Grape Seed – Great for the Heart, Tough on Cancer
Grape seed extract has many attributes – one them being the protection of the heart and arteries. However, that protection only extends to beneficial blood vessels. Studies, like the one below, show that grape seed actually inhibits the development of blood vessels – angiogenesis – to cancer cells.
That’s because it is able to selectively target a pathway used by the protein called Vascular Endothelial Growth Factor (VEGF), and inhibit its receptor activity, stopping it from finishing its “mission” to create the blood vessels that feed tumor growth.
The benefit of using grape seed extract is that it doesn’t carry side effects like Avastin, which can cause headaches, high blood pressure, dry skin, and rectal bleeding. Additionally, grape seed extract can regulate blood sugar levels, fight inflammation throughout your body, and of course, keep your cardiovascular system running smoothly.
Wen W, Lu J, Zhang K, Chen S. Grape seed extract inhibits angiogenesis via suppression of the vascular endothelial growth factor receptor signaling pathway. Cancer Prev Res (Phila). 2008 Dec;1(7):554-61.
Blockade of angiogenesis is an important approach for cancer treatment and prevention. VEGF is one of the most critical factors that induce angiogenesis and has thus become an attractive target for anti-angiogenesis treatment. However, most of current anti-VEGF agents often cause some side effects when given chronically. Identification of naturally occurring VEGF inhibitors derived from diet would be one alternative approach with an advantage of known safety. Grape seed extract (GSE), a widely used dietary supplement, is known to have anti-tumor activity. In this study, we have explored the activity of GSE on VEGF receptor and angiogenesis. We found that GSE could directly inhibit kinase activity of purified VEGFR2, a novel activity of GSE that has not been characterized. GSE could also inhibit VEGFR/MAPK mediated signaling pathway in endothelial cells. As a result, GSE could inhibit VEGF induced endothelial cell proliferation and migration as well as sprouts formation from aorta ring. In vivo assay further showed that GSE could inhibit tumor growth and tumor angiogenesis of MDA-MB-231 breast cancer cells in mice. Consistent with the in vitro data, GSE treatment of tumor bearing mice led to concomitant reduction of blood vessel density and phosphorylation of MAP kinase. Depletion of polyphenol with polyvinylpyrrolidone (PVPP) abolished the anti-angiogenesis activity of GSE, suggesting a water soluble fraction of polyphenol in GSE is responsible for the anti-angiogenesis activity. Taken together, this study indicates that GSE is a well-tolerated and inexpensive natural VEGF inhibitor and could potentially be useful in cancer prevention or treatment.