Cannabinoids, Blood-Brain Barrier, and Brain Disposition

Phytocannabinoids in neuromodulation: From omics to epigenetics

BACKGROUND

Recent developments in metabolomics, transcriptomic and epigenetics open up new horizons regarding the pharmacological understanding of phytocannabinoids as neuromodulators in treating anxiety, depression, epilepsy, Alzheimer's, Parkinson's disease and autism.

METHODS

The present review is an extensive search in public databases, such as Google Scholar, Scopus, the Web of Science, and PubMed, to collect all the literature about the neurobiological roles of cannabis extract, cannabidiol, 9-tetrahydrocannabinol specially focused on metabolomics, transcriptomic, epigenetic, mechanism of action, in different cell lines, induced animal models and clinical trials. We used bioinformatics, network pharmacology and enrichment analysis to understand the effect of phytocannabinoids in neuromodulation.

RESULTS

Cannabidomics studies show wide variability of metabolites across different strains and varieties, which determine their medicinal and abusive usage, which is very important for its quality control and regulation. CB receptors interact with other compounds besides cannabidiol and Δ9-tetrahydrocannabinol, like cannabinol and Δ8-tetrahydrocannabinol. Phytocannabinoids interact with cannabinoid and non-cannabinoid receptors (GPCR, ion channels, and PPAR) to improve various neurodegenerative diseases. However, its abuse because of THC is also a problem found across different epigenetic and transcriptomic studies. Network enrichment analysis shows CNR1 expression in the brain and its interacting genes involve different pathways such as Rap1 signalling, dopaminergic synapse, and relaxin signalling. CBD protects against diseases like epilepsy, depression, and Parkinson's by modifying DNA and mitochondrial DNA in the hippocampus. Network pharmacology analysis of 8 phytocannabinoids revealed an interaction with 10 (out of 60) targets related to neurodegenerative diseases, with enrichment of ErbB and PI3K-Akt signalling pathways which helps in ameliorating neuro-inflammation in various neurodegenerative diseases. The effects of phytocannabinoids vary across sex, disease state, and age which suggests the importance of a personalized medicine approach for better success.

CONCLUSIONS

Phytocannabinoids present a range of promising neuromodulatory effects. It holds promise if utilized in a strategic way towards personalized neuropsychiatric treatment. However, just like any drug irrational usage may lead to unforeseen negative effects. Exploring neuro-epigenetics and systems pharmacology of major and minor phytocannabinoid combinations can lead to success.

Therapeutic potential of cannabidiol in depression

Major depressive disorder (MDD) is a widespread and debilitating condition affecting a significant portion of the global population. Traditional treatment for MDD has primarily involved drugs that increase brain monoamines by inhibiting their uptake or metabolism, which is the basis for the monoaminergic hypothesis of depression. However, these treatments are only partially effective, with many patients experiencing delayed responses, residual symptoms, or complete non-response, rendering the current view of the hypothesis as reductionist. Cannabidiol (CBD) has shown promising results in preclinical models and human studies. Its mechanism is not well-understood, but may involve monoamine and endocannabinoid signaling, control of neuroinflammation and enhanced neuroplasticity. This chapter will explore CBD's effects in preclinical and clinical studies, its molecular mechanisms, and its potential as a treatment for MDD.

Potential of CBD Acting on Cannabinoid Receptors CB1 and CB2 in Ischemic Stroke

Stroke is one of the leading causes of death. It not only affects adult people but also many children. It is estimated that, every year, 15 million people suffer a stroke worldwide. Among them, 5 million people die, while 5 million people are left permanently disabled. In this sense, the research to find new treatments should be accompanied with new therapies to combat neuronal death and to avoid developing cognitive impairment and dementia. Phytocannabinoids are among the compounds that have been used by mankind for the longest period of history. Their beneficial effects such as pain regulation or neuroprotection are widely known and make them possible therapeutic agents with high potential. These compounds bind cannabinoid receptors CB1 and CB2. Unfortunately, the psychoactive side effect has displaced them in the vast majority of areas. Thus, progress in the research and development of new compounds that show efficiency as neuroprotectors without this psychoactive effect is essential. On the one hand, these compounds could selectively bind the CB2 receptor that does not show psychoactive effects and, in glia, has opened new avenues in this field of research, shedding new light on the use of cannabinoid receptors as therapeutic targets to combat neurodegenerative diseases such as Alzheimer's, Parkinson's disease, or stroke. On the other hand, a new possibility lies in the formation of heteromers containing cannabinoid receptors. Heteromers are new functional units that show new properties compared to the individual protomers. Thus, they represent a new possibility that may offer the beneficial effects of cannabinoids devoid of the unwanted psychoactive effect. Nowadays, the approval of a mixture of CBD (cannabidiol) and Δ9-THC (tetrahydrocannabinol) to treat the neuropathic pain and spasticity in multiple sclerosis or purified cannabidiol to combat pediatric epilepsy have opened new therapeutic possibilities in the field of cannabinoids and returned these compounds to the front line of research to treat pathologies as relevant as stroke.

Repeated cannabidiol treatment affects neuroplasticity and endocannabinoid signaling in the prefrontal cortex of the Flinders Sensitive Line (FSL) rat model of depression

Delayed therapeutic responses and limited efficacy are the main challenges of existing antidepressant drugs, thereby incentivizing the search for new potential treatments. Cannabidiol (CBD), non-psychotomimetic component of cannabis, has shown promising antidepressant effects in different rodent models, but its mechanism of action remains unclear. Herein, we investigated the antidepressant-like effects of repeated CBD treatment on behavior, neuroplasticity markers and lipidomic profile in the prefrontal cortex (PFC) of Flinders Sensitive Line (FSL), a genetic animal model of depression, and their control counterparts Flinders Resistant Line (FRL) rats. Male FSL animals were treated with CBD (10 mg/kg; i.p.) or vehicle (7 days) followed by Open Field Test (OFT) and the Forced Swimming Test (FST). The PFC was analyzed by a) western blotting to assess markers of synaptic plasticity and cannabinoid signaling in synaptosome and cytosolic fractions; b) mass spectrometry-based lipidomics to investigate endocannabinoid levels (eCB). CBD attenuated the increased immobility observed in FSL, compared to FRL in FST, without changing the locomotor behavior in the OFT. In synaptosomes, CBD increased ERK1, mGluR5, and Synaptophysin, but failed to reverse the reduced CB1 and CB2 levels in FSL rats. In the cytosolic fraction, CBD increased ERK2 and decreased mGluR5 expression in FSL rats. Surprisingly, there were no significant changes in eCB levels in response to CBD treatment. These findings suggest that CBD effects in FSL animals are associated with changes in synaptic plasticity markers involving mGluR5, ERK1, ERK2, and synaptophysin signaling in the PFC, without increasing the levels of endocannabinoids in this brain region.

A study on the possible neurotoxic effects of CUMYL-4CN-BINACA in Sprague Dawley rats

Substances such as Δ9-tetrahydrocannabinol (THC) and cannabidiol cross the blood-brain barrier. Detecting the damage of these substances in the brain provides important data in drug abuse studies. The aim of the study is to define the neurotoxicity of a novel synthetic cannabinoid (CUMYL-4CN-BINACA) in the Sprague-Dawley rats. Histopathological, immunohistochemical, behavioral, and biochemical examinations were performed to determine the acute and subacute toxicity of the cannabinoid. Three cannabinoid doses were administered for 2 days in the acute exposure groups and 14 days in the subacute exposure groups. Observations were made for 14 days and various changes such as mortality, injury, and illness were recorded daily. No mortality was determined. Serious pathological changes such as neurodegeneration, focal plague formation, vacuolation, edema, congestion, and fibrosis were observed in the cerebral cortex and hippocampus of the brain in a dose-dependent manner. Brain tissue caspase-3 activity showed that the cannabinoid triggered apoptosis in the rat brain. The detected cellular oxidative stress (higher lipid peroxidation and lower antioxidant enzyme activity) also supported neurotoxicity. Significant behavioral abnormalities were also observed in the acute groups, while no behavioral changes were detected in the subacute groups. This study showed for the first time that CUMYL-4CN-BINACA adversely affects the rat brain. It can be estimated that the abuse of the cannabinoid may harm human health in the same way.

Unveiling the Potential of Cannabinoids in Multiple Sclerosis and the Dawn of Nano-Cannabinoid Medicine

Multiple sclerosis is the predominant autoimmune disorder affecting the central nervous system in adolescents and adults. Specific treatments are categorized as disease-modifying, whereas others are symptomatic treatments to alleviate painful symptoms. Currently, no singular conventional therapy is universally effective for all patients across all stages of the illness. Nevertheless, cannabinoids exhibit significant promise in their capacity for neuroprotection, anti-inflammation, and immunosuppression. This review will examine the traditional treatment for multiple sclerosis, the increasing interest in using cannabis as a treatment method, its role in protecting the nervous system and regulating the immune system, commercially available therapeutic cannabinoids, and the emerging use of cannabis in nanomedicine. In conclusion, cannabinoids exhibit potential as a disease-modifying treatment rather than merely symptomatic relief. However, further research is necessary to unveil their role and establish the safety and advancements in nano-cannabinoid medicine, offering the potential for reduced toxicity and fewer adverse effects, thereby maximizing the benefits of cannabinoids.

