Cinnamon, the dry bark and twig of Cinnamomum spp., is one of the world’s most popular and oldest spices. Cinnamon extract has been found to possess potent antioxidant, antimicrobial, and antipyretic (fever reducing) properties. Several recent studies have found that cinnamon extract also has anticancer activity. Cinnamon extract was shown to inhibit blood cancer cell proliferation in laboratory experiments and melanoma tumor growth in mice. New research now shows that cinnamon extract also inhibits vascular endothelial growth factor (VEGF), a potent angiogenesis-stimulating protein.

As a critical factor in tumor angiogenesis—the process by which cancerous tumors develop their own blood supply—VEGF is a primary target for antiangiogenic cancer treatment. The identification of naturally occurring VEGF inhibitors derived from diet offers a potential approach for cancer prevention. Using laboratory tests, scientists associated with the US Department of Agriculture and the Beckman Research Institute found cinnamon extract to be a potent inhibitor of the primary receptor for VEGF, VEGF receptor-2, on endothelial cells—the cells that line the inner walls of blood vessels and that are activated during tumor angiogenesis. In cell cultures and in mice, cinnamon extract inhibited VEGF-induced endothelial cell proliferation and the formation of tumor blood vessels.

The research identified compounds called procyanidins, types of polyphenols, as the active components in cinnamon extract that inhibit angiogenesis. It has been well established that polyphenols, especially flavonoids, are beneficial active components found in many natural food products, including red wine, tea, coffee, fruits, vegetables, beans (soy), grains, seeds and spices. Recently, polyphenols extracted from various plants, including soy, berry, pomegranate, grape seed extract and green tea, have been found to be potent inhibitors of angiogenesis.

The new study, published in the journal Carcinogenesis, revealed a novel activity in cinnamon and identified a natural VEGF inhibitor that could potentially be useful in cancer prevention and/or treatment. These new data are in agreement with other studies in which several natural products were shown to inhibit VEGF receptor-2, including catechins from green tea extract, delphinidin, ellagic acid, as well as grape seed extract.