Objectives: The objective of this study was to investigate the effects of a novel pharmaceutical agent, a catalytic oxidoreductant, after concussions in a murine model. The oxidoreductant was a metalloporphyrin manganese (111)-tetrakis (N-ethylpyridinium-2-yl) porphyrin (MnTE-2-PyP). The overarching hypothesis was that post-concussion administration of this novel therapy would reduce secondary injury and thereby protect the brain after a single concussion or after multiple concussions. We tested the hypothesis that the oxidoreductant would detoxify reactive oxygen species and inhibit Nuclear Factor--kappa B (NF-κB) signaling which would confer tissue protection and prevent cognitive deficits after concussion through inhibition of the inflammation pathway. Design: We used an impact acceleration model to induce concussions/ mild TBIs in adult male mice with one contact to the head correlating to one concussion. The multiple concussion group received one concussion per day for 3 consecutive days, and uninjured animals made up the control group and underwent all procedures except for the impacts. The drug group received subcutaneous injections of the oxidoreductant 30 minutes after each impact, and administration continued daily until the time of euthanasia. The mice were humanely euthanized at either 6, 24, 72 hours, or 7 days post-TBI, and the brains were extracted for histological evaluation of reactive oxygen species, NF-κB activation, neuroimmune response, diffuse axonal injury, neuronal cell death, and gliosis. Results: Preliminary results demonstrate the post-injury administration reduced activation of NF-κB and associated neuroinflammation at all time points evaluated. Studies are on-going. Conclusions: The data suggests that post-concussion administration of MnTE-2-PyP is protective after brain injury and further research should be done to fully elucidate these effects. [ABSTRACT FROM AUTHOR]