Biological Evaluation and Molecular Docking Studies of Novel 1,3,4-Oxadiazole Derivatives of 4,6-Dimethyl-2-sulfanylpyridine-3-carboxamide.

To date, chronic inflammation is involved in most main human pathologies such as cancer, and autoimmune, cardiovascular or neurodegenerative disorders. Studies suggest that different prostanoids, especially prostaglandin E2, and their own synthase (cyclooxygenase enzyme-COX) can promote tumor growth by activating signaling pathways which control cell proliferation, migration, apoptosis, and angiogenesis. Non-steroidal anti-inflammatory drugs (NSAIDs) are used, alongside corticosteroids, to treat inflammatory symptoms particularly in all chronic diseases. However, their toxicity from COX inhibition and the suppression of physiologically important prostaglandins limits their use. Therefore, in continuation of our efforts in the development of potent, safe, non-toxic chemopreventive compounds, we report herein the design, synthesis, biological evaluation of new series of Schiff base-type hybrid compounds containing differently substituted N-acyl hydrazone moieties, 1,3,4-oxadiazole ring, and 4,6-dimethylpyridine core. The anti-COX-1/COX-2, antioxidant and anticancer activities were studied. Schiff base 13, containing 2-bromobenzylidene residue inhibited the activity of both isoenzymes, COX-1 and COX-2 at a lower concentration than standard drugs, and its COX-2/COX-1 selectivity ratio was similar to meloxicam. Furthermore, the results of cytotoxicity assay indicated that all of the tested compounds exhibited potent anti-cancer activity against A549, MCF-7, LoVo, and LoVo/Dx cell lines, compared with piroxicam and meloxicam. Moreover, our experimental study was supported by density functional theory (DFT) and molecular docking to describe the binding mode of new structures to cyclooxygenase.

Evaluation of Interactions of Selected Olivacine Derivatives with DNA and Topoisomerase II.

Olivacine and ellipticine are model anticancer drugs acting as topoisomerase II inhibitors. Here, we present investigations performed on four olivacine derivatives in light of their antitumor activity. The aim of this study was to identify the best antitumor compound among the four tested olivacine derivatives. The study was performed using CCRF/CEM and MCF-7 cell lines. Comet assay, polarography, inhibition of topoisomerase II activity, histone acetylation, and molecular docking studies were performed. Each tested compound displayed interaction with DNA and topoisomerase II, but did not cause histone acetylation. Compound 2 (9-methoxy-5,6-dimethyl-1-({[1-hydroxy-2-(hydroxymethyl)butan-2-yl]amino}methyl)-6H-pyrido[4,3-b]carbazole) was found to be the best candidate as an anticancer drug because it had the highest affinity for topoisomerase II and caused the least genotoxic damage in cells.

Anemarrhenae asphodeloides rhizoma Extract Enriched in Mangiferin Protects PC12 Cells against a Neurotoxic Agent-3-Nitropropionic Acid.

The rhizome of Anemarrhena asphodeloides Bunge, used in Traditional Chinese Medicine as a brain function-improving herb, is a promising source of neuroprotective substances. The aim of this study was to evaluate the protective action of xanthones from A. asphodeloides rhizomes on the PC12 cell line exposed to the neurotoxic agent-3-nitropropionic acid (3-NP). The xanthone-enriched fraction of the ethanolic extract of A. asphodeloides (abbreviated from now on as XF, for the Xanthone Fraction), rich in polyphenolic xanthone glycosides, in concentrations from 5 to 100 µg/mL, and 3-NP in concentrations from 2.5 to 15 mM, were examined. After 8, 16, 24, 48, and 72 h of exposure of cells to various combinations of 3-NP and XF, the MTT viability assay was performed and morphological changes were estimated by confocal fluorescence microscopy. The obtained results showed a significant increase in the number of cells surviving after treatment with XF with exposure to neurotoxic 3-NP and decreased morphological changes in PC12 cells in a dose and time dependent manner. The most effective protective action was observed when PC12 cells were pre-incubated with the XF. This effect may contribute to the traditional indications of this herb for neurological and cognitive complaints. However, a significant cytotoxicity observed at higher XF concentrations (over 10 µg/mL) and longer incubation time (48 h) requires caution in future research and thorough investigation into potential adverse effects.

Effect of Novel Pyrrolo[3,4-d]pyridazinone Derivatives on Lipopolysaccharide-Induced Neuroinflammation.

