Target identification is an important prerequisite for the study of medicine action mechanism. Currently,drug target identification is mostly based on various cell models in vitro. However,the growth microenvironment,nutrition metabolism,biological properties as well as functions are quite different between in vitro cell culture and physiological environment in vivo; wherefore,it is a challenging scientific issue to establish an effective method for identifying drug targets in vivo condition. In this study,we successfully prepared a kind of magnetic nanoparticles( MNPs) which can be chemically modified by the hydroxyl structure of natural bioactive compound echinacoside( ECH) via the epoxy group label on the surface of MNPs. Therefore,organ-selective and recoverable nanoscale target-recognizing particles were prepared. We then intravenously injected the ECH-binding MNPs into rats and distributed them to specific organs in vivo. After cell endocytosis,ECH-binding MNPs captured target proteins in situ for further analysis. Based on this method,we discovered several potential target proteins in the spleen lysates for ECH,and preliminarily clarified the immuno-regulation mechanism of ECH. Collectively,our strategy developed a proof-of-concept technology using nanoparticles for in vivo target identification,and also provided a feasible approach for drug target prediction and pharmacological mechanism exploration.
Keywords: active ingredients of traditional Chinese medicine; echinacoside(ECH); in vivo; magnetic nanoparticles(MNPs); target identification.