Target Screening Of Paeoniflorin And Synephrine By Three G Protein-coupled Receptors And Its Mechanism

Sini San is a classic C hinese compound medicine,which is composed of Bupleurum,Peony,C itrus aurantium and Licorice.Its pharmacological effects include hypnosis,anti-depression,enhancement of gastrointestinal motility,anti-ulcer,liver protection,etc.Compound medicine is a remarkable feature of Chinese medicine in treating diseases,and the various chemical components contained in the compound are the material basis of its efficacy.It’s believed in theory of traditional C hinese medicine serum medicinal chemistry that after metabolization by the gastrointestinal tract,the number of chemical components in compound medicine are drastically reduced,making it easier to determine the active substance of the traditional C hinese compound medicine,thereby recognizing the target of the drug.Previous studies have proved that synephrine,paeoniflorin,glycyrrhizic acid,neohesperidin,naringin,hesperidin,saikosaponin,paeoniflorin,glycyrrhizin,etc.are the main active ingredients of Sini San in the serum.G protein-coupled receptors(G Protein-Coupled Receptor,GPC R)are a large family of transmembrane receptors involved in regulating a variety of important life events,.they are very important drug targets.At present,GPCR are highly related to depression especially the melatonin receptors,serotonin receptors and dopamine receptors.The antidepressant drugs used clinically,target monoamine receptors.In general,these drugs have certain side effects due to insufficient specificity.Based on the experience of serum medicinal chemistry of traditional C hinese medicine,this thesis screened and verified the molecular targets of Sini San,two metabolic components related to the central nervous system,paeoniflorin and synephrine.To clarify the pharmacological mechanism of the monomer active ingredients in Sini San.So as to provide a certain theoretical basis for screening out the monomer active ingredients of Sini San that may have antidepressant effects.The present study chose two compounds(aeoniflorin and synephrine)of Sini San,which are dissolved in blood.First of all,a conventional laboratory depression associated with overexpression vectors to establish stable cell lines,in order to construct a cannabinoid receptor build a drug screening platform with preset targets,and then use four G protein couplings related to depression(melatonin receptor MT1,melatonin receptor MT2,serotonin receptor 5HT1 B and dopamine receptor D2)Target screening was performed on the two blood components of Paeoniflorin and Synephrine in Sini San.Then use the "drug-receptor thermal stability shift" experiment(CESTA)to verify the binding of the active monomer to the target receptor,and finally use the specific antagonist and active monomer o f the melatonin receptor MT1/2 The above cell lines were processed together to further validate the results of the study.Our results suggested that the main blood components(paeoniflorin,synephrine)in Sini San have a higher affinity to melatonin receptor MT1.We have proved that synephrine can significantly increase phosphorylation level of ERK in over-expressed MT1 cells.Results from C ESTA further showed that: synephrine can significantly improve the stability of MT1 receptors in high temperature environments.The above results suggested that synephrine is a specific ligand for MT1 and can activate MT1 receptors.The downstream ERK pathway is mediated in a dose-dependent manner,indicating that synephrine may specifically bind to the melatonin receptor MT1 to activate the downstream ERK pathway to exert its antidepressant function.