Cannabinoid Receptors and the Endocannabinoid System: Signaling and Function in the Central Nervous System

Microglial cannabinoid receptor 2 and epigenetic regulation: Implications for the treatment of depression

Depression, often stress-induced, is closely related to neuroinflammation, in which microglia, the brain's immune cells, are the leading players. Microglia shift between a quiescent and an active state, promoting both pro- and anti-inflammatory responses. Cannabinoid type 2 (CB2) receptor encoded by the CNR2 gene is a key player to modulate inflammatory activity. CB2 receptor is highly controlled at the epigenetic level, especially in response to stressful stimuli, positioning it between stress, neuroinflammation, and depression. The following review addresses how epigenetic regulation of CNR2 expression affects depression and the dissection, further, of molecular pathways driving neuroinflammation-related depressive states. The present study emphasizes the therapeutic potential of CB2 receptor agonists that selectively interact with activated microglia and opens a new avenue for the treatment of depression associated with neuroinflammation. The review, therefore, provides a framework of underlying mechanisms for developing novel therapeutic strategies that focus on relieving symptoms by modulating the neuroinflammatory response. Finally, this review underlines the possibilities of therapeutic interventions taking into account CB2 receptors in combating depression.

Involvement of D2-like dopamine receptors within the ventral tegmental area in the cannabidiol's inhibitory effects on the methamphetamine-seeking behavior

Cannabidiol (CBD) is a non-psychoactive substance derived from marijuana. Although a comprehensive understanding of CBD's mechanism of action is still lacking, it is well-established that CBD can effectively mitigate the addictive properties associated with drugs. This study examined how CBD inhibits the acquisition and expression of methamphetamine-induced conditioned place preference (CPP) through D2-like dopamine receptors (D2R) in the ventral tegmental area (VTA). After recovery from surgery, animals were subjected to bilateral intra-VTA administration of different dosages (0.25, 1, and 4 μg/0.3 μl DMSO per side) of a selective D2R antagonist, sulpiride before intracerebroventricular (ICV) injection of CBD, during the conditioning phase (10 μg/5 μl DMSO) or once in the post-conditioning phase (50 μg/5 μl DMSO) of methamphetamine-induced CPP (daily subcutaneous injections of methamphetamine at 1 mg/kg over 5-day conditioning period). Findings revealed that CBD inhibits the acquisition and expression of methamphetamine reward memory. At the same time, microinjection of D2R antagonists into the VTA significantly reduced CBD's suppressive effect on the acquisition (0.25 μg; P<0.05, 1 and 4 μg; P<0.001) and expression (1 and 4 μg; P<0.01) of methamphetamine place preference. Moreover, D2R blockage alone in the VTA did not affect the formation and expression of methamphetamine-induced CPP. In addition, the present study showed that administration of intra-VTA sulpiride and ICV injection of CBD together does not cause place preference in the CPP paradigm. In conclusion, pharmacological manipulation of D2Rs in the VTA may alter CBD's suppressive effects on the methamphetamine-context associations.

Cannabinoid Receptor 2 (CB2R) as potential target for the pharmacological treatment of neurodegenerative diseases

The endocannabinoid system (ECS) is a ubiquitous physiological system that plays a crucial role in maintaining CNS homeostasis and regulating its functions. It includes cannabinoid receptors (CBRs), endogenous cannabinoids (eCBs), and the enzymes responsible for their synthesis and degradation. In recent years, growing evidence has highlighted the therapeutic potential of the ECS and CBRs, in a wide range of severe diseases and pathological conditions, including Alzheimer's and Parkinson's diseases, Amyotrophic Lateral Sclerosis, Multiple Sclerosis, Huntington's Disease, HIV-1 associated neurocognitive disorders, neuropathic pain and migraine. Targeting the cannabinoid type 2 receptor (CB2R) has gained attention due to its ability to (i) mitigate neuroinflammatory responses, (ii) regulate mitochondrial function and (iii) provide trophic support, all without eliciting the psychotropic actions associated with CB1R activation. This review aims to explore the potential of CB2R modulation as a strategy for the prevention and treatment of neurologic disorders, exploring both preclinical and clinical findings.

The emerging role of endocannabinoid system modulation in human fibroblast-like synoviocytes: Exploring new biomarkers and potential therapeutic targets

Human fibroblast-like synoviocytes (HFLS) are the predominant cellular component of the joint synovium. Their inflammation, known as synovitis, may contribute to the development of osteoarthritis (OA). HFLS secrete signaling factors that regulate joint function in response to mechanical trauma or OA progression. Among these factors, prostaglandin E2 (PGE2) is a key pro-inflammatory mediator, whereas prostamides, such as prostamide E2 (PME2), are synthesized from anandamide (AEA) by the same enzymes that produce PGE2. HFLS were isolated from both control subjects and OA patients (HFLS-OA) and stimulated with lipopolysaccharide (LPS, 10 ng/mL). Liquid chromatography-tandem mass spectrometry (LC-MS) was used to analyze PGE2 and PME2 secretion. Additionally, transcriptome and miRNA sequencing were conducted to identify changes in gene expression between HFLS and HFLS-OA cells. Five endocannabinoid-related genes were further validated by qPCR. Baseline PGE2 secretion differed between HFLS and HFLS-OA, with OA-related cells showing increased levels, while control cells primarily produced PME2. Upon pro-inflammatory stimulation, both cell types secreted PGE2. Changes in endocannabinoid levels and expression of endocannabinoid-related genes were observed in HFLS-OA following stimulation. miRNA sequencing revealed significant differences in miRNA expression between HFLS and HFLS-OA. Notably, HFLS-OA exhibited upregulation of Diacylglycerol lipase B (DAGLB) and downregulation of Fatty Acid-Binding Protein 4 and 5 (FABP4 and FABP5) gene expression compared to controls. The study suggests a reorganization of the endocannabinoid system in HFLS from OA patients, leading to altered cellular responses to pro-inflammatory stimuli. The molecular changes observed may drive or regulate the inflammatory response in OA synoviocytes, highlighting potential therapeutic targets. These findings provide insights into the potential mechanisms underlying OA pathogenesis and support the hypothesis of altered endocannabinoid system reactivity in HFLS in the context of inflammation.

Impaired mnemonic pattern separation associated with PTSD symptoms paradoxically improves with regular cannabis use

Posttraumatic stress disorder (PTSD) is associated with poor hippocampal function and disrupted pattern recognition. Cannabis use is highly prevalent in individuals with PTSD, yet the impact on these cognitive functions is poorly understood. Participants (n = 111) with a range of PTSD symptoms with and without regular cannabis use completed the mnemonic similarity task. We hypothesized that regular use would be associated with alterations in pattern separation ability in individuals with PTSD symptoms. High PTSD symptoms were associated with reduced pattern separation performance in minimal users. Regular users with high PTSD symptoms showed greater pattern separation, but reduced pattern separation with low PTSD symptoms. These results suggest that regular cannabis use may disrupt pattern separation and similar hippocampal-dependent processes, while it may improve pattern separation in individuals with high PTSD symptoms. These cross-sectional results require longitudinal follow-up studies to evaluate the causal effects of regular cannabis use on cognitive function in PTSD.

Electrophilic fluorination of cannabinol (CBN)

Several fluorinated cannabinol compounds (3a-g) were synthesised via an electrophilic fluorination process. This resulted in the formation of two mono-fluorinated aromatic ring products, a difluorinated aromatic ring product and four new oxidized poly-fluorinated cyclohexadienones. Two of these are difluorinated isomers and two are trifluorinated isomers.

The endocannabinoid and paracannabinoid systems in natural reward processes: possible pharmacological targets?

Natural rewards such as food, mating, and social interaction are essential for survival and species preservation, and their regulation involves a complex interplay of motivational, cognitive, and emotional processes. Over the past two decades, increasing attention has been directed toward the endocannabinoid system and its paracannabinoid counterpart as key modulators of these behaviors. This review aims to provide an integrated overview of the roles played by the endocannabinoid and paracannabinoid systems in regulating natural reward-driven behaviors, focusing on feeding, reproductive behavior, and social interaction. We highlight how the endocannabinoid system - mainly through CB1 receptor signaling - modulates central and peripheral circuits involved in energy homeostasis, reward processing, and emotional regulation. In parallel, we explore the role of paracannabinoids, such as oleoylethanolamide (OEA), palmitoylethanolamide (PEA), and stearoylethanolamide (SEA), which act primarily via non-cannabinoid receptors and contribute to the regulation of appetite, sexual motivation, and social behavior. Special attention is given to the relevance of these systems in the pathophysiology of obesity, eating disorders, sexual dysfunctions, and social impairments, as well as their potential as pharmacological targets. Overall, the evidence discussed supports a broader conceptualization of endocannabinoid and paracannabinoid signaling as pivotal regulators of natural rewards and opens new avenues for the development of targeted interventions for motivational and reward-related disorders.

Acute and subacute cardiovascular effects of synthetic cannabinoid JWH-018 in rat

PURPOSE

This study investigates the cardiovascular effects of the synthetic cannabinoid naphthalene-1-yl-(1-pentylindole-3-yl)methanone (JWH-018) in rats. The research aims to evaluate the pharmacologic, cardiologic, biochemical, and histopathological effects of acute and subacute administration at low and high doses. The primary research question is how JWH-018 impacts heart function, blood pressure, ECG patterns, and cardiac tissue integrity.

METHODS

Wistar albino rats were divided into five groups: control, acute low-dose (ALD, 0.5 mg/kg), acute high-dose (AHD, 5 mg/kg), subacute low-dose (SALD, 0.5 mg/kg for 14 days), and subacute high-dose (SAHD, 5 mg/kg for 14 days). Cardiovascular effects were assessed using echocardiography, hemodynamic and ECG analysis, histopathology, biochemical markers, and LC-MS/MS quantification of JWH-018 and its metabolites in heart tissue.

RESULTS

Acute high-dose JWH-018 caused bradycardia and hypotension, while subacute high-dose increased heart rate but continued to lower blood pressure. JWH-018 induced cardiac arrhythmias, conduction blocks, and ischemic ECG changes, with prolonged QT intervals in subacute high-dose rats. Histopathological findings revealed myocardial infarction-like features, including contraction bands and ischemic damage, particularly in subacute groups. Elevated pro-BNP and triglycerides indicated cardiac stress and metabolic effects. JWH-018 and its metabolites were detected in heart tissue, primarily in high-dose groups.

