Figure 2.
Osthole reduced airway hyperresponsiveness and airway inflammation. (a) Oral administration of osthole suppressed the development of AHR in mice with OVA-induced asthma. After OVA challenge, the airway resistance of treated mice was measured in response to increasing concentrations of methacholine (1–32 mg/ml) through invasive body plethysmography. The results are expressed as the pulmonary resistance in the ratio of lung resistance (RL) after PBS nebulization. (b) Numbers of pulmonary eosinophils and neutrophils were reduced in osthole-treated mice. After the pulmonary function parameters were measured, BALF was collected and stained with Liu’s stain. Cells from BALF were counted and classified as macrophages (Macro), eosinophils (Eos), neutrophils (Neu) and lymphocytes (Lym). (c) Lung sections were stained with H&E to measure infiltrated inflammatory cells. (d) Lung sections were stained with PAS to measure mucus hypersecretion. Inflammatory changes and mucus production are, respectively, presented as percentages of inflamed areas and PAS-positive areas in different experimental groups. The results are expressed as the mean±s.e.m. of six mice per group. *P<0.05, **P<0.01, ***P<0.001 vs the PC group.