Rywaniak Joanna, Luzak Boguslawa, Podsedek Anna, Dudzinska Dominika, Rozalski Marcin, Watala Cezary
Department of Haemostasis and Haemostatic Disorders, Central Veterans' Hospital, Medical University of Lodz , Lodz , Poland and.
Platelets. 2015;26(2):168-76. doi: 10.3109/09537104.2014.894970. Epub 2014 Mar 28.
Polyphenolic compounds of plant origin are well known to be beneficial to human health: they exert protective effects on haemostasis and have a particular influence on blood platelets. However, the anti-platelet properties of polyphenolic compounds observed so far have not been weighed against their potential cytotoxic action against platelets. The aim of this study was to demonstrate that anti-platelet and cytotoxic effects on blood platelets may interfere and therefore, may often lead to confusion when evaluating the properties of plant extracts or other agents towards blood platelets. The anti-platelet and cytotoxic in vitro effects of plant extracts obtained from the husks of walnuts (J. regia) and flowers of arnica (A. montana) on platelet reactivity and viability were examined. Platelet function was assessed using standard methods (flow cytometry: P-selectin expression, activation of GPIIbIIIa complex, vasodilator-stimulated phosphoprotein, VASP index; turbidimetric and impedance aggregometry) and newly set assays (flow cytometric monitoring of platelet cytotoxicity). The results reveal that none of the studied plant extracts demonstrated cytotoxicity towards blood platelets. The phenolic acid-rich extract of A. montana (7.5 and 15 µg/ml) significantly reduced the ADP-induced aggregation in both whole blood and PRP, and decreased the platelet reactivity index (PRI; VASP phosphorylation) in whole blood, while showing excellent antioxidant capacity. The extract of J. regia husks significantly reduced ADP-induced platelet aggregation in whole blood when applied at 7.5 µg/ml, and only slightly decreased the PRI at 15 µg/ml. Both examined extracts suppressed platelet hyper-reactivity, and such influence did not interfere with cytotoxic effects of the extracts. Thus, its high polyphenol content, excellent antioxidant capacity and distinct anti-platelet properties, in combination with its lack of toxicity, make the extract of A. montana flowers a possible candidate as an anti-platelet agent or a compounding diet supplement.
众所周知，植物源多酚类化合物对人体健康有益：它们对止血具有保护作用，并对血小板有特殊影响。然而，迄今为止观察到的多酚类化合物的抗血小板特性尚未与其对血小板的潜在细胞毒性作用相权衡。本研究的目的是证明对血小板的抗血小板和细胞毒性作用可能相互干扰，因此，在评估植物提取物或其他药物对血小板的特性时，可能常常导致混淆。研究了从核桃（J. regia）外壳和山金车花（A. montana）中获得的植物提取物对血小板反应性和活力的体外抗血小板和细胞毒性作用。使用标准方法（流式细胞术：P-选择素表达、GPIIbIIIa复合物激活、血管舒张刺激磷蛋白、VASP指数；比浊法和阻抗聚集法）和新建立的检测方法（血小板细胞毒性的流式细胞术监测）评估血小板功能。结果表明，所研究的植物提取物均未表现出对血小板的细胞毒性。富含酚酸的山金车花提取物（7.5和15μg/ml）显著降低了全血和富血小板血浆中ADP诱导的聚集，并降低了全血中的血小板反应性指数（PRI；VASP磷酸化），同时显示出优异的抗氧化能力。核桃外壳提取物在7.5μg/ml时显著降低了全血中ADP诱导的血小板聚集，而在15μg/ml时仅略微降低了PRI。两种检测提取物均抑制了血小板的高反应性，且这种影响并未干扰提取物的细胞毒性作用。因此，山金车花提取物因其高多酚含量、优异的抗氧化能力和独特的抗血小板特性，再加上其无毒性，使其有可能成为抗血小板药物或复合膳食补充剂的候选物。