CONCLUSIONS

JWH-018 has significant cardiovascular risks, causing heart rate dysregulation, hypotension, arrhythmias, and ischemic damage. These effects depend on dose and duration. The study highlights the potential dangers of synthetic cannabinoids, emphasizing that they should not be considered safe alternatives to natural cannabis.

Probing Native CB2 Receptor Mobility in Plasma Membranes of Living Cells by Fluorescence Recovery After Photobleaching

In this study, we employed a novel fluorescent probe, RO7304924 - which selectively targets cannabinoid 2 receptor (CB2R) - to assess the lateral mobility of CB2R within the plasma membrane of Chinese hamster ovary cells stably expressing a functional, untagged receptor variant. Utilizing confocal fluorescence recovery after photobleaching (FRAP), we quantified the diffusion coefficient and mobile fraction of CB2R, thereby demonstrating the efficacy of RO7304924 as an innovative tool for elucidating the dynamics of this major endocannabinoid-binding G protein-coupled receptor. Our present findings highlight the potential of combining advanced ligand-based fluorescent probes with FRAP for future investigations into the biochemical details of CB2R mobility in living cells, and its impact on receptor-dependent cellular processes.

Pharmacokinetics of cannabidiol, (-)-trans-Δ9-tetrahydrocannabinol, and their oxidative metabolites after intravenous and oral administration of a cannabidiol-dominant full-spectrum hemp product to beagle dogs

Introduction

This study investigated the pharmacokinetics, safety, and tolerability of a full-spectrum CBD-dominant oil formulated in medium-chain triglycerides (MCT oil) after a single intravenous (IV) administration, a single oral (PO) administration, and multiple oral administrations of CBD at a dose of 2.2 mg/kg in adult male and female beagle dogs.

Methods

The CBD-dominant extract was administered to adult, intact beagle dogs (male n = 4, female n = 2) once intravenously, once orally, and every 12 h orally for 21 days at a dose of 2.2 mg CBD/kg body weight (BW). Blood samples were collected at predetermined times to measure concentrations of serum CBD, 7-hydroxy-CBD (7-OH-CBD), 7-nor-7-carboxy-CBD (7-COOH-CBD), Δ9-tetrahydrocannabinol (Δ9-THC), 11-hydroxy-THC (11-OH-THC), and 11-carboxy-THC (11-COOH-THC). Serum CBD and Δ9-THC concentrations were analyzed to estimate various pharmacokinetic parameters. Selected physical, behavioral, hematologic, and blood chemical measurements were obtained before and during single and repeated dose administrations.

Results

Pharmacokinetics of CBD after IV administration indicated a median (range) systemic clearance (CL) of 7.06 (6.14-10.5) mL/min/kg, a steady-state volume of distribution (Vss) of 2.13 (1.10-2.85) L/kg, and a half-life of 291 (183-508) min. The median (range) extent of systemic availability of CBD after a single oral dose was 31.2 (17.7-35.7)%. Pharmacokinetics of Δ9-THC after IV administration were characterized by a CL of 8.85 (6.88-14.4) mL/min/kg, Vss of 1.98 (1.30-2.30) L/kg, and a half-life of 169 (139-476) min. The extent of systemic availability of Δ9-THC after PO administration was 40.9 (20.5-46.2)%. The test article was well tolerated in all dogs during the study. Although serum alkaline phosphatase concentrations increased during the repeated PO dose study, they remained within normal limits.

Discussion

Both CBD and Δ9-THC were rapidly cleared after IV administration and exhibited extensive volumes of distribution. Comparison of clearance to serum hepatic blood flow estimated the hepatic extraction ratio and extent of first pass metabolism after PO administration, which was confirmed by analyzing the single PO dose pharmacokinetic data. The AUC0-∞ for 7-OH-CBD after single IV compared to single PO dose was not different, suggesting complete absorption of CBD from the formulation in MCT oil when administered with canned dog food.

Impact of heterologous expression of Cannabis sativa tetraketide synthase on Phaeodactylum tricornutum metabolic profile

BACKGROUND

Pharmaceutical safety is an increasing global priority, particularly as the demand for therapeutic compounds rises alongside population growth. Phytocannabinoids, a class of bioactive polyketide molecules derived from plants, have garnered significant attention due to their interaction with the human endocannabinoid system, offering potential benefits for managing a range of symptoms and conditions. Traditional extraction from cannabis plants poses regulatory, environmental, and yield-related challenges. Consequently, microbial biosynthesis has emerged as a promising biotechnological alternative to produce cannabinoids in a controlled, scalable, and sustainable manner. Developing diatom-based biofactories represent a crucial step in advancing this biotechnology, enabling the efficient production of high-valued compounds such as cannabinoids.

RESULTS

We engineered the diatom Phaeodactylum tricornutum, a unicellular photosynthetic model organism prized for its naturally high lipid content, to produce olivetolic acid (OA), a key metabolic precursor to most cannabinoids. The genes encoding tetraketide synthase and olivetolic acid cyclase from cannabis were cloned onto episomal vectors and introduced using bacterial conjugation in two separate P. tricornutum transconjugant lines to evaluate enzyme activity and OA production in vivo. Both genes were successfully expressed, and the corresponding enzymes accumulated within the transconjugant lines. However, despite testing the cell extracts individually and in combination, OA accumulation was not detected suggesting potential conversion or utilization of OA by endogenous metabolic pathways within the diatoms. To investigate this further, we analyzed the impact of CsTKS expression on the diatom's metabolome, revealing significant alterations that may indicate metabolic flux redirection or novel pathway interactions.

CONCLUSIONS

Our study demonstrates the successful expression of cannabinoid biosynthetic genes in P. tricornutum but highlights challenges in OA accumulation, likely due to endogenous metabolic interactions. These findings underscore the complexity of metabolic engineering in diatoms and suggest the need for further pathway optimization and metabolic flux analysis to achieve efficient cannabinoid biosynthesis. This research contributes to advancing sustainable biotechnological approaches for cannabinoid production.

Withaferin A maintained microbiome and metabolome features in A53T transgenic mice via multi-omics integrated analysis

BACKGROUND

Withaferin A (WFA), a naturally occurring compound, has shown promise as a therapeutic agent for Parkinson's disease (PD), a neurodegenerative disorder associated with motor and gastrointestinal dysfunctions. However, its effects on gut microbiota metabolism remain poorly understood.

PURPOSE

This study aimed to elucidate the neuroprotective mechanisms of WFA in a PD mouse model by investigating its regulation of gut microbiota composition, metabolic pathways, and correlations with brain spatial metabolomics.

METHODS

Human SNCA-transgenic (A53T) mice were treated with WFA and evaluated using behavioral tests, immunohistochemistry, Western blot, and ELISA to assess motor/cognitive functions and PD-related pathology. Gut microbiota composition was analyzed via 16S rRNA sequencing, while untargeted fecal metabolomics and brain spatial metabolomics were employed to identify metabolic alterations.

RESULTS

WFA significantly improved motor performance, alleviated cognitive deficits, restored intestinal barrier integrity, and reduced neuroinflammation. It elevated the abundance of anti-inflammatory gut bacteria (e.g., Bifidobacterium, Dubosiella, Akkermansia) and reversed 55 fecal metabolites linked to sphingolipid metabolism, serotonergic synapses, and neuroactive ligand- receptor interactions. Spatial metabolomics revealed WFA's regulation of sphingolipid signaling pathways, including sphingosine kinase (Sphk1), ceramidase, sphingosine 1-phosphate receptor (S1PR5), and endocannabinoid receptor CB2 expression. Correlation analysis indicated a link between brain metabolite content and gut microbiota abundance.

CONCLUSION

Our findings highlight a potential mechanism of WFA that repairs neurons by modulating the sphingolipid signaling pathway within the microbiota-gut-brain axis.

Maintaining Mobility and Balance in Multiple Sclerosis: A Systematic Review Examining Potential Impact of Symptomatic Pharmacotherapy

BACKGROUND

Mobility disability (MD) manifests as walking dysfunction and postural instability in more than 90% of people with multiple sclerosis (MS) within 10 years of disease onset. Disease-modifying pharmacotherapies reduce rates of relapses and new lesions and slow disease progression, but ongoing decline in MD can persist or result from secondary, symptomatic pharmacotherapies. This systematic review focuses on symptomatic pharmacotherapies that potentially impact markers of MD in MS.

METHODS

PubMed/Medline, Google Scholar, and Scopus were searched between January 1990 and December 2024. Eligible studies were included on the basis of the following criteria: (1) randomized, placebo-controlled trials (RCTs); (2) confirmed MS diagnosis; (3) one MD-related outcome; and (4) one symptomatic pharmacotherapy; OR (5) multiple doses of a symptomatic pharmacotherapy. Results were uploaded to Rayyan: Intelligent Systematic Review software and screened by two blinded reviewers for eligibility. Risk of bias was assessed using the PEDRo Scale for quality assessment.

RESULTS

This review included 23 RCTs (all RCTs scored good-to-excellent on PEDRo Scale); 13 RCTs examined fampridine (4-aminopyridine) for its direct effects on MD, and 10 RCTs assessed indirect effects of symptomatic pharmacotherapies, including cannabinoids (n = 9), and baclofen (n = 1) on MD. The MD outcomes included gait (25-foot walk [T25FW], kinetics, and kinematics), community mobility (12-item MS Walking Scale [MSWS-12]), endurance (6-min walk [6MW]), balance (Berg Balance Scale [BBS], Dynamic Gait Index [DGI], Six-Spot Step Test, posturography, and falls), and functional mobility (Timed Up and Go [TUG] and 5 Times Sit-to-Stand [5STS]). Fampridine significantly improved gait (T25FW, MSWS-12), endurance (6MW), and functional mobility (5STS, TUG), with the largest effect on gait speed; changes in balance were inconclusive. Indirect pharmacotherapies, specifically cannabinoids mainly reduced spasticity (Modified Ashworth Scale, nine out of nine studies), but rarely improved pain (Numerical Rating Scale, two out of nine studies) or MD outcomes (two out of nine studies). Both direct and indirect pharmacotherapies resulted in adverse effects, notably dizziness (n = 366), urinary tract infection (n = 216), and nausea (n = 150), potentially impacting MD in MS.

