Protective Effect of Diphenhydramine against Traumatic Brain Injury in Rats via Modulation of Oxidative Stress and Inflammation

Background: Traumatic brain injury (TBI) is considered a major burden across the globe affecting both individuals and their families. Therefore, the present study was conducted to determine the protective effect of diphenhydramine (DPM) against TBI in experimental rats. Methods: The effect of DPM was evaluated on the cerebral edema (CE) and neuronal degeneration after the induction of experimental brain injury in rats. The effect of DPM was also investigated on the inflammatory cytokines, for example, tumor necrosis factor-alpha and interleukin 1 beta and oxidative stress markers, such as malondialdehyde, superoxide dismutase, and glutathione peroxidase. Western blot analysis was used to investigate the effect of DPM on B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax) and cleaved caspase-3. Results: Results of the study suggest that DPM causes reduction in CE and prevents neuronal degeneration. It also causes reduction in inflammation and oxidative stress in a dose-dependent manner. The level of Bax was found to be elevated, together with reduction in the Bcl-2 level in the DPM-treated group. Conclusion: DPM exerts a neuroprotective effect after TBI via the attenuation of oxidative stress, inflammation, and mitochondrial apoptosis pathways.