Category Archives: Alzheimer’s Disease (AD)

Cannabinoids for the treatment of neuropsychiatric symptoms, pain and weight loss in dementia.

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“Efficacious treatment for neuropsychiatric symptoms (NPS), pain and weight loss for dementia patients is desperately needed.

This review presents an up-to-date look at the literature investigating the use of cannabinoid for these symptoms in dementia.

RECENT FINDINGS:

We searched electronically for publications regarding cannabinoid use in dementia, with a focus on Alzheimer’s disease. Seven studies and one case report have been conducted to examine the use of cannabinoids for the treatment of NPS of dementia, and three of these trials reported on the effect of cannabinoids on weight. Five studies reported decreased agitation or improvements in sleep with cannabinoid use. One crossover trial found that cannabinoids positively impacted weight, whereas a chart review study found no impact on weight with cannabinoids, but an increase in food intake. There were no trials examining the use of cannabinoids for pain in dementia.

SUMMARY:

Findings from trials with small sample sizes and various clinical populations suggest that cannabinoid use may be well tolerated and effective for treatment of NPS such as agitation as well as weight and pain management in patients with dementia. Additional studies are necessary to further elucidate the relative risks and benefits of this treatment.”

https://www.ncbi.nlm.nih.gov/pubmed/29256923
https://insights.ovid.com/crossref?an=00001504-900000000-99303
http://journals.lww.com/co-psychiatry/Abstract/publishahead/Cannabinoids_for_the_treatment_of_neuropsychiatric.99303.aspx

Extract of Fructus Cannabis Ameliorates Learning and Memory Impairment Induced by D-Galactose in an Aging Rats Model.

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“Hempseed (Cannabis sativa L.) has been used as a health food and folk medicine in China for centuries.

In the present study, we sought to define the underlying mechanism by which the extract of Fructus Cannabis (EFC) protects against memory impairment induced by D-galactose in rats.

To accelerate aging and induce memory impairment in rats, D-galactose (400 mg/kg) was injected intraperitoneally once daily for 14 weeks. EFC (200 and 400 mg/kg) was simultaneously administered intragastrically once daily in an attempt to slow the aging process.

We found that EFC significantly increased the activity of superoxide dismutase, while lowering levels of malondialdehyde in the hippocampus. Moreover, EFC dramatically elevated the organ indices of some organs, including the heart, the liver, the thymus, and the spleen. In addition, EFC improved the behavioral performance of rats treated with D-galactose in the Morris water maze. Furthermore, EFC inhibited the activation of astrocytes and remarkably attenuated phosphorylated tau and suppressed the expression of presenilin 1 in the brain of D-galactose-treated rats.

These findings suggested that EFC exhibits beneficial effects on the cognition of aging rats probably by enhancing antioxidant capacity and anti-neuroinflammation, improving immune function, and modulating tau phosphorylation and presenilin expression.”

https://www.ncbi.nlm.nih.gov/pubmed/29234402
https://www.hindawi.com/journals/ecam/2017/4757520/

Cannabinoid Receptor Type 1 Agonist ACEA Protects Neurons from Death and Attenuates Endoplasmic Reticulum Stress-Related Apoptotic Pathway Signaling.

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Neurotoxicity Research

“Neurodegeneration is the result of progressive destruction of neurons in the central nervous system, with unknown causes and pathological mechanisms not yet fully elucidated. Several factors contribute to neurodegenerative processes, including neuroinflammation, accumulation of neurotoxic factors, and misfolded proteins in the lumen of the endoplasmic reticulum (ER).

Endocannabinoid signaling has been pointed out as an important modulatory system in several neurodegeneration-related processes, inhibiting the inflammatory response and increasing neuronal survival. Thus, we investigated the presumptive protective effect of the selective cannabinoid type 1 (CB1) receptor agonist) against inflammatory (lipopolysaccharide, LPS) and ER stress (tunicamycin) stimuli in an in vitro neuronal model (Neuro-2a neuroblastoma cells). Cell viability analysis revealed that ACEA was able to protect against cell death induced by LPS and tunicamycin.

This neuroprotective effect occurs via the CB1 receptor in the inflammation process and via the transient receptor potential of vanilloid type-1 (TRPV1) channel in ER stress. Furthermore, the immunoblotting analyses indicated that the neuroprotective effect of ACEA seems to involve the modulation of eukaryotic initiation factor 2 (eIF2α), transcription factor C/EBP homologous protein (CHOP), and caspase 12, as well as the survival/death p44/42 MAPK, ERK1/2-related signaling pathways.

Together, these data suggest that the endocannabinoid system is a potential therapeutic target in neurodegenerative processes, especially in ER-related neurodegenerative diseases.”

https://www.ncbi.nlm.nih.gov/pubmed/29134561

https://link.springer.com/article/10.1007%2Fs12640-017-9839-1

Reversal of age-related cognitive impairments in mice by an extremely low dose of tetrahydrocannabinol.

