OBJECTIVETo compare the toxicity of Euphorbia pekinensis before and after being processed by vinegar on normal liver cells LO2, and discuss its possible mechanism.

METHODLO2 cells were cultured in vitro, and processed with different concentrations of crude and vinegar-processed E. pekinensis. MTT assay was used to measure the inhibitory effect of LO2 cell; Hoechst 33258 staining was used to observe the morphological changes in apoptosis cell; Annexin V-FITC flow cytometry was used to analyze the apoptotic rate of LO2 cell; PI staining flow cytometry was used to analyze its impact on cell cycle. The level or content of ALT, AST, LDH, SOD, MDA and GSH were observed as well.

RESULTCompared with the negative control group, crude E. pekinensis at all concentrations could obviously inhibit LO2 cell proliferation, induce LO2 cell apoptosis and cause cell arrest in S phase, with significant differences (P <0.05). E. pekinensis could significantly increase the levels of ALT, AST and LDH (P <0.05) in the supernatant of cell culture fluid, significantly decrease the level of SOD and the content of GSH (P <0.05) , and significantly increase the content of MDA (P <0.05). Compared with the crude E. pekinensis group, E. pekinensis after being vinegar-processed can significantly reduce cell apoptotic rate, cell cycle arrest, activities of ALT, AST, LDH in the supernatant of cell culture fluid (P <0.05) , and remarkably increase the level of SOD and the content of GSH, but reduce the content of MDA in the supernatant of cell culture fluid.

CONCLUSIONVinegar-processed E. pekinensis can release the cytotoxicity of LO2 cell. Its mechanism may be related to the decrease in the oxidative damage of LO2 cells, thereby reducing the cell cycle arrest and apoptosis.