Protective effect of Paulownia tomentosa fruits in an experimental animal model of acute lung injury

Abstract

The fruits of Paulownia tomentosa (Thunb.) (PT) Steud. have been reported to exert a variety of biological activities. A previous study confirmed that compounds isolated from PT fruits (PTF) exerted anti-inflammatory effects on TNF-α-stimulated airway epithelial cells. However, there is no report on the protective effects of PTF on acute lung injury (ALI). Here, we examined the ameliorative effects of PTF in an experimental animal model of lipopolysaccharide (LPS)-induced ALI. In ALI mice, increased levels of inflammatory cell influx were confirmed in the lungs of mice, and an increase of microphage numbers, TNF-α, IL-6 and MCP-1 production and protein content were detected in mouse bronchoalveolar lavage fluid. However, these increases were significantly reversed with PTF pretreatment. In addition, PTF inhibited the increased expression of iNOS and COX-2 in the lungs of ALI mice. Furthermore, the upregulation of MAPK and NF-κB activation was decreased in the lungs of ALI mice by PTF. In the in vitro experiment, PTF pretreatment exerted an anti-inflammatory effect by inhibiting the secretion of nitric oxide, TNF-α and IL-6 in LPS-stimulated RAW264.7 macrophages. Collectively, these results indicated that PTF has ameliorative effects on airway inflammation in an experimental animal model of ALI.