Endogenous sulfur dioxide alleviates septic lung injury by suppressing Bax-mediated apoptosis of alveolar epithelial cells

Objective: To investigate the regulatory effect of endogenous sulfur dioxide (SO₂) on alveolar epithelial cell apoptosis in rats with sepsis-induced lung injury. Methods: Male Sprague Dawley rats were randomly divided into four groups: normal control group, sepsis group, sepsis + SO₂ group, and SO₂ control group. Each group was observed for 12 hours. Lung tissues from each group were subjected to HE pathological staining and semi-quantitative lung injury scoring. The BAX content in lung tissues was measured using ELISA, and apoptosis was assessed via TUNEL staining. Results: In rats with lung injury, the semi-quantitative lung injury score, BAX content, and TUNEL staining were significantly increased. After SO₂ intervention, these indicators (semi-quantitative lung injury score, BAX content, and TUNEL staining) were significantly reduced. Conclusion: Endogenous sulfur dioxide can exert a protective effect in sepsis-induced lung injury by inhibiting BAX-mediated apoptosis of alveolar epithelial cells.