Department of Studies in Biochemistry, University of Mysore, Mysore-570 006, Karnataka, India.
Curr Med Chem. 2013;20(8):1018-27.
Platelets are anuclear blood cells originating from bone megakaryocytes. Despite being anuclear, their number is maintained by apoptosis, a process of programmed cell death. The rate of apoptotic death of platelets is accelerated by oxidative and shear stress, ex vivo storage (blood banking conditions) and certain pathophysiological disorders. These factors initiate apoptotic events through the mitochondria- mediated intrinsic pathway. Besides, apoptotic platelets also release phosphatidylserine-positive membrane fractions called microparticles, which cause fibrin deposition and thrombus formation, and are involved in the promulgation of a host of disease conditions including cardiovascular diseases. In this context, several phytochemicals have been reported to be cardioprotective and work by inhibiting platelet aggregation or by dissolving the fibrin clots. Besides, ample reports focus on the positive effects of phytochemicals on normal physiology of platelets, but do not focus on their adverse effects on platelets. Moreover, platelets are reported to be extremely sensitive to therapeutic components in the blood. For example, resveratrol and thymoquinone are hitherto known compounds to possess proapoptotic effects on platelets. In contrast, cinnamtannin B1 and crocin exhibit antiapoptotic effects. Thus, the current review aims to elucidate the underlying mechanisms through which the phytochemicals mediate their effects on platelet apoptosis. Moreover, the need for scrutiny of therapeutic compounds for their effects on platelet functions before including them in treatment regimen is also being emphasized.
血小板是一种起源于骨髓巨核细胞的无核血细胞。尽管没有细胞核，但它们的数量通过凋亡来维持，凋亡是一种程序性细胞死亡的过程。血小板凋亡的死亡速度会被氧化和剪切应力、体外储存（血库条件）和某些病理生理紊乱加速。这些因素通过线粒体介导的内在途径引发凋亡事件。此外，凋亡的血小板还会释放出称为微粒体的带有磷脂酰丝氨酸的膜碎片，这些碎片会导致纤维蛋白沉积和血栓形成，并参与包括心血管疾病在内的多种疾病的发生。在这种情况下，已经有报道称几种植物化学物质具有心脏保护作用，它们可以通过抑制血小板聚集或溶解纤维蛋白凝块来发挥作用。此外，有大量的报道关注植物化学物质对血小板正常生理功能的积极影响，但不关注它们对血小板的不良反应。此外，据报道，血小板对血液中的治疗成分极其敏感。例如，白藜芦醇和百里醌迄今被认为对血小板具有促凋亡作用。相比之下，肉桂单宁 B1 和藏红花酸则表现出抗凋亡作用。因此，本综述旨在阐明植物化学物质通过何种机制介导其对血小板凋亡的影响。此外，还强调了在将治疗化合物纳入治疗方案之前，需要仔细研究它们对血小板功能的影响。
