Effect of melatonin on selected parameters of platelet activation, clot formation and overall potential of fibrinolysis

Abstract

Introduction: Melatonin produced in the pineal gland plays a key role in regulating sleep and wake hours. Synthetic melatonin is used as an adjunct to treat sleep disorders, regulate the sleep-wake rhythm and prevent ailments related to changing time zones or shift work. Its other applications are more widely described, including antioxidant and immunomodulatory properties – therefore melatonin supplementation may be beneficial in alleviating symptoms associated with the occurrence of COVID-19. However, reports on the influence of exogenous melatonin on the platelet, plasma and vascular hemostasis are ambiguous. Aim: The aim of the study was to evaluate the in vitro influence of melatonin on spontaneous and ADP-induced adhesion of platelets to fibrinogen, kinetic parameters of ADP-induced aggregation and selected elements of plasma haemostasis: general potential for clot formation and fibrinolysis, as well as kinetic parameters of the clot formation process, its stabilization and fibrinolysis. Material and methods: The study were performed with the use of the previously described research model, which includes the method of assessing platelet adhesion, a multi-parameter test for assessing platelets aggregation and a test that enables kinetic assessment of the clot formation process, the period of fibrin stabilization and its lysis. Results: Our preliminary studies indicated that melatonin at concentrations: 0.2-10 nmol/L does not show a significant and direct impact on the assessed kinetic parameters of the studied processes, important for platelet and plasma hemostasis. Conclusions: The pleiotropic effects of melatonin are increasingly applied, especially its antioxidant and immunomodulating properties, therefore further and in-depth in vitro as well as in vivo hemostasis studies followed by clinical observations of patients using melatonin are needed.