Objective: To investigate the protective effect and mechanism of magnesium isoglycyrrhizinate(MgIG) on liver injury induced by paclitaxel. Method: Normal human hepatocytes LO2 were used as the research object and were divided into blank group and MgIG groups (2.5

5

10

20 mg·L-1). Methylthiazoletetrazolium(MTT) assay was used to detect the effect of different concentrations of paclitaxel on injuries of LO2 cells and effect of MgIG on LO2 cell viability. Then the effect of MgIG on LO2 cell injuries induced by paclitaxel was detected

with aspartate aminotransferase(AST)

alanine aminotransferase(ALT) and other indexes to detect the degree of LO2 injuries by enzyme-linked immuno sorbent assay(ELISA). The effect of MgIG on cell cycle and apoptosis of LO2 cells was detected by flow cytometer. Western blot was used to detect the protein expression of apoptosis related protein. Result: As compared with blank group

1 mg·L-1 paclitaxel had obvious inhibitory effect on the proliferation of LO2 cells(P<0.01); 5

10

20 mg·L-1 MgIG had certain effect on promoting the proliferation of LO2 cells(P<0.05

P<0.01)

but had no significant effect on the cell morphology; 5

10

20 mg·L-1 MgIG can reduce the damage of paclitaxel on LO2 cells(P<0.05

P<0.01);5

10

20 mg·L-1 MgIG can reduce apoptosis related protein and G2/M arrest in LO2 cells induced by paclitaxel(P<0.05

P<0.01). Conclusion: MgIG can effectively reverse the LO2 damage induced by paclitaxel in vitro

and the mechanism may be related to the intervention on cell cycle and the depression on paclitaxel-induced apoptosis of liver cells.