Yin and yang of cannabinoid CB1 receptor: CB1 deletion in immune cells causes exacerbation while deletion in non-immune cells attenuates obesity

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“While blockade of cannabinoid receptor 1 (CB1) has been shown to attenuate diet-induced obesity (DIO), its relative role in different cell types has not been tested. The current study investigated the role of CB1 in immune vs non-immune cells during DIO by generating radiation-induced bone marrow chimeric mice that expressed functional CB1 in all cells except the immune cells or expressed CB1 only in immune cells. CB1-/- recipient hosts were resistant to DIO, indicating that CB1 in non-immune cells is necessary for induction of DIO. Interestingly, chimeras with CB1-/- in immune cells showed exacerbation in DIO combined with infiltration of bone-marrow-derived macrophages to the brain and visceral adipose tissue, elevated food intake, and increased glucose intolerance. These results demonstrate the opposing role of CB1 in hematopoietic versus non-hematopoietic cells during DIO and suggests that targeting immune CB1 receptors provides a new pathway to ameliorate obesity and related metabolic disorders.”

https://pubmed.ncbi.nlm.nih.gov/36093055/

https://www.cell.com/iscience/fulltext/S2589-0042(22)01266-4?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2589004222012664%3Fshowall%3Dtrue

Peripheral CB1 receptor blockade acts as a memory enhancer through a noradrenergic mechanism

Neuropsychopharmacology

“Peripheral inputs continuously shape brain function and can influence memory acquisition, but the underlying mechanisms have not been fully understood. Cannabinoid type-1 receptor (CB1R) is a well-recognized player in memory performance, and its systemic modulation significantly influences memory function. By assessing low arousal/non-emotional recognition memory in mice, we found a relevant role of peripheral CB1R in memory persistence. Indeed, the peripherally-restricted CB1R specific antagonist AM6545 showed significant mnemonic effects that were occluded in adrenalectomized mice, and after peripheral adrenergic blockade. AM6545 also transiently impaired contextual fear memory extinction. Vagus nerve chemogenetic inhibition reduced AM6545-induced mnemonic effect. Genetic CB1R deletion in dopamine β-hydroxylase-expressing cells enhanced recognition memory persistence. These observations support a role of peripheral CB1R modulating adrenergic tone relevant for cognition. Furthermore, AM6545 acutely improved brain connectivity and enhanced extracellular hippocampal norepinephrine. In agreement, intra-hippocampal β-adrenergic blockade prevented AM6545 mnemonic effects. Altogether, we disclose a novel CB1R-dependent peripheral mechanism with implications relevant for lengthening the duration of non-emotional memory.”

https://pubmed.ncbi.nlm.nih.gov/36088492/

https://www.nature.com/articles/s41386-022-01436-9

[Cannabinoids for the treatment of chronic pain – an overview of current medical knowledge]

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“Cannabis has been used in medicine for thousands of years, yet its use for therapeutic purposes is still controversial. Meta-analysis of the literature has shown the effectiveness of cannabinoids only in some diseases. Researchers are particularly interested in their use in chronic pain management, which analgesic effect has been proved in many studies. A review of the literature indicates that cannabinoid preparations may be effective in the treatment of some chronic pain disorders, particularly in neuropathic pain, and should be considered as a possible therapeutic choice in the absence of a satisfactory analgesic effect with standard medications. The increasing number of countries approving cannabinoids for medical use creates an opportunity to conduct more clinical trials and collect better-quality data necessary to establish clear guidelines and consistent recommendations for specific pain disorders.”

https://pubmed.ncbi.nlm.nih.gov/36086988/

Endocannabinoid System and the Otolaryngologist

Otolaryngologic Clinics of North America

“The endocannabinoid system is located throughout the central and peripheral nervous systems, endocrine system, gastrointestinal system, and within inflammatory cells. The use of medical cannabinoids has been gaining traction as a viable treatment option for varying illnesses in recent years. Research is ongoing looking at the effect of cannabinoids for treatment of common otolaryngologic pathologies. This article identifies common otolaryngologic pathologies where cannabinoids may have benefit, discusses potential drawbacks to cannabinoid use, and suggests future directions for research in the application of medical cannabinoids.”

https://pubmed.ncbi.nlm.nih.gov/36088164/

https://www.sciencedirect.com/science/article/abs/pii/S0030666522000767?via%3Dihub

Anti-Cancer Activity of Cannabis sativa Phytocannabinoids: Molecular Mechanisms and Potential in the Fight against Ovarian Cancer and Stem Cells

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“Ovarian cancer (OC) is the most lethal gynecological malignancy, with about 70% of cases diagnosed only at an advanced stage.

