Inhibition of airway smooth muscle tone by Chinese herbal medicines

The aim of the present study was to elucidate whether Chinese traditional herbal drugs, Gorei‐San (TJ‐17) and Toki‐Shakuyaku‐San (TJ‐23), affect airway smooth muscle tone and, if so, to determine what the mechanism of action is. Rabbit tracheal segments were isolated and the contractile responses to electrical field stimulation and acetylcholine were measured before and after the application of TJ‐17 or TJ‐23 under isometric conditions in vitro. Ouabain‐sensitive rubidium‐86 (86Rb) uptake by tissues in response to each drug was also measured. Each herbal medicine attenuated the contractile responses to electrical field stimulation and acetylcholine in a concentration‐dependent manner, the maximal inhibition of acetylcholine‐induced contraction being 37.5±4.9% for TJ‐17 and 42.4±5.3% for TJ‐23 (p