The heterogeneity and complexity of Cannabis extracts as antitumor agents

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“The Cannabis plant contains over 100 phytocannabinoids and hundreds of other components. The biological effects and interplay of these Cannabis compounds are not fully understood and yet influence the plant’s therapeutic effects.

Here we assessed the antitumor effects of whole Cannabis extracts, which contained significant amounts of differing phytocannabinoids, on different cancer lines from various tumor origins.

Our results show that specific Cannabis extracts impaired the survival and proliferation of cancer cell lines as well as induced apoptosis.

Our findings showed that pure (-)-Δ9trans-tetrahydrocannabinol (Δ9-THC) did not produce the same effects on these cell lines as the whole Cannabis extracts. Furthermore, Cannabis extracts with similar amounts of Δ9-THC produced significantly different effects on the survival of specific cancer cells.

In addition, we demonstrated that specific Cannabis extracts may selectively and differentially affect cancer cells and differing cancer cell lines from the same organ origin. We also found that cannabimimetic receptors were differentially expressed among various cancer cell lines and suggest that this receptor diversity may contribute to the heterogeneous effects produced by the differing Cannabis extracts on each cell line.

Our overall findings indicate that the effect of a Cannabis extract on a specific cancer cell line relies on the extract’s composition as well as on certain characteristics of the targeted cells.”

http://www.oncotarget.com/index.php?journal=oncotarget&page=article&op=view&path[]=26983

“Many previous reports highlight and demonstrate the anti-tumor effects of cannabinoids. In the last decade, accumulating evidence has indicated that phytocannabinoids might have antitumor properties. A number of in vitro and in vivo studies have demonstrated the effects of phytocannabinoids on tumor progression by interrupting several characteristic features of cancer. These studies suggest that specific cannabinoids such as Δ9-THC and CBD induce apoptosis and inhibit proliferation in various cancer cell lines.”

http://www.oncotarget.com/index.php?journal=oncotarget&page=article&op=view&path%5B%5D=26983&path%5B%5D=85698

https://pubmed.ncbi.nlm.nih.gov/31289609/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6609248/

Antitumor Cannabinoid Chemotypes: Structural Insights.

Image result for frontiers in pharmacology“Cannabis has long been known to limit or prevent nausea and vomiting, lack of appetite, and pain. For this reason, cannabinoids have been successfully used in the treatment of some of the unwanted side effects caused by cancer chemotherapy.

Besides their palliative effects, research from the past two decades has demonstrated their promising potential as antitumor agents in a wide variety of tumors.

Cannabinoids of endogenous, phytogenic, and synthetic nature have been shown to impact the proliferation of cancer through the modulation of different proteins involved in the endocannabinoid system such as the G protein-coupled receptors CB1, CB2, and GRP55, the ionotropic receptor TRPV1, or the fatty acid amide hydrolase (FAAH).

In this article, we aim to structurally classify the antitumor cannabinoid chemotypes described so far according to their targets and types of cancer. In a drug discovery approach, their in silico pharmacokinetic profile has been evaluated in order to identify appropriate drug-like profiles, which should be taken into account for further progress toward the clinic.

This analysis may provide structural insights into the selection of specific cannabinoid scaffolds for the development of antitumor drugs for the treatment of particular types of cancer.” https://www.ncbi.nlm.nih.gov/pubmed/31214034

“The first report on the antitumor activity of phytocannabinoids was published over four decades ago. During these last years, significant research has been focused on the therapeutic potential of cannabinoids to manage palliative effects in cancer patients. Besides such palliative applications, some cannabinoids have shown anticancer properties. Since inflammation is a common risk factor for cancer, and some cannabinoids have shown anti-inflammatory properties, they could play a role in chemoprevention.” https://www.frontiersin.org/articles/10.3389/fphar.2019.00621/full
“Antitumor effects of THC.” http://www.ncbi.nlm.nih.gov/pubmed/11097557
“Antitumor effects of cannabidiol” http://www.ncbi.nlm.nih.gov/pubmed/14617682
“Anti-tumour actions of cannabinoids.” https://www.ncbi.nlm.nih.gov/pubmed/30019449
“Extensive preclinical research has demonstrated that cannabinoids, the active ingredients of Cannabis sativa, trigger antitumor responses in different models of cancer.” https://www.ncbi.nlm.nih.gov/pubmed/29940172

Should Oncologists Recommend Cannabis?

