Chronic effects of platinum(IV) complex and its diamine ligand on rat heart function: comparison with cisplatin.

The aim of the present study was to compare the cardiodynamic parameters in the isolated rat heart in animals chronically treated with cisplatin, platinum(IV) complex and its diamine ligand. Sixty Wistar albino rats (8 weeks old) were divided into five groups: three experimental and two control groups. Animals in all groups were treated with a dose of 4 mg/kg body weight once a week for 4 weeks with different substances; experimental groups received cisplatin, ligand and octahedral platinum(IV) complex, and control groups received saline and dimethyl sulfoxide. After sacrificing the animals, hearts were isolated and perfused according to the Langendorff technique at gradually increased coronary perfusion pressures (40-120 cmH2O). The following parameters of cardiac function were continuously recorded: maximum and minimum rate of change of pressure in the left ventricle, systolic and diastolic left ventricular pressure, heart rate and coronary flow. The results showed statistically significant differences between all experimental groups in maximum and minimum rate of pressure development as well as in systolic pressure of the left ventricle, whereas cisplatin, ligand and the platinum(IV) complex had effects on heart contractility without significant influences on coronary circulation. The findings of the present study could be important for a better understanding of anticancer drug cardiac side effects. Our results indicate that compared to cisplatin as a "gold standard", novel platinum complexes and ligands do not possess fewer negative effects on the heart, indicating insufficient safety for their usage in terms of affecting cardiac function, a result that can be of great interest for further investigations.

A review of the key ingredients in industrial formulations of baby wet wipes.

The skin of newborns is classified as sensitive, with a higher risk of skin barrier disruption and irritation of a diapered area. Despite dermatologist recommendations to use only water and a cloth for cleaning, most of the population still relies on the comforts of modern parenting, which includes intensive daily usage of baby wet wipes. Novel baby formulations are designed following the concept of infant skin health, containing a gentle cleanser, suitable emollient, and buffer system enabling a slightly acidic pH value and they are free of ethyl alcohol. Thus, it is important to understand the chemical background of such a complex liquid formulation, with emphasis on its safety. In line with this, the present paper discusses the scientific background of various chemical compounds found in baby wipe formulations to improve the understanding of wet wipe designs and direct them toward more skin-friendly solutions.

Cyclohexyl analogues of ethylenediamine dipropanoic acid induce caspase-independent mitochondrial apoptosis in human leukemic cells.

We investigated the cytotoxicity of recently synthesized (S,S)-ethylendiamine-N,N'-di-2-(3-cyclohexyl)propanoic acid esters toward human leukemic cell lines and healthy blood mononuclear cells. Cell viability was assessed by acid phosphatase assay, apoptosis, and differentiation were analyzed by flow cytometry and electron microscopy, while intracellular localization of apoptosis-inducing factor (AIF) was determined by immunoblotting. It was demonstrated that methyl, ethyl, and n-propyl esters were toxic to HL-60, REH, MOLT-4, KG-1, JVM-2, and K-562 leukemic cell lines, while the nonesterified parental compound and n-butyl ester were devoid of cytotoxic action. The ethyl ester exhibited the highest cytotoxic activity (IC50 10.7 µM-45.4 µM), which was comparable to that of the prototypical anticancer drug cisplatin. The observed cytotoxic effect in HL-60 cells was associated with an increase in superoxide production and mitochondrial membrane depolarization, leading to apoptotic cell death characterized by phosphatidylserine externalization and DNA fragmentation in the absence of autophagic response. DNA fragmentation preceded caspase activation and followed AIF translocation from mitochondria to nucleus, which was indicative of caspase-independent apoptotic cell death. HL-60 cells treated with subtoxic concentration of the compound displayed morphological signs of granulocytic differentiation (nuclear indentations and presence of cytoplasmic primary granules), as well as an increased expression of differentiation markers CD11b and CD15. The cyclohexyl analogues of ethylenediamine dipropanoic acid were also toxic to peripheral blood mononuclear cells of both healthy controls and leukemic patients, the latter being more sensitive. Our data demonstrate that the toxicity of the investigated cyclohexyl compounds against leukemic cell lines is mediated by caspase-independent apoptosis associated with oxidative stress, mitochondrial dysfunction, and AIF translocation.

