Cannabinoids as anticancer therapeutic agents

The molecular anti-metastatic potential of CBD and THC from Lebanese Cannabis via apoptosis induction and alterations in autophagy

The medicinal plant Cannabis sativa L. (C. sativa) is currently being extensively studied to determine the full extent of its therapeutic pharmacological potential. Δ9-tetrahydocannabinol (THC) and cannabidiol (CBD) are the most thoroughly investigated compounds. We aimed to explore the anticancer activity of cannabinoids mixture isolated from the Lebanese C. sativa plant in ratios comparable to the local medicinal plant, to elucidate its mechanism of action in breast cancer cells in vitro. Cells were subjected to cytotoxicity assay, cell cycle analysis, Annexin V/PI dual staining, cell death ELISA, immunofluorescence, in addition to western blot analysis of apoptotic and autophagy markers. We further evaluated the anti-metastatic effect of cannabinoids on MDA-MB-231 using the scratch wound-healing, trans-well migration and invasion assays. Our results revealed the promising therapeutic benefits of CBD/THC on inhibiting the growth of breast cancer cells by promoting cellular fragmentation, phosphatidylserine translocation to the outer membrane leaflet and DNA fragmentation in both cell lines while inhibiting the motility of the triple negative breast cancer cells. In our study, CBD/THC mixture was found to exhibit a pro-apoptotic activity via the activation of the mitochondrial apoptotic pathway, independent from ROS production while also suggesting the activation of a caspase-dependent apoptotic pathway. Even though autophagy was altered upon exposure to the cannabinoid mixture, our data suggested that it is not the mechanism responsible of inducing cell death. In conclusion, our study demonstrates the promising therapeutic benefits of CBD and THC isolated from the Lebanese C. sativa plant on breast cancer cells in vitro.

Cannabinoid combination targets NOTCH1-mutated T-cell acute lymphoblastic leukemia through the integrated stress response pathway

In T-cell acute lymphoblastic leukemia (T-ALL), more than 50% of cases display autoactivation of Notch1 signaling, leading to oncogenic transformation. We have previously identified a specific chemovar of Cannabis that induces apoptosis by preventing Notch1 maturation in leukemia cells. Here, we isolated three cannabinoids from this chemovar that synergistically mimic the effects of the whole extract. Two were previously known, cannabidiol (CBD) and cannabidivarin (CBDV), whereas the third cannabinoid, which we termed 331-18A, was identified and fully characterized in this study. We demonstrated that these cannabinoids act through cannabinoid receptor type 2 and TRPV1 to activate the integrated stress response pathway by depleting intracellular Ca2+. This is followed by increased mRNA and protein expression of ATF4, CHOP, and CHAC1, which is hindered by inhibiting the upstream initiation factor eIF2α. The increased abundance of CHAC1 prevents Notch1 maturation, thereby reducing the levels of the active Notch1 intracellular domain, and consequently decreasing cell viability and increasing apoptosis. Treatment with the three isolated molecules resulted in reduced tumor size and weight in vivo and slowed leukemia progression in mice models. Altogether, this study elucidated the mechanism of action of three distinct cannabinoids in modulating the Notch1 pathway, and constitutes an important step in the establishment of a new therapy for treating NOTCH1-mutated diseases and cancers such as T-ALL.

Cannabidiol and fluorinated derivative anti-cancer properties against glioblastoma multiforme cell lines, and synergy with imidazotetrazine agents

BACKGROUND

Glioblastoma multiforme (GBM) is an aggressive cancer with poor prognosis, partly due to resistance to the standard chemotherapy treatment, temozolomide (TMZ). Phytocannabinoid cannabidiol (CBD) has exhibited anti-cancer effects against GBM, however, CBD's ability to overcome common resistance mechanisms to TMZ have not yet been investigated. 4'-Fluoro-cannabidiol (4'-F-CBD, or HUF-101/PECS-101) is a derivative of CBD, that exhibits increased activity compared to CBD during in vivo behavioural studies.

METHODS

This anti-cancer activity of cannabinoids against GBM cells sensitive to and representing major resistance mechanisms to TMZ was investigated. Cannabinoids were also studied in combination with imidazotetrazine agents, and advanced mass spectrometry with the 3D OrbiSIMS was used to investigate the mechanism of action of CBD.

RESULTS

CBD and 4'-F-CBD were found to overcome two major resistance mechanisms (methylguanine DNA-methyltransferase (MGMT) overexpression and DNA mismatch repair (MMR)-deficiency). Synergistic responses were observed when cells were exposed to cannabinoids and imidazotetrazine agents. Synergy increased with T25 and 4'-F-CBD. 3D OrbiSIMS analysis highlighted the presence of methylated-DNA, a previously unknown anti-cancer mechanism of action of CBD.

CONCLUSIONS

This work demonstrates the anti-cancer activity of 4'-F-CBD and the synergy of cannabinoids with imidazotetrazine agents for the first time and expands understanding of CBD mechanism of action.

Cannabidiol alleviates suture-induced corneal pathological angiogenesis and inflammation by inducing myeloid-derived suppressor cells

BACKGROUND

Currently, no perfect treatment for neovascularization and lymphangiogenesis exist, and each treatment method has its complications and side effects. This study aimed to investigate the anti-angiogenic and anti-inflammatory effects of cannabidiol and its mechanism of action.

METHOD

An in vivo corneal neovascularization (CNV) model was established using the suture method to investigate the inhibitory effects of CBD on suture-induced corneal inflammation, pathological blood vessel formation, and lymphangiogenesis. Additionally, the impact of CBD on immune cells was studied. In vitro methodologies, including cell sorting and co-culture, were employed to elucidate its mechanism of action.

RESULTS

Compared with the CNV group, CBD can inhibit CNV, lymphangiogenesis, and inflammation induced via the suture method. In addition, CBD specifically induced CD45+CD11b+Gr-1+ cell upregulation, which significantly inhibited the proliferation of CD4+ T lymphocytes in vitro and exhibited a CD31+ phenotype, proving that they were myeloid-derived suppressor cells (MDSCs). We administered anti-Gr-1 to mice to eliminate MDSCs in vivo and found that anti-Gr-1 partially reversed the anti-inflammatory and angiogenic effects of CBD. Furthermore, we found that compared with MDSCs in the normal group, CBD-induced MDSCs overexpress peroxisome proliferator-activated receptor-gamma (PPAR-γ). Administering PPAR-γ inhibitor in mice almost reversed the induction of MDSCs by CBD, demonstrating the role of PPAR-γ in the function of CBD.

CONCLUSION

This study indicates that CBD may induce MDSCs upregulation by activating the nuclear receptor PPAR-γ, exerting anti-inflammatory, antiangiogenic, and lymphangiogenic effects, and revealing potential therapeutic targets for corneal neovascularization and lymphangiogenesis.

Exploring anticancer properties of the phytoconstituents and comparative analysis of their chemical space parameters with USFDA-approved synthetic anticancer agents

The present review article thoroughly analyses natural products and their derived phytoconstituents as a rich source of plausible anticancer drugs. The study thoroughly explores the chemical components derived from various natural sources, thus emphasizing their unique structural characteristics and therapeutic potential as an anticancer agent. The review contains the critical chemical constituents' in-depth molecular mechanisms, their source's chemical structures and the categories. The review also comprises an exhaustive and comprehensive analysis of different chemical spacing parameters of the anticancer agents derived from natural products. It compares them with USFDA-approved synthetic anticancer drugs up to 2020, thus providing a meaningful understanding of the relationship between natural and synthetic compounds portraying the anticancer assets. The review also delves more deeply into the chemical analysis of the heterocyclic moieties from the natural product arena, illustrating the anticancer mechanisms. The present article is, therefore, expected to serve as a valuable resource for natural product and medicinal chemists, encouraging and promoting an integrated approach to exploit the potential of natural products in drug discovery development and translational research, which have a prerequisite of bench to bedside approach. The work could guide researchers toward innovative approaches for the ever-evolving field of anticancer drug discovery.

