Programa de Pós-Graduação em Farmacologia, Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Brazil.
Centro de Estudos Farmacêuticos e Cosméticos (CEFAC), Departamento de Farmácia, Faculdade de Farmácia, Odontologia e Enfermagem, Universidade Federal do Ceará 60431-327, Brazil.
J Ethnopharmacol. 2014;151(1):151-7. doi: 10.1016/j.jep.2013.10.008. Epub 2013 Nov 4.
Operculina macrocarpa is an ornamental climbing plant of the Northeastern Brazil extensively used in traditional medicine as depurative of the blood and for the treatment of thrombosis. To investigate the antiplatelet and anticoagulant potential of Operculina macrocarpa and to determine the possible mechanisms of action.
The Operculina macrocarpa tincture (OMT) was characterized by the polyphenol content and chromatographic profile established by HPLC with detection and quantification of three phenol acids (caffeic, clorogenic and gallic acids). The human platelet aggregation was induced in vitro by the agonists ADP, collagen, thrombin, epinephrine or arachidonic acid, and the antiplatelet effect of OMT was evaluated in the presence or absence of aspirin (a nonselective inhibitor of cyclooxygenase), pentoxifylline (a phosphodiesterase inhibitor), ticlopidine (a P2Y12 purinoceptor antagonist) or ODQ (a selective inhibitor of guanilate cyclase). The effect of OMT on the partial thromboplastin time, prothrombin time and bleeding time were investigated on human or rat plasma.
The strongest antiplatelet effect of OMT (50-400 µg/mL) was observed on the ADP- induced aggregation with inhibitions up to 55%, while among others agonists (epinephrine, collagen, thrombin and arachidonic acid) maximal inhibitions reached by OMT (200 µg/mL) were on platelet aggregation induced by collagen (18%) or epinephrine (20%). The antiplatelet effect of OMT (400 µg/mL) was comparable to aspirin, a nonspecific inhibitor of cyclooxygenase. The ticlopidine and pentoxifylline increased 5.1 and 3.8 fold the inhibitory effect of OMT on ADP-induced platelet aggregation, respectively. On the other hand, l-arginine, ODQ and aspirin showed a slightly or no effect on antiplatelet effect of OMT. The bleeding time in rats was significantly increased by OMT, but the tincture did not interfere on the activated partial thromboplastin or prothrombin time in human plasma.
This study showed that the tincture of Operculina macrocarpa has antiplatelet effect that cannot be attributed to a single biochemical mechanism and at least part of it cannot be related to the OMT inhibition of P2Y12 purinergic receptors.
Operculina macrocarpa 是巴西东北部一种具有观赏价值的攀缘植物，在传统医学中被广泛用作血液净化剂和治疗血栓的药物。本研究旨在探讨 Operculina macrocarpa 的抗血小板和抗凝特性，并确定其可能的作用机制。
采用高效液相色谱法（HPLC）测定 Operculina macrocarpa 酊剂（OMT）中的多酚含量和色谱特征，并用该方法检测和定量分析三种酚酸（咖啡酸、绿原酸和没食子酸）。采用 ADP、胶原、凝血酶、肾上腺素或花生四烯酸等激动剂在体外诱导人血小板聚集，并在存在或不存在阿司匹林（一种非选择性环氧化酶抑制剂）、己酮可可碱（一种磷酸二酯酶抑制剂）、噻氯匹定（一种 P2Y12 嘌呤能受体拮抗剂）或 ODQ（一种选择性鸟苷酸环化酶抑制剂）的情况下评估 OMT 的抗血小板作用。在人或大鼠血浆中研究 OMT 对部分凝血活酶时间、凝血酶原时间和出血时间的影响。
OMT（50-400μg/ml）对 ADP 诱导的聚集具有最强的抗血小板作用，抑制率高达 55%，而其他激动剂（肾上腺素、胶原、凝血酶和花生四烯酸）中，OMT（200μg/ml）对胶原（18%）或肾上腺素（20%）诱导的血小板聚集的最大抑制作用。OMT（400μg/ml）的抗血小板作用与非特异性环氧化酶抑制剂阿司匹林相当。噻氯匹定和己酮可可碱分别将 OMT 对 ADP 诱导的血小板聚集的抑制作用增加了 5.1 倍和 3.8 倍。另一方面，l-精氨酸、ODQ 和阿司匹林对 OMT 的抗血小板作用几乎没有影响。OMT 可显著延长大鼠的出血时间，但该酊剂不影响人血浆中的活化部分凝血活酶时间或凝血酶原时间。
本研究表明，Operculina macrocarpa 酊剂具有抗血小板作用，这种作用不能归因于单一的生化机制，至少部分作用不能归因于 OMT 对 P2Y12 嘌呤能受体的抑制作用。