Drug combination study of novel oxorhenium(V) complexes.

Three Re(V) complexes of structural formulas [ReOCl2L(PPh3)], where L is pyridine-2-carboxylic acid (C1), 3-methyl-pyridine-2-carboxylic acid (C2) and 6-methyl-pyridine-2-carboxylic acid (C3) were synthesized and characterized using NMR, IR spectroscopy and mass spectrometry. Crystal structures of all three complexes have been additionally confirmed by X-ray analysis. The biological activity has been investigated in the panel of tumor cell lines A549, PANC-1, MDA-MB-231, MCF-7, LS-174, EAhy.926 and one in non-tumor cell line MRC-5. Only C1 showed dose-dependent cytotoxic potential, particularly toward triple-negative breast adenocarcinoma cells MDA-MB-231 with IC50 68.90 ± 1.73 µM and pancreatic adenocarcinoma cells PANC-1 with IC50 69.84 ± 2.3 µM. Both cell lines are characterized by a highly invasive and resistant phenotype. Drug combination studies in PANC-1 cells with C1 and Verapamil hydrochloride (VRP), which is the established inhibitor of efflux transporter P-glycoprotein (Pgp), revealed enhancement of antiproliferative action of the complex in a dose-dependent manner, and slight arrest of cell cycle in the S phase. Also, a depletion of the glutathione (GSH) level by L-buthionine-sulfoximine (L-BSO) at sub-toxic concentrations (100 µM) caused an increase of activity of C1 to the IC50 57.67 ± 6.51 (µM). A morphological analysis in PANC-1 cells by dual acridine orange/ethidium bromide staining, revealed apoptotic potential of complex C1 and a slower kinetic of cell death induction, suggesting a different mechanism of action compared to cisplatin.

Current Development of Metal Complexes with Diamine Ligands as Potential Anticancer Agents.

BACKGROUND: The discovery of cisplatin and the subsequent research revealed the importance of dinitrogen-containing moiety for the anticancer action of metal complexes. Moreover, certain diamine ligands alone display cytotoxicity that contributes to the overall activity of corresponding complexes. OBJECTIVE: To summarize the current knowledge on the anticancer efficacy, selectivity, and the mechanisms of action of metal complexes with various types of diamine ligands. METHODS: The contribution of aliphatic acyclic, aliphatic cyclic, and aromatic diamine ligands to the anticancer activity and selectivity/toxicity of metal complexes with different metal ions were analyzed by comparison with organic ligand alone and/or conventional platinum-based chemotherapeutics. RESULTS: The aliphatic acyclic diamine ligands are present mostly in complexes with platinum. Aliphatic cyclic diamines are part of Pt(II), Ru(II) and Au(III) complexes, while aromatic diamine ligands are found in Pt(II), Ru(II), Pd(II) and Ir(III) complexes. The type and oxidation state of metal ions greatly influences the cytotoxicity of metal complexes with aliphatic acyclic diamine ligands. Lipophilicity of organic ligands, dependent on alkyl-side chain length and structure, determines their cellular uptake, with edda and eddp/eddip ligands being most useful in this regard. Aliphatic cyclic diamine ligands improved the activity/toxicity ratio of oxaliplatin-type complexes. The complexes with aromatic diamine ligands remain unexplored regarding their anticancer mechanism. The investigated complexes mainly caused apoptotic or necrotic cell death. CONCLUSION: Metal complexes with diamine ligands are promising candidates for efficient and more selective alternatives to conventional platinum-based chemotherapeutics. Further research is required to reveal the chemico-physical properties and molecular mechanisms underlying their biological activity.

Estimation of passive gastrointestinal absorption and membrane retention using PAMPA test, quantitative structure-permeability and quantitative structure-retention relationship analyses of ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoic acid and 1,3-propanediamine-N,N'-di-2-(3-cyclohexyl)propanoic acid derivatives.

