Biological evaluation of new organoruthenium(II) metallates containing 3-acetyl-8-methoxy-2H-chromen-2-one appended CNS donor Schiff bases

Organoruthenium metallocycle induced mutation in gld-1 tumor suppression gene in JK1466 strain and appreciable lifespan expansion

Four Ru(II) complexes (A2-A5) were synthesized from the reaction of coumarin Schiff base ligands (7da2-tsc, 7da3-mtsc, 7da4-etsc and 7da5-ptsc) with [RuHCl(CO)(PPh3)3]. The compounds were characterized by FT-IR, UV-Vis, 1H, 13C and 31P NMR, mass spectrometry and crystallographic analysis. Calf Thymus DNA (CT-DNA) binding studies revealed the intercalative mode of binding of the complexes with DNA. The results of Bovine serum albumin (BSA) binding studies established the interaction between BSA followed static quenching mechanism. The cytotoxic effects of the complexes and the ligands were evaluated against breast (MCF-7 and MDA-MB-231) and lung carcinoma cell lines (A549 and NCI-H460) using MTT assay. Complex A4 demonstrated potent cytotoxic effects on both breast and lung cancer cells. Furthermore, morphological observations and FACS analysis showed the decrease in cell density by complex A4 by induced morphological changes and apoptotic body formation and cell death in both breast and lung cancer cells. Moreover, the invertebrate model Caenorhabditis elegans was employed to assess the in vivo anticancer activity of compound A4. The findings indicated that the treatment with A4 reduced tumor development and significantly extended organismal lifespan by 64 % in the tumoral strain JK1466 without adversely affecting essential physiological functions of the worm. Additionally, A4 demonstrated an upregulation of two crucial antioxidant defense genes. Overall, these results suggested that the compound A4 can be a potential candidate with novel chemotherapeutic applications.

Effect of ruthenium(II) complexes on MDA-MB-231 cells and lifespan/tumor growth in gld-1mutant, Daf-16 TF and stress productive genes: A perspective study

Pincer type coumarin based N-substituted semicarbazone ligands HL1-4 and their corresponding ruthenium(II) complexes (1-4) were synthesized, analyzed and confirmed by various spectro analytical techniques. The molecular structure of the ligand HL3 and complex 3 was confirmed by single crystal X-ray diffraction analysis. The stoichiometry of complexes 1, 2 and 4 was confirmed by high resolution mass spectroscopy (HRMS). The binding affinity of the compounds with CT-DNA (Calf Thymus DNA) and BSA (Bovine Serum Albumin) was established by absorption and emission titration methods. The results of In vitro cytotoxicity showed the significant cytotoxic potential of the complexes against MDA-MB-231 cells (TNBC- Triple-negative breast cancer). Among the complexes, 1 and 4 have shown appreciable results. Further, antimigratory activity against the MDA-MB-231 cells was studied for the complexes 1 and 4. The percentage cell cycle arrest, apoptosis and necrosis were explored by flow cytometry. The in vivo anti-tumor activity of the complexes 1 and 4 using C. elegans as model organism was established by using the tumoral C. elegans strain JK1466 (gld-1(q485)), which bears a mutation in the gld-1 tumor suppressor gene. We have determined the effect of our complexes on tumor gonad reduction and found to be non toxic to the JK1466 worms and they have prolonged their mean lifespan with potential antioxidant ability by overcoming stress responses. Overall, our study reported herein demonstrated that the complexes 1 and 4 could be established as potential metallo-drugs substantiating further exploration.

Biomolecular Interactions of Cytotoxic Ruthenium Compounds with Thiosemicarbazone or Benzothiazole Schiff Base Chelates

Herein we illustrate the formation and characterization of new paramagnetic ruthenium compounds, trans-P-[RuCl(PPh₃ )₂ (pmt)]Cl (1) (Hpmt=1-((pyridin-2-yl)methylene)thiosemicarbazide), trans-P-[RuCl(PPh₃ )₂ (tmc)]Cl (2) (Htmc=1-((thiophen-2-yl)methylene)thiosemicarbazide) and a diamagnetic ruthenium complex, cis-Cl, trans-P-[RuCl₂ (PPh₃ )₂ (btm)] (3) (btm=2-((5-hydroxypentylimino)methyl)benzothiazole). Agarose gel electrophoresis experiments of the metal compounds illustrated dose-dependent binding to gDNA by 1-3, while methylene blue competition assays suggested that 1 and 2 are also DNA intercalators. Assessment of the effects of the compounds on topoisomerase function indicated that 1-3 are capable of inhibiting topoisomerase I activity in terms of the ability to nick supercoiled plasmid DNA. The cytotoxic activities of the metal complexes were determined against a range of cancer cell lines versus a non-tumorigenic control cell line, and the complexes were, in general, more cytotoxic towards the cancer cells, displaying IC₅₀ values in the low micromolar range. Time-dependent stability studies showed that in the presence of strong nucleophilic species (such as DMSO), the chloride co-ligands of 1-3 are rapidly substituted by the former as proven by the suppression of the substitution reactions in the presence of an excess amount of chloride ions. The metal complexes are significantly stable in both DCM and an aqueous phosphate buffer containing 2 % DMSO.

TGF-β1 mediated MAPK signaling pathway promotes collagen formation induced by Nano NiO in A549 cells

Nickel oxide nanoparticles (Nano NiO) could induce pulmonary fibrosis, however, the mechanisms are still unknown. The aim of the present study was to explore the roles of transforming growth factor-β1 (TGF-β1), mitogen-activated protein kinase (MAPK) pathway and MMPs/TIMPs balance in Nano NiO-induced pulmonary fibrosis. For that purpose, we first established Nano NiO-induced human lung adenocarcinoma epithelial cells (A549 cells) model of collagen excessive formation through detecting the levels of hydroxyproline (Hyp) and type I collagen (Col-I). Then the protein levels of TGF-β1, MAPKs, and MMPs/TIMPs were assessed by Western blot. The results showed that Nano NiO resulted in the increased contents of Hyp, Col-I, and TGF-β1, the MAPK pathway activation and MMPs/TIMPs imbalance with a dose-dependent manner. In addition, to investigate whether TGF-β1 mediated MAPK signaling pathway, A549 cells were treated by 100 μg/mL Nano NiO combined with TGF-β1, p38 MAPK, and ERK1/2 inhibitors (10 μM SB431542, 10 μM SB203580, and 10 μM U0126), respectively. We found that MAPK signal pathway was suppressed by TGF-β1 inhibitor. Meanwhile, the increased contents of Hyp and Col-I, and MMPs/TIMPs imbalance were alleviated by the p38 MAPK and ERK1/2 inhibitors, respectively. These findings indicated that the MAPK pathway and MMPs/TIMPs imbalance were involved in collagen excessive formation induced by Nano NiO.