Effect of long-term cannabidiol on learning and anxiety in a female Alzheimer’s disease mouse model

Frontiers - Crunchbase Company Profile & Funding

“Cannabidiol is a promising potential therapeutic for neurodegenerative diseases, including Alzheimer’s disease (AD).

Our laboratory has shown that oral CBD treatment prevents cognitive impairment in a male genetic mouse model of AD, the amyloid precursor protein 1 x presenilin 1 hemizygous (APPxPS1) mouse. However, as sex differences are evident in clinical populations and in AD mouse models, we tested the preventive potential of CBD therapy in female APPxPS1 mice.

In this study, 2.5-month-old female wildtype-like (WT) and APPxPS1 mice were fed 20 mg/kg CBD or a vehicle via gel pellets daily for 8 months and tested at 10.5 months in behavioural paradigms relevant to cognition (fear conditioning, FC; cheeseboard, CB; and novel object recognition test, NORT) and anxiety-like behaviours (elevated plus maze, EPM).

In the CB, CBD reduced latencies to find a food reward in APPxPS1 mice, compared to vehicle-treated APPxPS1 controls, and this treatment effect was not evident in WT mice. In addition, CBD also increased speed early in the acquisition of the CB task in APPxPS1 mice. In the EPM, CBD increased locomotion in APPxPS1 mice but not in WT mice, with no effects of CBD on anxiety-like behaviour. CBD had limited effects on the expression of fear memory.

These results indicate preventive CBD treatment can have a moderate spatial learning-enhancing effect in a female amyloid-β-based AD mouse model. This suggests CBD may have some preventive therapeutic potential in female familial AD patients.”

https://pubmed.ncbi.nlm.nih.gov/36238565/

“In conclusion, we found moderate effects of long-term oral CBD treatment on the acquisition of spatial learning by CBD in a female mouse model of familial AD. This suggests that preventive CBD may help limit some cognitive impairment in women with AD.”

https://www.frontiersin.org/articles/10.3389/fphar.2022.931384/full

Evaluating Cannabis sativa L.’s neuroprotection potential: From bench to bedside

Phytomedicine

“Background: Neurodegenerative diseases and dementia pose a global health challenge in an aging population, exemplified by the increasing incidence and prevalence of its most common form, Alzheimer’s disease. Although several approved treatments exist for Alzheimer’s disease, they only afford transient symptomatic improvements and are not considered disease-modifying. The psychoactive properties of Cannabis sativa L. have been recognized for thousands of years and now with burgeoning access to medicinal formulations globally, research has turned to re-evaluate cannabis and its myriad phytochemicals as a potential treatment and adjunctive agent for neurodegenerative diseases.

Purpose: This review evaluated the neuroprotective potential of C. sativa’s active constituents for potential therapeutic use in dementia and Alzheimer’s disease, based on published studies demonstrating efficacy in experimental preclinical settings associated with neurodegeneration.

Study design: Relevant information on the neuroprotective potential of the C. sativa’s phytoconstituents in preclinical studies (in vitro, in vivo) were included. The collated information on C. sativa’s component bioactivity was organized for therapeutic applications against neurodegenerative diseases.

Methods: The therapeutic use of C. sativa related to Alzheimer’s disease relative to known phytocannabinoids and other phytochemical constituents were derived from online databases, including PubMed, Elsevier, The Plant List (TPL, www.theplantlist.org), Science Direct, as well as relevant information on the known pharmacological actions of the listed phytochemicals.

Results: Numerous C. sativa -prevalent phytochemicals were evidenced in the body of literature as having efficacy in the treatment of neurodegenerative conditions exemplified by Alzheimer’s disease. Several phytocannabinoids, terpenes and select flavonoids demonstrated neuroprotection through a myriad of cellular and molecular pathways, including cannabinoid receptor-mediated, antioxidant and direct anti-aggregatory actions against the pathological toxic hallmark protein in Alzheimer’s disease, amyloid β.