Passive gastrointestinal absorption and membrane retention of twelve esters of (S,S)-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoic acid (EDCP) and (S,S)-1,3-propanediamine-N,N'-di-2-(3-cyclohexyl)propanoic acid (PDCP), as well as of these two non-esterified acids were estimated using PAMPA test. Artificial PAMPA membrane used in this study for the simulation of gastrointestinal barrier was solution of egg lecithin in dodecane (1 % w/v). All tested compounds belong to class III (high membrane retention and low permeation), whereas EDCP, dipentyl ester of PDCP (DPE-PDCP) and diisopentyl ester of PDCP (DIPE-PDCP) belong to class I (negligible membrane retention and low permeation). Finally, quantitative structure - permeability and structure - retention relationships models were created in order to find quantitative relationships between physico-chemical properties of tested compounds and PAMPA membrane permeability/membrane retention parameters. Statistically the most reliable models were analysed and used for the design of new compounds for which favourable membrane permeability and retention can be expected.

Synthesis, chemical characterization, PARP inhibition, DNA binding and cellular uptake of novel ruthenium(II)-arene complexes bearing benzamide derivatives in human breast cancer cells.

Inhibitors of poly(ADP-ribose) polymerase-1 (PARP-1) showed remarkable clinical efficacy in BRCA-mutated tumors. Based on the rational drug design, derivatives of PARP inhibitor 3-aminobenzamide (3-AB), 2-amino-4-methylbenzamide (L1) and 3-amino-N-methylbenzamide (L2), were coordinated to the ruthenium(II) ion, to form potential drugs affecting DNA and inhibiting PARP enzyme. The four conjugated complexes of formula: C1 [(ƞ6-toluene)Ru(L1)Cl]PF6, C2 [(ƞ6-p-cymene)Ru(L1)Cl]PF6, C3 [(ƞ6-toluene)Ru(L2)Cl2] and C4 [(ƞ6-p-cymene)Ru(L2)Cl2], have been synthesized and characterized. Colorimetric 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide (MTT) assay showed the highest antiproliferative activity of C1 in HCC1937, MDA-MB-231, and MCF-7 breast cancer cells. Efficiency of inhibition of PARP-1 enzymatic activity in vitro decreased in order: C2 > C4 > 3-AB>C1 > C3. ICP-MS study of intracellular accumulation and distribution in BRCA1-mutated HCC1937 revealed that C1-C4 entered cells within 24 h. The complex C1 showed the highest intracellular accumulation, nuclear-targeting properties, and exhibited the highest DNA binding (39.2 ±â€¯0.6 pg of Ru per µg of DNA) that resulted in the cell cycle arrest in the S phase.

An 8-hydroxyquinoline-proline hybrid with multidrug resistance reversal activity and the solution chemistry of its half-sandwich organometallic Ru and Rh complexes.

Herein the design and synthesis of a new 8-hydroxyquinoline derivative, (S)-5-chloro-7-((proline-1-yl)methyl)8-hydroxyquinoline (HQCl-Pro), with good water solubility and multidrug resistance reversal activity are reported. In this work the proton dissociation processes of HQCl-Pro and its complex formation with [Rh(η5-C5Me5)(H2O)3]2+, [Ru(η6-p-cymene)(H2O)3]2+ and [Ru(η6-toluene)(H2O)3]2+ were investigated by the combined use of pH-potentiometry, UV-visible spectrometry and 1H NMR spectroscopy. Our results revealed the prominent solution stability of the complexes in all cases. The lipophilicity of the complexes increased with the chloride ion concentration, and the complexes showed moderate log D values (-0.8 to +0.4) at pH 7.4 at all tested Cl- concentrations. The formation of mixed hydroxido complexes from the aqua complexes was characterized by relatively high pKa values (8.45-9.62 in chloride-free medium). Complexation processes are much slower with the Ru(η6-arene) triaqua cations than with [Rh(η5-C5Me5)(H2O)3]2+. Both the pKa values and H2O/Cl- exchange constants of the Ru-complexes are lower by 0.5-1.0 orders of magnitude than those of the Rh analogue. Arene loss (p-cymene and toluene) and oxidation were found in the case of Ru-complexes when an excess of HQCl-Pro and aromatic (N,N) bidentate ligands was added. The cytotoxicity and antiproliferative effect of HQCl-Pro and its complexes were assayed in vitro. In contrast to the structurally familiar 8-hydroxyquinoline, HQCl-Pro and its Rh(η5-C5Me5) complex were somewhat more effective against drug resistant Colo 320 adenocarcinoma human cells compared to the drug sensitive Colo 205 cells. The Ru- and Rh-complexes showed a similar metal uptake level after 4 h, while a longer incubation time resulted in higher cellular Rh concentration.

