A recent medical review from Polish researchers suggests cannabinoids could potentially be safe and therapeutic agents for treating cancer.
Researchers from Jagiellonian University Medical College in Poland recently investigated the mechanisms behind the anti-cancer effects of cannabinoids. Published in a recent issue of the peer-reviewed journal Advances in Hygiene and Experimental Medicine, the review found evidence in preclinical studies that cannabinoids effectively inhibit the growth of many tumor types.
In vitro cell experiments and animal trials have demonstrated the anti-cancer effects of cannabinoids. This anti-tumor efficacy has been found in phytocannabinoids, endocannabinoids, and synthetic cannabinoids. Phytocannabinoids, including tetrahydrocannabinol (THC) and cannabidiol (CBD), are derived from cannabis plants like marijuana and hemp. Endocannabinoids, such as anandamide and 2-arachidonoylglycerol (2-AG), are naturally synthesized on-demand from cell membrane arachidonic acid derivatives within the body. Synthetic cannabinoids are a class of man-made compounds that are designed to act like phytocannabinoids or endocannabinoids. Cannabinoids elicit their effects by binding to the endocannabinoid system’s receptors, CB1 and CB2, which stimulates chemical responses that encourage balance.
Through their interaction with cannabinoid receptors, cannabinoids can stimulate chemical responses response on cells that lead to the inhibition in cancer cell growth and even destroy cancer cells.
The main way that cannabinoids inhibit cancer cells, the review finds, is through apoptosis. Apoptosis is a process of programmed cell death that occurs in physiological and pathological conditions. Malignant cells typically have the ability to evade apoptosis, allowing them to stay alive. Cannabinoids, however, have been shown to prevent malignant cells from evading death by encouraging cancer cell apoptosis through autophagy and a not-well-understand pathway related to the endoplasmic reticulum.
Autophagy is a natural intracellular degradation system that breaks down and recycles cellular components. Autophagy plays a significant role in cancer and has the capability to either suppress tumors and protect against the disease or contribute to tumor growth. Cancers can upregulate autophagy to increase tumor growth and aggressiveness. Cannabinoids have been found to promote the autophagic death of cancer cells.
Mobilization of endoplasmic reticulum calcium stores can initiative the action of cell death pathways and sensitize mitochondria to stimuli that encourages apoptosis. This endoplasmic reticulum pathway activation of autophagy eventually leads to the apoptosis death of tumor cells.
The researchers also note that some evidence found in cellular studies indicates that cannabinoids may suppress the immune system or activate factors that encourage cell division, in turn enhancing the reproduction of cancer cells. They conclude by acknowledging that most data suggest cannabinoids could be beneficial in the treatment of cancer and urge for more research.
“Leading from this there is a an obvious need to further explore cannabinoid associated molecular pathways making it possible to develop safe therapeutic drug agents for patients in the future.”
As of now, 29 U.S. states have legalized marijuana for medical purposes. Of those, nearly all have approved cannabis specifically for the treatment of cancer.
You can access the entire study, “Cannabinoids – a new weapon against cancer?” via Advances in Hygiene and Experimental Medicine.