“Cannabis is a useful botanical with a wide range of therapeutic potential. Global prohibition over the past century has impeded the ability to study the plant as medicine. However, delta-9-tetrahydrocannabinol (THC) has been developed as a stand-alone pharmaceutical initially approved for the treatment of chemotherapy-related nausea and vomiting in 1986. The indication was expanded in 1992 to include treatment of anorexia in patients with the AIDS wasting syndrome. Hence, if the dominant cannabinoid is available as a schedule III prescription medication, it would seem logical that the parent botanical would likely have similar therapeutic benefits. The system of cannabinoid receptors and endogenous cannabinoids (endocannabinoids) has likely developed to help us modulate our response to noxious stimuli. Phytocannabinoids also complex with these receptors, and the analgesic effects of cannabis are perhaps the best supported by clinical evidence. Cannabis and its constituents have also been reported to be useful in assisting with sleep, mood, and anxiety. Despite significant in vitro and animal model evidence supporting the anti-cancer activity of individual cannabinoids-particularly THC and cannabidiol (CBD)-clinical evidence is absent. A single intervention that can assist with nausea, appetite, pain, mood, and sleep is certainly a valuable addition to the palliative care armamentarium. Although many healthcare providers advise against the inhalation of a botanical as a twenty-first century drug-delivery system, evidence for serious harmful effects of cannabis inhalation is scant and a variety of other methods of ingestion are currently available from dispensaries in locales where patients have access to medicinal cannabis. Oncologists and palliative care providers should recommend this botanical remedy to their patients to gain first-hand evidence of its therapeutic potential despite the paucity of results from randomized placebo-controlled clinical trials to appreciate that it is both safe and effective and really does not require a package insert.”

https://www.ncbi.nlm.nih.gov/pubmed/31161270

https://link.springer.com/article/10.1007%2Fs11864-019-0659-9

Modulation of the Endocannabinoid System as a Potential Anticancer Strategy.

 Image result for frontiers in pharmacology“Currently, the involvement of the endocannabinoid system in cancer development and possible options for a cancer-regressive effect of cannabinoids are controversially discussed. In recent decades, a number of preclinical studies have shown that cannabinoids have an anticarcinogenic potential. Therefore, especially against the background of several legal simplifications with regard to the clinical application of cannabinoid-based drugs, an extended basic knowledge about the complex network of the individual components of the endocannabinoid system is required. The canonical endocannabinoid system consists of the endocannabinoids N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol as well as the Gi/o protein-coupled transmembrane cannabinoidreceptors CB1 and CB2. As a result of extensive studies on the broader effect of these factors, other fatty acid derivatives, transmembrane and intracellular receptors, enzymes and lipid transporters have been identified that contribute to the effect of endocannabinoids when defined in the broad sense as “extended endocannabinoid system.” Among these additional components, the endocannabinoid-degrading enzymes fatty acid amide hydrolase and monoacylglycerol lipase, lipid transport proteins of the fatty acid-binding protein family, additional cannabinoid-activated G protein-coupled receptors such as GPR55, members of the transient receptor family, and peroxisome proliferator-activated receptors were identified as targets for possible strategies to combat cancer progression. Other endocannabinoid-related fatty acids such as 2-arachidonoyl glyceryl ether, O-arachidonoylethanolamine, N-arachidonoyldopamine and oleic acid amide showed an effect via cannabinoid receptors, while other compounds such as endocannabinoid-like substances exert a permissive action on endocannabinoid effects and act via alternative intracellular target structures. This review gives an overview of the modulation of the extended endocannabinoid system using the example of anticancer cannabinoid effects, which have been described in detail in preclinical studies.”

https://www.ncbi.nlm.nih.gov/pubmed/31143113

“In addition to the palliative effects of cannabinoid compounds in cancer treatment, the endocannabinoid system provides several targets for systemic anticancer treatment. Accordingly, preclinical studies suggest cannabinoids inhibit cancer progression via inhibition of cancer cell proliferation, neovascularization, invasion and chemoresistance, as well as induction of apoptosis, autophagy and increase of tumor immune surveillance.”

https://www.frontiersin.org/articles/10.3389/fphar.2019.00430/full

Anti-tumoural actions of cannabinoids.

