Department of Otolaryngology, Head and Neck Surgery, Technical University of Munich and Klinikum Rechts der Isar, Munich, Germany.
Institute for Medical Microbiology, Immunology and Hygiene, School of Medicine, Technical University of Munich, Munich, Germany.
Life Sci. 2024 Aug 1;350:122746. doi: 10.1016/j.lfs.2024.122746. Epub 2024 May 27.
Dysregulated platelet aggregation is a fatal condition in many bacterial- and virus-induced diseases. However, classical antithrombotics cannot completely prevent immunothrombosis, due to the unaddressed mechanisms towards inflammation. Thus, targeting platelet hyperactivation together with inflammation might provide new treatment options in diseases, characterized by immunothrombosis, such as COVID-19 and sepsis. The aim of this study was to investigate the antiaggregatory effect and mode of action of 1.8-cineole, a monoterpene derived from the essential oil of eucalyptus leaves, known for its anti-inflammatory proprieties.
Platelet activity was monitored by measuring the expression and release of platelet activation markers, i.e., P-selectin, CD63 and CCL5, as well as platelet aggregation, upon treatment with 1.8-cineole and stimulation with several classical stimuli and bacteria. A kinase activity assay was used to elucidate the mode of action, followed by a detailed analysis of the involvement of the adenylyl-cyclase (AC)-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway by Western blot and ELISA.
1.8-cineole prevented the expression and release of platelet activation markers, as well as platelet aggregation, upon induction of aggregation with classical stimuli and immunological agonists. Mechanistically, 1.8- cineole influences the activation of the AC-cAMP-PKA pathway, leading to higher cAMP levels and vasodilator-stimulated phosphoprotein (VASP) phosphorylation. Finally, blocking the adenosine A receptor reversed the antithrombotic effect of 1.8-cineole.
Given the recognized anti-inflammatory attributes of 1.8-cineole, coupled with our findings, 1.8-cineole might emerge as a promising candidate for treating conditions marked by platelet activation and abnormal inflammation.
血小板聚集失调是许多细菌和病毒诱导疾病的致命状态。然而，由于针对炎症的机制尚未得到解决，经典的抗血栓药物不能完全预防免疫血栓形成。因此，靶向血小板过度激活和炎症可能为 COVID-19 和败血症等以免疫血栓形成为特征的疾病提供新的治疗选择。本研究旨在研究 1.8-桉油醇（一种从桉树叶精油中提取的单萜烯，以其抗炎特性而闻名）的抗聚集作用及其作用机制。
通过测量血小板激活标志物（即 P-选择素、CD63 和 CCL5 的表达和释放）以及血小板聚集，监测血小板活性，在使用 1.8-桉油醇和几种经典刺激物和细菌刺激后进行测量。通过激酶活性测定法阐明作用机制，然后通过 Western blot 和 ELISA 详细分析涉及腺苷酸环化酶（AC）-环磷酸腺苷（cAMP）-蛋白激酶 A（PKA）通路的情况。
1.8-桉油醇可预防经典刺激物和免疫激动剂诱导聚集时血小板激活标志物的表达和释放以及血小板聚集。从机制上讲，1.8-桉油醇影响 AC-cAMP-PKA 通路的激活，导致更高的 cAMP 水平和血管扩张刺激磷蛋白（VASP）磷酸化。最后，阻断腺苷 A 受体可逆转 1.8-桉油醇的抗血栓作用。
鉴于 1.8-桉油醇公认的抗炎属性，再加上我们的发现，1.8-桉油醇可能成为治疗以血小板激活和异常炎症为特征的疾病的有前途的候选药物。