Cannabis sativa, which produces more than 150 phytocannabinoids, is used worldwide to alleviate numerous symptoms associated with various medical conditions. Recently, studies across a range of cancer types have demonstrated that the phytocannabinoids Δ9-trans-tetrahydrocannabinol (THC) and cannabidiol (CBD) have anti-cancer activity in vitro and in vivo, but also the potential to increase other drugs’ adverse effects.

THC and CBD act via several different biological and signaling pathways, including receptor-dependent and receptor-independent pathways. However, very few studies have examined the effectiveness of cannabis compounds against OC. Moreover, little is known about the effectiveness of cannabis compounds against cancer stem cells (CSCs) in general and OC stem cells (OCSCs) in particular. CSCs have been implicated in tumor initiation, progression, and invasion, as well as tumor recurrence, metastasis, and drug resistance. Several hallmarks and concepts describe CSCs. OCSCs, too, are characterized by several markers and specific drug-resistance mechanisms.

While there is no peer-reviewed information regarding the effect of cannabis and cannabis compounds on OCSC viability or development, cannabis compounds have been shown to affect genetic pathways and biological processes related to CSCs and OCSCs. Based on evidence from other cancer-type studies, the use of phytocannabinoid-based treatments to disrupt CSC homeostasis is suggested as a potential intervention to prevent chemotherapy resistance. The potential benefits of the combination of chemotherapy with phytocannabinoid treatment should be examined in ovarian cancer patients.”

https://pubmed.ncbi.nlm.nih.gov/36077833/

“Ovarian cancer is the most lethal gynecological malignancy. Cancer stem cells have been implicated in tumor initiation, progression, and invasion, as well as tumor recurrence, metastasis, and drug resistance. Cannabis is used worldwide to alleviate numerous symptoms associated with various medical conditions. Phytocannabinoids, produced by cannabis, were shown to have anti-cancer activity in cell lines and animal models, but also the potential to increase other drugs’ adverse effects. Yet, very few studies have examined the effectiveness of cannabis compounds against ovarian cancer. Cannabis compounds have been shown to affect genetic pathways and biological processes related to development of ovarian cancer stem cells. Phytocannabinoid-based treatments might be used to disrupt cancer stem cell homeostasis and thereby to prevent chemotherapy resistance. The potential benefits of the combination of chemotherapy with phytocannabinoid treatment could be examined in ovarian cancer patients.”

https://www.mdpi.com/2072-6694/14/17/4299/htm

Practical Considerations for the Use of Cannabis in Cancer Pain Management-What a Medical Oncologist Should Know

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“Pain is a highly debilitating emotional and sensory experience that significantly affects quality of life (QoL). Numerous chronic conditions, including cancer, are associated with chronic pain. In the setting of malignancy, pain can be a consequence of the tumor itself or of life-saving interventions, including surgery, chemotherapy, and radiotherapy. Despite significant pharmacological advances and awareness campaigns, pain remains undertreated in one-third of patients. To date, opioids have been the mainstay of cancer pain management. The problematic side effects and unsatisfactory pain relief of opioids have revived patients’ and physicians’ interest in finding new solutions, including cannabis and cannabinoids. The medical use of cannabis has been prohibited for decades, and it remains in Schedule 1 of the Misuse of Drugs Regulations. Currently, the legal context for its usage has become more permissive. Various preclinical and observational studies have aimed to prove that cannabinoids could be effective in cancer pain management. However, their clinical utility must be further supported by high-quality clinical trials.”

https://pubmed.ncbi.nlm.nih.gov/36078963/

https://www.mdpi.com/2077-0383/11/17/5036/htm

Cannabidiol (CBD) Protects Adipose-Derived Mesenchymal Stem Cells (ASCs) against Endoplasmic Reticulum Stress Development and Its Complications

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“Background: Recent studies suggested that individuals with metabolic disorders have altered function of adipocytes and adipose stem cell subpopulations, which impairs tissue homeostasis, promoting insulin resistance and diabetes development. The non-psychoactive phytocannabinoid CBD was found to modulate adipose tissue metabolism, however, its exact role in controlling ASCs’ fate is still poorly understood.

Objectives: This investigation aimed to elucidate whether pretreatment of ASCs with CBD can protect against ER stress development and maintain the cytophysiological properties of cells.

Methods: Human ASCs were cultured under control and adipogenic conditions. Prior to the experiments, cells in the experimental group were pretreated with CBD following the addition of an ER stress inducer-tunicamycin. After the experiments, the cells were subsequently tested for expression of the apoptotic, ER stress, and anti-inflammatory-related genes using RT-qPCR. Oxidative stress was analysed with flow cytometric assays.

