Assessment of antiproliferative activity of new half-sandwich arene Ru (II) furylbenzhydrazone complexes

The study attempts in finding an effective anticancer activity of six new arene ruthenium (II) complexes possessing the composition of [(eta(6)-arene)Ru(L)Cl] (arene = benzene (1-3) /p-cymene (4-6); L = 2-furyl methyl benzhydrazones). Elemental analysis, Fourier transform infrared spectroscopy (FT-IR), UV-vis, nuclear magnetic resonance (NMR), and high resolution mass spectrometry (HR-MS) techniques were utilized to study the synthesized complexes. The single crystal X-ray crystallography validated the bidentate mode of coordination of the benzhydrazone ligand and pseudo-octahedral geometry around ruthenium ion. MTT assay has been performed to assess the in vitro growth of cancer cell inhibition ability of all the complexes against MCF-7(breast carcinoma), HuH-7 (hepatocellular carcinoma), and HeLa (cervical cancer), along with non-cancerous L132 (human lung epithelium) cell lines. It has been found that all the six complexes exhibit good to excellent cytotoxicity toward the cancer cell lines tested with low IC50 values compared to cisplatin. Among the synthesized complexes, complex 6 shows potential cytotoxicity against all the cancer cell lines. The observed higher cytotoxicity of the complex 6 may be due to the electron donating methoxy group of the ligand and hydrophobic character of arene moiety. Eventually, the staining techniques such as AO-EB, HOECHST 33342, RH-123, and reactive oxygen species (ROS) establish that all the complexes bring about cell death via apoptosis. The present research results emphasize the more possibility to promote potential arene ruthenium anticancer agents.