Luteolin in Fruits and Vegetables Can Decrease Growth of Colon Cancer Cells
Eating a diet that includes lots of fruits and vegetables is considered one of the top recommendations for averting many types of cancer, including colon cancer. Researchers from Korea have found one mechanism of how this works. Luteolin, a citrus bioflavonoid, appears to inhibit a mechanism that is important for the growth of colon cancer cells.
Colon cancer is the second most frequent cause of cancer-related death in the Western World, including the United States. Lifestyle habits appear to highly influence the risk of colon cancer, including such factors as obesity, excessive red meat intake, low fiber intake, smoking cigarettes and drinking alcohol. Limiting even just one of these habits could reduce the number of colon cases by 13% according to a recent Danish study.
Flavonoids are compounds found in fruits, vegetables and certain beverages that have antioxidant effects. There have been over 4,000 identified. Flavonoids protect against cancer in part by decreasing oxidative stress that damages cells. In addition, these nutrients have anti-inflammatory and antitumor activity.
Luteolin is found in high amounts in parsley, thyme, peppermint, basil, celery, green peppers, and artichoke. A team of scientists lead by Professor Jung Han Yoon Park of the Department of Food Science and Nutrition at Hallym University, noted that luteolin has the ability to inhibit the cell-signaling pathways of insulin-like growth factors (IGF) which are known to stimulate the growth of colon cancer cells. These cells have elevated levels of IGF-II as compared to normal colon tissues.
The team had previously found that luteolin induces cell cycle arrest (halt of the cell cycle) and apoptosis (programmed cell death) in liver, lung, and prostate cancer as well as leukemia cell lines. The nutrient has also been shown to help decrease risk of ovarian cancer.
Professor Jung Han Yoon Park says, “Blocking these pathways (PI3K, Akt, and ERK1/2 and CDC25c) stops cancer cells from dividing and leads to cell death. A fuller understanding of the in-vivo results is essential to determine how it might be developed into an effective chemopreventive agent."
Do Young Lim, Han Jin Cho, Jongdai Kim, Chu Won Nho, Ki Won Lee and Jung Han Yoon Park. Luteolin decreases IGF-II production and downregulates insulin-like growth factor-I receptor signaling in HT-29 human colon cancer cells. BMC Gastroenterology, 2012
National Institutes of Health, Colon Cancer
Linus Pauling Institute, Oregon State University, Antioxidant Activities of Flavonoids by Dr. Donald R. Buhler and Dr. Cristobal Miranda
United States Department of Agriculture, Agricultural Research Service. “Luteolin Stars in Study of Healthful Plant Compounds” July 8, 2010.
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