Cerebrovascular Effects of Alcohol Combined with Tetrahydrocannabinol

Introduction: Alcohol (ethanol) and cannabis are among the most widely used recreational drugs in the world. With increased efforts toward legalization of cannabis, there is an alarming trend toward the concomitant (including simultaneous) use of cannabis products with alcohol for recreational purpose. While each drug possesses a distinct effect on cerebral circulation, the consequences of their simultaneous use on cerebral artery diameter have never been studied. Thus, we set to address the effect of simultaneous application of alcohol and (-)-trans-Δ-9-tetrahydrocannabinol (THC) on cerebral artery diameter. Materials and Methods: We used Sprague-Dawley rats because rat cerebral circulation closely mimics morphology, ultrastructure, and function of cerebral circulation of humans. We focused on the middle cerebral artery (MCA) because it supplies blood to the largest brain territory when compared to any other cerebral artery stemming from the circle of Willis. Experiments were performed on pressurized MCA ex vivo, and in cranial windows in vivo. Ethanol and THC were probed at physiologically relevant concentrations. Researchers were "blind" to experimental group identity during data analysis to avoid bias. Results: In males, ethanol mixed with THC resulted in greater constriction of ex vivo pressurized MCA when compared to the effects exerted by separate application of each drug. In females, THC, ethanol, or their mixture failed to elicit measurable effect. Vasoconstriction by ethanol/THC mixture was ablated by either endothelium removal or pharmacological block of calcium- and voltage-gated potassium channels of large conductance (BK type) and cannabinoid receptors. Block of prostaglandin production and of endothelin receptors also blunted constriction by ethanol/THC. In males, the in vivo constriction of MCA by ethanol/THC did not differ from ethanol alone. In females, the in vivo constriction of this artery by ethanol was significantly smaller than in males. However, artery constriction by ethanol/THC did not differ from the constriction in males. Conclusions: Our data point at the complex nature of the cerebrovascular effects elicited by simultaneous use of ethanol and THC. These effects include both local and systemic components.

Cannabis use disorder contributes to cognitive dysfunction in Veterans with traumatic brain injury

Background

While emerging evidence supports a link between traumatic brain injury (TBI) and progressive cognitive dysfunction in Veterans, there is insufficient information on the impact of cannabis use disorder (CUD) on long-term cognitive disorders. This study aimed to examine the incidences of cognitive disorders in Veterans with TBI and CUD and to evaluate their relationship.

Methods

This retrospective cohort study used the US Department of Veterans Affairs and Department of Defense administrative data from the Long-term Impact of Military-Relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium Phenotype study. Diagnoses suggesting cognitive disorders after a TBI index date were identified using inpatient and outpatient data from 2003 to 2022. We compared the differential cognitive disorders incidence in Veterans who had the following: (1) no CUD or TBI (control group), (2) CUD only, (3) TBI only, and (4) comorbid CUD+TBI. Kaplan-Meier analyses were used to estimate the overall cognitive disorders incidence in the above study groups. The crude and adjusted Cox proportional hazards models were used to estimate crude and adjusted hazard ratios (HRs) for cognitive disorders.

Results

A total of 1,560,556 Veterans [82.32% male, median (IQR) age at the time of TBI, 34.51 (11.29) years, and 61.35% white] were evaluated. The cognitive disorder incidence rates were estimated as 0.68 (95% CI, 0.62, 0.75) for CUD only and 1.03 (95% CI, 1.00, 1.06) for TBI only per 10,000 person-months of observations, with the highest estimated cognitive disorder incidence observed in participants with both TBI and CUD [1.83 (95% CI, 1.72, 1.95)]. Relative to the control group, the highest hazard of cognitive disorders was observed in Veterans with CUD+TBI [hazard ratio (HR), 3.26; 95% CI, 2.91, 3.65], followed by those with TBI only (2.32; 95 CI%, 2.13, 2.53) and with CUD (1.79; 95 CI%, 1.60, 2.00). Of note, in the CUD only subgroup, we also observed the highest risk of an early onset cognitive disorder other than Alzheimer's disease and Frontotemporal dementia.

Discussion

The results of this analysis suggest that individuals with comorbid TBI and CUD may be at increased risk for early onset cognitive disorders, including dementia.

Exploring the Antibacterial Potential of Semisynthetic Phytocannabinoid: Tetrahydrocannabidiol (THCBD) as a Potential Antibacterial Agent against Sensitive and Resistant Strains of Staphylococcus aureus

Antimicrobial resistance (AMR) is one of the most challenging problems and is responsible for millions of deaths every year. We therefore urgently require new chemical entities with novel mechanisms of action. Phytocannabinoids have been adequately reported for the antimicrobial effect but not seriously pursued because of either stringent regulatory issues or poor drug-like properties. In this regard, the current work demonstrated the antibacterial potential of tetrahydrocannabidiol (THCBD, 4), a semisynthetic phytocannabinoid, against Staphylococcus aureus, the second-most widespread bug recognized by the WHO. THCBD (4) was generated from cannabidiol and subjected to extensive antibacterial screening. In in vitro studies, THCBD (4) demonstrated a potent MIC of 0.25 μg/mL against Gram-positive bacteria, S. aureus ATCC-29213. It is interesting to note that THCBD (4) has demonstrated strong effectiveness against efflux pump-overexpressing (SA-1199B, SA-K2191, SA-K2192, and Mupr-1) and multidrug-resistant (MRSA-15187) S. aureus strains. THCBD (4) has also shown a good effect in kill kinetic assays against ATCC-29213 and MRSA-15187. In the checkerboard assay, THCBD (4) has shown additive/indifference effects with several well-known clinically used antibiotics, tetracycline, mupirocin, penicillin G, and ciprofloxacin. THCBD (4) also exhibited good permeability in the artificial skin model. Most importantly, THCBD (4) has significantly reduced CFU in mice's in vivo skin infection models and also demonstrated decent plasma exposure with 16-17% oral bioavailability. Acute dermal toxicity of THCBD (4) suggests no marked treatment-related impact on gross pathophysiology. This attractive in vitro and in vivo profile of plant-based compounds opens a new direction for new-generation antibiotics and warrants further detailed investigation.

Applications of Cannabinoids in Neuropathic Pain: An Updated Review

Neuropathic pain is experienced due to injury to the nerves, underlying disease conditions or toxicity induced by chemotherapeutics. Multiple factors can contribute to neuropathic pain such as central nervous system (CNS)-related autoimmune and metabolic disorders, nerve injury, multiple sclerosis and diabetes. Hence, development of pharmacological interventions to reduce the drawbacks of existing chemotherapeutics and counter neuropathic pain is an urgent unmet clinical need. Cannabinoid treatment has been reported to be beneficial for several disease conditions including neuropathic pain. Cannabinoids act by inhibiting the release of neurotransmitters from presynaptic nerve endings, modulating the excitation of postsynaptic neurons, activating descending inhibitory pain pathways, reducing neural inflammation and oxidative stress and also correcting autophagy defects. This review provides insights on the various preclinical and clinical therapeutic applications of cannabidiol (CBD), cannabigerol (CBG), and cannabinol (CBN) in various diseases and the ongoing clinical trials for the treatment of chronic and acute pain with cannabinoids. Pharmacological and genetic experimental strategies have well demonstrated the potential neuroprotective effects of cannabinoids and also elaborated their mechanism of action for the therapy of neuropathic pain.

Pharmacovigilance of unlicensed cannabidiol in European countries

Cannabidiol (CBD) is a multitarget agent possessing anti-inflammatory and antioxidant properties. Unlicensed CBD gained public favor for the care of general health and well-being as well as to get comfort from inflammatory complaints, pain, anxiety, mood, and sleep disorders. Safety profile of unlicensed CBD has been not sufficiently described. For this reason, suspected adverse reactions (SARs) to CBD unlicensed products were analyzed. Serious SARs to unlicensed CBD products in EudraVigilance, a system purchased by the European Medicines Agency, were analyzed for age, sex of the patient, adverse reactions, indication for use, and concomitant drugs. Serious SARs were 18.9% of all adverse events to unlicensed CBD; they were more frequent in men and adult people and, to a less extent, in children (3-11 years). About sex, in EudraVigilance serious Individual Cases Safety Reports of SARs to CBD in men are in the largest number (58.8%) with respect to women. Unlicensed CBD was used in the 38.8% of cases for treatment of epilepsy; more frequent adverse effects were: mental disorders, hepatic disorders, and aggravation of pre-existing epilepsy. Drugs or substances more frequently associated with SARs were the antiepileptics clobazam and valproic acid, followed by cannabis. Results suggest that precautions and appropriate surveillance of adverse effects should be taken when unlicensed CBD is used.

