Nuciferine Relaxes Tracheal Rings via the Blockade of VDLCC and NSCC Channels

• Published in: Planta medica Vol. 84; no. 2; p. 83
• Main Authors: Yang, Xiao, Yu, Meng-Fei, Lei, Jun, Peng, Yong-Bo, Zhao, Ping, Xue, Lu, Chen, Weiwei, Ma, Li-Qun, Liu, Qing-Hua, Shen, Jinhua
• Format: Journal Article
• Language: English
• Published: Germany 01.01.2018
• Subjects: Acetylcholine - metabolism; Animals; Aporphines - chemistry; Aporphines - metabolism; Aporphines - pharmacology; Calcium - metabolism; Calcium Channels - metabolism; Drugs, Chinese Herbal - pharmacology; Male; Mice; Mice, Inbred BALB C; Molecular Structure; Muscle Relaxation - drug effects; Muscle, Smooth - drug effects; Muscle, Smooth - metabolism; Nelumbo - chemistry; Parasympatholytics - pharmacology; Trachea - drug effects
• ISSN: 1439-0221
• DOI: 10.1055/s-0043-118178

This study aimed to elucidate the mechanisms of nuciferine (a main aporphine alkaloid of lotus leaf extract), which can induce relaxation in contracted tracheal rings. Under Ca -free and 2 mM Ca conditions, we found that nuciferine had no effect on the resting muscle tone of tracheal rings. In contrast, nuciferine relaxed high K -contracted mouse tracheal rings in a dose-dependent manner and inhibited both Ca influx and voltage-dependent L-type Ca channel currents induced by high K . Similarly, nuciferine also inhibited acetylcholine-induced contractions in mouse tracheal rings in a dose-dependent manner. Meanwhile, both acetylcholine-induced intracellular Ca influx and whole-cell currents of nonselective cation channels were blocked by nuciferine. Together, the results indicate that nuciferine-induced relaxation in tracheal rings mainly occurred due to the inhibition of extracellular Ca influx through the blockade of voltage-dependent L-type Ca channels and/or nonselective cation channels. These results suggest that nuciferine has a therapeutic effect on respiratory diseases associated with the aberrant contraction of airway smooth muscles and/or bronchospasm.