Mitochondria are the primary source of ATP for biosynthetic pathways but also are associated with the initiation of cell apoptosis and the generation of reactive oxygen species (ROS) in eukaryotic organisms.The primary source of ROS is mitochondria, especially when dysfunction of electron transport chain complexes Ⅰ and Ⅲ occur.In brief, electron flow leakage through these complexes is increased disproportionately such that superoxides are formed by combining with molecular oxygen.Dysfunction of each ETC complex especially complex I has been associated with several human diseases, including neurodegenerative, cardiovascular, and type Ⅱ diabetes as ROS damages cell macromolecules.