Interplay between the Glymphatic System and the Endocannabinoid System: Implications for Brain Health and Disease

The intricate mechanisms governing brain health and function have long been subjects of extensive investigation. Recent research has shed light on two pivotal systems, the glymphatic system and the endocannabinoid system, and their profound role within the central nervous system. The glymphatic system is a recently discovered waste clearance system within the brain that facilitates the efficient removal of toxic waste products and metabolites from the central nervous system. It relies on the unique properties of the brain's extracellular space and is primarily driven by cerebrospinal fluid and glial cells. Conversely, the endocannabinoid system, a multifaceted signaling network, is intricately involved in diverse physiological processes and has been associated with modulating synaptic plasticity, nociception, affective states, appetite regulation, and immune responses. This scientific review delves into the intricate interconnections between these two systems, exploring their combined influence on brain health and disease. By elucidating the synergistic effects of glymphatic function and endocannabinoid signaling, this review aims to deepen our understanding of their implications for neurological disorders, immune responses, and cognitive well-being.

Endocannabinoid and psychological responses to acute resistance exercise in trained and untrained adults

INTRODUCTION

This study examined the effects of acute resistance exercise on circulating endocannabinoid (eCB) and mood responses in trained and untrained healthy adults.

METHODS

Thirty-two healthy adults (22.1 ± 2.9 years) were recruited from trained (reporting resistance exercise at least twice per week for ≥ previous three months) and untrained (performing no resistance exercise for ≥ previous three months) groups. Participants (13 male, 19 female) completed three sets of resistance exercise (16 repetitions at 50% 1-repetition max, 12 repetitions at 70% 1-repetition max, 8 repetitions at 80% 1-repetition max). Resistance machines targeted the legs, chest, back, and abdominal muscles. Mood states, affect, and circulating eCB concentrations were evaluated before and after resistance exercise.

RESULTS

There were significant decreases in AEA, PEA, and OEA levels following acute resistance exercise (p <0.05; ds = -0.39, -0.48, -0.65, respectively), with no significant group differences or group by time interactions. 2-AG did not change significantly. Positive affect increased significantly following resistance exercise (p = 0.009), while negative affect decreased (p <0.001). Depressive symptoms, anger, confusion, and total mood disturbance decreased significantly (p <0.05), while vigor increased significantly following resistance exercise (p = 0.005). There were no significant group differences or group by time interactions for any psychological outcomes.

CONCLUSION

These results indicate that acute resistance exercise may reduce eCB and related lipid concentrations, which is opposite to the increase in lipids typically observed with acute aerobic exercise. Furthermore, psychological improvements occur after resistance exercise regardless of decreases in eCBs, supporting the notion that psychological changes with exercise likely occur through a wide variety of biological and environmental mechanisms.

Therapeutic considerations of bioactive compounds in Alzheimer's disease and Parkinson's disease: Dissecting the molecular pathways

Leading neurodegenerative diseases Alzheimer's disease (AD) and Parkinson's disease (PD) are characterized by the impairment of memory and motor functions, respectively. Despite several breakthroughs, there exists a lack of disease-modifying treatment strategies for these diseases, as the available drugs provide symptomatic relief and bring along side effects. Bioactive compounds are reported to bear neuroprotective properties with minimal toxicity, however, a detailed elucidation of their modes of neuroprotection is lacking. The review elucidates the neuroprotective mechanism(s) of some of the major phyto-compounds in pre-clinical and clinical studies of AD and PD to understand their potential in combating these diseases. Curcumin, eugenol, resveratrol, baicalein, sesamol and so on have proved efficient in countering the pathological hallmarks of AD and PD. Curcumin, resveratrol, caffeine and so on have reached the clinical phases of these diseases, while aromadendrin, delphinidin, cyanidin and xanthohumol are yet to be extensively explored in pre-clinical phases. The review highlights the need for extensive investigation of these compounds in the clinical stages of these diseases so as to utilize their disease-modifying abilities in the real field of treatment. Moreover, poor pharmacokinetic properties of natural compounds are constraints to their therapeutic yields and this review suggests a plausible contribution of nanotechnology in overcoming these limitations.

Pharmacological Evaluation of Signals of Disproportionality Reporting Related to Adverse Reactions to Antiepileptic Cannabidiol in VigiBase

Cannabidiol is the first cannabis-derived drug approved for the treatment of Lennox-Gastaut syndrome, Dravet syndrome, and Tuberous Sclerosis Complex. In the current study, we performed a descriptive analysis followed by a disproportionality analysis of potential adverse events caused by CBD extracted from the VigiBase® database. Furthermore, the biological plausibility of the association between CBD and the serotonin 5-HT1A receptor as a possible cause of adverse events was analyzed and discussed. Data were extracted from the VigiBase® database using the VigiLyze® signal detection and signal management tool. Adverse events in VigiBase® reports were coded using MedDRA, version 19 of Preferred Terms (PTs). Data were uploaded into SPSS software and analyzed via a disproportionality analysis. Statistically significant disproportionality signals for CBD were found for "weight decreased" (5.19 (95% CI: 4.54-5.70)), "hypophagia" (3.68 (95% CI: 3.22-5.27)), and "insomnia" (1.6 (95% CI: 1.40-1.83)). Positive IC025 values were found for "weight decreased" (2.2), "hypophagia" (1.3), and "insomnia" (0.5), indicating a surplus of reported cases. CBD's interactions with 5-HT1A serotonin receptors may offer a potential biological explanation for the occurrence of insomnia in patients. It is noteworthy that the risk profiles mentioned in the information for prescribing CBD as an antiepileptic agent by regulatory agencies showed disparities specifically related to the adverse event "insomnia".

FABP5 is important for cognitive function and is an important regulator of the physiological effects and pharmacokinetics of acute Δ9 tetrahydrocannabinol inhalation in mice

Fatty acid binding protein 5 (FABP5) interacts with the endocannabinoid system in the brain via intracellular transport of anandamide, as well as Δ9-tetrahydrocannabinol (THC), the main psychoactive component of cannabis. Previous work has established the behavioral effects of genetic deletion of FABP5, but not in the presence of THC. The present study sought to further elucidate the role of FABP5 on the pharmacokinetic and behavioral response to THC through global deletion. Adult FABP5+/+ and FABP5-/- mice were tested for behavioral response to THC using Open Field (OF), Novel Object Recognition (NOR), T-Maze, Morris Water Maze (MWM), and Elevated Plus Maze (EPM). An additional cohort of mice was used to harvest blood, brains, and liver samples to measure THC and metabolites after acute administration of THC. Behavioral tests showed that some cognitive deficits from FABP5 deletion, particularly in MWM, were blocked by THC administration, while this was not observed in other measures of memory and anxiety (such as T-Maze and EPM). Measurement of THC and metabolites in blood serum and brain tissue through UPLC-MS/MS analysis showed that the pharmacokinetics of THC was altered by FABP5. The present study shows further evidence of the importance of FABP5 in cognitive function. Additionally, results showed that FABP5 is an important regulator of the physiological effects and pharmacokinetics of THC.

Real-World Evidence of Factors Affecting Cannabidiol Exposure in Children with Drug-Resistant Developmental and Epileptic Encephalopathies

The identification of factors that affect cannabidiol (CBD) systemic exposure may aid in optimizing treatment efficacy and safety in clinical practice. In this study, we aimed to correlate CBD plasma concentrations at a steady state to demographic, clinical, and pharmacological characteristics as well as seizure frequency after the administration of a purified CBD oil solution in a real-world setting of children with drug-resistant developmental and epileptic encephalopathies (DEEs). Patients receiving oral CBD pharmaceutical products at maintenance were enrolled. Venous blood samples were drawn before the CBD morning dose, 12 h apart from the last evening dose (C0 or CBD trough concentration). A linear mixed-effect analysis was implemented to assess the correlation between C0 and clinical, laboratory, pharmacological, and lifestyle factors. Fifteen females and seven males with a median age of 12.8 years (ranging between 4.7 and 17.2) were included. The median CBD dose was 8.8 mg/kg/day (ranging between 2.6 and 22.5), and the CBD C0 median (range) was 48.2 ng/mL (3.5-366.3). The multivariate model showed a 109.6% increase in CBD C0 in patients with concomitant levothyroxine (β = 0.74 ± 0.1649, p < 0.001), 56.8% with food (β = 0.45 ± 0.1550, p < 0.01), and 116.0% after intake of a ketogenic diet (β = 0.77 ± 0.3141, p < 0.05). All patients included were responders without evidence of an association between C0 and response status. In children with DEEs, systemic concentrations of CBD may be significantly increased when co-administered with levothyroxine, food, or a ketogenic diet.

