Cannabinoids as Key Regulators of Inflammasome Signaling: A Current Perspective

Segura Lab - New publication in Frontiers in Immunology“Inflammasomes are cytoplasmic inflammatory signaling protein complexes that detect microbial materials, sterile inflammatory insults, and certain host-derived elements. Inflammasomes, once activated, promote caspase-1-mediated maturation and secretion of pro-inflammatory cytokines, interleukin (IL)-1β and IL-18, leading to pyroptosis. Current advances in inflammasome research support their involvement in the development of chronic inflammatory disorders in contrast to their role in regulating innate immunity.

Cannabis (marijuana) is a natural product obtained from the Cannabis sativa plant, and pharmacologically active ingredients of the plant are referred to as cannabinoids. Cannabinoids and cannabis extracts have recently emerged as promising novel drugs for chronic medical conditions. Growing evidence indicates the potent anti-inflammatory potential of cannabinoids, especially Δ9-tetrahydrocannabinol (Δ9-THC), cannabidiol (CBD), and synthetic cannabinoids; however, the mechanisms remain unclear. Several attempts have been made to decipher the role of cannabinoids in modulating inflammasome signaling in the etiology of chronic inflammatory diseases.

In this review, we discuss recently published evidence on the effect of cannabinoids on inflammasome signaling. We also discuss the contribution of various cannabinoids in human diseases concerning inflammasome regulation. Lastly, in the milieu of coronavirus disease-2019 (COVID-19) pandemic, we confer available evidence linking inflammasome activation to the pathophysiology of COVID-19 suggesting overall, the importance of cannabinoids as possible drugs to target inflammasome activation in or to support the treatment of a variety of human disorders including COVID-19.”

https://pubmed.ncbi.nlm.nih.gov/33584697/

“Cannabis has been shown to possess anti-inflammatory effects owing to its constituents, cannabinoids and terpenoids. Overall, cannabinoids hold a great promise as additional therapeutics to support the current treatment of chronic inflammatory diseases, along with COVID-19”

https://www.frontiersin.org/articles/10.3389/fimmu.2020.613613/full

A cannabidiol-loaded Mg-gallate metal-organic framework-based potential therapeutic for glioblastomas

 “Cannabidiol (CBD) has been shown to slow cancer cell growth and is toxic to human glioblastoma cell lines. Thus, CBD could be an effective therapeutic for glioblastoma.

In the present study, we explored the anticancer effect of cannabidiol loaded magnesium-gallate (CBD/Mg-GA) metal-organic framework (MOF) using the rat glioma brain cancer (C6) cell line.

Bioactive and microporous magnesium gallate MOF was employed for simultaneous delivery of two potential anticancer agents (gallic acid and CBD) to the cancer cells. Gallic acid (GA), a polyphenolic compound, is part of the MOF framework, while CBD is loaded within the framework. Slow degradation of CBD/Mg-GA MOF in physiological fluids leads to sustained release of GA and CBD.

CBD’s anti-cancer actions target mitochondria, inducing their dysfunction and generation of harmful reactive oxygen species (ROS). Anticancer effects of CBD/Mg-GA include a significant increase in ROS production and a reduction in anti-inflammatory responses as reflected by a significant decrease in TNF-α expression levels. Molecular mechanisms that underlie these effects include the modulation of NF-κB expression, triggering the apoptotic cascades of glioma cells. CBD/Mg-GA MOF has potential anti-cancer, anti-inflammatory and anti-oxidant properties.

Thus, the present study demonstrates that CBD/Mg-GA MOF may be a promising therapeutic for glioblastoma.”

https://pubmed.ncbi.nlm.nih.gov/33657198/

https://pubs.rsc.org/en/content/articlelanding/2021/TB/D0TB02780D#!divAbstract

Graphical abstract: A cannabidiol-loaded Mg-gallate metal–organic framework-based potential therapeutic for glioblastomas

CBD activation of TRPV1 induces oxidative signalling and subsequent ER stress in breast cancer cell lines

“Endoplasmic reticulum (ER) stress is an imbalance between the ER’s protein-folding load and capacity. It can be induced by various physiological conditions, activating the unfolded protein response to re-establish homeostasis, promoting cell survival. Under severe or chronic stress, apoptosis is induced. Normal cells generally do not experience continuous ER stress induction. The stressful conditions experienced in the tumour microenvironment facilitates chronic ER stress and UPR activation, which plays a pivotal role in tumour survival.

Exacerbation of pre-existing ER stress can trigger cancer cell death, with a minimal effect on normal cells.

Current literature suggests that cannabinoid treatment may induce cancer cell death via ER stress; however, little is known about the mechanisms of induction.

