Inhibition of Smooth Muscle Contraction by Magnolol and Honokiol in Porcine Trachea

• DOI: 10.1055/s-2003-40654
• Publication Date: 2003-07-16T08:16:02Z
• Authors: Chien-Hsin Ko; Hwei‐Hsien Chen; Yi-Ruu Lin; Ming‐Huan Chan
• Keywords: Honokiol; Magnolol

Magnolol and honokiol are the two major phenolic constituents of plant medicine "Houpo" (Magnolia obovata), which is used in treatment chest tightness asthma. The aim this study was to investigate influence magnolol on smooth muscle tone porcine trachea. (0.1 - 100 μM) inhibited carbachol- high K+-induced contractions a concentration-dependent fashion, but did not affect basal tension. After washout these pretreatments, K+-evoked were still abolished, suggesting that inhibition irreversible. also concentration-dependently decreased Ca2+-dependent contraction induced by K+ depolarization. Ca2+ channel antagonists attenuated carbachol-induced muscular response ∼30 %, further potentiate inhibitory actions contraction. However, effects carbachol-evoked contractile partially reversed after removal antagonist pretreatment. Alternatively, caffeine-elicited altered magnolol, honokiol, verapamil. In conclusion, relaxant tracheal suggest an association with blockade influx through voltage-operated channels instead release from intracellular stores. magnolol- honokiol-induced inhibitions may be relevant claimed therapeutic extract magnolia bark contribute their pharmacological acting as anti-asthmatic agents.