Cannabidiol alleviates neuroinflammation and attenuates neuropathic pain via targeting FKBP5

Microglia is a heterogeneous population that mediates neuroinflammation in the central nervous system (CNS) and plays a crucial role in developing neuropathic pain. FKBP5 facilitates the assembly of the IκB kinase (IKK) complex for the activation of NF-κB, which arises as a novel target for treating neuropathic pain. In this study, cannabidiol (CBD), a main active component of Cannabis, was identified as an antagonist of FKBP5. In vitro protein intrinsic fluorescence titration showed that CBD directly bound to FKBP5. Cellular thermal shift assay (CETSA) indicated that CBD binding increased the FKBP5 stability, which implies that FKBP5 is the endogenous target of CBD. CBD was found to inhibit the assembly of the IKK complex and the activation of NF-κB, therefore blocking LPS-induced NF-κB downstream pro-inflammatory factors NO, IL-1β, IL-6 and TNF-α. Stern-Volmer analysis and protein thermal shift assay revealed that tyrosine 113 (Y113) of FKBP5 was critical for FKBP5 interacting with CBD, which is consistent with in silico molecular docking simulation. FKBP5 Y113 mutation (Y113A) alleviated the effect of CBD inhibiting LPS-induced pro-inflammatory factors overproduction. Furthermore, systemic administration of CBD inhibited chronic constriction injury (CCI)-induced microglia activation and FKBP5 overexpression in lumbar spinal cord dorsal horn. These data imply that FKBP5 is an endogenous target of CBD.

Microglia NLRP3 Inflammasome and Neuroimmune Signaling in Substance Use Disorders

During the last decade, substance use disorders (SUDs) have been increasingly recognized as neuroinflammation-related brain diseases. Various types of abused drugs (cocaine, methamphetamine, alcohol, opiate-like drugs, marijuana, etc.) can modulate the activation status of microglia and neuroinflammation levels which are involved in the pathogenesis of SUDs. Several neuroimmune signaling pathways, including TLR/NF-кB, reactive oxygen species, mitochondria dysfunction, as well as autophagy defection, etc., have been implicated in promoting SUDs. Recently, inflammasome-mediated signaling has been identified as playing critical roles in the microglia activation induced by abused drugs. Among the family of inflammasomes, NOD-, LRR-, and pyrin-domain-containing protein 3 (NLRP3) serves the primary research target due to its abundant expression in microglia. NLRP3 has the capability of integrating multiple external and internal inputs and coordinately determining the intensity of microglia activation under various pathological conditions. Here, we summarize the effects of abused drugs on NLRP3 inflammasomes, as well as others, if any. The research on this topic is still at an infant stage; however, the readily available findings suggest that NLRP3 inflammasome could be a common downstream effector stimulated by various types of abused drugs and play critical roles in determining abused-drug-mediated biological effects through enhancing glia-neuron communications. NLRP3 inflammasome might serve as a novel target for ameliorating the development of SUDs.

Women are Taking the Hit: Examining the Unique Consequences of Cannabis Use Across the Female Lifespan

Cannabis use has risen dramatically in recent years due to global decriminalization and a resurgence in the interest of potential therapeutic benefits. While emerging research is shaping our understanding of the benefits and harms of cannabis, there remains a paucity of data specifically focused on how cannabis affects the female population. The female experience of cannabis use is unique, both in the societal context and because of the biological ramifications. This is increasingly important given the rise in cannabis potency, as well as the implications this has for the prevalence of Cannabis Use Disorder (CUD). Therefore, this scoping review aims to discuss the prevalence of cannabis use and CUD in women throughout their lifespan and provide a balanced prospective on the positive and negative consequences of cannabis use. In doing so, this review will highlight the necessity for continued research that goes beyond sex differences.

Cannabidiol for the Treatment of Brain Disorders: Therapeutic Potential and Routes of Administration

The use of cannabidiol (CBD) for treating brain disorders has gained increasing interest. While the mechanism of action of CBD in these conditions is still under investigation, CBD has been shown to affect numerous different drug targets in the brain that are involved in brain disorders. Here we review the preclinical and clinical evidence on the potential therapeutic use of CBD in treating various brain disorders. Moreover, we also examine various drug delivery approaches that have been applied to CBD. Due to the slow absorption and low bioavailability with the current oral CBD therapy, more efficient routes of administration to bypass hepatic metabolism, particularly pulmonary delivery, should be considered. Comparison of pharmacokinetic studies of different delivery routes highlight the advantages of intranasal and inhalation drug delivery over other routes of administration (oral, injection, sublingual, buccal, and transdermal) for treating brain disorders. These two routes of delivery, being non-invasive and able to achieve fast absorption and increase bioavailability, are attracting increasing interest for CBD applications, with more research and development expected in the near future.

Temozolomide Resistance in Glioblastoma by NRF2: Protecting the Evil

The transcription factor NRF2 is constitutively active in glioblastoma, a highly aggressive brain tumor subtype with poor prognosis. Temozolomide (TMZ) is the primary chemotherapeutic agent for this type of tumor treatment, but resistance to this drug is often observed. This review highlights the research that is demonstrating how NRF2 hyperactivation creates an environment that favors the survival of malignant cells and protects against oxidative stress and TMZ. Mechanistically, NRF2 increases drug detoxification, autophagy, DNA repair, and decreases drug accumulation and apoptotic signaling. Our review also presents potential strategies for targeting NRF2 as an adjuvant therapy to overcome TMZ chemoresistance in glioblastoma. Specific molecular pathways, including MAPKs, GSK3β, βTRCP, PI3K, AKT, and GBP, that modulate NRF2 expression leading to TMZ resistance are discussed, along with the importance of identifying NRF2 modulators to reverse TMZ resistance and develop new therapeutic targets. Despite the significant progress in understanding the role of NRF2 in GBM, there are still unanswered questions regarding its regulation and downstream effects. Future research should focus on elucidating the precise mechanisms by which NRF2 mediates resistance to TMZ, and identifying potential novel targets for therapeutic intervention.

Resident Astrocytes can Limit Injury to Developing Hippocampal Neurons upon THC Exposure

Cannabis legalization prompted the dilemma if plant-derived recreational drugs can have therapeutic potential and, consequently, how to address their regulation and safe distribution. In parallel, the steady worldwide decriminalization of cannabis and the enhanced content of its main psychoactive compound Δ⁹-tetrahydrocannabinol (THC), exposes populations to increasing amounts of cannabis and THC across all ages. While adverse effects of cannabis during critical stages of fetal neurodevelopment are investigated, these studies center on neurons alone. Thus, a gap of knowledge exists on how intercellular interactions between neighboring cell types, particularly astrocytes and neurons, could modify THC action. Here, we combine transcriptome analysis, transgenic models, high resolution microscopy and live cell imaging to demonstrate that hippocampal astrocytes accumulate in the strata radiatum and lacunosum moleculare of the CA1 subfield, containing particularly sensitive neurons to stressors, upon long term postnatal THC exposure in vivo. As this altered distribution is not dependent on cell proliferation, we propose that resident astrocytes accumulate in select areas to protect pyramidal neurons and their neurite extensions from pathological damage. Indeed, we could recapitulate the neuroprotective effect of astrocytes in vitro, as their physical presence significantly reduced the death of primary hippocampal neurons upon THC exposure (> 5 µM). Even so, astrocytes are also affected by a reduced metabolic readiness to stressors, as reflected by a downregulation of mitochondrial proteins. Thus, we find that astrocytes exert protective functions on local neurons during THC exposure, even though their mitochondrial electron transport chain is disrupted.

Novel Cannabinoid Receptor 2 (CB2) Low Lipophilicity Agonists Produce Distinct cAMP and Arrestin Signalling Kinetics without Bias

Cannabinoid Receptor 2 (CB2) is a promising target for treating inflammatory diseases. We designed derivatives of 3-carbamoyl-2-pyridone and 1,8-naphthyridin-2(1H)-one-3-carboxamide CB2-selective agonists with reduced lipophilicity. The new compounds were measured for their affinity (radioligand binding) and ability to elicit cyclic adenosine monophosphate (cAMP) signalling and β-arrestin-2 translocation with temporal resolution (BRET-based biosensors). For the 3-carbamoyl-2-pyridone derivatives, we found that modifying the previously reported compound UOSS77 (also known as S-777469) by appending a PEG2-alcohol via a 3-carbomylcyclohexyl carboxamide (UOSS75) lowered lipophilicity, and preserved binding affinity and signalling profile. The 1,8-naphthyridin-2(1H)-one-3-carboxamide UOMM18, containing a cis configuration at the 3-carboxamide cyclohexyl and with an alcohol on the 4-position of the cyclohexyl, had lower lipophilicity but similar CB2 affinity and biological activity to previously reported compounds of this class. Relative to CP55,940, the new compounds acted as partial agonists and did not exhibit signalling bias. Interestingly, while all compounds shared similar temporal trajectories for maximal efficacy, differing temporal trajectories for potency were observed. Consequently, when applied at sub-maximal concentrations, CP55,940 tended to elicit sustained (cAMP) or increasing (arrestin) responses, whereas responses to the new compounds tended to be transient (cAMP) or sustained (arrestin). In future studies, the compounds characterised here may be useful in elucidating the consequences of differential temporal signalling profiles on CB2-mediated physiological responses.

