The Carica papaya plant has been shown to be useful in a wide range of therapeutic use from anthelmintic effect of its latex to the aphrodisiac property of its root. Carica papaya leaves (CPL) is a popular remedy to treat dengue-induced thrombocytopaenia. This study was designed to explore the preliminary phytochemical analysis of CPL aqueous and methanol extracts. In this study flavonoids and phenolics were characterized by LC - TOF- MS, in which 19 compounds were detected in aqueous extract and 24 compounds were detected in methanol extract. This knowledge may help us devise better formulations to develop CPL into useful therapeutic agents for the management of thrombocytopaenia related disorders.

Previous studies have shown platelets play an important role in prothrombotic complications due to several factors such as hyperglycemia, oxidative stress, and hypercholesterolemia, which affected platelets reactivity. Platelets activation involves ADP stimulation via P2Y12 receptor, whereas reactive oxygen species (ROS) including superoxide anion and hydrogen peroxide (H2O2) produced by NADPH oxidase (Nox) act as the second messenger, which involved in platelets activation and may contribute to thrombus formation. The aim of the present study was to investigate the influence of Nox on the purinergic receptor (P2Y12 receptor) in activation of human platelets function stimulated by platelets agonist. This research explored the effects of Nox inhibitors and clopidogrel either alone or in combination, on various agonist-stimulated human platelets, including platelets aggregation and adhesion measured by modified LTA, expression of platelets activation markers, and calcium mobilization using flow cytometry, and ROS formation, NADPH oxidase activity, as well as cAMP levels by chemiluminescence assay. Taken together, findings from these experiments suggest that the combination of clopidogrel and Nox inhibitors synergistically reduced platelets aggregation, platelets adhesion, and expression of platelets activation marker during late activation, ROS formation, NADPH oxidase activity, calcium mobilization and increased cAMP levels in vitro. This combination showed that P2Y12receptor reactivity was influenced by the activation of NADPH oxidase. Thus, these data demonstrated a potential combination therapy to reduce the risk of thrombosis formation.