Conclusions: These findings provide strong evidence for a role of cannabis constituents, individually or in combination, as potential neuroprotectants timely to the emergent use of medicinal cannabis as a novel treatment for neurodegenerative diseases. Future randomized and controlled clinical studies are required to substantiate the bioactivities of phytocannabinoids and terpenes and their likely synergies.”

https://pubmed.ncbi.nlm.nih.gov/36209703/

https://www.sciencedirect.com/science/article/abs/pii/S0944711322005748?via%3Dihub

[Low-dose THC in geriatric and palliative patients]

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“Background: Cannabis-containing medicines have been successfully used in our practice for more than 20 years in pain and especially in geriatric and palliative patients. While it was initially a very indication-specific use (pain, loss of appetite, etc.) and also with higher THC doses, this changed over time to low THC doses and a therapy focus on suffering-perpetuating symptoms and especially on stress (Matrix of Symptoms).

Method: As part of the legally prescribed companion survey, we evaluated our data in parallel and discussed it publicly in a series of publications. Based on these published results, the article is intended to show an overview of our experiences.

Results: Low-dose THC has a positive effect on morbidity, side effects, quality of life and mortality in geriatric and palliative patients.

Conclusion: Early therapy is particularly appropriate in geriatric and palliative patients due to the clear benefit-risk ratio of low-dose THC.”

https://pubmed.ncbi.nlm.nih.gov/36195786/

Investigation on the neuroprotective effect of a cannabidiol-enriched non-psychotropic Cannabis sativa L. extract in an in vitro model of excitotoxicity

Fitoterapia

“The purpose of this study was to evaluate the neuroprotective effect of a cannabidiol-enriched non-psychotropic Cannabis sativa L. extract (CSE) and its main constituents, cannabidiol and β-caryophyllene. An in vitro model of glutamate-induced neuronal excitotoxicity using SH-SY5Y cells was optimized. The impact of CSE on glutamate-impaired cell viability, brain-derived neurotrophic factor release, CB1 protein expression, and ERK levels was evaluated. The involvement of CB1 modulation was verified by the cotreatment with the CB1 antagonist AM4113. CSE was able to significantly protect SH-SY5Y from glutamate-impaired cell viability, and to counteract the changes in brain-derived neurotrophic factor levels, with a mechanism of action involving ERK modulation. Moreover, CSE completely reversed the reduction of CB1 receptor expression induced by glutamate, and the presence of the CB1 antagonist AM4113 reduced CSE effectiveness, suggesting that CBr play a role in the modulation of neuronal excitotoxicity. This work demonstrated the in vitro effectiveness of CSE as a neuroprotective agent, proposing the whole cannabis phytocomplex as a more effective strategy, compared to its main constituents alone, and suggested further investigations by using more complex cell models before moving to in vivo studies.”

https://pubmed.ncbi.nlm.nih.gov/36179898/

https://www.sciencedirect.com/science/article/abs/pii/S0367326X22001939?via%3Dihub

Dynamic Changes in the Endocannabinoid System during the Aging Process: Focus on the Middle-Age Crisis

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“Endocannabinoid (eCB) signaling is markedly decreased in the hippocampus (Hip) of aged mice, and the genetic deletion of the cannabinoid receptor type 1 (CB1) leads to an early onset of cognitive decline and age-related histological changes in the brain. Thus, it is hypothesized that cognitive aging is modulated by eCB signaling through CB1.

In the present study, we detailed the changes in the eCB system during the aging process using different complementary techniques in mouse brains of five different age groups, ranging from adolescence to old age.

Our findings indicate that the eCB system is most strongly affected in middle-aged mice (between 9 and 12 months of age) in a brain region-specific manner. We show that 2-arachidonoylglycerol (2-AG) was prominently decreased in the Hip and moderately in caudate putamen (CPu), whereas anandamide (AEA) was decreased in both CPu and medial prefrontal cortex along with cingulate cortex (mPFC+Cg), starting from 6 months until 12 months. Consistent with the changes in 2-AG, the 2-AG synthesizing enzyme diacylglycerol lipase α (DAGLα) was also prominently decreased across the sub-regions of the Hip.

Interestingly, we found a transient increase in CB1 immunoreactivity across the sub-regions of the Hip at 9 months, a plausible compensation for reduced 2-AG, which ultimately decreased strongly at 12 months. Furthermore, quantitative autoradiography of CB1 revealed that [3H]CP55940 binding markedly increased in the Hip at 9 months. However, unlike the protein levels, CB1 binding density did not drop strongly at 12 months and at old age. Furthermore, [3H]CP55940 binding was significantly increased in the lateral entorhinal cortex (LEnt), starting from the middle age until the old age.