CONCLUSIONS

Fampridine may improve gait and functional mobility in MS, but its effect on balance requires further investigation in RCTs. Cannabinoids and baclofen may alleviate spasticity and pain, but seemingly have limited secondary effect on markers of MD, such as gait and postural stability. Clinicians should consider the impact of symptomatic pharmacotherapies on MD in MS, including potential side effects. Future research should explore integrating rehabilitation (e.g., balance training) with symptomatic pharmacotherapies, as this might enhance positive effects or combat deleterious effects on markers of MD.

Methylomic signature of current cannabis use in two first-episode psychosis cohorts

The rising prevalence and legalisation of cannabis worldwide have underscored the need for a comprehensive understanding of its biological impact, particularly on mental health. Epigenetic mechanisms, specifically DNA methylation, have gained increasing recognition as vital factors in the interplay between risk factors and mental health. This study aimed to explore the effects of current cannabis use and high-potency cannabis on DNA methylation in two independent cohorts of individuals experiencing first-episode psychosis (FEP) compared to control subjects. The combined sample consisted of 682 participants (188 current cannabis users and 494 never users). DNA methylation profiles were generated on blood-derived DNA samples using the Illumina DNA methylation array platform. A meta-analysis across cohorts identified one CpG site (cg11669285) in the CAVIN1 gene that showed differential methylation with current cannabis use, surpassing the array-wide significance threshold, and independent of the tobacco-related epigenetic signature. Furthermore, a CpG site localised in the MCU gene (cg11669285) achieved array-wide significance in an analysis of the effect of high-potency (THC = > 10%) current cannabis use. Pathway and regional analyses identified cannabis-related epigenetic variation proximal to genes linked to immune and mitochondrial function, both of which are known to be influenced by cannabinoids. Interestingly, a model including an interaction term between cannabis use and FEP status identified two sites that were significantly associated with current cannabis use with a nominally significant interaction suggesting that FEP status might moderate how cannabis use affects DNA methylation. Overall, these findings contribute to our understanding of the epigenetic impact of current cannabis use and highlight potential molecular pathways affected by cannabis exposure.

Five Years of Long COVID Syndrome: An Updated Review on Cardiometabolic and Psychiatric Aspects

Five years after the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, there is still a significant number of people who have survived COVID-19 but never fully recovered from the disease. They go through an odyssey of doctor visits and a multitude of diagnostic tests, which ultimately do not provide concrete correlations and answers to the question of how exactly long COVID (LC) affects both physical and mental health, and performance. Often, not even highly technical and highly specialized methods, such as cardiac magnetic resonance imaging (MRI), can provide further explanation. Various research efforts continue to investigate the causes, effects and possible treatments of LC, particularly its impact on cognition and mental health. Patients with LC may experience persistent symptoms, but new symptoms also occur. Based on available studies, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) does not only affect the pulmonary system, but nearly every major system and organ, from the brain and heart to the kidneys and immune system. What mechanisms could explain the persistent symptoms of LC and the inadequate recovery? How valuable is an early internal and neurological examination, particularly in the context of psychotherapy? In this review, we examined which factors could contribute to the persistence of LC symptoms and to what extent mitochondrial impairment by LC can explain the symptoms of LC.

Fatty acid amide hydrolase in comorbid borderline personality disorder and major depressive disorder: Imaging with [11C]CURB PET

Borderline personality disorder (BPD) is highly comorbid with major depressive disorder (MDD), and the comorbid condition is associated with poorer treatment outcomes, which necessitates the investigation of transdiagnostic biomarkers. Previous research suggests that fatty acid amide hydrolase (FAAH), an endocannabinoid enzyme, is elevated in the prefrontal cortex (PFC) in BPD; however, no study has examined FAAH density in individuals with comorbid conditions. We hypothesized that FAAH level would be elevated in the prefrontal cortex, anterior cingulate cortex and hippocampus of comorbid BPD + MDD compared to healthy controls, as these brain regions are linked to the pathobiology of both disorders. For an exploratory analysis, we hypothesized that brain FAAH would be positively correlated with symptom severity, aggression, and impulsivity. Fifteen unmedicated BPD + MDD cases and 15 age- and sex-matched healthy controls underwent a [11C]CURB positron emission tomography scan to measure λk3, an index of available FAAH. No significant group differences in [11C]CURB λk3 were observed between BPD + MDD patients and controls. Negative correlations were found between [11C]CURB λk3 and physical aggression scores in the dorsolateral PFC (r = -0.64, p = 0.04), ventrolateral PFC (r = -0.75, p = 0.01), medial PFC (r = -0.64, p = 0.03), and orbitofrontal cortex (r = -0.66, p = 0.03) in the BPD + MDD group. A positive correlation was found between [11C]CURB λk3 and impulsivity, as measured by the Barratt Impulsiveness Scale-11, in the ventrolateral PFC (r = 0.62, p = 0.04) of the BPD + MDD group. We suggest that the negative correlations between [11C]CURB λk3 and physical aggression could reflect a relationship between FAAH and planned aggression whereas the latter findings may reflect a positive relationship with impulsivity.

The CB1R of mPFC is involved in anxiety-like behavior induced by 0.8/2.65 GHz dual-frequency electromagnetic radiation

As mobile phones and communication base stations become more widespread, concerns have arisen regarding the potential risks of environmental exposure to multi-frequency electromagnetic radiation (EMR) and its effects on mental health. To address these concerns, our study established a dual-frequency EMR mouse model at 0.8/2.65 GHz to explore potential molecular mechanisms and intervention targets. Our results revealed that exposure to this dual-frequency EMR significantly induced anxiety-like behavior in mice. Molecular experiments further showed a significant decrease in cannabinoid receptor type 1 (CB1R) levels in the medial prefrontal cortex (mPFC) of the mice, along with a notable reduction in the endogenous cannabinoids 2-arachidonoylglycerol and anandamide. This led to a downregulation of the entire endocannabinoid system (ECS). Additional confirmation was obtained by overexpressing and knocking down CB1R in the mPFC. We found that increasing mPFC CB1R levels could effectively reduce anxiety-like behavior, while decreasing mPFC CB1R levels exacerbated it. Furthermore, we found dual-frequency EMR induced the change of ECS in the basolateral amygdala (BLA). Notably, female mice exhibited similar behavioral phenotypes and molecular mechanisms in response to dual-frequency EMR. In summary, our study demonstrates that anxiety induced by dual-frequency EMR is closely linked to the function of the ECS in the mPFC and BLA, and that CB1R expression in the mPFC plays a significant role in modulating emotional behavior in mice.

Targeting CB2 receptor with a novel antagonist reverses cognitive decline, neurodegeneration and pyroptosis in a TAU-dependent frontotemporal dementia mouse model

Frontotemporal dementia (FTD) comprises a group of disorders characterized by a progressive decline in behavior or language linked to the degeneration of the frontal and anterior temporal lobes followed by hippocampal atrophy. There are no effective treatments for FTD and for this reason, novel pharmacological targets, such as the endocannabinoid system (ECS), are being explored. Previous results from our laboratory showed a TAUP301L-dependent increase in CB2 receptor expression in hippocampal neurons of a FTD mouse model, alongside the neuroprotective impact of CB2 ablation. In this study, we evaluated the therapeutic potential of a new CB2 antagonist (PGN36) in our TAU-dependent FTD mouse model. Six-month-old mice received stereotaxic injections of an adeno-associated virus expressing human TAUP301L protein (AAV-TAUP301L) into the right hippocampus and were treated daily with PGN36 (5 mg/kg, i.p.) or vehicle for three weeks. By integrating behavioral tests, RNA-seq, qPCR expression analysis, and immunofluorescence in the AAV expressing TAU mouse model, we found that PGN36 treatment reverses key features of the neurodegenerative process triggered by TAUP301L overexpression. PGN36 treatment effectively countered TAUP301L-induced cognitive decline by reducing TAU protein expression levels and restoring markers of synaptic plasticity. Notably, we observed neuroprotection in the dentate gyrus granular layer, which we attribute to the modulation of pyroptosis. This programmed cell death pathway, is triggered by TAUP301L overexpression. PGN36 appears to modulate the pyroptotic cascade, thereby preventing the pyroptosis-induced neuronal loss. These findings collectively underscore the neuroprotective potential of this novel CB2 antagonist treatment against TAU-associated FTD.

Cannabinoids Activate Endoplasmic Reticulum Stress Response and Promote the Death of Avian Retinal Müller Cells in Culture

BACKGROUND/OBJECTIVES

Activation of cannabinoid CB1 or CB2 receptors induces the death of glial progenitors from the chick retina in culture. Here, by using an enriched retinal glial cell culture, we characterized some mechanisms underlying glial death promoted by cannabinoids.

METHODS AND RESULTS

Retinal cultures obtained from 8-day-old (E8) chick embryos and maintained for 12-15 days (C12-15) were used. MTT assays revealed that the CB1/CB2 agonist WIN 55,212-2 (WIN) decreased cell viability in the cultures in a time-dependent manner, with a concomitant increase in extracellular LDH activity, suggesting membrane integrity loss. Cell death was also dose-dependently induced by cannabidiol (CBD), Δ9-tetrahydrocannabinol (THC), and CP55940, another CB1/CB2 agonist. In contrast to WIN-induced cell death that was not blocked by either antagonist, the deleterious effect of CBD was blocked by the CB2 receptor antagonist SR144528, but not by PF514273, a CB1 receptor antagonist. WIN-treated cultures showed glial cells with large vacuoles in cytoplasm that were absent in cultures incubated with WIN plus 4-phenyl-butyrate (PBA), a chemical chaperone. Since cannabinoids induced the phosphorylation of eukaryotic initiation factor 2-alfa (eIF2α), these results suggest a process of endoplasmic reticulum (ER) swelling and stress. Incubation of the cultures with WIN for 4 h induced a ~five-fold increase in the number of cells labeled with the ROS indicator CM-H2DCFDA. WIN induced the phosphorylation of JNK but not of p38 in the cultures, and also induced an increase in the number of glial cells expressing cleaved-caspase 3 (c-CASP3). The decrease in cell viability and the expression of c-CASP3 was blocked by salubrinal, an inhibitor of eIF2α dephosphorylation.

