Anticancer Function and ROS-Mediated Multi-Targeting Anticancer Mechanisms of Copper (II) 2-hydroxy-1-naphthaldehyde Complexes

Strontium Attenuates Hippocampal Damage via Suppressing Neuroinflammation in High-Fat Diet-Induced NAFLD Mice

Non-alcoholic fatty liver disease (NAFLD) leads to hippocampal damage and causes a variety of physiopathological responses, including the induction of endoplasmic reticulum stress (ERS), neuroinflammation, and alterations in synaptic plasticity. As an important trace element, strontium (Sr) has been reported to have antioxidant effects, to have anti-inflammatory effects, and to cause the inhibition of adipogenesis. The present study was undertaken to investigate the protective effects of Sr on hippocampal damage in NAFLD mice in order to elucidate the underlying mechanism of Sr in NAFLD. The mouse model of NAFLD was established by feeding mice a high-fat diet (HFD), and the mice were treated with Sr. In the NAFLD mice, we found that treatment with Sr significantly increased the density of c-Fos⁺ cells in the hippocampus and inhibited the expression of caspase-3 by suppressing ERS. Surprisingly, the induction of neuroinflammation and the increased expression of inflammatory cytokines in the hippocampus following an HFD were attenuated by Sr treatment. Sr significantly attenuated the activation of microglia and astrocytes induced by an HFD. The expression of phospho-p38, ERK, and NF-κB was consistently significantly increased in the HFD group, and treatment with Sr decreased their expression. Moreover, Sr prevented HFD-induced damage to the ultra-structural synaptic architecture. This study implies that Sr has beneficial effects on repairing the damage to the hippocampus induced by an HFD, revealing that Sr could be a potential candidate for protection from neural damage caused by NAFLD.

Copper in cancer: From pathogenesis to therapy

One of the basic trace elements for the structure and metabolism of human tissue is copper. However, as a heavy metal, excessive intake or abnormal accumulation of copper in the body can cause inevitable damage to the organism because copper can result in direct injury to various cell components or disruption of the redox balance, eventually leading to cell death. Interestingly, a growing body of research reports that diverse cancers have raised serum and tumor copper levels. Tumor cells depend on more copper for their metabolism than normal cells, and a decrease in copper or copper overload can have a detrimental effect on tumor cells. New modalities for identifying and characterizing copper-dependent signals offer translational opportunities for tumor therapy, but their mechanisms remain unclear. Therefore, this article summarizes what we currently know about the correlation between copper and cancer and describes the characteristics of copper metabolism in tumor cells and the prospective application of copper-derived therapeutics.

In Vitro Evaluation of the Cytotoxic Potential of Thiosemicarbazide Coordinating Compounds in Hepatocyte Cell Culture

Cancer is a global medical problem and, despite research efforts in the field of tumor treatment, there is currently a shortage of specific anticancer drugs. Most anticancer drugs show significant side effects. The liver is the organ that has central functions in drug metabolism, being a major target of the harmful action of anticancer compounds. In this context, it is essential to evaluate the cytotoxic effects of potential anticancer substances. Therefore, hepatotoxicity and hepatocyte viability were determined in vitro to evaluate the action of seven new local thiosemicarbazide coordination compounds (CCT) on normal liver cells. Doxorubicin was used as a reference substance. The control group consisted of hepatocytes not exposed to CCT action. The cell viability of hepatocytes treated with CCT decreased significantly by 5-12% compared to the control, but was statistically significantly higher by 5-14% compared to doxorubicin, except after CMD-8 and CMT-67 influence, when it does not change. Thus, new local CCT had a selective effect on hepatocytes in vitro and were less hepatotoxic compared to doxorubicin, which may be the basis for further study of its potential in anticancer drugs.

Synthesis, Biological Evaluation, DNA Binding, and Molecular Docking of Hybrid 4,6-Dihydrazone Pyrimidine Derivatives as Antitumor Agents

In the present paper, on the basis of molecular hybridization, a series of 4,6-dihydrazone pyrimidine derivatives containing the pyridine moiety were synthesized, structurally characterized, and evaluated in vitro for their antitumor activity. According to the results, all the tested compounds demonstrated broad-spectrum antitumor activity against selected tumor cell lines (MCF-7, BGC-823, A549, and BEL-7402) and no obvious toxicity toward normal cells HL-7702. In particular, compounds 10a and 10f were found to be the most promising antitumor agents among the tested compounds against BGC-823 cells (IC₅₀ = 9.00 μM and 7.89 μM) and BEL-7402 cells (IC₅₀ = 6.70 μM and 7.66 μM), respectively. Compounds 10a and 10f exhibited higher potency against BGC-823 and BEL-7402 than the positive control 5-FU (IC₅₀ = 15.18 μM and 15.81 μM). Further mechanism investigations demonstrated that compounds 10a and 10f could significantly increase the level of cellular ROS and induce early apoptosis of BGC-823 cells in a dose-dependent manner. Moreover, the DNA binding results from UV/Vis, CD spectroscopy, and molecular docking studies indicated that 10a and 10f bind with DNA via groove binding and partial intercalation. These results demonstrated that 10a and 10f may serve as novel lead compounds for the discovery of more dihydrazone pyrimidine derivatives with improved antitumor potency and selectivity.

