Broccoli and human health: immunomodulatory effect of sulforaphane in a model of colon cancer.

The favourable properties of broccoli on human health are due to their abundant content of vitamins, minerals and isothiocyanates, the sulforaphane (SFN) being the most important. SFN is created from its precursor glucoraphanin and it is released by myrosinase enzymes produced during crushing of the plant. SFN has been shown to possess anti-inflammatory and anticancer properties. The aim of the study was to determine if SFN may affect the immune dialogue between human peripheral blood mononuclear cells (PBMCs) and HT-29 and RKO human colon cancer cells lines. Non- or mitogen-stimulated PBMCs were incubated with various concentrations of SFN, and the secretion of TNFα, IL-1β, IL-6, IFNγ, IL-2, IL-10 and IL-1ra was determined. In addition, the effect of SFN on the production of these cytokines by PBMCs co-cultured with colon carcinoma cells was examined. SFN exerted a concentration-dependent inhibitory effect on the inflammatory cytokine production by the immune cells. The impact of SFN on the interaction between immune and colon cancer cells underscores its capacity for cancer prevention and development.