Effects of hydrogen rich water on the expression of Nrf 2 and the oxidative stress in rats with traumatic brain injury

Results: (1) NSS score: compared with TBI group, NSS in HW group at 12, 24, 48 hours and 5 days were significantly decreased (12 hours: 9.83 ± 2.32 vs. 13.17 ± 2.71, 24 hours: 9.83 ± 2.79 vs. 13.50 ± 2.43, 48 hours: 7.50 ± 2.07 vs. 11.83 ± 2.14, 5 days: 5.50 ± 1.87 vs. 10.50 ± 2.43, all P < 0.05). (2) Compared with sham operation group, the activity of GSH-Px and CAT in TBI group were markedly declined after operation, while the MDA content was elevated significantly, especially at 24 hours [CAT (kU/g): 1.080 ± 0.312 vs. 3.571 ± 0.758, GSH-Px (kU/g): 9.195 ± 3.173 vs. 32.385 ± 10.619; MDA (µmol/g): 12.282 ± 2.896 vs. 4.349 ± 1.511, all P < 0.01]. Compared with TBI group, the parameters in HW group were improved, and they were similar as sham operation group. (3) RT-qPCR: no significant difference was found in the expression of Nrf2 mRNA at each time point in three groups. (4) Western Blot: the expression of Nrf2 nucleoprotein (gray value) in TBI group was apparently higher than that in sham operation group, and peaked at 24 hours (0.703 ± 0.262 vs. 0.238 ± 0.120, P < 0.05), and the expression in HW group was obviously higher than that in TBI group, especially at 24 hours (1.110 ± 0.372 vs. 0.703 ± 0.262, P < 0.05). (5) HE staining: the brain structure in sham operation group was found to be intact. However, there were different degrees of pathological changes at each time in TBI group, especially at 24 hours. The pathological damage of brain tissue in HW group was significantly milder. Conclusions: Hydrogen rich water can up-regulate the expression of Nrf2, and reduce oxidative damage of traumatic brain injury in rats. Nrf2 can up-regulate the expression of its downstream antioxidant enzymes, which may be the mechanism of the upregulation expression of Nrf2 in the study.