Advances in cannabinoid receptors pharmacology: from receptor structural insights to ligand discovery

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“The medicinal and recreational uses of Cannabis sativa have been recognized for thousands of years.

Today, cannabis-derived medicines are used to treat a variety of conditions, including chronic pain, epilepsy, multiple sclerosis, and chemotherapy-induced nausea. However, cannabis use disorder (CUD) has become the third most prevalent substance use disorder globally.

Cannabinoid receptors are the primary targets that mediate the effects of cannabis and its analogs. Despite their importance, the mechanisms of modulation and the full therapeutic potential of cannabinoid receptors remain unclear, hindering the development of the next generation of cannabinoid-based drugs.

This review summarizes the discovery and medicinal potential of phytocannabinoids and explores the distribution, signaling pathways, and functional roles of cannabinoid receptors. It also discusses classical cannabinoid drugs, as well as agonists, antagonists, and inverse agonists, which serve as key therapeutic agents.

Recent advancements in the development of allosteric drugs are highlighted, with a focus on positive and negative allosteric modulators (PAMs and NAMs) that target CB1 and CB2 receptors. The identification of multiple allosteric sites on the CB1 receptor and the structural basis for allosteric modulation are emphasized, along with the structure-based discovery of ago-BAMs for CB1.

This review concludes by examining the future potential of allosteric modulators in cannabinoid drug development, noting that ongoing progress in cannabinoid-derived drugs continues to open new avenues for therapeutic use and paves the way for future research into their full medicinal potential.”

https://pubmed.ncbi.nlm.nih.gov/39910211/

https://www.nature.com/articles/s41401-024-01472-9

The effects of recreational cannabis laws on alcohol and tobacco use among US adults, 2012 to 2022

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“Introduction: Many states have legalized cannabis for medicinal and recreational purposes in the past decade. However, it is unclear how recreational cannabis laws (RCLs) may affect alcohol and tobacco use among adults.

Methods: This is a cross-sectional study of 4.8 million adults from the 2012-2022 Behavioral Risk Factor Surveillance System. A difference-in-differences approach was used to examine the impact of RCLs on the use of alcohol and tobacco, adjusting for individual-level characteristics and time-varying state-level factors. The analyses were performed in 2024.

Results: Three alcohol use outcomes (current drinking, binge drinking, and heavy drinking) and two tobacco use outcomes (current tobacco use and smokeless tobacco use) were examined. Considering passage of cannabis laws as RCL implementation,

RCLs were not associated with any alcohol or tobacco use outcomes in the fully adjusted model. However, considering operational dispensary as RCL implementation, RCLs were associated with a decrease of 0.95 percentage point (95% CI, 1.80 to 0.09) in current drinking and a decrease of 0.48 percentage point (95% CI, 0.85 to 0.10) in current cigarette use.

Subgroup analysis showed that RCLs were associated with reductions in current drinking, binge drinking, and current cigarette use in multiple groups. However, RCLs were associated with increases in current smokeless tobacco use for some groups.

Conclusions: The findings suggest that while the overall effects of RCLs on the use of alcohol and tobacco may be limited, there are heterogeneous associations of RCLs with drinking and smoking by age, sex, race and ethnicity, education, and income.”

https://pubmed.ncbi.nlm.nih.gov/39909135/

https://www.ajpmonline.org/article/S0749-3797(25)00038-8/abstract

Study rationale and baseline data for pilot trial of dronabinol adjunctive treatment of agitation in Alzheimer’s dementia (THC-AD)

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“Agitation is a common complication of Alzheimer’s dementia (Agit-AD) associated with substantial morbidity, high healthcare service utilization, and adverse emotional and physical impact on care partners. There are currently no FDA-approved pharmacological treatments for Agit-AD.

We present the study design and baseline data for an ongoing multisite, three-week, double-blind, placebo-controlled, randomized clinical trial of dronabinol (synthetic tetrahydrocannabinol [THC]), titrated to a dose of 10 mg daily, in 80 participants to examine the safety and efficacy of dronabinol as an adjunctive treatment for Agit-AD.

Preliminary findings for 44 participants enrolled thus far show a predominately female, white sample with advanced cognitive impairment (Mini Mental Status Examination mean 7.8) and agitation (Neuropsychiatric Inventory-Clinician Agitation subscale mean 14.1). Adjustments to study design in light of the COVID-19 pandemic are described.