Comparative solution and structural studies of half-sandwich rhodium and ruthenium complexes bearing curcumin and acetylacetone.

Half-sandwich organometallic complexes of curcumin are extensively investigated as anticancer compounds. Speciation studies were performed to explore the solution stability of curcumin complexes formed with [Rh(η5-C5Me5)(H2O)3]2+. Acetylacetone (Hacac), as the simplest ß-diketone ligand bearing (O,O) donor set, was involved for comparison and its Ru(η6­p­cymene), Ru(η6­toluene) complexes were also studied. 1H NMR, UV-visible and pH-potentiometric titrations revealed a clear trend of stability constants of the acac complexes: Ru(η6­p­cymene) > Ru(η6­toluene) > Rh(η5-C5Me5). Despite this order, the highest extent of complex formation is seen for the Rh(η5-C5Me5) complexes at pH 7.4. Formation constant of [Rh(η5-C5Me5)(H2curcumin)(H2O)]+ reveals similar solution stability to that of the acac complex. Additionally, structures of two complexes were determined by X-ray crystallography. The in vitro cytotoxicity of curcumin was not improved by the complexation with these organometallic cations.

The organic ester O,O'-diethyl-(S,S)-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoate dihydrochloride attenuates murine breast cancer growth and metastasis.

Pharmacological treatment of cancer is mostly limited by drug-toxicity and resistance. It has been noticed that new organic ester ligand, O,O'-diethyl-(S,S)-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoate dihydrochloride (named DE-EDCP) showed effective cytotoxic capacities against several human and mouse cancer cell lines. However, its effects on tumor growth and metastasis are unexplored. The aim of present study was to examine the ability of DE-EDCP to inhibit 4T1 murine breast cancer growth and progression and to explore possible molecular mechanisms. DE-EDCP exhibited significant tumoricidal activity on human and murine breast cancer cell lines. Further, marked reduction of murine breast cancer growth and progression by DE-EDCP was shown. DE-EDCP exhibits fewer side-effects compared to cisplatin as a conventional chemotherapeutic. Results obtained from in vivo and in vitro experiments indicate that DE-EDCP induces apoptosis and inhibits proliferation of 4T1 cells. DE-EDCP increases percentage of 4T1 cells in late apoptosis, expression of pro-apoptotic Bax and caspase-3, while decreases expression of anti-apoptotic Bcl-2. DE-EDCP treatment increased the percentage of TUNEL-positive nuclei and reduced Ki-67 expression in breast cancer tissue. DE-EDCP decreased expression of cyclin D3 and Ki-67, increased expression of cyclin-dependent kinase inhibitors p16, p21 and p27 and arrested 4T1 cells in G0/G1 cell cycle phase. Expression of STAT3 and downstream regulated molecules, NANOG and SOX2, was reduced in 4T1 cells after DE-EDCP treatment. In conclusion, DE-EDCP impairs breast cancer growth and progression by triggering cancer cell death and inhibition of cancer cell proliferation. DE-EDCP might be of interest in the development of the new anticancer agent.

Comparative solution equilibrium and structural studies of half-sandwich ruthenium(II)(η6-toluene) complexes of picolinate derivatives.