Association between pre-diagnostic dietary copper, zinc, and copper-to-zinc ratio and severity of ovarian cancer

BACKGROUND

The impact of dietary trace elements intake on ovarian cancer (OC) severity is unknown.

OBJECTIVE

We firstly explore the relationship between dietary copper (Cu), zinc (Zn), and copper-to-zinc (Cu/Zn) ratio and severity of OC.

METHODS

This cross-sectional study included 701 women from the OC follow-up study between 2015 and 2020. Dietary information was collected by a validated food frequency questionnaire (FFQ). The severity information of OC including age at diagnosis, histological type, International Federation of Gynecology and Obstetrics (FIGO) stage, and histopathologic grade was ascertained from medical records. Logistic regression model was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of aforementioned associations.

RESULTS

Among 701 participants, the number of patients age at diagnosis older than 50 were 443 (63.2%). The number of patients diagnosed as serous, III-IV stage, and poorly differentiation OC were 477 (68.05%), 336 (47.93%), and 597 (85.16%), respectively. In addition, compared with the lowest tertile intake, higher possibility of non-serous OC was associated with the pre-diagnosis dietary Cu (OR = 2.39, 95% CI = 1.28-4.47, p trend < 0.05) and Cu/Zn ratio (OR = 2.06, 95% CI = 1.26-3.39, P trend < 0.05) in the highest tertile intake. The risk of poorly differentiation OC at diagnosis was significant inversely related to dietary Cu intake (OR = 0.40, 95% CI = 0.18-0.88, P trend < 0.05). Besides, the results of subgroup analyses were consistent with the main findings but not all of them showed statistical significance.

CONCLUSION

Pre-diagnostic dietary Cu and Cu/Zn ratio were contributed to reducing the severity of OC at diagnosis, especially for the risk of serous OC and poorly differentiation OC.

Copper(II) cation and bathophenanthroline coordination enhance therapeutic effects of naringenin against lung tumor cells

The development of new anticancer compounds is one of the challenges of bioinorganic and medicinal chemistry. Naringenin and its metal complexes have been recognized as promising inhibitors of cell proliferation, having enormous potential to act as an antioxidant and antitumorigenic agent. Lung cancer is the second most commonly diagnosed type of cancer. Therefore, this study is devoted to investigate the effects of Cu(II), naringenin (Nar), binary Cu(II)-naringenin complex (CuNar), and the Cu(II)-naringenin containing bathophenanthroline as an auxiliary ligand (CuNarBatho) on adenocarcinoma human alveolar basal epithelial cells (A549 cells) that are used as models for the study of drug therapies against lung cancer. The ternary complex shows selectivity being high cytotoxic against malignant cells. The cell death generated by CuNarBatho involves ROS production, loss of mitochondrial membrane potential, and depletion of GSH level and GSH/GSSG ratio. The structure-relationship activity was assessed by comparison with the reported Cu(II)-naringenin-phenanthroline complex. The CuNarBatho complex was synthesized and characterized by elemental analysis, molar conductivity, mass spectrometry, thermogravimetric measurements and UV-VIS, FT-IR, EPR, Raman and ¹H-NMR spectroscopies. In addition, the binding to bovine serum albumin (BSA) was studied at the physiological conditions (pH = 7.4) by fluorescence spectroscopy.

Metal Complexes in Target-Specific Anticancer Therapy: Recent Trends and Challenges

Cancer is characterized by abnormal cell differentiation in or on the part of the body. The most commonly used chemotherapeutic drugs are developed to target rapidly dividing cells, such as cancer cells, but they also damage healthy epithelial cells. This has serious consequences for normal cells and become responsible for the development of various disorders. Several strategies for delivering the cytotoxic drugs to cancerous sites that limit systemic toxicity and other adverse effects have recently been evolved. Among them, biomolecule-conjugated metal complexes-based cancer targeting strategies have shown tremendous advantages in cancer therapy. This review focuses on several chemoselective biomolecules-bound metal complexes as prospective cancer therapy-targeted agents. In this review, we presented the details of the various extra- and intracellular targeting mechanisms in cancer therapy. We also addressed the current clinical issues and recent therapeutic strategies in targeted cancer therapy that may pave a way for the future direction of metal complexes-based targeted cancer therapy.