CONCLUSIONS

These data suggest that cannabinoids induce the apoptosis of glial cells in culture by promoting ROS production, ER stress, JNK phosphorylation, and caspase-3 processing. The graphical abstract was created at Biorender.com.

Virtual library docking for cannabinoid-1 receptor agonists with reduced side effects

Virtual library docking can reveal unexpected chemotypes that complement the structures of biological targets. Seeking agonists for the cannabinoid-1 receptor (CB1R), we dock 74 million tangible molecules and prioritize 46 high ranking ones for de novo synthesis and testing. Nine are active by radioligand competition, a 20% hit-rate. Structure-based optimization of one of the most potent of these (Ki = 0.7 µM) leads to '1350, a 0.95 nM ligand and a full CB1R agonist of Gi/o signaling. A cryo-EM structure of '1350 in complex with CB1R-Gi1 confirms its predicted docked pose. The lead agonist is strongly analgesic in male mice, with a 2-20-fold therapeutic window over hypolocomotion, sedation, and catalepsy and no observable conditioned place preference. These findings suggest that unique cannabinoid chemotypes may disentangle characteristic cannabinoid side-effects from analgesia, supporting the further development of cannabinoids as pain therapeutics.

Impact of cannabinoids on cancer outcomes in patients receiving immune checkpoint inhibitor immunotherapy

Cannabinoids relieve pain, nausea, anorexia and anxiety, and improve quality of life in several cancer patients. The immunotherapy with checkpoint inhibitors (ICIs), although very successful in a subset of patients, is accompanied by moderate to severe immune-related adverse events (ir-AE) that often necessitate its discontinuation. Because of their role in symptomatic relief, cannabinoids have been used in combination with immune checkpoint inhibitor (ICI) immunotherapy. A few studies strongly suggest that the use of medicinal cannabis in cancer patients attenuates many of the ir-AE associated with the use of ICI immunotherapy and increase its tolerability. However, no significant beneficial effects on overall survival, progression free survival or cancer relapses were observed; rather, some of the studies noted adverse effects of concurrent administration of cannabinoids with ICI immunotherapy on the clinical benefits of the latter. Because of cannabinoids' well documented immunosuppressive effects mediated through the cannabinoid recptor-2 (CB2), we propose considering this receptor as an inhibitory immune checkpoint per se. A simultaneous neutralization of CB2, concurrent with cannabinoid treatment, may lead to better clinical outcomes in cancer patients receiving ICI immunotherapy. In this regard, cannabinoids such as cannabidiol (CBD) and cannabigerol (CBG), with little agonism for CB2, may be better therapeutic choices. Additional strategies e.g., the use of monoacylglycerol lipase (MAGL) inhibitors that degrade some endocannabinoids as well as lipogenesis and formation of lipid bilayers in cancer cells may also be explored. Future studies should take into consideration gut microbiota, CYP450 polymorphism and haplotypes, cannabinoid-drug interactions as well as genetic and somatic variations occurring in the cannabinoid receptors and their signaling pathways in cancer cells for personalized cannabis-based therapies in cancer patients receiving ICIs. This may lead to rational knowledge-based regimens tailored to individual cancer patients.

Electroacupuncture produces analgesic effects via cannabinoid CB1 receptor-mediated GABAergic neuronal inhibition in the rostral ventromedial medulla

OBJECTIVE

Electroacupuncture (EA) is commonly used for pain control in clinical practice, yet the precise mechanisms underlying its action are not fully understood. The rostral ventromedial medulla (RVM) plays a crucial role in the modulation of pain. GABAergic neurons in the RVM (GABARVM neurons) facilitate nociceptive transmission by inhibiting off-cells activity. This research examined the role of GABARVM neurons in the analgesic effects of EA.

METHODS

Nociceptive behavior was evaluated using inflammatory pain models induced by complete Freund's adjuvant (CFA) and neuropathic pain models induced by chronic constrictive injury (CCI). Also, in situ hybridization, chemogenetics, in vivo mouse calcium imaging, and in vivo electrophysiological recordings were used to determine neuronal activity and neural circuitry.

RESULTS

EA at the "Zusanli" (ST36) on the affected side produced a significant analgesic effect in both CFA and CCI models. CFA treatment and CCI elevated the calcium activity of GABARVM neurons. Also, EA reduced the calcium activity, neuronal firing rates, and c-Fos expression of GABARVM neurons in both pain models. Chemogenetic inhibition of GABARVM neurons increased nociceptive thresholds. Chemogenetic activation of GABARVM neurons caused increased pain sensitivity in control mice and negated the analgesic effects of EA in both pain models. Moreover, reducing cannabinoid CB1 receptors on GABARVM neurons counteracted the analgesic effects of EA in CFA and CCI-induced pain models.

CONCLUSIONS

The study indicates that the analgesic effect of EA in inflammatory and neuropathic pain is facilitated by CB1 receptor-mediated inhibition of GABARVM neurons.

Exploring Cannabidiol-TRPV3 Mediated Biological Activities-Findings From Molecular Docking, Simulation and Proteins Network Interactions

Transient receptor potential vanilloid 3 (TRPV3) is a thermosensitive calcium-permeable ion channel and has a function in sensory perception, epidermal barrier function, inflammation and keratinocyte proliferation. TRPV3 dysfunction is linked with chronic pain, atopic dermatitis and neurodegenerative disorders. This study compared the binding efficacy and molecular dynamics of cannabidiol- and eugenol-TRPV3 complex(s), elucidating their ligand-protein dynamics. Computational methods, including density functional theory, molecular docking and molecular dynamics simulations, assessed electronic properties, binding affinities and interaction stability, respectively. Cannabidiol showed a higher binding affinity (-7.73 ± 0.73 kcal/mol) than eugenol (-6.0 ± 0.05 kcal/mol), driven by denser hydrophilic and hydrophobic contacts. Molecular dynamics revealed the cannabidiol-TRPV3 complex stability, with steady atomic deviation and protein compactness. Furthermore, cannabidiol-induced diverse TRPV3 conformational states, while eugenol exhibited greater flexibility. These findings highlight cannabidiol's stable, dynamic interaction with TRPV3, suggesting its potential to exert TRPV3-mediated biological effects. In contrast, eugenol may serve in transient modulation. This study offers insights into ligand-ion channel interactions, guiding drug development for TRPV3-related conditions.

Age- and sex-dependent participation of the endocannabinoid system in locomotion and risk assessment of an ADHD rat model

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder affecting individuals across age groups. Impairments in executive function characterize ADHD and are often associated with elevated levels of risk-taking behaviors. The endocannabinoid system plays a crucial role in modulating prefrontal cortex circuits. Here, we assessed the effects of acute pharmacological manipulation of cannabinoid CB1 and CB2 receptors on locomotion and risk assessment/anxiety-like behaviors in an ADHD animal model during adolescence and adulthood. Further, we investigated the protein levels and gene expression of endocannabinoid system components (CB1, CB2, FAAH, MAGL) in the prefrontal cortex at both ages. During adolescence, activation of cannabinoid receptors aggravated the hyperactivity and risky behaviors of the ADHD model. These behavioral traits were more evident in female rats. In adulthood, manipulation of cannabinoid receptors did not alter hyperactivity but worsened risk assessment. Overall, gene expression levels of receptors and enzymes of the endocannabinoid system were increased in the ADHD model. Our findings suggest that the endocannabinoid system may operate differently in ADHD, and manipulating this system, especially in adolescents, could exacerbate deficits in inhibitory control.

Conditional Deletion of CB1 Receptor in Parvalbumin-Expressing GABAergic Neurons Results in Hearing Loss and Abnormal Auditory Brainstem Response in Mice

Cannabinoid receptors 1 (CB1Rs) are widely expressed throughout the central auditory system and play important roles in synaptic plasticity, auditory function, and development. However, the specific functions of CB1Rs in distinct neuronal subtypes in the central auditory system remain largely unclear. In the current study, we investigated whether CB1R deficiency in the parvalbumin (PV)-expressing interneurons, a major class of GABAergic interneurons, affects hearing function. We first systematically examined the neuronal localization and distribution of CB1Rs in the mouse central auditory system using double-label immunofluorescence and confocal laser scanning microscopy. Our findings revealed that CB1Rs are widely distributed across various auditory nuclei, with especially high expression levels observed in the cochlear nucleus (CN), superior olivary complex (SOC), and lateral lemniscus (LL). Furthermore, we established a genetic mouse model for conditional CB1R knockout specifically in PV interneurons, and performed auditory brainstem response (ABR) tests to measure the effects of this deletion on hearing. Surprisingly, the analysis of the ABR revealed that conditional deletion of CB1Rs specifically from PV interneurons elevated hearing threshold at 32 kHz, prolongated the latency of Wave 1, and decreased the amplitudes of Waves 1-4. Our findings provide a solid anatomical foundation for further investigations into the functional roles of CB1Rs in the central auditory system and highlight the critical role of CB1Rs expressed in inhibitory PV interneurons in maintaining normal auditory function.

Drugs from poisonous plants: Ethnopharmacological relevance to modern perspectives

The world of plant diversity is endlessly fascinating and essential for life on Earth. Since the inception of early civilization, humans have utilized plants for several purposes, particularly for their medicinal value. While some plants are known for their toxicity, they also contain beneficial phytochemicals that are important for both plants and humans, indicating their dual nature. This study aims to explore and synthesize the existing knowledge on various poisonous plant species found worldwide. It primarily focuses on the therapeutic potential of specific types of phytochemicals responsible for treating multiple diseases. This review includes a list of 70 poisonous plants with medicinal properties for treating various ailments, as well as some of their traditional uses. A few of these plants are emphasized, which have been tremendously explored and studied, hold significant potential to contribute to modern drug discovery. Furthermore, it addresses the possible prospects and challenges of using poisonous plants and their phytochemicals as therapeutic agents. Although the therapeutic potential of poisonous plants is substantial, many toxins remain unexplored. This review accentuates the need for rigorous scientific investigations, prior to clinical trials to validate their traditional uses, which would reveal the pharmacological interventions that will eventually advance human health and well-being.

