self-Regulation Therapy (SRT, procedure based on suggestion and classical conditioning), to improve coping with stress and emotionality by reproducing the positive effects of illegal drugs: cannabis, cocaine, ecstasy.

Results: SRT was superior to non-intervention for the 4 coping strategies (η2 = 0.829, 0.453, 0.411 and 0.606) and for positive (η2 = 0.371) and negative emotionality (η2 = 0.419). An improvement in scores was evidenced in the follow-up scores compared to the pre-intervention measures.

Conclusions: This study shows for the first time that it is possible to use illegal drugs, considered harmful to public health, to improve young people’s coping capacity and emotionality by reproducing their positive effects with SRT.”

https://pubmed.ncbi.nlm.nih.gov/34639687/

https://www.mdpi.com/1660-4601/18/19/10387

Efficacy of Δ 9 -Tetrahydrocannabinol (THC) Alone or in Combination With a 1:1 Ratio of Cannabidiol (CBD) in Reversing the Spatial Learning Deficits in Old Mice

Archive of "Frontiers in Aging Neuroscience".“Decline in cognitive performance, an aspect of the normal aging process, is influenced by the endocannabinoid system (ECS). Cannabinoid receptor 1 (CB1) signaling diminishes with advancing age in specific brain regions that regulate learning and memory and abolishing CB1 receptor signaling accelerates cognitive aging in mice.

We recently demonstrated that prolonged exposure to low dose (3 mg/kg/day) Δ9-tetrahydrocannabinol (THC) improved the cognitive performances in old mice on par with young untreated mice. Here we investigated the potential influence of cannabidiol (CBD) on this THC effect, because preclinical and clinical studies indicate that the combination of THC and CBD often exhibits an enhanced therapeutic effect compared to THC alone.

We first tested the effectiveness of a lower dose (1 mg/kg/day) THC, and then the efficacy of the combination of THC and CBD in 1:1 ratio, same as in the clinically approved medicine Sativex®. Our findings reveal that a 1 mg/kg/day THC dose still effectively improved spatial learning in aged mice. However, a 1:1 combination of THC and CBD failed to do so.

The presence of CBD induced temporal changes in THC metabolism ensuing in a transient elevation of blood THC levels. However, as CBD metabolizes, the inhibitory effect on THC metabolism was alleviated, causing a rapid clearance of THC. Thus, the beneficial effects of THC seemed to wane off more swiftly in the presence of CBD, due to these metabolic effects.

The findings indicate that THC-treatment alone is more efficient to improve spatial learning in aged mice than the 1:1 combination of THC and CBD.”

https://pubmed.ncbi.nlm.nih.gov/34526890/

“In conclusion, our observations indicate that 1 mg/kg/day THC dose is still effective in improving the spatial learning in aged mice. With regard to the efficacy, THC-alone has proved to be more efficient in improving spatial learning in aged mice than its 1:1 combination with CBD. However, the possibility of THC/CBD being efficient in other ratios or at the earliest time-points, like immediately after the treatment cease, cannot be negated. Possibly, reducing the dose of CBD may improve the efficacy of the THC/CBD combination.”

https://www.frontiersin.org/articles/10.3389/fnagi.2021.718850/full

A Review of the Potential Use of Pinene and Linalool as Terpene-Based Medicines for Brain Health: Discovering Novel Therapeutics in the Flavours and Fragrances of Cannabis

Archive of "Frontiers in Psychiatry".“”Medicinal cannabis” is defined as the use of cannabis-based products for the treatment of an illness. Investigations of cannabis compounds in psychiatric and neurological illnesses primarily focus on the major cannabinoids, cannabidiol (CBD) and Δ9-tetrahydrocannabinol (Δ9-THC), which are hypothesised to benefit multiple illnesses manifesting cognitive impairment, neurodegeneration and neuro-inflammation, as well as chronic pain, epilepsy and post-traumatic stress disorder, respectively.

