Therapeutic potential of alpha-tocopherol in reducing oxidative stress and inflammatory damage after experimental traumatic brain injury and pentylenetetrazol-induced seizures

The effects of alpha-tocopherol on seizure parameters, locomotor-cognitive functions, inflammatory response, oxidative stress response, histopathological changes, immunohistochemical parameters, and miRNA fold changes were investigated in rats with traumatic brain injury (TBI) and pentylenetetrazol (PTZ)-induced seizures. Sprague-Dawley male rats were randomly divided into three groups: Control (n = 8), TBI + PTZ (n = 10), and TBI + PTZ + tocopherol (n = 10). After inducing TBI in animals using the weight-drop method, increased post-injury seizure susceptibility was achieved by administering subconvulsive doses of PTZ. Saline was administered intraperitoneally to the control and TBI + PTZ groups for 6 days, while 500 mg/kg alpha-tocopherol was administered intraperitoneally to the TBI + PTZ + tocopherol group. Seizure intensity, seizure frequency, and total seizure duration were significantly reduced in the TBI + PTZ + tocopherol group compared to the TBI + PTZ group (p < 0.05). No significant adverse effects related to TBI and PTZ were observed in the animals' locomotor activity, anxiety-like behaviors, or learning and memory test outcomes. In the TBI + PTZ + tocopherol group, significant reductions were observed in inflammatory cytokine response, oxidative stress, and SUR1-TRPM4 channel activity compared to the TBI + PTZ group (p < 0.001). While degenerative and apoptotic neurons and the number of 8-OHdG-positive cells in the CA1 and dentate gyrus regions were limited in the TBI + PTZ + tocopherol group, downregulated miR-324-5p increased (p < 0.05). Alpha-tocopherol reduced the severity and duration of seizures, reduced oxidative stress and inflammation, and stabilized the thiol-disulfide balance. It also reduced degenerative cell structures and DNA damage in the cortex, hippocampus, and dentate gyrus. In conclusion, the findings of this study suggest that alpha-tocopherol is a potential neuroprotective agent that modulates early epileptogenic network instability in TBI and seizure susceptibility through multiple pathways, including oxidative stress, inflammation, and ion channel regulation.