Newly Synthesized Doxorubicin Complexes with Selected Metals-Synthesis, Structure and Anti-Breast Cancer Activity

Molecular Recognition on the Multisite Binding Surface of the Keplerate {Mo72Fe30} Giving Supramolecular Texturing and Modulating the Function of Guest Molecules

Molecular recognition underlies structure formation in supramolecular architectures either in materials or in living systems. Here, we used the nanoscale nontoxic Keplerate-type polyoxometalate (POM) {Mo72Fe30} as a template for the recognition of two different guest molecules [tetracycline (TC) and doxorubicin (DOX)] on the textured surface. By means of single crystal X-ray analysis and X-ray photoelectron spectroscopy (XPS), we revised the key features of the {Mo72Fe30} structure, showcasing the guest dimolybdenum units' {Mo2} location under the hexagonal pores and dynamic exchange of these units during dissolution in an aqueous medium. Based on the clarified POM structure, we demonstrated how the small differences between the TC and the DOX molecules can be recognized by the Keplerate surface, revealing the nature of the binding sites─{Mo6}/{FeO6} for TC and {FeO6} for DOX. Furthermore, using the Monte-Carlo method, we calculated the statistical distribution of the guest molecules in the stoichiometric compounds {Mo72Fe30}@TC12 and {Mo72Fe30}@DOX12, displaying the supramolecular ordering of the DOX species and randomization of the TC as a result of different coordinations to the POM surface. The produced {Mo72Fe30}@TC12 and {Mo72Fe30}@DOX12 associates were evaluated for bioactivity, showing how their interaction with POM can modulate the biological function of guest molecules.

The effects of metformin and PCL-sorafenib nanoparticle co-treatment on MCF-7 cell culture model of breast cancer

Despite breakthrough therapeutics in breast cancer, it is one of the main causes of mortality among women worldwide. Thus, drug therapies for treating breast cancer have recently been developed by scientists. Metformin and sorafenib are well-known therapeutics in breast cancer. In the present study, we combined sorafenib and PCL-sorafenib with metformin to improve drug absorption and promote therapeutic efficiency. The MCF-7 cells were treated with metformin, sorafenib, or PCL-sorafenib. The growth inhibitory effect of these drugs and cell viability were assessed using MTT and flow cytometry assays, respectively. The expression of targeted genes involved in cell proliferation, signaling, and the cell cycle was measured by real-time PCR. The results showed that MCF-7 cells treated with metformin/sorafenib and PCL-sorafenib/metformin co-treatment contributed to 50% viability compared to the untreated group. Moreover, PI and Annexin V staining tests showed that the cell viability for metformin/sorafenib and PCL-sorafenib/metformin was 38% and 17%, respectively. Furthermore, sorafenib/metformin and PCL-sorafenib/metformin lead to p53 gene expression increase by which they can increase ROS, thereby decreasing GPX4 gene expression. In addition, they affected the expression of BCL2 and BAX genes and altered the cell cycle. Together, the combination of PCL-sorafenib/metformin and sorafenib/metformin increased sorafenib absorption at lower doses and also led to apoptosis and oxidative stress increases in MCF-7 cells.

Exploring Substituted Tetrazoloquinazoline: Biological Activities, Molecular Docking Analysis, and Anti-Breast Cancer MCF7/HER2 Effects

Breast cancer is a condition where breast tissue cells grow uncontrollably. Various natural and synthesized compounds, such as quinazoline, have been studied for their potential as anticancer agents. Quinazoline derivatives have shown diverse bioactivities, including antimalarial, antifungal, antimicrobial, and anticancer properties. This research aims to synthesize substituted tetrazoloquinazoline and evaluate its potential as an anticancer agent using molecular docking studies with the Molecular Operating Environment (MOE) software. Furthermore, molecular dynamic was also performed to analyze the binding stability of this protein-ligand complex. Additionally, the physicochemical and pharmacokinetic properties of quinazoline compounds were assessed using the website https://www.swissadme.ch. The cytotoxic activity of the compounds was evaluated using the MTT assay. The docking results revealed that substituted tetrazoloquinazoline exhibited a significantly different range of binding free energy compared to the positive control. Moreover, the substituted tetrazoloquinazoline compounds comply with Lipinski's Rule of Five (Ro5), indicating that they are easily absorbable and have good permeability. The cytotoxic activity of the compounds was found to have an IC50 value of >1000 ppm, classifying them as noncytotoxic. It therefore paved the way for the discovery of promising next-generation drugs against breast cancer.

Chitosan-copper microparticles as doxorubicin microcarriers for bone tumor therapy

Doxorubicin (DOX) is a chemotherapeutic drug used in osteosarcoma treatments, usually administrated in very high dosages. This study proposes novel DOX microcarriers based on chitosan (CHT) physically crosslinked with copper(II) ions that will act synergically to inhibit tumor growth at lower drug dosage without affecting the healthy cells. Spherical CHT-Cu microparticles with a smooth surface and an average size of 30.1 ± 9.1 µm were obtained by emulsion. The release of Cu2+ ions from the CHT-Cu microparticles showed that 99.4 % of added cupric ions were released in 72 h of incubation in a complete cell culture medium (CCM). DOX entrapment in microparticles was conducted in a phosphate buffer solution (pH 6), utilizing the pH sensitivity of the polymer. The successful drug-loading process was confirmed by DOX emitting red fluorescence from drug-loaded microcarriers (DOX@CHT-Cu). The drug release in CCM showed an initial burst release, followed by sustained release. Biological assays indicated mild toxicity of CHT-Cu microparticles on the MG-63 osteosarcoma cell line, without affecting the viability of human mesenchymal stem cells (hMSCs). The DOX@CHT-Cu microparticles at concentration of 0.5 mg mL‒1 showed selective toxicity toward MG-63 cells.

Design, synthesis, in vitro and in silico evaluation of indole-based tetrazole derivatives as putative anti-breast cancer agents

A series of new indole-tetrazole derivatives were designed and synthesized to develop potential anti-breast cancer agents. The compounds exhibited in vitro anti-proliferative activity against ER-α positive T-47D (IC50 = 3.82-24.43 μM), MCF-7 (IC50 = 3.08-22.65 μM), and ER-α negative MDA-MB-231 (IC50 = 7.69-19.4 μM) human breast cancer cell lines. Compounds 5d and 5f displayed significant anti-proliferative activity compared to bazedoxifene (IC50 = 14.23 ± 0.68 μM), with IC50 values of 10.00 ± 0.59 and 3.83 ± 0.74 μM, respectively, against the ER-α dominant T-47D cell line. Also, both compounds showed non-significant cytotoxicity against normal cells HEK-293. Further, the ER-α binding affinity of 5d and 5f was assessed through a fluorescence polarization-based competitive binding assay, where 5d and 5f have shown significant binding with IC50 = 5.826 and 110.6 nM, respectively, as compared to the standard drug bazedoxifene (IC50 = 339.2 nM). Western blot analysis confirmed that compound 5d reduced ER-α protein expression in T-47D cells, hindering its transactivation and signalling pathways. Additionally, a molecular docking study suggests that compounds 5d and 5f bind in such a fashion that induces conformational changes in the protein, culminating in their antagonistic effect. Pharmacokinetic profiles showed that the compounds possessed drug-like properties. Furthermore, molecular dynamics simulation studies establish the dynamic stability and conformational behaviour of the ER-α protein and ligand complex of both compounds. Additionally, 5d and 5f ensure biological feasibility as per their DFT analysis through HOMO-LUMO energy gap analysis. In conclusion, compounds 5d and 5f, exhibiting significant ER-α antagonistic activity, can act as potential lead compounds for anti-breast cancer therapies.

