Ligand substituent effect on the cytotoxicity activity of two new copper(ii) complexes bearing 8-hydroxyquinoline derivatives: validated by MTT assay and apoptosis in MCF-7 cancer cell line (human breast cancer)

Curcumin chemo-sensitizes intrinsic apoptosis through ROS-mediated mitochondrial hyperpolarization and DNA damage in breast cancer cells

BACKGROUND

Curcumin (CUR), a polyphenol phyto-compound extracted from turmeric rhizome (Curcuma longa), suppresses cancer by inducing apoptosis while also limiting cell survival and proliferation. This in vitro and in silico research work focuses on the synergistic sensitization of Doxorubicin (DOXO) on regulating ROS-mediated apoptosis of the breast cancer cells (MDA-MB-231 and MCF-7) in DOXO-CUR co-treatment. We observed dose-dependent cytotoxicity, increased ROS production, and mtDNA fragmentation by reduced membrane potential. The combined molecular docking of Bcl2, Bax, and Caspase3 proteins with DOXO and CUR with lower binding energies proves the stable interactions of protein-ligand complexes in the combination doses.

METHODOLOGY

Cell survival was measured by MTT and flow cytometry assays. Mitochondrial ROS production, mtDNA condensation, and MMP depletion were documented using fluorescence micrographs. The enrichment analysis of the ROS pathway genes by RT-qPCR (relative fold change) indicates the activation of Caspase3-mediated intrinsic apoptosis. Autodock 4.2 and Gromac 2022.4 were performed for in silico binding interaction and stability analysis.

RESULT & CONCLUSION

Our study calculates the DOXO and CUR combination (0.33-+ 33 μM in MDA-MB-231 and 0.14 + 14 μM in MCF-7) shows maximum growth inhibition (70-75 %) by elevated oxidative stress and reduced membrane potential, which suggests that CUR could be a potential therapeutic agent for treating breast cancers in the near future. The method of apoptosis was further analyzed, where elevated cellular ROS level by CUR + DOXO combination therapy depleted mitochondrial membrane potential and enhanced the DNA condensation. The mitochondrial pro-apoptotic genes BAX, BAK, BIM, CASPASE9, and CASPASE3 and anti-apoptotic BCL2 gene expressions depicted triggering intrinsic apoptosis pathway, co-relating with the in silico molecular docking, simulation, and MM-PBSA energy calculations. The synergism between CUR and DOXO was also validated by increased binding affinity and reduced inhibitory constant against key proteins Bcl2, Bax, and Caspase3. Bcl2-DOXO showed BE: -5.03 and Bcl2-DOXO-CUR showed BE: -4.7. Whereas, Bax-DOXO binding energy was -5.49 and Bax-DOXO-CUR binding was -3.83. The most preferable synergistic binding was found with Caspase3 protein, where Caspase3-DOXO docking energy was -1.63 but Caspase3-DOXO-CUR combined docking energy was -3.51. The stability of protein-ligand complexes was accessed with MD simulations and binding free energy calculations, Bcl2-CUR-DOXO combination complex showed ∆G: -25.62, Bax-DOXO-CUR complex showed the maximum ∆G: -34.18, with Caspase3-CUR-DOXO complex (∆G: -15.18), indicating the proteins most stable conformation while interacting with CUR + DOXO combination. The correlation between the in vitro and in silico analysis of apoptosis pathway components widens the further research scope for proteomics and organoid studies, which might be worthy of successful clinical trials.

Advanced synthesis, comprehensive characterization, and potent cytotoxicity of 2,6-Bis(2-aminophenylimino)methyl)-4-methoxyphenol and its binuclear copper(II) complex

The imine base and Cu2+ precursors were combined using magnetic stirring to formulate the Cu2+ complexes. The formation of the imine base was confirmed by electronic and vibrational spectra, proton NMR, LC-mass spectrometry, and computational studies, which also optimized the final structure. The Cu2+ complexes were characterized using electronic and vibrational spectra, magnetic susceptibility, molar conductivity, a variable temperature magnetometer, and ESR spectroscopy. Cyclic voltammetry revealed electron transfer from Cu2+ to Cu+ within the complex. The in vitro tumour activity of the Cu2+ complexes and imine base were evaluated on the A431 cell line using the MTT assay. DFT studies validated the structural stability of the imine base. The antiferromagnetic behaviour observed at low temperatures suggests that these Cu2+ complexes could be useful in heavy magnetic materials. Due to their electron transfer properties, Cu2+ complexes also hold potential for use in electroplating systems and sensors. The complexes exhibited high efficacy on the cell line, aligning with clinical objectives. The Cu2+ complexes are represented as [MLR], where M is the metal, L is the imine base, and R = [C₆H₅COO] or R = [C₆H₄COO(NH₂)].