Findings from this study will provide guidance for the clinical utility of dronabinol for Agit-AD. ClinicalTrials.gov Identifier: NCT02792257.”

https://pubmed.ncbi.nlm.nih.gov/39890402/

https://www.intpsychogeriatrics.org/article/S1041-6102(25)00261-3/fulltext

“Clinical Trial Shows Synthetic Cannabis Reduces Agitation in Alzheimer’s Disease”

https://www.hopkinsmedicine.org/news/newsroom/news-releases/2024/10/clinical-trial-shows-synthetic-cannabis-reduces-agitation-in-alzheimers-disease

“Cannabidiol for behavior symptoms in Alzheimer’s disease (CANBiS-AD): a randomized, double-blind, placebo-controlled trial”

https://pubmed.ncbi.nlm.nih.gov/39890408/

The comparative effectiveness of medicinal cannabis for chronic pain versus prescription medication treatment

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“Reviews of the effectiveness of medicinal cannabis for chronic pain vary in their conclusions. IASP has identified that a key missing evidence in this debate is data from observational cohort studies, analyzed with comparative effectiveness methods.

In a medically supervised context to the use of marijuana for chronic pain, we identified 440 patients certified for medical marijuana by pain specialists in a single healthcare system. They were characterized by a battery of patient-reported outcomes stored electronically in the University of Pittsburgh Patient Outcomes Repository for Treatment (PORT).

At 3 months, 38.6% were responders, based on clinically meaningful improvements in pain, function, or global impression of change, and maintained this response at 6 months. In the 157 patients who were coprescribed opioids, at 6 months there was a mean 39.3% decrease in morphine milligram equivalents (P < 0.05 for the difference vs baseline).

In addition, 8114 patients treated in the same pain clinics with prescription pain medications instead (nonopioid or opioid) during the same timeframe were selected from PORT as a control group for comparison. They had a 34.9% rate of response at 3 months. Using the causal inference method of stratified modeling, logistic regression revealed an odds ratio of 2.6 in favor of medical marijuana vs medication treatment (P < 0.01). Potential harms data were not available in the PORT registry.

Medical marijuana was comparatively more effective than prescription medications for the treatment of chronic pain at 3 months, although the populations compared were slightly different.”

https://pubmed.ncbi.nlm.nih.gov/39878633/

https://journals.lww.com/pain/abstract/9900/the_comparative_effectiveness_of_medicinal.807.aspx

Exploring the diversity of cannabis cannabinoid and non-cannabinoid compounds and their roles in Alzheimer’s disease: A review

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“Cannabis sativa is recognized for its chemical diversity and therapeutic potential, particularly in addressing neurodegenerative diseases such as Alzheimer’s disease (AD). Given the complexity of AD, where single-target therapies often prove inadequate, a multi-target approach utilizing cannabis-derived compounds may offer promising alternatives.

This review first highlights the chemical diversity of cannabis by categorizing its compounds into cannabinoids and non-cannabinoids. It then examines studies investigating the effects of these compounds on AD-related pathological features.

By synthesizing existing knowledge, identifying research gaps, and facilitating comparative analysis, this review aims to advance future research and understanding. It underscores cannabis’s potential as a multi-target therapeutic strategy for AD, contributing valuable insights to ongoing scientific discussions.”

https://pubmed.ncbi.nlm.nih.gov/39866750/

“Cannabis sativa exhibits rich chemical diversity, categorized into cannabinoid and non-cannabinoid compounds.”

“The plant’s therapeutic potential is particularly relevant for treating neurodegenerative diseases like AD.”

“The discovery of the endocannabinoid system underscores the importance of cannabis-derived compounds in AD research.”

“A multi-target approach with cannabis compounds may overcome the limitations of single-target therapies in AD.”

“The review synthesizes existing research, identifies gaps, and aims to improve future studies on cannabis and AD.”

https://www.ibroneuroreports.org/article/S2667-2421(24)00119-2/fulltext


Molecular Mechanisms Underlying Neuroinflammation Intervention with Medicinal Plants: A Critical and Narrative Review of the Current Literature

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“Neuroinflammation is a key factor in the progression of neurodegenerative diseases, driven by the dysregulation of molecular pathways and activation of the brain’s immune system, resulting in the release of pro-inflammatory and oxidative molecules. This chronic inflammation is exacerbated by peripheral leukocyte infiltration into the central nervous system.

Medicinal plants, with their historical use in traditional medicine, have emerged as promising candidates to mitigate neuroinflammation and offer a sustainable alternative for addressing neurodegenerative conditions in a green healthcare framework.

