Protective effects and mechanisms of mogroside V on LPS-induced acute lung injury in mice

Context: Mogroside V, a compound isolated from Momordica grosvenori Swingle, which belongs to the Cucurbitaceae, is a traditional Chinese medicine reported to have anti-inflammatory potential in murine macrophages and a murine ear edema model. Objective: To investigate the effects and mechanisms of action of this compound in a model of acute lung injury (ALI) induced by lipopolysaccharides (LPS). Materials and methods: Female BALB/c mice were treated with commercial mogroside V (2.5, 5 and 10 mg/kg) for 1 h prior to intranasal injection of LPS (10 mu g in 50 mu l). After 12 h, airway inflammation in the ALI model was determined by the wet/dry weight (W/D) ratio, myeloperoxidase (MPO) activity of lung tissue, leukocyte recruitment and cytokine levels in the bronchoalveolar lavage fluid (BALF). Additionally, lung tissue was examined by histology and western blotting to investigate the changes in pathology and the signalling in the presence and absence of mogroside V. Results: Mogroside V at 5 and 10 mg/kg inhibited airway inflammation induced by LPS as measured by the decrease in the histological changes (44 and 67.3% reduction in lung injury score, respectively), a 28.9 and 55.3% reduction in lung MPO activity, and inflammatory cell counts, interleukin-1 beta (IL-1 beta, 382 and 280 pg/ml, respectively), IL-6 (378 and 232 pg/ml, respectively) and tumor necrosis factor-alpha (TNF-alpha, 12.5 and 7.8 ng/ml, respectively) levels in the BALF. Additionally, mogroside V treatment reduced the activation of cyclooxygenase 2 (COX-2), inducible NO synthase (iNOS), and the nuclear factor (NF)-kappa B. Discussions and conclusions: Together, these data suggest that mogroside V has the potential to protect against LPS-induced airway inflammation in a model of ALI.