This study proposed that cannabidiol (CBD) mechanism that occurred through the influx of Ca2+ via the TRPV1 receptor, and increasing ROS production affects protein folding and induces ER stress. ER stress was induced, and detection and quantification were completed using Thioflavin T staining and GRP78 by western blot analysis. The effect of cannabinoid treatment on ROS production and Ca2+ influx was measured. CBD was the most potent ER stress inducer, significantly increasing Ca2+ and ROS accumulation. Concomitant treatment with CBD and an antioxidant significantly increased cell viability and decreased ER stress induction in the MCF7 cell line. Concomitant treatment with a TRPV1 antagonist increased viability in this cell line.

In conclusion, the data suggested that CBD induced ER stress via Ca2+ influx through the TRPV1 receptor, thereby elevating intracellular ROS levels and disrupting protein folding.”

https://pubmed.ncbi.nlm.nih.gov/33604949/

https://iubmb.onlinelibrary.wiley.com/doi/10.1002/bab.2119

Cannabidiol inhibits human glioma by induction of lethal mitophagy through activating TRPV4

Publication Cover“Glioma is the most common primary malignant brain tumor with poor survival and limited therapeutic options. The non-psychoactive phytocannabinoid cannabidiol (CBD) has been shown to be effective against glioma; however, the molecular target and mechanism of action of CBD in glioma are poorly understood.

Here we investigated the molecular mechanisms underlying the antitumor effect of CBD in preclinical models of human glioma.

Our results showed that CBD induced autophagic rather than apoptotic cell death in glioma cells. We also showed that CBD induced mitochondrial dysfunction and lethal mitophagy arrest, leading to autophagic cell death. Mechanistically, calcium flux induced by CBD through TRPV4 (transient receptor potential cation channel subfamily V member 4) activation played a key role in mitophagy initiation. We further confirmed TRPV4 levels correlated with both tumor grade and poor survival in glioma patients. Transcriptome analysis and other results demonstrated that ER stress and the ATF4-DDIT3-TRIB3-AKT-MTOR axis downstream of TRPV4 were involved in CBD-induced mitophagy in glioma cells. Lastly, CBD and temozolomide combination therapy in patient-derived neurosphere cultures and mouse orthotopic models showed significant synergistic effect in both controlling tumor size and improving survival.

Altogether, these findings showed for the first time that the antitumor effect of CBD in glioma is caused by lethal mitophagy and identified TRPV4 as a molecular target and potential biomarker of CBD in glioma. Given the low toxicity and high tolerability of CBD, we therefore propose CBD should be tested clinically for glioma, both alone and in combination with temozolomide.”

https://pubmed.ncbi.nlm.nih.gov/33629929/

https://www.tandfonline.com/doi/abs/10.1080/15548627.2021.1885203?journalCode=kaup20

A phase 1b randomised, placebo-controlled trial of nabiximols cannabinoid oromucosal spray with temozolomide in patients with recurrent glioblastoma

British Journal of Cancer“Preclinical data suggest some cannabinoids may exert antitumour effects against glioblastoma (GBM). Safety and preliminary efficacy of nabiximols oromucosal cannabinoid spray plus dose-intense temozolomide (DIT) was evaluated in patients with first recurrence of GBM.

Results: The most common treatment-emergent adverse events (TEAEs; both parts) were vomiting, dizziness, fatigue, nausea and headache. Most patients experienced TEAEs that were grade 2 or 3 (CTCAE). In Part 2, 33% of both nabiximols- and placebo-treated patients were progression-free at 6 months. Survival at 1 year was 83% for nabiximols- and 44% for placebo-treated patients (p = 0.042), although two patients died within the first 40 days of enrolment in the placebo arm. There were no apparent effects of nabiximols on TMZ PK.

Conclusions: With personalised dosing, nabiximols had acceptable safety and tolerability with no drug-drug interaction identified. The observed survival differences support further exploration in an adequately powered randomised controlled trial.”

https://pubmed.ncbi.nlm.nih.gov/33623076/

https://www.nature.com/articles/s41416-021-01259-3

Cannabigerol Is a Potential Therapeutic Agent in a Novel Combined Therapy for Glioblastoma

cells-logo“Glioblastoma is the most aggressive cancer among primary brain tumours. As with other cancers, the incidence of glioblastoma is increasing; despite modern therapies, the overall mean survival of patients post-diagnosis averages around 16 months, a figure that has not changed in many years. Cannabigerol (CBG) has only recently been reported to prevent the progression of certain carcinomas and has not yet been studied in glioblastoma. Here, we have compared the cytotoxic, apoptotic, and anti-invasive effects of the purified natural cannabinoid CBG together with CBD and THC on established differentiated glioblastoma tumour cells and glioblastoma stem cells. CBG and THC reduced the viability of both types of cells to a similar extent, whereas combining CBD with CBG was more efficient than with THC. CBD and CBG, both alone and in combination, induced caspase-dependent cell apoptosis, and there was no additive THC effect. Of note, CBG inhibited glioblastoma invasion in a similar manner to CBD and the chemotherapeutic temozolomide. We have demonstrated that THC has little added value in combined-cannabinoid glioblastoma treatment, suggesting that this psychotropic cannabinoid should be replaced with CBG in future clinical studies of glioblastoma therapy.”