Untargeted metabolic analysis of Epaltes mexicana by LC-QTOF-MS: Terpenes with activity against human cancer cell lines

Epaltes mexicana is a plant widely used in traditional medicine and as a food in Mexico; however, its phytochemical and pharmacological studies are limited. This study aimed to identify the active secondary metabolites of Epaltes mexicana and determine its cytotoxic activity on cancer cell lines. Three organic extracts were obtained by maceration using n-hexane, dichloromethane, and methanol. The n-hexane extract was fractioned by simple column chromatography. Eight terpenes were annotated in collection 6 (C6) by LC-QTOF-MS using a gradient elution and Electrospray Ionization (ESI) in positive ion mode: 1) Gibberellin A15, 2) farfugin A, 3) dehydromyodesmone, 4) eremopetasitenin A1, 5) hydroxyisonobilin, 6) anhydrocinnzeylanine, 7) nigakilactone H and 8) taxodione. On the other hand, C6 showed a concentration-dependent cytotoxic effect on cancer cell lines MCF-7 (Emax = 74.69 ± 6.19 % and IC50 = 6.31 μg/mL), MDA-MB-231 (Emax = 79.28 ± 12.12 % and IC50 = 124.21 μg/mL), and SiHa (Emax = 82.96 ± 6.02 % and IC50 = 124.31 μg/mL). The C6 did not show a cytotoxic effect against DU-145 and non-cancerous cells from the mammary glands MCF-10A. These results indicate cytotoxic specificity on cancer cell lines and support the hypothesis that terpenes identified in E. mexicana must be investigated and developed for non-clinical and clinical trials as potential anti-cancer drugs.

In silico studies, synthesis, characterization and in vitro studies of levosulpiride derivatives

Aim: Breast cancer is the most recurring cancer among females and is being diagnosed as a major cause of death among women.Materials & methods: Levosulpiride Schiff base derivatives were synthesized and analyzed by physical and spectral (FTIR, 1H-NMR, 13C-NMR) analysis. MTT assay against MCF-7 (human breast cancer cell line), scavenging activity and Molecular docking against receptors 1M17, 3PP0, 3IOK and 4KIK along ADME pharmacokinetic studies were performed.Results & conclusion: L1 and L3 synthesized derivatives have revealed better percent cell viability and inhibitory concentration (IC50) with scavenging activity as of the parent compound. L1, L3 and L9 revealed significant docking scores compared with standard drugs. Most of the derivatives showed strong pharmacokinetic profiles while no drug crossed blood-brain barrier. The newly synthesized L1 and L3 levosulpiride-derived compounds have demonstrated promising anticancer properties against breast cancer cells.

Suppression of human lysozyme aggregation by a novel copper-based complex of 3,4-dimethoxycinnamic acid

In this work, a new Cu(II)-based complex as a chemotherapeutic drug agent, formulated as[Cu(DCA)4(H2O)2]⋅4H2O⋅4MeOH, (DCA = 3,4-dimethoxycinnamic acid), namely 1 was successfully synthesized utilizing DCA as a ligand to arrest fibrillation in Human lysozyme. The 1 was thoroughly characterized by single crystal X-ray diffraction (SC-XRD), spectroscopic (UV-Vis and FTIR) techniques, PXRD, and TGA analysis. Its crystal structure reveals a paddle wheel network around central copper metal ions. The Cu(II) metal ions exhibit a distorted square pyramidal configuration. The fluorescence titration studies showed moderate binding interaction of 1 with HuL with Ka of 6.3x105 M-1 at pH-2, 25 °C due to its interaction withAsp53, Tyr63, Val110, and Ala111 as shown by docking and simulation studies. 1suppresses the HuL fibrillation in a concentration-dependent manner, as demonstrated by ThT assay. At 200 µM concentration, it leads to the formation of smaller species of the protein in comparison to the control sample, as suggested by Light Scattering studies. The species formed are less hydrophobic and retain their native α-helix structure compared to the control samples, which are hydrophobic and form β-sheet rich amyloids as shown by ANS hydrophobicity assay and CD spectroscopy, respectively. Furthermore, morphological analysis of the species by AFM has demonstrated that, unlike mature amyloid fibrils in the control sample, HuL forms small-size aggregates in the presence of 1 under similar fibrillation conditions. It can be concluded that 1 effectively suppresses HuL fibrillation due to moderate binding to the protein.Communicated by Ramaswamy H. Sarma.

