摘要Xiaohuang Qudan decoction(XHQDD)is a classical traditional Chinese medicine(TCM)for-mula widely used in the treatment of cholestatic liver injury.Despite its widespread use,the protective mechanism of XHQDD against cholestatic liver injury remains incompletely under-stood.The aim of this study was to investigate whether XHQDD mediates its beneficial effects by inhibiting the Janus kinase 2(JAK2)/signal transducer and activator of transcription 3(STAT3)pathway and regulating TH17/Treg balance.To this end,the researchers used Sprague-Dawley(SD)rats and established a cholestatic liver injury model by oral administra-tion of alpha-naphthylisothiocyanate(ANIT).The experimental group was divided into six groups:Control(CON),ANIT,ursodeoxycholic acid(UDCA),XHQDD-low dose(XHQDD-L)group,XHQDD-medium dose(XHQDD-M)group,and XHQDD-high dose(XHQDD-H)groups.Then,after 7 d of treatment,various tests were performed to verify the results.Firstly,XHQDD and its drug-containing serum were analyzed by ultra-high performance liquid chro-matography-mass spectrometry/mass spectrometry(UPLC-MS/MS),and 14 blood-entry components were identified.Then,bile flow was monitored and found to be significantly re-duced in the model group,which was significantly reversed in the UDCA and XHQDD groups.To further assess ANIT-induced liver injury,hematoxylin and eosin(H&E)and Sirius red staining,alongside transmission electron microscopy(TEM),were employed to observe liver tissues,revealing hepatocellular injury,cholestasis,and hepatic fibrotic changes.Serum in-flammatory factors and liver injury indicators were assessed using enzyme-linked immun-osorbent assay(ELISA),indicating an inflammatory state in ANIT-induced liver injury rats.The expression levels of JAK2/STAT3-related genes and proteins in liver and intestinal tis-sues were measured via quantitative reverse transcription polymerase chain reaction(qRT-PCR),immunohistochemistry,immunofluorescence(IF)staining,and Western blottting(WB)assays.These studies revealed that the inflammatory state of liver-injured rats was inextric-ably linked to the inflammatory cascade associated with the JAK2/STAT3 pathway and that XHQDD may exert anti-inflammatory efficacy by inhibiting the JAK2/STAT3 pathway.Flow cytometry was used to determine the percentage of T helper 17(Th17)/regulatory T(Treg)cells in serum and hepatocytes,and it was further found that XHQDD was able to regulate Th17/Treg immune homeostasis in liver-injured rats.The findings suggest that XHQDD markedly alleviates inflammation in ANIT rats,potentially treating cholestasis and liver in-jury through JAK2/STAT3 inhibition and Th17/Treg balance regulation.