Effects of inhalable microparticle of flower of Lonicera japonica in a mouse model of COPD

Ethnopharmacological relevance: Flower of Lonicera japonica (FLJ) is a traditional herbal medicine widely used in East Asia as an anti-inflammatory and anti-oxidative agent. The purpose of this study is to develop an inhalable powder formulation of FLJ and to evaluate its biological effects in a mouse model of chronic obstructive pulmonary disease (COPD). Methods: Inhalable dry powder containing FLJ was produced by spray-drying with leucine as an excipient. Its aerodynamic properties and anti-inflammatory activities were evaluated using the Anderson cascade impactor (ACI) and a mouse model of COPD, respectively. Results: FLJ microparticle (FLJmp) had a hollow spherical shape in electron microscopy and showed aerodynamic properties suitable for inhalation (fine particle fraction of 54.0 +/- 4.68% and mass median aerodynamic diameter of 4.6 +/- 0.34 mu m). FLJmp decreased TNF-alpha and IL-6 expression in RAW264.7 cells activated by lipopolysaccharide (LPS). In mice challenged with LPS and cigarette smoke solution (CSS) to develop COPD, FLJmp decreased the levels of TNF-alpha and IL-6 in bronchoalveolar fluidas well as the number of inflammatory cells including neutrophils in peripheral blood. In addition, FLJmp induced recovery of elastin and collagen distribution, reduction of caspase-3 expression in lung tissues of COPD mice. Conclusions: Inhalational delivery of FLJ using a microparticle system is a promising strategy for the treatment of COPD. (C) 2013 Elsevier Ireland Ltd. All rights reserved.