Multiple Physiological and Biochemical Functions of Ascorbic Acid in Plant Growth, Development, and Abiotic Stress Response

Ascorbic acid (AsA) is an important nutrient for human health and disease cures, and it is also a crucial indicator for the quality of fruit and vegetables. As a reductant, AsA plays a pivotal role in maintaining the intracellular redox balance throughout all the stages of plant growth and development, fruit ripening, and abiotic stress responses. In recent years, the de novo synthesis and regulation at the transcriptional level and post-transcriptional level of AsA in plants have been studied relatively thoroughly. However, a comprehensive and systematic summary about AsA-involved biochemical pathways, as well as AsA's physiological functions in plants, is still lacking. In this review, we summarize and discuss the multiple physiological and biochemical functions of AsA in plants, including its involvement as a cofactor, substrate, antioxidant, and pro-oxidant. This review will help to facilitate a better understanding of the multiple functions of AsA in plant cells, as well as provide information on how to utilize AsA more efficiently by using modern molecular biology methods.

Influence of copper(I) nicotinate complex on the Notch1 signaling pathway in triple negative breast cancer cell lines

Triple negative breast cancer (TNBC) is a subtype of breast cancer which is characterized by its aggressiveness, poor and short overall survival. In this concept, there is a growing demand for metal-based compounds in TNBC therapy as copper complex that have a less toxic effect on normal cells and could stimulate apoptotic cell death. Additionally, Notch1 signaling pathway has received great attention as one of the most important potential targets for developing a novel therapeutic strategy. The present study is an attempt to assess the promising chemotherapeutic activities of copper(I) nicotinate (CNC) through its impact on the expression of downstream genes of Notch1 signaling pathway and the cell fate of TNBC. The co-treatment of TNBC cells with doxorubicin (Doxo) and CNC was also investigated. To approach the objective of the present study, TNBC cell lines; HCC1806 and MDAMB231, were utilized. MTT assay was used to determine the IC50 values of CNC and Doxo. After treatment, microtubule-associated protein light chain3 (LC3) were determined by flow cytometry. Additionally, qRT-PCR technique was used to detect the changes in genes levels that are involved Notch1 signaling pathway. Moreover, autophagosomes were monitored and imaged by Transmission electron microscopy. Treatment of TNBC cells with CNC modulated Notch1 signaling pathway in different manners with respect to the type of cells and the applied dose of CNC. The observed effects of CNC may reflect the possible anti-cancer activities of CNC in both types of TNBC. However, cell type and CNC dose should be considered.

Advancements in the Application of the Fenton Reaction in the Cancer Microenvironment

Cancer is a complex and multifaceted disease that continues to be a global health challenge. It exerts a tremendous burden on individuals, families, healthcare systems, and society as a whole. To mitigate the impact of cancer, concerted efforts and collaboration on a global scale are essential. This includes strengthening preventive measures, promoting early detection, and advancing effective treatment strategies. In the field of cancer treatment, researchers and clinicians are constantly seeking new approaches and technologies to improve therapeutic outcomes and minimize adverse effects. One promising avenue of investigation is the utilization of the Fenton reaction, a chemical process that involves the generation of highly reactive hydroxyl radicals (·OH) through the interaction of hydrogen peroxide (H2O2) with ferrous ions (Fe2+). The generated ·OH radicals possess strong oxidative properties, which can lead to the selective destruction of cancer cells. In recent years, researchers have successfully introduced the Fenton reaction into the cancer microenvironment through the application of nanotechnology, such as polymer nanoparticles and light-responsive nanoparticles. This article reviews the progress of the application of the Fenton reaction, catalyzed by polymer nanoparticles and light-responsive nanoparticles, in the cancer microenvironment, as well as the potential applications and future development directions of the Fenton reaction in the field of tumor treatment.

Ferroptosis and mitochondrial dysfunction in acute central nervous system injury

Acute central nervous system injuries (ACNSI), encompassing traumatic brain injury (TBI), non-traumatic brain injury like stroke and encephalomeningitis, as well as spinal cord injuries, are linked to significant rates of disability and mortality globally. Nevertheless, effective and feasible treatment plans are still to be formulated. There are primary and secondary injuries occurred after ACNSI. Most ACNSIs exhibit comparable secondary injuries, which offer numerous potential therapeutic targets for enhancing clinical outcomes. Ferroptosis, a newly discovered form of cell death, is characterized as a lipid peroxidation process that is dependent on iron and oxidative conditions, which is also indispensable to mitochondria. Ferroptosis play a vital role in many neuropathological pathways, and ACNSIs may induce mitochondrial dysfunction, thereby indicating the essentiality of the mitochondrial connection to ferroptosis in ACNSIs. Nevertheless, there remains a lack of clarity regarding the involvement of mitochondria in the occurrence of ferroptosis as a secondary injuries of ACNSIs. In recent studies, anti-ferroptosis agents such as the ferroptosis inhibitor Ferrostain-1 and iron chelation therapy have shown potential in ameliorating the deleterious effects of ferroptosis in cases of traumatic ACNSI. The importance of this evidence is extremely significant in relation to the research and control of ACNSIs. Therefore, our review aims to provide researchers focusing on enhancing the therapeutic outcomes of ACNSIs with valuable insights by summarizing the physiopathological mechanisms of ACNSIs and exploring the correlation between ferroptosis, mitochondrial dysfunction, and ACNSIs.

Increased Free Radical Generation during the Interaction of a Quinone-Quinoline Chelator with Metal Ions and the Enhancing Effect of Light

Schiff bases and similar molecules forming metal complexes may cause redox effects, which may also be influenced by light. Anthraquinones such as doxorubicin and idarubicin are widely used antitumor agents, which can generate reactive oxygen species (ROS), stimulated by both the presence of iron and copper ions and also by light. The generated ROS can cause DNA scission, cell membrane oxidation, and many other toxic effects. The redox activity of the quinone-quinoline chelator 2-phenyl-4-(butylamino)naphtho [2,3-h]quinoline-7,12-dione (Q1) was investigated in the presence of iron, copper, and zinc. The influence of light in these interactions was also examined. The chemically induced dynamic nuclear polarization (CIDNP), nuclear magnetic resonance (NMR), and electron paramagnetic resonance (EPR) methods were used to elucidate the molecular changes and ROS generation effects of the Q1 metal interactions. A model electron transfer reaction system between 1,4-dihydropyridine and Q1 was utilized to demonstrate that the chelate complexes of Q1 with both Fe(III) and Cu(II) ions were more redox active than Q1 itself. Similarly, CIDNP and NMR data showed that the concentration dependence of the free radicals yield is much higher in the presence of Fe(III) and Cu(II) ions, in comparison to Zn(II), and also that it increased in the presence of light. These findings underline the role of transition metal ions and Q1 in cyclic redox chain reactions and increase the prospect of the development of copper- and iron-based chelating agents, including Q1 and its derivatives, for anticancer therapy. Furthermore, these findings also signify the effect of light on enhancing ROS formation by Q1 and the prospect of utilizing such information for designing target specific anticancer drugs for photodynamic therapy.

Insights into the coordination chemistry of antineoplastic doxorubicin with 3d-transition metal ions Zn2+, Cu2+, and VO2+: a study using well-calibrated thermodynamic cycles and chemical interaction quantum chemistry models

We present a computational strategy based on thermodynamic cycles to predict and describe the chemical equilibrium between the 3d-transition metal ions Zn²⁺, Cu²⁺, and VO²⁺ and the widely used antineoplastic drug doxorubicin. Our method involves benchmarking a theoretical protocol to compute gas-phase quantities using DLPNO Coupled-Cluster calculations as reference, followed by estimating solvation contributions to the reaction Gibbs free energies using both explicit partial (micro)solvation steps for charged solutes and neutral coordination complexes, as well as a continuum solvation procedure for all solutes involved in the complexation process. We rationalized the stability of these doxorubicin-metal complexes by inspecting quantities obtained from the topology of their electron densities, particularly the bond critical points and non-covalent interaction index. Our approach allowed us to identify representative species in solution phase, infer the most likely complexation process for each case, and identify key intramolecular interactions involved in the stability of these compounds. To the best of our knowledge, this is the first study reporting thermodynamic constants for the complexation of doxorubicin with transition metal ions. Unlike other methods, our procedure is computationally affordable for medium-sized systems and provides valuable insights even with limited experimental data. Furthermore, it can be extended to describe the complexation process between 3d-transition metal ions and other bioactive ligands.

