RETRACTED: Synthesis, structural characterization and anti-breast cancer activity evaluation of three new Schiff base metal (II) complexes and their nanoparticles (Retracted article. See vol. 1275, 2023)

Two Schiff base ligands 2-((ethylamino)methyl)-6-methoxyphenol (HL1) and (E)-2-(((2-(dimethylamino) ethyl)imino)methyl)-6-methoxyphenol (HL2) with bi-nucleating or tri-nucleating mode have been successfully prepared via an one step organic condensation reaction, which were further applied in the synthesis of three new Cu(II) and Ni(II)-based coordination complexes [Cu(L-1)(2)](EtOH) (1), [Ni(L-1)(2)](EtOH) (2) and [Cu(L-2)(HL2)(SCN)](MeOH)(2) (3). Furthermore, a hand grinding technique has been used to decrease the particle diameter of complexes 1-3, thus forming nano-complexes. In biological activity research, we revealed the important function of nanoparticle 1 in the treatment of breast cancer. Mitochondria is critical in generating intracellular energy, and play a vital role in regulating cells life and death. Therefore, the apoptosis of MCF7 breast cancer cells after treated with nanoparticles was detected by Annexin V-FITC/PI method. The results showed that nanoparticles 1 could significantly raise apoptotic cells number, but not nanoparticles 2-3. Moreover, we assessed the mitochondrial membrane potential and reactive oxygen species (ROS) in MCF7 cancer cells, finally we draw this conclusion, nanoparticle 1 could damage the mitochondrial membrane, leading increased ROS level, and cause the apoptotic cell death. (C) 2019 Elsevier B.V. All rights reserved.