
Olive Oil Component Inhibits Angiogenesis in Colon Cancer
Summary: Olive oil, along with red wine and berries, contains
polyphenols, which have been shown to suppress inflammation, angiogenesis and
tumor growth. In a new study, researchers describe how one type of polyphenol
found in olive oil inhibits angiogenesis in a mouse model of colorectal cancer.
Mice fed a daily diet of the polyphenol DPE had a significant reduction in
tumor growth and angiogenesis compared with control mice. The antiangiogenic
effects were attributed to suppression of a key angiogenesis-stimulating
pathway in cancer. The results suggest that polyphenols in olive oil, red wine,
berries and other foods could be combined with cancer drugs or taken separately
as chemoprevention.
Consumption of olive oil has long been associated with health benefits such as
lower cholesterol and a reduced risk of cardiovascular disease. There have also
been suggestions that people with diets rich in olive oil may have a lower risk
of some cancers due to the anti-inflammatory properties of polyphenols
contained in olive oil. A polyphenol of olive oil, 2-(3, 4-dihydroxyphenil)
ethanol (DPE), which possesses both anti-inflammatory and anti-clotting
activities, has been shown to reduce the tumor necrosis factor alpha–induced
activation of the inflammatory pathway in an animal model of colon cancer.
Angiogenesis, the growth of new tumor blood vessels, also plays a critical role
in the development, progression and metastasis of cancer. Inflammation and
hypoxia, the lack of oxygen in tissues such as tumors, are closely linked to
angiogenesis in cancer development. Inflammation and hypoxia stimulate
angiogenesis through the upregulation of a number of cell signaling factors,
including hypoxia-inducible factor-1 alpha (HIF-1a), cyclooxygenase-2 (COX-2),
and prostaglandin E2 (PGE-2). PGE-2 has been shown to promote both tumor growth
and angiogenesis.
Given the established anti-inflammatory properties of olive oil, researchers in
Italy, Spain, and at the U.S. National Cancer Institute sought to find out
whether the olive oil polyphenol DPE could inhibit angiogenesis in mice with
implanted human colorectal cancers. The scientists also used several assays to
evaluate the specific anti-tumor and antiangiogenic activities of DPE. As
expected, DPE inhibited the production and activity of PGE-2, HIF-1 alpha, and
vascular endothelial growth factor, the primary angiogenesis-stimulating
protein, and inhibited the growth of colorectal cancer cells in vitro.
Mice that were fed DPE (10 mg/kg/day for 14 days) had reduced tumor growth,
likely due to the antiangiogenic effects of DPE.
Inflammation, angiogenesis and cancer development are closely linked processes
with a complex interplay of signaling pathways. This study indicates that
compounds with anti-inflammatory and antiangiogenic properties, such as DPE,
resveratrol and other polyphenols, might be combined with chemotherapy drugs or
used separately as chemoprevention.
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