Antioxidants meet molecular targets for cancer prevention and therapeutics.

A fine balance between oxidants and antioxidants is required for the normal functioning of living systems. A deregulation of this balance has been implicated in many adverse effects and diseases, including cancer. Extensive research has been done in the area of cancer prevention and therapeutics by a wide range of antioxidants, especially naturally occurring and diet-based agents. However, additional efforts are still needed toward clinical development of the most promising antioxidant agents. For this purpose, it is important to focus our efforts toward (i) defining/validating new targets; (ii) identifying novel agents followed by assessments of their efficacy, safety/toxicity, metabolism, and bioavailability in appropriate model systems; and (iii) conducting clinical trials in an appropriate population. Although research with specific antioxidants is important, an emerging critical issue that is up for a debate is whether the "whole foods" concept is better for cancer prevention than a single agent. Recent work has suggested that the dietary phytochemicals can enhance the bioavailability of different nutrients and can target multiple molecular pathways to yield a better response. Another critical issue that is often ignored during target-based agent development is a lack of focus on the appropriate population for a specific target. It is possible that a specific target may not be appropriate for certain people. Further, we need to design quick "phase 0" clinical trials to eliminate the agents with little clinical potential. Thus, multidisciplinary efforts of researchers from diverse scientific disciplines are needed in order to take the most promising antioxidant agents from the bench to the bedside.