stilbenes and Hyperhomocysteinemia

Aronia melanocarpa fruits (Rosaceae) are one of the richest plant sources of phenolic substances, and it has been shown to have various biological activities. Berries of A. melanocarpa (chokeberry) have been supposed to be beneficial for the prevention of cardiovascular events. In this study the influence of aronia extract on the clot formation (using human plasma and purified fibrinogen) and the fibrin lysis during the model of hyperhomocysteinemia was investigated.. Hyperhomocysteinemia was induced using a reduced form of Hcys (at final dose of 0.1mM) and the most reactive form of Hcys - its cyclic thioester, homocysteine thiolactone (HTL, 1 μM). The aim of our study in vitro was also to investigate the modifications of human plasma total proteins and the oxidative stress (by measuring the total antioxidant level - TAS) in plasma after incubation with Hcys, HTL and/or aronia extract. The biological properties of aronia extract were compared with the action of a well characterized antioxidative commercial polyphenol - resveratrol (3,4',5- trihydroxystilbene).. The HTL, like its precursor, Hcys stimulated polymerization of fibrinogen. The results also demonstrated that Hcys (0.1mM) and HLT at lower doses than Hcys (1 μM) reduced the fibrin lysis in human plasma. Moreover, Hcys and HTL change the level of thiol and amino groups in plasma total proteins and induce the oxidative stress in plasma. Our results indicate that aronia extract reduced the biotoxicity action of Hcys and HTL on hemostatic properties of fibrinogen or plasma, suggesting its possible protective properties in hyperhomocysteinemia - induced cardiovascular diseases. Moreover, our results showed that the extract from berries of A. melanocarpa due to antioxidant action, significantly reduced the oxidative stress (measured by TAS) in plasma during the model of hyperhomocysteinemia.. In the comparative studies, the extract from berries of A. melanocarpa and reseveratrol had similar protective properties. It gives hopes for development of diet supplements, which may be preventing thrombosis in pathological states where plasma procoagulant activity and oxidative stress are observed e.g. in hyperhomocysteinemia.

Topics: Adult; Anticoagulants; Antioxidants; Blood Coagulation; Cardiovascular Diseases; Coagulants; Dietary Supplements; Fibrinogen; Fruit; Homocysteine; Humans; Hyperhomocysteinemia; Models, Biological; Oxidative Stress; Photinia; Plant Extracts; Poland; Polymerization; Resveratrol; Stilbenes

Resveratrol (3,4',5-trihydroxystilben), a phenolic antioxidant synthesized in grapes and other plants, and also present in wine, has been suggested to help prevent cardiovascular events. In this study the influence of resveratrol on platelet aggregation during a model of hyperhomocysteinemia was investigated. We induced hyperhomocysteinemia using a reduced form of Hcys (final dose, 0.1 mM) and the most reactive form of Hcys, its cyclic thioester, homocysteine thiolactone (HTL, 1 µM). The aim of our study in vitro was also to investigate superoxide anion radical (O(2)(-)) generation after incubation of platelets with Hcys, HTL, and resveratrol. We have observed that HTL, like its precursor Hcys, stimulated the generation of (O(2)(-) in platelets and caused an augmentation of platelet aggregation induced by the strong physiological agonist thrombin. Our results in vitro also demonstrated that resveratrol reduced the toxic action of Hcys and HTL on blood platelet aggregation and superoxide anion radical production in platelets, suggesting its potential protective effects on hemostasis are negatively influenced by homocysteine and its derivatives.

Topics: Adult; Antioxidants; Blood Platelets; Homocysteine; Humans; Hyperhomocysteinemia; Platelet Aggregation; Resveratrol; Stilbenes; Superoxides; Young Adult

Resveratrol (3,4', 5 - trihydroxystilben), a phenolic antioxidant synthesized in grapes and vegetables and presents in wine, has been supposed to be beneficial for the prevention of cardiovascular events. In this study the influence of resveratrol on the clot formation (using human plasma and purified fibrinogen) and the fibrin lysis during model of hyperhomocysteinemia was investigated. We induced this process using a reduced form of Hcys (at final dose of 0.1mM) and the most reactive form of Hcys - its cyclic thioester, homocysteine thiolactone (HTL, 0.5μM). The aim of our study in vitro was to investigate the modifications of human plasma total proteins after incubation with Hcys, HTL and resveratrol. We observed that HTL, like its precursor, Hcys stimulated polymerization of fibrinogen. Our present results also demonstrated that Hcys (0.1mM) and HLT at lower doses than Hcys (0.5μM) reduced the fibrin lysis in human plasma. Moreover, Hcys and HTL change the level of thiol and amino groups in plasma total proteins. Our results indicate that resveratrol reduced the toxicity action of Hcys and HTL on hemostatic properties of fibrinogen or plasma, suggesting its possible protector role in hyperhomocysteinemia - induced cardiovascular diseases.