Cannabinoids modulate the microbiota-gut-brain axis in HIV/SIV infection by reducing neuroinflammation and dysbiosis while concurrently elevating endocannabinoid and indole-3-propionate levels

BACKGROUND

Although the advent of combination anti-retroviral therapy (cART) has transformed HIV into a manageable chronic disease, an estimated 30-50% of people living with HIV (PLWH) exhibit cognitive and motor deficits collectively known as HIV-associated neurocognitive disorders (HAND). A key driver of HAND neuropathology is chronic neuroinflammation, where proinflammatory mediators produced by activated microglia and macrophages are thought to inflict neuronal injury and loss. Moreover, the dysregulation of the microbiota-gut-brain axis (MGBA) in PLWH, consequent to gastrointestinal dysfunction and dysbiosis, can lead to neuroinflammation and persistent cognitive impairment, which underscores the need for new interventions.

METHODS

We performed RNA-seq and microRNA profiling in basal ganglia (BG), metabolomics (plasma) and shotgun metagenomic sequencing (colon contents) in uninfected and SIV-infected rhesus macaques (RMs) administered vehicle (VEH/SIV) or delta-9-tetrahydrocannabinol (THC) (THC/SIV).

RESULTS

Long-term, low-dose THC reduced neuroinflammation and dysbiosis and significantly increased plasma endocannabinoid, endocannabinoid-like, glycerophospholipid and indole-3-propionate levels in chronically SIV-infected RMs. Chronic THC potently blocked the upregulation of genes associated with type-I interferon responses (NLRC5, CCL2, CXCL10, IRF1, IRF7, STAT2, BST2), excitotoxicity (SLC7A11), and enhanced protein expression of WFS1 (endoplasmic reticulum stress) and CRYM (oxidative stress) in BG. Additionally, THC successfully countered miR-142-3p-mediated suppression of WFS1 protein expression via a cannabinoid receptor-1-mediated mechanism in HCN2 neuronal cells. Most importantly, THC significantly increased the relative abundance of Firmicutes and Clostridia including indole-3-propionate (C. botulinum, C. paraputrificum, and C. cadaveris) and butyrate (C. butyricum, Faecalibacterium prausnitzii and Butyricicoccus pullicaecorum) producers in colonic contents.

CONCLUSION

This study demonstrates the potential of long-term, low-dose THC to positively modulate the MGBA by reducing neuroinflammation, enhancing endocannabinoid levels and promoting the growth of gut bacterial species that produce neuroprotective metabolites, like indole-3-propionate. The findings from this study may benefit not only PLWH on cART, but also those with no access to cART and more importantly, those who fail to suppress the virus under cART.

Regio- and stereoselective synthesis of functionalized tetrahydro-benzochromenes and hexahydrochromenochromenones via [4 + 2] annulation of curcumins with nitrochromenes

A base-mediated regio- and stereoselective synthesis of functionalized tetrahydro-6H-benzo[c]chromenes and hexahydro-1H,6H-chromeno[6,5-c]chromenone is disclosed here. It involves a [4 + 2] annulation via cascade double and triple Michael reactions between curcumins and nitrochromenes in the presence of Cs₂CO₃ and DBU, respectively, at room temperature, and it offers a diverse array of products as single regio- and diastereomers in excellent yields under mild conditions. Preliminary studies towards developing an enantioselective version under organocatalytic conditions met with only limited success but revealed a potentially interesting kinetic resolution pathway.

ASRA Pain Medicine consensus guidelines on the management of the perioperative patient on cannabis and cannabinoids

BACKGROUND

The past two decades have seen an increase in cannabis use due to both regulatory changes and an interest in potential therapeutic effects of the substance, yet many aspects of the substance and their health implications remain controversial or unclear.

METHODS

In November 2020, the American Society of Regional Anesthesia and Pain Medicine charged the Cannabis Working Group to develop guidelines for the perioperative use of cannabis. The Perioperative Use of Cannabis and Cannabinoids Guidelines Committee was charged with drafting responses to the nine key questions using a modified Delphi method with the overall goal of producing a document focused on the safe management of surgical patients using cannabinoids. A consensus recommendation required ≥75% agreement.

RESULTS

Nine questions were selected, with 100% consensus achieved on third-round voting. Topics addressed included perioperative screening, postponement of elective surgery, concomitant use of opioid and cannabis perioperatively, implications for parturients, adjustment in anesthetic and analgesics intraoperatively, postoperative monitoring, cannabis use disorder, and postoperative concerns. Surgical patients using cannabinoids are at potential increased risk for negative perioperative outcomes.

CONCLUSIONS

Specific clinical recommendations for perioperative management of cannabis and cannabinoids were successfully created.

Pharmacovigilance on cannabidiol as an antiepileptic agent

Introduction: Cannabidiol (CBD) is an active chemical contained in the plant Cannabis sativa. It is a resorcinol-based compound that crosses the blood-brain barrier without causing euphoric effects. CBD has a plethora of pharmacological effects of therapeutic interest. CBD has been authorized in the European Union as an anticonvulsant against serious infantile epileptic syndromes, but its safety profile is still not sufficiently described. Methods: With the goal of expanding information on the safety of CBD use as an antiepileptic agent beyond the most common side effects known through clinical studies, an analysis of serious case reports on suspected adverse reactions (SARs) to CBD licensed as an anti-epileptic drug found in the EudraVigilance database is reported in this article. EudraVigilance is a system purchased by the European Medicines Agency (EMA) for monitoring the safety of medicinal products marketed in Europe. Results: The most frequent serious SARs to CBD in EudraVigilance were epilepsy aggravation, hepatic disorders, lack of efficacy, and somnolence. Discussion: Based on our analysis, the following precautions should be adopted for appropriate monitoring of potential adverse effects, more attention towards possible CBD medical use as an antiepileptic: awareness of interactions with other drugs, epilepsy aggravation, and drug effectiveness.

Measurement of Δ9THC and metabolites in the brain and peripheral tissues after intranasal instillation of a nanoformulation

BACKGROUND

Comparative bioavailability of cannabinoids following their administration by dosing routes has been studied previously, but there are no quantitative reports of distribution of Δ⁹THC, nor its metabolites, across various brain regions following intranasal (i.n.) administration. The aim of the present study was to determine the time course of Δ⁹THC transport from nose to brain and to quantify the distribution of Δ⁹THC and its metabolites in four brain regions.

METHODS

Δ⁹THC was formulated as a lipophilic nano-emulsion and instilled i.n. to three groups of adult mice and euthanized after 2, 4, and 8 h. Brains were dissected into 4 regions. Sensitive analytical methods (HPLC-MS) were utilized to quantify levels of Δ⁹THC and metabolites in brain regions and peripheral tissues. Data was expressed as mean concentrations (± SEM) of Δ⁹THC and metabolites in brain regions, blood, plasma, urine, and liver. Two-way analysis of variance was performed followed by post hoc multiple comparisons.

RESULTS

Peak concentrations of Δ⁹THC were reached at 2 h in the brain (15.9 ng/mg), blood (4.54 μg/mL), and plasma (4.56 μg /mL). The percentage of administered dose of Δ⁹THC transported to the brain (5.9%) was greater than in blood (1.7%), plasma (1.6%), urine (0.4%), and liver (0.1%). Concentrations of Δ⁹THC and its THC-COOH metabolite in the liver reached their highest levels at 8 h.

DISCUSSION

The present study is the first to report the uptake and distribution across brain regions of Δ⁹THC and its principal metabolites following i.n. administration. The systemic bioavailability (absorption into the blood) of intranasal Δ⁹THC was 1.7% of the administered dose, much lower than that reported by others after oral ingestion (7-10%) and inhalation (20-35%), but those prior studies did not measure the transport of Δ⁹THC into brain regions. Others have reported Δ⁹THC in the whole brain following i.n. instillation in a different species (rats) to be twice (5.9%) that following i.p. injections, while metabolites of Δ⁹THC in rat brain were lower after i.n. administration.

CONCLUSIONS

The intranasal route of a Δ⁹THC nanoformulation is an effective way to deliver cannabinoids to the brain, especially in those who cannot take the medication orally. Going forward, a metered dosing nasal spray will provide accurate and consistent doses.

Exploring the Potential of Cannabinoid Nanodelivery Systems for CNS Disorders

Cannabinoids have a major therapeutic value in a variety of disorders. The concepts of cannabinoids are difficult to develop, but they can be used and are advantageous for a number of diseases that are not sufficiently managed by existing treatments. Nanoconjugation and encapsulation techniques have been shown to be effective in improving the delivery and the therapeutic effectiveness of drugs that are poorly soluble in water. Because the bioavailability of cannabinoids is low, the challenge is to explore different administration methods to improve their effectiveness. Because cannabinoids cross the blood-brain-barrier (BBB), they modify the negative effects of inflammatory processes on the BBB and may be a key factor in the improvement of BBB function after ischemic disease or other conditions. This review discusses various types of cannabinoid administration, as well as nanotechnologies used to improve the bioavailability of these compounds in CNS diseases.

Single cannabidiol administration affects anxiety-, obsessive compulsive-, object memory-, and attention-like behaviors in mice in a sex and concentration dependent manner

RATIONALE

The behavioral effects of cannabidiol (CBD) are understudied, but are important, given its therapeutic potential and widespread use as a natural supplement.

OBJECTIVE

The objective of this study was to test whether a single injection of CBD affected anxiety-like or attention-like behavior, or memory in wildtype mice or mice with reported trait anxiety due to a targeted gene-deletion in a voltage-dependent potassium channel, Kv1.3.

