Reactive oxygen and nitrogen species (ROS/RNS) are collective terms that refer to a number
of oxygen- or nitrogen-containing reactive species. They are produced from various cellular pathways
as well as exogenous sources. ROS/RNS are able to cause damage to a variety of biomolecules,
including lipids, proteins, and nucleic acids, leading to tissue injury and disease processes. Under
certain circumstances, the well-controlled production of ROS/RNS also fulfils important physiological
roles, including antimicrobial activity and participation in cell signaling. The biological effects of
ROS/RNS, including both beneficial and detrimental effects are dependent on the types of ROS/RNS
and their concentrations and duration of exposure, as well as the types of tissues/cells that the
ROS/RNS are produced from or act on. The causal or contributing role of ROS/RNS in various diseases
makes it necessary to devise strategies to mitigate the tissue injury and therefore protect against the
disease process. Use of exogenous compounds with antioxidant properties and upregulation of
endogenous cellular antioxidant enzymes by chemical inducers are among the potential approaches to
the intervention of diseases with augmented ROS/RNS as underlying mechanisms.
Keywords: Alkoxyl radical, Hydrogen disulfide, Hydrogen peroxide, Hydroxyl radical, Hypochlorous
acid, Nitric oxide, Ozone, Peroxyl radical, Peroxynitrite, Singlet oxygen, Superoxide.