Pharmacokinetics and Side Effects of Δ9-Tetrahydrocannabinol and Cannabidiol in Patients with Different Stages of CKD

Introduction

Chronic kidney disease (CKD) affects approximately 10% of the global population and is associated with a large symptom burden. Medicinal cannabis is advised against in patients with severe CKD. However, pharmacokinetic and pharmacodynamic knowledge regarding their use in patients with CKD is lacking.

Methods

We aimed to investigate the pharmacokinetics and side effects of a single dose of Sativex, corresponding to 5.4 mg Δ9-tetrahydrocannabinol (THC) and 5 mg cannabidiol (CBD), in patients with CKD stages 4 and 5 compared with healthy volunteers (controls). The study was a nonrandomized and unblinded clinical study.

Results

Twenty controls and 29 patients with CKD completed the study. The area under the curve (AUC) for THC (median [interquartile range]) was 2.76 (1.77-3.48), 4.16 (3.35-5.28), and 4.31 (3.16-5.42) h × ng/ml for controls, and for patients with CKD stages 4 and 5, respectively, with significant differences between patients with CKD and controls. AUC for CBD and metabolites, and other pharmacokinetic parameters, such as maximum concentration (C max) and excretion of metabolites in urine were also significantly different between patients with CKD and controls. After 1.5 hours, numeric rating scale (NRS) scores for dizziness were significantly higher for each CKD group compared with controls (mean NRSscores: 0.7 and 1.5 vs. 0.1).

Conclusion

Total exposure to THC, CBD, and metabolites was higher in patients with CKD stages 4 and 5 compared with controls, and side effects may be more pronounced; however, the intersubject variability was high. If cannabis products are administered to patients with severe CKD, caution is needed.

Characterizing the Role of Endocannabinoid Receptor Cnr1 in Mouse Ovarian Granulosa Cells

The endocannabinoid receptors Cnr1 and Cnr2 have been found in reproductive organs such as the oviduct and uterus. These receptors bind to endocannabinoids, the arachinodoylethanolamine (AEA) and arachinodoylglycerol (2-AG), respectively. Both cannbinoid receptors have been investigated for their role in implantation and fertilization. However, not much is explored in terms of their role in ovarian granulosa cells. As these two receptors (especially Cnr1) have affinity towards the major component of Cannabis, tetrahydrocannabinol (THC), its usage raises concerns about the potential effects of THC on ovarian functions. Hence, it is important to characterize the role of endocannabinoid system in the ovarian granulosa cells. The objectives of this study were to use the mouse model to: (1) profile the expression pattern of the Cnr1 and Cnr2 and the endocannabinoid metabolizing enzymes (Faah and Mgll) in granulosa cells and (2) to determine the effect of the Cnr1 antagonist, AM251 on ovarian functions. We found that Cnr1 transcript abundance was higher (p < 0.05) at 4 h hCG than 24 h and 48 h eCG timepoints, whereas Cnr2 transcript decreased (p < 0.05) with follicular development. Conversely, Faah and Mgll transcripts were higher at 14 h hCG (p < 0.05) suggesting their upregulation after ovulation. The ovulation rate was lower in AM251 than vehicle-treated mice (p < 0.05), indicating that Cnr1 signaling may regulate ovulation. Further investigating the effect of AM251, we found that it significantly downregulated Ptgs2 and Pappa (p < 0.05). Overall, these data suggest that Cnr1, an important player in the endocannabinoid system, is important for ovulation.

CB1 receptor signaling: Linking neuroplasticity, neuronal types, and mental health outcomes

The endocannabinoid system (ECS) is crucial in the pathophysiology of mental disorders. Historically, cannabis has been utilized for centuries to mitigate symptoms of anxiety and depression; however, the precise role of cannabinoids in these conditions has only recently garnered extensive research attention. Despite the growing body of literature on the ECS and its association with mental health, several critical questions remain unresolved. This review primarily focuses on cannabinoid CB1 receptors (CB1R), providing an examination of their regulatory roles in states related to mental disorders. Evidence suggests that CB1R distribution occurs among various neuronal types, astrocytes, and subcellular membranes across multiple brain regions, potentially exhibiting both analogous and antagonistic effects. Additionally, various forms of stress have been shown to produce divergent impacts on CB1R signaling pathways. Furthermore, numerous CB1R agonists demonstrate biphasic, dose-dependent effects on anxiety and depression; specifically, low doses may exert anxiolytic effects, while higher doses can induce anxiogenic responses, a phenomenon observed in both rodent models and human studies. We also discuss the diverse underlying mechanisms that mediate these effects. We anticipate that this review will yield valuable insights into the role of CB1R in mental disorders and provide a framework for future research endeavors on CB1R and the ECS. This knowledge may ultimately inform therapeutic strategies aimed at alleviating symptoms associated with mental health conditions.

Hippocampal Apoptosis: Molecular Mechanisms Triggered by Toxic Cannabinoid Exposure: A Narrative Review

Hippocampal apoptosis is increasingly recognized as a significant consequence of toxic cannabinoid exposure, with profound implications for cognitive function and mental health. This narrative review comprehensively examines the molecular mechanisms underlying cannabinoid-induced apoptosis, focusing on the interplay of various bioactive compounds and their effects on neuronal integrity. We begin by discussing the key players in cannabinoid biology, followed by a synthesis of findings from animal and clinical studies that highlight the neurotoxic potential of cannabinoids. Central to our analysis are the roles of neuroinflammation and oxidative stress, which exacerbate neuronal damage and contribute to cell death. The activation of cannabinoid receptors, particularly CB1 and CB2, is scrutinized for its dual role in mediating neuroprotective and neurotoxic effects. We explore calcium dysregulation as a critical mechanism that leads to excitotoxicity, mitochondrial dysfunction, and the activation of pro-apoptotic pathways. Additionally, we address the inhibition of anti-apoptotic proteins, induction of endoplasmic reticulum (ER) stress, and disruption of neurotransmitter systems, all of which further facilitate apoptosis in hippocampal neurons. Alterations in neurotrophic factor levels are also examined, as they play a vital role in neuronal survival and plasticity. Ultimately, this review underscores the multifaceted nature of cannabinoid-induced hippocampal apoptosis and calls for further research to elucidate these complex interactions, aiming to inform clinical practices and public health policies regarding cannabinoid use. The findings presented herein highlight the urgent need for a nuanced understanding of the risks associated with cannabinoid exposure, particularly in vulnerable populations.

CANDI: a web server for predicting molecular targets and pathways of cannabis-based therapeutics

BACKGROUND

Cannabis sativa L. with a rich history of traditional medicinal use, has garnered significant attention in contemporary research for its potential therapeutic applications in various human diseases, including pain, inflammation, cancer, and osteoarthritis. However, the specific molecular targets and mechanisms underlying the synergistic effects of its diverse phytochemical constituents remain elusive. Understanding these mechanisms is crucial for developing targeted, effective cannabis-based therapies.

METHODS

To investigate the molecular targets and pathways involved in the synergistic effects of cannabis compounds, we utilized DRIFT, a deep learning model that leverages attention-based neural networks to predict compound-target interactions. We considered both whole plant extracts and specific plant-based formulations. Predicted targets were then mapped to the Reactome pathway database to identify the biological processes affected. To facilitate the prediction of molecular targets and associated pathways for any user-specified cannabis formulation, we developed CANDI (Cannabis-derived compound Analysis and Network Discovery Interface), a web-based server. This platform offers a user-friendly interface for researchers and drug developers to explore the therapeutic potential of cannabis compounds.

RESULTS

Our analysis using DRIFT and CANDI successfully identified numerous molecular targets of cannabis compounds, many of which are involved in pathways relevant to pain, inflammation, cancer, and other diseases. The CANDI server enables researchers to predict the molecular targets and affected pathways for any specific cannabis formulation, providing valuable insights for developing targeted therapies.

CONCLUSIONS

By combining computational approaches with knowledge of traditional cannabis use, we have developed the CANDI server, a tool that allows us to harness the therapeutic potential of cannabis compounds for the effective treatment of various disorders. By bridging traditional pharmaceutical development with cannabis-based medicine, we propose a novel approach for botanical-based treatment modalities.

An In Vitro Phytohormone Survey Reveals Concerted Regulation of the Cannabis Glandular Trichome Disc Cell Proteome

Cannabis (Cannabis sativa L.) flower glandular trichomes (GTs) are the main site of cannabinoid synthesis. Phytohormones, such as jasmonic acid (JA) and salicylic acid (SA), have been shown to increase cannabinoid content in cannabis flowers, but how this is regulated remains unknown. This study aimed to understand which biological processes in GT disc cells phytohormones control by using an in vitro assay. Live GT disc cells were isolated from a high-tetrahydrocannabinol cannabis cultivar and incubated on basal media plates supplemented with either kinetin (KIN), JA, SA, abscisic acid, ethephon, gibberellic acid, brassinolide, or sodium diethyldithiocarbamate. Quantitative proteomic analysis revealed that KIN, JA, and SA caused the greatest number of changes in the GT disc cell proteome. Surprisingly, none of the treatments concertedly increased cannabinoid content or the abundance of related biosynthetic proteins in the GT, suggesting that cannabinoid increases in previous in planta phytohormone studies are likely due to other processes, such as increased GT density. As well, KIN-, JA-, and SA-treated GTs had numerous differentially abundant proteins in common. Several were key proteins for leucoplast differentiation, cuticular wax and fatty acid metabolism, and primary metabolism regulation, denoting that cytokinin, JA, and SA signalling are likely important for coordinating cannabis GT differentiation and development.

