Cannabinoids as anticancer drugs: current status of preclinical research

“Drugs that target the endocannabinoid system are of interest as pharmacological options to combat cancer and to improve the life quality of cancer patients. From this perspective, cannabinoid compounds have been successfully tested as a systemic therapeutic option in a number of preclinical models over the past decades. As a result of these efforts, a large body of data suggests that the anticancer effects of cannabinoids are exerted at multiple levels of tumour progression via different signal transduction mechanisms. Accordingly, there is considerable evidence for cannabinoid-mediated inhibition of tumour cell proliferation, tumour invasion and metastasis, angiogenesis and chemoresistance, as well as induction of apoptosis and autophagy. Further studies showed that cannabinoids could be potential combination partners for established chemotherapeutic agents or other therapeutic interventions in cancer treatment. Research in recent years has yielded several compounds that exert promising effects on tumour cells and tissues in addition to the psychoactive Δ9-tetrahydrocannabinol, such as the non-psychoactive phytocannabinoid cannabidiol and inhibitors of endocannabinoid degradation. This review provides an up-to-date overview of the potential of cannabinoids as inhibitors of tumour growth and spread as demonstrated in preclinical studies.”

https://pubmed.ncbi.nlm.nih.gov/35277658/

Cannabidiol and Other Phytocannabinoids as Cancer Therapeutics

“Preclinical models provided ample evidence that cannabinoids are cytotoxic against cancer cells. Among the best studied phytocannabinoids, cannabidiol (CBD) is most promising for the treatment of cancer as it lacks the psychotomimetic properties of delta-9-tetrahydrocannabinol (THC). In vitro studies and animal experiments point to a concentration- (dose-)dependent anticancer effect. The effectiveness of pure compounds versus extracts is the subject of an ongoing debate. Actual results demonstrate that CBD-rich hemp extracts must be distinguished from THC-rich cannabis preparations. Whereas pure CBD was superior to CBD-rich extracts in most in vitro experiments, the opposite was observed for pure THC and THC-rich extracts, although exceptions were noted. The cytotoxic effects of CBD, THC and extracts seem to depend not only on the nature of cannabinoids and the presence of other phytochemicals but also largely on the nature of cell lines and test conditions. Neither CBD nor THC are universally efficacious in reducing cancer cell viability. The combination of pure cannabinoids may have advantages over single agents, although the optimal ratio seems to depend on the nature of cancer cells; the existence of a ‘one size fits all’ ratio is very unlikely. As cannabinoids interfere with the endocannabinoid system (ECS), a better understanding of the circadian rhythmicity of the ECS, particularly endocannabinoids and receptors, as well as of the rhythmicity of biological processes related to the growth of cancer cells, could enhance the efficacy of a therapy with cannabinoids by optimization of the timing of the administration, as has already been reported for some of the canonical chemotherapeutics. Theoretically, a CBD dose administered at noon could increase the peak of anandamide and therefore the effects triggered by this agent. Despite the abundance of preclinical articles published over the last 2 decades, well-designed controlled clinical trials on CBD in cancer are still missing. The number of observations in cancer patients, paired with the anticancer activity repeatedly reported in preclinical in vitro and in vivo studies warrants serious scientific exploration moving forward.”

https://pubmed.ncbi.nlm.nih.gov/35244889/

Cannabis as a potential compound against various malignancies, legal aspects, advancement by exploiting nanotechnology and clinical trials

“Various preclinical and clinical studies exhibited the potential of cannabis against various diseases, including cancer and related pain. Subsequently, many efforts have been made to establish and develop cannabis-related products and make them available as prescription products. Moreover, FDA has already approved some cannabis-related products, and more advancement in this aspect is still going on. However, the approved product of cannabis is in oral dosage form, which exerts various limitations to achieve maximum therapeutic effects. A considerable translation is on a hike to improve bioavailability, and ultimately, the therapeutic efficacy of cannabis by the employment of nanotechnology. Besides the well-known psychotropic effects of cannabis upon the use at high doses, literature has also shown the importance of cannabis and its constituents in minimising the lethality of cancer in the preclinical models. This review discusses the history of cannabis, its legal aspect, safety profile, the mechanism by which cannabis combats with cancer, and the advancement of clinical therapy by exploiting nanotechnology. A brief discussion related to the role of cannabinoid in various cancers has also been incorporated. Lastly, the information regarding completed and ongoing trials have also been elaborated.”

