ABSTRACT
Aim To investigate the toxicity of isopsor-alen in HepG2 cells and its effects on bile acid, bile acid synthesis and transport. Methods Cell viability was evaluated by MTT assay and bile acid was deter-mined inside HepG2 cells, with exposure to various isopsoralen for 24h. The mRNA transcription of BSEP, MRP2, MRP3, NTCP, OATP2, OSTα, CYP7A1, CYP27 A1 , FXR and PXR were assessed by real-time PCR. Results The cell viability was decreased dose-dependently with isopsoralen in HepG2 cells, and IC50 was 118. 1μmol·L-1 exposure to isopsoralen for 24h. Bile acid inside cells significantly increased with 100 and 400 μmol · L-1 isopsoralen. Isopsoralen caused the down-regulation of MRP2 , MRP3 , CYP7 A1 mRNA at 25 μmol · L-1 . Beside these, the up-regulation of OATP2,OSTα,CYP27A1,FXR,PXR with 100 μmol· L-1 isopsoralen, but there was no significant change of BSEP and NTCP. Conclusion The results show that isopsoralen induces bile acid accumulation and cytotox-icity which may be associated with the down-regulation of MRP2, MRP3 in HepG2 cells.