METHODS

Wildtype C57BL/6 J and Kv1.3-/- mice of both sexes were reared to adulthood and then administered an intraperitoneal injection of 10 or 20 mg/kg CBD. Mice were behaviorally-phenotyped using the marble-burying test, the light-dark box (LDB), short (1 h) and long-term (24 h) object memory test, the elevated-plus maze (EPM), and the object-based attention task in order to assess obsessive compulsive-, anxiety-, and attention-like behaviors, and memory.

RESULTS

We discovered that acute CBD treatment reduced marble burying in male, but not female mice. CBD was effective in lessening anxiety-like behaviors determined by the LDB test in both male and female wildtype mice, whereby the effective dose required to observe the effect in females was less. In Kv1.3-/- mice, CBD increased anxiety-like behaviors in the LDB in both sexes at the higher concentration of CBD and it similarly increased anxiety-like behavior in females in the EPM at the lower concentration of CBD. Long-term object memory was reduced in male wildtype mice at the lower concentration of CBD. Finally, ADHD- or attention-like behaviors were not altered by CBD in wildtype mice, but in Kv1.3-/- mice, females were observed to have a loss in attention while males demonstrated improved attention.

CONCLUSIONS

We conclude that administration of a single dose of CBD has immediate effects on mouse behavior that is dose, sex, and anxiety-state dependent - and that these behavioral outcomes are important to examine in parallel human trials.

Approaches for the discovery of drugs that target K Na 1.1 channels in KCNT1-associated epilepsy

INTRODUCTION

There are approximately 70 million people with epilepsy and about 30% of patients are not satisfactorily treated. A link between gene mutations and epilepsy is well documented. A number of pathological variants of KCNT1 gene (encoding the weakly voltage-dependent sodium-activated potassium channel - KNa 1.1) mutations has been found. For instance, epilepsy of infancy with migrating focal seizures, autosomal sleep-related hypermotor epilepsy or Ohtahara syndrome have been associated with KCNT1 gene mutations.

AREAS COVERED

Several methods for studies on KNa 1.1 channels have been reviewed - patch clamp analysis, Förster resonance energy transfer spectroscopy and whole-exome sequencing. The authors also review available drugs for the management of KCNT1 epilepsies.

EXPERT OPINION

The current methods enable deeper insights into electrophysiology of KNa 1.1 channels or its functioning in different activation states. It is also possible to identify a given KCNT1 mutation. Quinidine and cannabidiol show variable efficacy as add-on to baseline antiepileptic drugs so more effective treatments are required. A combined approach with the methods shown above, in silico methods and the animal model of KCNT1 epilepsies seems likely to create personalized treatment of patients with KCNT1 gene mutations.

Thermal decarboxylation of acidic cannabinoids in Cannabis species: identification of transformed cannabinoids by UHPLC-Q/TOF–MS

Decarboxylation of cannabidiolic acid (CBDA) is an important step for efficient production of the active pharmaceutical component cannabidiol (CBD) in Cannabis species. Acidic cannabinoids (ACBs) can be easily transformed into neutral cannabinoids via loss of carbon dioxide when exposed to heat. During the thermal process, several transformed products including psychotropic △9-tetrahydrocannabinol (△9-THC) and its isomers were produced through decarboxylation, hydration, isomerization, and oxidation, as identified by ultra-high-performance liquid chromatography quadrupole/time-of-flight mass spectrometry (UHPLC-Q/TOF MS). Their identification was carried out using authenticated standards and interpreting the MS/MS fragmentations. To investigate thermal decarboxylation, CBDA was extracted and isolated from inflorescence of Cannabis by ultrasonication extraction and two-step column chromatography. To investigate the decarboxylation yield of isolated CBDA and ACBs in Cannabis extract, samples were examined over a range of reaction temperatures (110–130 °C) and times (5–60 min). Time profiles of CBDA degradation and CBD formation were obtained as functions of the reaction temperature. In particular, most of the CBDA was converted into CBD at 130 °C for 20 min; this CBD was partially transformed to psychotropic THC isomers via cyclization. In addition to THC isomers, cannabielsoin acid (CBEA) and cannabielsoin (CBE) were also observed as minor oxidative transformed products. Based on structural identification and profiling data, thermal transformation pathways of CBDA are plausibly suggested. The results of decarboxylation of ACBs will provide important information on production of neutral cannabinoids, especially CBD, in Cannabis plants and quality control of Cannabis-based products in pharmaceutical and cosmetic industries.

Pharmacokinetics of Cannabidiol in Sprague-Dawley Rats After Oral and Pulmonary Administration

Introduction: Cannabidiol (CBD) is primarily consumed through ingestion and inhalation. Little is known about how CBD pharmacokinetics differ between routes of administration, and duration of pulmonary exposure. Methods: Pharmacokinetics, brain distribution, and urinary elimination of CBD and its major metabolites (6-hydroxy-cannabidiol [6-OH-CBD], 7-hydroxy-cannabidiol [7-OH-CBD], 7-carboxy-cannabidiol [7-COOH-CBD], and CBD-glucuronide) were evaluated in adult Sprague-Dawley rats following a single oral CBD ingestion (10 mg/kg in medium chain triglyceride oil; 24 male animals), and 1 or 14 days of repeated inhalation (0.9-13.9 mg/kg in propylene glycol [41%/59% by weight]; 5 male and 5 female animals per dose). Blood and brain tissue were collected at a single time point from each animal. Collection times were staggered from 5 min to 24 h postoral gavage or first (blood only) and final inhalation. Urine was collected 24 h postoral gavage or final inhalation. Samples were analyzed through liquid chromatography-mass spectrometry (LC-MS/MS). Results: CBD was more rapidly absorbed following inhalation than ingestion (T_max=5 min and 2 h, respectively). Inhalation resulted in a dose-responsive increase in CBD C_max and AUC_last. CBD C_max was 24-fold higher following the highest pulmonary dose (13.9 mg/kg) versus an oral dose of comparable concentration (10 mg/kg). C_max and AUC_last (0-16 h) trended higher following repeated exposure. Elimination was notably faster with repeated CBD inhalation (t_1/2=5.3 and 2.4 h on days 1 and 14, respectively). While metabolites were detectable in plasma, AUC_last (0-2 h) was at least 10- (7-OH-CBD, 7-COOH-CBD) to 100- (6-OH-CBD) fold lower than the parent compound. Metabolite concentration trended higher following repeated inhalation (6.7 mg/kg CBD); AUC_last (0-16 h) was ∼1.8-, ∼1.4-, and ∼2.4-fold higher following 14 days of exposure for 6-OH-CBD, 7-OH-CBD, and 7-COOH-CBD, respectively. CBD was detectable in brain homogenate tissue 24-h after 14-day inhalation (>3.5 mg/kg deposited dose) or a single oral administration. CBD metabolites were only measurable in brain tissue following the highest inhaled dose (13.9 mg/kg CBD). CBD, but not metabolites, was detectable in urine for all dose groups following 2 weeks of CBD inhalation. Neither CBD nor metabolites were present in urine after oral administration. Conclusion: CBD pharmacokinetics differ across oral and pulmonary routes of administration and acute or repeated dosing.

Combined alcohol and cannabinoid exposure leads to synergistic toxicity by affecting cerebellar Purkinje cells

Combined use of cannabis and alcohol results in greater psychoactive toxicity than either substance alone, but the underlying central mechanisms behind this worsened outcome remain unclear. Here we show that the synergistic effect of Δ⁹-tetrahydrocannabinol (THC) and ethanol on motor incoordination in mice is achieved by activating presynaptic type 1 cannabinoid receptors (CB₁R) and potentiating extrasynaptic glycine receptors (GlyR) within cerebellar Purkinje cells (PCs). The combination of ethanol and THC significantly reduces miniature excitatory postsynaptic current frequency in a CB₁R-dependent manner, while increasing the extrasynaptic GlyR-mediated chronic chloride current, both leading to decreased PC activity. Ethanol enhances THC actions by boosting the blood-brain-barrier permeability of THC and enriching THC in the cell membrane. Di-desoxy-THC, a designed compound that specifically disrupts THC-GlyR interaction without affecting the basic functions of CB₁R and GlyR, is able to restore PC function and motor coordination in mice. Our findings provide potential therapeutic strategies for overcoming the synergistic toxicity caused by combining cannabis and alcohol use.