The Use of Compounds Derived from Cannabis sativa in the Treatment of Epilepsy, Painful Conditions, and Neuropsychiatric and Neurodegenerative Disorders

Neurological disorders present a wide range of symptoms and challenges in diagnosis and treatment. Cannabis sativa, with its diverse chemical composition, offers potential therapeutic benefits due to its anticonvulsive, analgesic, anti-inflammatory, and neuroprotective properties. Beyond cannabinoids, cannabis contains terpenes and polyphenols, which synergistically enhance its pharmacological effects. Various administration routes, including vaporization, oral ingestion, sublingual, and rectal, provide flexibility in treatment delivery. This review shows the therapeutic efficacy of cannabis in managing neurological disorders such as epilepsy, neurodegenerative diseases, neurodevelopmental disorders, psychiatric disorders, and painful pathologies. Drawing from surveys, patient studies, and clinical trials, it highlights the potential of cannabis in alleviating symptoms, slowing disease progression, and improving overall quality of life for patients. Understanding the diverse therapeutic mechanisms of cannabis can open up possibilities for using this plant for individual patient needs.

Synthesis of novel indol-3-acetamido analogues as potent anticancer agents, biological evaluation and molecular modeling studies

Cannabinoids bind to cannabinoid receptors CB1 and CB2 and their antitumoral activity has been reported against some various cancer cell lines. Some synthetic cannabinoids possessing indole rings such as JWH-015 and JWH-133 particularly bind to the cannabinoid CB2 receptor and it was reported that they inhibit the proliferation and growth of various cancer cells without their psychoactive effects. However, the pharmacological action mechanisms of the cannabinoids are completely unknown. In this study, we report the synthesis of some new cannabinoidic novel indoles and evaluate their anticancer activity on various cancerous and normal cell lines (U87, RPMI 8226, HL60 and L929) using several cellular and molecular assays including MTT assay, real-time q-PCR, scratch assay, DAPI assay, Annexin V-PE/7AAD staining, caspase3/7 activity tests. Our findings indicated that compounds 7, 10, 13, 16, and 17 could reduce cell viability effectively. Compound 17 markedly increased proapoptotic genes (BAX, BAD, and BIM), tumor suppressor gene (p53) expression levels as well as the BAX/BCL-2 ratio in U87 cells. In addition, 17 inhibited cell migration. Based on these results, 17 was chosen for determining the mechanism of cell death in U87 cells. DAPI and Annexin V-7AAD staining results showed that 17 induced apoptosis, moreover activated caspase 3/7 significantly. Hence, compound 17, was selected as a lead compound for further pharmacomodulation. To rationalize the observed biological activities of 17, our study also included a comprehensive analysis using molecular docking and MD simulations. This integrative approach revealed that 17 fits tightly into the active site of the CB2 receptor and is involved in key interactions that may be responsible for its anti-proliferative effects.

Effects of Cannabidiol, ∆9-Tetrahydrocannabinol, and WIN 55-212-22 on the Viability of Canine and Human Non-Hodgkin Lymphoma Cell Lines

In our previous study, we demonstrated the impact of overexpression of CB1 and CB2 cannabinoid receptors and the inhibitory effect of endocannabinoids (2-arachidonoylglycerol (2-AG) and Anandamide (AEA)) on canine (Canis lupus familiaris) and human (Homo sapiens) non-Hodgkin lymphoma (NHL) cell lines' viability compared to cells treated with a vehicle. The purpose of this study was to demonstrate the anti-cancer effects of the phytocannabinoids, cannabidiol (CBD) and ∆9-tetrahydrocannabinol (THC), and the synthetic cannabinoid WIN 55-212-22 (WIN) in canine and human lymphoma cell lines and to compare their inhibitory effect to that of endocannabinoids. We used malignant canine B-cell lymphoma (BCL) (1771 and CLB-L1) and T-cell lymphoma (TCL) (CL-1) cell lines, and human BCL cell line (RAMOS). Our cell viability assay results demonstrated, compared to the controls, a biphasic effect (concentration range from 0.5 μM to 50 μM) with a significant reduction in cancer viability for both phytocannabinoids and the synthetic cannabinoid. However, the decrease in cell viability in the TCL CL-1 line was limited to CBD. The results of the biochemical analysis using the 1771 BCL cell line revealed a significant increase in markers of oxidative stress, inflammation, and apoptosis, and a decrease in markers of mitochondrial function in cells treated with the exogenous cannabinoids compared to the control. Based on the IC50 values, CBD was the most potent phytocannabinoid in reducing lymphoma cell viability in 1771, Ramos, and CL-1. Previously, we demonstrated the endocannabinoid AEA to be more potent than 2-AG. Our study suggests that future studies should use CBD and AEA for further cannabinoid testing as they might reduce tumor burden in malignant NHL of canines and humans.

Immunotherapy and Cannabis: A Harmful Drug Interaction or Reefer Madness?

A retrospective (N = 140) and a prospective (N = 102) observational Israeli study by Bar-Sela and colleagues about cannabis potentially adversely impacting the response to immunotherapy have together been cited 202 times, including by clinical practice guidelines. There have also been concerns on PubPeer outlining irregularities and unverifiable information in their statistics and numerous errors in calculating percentages. This reanalysis attempted to verify the data analysis while including non-parametric statistics. The corrected prospective report contained 22 p-values, but only one (4.5%) could be verified despite the authors being transparent about the N and statistics employed. Cannabis users were significantly (p < 0.0025) younger than non-users, but this was not reported in the retrospective report. There were also errors in percentage calculations (e.g., 13/34 reported as 22.0% instead of 38.2%). Overall, these observational investigations, and especially the prospective, appear to contain gross inaccuracies which could impact the statistical decisions (i.e., significant findings reported as non-significant or vice-versa). Although it is mechanistically plausible that cannabis could have immunosuppressive effects which inhibit the response to immunotherapy, these two reports should be viewed cautiously. Larger prospective studies of this purported drug interaction that account for potential confounds (e.g., greater nicotine smoking among cannabis users) may be warranted.

Biology and pathophysiology of symptomatic neuromas

ABSTRACT

Neuromas are a substantial cause of morbidity and reduction in quality of life. This is not only caused by a disruption in motor and sensory function from the underlying nerve injury but also by the debilitating effects of neuropathic pain resulting from symptomatic neuromas. A wide range of surgical and therapeutic modalities have been introduced to mitigate this pain. Nevertheless, no single treatment option has been successful in completely resolving the associated constellation of symptoms. While certain novel surgical techniques have shown promising results in reducing neuroma-derived and phantom limb pain, their effectiveness and the exact mechanism behind their pain-relieving capacities have not yet been defined. Furthermore, surgery has inherent risks, may not be suitable for many patients, and may yet still fail to relieve pain. Therefore, there remains a great clinical need for additional therapeutic modalities to further improve treatment for patients with devastating injuries that lead to symptomatic neuromas. However, the molecular mechanisms and genetic contributions behind the regulatory programs that drive neuroma formation-as well as the resulting neuropathic pain-remain incompletely understood. Here, we review the histopathological features of symptomatic neuromas, our current understanding of the mechanisms that favor neuroma formation, and the putative contributory signals and regulatory programs that facilitate somatic pain, including neurotrophic factors, neuroinflammatory peptides, cytokines, along with transient receptor potential, and ionotropic channels that suggest possible approaches and innovations to identify novel clinical therapeutics.

Investigating the Effects of a Synthetic Cannabinoid on the Pathogenesis of Leukemia and Leukemic Stem Cells: A New Therapeutic Approach

The popularity and usage of synthetic cannabinoids (SCs) are increasing due to their easy accessibility and psychoactive effects worldwide. Studies on cannabinoids on leukemic stem cells (LSC) and hematopoietic stem cells (HSCs), which are the precursors of leukemia cells, generally depend on the natural cannabinoid delta-9-THC. As there is only a limited number of studies focusing on the results of SC applications, the reflections upon LSCs have to be clarified. In this study, biological responses and antileukemic effects of JWH-018-one of the first produced and widely used SCs-were evaluated upon leukemia cells. Whether JWH-018 exhibited a preventive effect on both leukemic and HSCs was evaluated by presenting a therapeutic approach for the first time in the literature. Cells were analyzed in case of cell proliferation, apoptosis, and transcriptional expression profiling of some significant JAK/STAT and AKT/mTOR pathways, apoptotic, cell cycle regulation, and epigenetic chromatin remodeling-related genes following JWH-018 treatment. In conclusion, however, further studies are still needed upon both HSCs and LSCs to illuminate the effects of SCs on leukemogenesis on chronic myeloid leukemia (CML) more clearly; we consider that the JWH-018 can provide a therapeutic effect on the pathogenesis of leukemia and particularly upon LSCs and SCs might have therapeutic potential in addition to current therapy.

