Traumatic brain injury (TBI) is a serious neuropathology that causes secondary injury mechanisms, including dynamic interplay between ischemic, inflammatory, and cytotoxic processes. Fumaric acid esters (FAEs) showed beneficial effects in pre-clinical models of neuroinflammation and toxic oxidative stress, so the aim of the present work was to evaluate the potential beneficial effects of dimethyl fumarate (DMF), the most pharmacologically effective molecules among the FAEs, in a mouse model of TBI induced by controlled cortical impact (CCI). Mice were administered DMF orally at the doses of 1, 10, and 30 mg/kg 1 h and 4 h after CCI. We performed histological, molecular, and immunohistochemistry analysis on the traumatic penumbral areas of the brain 24 h after CCI. DMF treatment notably reduced histological damage and behavioral impairments, reducing neurodegeneration as evidenced by assessments of neuronal loss, Fluoro-Jade C, and TUNEL staining; also, treatment with DMF blocked the apoptosis process increasing B-cell lymphoma 2 (Bcl-2) expression in injured cortex. Further, DMF treatment up-regulated antioxidant Kelch-like ECH-associated protein 1/nuclear factor erythroid 2-related factor pathway, inducing activation of manganese superoxide dismutase and heme-oxygenase-1 and reducing 4-hydroxy-2-nonenal staining. Also, regulating the NF-κB pathway, DMF treatment decreased the severity of inflammation through a modulation of neuronal nitric oxide synthase, interleukin 1, tumor necrosis factor, cyclooxygenase 2, and myeloperoxidase activity, reducing ionized calcium-binding adapter molecule 1 and glial fibrillary acidic protein expression. Our results support the thesis that DMF may be an effective neuroprotectant after brain trauma and warrants further study.
Keywords: NF-κB; Nrf-2; TBI; inflammation; oxidative stress.