## 1 Introduction  
In chronic obstructive pulmonary disease (COPD), airflow to the lung is significantly restricted, making breathing difficult [1]. The main features of COPD are chronic bronchitis, excessive secretion of mucus, bronchiolar and vascular remodeling, pulmonary hypertension, emphysema, and pulmonary fibrosis [2]. Previous research indicated that COPD is becoming a greater public health burden worldwide because of the aging population and the increasing exposure to risk factors. During COPD, the indicators of chronic inflammation are the infiltration and fibrosis of cells, obstruction of peripheral airways, and inflammatory exudates accumulation in the lumen. The pathogenesis of COPD involves numerous proinflammatory cytokines and chemokines.  
Smoking is a significant cause of COPD. Cigarette smoke (CS) contains free radicals as well as reactive chemical compounds, such as aldehydes and semiquinones [3]. During lung inflammation, neutrophils and monocytes accumulate after exposure to CS. The CS thus increases chemotaxis, cell adhesion, and phagocytosis, and the release of superoxide anions and enzyme granules [4]. COPD presently has no cure, however therapies such as quitting smoking, using inhalers and pills, and respiratory rehabilitation may help slow the disease progression and control symptoms [5]. Drugs such as phosphodiesterase were 4 inhibitors, corticosteroids, and 2-agonists are currently used for treatment. However, existing medicines cannot stop disease development or prevent drug intolerance and severe adverse effects. Side effects of bronchodilators or steroids used for therapy include dry mouth, headache, weight gain, and easy bruising. Long-term use of these drugs can lead to intolerance, in which case they are no longer effective in slowing disease progression [6]. There is therefore a need to identify additional treatments for COPD that have high efficacy and low toxicity.  
Jakyakgamcho-tang (JGT) is an Asian herbal formula that consists of Paeoniae Radix (_Paeonia lactiflora_ [PERSON]) and Glycyrrhizae Radix et Rhiza (_Glycyrrhizae valensis_ [PERSON]). As demonstrated, JGT has analgesic [7], antispasmodic [8], anti-allergy effects [9], and anti-inflammatory [10]. Analysis by gas chromatography/mass spectroscopy found ten main active ingredients of JGT: albiforin, oxypaeoniflorin, ononin, isoliquiritin, glycyrrhizin, benzoic acid, liquiritin, gallic acid, benzoylpaeoniflorin, and paeoniflorin [11]. Glycyrol, a benzofuran coumarin from G. uralensis, was shown to have anti-inflammatory effects [12], and glycyrrhizin, a related compound, was found to prevent the replication of severe acute respiratory syndrome coronavirus (SARS-CoV) [13]. Moreover, evidence from an in vitro model showed that gancanoin N, a preynlated isoflavrone from G. uralensis, ameliorated the inflammatory response associated with acute pneumonia [14], and studies in animal models found that the total glucosides of _P. lactiflora_ regulated immune responses and had anti-inflammatory effects [15; 16]. In addition, an extract of _P. lactiflora_ was found to inhibit the human respiratory syncytial virus (HRSV) in vitro [17], and to have anti-influenza activity in vivo [18]. However, there have been no previous studies examining the efficacy of JGT for COPD. This research therefore tested the influences of JGT on COPD in mice induced by CS and lipopolysaccharide-acrylamide (LPS).