Abstract: OBJECTIVE: To investigate the mechanisms of apoptosis induced by natto lipopeptide in MCF-7 cells. METHODS: Logarithmic growth phase of MCF-7 cells were treated with natto lipopeptide at different concentration(0,1,2,4μg/mL) in vitro and cultuerd at 37℃ incubator. Cells were collected after 12 h. Flow cytometry was used to detect apoptosis;single cell gel electrophoresis was used to detect DNA damage and Western blot for detection of estrogen receptors α and β expression levels. RESULTS: Natto lipopeptide could induce apoptosis in MCF-7 cells(P<0.05). Olive tail moment and tail DNA levels increased significantly(P<0.05 or P<0.01),and 4μg/mL natto lipopeptide group significantly increased tail length compared wie control group(P<0.01). Compared wie control group,natto lipopeptide of 4μg/mL also had significant effects on the expressions of ERα and ERβ(P<0.05). CONCLUSION: Natto lipopeptide exposure could change the expression levels of ERα and ERβ and damage DNA of MCF-7 cells,contributing to apoptosis.

Key words: natto lipopeptide, MCF-7 cells, apoptosis, DNA damage, estrogen receptors