The Durk Pearson & Sandy Shaw®
Life Extension NewsTM
Volume 12 No.
1 • Feb. 2009
Indole-3-Carbinol, a Potent Tumor Suppressor Example:
Human Breast Cancer
A growing body of evidence documents the potent inhibition of the growth and invasion of a number of human cancers by indole-3-carbinol, a natural constituent of cruciferous vegetables such as broccoli and cauliflower. Its effects have been particularly well studied in its suppression of human breast cancer. For example, one study reported that indole-3-carbinol is a negative regulator of estrogen receptor alpha signaling in human breast cancer cells by inhibiting its binding to its cognate DNA responsive element, thereby suppressing breast cancer cell proliferation.
In another study, researchers report that indole-3-carbinol inhibits cell proliferation and in vitro markers of angiogenesis (expansion of tumor blood supply) in human endothelial cells in the presence of phorbol myristate acetate, a potent angiogenesis stimulator.
A very interesting new study further reports that indole-3-carbinol is a natural elastase enzymatic inhibitor that disrupts cyclin E protein processing, causing a G1 cell-cycle arrest (stopping progression of cell division) of human breast cancer cells. As the authors explain, “I3C [indole-3-carbinol] acts as a specific and potent noncompetitive enzymatic inhibitor of human neutrophil elastase activity, which is highly expressed in breast cancer cells and has been shown to be a prognostic marker for reduced survival rates of primary breast cancer patients.”
- Meng et al. Indole-3-carbinol is a negative regulator of estrogen receptor-alpha signaling in human tumor cells. J Nutr 130:2927-31 (2000).
- Hsiao-Ting et al. Inhibition of cell proliferation and in vitro markers of angiogenesis by indole-3-carbinol, a major indole metabolite present in cruciferous vegetables. J Agric Food Chem 53:5164-9 (2005).
- Nguyen et al. The dietary phytochemical indole-3-carbinol is a natural elastase enzymatic inhibitor that disrupts cyclin E protein processing. Proc Natl Acad Sci USA 105(50):19750-5 (2008).