In this review we will cover some research on cannabinoids and their anti-cancer treatment potential.
THC is the main active compound in Cannabis Sativa and it mimics the effect of anandamide and 2-arachidonoylglycerol, which bind the receptors CB1 and CB2. The effect of cannabinoids on central nervous system is result of CB1 receptor activation, although this receptor is not specific only for the nervous system. CB2 receptor was described as typical for the immune system but it could be find in other organs and systems.
Interestingly latest research shows that CB1 and CB2 receptors are expressed in many types of cancer cells.
So far cannabinoids have shown therapeutic effect in chemotherapy-induced nausea and vomiting. There are several cannabinoid-based medications that are approved already on the market.
Cannabinoids have also documented effect in cancer-associated pain. Another potential effect is appetite stimulation and attenuation of wasting.
Cancer studies with animal models have shown anti-tumor effect of THC and other cannabinoids.
What is the role of endocannabinoid system in cancer?
First we can answer the question “What is the endocannabinoid system?” – it is constituted by endocannabinoids (substances already available in the body), their receptors (for example, CB1 and CB2) and proteins involved in the synthesis, transport and degradation of the endocannabinoids.
Cancer research with animal models show that in many types of cancer there are increased levels of endocannabinoids and their receptors in the cancer cells. On the other hand the proteins involved in degradation of endocannabinoids are decreased in cancer cells.
There is lots of conflicting data. Some research shows that genetic inactivation of CB1 receptor increases intestinal tumor growth in colon carcinoma studies with mice.
How cannabinoids induce cancer cell death?
THC binds to cannabinoid receptors and activate them, which trigger a mechanism that leads to cell death, also known as apoptosis. This mechanism of cell death stimulated by cannabinoids was observed in glioma, melanoma, pancreatic and hepatic cancer cells.
CBD that has lower affinity to cannabinoid receptors and other cannabis-derived cannabinoids have also shown to trigger apoptosis.
There is also research data that cannabinoids inhibit cancer metastasis. CBD has shown significant anticancer effect in such research.