Previous studies have established the aggregation-inhibitory properties of synthetic ginsenoside derivatives, such as G-Rp (1, 3, and 4), as well as natural ginsenosides isolated from Panax ginseng, including 20(S)-Rg3, Rg6, F4, and Ro. However, the specific inhibitory mechanisms of G-Rk3, another bioactive compound derived from Panax ginseng, require further detailed investigation. This research aimed to evaluate the effects of G-Rk3 on agonist-induced human platelet aggregation. We assessed the suppression of platelet signaling components, including integrin αIIbβ3-mediated fibrinogen binding via flow cytometry, along with the mobilization of intracellular calcium, the release of dense granules, and the secretion of thromboxane B2. Furthermore, the modulation of phosphorylation within the PI3K/MAPK pathway was examined, alongside observations of thrombin-stimulated clot retraction in platelet-rich plasma. Treatment with G-Rk3 markedly elevated cyclic adenosine monophosphate (cAMP) levels, resulting in the substantial phosphorylation of the cAMP-dependent kinase targets vasodilator-stimulated phosphoprotein (VASP) and inositol 1,4,5-trisphosphate receptor (IP3R). G-Rk3 administration suppressed Ca2+ release from the dense tubular system and diminished overall platelet reactivity by deactivating the integrin αIIb/β3, which subsequently decreased fibrinogen binding. Additionally, G-Rk3 attenuated the phosphorylation of the MAPK and PI3K/Akt pathways, leading to a decline in both intracellular granule secretion and TXA2 generation. Ultimately, G-Rk3 successfully prevented platelet aggregation and subsequent fibrin-dependent thrombus formation. These findings indicate that G-Rk3 holds significant potential as a valuable prophylactic or therapeutic agent in the management of cardiovascular disorders driven by aberrant platelet aggregation and thrombogenesis.