Neuroinflammation is considered to be one of the potential causes for the development of neurodegenerative diseases, including Alzheimer's disease. In this study, we evaluated the effect of four newly synthesized pyrrolo[3,4-d]pyridazinone derivatives on the neuron-like PC12 cells under simulated inflammation conditions by preincubation with lipopolysaccharide (LPS). Our novel derivatives are selective cyclooxygenase-2 (COX-2) inhibitors and have similar effects to nonsteroidal anti-inflammatory drugs (NSAIDs). We assessed viability (LDH assay), metabolic activity (MTT assay), DNA damage (number of double-strand breaks measured by fast halo assay), and the neuronal features of cells (average neurite length and neurite outgrowth measured spectrofluorimetrically). DCF-DA and Griess assays were also performed, which allowed determining the impact of the tested compounds on the level of oxygen free radicals and nitrites. LPS administration significantly negatively affected the results in all tests performed, and treatment with the tested derivatives in most cases significantly reduced this negative impact. Multiple-criteria decision analysis indicated that overall, the best results were observed for compounds 2a and 2b at a concentration of 10 µM. The new derivatives showed intense activity against free oxygen radicals and nitrites. Reduced reactive oxygen species level also correlated with a decrease in the number of DNA damage. The compounds improved neuronal features, such as neurite length and outgrowth, and they also increased cell viability and mitochondrial activity. Our results suggest that derivatives 2a and 2b may also act additionally on mechanisms other than 3a and 3b.

Antitumor Activity of New Olivacine Derivatives.

Olivacine is an alkaloid-containing pyridocarbazole structure. It is isolated from the bark of the evergreen timber tree, Aspidosperma olivaceum. Its well-documented anticancer activity led to the synthesis of new derivatives, which are semisynthetic and fully synthetic pyridocarbazoles. This study aimed to evaluate the potential antineoplastic activity of four newly synthesized olivacine derivatives. Multidrug resistance is a common phenomenon causing failure in the chemotherapy of many tumors. It is mainly related to increased function of P-glycoprotein, an efflux pump removing cytostatic out of the cells. The cell lines used in the study were colorectal carcinoma cell lines: LoVo (doxorubicin-sensitive) and LoVo/DX (doxorubicin-resistant). The NHDF cell line was used to assess cell viability. First, the cells were incubated with olivacine derivatives. In the next step, the following assays were performed: DCF-DA assay, MTT assay, rhodamine 123 assay, detection of apoptosis, proliferation inhibition-mitotic index. The tested compounds showed higher antineoplastic potential and lower toxicity than the reference compound ellipticine. The results indicate that the new olivacine derivatives are good candidates for future anticancer drugs.

PPARs in Clinical Experimental Medicine after 35 Years of Worldwide Scientific Investigations and Medical Experiments.

This year marks the 35th anniversary of Professor Walter Wahli's discovery of the PPARs (Peroxisome Proliferator-Activated Receptors) family of nuclear hormone receptors. To mark the occasion, the editors of the scientific periodical Biomolecules decided to publish a special issue in his honor. This paper summarizes what is known about PPARs and shows how trends have changed and how research on PPARs has evolved. The article also highlights the importance of PPARs and what role they play in various diseases and ailments. The paper is in a mixed form; essentially it is a review article, but it has been enriched with the results of our experiments. The selection of works was subjective, as there are more than 200,000 publications in the PubMed database alone. First, all papers done on an animal model were discarded at the outset. What remained was still far too large to describe directly. Therefore, only papers that were outstanding, groundbreaking, or simply interesting were described and briefly commented on.

DNA Content of Various Fluids and Tissues of the Human Body.

Due to the scarcity of literature data on the DNA content of different human tissues, this study aimed to isolate DNA from different tissues and fluids of the human body together with the determination of its content in the samples studied. Material was collected and tests were performed between 1990 and 2010, during autopsies performed for prosecutor's offices in the Department of Forensic Medicine. Goiter and thyroid cancer tissues were obtained from the Department of General Surgery, Gastroenterology and Endocrinology of Wroclaw Medical University. Isolated samples were measured spectrophotometrically, yielding an R 260/280 nm between 1.5 and 1.6. In some cases (when a sufficiently pure preparation could not be obtained), isolation was continued using the silica-based commercial QIAquick PCR Purification Kit (Qiagen). If the sampling tissues showed signs of decomposition such as bad odour or colour, the results were calibrated by Real-Time PCR, using the Quantifiler DNA assay (Thermo Fisher Scientific, Applied Biosystems). The results have shown that the maximum amount of genetic material was obtained from hair roots, adrenal glands, gonads and lymph nodes. The lowest DNA content per gram or milliliter of tissue or body fluid was found in adipose tissue, blood, saliva, bile, sweat, tears and the vitreous body of the eye. The presented findings indicate the best sources of high-quality DNA from the human body: gonads, kidneys, muscle (including heart), blood and bones (after decalcification).

Unraveling the role of Breg cells in digestive tract cancer and infectious immunity.

Over the past two decades, regulatory B cells (Breg cells or Bregs) have emerged as an immunosuppressive subset of B lymphocytes playing a key role in inflammation, infection, allergy, transplantation, and cancer. However, the involvement of Bregs in various pathological conditions of the gastrointestinal tract is not fully understood and is the subject of much recent research. In this review, we aimed to summarize the current state of knowledge about the origin, phenotype, and suppressive mechanisms of Bregs. The relationship between the host gut microbiota and the function of Bregs in the context of the disturbance of mucosal immune homeostasis is also discussed. Moreover, we focused our attention on the role of Bregs in certain diseases and pathological conditions related to the digestive tract, especially Helicobacter pylori infection, parasitic diseases (leishmaniasis and schistosomiasis), and gastrointestinal neoplasms. Increasing evidence points to a relationship between the presence and number of Bregs and the severity and progression of these pathologies. As the number of cases is increasing year by year, also among young people, it is extremely important to understand the role of these cells in the digestive tract.

