The effects of 7-nitroindazole on serum neuron-specific enolase and astroglia-derived protein (S100β) levels after traumatic brain injury

We investigated the possible role of 7-nitroindazole (7-NI) in regulating serum neuron-specific enolase (NSE) and S100β levels in a rat model of traumatic brain injury (TBI). We also explored the possible mechanism by which 7-NI may affect the level of NSE and S100β. A total of 160 healthy adult male Sprague-Dawley rats were randomly divided into 2 groups: i) The saline-treated group and ii) the 7-NI-treated group. Using the random number table, the groups were further divided into four subgroups: i) The sham-injured group; ii) the TBI 6 h group; iii) the TBI 12 h group; and iv) the TBI 24 h group (n=20). Controlled cortical impact in rats was established. Serum NSE and S100β levels, nitric oxide (NO) level, water content, Evans blue (EB) content, malondialdehyde (MDA) level and total superoxide dismutase (T-SOD) level in the brain tissue were measured. NO synthase (NOS) activity was measured at 6, 12 and 24 h after TBI. Pathological changes in brain tissue were studied by hematoxylin and eosin (H&E) staining at each time-point. NSE and S100β levels, NO content, water content, EB content and MDA level in the brain tissue increased significantly after TBI. NOS activity was also increased significantly after TBI while T-SOD content in brain tissue was significantly reduced after TBI. H&E staining showed that brain damage was aggravated gradually after TBI. We concluded that the early application of 7-NI significantly reduced serum NSE and S100β levels after TBI. The neuroprotective effects of 7-NI may be associated with reduced NOS activity, reduced NO content, alleviated brain edema, lower blood-brain barrier permeability and oxidative stress. Serum NSE and S100β levels can reflect the therapeutic effect of 7-NI, which suggest a good diagnostic value.