Altogether, our findings clearly indicate a middle-age crisis in the eCB system, which could be a potential time window for therapeutic interventions to abrogate the course of cognitive aging.”

https://pubmed.ncbi.nlm.nih.gov/36142165/

“In conclusion, our observations indicate that the eCB system is most affected during the middle age in a brain region-specific manner. Taken together, the middle-age crisis in the eCB signaling corresponds well with the onset of neuroinflammatory glial activity and cognitive deficits in mice. We now hypothesize that late middle-age is the time period when a therapy based on the activation of the cannabinoid system has the highest efficacy to prevent cognitive aging and pathologies related to brain aging.”

https://www.mdpi.com/1422-0067/23/18/10254/htm

Effects of rich cannabidiol oil on behavioral disturbances in patients with dementia: A placebo controlled randomized clinical trial

Frontiers - Crunchbase Company Profile & Funding

“Background: Almost 90% of patients with dementia suffer from some type of neurobehavioral symptom, and there are no approved medications to address these symptoms.

Objective: To evaluate the safety and efficacy of the medical cannabis oil “Avidekel” for the reduction of behavioral disturbances among patients with dementia.

Materials and methods: In this randomized, double-blind, single-cite, placebo-controlled trial conducted in Israel (ClinicalTrials.gov: NCT03328676), patients aged at least 60, with a diagnosis of major neurocognitive disorder and associated behavioral disturbances were randomized 2:1 to receive either “Avidekel,” a broad-spectrum cannabis oil (30% cannabidiol and 1% tetrahydrocannabinol: 295 mg and 12.5 mg per ml, respectively; n = 40) or a placebo oil (n = 20) three times a day for 16 weeks. The primary outcome was a decrease, as compared to baseline, of four or more points on the Cohen-Mansfield Agitation Inventory score by week 16.

Results: From 60 randomized patients [mean age, 79.4 years; 36 women (60.0%)], 52 (86.7%) completed the trial (all eight patients who discontinued treatment were from the investigational group). There was a statistically significant difference in the proportion of subjects who had a Cohen-Mansfield Agitation Inventory score reduction of ≥ 4 points at week 16: 24/40 (60.0%) and 6/20 (30.0%) for investigational and control groups, respectively (χ2 = 4.80, P = 0.03). There was a statistically significant difference in the proportion of subjects who had a Cohen-Mansfield Agitation Inventory score reduction of ≥ 8 points at week 16: 20/40 (50%) and 3/20 (15%), respectively (χ2 = 6.42, P = 0.011). The ANOVA repeated measures analysis demonstrated significantly more improvement in the investigational group compared to the control group at weeks 14 and 16 (F = 3.18, P = 0.02). Treatment was mostly safe, with no significant differences in the occurrence of adverse events between the two groups.

Conclusion: In this randomized controlled trial, ‘Avidekel’ oil significantly reduced agitation over placebo in patients suffering from behavioral disturbances related to dementia, with non-serious side-effects. Further research is required with a larger sample size.”

https://pubmed.ncbi.nlm.nih.gov/36148467/

“Our findings suggest that rich-CBD cannabis oil may alleviate agitation in older patients with dementia.”

https://www.frontiersin.org/articles/10.3389/fmed.2022.951889/full

Therapeutic properties of multi-cannabinoid treatment strategies for Alzheimer’s disease

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“Alzheimer’s disease (AD) is a debilitating neurodegenerative disease characterized by declining cognition and behavioral impairment, and hallmarked by extracellular amyloid-β plaques, intracellular neurofibrillary tangles (NFT), oxidative stress, neuroinflammation, and neurodegeneration. There is currently no cure for AD and approved treatments do not halt or slow disease progression, highlighting the need for novel therapeutic strategies.

Importantly, the endocannabinoid system (ECS) is affected in AD. Phytocannabinoids, including cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC), interact with the ECS, have anti-inflammatory, antioxidant, and neuroprotective properties, can ameliorate amyloid-β and NFT-related pathologies, and promote neurogenesis. Thus, in recent years, purified CBD and THC have been evaluated for their therapeutic potential.

