Category Archives: Alzheimer’s Disease (AD)

Analogues of cannabinoids as multitarget drugs in the treatment of Alzheimer’s disease

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“Given that neuronal degeneration in Alzheimer’s disease (AD) is caused by the combination of multiple neurotoxic insults, current directions in the research of novel therapies to treat this disease attempts to design multitarget strategies that could be more effective than the simply use of acetylcholinesterase inhibitors; currently, the most used therapy for AD. One option, explored recently, is the synthesis of new analogues of cannabinoids that could competitively inhibit the acetylcholinesterase (AChE) enzyme and showing the classic neuroprotective profile of cannabinoid compounds. In this work, molecular docking has been used to design some cannabinoid analogues with such multitarget properties, based on the similarities of donepezil and Δ9-tetrahydrocannabinol. The analogues synthesized, compounds 1 and 2, demonstrated to have two interesting characteristics in different in vitro assays: competitive inhibition of AChE and competitive antagonism at the CB1/CB2 receptors. They are highly lipophilic, highlighting that they could easily reach the CNS, and apparently presented a low toxicity. These results open the door to the synthesis of new compounds for a more effective treatment of AD.”

https://pubmed.ncbi.nlm.nih.gov/33460612/

https://www.sciencedirect.com/science/article/abs/pii/S0014299921000285?via%3Dihub

The Neuroprotective Properties, Functions, and Roles of Cannabis sativa in Selected Diseases Related to the Nervous System

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“Background: Cannabis and its extracts are now being explored due to their huge health benefits. Although, the effect they elicit, whether on humans or rodents, may vary based on the age of the animal/subject and or the time in which the extract is administered. However, several debates exist concerning the various medical applications of these compounds. Nonetheless, their applicability as therapeutics should not be clouded based on their perceived negative biological actions.

Methods: Articles from reliable databases such as Science Direct, PubMed, Google Scholar, Scopus, and Ovid were searched. Specific search methods were employed using multiple keywords: ”Medicinal Cannabis; endocannabinoid system; cannabinoids receptors; cannabinoids and cognition; brain disorders; neurodegenerative diseases”. For the inclusion/exclusion criteria, only relevant articles related to medicinal Cannabis and its various compounds were considered.

Results: The current review highlights the role, effects, and involvement of Cannabis, cannabinoids, and endocannabinoids in preventing selected neurodegenerative diseases and possible amelioration of cognitive impairments. Furthermore, it also focuses on Cannabis utilization in many disease conditions such as Alzheimer’s and Parkinson’s disease among others.

Conclusion: In conclusion, the usage of Cannabis should be further explored as accumulating evidence suggests that it could be effective and somewhat safe, especially when adhered to the recommended dosage. Furthermore, in-depth studies should be conducted in order to unravel the specific mechanism underpinning the involvement of cannabinoids at the cellular level and their therapeutic applications.”

https://pubmed.ncbi.nlm.nih.gov/33504317/

https://www.eurekaselect.com/article/113707

Roles of Cannabidiol in the Treatment and Prevention of Alzheimer’s Disease by Multi-target Actions

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“Alzheimer’s Disease (AD) is one of the most common neurodegenerative diseases with chronic, progressive, and irreversible characteristics, affecting nearly 50 million older adults worldwide. The pathogenesis of AD includes the formation of senile plaques, the abnormal aggregation of tau protein and the gradual degeneration and death of cerebral cortical cells. The main symptoms are memory loss, cognitive decline and behavioral disorders. Studies indicate that cannabidiol (CBD) possesses various pharmacological activities, including anti-inflammatory, anti-oxidation and neuroprotective activities. It has been suggested as a potential multi-target medicine for the treatment of AD. In this review, we aim to summarize the underlying mechanisms and protective effects of CBD on signaling pathways and central receptors involved in the pathogenesis of AD, including the endocannabinoid system (eCBs), the Transient receptor potential vanilloid type 1(TRPV1) receptor, and the Peroxisome Proliferator-Activated Receptor (PPAR) receptor.”

https://pubmed.ncbi.nlm.nih.gov/33797364/

https://www.eurekaselect.com/article/115117

Cannabidiol Treatment Improves Glucose Metabolism and Memory in Streptozotocin-Induced Alzheimer’s Disease Rat Model: A Proof-of-Concept Study