Implantable 3D Printed Hydrogel Scaffolds Loading Copper-Doxorubicin Complexes for Postoperative Chemo/Chemodynamic Therapy

Biomaterial-based implants hold great potential for postoperative cancer treatment due to the enhanced drug dosage at the disease site and decreased systemic toxicity. However, the elaborate design of implants to avoid complicated chemical modification and burst release remains challenging. Herein, we report a three-dimensional (3D) printed hydrogel scaffold to enable sustained release of drugs for postoperative synergistic cancer therapy. The hydrogel scaffold is composed of Pluronic F127 and sodium alginate (SA) as well as doxorubicin (DOX) and copper ions (F127-SA/Cu-DOX hydrogel scaffold). Benefiting from the coordination of Cu(II) with both SA and DOX, burst release of DOX can be overcome, and prolonged release time can be achieved. The therapeutic efficiency can be adjusted by altering the amount of DOX and Cu(II) in the scaffolds. Moreover, apoptosis and ferroptosis of cancer cells can be induced through the combination of chemotherapy and chemodynamic therapy. In addition, DOX supplies excess hydrogen peroxide to enhance the efficiency of Cu-based chemodynamic therapy. When implanted in the resection site, hydrogel scaffolds effectively inhibit tumor growth. Overall, this study may offer a new strategy for fabricating local implants with synergistic therapeutic performance for preventing postoperative cancer recurrence.

New insights into the regulation of Cystathionine beta synthase (CBS), an enzyme involved in intellectual deficiency in Down syndrome

Down syndrome (DS), the most frequent chromosomic aberration, results from the presence of an extra copy of chromosome 21. The identification of genes which overexpression contributes to intellectual disability (ID) in DS is important to understand the pathophysiological mechanisms involved and develop new pharmacological therapies. In particular, gene dosage of Dual specificity tyrosine phosphorylation Regulated Kinase 1A (DYRK1A) and of Cystathionine beta synthase (CBS) are crucial for cognitive function. As these two enzymes have lately been the main targets for therapeutic research on ID, we sought to decipher the genetic relationship between them. We also used a combination of genetic and drug screenings using a cellular model overexpressing CYS4, the homolog of CBS in Saccharomyces cerevisiae, to get further insights into the molecular mechanisms involved in the regulation of CBS activity. We showed that overexpression of YAK1, the homolog of DYRK1A in yeast, increased CYS4 activity whereas GSK3β was identified as a genetic suppressor of CBS. In addition, analysis of the signaling pathways targeted by the drugs identified through the yeast-based pharmacological screening, and confirmed using human HepG2 cells, emphasized the importance of Akt/GSK3β and NF-κB pathways into the regulation of CBS activity and expression. Taken together, these data provide further understanding into the regulation of CBS and in particular into the genetic relationship between DYRK1A and CBS through the Akt/GSK3β and NF-κB pathways, which should help develop more effective therapies to reduce cognitive deficits in people with DS.

The Interaction of Anthracycline Based Quinone-Chelators with Model Lipid Membranes: 1H NMR and MD Study

Anthracycline antibiotics, e.g., doxorubicin, daunomycin, and other anthraquinones, are an important family of antitumor agents widely used in chemotherapy, which is currently the principal method for treating many malignancies. Thus, development of improved antitumor drugs with enhanced efficacy remains a high priority. Interaction of anthraquinone-based anticancer drugs with cell membranes attracts significant attention due to its importance in the eventual overcoming of multidrug resistance (MDR). The use of drugs able to accumulate in the cell membrane is one of the possible ways of overcoming MDR. In the present work, the aspects of interaction of anthraquinone 2-phenyl-4-(butylamino)naphtho[2,3-h]quinoline-7,12-dione) (Q1) with a model membrane were studied by means of NMR and molecular dynamics simulations. A fundamental shortcoming of anthracycline antibiotics is their high cardiotoxicity caused by reactive oxygen species (ROS). The important feature of Q1 is its ability to chelate transition metal ions responsible for ROS generation in vivo. In the present study, we have shown that Q1 and its chelating complexes penetrated into the lipid membrane and were located in the hydrophobic part of the bilayer near the bilayer surface. The chelate complex formation of Q1 with metal ions increased its penetration ability. In addition, it was found that the interaction of Q1 with lipid molecules could influence lipid mobility in the bilayer. The obtained results have an impact on the understanding of molecular mechanisms of Q1 biological activity.

Why Do Dietary Flavonoids Have a Promising Effect as Enhancers of Anthracyclines? Hydroxyl Substituents, Bioavailability and Biological Activity

Anthracyclines currently play a key role in the treatment of many cancers, but the limiting factor of their use is the widespread phenomenon of drug resistance and untargeted toxicity. Flavonoids have pleiotropic, beneficial effects on human health that, apart from antioxidant activity, are currently considered small molecules-starting structures for drug development and enhancers of conventional therapeutics. This paper is a review of the current and most important data on the participation of a selected series of flavonoids: chrysin, apigenin, kaempferol, quercetin and myricetin, which differ in the presence of an additional hydroxyl group, in the formation of a synergistic effect with anthracycline antibiotics. The review includes a characterization of the mechanism of action of flavonoids, as well as insight into the physicochemical parameters determining their bioavailability in vitro. The crosstalk between flavonoids and the molecular activity of anthracyclines discussed in the article covers the most important common areas of action, such as (1) disruption of DNA integrity (genotoxic effect), (2) modulation of antioxidant response pathways, and (3) inhibition of the activity of membrane proteins responsible for the active transport of drugs and xenobiotics. The increase in knowledge about the relationship between the molecular structure of flavonoids and their biological effect makes it possible to more effectively search for derivatives with a synergistic effect with anthracyclines and to develop better therapeutic strategies in the treatment of cancer.

New Iron Metabolic Pathways and Chelation Targeting Strategies Affecting the Treatment of All Types and Stages of Cancer

There is new and increasing evidence from in vitro, in vivo and clinical studies implicating the pivotal role of iron and associated metabolic pathways in the initiation, progression and development of cancer and in cancer metastasis. New metabolic and toxicity mechanisms and pathways, as well as genomic, transcription and other factors, have been linked to cancer and many are related to iron. Accordingly, a number of new targets for iron chelators have been identified and characterized in new anticancer strategies, in addition to the classical restriction of/reduction in iron supply, the inhibition of transferrin iron delivery, the inhibition of ribonucleotide reductase in DNA synthesis and high antioxidant potential. The new targets include the removal of excess iron from iron-laden macrophages, which affects anticancer activity; the modulation of ferroptosis; ferritin iron removal and the control of hyperferritinemia; the inhibition of hypoxia related to the role of hypoxia-inducible factor (HIF); modulation of the function of new molecular species such as STEAP4 metalloreductase and the metastasis suppressor N-MYC downstream-regulated gene-1 (NDRG1); modulation of the metabolic pathways of oxidative stress damage affecting mitochondrial function, etc. Many of these new, but also previously known associated iron metabolic pathways appear to affect all stages of cancer, as well as metastasis and drug resistance. Iron-chelating drugs and especially deferiprone (L1), has been shown in many recent studies to fulfill the role of multi-target anticancer drug linked to the above and also other iron targets, and has been proposed for phase II trials in cancer patients. In contrast, lipophilic chelators and their iron complexes are proposed for the induction of ferroptosis in some refractory or recurring tumors in drug resistance and metastasis where effective treatments are absent. There is a need to readdress cancer therapy and include therapeutic strategies targeting multifactorial processes, including the application of multi-targeting drugs involving iron chelators and iron-chelator complexes. New therapeutic protocols including drug combinations with L1 and other chelating drugs could increase anticancer activity, decrease drug resistance and metastasis, improve treatments, reduce toxicity and increase overall survival in cancer patients.

