Gallates inhibit cytokine-induced nuclear translocation of NF-kappaB and expression of leukocyte adhesion molecules in vascular endothelial cells

The role of tea and tea flavonoids in cardiovascular health

Consumption of green or black tea has been inversely associated with the development and progression of cardiovascular diseases. In this review, the current knowledge about protective effects of tea and tea constituents, particularly flavonoids, on the cardiovascular system is summarized. Underlying mechanisms for the beneficial effects of tea include vasculoprotective, antioxidative, antithrombogenic, anti-inflammatory, and lipid-lowering properties of tea flavonoids. Although promising experimental data on beneficial effects of tea in various cardiovascular diseases are available, results of clinical studies in humans are not uniform. A number of factors are discussed which may contribute to inconsistent data in humans. Overall, tea represents a promising tool for the prevention and treatment of cardiovascular disorders.

Inhibitory effect of dietary phenolic compounds on Chlamydia pneumoniae in cell cultures

Chlamydial infections are very common worldwide. All chlamydial species have a tendency to cause persistent infections, which have been associated to several chronic diseases including blinding trachoma, infertility and coronary heart disease (CHD). At present, no efficient treatment for the eradication of chronic chlamydial infections exists and, thus, new antichlamydial compounds are urgently needed. This study was designed to screen antichlamydial activity of natural flavonoids and other natural and structurally similar synthetic compounds against Chlamydia pneumoniae in human cell line (HL). HL cells were infected with C. pneumoniae and incubated 72 h with studied compounds. Reduction in the number of inclusions was determined with immunofluorescence staining. In vitro minimum inhibitory concentration was also determined for some of the most active compounds. Thirty seven percentage of the studied compounds (57 in total) were highly active against C. pneumoniae and all the studied compounds were non-toxic to the host cells at studied concentrations. Our study revealed direct antichlamydial effect for selected polyphenolic compounds against C. pneumoniae, in vitro. We also demonstrated the ability of some of the investigated compounds to accumulate inside cells or into cell membranes and cause inhibition, even when present only prior to infection.

Polyphenols-enriched Chardonnay white wine and sparkling Pinot Noir red wine identically prevent early atherosclerosis in hamsters

The effects of a white wine enriched with polyphenols (PEWW) from Chardonnay grapes and of a sparkling red wine (SRW) from Pinot Noir and Chardonnay grapes were studied for the first time on early atherosclerosis in hamsters. Animals were fed an atherogenic diet for 12 weeks. They received by force-feeding PEWW, SRW, ethanol 12% (ETH), or water as control (mimicking a moderate consumption of approximately 2 red wine glasses per meal for a 70 kg human). Plasma cholesterol concentrations were lower in groups that consumed PEWW and SRW accompanied by an increase in the ratio apo A-1/apo B. Liver-specific activities of superoxide dismutase and catalase were significantly increased by PEWW (38 and 16%, respectively) and by SRW (48 and 15%, respectively). PEWW and ETH significantly increased plasma antioxidant capacity and vitamin A concentrations. Aortic fatty streak area (AFSA) was significantly strongly reduced in the groups receiving PEWW (85%) and SRW (89%) in comparison with the control. AFSA was reduced by ethanol to a lesser extent (58%). These data suggest that tannins from the phenolics-enriched white wine induce a protective effect against early atherosclerosis comparable to that produced by sparkling red wine containing tanins and anthocyanins and dissociated from the antioxidant action of these compounds.

In vivo treatment of acute Chlamydia pneumoniae infection with the flavonoids quercetin and luteolin and an alkyl gallate, octyl gallate, in a mouse model

Increasing evidence suggests that plant polyphenolic compounds may protect from cardiovascular diseases, which have been addressed to their antioxidative properties. In addition, these compounds have been shown to possess anti-inflammatory and anti-microbial potential. In the present study we tested the effects of two flavonoid compounds, quercetin and luteolin, and one alkyl gallate, octyl gallate, on the course of acute Chlamydia pneumoniae infection in vivo. C57BL/6J mice were treated with quercetin, luteolin or octyl gallate for 3 days prior to and 10 days after C. pneumoniae inoculation. Lung tissue was analysed for the presence of chlamydia by culture and quantitative PCR, and inflammatory responses were assessed. Luteolin was found histologically to suppress inflammation in lung tissue, the development of C. pneumoniae-specific antibodies and the presence of chlamydia in lung tissue. Octyl gallate had no significant effect on the course of infection, but quercetin increased both the inflammatory responses and the chlamydial load in the lungs. The infection and inflammation-enhancing effects of quercetin treatment may be attributable to the dose and the route of administration and should be reassessed in further studies with lower doses or with different metabolites of the compound. Contrariwise, the effects of luteolin treatment suggest this compound to have potential in decreasing the infection load and inflammatory reactions in vivo.

