Objective        To synthesize the ruthenium complex [Ru(MeIm)

4

(bpy)

]

2+

and study its in vitro activity against liver cancer.       Methods        The characteristics of [Ru(MeIm)

4

(bpy)

]

2+

were detected by elemental analysis

electrospray mass spectrometry (ESI-MS) and nuclear magn

etic resonance (NMR)

its binding affinity for DNA was determined by competitive binding experiments

and its effect of proliferation of 3 human liver cancer cell lines (HepG

2

HCC-LM3 and MHCC-97L) was assayed by MTT assay. Morphological changes of apoptotic human liver cancer cells were observed with Hoechst33342 staining. Changes in cell apoptosis rate and cell cycle after exposure to drugs were detected by flow cytometry.       Results        [Ru(MeIm)

4

(bpy)

]

2+

was synthesized and characterized in the present study. Competitive binding experiments showed that [Ru(MeIm)

4

(bpy)

]

2+

could bind with DNA instead of EB and inhibit the proliferation of HepG

2

HCC-LM3 and MHCC-97L cells

especially of HepG

2

cells

in a concentration- and time-dependent manner. [Ru(MeIm)

4

(bpy)

]

2+

could induce the apoptosis of HepG

2

cells in a concentration-dependent manner and increase the apoptosis peak in Sub-G1 cells with the prolonged exposure to drugs. [Ru(MeIm)

4

(bpy)

]

2+

blocked the cell cycle at G

0

/G

1

phase when its concentration was 31.25 to 125 μg/ml and arrested the cell cycle at G

2

/M phase when its concentration was 250 μg/ml.       Conclusion        Synthesized [Ru(MeIm)

4

(bpy)

]

2+

  can inhibit the proliferation and induce apoptosis in HepG

2

cells.