Antiplatelet effects of Angelica dahurica extracts in rat platelets

Abstract

The In vitro antiplatelet aggregation activity was performed by using platelet aggregometer.

Platelet-rich plasma (PRP) and platelet-poor plasma (PPP) were prepared from rat blood adding anti-coagulated with 3.8% sodium citrated (9:1, v/v). PRP was incubated with 0.5% dimethyl sulfoxide (DMSO) or aspirin at the concentration of 0.5 and 1 mM (positive control) or ADE at the concentration of 0.1, 0.25, 0.5 and 1 mg/ml at 37 ^oC for 3 minutes. Then the aggregation-inducing agent, adenosine diphosphate (ADP) was added. Aggregation was measured using a platelet aggregometer. The percentage of inhibition of platelet aggregation was calculated.

The inhibitory effect of ADE against cyclooxygenase was performed using COX-fluorescent inhibitor screening assay kit. ADE was incubated directly with either COX-1 or COX-2 enzyme in assay buffer for 5 min. Then, arachidonic acid (AA) was added as substrate and ADHP (10-acetyl-3,7-dihydroxyphenoxazine)  for 2 min. The reaction between prostaglandin G₂ (PGG₂) and ADHP produces the highly fluorescent compound resorufin. Resorufin fluorescence can be analyzed with an excitation wavelength of 530-540 nm and an emission wavelength of 585-595 nm. The effect of ADE on COX activity was evaluated by Inhibition rate.