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“An early and persistent sign of Alzheimer’s disease (AD) is glucose hypometabolism, which can be evaluated by positron emission tomography (PET) with 18F-2-fluoro-2-deoxy-D-glucose ([18F]FDG). Cannabidiol has demonstrated neuroprotective and anti-inflammatory properties but has not been evaluated by PET imaging in an AD model. Intracerebroventricular (icv) injection of streptozotocin (STZ) is a validated model for hypometabolism observed in AD. This proof-of-concept study evaluated the effect of cannabidiol treatment in the brain glucose metabolism of an icv-STZ AD model by PET imaging. Wistar male rats received 3 mg/kg of STZ and [18F]FDG PET images were acquired before and 7 days after STZ injection. Animals were treated with intraperitoneal cannabidiol (20 mg/kg-STZ-cannabidiol) or saline (STZ-saline) for one week. Novel object recognition was performed to evaluate short-term and long-term memory. [18F]FDG uptake in the whole brain was significantly lower in the STZ-saline group. Voxel-based analysis revealed a hypometabolism cluster close to the lateral ventricle, which was smaller in STZ-cannabidiol animals. The brain regions with more evident hypometabolism were the striatum, motor cortex, hippocampus, and thalamus, which was not observed in STZ-cannabidiol animals. In addition, STZ-cannabidiol animals revealed no changes in memory index. Thus, this study suggests that cannabidiol could be an early treatment for the neurodegenerative process observed in AD.”

https://pubmed.ncbi.nlm.nih.gov/35163003/

https://www.mdpi.com/1422-0067/23/3/1076

Understanding the Modulatory Effects of Cannabidiol on Alzheimer’s Disease

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“Alzheimer’s disease (AD), the most common neurodegenerative disease, is characterized by progressive cognitive impairment. The deposition of amyloid beta (Aβ) and hyperphosphorylated tau is considered the hallmark of AD pathology. Many therapeutic approaches such as Food and Drug Administration-approved cholinesterase inhibitors and N-methyl-D-aspartate receptor antagonists have been used to intervene in AD pathology. However, current therapies only provide limited symptomatic relief and are ineffective in preventing AD progression. Cannabidiol (CBD), a phytocannabinoid devoid of psychoactive responses, provides neuroprotective effects through both cannabinoid and noncannabinoid receptors. Recent studies using an AD mouse model have suggested that CBD can reverse cognitive deficits along with Aβ-induced neuroinflammatory, oxidative responses, and neuronal death. Furthermore, CBD can reduce the accumulation of Aβ and hyperphosphorylation of tau, suggesting the possibility of delaying AD progression. Particularly, the noncannabinoid receptor, peroxisome proliferator-activated receptor gamma, has been suggested to be involved in multiple functions of CBD. Therefore, understanding the underlying mechanisms of CBD is necessary for intervening in AD pathology in depth and for the translation of preclinical studies into clinical settings. In this review, we summarize recent studies on the effect of CBD in AD and suggest problems to be overcome for the therapeutic use of CBD.”

https://pubmed.ncbi.nlm.nih.gov/34573232/

https://www.mdpi.com/2076-3425/11/9/1211


Cannabidiol regulates CB1-pSTAT3 signaling for neurite outgrowth, prolongs lifespan, and improves health span in Caenorhabditis elegans of Aβ pathology models

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“Cannabidiol (CBD), a phytocannabinoid from the Cannabis sativa plant, exhibits a broad spectrum of potential therapeutic properties for neurodegenerative diseases. An accumulation of amyloid-β (Aβ) protein is one of the most important neuropathology in neurodegenerative diseases like Alzheimer’s disease (AD). Data on the effect of CBD on the amelioration of Aβ-induced neurite degeneration and its consequences of life and health spans is sparse. This study aimed to investigate the effects of CBD on neurite outgrowth in cells and lifespan and health span in Caenorhabditis elegans (C. elegans). In human SH-SY5Y neuronal cells, CBD prevented neurite lesion induced by Aβ1-42 and increased the expression of fatty acid amide hydrolase (FAAH) and cannabinoid receptor 1 (CB1R). Furthermore, CBD both protected the reduction of dendritic spine density and rescued the activity of synaptic Ca2+ /calmodulin-dependent protein kinase II (CaMKII) from Aβ1-42 toxicity in primary hippocampal neurons. In C. elegans, we used the transgenic CL2355 strain of C. elegans, which expresses the human Aβ peptide throughout the nervous system and found that CBD treatment extended lifespan and improved health span. The neuroprotective effect of CBD was further explored by observing the dopaminergic neurons using transgenic dat-1: GFP strains using the confocal microscope. This study shows that CBD prevents the neurite degeneration induced by Aβ, by a mechanism involving CB1R activation, and extends lifespan and improves health span in Aβ-overexpressing worms. Our findings support the potential therapeutic approach of CBD for the treatment of AD patients.”

