Cannabis and its Constituents for Cancer: History, Biogenesis, Chemistry and Pharmacological Activities

Pharmacological Research “Cannabis has long been used for healing and recreation in several regions of the world. Over 400 bioactive constituents, including more than 100 phytocannabinoids, have been isolated from this plant. The non-psychoactive cannabidiol (CBD) and the psychoactive Δ9-tetrahydrocannabinol (Δ9-THC) are the major and widely studied constituents from this plant.

Cannabinoids exert their effects through the endocannabinoid system (ECS) that comprises cannabinoid receptors (CB1, CB2), endogenous ligands, and metabolizing enzymes. Several preclinical studies have demonstrated the potential of cannabinoids against leukemia, lymphoma, glioblastoma, and cancers of the breast, colorectum, pancreas, cervix and prostate.

Cannabis and its constituents can modulate multiple cancer related pathways such as PKB, AMPK, CAMKK-β, mTOR, PDHK, HIF-1α, and PPAR-γ. Cannabinoids can block cell growth, progression of cell cycle and induce apoptosis selectively in tumour cells. Cannabinoids can also enhance the efficacy of cancer therapeutics. These compounds have been used for the management of anorexia, queasiness, and pain in cancer patients.

Cannabinoid based products such as dronabinol, nabilone, nabiximols, and epidyolex are now approved for medical use in cancer patients. Cannabinoids are reported to produce a favourable safety profile. However, psychoactive properties and poor bioavailability limit the use of some cannabinoids. The Academic Institutions across the globe are offering training courses on cannabis. How cannabis and its constituents exert anticancer activities is discussed in this article. We also discuss areas that require attention and more extensive research.”

https://pubmed.ncbi.nlm.nih.gov/33246167/

https://www.sciencedirect.com/science/article/abs/pii/S1043661820316108?via%3Dihub

Education and communication are critical to effectively incorporating cannabis into cancer treatment

“Providers need to be better equipped to discuss medical cannabis with patients even if they are not willing to prescribe it. The oncology community would be well served to ensure that providers are aware of existing cannabis research and are able to incorporate it into their communications with patients instead of leaving patients to figure out medical cannabis on their own.”

https://pubmed.ncbi.nlm.nih.gov/32986251/

https://acsjournals.onlinelibrary.wiley.com/doi/10.1002/cncr.33204

Cancer patients’ experiences with medicinal cannabis-related care

 “Background: Little is known about medical cannabis (MC)-related care for patients with cancer using MC.

Methods: Semistructured telephone interviews were conducted in a convenience sample of individuals (n = 24) with physician-confirmed oncologic diagnoses and state/district authorization to use MC (Arizona, California, Florida, Illinois, Massachusetts, Oregon, New York, and Washington, DC) from April 2017 to March 2019. Standard qualitative techniques were used to assess the degree of MC-related health care oversight, MC practices, and key information sources.

Results: Among 24 participants (median age, 57 years; range, 30-71 years; 16 women [67%]), MC certifications were typically issued by a professional new to a patient’s care after a brief, perfunctory consultation. Patients disclosed MCuse to their established medical teams but received little medical advice about whether and how to use MC. Patients with cancer used MC products as multipurpose symptom management and as cancer-directed therapy, sometimes in lieu of standard-of-care treatments. Personal experimentation, including methodical self-monitoring, was an important source of MC know-how. Absent formal advice from medical professionals, patients relied on nonmedical sources for MC information.

Conclusions: Patients with cancer used MC with minimal medical oversight. Most received MC certifications through brief meetings with unfamiliar professionals. Participants desired but were often unable to access high-quality clinical information about MC from their established medical teams. Because many patients are committed to using MC, a product sustained by a growing industry, medical providers should familiarize themselves with the existing data for MM and its limitations to address a poorly met clinical need.”

https://pubmed.ncbi.nlm.nih.gov/32986266/

“Notably, oncology patients reported using medical cannabis (MC) for symptom management and as cancer‐directed therapy, sometimes instead of traditional treatments.”

https://acsjournals.onlinelibrary.wiley.com/doi/10.1002/cncr.33202

Activation of Cannabinoid Receptor 2 Prevents Colitis-Associated Colon Cancer through Myeloid Cell De-activation Upstream of IL-22 Production

iScience journal (@iScience_CP) | Twitter
” Here we show that delta-9-tetrahydrocannabinol (THC) attenuates colitis-associated colon cancer and colitis induced by anti-CD40.
 THC can prevent the development of colitis-associated colon cancer in mice.”

