Objective:To test whether the down-regulation of Notchl gene expression by curcumin could inhibit cell growth and induce apoptosis,which may be associated mechanistically with the down-regulation of NF-κB in breast cancer cells. Methods:Breast cancer cell lines MDA-MB-231 were cultured in vitro and treated with different dosages of curcumin(0, 1.25,5.0,20.0μmol/L)for dose-dependent assay and different time(0,24,48,72 h)at the dosage of 5.0μmol/L for time course assay.The changes of the mRNA and protein expression of Notchl and NF-κB were measured by RT-PCR and Western Blot,and MTT assay was used to measure the change of proliferation.Results:The mRNA and protein levels of Notch1 and NF-κB were decreased significantly in human breast cancer cell line with the increase of dosage of curcumin(P<0.05),and with the extension of time course(P<0.05).These changes suggested a dose- and time-dependent manner.The proliferation rate of cells also was significantly inhibited(P<0.05).Conclusion:The current results show that the Notch-1 signaling pathway is associated mechanistically with NF-κB activity during curcumin-induced cell growth inhibition and apoptosis of breast cancer cells.These results suggest that the down-regulation of Notch signaling by curcumin may be a novel strategy for the treatment of patients with breast cancer. Objective: To test whether the down-regulation of Notchl gene expression by curcumin could inhibit cell growth and induce apoptosis, which may be associated with mechanistically with the down-regulation of NF-κB in breast cancer cells. Methods: Breast cancer cell lines MDA- MB-231 were cultured in vitro and treated with different dosages of curcumin (0, 1.25, 5.0, 20.0 μmol / L) for dose-dependent assay and different time (0,24,48,72 h) at the dosage of 5.0 μmol / L for time course assay. The changes of the mRNA and protein expression of Notchl and NF-κΒ were measured by RT-PCR and Western Blot, and MTT assay was used to measure the change of proliferation. Results: The mRNA and protein levels of Notch1 and NF-κB were decreased significantly in human breast cancer cell line with the increase of dosage of curcumin (P <0.05), and with the extension of time course (P <0.05). These changes suggested a dose- and time- dependent manner. The proliferation rate of cells also was significantly inhibited (P <0.05) .Conclusion : The current results show that the Notch-1 signaling pathway is associated with mechanistically with NF-κB activity during curcumin-induced cell growth inhibition and apoptosis of breast cancer cells.These results suggest that the down-regulation of Notch signaling by curcumin may be a novel strategy for the treatment of patients with breast cancer.