Rutin and Quercetin Counter Doxorubicin-Induced Liver Toxicity in Wistar Rats via Their Modulatory Effects on Inflammation, Oxidative Stress, Apoptosis, and Nrf2

The presented study was performed to verify whether rutin and/or quercetin can inhibit liver injury induced by doxorubicin (DXR) in male Wistar rats. In this study, male Wistar rats were treated via the oral route with rutin and quercetin (50 mg/kg) either alone or in combination every other day for five weeks concomitant with receiving intraperitoneal DXR (2 mg/kg) two times a week for five successive weeks. Quercetin, rutin, and their combination significantly improved the deteriorated serum AST, ALT, and ALP activities and total bilirubin level, as well as albumin, AFP, and CA 19.9 levels in DXR-injected rats. Treatments of the DXR-injected group with quercetin and rutin prevented the elevation in liver lipid peroxidation and the reduction in superoxide dismutase, glutathione-S-transferase and glutathione peroxidase activities, and glutathione content. Treatments with quercetin and rutin significantly repressed the elevated expression of liver p53 and TNF-α and enhanced Nrf2 expression. Furthermore, the treatments significantly reduced DXR-induced liver histological changes. In conclusion, rutin and quercetin either alone or in combination may have potential preventive effects against DXR-induced hepatotoxicity through inhibiting oxidative stress, inflammation, and apoptosis as well as modulating the Nrf2 expression.

A Nanoarchitectonic Approach Enables Triple Modal Synergistic Therapies To Enhance Antitumor Effects

Improvement of antitumor effects relies on the development of biocompatible nanomaterials and combination of various therapies to produce synergistic effects and avoid resistance. In this work, we developed GBD-Fe, a nanoformulation that effectively integrated chemotherapy (CT), chemodynamic therapy (CDT), and photothermal therapy (PTT). GBD-Fe used gold nanorods as photothermal agents and encapsulated doxorubicin to amplify Fe³⁺-guided CDT effects by producing H₂O₂ and reducing the intracellular glutathione levels. In vitro and in vivo experiments were conducted to demonstrate the enhanced accumulation and antitumor effects of this tripronged therapy under magnetic resonance imaging (MRI) guidance. This tripronged approach of CT/CDT/PTT effectively induced tumor cytotoxicity and inhibited tumor growth in tumor-bearing mice and therefore represents a promising strategy to effectively treat tumors.

The Interplay of Ascorbic Acid with Quinones-Chelators—Influence on Lipid Peroxidation: Insight into Anticancer Activity

Ascorbic acid is a multifaceted compound that can perform both antioxidant and pro-oxidant activities in the redox reactions induced by transition metal ions, so its role in nature and especially in the human body is still the subject of debate. In the present study, we have examined the influence of ascorbic acid on lipid peroxidation in a model system that mimics the cell membrane, namely micelles of linoleic acid (LA), induced by chelate complexes of iron and copper ions with quinone-chelator 2-phenyl-4-(butylamino)-naphtholquinoline-7,12-dione (Q1). This quinone effectively generates reactive oxygen species and semiquinone radicals inside cancer cells via a cycling redox reaction. Here it was demonstrated that in the absence of quinone-chelator ascorbic acid significantly accelerates the lipid peroxidation induced by both Fe(II) and Cu(II) ions. It has been shown also that Q1 chelate complexes with Fe(II) and Cu(II) ions are redox active in the LA micelles oxidation. No effect of ascorbate was detected on the reactivity of chelate complex with Fe(II) ions. On the other hand, ascorbate performs pro-oxidant activity in Q1-Cu(II) complex induced reaction. We can conclude that ascorbate-driven redox cycling of Q1 may promote its anti-tumor activity.

Thyme Oil and Thymol Counter Doxorubicin-Induced Hepatotoxicity via Modulation of Inflammation, Apoptosis, and Oxidative Stress

Doxorubicin (DOX) is an effective anticancer agent with a wide spectrum of activities. However, it has many adverse effects on various organs especially on the liver. Thymol, one of the major components of thyme oil, has biological properties that include anti-inflammatory and antioxidant activities. Thus, this study was designed to examine thyme oil and thymol for their ability to prevent doxorubicin-induced hepatotoxicity in Wistar rats. Hepatotoxicity was induced by an intraperitoneal injection of doxorubicin, at a dose of 2 mg/kg bw/week, for seven weeks. Doxorubicin-injected rats were supplemented with thyme oil and thymol at doses 250 and 100 mg/kg bw, respectively, four times/week by oral gavage for the same period. Treatment of rats with thyme oil and thymol reversed the high serum activities of AST, ALT, and ALP and total bilirubin, AFP, and CA19.9 levels, caused by doxorubicin. Thyme oil and thymol also reduced the high levels of TNF-α and the decreased levels of both albumin and IL-4. These agents ameliorated doxorubicin-induced elevation in hepatic lipid peroxidation and associated reduction in GSH content and GST and GPx activities. Further, the supplementation with thyme oil and thymol significantly augmented mRNA expression of the level of antiapoptotic protein Bcl-2 and significantly downregulated nuclear and cytoplasmic levels of the hepatic apoptotic mediator p53. Thus, thyme oil and thymol successfully counteracted doxorubicin-induced experimental hepatotoxicity via their anti-inflammatory, antioxidant, and antiapoptotic properties.

Questioning Established Theories and Treatment Methods Related to Iron and Other Metal Metabolic Changes, Affecting All Major Diseases and Billions of Patients

The medical and scientific literature is dominated by highly cited historical theories and findings [...].

Mechanistic Insights of Chelator Complexes with Essential Transition Metals: Antioxidant/Pro-Oxidant Activity and Applications in Medicine

The antioxidant/pro-oxidant activity of drugs and dietary molecules and their role in the maintenance of redox homeostasis, as well as the implications in health and different diseases, have not yet been fully evaluated. In particular, the redox activity and other interactions of drugs with essential redox metal ions, such as iron and copper, need further investigation. These metal ions are ubiquitous in human nutrition but also widely found in dietary supplements and appear to exert major effects on redox homeostasis in health, but also on many diseases of free radical pathology. In this context, the redox mechanistic insights of mainly three prototype groups of drugs, namely alpha-ketohydroxypyridines (alpha-hydroxypyridones), e.g., deferiprone, anthraquinones, e.g., doxorubicin and thiosemicarbazones, e.g., triapine and their metal complexes were examined; details of the mechanisms of their redox activity were reviewed, with emphasis on the biological implications and potential clinical applications, including anticancer activity. Furthermore, the redox properties of these three classes of chelators were compared to those of the iron chelating drugs and also to vitamin C, with an emphasis on their potential clinical interactions and future clinical application prospects in cancer, neurodegenerative and other diseases.

