Antiplatelet and antioxidant effects of ethanol extract of <i>Geranium thunbergii</i>

In this experiment, we evaluated the antithrombotic and antioxidant activities using 70% ethanol extract of Geranium thunbergii ethanol extract (GTE).Platelets act a fundamental role in hemostasis and thrombosis, therefore, control of platelet aggregation is crucial in preventing cardiovascular disease.This study investigated the anti-platelet effects of GTE on human platelets.To confirm the effect of GTE on platelets, we evaluated the effect of GTE on human platelet aggregation and clot retraction.In addition, we analyzed the total polyphenol contents, total flavonoid contents, and anti-oxidant activity of GTE.As a result, GTE strongly inhibited collagen-induced human platelet aggregation, calcium mobilization, thromboxane A 2 production and clot retraction.Next, we investigated whether GTE can regulate signaling molecules and we found that GTE elevated the phosphorylation of 1, 4, 5-triphosphate receptor type I (InsP 3 R) and vasodilator-stimulated phosphoprotein and decreased the phosphorylation of extracellular signal-regulated kinase, myristoylated alanine-rich C kinase substrate, cytosolic phospholipase A 2 , mitogen-activated protein kinases p38, phosphatidylinositol-3 kinase, Akt, glycogen synthase kinase-3/, SYK, and phospholipase C 2 .Therefore, GTE is a potential therapeutic drug candidate to prevent platelet-related cardiovascular disease.