Water extract of Helminthostachys zeylanica attenuates LPS-induced acute lung injury in mice by modulating NF-κB and MAPK pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Previous studies showed that Helminthostachys zeylanica (L.) Hook. could reduce inflammatory responses in macrophage and brain astrocytes. AIM OF THE STUDY: In the present study, we evaluated whether an ethyl acetate extract (HZE) or a water extract (HZW) of H. zeylanica could reduce inflammatory responses in lung epithelial cells and ameliorate lipopolysaccharide (LPS)-induced acute lung injury in mice. METHODS: Human lung epithelial A549 cells were pre-treated with HZE or HZW (1-10µg/mL), then stimulated with LPS. BALB/c mice received oral HZW for 7 consecutive days, then an intratracheal instillation of LPS to induce lung injury. RESULTS: HZW reduced chemokine and proinflammatory cytokine production in LPS-activated A549 cells. HZW also suppressed ICAM-1 expression and reduced the adherence of acute monocytic leukemia cells to inflammatory A549 cells. HZE had less efficacy than HZW in suppressing inflammatory responses in A549 cells. In vivo, HZW significantly suppressed neutrophil infiltration and reduced the TNF-α and IL-6 levels in bronchoalveolar lavage fluid and serum from LPS-treated mice. HZW also modulated superoxide dismutase activity, glutathione, and myeloperoxidase activity in lung tissues from LPS-treated mice. HZW decreased the phosphorylation of mitogen-activated protein kinase and nuclear factor kappa B, and promoted heme oxygenase-1 expression in inflamed lung tissue from LPS-treated mice. CONCLUSION: Our findings suggested that HZW reduced lung injury in mice by reducing oxidative stress and inflammatory responses. HZW also reduced inflammatory responses in human lung epithelial cells.