A Co(III) Complex of 1-Amino-4-hydroxy-9,10-anthraquinone Exhibits Apoptotic Action against MCF-7 Human Breast Cancer Cells

A Co(III) complex of 1-amino-4-hydroxy-9,10-anthraquinone (QH) (Scheme-1) having the molecular formula CoQ₃ (Scheme-2) was prepared and characterized by elemental analysis, FTIR spectroscopy, UV-vis spectroscopy, fluorescence spectroscopy, and mass spectrometry. In the absence of a single crystal, the energy-optimized molecular structure of CoQ₃ was determined by employing computational methods that was validated using spectroscopic evidences, elemental analysis, and mass spectrometry data. The electrochemical properties of the complex were analyzed using cyclic voltammetry and indicate a substantial modification of the electrochemical properties of the parent amino-hydroxy-9,10-anthraquinone. CoQ₃ was thereafter tested on MCF-7 human breast cancer cells. The IC₅₀ value for a 24 h incubation was found to be (95 ± 0.05) μg/mL. The study showed that such cancer cells underwent both early and late apoptosis following the interaction with CoQ₃.

Free radical induced activity of an anthracycline analogue and its MnII complex on biological targets through in situ electrochemical generation of semiquinone

Cytotoxicity by anthracycline antibiotics is attributed to several pathways. Important among them are formation of free-radical intermediates. However, their generation makes anthracyclines cardiotoxic which is a concern on their use as anticancer agents. Hence, any change in redox behavior that address cardiotoxicity is welcome. Modulation of redox behavior raises the fear that cytotoxicity could be compromised. Regarding the generation of free radical intermediates on anthracyclines, a lot depends on the surrounding environment (oxic or anoxic), polarity and pH of the medium. In case of anthracyclines, one-electron reduction to semiquinone or two-electron reduction to quinone-dianion are crucial both for cytotoxicity and for cardiotoxic side effects. The disproportion-comproportionation equilibria at play between quinone-dianion, free quinone and semiquinone control biological activity. Whatever is the form of reduction, semiquinones are generated as a consequence of the presence of anthracyclines and these interact with a biological target. Alizarin, a simpler anthracycline analogue and its Mn^II complex were subjected to electrochemical reduction to realize what happens when anthracyclines are reduced by compounds present in cells as members of the electron transport chain. Glassy carbon electrode maintained at the pre-determined reduction potential of a compound was used for reduction of the compounds. Nucleobases and calf thymus DNA that were maintained in immediate vicinity of such radical generation were used as biological targets. Changes due to the generated species under aerated/de-aerated conditions on nucleobases and on DNA helps one to realize the process by which alizarin and its Mn^II complex might affect DNA. The study reveals alizarin was more effective on nucleobases than the complex in the free radical pathway. Difference in damage caused by alizarin and the Mn^II complex on DNA is comparatively less than that observed on nucleobases; the complex makes up for any inefficacy in the free radical pathway by its other attributes.

Synthesis, Spectroscopic, and Theoretical Study of Copper and Cobalt Complexes with Dacarbazine

Dacarbazine (DAC) 5-(3,3-dimethyl-1-triazenyl)imidazole-4-carboxamide is an imidazole-carboxamide derivative that is structurally related to purines. DAC belongs to the triazene compounds, which are a group of alkylating agents with antitumor and mutagenic properties. DAC is a non-cell cycle specific drug, active in all phases of the cellular cycle. In the frame of this work the 3d metal complexes (cobalt and copper) with dacarbazine were synthesized. Their spectroscopic properties by the use of FT-IR, FT-Raman, and ¹HNMR were studied. The structures of dacarbazine and its complexes with copper(II) and cobalt(II) were calculated using DFT methods. The effect of metals on the electronic charge distribution of dacarbazine was discussed on the basis of calculated NBO atomic charges. The reactivity of metal complexes in relation to ligand alone was estimated on the basis of calculated energy of HOMO and LUMO orbitals. The aromaticity of the imidazole ring in dacarbazine and the complexes were compared (on the basis of calculated geometric indices of aromaticity). Thermal stability of the investigated 3d-metal complexes with dacarbazine and the products of their thermal decomposition were analyzed.

Recent Developments in Effective Antioxidants: The Structure and Antioxidant Properties

Since the last few years, the growing interest in the use of natural and synthetic antioxidants as functional food ingredients and dietary supplements, is observed. The imbalance between the number of antioxidants and free radicals is the cause of oxidative damages of proteins, lipids, and DNA. The aim of the study was the review of recent developments in antioxidants. One of the crucial issues in food technology, medicine, and biotechnology is the excess free radicals reduction to obtain healthy food. The major problem is receiving more effective antioxidants. The study aimed to analyze the properties of efficient antioxidants and a better understanding of the molecular mechanism of antioxidant processes. Our researches and sparing literature data prove that the ligand antioxidant properties complexed by selected metals may significantly affect the free radical neutralization. According to our preliminary observation, this efficiency is improved mainly by the metals of high ion potential, e.g., Fe(III), Cr(III), Ln(III), Y(III). The complexes of delocalized electronic charge are better antioxidants. Experimental literature results of antioxidant assays, such as diphenylpicrylhydrazyl (DPPH) and ferric reducing activity power assay (FRAP), were compared to thermodynamic parameters obtained with computational methods. The mechanisms of free radicals creation were described based on the experimental literature data. Changes in HOMO energy distribution in phenolic acids with an increasing number of hydroxyl groups were observed. The antioxidant properties of flavonoids are strongly dependent on the hydroxyl group position and the catechol moiety. The number of methoxy groups in the phenolic acid molecules influences antioxidant activity. The use of synchrotron techniques in the antioxidants electronic structure analysis was proposed.

Unraveling the interaction between doxorubicin and DNA origami nanostructures for customizable chemotherapeutic drug release

Doxorubicin (DOX) is a common drug in cancer chemotherapy, and its high DNA-binding affinity can be harnessed in preparing DOX-loaded DNA nanostructures for targeted delivery and therapeutics. Although DOX has been widely studied, the existing literature of DOX-loaded DNA-carriers remains limited and incoherent. Here, based on an in-depth spectroscopic analysis, we characterize and optimize the DOX loading into different 2D and 3D scaffolded DNA origami nanostructures (DONs). In our experimental conditions, all DONs show similar DOX binding capacities (one DOX molecule per two to three base pairs), and the binding equilibrium is reached within seconds, remarkably faster than previously acknowledged. To characterize drug release profiles, DON degradation and DOX release from the complexes upon DNase I digestion was studied. For the employed DONs, the relative doses (DOX molecules released per unit time) may vary by two orders of magnitude depending on the DON superstructure. In addition, we identify DOX aggregation mechanisms and spectral changes linked to pH, magnesium, and DOX concentration. These features have been largely ignored in experimenting with DNA nanostructures, but are probably the major sources of the incoherence of the experimental results so far. Therefore, we believe this work can act as a guide to tailoring the release profiles and developing better drug delivery systems based on DNA-carriers.

Functional metal-organic framework-based nanocarriers for accurate magnetic resonance imaging and effective eradication of breast tumor and lung metastasis

The use of nanoscale metal-organic frameworks (MOFs) as drug delivery vehicles has attracted considerable attention in tumor therapy. In this study, novel biocompatible MOF-based nanocarriers were used as part of a facile and reproducible strategy for precision cancer theranostics. Both diagnostic (Mn²⁺) and therapeutic compounds (doxorubicin, DOX) were incorporated into the multifunctional MOF-based nanocarriers, which exhibited high colloidal stability and promoted T₁-weighted proton relaxivity and low-pH-activated drug release. The obtained MOF-based nanocarriers exhibited significantly high cellular uptake and efficient intracellular drug delivery into cancer cells, which resulted in high apoptosis and cytotoxicity, in addition to effectively inhibiting the migration of 4T1 breast cancer cells. Moreover, the MOF-based nanocarriers could intensively deliver diagnostic and therapeutic agents to tumors to enable precise visualization of the nanocarrier accumulation and accurate tumor positioning, diagnosis, and imaging-guided therapy using magnetic resonance imaging (MRI). In addition, the functional MOF-based nanocarriers exhibited effective ablation of the primary breast cancer, as well as significant inhibition of lung metastasis with a high survival rate. Therefore, the developed nanocarriers represent a viable platform for cancer theranostics.