Results: Cells pretreated with CBD displayed decreased apoptosis and enhanced proliferation rate. Additionally, the expression of pro-inflammatory cytokines and miRNAs was significantly reduced. The obtained results also demonstrated an obvious reduction in intracellular accumulated ROS and NO, as well as mitigated ER stress through the down-regulation of IRE-1PERKCHOP, and ATF6 transcripts upon CBD treatment.

Conclusion: The presented data provide the evidence that CBD protects ASCs against ER stress development and its complications and, thus, offers new insights for the management of obesity through the regulation of adipose tissue dynamics.”

https://pubmed.ncbi.nlm.nih.gov/36078578/

“The regenerative potential of ASCs in the treatment of multiple disorders lies in their differentiation, migration, and secretory activity. However, these conditions impair the cytophysiological properties of ASCs, limiting their application in autologous therapies. What is more, impaired ASCs in vivo suffer from reduced multipotency and produce a vast number of inflammatory cytokines and oxidative stress factors, which in turn contributes to disease progression. Hence, development of strategies that reverse their senescence and ageing, and, as a consequence, restore regenerative properties are strongly desirable.

To our knowledge, this is the first report on the impact of CBD pretreatment on metabolically impaired ASCs suffering from ER stress. Our current study revealed that CBD modulates ASCs metabolism by promoting their growth kinetics, multipotency, and viability, which due to enhanced ER stress were strongly limited. Taking into account that CBD lacks psychopharmacological activity, further studies aiming at unravelling its influence on different stem cells populations are recommended and justified. Further studies on the effects of CBD on ASCs could explore other measures of its regenerative capacity than studied in the presented research. Furthermore, unravelling the precise molecular mechanisms of action via CBD that protect ASCs against cytophysiological impairment would be valuable. While our findings are supported by the existing literature, our research was not free of limitations. An important drawback is that we did not explore which cannabinoid receptors are responsible for the observed effects of CBD. Thus, further experiments utilizing agonists and antagonists of cannabinoid receptors are necessary to elucidate which of them are involved in CBD’s way of action.

Taking into consideration that ASCs are nowadays a commonly applied tool in regenerative medicine, the ability to enhance their stemness and regenerative potential may contribute not only to more effective therapies but also to significantly reducing the costs associated with their isolation and expansion.”

https://www.mdpi.com/1660-4601/19/17/10864/htm

Regulation of Expression of Cannabinoid CB 2 and Serotonin 5HT 1A Receptor Complexes by Cannabinoids in Animal Models of Hypoxia and in Oxygen/Glucose-Deprived Neurons

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“Background: Cannabidiol (CBD) is a phytocannabinoid with potential in one of the most prevalent syndromes occurring at birth, the hypoxia of the neonate. CBD targets a variety of proteins, cannabinoid CB2 and serotonin 5HT1A receptors included. These two receptors may interact to form heteromers (CB2-5HT1A-Hets) that are also a target of CBD. 

Aims: We aimed to assess whether the expression and function of CB2-5HT1A-Hets is affected by CBD in animal models of hypoxia of the neonate and in glucose- and oxygen-deprived neurons. 

Methods: We developed a quantitation of signal transduction events in a heterologous system and in glucose/oxygen-deprived neurons. The expression of receptors was assessed by immuno-cyto and -histochemistry and, also, by using the only existing technique to visualize CB2-5HT1A-Hets fixed cultured cells and tissue sections (in situ proximity ligation PLA assay). 

Results: CBD and cannabigerol, which were used for comparative purposes, affected the structure of the heteromer, but in a qualitatively different way; CBD but not CBG increased the affinity of the CB2 and 5HT1A receptor-receptor interaction. Both cannabinoids regulated the effects of CB2 and 5HT1A receptor agonists. CBD was able to revert the upregulation of heteromers occurring when neurons were deprived of oxygen and glucose. CBD significantly reduced the increased expression of the CB2-5HT1A-Het in glucose/oxygen-deprived neurons. Importantly, in brain sections of a hypoxia/ischemia animal model, administration of CBD led to a significant reduction in the expression of CB2-5HT1A-Hets. 

Conclusions: Benefits of CBD in the hypoxia of the neonate are mediated by acting on CB2-5HT1A-Hets and by reducing the aberrant expression of the receptor-receptor complex in hypoxic-ischemic conditions. These results reinforce the potential of CBD for the therapy of the hypoxia of the neonate.”

https://pubmed.ncbi.nlm.nih.gov/36077095/

https://www.mdpi.com/1422-0067/23/17/9695/htm

Hemp-Derived Nanovesicles Protect Leaky Gut and Liver Injury in Dextran Sodium Sulfate-Induced Colitis

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“Hemp (Cannabis sativa L.) is used for medicinal purposes owing to its anti-inflammatory and antioxidant activities.