Five Ru(II)(η6-toluene) complexes formed with 2-picolinic acid and its various derivatives have been synthesized and characterized. X-ray structures of four complexes are also reported. Complex formation processes of [Ru(II)(η6-toluene)(H2O)3]2+ organometallic cation with the metal-free ligands were studied in aqueous solution in the presence of chloride ions by the combined use of 1H NMR spectroscopy, UV-visible spectrophotometry and pH-potentiometry. Solution stability, chloride ion affinity and lipophilicity of the complexes were characterized together with in vitro cytotoxic and antiproliferative activity in cancer cell lines being sensitive and resistant to classic chemotherapy and in normal cells as well. Formation of mono complexes such as [Ru(η6-toluene)(L)(Z)]+/0 (L: completely deprotonated ligand; Z = H2O/Cl-) with high stability and [Ru(η6-toluene)(L)(OH)] was found in solution. The pKa values (8.3-8.7) reflect the formation of low amount of mixed hydroxido species at pH 7.4 at 0.2 M KCl ionic strength. The complexes are fairly hydrophilic and show moderate chloride ion affinity and fast chloride-water exchange processes. The studied complexes exhibit no cytotoxic activity in human cancer cells (IC50 > 100 µM), only complexes formed with 2-picolinic acid (1) and its 3-methyl derivative (2) represented a moderate antiproliferative effect (IC50 = 84.8 (1), 79.2 µM (2)) on a multidrug resistant colon adenocarcinoma cell line revealing considerable multidrug resistant selectivity. Complexes 1 and 2 bind to human serum albumin covalently and relatively slowly with moderate strength at multiple binding sites without ligand cleavage.

In vitro and in vivo antimelanoma effect of ethyl ester cyclohexyl analog of ethylenediamine dipropanoic acid.

Melanoma, an aggressive skin tumor with high metastatic potential, is associated with high mortality and increasing morbidity. Multiple available chemotherapeutic and immunotherapeutic modalities failed to improve survival in advanced disease, and the search for new agents is ongoing. The aim of this study was to investigate antimelanoma effects of O,O-diethyl-(S,S)-ethylenediamine-N,N'di-2-(3-cyclohexyl) propanoate dihydrochloride (EE), a previously synthesized and characterized organic compound. Mouse melanoma B16 cell viability was assessed using acid phosphatase, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, sulforhodamine B, and lactate dehydrogenase assays. Apoptosis and autophagy were investigated using flow cytometry, fluorescence and electron microscopy, and western blotting. In vivo antitumor potential was assessed in subcutaneous mouse melanoma model after 14 days of treatment with EE. Tumor mass and volume were measured, and RT-PCR was used for investigating the expression of autophagy-related, proapoptotic, and antiapoptotic molecules in tumor tissue. Investigated organic compound exerts significant cytotoxic effect against B16 cells. EE induced apoptosis, as confirmed by phosphatidyl serine externalisation, caspase activation, and ultrastructural features typical for apoptosis seen on fluorescence and electron microscopes. The apoptotic mechanism included prompt disruption of mitochondrial membrane potential and oxidative stress. No autophagy was observed. Antimelanoma action and apoptosis induction were confirmed in vivo, as EE decreased mass and volume of tumors, and increased expression of several proapoptotic genes. EE possesses significant antimelanoma action and causes caspase-dependent apoptosis mediated by mitochondrial damage and reactive oxygen species production. Decrease in tumor growth and increase in expression of proapoptotic genes in tumor tissue suggest that EE warrants further investigation as a candidate agent in treating melanoma.

Antileukemic action of novel diamine Pt(II) halogenido complexes: Comparison of the representative novel Pt(II) with corresponding Pt(IV) complex.

This study presents the synthesis, characterization, and antitumor action of five new Pt(II) halogenido, chlorido, and iodido complexes with edda type of ligands. (S,S)-Ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoic acid dihydrochloride and its methyl, ethyl, and n-propyl esters were prepared according to the previously reported procedure. All investigated complexes were characterized by IR, ESI-MS (1 H, 13 C, and HMBC) NMR spectroscopy, and elemental analysis. Their cytotoxic action was investigated in four human tumor cell lines: promyelocytic (HL-60) and lymphocytic (REH) leukemia, glioma (U251), and lung carcinoma (H460). Cell viability was assessed by acid phosphatase and LDH assay, while oxidative stress and cell death parameters were analyzed by flow cytometry. The results showed that novel Pt(II) complexes exhibited antitumor action superior to precursor ligands, with iodido complexes being more efficient than corresponding chlorido complexes. Human promyelocytic cell line (HL-60) was the most sensitive to antitumor action of all investigated substances and was used for investigation of the underlying mode of antileukemic action. The investigated Pt(II) complexes showed more potent antileukemic action than corresponding Pt(IV) complex, through induction of oxidative stress and apoptosis, evidenced by caspase (8, 9, and 3) activation and phosphatidylserine externalization.