https://pubmed.ncbi.nlm.nih.gov/35321629/

Cannabidiol Inhibits Tumorigenesis in Cisplatin-Resistant Non-Small Cell Lung Cancer via TRPV2

“Chemotherapy forms the backbone of current treatments for many patients with advanced non-small-cell lung cancer (NSCLC). However, the survival rate is low in these patients due to the development of drug resistance, including cisplatin resistance. In this study, we developed a novel strategy to combat the growth of cisplatin-resistant (CR) NSCLC cells. We have shown that treatment with the plant-derived, non-psychotropic small molecular weight molecule, cannabidiol (CBD), significantly induced apoptosis of CR NSCLC cells. In addition, CBD treatment significantly reduced tumor progression and metastasis in a mouse xenograft model and suppressed cancer stem cell properties. Further mechanistic studies demonstrated the ability of CBD to inhibit the growth of CR cell lines by reducing NRF-2 and enhancing the generation of reactive oxygen species (ROS). Moreover, we show that CBD acts through Transient Receptor Potential Vanilloid-2 (TRPV2) to induce apoptosis, where TRPV2 is expressed on human lung adenocarcinoma tumors. High expression of TRPV2 correlates with better overall survival of lung cancer patients. Our findings identify CBD as a novel therapeutic agent targeting TRPV2 to inhibit the growth and metastasis of this aggressive cisplatin-resistant phenotype in NSCLC.”

https://pubmed.ncbi.nlm.nih.gov/35267489/

Cannabidiol Induces Cell Death in Human Lung Cancer Cells and Cancer Stem Cells

“Currently, there is no effective therapy against lung cancer due to the development of resistance. Resistance contributes to disease progression, recurrence, and mortality. The presence of so-called cancer stem cells could explain the ineffectiveness of conventional treatment, and the development of successful cancer treatment depends on the targeting also of cancer stem cells. Cannabidiol (CBD) is a cannabinoid with anti-tumor properties. However, the effects on cancer stem cells are not well understood. The effects of CBD were evaluated in spheres enriched in lung cancer stem cells and adherent lung cancer cells. We found that CBD decreased viability and induced cell death in both cell populations. Furthermore, we found that CBD activated the effector caspases 3/7, increased the expression of pro-apoptotic proteins, increased the levels of reactive oxygen species, as well as a leading to a loss of mitochondrial membrane potential in both populations. We also found that CBD decreased self-renewal, a hallmark of cancer stem cells. Overall, our results suggest that CBD is effective against the otherwise treatment-resistant cancer stem cells and joins a growing list of compounds effective against cancer stem cells. The effects and mechanisms of CBD in cancer stem cells should be further explored to find their Achilles heel.”

https://pubmed.ncbi.nlm.nih.gov/34832951/

Lung cancer patient who had declined conventional cancer treatment: could the self-administration of ‘CBD oil’ be contributing to the observed tumour regression?

b-on, bliblioteca do conhecimento online | BMJ“Conventional lung cancer treatments include surgery, chemotherapy and radiotherapy; however, these treatments are often poorly tolerated by patients. Cannabinoids have been studied for use as a primary cancer treatment. Cannabinoids, which are chemically similar to our own body’s endocannabinoids, can interact with signalling pathways to control the fate of cells, including cancer cells. We present a patient who declined conventional lung cancer treatment. Without the knowledge of her clinicians, she chose to self-administer ‘cannabidiol (CBD) oil’ orally 2-3 times daily. Serial imaging shows that her cancer reduced in size progressively from 41 mm to 10 mm over a period of 2.5 years. Previous studies have failed to agree on the usefulness of cannabinoids as a cancer treatment. This case appears to demonstrate a possible benefit of ‘CBD oil’ intake that may have resulted in the observed tumour regression. The use of cannabinoids as a potential cancer treatment justifies further research.”