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Neurobiology of Aging

“This study was designed to test our hypothesis that an ultra-low dose of delta-9 tetrahydrocannabinol (THC) reverses age-dependent cognitive impairments in old mice and to examine the possible biological mechanisms that underlie this behavioral effect. These findings suggest that extremely low doses of THC that are devoid of any psychotropic effect and do not induce desensitization may provide a safe and effective treatment for cognitive decline in aging humans.”  https://www.ncbi.nlm.nih.gov/pubmed/29107185

“Cognitive decline is an integral aspect of aging. The idea that age-related cognitive decline can be reversed and that the old brain can be revitalized is not new. It has been previously suggested that the endocannabinoid system is part of an antiaging homeostatic defense system.  In previous studies, we have shown that ultra-low doses of tetrahydrocannabinol (THC, the main psychotropic ingredient in cannabis) protected young mice from cognitive impairments that were evoked by various insults. In the present study, we tested our hypothesis that a single ultra-low dose of THC can reverse age-dependent cognitive decline in mice. Here, we show that a single extremely low dose of THC devoid of any psychotropic activity can trigger an endogenous compensatory mechanism that improves cognitive functioning in old mice and that this effect lasts for at least several weeks. Since THC in high doses (dronabinol, 1–10 mg) is already approved for medical treatments in humans, and since its safety profile is well characterized, we believe that the initiation of clinical trials with ultra-low doses of THC designed to reverse cognitive decline in elderly patients should be straightforward.”  http://www.sciencedirect.com/science/article/pii/S0197458017303214

“Reversal of age-related cognitive impairments in mice by an extremely low dose of tetrahydrocannabinol. These findings suggest that extremely low doses of THC that are devoid of any psychotropic effect and do not induce desensitization may provide a safe and effective treatment for cognitive decline in aging humans.”   http://www.neurobiologyofaging.org/article/S0197-4580(17)30321-4/fulltext

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

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“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

Effects of cannabidiol interactions with Wnt/β-catenin pathway and PPARγ on oxidative stress and neuroinflammation in Alzheimer’s disease.

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“Alzheimer’s disease (AD) is a neurodegenerative disease, in which the primary etiology remains unknown. AD presents amyloid beta (Aβ) protein aggregation and neurofibrillary plaque deposits. AD shows oxidative stress and chronic inflammation.

In AD, canonical Wingless-Int (Wnt)/β-catenin pathway is downregulated, whereas peroxisome proliferator-activated receptor γ (PPARγ) is increased. Downregulation of Wnt/β-catenin, through activation of glycogen synthase kinase-3β (GSK-3β) by Aβ, and inactivation of phosphatidylinositol 3-kinase/Akt signaling involve oxidative stress in AD.

Cannabidiol (CBD) is a non-psychotomimetic phytocannabinoid from Cannabis sativa plant. In PC12 cells, Aβ-induced tau protein hyperphosphorylation is inhibited by CBD. This inhibition is associated with a downregulation of p-GSK-3β, an inhibitor of Wnt pathway. CBD may also increase Wnt/β-catenin by stimulation of PPARγ, inhibition of Aβ and ubiquitination of amyloid precursor protein.

CBD attenuates oxidative stress and diminishes mitochondrial dysfunction and reactive oxygen species generation. CBD suppresses, through activation of PPARγ, pro-inflammatory signaling and may be a potential new candidate for AD therapy.”

https://www.ncbi.nlm.nih.gov/pubmed/28981597

https://academic.oup.com/abbs/article-abstract/49/10/853/3978657/Effects-of-cannabidiol-interactions-with-Wnt?redirectedFrom=fulltext

Delta-9-Tetrahydrocannabinol (∆9-THC) Induce Neurogenesis and Improve Cognitive Performances of Male Sprague Dawley Rats.

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Neurotoxicity Research

“Neurogenesis is influenced by various external factors such as enriched environments. Some researchers had postulated that neurogenesis has contributed to the hippocampal learning and memory. This project was designed to observe the effect of Delta-9-tetrahydrocannabinol (∆9-THC) in cognitive performance that influenced by the neurogenesis.

Different doses of ∆9-THC were used for observing the neurogenesis mechanism occurs in the hippocampus of rats. The brains were stained with antibodies, namely BrdU, glial fibrillary acidic protein (GFAP), nestin, doublecortin (DCX) and class III β-tubulin (TuJ-1). The cognitive test was used novel-object discrimination test (NOD) while the proteins involved, DCX and brain-derived neurotrophic factor (BDNF), were measured.

Throughout this study, ∆9-THC enhanced the markers involved in all stages of neurogenesis mechanism. Simultaneously, the cognitive behaviour of rat also showed improvement in learning and memory functions observed in behavioural test and molecular perspective.