Multifaceted Characterization and Therapeutic Evaluation of Co-precipitated Cobalt Ferrite Nanoparticles for Magnetic Hyperthermia Cancer Therapy

Aim

Magnetic-mediated hyperthermia has emerged as a promising therapeutic approach for treating cancer. This technique employs the heat dissipated by the magnetic nanoparticles when subjected to an external varying magnetic field, to bring about localized hyperthermia in tumor tissues. Owing to their conducive and tuneable "physical, chemical, and magnetic" characteristics, cobalt ferrite (CoFe2O4) nanoparticles are recognized as emerging contenders. The aim of the present work was to enhance the magnetic characteristics and guarantee the efficacy of CoFe2 O4 nanoparticles in targeting and eliminating cancer cells.

Methods

CoFe2O4 nanoparticles were synthesized using the chemical co-precipitation route and underwent rigorous structural, morphological, and magnetic characterization techniques. The synthesized particles were then subjected to in vitro studies to evaluate their cytotoxicity and antimicrobial susceptibility.

Results

The characterization techniques confirmed the cubic structure, ferrite phase, and spherical and magnetic nature of CoFe2O4 nanoparticles. The zeta potential was found to be - 0.0048V (4.8 mV). Cytotoxicity analysis exhibited decreased cell viability with increasing concentrations of CoFe2O4 nanoparticles. Antimicrobial studies displayed good inhibiting properties.

Conclusion

The zeta potential of the synthesized CoFe2O4 nanoparticles was found to be higher than that of the breast cancer cells (MCF-7) which proves the synthesized drug to be effective. The in vitro studies also disclose the efficacy of the drug over cancer cells.

An 8-aminoquinoline-naphthyl copper complex causes apoptotic cell death by modulating the expression of apoptotic regulatory proteins in breast cancer cells

Breast cancer is one of the most common cancers globally and a leading cause of cancer-related deaths among women. Despite the combination of chemotherapy with targeted therapy, including monoclonal antibodies and kinase inhibitors, drug resistance and treatment failure remain a common occurrence. Copper, complexed to various organic ligands, has gained attention as potential chemotherapeutic agents due to its perceived decreased toxicity to normal cells. The cytotoxic efficacy and the mechanism of cell death of an 8-aminoquinoline-naphthyl copper complex (Cu8AqN) in MCF-7 and MDA-MB-231 breast cancer cell lines was investigated. The complex inhibited the growth of MCF-7 and MDA-MB-231 cells with IC50 values of 2.54 ± 0.69 μM and 3.31 ± 0.06 μM, respectively. Nuclear fragmentation, annexin V binding, and increased caspase-3/7 activity indicated apoptotic cell death. The loss of mitochondrial membrane potential, an increase in caspase-9 activity, the absence of active caspase-8 and a decrease of tumour necrosis factor receptor 1(TNFR1) expression supported activation of the intrinsic apoptotic pathway. Increased ROS formation and increased expression of haem oxygenase-1 (HMOX-1) indicated activation of cellular stress pathways. Expression of p21 protein in the nuclei was increased indicating cell cycle arrest, whilst the expression of inhibitor of apoptosis proteins (IAPs); cIAP1, XIAP and survivin were decreased, creating a pro-apoptotic environment. Phosphorylated p53 species; phospho-p53(S15), phospho-p53(S46), and phospho-p53(S392) accumulated in MCF-7 cells indicating the potential of Cu8AqN to restore p53 function in the cells. In combination, the data indicates that Cu8AqN is a useful lead molecule worthy of further exploration as a potential anti-cancer drug.

