A method of treating, reversing, or ameliorating type 2 diabetes (DM) includes administering to a host in need thereof a therapeutically effective amount of a mitochondria-targeted antioxidant, such as mito-TEMPO (2-(2,2,6,6-Tetramethylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl)triphenylphosphonium chloride).