Luteolin Mitigates Acute Lung Injury Through Immune Modulation and Antinecroptosis Effects by Targeting the BTK and FLT3 Signaling Pathways

Overactive immune responses and lung cell damage exacerbate acute lung injury (ALI). Luteolin, a flavonoid commonly found in traditional herbs, shows potential as an anti-ALI agent in pharmacological and clinical research, although its biological mechanism is not fully understood. This study aims to investigate whether luteolin can ameliorate ALI through its immune-modulatory and antinecroptosis mechanisms. We found that luteolin significantly inhibits the cellular activity of the FLT3-dependent monocyte cell line MOLM-13 and BTK-dependent B-cell line TMD-8. Through molecular docking and HTRF detection, it was confirmed that luteolin inhibits BTK and FLT3 enzyme activity by binding to their kinase domains, with IC₅₀ values of 0.78 and 0.35 μM, respectively. In a TNF-α-induced lung epithelial cell injury model, luteolin reduced the increased expression of IL1B, IL6, and CXCL8 mRNAs by blocking the necroptosis signal TNF-α/BTK/MLKL. Furthermore, using a Balb/c mouse ALI model with intratracheal LPS infusion (5 mg/kg), it was observed that luteolin improved lung function and pathology, regulated immune cell infiltration, and reduced cell death in pulmonary tissues by inhibiting BTK and FLT3 protein phosphorylation. In conclusion, luteolin acts as a natural BTK and FLT3 inhibitor, effectively preventing ALI both in vivo and in vitro through its immune-modulating and antinecroptosis properties.