Search for new biologically active compounds: in vitro studies of antitumor and antimicrobial activity of dirhodium(II,II) paddlewheel complexes.

Four neutral Rh1-Rh4 complexes of the general formula [Rh2(CH3COO)4L2], where L is an N-alkylimidazole ligand, were synthesized and characterized using various spectroscopic techniques, and in the case of Rh4 the crystal structure was confirmed. Investigation of the interactions of these complexes with HSA by fluorescence spectroscopy revealed that the binding constants Kb are moderately strong (∼104 M-1), and site-marker competition experiments showed that the complexes bind to Heme site III (subdomain IB). Competitive binding studies for CT DNA using EB and HOE showed that the complexes bind to the minor groove, which was also confirmed by viscosity experiments. Molecular docking confirmed the experimental data for HSA and CT DNA. Antimicrobial tests showed that the Rh2-Rh4 complexes exerted a strong inhibitory effect on G+ bacteria B. cereus and G- bacteria V. parahaemolyticus as well as on the yeast C. tropicalis, which showed a higher sensitivity compared to fluconazole. The cytotoxic activity of Rh1-Rh4 complexes tested on three cancer cell lines (HeLa, HCT116 and MDA-MB-231) and on healthy MRC-5 cells showed that all investigated complexes elicited more efficient cytotoxicity on all tested tumor cells than on control cells. Investigation of the mechanism of action revealed that the Rh1-Rh4 complexes inhibit cell proliferation via different mechanisms of action, namely apoptosis (increase in expression of the pro-apoptotic Bax protein and caspase-3 protein in HeLa and HCT116 cells; changes in mitochondrial potential and mitochondrial damage; release of cytochrome c from the mitochondria; cell cycle arrest in G2/M phase in both HeLa and HCT116 cells together with a decrease in the expression of cyclin A and cyclin B) and autophagy (reduction in the expression of the protein p62 in HeLa and HCT116 cells).

Its all about IFN-λ4: Protective role of IFNL4 polymorphism against COVID-19-related pneumonia in females.

Despite the pivotal role of IFN-λs in the innate immune response, the data on its genetic polymorphism in relation to COVID-19 severity are scarce and contradictory. In the present study, we aimed to determine if the presence of the most frequent functional single nucleotide polymorphisms (SNPs) of the two most important IFN-λs coding genes, namely IFNL3 and IFNL4, alters the likelihood of SARS-CoV-2-infected patients to develop more severe form of the disease. This observational cohort study involved 178 COVID-19 patients hospitalized at the University Clinical Centre Kragujevac, Serbia. Patients' demographics, clinical characteristics, and laboratory parameters were collected at admission. COVID-19 signs and symptoms were assessed during the hospital stay, with the worst condition determining the disease severity. Genotyping for IFNL3 (rs12980275 and rs8099917) and IFNL4 (rs12979860 and rs368234815) SNPs was conducted using TaqMan assays. Our study revealed carriers of IFNL3 and IFNL4 minor alleles to be less likely to progress from mild to moderate COVID-19, that is, to develop COVID-19-related pneumonia. After adjustment for other factors of influence, such as age, sex, and comorbidities, the likelihood of pneumonia development remained significantly associated with IFNL4 polymorphism (odds ratios [ORs] [95% confidence interval (95% CI)]: 0.233 [0.071; 0.761]). When the patients were stratified according to sex, the protective role of IFNL4 minor alleles, controlled for the effect of comorbidities, remained significant only in females (OR [95% CI]: 0.035 [0.003; 0.408]). Our results strongly suggest that IFNL4 rs12979860 and rs368234815 polymorphisms independently predict the risk of COVID-19-related pneumonia development in females.

IFNL3/4 polymorphisms as a two-edged sword: An association with COVID-19 outcome.