Fumarato and Phthalato Bridged Dinuclear Metal-Organic Cu(II) and Mn(II) Compounds involving Infinite Fumarate-water Assemblies and Unusual Structure-guiding H-bonded Synthons: Antiproliferative Evaluation and Theoretical Studies

Two new dinuclear coordination compounds viz. [Cu2(µ-fum)(phen)2(H2O)6](fum)•6H2O (1) and [Mn2(µ-phth)2(phen)4]•2H2O (2) (phen = 1,10-phenanthroline, fum = fumarate and phth = phthalate) have been synthesized and characterized by elemental analysis, single...

A selective CuII complex with 4-fluorophenoxyacetic acid hydrazide and phenanthroline displays DNA-cleaving and pro-apoptotic properties in cancer cells

The thin line between efficacy and toxicity has challenged cancer therapy. As copper is an essential micronutrient and is important to tumor biology, CuII complexes emerged as an alternative to chemotherapy; however, its biological properties need to be better understood. Thus, we report in vitro the antitumor effects of two CuII complexes named [Cu(4-fh)(phen)(ClO4)2] (complex 1) and [Cu(4-nh)(phen)(ClO4)2]·H2O (complex 2), in which 4-fh = 4-fluorophenoxyacetic acid hydrazide; 4-nh = 4-nitrobenzoic hydrazide and phen = 1,10-phenanthroline. Both complexes presented cytotoxic activity against tumor cells, but only complex 1 showed significant selectivity. Complex 1 also induced DNA-damage, led to G0/G1 arrest and triggered apoptosis, which was initiated by an autophagy dysfunction. The significant in vitro selectivity and the action mechanism of complex 1 are noteworthy and reveal this prodrug as promising for anticancer therapy.

Depicting the DNA Binding and Cytotoxicity Studies against Human Colorectal Cancer of Aquabis (1-Formyl-2-Naphtholato-k2O,O′) Copper(II): A Biophysical and Molecular Docking Perspective

In this study, we attempted to examine the biological activity of the copper(II)–based small molecule aquabis (1-formyl-2-naphtholato-k2O,O′)copper(II) (1) against colon cancer. The characterization of complex 1 was established by analytical and spectral methods in accordance with the single-crystal X-ray results. A monomeric unit of complex 1 exists in an O4 (H2O) coordination environment with slightly distorted square pyramidal geometry (τ = ~0.1). The interaction of complex 1 with calf thymus DNA (ctDNA) was determined by employing various biophysical techniques, which revealed that complex 1 binds to ctDNA at the minor groove with a binding constant of 2.38 × 105 M–1. The cytotoxicity of complex 1 towards human colorectal cell line (HCT116) was evaluated by the MTT assay, which showed an IC50 value of 11.6 μM after treatment with complex 1 for 24 h. Furthermore, the apoptotic effect induced by complex 1 was validated by DNA fragmentation pattern, which clarified that apoptosis might be regulated through the mitochondrial-mediated production of reactive oxygen species (ROS) causing DNA damage pathway. Additionally, molecular docking was also carried out to confirm the recognition of complex 1 at the minor groove.

Experimental and Theoretical DFT Study of Cu(I)/N,N-Disubstituted-N'-acylthioureato Anticancer Complexes: Actin Cytoskeleton and Induction of Death by Apoptosis in Triple-Negative Breast Tumor Cells

Six complexes with the general formula [Cu(acylthioureato)(PPh₃)₂] were synthesized and characterized using spectroscopic techniques (IR, UV/visible, and 1D and 2D NMR), mass spectrometry, elemental analysis, and X-ray diffraction. Interpretation of the in vitro cytotoxicity data of Cu(I) complexes took into account their stability in cell culture medium. DFT calculations showed that NMR properties, such as the shielding of carbon atoms, are affected by relativistic effects, supported by the ZORA Hamiltonian in the theoretical calculations. Additionally, the calculation of the energies of the frontier molecular orbitals predicted that the structural changes of the acylthiourea ligands did not cause marked changes in the reactivity descriptors. All complexes were cytotoxic to the evaluated tumor cell lines [MDA-MB-231 (triple-negative breast cancer, TNBC), MCF-7 (breast cancer), and A549 (lung cancer)]. In the MDA-MB-231 cell line, complex 1 significantly altered the cytoskeleton of the cells, reducing the density and promoting the condensation of F-actin filaments. In addition, the compound caused an increase in the percentage of cells in the fragmented DNA region (sub-G0) and induced cell death via the apoptotic pathway starting at the IC₅₀ concentration. Taken together, the results show that complex 1 has cytotoxic and apoptotic effects on TNBC cells, which is a cell line originating from an aggressive, difficult-to-treat breast cancer.