Administration of ∆9-THC was observed to enhance the neurogenesis in the brain, especially in hippocampus thus improved the cognitive function of rats.”

https://www.ncbi.nlm.nih.gov/pubmed/28933048

https://link.springer.com/article/10.1007%2Fs12640-017-9806-x

Receptor-heteromer mediated regulation of endocannabinoid signaling in activated microglia. Role of CB1 and CB2 receptors and relevance for Alzheimer’s disease and levodopa-induced dyskinesia.

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“Endocannabinoids are important regulators of neurotransmission and, acting on activated microglia, they are postulated as neuroprotective agents. Endocannabinoid action is mediated by CB1 and CB2 receptors, which may form heteromeric complexes (CB1-CB2Hets) with unknown function in microglia.

We aimed at establishing the expression and signaling properties of cannabinoidreceptors in resting and LPS/IFN-γ-activated microglia. Unlike CB1, CB2 receptors and CB1-CB2Hets were upregulated in activated microglia. Resting cell refractory CB2 receptors became robustly coupled to Gi in activated cells, in which CB1-CB2Hets mediated a positive cross-talk. Resting cells were refractory while activated cells were highly responsive to cannabinoids. Interestingly, similar results were obtained in cultures treated with ß-amyloid (Aß1-42). Activation microglial markers were detected in the striatum of a Parkinson’s disease (PD) model and, remarkably, in primary microglia cultures from the hippocampus of mutant β-amyloid precursor protein (APPSw,Ind) mice, a transgenic Alzheimer’s disease (AD) model. Also of note was the similar cannabinoid receptor signaling found in primary cultures of microglia from APPSw,Ind and in cells from control animals activated using LPS plus IFN- γ. Expression of CB1-CB2Hets was increased in the striatum from rats rendered dyskinetic by chronic levodopa treatment.

In summary, our results showed sensitivity of activated microglial cells to cannabinoids, increased CB1-CB2Het expression in activated microglia and in microglia from the hippocampus of an AD model, and a correlation between levodopa-induced dyskinesia and striatal microglial activation in a PD model. Cannabinoid receptors and the CB1-CB2 heteroreceptor complex in activated microglia have potential as targets in the treatment of neurodegenerative diseases.”

https://www.ncbi.nlm.nih.gov/pubmed/28843453

http://www.sciencedirect.com/science/article/pii/S0889159117304038

Modulation of Astrocyte Activity by Cannabidiol, a Nonpsychoactive Cannabinoid.

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“The astrocytes have gained in recent decades an enormous interest as a potential target for neurotherapies, due to their essential and pleiotropic roles in brain physiology and pathology. Their precise regulation is still far from understood, although several candidate molecules/systems arise as promising targets for astrocyte-mediated neuroregulation and/or neuroprotection.

The cannabinoid system and its ligands have been shown to interact and affect activities of astrocytes. Cannabidiol (CBD) is the main non-psychotomimetic cannabinoid derived from Cannabis. CBD is devoid of direct CB1 and CB2 receptor activity, but exerts a number of important effects in the brain. Here, we attempt to sum up the current findings on the effects of CBD on astrocyte activity, and in this way on central nervous system (CNS) functions, across various tested models and neuropathologies.

The collected data shows that increased astrocyte activity is suppressed in the presence of CBD in models of ischemia, Alzheimer-like and Multiple-Sclerosis-like neurodegenerations, sciatic nerve injury, epilepsy, and schizophrenia. Moreover, CBD has been shown to decrease proinflammatory functions and signaling in astrocytes.”

https://www.ncbi.nlm.nih.gov/pubmed/28788104

http://www.mdpi.com/1422-0067/18/8/1669

Modeling Neurodegenerative Disorders for Developing Cannabinoid-Based Neuroprotective Therapies.

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Methods in Enzymology

“The increase in lifespan during the last 50 years, mainly in developed countries, has originated a progressive elevation in the incidence of chronic neurodegenerative disorders, for which aging is the key risk factor. This fact will definitively become the major biomedical challenge during the present century, in part because the expectation of a persisting elevation in the population older than 65 years over the whole population and, on the other hand, because the current lack of efficacious therapies to control these disorders despite years of intense research.

This chapter will address this question and will stress the urgency of developing better neuroprotective and neurorepair strategies that may delay/arrest the progression of these disorders, reviewing the major needs to solve the causes proposed for the permanent failures experienced in recent years, e.g., to develop multitarget strategies, to use more predictive experimental models, and to identify early disease biomarkers.

This chapter will propose the cannabinoids and their classic (e.g., endocannabinoid receptors and enzymes) and nonclassic (e.g., peroxisome proliferator-activated receptors, transcription factors) targets as a useful strategy for developing novel therapies for these disorders, based on their broad-spectrum neuroprotective profile, their activity as an endogenous protective system, the location of the endocannabinoid targets in cell substrates critical for neuronal survival, and their ability to serve for preservation and rescue, but also for repair and/or replacement, of neurons and glial cells against cytotoxic insults.”

https://www.ncbi.nlm.nih.gov/pubmed/28750802

http://www.sciencedirect.com/science/article/pii/S0076687917301787?via%3Dihub