The cannabis plant contains >500 compounds, including terpenes responsible for the flavour and fragrance profiles of plants. Recently, research has begun providing evidence on the potential use of certain plant-derived terpenes in modern medicine, demonstrating anti-oxidant, anti-inflammatory, and neuroprotective effects of these compounds.

This review examined the effects of two key terpenes, pinene and linalool, on parameters relevant to neurological and psychiatric disorders, highlighting gaps in the literature and recommendations for future research into terpene therapeutics.

Overall, evidence is mostly limited to preclinical studies and well-designed clinical trials are lacking. Nevertheless, existing data suggests that pinene and linalool are relevant candidates for further investigation as novel medicines for illnesses, including stroke, ischemia, inflammatory and neuropathic pain (including migraine), cognitive impairment (relevant to Alzheimer’s disease and ageing), insomnia, anxiety, and depression.

Linalool and pinene influence multiple neurotransmitter, inflammatory and neurotrophic signals as well as behaviour, demonstrating psycho-activity (albeit non-intoxicating).   Optimising the phytochemical profile of cannabis chemovars to yield therapeutic levels of beneficial terpenes and cannabinoids, such as linalool, pinene and CBD, could present a unique opportunity to discover novel medicines to treat psychiatric and neurological illnesses; however, further research is needed.”

https://pubmed.ncbi.nlm.nih.gov/34512404/

“Overall, it appears that the importance of the terpene profile of plants to humans extends further than mere olfactory and gustatory delight. Rather, these compounds have the potential for use as treatments for serious chronic neurological and psychiatric illnesses.”

https://www.frontiersin.org/articles/10.3389/fpsyt.2021.583211/full

The Endocannabinoid System: A Potential Target for the Treatment of Various Diseases

ijms-logo“The Endocannabinoid System (ECS) is primarily responsible for maintaining homeostasis, a balance in internal environment (temperature, mood, and immune system) and energy input and output in living, biological systems.

In addition to regulating physiological processes, the ECS directly influences anxiety, feeding behaviour/appetite, emotional behaviour, depression, nervous functions, neurogenesis, neuroprotection, reward, cognition, learning, memory, pain sensation, fertility, pregnancy, and pre-and post-natal development.

The ECS is also involved in several pathophysiological diseases such as cancer, cardiovascular diseases, and neurodegenerative diseases. In recent years, genetic and pharmacological manipulation of the ECS has gained significant interest in medicine, research, and drug discovery and development.

The distribution of the components of the ECS system throughout the body, and the physiological/pathophysiological role of the ECS-signalling pathways in many diseases, all offer promising opportunities for the development of novel cannabinergic, cannabimimetic, and cannabinoid-based therapeutic drugs that genetically or pharmacologically modulate the ECS via inhibition of metabolic pathways and/or agonism or antagonism of the receptors of the ECS. This modulation results in the differential expression/activity of the components of the ECS that may be beneficial in the treatment of a number of diseases.

This manuscript in-depth review will investigate the potential of the ECS in the treatment of various diseases, and to put forth the suggestion that many of these secondary metabolites of Cannabis sativa L. (hereafter referred to as “C. sativa L.” or “medical cannabis”), may also have potential as lead compounds in the development of cannabinoid-based pharmaceuticals for a variety of diseases.”

https://pubmed.ncbi.nlm.nih.gov/34502379/

https://www.mdpi.com/1422-0067/22/17/9472

 

“Cannabis sativa L. as a Natural Drug Meeting the Criteria of a Multitarget Approach to Treatment”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7830475/

Medical cannabinoids for treatment of neuropsychiatric symptoms in dementia: systematic review

SciELO - Trends in Psychiatry and Psychotherapy“Introduction: Neuropsychiatric symptoms are an integral component of the natural history of dementia, occurring from prodromal to advanced stages of the disease process and leading to increased burden and morbidity. Clinical presentations are pleomorphic, and clinical management often requires combination of pharmacological and non-pharmacological interventions. However, limited efficacy and a non-negligible incidence of adverse events of psychotropic drugs reinforce the need for novel therapeutic options.

