Role of Melatonin in Traumatic Brain Injury and Spinal Cord Injury

Figure 3

Role of melatonin in several stress conditions. CNS injury includes TBI and SCI which leads to oxidative stress which promotes ROS at a very high level compared to that of antioxidants and plays an important role in the pathogenesis of disease. ROS reacts with PUFA of lipid membranes which results in lipid peroxidation. ROS can also damage DNA and protein which leads to protein oxidation and DNA damage. Melatonin acts as a radical scavenger as it reduces the level of ROS. Fenton reaction leads to the production of hydroxyl radical OH associated with mitochondrial complexes and melatonin has metal binding capacity which may form chelating compound and reduce OH generation. Melatonin is a natural ligand for a nuclear retinoid related orphan nuclear hormone receptor superfamily RZR/ROR. Melatonin involves the regulation of expression antioxidant enzymes like GPx, GR, and SOD by involving MT1/MT2 and ROR receptors. Melatonin acts as an antinitrosative agent by reducing ONOO. CNS injury triggers cerebral inflammation which involves NF- which is a key player in secondary injury. Here melatonin acts as an antineuroinflammatory agent and inhibits the activation of NF- and its binding to DNA.