Topics: Adult; Fibrinogen; Homocysteine; Humans; Hyperhomocysteinemia; Resveratrol; Stilbenes

Hyperhomocysteinemia is characterized by an increase of plasma homocysteine, a thiol-containing amino acid produced during methionine metabolism. Hyperhomocysteinemia has often been associated with coronary artery disease, vascular thrombosis and the development of premature atherosclerosis. We have recently demonstrated that the supplementation of catechin, a polyphenol found in the red wine, significantly reduced plasma homocysteine level in cystathionine beta synthase (CBS) deficient mice, a murine model of hyperhomocysteinemia. In the present study, we have investigated the influence of another well-studied polyphenol found in red wine, resveratrol, on hyperhomocysteinemia. After two months on high methionine diet, heterozygous Cbs deficient mice were administrated the resveratrol in drinking water (0.001%) for one month. High methionine diet significantly increased serum homocysteine levels, and decreased the serum activity of HDL-associated enzyme paraoxonase-1. Chronic administration of resveratrol significantly increased plasma homocysteine level, which was associated with a decreased serum paraoxonase-1 activity, in hyperhomocysteinemic mice. Then we looked at gene expression of several proteins involved in HDL stability and found a down-regulation of lecithin:cholesterol acyltransferase. In conclusion, we found a deleterious effect of resveratrol onto homocysteine and HDL metabolism in a murine model of hyperhomocysteinemia.

Topics: Animals; Apolipoprotein A-I; Cystathionine beta-Synthase; Dietary Supplements; Gene Expression Regulation; Genotype; Hyperhomocysteinemia; Lipid Metabolism; Liver; Mice; Phosphatidylcholine-Sterol O-Acyltransferase; Resveratrol; S-Adenosylhomocysteine; S-Adenosylmethionine; Scavenger Receptors, Class B; Stilbenes

Hyperhomocysteinemia is a recognized risk factor for vascular disease, but pathogenetic mechanisms involved in its vascular actions are largely unknown. Because VCAM-1 expression is crucial in monocyte adhesion and early atherogenesis, we evaluated the NF-kappaB-related induction of VCAM-1 by homocysteine (Hcy) and the possible inhibitory effect of dietary polyphenolic antioxidants, such as trans-resveratrol (RSV) and hydroxytyrosol (HT), which are known inhibitors of NF-kappaB-mediated VCAM-1 induction. In human umbilical vein endothelial cells (HUVEC), Hcy, at 100 micromol/l, but not cysteine, induced VCAM-1 expression at the protein and mRNA levels, as shown by enzyme immunoassay and Northern analysis, respectively. Transfection studies with deletional VCAM-1 promoter constructs demonstrated that the two tandem NF-kappaB motifs in the VCAM-1 promoter are necessary for Hcy-induced VCAM-1 gene expression. Hcy-induced NF-kappaB activation was confirmed by EMSA, as shown by the nuclear translocation of its p65 (RelA) subunit and the degradation of the inhibitors IkappaB-alpha and IkappaB-beta by Western analysis. Hcy also increased intracellular reactive oxygen species by NAD(P)H oxidase activation, as shown by the membrane translocation of its p47(phox) subunit. NF-kappaB inhibitors decreased Hcy-induced intracellular reactive oxygen species and VCAM-1 expression. Finally, we found that nutritionally relevant concentrations of RSV and HT, but not folate and vitamin B6, reduce (by >60% at 10(-6) mol/l) Hcy-induced VCAM-1 expression and monocytoid cell adhesion to the endothelium. These data indicate that pathophysiologically relevant Hcy concentrations induce VCAM-1 expression through a prooxidant mechanism involving NF-kappaB. Natural Mediterranean diet antioxidants can inhibit such activation, suggesting their possible therapeutic role in Hcy-induced vascular damage.

Topics: Antioxidants; Cell Adhesion; Cells, Cultured; Diet, Mediterranean; Dose-Response Relationship, Drug; Endothelial Cells; Flavonoids; Homocysteine; Humans; Hyperhomocysteinemia; I-kappa B Proteins; Monocytes; Mutation; NADPH Oxidases; Phenols; Phenylethyl Alcohol; Phosphorylation; Polyphenols; Promoter Regions, Genetic; Proteasome Endopeptidase Complex; Protein Transport; Reactive Oxygen Species; Resveratrol; RNA, Messenger; Stilbenes; Transcription Factor RelA; Transcription, Genetic; Transfection; Tumor Necrosis Factor-alpha; Up-Regulation; Vascular Cell Adhesion Molecule-1