Antioxidant therapies in traumatic brain injury

Oxidative stress plays a crucial role in traumatic brain injury (TBI) pathogenesis. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) formed in excess after TBI synergistically contribute to secondary brain damage together with lipid peroxidation products (reactive aldehydes) and inflammatory mediators. Furthermore, oxidative stress, endoplasmic reticulum stress and inflammation potentiate each other. Following TBI, excessive oxidative stress overloads the endogenous cellular antioxidant system leading to cell death. To combat oxidative stress, several antioxidant therapies were tested in preclinical animal models of TBI. These include free radical scavengers, activators of antioxidant systems, Inhibitors of free radical generating enzymes and antioxidant enzymes. Many of these therapies showed promising outcomes including reduced edema, blood-brain barrier (BBB) protection, smaller contusion volume, and less inflammation. In addition, many antioxidant therapies also promoted better sensory, motor, and cognitive functional recovery after TBI. Overall, preventing oxidative stress is a viable therapeutic option to minimize the secondary damage and to improve the quality of life after TBI.