Water-soluble galactosamine derivative of β-cyclodextrin as protective ligand and targeted carrier for delivery of toxic anthracycline drug

β-cyclodextrin modified with an electron-rich aromatic triazole linker and targeting moiety (galactosamine) was synthesized and studied as a carrier for the anticancer drug, doxorubicin (DOX), with the aim of targeting the pathological cells, reducing the cardiotoxic side effects and increasing the binding of the drug to DNA. The β-cyclodextrins modified with galactosamine (βCDGAL) are non-toxic and highly soluble in aqueous medium compared to the native βCD and βCD modified only with aromatic moiety, such as triazole linker. Molecular modelling and NMR study gave a deeper insight into the ligand structure, providing an explanation for its increased solubility, and the drug-ligand interactions. The triazole linker strengthened the drug binding and introduced pH dependence of the complex stability constants for βCDGAL derivative, as confirmed by the voltammetry measurements. Spectroscopic studies have shown that entrapment of the DOX in βCDGAL cavity reduces the stability constant of the DOX:Fe(III) complex responsible for the production of cardiotoxic reactive oxygen species and additionally supports the binding of the drug to the double strand DNA. The MTT assay and confocal microscopy results showed that despite encapsulation of the drug in the cyclodextrin molecule, its cytotoxic effect on the liver cancer cell line (HepG2) is comparable to that of the free, non-protected drug.

Encapsulated doxorubicin crystals influence lysolipid temperature-sensitive liposomes release and therapeutic efficacy in vitro and in vivo

Doxorubicin (DOX)-loaded lysolipid temperature-sensitive liposomes (LTSLs) are a promising stimuli-responsive drug delivery system that rapidly releases DOX in response to mild hyperthermia (HT). This study investigates the influence of loaded DOX crystals on the thermosensitivity of LTSLs and their therapeutic efficacy in vitro and in vivo. The properties of DOX crystals were manipulated using different remote loading methods (namely (NH₄)₂SO₄, NH₄-EDTA and MnSO₄) and varying the lipid:DOX weight ratio during the loading step. Our results demonstrated that (NH₄)₂SO₄ or NH₄-EDTA remote loading methods had a comparable encapsulation efficiency (EE%) into LTSLs in contrast to the low DOX EE% obtained using the metal complexation method. Cryogenic transmission electron microscopy (cryo-TEM) revealed key differences in the nature of DOX crystals formed inside LTSLs based on the loading buffer or/and the lipid:DOX ratio used, resulting in different DOX release profiles in response to mild HT. The in vitro assessment of DOX release/uptake in CT26 and PC-3 cells revealed that the use of a high lipid:DOX ratio exhibited a fast and controlled release profile in combination with mild HT, which correlated well with their cytotoxicity studies. Similarly, in vivo DOX release, tumour growth inhibition and mice survival rates were influenced by the physicochemical properties of LTSLs payload. This study demonstrates, for the first time, that the characteristics of DOX crystals loaded into LTSLs, and their conformational rearrangement during HT, are important factors that impact the TSLs performance in vivo.

Trying to Solve the Puzzle of the Interaction of Ascorbic Acid and Iron: Redox, Chelation and Therapeutic Implications

Iron and ascorbic acid (vitamin C) are essential nutrients for the normal growth and development of humans, and their deficiency can result in serious diseases. Their interaction is of nutritional, physiological, pharmacological and toxicological interest, with major implications in health and disease. Millions of people are using pharmaceutical and nutraceutical preparations of these two nutrients, including ferrous ascorbate for the treatment of iron deficiency anaemia and ascorbate combination with deferoxamine for increasing iron excretion in iron overload. The main function and use of vitamin C is its antioxidant activity against reactive oxygen species, which are implicated in many diseases of free radical pathology, including biomolecular-, cellular- and tissue damage-related diseases, as well as cancer and ageing. Ascorbic acid and its metabolites, including the ascorbate anion and oxalate, have metal binding capacity and bind iron, copper and other metals. The biological roles of ascorbate as a vitamin are affected by metal complexation, in particular following binding with iron and copper. Ascorbate forms a complex with Fe³⁺ followed by reduction to Fe²⁺, which may potentiate free radical production. The biological and clinical activities of iron, ascorbate and the ascorbate–iron complex can also be affected by many nutrients and pharmaceutical preparations. Optimal therapeutic strategies of improved efficacy and lower toxicity could be designed for the use of ascorbate, iron and the iron–ascorbate complex in different clinical conditions based on their absorption, distribution, metabolism, excretion, toxicity (ADMET), pharmacokinetic, redox and other properties. Similar strategies could also be designed in relation to their interactions with food components and pharmaceuticals, as well as in relation to other aspects concerning personalized medicine.

Redox Interactions of Vitamin C and Iron: Inhibition of the Pro-Oxidant Activity by Deferiprone

Ascorbic acid (AscH₂) is one of the most important vitamins found in the human diet, with many biological functions including antioxidant, chelating, and coenzyme activities. Ascorbic acid is also widely used in medical practice especially for increasing iron absorption and as an adjuvant therapeutic in iron chelation therapy, but its mode of action and implications in iron metabolism and toxicity are not yet clear. In this study, we used UV–Vis spectrophotometry, NMR spectroscopy, and EPR spin trapping spectroscopy to investigate the antioxidant/pro-oxidant effects of ascorbic acid in reactions involving iron and the iron chelator deferiprone (L1). The experiments were carried out in a weak acidic (pH from 3 to 5) and neutral (pH 7.4) medium. Ascorbic acid exhibits predominantly pro-oxidant activity by reducing Fe³⁺ to Fe²⁺, followed by the formation of dehydroascorbic acid. As a result, ascorbic acid accelerates the redox cycle Fe³⁺ ↔ Fe²⁺ in the Fenton reaction, which leads to a significant increase in the yield of toxic hydroxyl radicals. The analysis of the experimental data suggests that despite a much lower stability constant of the iron–ascorbate complex compared to the FeL1₃ complex, ascorbic acid at high concentrations is able to substitute L1 in the FeL1₃ chelate complex resulting in the formation of mixed L1₂AscFe complex. This mixed chelate complex is redox stable at neutral pH = 7.4, but decomposes at pH = 4–5 during several minutes at sub-millimolar concentrations of ascorbic acid. The proposed mechanisms play a significant role in understanding the mechanism of action, pharmacological, therapeutic, and toxic effects of the interaction of ascorbic acid, iron, and L1.

Recent Development in Indole Derivatives as Anticancer Agents for Breast Cancer

BACKGROUND

Breast Cancer (BC) is the second most common cause of cancer related deaths in women. Due to severe side effects and multidrug resistance, current therapies like hormonal therapy, surgery, radiotherapy and chemotherapy become ineffective. Also, the existing drugs for BC treatment are associated with several drawbacks such as poor oral bioavailability, non-selectivity and poor pharmacodynamics properties. Therefore, there is an urgent need for the development of more effective and safer anti BC agents.

OBJECTIVE

This article explored in detail the possibilities of indole-based heterocyclic compounds as anticancer agents with breast cancer as their major target.

METHODS

Recent literature related to indole derivatives endowed with encouraging anti BC potential is reviewed. With special focus on BC, this review offers a detailed account of multiple mechanisms of action of various indole derivatives: aromatase inhibitor, tubulin inhibitor, microtubule inhibitor, targeting estrogen receptor, DNA-binding mechanism, induction of apoptosis, inhibition of PI3K/AkT/NFkB/mTOR, and HDAC inhibitors, by which these derivatives have shown promising anticancer potential.

