Quercitrin exhibits important effect on P-selectin exposure and αIIbβ3 integrin activation following agonist stimulation
Next, we investigated the effects of quercitrin on P-selectin exposure and αIIbβ3 integrin activation, which are key processes driving the positive feedback cycle of platelet activation. Because quercitrin prevented platelet aggregation and ADP secretion induced by CRP and U46619 stimulation, we examined P-selectin exposure and αIIbβ3 integrin activation using CRP (0.1 µg/ml) or U46619 (3 µM). Following 10 minutes of pre-incubation, quercitrin significantly inhibited CRP- or U46619-induced P-selectin exposure (Figure 2A and 2C) and αIIbβ3 integrin activation (Figure 2B and 2D) in a concentration-dependent manner (10, 20, and 30 µM), whereas quercitrin failed to block the effects of thrombin stimulation (Figure S3). These results suggest that quercitrin selectively inhibits platelet activation through effects on granule secretion and αIIbβ3 integrin activation.