The Endocannabinoid System: A Target for Cancer Treatment

Implication of the endocannabidiome and metabolic pathways in fragile X syndrome pathophysiology

Fragile X Syndrome (FXS) results from the silencing of the FMR1 gene and is the most prevalent inherited cause of intellectual disability and the most frequent monogenic cause of autism spectrum disorder. It is well established that Fragile X individuals are subjected to a wide array of comorbidities, ranging from cognitive, behavioural, and medical origin. Furthermore, recent studies have also described metabolic impairments in FXS individuals. However, the molecular mechanisms linking FMRP deficiency to improper metabolism are still misunderstood. The endocannabinoidome (eCBome) is a lipid-based signalling system that regulates several functions across the body, ranging from cognition, behaviour and metabolism. Alterations in the eCBome have been described in FXS animal models and linked to neuronal hyperexcitability, a core deficit of the disease. However, the potential link between dysregulation of the eCBome and altered metabolism observed in FXS remains unexplored. As such, this review aims to overcome this issue by describing the most recent finding related to eCBome and metabolic dysfunctions in the context of FXS. A better comprehension of this association will help deepen our understanding of FXS pathophysiology and pave the way for future therapeutic interventions.

Anticancer effect of minor phytocannabinoids in preclinical models of multiple myeloma

Multiple myeloma (MM) is a blood cancer caused by uncontrolled growth of clonal plasmacells. Bone disease is responsible for the severe complications of MM and is caused by myeloma cells infiltrating the bone marrow and inducing osteoclast activation. To date, no treatment for MM is truly curative since patients relapse and become refractory to all drug classes. Cannabinoids are already used as palliative in cancer patients. Furthermore, their proper anticancer effect was demonstrated in many cancer models in vitro, in vivo, and in clinical trials. Anyway, few information was reported on the effect of cannabinoids on MM and no data has been provided on minor phytocannabinoids such as cannabigerol (CBG), cannabichromene (CBC), cannabinol (CBN), and cannabidivarin (CBDV). Scientific literature also reported cannabinoids beneficial effect against bone disease. Here, we examined the cytotoxic activity of CBG, CBC, CBN, and CBDV in vitro in MM cell lines, their effect in modulating MM cells invasion toward bone cells and the bone resorption. Subsequently, according to the in vitro results, we selected CBN for in vivo study in a MM xenograft mice model. Results showed that the phytocannabinoids inhibited MM cell growth and induced necrotic cell death. Moreover, the phytocannabinoids reduced the invasion of MM cells toward osteoblast cells and bone resorption in vitro. Lastly, CBN reduced in vivo tumor mass. Together, our results suggest that CBG, CBC, CBN, and CBDV can be promising anticancer agents for MM.

Inflammation and cancer: friend or foe?

Chronic inflammation plays a crucial role in the onset and progression of pathologies like neurodegenerative and cardiovascular diseases, diabetes, and cancer, since tumor development and chronic inflammation are linked, sharing common signaling pathways. At least 20% of breast and colorectal cancers are associated with chronic inflammation triggered by infections, irritants, or autoimmune diseases. Obesity, chronic inflammation, and cancer interconnection underscore the importance of population-based interventions in maintaining healthy body weight, to disrupt this axis. Given that the dietary inflammatory index is correlated with an increased risk of cancer, adopting an anti-inflammatory diet supplemented with nutraceuticals may be useful for cancer prevention. Natural products and their derivatives offer promising antitumor activity with favorable adverse effect profiles; however, the development of natural bioactive drugs is challenging due to their variability and complexity, requiring rigorous research processes. It has been shown that combining anti-inflammatory products, such as non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and statins, with plant-derived products demonstrate clinical utility as accessible adjuvants to traditional therapeutic approaches, with known safety profiles. Pharmacological approaches targeting multiple proteins involved in inflammation and cancer pathogenesis emerge as a particularly promising option. Given the systemic and multifactorial nature of inflammation, comprehensive strategies are essential for long term success in cancer therapy. To gain insights into carcinogenic phenomena and discover diagnostic or clinically relevant biomarkers, is pivotal to understand genetic variability, environmental exposure, dietary habits, and TME composition, to establish therapeutic approaches based on molecular and genetic analysis. Furthermore, the use of endocannabinoid, cannabinoid, and prostamide-type compounds as potential therapeutic targets or biomarkers requires further investigation. This review aims to elucidate the role of specific etiological agents and mediators contributing to persistent inflammatory reactions in tumor development. It explores potential therapeutic strategies for cancer treatment, emphasizing the urgent need for cost-effective approaches to address cancer-associated inflammation.

Canonical DDR activation by EMT inducing agent 5-Fluorouracil is modulated by a cannabinoid based combinatorial approach via inducing autophagy and suppression of vimentin expression

Anastasis cascade including induction of Epithelial to Mesenchymal Transition (EMT), DNA repair, and stimulation of pro-survival mediators collectively exaggerate therapy resistance in cancer prognosis. The extensive implications of DNA-damaging agents are clinically proven futile for the rapid development of disease recurrence during treatment regime. Herein we report a glycosidic derivative of Δ9-tetrahydrocannabinol (THC-9-OG) abrogates sub-toxic doses of 5-Fluorouracil (5FU) induced EMT in colon cancer cells nullifying DNA repairing mechanism. Our in vitro and in vivo data strongly proclaims that THC-9-OG could not only abrogate 5FU mediated background EMT activation through stalling matrix degradation as well as murine 4T1 lung metastasis but also vigorously diminished Rad-51 repairing mediator along with stimulation of γ-H2AX foci formation. The combinatorial treatment (5FU + THC-9-OG) in Apc knockout colorectal carcinoma model conferred remission of the crypt progenitor phenotype which was prominently identified in 5FU treatment. Mechanistically, we demonstrated that 5FU plus THC-9-OG significantly attenuated major EMT inducer Vimentin via extensive ROS generation along with autophagy induction via LC3B I-II conversion and p62 degradation in a p-ATM dependent manner. Additionally, Cannabinoid receptor CB1 was responsible for abrogation of Vimentin since we found increase in the expression of γH2AX and decrease in vimentin expression in CB1 agonist (ACEA) plus 5FU treated cells. Nutshell, our results unveil a new direction of Cannabinoid based combinatorial approach to control background EMT along with robust enhancing of DNA damage potential of sub-toxic concentration of 5FU resulting immense inhibition of distant metastasis coupled with triggering cell death in vitro and in vivo.

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.

Targeting the Endocannabinoid System Present in the Glioblastoma Tumour Microenvironment as a Potential Anti-Cancer Strategy

The highly aggressive and invasive glioblastoma (GBM) tumour is the most malignant lesion among adult-type diffuse gliomas, representing the most common primary brain tumour in the neuro-oncology practice of adults. With a poor overall prognosis and strong resistance to treatment, this nervous system tumour requires new innovative treatment. GBM is a polymorphic tumour consisting of an array of stromal cells and various malignant cells contributing to tumour initiation, progression, and treatment response. Cannabinoids possess anti-cancer potencies against glioma cell lines and in animal models. To improve existing treatment, cannabinoids as functionalised ligands on nanocarriers were investigated as potential anti-cancer agents. The GBM tumour microenvironment is a multifaceted system consisting of resident or recruited immune cells, extracellular matrix components, tissue-resident cells, and soluble factors. The immune microenvironment accounts for a substantial volume of GBM tumours. The barriers to the treatment of glioblastoma with cannabinoids, such as crossing the blood-brain barrier and psychoactive and off-target side effects, can be alleviated with the use of nanocarrier drug delivery systems and functionalised ligands for improved specificity and targeting of pharmacological receptors and anti-cancer signalling pathways. This review has shown the presence of endocannabinoid receptors in the tumour microenvironment, which can be used as a potential unique target for specific drug delivery. Existing cannabinoid agents, studied previously, show anti-cancer potencies via signalling pathways associated with the hallmarks of cancer. The results of the review can be used to provide guidance in the design of future drug therapy for glioblastoma tumours.