https://pubmed.ncbi.nlm.nih.gov/33817834/

“We showed that CBD extends lifespan and improves health span in Aβ-expression C. elegans. Taken together, our findings highlight the neuroprotective benefits of CBD and its therapeutic potential for neurodegenerative conditions such as AD.”

https://faseb.onlinelibrary.wiley.com/doi/10.1096/fj.202002724R

Cannabidiol protects against Alzheimer’s disease in C. elegans via ROS scavenging activity of its phenolic hydroxyl groups

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European Journal of Pharmacology


“Recent discoveries have implicated the potential of Cannabidiol (CBD) in the prevention of Alzheimer’s disease (AD). However, how CBD affects such neurodegenerative disorders remains unclear. Herein, Caenorhabditis elegans (C. elegans) was used as the model organism to elucidate the mechanism by which CBD ameliorates AD in vivo. CBD was found to alleviate the progression of Aβ-induced AD but not tau protein-induced AD or α-syn-induced Parkinson’s disease. CBD inhibited the aggregation of Aβ in C. elegans. However, CBD failed to prevent the formation of β-sheet aggregation in vitro. Moreover, CBD was found to scavenge reactive oxygen species (ROS) in vivo without inducing the overexpression of antioxidative genes. In addition, CBD treatment enhanced the worm resistance to oxidative stress, which was independent of the classical transcription factors DAF-16 and SKN-1. These results supported that the in vivo antioxidative activity of CBD was most likely due to its intrinsic antioxidative property. Furthermore, the phenolic hydroxyl groups of CBD were found to be critical for scavenging ROS in vitro and in vivo, alleviating the aggregation of Aβ in vivo, and ameliorating Aβ-associated neurotoxicity. These studies show that CBD protects against AD in C. elegans via the ROS scavenging activity of its phenolic hydroxyl groups, which provides insight for further structure-activity relationship studies of CBD as an AD therapeutic.”

https://pubmed.ncbi.nlm.nih.gov/35181336/

https://www.sciencedirect.com/science/article/abs/pii/S0014299922000905?via%3Dihub

Cannabinol inhibits oxytosis/ferroptosis by directly targeting mitochondria independently of cannabinoid receptors

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“The oxytosis/ferroptosis regulated cell death pathway recapitulates many features of mitochondrial dysfunction associated with the aging brain and has emerged as a potential key mediator of neurodegeneration. It has thus been proposed that the oxytosis/ferroptosis pathway can be used to identify novel drug candidates for the treatment of age-associated neurodegenerative diseases that act by preserving mitochondrial function. Previously, we identified cannabinol (CBN) as a potent neuroprotector. Here, we demonstrate that not only does CBN protect nerve cells from oxytosis/ferroptosis in a manner that is dependent on mitochondria and it does so independently of cannabinoid receptors. Specifically, CBN directly targets mitochondria and preserves key mitochondrial functions including redox regulation, calcium uptake, membrane potential, bioenergetics, biogenesis, and modulation of fusion/fission dynamics that are disrupted following induction of oxytosis/ferroptosis. These protective effects of CBN are at least partly mediated by the promotion of endogenous antioxidant defenses and the activation of AMP-activated protein kinase (AMPK) signaling. Together, our data highlight the potential of mitochondrially-targeted compounds such as CBN as novel oxytotic/ferroptotic inhibitors to rescue mitochondrial dysfunction as well as opportunities for the discovery and development of future neurotherapeutics.”

https://pubmed.ncbi.nlm.nih.gov/34999187/

“ACTIVE INGREDIENT IN CANNABIS PROTECTS AGING BRAIN CELLS”

https://www.salk.edu/news-release/active-ingredient-in-cannabis-protects-aging-brain-cells/

Cannabidiol induces autophagy and improves neuronal health associated with SIRT1 mediated longevity

