Anti-Atherosclerotic Properties of Aronia melanocarpa Extracts Influenced by Their Chemical Composition Associated with the Ripening Stage of the Berries.

The high content of bioactive compounds in Aronia melanocarpa fruit offers health benefits. In this study, the anti-atherosclerotic effect of Aronia extracts was assessed. The impact on the level of adhesion molecules and the inflammatory response of human umbilical vein endothelial cells (HUVECs) was shown in relation to the chemical composition and the stage of ripening of the fruits. Samples were collected between May (green, unripe) and October (red, overripe) on two farms in Poland, which differed in climate. The content of chlorogenic acids, anthocyanins, and carbohydrates in the extracts was determined using HPLC-DAD/RI. The surface expression of ICAM-1 and VCAM-1 in HUVECs was determined by flow cytometry. The mRNA levels of VCAM-1, ICAM-1, IL-6, and MCP-1 were assessed using the quantitative real-time PCR method. The farms' geographical location was associated with the quantity of active compounds in berries and their anti-atherosclerotic properties. Confirmed activity for green fruits was linked to their high chlorogenic acid content.

The role of oxidative stress and NADPH oxidase in the pathogenesis of atherosclerosis.

Reactive oxygen species (ROS) play a key role in the pathogenesis of atherosclerosis. The main mechanisms which are involved are low-density lipoprotein oxidative modification, inactivation of nitric oxide and modulation of redox-sensitive signaling pathways. ROS contribute to several aspects of atherosclerosis including endothelial cell dysfunction, monocyte/macrophage recruitment and activation, stimulation of inflammation, and inducing smooth muscle cell migration and proliferation. NADPH oxidase is the main source of ROS in the vasculature. This enzyme consists of a membrane-bound heterodimer of gp91phox and p22phox, cytosolic regulatory subunits p47phox, p67phox and p40phox, and small GTP-binding proteins rac1 and rac 2. Seven distinct isoforms of this enzyme have been identified, of which four (NOX1, 2, 4 and 5) may have cardiovascular function. In this paper, we review the current state of knowledge concerning the role of oxidative stress and NOX enzymes in pathogenesis of atherosclerosis. Moreover, we analyze the experimental studies that explore the relationship between the NOX family and atherosclerosis.

Synthesis and characterization of genistein conjugated with gold nanoparticles and the study of their cytotoxic properties.

Gold nanoparticles conjugated with drug substances are used in diagnostics and therapies. Apart from the combinations involving gold nanoparticles conjugated with drug substances through linkers, a direct bonding is also known. In our paper the example of such a direct bonding between gold nanoparticles and genistein (AuNPs-GE) is presented. This conjugate was obtained in a one-pot synthesis and the formation of AuNPs-GE was monitored in terms of color change and UV-Vis spectroscopy. It has been shown that genistein reduces Au3+ ions to spherical Au0 nanocrystallites and acts as a stabilizing agent. The efficiency of the purification of the conjugate from free genistein was controlled by the capillary electrophoresis. Gold nanoparticles are homogeneously shaped and have a narrow range of size from 14 to 33nm and the size of the nanoparticles modified with genistein is around 64.64±0.41nm, as measured by the TEM and DSL techniques, respectively. The zeta potential of the gold nanoparticles modified with genistein is -19.32±0.82mV and suggests a high stability of the nanoparticles and lower toxicity for the normal cells. The identity of genistein on the gold nanoparticles was proved by the electrochemistry, NMR and Raman spectroscopy. The mechanism of the conjugate forming has been proposed. The coverage of gold nanoparticles with genistein 5.09% (m/m) has been calculated from the TGA analysis. Moreover, it has been proved that the obtained conjugate is characterized by a high cytotoxic activity towards cancer cells, as observed in the cell line test.

Mycophenolate mofetil--a new atheropreventive drug?