Buds and Bugs: A Fascinating Tale of Gut Microbiota and Cannabis in the Fight against Cancer

Emerging research has revealed a complex bidirectional interaction between the gut microbiome and cannabis. Preclinical studies have demonstrated that the gut microbiota can significantly influence the pharmacological effects of cannabinoids. One notable finding is the ability of the gut microbiota to metabolise cannabinoids, including Δ9-tetrahydrocannabinol (THC). This metabolic transformation can alter the potency and duration of cannabinoid effects, potentially impacting their efficacy in cancer treatment. Additionally, the capacity of gut microbiota to activate cannabinoid receptors through the production of secondary bile acids underscores its role in directly influencing the pharmacological activity of cannabinoids. While the literature reveals promising avenues for leveraging the gut microbiome-cannabis axis in cancer therapy, several critical considerations must be accounted for. Firstly, the variability in gut microbiota composition among individuals presents a challenge in developing universal treatment strategies. The diversity in gut microbiota may lead to variations in cannabinoid metabolism and treatment responses, emphasising the need for personalised medicine approaches. The growing interest in understanding how the gut microbiome and cannabis may impact cancer has created a demand for up-to-date, comprehensive reviews to inform researchers and healthcare practitioners. This review provides a timely and invaluable resource by synthesizing the most recent research findings and spotlighting emerging trends. A thorough examination of the literature on the interplay between the gut microbiome and cannabis, specifically focusing on their potential implications for cancer, is presented in this review to devise innovative and effective therapeutic strategies for managing cancer.

Anti-proliferative effect of Cannabidiol in Prostate cancer cell PC3 is mediated by apoptotic cell death, NFκB activation, increased oxidative stress, and lower reduced glutathione status

Prostate cancer is the second most frequent cancer diagnosed in men in the world today. Almost all prostate cancers are adenocarcinomas and develop from gland cells. We used the PC3 prostate cancer cell line, which is well studied and derived from a bone metastasis of a grade IV prostatic adenocarcinoma. Cannabidiol (CBD), a major non-psychoactive constituent of cannabis, is a cannabinoid with anti-tumor properties but its effects on prostate cancer cells are not studied in detail. Here, we found cannabidiol decreased prostate cancer cell (PC3) viability up to 37.25% and induced apoptotic cell death in a time and dose-dependent manner. We found that CBD activated the caspases 3/7 pathways and increased DNA fragmentation. Furthermore, we observed an increase of pro-apoptotic genes Bax, an increased level of reactive oxygen species, lower reduced glutathione level, and altered mitochondrial potential in response to CBD treatment leading to lower cellular ATP. Overall, our results suggest that CBD may be effective against prostate cancer cells.

Inhalant Cannabidiol Inhibits Glioblastoma Progression Through Regulation of Tumor Microenvironment

Introduction: Glioblastoma (GBM) is the most common invasive brain tumor composed of diverse cell types with poor prognosis. The highly complex tumor microenvironment (TME) and its interaction with tumor cells play important roles in the development, progression, and durability of GBM. Angiogenic and immune factors are two major components of TME of GBM; their interplay is a major determinant of tumor vascularization, immune profile, as well as immune unresponsiveness of GBM. Given the ineffectiveness of current standard therapies (surgery, radiotherapy, and concomitant chemotherapy) in managing patients with GBM, it is necessary to develop new ways of treating these lethal brain tumors. Targeting TME, altering tumor ecosystem may be a viable therapeutic strategy with beneficial effects for patients in their fight against GBM. Materials and Methods: Given the potential therapeutic effects of cannabidiol (CBD) in a wide spectrum of diseases, including malignancies, we tested, for the first time, whether inhalant CBD can inhibit GBM tumor growth using a well-established orthotopic murine model. Optical imaging, histology, immunohistochemistry, and flow cytometry were employed to describe the outcomes such as tumor progression, cancer cell signaling pathways, and the TME. Results: Our findings showed that inhalation of CBD was able to not only limit the tumor growth but also to alter the dynamics of TME by repressing P-selectin, apelin, and interleukin (IL)-8, as well as blocking a key immune checkpoint-indoleamine 2,3-dioxygenase (IDO). In addition, CBD enhanced the cluster of differentiation (CD) 103 expression, indicating improved antigen presentation, promoted CD8 immune responses, and reduced innate Lymphoid Cells within the tumor. Conclusion: Overall, our novel findings support the possible therapeutic role of inhaled CBD as an effective, relatively safe, and easy to administer treatment adjunct for GBM with significant impacts on the cellular and molecular signaling of TME, warranting further research.

Functional Profiling of Soft Tissue Sarcoma Using Mechanistic Models

Soft tissue sarcoma is an umbrella term for a group of rare cancers that are difficult to treat. In addition to surgery, neoadjuvant chemotherapy has shown the potential to downstage tumors and prevent micrometastases. However, finding effective therapeutic targets remains a research challenge. Here, a previously developed computational approach called mechanistic models of signaling pathways has been employed to unravel the impact of observed changes at the gene expression level on the ultimate functional behavior of cells. In the context of such a mechanistic model, RNA-Seq counts sourced from the Recount3 resource, from The Cancer Genome Atlas (TCGA) Sarcoma project, and non-diseased sarcomagenic tissues from the Genotype-Tissue Expression (GTEx) project were utilized to investigate signal transduction activity through signaling pathways. This approach provides a precise view of the relationship between sarcoma patient survival and the signaling landscape in tumors and their environment. Despite the distinct regulatory alterations observed in each sarcoma subtype, this study identified 13 signaling circuits, or elementary sub-pathways triggering specific cell functions, present across all subtypes, belonging to eight signaling pathways, which served as predictors for patient survival. Additionally, nine signaling circuits from five signaling pathways that highlighted the modifications tumor samples underwent in comparison to normal tissues were found. These results describe the protective role of the immune system, suggesting an anti-tumorigenic effect in the tumor microenvironment, in the process of tumor cell detachment and migration, or the dysregulation of ion homeostasis. Also, the analysis of signaling circuit intermediary proteins suggests multiple strategies for therapy.

The current role of cannabis and cannabinoids in health: A comprehensive review of their therapeutic potential

There has been an increased interest of the scientific community in cannabis and its constituents for therapeutic purposes. Although it is believed that cannabinoids can be effective for a few different conditions and syndromes, there are little objective data that clearly support the use of cannabis, cannabis extracts or even cannabidiol (CBD) oil. This review aims to explore the therapeutic potential of phytocannabinoids and synthetic cannabinoids for the treatment of several diseases. A broad search covering the past five years, was performed in PubMed and ClinicalTrial.gov databases, to identify papers focusing on the use of medical phytocannabinoids in terms of tolerability, efficacy and safety. Accordingly, there are preclinical data supporting the use of phytocannabinoids and synthetic cannabinoids for the management of neurological pathologies, acute and chronical pain, cancer, psychiatric disorders and chemotherapy-induced emetic symptoms. However, regarding the clinical trials, most of the collected data do not fully support the use of cannabinoids in the treatment of such conditions. Consequently, more studies are still needed to clarify ascertain if the use of these compounds is useful in the management of different pathologies.

