Abstract
The term free radical refers to any chemical species capable of independent existence that contains one or more unpaired electrons. Free radicals and related reactive species are formed in biological systems, and can cause detrimental as well as beneficial biological effects. Free radical biomedicine deals with the biological effects of free radicals and related reactive species as well as antioxidants with an emphasis on the involvement of these reactive species and antioxidants in heath and disease. This chapter provides a brief historical overview of this rapidly evolving field and introduces common terms and concepts in free radical biomedicine. These include reactive oxygen and nitrogen species (ROS/RNS), antioxidants, oxidative stress, redox signaling, and free radical paradigm. The aims and layout of the book are also described in this chapter.
Keywords: Antioxidants, Free radical biomedicine, Free radical paradigm, Free radicals, Nitrative stress, Nitrosative stress, Oxidative stress, Reactive nitrogen species, Reactive oxygen species, Redox signaling.