Effect of hydrogen on mitochondrial function in brain tissues of mice with sepsis-associated encephalopathy

Objective To evaluate the effect of hydrogen on the mitochondrial function in brain tissues of mice with sepsis-associated encephalopathy (SAE). Methods Two hundred and sixty-eight healthy male C57 mice, aged 6 weeks, weighing 20-25 g, were divided into 4 groups (n=67 each) using a random number table method: sham operation group (group SH), sham operation plus hydrogen gas group (group SH+ H2), group SAE, and SAE plus hydrogen gas group (group SAE+ H2). Sepsis was produced by cecal ligation and puncture in anesthetized mice.The mice in group SH+ H2 and group SAE+ H2 inhaled 2% hydrogen gas for 1 h starting from 1 and 6 h after operation, respectively.The postoperative 7-day survival rate was recorded.Brain tissues were obtained at 24 h after operation to count the normal neurons in hippocampal CA1 region.At 6, 12 and 24 h after operation, hippocampal mitochondria were isolated for determination of mitochondrial membrane potential (MMP) by fluorescence spectrophotometry and ATP content by a bioluminescence assay.Y-maze (spontaneous alternation) test was performed at days 3, 5 and 7 after operation. Results Compared with group SH, the 7-day survival rate was significantly decreased, the number of normal neurons in hippocampal CA1 region, MMP, mitochondrial ATP content and spontaneous alternation percentage in Y-maze test were significantly decreased in group SAE and group SAE+ H2 (P<0.05). Compared with group SAE, the 7-day survival rate, the number of normal neurons in hippocampal CA1 region, MMP, mitochondrial ATP content and spontaneous alternation percentage in Y-maze test were significantly increased in group SAE+ H2 (P<0.05). Conclusion The mechanism by which hydrogen reduces SAE is probably associated with improving mitochondrial function in brain tissues of mice. Key words: Hydrogen; Sepsis; Brain; Mitochondria