Abstract: Objective To investigate the protective effect of hydrogen against hyperoxia-induced oxidative stress injury in
premature rat type II alveolar epithelial cells (AECs). Methods The type II AECs isolated from premature rats were randomly
divided into air (21% oxygen) control group, hyperoxia (95% oxygen) control group, air + hydrogen group, and hyperoxia+
hydrogen group. The cells with hydrogen treatment were cultured in the presence of rich hydrogen. After the corresponding
exposure for 24 h, the cell morphology was observed microscopically. MTT assay was used to evaluated the cell proliferation
ability, and JC-1 fluorescence probe was used to detect the mitochondrial membrane potential ( △Ψ) changes of the type II
AECs. The concentration of maleic dialdehyde (MDA) and superoxide dismutase (SOD) activity in the cell supernatant were
detected using colorimetric method. Results No significant differences were found in cell growth or measurements between
air control and air + hydrogen groups. Compared with air control group, the cells exposed to hyperoxia showed significantly
suppressed proliferation, reduced mitochondrial membrane potential, increased MDA content, and decreased SOD activity.
Intervention with hydrogen resulted in significantly increased cell proliferation and SOD activity and lowered MDA content,
and restored the mitochondrial membrane potential in the cells with hyperoxia exposure (P<0.05). Conclusion Hydrogen can
significantly reduce hyperoxia-induced oxidative stress injury in premature rat type II AECs, improve the cellular antioxidant
capacity, stabilize the mitochondrial membrane potential, and reduce the inhibitory effect of hyperoxia on cell proliferation.