Curcumin, the pigment responsible for the yellow color of the spice turmeric, has been found to block the activity of a hormone associated with the development of colorectal cancer.
Researchers at the University of Texas Medical Branch at Galveston (UTMB) worked with curcumin and cell cultures to link a gastrointestinal hormone to the production of an inflammatory protein that accelerates the growth of a variety of cancer cells. The study, was published in the September 2006 issue of Clinical Cancer Research.
Hormonal management is a new method of cancer treatment or prevention identified in this study. A gastrointestinal hormone called neurotensin has been linked to the production of an inflammatory protein that accelerates the growth of a variety of cancer cells. About a third of all colorectal cancer cells have the receptor for neurotensin, which is generated in response to consumption of fat.
The researchers of the current study found that this gastrointestinal hormone reduced production of IL-8, an inflammatory protein that plays a role in the growth and spread of a variety of human cancer cells, including colorectal and pancreatic tumor cells. The researchers discovered that in addition to increasing the rate of growth of colon cancer cells, neurotensin is also implicated in cell migration and metastasis. However, all these negative effects of neurotensin were turned off by the turmeric-derived curcumin.
"Our findings suggest that curcumin may be useful for colon cancer treatment, as well as potential colon cancer suppression, in cells that respond to this gastrointestinal hormone, neurotensin," said Dr. Mark Evers, senior author and director of UTMB's Sealy Center for Cancer Cell Biology.
The University of Texas researchers found the gastrointestinal hormone neurotensin, which is generated in response to fat consumption, reduced production of IL-8, a potent inflammatory protein that accelerates the growth and spread of a variety of human cancer cells, including colorectal and pancreatic tumor cells. Colorectal cancer accounts for nine per cent of new cancer cases every year worldwide. The highest rates are in the developed world; Asia and Africa have the lowest rates, which calls into question diet-related factors.
"We found that in colon cancer cells, neurotensin increases not just the rate of growth but also other critical things, including cell migration and metastasis," said Evers. "The fact that all that can be turned off by this natural product, curcumin, was really remarkable."
According to the researchers, neurotensin's influence depends on biochemical signaling pathways inside the cell. They claim their experiments showed curcumin diminished those signals and thereby decreased the production of IL-8. Experiments also showed neurotensin increased the migration of colorectal cancer cells, and that curcumin could suppress this migration -- possibly reducing the ability of colorectal cancer to spread to other locations in the body.
The researchers suggest that curcumin may be useful to support the health of colon cancer patients and that it may be useful in suppressing colon cancer in cells that respond to the gastrointestinal hormone neurotensin.
Xiaofu Wang et al. "Curcumin inhibits neurotensin-mediated interleukin-8 production and migration of HCT116 human colon cancer cells." Clinical Cancer Research. Sep 15, 2006; 12 (18).