Study On Antithrombosis Of Osthole And Its Mechanisms

Objective: To study on antithrombosis of osthole and its mechanisms. Methods: Rat model of artery-vein bypass thrombosis was used to measure the thrombus weight, the levels of NO in serum, TXB2 and 6-keto-PGF1αin plasma. Mouse model of thrombosis by injecting collagen-adrenaline to the tail vein was applied to observe numbers of dead mice in 5 minutes and recovery mice from hemiplegia in 15 minutes. Rat model of venous thrombosis was made to measure the thrombus weight. The rate of human platelet aggregation induced by ADP, thrombin and arachidonic acid was measured by turbidimetry. The free calcium concentration in platelets was measured with fluo-3/AM flow cytometric assay. The expression of IP3R-3 on human platelet membrane was observed using laser scanning confocal microscope. Results: After treated with osthole 10-40 mg/kg, artery-vein bypass thrombus weight, plasma TXB2 level and the ratio of TXB2 /6-keto-PGF1αwere reduced, while serum NO level was increased (P<0.05, P0.01). In mouse model of thrombosis, the death rate in 5 minutes was reduced, the recovery rate in 15 minutes was increased in osthole-treated mice (P<0.01). Rats venous thrombosis in osthole groups was inhibited and thrombus weight was decreased (P<0.01). Human platelet aggregation induced by ADP, thrombin and arachidonic acid in vitro was inhibited by osthole, the IC50 value was 0.444 mg/ml, 0.186 mg/ml and 0.421 mg/ml, respectively. After human platelets were incubated with osthole, the intracellular concentration of free calcium induced by thrombin was reduced (P<0.05) and the expression of IP3R-3 on human platelets was inhibited in dose dependent manner (P<0.01). Conclusion: Osthole had the effect of antithrombosis, and its mechanisms might be associated with inhibition on the activation of platelets, including increase of NO level, reduction of TXB2 level and TXB2/6-keto-PGFlαratio, inhibition on the increase of free intracellular calcium level and the expression of IP3R-3 on human platelets.