Tumor microenvironment-derived monoacylglycerol lipase provokes tumor-specific immune responses and lipid profiles

We recently described that monoacylglycerol lipase (MGL) is present in the tumor microenvironment (TME), increasing tumor growth. In this study we compare the implications of MGL deficiency in the TME in different tumor types. We show that subcutaneous injection of KP (KrasLSL-G12D/p53fl/fl, mouse lung adenocarcinoma) or B16-F10 cells (mouse melanoma) induced tumor growth in MGL wild type (WT) and knockout (KO) mice. MGL deficiency in the TME attenuated the growth of KP cell tumors whereas tumors from B16-F10 cells increased in size. Opposite immune cell profiles were detected between the two tumor types in MGL KO mice. In line with their anti-tumorigenic function, the number of CD8+ effector T cells and eosinophils increased in KP cell tumors of MGL KO vs. WT mice whereas their presence was reduced in B16-F10 cell tumors of MGL KO mice. Differences were seen in lipid profiles between the investigated tumor types. 2-arachidonoylglycerol (2-AG) content significantly increased in KP, but not B16-F10 cell tumors of MGL KO vs. WT mice while other endocannabinoid-related lipids remained unchanged. However, profiles of phospho- and lysophospholipids, sphingomyelins and fatty acids in KP cell tumors were clearly distinct to those measured in B16-F10 cell tumors. Our data indicate that TME-localized MGL impacts tumor growth, as well as levels of 2-AG and other lipids in a tumor specific manner.

Detrimental influence of industrial effluents, especially heavy metals, on limnological parameters of water and nutritional profile in addition to enzymatic activities of fish, Sperata seenghala (Sykes, 1839) from diverse Ramsar sites, India (Punjab)

The present research was designed to determine the nutritive value of the liver and intestine of fish, Sperata seenghala, the impact of effluence load on limnological parameters of water and proximate composition of fish organs, especially on fatty acids, liver enzymatic activities, seasonal variations in the nutritional profile of fish, and to check and compare the pollution status of Ramsar sites in Punjab by calculating the water quality index, heavy metal pollution index, and metal index from June 2018 to August 2020. WQI of Harike wetland was found to be 53.95, which depicts that water quality in this region is "poor". At Nangal wetland, water quality index was reported to be "excellent" quality water and fit for the whole ecological unit. Overall heavy metal pollution index for Harike wetland was reported 174.569, whereas for Nangal wetland it was 5.994, depicting massive contaminant loads in a polluted region. MI value was also recorded as being higher (6.9336) in polluted habitat than in control habitat (0.8175). In fish liver, significant (p < 0.05) higher mean total lipids (6.73%), total proteins (3.98%), moisture (77.69%), ash (3.56%), and carbohydrates (3.79%) were observed in the samples from Nangal wetland than Harike wetland. A similar trend was reported in all biochemical contents of the fish intestine. Enzyme activities such as aspartate-aminotransferase and alanine-aminotransferase were significantly elevated (p < 0.05) in the specimens collected from the polluted region. The mean total n-3 (except in spring), n-6 polyunsaturated fatty acids (except in winter), and average monounsaturated and saturated fatty acids diminished significantly (p < 0.05) in the liver of fish from contaminated habitat than control site. In the intestine of fish collected from the polluted region, significant reductions in the mean total n-3 (except in autumn as well as summer), total n-6 PUFAs (in autumn and winter), and total SFAs were reported than control site.

The evolution of cannabinoid receptors in cancer

Cannabis sativa (cannabis) has been used as a therapeutic treatment for centuries treating various diseases and disorders. However, racial propaganda led to the criminalization of cannabis in the 1930s preventing opportunities to explore marijuana in therapeutic development. The increase in recreational use of cannabis further grew concern about abuse, and lead to further restrictions and distribution of cannabis in the 1970s when it was declared to be a Schedule I drug in the USA. In the late 1990s in some states, legislation assisted in legalizing the use of cannabis for medical purposes under physician supervision. As it has been proven that cannabinoids and their receptors play an essential role in the regulation of the physiological and biological processes in our bodies. The endocannabinoid system (ECS) is the complex that regulates the cell-signaling system consisting of endogenous cannabinoids (endocannabinoids), cannabinoid receptors, and the enzymes responsible for the synthesis and degradation of the endocannabinoids. The ECS along with phytocannabinoids and synthetic cannabinoids serves to be a beneficial therapeutic target in treating diseases as they play roles in cell homeostasis, cell motility, inflammation, pain-sensation, mood, and memory. Cannabinoids have been shown to inhibit proliferation, metastasis, and angiogenesis and even restore homeostasis in a variety of models of cancer in vitro and in vivo. Cannabis and its receptors have evolved into a therapeutic treatment for cancers. This article is categorized under: Cancer > Molecular and Cellular Physiology.

Systematic Modification of the Substitution Pattern of the 7-Hydroxy-5-oxopyrazolo[4,3-b]pyridine-6-carboxamide Scaffold Enabled the Discovery of New Ligands with High Affinity and Selectivity for the Cannabinoid Type 2 Receptor

Selective ligands of the CB2 receptor are receiving considerable attention due to their potential as therapeutic agents for a variety of diseases. Recently, 7-hydroxy-5-oxopyrazolo[4,3-b]pyridine-6-carboxamide derivatives were shown to act at the CB2 receptor either as agonists or as inverse agonists/antagonists in vitro and to have anti-osteoarthritic activity in vivo. In this article, we report the synthesis, pharmacological profile, and molecular modeling of a series of twenty-three new 7-hydroxy-5-oxopyrazolo[4,3-b]pyridine-6-carboxamides with the aim of further developing this new class of selective CB2 ligands. In addition to these compounds, seven other analogs that had been previously synthesized were included in this study to better define the structure-activity relationship (SAR). Ten of the new compounds studied were found to be potent and selective ligands of the CB2 receptor, with K_i values ranging from 48.46 to 0.45 nM and CB1/CB2 selectivity indices (SI) ranging from >206 to >4739. In particular, compounds 54 and 55 were found to be high-affinity CB2 inverse agonists that were not active at all at the CB1 receptor, whereas 57 acted as an agonist. The functional activity profile of the compounds within this structural class depends mainly on the substitution pattern of the pyrazole ring.

Validating the anti-lymphoma pharmacodynamic actions of the endocannabinoids on canine non-Hodgkin lymphoma

AIMS

This study established the in vitro anti-lymphoma pharmacodynamic actions of the endocannabinoids (anandamide-AEA and 2-arachidonoylglycerol-2AG) on canine non-Hodgkin lymphoma (NHL) and human NHL cells.

MAIN METHODS

The expression of cannabinoid (CB₁ and CB₂) receptors in various canine NHL cells {1771, CLBL-1, CLL-1, peripheral blood mononuclear cells (PBMCs)} was studied using Quantitative real-time PCR (RT-qPCR). Anti-lymphoma cell viability assay was performed to assess the effect of endocannabinoids on various canine and human NHL cells (1771, CLBL-1, CLL-1, Ramos cells). The spectrophotometric and fluorometric procedures evaluated oxidative stress, inflammation, apoptosis, and mitochondrial function markers. SAS® and Prism-V La Jolla, CA, USA, were used for statistical analysis.

KEY FINDINGS

The current study validated the presence of CB₁ and CB₂ receptors in the canine NHL cells. There was a significantly higher expression of CB₁ and CB₂ receptors in B-cell lymphoma (BCL) cells (1771, CLBL-1, Ramos) compared to canine T-cell lymphoma (TCL) cells (CL-1). AEA and 2AG dose and time-dependently exhibited significant but differential anti-lymphoma effects on canine and human NHL cells. Anti-lymphoma pharmacodynamic actions of the endocannabinoids in the canine 1771 NHL cells revealed a significant alteration in the markers of oxidative stress, inflammation, and a decrease in mitochondrial function without altering the apoptotic markers.

