A novel series of selenylated imidazo[1,2-a]pyridines were designed and synthesized with a view to a promising activity against breast cancer cell. The compounds, 7-methyl-3-(naphthalene-1-ylselanyl)-2phenylimidazo[1,2-a]pyridine, named IP-Se-05, and 34(2-methoxyphenyl)selany1)-7-methyl-2phenylimidazo[1,2-a]pyridine, named IP-Se-06, showed high cytotoxicity for MCF-7 cells (IC50= 26.0 mu M and 12.5 mu M, respectively). Both the compounds inhibited the cell proliferation and caused decrease in the number of cells in the G2/M phase of cell cycle. IP-Se-05 and IP-Se-06 were also evaluated for effects on CT DNA and DNA of MCF-7 cells. The compounds intercalated into CT-DNA and both treatments caused cleavage of DNA in cells. In addition, the compounds induced cell death by apoptosis. However, the presence of (2-methoxyphenyl) selenyl moiety at the imidazo[1,2-ajpyridine (IP-Se-06) appears to have a better antitumor effect with higher cytotoxicity at a lower concentration and caused less necrosis. Overall, the current study established IP-Se-06 more than IP-Se-05 as a potential prototype compound to be employed as an antiproliferative agent for the treatment of breast cancer. (C) 2018 Elsevier Inc. All rights reserved.