Cannabinoids in Chronic Pain Management: A Review of the History, Efficacy, Applications, and Risks

Background/Objectives: Chronic pain remains a pervasive and challenging public health issue, often resistant to conventional treatments such as opioids, which carry substantial risks of dependency and adverse effects. Cannabinoids, bioactive compounds derived from the Cannabis sativa plant and their synthetic analogs, have emerged as a potential alternative for pain management, leveraging their interaction with the endocannabinoid system to modulate pain and inflammation. Methods: The current, evolving literature regarding the history, efficacy, applications, and safety of cannabinoids in the treatment of chronic pain was reviewed and summarized to provide the most current review of cannabinoids. Results: Evidence suggests that cannabinoids provide moderate efficacy in managing neuropathic pain, fibromyalgia, cancer-related pain, and multiple sclerosis-related spasticity. Patient-reported outcomes further indicate widespread perceptions of cannabinoids as a safer alternative to opioids, with potential opioid-sparing effects. However, the quality of existing evidence is limited by small sample sizes and methodological inconsistencies. Regulatory barriers, including the classification of cannabis as a Schedule I substance in the United States, continue to hinder robust research and clinical integration. Moreover, the risks associated with cannabinoids, such as psychiatric effects, addiction potential, and drug interactions, necessitate cautious application. Conclusions: Cannabinoids represent a promising, albeit complex, alternative for chronic pain management, particularly given the limitations and risks of traditional therapies such as opioids. However, significant deficiencies remain in the research. While smaller trials and systematic reviews indicate therapeutic potential, the quality of evidence is often low due to limited sample sizes, short study durations, and methodological inconsistencies. Large-scale, randomized controlled trials with long-term follow-up are urgently needed to confirm efficacy and safety across diverse patient populations and pain etiologies.

Chronic orofacial pain and pharmacological management-a clinical guide

Orofacial pain is a widespread health concern that significantly hinders an individual's capacity to engage in daily activities. This type of pain can be classified into three main categories: nociceptive pain, neuropathic pain, and nociplastic pain. Each category involves different mechanisms and requires specific treatment approaches. For optimal treatment of orofacial pain disorders, a multidisciplinary pain management approach is essential. This approach should integrate both nonpharmacological and pharmacological modalities to address the diverse underlying causes and manifestations of pain. In this review, we focus on the current evidence and advancements in the pharmacological management of chronic orofacial pain. We explored the effectiveness of different medications, their mechanisms of action, and their role within a comprehensive pain management plan.

Escitalopram reverses anxiety-like and despair behavior and affects endocannabinoid-related genes expression in the brain of adolescent male rats subjected to early life stress

Due to the increasing prevalence of depressive and anxiety disorders in youth, a growing interest in the endocannabinoid system (ECS) as a potential alternative target point for treatment arised. This study aimed to investigate whether chronic administration of escitalopram reverses behavioral changes induced by maternal separation in male adolescent Wistar rats and explore the corresponding neurochemical changes in the ECS. The pups were separated from their dams for 360 min daily from postnatal day (PND) 2 until PND 15. Later, male rats were administered escitalopram (10 mg/kg i.p.) during their adolescent period (PND 35 - PND 55). Behavioral assessments were conducted in late adolescence (PND 54 - PND 57) in one group, and brain structures were dissected for biochemical analysis in the subsequent group of rats on PND 56. Expression of genes encoding: CB1 receptor, enzyme that catalyzes synthesis (NAPE-PLD) and degradation (FAAH) of anandamide (a full agonist of CB1 receptor) was evaluated using qRT-PCR. The corresponding protein levels were estimated via Western blot analysis. Our study revealed that maternal separation induced anxiety and despair-like behavior in adolescent rats. Escitalopram reversed anxiety-like behavior and attenuated signs of despair behavior. The escitalopram administration has been followed by a decrease in the studied genes expression in the amygdala, the hypothalamus, and the hippocampus, what might suggest that the endocannabinoid system is involved in the mechanism of its action in adolescents. However Western blot analysis did not indicate significant alterations in the protein levels, so more detailed studies are needed to verify this hypothesis.

The Effects of Indirect and Direct Modulation of Endocannabinoid System Function on Anxiety-Related Behavior in Mice Assessed in the Elevated Plus Maze Test

BACKGROUND

The endocannabinoid system (ECS) is one of the most important systems modulating functions in the body. The ECS, via cannabinoid (CB: CB1 and CB2) receptors, endocannabinoids occurring in the brain (e.g., anandamide (AEA) and 2-arachidonoylglycerol (2-AG)) and enzymes degrading endocannabinoids in the brain (fatty-acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL)), plays a key role in the regulation of mood and anxiety. However, the effects of cannabinoid compounds on anxiety-related responses are complex and yield mixed results depending on the type of pharmacological manipulation (direct or indirect) of functions of the ECS, as well as the kinds of cannabinoids, dosage and procedure.

METHODS

The aim of this study was to determine and compare the influence of the direct (via CB receptors ligands) and indirect (via inhibition of enzymes degrading endocannabinoids in the brain) pharmacological modulation of ECS function on anxiety-like responses in mice in the elevated plus maze (EPM) test. For this purpose, in the first step of the experiments, we used selected ligands of CB1, CB1/CB2 and CB2 receptors to assess which types of CB receptors are involved in anxiety-related responses in mice. Next, we used inhibitors of FAAH (which breaks down AEA) or MAGL (which breaks down 2-AG) to assess which endocannabinoid is more responsible for anxiety-related behavior in mice.

RESULTS

The results of our presented research showed that an acute administration of CB1 receptor agonist oleamide (5-20 mg/kg) had no influence on anxiety-related responses and CB1 receptor antagonist AM 251 (0.25-3 mg/kg) had anxiogenic effects in the EPM test in mice. In turn, an acute administration of mixed CB1/CB2 receptor agonist WIN55,212-2 used at a dose of 1 mg/kg had an anxiolytic effect observed in mice in the EPM test. What is of interest is that both the acute administration of a CB2 receptor agonist (JWH 133 at the doses of 1 and 2 mg/kg) and antagonist (AM 630 at the doses of 0.5-2 mg/kg) had anxiogenic effects in this procedure. Moreover, we revealed that an acute administration of only FAAH inhibitor URB 597 (0.3 mg/kg) had an anxiolytic effect, while MAGL inhibitor JZL 184 (at any used doses (2-40 mg/kg)) after an acute injection had no influence on anxiety behavior in mice, as observed in the EPM test.

CONCLUSIONS

In our experiments, we confirmed the clearly significant involvement of the ECS in anxiety-related responses. In particular, the pharmacological indirect manipulation of ECS functions is able to elicit promising anxiolytic effects. Therefore, the ECS could be a potential target for novel anxiolytic drugs; however, further studies are needed.

The endocannabinoid system and ophthalmic pathologies: a review of molecular mechanisms and its implications for clinical practice

Within the last decade the role of the endocannabinoid system (ECS) has been a significant part of ophthalmic research, including both ocular physiology and the development of eye pathologies. It is known that this widespread cell-signaling system is involved in retinal neurobiological processes, including visual signal processing, as well as neurotransmission. Furthermore, various research indicated the involvement of ECS in the molecular basis of various pathologies, mostly glaucoma, diabetic retinopathy, and age-related macular degeneration (AMD). Therefore, the researchers believe that this biological system, its receptors, pathways, and ligands might be considered as an auxiliary compound to reduce the number of patients suffering from ophthalmic diseases. Despite presented in the literature effects of the endocannabinoid system in the eye, none of the current ECS reviews presented a comprehensive description of the endocannabinoid system, its compounds, and, subsequently ophthalmic disorders. Thus, the aim of this review was to summarize all the major data, including the most up-to-date research, concerning a correlation between the endocannabinoid system and the major ophthalmic pathologies.

Network analysis of the hair-based nine hormones from four neuroendocrine systems

INTRODUCTION

The stress response maintains the homeostasis of the body's internal environment and normal physiological activities, involving several neuroendocrine systems, such as the HPA axis, the HPG axis, the endocannabinoid system, and the melatonin system. However, studies on the intricate interactions among the four neuroendocrine systems are lacking, and it is not clear how these interactions are affected by demographic variables. The aim of this study was to investigate the network characteristics of hormonal networks comprising nine hormones from four neuroendocrine systems and how they were affected by demographic variables.

METHODS

252 healthy current students were recruited from Southeast University, China. The concentrations of nine hormones in their hair were measured by LC/MS methods, and hormonal network was constructed. Network analysis was used to characterize the interrelationships between hormones or neuroendocrine systems, central hormones, bridge hormones, hormonal network characteristics, and their changes in response to demographic variables.

RESULTS

Complex interactions between the HPA axis, the HPG axis, the ECS and the melatonin system formed a sparse and stable network, with cortisol and cortisone being the central hormones and melatonin as the bridge hormone. Demographic variables did not affect the overall characteristics of the network or the central hormone, but a number of specific connections in the network changed and the bridge hormones became cortisone and progesterone.

CONCLUSION

The interactions between the four stress-related neuroendocrine systems were relatively stable and were centered and initiated by the HPA axis. Demographic variables did not affect the overall structure of the network, but influenced local features of the network, such as edge weights and bridge centrality.

Targeting cryptic allosteric sites of G protein-coupled receptors as a novel strategy for biased drug discovery

G protein-coupled receptors (GPCRs) represent the largest family of membrane receptors and are highly effective targets for therapeutic drugs. GPCRs couple different downstream effectors, including G proteins (such as Gi/o, Gs, G12, and Gq) and β-arrestins (such as β-arrestin 1 and β-arrestin 2) to mediate diverse cellular and physiological responses. Biased signaling allows for the specific activation of certain pathways from the full range of receptors' signaling capabilities. Targeting more variable allosteric sites, which are spatially different from the highly conserved orthosteric sites, represents a novel approach in biased GPCR drug discovery, leading to innovative strategies for targeting GPCRs. Notably, the emergence of cryptic allosteric sites on GPCRs has expanded the repertoire of available drug targets and improved receptor subtype selectivity. Here, we conduct a summary of recent progress in the structural determination of cryptic allosteric sites on GPCRs and elucidate the biased signaling mechanisms induced by allosteric modulators. Additionally, we discuss means to identify cryptic allosteric sites and design biased allosteric modulators based on cryptic allosteric sites through structure-based drug design, which is an advanced pharmacotherapeutic approach for treating GPCR-associated diseases.

