Study On The Superior Effect Mechanism Of Bushen Qingli Recipe Combined With Ursodeoxycholic Acid Mediated By Placental Transporter

Intrahepatic cholestasis of pregnancy(ICP),as a specific complication with quite high incidence in the second or third trimester of pregnancy,which will directly affect the health of the pregnant women and fetuses.Ursodeoxycholic acid is a first-line drug approved by the FDA for the treatment of ICP and is easy to cause drug resistance.UDCA is often used in combination with Chinese herbs with the effects of soothing liver,removing jaundice,tonifying kidney and miscarriage prevention in the clinical practice of traditional Chinese medicine to improve side effects.This study aims to explore the superior mechanism by combiting Bushen Qingle Recipe with UDCA from the perspective of placental transporter.This study firstly established the model of pregnant rat to reveal effects on the pharmacokinetic parameters of UDCA on the maternal side and fetal side,when UDCA combined with Bushen Qingli Recipe or its main active ingredients(Scoparone and Baicalin),the results indicated that AUC0-∞和Cmax are improved to different degrees,and both can promote the absorption and transport of UDCA.The test established BeWo cell model to study the effects of BuShenQingLi Recipe and its main active components on UDCA uptake and transport.The results indicated that this recipe can improve bidrection transcellular transport of UDCA,and the transport rate in the maternal-fetal direction(AP-BL)is higher than the opposite direction,which leaded to the increasing accumulation of UDCA in the basolateral side to exerting the efficacy.The main active components was approved that only Scoparone and Baicalin can significantly affect the uptake of UDCA by BeWo cells.This study explored the Scoparone and Baicalin uptake and transport characteristics across placental barrier by Bewo cell model.The results displayed that Scoparone transports across placental barrier was in a passive diffusion manner without the involvement of transporters,while Baicalin transport via both facilitated passive mechanism with low permeability and active transport mediated by influx transporters covering OATP1A2(Apical),OATP2B1(Basolateral),MCTs and CNTs and efflux transporters such as BCRP and MRP2.The MDCK-hMDR1 and MDCK-hBCRP overexpression transporter cell models were used to identify its interactive relationship between the main active ingredients,Scoparone and Baicalin,and different efflux transporters P-gp,BCRP and MRP2.The interaction research of the two components with the classical fluorescent probe substrates of the three efflux transporters illustrated Scoparone is non-subatrate of this three efflux transporters,but a kind of non-competitive inhibitor of BCRP.Baicalin is a substrate of BCRP and MRP2,repectively.And it also inhibited P-gp-mediated efflux with type of non-competitive type inhibition and BCRP transporter with the mixed type of competitive and non-competitive type inhibition.According to the data above,the computer molecular docking model was used to study the docking mode between baicalin and different transporters,which showed that the affinity of Baicalin with BCRP was lower than that of P-gp,which had the docking advantage of chemical structure,and its inhibition effect on BCRP was stronger than that of P-gp.Based on the results above,the molecular mechanism of Bushen Qingli Recipe combined with UDCA was researched by BeWo cells and MDCK-hBCRP cell model.The results of uptake and transport experiments indicated that Scoparone and Baicalin all can promote UDCA transport.The results obtained from different cell models was consistent,illustrating that both can affect UDCA transmembrane transport by regulating BCRP transporters.RT-PCR trial was used to examine the changes of the expression levels of various transporter genes in the placenta before and after drug combination,which showed that UDCA alone can increase the expression of multiple transporter mRNAs on the barrier,while there was no significant change when taken Scoparone and Baicalin alone or with UDCA,implying that possible interaction mainly depends on the function changes of the transporter.When combined with BuShenQingLi Recipe,the effect UDCA promoting gene expression would be strengthened,which may be a superposition reaction contributed to changes from carrier functions and expressions.In summary,this topic by animal models in vivo,different cell models in vitro and other experimental methods,jointly clarified the promoting mechanism of Bushen Qingli Recipe and the main active components Scoparone and Baicalin on the bidirectional transport of UDCA on the placental barrier,which mainly affects various transporters such as OATPs and BCRP related to UDCA transport to influent the UDCA transport process,revealing the superior mechanism of the combination of Bushen Qingli and its main active ingredients with UDCA based on the perspective of placental drug transporters.