Study On Activity And Mechanism Of Total Saponins Of Platycodonis Radix Against Drug-Induced Liver Injury Induced By APAP

Drug-induced liver injury(DILI)is the liver injury caused by drugs and/or their metabolites.It is reported that 10% of acute hepatitis,more than 50% of acute liver failure and drug withdrawal were related to DILI.In recent years,the incidence rate of DILI in China is higher than that of in the western developed countries,which seriously threated people’s health.Acetaminophen(APAP)is a commonly used as antipyretic and analgesic in clinic.It is safe in the treatment dose.But when overdose administrated,it will lead to liver injury,even acute liver failure.N-acetyl cysteine(NAC),the only FDA-approved antidote,has partical efficacy.However,the treatment window is narrow and the side effects are large.Therefore,it is urgently needed to research and develop new drugs to prevent and treat DILI.Platycodonis Radix is derived from the dried root of Platycodon grandiflorum(Jacq.)A.DC.Its main active component is platycodins,which has antioxidant,anti-inflammatory,anti liver injury,anti-tumor,anti-virus and other pharmacological effects.Traditional Chinese medicine generally oral administrated,so the ingredients of Platycodonis Radix entering the intestinal tract can be transformed by the intestinal flora,and then enter the blood circulation.Hence,the microbiota biotransfrorm play a key role on the activities and mechanisms of those compounds.Polysaccharides can regulate the composition of intestinal flora to change the pharmaceutical kinetics of saponins,and then affect its activity.Network pharmacology is a network technology analysis method to study the interaction between drugs and diseases,which is consistent with the holistic view of traditional Chinese medicine in the treatment of diseases.It can reveal the mechanism of platycodin in the treatment of DILI based on multi-component,multi-target and multi-channel ways.Molecular docking technology is an effective method to study the binding mechanism between natural products and target proteins,which is often used to screen effective substances.Based on the above works,the potential targets and signaling pathways of total saponins of Platycodonis Radix in the treatment of DILI were analyzed by network pharmacology method,and then the mechanism of total saponins of Platycodonis Radix against APAP induced liver injury in mice was confirmed by experiments,and the effects of Platycodonis Radix polysaccharides on the efficacy and mechanism of total saponins of Platycodonis Radix against DILI were also discussed.Finally,the binding mechanism of platycodin D2,platycodin D3,platycodin D,Deapio-platycodin D3,Deapio-platycodin D,3-O-beta-D-Glucopyranosylplatycodigenin,platycogenin and CYP2E1,TLR4,NF-κB p65,Nrf2,p38 proteins was studied by molecular docking technology.The main results are as follows:1.289 action targets of platycodin and 940 DILI related targets were obtained by network pharmacology analysis.The network diagram of component disease common target and interaction network of common target protein were depicted by Cytoscape software,and 57 common targets of platycodin and DILI were obtained by intersection.GO process and KEGG pathway enrichment analysis of common targets showed that platycodin could play a therapeutic role in DILI through toll like receptor,MAPK,NOD like receptor,JAK-STAT,T cell receptor,and other signaling pathway,PPAR signaling pathway and other signaling pathways.2.Acute DILI model of mice was established using APAP.The levels of ALT,AST,TNF-α,IL-1 β in serum and MDA,SOD,GSH Px,GSH in liver tissue were measured.The pathological changes of liver tissue were observed by hematoxylin eosin(H & E)staining.The levels of CYP2E1,TLR4,NF-κB p65,Nrf2,HO-1,MAPK p38,p-p38 in liver tissue were detected by Western blot to evaluate the protective effect of Platycodon grandiflorum saponins on hepatocyte injury in mice.The results showed that compared with the model group,the total saponins of Platycodonis Radix group could significantly reduce the levels of ALT,AST,TNF-αand IL-1 β in serum,decrease the levels of MDA in liver tissue,increase the levels of SOD,GSH PX and GSH in liver tissue,improve the pathological morphology of liver tissue induced by APAP,and significantly down regulate CYP2E1,TLR4,NF-κB p65 and p-p38.Nrf2 and HO-1 increased,which had a good control effect on DILI.Platycodonis Radix polysaccharides could improve the activity of total saponins to a certain extent.3.From RCSB PDB protein data bank,the crystal structures of TLR4,NF-κB p65,Nrf2,CYP2E1 and p38 were downloaded from PDB(https://pubchem.ncbi.nlm.nih.gov/)The molecular structures of platycodin D2,platycodin D3,platycodin D,Deapio-platycodin D3,Deapio-platycodin D,3-O-beta-D-Glucopyranosylplatycodigenin,platycogenin,were downloaded from the database The modular docking of the target protein with the compound.The docking results showed that these compounds and protein receptors were bound by van der Waals,hydrogen bond,Alkyl,Pi Alkyl and other ways.The scoring and binding mechanism of compounds and protein were related to the structure of compounds,and there was a structure-activity relationship,among which hydrogen bond had the greatest impact on the scoring of compound binding.