Atherosclerosis is a form of chronic inflammation in which endothelial cell dysfunction, fibroproliferative process, oxidative stress and inflammatory cell activation are linked to plaque development and destabilization. T-lymphocytes also play a key role in pathogenesis of atherosclerosis. As a consequence, the suggested concept that modulation of an immunological response could be an appropriate target in the prevention of cardiovascular disease, is an important focus of research. Mycophenolate mofetil (MMF) is an inhibitor of inosine monophosphate dehydrogenase (IMPDH), that exerts anti-proliferative and pro-apototic effects, particularly on activated T-lymphocytes. MMF has other anti-atherogenic effects at the level of endothelial cells, monocytes/macrophages, smooth muscle cells and dendritic cells. In addition, MMF exhibits anti-oxidative properties. The present review paper provides an overview about the mechanisms of anti-atherosclerotic properties of MMF.

[Mitogen-activated protein kinases in atherosclerosis]. / Kinazy aktywowane mitogenami i ich znaczenie w patogenezie miazdzycy.

Intracellular signalling cascades, in which MAPK (mitogen-activated protein kinases) intermediate, are responsible for a biological response of a cell to an external stimulus. MAP kinases, which include ERK1/2 (extracellular signalling-regulated kinase), JNK (c-Jun N-terminal kinase) and p 38 MAPK, regulate the activity of many proteins, enzymes and transcription factors and thus have a wide spectrum of biological effects. Many basic scientific studies have defined numerous details of their pathway organization and activation. There are also more and more studies suggesting that individual MAP kinases probably play an important role in the pathogenesis of atherosclerosis. They may mediate inflammatory processes, endothelial cell activation, monocyte/macrophage recruitment and activation, smooth muscle cell proliferation and T-lymphocyte differentiation, all of which represent crucial mechanisms involved in pathogenesis of atherosclerosis. The specific inhibition of an activity of the respective MAP kinases may prove a new therapeutic approach to attenuate atherosclerotic plaque formation in the future. In this paper, we review the current state of knowledge concerning MAP kinase-dependent cellular and molecular mechanisms underlying atherosclerosis.

Mycophenolic acid attenuates the tumour necrosis factor-α-mediated proinflammatory response in endothelial cells by blocking the MAPK/NF-κB and ROS pathways.

BACKGROUND: Mycophenolate mofetil (MMF) has beneficial effects in cardiac transplant patients beyond the suppression of tissue rejection. Moreover, mycophenolic acid (MPA), its active metabolite, has been associated with positive effects on atherosclerosis in animal models. The attachment of leukocytes to the vascular endothelium and the subsequent migration of these cells into the vessel wall are early events in inflammation and atherosclerosis. The aim of this study was to investigate the effects of MPA on tumour necrosis-α (TNF-α)-induced, endothelial cell proinflammatory responses and the underlying mechanisms. METHODS AND RESULTS: Human aortic endothelial cells (HAECs) were treated with different concentrations (primarily 50 µM) of MPA before treatment with TNF-α. The surface protein and mRNA expressions of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were determined by flow cytometry and real-time RT-PCR, respectively. Adhesion of leukocytes to TNF-α-treated HAECs was evaluated by an adhesion assay. Activation of mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) was evaluated by measuring the levels of their phosphorylation using flow cytometry. NF-κB p65 translocation was detected by Western blotting. The production of reactive oxygen species (ROS) was determined by reduction in fluorescent 2',7'-dichlorofluorescein diacetate (H2 DCFH-DA). MPA significantly inhibits TNF-α-induced ICAM-1, VCAM-1 surface protein and mRNA expression as well as adhesion of mononuclear leukocytes to HAEC. ICAM-1 and VCAM-1 expressions were also reduced by antioxidants such as pyrrolidine dithiocarbamate, diphenylene iodonium and apocynin. MPA inhibited TNF-α-stimulated ROS generation similarly to apocynin. TNF-α increased ICAM-1 and VCAM-1 expression via c-Jun NH2 -terminal kinase (JNK), extracellular signal-regulated kinase (ERK1/2) and p38 MAPK. MPA and apocynin inhibited TNF-α-induced phosphorylation of all three MAP kinases. Furthermore, TNF-α-induced NF-κB activation was attenuated by SP600125 (JNK inhibitor), PD98059 (ERK1/2 inhibitor, SB203580 (p38 MAPK inhibitor) and MPA. MPA also inhibited TNF-α-induced nuclear translocation of NF-κB p65. CONCLUSION: These results suggest that, in addition to the prevention of rejection, MPA may be a promising approach for the treatment of inflammatory vascular disease.