Therapeutic potential of minor cannabinoids in psychiatric disorders: A systematic review

Interest in cannabinoids' therapeutic potential in mental health is growing, supported by evidence of the involvement of the endocannabinoid system in psychiatric disorders such as anxiety, depression, and addiction. While the major cannabinoids cannabidiol (CBD) and Δ9-tetrahydrocannabinol (Δ9-THC) have been more extensively researched, approximately 120 minor cannabinoids from the cannabis plant have been identified. Although some displayed promising pharmacological profiles, research on their application for psychiatric disorders is fragmented. This systematic review evaluates, for the first time, both preclinical and clinical studies exploring minor cannabinoids' therapeutic potential in psychiatric disorders. 22 preclinical studies and one clinical study were included, investigating various minor cannabinoids in substance use disorders, anxiety disorders, depressive disorders, trauma and stressor-related disorders, psychotic disorders, neurodevelopmental disorders, and eating disorders. Despite the heterogeneous results and the moderate to high risk of bias in several articles, certain compounds demonstrate promise for further investigation. Δ8-tetrahydrocannabidivarin (Δ8-THCV) exhibited potential for nicotine addiction; Δ9-tetrahydrocannabidivarin (Δ9-THCV) for psychotic-like symptoms; cannabidiolic acid methyl ester (CBDA-ME) alleviated anxiety and depression-like symptoms, and cannabidivarin (CBDV) autism spectrum disorder-like symptoms.

The role of cannabis on total hip and knee surgeries outcomes: a systematic review and meta-analysis

PURPOSE

Cannabis refers to medications derived from the Cannabis plant. Cannabis has long been used to treat a wide range of conditions. The widespread legalization of cannabis has increased its use. This meta-analysis evaluates the effects of preoperative cannabis usage on TKA and THA outcomes and complications.

METHODS

This review follows CRD Guidance for Undertaking Reviews in Healthcare and PRISMA 2020 guidelines. On October 12, 2023, we extensively searched MEDLINE (PubMed), Scopus, Cochrane Central Register of Controlled Trials, and Web of Science. There were no time, place, or language restrictions. We also examined the references and citations in the included publications to find relevant research.

RESULTS

We found 208 references in PubMed/Medline, Scopus, Web of Science, and other databases. After reviewing all publications, we identified 18 references that match the requirements for further assessment. The odds ratios (ORs) for reoperation and readmission are 1.35 (95% CI: 0.69, 2.66, and p-value = 0.38), and 0.89 (95% CI: 0.41, 1.92, and p-value = 0.76). Inpatient morphine milligram equivalent (MME) and length of stay (LOS) have a mean difference (MD) of -1.71 (95% CI: -13.46, 10.05, and p-value = 0.78), and - 0.13 (95% CI: -0.33, 0.08, and p-value = 0.23). The MD of the VAS pain score 24-72 h after surgery is 0.40 (95% CI: -0.07, 0.87, and p-value = 0.10). The odds ratio for PTE and DVT is 1.54 (95% CI: 0.1, 23.24, and p-value = 0.75), and 1.38 (95% CI: 1.08, 1.77, and p-value = 0.01), respectively.

CONCLUSION

Cannabis users experienced significantly higher rates of DVT following THA and TKA. Our subgroup analysis found that cannabis users who underwent TKA had considerably higher rates of reoperation (p-value = 0.10) and readmission (p-value ≤ 0.01), while those who underwent THA had significantly lower rates of PTE. These findings highlight the need to include cannabis use as a risk factor in surgical planning and patient care protocols, and further studies are warranted.

PROSPERO REGISTRATION

This study design and protocol were performed in accordance with the PRISMA Statement. The protocol was registered previously on PROSPERO CRD42024551078.

Bridging past and present: exploring Cannabis traditions in Armenia through ethnobotanical interviews and bibliographic prospecting

BACKGROUND

Cannabis sativa L. (Cannabaceae) has been widely used by humans throughout its history for a variety of purposes (medicinal, alimentary and other uses). Armenia, with its rich cultural history and diverse ecosystems, offers a unique context for ethnobotanical research about traditional uses of Cannabis. The present work aims to study and preserve the local traditional knowledge about Cannabis in Armenia by conducting interviews with informants and through a literature review.

METHODS

The first part of the dataset was gathered with ethnobotanical surveys, through questionnaires conducted with 27 informants. The second part of the data was obtained from a comprehensive bibliographic search in English, Armenian and Russian language. Since the data acquisition was different, the quantitative analyses (calculation of the number of use reports and percentages) were performed separately.

RESULTS

During the interviews 52 use reports and 3 vernacular names were recorded, while the bibliographic data from 20 references, provided us with 56 use reports and 17 Cannabis vernacular names, from the 5th century to 2020. Our results indicate that medicinal applications, particularly for human ailments, and fibre use have markedly dwindled, contrasting with earlier epochs. However, the Cannabis seeds continue to be consumed in celebrative and symbolic dishes such as aghandz and tolma.

CONCLUSIONS

The recent decline in the medicinal use of Cannabis contrasts with earlier periods when access to pharmacological remedies was limited, and societal views of the plant were more positive. This shift can be partly attributed to the impact of legal restrictions. In contrast, the use of Cannabis seeds for alimentary purposed is importantly maintained nowadays. As medicinal use, fibre use has also declined, largely due to the availability of more competitive modern products. The loss of vernacular names over time, as detected in this study, also reflects the erosion of traditional knowledge, which correlates with diminishing use. Despite the small sample size and limited geographic scope, the combination of two approaches-information from contemporary informants and a systematic bibliographic review-has provided valuable insights into the changes in the traditional use of Cannabis in Armenia, that has not been explored in this way before.

Phytocanabinoids and synthetic cannabinoids: from recreational consumption to potential therapeutic use - a review

Cannabinoids are part of the most popular group of illicit substances in the Western world. The word "cannabinoid" refers to any chemical substance, regardless of structure or origin, that binds to the body's cannabinoid receptors and that has effects similar to those produced by the Cannabis plant. Regarding their origin, cannabinoids can be classified into endocannabinoids, phytocannabinoids and synthetic cannabinoids. The behavioral and physiological effects of cannabinoids have received particular attention over the last few decades, including sensations of euphoria, relaxation and loss of concentration, with their repeated use being associated with short and long-term side effects, including respiratory and cardiovascular disorders, cognitive changes, psychoses, schizophrenia and mood disorders. On the other hand, recent investigations have proposed a promising therapeutic potential of cannabinoid-based drugs for a wide range of medical situations, including neurological and psychiatric disorders, among other indications. The growing popularity in the use of cannabinoid-based compounds, both for recreational and therapeutic purposes, has been accompanied by an equally continuous and growing evolution of knowledge regarding their potential harmful and beneficial effects. However, there are several open questions and challenges to be answered, which require more and better investigations. This article's main objectives are: i) to understand the importance of the action of cannabinoids in humans; ii) identify the different types of cannabinoids that exist and understand the differences in their action; iii) distinguish the legislative framework for cannabinoid consumption; iv) identify the possible adverse effects of cannabinoid consumption, as well as their potential benefits; v) know the existing medical-scientific evidence in terms of therapeutic potential, particularly in relation to aspects of safety and efficacy; vi) encourage critical thinking about the recreational consumption and therapeutic use of cannabinoids, based both on currently available evidence and gaps in knowledge.

International Symposium on Ruminant Physiology: The involvement of the endocannabinoid system in metabolic and inflammatory responses in dairy cows during negative energy balance

The endocannabinoid system (ECS) is involved in the regulation of energy metabolism, immune function and reproduction in mammals. The ECS is consisted of the endocannabinoid (eCB) ligands, enzymes, and cannabinoid receptors. In mammals, the cannabinoid-1 receptor (CB1/CNR1) is expressed in the central nervous system and in peripheral tissues; and its activation increases anabolic processes. The cannabinoid-2 receptor (CB2/CNR2) is most highly expressed in immune cells, and its activation exerts mainly anti-inflammatory effects. Until recently, little was known about the involvement of the ECS in physiological responses in dairy cows. As peripartum dairy cows undergo vast changes in energy metabolism and immune function, processes that are regulated by the ECS, several studies characterized ECS components in transition cows. Concentrations of eCB in the adipose tissue were higher postpartum (PP), and levels of the eCB N-arachidonoylethanolamide (AEA) were increased PP compared with prepartum. Exogenous injections of AEA to transition cows may increase adipose deposition, but did not affect feed intake. In vitro models showed that bovine adipocyte metabolism was differentially affected by CB1 agonists and antagonists in nonlactating non-gestating compared with PP cows. Thus, the responses of the PP dairy cows to ECS modulations may be related to the physiological and reproductive stage of the cow. Currently, whole-body ECS activation via agonists is mostly not feasible in vivo in livestock. Alternatively, downregulation of ECS activation can be achieved by supplementation of omega-3 (n-3) fatty acids. Indeed, in vivo studies with transition cows supplemented with n-3 showed a moderate downregulation of ECS components in the blood, adipose and liver, improved systemic insulin sensitivity, but evidently reduced insulin sensitivity in the adipose tissue PP. The abundance of CB1 was lower in immune cells, and anti-inflammatory effects were found in PP cows supplemented with n-3; possibly associating ECS downregulation with immune function. The physiological impact of ECS activation is an exciting and complex area of research, that could influence the physiology of dairy cows during metabolic and inflammatory challenges. Dairy cows may be an experimental model for ECS modulations, with broader relevance to female mammals. More research is required on how selective ECS activation/downregulation in tissues could affect immune-metabolic function in dairy cows.

Early psilocybin intervention alleviates behavioral despair and cognitive impairment in stressed Wistar rats

Chronic stress exerts profound effects on mental health, contributing to disorders such as depression, anxiety, and cognitive impairment. This study examines the potential of psilocybin to alleviate behavioral despair and cognitive deficits in a rodent model of chronic stress, focusing on the interplay between the Hypothalamic-Pituitary-Adrenal (HPA) axis and the Endocannabinoid System (ECS). Twenty-two male Wistar rats were divided into control and stress groups. Animals within the stress group were exposed to predator odor and chronic social instability to induce chronic stress, and were either sham treated, or given psilocybin. Behavioral assessments were conducted using the Open Field Test, Sucrose Preference Test, Novel Object Recognition, Elevated Plus Maze, and Forced Swimming Test to evaluate locomotion, anhedonia, memory, anxiety, and behavioral despair, respectively. Blood and brain samples were analyzed for biochemical markers. Results indicated that psilocybin significantly reduced stress-induced behavioral despair and cognitive impairments, likely through ECS-mediated downregulation of the HPA axis. These findings suggest that early intervention with psilocybin has sustained beneficial effects on stress-related behavioral and cognitive disturbances, underscoring its potential as a novel therapeutic approach for stress-related mental health disorders.

