Gilani Anwarul Hassan, Khan Arif-Ullah, Ghayur Muhammad N, Ali Syed Faizan, Herzig Joachim W
Department of Biological and Biomedical Sciences, Aga Khan University Medical College, Karachi 74800, Pakistan.
Basic Clin Pharmacol Toxicol. 2006 Nov;99(5):365-73. doi: 10.1111/j.1742-7843.2006.pto_507.x.
Rooibos tea has been widely used for abdominal spasm and diarrhoea. The aim of the present study was to explore the possible mechanism for its use in such ailments. Its aqueous extract (RT) at 0.3-10 mg/ml produced relaxation of spontaneous and low K(+) (25 mM)-induced contractions of rabbit jejunum, with weak effect on high K(+) (80 mM)-induced contractions. In the presence of glibenclamide, relaxation of low K(+)-induced contractions was prevented. Cromakalim inhibited contractions induced by low K(+), but not high K(+), while verapamil did not differentiate in its inhibitory effect on contractions produced by the two concentrations of K(+). RT also exhibited antidiarrhoeal and antisecretory activities in mice. The spasmolytic effect was concentrated in organic fractions. Its constituents, chrysoeriol, orientin and vitexin showed a similar pattern of spasmolytic effects to the extract, while rutin was more like verapamil. So Rooibos tea possesses a combination of dominant K(ATP) channel activation and weak Ca(++) antagonist mechanisms and hence justifies its use in hyperactive gastrointestinal disorders.
路易波士茶已被广泛用于治疗腹部痉挛和腹泻。本研究的目的是探索其用于此类疾病的可能机制。其浓度为0.3 - 10毫克/毫升的水提取物（RT）可使兔空肠的自发性收缩和低钾（25毫摩尔）诱导的收缩松弛，而对高钾（80毫摩尔）诱导的收缩作用较弱。在格列本脲存在的情况下，低钾诱导的收缩松弛被抑制。克罗卡林抑制低钾诱导的收缩，但不抑制高钾诱导的收缩，而维拉帕米对两种浓度钾诱导的收缩的抑制作用无差异。RT在小鼠中还表现出止泻和抗分泌活性。解痉作用集中在有机组分中。其成分白杨素、木犀草素和牡荆素显示出与提取物相似的解痉作用模式，而芦丁更类似于维拉帕米。因此，路易波士茶具有主要的钾离子通道激活和较弱的钙离子拮抗剂机制的组合，从而证明其可用于治疗胃肠道功能亢进性疾病。
