Abstract: AIM: To investigate the effects of cornel iridoid glycoside (CIG) on platelet aggregation and bleeding time.METHODS: Born's turbidimetry was used to measure platelet aggregation rate in rabbits (in vitro) and blood stasis model rats (in vivo). The tail-cutting method was applied to determine the bleeding time in rats. The blood stasis rat model was established by adrenalin and ice water stimulus method.RESULTS: In vitro study showed that CIG (0.75～3 mg/mL)significantly inhibited platelet aggregation induced by ADP or AA (P<0.05, P<0.01), and CIG (6～12 mg/mL)obviously inhibited platelet aggregation induced by PAF (P<0.01) in rabbits. In vivo study demonstrated that intragastric administration of CIG (180 mg/kg) markedly inhibited platelet aggregation induced by ADP in blood stasis model rats (P<0.01), and prolonged the bleeding time in normal rats (P<0.05).CONCLUSION: CIG has the effect of anti-platelet aggregation, and its high dose can prolong the bleeding time.

Key words: Cornel iridoid glycoside, Platelet aggregation, Bleeding time