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“The endocannabinoid system has emerged as a considerable target for the treatment of diverse diseases.

In addition to the well-established palliative effects of cannabinoids in cancer therapy, phytocannabinoids, synthetic cannabinoid compounds as well as inhibitors of endocannabinoid degradation have attracted attention as possible systemic anticancer drugs.

As a matter of fact, accumulating data from preclinical studies suggest cannabinoids elicit effects on different levels of cancer progression, comprising inhibition of proliferation, neovascularisation, invasion and chemoresistance, induction of apoptosis and autophagy as well as enhancement of tumour immune surveillance.

Although the clinical use of cannabinoid receptor ligands is limited by their psychoactivity, nonpsychoactive compounds, such as cannabidiol, have gained attention due to preclinically established anticancer properties and a favourable risk-to-benefit profile.

Thus, cannabinoids may complement the currently used collection of chemotherapeutics, as a broadly diversified option for cancer treatment, while counteracting some of their severe side effects.” https://www.ncbi.nlm.nih.gov/pubmed/30019449

“During the last few decades, a large body of evidence has accumulated to suggest endocannabinoids, phytocannabinoids and synthetic cannabinoids exert an inhibitory effect on cancer growth via blockade of cell proliferation and induction of apoptosis. Some studies support the hypothesis that cannabinoids may enhance immune responses against the progressive growth and spread of tumours.”  https://bpspubs.onlinelibrary.wiley.com/doi/full/10.1111/bph.14426#bph14426-fig-0001
“Previous research has shown that cannabinoids can help lessen side effects of anti-cancer therapies. Now a new British Journal of Pharmacology review has examined their potential for the direct treatment of cancer. Studies have shown that cannabinoids may stop cancer cells from dividing and invading normal tissue, and they may block the blood supply to tumors. Some studies also indicate that cannabinoids may enhance the body’s immune response against the growth and spread of tumors.” https://www.eurasiareview.com/19072018-cannabinoids-may-have-a-vast-array-of-anti-cancer-effects/
“Cannabinoids may have a vast array of anti-cancer effects” https://www.sciencedaily.com/releases/2018/07/180718082143.htm

“Cannabinoids may have a vast array of anti-cancer effects”  https://www.eurekalert.org/pub_releases/2018-07/w-cmh071718.php

Marijuana may help fight cancer” https://nypost.com/2018/07/18/marijuana-may-help-fight-cancer/

“Cannabis stops cancer spreading and boosts immune system, say scientists. Studies show cannabinoids can stop cancer cells from dividing and spreading, and blocks blood supply to tumours” https://www.plymouthherald.co.uk/news/health/cannabis-can-cure-cancer-proof-1803485
“Cannabis stops cancer spreading and boosts immune system, say scientists. Cannabis can act as a treatment for cancer and boost the immune system, claims a new study.” https://www.devonlive.com/news/health/cannabis-can-cure-cancer-proof-1803485
“Cannabis stops cancer spreading and boosts immune system, say scientists. Cannabis can act as a treatment for cancer and boost the immune system, claims a new study.” https://www.cornwalllive.com/news/uk-world-news/cannabis-can-cure-cancer-proof-1803485
Cannabis ‘can act as a treatment for cancer’. Cannabis can enhance the immune system and act as a treatment for cancer, claims a new study. Scientists at Rostock University Medical Centre in Germany claimed the benefits following a review of more than 100 studies.” https://www.thelondoneconomic.com/news/cannabis-can-act-as-a-treatment-for-cancer/19/07/

Cannabinoids as a Promising Therapeutic Approach for the Treatment of Glioblastoma Multiforme: A Literature Review

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“Gliobalstoma multiforme (GBM) or grade 4 astrocytoma is the most malignant form of primary brain tumor. Treatment of glioblastoma is difficult despite of surgery, radiotherapy and chemotherapy. Patients with glioblastoma survive for less than 12 months.

