OBJECTIVETo observe the airway inflammatory change in asthmatic rats complicated with chronic obstructive pulmonary disease (COPD) and to assess the intervention effects of Chinese herbs for reinforcing Shen and supplementing qi (CH) on it.

METHODSEighty-four Norway rats were randomized into 7 groups, the normal control group (A), the COPD model group (B), the asthma model group (C), the combined COPD and the asthma model group (D), and the three CH treated groups (E, F and G, combined model rats administered by low-, moderate- and high- dose CH, respectively), 12 rats in each group. Changes of symptoms, pathologic changes of the lung tissue, airway reactivity, and serum levels of interleukin-4, interleukin-6, interleukin-8 (IL-4, IL-6, and IL-8) and interferon-gamma (IFN-gamma) in rats were observed.

RESULTSSymptoms were alleviated in the three CH treated groups. Similar pathological features were shown in group B and D, showing inflammatory cell, mainly lymphocyte, infiltration in bronchial and lung tissues, with cilia denudation, partial alveolar wall rupture, alveolar cavity expansion, and accompanied with evident eosinophilic infiltration. These inflammatory exudation in group E-G was alleviated, while in group C, it developed showing a trend similar to that in group D. Airway resistance raised along with the concentration of Mch used. In group D, the serum level of IL-4 was higher than that in group B, and level of INF-gamma was lower than that in group A, B and C (all P <0.05). CH showed a lowering effect on serum levels of IL-4 and -8, and a dose-dependent rising effect on IFN-gamma.

CONCLUSIONSIL- 4 significantly increased and INF-gamma decreased in rat model of combined COPD and asthma, its mechanism is similar to that of Th1/Th2 imbalance in asthma. Chinese herbs for reinforcing Shen and supplementing qi could improve the symptoms and inhibit the airway inflammation in the combined COPD and asthma model rats, its mechanism might be related with the alleviation of TH1/TH2 imbalance.