Coronavirus Disease 2019 (COVID-19) has been ranked among the most fatal infectious diseases worldwide, with host's immune response significantly affecting the prognosis. With an aim to timely predict the most likely outcome of SARS-CoV-2 infection, we investigated the association of IFNL3 and IFNL4 polymorphisms, as well as other potentially relevant factors, with the COVID-19 mortality. This prospective observational case-control study involved 178 COVID-19 patients, hospitalized at Corona Center or Clinic for Infectious Diseases of University Clinical Centre Kragujevac, Serbia, followed up until hospital discharge or in-hospital death. Demographic and clinical data on all participants were retrieved from the electronic medical records, and TaqMan assays were employed in genotyping for IFNL3 and IFNL4 single nucleotide polymorphisms (SNPs), namely rs12980275, rs8099917, rs12979860, and rs368234815. 21.9% and 65.0% of hospitalized and critically ill COVID-19 patients, respectively, died in-hospital. Multivariable logistic regression analysis revealed increased Charlson Comorbidity Index (CCI), N/L, and lactate dehydrogenase (LDH) level to be associated with an increased likelihood of a lethal outcome. Similarly, females and the carriers of at least one variant allele of IFNL3 rs8099917 were almost 36-fold more likely not to survive SARS-CoV-2 infection. On the other hand, the presence of at least one ancestral allele of IFNL4 rs368234815 decreased more than 15-fold the likelihood of mortality from COVID-19. Our results suggest that, in addition to LDH level, N/L ratio, and CCI, IFNL4 rs368234815 and IFNL3 rs8099917 polymorphisms, but also patients' gender, significantly affect the outcome of COVID-19.

New ruthenium(II) complexes with quinone diimine and substituted bipyridine as inert ligands: synthesis, characterization, mechanism of action, DNA/HSA binding affinity and cytotoxic activity.

This paper presents the synthesis and structural characterization of a series of new ruthenium(II) complexes 1-7, with the general formula mer-[RuL3(N-N)Cl]Cl, where L is 2,2':6',2''-terpyridine (tpy) or 4'-(4-chlorophenyl)-2,2':6',2''-terpyridine (Cl-Ph-tpy) and N-N is o-benzoquinonediimine (o-bqdi), 2,3-naphthoquinonediimine (nqdi), 4,4'-dimethyl-2,2'-bipyridine (dmbpy) or 2,2'-bipyridine-4,4'-dicarboxylic acid (dcbpy). The kinetic results showed that the ligand substitution reactions of new Ru(II)-polypyridyl complexes with biomolecules were affected by different substituents and the aromaticity of meridional tridentate and bidentate spectator ligands as well as by the nature of the entering nucleophile. The reactivity of the complexes increases in the order: dmbpy < dcbipy < nqdi < o-bqdi. In addition, quantum chemical calculations were performed to support the interpretation and discussion of the experimental data. Furthermore, combining ethidium bromide (EB) and Hoechst 33258 (2-(4-hydroxyphenyl)-5-[5-(4-methylpiperazine-1-yl)benzimidazo-2-yl]-benzimidazole) fluorescence assay results implied that 1-7 might interact with calf thymus DNA through partial intercalation and/or minor groove binding. The human serum albumin (HAS)-fluorescence binding studies involving the site markers, eosin Y, as a marker for site I of subdomain IIA, and ibuprofen, as a marker for site II of subdomain IIIA, showed that Ru(II) compounds bind to both sites with moderately strong affinity (Kb = 104-106 M-1). Moreover, these DNA/HSA experimental results were confirmed by molecular docking. Complexes 2, 5 and 6 exerted good to strong and highly selective cytotoxic activity against breast adenocarcinoma (MDA-MB 231), colorectal carcinoma (HCT116) and cervix adenocarcinoma (HeLa). Depending on their structure and cell line, the complexes acted differently in terms of their influence on autophagy, the cell cycle and the engaged apoptotic pathway.

Anticancer potential of some ß-diketonates: DNA interactions, protein binding properties, and molecular docking study.

With the goal to discover a new antitumor drug with the better or similar effects to existing, a small series of ß-diketonate was tested on a cisplatin-resistant MDA-MB-231 and HeLa tumor cell lines, and nontumor MRC-5 cell line. All compounds showed notable cytotoxicity against both tumor cell lines and good selectivity. Importantly, ß-diketonates displayed greater selectivity than cisplatin, which is the crucial factor for a new antitumor drug candidate. Further, investigations with biomacromolecules such as DNA and serum albumin were performed. Investigations showed that tested compounds bind to DNA through intercalation and have appropriate affinity for binding to bovine serum albumin. In addition, the molecular docking study was performed to investigate more specifically the sites and binding mode of tested ß-diketonate to DNA or bovine serum albumin. In conclusion, all results indicated the big potential of these compounds for application in clinical practice in future.

