Acute lung injury (ALI) often leads to high mortality, and there is as yet no effective drug treatment. The present study aimed to investigate protective effects of mogroside IIIE (MGIIIE, a cucurbitane-type triterpenoid from Siraitia grosvenorii Fruits) in experimental ALI and its underlying mechanism. MGIIIE (1, 10 0r 20 mg/kg) was orally administered for 1 h before a single intratracheal administration of lipopolysaccharide (LPS, 5 mg/kg). MGIIIE treatment dose-dependently suppressed pulmonary oedema, pro-inflammatory mediators (IL-1β, IL-6, TNF-α and HMGB1) release and higher MPO activity in lung tissues induced by LPS challenge. Molecular researches showed that mogroside IIIE (20 mg/kg) not only increased the phosphorylation of adenosine 5'-monophosphate-activated protein kinase (AMPK) but suppressed the over-expression of toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88). In addition, MGIIIE also inhibited the activation of MAPKs and nuclear factor κB (NF-κB) signalling in lung tissues from LPS-challenged mice. Similar antiinflammatory effects of MGIIIE were obtained in LPS-treated macrophages. Compound C (a pharmacological AMPK inhibitor) obviously reversed the antiinflammatory effect of MGIIIE in LPS-induced ALI mice. Taken together, AMPK activation plays a crucial role in the antiinflammatory effects of MGIIIE in LPS-induced ALI by down-regulating TLR4/MAPK/NF-κB signalling pathways. Copyright © 2017 John Wiley & Sons, Ltd.
Keywords: AMPK; TLR4; acute lung injury; lipopolysaccharide; mogroside IIIE.
Copyright © 2017 John Wiley & Sons, Ltd.