Antitumor mechanism of cannabidiol hidden behind cancer hallmarks

Cannabidiol effects in stem cells: A systematic review

Stem cells play a critical role in human tissue regeneration and repair. In addition, cancer stem cells (CSCs), subpopulations of cancer cells sharing similar characteristics as normal stem cells, are responsible for tumor metastasis and resistance to chemo- and radiotherapy and to tumor relapse. Interestingly, all stem cells have cannabinoid receptors, such as cannabidiol (CBD), that perform biological functions. The aim of this systematic review was to analyze the effect of CBD on both somatic stem cells (SSCs) and CSCs. Of the 276 articles analyzed, 38 were selected according to the inclusion and exclusion criteria. A total of 27 studied the effect of CBD on SSCs, finding that 44% focused on CBD differentiation effect and 56% on its protective activity. On the other hand, 11 articles looked at the effect of CBD on CSCs, including glioblastoma (64%), lung cancer (27%), and breast cancer (only one article). Our results showed that CBD exerted a differentiating and protective effect on SCCs. In addition, this molecule demonstrated an antiproliferative effect on some CSCs, although most of the analyses were performed in vitro. Therefore, although in vivo studies should be necessary to justify its clinical use, CBD and its receptors could be a specific target to act on both SSCs and CSCs.

Cannabidiol Suppresses Metastatic Castration-Resistant Prostate Cancer Progression and Recurrence through Modulating Tryptophan Catabolism

Metastatic castration-resistant prostate cancer (mCRPC) is an aggressive phenotype of prostate cancer (PC). Tryptophan oxidative catabolism by indoleamine 2,3-dioxygenase-1 (IDO1) cleaves the indole ring to kynurenine (Kyn), an endogenous ligand for the aryl hydrocarbon receptor (AhR), which activates multiple tumorigenesis pathways. The IDO1-Kyn-AhR axis is aberrantly dysregulated in mCRPC. (-)-Cannabidiol (CBD) is a nonpsychoactive phytocannabinoid. CBD showed antitumor activities against human malignancies, including PC. CBD showed potent in vitro dose-dependent reduction of viability and clonogenicity of diverse human PC cell lines. CBD reduced the expression of IDO1 and AhR in PC cells. A daily 15 mg/kg oral dose of CBD for 30 days effectively suppressed the progression of the mCRPC CWR-R1ca-Luc cells xenografted in male nude mice. Continued CBD oral dosing for an additional 45 days suppressed the CWR-R1ca-Luc tumor locoregional and distant recurrences after the primary tumors' surgical excision. Collected CBD-treated tumors showed a reduced level of IDO1 expression. CBD-treated mice displayed a significant systemic reduction of Kyn. CBD is a novel, nonpsychoactive phytocannabinoid lead useful for the control of mCRPC via targeting the tryptophan catabolism.

Responsive Supramolecular Nanomicelles Formed through Self-Assembly of Acyclic Cucurbit[n]uril for Targeted Drug Delivery to Cancer Cells

The supramolecular drug delivery systems (SDDSs) based on host-guest recognition through noncovalent interactions, capable of responsive behavior and dynamic switching to external stimuli, have attracted considerable attention in cancer therapy. In this study, a targeted dual-functional drug delivery system was designed and synthesized. A hydrophilic macrocyclic host molecule (acyclic cucurbit[n]uril ACB) was modified with folic acid (FA) as a targeting ligand. The guest molecule consists of a disulfide bond attached to adamantane (DA) and cannabidiol (CBD) at both ends of the response element of glutathione. Recognition and self-assembly of host and guest molecules successfully functionalize supramolecular nanomicelles (SNMs), targeting cancer cells and releasing drugs in a high glutathione environment. The interactions between host and guest molecules were investigated by using nuclear magnetic resonance (NMR), fluorescence titration, Fourier-transform infrared spectroscopy (FT-IR), and thermal analysis (TGA). Transmission electron microscopy (TEM) and dynamic light scattering (DLS) confirmed the nanostructure of the SNMs. Experimentation with 5,5'-dithiobis (2-nitrobenzoic acid) (DTNB) demonstrated the responsiveness of SNMs to glutathione (GSH). In vitro cytotoxicity assays demonstrated that SNMs had a greater targeting efficacy for four types of cancer cells (HeLa, HCT-116, A549, and HepG2) compared to normal 293T cells. Cellular uptake studies revealed that HeLa cells more readily absorbed SNMs, leading to their accumulation in the tumor cell cytoplasm. Fluorescence colocalization assays verified that SNMs efficiently accumulated in organelles related to energy metabolism and signaling, including mitochondria and the endoplasmic reticulum, affecting cellular metabolic death. Both flow cytometry and confocal nuclear staining assays confirmed that SNMs effectively induced apoptosis over time, ultimately resulting in the death of cancer cells. These findings demonstrate that SNMs exhibit excellent targeting ability, responsiveness, high bioavailability, and stability, suggesting significant potential in drug delivery applications.