“Study reveals how cannabinoids may be useful to prevent colon cancer”   https://medicalxpress.com/news/2020-09-reveals-cannabinoids-colon-cancer.html

“Key cannabis chemical may help prevent colon cancer, researchers say”   https://www.heraldmailmedia.com/news/nation/key-cannabis-chemical-may-help-prevent-colon-cancer-researchers-say/article_7afd0a72-eead-57f0-a1d3-006be62b7469.html

“Treatment with a cannabinoid prevented the development of colon cancers in mice” https://www.news-medical.net/news/20200915/Treatment-with-a-cannabinoid-prevented-the-development-of-colon-cancers-in-mice.aspx

Figure thumbnail fx1

Cannabis sativa L. Extracts can reverse drug resistance in colorectal carcinoma cells in vitro

Synergy“Multidrug resistance (MDR) to known chemotherapeutic agents is increasing while the development of new drugs is lacking behind. Combination therapies might increase the development of effective treatment.

Anticancer properties of C. sativa L. have been extensively studied against various cancer cell lines but research on its effectiveness on MDR in cancer is less documented.

Aim

To determine the potential resistant reversal of the cytostatic drug doxorubicin by C. sativa L. extracts through combination studies.

Method

The cytotoxic effect of the different C. sativa L. extracts was assessed against a panel of human colon cancer cells (HT-29, Caco-2, HCT-15, LS513) and normal colon cells (CCD-18Co) by MTT assay. Drug-extract combination studies were performed on HCT-15 and LS513 MDR cells.

Results

DCM: methanol- and H2O extracts moderately inhibited the growth in HCT-15 and LS513 cells (IC50: 20–100 μg/ml). DCM- and H2O extracts potently inhibited HT-29 cell growth. Higher concentrations (100 μg/ml) of the hexane- and DCM- extracts slightly stimulated growth in Caco-2 cells. All the C. sativa L. extracts were more cytotoxic towards the cancerous cells than towards the normal colon cells. Combination studies between doxorubicin and the C. sativa L. extracts revealed synergistic growth inhibitory effects (CI < 1). The sensitivity to doxorubicin increased in HCT-15 and LS513 cells by 2.08- to 74.07-fold and 2.21- to 300.7-fold, respectively, compared to verapamil which improved it by 1.41-fold and 0.05-fold, respectively.

Conclusion

C. sativa L. extracts possess direct selective cytotoxic effect on colon cells and have a potential to reverse doxorubicin resistance.”

https://www.sciencedirect.com/science/article/abs/pii/S2213713019300021

Cannabinoid Effects on Experimental Colorectal Cancer Models Reduce Aberrant Crypt Foci (ACF) and Tumor Volume: A Systematic Review

See the source image “Colorectal cancer represents a heavy burden for health systems worldwide, being the third most common cancer worldwide. Despite the breakthroughs in medicine, current chemotherapeutic options continue to have important side effects and may not be effective in preventing disease progression.

Cannabinoids might be substances with possible therapeutic potential for cancer because they can attenuate the side effects of chemotherapy and have antiproliferative and antimetastatic effects.

We aim to determine, through a systematic review of experimental studies performed on animal CRC models, if cannabinoids can reduce the formation of preneoplastic lesions (aberrant crypt foci), number, and volume of neoplastic lesions.

Results: Eight in vivo experimental studies were included in the analysis after the full-text evaluation. Seven studies were azoxymethane (AOM) colorectal cancer models, and four studies were xenograft models. Cannabidiol botanical substance (CBD BS) and rimonabant achieved high aberrant crypt foci (ACF) reduction (86% and 75.4%, respectively). Cannabigerol, O-1602, and URB-602 demonstrated a high capacity for tumor volume reduction. Induction of apoptosis, interaction with cell survival, growth pathways, and angiogenesis inhibition were the mechanisms extracted from the studies that explain cannabinoids’ actions on CRC.

Conclusions: Cannabinoids have incredible potential as antineoplastic agents as experimental models demonstrate that they can reduce tumor volume and ACF formation. It is crucial to conduct more experimental studies to understand the pharmacology of cannabinoids in CRC better.”

https://pubmed.ncbi.nlm.nih.gov/32765628/

“Current literature findings demonstrate that cannabinoids might have potential as antineoplastic agents because they can reduce tumor volume and ACF formation.”

https://www.hindawi.com/journals/ecam/2020/2371527/

Cytotoxic Effects of Cannabinoids on Human HT-29 Colorectal Adenocarcinoma Cells: Different Mechanisms of THC, CBD, and CB83

ijms-logo “In this study, we investigated the effects of exposition to IC50 dose for 24 h of a new synthetic cannabinoid (CB83) and of phytocannabinoids Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) on HT-29 colorectal carcinoma cells. Cell viability and proliferative activity evaluated using the MTT, lactate dehydrogenase (LDH), and CyQUANT assays showed that cell viability was significantly affected when CB83, THC, and CBD were administered to cells.