Considering to biology function of glioblastoma, researchers have recently offered new therapeutic approaches such as cannabinoid therapy for glioblastoma.

Cannabinoids are active compounds of Cannabis sativa that operate in the body similar to endogenous canabinoids –the endocannabinoids- through cell surface receptors.

It is interesting that cannabinoids could exert a wide spectrum from antiproliferative effects in condition of the cell culture, animal models of glioblastoma and clinical trials.

As a result, Cannabinoids seem to modulate intracellular signaling pathways and the endoplasmic reticulum stress response in glioma cells.

Those play antitumoral effects through apoptosis induction and inhibition of glioblastoma angiogenesis.

The goal of this study was to discuss cannabinoid therapy and also what cellular mechanisms are involved in the tumoricidal effect of the cannabinoids.

In this review article, we will focus on cannabinoids, their receptor dependent functional roles against glioblastoma acccording to growth, angiogenesis, metastasis, and future purposes in exploring new possible therapeutic opportunities.”

http://journals.sbmu.ac.ir/Neuroscience/article/view/13655

INSIGHT ON THE IMPACT OF ENDOCANNABINOID SYSTEM IN CANCER: A REVIEW.

British Journal of Pharmacology banner

“In the last decades, the endocannabinoid system has attracted a great interest in medicine and cancer disease is probably one of its most promising therapeutic areas.

On the one hand, endocannabinoid system expression has been found altered in numerous types of tumours compared to healthy tissue, and this aberrant expression has been related to cancer prognosis and disease outcome, suggesting a role of this system in tumour growth and progression that depends on cancer type.

On the other hand, it has been reported that cannabinoids exert an anticancer activity by inhibiting the proliferation, migration and/or invasion of cancer cells; and also tumour angiogenesis.

The endocannabinoid system may be considered as a new therapeutic target, although further studies to fully establish the effect of cannabinoids on tumour progression remain necessary.”

https://www.ncbi.nlm.nih.gov/pubmed/29663308

A Review of the Therapeutic Antitumor Potential of Cannabinoids.

:Image result for J Altern Complement Med.

“The aim of this review is to discuss cannabinoids from a preclinical and clinical oncological perspective and provide the audience with a concise, retrospective overview of the most significant findings concerning the potential use of cannabinoids in cancer treatment.

RESULTS:

Cannabis sativa is a plant rich in more than 100 types of cannabinoids. Besides exogenous plant cannabinoids, mammalian endocannabinoids and synthetic cannabinoid analogues have been identified. Cannabinoid receptors type 1 (CB1) and type 2 (CB2) have been isolated and characterized from mammalian cells. Through cannabinoid receptor and non-receptor signaling pathways, cannabinoids show specific cytotoxicity against tumor cells, while protecting healthy tissue from apoptosis. The dual antiproliferative and proapoptotic effects of cannabinoids and associated signaling pathways have been investigated on a large panel of cancer cell lines. Cannabinoids also display potent anticancer activity against tumor xenografts, including tumors that express high resistance to standard chemotherapeutics. Few studies have investigated the possible synergistic effects of cannabinoids with standard oncology therapies, and are based on the preclinically confirmed concept of “cannabinoid sensitizers.” Also, clinical trials aimed to confirm the antineoplastic activity of cannabinoids have only been evaluated on a small number of subjects, with no consensus conclusions regarding their effectiveness.

CONCLUSIONS:

A large number of cannabinoid compounds have been discovered, developed, and used to study the effects of cannabinoids on cancers in model systems. However, few clinical trials have been conducted on the use of cannabinoids in the treatment of cancers in humans. Further studies require extensive monitoring of the effects of cannabinoids alone or in combination with standard anticancer strategies. With such knowledge, cannabinoids could become a therapy of choice in contemporary oncology.”

Cannabinoids as Modulators of Cell Death: Clinical Applications and Future Directions.