SIGNIFICANCE

Establishing the anti-lymphoma pharmacodynamic actions of endocannabinoids may provide new therapeutic interventions and expedite cannabinoid research.

Cannabis: a multifaceted plant with endless potentials

Cannabis sativa, also known as "hemp" or "weed," is a versatile plant with various uses in medicine, agriculture, food, and cosmetics. This review attempts to evaluate the available literature on the ecology, chemical composition, phytochemistry, pharmacology, traditional uses, industrial uses, and toxicology of Cannabis sativa. So far, 566 chemical compounds have been isolated from Cannabis, including 125 cannabinoids and 198 non-cannabinoids. The psychoactive and physiologically active part of the plant is a cannabinoid, mostly found in the flowers, but also present in smaller amounts in the leaves, stems, and seeds. Of all phytochemicals, terpenes form the largest composition in the plant. Pharmacological evidence reveals that the plants contain cannabinoids which exhibit potential as antioxidants, antibacterial agents, anticancer agents, and anti-inflammatory agents. Furthermore, the compounds in the plants have reported applications in the food and cosmetic industries. Significantly, Cannabis cultivation has a minimal negative impact on the environment in terms of cultivation. Most of the studies focused on the chemical make-up, phytochemistry, and pharmacological effects, but not much is known about the toxic effects. Overall, the Cannabis plant has enormous potential for biological and industrial uses, as well as traditional and other medicinal uses. However, further research is necessary to fully understand and explore the uses and beneficial properties of Cannabis sativa.

Cannabinoid and Opioid Receptor Affinity and Modulation of Cancer-Related Signaling Pathways of Machaeriols and Machaeridiols from Machaerium Pers

Machaeriols and machaeridiols are unique hexahydrodibenzopyran-type aralkyl phytocannabinoids isolated from Machaerium Pers. Earlier studies of machaeriol A (1) and B (2) did not show any affinity for cannabinoid receptor 1 (CB1 or CNR1), although they are structural analogs of psychoactive hexahydrocannabinol. This study comprehensively reports on the affinities of isolated Machaerium Pers. compounds, namely machaeriol A-D (1-4) and machaeridiol A-C (5-7), against cannabinoid (CB1 and CB2) and opioid (κ, δ and µ) receptors. Among the isolated compounds, machaeriol D (4) and machaeridiol A-C (5-7) showed some selective binding affinity for the CB2 receptor, using a radioligand binding assay, with K_i values of >1.3, >1.77, >2.18 and >1.1 μM, respectively. On the other hand, none of the compounds showed any binding to the CB1 receptor. Due to recent reports on the anticancer potential of the endocannabinoid system, compounds 1-7 were tested against a battery of luciferase reporter gene vectors that assess the activity of many cancer-related signaling pathways, including Stat3, Smad2/3, AP-1, NF-κB, E2F, Myc, Ets, Notch, FoxO, Wnt, Hedgehog and pTK in HeLa and T98G glioblastoma cells. Complete dose-response curves have been determined for each compound in both of these cell lines, which revealed that machaeridiol 6 displayed activities (IC₅₀ in µM in HeLa and T98G cells) towards Stat3 (4.7, 1.4), Smad2/3 (1.2, 3.0), AP-1 (5.9, 4.2), NF-κB (0.5, 4.0), E2F (5.7, 0.7), Myc (5.3, 2.0), ETS (inactive, 5.9), Notch (5.3, 4.6), Wnt (4.2, inactive) and Hedgehog (inactive, 5.0). Furthermore, a combination study between machaeriol C (3) and machaeridiol B (6) displayed additive effects for E2F, ETS, Wnt and Hedgehog pathways, where these compounds individually were either minimally active or inactive. None of the compounds inhibited luciferase expression driven by the minimal thymidine kinase promoter (pTK), indicating the lack of general cytotoxicity for luciferase enzyme inhibition at the 50 µM concentration in both of these cell lines. The significance of the inhibition of these signaling pathways via machaeridiol 5-7 and their cross-talk potential has been discussed.

Therapeutic targeting of the tumor microenvironments with cannabinoids and their analogs: Update on clinical trials

Cancer is a major global public health concern that affects both industrialized and developing nations. Current cancer chemotherapeutic options are limited by side effects, but plant-derived alternatives and their derivatives offer the possibilities of enhanced treatment response and reduced side effects. A plethora of recently published articles have focused on treatments based on cannabinoids and cannabinoid analogs and reported that they positively affect healthy cell growth and reverse cancer-related abnormalities by targeting aberrant tumor microenvironments (TMEs), lowering tumorigenesis, preventing metastasis, and/or boosting the effectiveness of chemotherapy and radiotherapy. Furthermore, TME modulating systems are receiving much interest in the cancer immunotherapy field because it has been shown that TMEs have significant impacts on tumor progression, angiogenesis, invasion, migration, epithelial to mesenchymal transition, metastasis and development of drug resistance. Here, we have reviewed the effective role of cannabinoids, their analogs and cannabinoid nano formulations on the cellular components of TME (endothelial cells, pericytes, fibroblast and immune cells) and how efficiently it retards the progression of carcinogenesis is discussed. The article summarizes the existing research on the molecular mechanisms of cannabinoids regulation of the TME and finally highlights the human studies on cannabinoids' active interventional clinical trials. The conclusion outlines the need for future research involving clinical trials of cannabinoids to demonstrate their efficacy and activity as a treatment/prevention for various types of human malignancies.

Blood Oxylipin Profiles as Markers of Oncological Diseases

Oxylipins are signal lipid molecules formed from polyunsaturated fatty acids (PUFAs) in several multienzymatic metabolic pathways, such as cyclooxygenase (COX), lipoxygenase (LOX), epoxygenase (CYP), and anandamide pathways, as well as non-enzymatically. The pathways of PUFA transformation are activated in parallel, yielding a mixture of physiologically active substances. Although the association of oxylipins with carcinogenesis had been established a long time ago, only recently analytical methods have advanced to a degree allowing detection and quantification of oxylipins from different classes (oxylipin profiles). The review describes current approaches to the HPLC-MS/MS analysis of oxylipin profiles and compares oxylipin profiles from patients with oncological diseases (breast cancer, colorectal cancer, ovarian cancer, lung cancer, prostate cancer, liver cancer). The possibility of using blood oxylipin profiles as biomarkers in oncological diseases is discussed. Understanding the patterns of PUFA metabolism and physiological activity of combinations of oxylipins will improve early diagnostics of oncological diseases and evaluation of disease prognosis.

The endocannabinoid system, a new gatekeeper in the pharmacology of human hepatocellular carcinoma

Despite numerous prevention methodologies and treatment options, hepatocellular carcinoma (HCC) still remains as the third leading life-threatening cancer. It is thus pertinent to develop new treatment modality to fight this devastating carcinoma. Ample recent studies have shown the anti-inflammatory and antitumor roles of the endocannabinoid system in various forms of cancers. Preclinical studies have also confirmed that cannabinoid therapy can be an optimal regimen for cancer treatments. The endocannabinoid system is involved in many cancer-related processes, including induction of endoplasmic reticulum (ER) stress-dependent apoptosis, autophagy, PITRK and ERK signaling pathways, cell invasion, epithelial-mesenchymal transition (EMT), and cancer stem cell (CSC) phenotypes. Moreover, changes in signaling transduction of the endocannabinoid system can be a potential diagnostic and prognostic biomarker for HCC. Due to its pivotal role in lipid metabolism, the endocannabinoid system affects metabolic reprogramming as well as lipid content of exosomes. In addition, due to the importance of non-coding RNAs (ncRNAs), several studies have examined the relationship between microRNAs and the endocannabinoid system in HCC. However, HCC is a pathological condition with high heterogeneity, and therefore using the endocannabinoid system for treatment has faced many controversies. While some studies favored a role of the endocannabinoid system in carcinogenesis and tumor induction, others exhibited the anticancer potential of endocannabinoids in HCC. In this review, specific studies delineating the relationship between endocannabinoids and HCC are examined. Based on collected findings, detailed studies of the molecular mechanism of endocannabinoids as well as preclinical studies for investigating therapeutic or carcinogenic impacts in HCC cancer are strongly suggested.

