Docking studies, cytotoxicity evaluation and interactions of binuclear copper(ii) complexes with s-isoalkyl derivatives of thiosalicylic acid with some relevant biomolecules

The numerous side effects of platinum based chemotherapy has led to the design of new therapeutics with platinum replaced by another transition metal. Here, we investigated the interactions of previously reported copper(II) complexes containing S-isoalkyl derivatives, the salicylic acid with guanosine-5′-monophosphate and calf thymus DNA (CT-DNA) and their antitumor effects, in a colon carcinoma model. All three copper(II) complexes exhibited an affinity for binding to CT-DNA, but there was no indication of intercalation or the displacement of ethidium bromide. Molecular docking studies revealed a significant affinity of the complexes for binding to the minor groove of B-form DNA, which coincided with DNA elongation, and a higher affinity for binding to Z-form DNA, supporting the hypothesis that the complex binding to CT-DNA induces a local transition from B-form to Z-form DNA. These complexes show a moderate, but selective cytotoxic effect toward colon cancer cells in vitro. Binuclear complex of copper(II) with S-isoamyl derivative of thiosalicylic acid showed the highest cytotoxic effect, arrested tumor cells in the G2/M phase of the cell cycle, and significantly reduced the expression of inflammatory molecules pro-IL-1β, TNF-α, ICAM-1, and VCAM-1 in the tissue of primary heterotopic murine colon cancer, which was accompanied by a significantly reduced tumor growth and metastases in the lung and liver

The role of regulatory T cells in the modulation of anti-tumor immune response

It has been shown that the loss of regulatory function by deple­ + Regulatory T cells (Treg) represent a subset of CD4 T cells whose function is to suppress immune responses. Treg lymphocytes can be divided into two subsets: natural nTreg lymphocytes that are developed in the thymus and inducible iTreg lymphocytes, which originate from conventional T lymphocytes on the periphery. The majority of Treg lymphocytes express high levels of interleukin­2 (IL­2) receptor α chain (CD25) and transcription factor FoxP3 (critical for the development and suppressor activity of iTreg lymphocytes). Cancer cells can modulate anti­tumor immune response indirectly, through the activation of Treg lymphocytes. tion of tumor­induced Treg lymphocytes may enhance effectors response, resulting in tumor rejection, while the increased number of Treg lymphocytes effectively prevents tumor destruction. nTreg lymphocytes express increasingly CTLA­4 and membrane­ bound TGF­β, which inhibits cytokine production and responses of effectors lymphocytes. iTreg lymphocytes secrete immunosuppressive cytokines such as IL­10 and TGF­β. Treg lymphocytes represent one of important obstruction in anti­tumor immunity

Palladium(II) complexes with R(2)edda derived ligands. Part IV. O,O '-dialkyl esters of (S,S)-ethylenediamine-N,N '-di-2-(4-methyl)-pentanoic acid dihydrochloride and their palladium(II) complexes: Synthesis, characterization and in vitro antitumoral acti

Four novel bidentate N,N'-ligand precursors, including O,O'-dialkyl esters (alkyl = ethyl, n-propyl, n-butyl and n-pentyl), L1 center dot 2HCl-L4 center dot 2HCl, of (S,S)-ethylenediamine-N,N'-di-2-(4-methyl)-pentanoic acid dihydrochloride [(S,S)-H(4)eddl]Cl-2 and the corresponding palladium(II) complexes 1-4, were prepared and characterized by IR, H-1 NMR and C-13 NMR spectroscopy and elemental analysis. In vitro cytotoxicity of all compounds was determined against chronic lymphocytic leukemia cells (CLL). The compounds were found to exhibit higher antitumoral activity than cisplatin. The most active compound 2, [PdCl2{(S,S)-nPr(2)eddl}], was found to be 13.6 times more active than cisplatin on CLL cells. (C) 2010 Elsevier Masson SAS. All rights reserved

Dehydrozingerone based 1-acetyl-5-aryl-4,5-dihydro-1H-pyrazoles: Synthesis, characterization and anticancer activity

A small series of 1-acetyl-5-aryl-4,5-dihydro-1H-pyrazoles (aryl = 4-hydroxy-3-methoxyphenyl and 4-alkoxy-3-methoxyphenyl) was prepared, starting from 4-(4-hydroxy-3-methoxyphenyl)-3-buten-2-one, dehydrozingerone, and its alkyl derivatives. Their in vitro cytotoxic activity against some cancer cell lines was tested, showing significant anticancer activity. All the new compounds were well characterized by IR, H-1, C-13 NMR and ESI-MS spectroscopy and physical data, whereas structures of two of them were determined by single crystal X-ray analysis. (C) 2016 Elsevier B.V. All rights reserved

Characterization, modes of interactions with DNA/BSA biomolecules and anti-tumor activity of newly synthesized dinuclear platinum(II) complexes with pyridazine bridging ligand

