Does endurance exercise improve cerebral edema, systemic inflammation, and oxidative stress in male rats with previous exercise history after traumatic brain injury?

Abstract

Background and purposeTraumatic brain injury (TBI) is a common complication in athletes participating in sports competitions. Previous studies have shown that prior exercise can prevent the development of cerebral edema, oxidative stress, and inflammation after TBI. This study investigated the effects of exercise after TBI in male rats with a previous exercise history.Materials and methodsRats were divided into five groups: Sham, only-TBI, Pre-Exercise + Sham, Pre-Exercise + TBI, and Pre-Exercise + TBI + Post-Exercise. The Marmarou's method created diffuse TBI of moderate intensity. Endurance exercise was performed for 8 weeks, 5 days a week, with a treadmill before and after TBI. The following exercise was performed 1 week after TBI. At the end of the study of each group, cerebral edema (by determining brain water content), oxidative factors (by measuring malondialdehyde (MDA), carbonyl protein (CP), and total antioxidant activity (TAC)), and inflammatory factors (by measuring interleukin 1 beta (IL-1 beta)) of serum were evaluated.ResultsAn increase in brain water content and serum levels of MDA, IL1 beta, and CP appeared in the only-TBI group compared to the Sham group, while the amount of serum TAC was reduced. The amount of serum MDA decreased in the Pre-Exercise + TBI + Post-Exercise group compared to the only-TBI group. The amount of serum CP and IL-1 beta, and brain water content in the Pre-Exercise + TBI + Post-Exercise group and Pre-Exercise + TBI group was reduced compared to the only-TBI group.ConclusionIn conclusion, TBI increased edema brain, systemic oxidative stress and inflammation, as evidenced by elevated brain water content, serum MDA, protein carbonyl, and IL-1 beta levels. Combined previous and subsequent exercise in TBI showed partial neuroprotective effects. These findings suggest an effect of endurance exercise on post-TBI pathophysiology in subjects with previous history.