Animal experiment:

Platelet aggregation is investigated in the assay. Washed platelets (200 μL of a suspension containing 3 × 108 cells/mL in Tyrode HEPES buffer, pH 7.4) are incubated for 3 min at 37℃ in the presence or absence of different concentrations of OPC-33540, OPC-33536, and Cilostamide alone, or in combination with 3 nM PGE1, followed by incubation with 5 μL of 2 units/mL of thrombin for 5 min at 37℃. The intensity of light transmitted over 5 min is measured using a PAM-8C aggregometer. The inhibition rate is calculated by comparison of maximum aggregation rates with the control value[1].

Cilostamide is a selective and potent PDE3 inhibitor, with IC50s of 27 nM and 50 nM for PDE3A and PDE3B, respectively, and has antithrombotic and anti-intimal hyperplastic activity.

Cilostamide is a selective and potent PDE3 inhibitor, with IC50s of 27 nM and 50 nM for PDE3A and PDE3B, respectively, and has antithrombotic and anti-intimal hyperplastic activity. Cilostamide weakly inhibits PDE2, PDE4, PDE5, PDE7, and PDE1, with IC50s of 12.5, 88.8, 15.2, 22.0 and >300 μM, respectively. Cilostamide potently inhibits thrombin-induced platelet aggregation (IC50, 1.1 μM)[1].

References:
[1]. Sudo T, et al. Potent effects of novel anti-platelet aggregatory cilostamide analogues on recombinant cyclic nucleotide phosphodiesterase isozyme activity. Biochem Pharmacol. 2000 Feb 15;59(4):347-56.