Phytochemical Analysis, Antioxidant, Antimicrobial, and Cytotoxic Activity of Different Extracts of Xanthoparmelia stenophylla Lichen from Stara Planina, Serbia.

The aim of this study was to identify some of the secondary metabolites present in acetonic, methanolic, and hexanic extracts of lichen Xanthoparmelia stenophylla and to examine their antioxidant, antimicrobial, and cytotoxic activity. Compounds of the depsid structure of lecanoric acid, obtusic acid, and atranorin as well as usnic acid with a dibenzofuran structure were identified in the extracts by HPLC. The acetone extract was shown to have the highest total phenolic (167.03 ± 1.12 mg GAE/g) and total flavonoid content (178.84 ± 0.93 mg QE/g) as well as the best antioxidant activity (DPPH IC50 = 81.22 ± 0.54). However, the antimicrobial and antibiofilm tests showed the best activity of hexanic extract, especially against strains of B. cereus, B. subtilis, and S. aureus (MIC < 0.08, and 0.3125 mg/mL, respectively). Additionally, by using the MTT method, the acetonic extract was reported to exhibit a strong cytotoxic effect on the HeLa and HCT-116 cell lines, especially after 72 h (IC50 = 21.17 ± 1.85 and IC50 = 21.48 ± 3.55, respectively). The promising antioxidant, antimicrobial, and cytotoxic effects of Xanthoparmelia stenophylla extracts shown in the current study should be further investigated in vivo and under clinical conditions.

Synthesis, Characterization, Antitumor Potential, BSA and DNA Binding Properties, and Molecular Docking Study of Some Novel 3-Hydroxy-3- Pyrrolin-2-Ones.

BACKGROUND: In order to make progress in discovering the new agents for cancer treatment with improved properties and considering the fact that 3-hydroxy-3-pyrrolin-2-ones belong to a class of biologically active compounds, we tested series of eleven novels 1,5-diaryl-4-(2- thienylcarbonyl)-3-hydroxy-3-pyrrolin-2-ones for their antitumor potential. METHODS: All novel compounds were characterized by spectral (IR, NMR, MS) and elemental analysis. All novel 3-hydroxy-3-pyrrolin-2-ones were screened for their cytotoxic activity on two cancer cell lines, SW480 and MDA-MB 231, and non-transformed fibroblasts (MRC-5). RESULTS: Compounds B8, B9, and B10 showed high cytotoxicity on SW480 cells together with good selectivity towards MRC-5 cells. It is important to empathize that the degree of selectivity of B8 and B10 was high (SI = 5.54 and 12.09, respectively). Besides, we explored the mechanisms of cytotoxicity of novel derivatives, B8, B9, and B10. The assay showed that tested derivatives induce an apoptotic type of cell death in SW480 cells, with a minor percent of necrotic cells. Additionally, to better understand the suitability of the compounds for potential use as anticancer medicaments, we studied their interactions with biomacromolecules (DNA or BSA). The results indicated that the tested compounds have a great affinity to displace EB from the EB-DNA complex through intercalation. Also, DNA and BSA molecular docking study was performed to predict the binding mode and the interaction region of the compounds. CONCLUSION: Achieved results indicate that our compounds have the potential to become candidates for use as medicaments.

Chelidonium majus crude extract induces activation of peripheral blood mononuclear cells and enhances their cytotoxic effect toward HeLa cells.

The aim of the study was to examine the immunomodulatory effect of crude Chelidonium majus L ethanolic extract on ex vivo harvested peripheral blood mononuclear cells (PBMNCs). PBMNCs were isolated by density gradient centrifugation. The PBMNC cytotoxicity assay was performed with HeLa tumor cells as target cells. MTT assay was used to estimate the proliferation effect of extract and cytotoxic efficiency of treated PBMNCs. Flow cytometric analysis was used for immunophenotyping. Treatment induced moderate proliferative response, perturbation in PBMNC ratios, and the emergence of some unconventional subpopulations. The percentage ratio of double positive CD4+ and CD8+ T lymphocytes and monocytes, ratio of T and B lymphocytes expressing CD14, and percentage of NK cells expressing CD57 increased after treatment, indicating activation of PBMNC subpopulations. Cytotoxic activity against HeLa cells was enhanced. Activation of PBMNCs and enhancement of their cytotoxic effect toward HeLa cells indicate the immunostimulatory effect of Ch. majus ethanolic extract.