The Cytotoxic Effect of Copper (II) Complexes with Halogenated 1,3-Disubstituted Arylthioureas on Cancer and Bacterial Cells

A series of eight copper (II) complexes with 3-(4-chloro-3-nitrophenyl)thiourea were designed and synthesized. The cytotoxic activity of all compounds was assessed in three human cancer cell lines (SW480, SW620, PC3) and human normal keratinocytes (HaCaT). The complexes 1, 3, 5, 7 and 8 were cytotoxic to the studied tumor cells in the low micromolar range, without affecting the normal cells. The complexes 1, 3, 7 and 8 induced lactate dehydrogenase (LDH) release in all cancer cell lines, but not in the HaCaT cells. They provoked early apoptosis in pathological cells, especially in SW480 and PC3 cells. The ability of compounds 1, 3, 7 and 8 to diminish interleukin-6 (IL-6) concentration in a cell was established. For the first time, the influence of the most promising Cu (II) complexes on intensities of detoxifying and reactive oxygen species (ROS) scavenging the enzymes of tumor cells was studied. The cytotoxic effect of all copper (II) conjugates against standard and hospital bacterial strains was also proved.

The quinazoline derivative, 04NB-03, induces cell cycle arrest and apoptosis in hepatocellular carcinoma cells in a reactive oxygen species-dependent manner

Hepatocellular carcinoma (HCC) is one of the most deadly malignancies worldwide. However, current therapeutic drugs for HCC are far from satisfactory. Thus, the development of new drugs is urgently needed. In this study, we identified a novel quinazoline derivative, 04NB-03, with potent anti-HCC activities both in vitro and in vivo. 04NB-03 effectively suppressed the viability and proliferation of HCC cells. It induced both cell cycle arrest at the G2/M phase and apoptosis in concentration- and time-dependent manners. Moreover, 04NB-03 treatment significantly reduced xenograft tumor growth without notable toxic effects. Mechanistically, 04NB-03 induced endogenous reactive oxygen species (ROS) accumulation in concentration- and time-dependent manners. Scavenging the ROS reversed 04NB-03-induced cell cycle arrest and apoptosis. Taken together, these results indicate that the quinazoline derivative, 04NB-03, inhibits the growth of HCC cells through the induction of cell cycle arrest and apoptosis in an ROS-dependent manner. 04NB-03 is, therefore, a potential small molecule candidate for the development of antitumor drugs targeting HCC.

Transition metals and metal complexes in autophagy and diseases

Transition metals refer to the elements in the d and ds blocks of the periodic table. Since the success of cisplatin and auranofin, transition metal-based compounds have become a prospective source for drug development, particularly in cancer treatment. In recent years, extensive studies have shown that numerous transition metal-based compounds could modulate autophagy, promising a new therapeutic strategy for metal-related diseases and the design of metal-based agents. Copper, zinc, and manganese, which are common components in physiological pathways, play important roles in the progression of cancer, neurodegenerative diseases, and cardiovascular diseases. Furthermore, enrichment of copper, zinc, or manganese can regulate autophagy. Thus, we summarized the current advances in elucidating the mechanisms of some metals/metal-based compounds and their functions in autophagy regulation, which is conducive to explore the intricate roles of autophagy and exploit novel therapeutic drugs for human diseases.

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.

2-Methylimidazole Copper Iminodiacetates for the Adsorption of Oxygen and Catalytic Oxidation of Cyclohexane

The mixed-ligand copper(II) iminodiacetates [Cu(ida)(2-mim)(H₂O)₂]·H₂O (1), [Cu(ida)(2-mim)₂]·2H₂O (2), [Cu(ida)(2-mim)(H₂O)]_n·4.5nH₂O (3), and [Cu₂(ida)₂(2-mim)₂]_n·nH₂O (4) (H₂ida = iminodiacetic acid, 2-mim = 2-methylimidazole) were obtained from neutral or alkaline solutions at different temperatures. The novel complex 4 contains very small holes with diameters of 2.9 Å, which can adsorb O₂ selectively and reversibly between 1.89 to 29.90 bars, compared with the different gases of N₂, H₂, CO₂, and CH₄. This complex is stable up to 150 °C based on thermal analyses and XRD patterns. The four complexes show catalytic activities that facilitate the conversion of cyclohexane to cyclohexanol and cyclohexanone with hydrogen peroxide in a solution. The total conversion is 31% for 4.