Natural Product Research Division, Department of Biological and Biomedical Sciences, The Aga Khan University Medical College, Karachi, Pakistan.
Pharm Biol. 2010 Nov;48(11):1240-6. doi: 10.3109/13880201003727960. Epub 2010 Sep 7.
Holarrhena antidysenterica Wall. (Apocynaceae) is widely used in traditional medical system for treatment of constipation, colic, and diarrhea.
This study was carried out to provide pharmacological basis for medicinal use of Holarrhena antidysenterica in gastrointestinal disorders.
Hydro-ethanolic crude extract of Holarrhena antidysenterica (HaCE) and its fractions were studied in various gastrointestinal isolated tissue preparations.
In guinea pig ileum tissues, HaCE at 0.3-10 mg/mL caused pyrilamine-sensitive spasmogenic effect. When tested in spontaneously contracting rabbit jejunum preparations, HaCE (0.01-3.0 mg/mL) caused moderate stimulation, followed by a relaxant effect at next higher concentrations. In presence of pyrilamine, the contractile effect was blocked and the relaxation was observed at lower concentrations (0.01-0.3 mg/mL). HaCE inhibited the high K(+) (80 mM)-induced contractions at concentration range of 0.01-1.0 mg/mL and shifted Ca(++) concentration response curves to the right, like that caused by verapamil. Activity-directed fractionation revealed that the spasmogenic component was concentrated in the aqueous fraction, while the spasmolytic component was concentrated in the organic fraction.
These results indicate that the gut stimulant and relaxant activities of Holarrhena antidysenterica are mediated possibly through activation of histamine receptors and Ca(++) channel blockade, respectively and this study provides sound mechanistic background for its usefulness in gut motility disorders such as constipation, colic, and possibly diarrhea.
钩吻（夹竹桃科）在传统医学系统中被广泛用于治疗便秘、绞痛和腹泻。
本研究旨在为钩吻在胃肠道疾病中的药用提供药理学依据。
研究了钩吻的水-乙醇粗提取物（HaCE）及其馏分在各种胃肠道分离组织制剂中的作用。
在豚鼠回肠组织中，HaCE 在 0.3-10mg/mL 时引起吡拉明敏感的痉挛性效应。在自发收缩的兔空肠制剂中进行测试时，HaCE（0.01-3.0mg/mL）引起适度刺激，随后在下一个较高浓度时产生松弛作用。在使用吡拉明的情况下，收缩作用被阻断，在较低浓度（0.01-0.3mg/mL）下观察到松弛作用。HaCE 抑制高 K+（80mM）诱导的收缩，浓度范围为 0.01-1.0mg/mL，并像维拉帕米一样使 Ca++浓度反应曲线向右移位。活性导向的分级分离表明，痉挛性成分集中在水相部分，而痉挛性成分集中在有机相部分。
这些结果表明，钩吻的肠道刺激和松弛活性可能分别通过激活组胺受体和钙通道阻断来介导，本研究为其在便秘、绞痛和可能的腹泻等肠道运动障碍中的应用提供了可靠的机制背景。