Antioxidant, Antigenotoxic and Cytotoxic Activity of Essential Oils and Methanol Extracts of Hyssopus officinalis L. Subsp. aristatus (Godr.) Nyman (Lamiaceae).

Hyssopus officinalis L. is a well-known aromatic plant used in traditional medicine and the food and cosmetics industry. The aim of this study is to assess the antioxidant, genotoxic, antigenotoxic and cytotoxic properties of characterized hyssop essential oils and methanol extracts. Chemical composition was analyzed by gas chromatography - mass spectrometry (GC-MS) and liquid chromatography with diode array detection and mass spectrometry (LC-DAD-MS), respectively. Antioxidant activity was examined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) tests; genotoxic and antigenotoxic activity were examined by the comet assay, while cytotoxicity was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide dye (MTT) test against tumor cell lines (SW480, MDA-MB 231, HeLa) and non-transformed human lung fibroblast cell lines (MRC-5). The essential oils were rich in monoterpene hydrocarbons (e.g., limonene; 7.99-23.81%), oxygenated monoterpenes (1,8-cineole; 38.19-67.1%) and phenylpropanoids (methyl eugenol; 0.00-28.33%). In methanol extracts, the most abundant phenolics were chlorogenic and rosmarinic acid (23.35-33.46 and 3.53-17.98 mg/g, respectively). Methanol extracts expressed moderate to weak antioxidant activity (DPPH IC50 = 56.04-199.89 µg/mL, FRAP = 0.667-0.959 mmol Fe2+/g). Hyssop preparations significantly reduced DNA damage in human whole blood cells, induced by pretreatment with hydrogen peroxide. Methanol extracts exhibited selective and potent dose- and time-dependent activity against the HeLa cell line. Results of the current study demonstrated notable H. officinalis medicinal potential, which calls for further investigation.

SARS-CoV-2 infection induces mixed M1/M2 phenotype in circulating monocytes and alterations in both dendritic cell and monocyte subsets.

Clinical manifestations of SARS-CoV-2 infection range from mild to critically severe. The aim of the study was to highlight the immunological events associated with the severity of SARS-CoV-2 infection, with an emphasis on cells of innate immunity. Thirty COVID-19 patients with mild/moderate symptoms and 27 patients with severe/critically severe symptoms were recruited from the Clinical Center of Kragujevac during April 2020. Flow cytometric analysis was performed to reveal phenotypic and functional alterations of peripheral blood cells and to correlate them with the severity of the disease. In severe cases, the number of T and B lymphocytes, dendritic cells, NK cells, and HLA-DR-expressing cells was drastically decreased. In the monocyte population proportion between certain subsets was disturbed and cells coexpressing markers of M1 and M2 monocytes were found in intermediate and non-classical subsets. In mild cases decline in lymphocyte number was less pronounced and innate immunity was preserved as indicated by an increased number of myeloid and activated dendritic cells, NK cells that expressed activation marker at the same level as in control and by low expression of M2 marker in monocyte population. In patients with severe disease, both innate and adoptive immunity are devastated, while in patients with mild symptoms decline in lymphocyte number is lesser, and the innate immunity is preserved.

Homo- and hetero-dinuclear Pt(II)/Pd(II) complexes: studies of hydrolysis, nucleophilic substitution reactions, DNA/BSA interactions, DFT calculations, molecular docking and cytotoxic activity.