Integrated transcriptome and cell phenotype analysis suggest involvement of PARP1 cleavage, Hippo/Wnt, TGF-β and MAPK signaling pathways in ovarian cancer cells response to cannabis and PARP1 inhibitor treatment

Introduction: Cannabis sativa is utilized mainly for palliative care worldwide. Ovarian cancer (OC) is a lethal gynecologic cancer. A particular cannabis extract fraction ('F7') and the Poly(ADP-Ribose) Polymerase 1 (PARP1) inhibitor niraparib act synergistically to promote OC cell apoptosis. Here we identified genetic pathways that are altered by the synergistic treatment in OC cell lines Caov3 and OVCAR3. Materials and methods: Gene expression profiles were determined by RNA sequencing and quantitative PCR. Microscopy was used to determine actin arrangement, a scratch assay to determine cell migration and flow cytometry to determine apoptosis, cell cycle and aldehyde dehydrogenase (ALDH) activity. Western blotting was used to determine protein levels. Results: Gene expression results suggested variations in gene expression between the two cell lines examined. Multiple genetic pathways, including Hippo/Wnt, TGF-β/Activin and MAPK were enriched with genes differentially expressed by niraparib and/or F7 treatments in both cell lines. Niraparib + F7 treatment led to cell cycle arrest and endoplasmic reticulum (ER) stress, inhibited cell migration, reduced the % of ALDH positive cells in the population and enhanced PARP1 cleavage. Conclusion: The synergistic effect of the niraparib + F7 may result from the treatment affecting multiple genetic pathways involving cell death and reducing mesenchymal characteristics.

Role of Cannabinoids in Oral Cancer

Cannabinoids have incited scientific interest in different conditions, including malignancy, due to increased exposure to cannabis. Furthermore, cannabinoids are increasingly used to alleviate cancer-related symptoms. This review paper aims to clarify the recent findings on the relationship between cannabinoids and oral cancer, focusing on the molecular mechanisms that could link cannabinoids with oral cancer pathogenesis. In addition, we provide an overview of the current and future perspectives on the management of oral cancer patients using cannabinoid compounds. Epidemiological data on cannabis use and oral cancer development are conflicting. However, in vitro studies assessing the effects of cannabinoids on oral cancer cells have unveiled promising anti-cancer features, including apoptosis and inhibition of cell proliferation. Downregulation of various signaling pathways with anti-cancer effects has been identified in experimental models of oral cancer cells exposed to cannabinoids. Furthermore, in some countries, several synthetic or phytocannabinoids have been approved as medical adjuvants for the management of cancer patients undergoing chemoradiotherapy. Cannabinoids may improve overall well-being by relieving anxiety, depression, pain, and nausea. In conclusion, the link between cannabinoid compounds and oral cancer is complex, and further research is necessary to elucidate the potential risks or their protective impact on oral cancer.

Cannabinoids in anesthesia and chronic pain: Where do we stand?

Cannabis derivatives have been conventionally employed globally for their curative and restorative properties for various ailments. However, its recreational use and consequent legal restrictions have substantially cramped its scientific research. An emerging interest regarding the profound therapeutic potential of cannabinoids has been observed among clinicians. Despite a rich cultural background, high-quality research on cannabinoids is lacking in the Indian scenario. This review readdresses the challenges on this front and brings an insight into the current status of cannabinoids and their utility in scientific exploration. Cannabinoids have a significant medicinal value in various clinical disorders. Its use so far has been based on scarce resources and corroborations, as evidence-based substantiation is limited. Through this review article, we emphasize the remarkable role enacted by cannabinoids in the treatment of various clinical disorders and an utterly significant need to formulate stringent research methodologies to promote its systematic investigation.

Exploring the therapeutic potential of natural compounds modulating the endocannabinoid system in various diseases and disorders: review

Cannabinoid receptors, endogenous cannabinoids (endocannabinoids), and the enzymes involved in the biosynthesis and degradation of the endocannabinoids make up the endocannabinoid system (ECS). The components of the ECS are proven to modulate a vast bulk of various physiological and pathological processes due to their abundance throughout the human body. Such discoveries have attracted the researchers' attention and emerged as a potential therapeutical target for the treatment of various diseases. In the present article, we reviewed the discoveries of natural compounds, herbs, herbs formula, and their therapeutic properties in various diseases and disorders by modulating the ECS. We also summarize the molecular mechanisms through which these compounds elicit their properties by interacting with the ECS based on the existing findings. Our study provides the insight into the use of natural compounds that modulate ECS in various diseases and disorders, which in turn may facilitate future studies exploiting natural lead compounds as novel frameworks for designing more effective and safer therapeutics.

Targeting Nrf2 Signaling Pathway in Cancer Prevention and Treatment: The Role of Cannabis Compounds

The development and progression of cancer are associated with the dysregulation of multiple pathways involved in cell proliferation and survival, as well as dysfunction in redox balance, immune response, and inflammation. The master antioxidant pathway, known as the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, regulates the cellular defense against oxidative stress and inflammation, making it a promising cancer prevention and treatment target. Cannabinoids have demonstrated anti-tumor and anti-inflammatory properties, affecting signaling pathways, including Nrf2. Increased oxidative stress following exposure to anti-cancer therapy prompts cancer cells to activate antioxidant mechanisms. This indicates the dual effect of Nrf2 in cancer cells-influencing proliferation and apoptotic processes and protecting against the toxicity of anti-cancer therapy. Therefore, understanding the complex role of cannabinoids in modulating Nrf2 might shed light on its potential implementation as an anti-cancer support. In this review, we aim to highlight the impact of cannabinoids on Nrf2-related factors, with a focus on cancer prevention and treatment. Additionally, we have presented the results of several research studies that combined cannabidiol (CBD) with other compounds targeting Nrf2. Further studies should be directed toward exploring the anti-inflammatory effects of cannabinoids in the context of cancer prevention and therapy.

Cannabis as a Source of Approved Drugs: A New Look at an Old Problem

Cannabis plants have been used in medicine since ancient times. They are well known for their anti-diabetic, anti-inflammatory, neuroprotective, anti-cancer, anti-oxidative, anti-microbial, anti-viral, and anti-fungal activities. A growing body of evidence indicates that targeting the endocannabinoid system and various other receptors with cannabinoid compounds holds great promise for addressing multiple medical conditions. There are two distinct avenues in the development of cannabinoid-based drugs. The first involves creating treatments directly based on the components of the cannabis plant. The second involves a singular molecule strategy, in which specific phytocannabinoids or newly discovered cannabinoids with therapeutic promise are pinpointed and synthesized for future pharmaceutical development and validation. Although the therapeutic potential of cannabis is enormous, few cannabis-related approved drugs exist, and this avenue warrants further investigation. With this in mind, we review here the medicinal properties of cannabis, its phytochemicals, approved drugs of natural and synthetic origin, pitfalls on the way to the widespread clinical use of cannabis, and additional applications of cannabis-related products.

Tetrahydrocannabinols: potential cannabimimetic agents for cancer therapy

Tetrahydrocannabinols (THCs) antagonize the CB1 and CB2 cannabinoid receptors, whose signaling to the endocannabinoid system is essential for controlling cell survival and proliferation as well as psychoactive effects. Most tumor cells express a much higher level of CB1 and CB2; THCs have been investigated as potential cancer therapeutic due to their cannabimimetic properties. To date, THCs have been prescribed as palliative medicine to cancer patients but not as an anticancer modality. Growing evidence of preclinical research demonstrates that THCs reduce tumor progression by stimulating apoptosis and autophagy and inhibiting two significant hallmarks of cancer pathogenesis: metastasis and angiogenesis. However, the degree of their anticancer effects depends on the origin of the tumor site, the expression of cannabinoid receptors on tumor cells, and the dosages and types of THC. This review summarizes the current state of knowledge on the molecular processes that THCs target for their anticancer effects. It also emphasizes the substantial knowledge gaps that should be of concern in future studies. We also discuss the therapeutic effects of THCs and the problems that will need to be addressed in the future. Clarifying unanswered queries is a prerequisite to translating the THCs into an effective anticancer regime.

The Influence of Oral Cannabidiol on 24-h Ambulatory Blood Pressure and Arterial Stiffness in Untreated Hypertension: A Double-Blind, Placebo-Controlled, Cross-Over Pilot Study

INTRODUCTION

Studies reveal that cannabidiol may acutely reduce blood pressure and arterial stiffness in normotensive humans; however, it remains unknown if this holds true in patients with untreated hypertension. We aimed to extend these findings to examine the influence of the administration of cannabidiol on 24-h ambulatory blood pressure and arterial stiffness in hypertensive individuals.

