Department of Physiological Sciences, Eastern Virginia Medical School, PO Box 1980, Norfolk, VA 23501-1980, USA.
J Cardiovasc Pharmacol. 2010 May;55(5):522-30. doi: 10.1097/FJC.0b013e3181d64b33.
Compounds with the stilbene pharmacophore and other nonsteroidal estrogens have previously been shown to inhibit thrombin-induced elevation of intracellular free calcium ([Ca]i) in human platelets. Thrombin elevates [Ca]i in platelets predominantly by activating a store-operated Ca entry (SOCE) mechanism, probably involving STIM1 and Orai1 although other components may be involved.
Human platelets were loaded with the Ca sensitive indicator fura-2, various concentrations of stilbene compounds and other nonsteroidal estrogens were added to the platelets, and thrombin was added to elevate [Ca]i. The degree of inhibition by each compound was determined at the peak increase in [Ca]i induced by thrombin.
The additional compounds that were examined in the present study were analogs of diethylstilbestrol (DES), namely trans-resveratrol, hexestrol, tetrahydrochrysene (THC), indenestrol, isoflavones, flavones, and flavanones. DES, indenestrols, and substituted THC diols had the highest inhibitory activity. Dietary polyphenols were less active, and isoflavones were more active than flavones. Glycosides of flavones, flavanones, and isoflavones were inactive. Equol (a product of isoflavone metabolism) had low activity. Among the compounds with a stilbene moiety the presence of unsubstituted phenyl hydroxyls in the para- position were required for activity. Esterification of hydroxyls and bulky substituents at a hydroxyl group diminished or abolished activity. Presence of the ethyl side chains enhanced activity, and shortening or removal of these side chains was detrimental to activity. Presence of the conjugated double bound was necessary for activity. Reduction of the double bond (in fused rings such as equol, dihydrogenistein, indanestrol, or in open chain stilbene derivatives) or repositioning of this double bond outside the stilbene moiety was detrimental to activity, because phenyl rings are not co-planar and have to be at a certain angle to each other.
DES likely represents the pharmacophore of this group of nonsteroidal estrogens as an inhibitor of SOCE in platelets.
具有芪类药效团和其他非甾体雌激素的化合物以前已被证明可抑制凝血酶诱导的人血小板细胞内游离钙 ([Ca]i) 升高。凝血酶通过激活储存操作的钙内流 (SOCE) 机制升高血小板中的 [Ca]i，该机制可能涉及 STIM1 和 Orai1，尽管可能涉及其他成分。
用人血小板负载 Ca 敏感指示剂 fura-2，向血小板中加入各种浓度的芪类化合物和其他非甾体雌激素，然后加入凝血酶以升高 [Ca]i。在凝血酶诱导的 [Ca]i 峰值增加时，确定每种化合物的抑制程度。
在本研究中检查的其他化合物是己烯雌酚 (DES) 的类似物，即反式白藜芦醇、己烷雌酚、四氢苊 (THC)、茋代雌酚、异黄酮、黄酮和黄烷酮。DES、茋代雌酚和取代的 THC 二醇具有最高的抑制活性。膳食多酚的活性较低，异黄酮的活性高于黄酮。黄酮、黄烷酮和异黄酮的糖苷没有活性。雌马酚 (异黄酮代谢的产物) 活性低。具有芪类部分的化合物中，在对位具有未取代的苯羟基本身是活性所必需的。羟基酯化和在一个羟基上的大取代基降低或消除了活性。乙基侧链的存在增强了活性，缩短或去除这些侧链对活性有害。共轭双键的存在是活性所必需的。双键的还原 (在如雌马酚、二氢异雌甾酮、茋代雌酚或开链芪衍生物中的稠合环中) 或重新定位该双键在芪类部分之外对活性有害，因为苯环不是共面的，并且必须彼此成一定角度。
DES 可能代表了这组非甾体雌激素的药效团，作为血小板中 SOCE 的抑制剂。
