Excessive
reactive oxygen species production during
acute lung injury (ALI) will aggravate the inflammatory process and endothelial barrier dysfunction.
Carnosol is a natural phenolic
diterpene with
antioxidant and anti-inflammatory properties, but its role in treating
sepsis-induced ALI remains unclear. This study aims to explore the protective effects and underlying mechanisms of
carnosol in
sepsis-induced ALI. C57BL/6 mouse were preconditioned with
carnosol for 1 h, then the model of
lipopolysaccharide (LPS)-induced
sepsis was established. The degree of
pulmonary edema, oxidative stress, and
inflammation were detected. Endothelial barrier function was evaluated by apoptosis and cell junctions. In vitro, Mito Tracker Green probe,
JC-1 staining, and
MitoSOX staining were conducted to investigate the effect of
carnosol on mitochondria. Finally, we investigated the role of nuclear factor-erythroid 2-related factor (Nrf2)/
sirtuin-3 (
SIRT3) in
carnosol against ALI.
Carnosol alleviated LPS-induced pulmonary oxidative stress and
inflammation by inhibiting excess mitochondrial
reactive oxygen species production and maintaining mitochondrial homeostasis. Furthermore,
carnosol also attenuated LPS-induced endothelial cell barrier damage by reducing vascular endothelial cell apoptosis and restoring
occludin, ZO-1, and
vascular endothelial-Cadherin expression in vitro and in vivo. In addition,
carnosol increased Nrf2 nuclear translocation to promote
SIRT3 expression. The protective effects of
carnosol on ALI were largely abolished by inhibition of Nrf2/
SIRT3. Our study has provided the first evidence that the Nrf2/
SIRT3 pathway is a protective target of the endothelial barrier in ALI, and
carnosol can serve as a potential therapeutic candidate for ALI by utilizing its ability to target this pathway.