Grape Seed and Skin Extracts Inhibit Platelet Function and Release of Reactive Oxygen Intermediates

Red wine and purple grape juice contain polymeric flavonoids with antioxidant properties believed to be protective against cardiovascular events but the alcohol and sugar content of these beverages has curtailed their medicinal use. Acute cardiac events are also associated with enhanced inflammation and thrombosis. In this study, the extracts from grape skins or seeds were examined for their anti-inflammatory properties and effect on platelet release of reactive oxygen intermediates. Incubation of platelets with seed or skin extract led to a decrease in platelet aggregation from 68.8+/-19.8% to 45+/-3.6% for seeds and to 27+/-7.2% for skin, respectively (P<0.05). Platelet incubation with grape skin or seed extracts led to a marked decrease in superoxide release from 73+/-6.2 to 2+/-3.4 for grape seeds and to 0.33+/-0.57 for grape skin (chemilum. units; P<0.05) as well as a significant increase in radical-scavenging activity, decrease in reactive oxygen species release by confocal microscopy, and enhanced platelet NO was measured using an NO-sensitive microelectrode. These effects were dose dependent for both grape extracts. Coincubation with seeds and skins led to additive inhibition of platelet aggregation, enhanced NO release, and prevented superoxide production. Incubation with seed or skin extracts led to an immediate attenuation of release of the inflammatory mediator, soluble CD40 ligand. Thus, the extracts from purple grape skins and seeds inhibit platelet function and platelet-dependent inflammatory responses at pharmacologically relevant concentrations. These findings suggest potentially beneficial platelet-dependent antithrombotic and anti-inflammatory properties of purple grape-derived flavonoids.

Anti-inflammatory inhibition of endothelial cell adhesion molecule expression by flavone derivatives

Endothelial expression of cell adhesion molecules (CAM) including VCAM-1, E-selectin, and PECAM-1 plays a leading role in atherosclerosis. Phenolic flavones have been shown to have an anti-inflammatory property. This study examines whether 3',4'-dimethoxy-7-hydroxyflavone (methoxyflavone) and 2',3',7-trihydroxyflavone (hydroxyflavone) inhibited monocyte adhesion to TNF-alpha-activated endothelium via reduction of CAM expression in human umbilical vein endothelial cells (HUVEC). In stimulated HUVEC the expression of VCAM-1 and E-selectin was enhanced with increasing mRNA levels. Methoxyflavone markedly interfered with the THP-1 monocyte adhesion to TNF-alpha-stimulated HUVEC. At concentrations of > or =25 microM, methoxyflavone blocked the induction of VCAM-1 but not that of E-selectin on the activated HUVEC. Immunocytochemical staining showed that methoxyflavone modestly inhibited PECAM-1 expression induced by TNF-alpha. In contrast, hydroxyflavone minimally inhibited TNF-alpha-stimulated E-selectin expression without affecting VCAM-1 level. The inhibitory effect of methoxyflavone on THP-1 adhesion to HUVEC appears to be greater than that of hydroxyflavone, most likely due to a greater inhibition of CAM expression. Thus, some flavone derivatives containing methoxy groups may have therapeutic potential attenuating inflammatory response-related atherosclerosis.

Phenolic acid derivatives with potential anticancer properties--a structure-activity relationship study. Part 1: methyl, propyl and octyl esters of caffeic and gallic acids

The antiproliferative and cytotoxic properties of polyphenolic acid derivatives, structurally related with the natural models caffeic and gallic acids, have been tested in human cervix adenocarcinoma cells (HeLa). Simultaneous structural information was obtained for these compounds through theoretical ab initio methods. This study was conducted for the following esters: methyl caffeate (MC, 1), propyl caffeate (PC, 2), octyl caffeate (OC, 3), methyl gallate (MG, 4), propyl gallate (PG, 5) and octyl gallate (OG, 6). A significant growth-inhibition effect was assessed for some of these compounds, clearly dependent on their structural characteristics. Marked structure-activity relationships (SARs)--namely the number of hydroxyl ring substituents--were found to rule the biological effect of such systems.

Phenolics from commercialized grape extracts prevent early atherosclerotic lesions in hamsters by mechanisms other than antioxidant effect

The aim of this study was to evaluate the antiatherosclerotic effect of commercially available phenolic-rich extracts from grape seeds (ExGrape seeds, EGS; grape seed extract, GSE) and marc (ExGrape total, EGT) in cholesterol-fed hamsters and to investigate possible operating mechanisms. These extracts fed at a moderate dose mimicking two glasses of red wine per meal reduced plasma cholesterol (-11% on average) but did not affect plasma antioxidant capacity of hamsters. The extracts prevented the development of aortic atherosclerosis by 68% (EGS), 63% (EGT), and 34% (GSE). Elsewhere, in an ex vivo experiment using rat aortic rings, EGS (7 microg/mL) induced 77% endothelium-dependent relaxation, whereas EGT and GSE (30 microg/mL) induced 84 and 72%, respectively. These results suggests that phenolic extracts from grape seeds and marc are beneficial in inhibiting atherosclerosis by indirect mechanism(s).