RESULTS

Exhaustive literature survey indicated that indole derivatives are associated with properties of inducing apoptosis and disturbing tubulin assembly. Indoles are also associated with the inhibition of NFkB/mTOR/PI3K/AkT and regulation of estrogen-mediated activity. Furthermore, indole derivatives have been found to modulate critical targets such as topoisomerase and HDAC. These derivatives have shown significant activity against breast cancer cells.

CONCLUSION

In BC, indole derivatives seem to be quite competent and act through various mechanisms that are well established in case of BC. This review has shown that indole derivatives can further be explored for the betterment of BC chemotherapy. A lot of potential is still hidden which demands to be discovered for upgrading BC chemotherapy.

Doxorubicin-loaded polyphosphate glass microspheres for transarterial chemoembolization

The standard of care for intermediate stage hepatocellular carcinoma is transarterial chemoembolization (TACE). Drug-eluting bead TACE (DEB-TACE) has emerged as a leading form of TACE, as it uses highly calibrated microspheres to deliver consistent embolization and controlled drug release to the tumor microenvironment. We report here on doxorubicin (DOX)-loaded polyphosphate glass microspheres (PGM) as a novel resorbable, radiopaque, preloaded DEB-TACE platform. Coacervate composed of polyphosphate chains complexed with Ba²⁺ , Ca²⁺ , and Cu²⁺ can be loaded with DOX prior to PGM synthesis, with PGM production achieved using a water-in-oil emulsion technique at room temperature yielding highly spherical particles in clinically relevant size fractions. In vitro, DOX release was found to be linear, pH dependent, and in accordance with Type II non-Fickian transport. PGM degradation was characterized by an initial burst release of degradation products over 7 days, followed by a plateau in mass loss at approximately 75% over a period of several weeks. in vitro studies indicate that PGM degradation products, namely Cu²⁺ , are cytotoxic and may interact with eluted DOX to impair its pharmacological activity. With additional compositional considerations, this approach may prove promising for DEB-TACE applications.

Molecular dynamics simulation of Doxorubicin loading with N-isopropyl acrylamide carbon nanotube in a drug delivery system

BACKGROUND AND OBJECTIVE

Doxorubicin is one of the common drugs used for cancer therapy. Molecular dynamics were applied to investigate the loading of Doxorubicin with thermosensitive N-isopropyl acrylamide Carbon nanotube carrier.

METHODS

The results showed that the smaller polymer chain length has more decrease of gyration radius. A decrease of gyration radius resulted in more concentrated aggregation with stronger bonds. Therefore, the shorter the polymer chain lengths, the more stable polymer interaction and better Doxorubicin delivery. Smaller polymers also form more hydrogen bonds with the drug leading to stronger and more stable carriers.

RESULTS

A lower amount of wall shear stress was found near the inner wall of the artery, distal to the plaque region (stenosis), and in both percentages of stenosis the maximum wall shear stress will accrue in the middle of the stenosis; however it is much more in the higher rate of stenosis.

CONCLUSIONS

The results indicated that N-isopropyl acrylamide - Carbon nanotube is suitable for the delivery of Doxorubicin, and five mer N-isopropyl acrylamide is the optimum carrier for Doxorubicin loading.

Removal of doxorubicin by magnetic copper phosphate nanoflowers for individual urine source separation

Doxorubicin (DOX) originated from users' urine has been an emerging environmental pollutant due to its significant genotoxicity to mankind. Thus, urine source separation is a potential strategy to isolate DOX at a higher concentration and reduce the burden of downstream wastewater treatment. To develop highly efficient, easy separation and retrievable materials for individual patient to conveniently remove DOX from own urine, magnetic Cu₃(PO₄)₂ nanoflowers were prepared through anchoring amino-functionalized magnetic nanoparticles on the Cu₃(PO₄)₂ nanoflowers. Characterizations revealed the magnetic nanoflowers were spherical in shape with a mean size of 15 μm, and porous and hierarchical in structure. Magnetic nanoparticles located the surface of petals. Multibatch experiments were performed to assess the removal performance of DOX from aqueous solution. The magnetic nanoflowers exhibited excellent removal efficiency of DOX under weakly alkaline condition at ambient temperature. Linear and non-linear analyses were carried out to compare the best fitting kinetics and isotherms. Sorption kinetic data best fitted the pseudo-second order model. The Freundlich isotherm explained equilibrium sorption data with R² = 0.993 higher than that for the Langmuir isotherm. When the pH of synthetic urine was adjusted to weakly alkaline (pH 8.0-9.0), over 95% of DOX (20 mg L^-1) was removed by a little of magnetic nanoflowers (50 mg L^-1) within 5 min. Meanwhile, the magnetic nanoflowers could be easily separated and recovered from the synthetic urine by a magnet. So, for individual urine source separation strategy, the magnetic nanoflower seems to be an efficient, convenient and inexpensive approach to remove DOX from human urine.

Influence of copper (I) nicotinate complex and autophagy modulation on doxorubicin-induced cytotoxicity in HCC1806 breast cancer cells

PURPOSE

Doxorubicin is regarded as the most therapeutic active agent available for triple-negative breast cancer (TNBC) treatment. However, the development of drug resistance and toxicity limits its effectiveness. Thus, developing novel strategies for TNBC treatment remains a significant challenge and doxorubicin-based combinations either by metal complexes (Copper I nicotinate complex) or with autophagy modulators could provide novel strategies and alternative strategies contributed to cancer cell death pathways, autophagy and apoptosis.

MATERIALS AND METHODS

The viability of HCC1806 TNBC cells and IC₅₀ values of Doxorubicin (DOX), Torin-1 (TOR), Chloroquine (CQ) and Copper (I) nicotinate complex (CNC) were assessed by MTT assay. ELISA was used for detecting microtubule-associated protein 1 light chain 3 (LC3) level. Real time PCR was used to determine (NBR1) gene expression. Cell cycle analysis and quantitative detection of acid vesicular organelles (AVOs) was performed by flow cytometry. TOR and CQ were used as autophagy modulators for induction and suppression of autophagy, respectively.

RESULTS

The half-maximal inhibition effect of TOR combination with DOX was revealed to the induction of autophagic cell death and apoptotic cell death. On the other hand, combination of CQ with DOX increased the growth inhibitory effect, induced accumulation of AVOs and suppressed apoptotic cell death. However, combination of CNC with DOX inhibited autophagy and induced cell cycle arrest.

CONCLUSION

Doxorubicin drug based combinations either with TOR, CQ or CNC could positively affect DOX effectiveness and reduce DOX doses applied on HCC1806 cells through modulation of autophagy.

Secreted cellular prion protein binds doxorubicin and correlates with anthracycline resistance in breast cancer

Anthracyclines are amongst the most effective chemotherapeutics ever developed, but they produce grueling side-effects, serious adverse events and resistance often develops over time. We found that these compounds can be sequestered by secreted cellular Prion protein (PrPC), blocking their cytotoxic activity. This effect was dose-dependent using either cell line-conditioned medium or human serum as a source of PrPC. Genetic depletion of PrPC or inhibition of binding via chelation of ionic copper prevented the interaction and restored cytotoxic activity. This was more pronounced for doxorubicin than its epimer, epirubicin. Investigating the relevance to breast cancer management, we found that the levels of PRNP transcript in pre-treatment tumor biopsies stratified relapse-free survival after neoadjuvant treatment with anthracyclines, particularly amongst doxorubicin-treated patients with residual disease at surgery (p=2.8E-08). These data suggest that local sequestration could mediate treatment resistance. Consistent with this, tumor cell expression of PrPC protein correlated with poorer response to doxorubicin but not epirubicin in an independent cohort analyzed by immunohistochemistry, particularly soluble isoforms released into the extracellular environment by shedding (p=0.015). These findings have important potential clinical implications for frontline regimen decision-making. We suggest there is warranted utility for prognostic PrPC/PRNP assays to guide chemo-sensitization strategies that exploit an understanding of PrPC-anthracycline-copper ion complexes.