Potential, Limitations and Risks of Cannabis-Derived Products in Cancer Treatment

The application of cannabis products in oncology receives interest, especially from patients. Despite the plethora of research data available, the added value in curative or palliative cancer care and the possible risks involved are insufficiently proven and therefore a matter of debate. We aim to give a recommendation on the position of cannabis products in clinical oncology by assessing recent literature. Various types of cannabis products, characteristics, quality and pharmacology are discussed. Standardisation is essential for reliable and reproducible quality. The oromucosal/sublingual route of administration is preferred over inhalation and drinking tea. Cannabinoids may inhibit efflux transporters and drug-metabolising enzymes, possibly inducing pharmacokinetic interactions with anticancer drugs being substrates for these proteins. This may enhance the cytostatic effect and/or drug-related adverse effects. Reversely, it may enable dose reduction. Similar interactions are likely with drugs used for symptom management treating pain, nausea, vomiting and anorexia. Cannabis products are usually well tolerated and may improve the quality of life of patients with cancer (although not unambiguously proven). The combination with immunotherapy seems undesirable because of the immunosuppressive action of cannabinoids. Further clinical research is warranted to scientifically support (refraining from) using cannabis products in patients with cancer.

Role of omega-3 and omega-6 endocannabinoids in cardiopulmonary pharmacology

Endocannabinoids are derived from dietary omega-3 and omega-6 fatty acids and play an important role in regulation of inflammation, development, neurodegenerative diseases, cancer, and cardiovascular diseases. They elicit this effect via interactions with cannabinoid receptors 1 and 2 which are also targeted by plant derived cannabinoid from cannabis. The evidence of the involvement of the endocannabinoid system in cardiopulmonary function comes from studies that show that cannabis consumption leads to cardiovascular effect such as arrythmia and is beneficial in lung cancer patients. Moreover, omega-3 and omega-6 endocannabinoids play several important roles in cardiopulmonary system such as causing airway relaxation, suppressing atherosclerosis and hypertension. These effects are mediated via the cannabinoids receptors that are abundant in the cardiopulmonary system. Overall, this chapter reviews the known role of phytocannabinoids and endocannabinoids in the cardiopulmonary context.

An Individuality of Response to Cannabinoids: Challenges in Safety and Efficacy of Cannabis Products

Since legalization, cannabis/marijuana has been gaining considerable attention as a functional ingredient in food. ∆-9 tetrahydrocannabinol (THC), cannabidiol (CBD), and other cannabinoids are key bioactive compounds with health benefits. The oral consumption of cannabis transports much less hazardous chemicals than smoking. Nevertheless, the response to cannabis is biphasically dose-dependent (hormesis; a low-dose stimulation and a high-dose inhibition) with wide individuality in responses. Thus, the exact same dose and preparation of cannabis may be beneficial for some but toxic to others. The purpose of this review is to highlight the concept of individual variations in response to cannabinoids, which leads to the challenge of establishing standard safe doses of cannabis products for the general population. The mechanisms of actions, acute and chronic toxicities, and factors affecting responses to cannabis products are updated. Based on the literature review, we found that the response to cannabis products depends on exposure factors (delivery route, duration, frequency, and interactions with food and drugs), individual factors (age, sex), and susceptibility factors (genetic polymorphisms of cannabinoid receptor gene, N-acylethanolamine-hydrolyzing enzymes, THC-metabolizing enzymes, and epigenetic regulations). Owing to the individuality of responses, the safest way to use cannabis-containing food products is to start low, go slow, and stay low.

Cannabinoids in the Modulation of Oxidative Signaling

Cannabis sativa-derived compounds, such as delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), and components of the endocannabinoids system, such as N-arachidonoylethanolamide (anandamide, AEA) and 2-arachidonoylglycerol (2-AG), are extensively studied to investigate their numerous biological effects, including powerful antioxidant effects. Indeed, a series of recent studies have indicated that many disorders are characterized by alterations in the intracellular antioxidant system, which lead to biological macromolecule damage. These pathological conditions are characterized by an unbalanced, and most often increased, reactive oxygen species (ROS) production. For this study, it was of interest to investigate and recapitulate the antioxidant properties of these natural compounds, for the most part CBD and THC, on the production of ROS and the modulation of the intracellular redox state, with an emphasis on their use in various pathological conditions in which the reduction of ROS can be clinically useful, such as neurodegenerative disorders, inflammatory conditions, autoimmunity, and cancers. The further development of ROS-based fundamental research focused on cannabis sativa-derived compounds could be beneficial for future clinical applications.

The Effect of Cannabis Plant Extracts on Head and Neck Squamous Cell Carcinoma and the Quest for Cannabis-Based Personalized Therapy

Cannabis sativa plants have a wide diversity in their metabolite composition among their different chemovars, facilitating diverse anti-tumoral effects on cancer cells. This research examined the anti-tumoral effects of 24 cannabis extracts representative of three primary types of chemovars on head and neck squamous cell carcinoma (HNSCC). The chemical composition of the extracts was determined using High-Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS). The most potent anti-tumoral extracts were type III decarboxylated extracts, with high levels of Cannabidiol (CBD). We identified extract 296 (CAN296) as the most potent in inducing HNSCC cell death via proapoptotic and anti-proliferative effects. Using chemical fractionation of CAN296, we identified the CBD fraction as the primary inducer of the anti-tumoral activity. We succeeded in defining the combination of CBD with cannabichromene (CBC) or tetrahydrocannabinol (THC) present in minute concentrations in the extract, yielding a synergic impact that mimics the extract's full effect. The cytotoxic effect could be maximized by combining CBD with either CBC or THC in a ratio of 2:1. This research suggests using decarboxylated CBD-type extracts enriched with CBC for future preclinical trials aimed at HNSCC treatment.

Cannabinoid receptor 2 plays a pro-tumorigenic role in non-small cell lung cancer by limiting anti-tumor activity of CD8+ T and NK cells

Cannabinoid (CB) receptors (CB₁ and CB₂) are expressed on cancer cells and their expression influences carcinogenesis in various tumor entities. Cells of the tumor microenvironment (TME) also express CB receptors, however, their role in tumor development is still unclear. We, therefore, investigated the role of TME-derived CB₁ and CB₂ receptors in a model of non-small cell lung cancer (NSCLC). Leukocytes in the TME of mouse and human NSCLC express CB receptors, with CB₂ showing higher expression than CB₁. In the tumor model, using CB₁- (CB₁ ^-/-) and CB₂-knockout (CB₂ ^-/-) mice, only deficiency of CB₂, but not of CB₁, resulted in reduction of tumor burden vs. wild type (WT) littermates. This was accompanied by increased accumulation and tumoricidal activity of CD8⁺ T and natural killer cells, as well as increased expression of programmed death-1 (PD-1) and its ligand on lymphoid and myeloid cells, respectively. CB₂ ^-/- mice responded significantly better to anti-PD-1 therapy than WT mice. The treatment further increased infiltration of cytotoxic lymphocytes into the TME of CB₂ ^-/- mice. Our findings demonstrate that TME-derived CB₂ dictates the immune cell recruitment into tumors and the responsiveness to anti-PD-1 therapy in a model of NSCLC. CB₂ could serve as an adjuvant target for immunotherapy.

