Antiplatelet effect of demethyldiisoeugenol

A semisynthetic chemical compound, demethyldiisoeugenol, concentration dependently inhibited platelet aggregation and ATP release stimulated by thrombin (0.1 U/mL), platelet-activating factor (2 ng/mL), arachidonic acid (100 μM), collagen (10 μg/mL), and U46619 (1 μM) in rabbit washed platelets. The IC₅₀ values of demethyldiisoeugenol on the inhibition of platelet aggregation induced by these five agonists were 157.3 ± 22.3, 156.2 ± 12.9, 53.6 ± 4.7, 54.5 ± 3.9, and 87.7 ± 3.2 μM, respectively. Demethyldiisoeugenol also inhibited thromboxane B₂ formation induced by thrombin, platelet-activating factor, arachidonic acid, and collagen, and prostaglandin D₂ formation was induced by arachidonic acid. The rising intracellular Ca²⁺ concentration stimulated by these five platelet aggregation inducers was inhibited by demethyldiisoeugenol, while formation of inositol monophosphate was unaffected. Platelet cAMP and cGMP levels were unchanged by demethyldiisoeugenol. It is concluded that demethyldiisoeugenol may directly inhibit both intracellular calcium mobilization and cyclooxygenase activity in platelets.