Aims: To review the evidence supporting the use of medical cannabinoids for the treatment of neuropsychiatric symptoms of dementia (NPS).

Results: Fifteen publications with original clinical data were retrieved, being 5 controlled clinical trials, 3 open-label/observational studies, and 7 case reports. Most studies indicated that the use of medical cannabinoids engendered favorable outcomes for the treatment of neuropsychiatric symptoms related to moderate and advanced stages of dementia, particularly agitation, aggressive behavior and sleep and sexual disinhibition.

Conclusion: Medical cannabinoids represent a promising pharmacological approach for the treatment of NPS, with preliminary evidence of benefit at least in moderate to severe dementia. Controlled trials with longitudinal design and larger samples are required to examine the long-term efficacy of these drugs in different types and stages of dementia, in addition to their adverse events and risk of interactions with other drugs. Many pharmacological details are yet to be determined, such as dosing, treatment duration and concentrations of active compounds (e.g., CBD/THC ratio) in commercial preparations of medical cannabinoids.”

https://pubmed.ncbi.nlm.nih.gov/34374269/

Cannabinoids in the management of frontotemporal dementia: a case series

 “Background: Frontotemporal dementia (FTD) is characterized by progressive deterioration in behaviors, executive function and/or language. The behavioral variant (Bv) is characterized by disinhibition and obsessive/compulsive behaviors. These symptoms are sometimes resistant to medications. This series examines patients suffering with treatment-resistant Bv-FTD who were prescribed cannabinoid and related compounds for other indications.

Case presentation: Three FTD cases from a dementia clinic were identified. These patients had disability due to behavior despite typical pharmacologic management. These patients were prescribed marijuana for comorbidities (anxiety, insomnia and pain). In all cases, use of cannabinoid products showed significant improvements in behavior and in the primary indication for prescription.

Conclusion: Review of these cases demonstrates potential for the use of cannabinoids in the management of treatment-resistant Bv-FTD.”

https://pubmed.ncbi.nlm.nih.gov/33190583/

“Frontotemporal dementia is a complicated and difficult disease that can be challenging to manage and often leads to significant burden on caregivers. Sometimes management of behavioral changes is difficult even with medications. In this case series, we report three cases of patients with behavior that was resistant to typical treatment who showed improvement in behavior when they were prescribed medical marijuana for other reason.”

https://www.futuremedicine.com/doi/10.2217/nmt-2020-0048

Emerging potential of cannabidiol in reversing proteinopathies

Ageing Research Reviews “The aberrant accumulation of disease-specific protein aggregates accompanying cognitive decline is a pathological hallmark of age-associated neurological disorders, also termed as proteinopathies, including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis and multiple sclerosis.

Along with oxidative stress and neuroinflammation, disruption in protein homeostasis (proteostasis), a network that constitutes protein surveillance system, plays a pivotal role in the pathobiology of these dementia disorders.

Cannabidiol, a non-psychotropic phytocannabinoid of Cannabis sativa, is known for its pleiotropic neuropharmacological effects on the central nervous system, including the ability to abate oxidative stress, neuroinflammation, and protein misfolding. Over the past years, compelling evidence has documented disease-modifying role of cannabidiol in various preclinical and clinical models of neurological disorders, suggesting the potential therapeutic implications of cannabidiol in these disorders.

Because of its putative role in the proteostasis network in particular, cannabidiol could be a potent modulator for reversing not only age-associated neurodegeneration but also other protein misfolding disorders. However, the current understanding is insufficient to underpin this proposition. In this review, we discuss the potentiality of cannabidiol as a pharmacological modulator of the proteostasis network, highlighting its neuroprotective and aggregates clearing roles in the neurodegenerative disorders.

We anticipate that the current effort will advance our knowledge on the implication of CBD in proteostasis network, opening up a new therapeutic window for ageing proteinopathies.”

https://pubmed.ncbi.nlm.nih.gov/33181336/

“Cannabidiol reduces oxidative stress and neuroinflammation of brain.”

https://www.sciencedirect.com/science/article/pii/S1568163720303445?via%3Dihub

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