Background:
Series of evidences have shown that interleukin-6 (IL-6) could play an important role in the pathogenesis of colon cancer. Inositol hexaphosphate (IP6) is a naturally occurring polyphosphorylated carbohydrate, found in many plant sources and in certain high-fi ber diets. Over the past few years interest in IP6 has stemmed mostly from its potentially important antineoplastic activity against various types of cancer, including colon cancer. Moreover, it was pointed out that IP6 has ability to act on the host immune functions and infl ammatory processes by controlling the synthesis of cytokines such as IL-6. The aim of this study was to evaluate the infl uence of IP6 on IL-6 secretion by malignant epithelial colorectal Caco-2 cells.

Material and Methods:
The Caco-2 cells were treated with IP6 at the concentrations of 1.0; 2.5; 5.0 mM for 1; 6; 12 and 24 hours. The level of IL-6 was measured by enzyme-linked immunosorbent assay. The concentration of IL-6 was related to the amount of total cell protein which was estimated by the Bradford method (pg/mg).

Results:
It was found that colorectal Caco-2 cells constitutively secreted IL-6 at the constant level during 24 hour culture. IP6 down-regulated IL-6 secretion in a dose and time dependent manner. Conclusion old The present fi ndings demonstrate that IP6 in the lumen of the large intestine may play an immunoregulatory role by inducing changes in IL-6 secretion by epithelial colon cells.