Three dinuclear complexes [Pd2(tpbd)Cl2]Cl2 (PP1), [Pt2(tpbd)Cl2]Cl2 (PP2) and [PdPt(tpbd)Cl2]Cl2 (PP3) (tpbd = N,N,N',N'-tetrakis(2-pyridylmethyl)benzene-1,4-diamine) have been synthesized and characterized and the protonation constants of their corresponding diaqua analogues have been determined. Also, in water solution, the aqua analogues of these complexes exist as mono-hydroxo, di-hydroxo and dimer µ-hydroxo complexes in the pH between 3.0 and 11.0. Substitution reactions with sulfur- and nitrogen-donor nucleophiles, such as thiourea (Tu), l-methionine (l-Met), glutathione (GSH) and guanosine-5'-monophosphate (5'-GMP), were studied at pH 7.2 by conventional and stopped-flow UV-Vis spectrophotometry and the observed reactivity follows the order: Tu > l-Met > GSH > 5'-GMP. Also, the interactions with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) were investigated. Competitive studies with DNA were performed in the presence of ethidium bromide and Hoechst dye 33258 as well. The complexes possess the strong ability to react with CT-DNA exhibiting intercalation and more preferable minor groove binding. Nevertheless, all complexes showed a good binding affinity toward BSA with relatively high binding constants. The nature of the binding forces between complexes and biomolecules has been identified as hydrophobic. Experimental results were compared with the molecular docking results, while the relative stability and thermodynamic properties of dinuclear complexes were compared with their mononuclear units by DFT calculations. Among three tested complexes, PP2 showed the most powerful cytotoxic effect on HTB140 and H460 cancer cell lines after 48 h of treatment and exerted a strong long-term influence on the proliferation potential of both tested cell lines. PP2 induced the inhibition of autophagy, G2/M cell cycle arrest and mitotic catastrophe.

The Effects of Newly Synthesized Platinum(IV) Complexes on Cytotoxicity and Radiosensitization of Human Tumour Cells In Vitro.

AIM: Newly synthesized platinum(IV) complexes with ethylenediamine-N,N'-diacetate ligands (EDDA-type) (butyl-Pt and pentyl-Pt) were investigated against two cancer (A549 lung, and HTB 140 melanoma) and one non-cancerous (MRC-5 embryonic lung fibroblast) human cell lines. MATERIALS AND METHODS: The effects of these agents were compared with those of cisplatin after 6-, 24- and 48-h treatment. Sulforhodamine-B (SRB) assay was performed to estimate the cytotoxic effect, while the inhibitory effect on cell proliferation was measured using 5-bromo-2,-deoxyuridine (BrdU) incorporation assay. Cell cycle analysis was performed by flow cytometry. Type of cell death induced by these agents was determined by electrophoretic analysis of DNA, flow cytometry and by western blot analysis of proteins involved in induction of apoptosis. The effects of gamma irradiation, alone and in combination with platinum-based compounds, were examined by clonogenic and SRB assays. RESULTS: All examined platinum-based compounds had inhibitory and antiproliferative effects on A549 cells, but not on HTB140 and MRC-5 cells. Butyl-Pt, pentyl-Pt and cisplatin arrested the cell cycle in the S-phase and induced apoptotic cell death via regulation of expression of B-cell lymphoma 2 (BCL2) and BCL2-associated X (BAX) proteins. Platinum-based compounds increased the sensitivity of A549 cells to gamma irradiation. Butyl-Pt and pentyl-Pt showed better antitumour effects against A549 cells than did cisplatin, by interfering in cell proliferation and the cell cycle, and by triggering apoptosis. CONCLUSION: The effects of gamma irradiation on tumour cells may be amplified by pre-treatment of cells with platinum-based compounds.

Effect of ß-cyclodextrin encapsulation on cytotoxic activity of acetylshikonin against HCT-116 and MDA-MB-231 cancer cell lines.

