Attenuation of diffuse axonal injury by intraperitoneal injection of hydrogen via reducing oxidative stress in rats

To investigate the role of oxidative stress in diffuse axonal injury (DAI) and the therapeutic action of hydrogen in DAI models. Methods Totally 118 adult male SD rats were divided into 3 groups with 39 in each: sham, DAI, and DAI + hydrogen treatment. Rat diffuse axonal injury was induced by an experimental facility, which was developed to make the rat head spin 90 degrees at the moment to cause shearing injury. Hydrogen gas of high purity was injected intraperitoneally into rats of DAI model twice per day (10mL/kg). The modified neurological severity score (mNSS), histomorphology, propidium iodide (PI) staining, SOD activity, CAT activity and MDA content in the brain were assayed at 6h, 1d, 3d and 7d after DAI. Results MDA content, PI positive cells, swelling never cells, degenerated cells, glial cells and neurological severity scores were significantly increased, while SOD and CAT activities were decreased in the brain tissues of DAI rats (P<0.01). Hydrogen treatment could reverse these changes mentioned above. Conclusion Oxidative stress is involved in DAI pathophysiological process in acute phase. The decline of antioxidant enzyme activities and production of large numbers of free radicals may lead to the deterioration of brain damage. Hydrogen gas can improve acute brain injury in DAI by improving antioxidant enzyme activities and reducing free radical damage. Reducing the level of oxidative stress is of great significance in the treatment of DAI.

Changes of immuno-inflammatory responses by intraperitoneal injection of hydrogen after diffuse axonal injury in rats

To explore the role of immuno-inflammatory reaction in diffuse axonal injury (DAI) and the therapeutic action of hydrogen in DAI model. Methods Totally 96 adult male SD rats were divided into 8 groups (n=12 in each): normal group, sham group, DAI groups (6h, 1d and 3d) and DAI with hydrogen treatment groups(6h, 1d and 3d). Rat DAI model was induced by an experimental facility developed to make the rat head spin 90 degrees at the moment to cause shearing injury. Hydrogen gas of high purity was injected intraperitoneally to DAI rat models twice per day (10mL/kg). The histo-morphology, GFAP immunofluorescent staining, Western blotting (IL-6, IL-1, JNK and p-JNK) in parietal cortex were investigated at 6h, 1d and 3d after DAI. Results DAI-related changes such as axon swelling and axonal ball were found in the conjunction area between DAI-affected parietal cortex and corpus callosum compared with those in sham group. The number of GFAP-positive cells as well as IL-6, IL-1, JNK and p-JNK expressions were significantly increased after DAI (P<0.05, P<0.01). Hydrogen treatment could reverse the changes mentioned above. Conclusion Immuno-inflammatory reaction is involved in DAI pathophysiological process in acute phase. The release of large numbers of inflammatory factors and activation of astrocytes may lead to the deterioration of brain damage. Hydrogen can improve acute brain injury of DAI by reducing immuno-inflammatory reaction.