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.

A zebrafish HCT116 xenograft model to predict anandamide outcomes on colorectal cancer

Colon cancer is one of the leading causes of death worldwide. In recent years, cannabinoids have been extensively studied for their potential anticancer effects and symptom management. Several in vitro studies reported anandamide's (AEA) ability to block cancer cell proliferation and migration, but evidence from in vivo studies is still lacking. Thus, in this study, the effects of AEA exposure in zebrafish embryos transplanted with HCT116 cells were evaluated. Totally, 48 hpf xenografts were exposed to 10 nM AEA, 10 nM AM251, one of the cannabinoid 1 receptor (CB1) antagonist/inverse agonists, and to AEA + AM251, to verify the specific effect of AEA treatment. AEA efficacy was evaluated by confocal microscopy, which demonstrated that these xenografts presented a smaller tumor size, reduced tumor angiogenesis, and lacked micrometastasis formation. To gain deeper evidence into AEA action, microscopic observations were completed by molecular analyses. RNA seq performed on zebrafish transcriptome reported the downregulation of genes involved in cell proliferation, angiogenesis, and the immune system. Conversely, HCT116 cell transcripts resulted not affected by AEA treatment. In vitro HCT116 culture, in fact, confirmed that AEA exposure did not affect cell proliferation and viability, thus suggesting that the reduced tumor size mainly depends on direct effects on the fish rather than on the transplanted cancer cells. AEA reduced cell proliferation and tumor angiogenesis, as suggested by socs3 and pcnp mRNAs and Vegfc protein levels, and exerted anti-inflammatory activity, as indicated by the reduction of il-11a, mhc1uba, and csf3b mRNA. Of note, are the results obtained in groups exposed to AM251, which presence nullifies AEA's beneficial effects. In conclusion, this study promotes the efficacy of AEA in personalized cancer therapy, as suggested by its ability to drive tumor growth and metastasis, and strongly supports the use of zebrafish xenograft as an emerging model platform for cancer studies.

Therapeutic Effects of Medicinal Cannabinoids on the Gastrointestinal System in Pediatric Patients: A Systematic Review

Changes in cannabis legalization have generated interest in medicinal cannabinoids for therapeutic uses, including those that target the gastrointestinal (GI) tract. These effects are mediated through interactions with the endocannabinoid system. Given the increasing societal awareness of the therapeutic potential of cannabinoids, it is important to ensure pediatric representation in clinical studies investigating cannabinoid use. This systematic review aims to assess the efficacy of medicinal cannabinoids in treating GI symptoms in pediatric patients. A literature search of Medline, Embase, CINAHL, Web of Science, and the Cochrane Library was performed from inception until June 23, 2020. Study design, patient characteristics, type, dose and duration of medicinal cannabinoid therapy, and GI outcomes were extracted. From 7303 records identified, 5 studies met all inclusion criteria. Included studies focused on chemotherapy-induced nausea, inflammatory bowel disease, and GI symptoms associated with severe complex motor disorders. Results varied based on the symptom being treated, the type of cannabinoid, and the patient population. Medicinal cannabinoids may have a potential role in treating specific GI symptoms in specific patient populations. The limited number and heterogenicity of included studies highlight the demand for future research to distinguish effects among different cannabinoid types and patient populations and to examine drug interactions. As interest increases, higher quality studies are needed to understand the efficacy of cannabinoids as a pediatric GI treatment and whether these benefits outweigh the associated risks (Registration Number: PROSPERO CRD42020202486).

Metabolomic profile of prostate cancer-specific survival among 1812 Finnish men

BACKGROUND

Abnormal metabolism and perturbations in metabolic pathways play significant roles in the development and progression of prostate cancer; however, comprehensive metabolomic analyses of human data are lacking and needed to elucidate the interrelationships.

METHODS

We examined the serum metabolome in relation to prostate cancer survival in a cohort of 1812 cases in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. Using an ultrahigh-performance LC-MS/MS platform, we identified 961 known metabolites in prospectively collected serum. Median survival time from diagnosis to prostate cancer-specific death (N=472) was 6.6 years (interquartile range=2.9-11.1 years). Cox proportional hazards regression models estimated hazard ratios and 95% confidence intervals of the associations between the serum metabolites (in quartiles) and prostate cancer death, adjusted for age at baseline and diagnosis, disease stage, and Gleason sum. In order to calculate risk scores, we first randomly divided the metabolomic data into a discovery set (70%) and validated in a replication set (30%).

RESULTS

Overall, 49 metabolites were associated with prostate cancer survival after Bonferroni correction. Notably, higher levels of the phospholipid choline, amino acid glutamate, long-chain polyunsaturated fatty acid (n6) arachidonate (20:4n6), and glutamyl amino acids gamma-glutamylglutamate, gamma-glutamylglycine, and gamma-glutamylleucine were associated with increased risk of prostate cancer-specific mortality (fourth versus first quartile HRs=2.07-2.14; P-values <5.2×10^-5). By contrast, the ascorbate/aldarate metabolite oxalate, xenobiotics S-carboxymethyl-L-cysteine, fibrinogen cleavage peptides ADpSGEGDFXAEGGGVR and fibrinopeptide B (1-12) were related to reduced disease-specific mortality (fourth versus first quartile HRs=0.82-0.84; P-value <5.2×10^-5). Further adjustment for years from blood collection to cancer diagnosis, body mass index, smoking intensity and duration, and serum total and high-density lipoprotein cholesterol did not alter the results. Participants with a higher metabolic score based on the discovery set had an elevated risk of prostate cancer-specific mortality in the replication set (fourth versus first quartile, HR=3.9, P-value for trend<0.0001).

CONCLUSIONS

The metabolic traits identified in this study, including for choline, glutamate, arachidonate, gamma-glutamyl amino acids, fibrinopeptides, and endocannabinoid and redox pathways and their composite risk score, corroborate our previous analysis of fatal prostate cancer and provide novel insights and potential leads regarding the molecular basis of prostate cancer progression and mortality.

The Therapeutic Potential of the Endocannabinoid System in Age-Related Diseases

The endocannabinoid system (ECS) dynamically regulates many aspects of mammalian physiology. ECS has gained substantial interest since growing evidence suggests that it also plays a major role in several pathophysiological conditions due to its ability to modulate various underlying mechanisms. Furthermore, cannabinoids, as components of the cannabinoid system (CS), have proven beneficial effects such as anti-inflammatory, immunomodulatory, neuromodulatory, antioxidative, and cardioprotective effects. In this comprehensive review, we aimed to describe the complex interaction between CS and most common age-related diseases such as neuro-degenerative, oncological, skeletal, and cardiovascular disorders, together with the potential of various cannabinoids to ameliorate the progression of these disorders. Since chronic inflammation is postulated as the pillar of all the above-mentioned medical conditions, we also discuss in this paper the potential of CS to ameliorate aging-associated immune system dysregulation.

Cannabidiol for the treatment of autism spectrum disorder: hope or hype?