Activity of CoII-Quinalizarin: A Novel Analogue of Anthracycline-Based Anticancer Agents Targets Human DNA Topoisomerase, Whereas Quinalizarin Itself Acts via Formation of Semiquinone on Acute Lymphoblastic Leukemia MOLT-4 and HCT 116 Cells

Quinalizarin (THAQ), a hydroxy-9,10-anthraquinone analogue of the family of anthracycline anticancer drugs and an inhibitor of protein kinase, was observed for its anticancer activity. Because apart from showing anticancer activity, anthracyclines and their analogues also show cardiotoxic side effects, believed to be addressed through metal complex formation; an effort was made to realize this by preparing a Co^II complex of THAQ. The aim of this study was to find out if complex formation leads to a decrease in the generation of intermediates that are responsible for toxic side effects. However, because this also meant that efficacy on cancer cells would be compromised, studies were undertaken on two cancer cell lines, namely, acute lymphoblastic leukemia (ALL) MOLT-4 and HCT116 cells. The complex decreases the flow of electrons from NADH to molecular oxygen (O₂) in the presence of NADH dehydrogenase forming less semiquinone than THAQ. It showed increased affinity toward DNA with binding constant values remaining constant over the physiological pH range unlike THAQ (for which decrease in binding constant values with increase in pH was observed). The complex is probably a human DNA topoisomerase I and human DNA topoisomerase II poison acting by stabilizing the covalent topoisomerase-cleaved DNA adduct, a phenomenon not observed for THAQ. Activity of the compounds on cancer cells suggests that THAQ was more effective on ALL MOLT-4 cells, whereas the complex performed better on HCT116 cells. Results suggest that the formation of semiquinone probably dominates the action because of THAQ, whereas the performance of the complex is attributed to increased DNA binding, inhibition of topoisomerase, and so forth. Inspite of a decrease in the generation of superoxide by the complex, it did not hamper efficacy on either cell line, probably compensated by improved DNA binding and inhibition of topoisomerase enzymes which are positive attributes of complex formation. A decrease in superoxide formation suggests that the complex could be less cardiotoxic, thus increasing its therapeutic index.

Seleno-l-methionine and l-ascorbic acid differentiate the biological activity of doxorubicin and its metal complexes as a new anticancer drugs candidate

The most important problems of anti-cancer therapy include the toxicity of the drugs applied to healthy cells and the multi-drug cells resistance to chemotherapeutics. One of the most commonly used anticancer drugs is doxorubicin (DOX) used to treat certain leukemias and non-Hodgkin's lymphomas, as well as bladder, breast, stomach, lung, ovarian, thyroid, multiple myeloma and other cancers. Preliminary studies showed that metal complex with DOX improve its cytostatic activity with changes in their molecular structure and distribution of electrons, resulting in a substantial change of its biological activity (including antitumor activity). Thus, there is a chance to receiving derivatives of DOX with low toxicity for the healthy body cells, thus increasing its therapeutic selectivity. In the present study we examined the influence of Mn, Mg, Fe, Co and Ni, seleno-l-methionine and vitamin C on biological activity of DOX in prokaryotic model - Escherichia coli RFM443, with plasmid transcriptional fusion of recA promoter and luxCDABE as a reporter gene. Cytotoxic potency of tested chemicals was calculated on the basis of the bacteria culture growth inhibition (GI%) values. Genotoxic properties were calculated on the basis of the fold increase (FI) of relative luminescence units (RLU) values compared to control. Obtained results showed that doxorubicin metal complexes particularly with Ni, Co and Fe increased the cyto- and genotoxic activities of DOX. Bacteria culture supplemented with SeMet and vitamin C differentiate the DOX and its metal complexes toxicity. It seems, that DOX-Ni, DOX-Fe and DOX-Co complexes could be potent cytostatic drug candidates. Moreover, we noticed different sensitivity of recA::luxCDABE for 3 h and 24 h cultures of bacteria strain. It suggests, that the potency of genetic construct reactivity- recA::luxCDABE in E. coli depends on the growth-phase of bacterial culture.

Metal ion assisted interface re-engineering of a ferritin nanocage for enhanced biofunctions and cancer therapy

The bottom-up self-assembly of protein subunits into supramolecular nanoarchitectures is ubiquitously exploited to recapitulate and expand the features of natural proteins to advance nanoscience in medicine. Various chemical and biological re-engineering approaches are available to render diverse functions in the given proteins. They are, unfortunately, capable of compromising protein integrity and stability after extensive modifications. In this study, we introduce a new protein re-engineering method, metal ion assisted interface re-engineering (MAIR), to serve as a robust and universal strategy to extend the functions of self-assembly proteins by boosting structural features to advance their diverse biomedical applications. In particular, the MAIR strategy was applied to a widely used natural protein, ferritin, as a model protein to coordinate with copper ions in its mutagenic artificial metal binding domain. Structure directed rational protein mutagenesis was carried out at the C2 interface amino acid residues of the ferritin subunit for metal ion coordination site optimization. Copper binding at the artificial binding pocket was highly specific over the other divalent ions present in physiological fluids, and the structurally embedded copper ion in turn strengthened the overall protein integrity and stability. In the presence of isotopic copper-64, the interface re-engineered ferritin worked as a chelator-free molecular nanoprobe with an extraordinarily high specific activity to allow PET imaging of tumors in live animals. We also found that the re-engineered ferritin coordinating with copper ions demonstrates high drug loading capacity of a widely used anti-cancer agent, doxorubicin (DOX), to achieve significant drug retention at the tumor site and enhance tumor regression for improved anti-cancer effects. The MAIR approach, thus, exploited the copper ion to facilitate efficient one-step labeling of mutant ferritin derivatives for simultaneous molecular imaging and drug delivery. The reported interface re-engineering strategy provides an unparalleled opportunity to expand protein biofunctions to serve as a new theranostic agent in cancer research.

Possible Mechanisms of the Prevention of Doxorubicin Toxicity by Cichoric Acid-Antioxidant Nutrient

Skin is the largest organ in the human body, and which protects organism against unfavorable external factors e.g., chemicals, environment pollutants, allergens, microorganisms, and it plays a crucial role in maintaining general homeostasis. It is also an important target of oxidative stress due to the activity of oxygen reactive species (ROS), which are constantly generated in the fibroblasts in response to exogenous or endogenous prooxidant agents. An example of such compound with proved prooxidant activity is Doxorubicin (DOX), which is an effective anticancer agent belongs in anthracycline antibiotic group. Increasingly frequent implementation of various strategies to reduce undesirable DOX side effects was observed. Very promising results come from the combination of DOX with dietary antioxidants from the polyphenol group of compounds, such as cichoric acid (CA) in order to lower oxidative stress level. The aim of this work was to evaluate the influence of CA combined with DOX on the oxidative stress parameters in fibroblasts, which constitute the main cells in human skin. We also wanted to examine anti-apoptotic activity of CA in fibroblasts treated with selected concentrations of DOX. Results obtained from the combination of DOX with CA revealed that CA exhibits cytoprotective activity against DOX-induced damage by lowering oxidative stress level and by inhibiting apoptosis. The present finding may indicate that CA may serve as antioxidative and anti-apoptotic agent, active against DOX-induced damage.

Self-assembly of a metallo-peptide into a drug delivery system using a “switch on” displacement strategy

Two newly designed tripeptides and their corresponding Cu²⁺ conjugates self-assemble into nanometric structures of different morphologies. These self-assembled metallo-peptide networks can serve as a drug delivery platform using a fluorescent-based "Turn-On" displacement strategy.