N,N'-disubstituted Ureas as Novel Antiplatelet Agents: Synthesis, Pharmacological Evaluation and In Silico Studies

Introduction: Thrombotic disorders are among the leading causes of morbidity and mortality worldwide. Drugs used in the prevention and treatment of atherothrombosis have pharmacokinetic limitations and adverse effects such as hemorrhagic conditions, highlighting the importance of developing more effective antiplatelet agents. Methods: In this work, we synthesized N,N'-disubstituted ureas 3a-3j and evaluated their antiplatelet profiles through in vitro, ex vivo, and in silico studies. Results: The synthesized derivatives exhibited a selective inhibitory profile against platelet aggregation induced by arachidonic acid (AA) in vitro, without significantly affecting other aspects of primary hemostasis and blood coagulation. The compounds that showed inhibition greater than 85% were submitted to the analysis of their potency by calculating the concentration required to inhibit 50% of platelet aggregation induced by AA (IC50). Urea derivative 3a was the most potent with IC50 of 1.45 mu M. Interestingly, this derivative inhibited more than 90% of platelet aggregation induced by AA ex vivo, with a similar effect to acetylsalicylic acid. In the hemolysis assay, most of the urea derivatives presented values below 10% suggesting good hemocompatibility. Additionally, the compounds tested at 100 mu M also showed no cytotoxic effects in HepG2 and Vero cells. The in silico results suggested that compound 3a may bind to the key residue of COX-1 similar to AA and known COX-1 inhibitors, and the results are also in agreement with our SAR, which suggests that the inhibition: of this enzyme is the most likely mechanism of antiplatelet activity. Conclusion Therefore, these results demonstrated that N,N'-disubstituted ureas are promising candidates for the development of novel antiplatelet agents.