Curdione attenuates thrombin-induced human platelet activation: β1-tubulin as a potential therapeutic target.

Rhizoma Curcumae, the dry rhizomes derived from Curcuma aromatica Salisb., are a classical Chinese medicinal herb used to activate blood circulation, remove blood stasis and alleviate pain. Our previous study proved that curdione, a sesquiterpene compound isolated from the essential oil of Curcuma aromatica Salisb. can inhibit platelet activation suggesting its significant anticoagulant and antithrombotic effects. However, the underlying mechanism of curdione mediated anti-platelet effect has not been fully elucidated. Platelet proteins extracted from washed human platelets, including normal group (treated with normal saline), thrombin group and curdione group were digested and analysed by nano ESI-LC-MS/MS. UniProt database and SIEVE software were employed to identify and reveal the differentially expressed proteins. Furthermore, possible mechanisms involved were explored by Ingenuity Pathway Analysis (IPA) Software and validated by western blot experiments. Twenty-two differentially expressed proteins between the normal and thrombin group were identified. Compared with the thrombin group, the curdione treatment was significantly down-regulated only 2 proteins (Talin1 and β1-tubulin). Bioinformatics analysis showed that Talin1 and β1-tubulin could be involved in the integrin signal pathway. The results of western blot analysis were consistent with that of the proteomics data. Vinculin, identified in IPA database was involved in the formation of cell cytoskeletal. The down-regulation of β1-tubulin facilitated the decrease in vinculin/Talin1. Curdione regulated the expression of vinculin and Talin1 by β1-tubulin affecting the integrin signalling pathway and eventually inhibiting platelet activation. The β1-tubulin may be a potential target of curdione, which attenuates thrombin-induced human platelet activation.