Acetylshikonin (AcSh), as a red colored pigment found in roots of the plants from family Boraginaceae, showed excellent cytotoxic activity. Due to its hydrophobic nature, and thus poor bioavailability, the aim of this study was to prepare acetylshikonin/ß-cyclodextrin (AcSh/ß-CD) inclusion complex by using coprecipitation method, characterize obtained system by using UV/VIS, IR and 1H NMR spectroscopy, and determine cytotoxic activity. Phase solubility test indicated formation of AL-type binary system (substrate/ligand ratio was 1:1 M/M), with stability constant Ks of 306.01 M-1. Formation of noncovalent bonds between inner layer of the hole of ß-CD and AcSh was observed using spectroscopic methods. Notable changes in chemical shifts of two protons (-0.020 ppm) from naphthoquinone moiety (C6-H and C7-H), as well as protons from hydroxyl groups (-0.013 and -0.009, respectively) attached to C5 and C8 carbons from naphthoquinone part indicate that the molecule of AcSh enters the ß-CD cavity from the aromatic side. Cytotoxic activity against HCT-116 and MDA-MB-231 cell lines was measured by MTT test and clonogenic assay. Mechanisms of action of free AcSh and inclusion complex were assessed by flow cytometry. In comparison to free AcSh, AcSh/ß-CD showed stronger short-term effect on HCT-116 cells and superior long-term effect on both cell lines. Inclusion complex induced more pronounced cell cycle arrest and autophagy inhibition, and induced increase in accumulation of intracellular ROS more effectively than free AcSh. In conclusion, AcSh/ß-CD binary system showed better performances regarding cytotoxic activity against tested tumor cell lines.

Synthesis, Anticancer Evaluation and Synergistic Effects with cisplatin of Novel Palladium Complexes: DNA, BSA Interactions and Molecular Docking Study.

BACKGROUND: In order to discover new agents for chemotherapy with improved properties compared to the existing agents and bearing in mind the fact that some Pd complexes possess better antitumor activity and exhibit less kidney toxicity compared to cisplatin, a series of novel square-planar palladium(II) complexes [Pd (L)2] (3a-f) with O,O bidentate ligands [L = ethyl 2- hydroxy-alkyl(aryl)-4-oxo-2-butenoate] were synthesized. METHODS: All complexes were characterized by spectral (UV-Vis, IR, NMR, ESI-MS) and X-ray analysis and examined for their cytotoxic effect on human cancer cell lines HeLa and MDA-MB 231 and normal fibroblasts (MRC-5). Fluorescence spectroscopic method was used for investigations of the interactions between CT-DNA or bovine serum albumin (BSA) and complex 3c. Viscosity measurements and molecular docking study were performed to confirm the mode of interactions between DNA and BSA and complex 3c. RESULTS: Complexes that showed the best results, 3c, 3d, and 3e, were placed under further investigations. Selected complexes induced apoptosis and cell cycle arrest in HeLa and MDA-MB 231 cells. Low concentrations of 3c and 3e showed strong to moderate synergism with low concentrations of cisplatin. The interaction of 3d with cisplatin was antagonistic in all used concentrations, but low IC50 value indicates its usefulness as a single cytotoxic agent. It was also noted that the change of viscosity is more pronounced in DNA solution after addition of complex 3c. CONCLUSION: Obtained results indicate that the novel palladium(II) complexes have the potential to become candidates for treatment in anticancer therapy.

Correction: Chronic Hepatitis C: Conspectus of immunological events in the course of fibrosis evolution.

[This corrects the article DOI: 10.1371/journal.pone.0219508.].

Chronic Hepatitis C: Conspectus of immunological events in the course of fibrosis evolution.

In chronically infected HCV patients emergence and evolution of fibrosis, as a consequence of virus persistence, can be considered as an indicator of disease advancement. Therefore the aim of this study was to correlate alterations of immune response in chronic HCV patients with liver histopathology. Sera cytokine levels and frequency of circulating and liver infiltrating cells were evaluated using 13plex Kit Flow Cytomix, flow cytometry and immunohistochemistry. We found that the number of circulating T lymphocytes (including CD4+, CD8+ and Treg) and B lymphocytes, as well as DCs, was higher in patients with no fibrosis than in healthy subjects. In patients with fibrosis frequency of these cells decreased, and contrarily, in the liver, number of T and B lymphocytes gradually increased with fibrosis. Importantly, in patients with advanced fibrosis, liver infiltrating regulatory T cells and DC-SIGN+ mononuclear cells with immunosuppressive and wound-healing effector functions were abundantly present. Cytokine profiling showed predominance of proinflammatory cytokines in patients with no fibrosis and a tendency of decline in level of all cytokines with severity of liver injury. Lower but sustained IL-4 production refers to Th2 predominance in higher stages of fibrosis. Altogether, our results reveal graduall alterations of immunological parameters during fibrosis evolution and illustrate the course of immunological events through disease progression.