Modeling the Effect of Cannabinoid Exposure During Human Neurodevelopment Using Bidimensional and Tridimensional Cultures

Our knowledge about the consumption of cannabinoids during pregnancy lacks consistent evidence to determine whether it compromises neurodevelopment. Addressing this task is challenging and complex since pregnant women display multiple confounding factors that make it difficult to identify the real effect of cannabinoids' consumption. Recent studies shed light on this issue by using pluripotent stem cells of human origin, which can recapitulate human neurodevelopment. These revolutionary platforms allow studying how exogenous cannabinoids could alter human neurodevelopment without ethical concerns and confounding factors. Here, we review the information to date on the clinical studies about the impact of exogenous cannabinoid consumption on human brain development and how exogenous cannabinoids alter nervous system development in humans using cultured pluripotent stem cells as 2D and 3D platforms to recapitulate brain development.

Synthetic CB1 Cannabinoids Promote Tunneling Nanotube Communication, Cellular Migration, and Epithelial-Mesenchymal Transition in Pancreatic PANC-1 and Colorectal SW-620 Cancer Cell Lines

Metastasizing cancer cells surreptitiously can adapt to metabolic activity during their invasion. By initiating their communications for invasion, cancer cells can reprogram their cellular activities to initiate their proliferation and migration and uniquely counteract metabolic stress during their progression. During this reprogramming process, cancer cells' metabolism and other cellular activities are integrated and mutually regulated by tunneling nanotube communications to alter their specific metabolic functional drivers of tumor growth and progression. Here, we investigated the in vitro effects of the synthetic CB1 cannabinoids AM-404, arvanil, and olvanil on human pancreatic PANC-1 and colorectal SW-620 cancer cell lines to understand further cellular behaviors and the potential risks of their use in cancer therapy. For the first time, the synthetic CB1 cannabinoids AM-404, arvanil, and olvanil significantly altered cancer cells in forming missile-like shapes to induce tunneling nanotube (TNT) communications in PANC-1 cells. Oseltamivir phosphate (OP) significantly prevented TNT formation. To assess the key survival pathways critical for pancreatic cancer progression, we used the AlamarBlue assay to determine synthetic CB1 cannabinoids to induce the cell's metabolic viability drivers to stage migratory intercellular communication. The synthetic CB1 cannabinoids significantly increased cell viability compared to the untreated control for PANC-1 and SW-620 cells, and this response was significantly reduced with the NMBR inhibitor BIM-23127, neuraminidase-1 inhibitor OP, and MMP-9 inhibitor (MMP-9i). CB1 cannabinoids also significantly increased N-cadherin and decreased E-cadherin EMT markers compared to the untreated controls, inducing the process of metastatic phenotype for invasion. BIM-23127, MMP9i, and OP significantly inhibited CB1 agonist-induced NFκB-dependent secretory alkaline phosphatase (SEAP) activity. To confirm this concept, we investigated the migratory invasiveness of PANC-1 and SW-620 cancer cells treated with the synthetic CB1 cannabinoids AM-404, arvanil, and olvanil in a scratch wound assay. CB1 cannabinoids significantly induced the rate of migration and invasiveness of PANC-1 cancer cells, whereas they had minimal effect on the rate of migration of already metastatic SW-620 cancer cells. Interestingly, olvanil-treated SW-620 cells significantly enhanced the migration rate and invasiveness of these cells. The data support the cellular and molecular mechanisms of the synthetic CB1 cannabinoids, orchestrating intercellular conduits to enhance metabolic drivers to stage migratory intercellular communication in pancreatic cancer cells.

Xixin Decoction's novel mechanism for alleviating Alzheimer's disease cognitive dysfunction by modulating amyloid-β transport across the blood-brain barrier to reduce neuroinflammation

Purpose

Xixin Decoction (XXD) is a classical formula that has been used to effectively treat dementia for over 300 years. Modern clinical studies have demonstrated its significant therapeutic effects in treating Alzheimer's disease (AD) without notable adverse reactions. Nevertheless, the specific mechanisms underlying its efficacy remain to be elucidated. This investigation sought to elucidate XXD's impact on various aspects of AD pathology, including blood-brain barrier (BBB) impairment, neuroinflammatory processes, and amyloid-β (Aβ) deposition, as well as the molecular pathways involved in these effects.

Methods

In vitro experiments were conducted using hCMEC/D3 and HBVP cell coculture to establish an in vitro blood-brain barrier (BBB) model. BBB damage was induced in this model by 24-h exposure to 1 μg/mL lipopolysaccharide (LPS). After 24, 48, and 72 h of treatment with 10% XXD-medicated serum, the effects of XXD were assessed through Western blotting, RT-PCR, and immunofluorescence techniques. In vivo, SAMP8 mice were administered various doses of XXD via gavage for 8 weeks, including high-dose XXD group (H-XXD) at 5.07 g kg-1·d-1, medium-dose XXD group (M-XXD) at 2.535 g kg-1·d-1, and low-dose XXD group (L-XXD) at 1.2675 g kg-1·d-1. Cognitive function was subsequently evaluated using the Morris water maze test. BBB integrity was evaluated using Evans blue staining, and protein expression levels were analyzed via ELISA, Western blotting, and immunofluorescence.

Results

In vitro experiments revealed that XXD-containing serum, when cultured for 24, 48, and 72 h, could upregulate the expression of P-gp mRNA and protein, downregulate CB1 protein expression, and upregulate CB2 and Mfsd2a protein expression. In vivo studies demonstrated that XXD improved spatial learning and memory abilities in SAMP8 mice, reduced the amount of Evans blue extravasation in brain tissues, modulated the BBB-associated P-gp/ECS axis, RAGE/LRP1 receptor system, as well as MRP2 and Mfsd2a proteins, and decreased the accumulation of Aβ in the brains of SAMP8 mice. Additionally, XXD upregulated the expression of TREM2, downregulated IBA1, TLR1, TLR2, and CMPK2 expression, and reduced the levels of pro-inflammatory factors NLRP3, NF-κB p65, COX-2, TNF-α, and IL-1β in the hippocampal tissues.

Conclusion

XXD may exert its effects by regulating the P-gp/ECS axis, the RAGE/LRP1 receptor system, and the expression of MRP2 and Mfsd2a proteins, thereby modulating the transport function of the BBB to expedite the clearance of Aβ, reduce cerebral Aβ accumulation, and consequently inhibit the activation of microglia induced by Aβ aggregation. This process may suppress the activation of the CMPK2/NLRP3 and TLRs/NF-κB pathways, diminish the production of inflammatory cytokines and chemokines, alleviate neuroinflammation associated with microglia in the brain of AD, and ultimately improve AD pathology.

Gastrodin Ameliorates Post-Stroke Depressive-Like Behaviors Through Cannabinoid-1 Receptor-Dependent PKA/RhoA Signaling Pathway

Post-stroke depression (PSD) is a significant complication in stroke patients, increases long-term mortality, and exaggerates ischemia-induced brain injury. However, the underlying molecular mechanisms and effective therapeutic targets related to PSD have remained elusive. Here, we employed an animal behavioral model of PSD by combining the use of middle cerebral artery occlusion (MCAO) followed by spatial restraint stress to study the molecular underpinnings and potential therapies of PSD. Interestingly, we found that sub-chronic application of gastrodin (Gas), a traditional Chinese medicinal herb Gastrodia elata extraction, relieved depression-related behavioral deficits, increased the impaired expression of synaptic transmission-associated proteins, and restored the altered spine density in hippocampal CA1 of PSD animals. Furthermore, our results indicated that the anti-PSD effect of Gas was dependent on membrane cannabinoid-1 receptor (CB1R) expression. The contents of phosphorated protein kinase A (p-PKA) and phosphorated Ras homolog gene family member A (p(ser188)-RhoA) were decreased in the hippocampus of PSD-mice, which was reversed by Gas treatment, and CB1R depletion caused a diminished efficacy of Gas on p-PKA and p-RhoA expression. In addition, the anti-PSD effect of Gas was partially blocked by PKA inhibition or RhoA activation, indicating that the anti-PSD effect of Gas is associated with the CB1R-mediated PKA/RhoA signaling pathway. Together, our findings revealed that Gas treatment possesses protective effects against the post-stroke depressive-like state; the CB1R-involved PKA/RhoA signaling pathway is critical in mediating Gas's anti-PSD potency, suggesting that Gas application may be beneficial in the prevention and adjunctive treatment of PSD.

Frequent recreational cannabis use and its association with caries and severe tooth loss: Findings from the National Health and Nutrition Examination Survey, 2015-2018

BACKGROUND

The aim of this study was to examine the association of frequent recreational cannabis (FRC) use with untreated coronal caries, untreated root surface caries, and severe tooth loss.

METHODS

This cross-sectional study analyzed data obtained from 5,656 people, aged 18 through 59 years, who participated in the National Health and Nutrition Examination Survey from 2015 through 2018. FRC use was defined as self-reported use of marijuana or hashish at least once per month for the past 12 months. Log-binomial and logistic regression analyses were conducted before and after controlling for sociodemographic and behavioral factors to examine the association between FRC use and untreated coronal caries, root surface caries, and severe tooth loss.

RESULTS

Compared with non-FRC users, people reporting FRC use had 17% higher probabilities of having untreated coronal caries (95% CI, 1.02 to 1.35), 55% higher odds of having untreated root surface caries (95% CI, 1.21 to 1.99), and 41% higher odds of having severe tooth loss (95% CI, 1.00 to 1.99) after controlling for age, sex, race or ethnicity, nativity, education, family income to poverty ratio, and alcohol consumption.

CONCLUSIONS

This study suggests that FRC use is associated with increased coronal caries, root surface caries, and severe tooth loss in the US adult population. Further longitudinal studies are warranted to assess the impact of varying frequencies, quantities, and forms of cannabis use.

PRACTICAL IMPLICATIONS

Dental care professionals should be aware that FRC use may be associated with caries and tooth loss.