Zerumbone from zingiber zerumbet ameliorates lipopolysaccharide-induced ICAM-1 and cytokines expression via p38 MAPK/JNK-IκB/NF-κB pathway in mouse model of acute lung injury

Acute lung injury (ALI) is a clinical syndrome with high morbidity and mortality rates mainly caused by Gram-negative bacteria. Nevertheless, an effective treatment strategy for ALI is yet to be developed. Zerumbone, a sesquiterpene isolated from Zingiber zerumbet Smith, possesses several advantageous bioeffects such as antioxidation, anti-inflammation, and antiulcer. Pretreatment of zerumbone inhibited lipopolysaccharide (LPS)-induced arterial blood gas exchange, neutrophils infiltration, and increased pulmonary vascular permeability. LPS-induced expression of intercellular adhesion molecule-1 (ICAM-1) was inhibited by zerumbone at a lower concentration than that of vascular cell adhesion molecule-1 (VCAM-1). In addition, proinflammatory cytokines, such as interleukin (IL)-1β and macrophage inflammatory protein (MIP)-2 were suppressed by zerumbone. The phosphorylation of nuclear factor (NF)-κB, a proinflammatory transcription factor, and degradation of inhibitor of κB (IκB), an inhibitor of NF-κB, were also reduced by zerumbone. Furthermore, we found the inhibitory concentration of zerumbone on phosphorylation of p38 mitogen-activated protein kinase (MAPK) and c-Jun NH2-terminal kinase (JNK) was lower than that of extracellular signal-regulated kinase (ERK). In conclusion, zerumbone could be a potential protective agent for ALI, possibly via expression of ICAM-1, IL-1β, and MIP-2. The protective mechanism of zerumbone was by reversing the activation of p38 MAPK/JNK-IκB/NF-κB pathway.