The Use of Cannabis and Its Effects on Postpartum Depression

Cannabis use and depression management have been studied, with a preponderance of exacerbating effects, but there are few studies on postpartum depression (PPD). Depression affects a significant number of women, with a portion of it manifesting as PPD in childbearing women in the United States each year. The pharmacologic management approaches have disadvantages such as side effects, cost-benefit ratio, contraindications, use reluctance, medication adherence, and stigmatization in patients. Anecdotal claims of medical cannabis' therapeutic benefits have led to widespread legalization in several regions, making cannabis and its extracts a possible alternative. Cannabis is widely used during pregnancy and in general. Even though substance use disorders exacerbating depression symptoms have been reported, there are increasing reports and evidence about the therapeutic benefit of dose-dependent cannabis or its extracts in some depression symptoms, such as acute psychosocial stress relief, its purported anxiolytic effect, appetite, and sleep quality, thus stimulating more interest that may be inferred to depression. PPD marijuana use is unclear. This paper reviewed works of literature that claimed cannabis' therapeutic benefit in treating depression and, by extension, PPD. Our findings show the link between cannabis and PPD has not been fully explored. Self-reported studies link marijuana uses to positive mood, anxiety relief, sleep regulation, nausea and vomiting reduction, and appetite stimulation-all PPD symptoms. Others opposed postpartum marijuana use.

Cannabidivarin alleviates neuroinflammation by targeting TLR4 co-receptor MD2 and improves morphine-mediated analgesia

Toll-like receptor 4 (TLR4) is a pattern-recognition receptor (PRR) that regulates the activation of immune cells, which is a target for treating inflammation. In this study, Cannabidivarin (CBDV), an active component of Cannabis, was identified as an antagonist of TLR4. In vitro, intrinsic protein fluorescence titrations revealed that CBDV directly bound to TLR4 co-receptor myeloid differentiation protein 2 (MD2). Cellular thermal shift assay (CETSA) showed that CBDV binding decreased MD2 stability, which is consistent with in silico simulations that CBDV binding increased the flexibility of the internal loop of MD2. Moreover, CBDV was found to restrain LPS-induced activation of TLR4 signaling axes of NF-κB and MAPKs, therefore blocking LPS-induced pro-inflammatory factors NO, IL-1β, IL-6 and TNF-α. Hot plate test showed that CBDV potentiated morphine-induced antinociception. Furthermore, CBDV attenuated morphine analgesic tolerance as measured by the formalin test by specifically inhibiting chronic morphine-induced glial activation and pro-inflammatory factors expression in the nucleus accumbent. This study confirms that MD2 is a direct binding target of CBDV for the anti-neuroinflammatory effect and implies that CBDV has great translational potential in pain management.

Mitofusin 2 confers the suppression of microglial activation by cannabidiol: Insights from in vitro and in vivo models

Currently, there is increasing attention on the regulatory effects of cannabidiol (CBD) on the inflammatory response and the immune system. However, the mechanisms have not yet been completely revealed. Mitofusin 2 (Mfn2) is a mitochondrial fusion protein involved in the inflammatory response. Here, we investigated whether Mfn2 confers the anti-inflammatory effects of CBD. We found that treatment with CBD decreased the levels of tumor necrosis factor α, interleukin 6, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and ionized calcium-binding adaptor molecule-1 (Iba1) in lipopolysaccharide (LPS)-challenged microglia. CBD also significantly suppressed the increase in reactive oxygen species (ROS) and the decline of mitochondrial membrane potential in BV-2 cells subjected to LPS. Interestingly, CBD treatment increased the expression of Mfn2, while knockdown of Mfn2 blocked the effect of CBD. By contrast, overexpression of Mfn2 reversed the increase in the levels of iNOS, COX-2, and Iba1 induced by Mfn2 small interfering RNA. In mice challenged with LPS, we found that CBD ameliorated the anxiety responses and cognitive deficits, increased the level of Mfn2, and decreased the expression of Iba1. Since neuro-inflammation and microglial activation are the common events that are observed in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis, we treated EAE mice with CBD. Mice that received CBD showed amelioration of clinical signs, reduced inflammatory response, and increased myelin basic protein level. Most importantly, the adeno-associated virus delivery of short hairpin RNA against Mfn2 reversed the protective effects of CBD. Altogether, these results indicate that Mfn2 is an essential immunomodulator conferring the anti-inflammatory effects of CBD. Our results also shed new light on the mechanisms underlying the protective effects of CBD against inflammatory diseases including multiple sclerosis.

The prevalence, mechanism of action, and toxicity of Nigerian psychoactive plants

Cannabis sativa, Datura stramonium, Nicotiana tabacum, and Carica papaya are plants that naturally grow in Nigeria. They are reportedly rich in neuroactive compounds that are capable of reacting with the nervous system to elicit psychoactive and/or toxic effects that deter predators. However, despite the toxicological potential of these plants, their recreational use is on the rise due to the psychoactivity they proffer and prevalence in Nigeria. The aim of the present study is to evaluate the plants' recreational use, mechanism of actions and toxicities. Relevant published documents on psychoactive plants in Nigeria were obtained from Web of Science between 2002 and 2020. Non-English documents, documents not in Science Citation Index Expanded and Google Scholar were removed while 1186 documents were reviewed. Results showed that the plants are recreationally used in Nigeria with a higher prevalence than the global frequency. They are very addictive and lead to dependence. The plants were also observed to elicit different mechanism of action, though the activation of monoaminergic neurotransmission system was common to all. Regrettably, the plants could be toxic when ingested under non-medical conditions. Conclusively, these plants are addictive with potential toxic effects. Therefore, control of the recreational use of these plants should be revamped and overhauled.

Statement on safety of cannabidiol as a novel food: data gaps and uncertainties

The European Commission has determined that cannabidiol (CBD) can be considered as a novel food (NF), and currently, 19 applications are under assessment at EFSA. While assessing these, it has become clear that there are knowledge gaps that need to be addressed before a conclusion on the safety of CBD can be reached. Consequently, EFSA has issued this statement, summarising the state of knowledge on the safety of CBD consumption and highlighting areas where more data are needed. Literature searches for both animal and human studies have been conducted to identify safety concerns. Many human studies have been carried out with Epidyolex^®, a CBD drug authorised to treat refractory epilepsies. In the context of medical conditions, adverse effects are tolerated if the benefit outweighs the adverse effect. This is, however, not acceptable when considering CBD as a NF. Furthermore, most of the human data referred to in the CBD applications investigated the efficacy of Epidyolex (or CBD) at therapeutic doses. No NOAEL could be identified from these studies. Given the complexity and importance of CBD receptors and pathways, interactions need to be taken into account when considering CBD as a NF. The effects on drug metabolism need to be clarified. Toxicokinetics in different matrices, the half‐life and accumulation need to be examined. The effect of CBD on liver, gastrointestinal tract, endocrine system, nervous system and on psychological function needs to be clarified. Studies in animals show significant reproductive toxicity, and the extent to which this occurs in humans generally and in women of child‐bearing age specifically needs to be assessed. Considering the significant uncertainties and data gaps, the Panel concludes that the safety of CBD as a NF cannot currently be established.

Effects of Cannabidiol on Locomotor Activity

Cannabidiol (CBD) is the second cannabinoid, in order of importance after Δ9-tetrahydrocannabinol (THC), from Cannabis sativa. Unlike THC, CBD does not cause psychotomimetic effects, and although these compounds have the same chemical formula, their pharmacological characteristics are not equivalent. Preclinical studies suggest that CBD has anti-inflammatory, analgesic, anxiolytic, antiemetic, anticonvulsant, and antipsychotic properties and influences the sleep–wake cycle. The evaluation of effects on spontaneous motor activity is crucial in experimental pharmacology, and the careful measurement of laboratory animal movement is an established method to recognize the effects of stimulant and depressant drugs. The potential influence of CBD on locomotor activity has been investigated through numerous in vivo experiments. However, there is no clear picture of the impact of CBD on these issues, even though it is administered alone for medical uses and sold with THC as a drug for pain caused by muscle spasms in multiple sclerosis, and it was recently licensed as a drug for severe forms of infantile epilepsy. On this basis, with the aim of developing deeper knowledge of this issue, scientific data on CBD’s influence on locomotor activity are discussed here. We conducted research using PubMed, Scopus, Google Scholar, and a search engine for literature between January 2009 and December 2021 on life sciences and biomedical topics using the keywords “motor activity”, “locomotor activity”, and “locomotion” in combination with “cannabidiol”. In this article, we discuss findings describing the effects on locomotor activity of the CBD precursor cannabidiolic acid and of CBD alone or in combination with THC, together with the effects of CBD on locomotor modifications induced by diseases and on locomotor changes induced by other substances.

Differential Interaction of Cannabidiol with Biomembranes Dependent on Cholesterol Concentration

Cannabidiol (CBD), the major nonpsychoactive component of plant-derived cannabinoids, has been reported to have a broad range of potential beneficial pharmacological effects on the central nervous system (CNS). In this study, the droplet interface bilayer, a model cell membrane, is used to examine the effects of CBD on passive water permeability, a fundamental membrane biophysical property. The presence of CBD decreases the water permeability of model lipid membranes composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and at low concentrations of cholesterol (Chol) (20 mol %) in DOPC, whereas when higher concentrations of Chol are present (33 mol %), CBD has an opposing effect, increasing water permeability. The diametric effect in water permeability change upon addition of CBD to Chol-low and Chol-high bilayers signifies a variant interaction of CBD, depending on the initial state of bilayer packing and fluidity. Additionally, differential scanning calorimetry studies provide evidence that there are selective changes in thermotropic behavior for CBD with DOPC and with DOPC/Chol membranes, respectively, supportive of these varying membrane interactions of CBD dependent upon cholesterol. The intriguing ability of CBD to sensitively respond to membrane Chol concentrations in modifying physical properties highlights the significant impact that CBD can have on heterogeneous biomembranes including those of the CNS, the neurons of which are enriched in Chol to a point where up to a quarter of the body's total Chol is in the brain, and defective brain Chol homeostasis is implicated in neurodegenerative diseases.

