Tubuloside A attenuates sepsis-induced acute lung injury by modulating the NF-κB p50-Nrf2/GPX4 axis to suppress inflammation, oxidative stress and ferroptosis.

Sepsis-induced acute lung injury (ALI) remains a critical factor contributing to mortality in intensive care units, and effective therapeutic strategies are still lacking. The present research explores the defensive impacts and associated mechanisms of Tubuloside A (TA), an active phenanthrenoid glycoside extracted from Cistanche deserticola, in sepsis-induced ALI. Utilizing both a cecal ligation and puncture (CLP) mouse model and LPS-stimulated MLE-12 alveolar epithelial cells, we found that TA markedly attenuated lung injury, as indicated by improved histopathological features, reduced pulmonary edema, and maintenance of alveolar structure. Mechanistically, TA provided multifaceted protection by concurrently inhibiting oxidative stress, ferroptosis, and inflammatory signaling-critical drivers of sepsis-induced ALI. Treatment with TA diminished lipid peroxidation, restored GPX4 expression, and inhibited pro-inflammatory cytokines (TNF-α, IL-6, IL-1β). Network pharmacology identified NFKB1 as a therapeutic target of TA against ALI. Molecular docking predicted and SPR analysis verified that TA binds to NF-κB p50. Notably, functional validation via NF-κB p50 overexpression abolished TA-mediated protection and re-sensitized cells to ferroptosis, confirming NF-κB p50 as a central regulatory node. Furthermore, TA activated Nrf2 signaling in an NF-κBp50-dependent manner, as demonstrated by nuclear translocation assays and rescue experiments. Calcein AM imaging and iron chelation studies confirmed that TA's anti-ferroptotic effect requires functional NF-κB/Nrf2/GPX4 crosstalk. Collectively, our findings reveal that TA ameliorates sepsis-ALI by targeting the NF-κBp50-Nrf2/GPX4 axis to coordinately inhibit inflammation, oxidative stress, and ferroptosis, highlighting its potential as a multi-target phytotherapeutic agent for acute respiratory disorders.