A novel copper(II) mononuclear complex with the non-steroidal anti-inflammatory drug diclofenac: Structural characterization and biological activity

Iron(III) Complexes with Non-Steroidal Anti-Inflammatory Drugs: Structure, Antioxidant and Anticholinergic Activity, and Interaction with Biomolecules

One the main research goals of bioinorganic chemists is the synthesis of novel coordination compounds possessing biological potency. Within this context, three novel iron(III) complexes with the non-steroidal anti-inflammatory drugs diflunisal and diclofenac in the presence or absence of the nitrogen donors 1,10-phenanthroline or pyridine were isolated and characterized by diverse techniques. The complexes were evaluated for their ability to scavenge in vitro free radicals such as hydroxyl, 1,1-diphenyl-2-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals, revealing their selective potency towards hydroxyl radicals. The in vitro inhibitory activity of the complexes towards the enzymes acetylcholinesterase and butyrylcholinesterase was evaluated, and their potential to achieve neuroprotection appeared promising. The interaction of the complexes with calf-thymus DNA was examined in vitro, revealing their ability to intercalate in-between DNA nucleobases. The affinity of the complexes for serum albumins was evaluated in vitro and revealed their tight and reversible binding.

Towards the Development of Novel Diclofenac Multicomponent Pharmaceutical Solids

Multicomponent pharmaceutical materials offer new opportunities to address drug physicochemical issues and to obtain improved drug formulation, especially on oral administration drugs. This work reports three new multicomponent pharmaceutical crystals of the non-steroidal anti-inflammatory drug diclofenac and the nucleobases adenine, cytosine, and isocytosine. They have been synthesized by mechanochemical methods and been characterized in-depth in solid-state by powder and single crystal X-ray diffraction, as well as other techniques such as thermal analyses and infrared spectroscopy. Stability and solubility tests were also performed on these materials. This work aimed to evaluate the physicochemical properties of these solid forms, which revealed thermal stability improvement. Dissociation of the new phases was observed in water, though. This fact is consistent with the reported observed layered structures and BFDH morphology calculations.

NSAID-Based Coordination Compounds for Biomedical Applications: Recent Advances and Developments

After the serendipitous discovery of cisplatin, a platinum-based drug with chemotherapeutic effects, an incredible amount of research in the area of coordination chemistry has been produced. Other transition metal compounds were studied, and several new relevant metallodrugs have been synthetized in the past few years. This review is focused on coordination compounds with first-row transition metals, namely, copper, cobalt, nickel or manganese, or with zinc, which have potential or effective pharmacological properties. It is known that metal complexes, once bound to organic drugs, can enhance the drugs' biological activities, such as anticancer, antimicrobial or anti-inflammatory ones. NSAIDs are a class of compounds with anti-inflammatory properties used to treat pain or fever. NSAIDs' properties can be strongly improved when included in complexes using their compositional N and O donor atoms, which facilitate their coordination to metal ions. This review focuses on the research on this topic and on the promising or effective results that complexes of first-row transition metals and NSAIDs can exhibit.

Silver(I) complexes containing diclofenac and niflumic acid induce apoptosis in human-derived cancer cell lines

We investigated the anti-cancer activity of [Ag(μ-dicl)]_n 1 and [AgH(nif)₂] 2 complexes against human cancer cell lines (MCF-7, HT-29, and HepG2) and mouse fibroblast (3T3-L1) cell line. Anti-proliferative activity was monitored by XTT cell viability and LDH leakage assays. Cell death mode was evaluated by multi-caspase activity, annexin V cytofluorimetric, MMP, cell cycle arrest, and ROS generation assays. Antioxidant capacity was evaluated on SOD, GPx, GR, and CAT enzymes. The XTT and LDH assay results showed that both complexes exhibited strong cytotoxicity against the tested cancer cell lines. The apoptotic mechanisms of the complexes were demonstrated by loss of MMP and increase in phosphatidylserine translocation, sub-G1 phase, and multi-caspase activity. Besides, both complexes induced the oxidative stress in MCF-7 cells by decreasing the activity of GPx, GR, and CAT enzymes. In conclusion, both Ag(I) complexes, especially 1, warrant for further in vivo evaluation as a new alternative in cancer treatment.HighlightsAg(I) complexes inhibited cell proliferation and induced LDH leakage in human cancer cell lines.Ag(I) complexes induced apoptosis through MMP disruption and ROS generation.Ag(I) complexes mimicked the multi-caspase activity.Ag(I) complexes increased the accumulation of sub-G1 phase.Ag(I) complexes inhibited the activity of antioxidant system enzymes.

