Polyamines are small cationic molecules required for cellular proliferation and are detected at higher concentrations in most tumour tissues, compared to normal tissues. Agmatine (AGM), a biogenic amine, is able to arrest proliferation in cell lines by depleting intracellular polyamine levels. It enters mammalian cells via the polyamine transport system. Agmatine is able to induce oxidative stress in mitochondria at low concentrations (10 or 100 lM), while at higher concentrations (e.g. 1-2 mM) it does not affect mitochondrial respiration and is ineffective in inducing any oxidative stress. As this effect is strictly correlated with the mitochondrial permeability transition induction and the triggering of the pro-apoptotic pathway, AGM may be considered as a regulator of this type of cell death. Furthermore, polyamine transport is positively correlated with the rate of cellular proliferation. By increasing the expression of antizyme, a protein that inhibits polyamine biosynthesis and transport, AGM also exhibits a regulatory effect on cell proliferation. Methylglyoxal bis(guanylhydrazone) (MGBG), a competitive inhibitor of S-adenosyl-L-methionine decarboxylase, displaying anticancer activity, is a structural analogue of the natural polyamine spermidine. MGBG has been extensively studied, preclinically as well as clinically, and its anticancer activity has been attributed to the inhibition of polyamine biosynthesis and also to its effect on mitochondrial function. Numerous findings have suggested that MGBG might be used as a chemotherapeutic agent against cancer.

Abstract-A multidisciplinary project was developed, combining the synthesis of a series of b-nitrostyrene derivatives and the determination of their physicochemical parameters (redox potentials, partition coefficients), to the evaluation of the corresponding antibacterial activity. A complete conformational analysis was also performed, in order to get relevant structural information. Subsequently, a structure-property-activity (SPAR) approach was applied, through linear regression analysis, aiming at obtaining a putative correlation between the physicochemical parameters of the compounds investigated and their antibacterial activity (both against standard strains and clinical isolates). The b-nitrostyrene compounds displayed a lower activity towards all the tested bacteria relative to the b-methyl-b-nitrostyrene analogues. This was observed particularly for the 3-hydroxy-4-methoxy-b-methyl-bnitrostyrene (IVb) against the Gram-positive bacteria (Staphylococcus aureus, Enterococcus faecalis and Enterococcus faecium). The SPAR results revealed the existence of a clear correlation between the redox potentials and the antibacterial activity of the series of b-nitrostyrene derivatives under study.

In the present work, lipophilic caffeic and ferulic acid derivatives were synthesized, and their cytotoxicity on cultured breast cancer cells was compared. A total of six compounds were initially evaluated: caffeic acid (CA), hexyl caffeate (HC), caffeoylhexylamide (HCA), ferulic acid (FA), hexyl ferulate (HF), and feruloylhexylamide (HFA). Cell proliferation, cell cycle progression, and apoptotic signaling were investigated in three human breast cancer cell lines, including estrogen-sensitive (MCF-7) and insensitive (MDA-MB-231 and HS578T). Furthermore, direct mitochondrial effects of parent and modified compounds were investigated by using isolated liver mitochondria. The results indicated that although the parent compounds presented no cytotoxicity, the new compounds inhibited cell proliferation and induced cell cycle alterations and cell death, with a predominant effect on MCF-7 cells. Interestingly, cell cyle data indicates that effects on nontumor BJ fibroblasts were predominantly cytostatic and not cytotoxic. The parent compounds and derivatives also promoted direct alterations on hepatic mitochondrial bioenergetics, although the most unexpected and never before reported one was that FA induces the mitochondrial permeability transition. The results show that the new caffeic and ferulic acid lipophilic derivatives show increased cytotoxicity toward human breast cancer cell lines, although the magnitude and type of effects appear to be dependent on the cell type. Mitochondrial data had no direct correspondence with effects on intact cells suggesting that this organelle may not be a critical component of the cellular effects observed. The data provide a rational approach to the design of effective cytotoxic lipophilic hydroxycinnamic derivatives that in the future could be profitably applied for chemopreventive and/or chemotherapeutic purposes.

The aim of this work was to investigate the effects of cell handling and storage on cell integrity and 1 H high resolution magic angle spinning (HRMAS) NMR spectra. Three different cell types have been considered (lung tumoral, amniocytes, and MG-63 osteosarcoma cells) in order for sample-dependent effects to be identified. Cell integrity of fresh cells and cells frozen in cryopreservative solution was ∼70-80%, with the former showing higher membrane degradation, probably enzymatic, as indicated by increased phosphocholine (PC) and/or glycerophosphocholine (GPC). Unprotected freezing (either gradual or snap-freezing) was found to lyse cells completely, similar to mechanical cell lysis. Besides enhanced metabolites visibility, lysed cells showed a different lipid profile compared to intact cells, with increased choline, PC, and GPC and decreased phosphatidylcholine (PTC). Cell lysis has, therefore, a significant effect on cell lipid composition, making handling reproducibility an important issue in lipid analysis. Sample spinning was found to disrupt 5-25% of cells, depending on cell type, and HRMAS was shown to be preferable to solution-state NMR of suspensions or supernatant, giving enhanced information on lipids and comparable resolution for smaller metabolites. Relaxation-and diffusion-edited NMR experiments gave limited information on intact cells, compared to lysed cells. The 1 H HRMAS spectra of the three cell types are compared and discussed.Nuclear magnetic resonance (NMR) spectroscopy has been, in recent years, increasingly employed for the analysis of metabolic processes in biological systems because of its ability to provide rapid detection of many different metabolites present in complex systems such as biofluids, biological tissues, or cells. The analysis of the metabolome of biological systems provides important information on their biochemical phenotypes and on the metabolic changes occurring in response to external stimuli, e.g., drug exposure, disease onset, medication. 1,2The study of cellular metabolism using NMR has been successfully carried out with strong emphasis on cell extracts, either hydrophilic or lipophilic. For instance, acidic extracts, in the presence of ice-cold perchloric acid (PCA) or trichloroacetic acid (TCA), allow polar metabolites to be identified 3,4 as shown for PCA extracts of human colon adenocarcinoma cells 5 and human osteosarcoma cells 6,7 and TCA extracts of human rhabdomyosarcoma cells 8 and human lung cancer cells. 9 Other extraction methods have been used to identify aqueous and lipophilic metabolites, for instance in human colon carcinoma cells, 10 rat astrocyte cells, 11 human prostate cancer cells, 12 and human lung carcinoma cell lines. 13 In addition to the unavoidable selectivity of extraction methods, rendered useful only when the nature of the compounds of interest is known a priori, sample extraction may involve significant loss of particular cellular components, retained in the residual insoluble precipitate and not amenable to study by solution-st...