O'Kennedy Niamh, Crosbie Lynn, van Lieshout Machteld, Broom John I, Webb David J, Duttaroy Asim K
Provexis plc, The Rowett Research Institute, Aberdeen, United Kingdom.
Am J Clin Nutr. 2006 Sep;84(3):570-9. doi: 10.1093/ajcn/84.3.570.
Natural antithrombotic agents that influence platelet function are of potential interest for primary prevention of cardiovascular disease. Previous reports showed that tomato extracts inhibit platelet aggregation in vitro, but little is known of the active components, their mode of action, or their efficacy in vivo.
The objectives of the study were to examine the antiplatelet activity of specific tomato components by in vitro experimentation and to establish their ex vivo efficacy in healthy humans.
The mechanisms of action of antiplatelet components isolated from tomato extracts were examined in vitro. A 7-h time-course study was carried out in cannulated human subjects (n = 23) to determine the ex vivo efficacy of a supplement drink containing tomato extract and the onset and duration of antiplatelet effects.
The inhibition of ADP-, collagen-, thrombin-, and arachidonate-mediated platelet aggregation by tomato extract components appears to be linked to the inhibition of glycoprotein IIb/IIIa and platelet secretory mechanisms. We found a significant inhibition of baseline platelet function, from 2.9 +/- 1.4% (optimal ADP concentrations; P = 0.03) to 20.0 +/- 4.9% (suboptimal ADP concentrations; P < 0.001), 3 h after supplementation with a dose of tomato extract equivalent to 6 tomatoes. The observed effects persisted for >12 h. Coagulation variables were not affected.
The ingestion of tomato components with in vitro antiplatelet activity significantly affects ex vivo platelet function. The reported cardioprotective effects of tomatoes are potentially linked to a modulation of platelet function.
影响血小板功能的天然抗血栓形成剂对心血管疾病的一级预防具有潜在意义。先前的报告表明，番茄提取物在体外可抑制血小板聚集，但对其活性成分、作用方式或体内疗效了解甚少。
本研究的目的是通过体外实验检测特定番茄成分的抗血小板活性，并确定其在健康人体内的体外疗效。
对从番茄提取物中分离出的抗血小板成分的作用机制进行体外研究。在插管的人体受试者（n = 23）中进行了一项为期7小时的时间进程研究，以确定含番茄提取物的补充饮料的体外疗效以及抗血小板作用的起效时间和持续时间。
番茄提取物成分对ADP、胶原、凝血酶和花生四烯酸介导的血小板聚集的抑制作用似乎与糖蛋白IIb/IIIa和血小板分泌机制的抑制有关。我们发现，在补充相当于6个番茄剂量的番茄提取物3小时后，基线血小板功能受到显著抑制，从2.9±1.4%（最佳ADP浓度；P = 0.03）降至20.0±4.9%（次佳ADP浓度；P < 0.001）。观察到的效果持续超过12小时。凝血变量未受影响。
摄入具有体外抗血小板活性的番茄成分会显著影响体外血小板功能。报告的番茄对心脏的保护作用可能与血小板功能的调节有关。
