The study of influence inositolhexaphosphate on proliferation and apoptosis in cells isolated out of colorectal cancer

Introduction: Apoptosis - programmed cell death significantly participates in maintaining of tissue homeostasis. Its alteration is leading to cancer disease. Inositolhexaphosphate (IP6) is naturally occurring substance that is present in most legumes, cereals and seems. IP6 and its lower phosphorylated forms are also found in most mammalian cells, where they assist in regulatory a variety of important cellular function (including regulation of cell cycle). Methods: This work has been engaged in the study of influence IP6 on apoptosis in cells isolated out of colorectal cancer by in vitro quantification enzymatic activity of caspase 3 in cell extract. Results: It has proved by the Student's t-test that IP6 statistically significant influence apoptosis in cells isolated out of colorectal cancer

Study of Pathobiochemistry of Catecholamine Cardiotoxicity: Role of Free Iron Ions and Their Chelation as a Possibility of Pharmacological Cardioprotec-tion.

Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Mgr. Pavlína HAŠKOVÁ Supervisor: doc. PharmDr. Tomáš ŠIMŮNEK, Ph.D. Title of Doctoral Thesis: Study of pathobiochemistry of catecholamine cardiotoxicity: Role of free iron ions and their chelation as a possibility of pharmacological cardioprotec- tion. Catecholamine cardiotoxicity is known for a long time, but its patho- genesis is still incompletely understood. Although traditionally attributed to excessive β-adrenergic stimulation, there is a hypothesis that the catecholamine- induced cardiac cell damage includes involvement of oxidation products of catecholamines, which may arise due to spontaneous oxidation of catechola- mines under aerobic conditions. Spontaneous oxidation of catecholamines is a sequence of redox reactions leading to the formation of numerous reactive in- termediates, such as o-semiquinones and o-quinones, including aminochromes that are subject to redox cyclization generating reactive oxygen species (ROS). The generated ROS and aminochromes are toxic for cells. In addition, the autooxidation may be catalyzed by transition metals, which suggests that free intracellular iron (Fe) ions - the most abundant transition metal in the body - can promote not only the Haber-Weiss..

In Vitro Characterization of the Pharmacological Properties of the Anti-Cancer Chelator, Bp4eT, and Its Phase I Metabolites.

Cancer cells have a high iron requirement and many experimental studies, as well as clinical trials, have demonstrated that iron chelators are potential anti-cancer agents. The ligand, 2-benzoylpyridine 4-ethyl-3-thiosemicarbazone (Bp4eT), demonstrates both potent anti-neoplastic and anti-retroviral properties. In this study, Bp4eT and its recently identified amidrazone and semicarbazone metabolites were examined and compared with respect to their anti-proliferative activity towards cancer cells (HL-60 human promyelocytic leukemia, MCF-7 human breast adenocarcinoma, HCT116 human colon carcinoma and A549 human lung adenocarcinoma), non-cancerous cells (H9c2 neonatal rat-derived cardiomyoblasts and 3T3 mouse embryo fibroblasts) and their interaction with intracellular iron pools. Bp4eT was demonstrated to be a highly potent and selective anti-neoplastic agent that induces S phase cell cycle arrest, mitochondrial depolarization and apoptosis in MCF-7 cells. Both semicarbazone and amidrazone metabolites showed at least a 300-fold decrease in cytotoxic activity than Bp4eT towards both cancer and normal cell lines. The metabolites also lost the ability to: (1) promote the redox cycling of iron; (2) bind and mobilize iron from labile intracellular pools; and (3) prevent 59Fe uptake from 59Fe-labeled transferrin by MCF-7 cells. Hence, this study demonstrates that the highly active ligand, Bp4eT, is metabolized to non-toxic and pharmacologically inactive analogs, which most likely contribute to its favorable pharmacological profile. These findings are important for the further development of this drug candidate and contribute to the understanding of the structure-activity relationships of these agents

Intravenous rutin in rat exacerbates isoprenaline-induced cardiotoxicity likely due to intracellular oxidative stress