https://pubmed.ncbi.nlm.nih.gov/33562819/

“Among primary brain tumours, glioblastoma is the most aggressive. As early relapses are unavoidable despite standard-of-care treatment, the cannabinoids delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) alone or in combination have been suggested as a combined treatment strategy for glioblastomas. However, the known psychoactive effects of THC hamper its medical applications in these patients with potential cognitive impairment due to the progression of the disease. Therefore, nontoxic cannabigerol (CBG), being recently shown to exhibit anti-tumour properties in some carcinomas, is assayed here for the first time in glioblastoma with the aim to replace THC. We indeed found CBG to effectively impair the relevant hallmarks of glioblastoma progression, with comparable killing effects to THC and in addition inhibiting the invasion of glioblastoma cells. Moreover, CBG can destroy therapy-resistant glioblastoma stem cells, which are the root of cancer development and extremely resistant to various other treatments of this lethal cancer. CBG should present a new yet unexplored adjuvant treatment strategy of glioblastoma.”

https://www.mdpi.com/2073-4409/10/2/340

Induced Fit Docking and Automated QSAR Studies Reveal the ER-α Inhibitory Activity of Cannabis sativa in Breast Cancer

Background: Breast Cancer (BC), a common death-causing disease and the deadliest cancer next to lung cancer, is characterized by an abnormal growth of cells in the tissues of the breast. BC chemotherapy is marked by targeting the activities of some receptors such as Estrogen Receptor alpha (ER-α). At present, one of the most commonly used and approved marketed therapeutic drug for BC is tamoxifen. Despite the short term success of tamoxifen usage, its long time treatment has been associated with significant side effects. Therefore, there is a pressing need for the development of novel anti-estrogens for the prevention and treatment of BC.

Objective: In this study, we evaluate the inhibitory effect of Cannabis Sativa phyto-constituents on ER-α.

Method: Glide and Induced Fit Docking followed by ADME, Automated QSAR and Binding free energy (ΔGbind) studies were used to evaluate the anti-breast cancer and ER-α inhibitory activity of Cannabis sativa, which has been reported to be effective in inhibiting breast cancer cell proliferation.

Results: Phyto-constituents of Cannabis sativa possess lower docking scores and good ΔGbind when compared to that of tamoxifen. ADME and AutoQSAR studies revealed that our lead compounds demonstrated the properties required to make them promising therapeutic agents.

Conclusion: The results of this study suggest that Naringenin, Dihydroresveratrol, Baicalein, Apigenin and Cannabitriol could have relatively better inhibitory activity than tamoxifen and could be a better and patent therapeutic candidate in the treatment of BC. Further research such as in vivo and/or in vitro assays could be conducted to attest the ability of these compounds.”

https://pubmed.ncbi.nlm.nih.gov/33563181/

https://www.eurekaselect.com/190950/article

 

The pro-apoptosis effects of Echinacea purpurea and Cannabis sativa extracts in human lung cancer cells through caspase-dependent pathway

 Logo of bmccmt“Considering the advantages of using medicinal herbs as supplementary treatments to sensitize conventional anti-cancer drugs, studying functional mechanisms and regulatory effects of Echinacea purpurea (as a non-cannabinoid plant) Image result for echinacea purpurea

and Cannabis sativa (as a cannabinoid plant) are timely and required.Image result for cannabis sativa

The potential effects of such herbs on lung cancer cell growth, apoptosis, cell cycle distribution, cellular reactive oxygen species (ROS) level, caspase activity and their cannabinomimetic properties on the CB2 receptor are addressed in the current study.

