Lipopolysaccharide induced lung inflammation is inhibited by Lonicera japonica

Chronic obstructive pulmonary disease (COPD) is characterized by lung inflammation with neutrophil infiltration and increased levels of proin-flammatory cytokines. This study was conducted to evaluate the protective effect of Lonicera japonica (LJ) against lipopolysaccaride (LPS)-induced lung inflammation which resembles a COPD-like acute disease. Balb/c mice were treated once with LJ flower extract via an oral injection, after which they were administered LPS (0.5 mg/kg body wt) to induce acute airway inflammation. At 3 days after LPS stimulation, in vivo study demonstrated that the influx of neutrophils and total cells were decreased significantly in LJ pretreated group compared to LPS only treated group. In addition, TNF-α and IL-6 levels in bronchoalveloar lavage (BAL) fluid were decreased in LJ pretreated group. The histological results demonstrated that LJ attenuated the LPS induced lung inflammation. Furthermore, the expression of neutrophil elastase was decreased in LJ pretreated group. Taken together, these data suggest that LJ exerts protective effects against LPS-induced lung inflammation; therefore, this herbal medicine may represent a novel therapeutic agent for the treatment of lung inflammation, particularly for the treatment of COPD.