Reactive Oxygen Species (ROS) is a type of unstable molecule that contains oxygen and that easily reacts with other molecules in a cell. A buildup of reactive oxygen species in cells may cause damage to DNA, RNA, and proteins, and may cause cell death. Reactive oxygen species are free radicals, also called oxygen radicals.
Traditionally, ROS have been thought of as useless by-products of respiratory metabolism in mitochondria and believed to be generally harmful to biological systems. Growing evidence shows that, in many instances, ROS generation is not a useless or harmful process but, rather, an essential element for certain biological responses.
ROS, such as H2O2, have been demonstrated to be critical factors in normal cellular signal transduction and have the potential to regulate glucose-stimulated insulin secretion (GSIS) in β-cells, excessive and/or sustained ROS production can directly or indirectly disturb the integrity and physiological function of cellular macromolecules, such as DNA, protein, or lipids.
Diabetes mellitus (DM) is an independent risk factor of heart failure. The Framingham Heart Study reported that the frequency of heart failure is 2-fold higher in male diabetics and 5-fold higher in female diabetics than in age-matched control subjects.
An increase in reactive oxygen species (ROS) has been regarded as a dominant mechanism of cardiac dysfunction in patients with DM. ROS are important intracellular signaling molecules and mediate various cellular functions, including activation of transcriptional factors, protein kinases, and ion channels; however, high levels of ROS are detrimental to cardiomyocytes.