Platinum-based drugs are widely recognized efficient anti-tumor agents, but faced with multiple undesirable effects. Here, four dinuclear platinum(II) complexes, [{Pt(1,2-pn)Cl}2(μ-pydz)]Cl2 (C1), [{Pt(ibn)Cl}2(μ-pydz)]Cl2 (C2), [{Pt(1,3-pn)Cl}2(μ-pydz)]Cl2 (C3) and [{Pt(1,3-pnd)Cl}2(μ-pydz)]Cl2 (C4), were designed (pydz is pyridazine, 1,2-pn is ( ±)-1,2-propylenediamine, ibn is 1,2-diamino-2-methylpropane, 1,3-pn is 1,3-propylenediamine, and 1,3-pnd is 1,3-pentanediamine). Interactions and binding ability of C1–C4 complexes with calf thymus DNA (CT-DNA) has been monitored by viscosity measurements, UV–Vis, fluorescence emission spectroscopy and molecular docking. Binding affinities of C1–C4 complexes to the bovine serum albumin (BSA) has been monitored by fluorescence emission spectroscopy. The tested complexes exhibit variable cytotoxicity toward different mouse and human tumor cell lines. C2 shows the most potent cytotoxicity, especially against mouse (4T1) and human (MDA-MD468) breast cancer cells in the dose- and time-dependent manner. C2 induces 4T1 and MDA-MD468 cells apoptosis, further documented by the accumulation of cells at sub-G1 phase of cell cycle and increase of executive caspase 3 and caspase 9 levels in 4T1 cells. C2 exhibits anti-proliferative effect through the reduction of cyclin D3 and cyclin E expression and elevation of inhibitor p27 level. Also, C2 downregulates c-Myc and phosphorylated AKT, oncogenes involved in the control of tumor cell proliferation and death. In order to measure the amount of platinum(II) complexes taken up by the cells, the cellular platinum content were quantified. However, C2 failed to inhibit mouse breast cancer growth in vivo. Chemical modifications of tested platinum(II) complexes might be a valuable approach for the improvement of their anti-tumor activity, especially effects in vivo

Cytotoxicity of palladium(II) complexes with some alkyl derivates of thiosalicylic acid. Crystal structure of the bis(S-butyl-thiosalicylate)palladium(II) complex, [Pd(S-bu-thiosal)(2)]

The spectroscopically predicted structure of the obtained bis(S-butyl-thiosalicylate)palladium(II) complex, [Pd(S-bu-thiosal)(2)], was confirmed by an X-ray structural study. The asymmetric unit of [Pd(S-bu-thiosal)(2)] consists of neutral complex molecules, where the Pd(II) ion is placed in a cis-square-planar coordination environment formed by O and S atoms of two deprotonated S-butyl-thiosalicylic acid ligands. The cytotoxic effects of the S-alkyl (R = benzyl (L1), methyl (L2), ethyl (L3), propyl (L4) and butyl (L5)) derivatives of thiosalicylic acid and the corresponding palladium(II) complexes are reported here. The analysis of cancer cell viability showed that all the tested complexes are cytotoxic to human colon carcinoma cells (HCT-116 and CaCo-2) and human lung carcinoma epithelial cells (A549). The antitumor activities of the above mentioned Pd(II) complexes are higher in comparison to the corresponding ligands. (C) 2015 Elsevier Ltd. All rights reserved

Graphene Quantum Dots Attenuate Concanavalin A-Induced Hepatitis

50th International Liver Congress of the European-Association-for-the-Study-of-the-Liver, Apr 22-26, 2015, Vienna, Austri

Large Graphene Quantum Dots Alleviate Immune-Mediated Liver Damage

We investigated the effect of large (40 nm) graphene quantum dots (GQDs) in concanavalin A (Con A; 12 mg/kg i.v.)-induced mouse hepatitis, a T cell-mediated liver injury resembling fulminant hepatitis in humans. Intravenously injected GQDs (50 mg/kg) accumulated in liver and reduced Con A-mediated liver damage, as demonstrated by histopathological analysis and a decrease in liver lipid peroxidation and serum levels of liver transaminases. The cleavage of apoptotic markers caspase-3/PARP and mRNA levels of proapoptotic mediators Puma, Noxa, Bax, Bak1, Bim, Apaf1, and p21, as well as LC3-I conversion to autophagosome-associated LC3-II and expression of autophagy-related (Atg) genes Atg4b, Atg7, Atg12, and beclin-1, were attenuated by GQDs, indicating a decrease in both apoptosis and autophagy in the liver tissue. This was associated with the reduced liver infiltration of immune cells, particularly the T cells producing proinflammatory cytokine IFN-?, and a decrease in IFN-gamma serum levels. In the spleen of GQD-exposed mice, mRNA expression of IFN-? and its transcription factor T-bet was reduced, while that of the IL-33 ligand ST2 was increased. The hepatoprotective effect of GQDs was less pronounced in ST2-deficient mice, indicating that it might depend on ST2 upregulation. In vitro, GQDs inhibited splenocyte IFN-gamma production, reduced the activation of extracellular signal-regulated kinase in macrophage and T cell lines, inhibited macrophage production of the free radical nitric oxide, and reduced its cytotoxicity toward hepatocyte cell line HepG2. Therefore, GQDs alleviate immune-mediated fulminant hepatitis by interfering with T cell and macrophage activation and possibly by exerting a direct hepatoprotective effect