CBD reversed and prevented the development of cognitive deficits in AD rodent models, and low-dose THC improved cognition in aging mice. Importantly, CBD, THC, and other phytochemicals present in Cannabis sativa interact with each other in a synergistic fashion (the “entourage effect”) and have greater therapeutic potential when administered together, rather than individually. Thus, treatment of AD using a multi-cannabinoid strategy (such as whole plant cannabis extracts or particular CBD:THC combinations) may be more efficacious compared to cannabinoid isolate treatment strategies.

Here, we review the current evidence for the validity of using multi-cannabinoid formulations for AD therapy. We discuss that such treatment strategies appear valid for AD therapy but further investigations, particularly clinical studies, are required to determine optimal dose and ratio of cannabinoids for superior effectiveness and limiting potential side effects. Furthermore, it is pertinent that future in vivo and clinical investigations consider sex effects.”

https://pubmed.ncbi.nlm.nih.gov/36117622/

“This mini review highlights that multi-cannabinoid combination treatment strategies are valid candidates for novel AD therapies. However, further investigations, and in particular, clinical studies, are required to determine optimal dose and ratio of cannabinoids for treatment of behavioral, cognitive, and pathological symptoms of AD thereby also considering other cannabinoids in addition to the current focus on THC and CBD (most cannabis extract studies did not profile cannabinoid content beyond those two phytocannabinoids). Importantly, all relevant studies reviewed were carried out in one sex/gender only. Given that sex-specificity is evident in AD transgenic mouse models (van Eersel et al., 2015Jiao et al., 2016) and gender differences are seen in dementia (Oveisgharan et al., 2018) as well as in the ECS and the response to cannabis (Craft et al., 2013), it is pertinent that these future investigations consider both sexes.”

https://www.frontiersin.org/articles/10.3389/fnins.2022.962922/full

Neuroprotective potential of Cannabis sativa-based oils in Caenorhabditis elegans

Scientific Reports

“Substances from the Cannabis sativa species, especially cannabidiol (CBD) and Delta-9-tetrahydrocannabinol (Δ9-THC), have attracted medical attention in recent years. The actions of these two main cannabinoids modulate the cholinergic nervous system (CholNS) involving development, synaptic plasticity, and response to endogenous and environmental damage, as a characteristic of many neurodegenerative diseases.

The dynamics of these diseases are mediated by specific neurotransmitters, such as the GABAergic nervous system (GNS) and the CholNS. The nematode Caenorhabditis elegans is an important experimental model, which has different neurotransmitter systems that coordinate its behavior and has a transgene strain that encodes the human β-amyloid 1-42 peptide in body wall muscle, one of the main proteins involved in Alzheimer´s disease.

Therefore, the objective of this study was to evaluate the protective potential of terpenoids found in C. sativa in the GNS and CholNS of C. elegans. The effect of two C. sativa oils with variations in CBD and THC concentrations on acetylcholinesterase (AChE) activity, lipid peroxidation, and behavior of C. elegans was evaluated.

C. sativa oils were efficient in increasing pharyngeal pumping rate and reducing defecation cycle, AChE activity, and ROS levels in N2 strains. In the muscle:Abeta1-42 strain, mainly when using CBD oil, worm movement, body bends, and pharyngeal pumping were increased, with a reduced AChE activity.

Consequently, greater investments in scientific research are needed, in addition to breaking the taboo on the use of the C. sativa plant as an alternative for medicinal use, especially in neurodegenerative diseases, which have already shown positive initial results.”

https://pubmed.ncbi.nlm.nih.gov/36100636/

https://www.nature.com/articles/s41598-022-19598-3

An Ultra-Low Dose of ∆9-Tetrahydrocannabinol Alleviates Alzheimer’s Disease-Related Cognitive Impairments and Modulates TrkB Receptor Expression in a 5XFAD Mouse Model

ijms-logo

“Alzheimer’s disease (AD) is the most common form of dementia, but there is still no available treatment.