Results: Echinacea purpurea (EP) root extract induced a considerable decrease in A549 viable cells, showing a time and dose-dependent response. The cell toxicity of EP was accompanied by induction of early apoptosis and cell accumulation at the sub G1 phase of the cell cycle. The elevation of cellular ROS level and caspase 3 activity indicate ROS-induced caspase-dependent apoptosis following the treatment of A549 cells by EP extract. The observed effects of EP extract on A549 growth and death were abrogated following blockage of CB2 using AM630, a specific antagonist of the CB2 receptor. Increasing concentrations of Cannabis sativa (CS) induced A549 cell death in a time-dependent manner, followed by induction of early apoptosis, cell cycle arrest at sub G1 phase, elevation of ROS level, and activation of caspase 3. The CB2 blockage caused attenuation of CS effects on A549 cell death which revealed consistency with the effects of EP extract on A549 cells.

Conclusions: The pro-apoptotic effects of EP and CS extracts on A549 cells and their possible regulatory role of CB2 activity might be attributed to metabolites of both herbs. These effects deserve receiving more attention as alternative anti-cancer agents.”

https://pubmed.ncbi.nlm.nih.gov/33446187/

“Both cannabinoid receptors and naturally occurring cannabinoids, known as phytocannabinoids, have potential therapeutic applications based on their pivotal roles in regulating immunologic responses, alleviating inflammation, tumor cell proliferation, angiogenesis, invasion, and migration. Based on the findings, it can be postulated that EP and CS extracts can inhibit lung cancer cell growth and induce apoptosis and should be considered as an alternative anti-cancer agent in lung cancer.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7809807/

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The Role of Cannabinoids as Anticancer Agents in Pediatric Oncology

cancers-logo“Cannabinoids are a group of chemicals that bind to receptors in the human body and, in turn, modulate the endocannabinoid system (ECS). They can be endogenously produced, synthetic, or derived from the plant Cannabis sativa L.

Research over the past several decades has shown that the ECS is a cellular communication network essential to maintain multiple biological functions and the homeostasis of the body. Indeed, cannabinoids have been shown to influence a wide variety of biological effects, including memory, pain, reproduction, bone remodeling or immunity, to name a few.

Unsurprisingly, given these broad physiological effects, alterations of the ECS have been found in different diseases, including cancer. In recent years, the medical use of cannabis has been approved in different countries for a variety of human conditions. However, the use of these compounds, specifically as anticancer agents, remains controversial.

Studies have shown that cannabinoids do have anticancer activity in different tumor types such as breast cancer, melanoma, lymphoma and adult brain cancer. Specifically, phytocannabinoids Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) has been shown to induce apoptosis and inhibit proliferation of adult cancer cells, as well as modulate angiogenesis and metastasis.

Despite increasing evidence that cannabinoids elicit antitumor effects in adult cancers, there is minimal data available on their effects in children or in pediatric cancers despite public and clinical demand for information. Here we describe a comprehensive and critical review of what is known about the effects of cannabinoids on pediatric cancers, highlight current gaps in knowledge and identify the critical issues that need addressing before considering these promising but controversial drugs for use in pediatric oncology.”

https://pubmed.ncbi.nlm.nih.gov/33466435/

https://www.mdpi.com/2072-6694/13/1/157

Cannabis-Derived Compounds Cannabichromene and Δ9-Tetrahydrocannabinol Interact and Exhibit Cytotoxic Activity against Urothelial Cell Carcinoma Correlated with Inhibition of Cell Migration and Cytoskeleton Organization

molecules-logo“Cannabis sativa contains more than 500 constituents, yet the anticancer properties of the vast majority of cannabis compounds remains unknown. We aimed to identify cannabis compounds and their combinations presenting cytotoxicity against bladder urothelial carcinoma (UC), the most common urinary system cancer.

An XTT assay was used to determine cytotoxic activity of C. sativa extracts on T24 and HBT-9 cell lines. Extract chemical content was identified by high-performance liquid chromatography (HPLC). Fluorescence-activated cell sorting (FACS) was used to determine apoptosis and cell cycle, using stained F-actin and nuclei. Scratch and transwell assays were used to determine cell migration and invasion, respectively. Gene expression was determined by quantitative Polymerase chain reaction (PCR).

The most active decarboxylated extract fraction (F7) of high-cannabidiol (CBD) C. sativa was found to contain cannabichromene (CBC) and Δ9-tetrahydrocannabinol (THC). Synergistic interaction was demonstrated between CBC + THC whereas cannabinoid receptor (CB) type 1 and type 2 inverse agonists reduced cytotoxic activity.

Treatments with CBC + THC or CBD led to cell cycle arrest and cell apoptosis. CBC + THC or CBD treatments inhibited cell migration and affected F-actin integrity. Identification of active plant ingredients (API) from cannabis that induce apoptosis and affect cell migration in UC cell lines forms a basis for pre-clinical trials for UC treatment.”

https://pubmed.ncbi.nlm.nih.gov/33477303/

https://www.mdpi.com/1420-3049/26/2/465