METHODS

Sixteen volunteers (eight females) with untreated hypertension (elevated blood pressure, stage 1, stage 2) were given oral cannabidiol (150 mg every 8 h) or placebo for 24 h in a randomised, placebo-controlled, double-blind, cross-over study. Measures of 24-h ambulatory blood pressure and electrocardiogram (ECG) monitoring and estimates of arterial stiffness and heart rate variability were obtained. Physical activity and sleep were also recorded.

RESULTS

Although physical activity, sleep patterns and heart rate variability were comparable between groups, arterial stiffness (~ 0.7 m/s), systolic blood pressure (~ 5 mmHg), and mean arterial pressure (~ 3 mmHg) were all significantly (P < 0.05) lower over 24 h on cannabidiol when compared to the placebo. These reductions were generally larger during sleep. Oral cannabidiol was safe and well tolerated with no development of new sustained arrhythmias.

CONCLUSIONS

Our findings indicate that acute dosing of cannabidiol over 24 h can lower blood pressure and arterial stiffness in individuals with untreated hypertension. The clinical implications and safety of longer-term cannabidiol usage in treated and untreated hypertension remains to be established.

The Anti-Inflammatory Effects of Cannabis sativa Extracts on LPS-Induced Cytokines Release in Human Macrophages

Inflammation is the response of the innate immune system to any type of injury. Although acute inflammation is critical for survival, dysregulation of the innate immune response leads to chronic inflammation. Many synthetic anti-inflammatory drugs have side effects, and thus, natural anti-inflammatory compounds are still needed. Cannabis sativa L. may provide a good source of anti-inflammatory molecules. Here, we tested the anti-inflammatory properties of cannabis extracts and pure cannabinoids in lipopolysaccharide (LPS)-induced inflammation in human THP-1 macrophages. We found that pre-treatment with cannabidiol (CBD), delta-9-tetrahydrocannabinol (THC), or extracts containing high levels of CBD or THC reduced the level of induction of various cytokines. The CBD was more efficient than THC, and the extracts were more efficient than pure cannabinoids. Finally, IL-6, IL-10, and MCP-1 cytokines were most sensitive to pre-treatments with CBD and THC, while IL-1β, IL-8, and TNF-α were less responsive. Thus, our work demonstrates the potential of the use of cannabinoids or/and cannabis extracts for the reduction of inflammation and establishes IL-6 and MCP-1 as the sensitive markers for the analysis of the effect of cannabinoids on inflammation in macrophages.

Cytotoxic Effects of Combinative ZnPcS4 Photosensitizer Photodynamic Therapy (PDT) and Cannabidiol (CBD) on a Cervical Cancer Cell Line

The most prevalent type of gynecological malignancy globally is cervical cancer (CC). Complicated by tumor resistance and metastasis, it remains the leading cause of cancer deaths in women in South Africa. Early CC is managed by hysterectomy, chemotherapy, radiation, and more recently, immunotherapy. Although these treatments provide clinical benefits, many patients experience adverse effects and secondary CC spread. To minimize this, novel and innovative treatment methods need to be investigated. Photodynamic therapy (PDT) is an advantageous treatment modality that is non-invasive, with limited side effects. The Cannabis sativa L. plant isolate, cannabidiol (CBD), has anti-cancer effects, which inhibit tumor growth and spread. This study investigated the cytotoxic combinative effect of PDT and CBD on CC HeLa cells. The effects were assessed by exposing in vitro HeLa CC-cultured cells to varying doses of ZnPcS₄ photosensitizer (PS) PDT and CBD, with a fluency of 10 J/cm² and 673 nm irradiation. HeLa CC cells, which received the predetermined lowest dose concentrations (ICD₅₀) of 0.125 µM ZnPcS₄ PS plus 0.5 µM CBD to yield 50% cytotoxicity post-laser irradiation, reported highly significant and advantageous forms of cell death. Flow cytometry cell death pathway quantitative analysis showed that only 13% of HeLa cells were found to be viable, 7% were in early apoptosis and 64% were in late favorable forms of apoptotic cell death, with a minor 16% of necrosis post-PDT. Findings suggest that this combined treatment approach can possibly induce primary cellular destruction, as well as limit CC metastatic spread, and so warrants further investigation.

Cannabinoids as Prospective Anti-Cancer Drugs: Mechanism of Action in Healthy and Cancer Cells

Endogenous and exogenous cannabinoids modulate many physiological and pathological processes by binding classical cannabinoid receptors 1 (CB1) or 2 (CB2) or non-cannabinoid receptors. Cannabinoids are known to exert antiproliferative, apoptotic, anti-migratory and anti-invasive effect on cancer cells by inducing or inhibiting various signaling cascades. In this chapter, we specifically emphasize the latest research works about the alterations in endocannabinoid system (ECS) components in malignancies and cancer cell proliferation, migration, invasion, angiogenesis, autophagy, and death by cannabinoid administration, emphasizing their mechanism of action, and give a future perspective for clinical use.

Anticancer and chemosensitization effects of cannabidiol in 2D and 3D cultures of TNBC: involvement of GADD45α, integrin-α5, -β5, -β1, and autophagy

To date, promising therapy for triple negative breast cancer (TNBC) remains a serious concern clinically because of poor prognosis, resistance, and recurrence. Herein, anti-cancer potential of synthetic cannabidiol (CBD; Purisys, GA; GMP grade) was explored either alone or as a chemosensitizer followed by post-treatment with doxorubicin (DOX) in TNBC (i.e., MDA-MB-231 and MDA-MB-468) cells. In comparison to 2D cultures, CBD showed greater IC₅₀ values in 3D (LDP2 hydrogel based) cultures of MDA-MB-231 (6.26-fold higher) and MDA-MB-468 (10.22-fold higher) cells. Next-generation RNA sequencing revealed GADD45A, GADD45G, FASN, LOX, and integrin (i.e., -α5, -β5) genes to be novelly altered by CBD in MDA-MB-231 cells. CIM-16 plate-based migration assay and western blotting disclosed that CBD induces anti-migratory effects in TNBC cells by decreasing fibronectin, vimentin, and integrins-α5, -β5, and -β1. Western blotting, RT-qPCR, and immunocytochemistry revealed that CBD inhibited autophagy (decreased Beclin1, and ATG-5, -7, and -16) of TNBC cells. CBD pre-treatment increased DOX sensitivity in TNBC cells. CBD pre-treatment accompanied by DOX treatment decreased LOX and integrin-α5, and increased caspase 9 protein respectively in MDA-MB-468 cells.

Antiviral activity of medicinal plant-derived products against SARS-CoV-2

This review presents information from several studies that have demonstrated the antiviral activity of extracts (Andrographis paniculata, Artemisia annua, Artemisia afra, Cannabis sativa, Curcuma longa, Echinacea purpurea, Olea europaea, Piper nigrum, and Punica granatum) and phytocompounds derived from medicinal plants (artemisinins, glycyrrhizin, and phenolic compounds) against SARS-CoV-2. A brief background of the plant products studied, the methodology used to evaluate the antiviral activity, the main findings from the research, and the possible mechanisms of action are presented. These plant products have been shown to impede the adsorption of SARS-CoV-2 to the host cell, and prevent multiplication of the virus post its entry into the host cell. In addition to antiviral activity, the plant products have also been demonstrated to exert an immunomodulatory effect by controlling the excessive release of cytokines, which is commonly associated with SARS-CoV-2 infections.

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

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.

An Examination of the Anti-Cancer Properties of Plant Cannabinoids in Preclinical Models of Mesothelioma

Simple Summary

Mesothelioma is a deadly disease with few treatment options. Phytocannabinoids derived from the cannabis plant are garnering interest for their anti-cancer properties, however very little is known about their effects in mesothelioma. We aimed to assess whether phytocannabinoids have anti-cancer effects in mesothelioma and potential modes of action. We showed that several phytocannabinoids inhibited growth of mesothelioma cells, with two phytocannabinoids, cannabidiol (CBD) and cannabigerol (CBG), being the most potent. CBD and CBG also inhibited mesothelioma cell migration and invasion. Gene expression analysis highlighted signalling pathways that play a role in how CBD and CBG may exert their anti-cancer effects. CBD and CBG were unable to increase survival in a rat model of mesothelioma but this may be due to limitations in the drug delivery method.

