ABSTRACT
This chapter aims to provide insight into the complicated and divergent mechanisms by which synthetic phenolic antioxidants may exert their effects in living organisms. Atherosclerosis and coronary heart disease are among the most widespread diseases for which a causal link to oxidative stress is assumed to exist and for which chemoprevention by antioxidants is investigated. Induction of xenobiotic-metabolizing enzymes is the most thoroughly elaborated explanation for the protective properties of antioxidants against mutagens and carcinogens. Aldehyde dehydrogenase is the most recent member of the antioxidant-inducible enzyme group. The oxidative metabolism of tert-butyl-4-hydroxyanisole and butylated hydroxytoluene has been studied extensively. These studies provided evidence for the formation of reactive metabolites and of reactive oxygen species (ROS) both of which are assumed to be linked to the biological actions of these compounds. The chapter describes targets for the growth controlling action of ROS that may be enzymes switching on proliferation genes, e.g., the oxidative activation of protein kinase C.
