Cannabidiol, better known as CBD, continues to grow in popularity around the world as users tout it’s supposed ability to do everything from relieve pain to reduce stress to help lower blood pressure. Now, researchers have found that inhaling CBD can shrink glioblastoma, a very aggressive and deadly brain tumor, in mice.
According to the study, CBD, the second-most active ingredient in marijuana, diminishes the support from its microenvironment the tumor needs to thrive.
“We saw a significant reduction in the size of the tumor and its microenvironment was different,” says study co-author Dr. Babak Baban, immunologist and associate dean for research at the Dental College of Georgia (DCG) at Augusta University, in a statement.
The researchers discovered that CBD works well for changing the tumor’s environment in an unfavorable way—for the tumor, that is. For instance, it restores levels of inflammation that will attack the tumor. Once a tumor establishes itself in the body, it changes the body’s natural defense in its favor by turning inflammation meant to protect the body to chronic, which ends up protecting the tumor instead of fighting it. This new microenvironment allows the tumor to thrive.
In particular, a glioblastoma tumor increases the activity of natural immune checkpoints that are meant to protect the body from an excessive immune response. However, in this case the decreased immune response ends up protecting the tumor, not the body. It also reduces the number of cytotoxic T cells that could fight the tumor. CBD seems to reverse this process by improving the body’s “immune mix.” In the study, shrinkage of the tumor could be observed after only a week of inhaling CBD.
While currently the findings have only been proved in mice, there is hope that the treatment will work in humans with glioblastoma, too. “It’s probably one of the most aggressive cancers period. We are in desperate need of research and more treatments,” said Dr. Baban. ”What we have right now is not working very well.”
To date, glioblastoma is treated with surgery, chemotherapy, and radiation therapy. “Surgery does not offer a cure but it does offer an important first step in maximizing quality of life and prognosis,” added MCG neurosurgeon Dr. Martin Rutkowski. “Family members will bring patients in and say they are just not thinking right, that their memory is all over the place, or that they got fired from their job because they are no longer doing things right that they have been doing for 30 years.” CBD could become a safe and potent addition to the treatment of glioblastoma patients.
The DCG study was the first to test CBD in an animal model of glioblastoma. The researchers created the most realistic model possible by using human glioblastoma cells. Once the tumor was established in the mice’s brains, the researchers administered a daily dose of either inhaled CBD or a placebo (for the control group) for seven days before reexamining the tumor and its tissue. The researchers point out that they didn’t use any therapies other than CBD to encourage shrinkage of the tumor. “CBD is a very smart regulator,” said Dr. Baban. It also showed helpful regulations in the case of COVID, he added.
Following the promising first results, the researchers plan to examine for how long the positive changes last and how CBD affects cancer stem cells and the cancer’s recurrence rate. The researchers are hopeful: When they incubated tumor cells in CBD for an earlier study, the CBD prevented the growth of a tumor.
The study is published in the journal Cannabis and Cannabinoid Research.