Synthesis of quercetin derivatives as cytotoxic against breast cancer MCF-7 cell line in vitro and in silico studies

Background: Quercetin being antioxidant and antiproliferative agent acts by inhibiting CDK2, with an increase in cancer prevalence there is a need to profile quercetin derivatives as CDK2 inhibitors.Materials & method: Schiff bases of quercetin were synthesized as cytotoxic agents against the MCF7 cell line. FTIR, 1H-NMR and 13C-NMR, CHNS/O analysis were employed along with in vivo and in silico activities.Results & conclusion: 2q, 4q, 8q and 9q derivatives have maximum cytotoxic effect with IC50 values 39.7 ± 0.7, 36.65 ± 0.25, 35.49 ± 0.21 and 36.99 ± 0.45, respectively. Molecular docking also confirmed these results 8q has the highest binding potential of -9.165 KJ/mole making it a potent inhibitor of CDK2. These derivatives can be used as lead compounds as potent CDK2 inhibitors.

CogniFiber: Harnessing Biocompatible and Biodegradable 1D Collagen Nanofibers for Sustainable Nonvolatile Memory and Synaptic Learning Applications

Here, resistive switching (RS) devices are fabricated using naturally abundant, nontoxic, biocompatible, and biodegradable biomaterials. For this purpose, 1D chitosan nanofibers (NFs), collagen NFs, and chitosan-collagen NFs are synthesized by using an electrospinning technique. Among different NFs, the collagen-NFs-based device shows promising RS characteristics. In particular, the optimized Ag/collagen NFs/fluorine-doped tin oxide RS device shows a voltage-tunable analog memory behavior and good nonvolatile memory properties. Moreover, it can also mimic various biological synaptic learning properties and can be used for pattern classification applications with the help of the spiking neural network. The time series analysis technique is employed to model and predict the switching variations of the RS device. Moreover, the collagen NFs have shown good cytotoxicity and anticancer properties, suggesting excellent biocompatibility as a switching layer. The biocompatibility of collagen NFs is explored with the help of NRK-52E (Normal Rat Kidney cell line) and MCF-7 (Michigan Cancer Foundation-7 cancer cell line). Additionally, the biodegradability of the device is evaluated through a physical transient test. This work provides a vital step toward developing a biocompatible and biodegradable switching material for sustainable nonvolatile memory and neuromorphic computing applications.

Synthesis, Structure-Activity Relationship, and Mechanism of a Series of Diarylhydrazide Compounds as Potential Antifungal Agents

A series of simple diarylhydrazide derivatives (45 examples) were well-designed, prepared, and screened for their antifungal activities both in vitro and in vivo. Bioassay results suggested that all designed compounds had significant activity against Alternaria brassicae (EC₅₀ = 0.30-8.35 μg/mL). Among of them, 2c, as the highest activity compound, could effectively inhibit the growth of plant pathogens Pyricularia oryza, Fusarium solani, Alternaria solani, Alternaria brassicae, and Alternaria alternate and was more potent than carbendazim and thiabendazole. 2c showed almost 100% protection at 200 μg/mL in vivo activity against A. solani in tomato. Moreover, 2c did not affect the germination of cowpea seed and the growth of normal human hepatocytes. The preliminary mechanistic exploration documented that 2c could result in the abnormal morphology and irregular structure of the cell membrane, destroy the function of mitochondria, increase the reactive oxygen species, and inhibit the proliferation of hypha cell. The above results manifested that target compound 2c could be a potential fungicidal candidate against phytopathogenic diseases for its excellent fungicidal activities.

Design, synthesis, cytotoxic activities, and molecular docking of chalcone hybrids bearing 8-hydroxyquinoline moiety with dual tubulin/EGFR kinase inhibition