Synthesis, characterization, anticancer evaluation and mechanisms of cytotoxic activity of novel 3-hydroxy-3-pyrrolin-2-ones bearing thenoyl fragment: DNA, BSA interactions and molecular docking study.

In order to make a progress in discovering a new agents for chemotherapy with improved properties and bearing in mind the fact that substituted 3-hydroxy-3-pyrrolin-2-ones belong to a class of biologically active compounds, series of novel 1,5-diaryl-4-(2-thienylcarbonyl)-3-hydroxy-3-pyrrolin-2-ones were synthesized and characterized by spectral (UV-Vis, IR, NMR, ESI-MS), X-ray and elemental analysis. All compounds were examined for their cytotoxic effect on human cancer cell lines HeLa and MDA-MB 231 and normal fibroblasts (MRC-5). Four compounds, 3-hydroxy-1-(p-tolyl)-4-(2-thienylcarbonyl)-5-(4-chlorophenyl)-2,5-dihydro-1H-pyrrol-2-one (D10), 3-hydroxy-1-(3-nitrophenyl)-4-(2-thienylcarbonyl)-5-(4-(benzyloxy)phenyl)-2,5-dihydro-1H-pyrrol-2-one (D13), 3-hydroxy-1-(4-nitrophenyl)-4-(2-thienylcarbonyl)-5-(4-(benzyloxy)phenyl)-2,5-dihydro-1H-pyrrol-2-one (D14), and 3-hydroxy-1-(4-chlorophenyl)-4-(2-thienylcarbonyl)-5-(4-(benzyloxy)phenyl)-2,5-dihydro-1H-pyrrol-2-one (D15), that showed the highest cytotoxicity against malignant cells and the best selectivity towards normal cells were selected for further experiments. Results obtained by investigating mechanisms of cytotoxic activity suggest that selected 3-hydroxy-3-pyrrolin-2-one derivatives in HeLa cells induce apoptosis that is associated with S phase arrest (D13, D15, and D10) or unrelated to cell cycle distribution (D14). Additionally, to better understand their suitability for potential use as anticancer medicaments we studied the interactions between biomacromolecules (DNA or BSA) and D13 and D15. The results indicated that D13 and D15 have great affinity to displace EB from the EB-DNA complex through intercalation [Ksv = (3.7 ±â€¯0.1) and (3.4 ±â€¯0.1) × 103 M-1, respectively], an intercalative mode also confirmed through viscosity measurements. Ka values, obtained as result of fluorescence titration of BSA with D13 and D15 [Ka = (4.2 ±â€¯0.2) and (2.6 ±â€¯0.2) × 105 M, respectively], support the fact that a significant amount of the tested compounds could be transported and distributed through the cells. In addition, by DNA and BSA molecular docking study for D13, D14 and D15 is determined and predicted the binding mode and the interaction region.

New monofunctional platinum(II) and palladium(II) complexes: Studies of the nucleophilic substitution reactions, DNA/BSA interaction, and cytotoxic activity.

Four new complexes [Pd(H2LtBu)Cl]Cl (Pd1), [Pt(H2LtBu)Cl]Cl (Pt1), [Pd(Me2LtBu)Cl]Cl (Pd2) and [Pt(Me2LtBu)Cl]Cl (Pt2) (where H2LtBu = 2,6-bis(5-(tert-butyl)-1H-pyrazol-3-yl)pyridine and Me2LtBu = 2,6-bis(5-(tert-butyl)-1-methyl-1H-pyrazol-3-yl)pyridine) were synthesized and characterized by elemental microanalysis, IR, 1H NMR and ESI-MS methods. The reactivity of complexes towards thiourea (Tu), l-methionine (l-Met), l-cysteine (l-Cys) and guanosine-5'-monophosphate (5'-GMP) was investigated. The obtained order was established as follows: Tu > l-Cys > l-Met > 5'-GMP. Complexes Pd1 and Pt1, that contain H2LtBu as chelator, showed higher reactivity towards biomolecules than those with Me2LtBu. The interaction of complexes with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) was studied by UV-Vis and fluorescence spectroscopy. The results have shown that complexes can bind to DNA exhibiting high binding constants (Kb = 104 M-1). Obtained results during the examination of competitive reaction with ethidium bromide (EB) showed that complexes can replace EB-bound DNA. High values of binding constants indicate good binding affinity of complexes towards BSA. We evaluated the stability differences between complexes based on terpy as well as H2LtBu/Me2LtBu by DFT calculations (B3LYP(CPCM)/LANL2DZp), showing that both tridentate ligand systems lead to complexes of similar stability. The results of biological testing showed that all complexes exert moderate to high selective cytotoxicity, inducing apoptosis and autophagy in HeLa and PANC-1 tumor cell lines. Pd1 exhibited the strongest cytotoxic effect. Finally, cell cycle analysis showed that in HeLa cells Pd1, Pd2 and Pt1 induced accumulation of cells in S phase, whereas in PANC-1 cells Pd2 and Pt1 induced G2/M cycle arrest and Pd1 induced G0/G1 arrest.

