Ginsenoside Rb1 attenuates hyperoxia-induced lung injury in neonatal rats by inhibiting ferroptosis via the system Xc- pathway.

BACKGROUND

Hyperoxia-induced lung injury (HALI) is a common and severe complication in neonatal intensive care units, and there is currently no effective therapy available. Ferroptosis, a newly recognized form of iron-dependent regulated cell death, has recently been implicated in the pathogenesis of this disease. Ginsenosides are bioactive components extracted from ginseng. Among them, ginsenoside Rb1 (GsRb1) belongs to the protopanaxadiol-type saponins, and its molecular structure is C54H92O23. This study aimed to investigate the protective effects and underlying mechanisms of GsRb1 in neonatal rats with hyperoxia-induced lung injury.

METHODS

A neonatal rat model of hyperoxia-induced lung injury and an in vitro alveolar epithelial cell model of hyperoxic damage were established. Histopathological changes, inflammatory cytokines, oxidative stress, and key ferroptosis-related proteins like the solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) expression were assessed using hematoxylin-eosin staining, enzyme-linked immunosorbent assay, Western blotting, transmission electron microscopy, and immunofluorescence. The ferroptosis inhibitor, liproxstatin-1(Lip-1), and the system Xc- inhibitor, erastin, were used for mechanistic validation.

RESULTS

GsRb1 significantly alleviated hyperoxia-induced alveolar structural disruption, pulmonary edema, and elevated levels of inflammatory cytokines (interleukin (IL)-1β, IL-6, and tumor necrosis factor-α(TNF-α)). Moreover, GsRb1 reversed the characteristic features of hyperoxia-induced ferroptosis, including decreased intracellular ferrous iron and malondialdehyde levels, improved mitochondrial morphology, and regulation of ferroptosis-associated proteins, i.e., upregulating SLC7A11, GPX4, and Ferritin heavy chain 1 (FTH1) while downregulating Transferrin receptor protein (TFR). The protective effects of GsRb1 were comparable to those of the classical ferroptosis inhibitor Lip-1. Molecular docking analysis revealed that GsRb1 could directly and stably bind to the active pocket of the SLC7A11. Furthermore, GsRb1 reversed erastin-induced pulmonary injury and ferroptosis, confirming that its protective effects depend on system Xc- pathway activation.

CONCLUSION

GsRb1 exerts protective effects against hyperoxia-induced lung injury in neonatal rats by targeting SLC7A11 to activate the system Xc- pathway, thereby inhibiting ferroptosis in alveolar epithelial cells.