IS has a strong ability to increase platelet activity both in vitro and in vivo. (A-C) The whole blood was pretreated with indicated concentrations of IS for 15 minutes and then stimulated with 2 μg/mL collagen. (A-B) Flow cytometric analysis of the expression of P-selectin and activated GPIIb/IIIa in platelets in response to 2 μg/mL collagen (n = 6). (C) Flow cytometric analysis of the percentage of platelet-monocyte aggregates in vitro (n = 6). (D) Representative images of thrombus formation on a collagen-coated flow chamber under shear-flow conditions using whole blood pretreated with different concentrations of IS (i). Scale bar, 50 μm. Quantification of the area of platelet adhesion for each group (n = 6) (ii). (A-D) Data are mean ± SD. *P < .05, **P < .01 vs control group; ^#P < .05, ^##P < .01 vs collagen group, ANOVA. (E-I) Mice were IP injected with IS (100 mg/kg per day) for 8 weeks. (E) Serum IS levels were measured by high-pressure liquid chromatography (n = 8). (F) Flow cytometric analysis of P-selectin expression in platelets in response to 2 μg/mL collagen or 0.05 U/mL thrombin (n = 6). (G) Flow cytometric analysis of the concentration of PMPs in whole blood (n = 6). (H) Flow cytometric analysis of platelet-monocyte aggregates formation in whole blood in vivo (i). The histogram shows the percentage of platelet-monocyte aggregates in whole blood (n = 6) (ii). (I) The time for carotid artery occlusion by thrombus in a FeCl₃-induced thrombosis model (n = 6). (E-I) Data are mean ± SD. *P < .05, **P < .01 vs vehicle group, Student t test.