Naphthoquinone rich Onosma visianii Clem (Boraginaceae) root extracts induce apoptosis and cell cycle arrest in HCT-116 and MDA-MB-231 cancer cell lines.

In the present study, five root extracts of Onosma visianii Clem were investigated for their in vitro cytotoxic activity. On the basis of HPLC-PDA analysis, these extracts have proved to be a rich source of naphthoquinones as natural colourants for food and cosmetic industry. All investigated root extracts contain acetylshikonin, isobutyrylshikonin and α-methylbutyrylshikonin as major compounds. As the most abundant source of active compounds for antitumour therapy, acetone, chloroform and ethyl acetate extracts showed strong cytotoxic activity towards HCT-116 and MDA-MB-231 cancer cell lines. Also, these extracts induced apoptosis and cell cycle arrest in HCT-116 and MDA-MB-231 cancer cell lines.

New dinuclear palladium(II) complexes: Studies of the nucleophilic substitution reactions, DNA/BSA interactions and cytotoxic activity.

Six new dinuclear Pd(II) complexes, [{Pd(2,2'-bipy)Cl}2(µ-pz)](ClO4)2 (Pd1), [{Pd(dach)Cl}2(µ-pz)](ClO4)2 (Pd2), [{Pd(en)Cl}2(µ-pz)](ClO4)2 (Pd3), [{Pd(2,2'-bipy)Cl}2(µ-4,4'-bipy)](ClO4)2 (Pd4), [{Pd(dach)Cl}2(µ-4,4'-bipy)](ClO4)2 (Pd5) and [{Pd(en)Cl}2(µ-4,4'-bipy)](ClO4)2 (Pd6) (where 2,2'-bipy=2,2'-bipyridyl, pz=pyrazine, dach=trans-(±)-1,2-diaminocyclohexane, en=ethylenediamine, 4,4'-bipy=4,4'-bipyridyl) have been synthesized and characterized by elemental microanalysis, IR, 1H NMR and MALDI-TOF mass spectrometry. The pKa values of corresponding diaqua complexes were determined by spectrophotometric pH titration. Substitution reactions with thiourea (Tu), l-methionine (l-Met), l-cysteine (l-Cys), l-histidine (l-His) and guanosine-5'-monophosphate (5'-GMP) were studied under the pseudo-first order conditions at pH7.2. Reactions of Pd1 with Tu, l-Met and l-Cys were followed by decomposition of complexes, while structures of dinuclear complexes were preserved during the substitution with nitrogen donors. Interactions with calf-thymus DNA (CT-DNA) were followed by absorption spectroscopy and fluorescence quenching measurements. All complexes can bind to CT-DNA exhibiting high intrinsic binding constants (Kb=104-105M-1). Competitive studies with ethidium bromide (EB) have shown that complexes can displace DNA-bound EB. High values of binding constants towards bovine serum albumin protein (BSA) indicate good binding affinity. Finally, all complexes showed moderate to high cytotoxic activity against HeLa (human cervical epithelial carcinoma cell lines) and MDA-MB-231 (human breast epithelial carcinoma cell lines) tumor cell lines inducing apoptotic type cell death, whereas normal fibroblasts were significantly less sensitive. The impact on cell cycle of these cells was distinctive, where Pd4, Pd5 and Pd6 showed the most prominent effect arresting MDA-MB-231 (human lung fibroblast cell lines) cell in G1/S phase of cell cycle.