FIG. 2.

First formulation of the concept of oxidative stress. Shown here is a contemporary depiction of oxidative stress (Sies H and Stahl W, 2014, unpublished) that encompasses the original definition (58, 59) with inclusion of redox signaling (75), which was unknown at the time of the original formulation of the concept. The original concept presented an overview of reactive oxygen species, antioxidant defenses, the nature of oxidative damage, processes elicited by oxidative stress, and cellular and medical aspects (59). This clear delineation has served to guide research in a broad range of disciplines, including diet and nutrition, cardiology, diabetes, neurodegeneration, dermatology, ophthalmology, toxicology, environmental health, drug development, immune function, and carcinogenesis.