The present study established thirteen novel 8-hydroxyquinoline/chalcone hybrids3a-mof hopeful anticancer activity. According to NCI screening and MTT assay results, compounds3d-3f, 3i,3k,and3ldisplayed potent growth inhibition on HCT116 and MCF7 cells compared to Staurosporine. Among these compounds,3eand3fshowed outstanding superior activity against HCT116 and MCF7 cells and better safety toward normal WI-38 cells than Staurosporine. The enzymatic assay revealed that3e,3d, and3ihad goodtubulin polymerization inhibition (IC₅₀ = 5.3, 8.6, and 8.05 µM, respectively) compared to the reference Combretastatin A4 (IC₅₀ = 2.15 µM). Moreover,3e,3l, and3fexhibited EGFR inhibition (IC₅₀ = 0.097, 0.154, and 0.334 µM, respectively) compared to Erlotinib (IC₅₀ = 0.056 µM). Compounds3eand3fwere investigated for their effects on the cell cycle, apoptosis induction, andwnt1/β-cateningene suppression. The apoptosis markers Bax, Bcl2, Casp3, Casp9, PARP1, and β-actin were detected by Western blot. In-silico molecular docking, physicochemical, and pharmacokinetic studies were implemented for the validation of dual mechanisms and other bioavailability standards. Hence, Compounds3eand3fare promising antiproliferative leads with tubulin polymerization and EGFR kinase inhibition.

Structural, Theoretical Investigations, Hirshfeld Surface Analysis, and Cytotoxicity Profile of a Neocuproine-Co(II)-Based Discrete Homodinuclear Complex

In this work, we aimed to synthesize a new cobalt(II) complex, namely [Co₂(μ-HIPA)(NC)₂(H₂O)₃(NO₃)]·(NO₃)(C₂H₅OH)(1) (where H₃IPA = 5-hydroxy isophthalic acid and NC = 2,9-dimethyl-1,10-phenanthroline or neocuproine), as a promising chemotherapeutic agent. The diffraction (single crystal-XRD and powder-XRD), spectroscopic (FTIR and UV-visible), molar conductance, and thermal techniques were used to characterize complex 1. Single-crystal X-ray diffraction analysis reveals that Co(II) exists in an octahedral geometry, with the ligation of four oxygen atoms, and two nitrogen atoms. Topological analysis of complex 1 reveals 2,6C6 topological type as an underlying net. The plausible intermolecular interactions within complex 1 that control the crystal packing were analyzed by Hirshfeld surface analysis. In vitro cytotoxicity of complex 1 was evaluated against acute myeloid leukemia (THP-1), colorectal (SW480), and prostate (PC-3) cancer cell lines by utilizing an MTT assay. The result shows that complex 1 can inhibit the growth of cancer cells (THP-1, SW480, and PC-3) at lower inhibitory concentration (IC₅₀) values of > 100, 43.6, and 95.1 µM respectively. The morphological changes induced by complex 1 on THP-1 and SW480 cancer cell lines were carried out with acridine orange/ethidium bromide staining methods. Additionally, comprehensive molecular docking studies were performed to understand the potential binding interactions of complex 1 with different bio-macromolecules.

Promising anticancer agents based on 8-hydroxyquinoline hydrazone copper(II) complexes

We report the synthesis and characterization of a group of benzoylhydrazones (Lⁿ) derived from 2-carbaldehyde-8-hydroxyquinoline and benzylhydrazides containing distinct para substituents (R = H, Cl, F, CH₃, OCH₃, OH and NH₂, for L^1-7, respectively; in L⁸ isonicotinohydrazide was used instead of benzylhydrazide). Cu(II) complexes were prepared by reaction of each benzoylhydrazone with Cu(II) acetate. All compounds were characterized by elemental analysis and mass spectrometry as well as by FTIR, UV-visible absorption, NMR or electron paramagnetic resonance spectroscopies. Complexes isolated in the solid state (1-8) are either formulated as [Cu(HL)acetate] (with L¹ and L⁴) or as [Cu(Lⁿ)]₃ (n = 2, 3, 5, 6, 7 and 8). Single crystal X-ray diffraction studies were done for L⁵ and [Cu(L⁵)]₃, confirming the trinuclear formulation of several complexes. Proton dissociation constants, lipophilicity and solubility were determined for all free ligands by UV-Vis spectrophotometry in 30% (v/v) DMSO/H₂O. Formation constants were determined for [Cu(LH)], [Cu(L)] and [Cu(LH_-1)] for L = L¹, L⁵ and L⁶, and also [Cu(LH_-2)] for L = L⁶, and binding modes are proposed, [Cu(L)] predominating at physiological pH. The redox properties of complexes formed with L¹, L⁵ and L⁶ are investigated by cyclic voltammetry; the formal redox potentials fall in the range of +377 to +395 mV vs. NHE. The binding of the Cu(II)-complexes to bovine serum albumin was evaluated by fluorescence spectroscopy, showing moderate-to-strong interaction and suggesting formation of a ground state complex. The interaction of L¹, L³, L⁵ and L⁷, and of the corresponding complexes with calf thymus DNA was evaluated by thermal denaturation. The antiproliferative activity of all compounds was evaluated in malignant melanoma (A-375) and lung (A-549) cancer cells. The complexes show higher activity than the corresponding free ligand, and most complexes are more active than cisplatin. Compounds 1, 3, 5, and 8 were selected for additional studies: while these complexes induce reactive oxygen species and double-strand breaks in both cancer cells, their ability to induce cell-death by apoptosis varies. Within the set of compounds tested, 8 emerges as the most promising one, presenting low IC₅₀ values, and high induction of oxidative stress and DNA damage, which eventually lead to high rates of apoptosis.

