In this work, five novel phosphonium salts derived from the Michael reaction were screened for their antiplatelet activity. Our findings revealed that compounds 2a, 2b, 2c, and 2d significantly inhibit platelet aggregation triggered by ADP or collagen (P < 0.001). Notably, compound 2c inhibited the arachidonic acid pathway (P < 0.001). Moreover, the selected compounds reduce CD62-P expression and inhibit GPIIb/IIIa activation. The interactions of the active compounds with their targets, ADP and collagen receptors, P2Y12 and GPVI respectively were investigated in silico using molecular docking studies. The results revealed a strong affinity of the active compounds for P2Y12 and GPVI. Additionally, cytotoxicity assays on platelets, erythrocytes, and human embryonic kidney HEK293 cells showed that compounds 2a, 2c and 2d were non-toxic even at high concentrations. In summary, our study shows that phosphonium salts can have strong antiplatelet power and suggests that compounds 2a, 2c and 2d could be promising antiplatelet agents for the management of cardiovascular diseases.

Lauryl gallate (LG, E312) is an antioxidant with hydrophobic properties that contribute to its activity by increasing affinity for membranes and acting on the lipid phase transition and likely the lateral membrane organization. Here, we show that LG at a low concentration has the ability to spontaneously induce washed human platelet shape change, filopodia emission, granule secretion, and aggregation. LG was able to activate intracellular signaling pathways, including Akt, p38MAP kinase, inositol phosphate, and calcium responses, as well as to trigger cyclic adenosine monophosphate decrease and αIIbβ3 integrin activation. LG significantly potentiated platelet aggregation induced by low concentrations of agonists, and the addition of low doses of LG to human blood strongly increased the platelet thrombotic response under arterial flow on a collagen matrix. Morphological analysis by scanning electron microscopy indicated that contrary to low doses, high concentrations of LG induced dramatic platelet membrane modifications associated with calcium influx, lactate dehydrogenase leakage, and a slow platelet aggregation response. Interestingly, a local flash application of LG efficiently decreased the tail bleeding time in rats. LG action was rapid and significantly more efficient than tranexamic acid, an antifibrinolytic agent, pointing to its hemostatic potential. Overall, our results indicate that LG, likely through its capacity to modify membrane lateral organization, has important pro-aggregant and antihemorrhagic properties.