In Vitro Antitumor Effect of Oils Rich in CBD and THC Cannabis Extract in Canine Prostate Carcinoma Cell Lines

Prostate cancer is one of the leading causes of cancer-related deaths worldwide, even when diagnosed at an early stage in humans and dogs. Dogs have a significant incidence of spontaneous prostate cancer, which is highly similar to human androgen-independent prostate cancer and represents a valuable model for comparative studies. Cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) are the two main cannabinoids extracted from Cannabis sativa and have demonstrated antiproliferative and anti-invasive properties in different tumor types. In this study, CBD or THC-rich extracts inhibited the proliferation of two canine prostatic carcinoma cell lines, PC1 and PC2, showing an IC50 of 3.43 and 3.57 μM for CBD rich extracts, and 4.90 and 4.48 μM THC rich extracts, respectively. Cell death was also observed with both Annexin V and Propidium iodide staining for the canine cell lines. These results provide new information concerning the use of rich oil in canine PC and open a promising opportunity for further in vitro and in vivo studies to establish the mechanisms of action of these compounds using dogs as a natural model for prostatic carcinoma.

Cannabigerol Induces Autophagic Cell Death by Inhibiting EGFR-RAS Pathways in Human Pancreatic Ductal Adenocarcinoma Cell Lines

Pancreatic ductal adenocarcinoma (PDAC) is the most frequent infiltrating type of pancreatic cancer. The poor prognosis associated with this cancer is due to the absence of specific biomarkers, aggressiveness, and treatment resistance. PDAC is a deadly malignancy bearing distinct genetic alterations, the most common being those that result in cancer-causing versions of the KRAS gene. Cannabigerol (CBG) is a non-psychomimetic cannabinoid with anti-inflammatory properties. Regarding the anticancer effect of CBG, up to now, there is only limited evidence in human cancers. To fill this gap, we investigated the effects of CBG on the PDAC cell lines, PANC-1 and MIAPaCa-2. The effect of CBG activity on cell viability, cell death, and EGFR-RAS-associated signaling was investigated. Moreover, the potential synergistic effect of CBG in combination with gemcitabine (GEM) and paclitaxel (PTX) was investigated. MTT was applied to investigate the effect of CBG on PDAC cell line viabilities. Annexin-V and Acridine orange staining, followed by cytofluorimetric analysis and Western blotting, were used to evaluate CBG's effect on cell death. The modulation of EGFR-RAS-associated pathways was determined by Western blot analysis and a Milliplex multiplex assay. Moreover, by employing the MTT data and SynergyFinder Plus software analysis, the effect of the combination of CBG and chemotherapeutic drugs was determined.

Natural products as a source of new anticancer chemotypes

INTRODUCTION

Exploring the chemical diversity and molecular mechanisms of natural products continues to be an important research area for identifying novel promising therapeutic approaches for fighting cancer. This is a complex disease and poses important challenges, which require not only targeted interventions to improve chemotherapy efficacy and tolerability, but also adjuvant strategies to counteract chemoresistance development and relapses.

AREAS COVERED

After a brief description of the recent literature on the anticancer potential of natural compounds, we searched for patents following the PRISMA guidelines, filtering the results published from 2019 onwards. In addition, some relevant publications from the overall scientific literature were also discussed.

EXPERT OPINION

This review comprehensively covers and analyzes the most recent advances on the anticancer mechanism of licensed natural compounds and their chemical optimization. Patentability of natural compounds was discussed according to the recent legislation in the U.S.A. and Europe.

Anti-oxidant effects of cannabidiol relevant to intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a subtype of stroke with a high mortality rate. Oxidative stress cascades play an important role in brain injury after ICH. Cannabidiol, a major non-psychotropic phytocannabinoids, has drawn increasing interest in recent years as a potential therapeutic intervention for various neuropsychiatric disorders. Here we provide a comprehensive review of the potential therapeutic effects of cannabidiol in countering oxidative stress resulting from ICH. The review elaborates on the various sources of oxidative stress post-ICH, including mitochondrial dysfunction, excitotoxicity, iron toxicity, inflammation, and also highlights cannabidiol's ability to inhibit ROS/RNS generation from these sources. The article also delves into cannabidiol's role in promoting ROS/RNS scavenging through the Nrf2/ARE pathway, detailing both extranuclear and intranuclear regulatory mechanisms. Overall, the review underscores cannabidiol's promising antioxidant effects in the context of ICH and suggests its potential as a therapeutic option.