Abstract: AIM: To investigate the changes of bile acid metabolism in healthy adults after taking acetaminophen.  METHODS: Ten healthy subjects were enrolled and the serum samples of subjects before and after multiple administration of acetaminophen were collected. They were divided into pre-dose group (PD), fifth-dose gro-up (FD) and eighth-dose group (ED). A high performance liquid chromatography-tandem mass spectrometric method (HPLC-MS/MS) was used to quantify 15 target-edbile acid metabolites in human plasma, combined with principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA)to investigate the changes of bile acid metabolism profile in healthy adults after taking acetaminophen. And the biochemical indicators of each group were detected. RESULTS: There was a change in the bile acid spectrum of human serum after taking acetaminophen. Compared with group PD, the taurochenodeoxycholicacid (TCDCA), glycocholicacid (GCA), glycochenodeoxycholic acid (GCDCA) and tauroursodeoxycholic acid (TUDCA) levels were significantly increased (P<0.05). There was no obvious changes in biochemical indicators. GCA and GCDCA were the most sen-sitive indicators of bile acid. CONCLUSION: GCA and GCDCA can be used as potential biomarkers of early liver injury caused by acetaminophen.

Key words: acetaminophen, bile acid, metabolomics, LC-MS