OBJECTIVETo study the effect of Zilongjin (ZLJ, a composite Chinese drug) on proliferation and apoptosis of human breast carcinoma cell line MCF-7.

METHODSMCF-7 cells were randomly divided into four groups depending on the culture solution used, the control group, cultured with 1640 medium not contained ZLJ; and the three ZJL groups cultured with medium contained low (1.5 mg/mL), moderate (3 mg/mL) and high (6 mg/mL) dosage of ZLJ crude drug respectively. The changes of cell proliferation were assessed by cell growth curve assay and methyl thiazolyl tetrazolium (MTT) assay. And the cell apoptosis was analyzed by flow cytometry, Hoechst 33342 staining and DNA ladder assay.

RESULTSCompared with that in the normal control, the counts of cells in the three ZLJ groups were decreased significantly (P<0.05) at such time point as 24, 48, 72, 96, 120, and 144 h. Furthermore, apart from the comparison of the growth inhibition rate between the low and moderate dosage group at 24 and 72 h which were found to be no significant difference (P>0.05), the comparison f that among the three ZLJ groups appeared to be significant difference (P<0.05). The inhibitory effect of ZLJ on cell proliferation of MCF-7 was time- and dose-dependent; it could retard cells in G0/G1 cell phase; apoptosis of MCF-7 cell was induced by moderate and high dosage of ZLJ with revealing of apoptotic body and DNA ladder formation.

CONCLUSIONZLJ shows cell proliferation inhibitory and apoptosis inducing effects on human breast cancer cell line MCF-7, and thus to realize its anti-tumor action.