Figure 1: Therapeutic approaches to restore redox balance. 1) Augment NO˙ bioactivity catalyzed by nitric oxide synthase; 2) Block production of ROS produced by mitochondrial electron transport chain, NADPH oxidase, xanthine oxidase or uncoupled NOS; 3) Scavange toxic oxidants by replacing deficient enzymatic and non-enzymatic antioxidants such as SOD, catalase, GSH, ascorbic acid, tocopherol, and carotenoids.