We evaluated the protective effect of nanovesicles isolated from hemp plant parts (root, seed, hemp sprout, and leaf) in dextran sulfate sodium (DSS)-induced colitis in mice.

The particle sizes of root-derived nanovesicles (RNVs), seed-derived nanovesicles (SNVs), hemp sprout-derived nanovesicles (HSNVs), and leaf-derived nanovesicles (LNVs) were within the range of 100-200 nm as measured by nanoparticle tracking analysis. Acute colitis was induced in C57BL/N mice by 5% DSS in water provided for 7 days.

RNVs were administered orally once a day, leading to the recovery of both the small intestine and colon lengths. RNVs, SNVs, and HSNVs restored the tight (ZO-1, claudin-4, occludin) and adherent junctions (E-cadherin and α-tubulin) in DSS-induced small intestine and colon injury. Additionally, RNVs markedly reduced NF-κB activation and oxidative stress proteins in DSS-induced small intestine and colon injury. Tight junction protein expression and epithelial cell permeability were elevated in RNV-, SNV-, and HSNV-treated T84 colon cells exposed to 2% DSS. Interestedly, RNVs, SNVs, HSNVs, and LNVs reduced ALT activity and liver regeneration marker proteins in DSS-induced liver injury.

These results showed for the first time that hemp-derived nanovesicles (HNVs) exhibited a protective effect on DSS-induced gut leaky and liver injury through the gut-liver axis by inhibiting oxidative stress marker proteins.”

https://pubmed.ncbi.nlm.nih.gov/36077356/

“In summary, we successfully identified and characterized edible-plant nanovesicles from different hemp (Cannabis sativa L.) parts (root; RNVS, seed; SNVS, hemp sprout; HSNVs, leaf; LNVs). RNVs markedly alleviated leaky gut and intestinal barrier proteins such as tight junction and adherent junction proteins and reduced NF-κB activation and oxidative stress markers in DSS-induced colitis. Additionally, NVs, SNVs, HSNVs, and LNVs administration reduced liver damage markers and elevated liver regeneration markers. Therefore, this is the first study using hemp-derived nanovesicles in protection against colitis that can be a novel therapeutic strategy to treat IBD.”

https://www.mdpi.com/1422-0067/23/17/9955/htm

Children and adolescents with ASD treated with CBD-rich cannabis exhibit significant improvements particularly in social symptoms: an open label study

Translational Psychiatry

“In recent years there has been growing interest in the potential benefits of CBD-rich cannabis treatment for children with ASD. Several open label studies and one double-blind placebo-controlled study have reported that CBD-rich cannabis is safe and potentially effective in reducing disruptive behaviors and improving social communication. However, previous studies have mostly based their conclusions on parental reports without the use of standardized clinical assessments.

Here, we conducted an open label study to examine the efficacy of 6 months of CBD-rich cannabis treatment in children and adolescents with ASD. Longitudinal changes in social communication abilities and restricted and repetitive behaviors (RRB) were quantified using parent report with the Social Responsiveness Scale and clinical assessment with the Autism Diagnostic Observation Schedule (ADOS). We also quantified changes in adaptive behaviors using the Vineland, and cognitive abilities using an age-appropriate Wechsler test. Eighty-two of the 110 recruited participants completed the 6-month treatment protocol.

While some participants did not exhibit any improvement in symptoms, there were overall significant improvements in social communication abilities as quantified by the ADOS, SRS, and Vineland with larger improvements in participants who had more severe initial symptoms. Significant improvements in RRB were noted only with parent-reported SRS scores and there were no significant changes in cognitive scores.

These findings suggest that treatment with CBD-rich cannabis can yield improvements, particularly in social communication abilities, which were visible even when using standardized clinical assessments. Additional double-blind placebo-controlled studies utilizing standardized assessments are highly warranted for substantiating these findings.”

https://pubmed.ncbi.nlm.nih.gov/36085294/

“Accumulating evidence, mostly from open-label uncontrolled studies suggest that CBD-rich cannabis may yield benefits for some individuals with ASD. In this study we demonstrate that this benefit includes improvement in social communication abilities, particularly for participants with high initial severity of core ASD symptoms. Moreover, this is the first study to examine the efficacy of cannabis treatment using both standardized clinical assessments (i.e., ADOS), parent interviews (i.e., Vineland) and questionnaires (i.e., SRS). Despite differences in individual scores reported by parents and clinicians, the convergence of evidence regarding overall improvements following treatment strengthens the conclusions. These positive findings motivate further double-blind placebo-controlled studies for determining the efficacy of treatment with specific cannabis strains and/or synthetic cannabinoids.”

https://www.nature.com/articles/s41398-022-02104-8