Ru(II)/diclofenac-based complexes: DNA, BSA interaction and their anticancer evaluation against lung and breast tumor cells

Ruthenium(ii) diclofenac-based complexes of the general formula [Ru(dicl)(P-P)(bpy)]PF6 [dicl = diclofenac, bpy = 2,2'-bipyridine, and P-P = 1,4'-bis(diphenylphosphino)butane (dppb) (1), 1,2'-bis(diphenylphosphino)ethane (dppe) (2), 1,3'-bis(diphenylphosphino)propane (dppp) (3) and 1,1'-bis(diphenylphosphino)ferrocene (dppf) (4)] are synthesized. The complexes (1-4) are characterized by elemental analyses, infrared, NMR, and UV-vis spectroscopy and (3) and (4) are characterized by single crystal X-ray diffraction. The DNA binding of complexes (1-4), studied by circular dichroism (CD) and Hoechst 33 258 staining assay, indicates their binding with the minor grooves. The complexes interact with BSA with binding constants (Kb) in the range of 2.5 × 103-5.5 × 104 M-1. The complexes exhibit high cytotoxicity against the tumor cell lines A549, MDA-MB-231, and MCF-7 with IC50 values ranging from 0.56 to 15.28 μM. The complexes are more selective for the hormone-dependent MCF-7 breast tumor cell line and complex (1) is the most potent one. The study demonstrates the anticancer activity of ruthenium(ii)/diclofenac-based complexes.

Metal Complexes as Promising Agents for Biomedical Applications

Background::

In this review article, a brief overview of novel metallotherapeutic agents (with an emphasis on the complexes of essential biometals) promising for medical application is presented. We have also focused on the recent work carried out by our research team, specifically the development of redox-active antimicrobial complexes of sterically hindered diphenols with some essential biometals (copper, zinc, nickel).

Results::

The complexes of essential metals (manganese, iron, cobalt, nickel, copper, zinc) described in the review show diverse in vitro biological activities, ranging from antimicrobial and antiinflammatory to antiproliferative and enzyme inhibitory. It is necessary to emphasize that the type of organic ligands in these metal complexes seems to be responsible for their pharmacological activities. In the last decades, there has been a significant interest in synthesis and biological evaluation of metal complexes with redox-active ligands. A substantial step in the development of these redox-active agents is the study of their physicochemical and biological properties, including investigations in vitro of model enzyme systems, which can provide evidence on a plausible mechanism underlying the pharmacological activity. When considering the peculiarities of the pharmacological activity of the sterically hindered diphenol derivatives and their nickel(II), copper(II) and zinc(II) complexes synthesized, we took into account the following: (i) all these compounds are potential antioxidants and (ii) their antimicrobial activity possibly results from their ability to affect the electron-transport chain.

Conclusion::

We obtained novel data demonstrating that the level of antibacterial and antifungal activity in the series of the above-mentioned metal-based antimicrobials depends not only on the nature of the phenolic ligands and complexing metal ions, but also on the lipophilicity and reducing ability of the ligands and metal complexes, specifically regarding the potential biotargets of their antimicrobial action – ferricytochrome c and the superoxide anion radical. The combination of antibacterial, antifungal and antioxidant activity allows one to consider these compounds as promising substances for developing therapeutic agents with a broad spectrum of activities.

