Figure 2. Long-term effect of Bufei Yishen formula (BYF) on the histological changes in lung tissues of chronic obstructive pulmonary disease (COPD) rats.

COPD rats were intragastricly treated with BYF (4.44 g/kg) and aminophylline (APL, 2.3 mg/kg) once daily from week 9 to 20. On week 32, the lung tissues of COPD rats were collected. Histological changes were detected using H&E staining (original magnification ×100) (A). The lung injury scores of all groups were evaluated (B). Bronchial wall thickness (C), bronchiole stenosis (D), small pulmonary vessels wall thickness (E), alveolar number (F), and alveolar diameter (G) were analyzed. Values represent the means ± SEM. *p < 0.05, **p < 0.01 vs. model.