The results obtained showed that the reduced glutathione/oxidized glutathione ratio was significantly reduced in the cells exposed to CBD and significantly increased in the cells treated with the CB83 when compared to the controls. CBD treatment causes a significant increase in malondialdehyde content. The catalase activity was significantly reduced in HT-29 cells after incubation with CB83, THC, and CBD. The activities of glutathione reductase and glutathione peroxidase were significantly increased in cells exposed to THC and significantly decreased in those treated with CBD. The ascorbic acid content was significantly reduced in cells exposed to CB83, THC, and CBD. The ultrastructural investigation by TEM highlighted a significantly increased percentage of cells apoptotic and necrotic after CB83 exposition. The Annexin V-Propidium Iodide assay showed a significantly increased percentage of cells apoptotic after CB83 exposition and necrotic cells after CBD and THC exposition.

Our results proved that only CBD induced oxidative stress in HT-29 colorectal carcinoma cells via CB receptor-independent mechanisms and that CB83 caused a mainly CB2 receptor-mediated antiproliferative effect comparable to 5-Fuorouracil, which is still the mainstay drug in protocols for colorectal cancer.”

https://pubmed.ncbi.nlm.nih.gov/32752303/

https://www.mdpi.com/1422-0067/21/15/5533

Anti-Cancer Potential of Cannabinoids, Terpenes, and Flavonoids Present in Cannabis

cancers-logo“In recent years, and even more since its legalization in several jurisdictions, cannabis and the endocannabinoid system have received an increasing amount of interest related to their potential exploitation in clinical settings. Cannabinoids have been suggested and shown to be effective in the treatment of various conditions. In cancer, the endocannabinoid system is altered in numerous types of tumours and can relate to cancer prognosis and disease outcome. Additionally, cannabinoids display anticancer effects in several models by suppressing the proliferation, migration and/or invasion of cancer cells, as well as tumour angiogenesis. However, the therapeutic use of cannabinoids is currently limited to the treatment of symptoms and pain associated with chemotherapy, while their potential use as cytotoxic drugs in chemotherapy still requires validation in patients. Along with cannabinoids, cannabis contains several other compounds that have also been shown to exert anti-tumorigenic actions. The potential anti-cancer effects of cannabinoids, terpenes and flavonoids, present in cannabis, are explored in this literature review.”

https://pubmed.ncbi.nlm.nih.gov/32708138/

https://www.mdpi.com/2072-6694/12/7/1985

Possible Enhancement of Photodynamic Therapy (PDT) Colorectal Cancer Treatment when Combined with Cannabidiol.

“Colorectal cancer (CRC) has a high mortality rate and is one of the most difficult diseases to manage due to tumour resistance and metastasis. The treatment of choice for CRC is reliant on the phase and time of diagnosis. Despite several conventional treatments available to treat CRC (surgical excision, chemo-, radiation- and immune-therapy), resistance is a major challenge, especially if it has metastasized. Additionally, these treatments often cause unwanted adverse side effects and so it remains imperative to investigate, alternative combination therapies.

Photodynamic Therapy (PDT) is a promising treatment modality for the primary treatment of CRC, since it is non-invasive, has few side effects and selectively damages only cancerous tissues, leaving adjacent healthy structures intact. PDT involves three fundamentals: a Photosensitizer (PS) drug localized in tumour tissues, oxygen and light. Upon PS excitation using a specific wavelength of light, an energy transfer cascade occurs, that ultimately yields cytotoxic species, which in turn induces cell death.

Cannabidiol (CBD) is a cannabinoid compound derived from the Cannabis sativa plant, which is found to exert anticancer effects on CRC through different pathways, inducing apoptosis and so inhibits tumour metastasis and secondary spread.

This review paper highlights current conventional treatment modalities for CRC and their limitations, as well as discusses the necessitation for further investigation into unconventional active nanoparticle targeting PDT treatments for enhanced primary CRC treatment. This can be administered in combination with CBD, to prevent CRC secondary spread and so enhance the synergistic efficacy of CRC treatment outcomes, with less side effects.”

https://www.ncbi.nlm.nih.gov/pubmed/32294046

http://www.eurekaselect.com/180902/article

Cannabinoids as anticancer therapeutic agents.

Cell Cycle Journal are Co-Sponsoring #ACCM15 – The Cell Division Lab “The recent announcement of marijuana legalization in Canada spiked many discussions about potential health benefits of Cannabis sativaCannabinoids are active chemical compounds produced by cannabis, and their numerous effects on the human body are primarily exerted through interactions with cannabinoid receptor types 1 (CB1) and 2 (CB2). Cannabinoids are broadly classified as endo-, phyto-, and synthetic cannabinoids. In this review, we will describe the activity of cannabinoids on the cellular level, comprehensively summarize the activity of all groups of cannabinoids on various cancers and propose several potential mechanisms of action of cannabinoids on cancer cells.”

https://www.ncbi.nlm.nih.gov/pubmed/32249682

“Endocannabinoids and phytocannabinoids can be used for cancer therapy. Cannabis extracts have stronger anti-tumor capacity than single cannabinoids. Combination of several cannabinoids may have more potent effect on cancer.”

https://www.tandfonline.com/doi/abs/10.1080/15384101.2020.1742952?journalCode=kccy20