Anti-asthmatic mechanism of the Huashanshen dripping pill via suppressing contraction of the airway smooth muscle

Background: The Huashanshen (HSS) dripping pill has been widely used in asthma for a long time in China. However, the relaxant mechanism of HSS is not well understood. Methods: In this report, high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was used to identify the constituents in rat plasma after oral administration of HSS. Ovalbumin-sensitized allergic asthma and isolated trachea were studied for the anti-asthmatic mechanism of HSS. Results: D-anisodamine, L-anisodamine, scopolamine and atropine were detected in the rat plasma containing HSS. It was clear that the HSS inhibited the release of inflammatory mediators, regulated the balance of T-helper 1 and T-helper 2 to reduce the airway inflammation, and relaxed the tracheal smooth muscle by controlling the KCa channel, Ca2+ influx and release to reduce the airway hyperresponsiveness. Conclusion: Atropine, anisodamine and scopolamine might be active compounds of HSS which inhibited the release of inflammatory mediators, regulated the balance of Th1/Th2, and relaxed the tracheal smooth muscle to reduce airway hyperresponsiveness.