RESUMO
Aim To compare the cytotoxicity of geni-poside (GS)and its metabolite genipin (GP)on hu-man hepatocelluar HepG2 cells and explore the sub-stance and mechanism of hepatotoxicity induced by Fructus Gardeniae.Methods The cytotoxic effect of GS and GP was analyzed by MTT method;the antioxi-dant enzyme activities of manganese superoxide dis-mutase (Mn-SOD),catalase (CAT)and levels of glu-tathione (GSH)were detected by respective kits;the change of intracellular reactive oxygen species (ROS ) was measured by 2′,7′-dichlorofluorescin diacetate (DCFH-DA)staining method;multiparameter cytotox-icity analysis (cell loss,nuclear size and morphologi-cal changes,DNA content,cell membrane permeabili-ty,mitochondrial membrane potential changes,cyto-chrome C release ) were measured simultaneously by high content screening (HCS)assays.Results No cytotoxicity was found in GS (20~1 000 μmol·L-1 ) groups (P>0.05 ),but GP was found to exert obvi-ous cytotoxic effect,and 50μmol·L-1 GP could obvi-ously inhibit HepG2 cell proliferation (P0. 0 5 ),GP could significantly decrease the activity of Mn-SOD,CAT and the level of GSH,and obviously increase the content of ROS (P0.05 ). Conclusion GP is the direct substance of hepatotox-icity induced by Fructus Gardeniae,and the mecha-nism might be associated with oxidative stress,mito-chondria injury and apoptosis.