Effect of San'ao Decoction and its Analogous Prescription on Airway Responsiveness in Asthmatic Mice Induced by Ovalbumin Sensitization and RSV Infection

In this study, the effect of San'ao decoction (SAD) and its analogous prescription (AP) on airway responsiveness in asthmatic mice induced by ovalbumin (OVA) sensitization and respiratory syncytial virus (RSV) infection was studied. A total of 70 mice were randomly divided into seven groups as follows: phosphate-buffered saline (PBS) control group, model group, dexamethasone group, SAD-S group, SAD-L group, AP-S group, and AP-L group. An asthma model was established by OVA sensitization with multipoint intraperitoneal injection, followed by repeated inhalation of OVA and repeated intranasal instillation of RSV (1.0 × 106.5 TCID50/mL in 50 μL). Pathological changes in airway responsiveness, which were indicated by lung resistance (RL) stimulated by Ach, were determined and observed by lung histopathology. The results showed that when mice were stimulated by Ach (45, 135, 405 μg/mL), RL was significantly increased in model group (compared with the baseline value) compared with that in PBS control group (P < 0.05, P < 0.01). After receiving drugs, mice in five groups, especially in AP-S group, showed decreased values of increased RL, as well as bronchial inflammation. SAD and its AP may suppress airway hyperresponsiveness so they can have the therapeutic effect on asthmatic mice induced by OVA sensitization and RSV infection, especially the AP of SAD.