https://pubmed.ncbi.nlm.nih.gov/34649854/

“Patient’s perspective

“I was not very interested in traditional cancer treatments as I was worried about the risks of surgery, and I saw my late husband suffer through the side effects of radiotherapy. My relative suggested that I should try ‘cannabidiol (CBD) oil’ to treat my cancer, and I have been taking it regularly ever since. I am ‘over the moon’ with my cancer shrinking, which I believe was caused by the ‘CBD oil’. I am tolerating it very well and I intend to take this treatment indefinitely.””

https://casereports.bmj.com/content/14/10/e244195

“Cannabis oil led to lung cancer regression in 80-year-old woman: Report”

https://www.freepressjournal.in/world/cannabis-oil-led-to-lung-cancer-regression-in-80-year-old-woman-report

“Case Report: Lung Cancer Shrinks in Patient Using CBD Oil”

https://www.medscape.com/viewarticle/960949

“Daily use of cannabidiol (‘CBD’) oil may be linked to lung cancer regression”

https://www.bmj.com/company/newsroom/daily-use-of-cannabidiol-cbd-oil-may-be-linked-to-lung-cancer-regression/

The antitumor activity of cannabidiol on lung cancer cell lines A549 and H1299: the role of apoptosis

Publication Cover“In the recent years, the application of new antitumor drugs has focused on the replacement of conventional chemotherapeutics with compounds derived from natural products.

Cannabidiol (CBD) is one of the 113 cannabinoids derived from the plant Cannabis sativa and is characterized with complex and not entirely understood biological function. Unlike the other most abundant cannabinoid in Cannabis sativa – tetrahydrocannabinol, cannabidiol has low affinity to the endocannabinoid receptors and the manifestation of its activity does not appear to rely on the endocannabinoid system.

Cannabidiol is used in the treatment of many diseases including some types of cancer.

The aim of our study was to evaluate the cytotoxic activity of cannabidiol and its effect on the process of programmed cell death. This process is directly involved in the antitumor effect of many drugs.

We found that CBD treatment led to a dose-dependant apoptosis increase in p53 positive A549 cells.

Several studies have demonstrated that cannabinoids also have antineoplastic effect and are usually accompanied with no negative side effects such as the ones produced by the conventional chemotherapy treatment.”

https://www.tandfonline.com/doi/full/10.1080/13102818.2021.1915870

Association Between Smoking Cannabis and Quitting Cigarettes in a Large American Cancer Society Cohort

Cancer Epidemiology, Biomarkers & Prevention“Background: Cannabis use is increasing, including among smokers, an at-risk population for cancer. Research is equivocal on whether using cannabis inhibits quitting cigarettes. The current longitudinal study investigated associations between smoking cannabis and subsequently quitting cigarettes.

Results: Adjusted cigarette quitting rates at follow-up did not differ significantly by baseline cannabis smoking status [never 36.2%, 95% confidence interval (CI), 34.5%-37.8%; former 34.1%, CI, 31.4%-37.0%; recent 33.6%, CI, 30.1%-37.3%], nor by frequency of cannabis smoking (low 31.4%, CI, 25.6%-37.3%; moderate 36.7%, CI, 30.7%-42.3%; high 34.4%, CI, 28.3%-40.2%) among recent baseline cannabis smokers. In cross-sectional analyses conducted at follow-up the proportion of cigarette smokers intending to quit smoking cigarettes in the next 30 days did not differ by cannabis smoking status (p=0.83).

