Institute for Ethical Medicine Research, College of Pharmacy, South-Central University for Nationalities, Minyuan Road 708, Hongshan District, Wuhan, Hubei, PR China.
J Ethnopharmacol. 2013 Oct 28;150(1):196-201. doi: 10.1016/j.jep.2013.08.027. Epub 2013 Aug 27.
The leaf of Elaeagnus pungens thunb. (Family Elaeagnaceae) has been documented as an effective herb for the treatment of asthma and chronic bronchitis in traditional Chinese medicine. In the past years, only a few of preliminary studies reported the chemical constituents and pharmacology effects of the herb, but their action on the tracheal relaxation has not been investigated.
To investigate the relaxing effect and mechanism of the extracts from Elaeagnus pungens leaves on guinea pig tracheal smooth muscle and bronchi smooth muscle cells.
Four fractions of different polarities from Elaeagnus pungens leaves were tested to the tracheal strips on the resting tension or pre-contracted by histamine (20 μM) and acetylcholine (20 μM). Inhibitory effects of the 1-butanol fraction (400mg/ml) on cumulative histamine and acetylcholine (0.2-20 μM) induced contraction were measured. In order to determine the mediators on the 1-butanol fraction effect, the relaxing effect of the 1-butanol fraction was evaluated in the absence and presence of β-adrenoceptor antagonists (1 μM propranolol), K(+) channels-blockers (4-aminopyridine (2mM), tetraethylammonium chloride (5mM) or glibenclamide (10 μM)), the cyclooxygenase inhibitor (indomethacin, 10 μM), nitric oxide synthase inhibitor (Nω-nitro-L-arginine methyl ester, 100 μM) or L-type Ca(2+) channel inhibitor (nifedipine, 1 μM). Moreover, [Ca(2+)]i in bronchi smooth muscle cells was analyzed by measuring the fluorescence intensity with confocal system.
1-Butanol fraction induced the highest relaxant effect among four fractions of different polarities from Elaeagnus pungens leaves, and significantly relaxed the tracheal strip in the concentration-dependent manner on the resting tension and pre-contracted by histamine phosphate and acetylcholine. It also produced an unparallel rightward shift of the cumulative concentration-response curve of histamine or acetylcholine. Furthermore, the relaxant effect of 1-butanol fraction was not affected by propranolol, glibenclamide, tetraethylammonium chloride, 4-aminopyridine, indomethacin and Nω-nitro-L-arginine methyl ester. However, 1-butanol fraction-induced relaxation decreased after adding nifedipine. It also concentration-dependently inhibited CaCl2-induced contraction in the Ca(2+)-free, 60mM K(+)-containing solution. Additionally, [Ca(2+)]i in the BSMCs significantly reduced after administration of the 1-butanol fraction.
The 1-butanol fraction from Elaeagnus pungens leaves resulted in a relaxation in the non-precontracted and pre-contracted tracheal strips. The relaxant effect was not related to K(+) channels, NO, cGMP or β-adrenoceptors, but related to the inhibition of Ca(2+) influx through L-type Ca(2+) channels.
胡颓子属（胡颓子科）叶已被记录为一种有效的草药，可用于治疗中医中的哮喘和慢性支气管炎。在过去的几年中，只有少数初步研究报告了该草药的化学成分和药理学作用，但尚未研究其对气管松弛的作用。
研究胡颓子叶提取物对豚鼠气管平滑肌和支气管平滑肌细胞的松弛作用及其机制。
用不同极性的胡颓子叶的 4 个馏分作用于组胺（20 μM）和乙酰胆碱（20 μM）预收缩的气管条带，检测其静息张力。测量 1-丁醇馏分（400mg/ml）对累积组胺和乙酰胆碱（0.2-20 μM）诱导收缩的抑制作用。为了确定 1-丁醇馏分作用的介质，在不存在和存在β-肾上腺素能受体拮抗剂（1 μM 普萘洛尔）、K+通道阻滞剂（2mM 4-氨基吡啶、5mM 四乙铵或 10 μM 格列本脲）、环氧化酶抑制剂（吲哚美辛，10 μM）、一氧化氮合酶抑制剂（Nω-硝基-L-精氨酸甲酯，100 μM）或 L 型钙通道抑制剂（1 μM 硝苯地平）的情况下，评估 1-丁醇馏分的松弛作用。此外，通过测量共聚焦系统中的荧光强度来分析支气管平滑肌细胞中的[Ca 2+]i。
在胡颓子叶的 4 个不同极性馏分中，1-丁醇馏分诱导的松弛作用最强，对静息张力和磷酸组胺和乙酰胆碱预收缩的气管条带呈浓度依赖性显著松弛。它还使组胺或乙酰胆碱累积浓度反应曲线产生了平行的右移。此外，1-丁醇馏分的松弛作用不受普萘洛尔、格列本脲、四乙铵、4-氨基吡啶、吲哚美辛和 Nω-硝基-L-精氨酸甲酯的影响。然而，加入硝苯地平后，1-丁醇馏分诱导的松弛作用减少。它还浓度依赖性地抑制了无钙、60mM K+ 溶液中氯化钙诱导的收缩。此外，给予 1-丁醇馏分后，BSMCs 中的[Ca 2+]i 显著降低。
胡颓子叶的 1-丁醇馏分导致非预收缩和预收缩的气管条带松弛。松弛作用与 K+通道、NO、cGMP 或β-肾上腺素能受体无关，而是与通过 L 型钙通道抑制钙内流有关。