<p><b>Objectives</b>: Rutin, quercetin-3-<i>O</i>-rutinoside, a natural flavonol glycoside, has shown various <i>in vitro</i> benefits with potential use treating human diseases, especially cardiovascular system disorders. Antioxidant properties are assumed to underlie the majority of these benefits. Yet rutin pro-oxidant properties have been reported as well. Our research group has recently shown aggravating effects on isoprenaline (ISO)-induced cardiotoxicity in Wistar:Han rats after 24 hours.</p> <p><b>Methods</b>: This study was designed to examine in more detail the reasons for the negative effects of rutin (11.5 and 46 mg/kg, i.v.) after administration of ISO (100 mg/kg, s.c.) in rats within 2 hours of continuous experiment and in the H9c2 cardiomyoblast-derived cell line.</p> <p><b>Results</b>: Like our previous findings, rutin did not (11.5 or 46 mg/kg, i.v.) reduce the ISO-induced mortality within 2 hours although the lower dose significantly reduced cardiac troponin T (cTnT) and partly improved the histological findings. In contrast, the higher dose increased the mortality in comparison with solvent (1.26% w/v sodium bicarbonate). This was not caused by any specific haemodynamic disturbances. It appears to be associated with oxidative stress as rutin enhanced intracellular reactive oxygen species formation <i>in vitro</i> and had the tendency to increase it <i>in vivo</i>.</p> <p><b>Conclusions</b>: Rutin, likely due to its pro-oxidative effects, can exacerbate catecholamine cardiotoxicity depending on the dose used.</p

Structure-Activity Relationships of Novel Salicylaldehyde Isonicotinoyl Hydrazone (SIH) Analogs: Iron Chelation, Anti-Oxidant and Cytotoxic Properties

<div><p>Salicylaldehyde isonicotinoyl hydrazone (SIH) is a lipophilic, tridentate iron chelator with marked anti-oxidant and modest cytotoxic activity against neoplastic cells. However, it has poor stability in an aqueous environment due to the rapid hydrolysis of its hydrazone bond. In this study, we synthesized a series of new SIH analogs (based on previously described aromatic ketones with improved hydrolytic stability). Their structure-activity relationships were assessed with respect to their stability in plasma, iron chelation efficacy, redox effects and cytotoxic activity against MCF-7 breast adenocarcinoma cells. Furthermore, studies assessed the cytotoxicity of these chelators and their ability to afford protection against hydrogen peroxide-induced oxidative injury in H9c2 cardiomyoblasts. The ligands with a reduced hydrazone bond, or the presence of bulky alkyl substituents near the hydrazone bond, showed severely limited biological activity. The introduction of a bromine substituent increased ligand-induced cytotoxicity to both cancer cells and H9c2 cardiomyoblasts. A similar effect was observed when the phenolic ring was exchanged with pyridine (<i>i.e.</i>, changing the ligating site from <i>O</i>, <i>N</i>, <i>O</i> to <i>N</i>, <i>N</i>, <i>O</i>), which led to pro-oxidative effects. In contrast, compounds with long, flexible alkyl chains adjacent to the hydrazone bond exhibited specific cytotoxic effects against MCF-7 breast adenocarcinoma cells and low toxicity against H9c2 cardiomyoblasts. Hence, this study highlights important structure-activity relationships and provides insight into the further development of aroylhydrazone iron chelators with more potent and selective anti-neoplastic effects.</p></div

Cytotoxic effects of the chelator, SIH (A), and the new analogues (B–L) against MCF-7 breast cancer cells.

<p>For the determination of their cytotoxic activity, MCF-7 breast adenocarcinoma cells were incubated with the analogs (0.01–3000 µM) for 72 h/37°C. Results are Mean ±SD (<i>n</i>≥4 experiments). Statistical significance (ANOVA): * <i>p</i><0.05, ** <i>p</i><0.01, *** <i>p</i><0.001 as compared to the control (untreated) group.</p