College of Pharmacy, Dongguk University, Goyang 410-820.
Department of Internal Medicine, College of Korean Medicine, Dongguk University, Gyeongju 780-714, Republic of Korea.
Biomol Ther (Seoul). 2014 May;22(3):254-9. doi: 10.4062/biomolther.2014.008.
The pentacyclic triterpenoid ursolic acid (UA) and its isomer oleanolic acid (OA) are ubiquitous in food and plant medicine, and thus are easily exposed to the population through natural contact or intentional use. Although they have diverse health benefits, reported cardiovascular protective activity is contentious. In this study, the effect of UA and OA on platelet aggregation was examined on the basis that alteration of platelet activity is a potential process contributing to cardiovascular events. Treatment of UA enhanced platelet aggregation induced by thrombin or ADP, which was concentration-dependent in a range of 5-50 μM. Quite comparable results were obtained with OA, in which OA-treated platelets also exhibited an exaggerated response to either thrombin or ADP. UA treatment potentiated aggregation of whole blood, while OA failed to increase aggregation by thrombin. UA and OA did not affect plasma coagulation assessed by measuring prothrombin time and activated partial thromboplastin time. These results indicate that both UA and OA are capable of making platelets susceptible to aggregatory stimuli, and platelets rather than clotting factors are the primary target of them in proaggregatory activity. These compounds need to be used with caution, especially in the population with a predisposition to cardiovascular events.
五环三萜熊果酸（UA）及其异构体齐墩果酸（OA）广泛存在于食物和植物药中，因此很容易通过自然接触或有意使用暴露于人群中。尽管它们具有多种健康益处，但报道的心血管保护活性存在争议。在这项研究中，根据改变血小板活性是导致心血管事件的潜在过程这一假设，研究了 UA 和 OA 对血小板聚集的影响。UA 的处理增强了由凝血酶或 ADP 诱导的血小板聚集，其在 5-50 μM 的范围内呈浓度依赖性。OA 也得到了相当可比的结果，其中 OA 处理的血小板对凝血酶或 ADP 的反应也明显增强。UA 处理增强了全血的聚集，而 OA 未能通过凝血酶增加聚集。UA 和 OA 不影响通过测量凝血酶原时间和活化部分凝血活酶时间评估的血浆凝血。这些结果表明，UA 和 OA 都能够使血小板易受聚集刺激，而血小板而不是凝血因子是它们在促聚集活性中的主要靶标。这些化合物需要谨慎使用，特别是在易发生心血管事件的人群中。