Inhibition of human recombinant T-type calcium channels by phytocannabinoids in vitro

BACKGROUND AND PURPOSE

T-type Ca channels (I_Ca ) regulate neuronal excitability and contribute to neurotransmitter release. The phytocannabinoids Δ⁹ -tetrahydrocannabinol and cannabidiol effectively modulate T-type I_Ca , but effects of other biologically active phytocannabinoids on these channels are unknown. We thus investigated the modulation of T-type I_Ca by low abundance phytocannabinoids.

EXPERIMENTAL APPROACH

A fluorometric (FLIPR) assay was used to investigate modulation of human T-type I_Ca (Ca_V 3.1, 3.2 and 3.3) stably expressed in FlpIn-TREx HEK293 cells. The biophysical effects of some compounds were examined using whole-cell patch clamp recordings from the same cells.

KEY RESULTS

In the FLIPR assay, all eleven phytocannabinoids tested modulated T-type I_Ca , with most inhibiting Ca_V 3.1 and Ca_V 3.2 more effectively than Ca_V 3.3. Cannabigerolic acid was the most potent inhibitor of Ca_V 3.1 (pIC₅₀ 6.1 ± 0.6) and Ca_V 3.2 (pIC₅₀ 6.4 ± 0.4); in all cases phytocannabinoid acids were more potent than their corresponding neutral forms. In patch clamp recordings, cannabigerolic acid inhibited Ca_V 3.1 and 3.2 with similar potency to the FLIPR assay, the inhibition was associated with significant hyperpolarizing shift in activation and steady state inactivation of these channels. In contrast, cannabidiol, cannabidivarin and cannabigerol only affected channel inactivation.

CONCLUSION AND IMPLICATIONS

Modulation of T-type calcium channels is a common property of phytocannabinoids, which all increase steady state inactivation at physiological membrane potentials, with some also affecting channel activation. Thus, T-type I_Ca may be a common site of action for phytocannabinoids, and the diverse actions of phytocannabinoids on channel gating may provide insight into structural requirement for selective T-type I_Ca modulators.

Effects of Cannabidiol on Parkinson’s Disease in a Transgenic Mouse Model by Gut-Brain Metabolic Analysis

Parkinson's disease (PD) is a common neurodegenerative disease characterized by a disorder of the dopaminergic system in the midbrain, causing classical PD motor symptoms. The therapeutic effect of cannabidiol (CBD) on PD has been a research frontier in recent years. However, the pathogenesis of PD and the therapeutic mechanism of cannabinoid remain unclear. To further study the causes of PD and the effect of CBD on PD, we exposed the PD transgenic mouse model to CBD and then estimated the motorial and postural coordination through a modified swim test. Afterwards, the mechanism was investigated via the histopathology of substantia nigra and the gut-brain metabolic analysis in the approach of UHPLC-TOF-MS. The results showed that CBD significantly improved motor deficits of PD model and protected the substantia nigra area. The metabolic function of fatty acid biosynthesis, arginine biosynthesis/metabolism, butanoate (ketone body) metabolism, β-alanine metabolism, and pantothenate/CoA biosynthesis was highlighted in the pathological and therapeutic process along the gut-brain axis. In conclusion, CBD could attenuate PD via the neuroprotective effect on the midbrain. The attenuation of the central nervous system in turn improved motor performance of PD, which might be partially induced by the metabolic interaction between the gut-brain. In view of gut-brain metabolomics, the mechanism of PD pathogenesis and the effect of CBD on PD are highly related to the biosynthesis and metabolism of energy and essential substance.

Pharmacotechnical and analytical preformulation studies for cannabidiol orodispersible tablets

Obtaining orodispersible tablets (ODT) containing substances from the second Biopharmaceutical Class has raised concerns as the dissolution test is challenging. This study aimed to select suitable excipients for developing orodispersible tablets containing cannabidiol (CBD) by direct compression method. No similar studies were found in the literature. Excipients from different classes were characterized using the SeDeM-ODT tool: fillers – lactose (LCT) and microcrystalline cellulose (CelMC), sweeteners – sorbitol (SRB) and mannitol (MNT), disintegrants – sodium starch glycolate (SSG), sodium croscarmellose (CCS), soy polysaccharides (Emcosoy® – EMCS) and two co-processed excipients (Prosolv®-ODT G2 – PODTG2 and Prosolv® EasyTab sp – PETsp). Drug compatibility with excipients in binary mixtures (1:1) was verified by Differential Scanning Calorimetry (DSC) and Fourier Transform-Infrared (FTIR) spectroscopy. Using the SeDeM-ODT expert system, the fillers and the co-processed excipients showed good properties regarding compressibility and disintegration behavior. Also, the DSC and FTIR results showed that small or no interactions between the CBD and the excipients took place.

The Endocannabinoid System: A Potential Target for the Treatment of Various Diseases

The Endocannabinoid System (ECS) is primarily responsible for maintaining homeostasis, a balance in internal environment (temperature, mood, and immune system) and energy input and output in living, biological systems. In addition to regulating physiological processes, the ECS directly influences anxiety, feeding behaviour/appetite, emotional behaviour, depression, nervous functions, neurogenesis, neuroprotection, reward, cognition, learning, memory, pain sensation, fertility, pregnancy, and pre-and post-natal development. The ECS is also involved in several pathophysiological diseases such as cancer, cardiovascular diseases, and neurodegenerative diseases. In recent years, genetic and pharmacological manipulation of the ECS has gained significant interest in medicine, research, and drug discovery and development. The distribution of the components of the ECS system throughout the body, and the physiological/pathophysiological role of the ECS-signalling pathways in many diseases, all offer promising opportunities for the development of novel cannabinergic, cannabimimetic, and cannabinoid-based therapeutic drugs that genetically or pharmacologically modulate the ECS via inhibition of metabolic pathways and/or agonism or antagonism of the receptors of the ECS. This modulation results in the differential expression/activity of the components of the ECS that may be beneficial in the treatment of a number of diseases. This manuscript in-depth review will investigate the potential of the ECS in the treatment of various diseases, and to put forth the suggestion that many of these secondary metabolites of Cannabis sativa L. (hereafter referred to as "C. sativa L." or "medical cannabis"), may also have potential as lead compounds in the development of cannabinoid-based pharmaceuticals for a variety of diseases.

Novel Machaeriol Analogues as Modulators of Cannabinoid Receptors: Structure-Activity Relationships of (+)-Hexahydrocannabinoids and Their Isoform Selectivities

Machaeriols are an important class of compounds that structurally resemble tetrahydrocannabinol (Δ⁹-THC), with the major differences being inverted stereochemistry at the ring junction as [6aR, 10aR] and an additional stereocenter at the C9 position of the A-ring due to saturation. A previous study reported that machaeriols did not show any cannabinoid receptor activity, even though these hexahydrodibenzopyran analogues mimic a privileged (+)-tetrahydrocannabinoid scaffold. To unravel structural requisites for modulation of cannabinoid receptors, a simple late-stage divergent approach was undertaken to functionalize the machaeriol scaffold using the Suzuki coupling reaction. Fourteen hexahydro analogues were synthesized and screened against both cannabinoid receptor isoforms, CB₁ and CB₂. Interestingly, many of the analogues showed a significant binding affinity for both receptors; however, two analogues, 11H and 11J, were identified as possessing CB₂ receptor-selective functional activity in the GTPγS assay; they were found to be micromolar-range agonists, with EC₅₀ values of 5.7 and 16 μM, respectively. Furthermore, molecular dynamics simulations between the CB₂ receptor and two novel analogues resulted in unique interaction profiles by tightly occupying the active ligand-binding domain of the CB₂ receptor and maintaining stable interactions with the critical residues Phe94, Phe281, and Ser285. For the first time, with the aid of structure-activity relationships of (+)-hexahydrocannabinoids, CB₂ selective agonists were identified with late-stage diversification using palladium-mediated C-C bond formation. By simply switching to (R)-citronellal as a chiral precursor, enantiomerically pure (-)-hexahydrocannabinoids with better CB₁/CB₂ receptor isoform selectivity can be obtained using the current synthetic approach.

Cannabinoids in Neurology - Position paper from Scientific Departments from Brazilian Academy of Neurology

Cannabinoids comprehend endocannabinoids, phytocannabinoids, and synthetic cannabinoids, with actions both in the central and peripherical nervous systems. A considerable amount of publications have been made in recent years, although cannabis has been known for over a thousand years. Scientific Departments from the Brazilian Academy of Neurology described evidence for medical use in their areas. Literature is constantly changing, and possible new evidence can emerge in the next days or months. Prescription of these substances must be discussed with patients and their families, with knowledge about adverse events and their efficacy.