Novel octahedral Pt(IV) complex with di-n-propyl-(S,S)-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoato ligand exerts potent immunomodulatory effects.

We have recently reported that a novel octahedral Pt(IV) complex with di-n-propyl-(S,S)-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoato ligand has a potent cytotoxic effect on glioma, melanoma and fibrosarcoma cell lines. In this work, we investigated the influence of the Pt(IV) compound on immune cells. We determined its effect on the viability of spleen cells and lymph node cells and on their capability to produce interferon (IFN)-γ and interleukin (IL)-17. Also, we researched the compound's impact on peritoneal macrophages and generation of NO in these cells. Our results show that the complex has limited influence on cell viability of immune cells, but profound inhibitory effect on the production of examined immune mediators. These results are valuable as they show that the novel Pt(IV) complex applied in concentrations which are effective against tumor cells do not affect immune cell viability. Moreover, they also imply that the complex has immunomodulatory properties.

Novel methylene modified cyclohexyl ethylenediamine-N,N'-diacetate ligands and their platinum(IV) complexes. Influence on biological activity.

This paper focuses on the synthesis, characterization and biological activity of new N,N'-methylene modified cyclohexyl ethylenediamine-N,N'-diacetate (edda)-type ligands and their Pt(IV) complexes. Both the ligands and complexes were characterized by infrared, UV-vis, ESI-MS, 1D ((1)H, (13)C, (195)Pt) and 2D (COSY, HSQC, HMBC) NMR spectroscopy and elemental analysis. The possible correlation between the reduction potentials and the cytotoxicity of the complexes was examined. The potential antitumoral activity of all compounds was tested in vitro on human melanoma A375, human glioblastoma U251, human prostate cancer PC3, human colon cancer HCT116, mouse melanoma B16 and mouse colon cancer CT26CL25 cells, as well as primary fibroblasts and keratinocytes. The results obtained revealed strong antitumor potential of the newly synthesized drugs with preserved efficacy against cisplatin resistant lines and less toxicity towards nonmalignant counterparts. The mechanism found to be responsible for the observed tumoricidal action of each synthesized compound was induction of apoptosis generally accompanied with caspase activation. Taken together, the effective response to the treatment of a wide range of different cell lines, including cisplatin resistant subclones, as well as induction of apoptosis, as the mechanism suggested to be the most desirable way of eliminating malignant cells, represents a great advantage of this novel group of drugs in comparison to other members in this metallo-drug family.

Synthesis and in vitro anticancer activity of ruthenium-cymene complexes with cyclohexyl-functionalized ethylenediamine-N,N'-diacetate-type ligands.

Herein we describe the synthesis, characterization, and anticancer activity of novel p-cymeneruthenium(II) complexes containing methyl, ethyl, n-propyl, and n-butyl esters of (S,S)-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoic acid. The results of IR, UV/Vis, ESIMS, (1)H, and (13)C NMR characterization reveal that ligand coordination occurs through nitrogen donor atoms of the ester ligands, with the organoruthenium moiety being kept in complex. These ruthenium(II) complexes are cytotoxic toward various cancer cell lines including leukemic HL-60, K562, and REH cells (IC(50): 1.0-20.2 µM), with the n-butyl ester complex being the most effective. It causes apoptotic cell death associated with mitochondrial depolarization, caspase activation, phosphatidylserine exposure, and DNA fragmentation. Importantly, the n-butyl ester complex is more effective against leukemic patients' blood mononuclear cells relative to those from healthy control subjects, thus indicating a fairly selective antileukemic action of Ru(II)-based compounds.