Abstract: AIM: To investigate the effects of quercetins extracted and isolated from the flos sophorae immaturus and apoptosis in MCF-7 human breast cancer cell. METHODS: With the alkali-soluble acid precipitation methods, the quercetins were extracted from flos sophorae immaturus and were identificated by Infrared spectrophotometry. Colorimetric MTT assay was used to measure the prolification inhibitions of the quercetin in MCF-7 cells. The apoptosis of treated cells were examined by DNA agarose gel electrophoresis analysis of DNA fragmentation and flow cytometry using fluorescein labeling FITC- Annexin V/PI, respectively.RESULTS: MTT results showed that the different doses of quercetin can inhibit the growth of MCF-7 cells in dose- and time-dependent significantly(P<0.05). The characteristic bands of apoptosis by DNA electrophoresis were found in MCF-7 cells treated by quercetin at 10.0 mmol/L for 2 d. The rates of apoptosis of MCF-7 cells which were treated with quercetin at 10.0 mmol/L for 1 d, 2 d and 3 d were (9.2±1.5)%, (30.0±11.8)% and (60.8±10.6)%, respectively. CONCLUSION: The quercetins can be purified from the flos sophorae immaturus with the alkali-soluble acid precipitation methods. The quercetin can inhibit the growth and apoptosis in MCF-7 cells.

Key words: Quercetin, Flos sophorae immaturus, MCF-7 cell, Apoptosis