The effects of hydrogen treatment in a cigarette smoke solution-induced chronic obstructive pulmonary disease-like changes in an animal model

Background: Molecular hydrogen, with its antioxidant and anti-inflammatory properties, may be suitable for the prevention and treatment of chronic obstructive pulmonary disease (COPD). This study aims to investigate the therapeutic efficacy of hydrogen-oxygen (H2/O2) treatment in cigarette smoke solution (CSS)-induced COPD-like injury in a female BALB/c mouse model. Methods: Thirty mice were randomly assigned to three groups: Control (n=8), COPD (n=10), and COPD + H2/O2 (n=12). CSS was administered by intraperitoneal (IP) injection twice weekly for 6 weeks during the COPD induction phase. Simultaneously, the COPD + H2/O2 group started received 75 minutes of inhalation therapy (42% H2) delivered by the Oxy-Hydrogen Generator twice daily for 9 weeks. Mice body weights and survival were measured throughout the study period. Neutrophil elastase (NE) activity and lung histopathological changes were also evaluated. Results: The results showed a higher survival rate in the COPD + H2/O2 group compared to the COPD group (100% vs. 80%) during the induction phase. Slight decreases in body weight gains were observed in the COPD and COPD + H2/O2 groups during the first 15 days of the induction phase, but there was no significant difference in mean body weights among the three groups throughout the study period. NE activity was numerically lower in the COPD + H2/O2 group compared to the COPD group. The histopathological evaluation showed significant improvements in the H2/O2-treated mice with respect to mean linear intercept (MLI) and lesion (inflammation and emphysema) scores. Improvements in goblet cell hypertrophy and hyperplasia of airway epithelium were not significant. Conclusions: A 9-week H2/O2 inhalation therapy delivered by the Oxy-Hydrogen Generator to CSS-induced COPD-like injury in mice showed improvement in survival rate, alveolar structural changes, and histopathological lesion scores of the lung. Keywords: Hydrogen gas; chronic obstructive pulmonary disease (COPD); inflammation; oxidative stress.