Abstract

Mesothelioma is an aggressive cancer with limited treatment options and a poor prognosis. Phytocannabinoids possess anti-tumour and palliative properties in multiple cancers, however their effects in mesothelioma are unknown. We investigated the anti-cancer effects and potential mechanisms of action for several phytocannabinoids in mesothelioma cell lines. A panel of 13 phytocannabinoids inhibited growth of human (MSTO and H2452) and rat (II-45) mesothelioma cells in vitro, and cannabidiol (CBD) and cannabigerol (CBG) were the most potent compounds. Treatment with CBD or CBG resulted in G0/G1 arrest, delayed entry into S phase and induced apoptosis. CBD and CBG also significantly reduced mesothelioma cell migration and invasion. These effects were supported by changes in the expression of genes associated with the cell cycle, proliferation, and cell movement following CBD or CBG treatment. Gene expression levels of CNR1, GPR55, and 5HT1A also increased with CBD or CBG treatment. However, treatment with CBD or CBG in a syngeneic orthotopic rat mesothelioma model was unable to increase survival. Our data show that cannabinoids have anti-cancer effects on mesothelioma cells in vitro and alternatives of drug delivery may be needed to enhance their effects in vivo.

Improved Therapeutic Efficacy of CBD with Good Tolerance in the Treatment of Breast Cancer through Nanoencapsulation and in Combination with 20(S)-Protopanaxadiol (PPD)

Cannabidiol (CBD), a nonpsychoactive major component derived from Cannabis sativa, widely used in neurodegenerative diseases, has now been proven to have growth inhibitory effects on many tumor cell lines, including breast tumors. Meanwhile CBD can effectively alleviate cancer-associated pain, anxiety, and depression, especially tumor cachexia, thus it is very promising as an anti-tumor drug with unique advantages. 20(S)-Protopanaxadiol (PPD) derived from the best-known tonic Chinese herbal medicine Ginseng was designed to be co-loaded with CBD into liposomes to examine their synergistic tumor-inhibitory effect. The CBD-PPD co-loading liposomes (CP-liposomes) presented a mean particle size of 138.8 nm. Further glycosyl-modified CP-liposomes (GMCP-liposomes) were prepared by the incorporation of n-Dodecyl β-D-maltoside (Mal) into the liposomal bilayer with glucose residue anchored on the surface to act as a ligand targeting the GLUT1 receptor highly expressed on tumor cells. In vivo studies on murine breast tumor (4T1 cells)-bearing BALB/c mice demonstrated good dose dependent anti-tumor efficacy of CP-liposomes. A high tumor inhibition rate (TIR) of 82.2% was achieved with good tolerance. However, glycosylation modification failed to significantly enhance TIR of CP-liposomes. In summary, combined therapy with PPD proved to be a promising strategy for CBD to be developed into a novel antitumor drug, with characteristics of effectiveness, good tolerance, and the potential to overcome tumor cachexia.

Acute Cannabigerol Administration Lowers Blood Pressure in Mice

Cannabigerol is a cannabinoid compound synthesized by Cannabis sativa, which in its acid form acts as the substrate for both Δ⁹-tetraydrocannabinol and cannabidiol formation. Given its lack of psychoactive effects, emerging research has focused on cannabigerol as a potential therapeutic for health conditions including algesia, epilepsy, anxiety, and cancer. While cannabigerol can bind to classical cannabinoid receptors, it is also an agonist at α2-adrenoreceptors (α2AR) which, when activated, inhibit presynaptic norepinephrine release. This raises the possibility that cannabigerol could activate α2AR to reduce norepinephrine release to cardiovascular end organs to lower blood pressure. Despite this possibility, there are no reports examining cannabigerol cardiovascular effects. In this study, we tested the hypothesis that acute cannabigerol administration lowers blood pressure. Blood pressure was assessed via radiotelemetry at baseline and following intraperitoneal injection of cannabigerol (3.3 and 10 mg/kg) or vehicle administered in a randomized crossover design in male C57BL/6J mice. Acute cannabigerol significantly lowered mean blood pressure (-28 ± 2 mmHg with 10 mg/kg versus -12 ± 5 mmHg vehicle, respectively; p = 0.018), with no apparent dose responsiveness (-22 ± 2 mmHg with 3.3 mg/kg). The depressor effect of cannabigerol was lower in magnitude than the α2AR agonist guanfacine and was prevented by pretreatment with the α2AR antagonist atipamezole. These findings suggest that acute cannabigerol lowers blood pressure in phenotypically normal mice likely via an α2AR mechanism, which may be an important consideration for therapeutic cannabigerol administration.

Cannabinoids orchestrate cross-talk between cancer cells and endothelial cells in colorectal cancer

Medical marijuana has been approved by the FDA for treating chemotherapy-induced nausea and vomiting. However, less is known about its direct effects on tumor cells and the tumor microenvironment. In this study, RNA-sequencing datasets in the NCBI GEO repository were first analyzed; upregulation of cannabinoid receptors was observed in both primary and metastatic colorectal cancer (CRC) tumor tissues. An increase of cannabinoid receptors was also found in patients with CRC, azoxymethane/dextran sulfate sodium-induced CRC and CRC metastatic mouse models. Δ⁹-Tetrahydrocannabinol (Δ⁹-THC)-induced tumor progression in both primary and metastatic mouse models and also increased angiogenesis. A human growth factor antibody array indicated that Δ⁹-THC promoted the secretion of angiogenic growth factors in CRC, leading to the induction of tube formation and migration in human-induced pluripotent stem cell-derived vascular endothelial cells. The nuclear translocation of STAT1 played important roles in Δ⁹-THC-induced angiogenesis and tumor progression. Pharmacological treatment with STAT1 antagonist or abrogation of STAT1 with CRISPR/Cas9-based strategy rescued those effects of Δ⁹-THC in CRC. This study demonstrates that marijuana might increase the risk of CRC progression and that inhibition of STAT1 is a potential strategy for attenuating these side effects.

Cannabinol Inhibits Cellular Proliferation, Invasion, and Angiogenesis of Neuroblastoma via Novel miR-34a/tRiMetF31/PFKFB3 Axis

Simple Summary

The prognosis of high-risk neuroblastoma is poor due to its high relapse rate. To date, no effective treatment for this disease has been developed. In this study, we utilized two neuroblastoma cell lines (IMR-5 and SK-N-AS) as a model system to explore the effects of cannabinol (CBN) on neuroblastoma and elucidate the potential mechanisms of action. We reveal an inhibitory role of CBN on neuroblastoma cell proliferation, invasion, and angiogenesis through miR-34a-mediated targeting. We identified 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) as a direct target of a novel 31 nt tRNA_i^Met fragment tRiMetF31 generated from miR-34a-guided cleavage, highlighting the crucial role of the miR-34a/tRiMetF31/PFKFB3 axis in CBN-mediated suppression in neuroblastoma biology.

Abstract

High-risk neuroblastoma is an aggressive pediatric tumor. Despite great advances in neuroblastoma therapy and supportive care protocols, no curative treatment is available for most patients with this disease. Here, we uncover that CBN attenuated the cell proliferation, invasion, and angiogenesis of neuroblastoma cell lines in a dose-dependent manner via the inhibition of the AKT pathway and the upregulation of miR-34a that targets E2F1. Both miR-34a and a 31-nt tRNA_i^Met fragment (tRiMetF31) derived from miR-34a-guided cleavage were downregulated in 4 examined neuroblastoma cell lines inversely correlated with the levels of its direct target, the PFKFB3 protein. Moreover, ectopic tRiMetF31 suppressed proliferation, migration, and angiogenesis in the studied neuroblastoma cell lines. Conversely, tRiMetF31 knockdown promoted PFKFB3 expression, resulting in enhanced angiogenesis. Our findings reveal a suppressive role of CBN in neuroblastoma tumorigenesis, highlighting a novel and crucial miR-34a tumor suppressor network in CBN’s antineuroblastoma actions.

