Traumatic brain injury: oxidative stress and neuroprotection.

SIGNIFICANCE: A vast amount of circumstantial evidence implicates high energy oxidants and oxidative stress as mediators of secondary damage associated with traumatic brain injury. The excessive production of reactive oxygen species due to excitotoxicity and exhaustion of the endogenous antioxidant system induces peroxidation of cellular and vascular structures, protein oxidation, cleavage of DNA, and inhibition of the mitochondrial electron transport chain. RECENT ADVANCES: Different integrated responses exist in the brain to detect oxidative stress, which is controlled by several genes termed vitagens. Vitagens encode for cytoprotective heat shock proteins, and thioredoxin and sirtuins. CRITICAL ISSUES AND FUTURE DIRECTIONS: This article discusses selected aspects of secondary brain injury after trauma and outlines key mechanisms associated with toxicity, oxidative stress, inflammation, and necrosis. Finally, this review discusses the role of different oxidants and presents potential clinically relevant molecular targets that could be harnessed to treat secondary injury associated with brain trauma.