Nelumbo nucifera leaves extracts inhibit mouse airway smooth muscle contraction.
BACKGROUND
Alkaloids extracted from lotus leaves (AELL) can relax vascular smooth muscle. However, whether AELL has a similar relaxant role on airway smooth muscle (ASM) remains unknown. This study aimed to explore the relaxant property of AELL on ASM and the underlying mechanism.


METHODS
Alkaloids were extracted from dried lotus leaves using the high temperature rotary evaporation extraction method. The effects of AELL on mouse ASM tension were studied using force measuring and patch-clamp techniques.


RESULTS
It was found that AELL inhibited the high K+or acetylcholine chloride (ACh)-induced precontraction of mouse tracheal rings by 64.8 ± 2.9%, or 48.8 ± 4.7%, respectively. The inhibition was statistically significant and performed in a dose-dependent manner. Furthermore, AELL-induced smooth muscle relaxation was partially mediated by blocking voltage-dependent Ca2+channels (VDCC) and non-selective cation channels (NSCC).


CONCLUSIONS
AELL, which plays a relaxant role in ASM, might be a new complementary treatment to treat abnormal contractions of the trachea and asthma.
Xiao
X
Yang
Lu
L
Xue
Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, 430074, China.
Qingyang
Q
Zhao
Wuhan Youzhiyou Biopharmaceutical Co., Ltd., 666 Gaoxin Road, Biolake, Wuhan, 430075, China.
Congli
C
Cai
Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, 430074, China. qinghualiu95@163.com.
Qing-Hua
QH
Liu
Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, 430074, China. shenjinhua2013@163.com.
Jinhua
http://orcid.org/0000-0002-3213-7365
J
Shen
D000109:Acetylcholine / Q000378:metabolism; D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009119:Muscle Contraction / Q000187:drug effects*; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D031653:Nelumbo / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D014132:Trachea / Q000187:drug effects / Q000502:physiology
D000470:Alkaloids; D010936:Plant Extracts; D000109:Acetylcholine
Airway smooth muscle; Alkaloids; Asthma; Ca2+ channel; Tracheal relaxation