CuI and CuII complexes with phosphine derivatives of fluoroquinolone antibiotics - A comparative study on the cytotoxic mode of action.

In this paper, we present a comparative study on the cytotoxic mode of action of copper(I) and copper(II) complexes with phosphine derivatives of fluoroquinolone antibiotics (ciprofloxacin HCp and norfloxacin HNr). The in vitro cytotoxic activity of four new compounds was tested against two selected cancer cell lines. All complexes exhibited much better cytotoxicity against both cell lines than unmodified fluoroquinolone antibiotics, their phosphines (PCp, PNr), chalcogenide derivatives (oxides: OPCp, OPNr; sulfides: SPCp, SPNr and selenides: SePCp, SePNr) and previously described by us complexes with phosphines derived from different fluoroquinolones: lomefloxacin (HLm) and sparfloxacin (HSf) as well as cisplatin. Apoptosis, observed at a great predominance, was induced by all studied complexes. Importantly, it was concluded that coordination compounds with Cu(I) ion ([CuI-PNr] and [CuI-PCp]) were much more active than those with Cu(II) ion ([OPNr-CuII], [OPCp-CuII]), even though the highest efficacy to produce reactive oxygen species, participating in overall cytotoxicity, was proved for copper(II) complexes among all studied compounds. Herein, we discuss not only results obtained for copper(I)/(II) complexes with phosphines derived from HNr and HCp but we also compare them to previously described data for complexes with HLm and HSf derivatives. This is the first insight into a structure-activity relationship of copper complexes with phosphine derivatives of fluoroquinolone antibiotics.

Interaction of methotrexate, an anticancer agent, with copper(II) ions: coordination pattern, DNA-cleaving properties and cytotoxic studies.

The acid-base properties and the Cu(II) binding processes of methotrexate (MTX) were characterized by selected spectroscopic techniques and potentiometric measurements. The pH titration data showed that MTX behaves as a triprotic ligand. The deprotonation constants were determined for α-COOH and γ-COOH groups and (N1)H+ from the pteridine ring. Taking all the obtained results into consideration, a coordination pattern was proposed. The DNA-cleaving activity and reactive oxygen species (ROS) generation were investigated for both MTX and the Cu(II)-MTX system. The complex displayed a promising nuclease activity toward plasmid DNA in the presence of hydrogen peroxide. Interestingly, the induction of ROS, such as hydroxyl radicals, superoxide anions or singlet oxygen, was excluded and a different mechanism of DNA degradation was proposed. As MTX is now commonly used in anticancer therapy i.e. against lung cancer, basic cell-based studies were carried out to establish if its Cu(II) complex exhibits higher cytotoxic properties than the ligand alone. Activities of both compounds were also tested against colon carcinoma. Moreover, the determined values of IC50 were confronted with the cytotoxic activity of cisplatin.

Methionine restriction restores a younger metabolic phenotype in adult mice with alterations in fibroblast growth factor 21.

Methionine restriction (MR) decreases body weight and adiposity and improves glucose homeostasis in rodents. Similar to caloric restriction, MR extends lifespan, but is accompanied by increased food intake and energy expenditure. Most studies have examined MR in young animals; therefore, the aim of this study was to investigate the ability of MR to reverse age-induced obesity and insulin resistance in adult animals. Male C57BL/6J mice aged 2 and 12 months old were fed MR (0.172% methionine) or control diet (0.86% methionine) for 8 weeks or 48 h. Food intake and whole-body physiology were assessed and serum/tissues analyzed biochemically. Methionine restriction in 12-month-old mice completely reversed age-induced alterations in body weight, adiposity, physical activity, and glucose tolerance to the levels measured in healthy 2-month-old control-fed mice. This was despite a significant increase in food intake in 12-month-old MR-fed mice. Methionine restriction decreased hepatic lipogenic gene expression and caused a remodeling of lipid metabolism in white adipose tissue, alongside increased insulin-induced phosphorylation of the insulin receptor (IR) and Akt in peripheral tissues. Mice restricted of methionine exhibited increased circulating and hepatic gene expression levels of FGF21, phosphorylation of eIF2a, and expression of ATF4, with a concomitant decrease in IRE1α phosphorylation. Short-term 48-h MR treatment increased hepatic FGF21 expression/secretion and insulin signaling and improved whole-body glucose homeostasis without affecting body weight. Our findings suggest that MR feeding can reverse the negative effects of aging on body mass, adiposity, and insulin resistance through an FGF21 mechanism. These findings implicate MR dietary intervention as a viable therapy for age-induced metabolic syndrome in adult humans.

Copper(I) (pseudo)halide complexes with neocuproine and aminomethylphosphines derived from morpholine and thiomorpholine - in vitro cytotoxic and antimicrobial activity and the interactions with DNA and serum albumins.

Herein, a series of CuI or CuNCS complexes with neocuproine (2,9-dimethyl-1,10-phenanthroline: dmp) and two tris(aminomethyl)phosphines derived from morpholine (P(CH2 N(CH2 CH2 )2 O)3 ) or thiomorpholine (P(CH2 N(CH2 CH2 )2 S)3 ) were tested as cytotoxic agents in vitro towards mouse colon carcinoma (CT26) and human lung adenocarcinoma (A549). The studies showed that the complexes exhibit potential antitumor properties, displayed by IC50 values below 10 µm towards the tested cell lines, in the case of 4-h incubation time with the examined compounds. Moreover, a high antimicrobial activity of all the complexes was observed against Staphylococcus aureus and Candida albicans with minimal inhibitory concentrations equal to 1-2 µg/mL. To gain insight into the molecular mechanism of biological activity of the complexes, we investigated also their interactions with plasmid DNA (pUC18) and the human and bovine serum albumins. Gel electrophoresis experiments demonstrated that all the compounds were comparably efficient in DNA degradation process; however, luminescence quenching showed surprising dependence on the interactions strength of the used compounds with the albumins. Apart from exceptionally effective [CuI(dmp)P(CH2 N(CH2 CH2 )2 O)3 ], the complexes with P(CH2 N(CH2 CH2 )2 O)3 quenched more strongly luminescence of bovine serum albumin, while the complexes with P(CH2 N(CH2 CH2 )2 S)3 were more active in the quenching of human serum albumin luminescence.

Di-µ-iodido-bis-[(dimethyl 2,2'-biquinoline-4,4'-dicarboxyl-ate-κ(2)N,N')copper(I)].

In the centrosymmetric dinuclear title complex, [Cu(2)I(2)(C(22)H(16)N(2)O(4))(2)], the Cu(I) atom is coordinated in a distorted tetra-hedral geometry by an N,N'-bidentate dimethyl 2,2'-biquinoline-4,4'-dicarboxyl-ate ligand and two symmetry-related I atoms, which act as bridges to a symmetry-related Cu(I) atom. The distance between the Cu(I) atoms within the dinuclear unit is 2.6723 (11) Å.