A Low Dose of Pure Cannabidiol Is Sufficient to Stimulate the Cytotoxic Function of CIK Cells without Exerting the Downstream Mediators in Pancreatic Cancer Cells

Despite numerous studies conducted over the past decade, the exact role of the cannabinoid system in cancer development remains unclear. Though research has focused on two cannabinoid receptors (CB1, CB2) activated by most cannabinoids, CB2 holds greater attention due to its expression in cells of the immune system. In particular, cytokine-induced killer cells (CIKs), which are pivotal cytotoxic immunological effector cells, express a high-level of CB2 receptors. Herein, we sought to investigate whether inducing CIK cells with cannabidiol can enhance their cytotoxicity and if there are any possible counter effects in its downstream cascade of phosphorylated p38 and CREB using a pancreatic ductal adenocarcinoma cell line (PANC-1). Our results showed that IL-2 modulates primarily the expression of the CB2 receptor on CIK cells used during ex vivo CIK expansion. The autophagosomal-associated scaffold protein p62 was found to co-localize with CB2 receptors in CIK cells and the PANC-1 cell line. CIK cells showed a low level of intracellular phospho-p38 and, when stimulated with cannabidiol (CBD), a donor specific variability in phospho-CREB. CBD significantly decreases the viability of PANC-1 cells presumably by increasing the cytotoxicity of CIK cells. Taken together, in our preclinical in vitro study, we propose that a low effective dose of CBD is sufficient to stimulate the cytotoxic function of CIK without exerting any associated mediator. Thus, the combinatorial approach of non-psychoactive CBD and CIK cells appears to be safe and can be considered for a clinical perspective in pancreatic cancer.

Cannabis Biomolecule Effects on Cancer Cells and Cancer Stem Cells: Cytotoxic, Anti-Proliferative, and Anti-Migratory Activities

Cancer is a complex family of diseases affecting millions of people worldwide. Gliomas are primary brain tumors that account for ~80% of all malignant brain tumors. Glioblastoma multiforme (GBM) is the most common, invasive, and lethal subtype of glioma. Therapy resistance and intra-GBM tumoral heterogeneity are promoted by subpopulations of glioma stem cells (GSCs). Cannabis sativa produces hundreds of secondary metabolites, such as flavonoids, terpenes, and phytocannabinoids. Around 160 phytocannabinoids have been identified in C. sativa. Cannabis is commonly used to treat various medical conditions, and it is used in the palliative care of cancer patients. The anti-cancer properties of cannabis compounds include cytotoxic, anti-proliferative, and anti-migratory activities on cancer cells and cancer stem cells. The endocannabinoids system is widely distributed in the body, and its dysregulation is associated with different diseases, including various types of cancer. Anti-cancer activities of phytocannabinoids are mediated in glioma cells, at least partially, by the endocannabinoid receptors, triggering various cellular signaling pathways, including the endoplasmic reticulum (ER) stress pathway. Specific combinations of multiple phytocannabinoids act synergistically against cancer cells and may trigger different anti-cancer signaling pathways. Yet, due to scarcity of clinical trials, there remains no solid basis for the anti-cancer therapeutic potential of cannabis compounds.

Medical Cannabis in Pediatric Oncology: Friend or Foe?

The antineoplastic effects of cannabis have been known since 1975. Since the identification of the components of the endogenous cannabinoid system (ECS) in the 1990s, research into the potential of cannabinoids as medicine has exploded, including in anti-cancer research. However, nearly all of this research has been on adults. Physicians and governing bodies remain cautious in recommending the use of cannabis in children, since the ECS develops early in life and data about cannabis exposure in utero show negative outcomes. However, there exist many published cases of use of cannabis in children to treat pediatric epilepsy and chemotherapy-induced nausea and vomiting (CINV) that show both the safety and efficacy of cannabis in pediatric populations. Additionally, promising preclinical evidence showing that cannabis has anti-cancer effects on pediatric cancer warrants further investigation of cannabis' use in pediatric cancer patients, as well as other populations of pediatric patients. This review aims to examine the evidence regarding the potential clinical utility of cannabis as an anti-cancer treatment in children by summarizing what is currently known about uses of medical cannabis in children, particularly regarding its anti-cancer potential.

Inhibitors of Bacterial Extracellular Vesicles

Both Gram-positive and Gram-negative bacteria can secrete extracellular vesicles (EVs), which contain numerous active substances. EVs mediate bacterial interactions with their hosts or other microbes. Bacterial EVs play a double-edged role in infections through various mechanisms, including the delivery of virulence factors, modulating immune responses, mediating antibiotic resistance, and inhibiting competitive microbes. The spread of antibiotic resistance continues to represent a difficult clinical challenge. Therefore, the investigation of novel therapeutics is a valuable research endeavor for targeting antibiotic-resistant bacterial infections. As a pathogenic substance of bacteria, bacterial EVs have gained increased attention. Thus, EV inhibitors are expected to function as novel antimicrobial agents. The inhibition of EV production, EV activity, and EV-stimulated inflammation are considered potential pathways. This review primarily introduces compounds that effectively inhibit bacterial EVs and evaluates the prospects of their application.

Anti-Microbial Activity of Phytocannabinoids and Endocannabinoids in the Light of Their Physiological and Pathophysiological Roles

Antibiotic resistance has become an increasing challenge in the treatment of various infectious diseases, especially those associated with biofilm formation on biotic and abiotic materials. There is an urgent need for new treatment protocols that can also target biofilm-embedded bacteria. Many secondary metabolites of plants possess anti-bacterial activities, and especially the phytocannabinoids of the Cannabis sativa L. varieties have reached a renaissance and attracted much attention for their anti-microbial and anti-biofilm activities at concentrations below the cytotoxic threshold on normal mammalian cells. Accordingly, many synthetic cannabinoids have been designed with the intention to increase the specificity and selectivity of the compounds. The structurally unrelated endocannabinoids have also been found to have anti-microbial and anti-biofilm activities. Recent data suggest for a mutual communication between the endocannabinoid system and the gut microbiota. The present review focuses on the anti-microbial activities of phytocannabinoids and endocannabinoids integrated with some selected issues of their many physiological and pharmacological activities.

Novel Psychoactive Substances: The Razor's Edge between Therapeutical Potential and Psychoactive Recreational Misuse

BACKGROUND

Novel psychoactive substances (NPS) are compounds of natural and synthetic origin, similar to traditional drugs of abuse. NPS are involved in a contemporary trend whose origin lies in a thinner balance between legitimate therapeutic drug research and legislative control. The contemporary NPS trend resulted from the replacement of MDMA by synthetic cathinones in 'ecstasy' during the 2000s. The most common NPS are synthetic cannabinoids and synthetic cathinones. Interestingly, during the last 50 years, these two classes of NPS have been the object of scientific research for a set of health conditions.

METHODS

Searches were conducted in the online database PubMed using boolean equations.

RESULTS

Synthetic cannabinoids displayed protective and therapeutic effects for inflammatory, neurodegenerative and oncologic pathologies, activating the immune system and reducing inflammation. Synthetic cathinones act similarly to amphetamine-type stimulants and can be used for depression and chronic fatigue.

CONCLUSIONS

Despite the scientific advances in this field of research, pharmacological application of NPS is being jeopardized by fatalities associated with their recreational use. This review addresses the scientific achievements of these two classes of NPS and the toxicological data, ending with a reflection on Illicit and NPS control frames.

Combination of cannabidiol with low‑dose naltrexone increases the anticancer action of chemotherapy in vitro and in vivo

We previously reported that both cannabidiol (CBD) and low‑dose naltrexone (LDN) exhibit complex effects on G‑protein coupled receptors, which can impact the expression and function of other members of this superfamily. These receptors feed into and interact with central signalling cascades that determine the ease by which cells engage in apoptosis, and can be used as a way to prime cancer cells to other treatments. The present study was designed to investigate the effect of combining these two agents on cancer cell lines in vitro and in a mouse model, and focused on how the sequence of administration may affect the overall action. The results showed both agents had minimal effect on cell numbers when used simultaneously; however, the combination of LDN and CBD, delivered in this specific sequence, significantly reduced the number of cells, and was superior to the regimen where the order of the agents was reversed. For example, there was a 35% reduction in cell numbers when using LDN before CBD compared to a 22% reduction when using CBD before LDN. The two agents also sensitised cells to chemotherapy as significant decreases in cell viability were observed when they were used before chemotherapy. In mouse models, the use of both agents enhanced the effect of gemcitabine, and crucially, their use resulted in no significant toxicity in the mice, which actually gained more weight compared to those without this pre‑treatment (+6.5 vs. 0%). Overall, the results highlight the importance of drug sequence when using these drugs. There is also a need to translate these observations into standard chemotherapy regimens, especially for common tumour types where treatment is often not completed due to toxicities.