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“Endocannabinoids are bioactive lipids that modulate various physiological processes through G-protein-coupled receptors (CB1 and CB2) and other putative targets. By sharing the activation of the same receptors, some phytocannabinoids and a multitude of synthetic cannabinoids mimic the effects of endocannabinoids.

In recent years, a growing interest has been dedicated to the study of cannabinoids properties for their analgesic, antioxidant, anti-inflammatory and neuroprotective effects. In addition to these well-recognized effects, various studies suggest that cannabinoids may affect cell survival, cell proliferation or cell death. These observations indicate that cannabinoids may play an important role in the regulation of cellular homeostasis and, thus, may contribute to tissue remodelling and cancer treatment.

For a long time, the study of cannabinoid receptor signalling has been focused on the classical adenylyl cyclase/cyclic AMP/protein kinase A (PKA) pathway. However, this pathway does not totally explain the wide array of biological responses to cannabinoids. In addition, the diversity of receptors and signalling pathways that endocannabinoids modulate offers an interesting opportunity for the development of specific molecules to disturb selectively the endogenous system.

Moreover, emerging evidences suggest that cannabinoids ability to limit cell proliferation and to induce tumour-selective cell death may offer a novel strategy in cancer treatment.

This review describes the main properties of cannabinoids in cell death and attempts to clarify the different pathways triggered by these compounds that may help to understand the complexity of respective molecular mechanisms and explore the potential clinical benefit of cannabinoids use in cancer therapies.”

https://www.ncbi.nlm.nih.gov/pubmed/28425013

ENDOCANNABINOID SYSTEM: A multi-facet therapeutic target.

Image result for Curr Clin Pharmacol.

“Cannabis sativa is also popularly known as marijuana. It is being cultivated and used by man for recreational and medicinal purposes from many centuries.

Study of cannabinoids was at bay for very long time and its therapeutic value could not be adequately harnessed due to its legal status as proscribed drug in most of the countries.

The research of drugs acting on endocannabinoid system has seen many ups and down in recent past. Presently, it is known that endocannabinoids has role in pathology of many disorders and they also serve “protective role” in many medical conditions.

Several diseases like emesis, pain, inflammation, multiple sclerosis, anorexia, epilepsy, glaucoma, schizophrenia, cardiovascular disorders, cancer, obesity, metabolic syndrome related diseases, Parkinson’s disease, Huntington’s disease, Alzheimer’s disease and Tourette’s syndrome could possibly be treated by drugs modulating endocannabinoid system.

Presently, cannabinoid receptor agonists like nabilone and dronabinol are used for reducing the chemotherapy induced vomiting. Sativex (cannabidiol and THC combination) is approved in the UK, Spain and New Zealand to treat spasticity due to multiple sclerosis. In US it is under investigation for cancer pain, another drug Epidiolex (cannabidiol) is also under investigation in US for childhood seizures. Rimonabant, CB1 receptor antagonist appeared as a promising anti-obesity drug during clinical trials but it also exhibited remarkable psychiatric side effect profile. Due to which the US Food and Drug Administration did not approve Rimonabant in US. It sale was also suspended across the EU in 2008.

Recent discontinuation of clinical trial related to FAAH inhibitor due to occurrence of serious adverse events in the participating subjects could be discouraging for the research fraternity. Despite of some mishaps in clinical trials related to drugs acting on endocannabinoid system, still lot of research is being carried out to explore and establish the therapeutic targets for both cannabinoid receptor agonists and antagonists.

One challenge is to develop drugs that target only cannabinoid receptors in a particular tissue and another is to invent drugs that acts selectively on cannabinoid receptors located outside the blood brain barrier. Besides this, development of the suitable dosage forms with maximum efficacy and minimum adverse effects is also warranted.

Another angle to be introspected for therapeutic abilities of this group of drugs is non-CB1 and non-CB2 receptor targets for cannabinoids.

In order to successfully exploit the therapeutic potential of endocannabinoid system, it is imperative to further characterize the endocannabinoid system in terms of identification of the exact cellular location of cannabinoid receptors and their role as “protective” and “disease inducing substance”, time-dependent changes in the expression of cannabinoid receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/27086601