Assessing Cannabidiol as a Therapeutic Agent for Preventing and Alleviating Alzheimer's Disease Neurodegeneration

Future Therapeutic Strategies for Alzheimer's Disease: Focus on Behavioral and Psychological Symptoms

Alzheimer's disease (AD) is a progressive, degenerative brain disorder that impairs memory and thinking skills, leading to significant economic and humanistic burdens. It is associated with various neuropsychiatric symptoms (NPS) such as anxiety, agitation, depression, aggression, apathy, and psychosis. NPSs are common in patients with AD, affecting up to 97% of individuals diagnosed with AD. The severity of NPS is linked to disease progression and cognitive decline. NPS in Alzheimer's disease leads to increased morbidity, mortality, caregiver burden, earlier nursing home placement, and higher healthcare costs. Despite their significant impact, clinical research on NPS in AD is limited. In clinical settings, accurately distinguishing and diagnosing NPS related to AD remains a challenge. Additionally, conventional treatments for NPS in AD are often ineffective, highlighting the need for new therapies that target these specific symptoms. Understanding these comorbidities can aid in early diagnosis and better management of AD. In this review, we provide a summary of the various neurological and psychiatric symptoms (NPS) associated with AD and new candidates under development for the treatment of NPS based on their therapeutic targets and mechanisms. On top of the conventional NPS studied so far, this review adds recent advancements in the understanding of social functional impairment in AD. This review also provides information that can contribute to the advancement of studies and translational research in this field by emphasizing therapeutic targets and mechanisms of action focused on AD-related NPS rather than conventional mechanisms targeted in AD drug development. Above all, considering the relative lack of research in this new field despite the importance of clinical, medical, and translational research, it may increase interest in NPS in AD, its pathophysiological mechanisms, and potential therapeutic candidates such as molecules with antioxidant potential.

A systematic study of molecular targets of cannabidiol in Alzheimer's disease

Background

Alzheimer's disease (AD) is a prevalent, incurable, and chronic neurodegenerative condition characterized by the accumulation of amyloid-β protein (Aβ), disrupting various bodily systems. Despite the lack of a cure, phenolic compounds like cannabidiol (CBD), a non-psychoactive component of cannabis, have emerged as potential therapeutic agents for AD.

Objective

This systematic review explores the impact of different types of cannabidiol on AD, unveiling their neuroprotective mechanisms.

Methods

The research used PubMed, Scopus, and Web of Science databases with keywords like "Alzheimer's disease" and "Cannabidiol." Studies were evaluated based on title, abstract, and relevance to treating AD with CBD. No restrictions on research type or publication year. Excluded were hypothesis papers, reviews, books, unavailable articles, etc.

Results

Microsoft Excel identified 551 articles, with 92 included in the study, but only 22 were thoroughly evaluated. In-vivo and in-silico studies indicate that CBD may disrupt Aβ42, reduce pro-inflammatory molecule release, prevent reactive oxygen species formation, inhibit lipid oxidation, and counteract Aβ-induced increases in intracellular calcium, thereby protecting neurons from apoptosis.

Conclusions

In summary, the study indicates that CBD and its analogs reduce the production of Aβ42. Overall, these findings support the potential of CBD in alleviating the underlying pathology and symptoms associated with AD, underscoring the crucial need for further rigorous scientific investigation to elucidate the therapeutic applications and mechanisms of CBD in AD.

Cannabidiol, a plant-derived compound, is an emerging strategy for treating cognitive impairments: comprehensive review of randomized trials

Background

Finding new strategies to treat cognitive disorders is a challenging task. Medication must defeat the blood-brain barrier. Cannabidiol (CBD), a non-intoxicating compound of the cannabis plant, has gained recognition as a nutraceutical for its potential effectiveness in treating anxiety, oxidative stress, convulsions, and inflammation. However, the dose, tolerable upper intake, formulation, administration routes, comorbidities, diet, and demographic factors to reverse cognitive impairments have not been completely explored. Trials using CBD as a primary intervention have been conducted to alleviate cognitive issues. This review evaluates the benefits of CBD supplementation, research design, formulations, and outcomes reported in randomized clinical trials.

Methods

An evidence-based systematic literature review was conducted using PUBMED and the Florida International University Research Library resources. Fourteen randomized trials were selected for review, and their designs and outcomes were compared conceptually and in the form of resume tables.