The Transdermal Delivery of Therapeutic Cannabinoids

Recently, several studies have indicated an increased interest in the scientific community regarding the application of Cannabis sativa plants, and their extracts, for medicinal purposes. This plant of enormous medicinal potential has been legalised in an increasing number of countries globally. Due to the recent changes in therapeutic and recreational legislation, cannabis and cannabinoids are now frequently permitted for use in clinical settings. However, with their highly lipophilic features and very low aqueous solubility, cannabinoids are prone to degradation, specifically in solution, as they are light-, temperature-, and auto-oxidation-sensitive. Thus, plant-derived cannabinoids have been developed for oral, nasal-inhalation, intranasal, mucosal (sublingual and buccal), transcutaneous (transdermal), local (topical), and parenteral deliveries. Among these administrations routes, topical and transdermal products usually have a higher bioavailability rate with a prolonged steady-state plasma concentration. Additionally, these administrations have the potential to eliminate the psychotropic impacts of the drug by its diffusion into a nonreactive, dead stratum corneum. This modality avoids oral administration and, thus, the first-pass metabolism, leading to constant cannabinoid plasma levels. This review article investigates the practicality of delivering therapeutic cannabinoids via skin in accordance with existing literature.

Impact of smoking cannabidiol (CBD)-rich marijuana on driving ability

To investigate effects of smoking cannabidiol (CBD)-rich marijuana on driving ability and determine free CBD and Δ⁹-tetrahydrocannabinol (THC) concentrations in capillary blood samples, a randomised, double-blind, placebo-controlled, two-way crossover pilot study was conducted with 33 participants. Participants smoked a joint containing 500 mg of tobacco and either 500 mg of CBD-rich marijuana (16.6% total CBD; 0.9% total THC) or 500 mg of a placebo substance, then performed three different dimensions of the Vienna Test System TRAFFIC examining reaction time, behaviour under stress, and concentration performance. For further assessment of participants' fitness to drive, three tests of balance and coordination were evaluated and vital signs (blood pressure and pulse) were measured. Dried blood spot samples of capillary blood were taken after smoking and after completion of the tests to determine the cannabinoid concentrations (CBD, THC and THC-metabolites). The results revealed no significant differences between the effects of smoking CBD-rich marijuana and placebo on reaction time, motor time, behaviour under stress, or concentration performance. Maximum free CBD and THC concentrations in capillary blood were detected shortly after smoking, ranging between 2.6-440.0 ng/mL and 6.7-102.0 ng/mL, respectively. After 45 min, capillary blood concentrations had already declined and were in the range of 1.9-135.0 ng/mL (free CBD) and 0.9-38.0 ng/mL (free THC). Although the observed levels of free THC concentrations have been reported to cause symptoms of impairment in previous studies in which THC-rich marijuana was smoked, no signs of impairment were found in the current study. This finding suggests that higher CBD concentrations cause a negative allosteric effect in the endocannabinoid system, preventing the formation of such symptoms. Nevertheless, it is recommended that consumers refrain from driving for several hours after smoking CBD-rich marijuana, as legal THC concentration limits may be exceeded. Supplemental data for this article is available online at https://doi.org/10.1080/20961790.2021.1946924 .

The Potential Use of Cannabis in Tissue Fibrosis

Fibrosis is a condition characterized by thickening or/and scarring of various tissues. Fibrosis may develop in almost all tissues and organs, and it may be one of the leading causes of morbidity and mortality. It provokes excessive scarring that excels the usual wound healing response to trauma in numerous organs. Currently, very little can be done to prevent tissue fibrosis, and it is almost impossible to reverse it. Anti-inflammatory and immunosuppressive drugs are among the few treatments that may be efficient in preventing fibrosis. Numerous publications suggest that cannabinoids and extracts of Cannabis sativa have potent anti-inflammatory and anti-fibrogenic properties. In this review, we describe the types and mechanisms of fibrosis in various tissues and discuss various strategies for prevention and dealing with tissue fibrosis. We further introduce cannabinoids and their potential for the prevention and treatment of fibrosis, and therefore for extending healthy lifespan.

Neurofibromatosis: Molecular Pathogenesis and Natural Compounds as Potential Treatments

The neurofibromatosis syndromes, including NF1, NF2, and schwannomatosis, are tumor suppressor syndromes characterized by multiple nervous system tumors, particularly Schwann cell neoplasms. NF-related tumors are mainly treated by surgery, and some of them have been treated by but are refractory to conventional chemotherapy. Recent advances in molecular genetics and genomics alongside the development of multiple animal models have provided a better understanding of NF tumor biology and facilitated target identification and therapeutic evaluation. Many targeted therapies have been evaluated in preclinical models and patients with limited success. One major advance is the FDA approval of the MEK inhibitor selumetinib for the treatment of NF1-associated plexiform neurofibroma. Due to their anti-neoplastic, antioxidant, and anti-inflammatory properties, selected natural compounds could be useful as a primary therapy or as an adjuvant therapy prior to or following surgery and/or radiation for patients with tumor predisposition syndromes, as patients often take them as dietary supplements and for health enhancement purposes. Here we review the natural compounds that have been evaluated in NF models. Some have demonstrated potent anti-tumor effects and may become viable treatments in the future.

Cannabinoids, Medical Cannabis, and Colorectal Cancer Immunotherapy

Colorectal cancer is a major public health problem. Unfortunately, currently, no effective curative option exists for this type of malignancy. The most promising cancer treatment nowadays is immunotherapy which is also called biological or targeted therapy. This type of therapy boosts the patient's immune system ability to fight the malignant tumor. However, cancer cells may become resistant to immunotherapy and escape immune surveillance by obtaining genetic alterations. Therefore, new treatment strategies are required. In the recent decade, several reports suggest the effectiveness of cannabinoids and Cannabis sativa extracts for inhibiting cancer proliferation in vitro and in vivo, including intestinal malignancies. Cannabinoids were shown to modulate the pathways involved in cell proliferation, angiogenesis, programmed cell death and metastasis. Because of that, they are proposed as adjunct therapy for many malignancies. By far less information exists on the potential of the use of cannabis in combination with immunotherapy. Here, we explore the possibility of the use of cannabinoids for modulation of immunotherapy of colon cancer and discuss possible advantages and limitations.

Synergistic Interactions of Cannabidiol with Chemotherapeutic Drugs in MCF7 Cells: Mode of Interaction and Proteomics Analysis of Mechanisms

Cannabidiol (CBD), a nonpsychoactive phytocannabinoid, has recently emerged as a potential cytotoxic agent in addition to its ameliorative activity in chemotherapy-associated side effects. In this work, the potential interactions of CBD with docetaxel (DOC), doxorubicin (DOX), paclitaxel (PTX), vinorelbine (VIN), and 7-ethyl-10-hydroxycamptothecin (SN-38) were explored in MCF7 breast adenocarcinoma cells using different synergy quantification models. The apoptotic profiles of MCF7 cells after the treatments were assessed via flow cytometry. The molecular mechanisms of CBD and the most promising combinations were investigated via label-free quantification proteomics. A strong synergy was observed across all synergy models at different molar ratios of CBD in combination with SN-38 and VIN. Intriguingly, synergy was observed for CBD with all chemotherapeutic drugs at a molar ratio of 636:1 in almost all synergy models. However, discording synergy trends warranted the validation of the selected combinations against different models. Enhanced apoptosis was observed for all synergistic CBD combinations compared to monotherapies or negative controls. A shotgun proteomics study highlighted 121 dysregulated proteins in CBD-treated MCF7 cells compared to the negative controls. We reported the inhibition of topoisomerase II β and α, cullin 1, V-type proton ATPase, and CDK-6 in CBD-treated MCF7 cells for the first time as additional cytotoxic mechanisms of CBD, alongside sabotaged energy production and reduced mitochondrial translation. We observed 91 significantly dysregulated proteins in MCF7 cells treated with the synergistic combination of CBD with SN-38 (CSN-38), compared to the monotherapies. Regulation of telomerase, cell cycle, topoisomerase I, EGFR1, protein metabolism, TP53 regulation of DNA repair, death receptor signalling, and RHO GTPase signalling pathways contributed to the proteome-wide synergistic molecular mechanisms of CSN-38. In conclusion, we identified significant synergistic interactions between CBD and the five important chemotherapeutic drugs and the key molecular pathways of CBD and its synergistic combination with SN-38 in MCF7 cells. Further in vivo and clinical studies are warranted to evaluate the implementation of CBD-based synergistic adjuvant therapies for breast cancer.