RATIONALE

Autism spectrum disorder (ASD) is defined as a group of neurodevelopmental disorders whose symptoms include impaired communication and social interaction, restricted and repetitive patterns of behavior, and varying levels of intellectual disability. ASD is observed in early childhood and is one of the most severe chronic childhood disorders in prevalence, morbidity, and impact on society. It is usually accompanied by attention deficit hyperactivity disorder, anxiety, depression, sleep disorders, and epilepsy. The treatment of ASD has low efficacy, possibly because it has a heterogeneous nature, and its neurobiological basis is not clearly understood. Drugs such as risperidone and aripiprazole are the only two drugs available that are recognized by the Food and Drug Administration, primarily for treating the behavioral symptoms of this disorder. These drugs have limited efficacy and a high potential for inducing undesirable effects, compromising treatment adherence. Therefore, there is great interest in exploring the endocannabinoid system, which modulates the activity of other neurotransmitters, has actions in social behavior and seems to be altered in patients with ASD. Thus, cannabidiol (CBD) emerges as a possible strategy for treating ASD symptoms since it has relevant pharmacological actions on the endocannabinoid system and shows promising results in studies related to disorders in the central nervous system.

OBJECTIVES

Review the preclinical and clinical data supporting CBD's potential as a treatment for the symptoms and comorbidities associated with ASD, as well as discuss and provide information with the purpose of not trivializing the use of this drug.

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.

A Comprehensive Review on the Anti-Cancer Effects of Oleuropein

In Mediterranean cuisine and culture, olive oil and olive fruits play a significant role. Many people believe that those who consume olive oil and its fruit live longer and have a decreased risk of illness. Olive leaves were used to treat a range of diseases in ancient times, including malaria fever and lower earaches. Although it was not understood at the time what key components were responsible for these effects because they had not yet been discovered, Oleuropein is now recognized as one of the primary elements in immature olive fruits and leaves. Later research was carried out to determine the effects of this molecule, and it was determined that it functions as an antioxidant. Oleuropein consumption has aided in cancer treatment over the years, and this was assumed to be owing to its antioxidant properties. Oleuropein’s effects on cancer, however, go beyond that; it is now known that Oleuropein functions as both an anti-proliferative and an apoptotic promoter in many cancer cells. The kinetics and dosages of Oleuropein and the mechanisms behind its involvement and effects in cancer are explored in this review. Finally, the effects of Oleuropein in combination with anticancer medicines are investigated.

Developing the Cannabinoid Receptor 2 (CB2) pharmacopoeia: past, present, and future

Cannabinoid Receptor 2 (CB2) is a G protein-coupled receptor (GPCR) with considerable, though as yet unrealised, therapeutic potential. Promising preclinical data supports the applicability of CB2 activation in autoimmune and inflammatory diseases, pain, neurodegeneration, and osteoporosis. A diverse pharmacopoeia of cannabinoid ligands is available, which has led to considerable advancements in the understanding of CB2 function and extensive preclinical evaluation. However, until recently, most CB2 ligands were highly lipophilic and as such not optimal for clinical application due to unfavourable physicochemical properties. A number of strategies have been applied to develop CB2 ligands to achieve closer to 'drug-like' properties and a few such compounds have now undergone clinical trial. We review the current state of CB2 ligand development and progress in optimising physicochemical properties, understanding advanced molecular pharmacology such as functional selectivity, and clinical evaluation of CB2-targeting compounds.

Untargeted metabolomics identifies the potential role of monocarboxylate transporter 6 (MCT6/SLC16A5) in lipid and amino acid metabolism pathways

Monocarboxylate transporter 6 (MCT6; SLC16A5) is an orphan transporter protein with expression in multiple tissues. The endogenous function of MCT6 related to human health and disease remains unknown. Our previous transcriptomic and proteomic analyses in Mct6 knockout (KO) mice suggested that MCT6 may play a role in lipid and glucose homeostasis, but additional evidence is required. Thus, the objective of this study was to further explore the impact of MCT6 on metabolic function using untargeted metabolomic analysis in Mct6 KO mice. The plasma from male and female mice and livers from male mice were submitted for global metabolomics analysis to assess the relative changes in endogenous small molecules across the liver and systemic circulation associated with absence of Mct6. More than 782 compounds were detected with 101 and 51 metabolites significantly changed in plasma of male and female mice, respectively, and 100 metabolites significantly changed in the livers of male mice (p < .05). Significant perturbations in lipid metabolism were annotated in the plasma and liver metabolome, with additional alterations in the amino acid metabolism pathway in plasma samples from male and female mice. Elevated lipid diacylglycerol and altered fatty acid metabolite concentrations were found in liver and plasma samples of male Mct6 KO mice. Significant reduction of N-terminal acetylated amino acids was found in plasma samples of male and female Mct6 KO mice. In summary, the present study confirmed the significant role of MCT6 in lipid and amino acid homeostasis, suggesting its contribution in metabolic diseases.

The oncogenic lysophosphatidylinositol (LPI)/GPR55 signaling

GPR55 is a class A orphan G protein-coupled receptor that has drawn important therapeutic attention in the last decade because of its role in pathophysiological processes including vascular functions, metabolic dysfunction, neurodegenerative disorders, or bone turnover among others. Several cannabinoids of phytogenic, endogenous, and synthetic nature have shown to modulate this receptor leading to propose it as a member of the endocannabinoid system. The putative endogenous GPR55 ligand is L-α-lysophosphatidylinositol (LPI) and it has been associated with several processes that control cell survival and tumor progression. The relevance of GPR55 in cancer is currently being extensively studied in vitro and in vivo using diverse cancer models. The LPI/GPR55 axis has been reported to participate in pro-oncogenic processes including cellular proliferation, differentiation, migration, invasion, and metastasis being altered in several cancer cells via G_12/13 and G_q signaling. Moreover, GRP55 and its bioactive lipid have been proposed as potential biomarkers for cancer diagnosis. Indeed, GPR55 overexpression or high expression has been shown to correlate with cancer aggressiveness in specific tumors including acute myeloid leukemia, uveal melanoma, low grade glioma and renal cancer. This review aims to analyze and summarize current evidence on the cancerogenic role of the LPI/GPR55 axis providing a critical view of the therapeutic prospects of this promising target.

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.

Cannabinoids: Therapeutic Use in Clinical Practice

Medical case reports suggest that cannabinoids extracted from Cannabis sativa have therapeutic effects; however, the therapeutic employment is limited due to the psychotropic effect of its major component, Δ9-tetrahydrocannabinol (THC). The new scientific discoveries related to the endocannabinoid system, including new receptors, ligands, and mediators, allowed the development of new therapeutic targets for the treatment of several pathological disorders minimizing the undesirable psychotropic effects of some constituents of this plant. Today, FDA-approved drugs, such as nabiximols (a mixture of THC and non-psychoactive cannabidiol (CBD)), are employed in alleviating pain and spasticity in multiple sclerosis. Dronabinol and nabilone are used for the treatment of chemotherapy-induced nausea and vomiting in cancer patients. Dronabinol was approved for the treatment of anorexia in patients with AIDS (acquired immune deficiency syndrome). In this review, we highlighted the potential therapeutic efficacy of natural and synthetic cannabinoids and their clinical relevance in cancer, neurodegenerative and dermatological diseases, and viral infections.

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.

Targeting the Endocannabinoidome in Pancreatic Cancer

Pancreatic Ductal adenocarcinoma (PDAC), the most common malignancy of the pancreas, is an aggressive and lethal form of cancer with a very high mortality rate. High heterogeneity, asymptomatic initial stages and a lack of specific diagnostic markers result in an end-stage diagnosis when the tumour has locally advanced or metastasised. PDAC is resistant to most of the available chemotherapy and radiation therapy treatments, making surgery the most potent curative treatment. The desmoplastic tumour microenvironment contributes to determining PDAC pathophysiology, immune response and therapeutic efficacy. The existing therapeutic approaches such as FDA-approved chemotherapeutics, gemcitabine, abraxane and folfirinox, prolong survival marginally and are accompanied by adverse effects. Several studies suggest the role of cannabinoids as anti-cancer agents. Cannabinoid receptors are known to be expressed in pancreatic cells, with a higher expression reported in pancreatic cancer patients. Therefore, pharmacological targeting of the endocannabinoid system might offer therapeutic benefits in pancreatic cancer. In addition, emerging data suggest that cannabinoids in combination with chemotherapy can increase survival in transgenic pancreatic cancer murine models. This review provides an overview of the regulation of the expanded endocannabinoid system, or endocannabinoidome, in PDAC and will explore the potential of targeting this system for novel anticancer approaches.

