OBJECTIVETo observe the effects of huatan jiangqi capsule (HJC) on the expression levels and functions of multi-drug resistance-associated protein 1 (MRP1) in the bronchial epithelial cells of chronic obstructive pulmonary disease (COPD) model rats, and to explore the mechanism of HJC for treating COPD.

METHODSTwenty-four male wistar rats were randomly divided into the normal control group, the model group, and HJC group. Except the normal control group, the COPD rat model was established in the rest groups using quantitative stimulation with tobacco, SO2, and caroid aerosol rebreathing method. The indices of the post-treatment lung functions, the cell counts of bronchoalveolar lavage fluid (BALF), the pathological features of the lung tissue were observed. The concentration of LTC, in lung tissues was also examined by ELISA. The expression of MRP1 of the pulmonary tracheal epithelium was detected using immunohistochemical assay.

RESULTS(1) The pulmonary compliance, the forced expiratory volume at 0. 3 second (FEV 0.3%)/the forced vital capacity (FVC), the peak expiratory flow, the maximum mid expiratory flow decreased more significantly in the model group than in the normal control group (P < 0.05). The aforesaid pulmonary function indices obviously increased in the HJC group when compared with the model group (P < 0.05). (2) The air inflammation was aggravated with obvious emphysema in the model group. The inflammation and emphysema occurred in the HJC group in a milder degree. (3) Compared with the normal control group, the levels of LTC4 significantly increased in the lung tissue of the model group and HJC group (P < 0.01). Compared with the model group, the levels of LTC4 significantly decreased in the lung tissues of the HJC group (P < 0.05). (4) Compared with the normal control group, the protein expression of the bronchial epithelial MRP1 significantly decreased in the model group (P < 0.01). Compared with the model group, the protein expression of the bronchial epithelial MRP1 were significantly enhanced in the HJC group (P < 0.05).

CONCLUSIONHJC could effectively alleviate the lung inflammation, postpone the occurrence and development of COPD possibly through effecting the functions and expressions of MRP1 in COPD rats.