Ameer Omar Ziad, Salman Ibrahim M, Siddiqui Mohammad Jamshed Ahmad, Yam Mun Fei, Sriramaneni Raghava Naidu, Sadikun Amirin, Ismail Zhari, Shah Amin Malik, Asmawi Mohd Zaini
Department of Physiology & Pharmacology, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Penang, Malaysia.
J Acupunct Meridian Stud. 2009 Dec;2(4):288-93. doi: 10.1016/S2005-2901(09)60070-4.
This study aimed to elucidate the mechanism(s) of the spasmogenic action of Loranthus ferrugineus in isolated guinea pig ileum. Thus the contractile responses of guinea pig ileum to graded additions of either L. ferrugineus methanol extract or its n-butanol fraction were tested in the presence and absence of various pharmacological interventions. The data showed that L. ferrugineus methanol extract and the n-butanol fraction produced a concentration-dependent spasmogenic effect in isolated guinea pig ileum segments. These effects were significantly inhibited in the presence of 1 microM atropine. In contrast, the response to the lowest concentrations of L. ferrugineus methanol extract (0.25, 0.5 and 1 mg/mL) and n-butanol fraction of L. ferrugineus (0.125, 0.25 and 0.5 mg/mL) were considerably enhanced in the presence of 0.05 microM neostigmine. Neither L. ferrugineus methanol extract nor n-butanol fraction contractile responses were affected upon the incubation of the ileal segments with 100 microM hexamethonium. The results of this study show that the spasmogenic effect of L. ferrugineus is possibly mediated through a direct action on intestinal muscarinic receptors. It is suggested that the bioactive constituents of L. ferrugineus serve as a substrate for acetylcholinesterase.
本研究旨在阐明锈毛桑寄生对豚鼠离体回肠产生致痉作用的机制。因此，在有无各种药理学干预的情况下，检测了豚鼠回肠对不同浓度锈毛桑寄生甲醇提取物或其正丁醇部位的收缩反应。数据表明，锈毛桑寄生甲醇提取物和正丁醇部位在豚鼠离体回肠段产生浓度依赖性致痉作用。在存在1微摩尔阿托品的情况下，这些作用受到显著抑制。相反，在存在0.05微摩尔新斯的明的情况下，对最低浓度的锈毛桑寄生甲醇提取物（0.25、0.5和1毫克/毫升）和锈毛桑寄生正丁醇部位（0.125、0.25和0.5毫克/毫升）的反应明显增强。用100微摩尔六甲铵孵育回肠段后，锈毛桑寄生甲醇提取物和正丁醇部位的收缩反应均未受到影响。本研究结果表明，锈毛桑寄生的致痉作用可能是通过对肠道毒蕈碱受体的直接作用介导的。提示锈毛桑寄生的生物活性成分可作为乙酰胆碱酯酶的底物。