Δ9-tetrahydrocannabinol (THC) is emerging as a promising therapeutic agent. Using THC in conventional high doses may have deleterious effects. Therefore, we propose to use an ultra-low dose of THC (ULD-THC). We previously published that a single injection of ULD-THC ameliorated cognitive functioning in several models of brain injuries as well as in naturally aging mice.

Here, 5xFAD AD model mice received a single treatment of ULD-THC (0.002 mg/kg) after disease onset and were examined in two separate experiments for cognitive functions, neurotropic, and inflammatory factors in the hippocampus.

We show that a single injection of ULD-THC alleviated cognitive impairments in 6- and 12-month-old 5xFAD mice. On the biochemical level, our results indicate an imbalance between the truncated TrkB receptor isoform and the full receptor, with AD mice showing a greater tendency to express the truncated receptor, and ULD-THC improved this imbalance. We also investigated the expression of three AD-related inflammatory markers and found an ameliorating effect of ULD-THC.

The current research demonstrates for the first time the beneficial effects of a single ultra-low dose of THC in a mouse model of AD after disease onset.”

https://pubmed.ncbi.nlm.nih.gov/36012711/

“The current research demonstrates for the first time the beneficial effects of a single ultra-low dose of THC in a mouse model of AD after disease onset. As THC is a cheap, widely available substance already approved for use in other conditions, this research brings us closer to understanding its mechanisms and will possibly lead to new treatments.”

https://www.mdpi.com/1422-0067/23/16/9449/htm

Interacting binding insights and conformational consequences of the differential activity of cannabidiol with two endocannabinoid-activated G-protein-coupled receptors

“Cannabidiol (CBD), the major non-psychoactive phytocannabinoid present in the plant Cannabis sativa, has displayed beneficial pharmacological effects in the treatment of several neurological disorders including, epilepsy, Parkinson’s disease, and Alzheimer’s disease. In particular, CBD is able to modulate different receptors in the endocannabinoid system, some of which belong to the family of G-protein-coupled receptors (GPCRs). Notably, while CBD is able to antagonize some GPCRs in the endocannabinoid system, it also seems to activate others. The details of this dual contrasting functional feature of CBD, that is, displaying antagonistic and (possible) agonistic ligand properties in related receptors, remain unknown. Here, using computational methods, we investigate the interacting determinants of CBD in two closely related endocannabinoid-activated GPCRs, the G-protein-coupled receptor 55 (GPR55) and the cannabinoid type 1 receptor (CB1). While in the former, CBD has been demonstrated to function as an antagonist, the way by which CBD modulates the CB1 receptor remains unclear. Namely, CBD has been suggested to directly trigger receptor’s activation, stabilize CB1 inactive conformations or function as an allosteric modulator. From microsecond-length unbiased molecular dynamics simulations, we found that the presence of the CBD ligand in the GPR55 receptor elicit conformational changes associated with antagonist-bound GPCRs. In contrast, when the GPR55 receptor is simulated in complex with the selective agonist ML186, agonist-like conformations are sampled. These results are in agreement with the proposed modulatory function of each ligand, showing that the computational techniques utilized to characterize the GPR55 complexes correctly differentiate the agonist-bound and antagonist-bound systems. Prompted by these results, we investigated the role of the CBD compound on the CB1 receptor using similar computational approaches. The all-atom MD simulations reveal that CBD induces conformational changes linked with agonist-bound GPCRs. To contextualize the results we looked into the CB1 receptor in complex with a well-established antagonist. In contrast to the CBD/CB1 complex, when the CB1 receptor is simulated in complex with the ligand antagonist AM251, inactive conformations are explored, showing that the computational techniques utilized to characterize the CB1 complexes correctly differentiate the agonist-bound and antagonist-bound systems. In addition, our results suggest a previously unknown sodium-binding site located in the extracellular domain of the CB1 receptor. From our detailed characterization, we found particular interacting loci in the binding sites of the GPR55 and the CB1 receptors that seem to be responsible for the differential functional features of CBD. Our work will pave the way for understanding the CBD pharmacology at a molecular level and aid in harnessing its potential therapeutic use.”

https://pubmed.ncbi.nlm.nih.gov/36016551/

https://www.frontiersin.org/articles/10.3389/fphar.2022.945935/full