This review evaluates the effects of medicinal plants on neuroinflammation, emphasizing their mechanisms of action, effective dosages, and clinical implications, based on a systematic search of databases such as PubMed, SCOPUS, and Web of Science.

The key findings highlight that plants like Cleistocalyx nervosum var. paniala, Curcuma longa

Cannabis sativa,

and Dioscorea nipponica reduce pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β), inhibit enzymes (COX-2 and iNOS), and activate antioxidant pathways, particularly Nrf2. NF-κB emerged as the primary pro-inflammatory pathway inhibited across studies. While the anti-inflammatory potential of these plants is significant, the variability in dosages and phytochemical compositions limits clinical translation.

Here, we highlight that medicinal plants are effective modulators of neuroinflammation, underscoring their therapeutic potential. Future research should focus on animal models, standardized protocols, and safety assessments, integrating advanced methodologies, such as genetic studies and nanotechnology, to enhance their applicability in neurodegenerative disease management.”

https://pubmed.ncbi.nlm.nih.gov/39861194/

“Addressing neuroinflammation to reduce disease severity and improve patient outcomes is a promising strategy against neurodegeneration. From a molecular perspective, there are several conventional drug targets for neuroinflammation, such as enzymes, receptors, and ion channels. However, the high cost of synthetic drugs presents a challenge, emphasizing the need for alternative approaches. This has heightened interest in naturally occurring medicinal plants known for their antioxidant, anti-inflammatory, and neuroprotective properties. These plants are often more cost-effective and have been safely utilized in treatments for thousands of year.”

https://www.mdpi.com/1424-8247/18/1/133

Optimization and Evaluation of Cannabis-Based Magistral Formulations: A Path to Personalized Therapy

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“Introduction: The official implementation of pharmaceutical-grade cannabis raw materials for medicinal use has permitted doctors to prescribe and pharmacists to prepare cannabis-based formulations. The objective of the pharmaceutical development and manufacturing process optimization work was to propose a suppository formulation containing doses of 25 mg and 50 mg of tetra-hydrocannabinol (∆-9-THC) as an alternative to existing inhalable or orally administered formulations. The formulation could be used for rectal or vaginal administration, thereby providing dosage control in the treatment of endometriosis and other conditions involving pain. In this study, two substrates from suppositories with standardized Cannabis extractum normatum (CEX) were used: cocoa butter and Witepsol® H15.

Materials and methods: The long-term stability of CEX was investigated over a period of up to 24 months. The concentrations of ∆-9-THC, cannabidiol (CBD), and cannabinol (CBN) were determined using an HPLC method. Furthermore, the water content of the extract, the ethanol residue, and the microbiological purity were determined. The pharmaceutical properties of CEX-incorporated suppositories, namely content uniformity, hardness, softening time, total deformation time, disintegration time, and the release profile of ∆-9-THC, CBD, and CBN, were evaluated in order to develop optimal preparation procedures for pharmacists.

Results and discussion: Following a 24-month stability study on CEX, no significant alterations in component content were observed beyond the specified requirements. The disintegration time, total deformation time, and hardness of the suppositories based on Witepsol® H15 with CEX were found to be longer and higher, respectively, than those of suppositories formulated with cocoa butter. In vitro studies demonstrated that suppositories prepared with Witepsol® H15 exhibited superior release of ∆-9-THC compared to those prepared with cocoa butter.

Conclusions: We suggest that pharmacists making prescription drugs in a pharmacy setting in the form of medical marijuana suppositories will receive a better release profile of the drug by choosing Witepsol® H15 as a substrate.”

https://pubmed.ncbi.nlm.nih.gov/39861136/

https://www.mdpi.com/1424-8247/18/1/73

Unveiling Cannabinoids and Terpenes Diversity in Cannabis sativa L. from Northern India for Future Breeding Strategies

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“Cannabis sativa L. is an important medicinal plant with high commercial value.

In recent years, the research interest in cannabidiol (CBD) and terpene-rich cannabis has been rapidly expanding due to their high therapeutic potential.

The present study aims to explore the phytocannabinoids and terpenes diversity in Cannabis sativa collected from different parts of northern India.

