A team of scientists testing the effects of CBD and THC on ovarian cancer cells have found that both show promising anti-cancer effects.
While still in the early stages, researchers say these preliminary findings from the laboratory present an important opportunity to develop effective new therapies for a cancer that is hard to diagnose and even harder to treat.
Ovarian cancer kills more patients than any other gynecological cancer, affecting around 7,000 women every year in the UK.
Although there have been some advances in treatments, available drugs are not always effective and often come with side effects, meaning new options are desperately needed.
“Ovarian cancer remains one of the deadliest gynecological malignancies, characterized by late diagnosis, high recurrence rates, and limited effective treatment options,” said Dr Siyao Tong of Khon Kaen University, lead author of the article in Frontiers in Pharmacology.
“Our goal is to find alternative drugs that can improve efficacy and potentially reduce toxicity, ultimately bringing new hope to patients facing this challenging disease.”
Effects of CBD and THC on ovarian cancer cells
With CBD and THC both showing potential effects against other cancers in early studies, Tong and colleagues decided to test them against ovarian cancer cells.
The researchers took two different lines of ovarian cancer cells, one of which is sensitive to platinum-derived drugs and one of which is resistant, and challenged the lines with CBD, THC, or both, to see if the cells could survive and reproduce after exposure. The scientists also challenged a line of healthy cells to see if the compounds damaged them.
They found that cells for both cancer lines, which had been treated with CBD or THC, formed fewer and smaller colonies of cells. Though both compounds worked to prevent cancer cells from reproducing, combining them gave particularly good results. Although neither compound alone killed a large proportion of cancer cells, a combination of the two was very successful.
The researchers say it’s possible that THC and CBD act on the cancer cells in different ways, and when used together, their effects are amplified.
Tong added that the ‘inhibitory effect was most pronounced’ when CBD and THC were used in a 1:1 ratio.
Additional assays showed that the compounds prevented cells from migrating, meaning they may be able to stop ovarian cancer from spreading to other parts of the body.
Both cell lines were similarly affected, suggesting that the compounds could work equally well for different types of ovarian cancer.
The compounds and their combinations also had minimal effects on healthy cells, which suggests that patients might find treatments made from them less toxic and easier to tolerate than current drugs.
To understand the mechanism behind these anti-cancer effects, the scientists looked at cell signaling pathways.
The PI3K/AKT/mTOR pathway is overactivated in ovarian cancer cells, which contributes to tumor development and treatment resistance.
The CBD and THC compounds seemed to restore normal regulation of the pathway, which could explain why the cancer cells couldn’t reproduce and began to die off after treatment.
Looking to the future – limitations and areas for further research
However, much more work remains to be done before these results can be translated into practical treatments.
The scientists call for further research, which can establish if and how these compounds can be used as effective new ovarian cancer therapies.
“Although our study is still preliminary, it lays an important foundation for future research into the potential applications of CBD and THC in ovarian cancer treatment,” said Tong.
“By confirming their anti-cancer activity and identifying key molecular mechanisms, our findings are expected to drive further preclinical research. If future studies confirm these effects, CBD-THC combination therapy may ultimately contribute to the development of new treatment strategies.”
The study also has some limitations, including the fact that all experiments were conducted in vitro, so the results may not fully reflect the complexity of tumor behavior in living organisms.
Examining the effects in in vivo models, alongside pharmacokinetic data, which is crucial for determining whether CBD/THC can be safely and effectively used clinically.
“While the results are encouraging, more studies are needed before these findings can be applied to patient treatment,” Tong added.