The Technological Process of Obtaining New Linen Dressings Did Not Cause the Loss of Their Wound-Healing Properties.

BACKGROUND: Linen dressings were invented a few years ago but are still being worked on. METHODS: The obtained fabrics from the traditional variety of flax (Nike), two transgenic types of flax (M50 and B14) and the combination of these two flax fibers (M50 + B14) were tested in direct contact in cell cultures. Cell viability tests were performed, and the proliferation potential of cells on Balb3T3 and NHEK cell lines was checked using the Sulforhodamine-B (SRB) test. Moreover, the effect of new linen fabrics on apoptosis of THP-1 cells, as well as on the cell cycle of NHEK, HMCEV and THP-1, cells after 24 h of incubation was assessed. RESULTS: All tested linen fabrics did not raise the number of necrotic cells. The tested fabrics caused a statistically significant decrease in the total protein content in skin cancer (except for 0.5 cm of Nike-type fabrics). The smallest cells in the apoptotic phase were in cultures treated with M50 fiber on an area of 0.5 cm. After 48 h of incubation of HEMVEC, NHEK and THP-1 cells with the tested fabrics, the growth of S-phase cells was noticed in all cases. At the same time, the greatest increase was observed with the use of B14 fabric. Necrosis is not statistically significant. CONCLUSIONS: All the obtained flax fibers in the form of flax dressings did not lose their wound-healing properties under the influence of the technological process. New dressings made of genetically modified flax are a chance to increase the effectiveness of treatment of difficult healing wounds.

Solution studies of some new oxamides - co-ordination behaviour towards Cu(II) ions.

The co-ordination chemistry of some new oxamides towards Cu(II) ions was studied using various techniques: potentiometry, voltammetry, spectroscopy (UV-Vis, CD and EPR) and ESI-MS spectrometry. All tested compounds chelate the copper(II) ions with formation of 1:1 and 1:2 (metal-to-ligand ratio) complexes. The Cu(II) ions are bound by 1N, 2N or 3N nitrogen donor systems. Additionally, an unusual co-ordination to amide N-atoms without additional anchoring site is suggested. The (14)N hyperfine splitting observed for the system ox6-Cu(II) above pH 10 clearly indicates the involvement of at least three N donor atoms in the copper ion binding. Moreover, the surrounding by three amide-N and one carbonyl-O stabilizes the high oxidation state of copper(III), although such complexes are very unstable in solution.

Coordination of thiouridine monophosphates with selected metal ions.

Potentiometric and spectroscopic data obtained for the complexes of two thio-substituted uridine-monophosphates with Cu(2+), Ni(2+) and Cd(2+) ions have shown that both thionucleotide are more effective ligands than their nucleoside analogues. The basic binding site for all metal ions is the sulfur atom. The chelation by adjacent N(3) donor is also likely, although unfavorable four-membered chelate ring is formed.

Effect of metal ionic radius and chelate ring alternation motif on stabilization of trivalent nickel and copper in binuclear complexes with double cis-oximato bridges.

Oxime ligands are able to form stable binuclear species with copper(II) ions in aqueous solution. They also have a strong tendency to decrease the Mn+/(n-1)+ redox potentials of the central ions. Ligands possessing the hydroxyimino groups together with other powerful sigma-donor groups can be very efficient chelating agents able to facilitate the stabilisation of high oxidation states of 3d-metals. Here we report the synthesis, structural characterization and redox behaviour of mononuclear and binuclear complexes based on hydroxyiminoamide tetradentate open-chain ligands. In all mononuclear anionic complexes the central atom is situated in a square-planar surrounding of four nitrogen atoms. This pseudo-macrocyclic conformation is due to the presence of short intramolecular hydrogen bonds uniting the cis-oximate oxygen atoms. The square-planar surrounding of the strong sigma-donors facilitates efficient stabilization of the trivalent state of copper and nickel ions. In cyclic voltammetry studies the quasi-reversible processes M2+-->M3+ can be observed. In the binuclear complexes the coordinatively saturated octahedral ion M[prime or minute] is bound to the two oxygen atoms of the bridging oximate groups and the four nitrogen atoms of the tetradentate ligand tren. Two metal ions (M and M') are linked by the double cis-oximate bridge and are incorporated in a six-membered bimetallic chelate ring. Metallamacrocycle formation leads to certain changes in the structural parameters of the binuclear complexes as compared to those observed in the mononuclear species. Also the study of the electrochemical activity of binuclear complexes has shown important differences in their redox behaviour as compared to their mononuclear precursors.