Wienkötter N, Begrow F, Kinzinger U, Schierstedt D, Verspohl E J
Department of Pharmacology, Institute of Medicinal Chemistry, Münster, Germany.
Planta Med. 2007 Jun;73(7):629-35. doi: 10.1055/s-2007-981535. Epub 2007 Jun 12.
Thyme is a broncholytic und secretomotoric agent. Thus, our aim was to investigate the influence of a thyme extract on beta (2)-receptors in competition binding experiments and relaxation experiments on rat uteri and trachea. Furthermore, the influence of the extract on respiratory clearance was of interest. Binding experiments were performed using purified rat lung membranes with the beta(2)-receptor ligand [(125)I]-CYP {[(125)I]-(+/-)-Iodocyanopindolol}. The transport of the fluorescence dye rhodamin 123 concerning ciliary action in the tracheal area of a mouse was investigated using a microdialysis technique. The thyme extract reduces only slightly [(125)I]-CYP binding and amplifies the displacement of [(125)I]-CYP by propranolol (non-specific beta-receptor antagonist): the displacement curve in the concentration range representing beta (2)-receptors (nM) is shifted to the left. Thyme extract had relaxing effects on organs possessing beta (2)-receptors (uterus and trachea). The propranolol-induced antagonism to isoprenaline is reverted concentration-dependently by the extract. A duplication of the rate of ciliary clearance by the extract was observed.
百里香是一种支气管溶解剂和促分泌剂。因此，我们的目的是在大鼠子宫和气管的竞争结合实验和舒张实验中研究百里香提取物对β₂受体的影响。此外，提取物对呼吸道清除的影响也备受关注。结合实验使用纯化的大鼠肺膜和β₂受体配体[(¹²⁵)I]-CYP{[(¹²⁵)I]-(±)-碘氰吲哚洛尔}进行。使用微透析技术研究了荧光染料罗丹明123在小鼠气管区域关于纤毛运动的转运。百里香提取物仅轻微降低[(¹²⁵)I]-CYP结合，并增强普萘洛尔（非特异性β受体拮抗剂）对[(¹²⁵)I]-CYP的置换作用：代表β₂受体（纳摩尔）浓度范围内的置换曲线向左移动。百里香提取物对具有β₂受体的器官（子宫和气管）有舒张作用。提取物浓度依赖性地逆转了普萘洛尔对异丙肾上腺素的拮抗作用。观察到提取物使纤毛清除率加倍。
1）结合研究和生物学效应均证明百里香提取物对β₂受体有影响：从普萘洛尔置换曲线（纳摩尔）的移动可以推断，百里香提取物的成分与大鼠肺组织中的β₂受体有轻微相互作用。由于未达到完整的竞争曲线，这种效应是间接的。2）植物提取物使普萘洛尔对异丙肾上腺素舒张作用的拮抗作用减弱，揭示了其与大鼠子宫和气管中β₂受体至少存在间接相互作用。3）推测存在另一种机制，因为在高提取物浓度下异丙肾上腺素诱导的舒张作用是完全的，而普萘洛尔在β₂受体处的置换作用仅较弱。4）百里香提取物对β₂受体系统有间接（调节）作用。5）体内黏液纤毛清除功能得到改善。其机制仍有待阐明。
