A naturally occurring antioxidant found in fruits and vegetables selectively kills leukemia cells without harming healthy cells, according to a new study. Researchers from the University of Pittsburgh School of Medicine published their findings online in the Journal of Biological Chemistry. The findings promise an effective, nontoxic approach to treating leukemia.
"Current treatments for leukemia, such as chemotherapy and radiation, often damage healthy cells and tissues and can produce unwanted side effects for many years afterward. So, there is an intensive search for more targeted therapies for leukemia worldwide," said corresponding author Xiao-Ming Yin, M.D., Ph.D., associate professor of pathology, University of Pittsburgh School of Medicine.
Yin and his co-workers isolated a naturally modified anthocyanidin, known as cyanidin-3-rutinoside or C-3-R, from black raspberries and observed its effects on human leukemia and lymphoma cell cultures. The researchers found that low doses of C-3-R caused about half of the human leukemia cells to die within 18 hours of treatment. When the dose was more than doubled, all of the leukemia cells died; the research team noted the same response in lymphoma cells.
Yin and his team focused on one of the most common anthocyanidins, which are forms of anthocyanins -- water-soluble flavonoids that give fruits and vegetables their color, and are thought to aid in attracting honeybees to plants. The authors noted that previous studies have demonstrated the antioxidant benefits of anthocyanidins.
The researchers reported that C-3-R induced an "oxidative stress" in tumor cells but not in healthy cells. According to Yin, these results indicate that C-3-R is highly selective against cancer cells and offers "a very promising approach for treating a variety of human leukemias and, perhaps, lymphomas as well."
Both leukemia and lymphoma are types of cancer. According to the National Cancer Institute, 44,000 cases of leukemia will be diagnosed in the United States in 2007 and some 22,000 leukemia-related deaths will occur in 2007. The Leukemia and Lymphoma Society reported that more than 66,000 new cases of lymphoma were diagnosed in 2006.