Results

CBD showed improvement in anxiety and cognitive impairments in 9 out of 16 analyzed trials. However, the variability could be justified due to the diversity of the trial designs, underpowered studies, assayed population, uncontrolled results for comorbidities, medications, severity of drug dependence, compliances, and adherences. Overall, oral single doses of 200 mg-1,500 mg or vaporized 13.75 mg of CBD were shown to be effective at treating anxiety and cognition with a good safety profile and no drug addiction behaviors. Conversely, results that did not have a significant effect on treating cognitive impairments can be explained by various factors such as THC or other abuse drugs masking effect, low dose, and unknown purity of CBD. Furthermore, CBD shows potential properties that can be tested in the future for Alzheimer's disease.

Conclusion

As medical cannabis becomes more accessible, it is essential to understand whether medication rich in CBD exerts a beneficial effect on cognitive disorders. Our study concludes that CBD is a promising candidate for treating neurocognitive disorders; however, more studies are required to define CBD as a therapeutic candidate for managing cognitive disorders.

Opioid and Cannabinoid Systems in Pain: Emerging Molecular Mechanisms and Use in Clinical Practice, Health, and Fitness

Pain is an unpleasant sensory and emotional experience. Adequate pain control is often challenging, particularly in patients with chronic pain. Despite advances in pain management, drug addiction, overtreatment, or substance use disorders are not rare. Hence the need for further studies in the field. The substantial progress made over the last decade has revealed genes, signalling pathways, molecules, and neuronal networks in pain control thus opening new clinical perspectives in pain management. In this respect, data on the epigenetic modulation of opioid and cannabinoid receptors, key actors in the modulation of pain, offered new perspectives to preserve the activity of opioid and endocannabinoid systems to increase the analgesic efficacy of opioid- and cannabinoid-based drugs. Similarly, upcoming data on cannabidiol (CBD), a non-psychoactive cannabinoid in the marijuana plant Cannabis sativa, suggests analgesic, anti-inflammatory, antioxidant, anticonvulsivant and ansiolitic effects and supports its potential application in clinical contexts such as cancer, neurodegeneration, and autoimmune diseases but also in health and fitness with potential use in athletes. Hence, in this review article, we summarize the emerging epigenetic modifications of opioid and cannabinoid receptors and focus on CBD as an emerging non-psychoactive cannabinoid in pain management in clinical practice, health, and fitness.

Cannabidiol improves the cognitive function of SAMP8 AD model mice involving the microbiota-gut-brain axis

Cannabidiol (CBD), a natural component extracted from Cannabis sativa L. exerts neuroprotective, antioxidant, and anti-inflammatory effects in Alzheimer's disease (AD), a disease characterized by impaired cognition and accumulation of amyloid-B peptides (Aβ). Interactions between the gut and central nervous system (microbiota-gut-brain axis) play a critical role in the pathogenesis of neurodegenerative disorder AD. At present investigations into the mechanisms underlying the neuroprotective action of CBD in AD are not conclusive. The aim of this study was thus to examine the influence of CBD on cognition and involvement of the microbiota-gut-brain axis using a senescence-accelerated mouse prone 8 (SAMP8) model. Data demonstrated that administration of CBD to SAMP8 mice improved cognitive function as evidenced from the Morris water maze test and increased hippocampal activated microglia shift from M1 to M2. In addition, CBD elevated levels of Bacteriodetes associated with a fall in Firmicutes providing morphologically a protective intestinal barrier which subsequently reduced leakage of intestinal toxic metabolites. Further, CBD was found to reduce the levels of hippocampal and colon epithelial cells lipopolysaccharide (LPS), known to be increased in AD leading to impaired gastrointestinal motility, thereby promoting neuroinflammation and subsequent neuronal death. Our findings demonstrated that CBD may be considered a beneficial therapeutic drug to counteract AD-mediated cognitive impairment and restore gut microbial functions associated with the observed neuroprotective mechanisms.

Modulation of Oxidative Stress and Neuroinflammation by Cannabidiol (CBD): Promising Targets for the Treatment of Alzheimer's Disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease and the most common form of dementia globally. Although the direct cause of AD remains under debate, neuroinflammation and oxidative stress are critical components in its pathogenesis and progression. As a result, compounds like cannabidiol (CBD) are being increasingly investigated for their ability to provide antioxidant and anti-inflammatory neuroprotection. CBD is the primary non-psychotropic phytocannabinoid derived from Cannabis sativa. It has been found to provide beneficial outcomes in a variety of medical conditions and is gaining increasing attention for its potential therapeutic application in AD. CBD is not psychoactive and its lipophilic nature allows its rapid distribution throughout the body, including across the blood-brain barrier (BBB). CBD also possesses anti-inflammatory, antioxidant, and neuroprotective properties, making it a viable candidate for AD treatment. This review outlines CBD's mechanism of action, the role of oxidative stress and neuroinflammation in AD, and the effectiveness and limitations of CBD in preclinical models of AD.