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“Autophagy is a catabolic process to eliminate defective cellular molecules via lysosome-mediated degradation. Dysfunctional autophagy is associated with accelerated aging, whereas stimulation of autophagy could have potent anti-aging effects. We report that cannabidiol (CBD), a natural compound from Cannabis sativa, extends lifespan and rescues age-associated physiological declines in C. elegans. CBD promoted autophagic flux in nerve-ring neurons visualized by a tandem-tagged LGG-1 reporter during aging in C. elegans. Similarly, CBD activated autophagic flux in hippocampal and SH-SY5Y neurons. Furthermore, CBD-mediated lifespan extension was dependent on autophagy genes (bec-1, vps-34, and sqst-1) confirmed by RNAi knockdown experiments. C. elegans neurons have previously been shown to accumulate aberrant morphologies, such as beading and blebbing, with increasing age. Interestingly, CBD treatment slowed the development of these features in anterior and posterior touch receptor neurons (TRN) during aging. RNAi knockdown experiments indicated that CBD-mediated age-associated morphological changes in TRNs require bec-1 and sqst-1, not vps-34. Further investigation demonstrated that CBD-induced lifespan extension and increased neuronal health require sir-2.1/SIRT1. These findings collectively indicate the anti-aging benefits of CBD treatment, in both in vitro and in vivo models, and its potential to improve neuronal health and longevity.”

https://pubmed.ncbi.nlm.nih.gov/35445360/

Cannabis terpenes display variable protective and anti-aggregatory actions against neurotoxic β amyloid in vitro: highlighting the protective bioactivity of α-bisabolol in motorneuronal-like NSC-34 cells

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“Background: Terpenes form a diverse class of naturally occurring chemicals ascribed various biological activities. Cannabis contains over 400 different terpenes of varying chemical complexity which may add to the known biological activities of phytocannabinoids of relevance to the increasing use of medical cannabis; however, to date have been incompletely characterized. We assessed three terpenes predominant in cannabis: α-bisabolol, myrcene and β-caryophyllene for neuroprotective and anti-aggregative properties in both undifferentiated and differentiated NSC-34 motorneuronal-like cells as a sensitive model for neurotoxicity to oxidative stress and amyloid β (Aβ1-42) protein exposure.

Methods: Cell viability was assessed biochemically using the MTT assay in the presence of either α-bisabolol, myrcene and β-caryophyllene (1-1000 µM) for 48 hr. Sub-toxic threshold test concentrations of each terpene were then applied to cells, alone or with concomitant incubation with the lipid peroxidant tert-butyl hyrdroperoxide (t-BHP) or amyloid β (Aβ1-42; 0-1 µM) to assess neuroprotective effects. Direct effects of each terpene on Aβ fibril formation and aggregation were also evaluated using the Thioflavin T (ThT) fluorometric kinetic assay, circular dichroism and transmission electron microscopy (TEM) to visualise fibril and aggregate morphology.

Results: Terpenes were intrinsically benign to NSC-34 cells up to 100 µM. No significant antioxidant effects were observed following t-BHP administration with myrcene and β-caryophyllene, however α-bisabolol provided a modest but significant increase in cell viability in undifferentiated cells. α-bisabolol also demonstrated a significant neuroprotective effect against amyloid β exposure, with β-caryophyllene also providing a lesser, but significant increase in cell viability. Protective effects of terpenes were more pronounced in undifferentiated versus differentiated cells, attributable more so to an attenuated loss of cell viability in response to Aβ1-42 following NSC-34 cell differentiation. Neuroprotection was associated with a direct inhibition of Aβ1-42 fibril and aggregate density, evidenced by both attenuated ThT fluorescence kinetics and both spectral and microscopic evidence of altered and diminished density of Aβ aggregates. While myrcene and β-caryophyllene also elicited reductions in ThT fluorescence and alterations in Aβ aggregation, these were less well associated with neuroprotective capacity.

Conclusions: These findings highlight a neuroprotective role of α-bisabolol against Aβ-mediated neurotoxicity associated with an inhibition of Aβ fibrillization and modest antioxidant effect against lipid peroxidation, while β-caryophyllene also provided a small but significant measure of protection to Aβ-mediated neurotoxicity. Anti-aggregatory effects were not directly correlated with neuroprotective efficacy. This demonstrates that bioactivity of selected terpenes should be a consideration in the emergent use of medicinal cannabis formulations for the treatment of neurodegenerative diseases.”

https://pubmed.ncbi.nlm.nih.gov/35278524/