Conclusions: Results do not support the hypothesis that cannabis smoking inhibits quitting cigarette smoking among adults.”

https://pubmed.ncbi.nlm.nih.gov/34348959/

“Results do not support the hypothesis that cannabis smoking inhibits quitting cigarette smoking among adults.” https://cebp.aacrjournals.org/content/early/2021/08/04/1055-9965.EPI-20-1810

Cancer Initiation, Progression and Resistance: Are Phytocannabinoids from Cannabis sativa L. Promising Compounds?

molecules-logo“Cannabis sativa L. is a source of over 150 active compounds known as phytocannabinoids that are receiving renewed interest due to their diverse pharmacologic activities. Indeed, phytocannabinoids mimic the endogenous bioactive endocannabinoids effects through activation of CB1 and CB2 receptors widely described in the central nervous system and peripheral tissues.

All phytocannabinoids have been studied for their protective actions towards different biological mechanisms, including inflammation, immune response, oxidative stress that, altogether, result in an inhibitory activity against the carcinogenesis.

The role of the endocannabinoid system is not yet completely clear in cancer, but several studies indicate that cannabinoid receptors and endogenous ligands are overexpressed in different tumor tissues.

Recently, in vitro and in vivo evidence support the effectiveness of phytocannabinoids against various cancer types, in terms of proliferation, metastasis, and angiogenesis, actions partially due to their ability to regulate signaling pathways critical for cell growth and survival.

The aim of this review was to report the current knowledge about the action of phytocannabinoids from Cannabis sativa L. against cancer initiation and progression with a specific regard to brain, breast, colorectal, and lung cancer as well as their possible use in the therapies. We will also report the known molecular mechanisms responsible for such positive effects.

Finally, we will describe the actual therapeutic options for Cannabis sativa L. and the ongoing clinical trials.”

https://pubmed.ncbi.nlm.nih.gov/34063214/

https://www.mdpi.com/1420-3049/26/9/2668

The pro-apoptosis effects of Echinacea purpurea and Cannabis sativa extracts in human lung cancer cells through caspase-dependent pathway

 Logo of bmccmt“Considering the advantages of using medicinal herbs as supplementary treatments to sensitize conventional anti-cancer drugs, studying functional mechanisms and regulatory effects of Echinacea purpurea (as a non-cannabinoid plant) Image result for echinacea purpurea

and Cannabis sativa (as a cannabinoid plant) are timely and required.Image result for cannabis sativa

The potential effects of such herbs on lung cancer cell growth, apoptosis, cell cycle distribution, cellular reactive oxygen species (ROS) level, caspase activity and their cannabinomimetic properties on the CB2 receptor are addressed in the current study.

Results: Echinacea purpurea (EP) root extract induced a considerable decrease in A549 viable cells, showing a time and dose-dependent response. The cell toxicity of EP was accompanied by induction of early apoptosis and cell accumulation at the sub G1 phase of the cell cycle. The elevation of cellular ROS level and caspase 3 activity indicate ROS-induced caspase-dependent apoptosis following the treatment of A549 cells by EP extract. The observed effects of EP extract on A549 growth and death were abrogated following blockage of CB2 using AM630, a specific antagonist of the CB2 receptor. Increasing concentrations of Cannabis sativa (CS) induced A549 cell death in a time-dependent manner, followed by induction of early apoptosis, cell cycle arrest at sub G1 phase, elevation of ROS level, and activation of caspase 3. The CB2 blockage caused attenuation of CS effects on A549 cell death which revealed consistency with the effects of EP extract on A549 cells.

Conclusions: The pro-apoptotic effects of EP and CS extracts on A549 cells and their possible regulatory role of CB2 activity might be attributed to metabolites of both herbs. These effects deserve receiving more attention as alternative anti-cancer agents.”

https://pubmed.ncbi.nlm.nih.gov/33446187/

“Both cannabinoid receptors and naturally occurring cannabinoids, known as phytocannabinoids, have potential therapeutic applications based on their pivotal roles in regulating immunologic responses, alleviating inflammation, tumor cell proliferation, angiogenesis, invasion, and migration. Based on the findings, it can be postulated that EP and CS extracts can inhibit lung cancer cell growth and induce apoptosis and should be considered as an alternative anti-cancer agent in lung cancer.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7809807/

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