Putative mechanisms of action for indole-3-carbinol in the prevention of colorectal cancer

Abstract

Background: Multiple factors are known to contribute to the development of cancer and numerous agents have been shown to confer some protection. Diets high in vegetables, especially cruciferous vegetables (broccoli, Brussels sprouts, cabbage etc.) provide such protection. Objective: To define the phytonutrients within this group of vegetables and how their chemoprotective properties might be conferred. Methods: Cruciferous vegetables provide the only human dietary source of a class of phytonutrients, the glucosinolates. The glucosinolate breakdown products, which include indole-3-carbinol and sulforaphane, have demonstrated various anticancer actions in laboratory studies. We give a brief overview of current understanding of the chemopreventive pathways for indole-3-carbinol in various human cancers and how this may relate, in particular, to colorectal cancer; the supporting evidence; and our opinion of its anticancer properties. The review is limited by the lack of bioavailability data in humans. Results: Indole-3-carbinol interacts with a multitude of intracellular processes, which may halt tumourgenesis and induce apoptosis.

Keywords::

• chemoprevention
• colorectal cancer
• cruciferous vegetables
• indole-3-carbinol
• Phase II enzymes