Abstract: ObjectiveTo explore the effect of anthocyanin cyanidin-3-glucoside(Cy-3g)on human platelet activation,aggregation and its mechanism.MethodsThe expression of activiated GPIIbIIIa and P-selectin on platelet surface were examined with flow cytometry in vitro.Platelet aggregation induced by adenosine diphosphate(ADP)was measured with platelet aggregometer;calcium level in the platelet cytoplasma was analyzed with Fluo-3 AM staining.ResultsThe expression of activated GPIIbIIIa was significantly decreased by 50μmol/L Cy-3g(73.92% ±14.02%)compared with the control buffer(93.36% ±2.02%,P<0.05).The expression of P-selectin on platelet surface was not significantly different among the groups.Platelet aggregation of human platelet rich plasma(PRP)induced by ADP can be inhibited by Cy-3g at different doses(0.5μmol/L,5μmol/L,and 50μmol/L),which were all significantly lower than that of the control(P<0.001).The fluorescence intensity of calcium was decreased by 50μmol/L Cy-3g(51.73±6.89%)in washed platelets(P<0.01).ConclusionCy-3g could inhibit the expression of platelet GPIIbIIIa and aggregation induced by ADP in vitro.The decreased platelet cytoplasmic calcium may be one of the mechanism.The results suggest that Cy-3g may have a positive role in the prevention of cardiovascular diseases.