Our findings revealed that the cannabinoids and terpenes synthesize together in capitate stalked and capitate sessile glandular trichomes, whereas bulbous glands synthesize only terpenes. The North Indian C. sativa is mainly dominated by tetrahydrocannabinol (THC). The CBD-rich plant diversity is nominal (1.11%) in studied north Indian C. sativa. The essential oil profiling reveals (E)-caryophyllene (10.30-36.80%) as the major constituent, followed by α-humulene (0.50-15.29%) and α-bisabolol (0.00-16.40%) in the North Indian population.

The cannabinoids and terpenes content showed significant diversity among and within the five studied populations. The correlation analysis between cannabinoids and terpenes indicates that α-pinene, β-pinene, and limonene positively correlated with CBD content. Similarly, α- and β-selinene correlate positively with tetrahydrocannabinolic acid (THCA) content. This study could help to identify the key cultivars from India and establish a consistent chemotype for future breeding programs.”

https://pubmed.ncbi.nlm.nih.gov/39853702/

https://onlinelibrary.wiley.com/doi/10.1002/cbdv.202402278

Cannabinoid receptor 1 ligands: Biased signaling mechanisms driving functionally selective drug discovery

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“G protein-coupled receptors (GPCRs) adopt conformational states that activate or inhibit distinct signaling pathways, including those mediated by G proteins or β-arrestins. Biased signaling through GPCRs may offer a promising strategy to enhance therapeutic efficacy while reducing adverse effects.

Cannabinoid receptor 1 (CB1), a key GPCR in the endocannabinoid system, presents therapeutic potential for conditions such as pain, anxiety, cognitive impairment, psychiatric disorders, and metabolic diseases.

This review examines the structural conformations of CB1 coupling to different signaling pathways and explores the mechanisms underlying biased signaling, which are critical for the design of functionally selective ligands. We discuss the structure-function relationships of endogenous cannabinoids (eCBs), phytocannabinoids, and synthetic cannabinoid ligands with biased properties. Challenges such as the complexity of ligand bias screening, the limited availability of distinctly biased ligands, and the variability in receptor signaling profiles in vivo have hindered clinical progress.

Although the therapeutic potential of biased ligands in various clinical conditions remains in its infancy, retrospective identification of such molecules provides a strong foundation for further development. Recent advances in CB1 crystallography, particularly insights into its conformations with G proteins and β-arrestins, now offer a framework for structure-based drug design. While there is still a long way to go before biased CB1 ligands can be widely used in clinical practice, ongoing multidisciplinary research shows promise for achieving functional selectivity in targeting specific pathways.

These progresses could lead to the development of safer and more effective cannabinoid-based therapies in the future.”

https://pubmed.ncbi.nlm.nih.gov/39828030/

https://www.sciencedirect.com/science/article/abs/pii/S0163725825000075?via%3Dihub

∆9-Tetrahydrocannabinol Increases Growth Factor Release by Cultured Adipose Stem Cells and Adipose Tissue in vivo

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“Background: Because of its biocompatibility and its soft and dynamic nature, the grafting of adipose tissue is regarded an ideal technique for soft-tissue repair. The adipose stem cells (ASCs) contribute significantly to the regenerative potential of adipose tissue, because they can differentiate into adipocytes and release growth factors for tissue repair and neovascularization to facilitate tissue survival. The present study tested the effect of administering a chronic low dose of ∆9-tetrahydrocannabinol (THC) on these regenerative properties, in vitro and in vivo.

Methods: Human ASCs were exposed to increasing concentrations of THC. Resazurin conversion was applied to investigate the effect on metabolic activity, cell number was assessed by crystal violet staining, tri-linear differentiation was evaluated by specific colorimetric approaches, and the release of growth factors was analyzed by ELISA. Two groups of mice were treated daily either with a low dose of THC (3 mg/kg) or a vehicle solution. After 3 weeks, adipose tissue was obtained from excised fat deposits, homogenized and tested for growth factor contents.

Results: THC decreased ASC proliferation but increased metabolic activity as well as adipogenic and chondrogenic differentiation. A low concentration of THC (1 µM) enhanced the growth factor release by ASCs. The concentration of these cytokines was also increased in adipose tissue of mice treated with THC.

Conlusion: Our results indicate that chronic activation of the endocannabinoid system promoted differentiation and growth factor release of ASCs, which could be of specific value for enhancing the regenerative potential of adipose tissue.”

https://pubmed.ncbi.nlm.nih.gov/39825991/

“Our findings may offer a new approach for improved application of adipose tissue in regenerative medicine.”

https://link.springer.com/article/10.1007/s13770-024-00692-8