Chemoprevention is an attempt to use either naturally occurring or synthetic substances or their mixtures to inhibit, reverse, or delay the progress of carcinogenesis, before the malignancy manifests. Numerous chemical substances have been found to prevent or halt carcinogenesis, and it is noticeable that a substantial body of chemopreventive agents are derived from our daily diet, particularly vegetables and fruits (Surh, Y.-J., Nature Rev. Cancer, 2003). Accumulating evidence from population-based and laboratory studies support association between regular consumption of fruits and vegetables and the reduced risk of certain cancers. A wide array of phytochemicals derived from edible plants have been reported to possess ability to intervene in a specific stage of carcinogenic process. Multiple mechanisms have been proposed to account for the anti-carcinogenic actions of dietary constituents, but more attention has recently been focussed on intracellular signaling cascades as common molecular targets of a vast variety of chemopreventive phytochemicals.

Keywords: Chemoprevention, Phytochemicals, Signal transduction, NF-kappa B, AP-1, Mitogen-activated protein kinases, Nrf2, Beta-catenin