Copper Coordination Compounds as Biologically Active Agents

Copper-containing coordination compounds attract wide attention due to the redox activity and biogenicity of copper ions, providing multiple pathways of biological activity. The pharmacological properties of metal complexes can be fine-tuned by varying the nature of the ligand and donor atoms. Copper-containing coordination compounds are effective antitumor agents, constituting a less expensive and safer alternative to classical platinum-containing chemotherapy, and are also effective as antimicrobial, antituberculosis, antimalarial, antifugal, and anti-inflammatory drugs. 64Сu-labeled coordination compounds are promising PET imaging agents for diagnosing malignant pathologies, including head and neck cancer, as well as the hallmark of Alzheimer's disease amyloid-β (Aβ). In this review article, we summarize different strategies for possible use of coordination compounds in the treatment and diagnosis of various diseases, and also various studies of the mechanisms of antitumor and antimicrobial action.

Synthesis, crystal structures and characterizations of three new copper(II) complexes including anti-inflammatory diclofenac

Three new diclofenac-based copper(II) complexes, namely tetrakis{μ-2-[2-(2,6-dichloroanilino)phenyl]acetato-κ2 O:O′}bis(methanol-κO)copper(II), [Cu2(μ-dicl)4(CH3OH)2] (1), bis{2-[2-(2,6-dichloroanilino)phenyl]acetato-κ2 O,O′}bis(1-vinyl-1H-imidazole-κN 3)copper(II), [Cu(dicl)2(vim)2] (2), and bis{2-[2-(2,6-dichloroanilino)phenyl]acetato-κ2 O,O′}bis(1H-imidazole-κN 3)copper(II), [Cu(dicl)2(im)2] (3) [dicl is diclofenac (C14H10Cl2NO2), vim is 1-vinylimidazole (C5H6N2) and im is imidazole (C3H4N2)], have been synthesized and characterized by elemental analysis, FT–IR spectroscopy, thermal analysis and single-crystal X-ray diffraction. X-ray diffraction analysis shows that complex 1 consists of dimeric units in which the dicl ligand exhibits a bidentate syn,syn-μ2 coordination mode linking two copper(II) centres. Complexes 2 and 3 have mononuclear units with the general formula [Cu(dicl)2 L 2] (L is vim or im) in which the CuII ions are octahedrally coordinated by two L and two dicl chelating ligands. The L and dicl ligands both occupy the trans positions of the coordination octahedron. The different coordination modes of dicl in the title complexes were revealed by Fourier transform IR (FT–IR) spectroscopy. The spin matching between the copper(II) centres in the dimeric [Cu2(μ-dicl)4(CH3OH)2] units was also confirmed by magnetic data to be lower than the spin-only value and electron paramagnetic resonance (EPR) spectra. The thermal properties of the complexes were investigated by thermogravimetric (TG) and differential thermal analysis (DTA) techniques.

A Perspective - can copper complexes be developed as a novel class of therapeutics?

Although copper-ligand complexes appear to be promising as a new class of therapeutics, other than the family of copper(ii) coordination compounds referred to as casiopeínas these compounds have yet to reach the clinic for human use. The pharmaceutical challenges associated with developing copper-based therapeutics will be presented in this article along with a discussion of the potential for high-throughput chemistry, computer-aided drug design, and nanotechnology to address the development of this important class of drug candidates.

Efficient copper-based DNA cleavers from carboxylate benzimidazole ligands

Four copper(II) coordination compounds from 2-benzimidazole propionic acid (Hbzpr) and 4-(benzimidazol-2-yl)-3-thiobutanoic acid (Hbztb) were synthesized and fully characterized by elemental analyses, electronic spectroscopy, FT-IR and mass spectrometry. The molecular structure for the four complexes was confirmed by single-crystal X-ray crystallography. The DNA-interacting properties of the two trinuclear and two mononuclear compounds were investigated using different spectroscopic techniques including absorption titration experiments, fluorescence spectroscopy and circular dichroism spectroscopy. Trinuclear [Cu₃(bzpr)₄(H₂O)₂](NO₃)₂·3H₂O·CH₃OH (2) and [Cu₃(bzpr)₄Cl₂]·3H₂O (3) bind to DNA through non-intercalative interactions, while for mononuclear [Cu(bzpr)₂(H₂O)]·2H₂O (1) and [Cu(bztb)₂]·2H₂O (4), at minor concentrations in relation to the DNA, a groove binding interaction is favored, while at higher concentrations an intercalative mode is preferred. The nuclease properties of all complexes were studied by gel electrophoresis, which showed that they were able to cleave supercoiled plasmid DNA (form I) to the nicked form (form II). Compound 4 is even capable of generating linear form III (resulting from double-strand cleavage). The proposed mechanism of action involves an oxidative pathway (Fenton-type reaction), which produces harmful reactive species, like hydroxyl radicals.

