Detoxication of chemical carcinogens and chemoprevention

Cancer chemoprevention is an approach that uses natural or synthetic agents, dietary supplements, or foods to block, retard, or even reverse the carcinogenic process. Modulation of the expression of enzymes affecting carcinogen detoxication, such as glutathione S-transferases and UDP-glucuronosyl transferases, is an effective means for cancer chemoprevention. This strategy seeks to alter carcinogen metabolism to facilitate elimination, resulting in protection against mutagenesis, carcinogenesis, and other forms of toxicity mediated by the reactive intermediates of carcinogens. This chapter describes the enzymes involved in carcinogen metabolism and detoxication, along with a discussion of agents that modulate their expression and their effects in animal models of carcinogenesis or human clinical trials.