Glioblastoma multiforme (GBM) is an aggressive type of brain cancer that rarely sees a patient live beyond 15 months post treatment, despite having surgery, radiotherapy and chemotherapy. GBMs have a very invasive nature and can break down the blood-brain barrier, causing cerebral edema and severe symptoms in patients. It is notably one of the most difficult cancers to treat.
Extra virgin olive oil (EVOO) is known to help prevent a variety cancers such as colorectal, prostate, lung, endometrial and breast cancer. A new study, published in the Journal of Nutritional Biochemistry, Jan 2016, reports that the “chemopreventive ability of EVOO is not only due to fatty acids but also to its content of phenolic compounds such as polyphenols and flavonoids.”
See more: Olive Oil Health Benefits
It is known that oleuropein, a phenolic compound in olive oil, inhibits glioblastoma cell migration. It is also known that oleocanthal, a powerful anti-inflammatory compound in olive oil, down-regulates cyclooxygenase‑2 (COX‑2) expression in colon cancer cells.
However, until now, a study investigating the anti-inflammatory effects of EVOO compounds against cytokines (inflammatory molecules) in glioblastoma cells had never before been conducted.
This new in-vitro study shows that EVOO does in fact reduce the production of chronic inflammation on glioblastoma progression via one particular proinflammatory molecule, tumor necrosis factor alpha (TNF‑a). The proinflammatory cytokine, TNF‑a, directly induces COX‑2, an inflammatory biomarker in glioblastoma cells.
In the study, the cells were incubated for 24 hours with and without the presence of olive oil compounds, oleic acid, tyrosol and hydroxytyrosol. The cells were then subject to TNF‑a stimulation for a further 24 hours.
As expected, TNF‑a caused a marked increase in COX‑2 expression. Oleic acid inhibited this expression by 61.7 percent, tyrosol inhibited it by 36.5 percent, while hydroxytyrosol did not show any significant differences.
Further investigations were conducted to understand the mechanisms behind these inhibitory actions.
In a concentration-dependent manner there was, “inhibition of TNF‑a induced down-stream signalling pathways,” the pathways varying for both oleic acid and tyrosol. The researchers also investigated another proinflammatory molecule secreted by glioblastoma cells, prostaglandin E2 (PGE2). Again, the results showed that oleic acid and tyrosol significantly reduced TNF‑a induced PGE2 by 45.4 percent and 71.5 percent, respectively.
Lastly, the researchers analyzed the effects of oleic acid and tyrosol on human brain microvascular endothelial cell migration “by directly targeting the chemotactic activity of PGE2.The results showed that the olive oil compounds block the endothelial cell migration through different cellular mechanisms.”
Overall, what the research shows is that dietary interventions such as using EVOO can help reduce brain tumors by down-regulating proinflammatory molecules and preventing chronic inflammation within the microenvironment that drives the glioblastoma growth.
The researchers said the results of the study suggest that, “Given that cancer development and progression is a multistep process, supplementation with olive oil may represent an efficient dietary intervention in the prevention and/or management of glioblastoma.”