The use of the Gelot emulsifier in diclofenac sodium semi-solid preparations

In topical formulations, the rheological parameters and pharmaceutical availability of many active agents have been improved by the addition of modern excipients. This translates into increased interest in the topical use of NSAIDs. The aim of this study was to create series of effective oil in water (O/W) diclofenac sodium cream formulations that differ in the applied fatty phase, utilizing Gelot TM64 (Gattefosse) (a modern non-ionic emulsifier). In the produced prescriptions, estimation was made of the effect of this on the rheological parameters and the pharmaceutical availability of the diclofenac sodium. Herein, the hydrophilic petrolatum-based cream demonstrated the highest rate of release of the active agent, as well as the best set of beneficial rheological parameters.

Four monomeric copper(ii) complexes of non-steroidal anti-inflammatory drug Ibuprofen and N-donor ligands: syntheses, characterization, crystal structures and cytotoxicity studies

The cytotoxic effects of four new Ibuprofen–Cu(ii) complexes were tested finding significant cytotoxicity on human melanoma cell line HT-144.

Facile synthesis, crystal structure and bioactivity evaluation of two novel barium complexes based on 2,4,6-trichlorophenoxyacetic acid and o-ferrocenylcarbonyl benzoic acid

With a microwave method, two novel Ba(ii) complexes were synthesized for the first time and their allelopathic and antifungal activity was evaluated.

Adsorption and co-adsorption of diclofenac and Cu(II) on calcareous soils

Pharmaceuticals are emerging contaminants and their presence in different compartments of the environment has been detected in many countries. In this study, laboratory batch experiments were conducted to characterize the adsorption of diclofenac, a widely used non-steroidal anti-inflammatory drug, on six calcareous soils. The adsorption of diclofenac was relatively low, which may lead to a risk of groundwater contamination and plant uptake. A correlation between the soil-water distribution coefficient Kd and soil characteristics has been highlighted. Indeed, diclofenac adsorption as a function of soil organic matter content (% OM) and Rt=% CaCO3/% OM was successfully described through a simple empirical model, indicating the importance of considering the inhibiting effect of CaCO3 on OM retention properties for a better assessment of diclofenac fate in the specific case of calcareous soils. The simultaneous co-adsorption of diclofenac and copper - a ubiquitous pollutant in the environment - at the water/soil interface, was also investigated. It appeared quite unexpectedly that copper did not have a significant influence on diclofenac retention.

DNA-interacting and biological properties of copper(ii) complexes from amidino-O-methylurea

Two copper(ii) complexes from the water-soluble amidino-O-methylureas exhibit interesting activities which are of paramount importance for biological applications.

Design and optimization of drugs used to treat copper deficiency

INTRODUCTION

Copper is an essential element in the human organism. Furthermore, copper deficiency is rare; however, the hematologic manifestations associated with copper deficiency, such as anemia, leukopenia, neutropenia, myeloneuropathy and osteoporosis, are well known.

AREAS COVERED

The authors present an overview of the various commercially available drugs used in the treatment of copper deficiency. Furthermore, the authors offer a description of copper complexes, as potential pharmaceutically active compounds, that can be used in the design of new formulations with therapeutic potential.

EXPERT OPINION

Progress in the synthesis of new metallo-organic complexes (such as the copper-pullulan complex) and the chelated form of copper have provided new avenues for drug design that combat copper deficiency. The copper-pullulan complex, as an active compound, has been designed in its solid dosage form, and its optimization in the treatment of copper deficiency has been furthered through advancements in experimental design methodology. The authors believe that the numerous ongoing studies, evaluating the synthesis of these complexes, should produce new additions to the copper deficiency therapeutic armamentarium in the future.