Astaxanthin prevents against lipopolysaccharide-induced acute lung injury and sepsis via inhibiting activation of MAPK/NF-κB

Background: Endotoxin-induced acute inflammatory diseases such as sepsis, mediated by excessive production of various pro-inflammatory cytokines remain the leading cause of mortality in critically ill patients. Lipopolysaccharide (LPS), the characteristic endotoxin found in the outer membrane of Gram-negative bacteria, can induce the innate immunity system and through Mitogen activated protein kinase (MAPK) and Nuclear Factor-κB (NF-κB), increase the production of inflammatory mediators. Astaxanthin (ASX), a xanthophyll carotenoid, exerts beneficial effects against oxidation, inflammation, and cancer. But poor evidence has been reported that whether it has protective effects on LPS-induced injury. This study aims to investigate the effects of ASX on LPS-induced sepsis and acute lung injury and to demonstrate its mechanisms.

Methods: Mouse prime macrophage (MPM) challenged with LPS were used for in vitro pharmacological activity and mechanistic studies. Inflammatory facors (tumor necrosis factor-alpha and interleukin-6 levels) in MPM were determined. The mouse models of LPS-induced sepsis and acute lung injury administrated with or without the compound were used for in vivo studies.

Results: Pre-treatment of MPM with ASX inhibited MAPK/NF-κB signaling pathway, and attenuated LPS-increased inflammatory factors in vitro. In animal models of LPS-induced sepsis and acute lung injury, administration of ASX significantly improved survival and protected lung injury. Subsequently, ASX was shown to suppress LPS-induced inflammatory factors increase, MAPK phosphorylation, and NF-κB activation in vivo.

Conclusions: ASX exerts impressively protective effects on LPS-induced injury in vitro and in vivo. Taken together, it might be used as a potential candidate for clinical sepsis.