A narrative review of the ethnomedicinal usage of Cannabis sativa Linnaeus as traditional phytomedicine by folk medicine practitioners of Bangladesh

BACKGROUND

There is a worldwide interest in the use of Cannabis sativa for biomedicine purposes. Cannabis has ethnomedicinal usage as a natural medicine in Bangladesh and cultivated during the British Empire period for revenues.

OBJECTIVE

Folk medicine practitioners (FMPs) from different districts of Bangladesh have been using Cannabis sativa, but until now there have not been any compiled studies particularly regarding this practice. Hence, this review is an effort to retrieve the traditional usage of Cannabis sativa as a phytomedicine from published ethnomedicinal studies.

METHODS AND MATERIALS

Information was searched by using the search terms "ethnomedicinal Cannabis sativa and Bangladesh"; "Bangladesh cannabaceae and ethnomedicinal survey"; "ganja, bhang and folk medicine Bangladesh"; "tetrahydrocannabinol (THC), cannabinoid and therapeutic, clinical trial"; and "cannabis and pharmacological/biological" and retrieved from ethnobotanical articles available on PubMed, Scopus, Science Direct, and Google Scholar databases. A search of the relevant scientific literature also was conducted to assess the efficacy of the ethnomedicinal usage of Cannabis sativa.

RESULTS

While reviewing over 200 ethnomedicinal plants' survey articles, we found that FMPs of Bangladesh from 12 different districts used Cannabis sativa to treat cited ailments like sleep-associated problems (n=5), neuropsychiatric and CNS problems (n=5), and infections and respiratory problems (n=5) followed by rheumatism, gastrointestinal, gynecological (n=4 each), cancer, sexual, and other ailments including hypertension, headache, itch, increases bile secretion, abortifacient, dandruff, fever, and urinary problems (n=1 each). There are a total of 15 formulations identified from the 11 out of 18 ethnomedicinal plant survey reports. The leaf was the main plant part used (53.8%), followed by root (23%), seed (7.7%) and flower, inflorescence, resin, and all parts 3.8% respectively.

CONCLUSIONS

Sales and cultivation of Cannabis are illegal at present in Bangladesh, but the use of Cannabis sativa as a natural phytomedicine has been practiced traditionally by folk medicine practitioners of Bangladesh for many years and validated through relevant pharmacological justification. Although Cannabis sativa possesses ethnomedicinal properties in the folk medicine of Bangladesh, it is, furthermore, needed to conduct biological research to consolidate pharmacological justification about the prospects and challenges of Cannabis and cannabinoids' use in Bangladesh as safer biomedicine in the future.

Cannabinoids as Key Regulators of Inflammasome Signaling: A Current Perspective

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.

Therapeutic potential of cannabinoids in combination cancer therapy

Derivatives of the plant Cannabis sativa have been used for centuries for both medical and recreational purposes, as well as industrial. The first proof of its medicinal use comes from ancient China, although there is evidence of its earlier utilization in Europe and Asia. In the 19th century, European practitioners started to employ cannabis extracts to treat tetanus, convulsions, and mental diseases and, in 1851, cannabis made its appearance in the Pharmacopoeia of the United States as an analgesic, hypnotic and anticonvulsant. It was only in 1937 that the Marijuana Tax Act prohibited the use of this drug in the USA. The general term Cannabis is commonly used by the scientific and scholar community to indicate derivatives of the plant Cannabis sativa. The word cannabinoid is a term describing chemical compounds that are either derivate of Cannabis (phytocannabinoids) or artificial analogues (synthetic) or are produced endogenously by the body (endocannabinoids). A more casual term "marijuana" or "weed", a compound derived from dried Cannabis flower tops and leaves, has progressively superseded the term cannabis when referred to its recreational use. The 2018 World health organisation (WHO) data suggest that nearly 2.5% of the global population (147 million) uses marijuana and some countries, such as Canada and Uruguay, have already legalised it. Due to its controversial history, the medicinal use of cannabinoids has always been a centre of debate. The isolation and characterisation of Δ⁹ tetrahydrocannabinol (THC), the major psychoactive component of cannabis and the detection of two human cannabinoid receptor (CBRs) molecules renewed interest in the medical use of cannabinoids, boosting research and commercial heed in this sector. Some cannabinoid-based drugs have been approved as medications, mainly as antiemetic, antianorexic, anti-seizure remedies and in cancer and multiple sclerosis patients' palliative care. Nevertheless, due to the stigma commonly associated with these compounds, cannabinoids' potential in the treatment of conditions such as cancer is still largely unknown and therefore underestimated.

Virulence-attenuated Salmonella engineered to secrete immunomodulators reduce tumour growth and increase survival in an autochthonous mouse model of breast cancer

The ultimate goal of bacterial based cancer therapy is to achieve non-toxic penetration and colonisation of the tumour microenvironment. To overcome this efficacy-limiting toxicity of anticancer immunotherapy, we have tested a therapy comprised of systemic delivery of a vascular disrupting agent to induce intratumoral necrotic space, cannabidiol to temporarily inhibit angiogenesis and acute inflammation, and a strain of Salmonella Typhimurium that was engineered for non-toxic colonisation and expression of immunomodulators within the tumour microenvironment. This combination treatment strategy was administered to transgenic mice burdened with autochthonous mammary gland tumours and demonstrated a statistically significant 64% slower tumour growth and a 25% increase in mean survival time compared to control animals without treatment. These experiments were accomplished with minimal toxicity as measured by less than 7% weight loss and a return to normal weight gain within three days following intravenous administration of the bacteria. Thus, non-toxic, robust colonisation of the microenvironment was achieved to produce a significant antitumor effect.

Applications of Graphene and Graphene Oxide in Smart Drug/Gene Delivery: Is the World Still Flat?

Graphene, a wonder material, has made far-reaching developments in many different fields such as materials science, electronics, condensed physics, quantum physics, energy systems, etc. Since its discovery in 2004, extensive studies have been done for understanding its physical and chemical properties. Owing to its unique characteristics, it has rapidly became a potential candidate for nano-bio researchers to explore its usage in biomedical applications. In the last decade, remarkable efforts have been devoted to investigating the biomedical utilization of graphene and graphene-based materials, especially in smart drug and gene delivery as well as cancer therapy. Inspired by a great number of successful graphene-based materials integrations into the biomedical area, here we summarize the most recent developments made about graphene applications in biomedicine. In this paper, we review the up-to-date advances of graphene-based materials in drug delivery applications, specifically targeted drug/ gene delivery, delivery of antitumor drugs, controlled and stimuli-responsive drug release, photodynamic therapy applications and optical imaging and theranostics, as well as investigating the future trends and succeeding challenges in this topic to provide an outlook for future researches.

In search of preventive strategies: novel high-CBD Cannabis sativa extracts modulate ACE2 expression in COVID-19 gateway tissues

With the current COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there is an urgent need for new therapies and prevention strategies that can help curtail disease spread and reduce mortality. The inhibition of viral entry and thus spread is a plausible therapeutic avenue. SARS-CoV-2 uses receptor-mediated entry into a human host via the angiotensin-converting enzyme 2 (ACE2), which is expressed in lung tissue as well as the oral and nasal mucosa, kidney, testes and gastrointestinal tract. The modulation of ACE2 levels in these gateway tissues may be an effective strategy for decreasing disease susceptibility. Cannabis sativa, especially those high in the anti-inflammatory cannabinoid cannabidiol (CBD), has been found to alter gene expression and inflammation and harbour anti-cancer and anti-inflammatory properties. However, its effects on ACE2 expression remain unknown. Working under a Health Canada research license, we developed over 800 new C. sativa cultivars and hypothesized that high-CBD C. sativa extracts may be used to down-regulate ACE2 expression in target COVID-19 tissues. Using artificial 3D human models of oral, airway and intestinal tissues, we identified 13 high-CBD C. sativa extracts that decrease ACE2 protein levels. Some C. sativa extracts down-regulate serine protease TMPRSS2, another critical protein required for SARS-CoV-2 entry into host cells. While our most effective extracts require further large-scale validation, our study is important for future analyses of the effects of medical cannabis on COVID-19. The extracts of our most successful novel high-CBD C. sativa lines, pending further investigation, may become a useful and safe addition to the prevention/treatment of COVID-19 as an adjunct therapy.