Investigations on Anticancer Potentials by DNA Binding and Cytotoxicity Studies for Newly Synthesized and Characterized Imidazolidine and Thiazolidine-Based Isatin Derivatives

Imidazolidine and thiazolidine-based isatin derivatives (IST-01-04) were synthesized, characterized, and tested for their interactions with ds-DNA. Theoretical and experimental findings showed good compatibility and indicated compound-DNA binding by mixed mode of interactions. The evaluated binding parameters, i.e., binding constant (Kb), free energy change (ΔG), and binding site sizes (n), inferred comparatively greater and more spontaneous binding interactions of IST-02 and then IST-04 with the DNA, among all compounds tested under physiological pH and temperature (7.4, 37 °C). The cytotoxic activity of all compounds was assessed against HeLa (cervical carcinoma), MCF-7 (breast carcinoma), and HuH-7 (liver carcinoma), as well as normal HEK-293 (human embryonic kidney) cell lines. Among all compounds, IST-02 and 04 were found to be cytotoxic against HuH-7 cell lines with percentage cell toxicity of 75% and 66%, respectively, at 500 ng/µL dosage. Moreover, HEK-293 cells exhibit tolerance to the increasing drug concentration, suggesting these two compounds are less cytotoxic against normal cell lines compared to cancer cell lines. Hence, both DNA binding and cytotoxicity studies proved imidazolidine (IST-02) and thiazolidine (IST-04)-based isatin derivatives as potent anticancer drug candidates among which imidazolidine (IST-02) is comparatively the more promising.

In silico studies of interactions of peptide-conjugated cholesterol metabolites and betulinic acid with EGFR, LDR, and N-terminal fragment of CCKA receptors

In this work, we designed three new ligands by conjugating cholesterol metabolites 3-hydroxy-5-cholestenoic acid (3-HC) and 3-oxo-4-cholestenoic acid (3-OC) and the natural tri-terpenoid betulinic acid with the tumor-targeting peptide YHWYGYTPQNVI. Molecular interactions with the unconjugated peptide and the conjugates were examined with three receptors that are commonly overexpressed in pancreatic adenocarcinoma cells using ligand docking and molecular dynamics. This study demonstrated the utility of the designed conjugates as a valuable scaffold for potentially targeting EGFR and LDLR receptors. Our results indicate that the conjugates showed strong binding affinities and formation of stable complexes with EGFR, while the unconjugated peptide, BT-peptide conjugate, an 3-HC-peptide conjugate showed the formation of fairly stable complexes with LDLR receptor. For EGFR, two receptor kinase domains were explored. Interactions with the N-terminal domain of CCKA-R were relatively weaker. For LDLR, binding occurred in the beta-propeller region. For the N-terminal fragment of CCKA-R, the conjugates induced significant conformational changes in the receptor. The molecular dynamic simulations for 100 ns demonstrate that BT-peptide conjugates and the unconjugated peptide had the highest binding and formed the most stable complexes with EGFR. RMSD and trajectory analyses indicate that these molecules transit to a dynamically stable configuration in most cases within 60 ns. NMA analysis indicated that amongst the conjugates that showed relatively higher interactions with the respective receptors, the highest potential for deformability was seen for the N-terminal-47 amino acid region of the CCKA-R receptor with and the lowest for the LDLR-receptor. Thus, the newly designed compounds may be evaluated in the future toward developing drug delivery materials for targeting tumor cells overexpressing LDLR or EGFR.