Curcumin provides neuroprotection in model of traumatic brain injury via the Nrf2-ARE signaling pathway

Curcumin has been found to play the protective role in many neurological disorders, however, its roles and the underlying molecular mechanisms in traumatic brain injury (TBI) are not fully understood. The aim of this study was to investigate the potential neuroprotection of curcumin and the possible role of Nrf2-ARE pathway in the weight-drop model of TBI. The administration of curcumin (100 mg/kg, i.p.) significantly ameliorated secondary brain injury induced by TBI, such as brain water content, oxidative stress, neurological severity score, and neuronal apoptosis. Curcumin possessed anti-apoptotic character evidenced by elevating Bcl-2 content and reducing that of cleaved caspase-3. Moreover, curcumin markedly enhanced the translocation of Nrf2 from the cytoplasm to the nucleus, proved by the results of western blot and immunofluorescence, subsequently increased the expression of downstream factors such as heme oxygenase 1 (HO1) and NAD(P)H: quinone oxidoreductase 1 (NQO1) and prevented the decline of antioxidant enzyme activities. In conclusion, curcumin could increase the activities of antioxidant enzymes and attenuate brain injury in the model of TBI, possibly via the activation of the Nrf2-ARE pathway.