Cannabinoids, their cellular receptors, and effects on the invasive phenotype of carcinoma and metastasis

BACKGROUND

The morbidity and mortality of cancer are significantly impacted by the invasive and metastatic potential of particular subgroups of malignant cells within a tumor. The particular pre-metastatic properties of cancerous cells are thus a critical target for novel therapeutics in the oncology field. Cannabinoid molecules have been investigated in recent years in the context of invasion and metastasis of various malignancies, with varying effects reported in the literature.

RECENT FINDINGS

There was substantial variability in the findings reported by the literature of the effects of cannabinoid molecules on cancer cell invasion and metastasis. These effects varied depending on which ligand and which of the CB1, CB2, or GPR55 receptors were investigated. These findings suggest a role for the phenomenon of biased signaling in explaining the diversity of effects of cannabinoid molecules on cancer cell invasion.

CONCLUSION

While substantially more investigation is required into the effects of cannabinoid molecules on cancer cell invasion and metastasis, we describe in this review the significant diversity in the responses of cancer cells to cannabinoid molecules in terms of their invasive and metastatic capacities.

Probing GPCR Dimerization Using Peptides

G protein-coupled receptors (GPCRs) are the largest class of membrane proteins and the most common and extensively studied pharmacological target. Numerous studies over the last decade have confirmed that GPCRs do not only exist and function in their monomeric form but in fact, have the ability to form dimers or higher order oligomers with other GPCRs, as well as other classes of receptors. GPCR oligomers have become increasingly attractive to investigate as they have the ability to modulate the pharmacological responses of the receptors which in turn, could have important functional roles in diseases, such as cancer and several neurological & neuropsychiatric disorders. Despite the growing evidence in the field of GPCR oligomerisation, the lack of structural information, as well as targeting the 'undruggable' protein-protein interactions (PPIs) involved in these complexes, has presented difficulties. Outside the field of GPCRs, targeting PPIs has been widely studied, with a variety of techniques being investigated; from small-molecule inhibitors to disrupting peptides. In this review, we will demonstrate several physiologically relevant GPCR dimers and discuss an array of strategies and techniques that can be employed when targeting these complexes, as well as provide ideas for future development.

Enhancement of Conventional and Photodynamic Therapy for Treatment of Cervical Cancer with Cannabidiol

Cervical cancer (CC) is the fourth most diagnosed cancer in women worldwide. Conventional treatments include surgery, chemo- and radiotherapy, however these are invasive and may cause severe side effects. Furthermore, approximately 70% of late-stage CC patients experience metastasis, due to treatment resistance and limitations. Thus, there is a dire need to investigate alternative therapeutic combination therapies. Photodynamic therapy (PDT) is an alternative CC treatment modality that has been clinically proven to treat primary CC, as well as to limit secondary metastasis. Since PDT is a non-invasive localized treatment, with fewer side effects and lessened resistance to dose repeats, it is considered far more advantageous. However, more clinical trials are required to refine its delivery and dosing, as well as improve its ability to activate specific immune responses to eradicate secondary CC spread. Cannabidiol (CBD) isolates have been shown to exert in vitro CC anticancer effects, causing apoptosis post treatment, as well as inducing specific immune responses, which obstruct tumor invasion and angiogenesis, and so hinder CC metastatic spread. This review paper discusses the current conventional and alternative PDT treatment modalities for CC, as well as their limitations over the last 10 years. It has a particular focus on the combinative administration of CBD with these treatments in order to prevent CC secondary migration and so possibly encourage future research studies to focus on this synergistic effect to eradicate CC.

Cannabinoids in Breast Cancer: Differential Susceptibility According to Subtype

Although cannabinoids have been used for centuries for diverse pathological conditions, recently, their clinical interest and application have emerged due to their diverse pharmacological properties. Indeed, it is well established that cannabinoids exert important actions on multiple sclerosis, epilepsy and pain relief. Regarding cancer, cannabinoids were first introduced to manage chemotherapy-related side effects, though several studies demonstrated that they could modulate the proliferation and death of different cancer cells, as well as angiogenesis, making them attractive agents for cancer treatment. In relation to breast cancer, it has been suggested that estrogen receptor-negative (ER-) cells are more sensitive to cannabinoids than estrogen receptor-positive (ER+) cells. In fact, most of the studies regarding their effects on breast tumors have been conducted on triple-negative breast cancer (TNBC). Nonetheless, the number of studies on human epidermal growth factor receptor 2-positive (HER2+) and ER+ breast tumors has been rising in recent years. However, besides the optimistic results obtained thus far, there is still a long way to go to fully understand the role of these molecules. This review intends to help clarify the clinical potential of cannabinoids for each breast cancer subtype.

Endocannabinoid System and Tumour Microenvironment: New Intertwined Connections for Anticancer Approaches

The tumour microenvironment (TME) is now recognised as a hallmark of cancer, since tumour:stroma crosstalk supports the key steps of tumour growth and progression. The dynamic co-evolution of the tumour and stromal compartments may alter the surrounding microenvironment, including the composition in metabolites and signalling mediators. A growing number of evidence reports the involvement of the endocannabinoid system (ECS) in cancer. ECS is composed by a complex network of ligands, receptors, and enzymes, which act in synergy and contribute to several physiological but also pathological processes. Several in vitro and in vivo evidence show that ECS deregulation in cancer cells affects proliferation, migration, invasion, apoptosis, and metastatic potential. Although it is still an evolving research, recent experimental evidence also suggests that ECS can modulate the functional behaviour of several components of the TME, above all the immune cells, endothelial cells and stromal components. However, the role of ECS in the tumour:stroma interplay remains unclear and research in this area is particularly intriguing. This review aims to shed light on the latest relevant findings of the tumour response to ECS modulation, encouraging a more in-depth analysis in this field. Novel discoveries could be promising for novel anti-tumour approaches, targeting the microenvironmental components and the supportive tumour:stroma crosstalk, thereby hindering tumour development.

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.

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.

Cannabinoids-A New Perspective in Adjuvant Therapy for Pulmonary Hypertension

Currently, no treatment can completely cure pulmonary hypertension (PH), which can lead to right ventricular failure and, consequently, death. Therefore, searching for new therapies remains important. Increased resistance in pulmonary circulation is mainly caused by the excessive contraction and proliferation of small pulmonary arteries. Cannabinoids, a group of lipophilic compounds that all interact with cannabinoid receptors, exert a pulmonary vasodilatory effect through several different mechanisms, including mechanisms that depend on vascular endothelium and/or receptor-based mechanisms, and may also have anti-proliferative and anti-inflammatory properties. The vasodilatory effect is important in regulating pulmonary resistance, which can improve patients’ quality of life. Moreover, experimental studies on the effects of cannabidiol (plant-derived, non-psychoactive cannabinoid) in animal PH models have shown that cannabidiol reduces right ventricular systolic pressure and excessive remodelling and decreases pulmonary vascular hypertrophy and pulmonary vascular resistance. Due to the potentially beneficial effects of cannabinoids on pulmonary circulation and PH, in this work, we review whether cannabinoids can be used as an adjunctive therapy for PH. However, clinical trials are still needed to recommend the use of cannabinoids in the treatment of PH.