The tea flavonoid epigallocatechin-3-gallate reduces cytokine-induced VCAM-1 expression and monocyte adhesion to endothelial cells

Attachment of leukocytes to the vascular endothelium and the subsequent migration of cells into the vessel wall are early events in atherogenesis. This process requires the expression of endothelial adhesion molecules. Since tea catechins are reputed to promote antiatherogenic activities, we investigated the effects of various tea catechins-i.e., epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), and epigallocatechin-3-gallate (EGCG)-on cytokine-induced expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial leukocyte adhesion molecule-1 (E-selectin) in HUVECs by ELISA. EGCG and to a lesser extent ECG prevented the induction of VCAM-1 expression in a concentration-dependent manner after stimulation with TNF-alpha, whereas EC and EGC were without effect. EGCG also inhibited the IL-1beta-induced induction of VCAM-1 expression. Inhibition of cytokine-induced VCAM-1 expression was manifested already on the transcriptional level. Furthermore, EGCG reduced the TNF-alpha-induced adhesion of THP-1 cells to HUVECs. EGCG did not influence TNF-alpha-stimulated NF-kappaB activation.

Inhibition of fucosyltransferase VII by gallic acid and its derivatives

Gallic acid (GA) and several gallate derivatives were identified as inhibitors of fucosyltransferase VII (FucT VII). The inhibition by GA and (-)-epigallocatechin gallate (EGCG) is time-dependent and irreversible. GA and EGCG showed inhibition with IC(50) of 60 and 700 nM, respectively, after pre-incubation with FucT VII in the presence of MnCl(2). Absence of MnCl(2) results in significantly weaker inhibition. Complexation of Mn(2+) with GA, EGCG, and gallate esters was observed. Such complexation, however, is not rate-limiting for the inhibition of FucT VII. Therefore, time-dependent inhibition of fucosyltransferases by GA and EGCG is likely due to the slow inactivation by the inhibitors or Mn-inhibitor complex. Although Mg(2+) or Ca(2+) can replace Mn(2+) for FucT VII activation, none forms a complex with GA or EGCG and hence results in weaker inhibition of FucT VII. GA and EGCG also inhibit FucT IV and alpha2,3-(N)-sialyltransferase in the low micromolar range. The structure-function divergence could be observed, as EGCG, but not GA or gallate esters, inhibits Zn(2+) containing metalloproteases such as TNFalpha convertase, matrix metalloproteases 2 and 7.

Flavones mitigate tumor necrosis factor-alpha-induced adhesion molecule upregulation in cultured human endothelial cells: role of nuclear factor-kappa B

Flavones have been classified as anti-atherogenic agents that inhibit monocyte adhesion to stimulated endothelium, possibly by blocking induction of cell adhesion molecules (CAM). This anti-atherogenic feature of these flavonoids appears to be related to their chemical structures. Flavones may interfere with key signaling events involved in endothelial cell activation by inflammatory mediators. This study examined the effects of flavones on the induction of CAM and the translocation and DNA binding of nuclear factor-kappa B (NF-kappa B) in TNF-alpha-activated human umbilical vein endothelial cells (HUVEC). The effects of flavones, luteolin and apigenin, on adhesion of THP-1 monocytes to the TNF-alpha-activated HUVEC, protein expression and mRNA levels of vascular cell adhesion molecule-1 (VCAM-1), intracellular cell adhesion molecule-1 (ICAM-1) and E-selectin, and nuclear appearance and DNA binding activity of NF-kappa B were determined. Flavanols, flavonols, and flavanones were used for comparison. TNF-alpha significantly induced HUVEC protein expression of VCAM-1, ICAM-1, and E-selectin with increasing mRNA levels. Luteolin and apigenin inhibited the TNF-alpha-induced upregulation of THP-1 adhesion and VCAM-1 expression; these inhibitory effects were dose-dependent. The flavones at doses of > or =25 micromol/L almost completely abolished the increased CAM protein and mRNA regardless of their anti-oxidative activity. With the exception of the flavonol quercetin, flavonoids had no such effect; quercetin substantially attenuated the CAM induction. The flavones inhibited nuclear translocation and DNA binding activity of the NF-kappa B-containing binding site in the promoter region of the CAM genes in TNF-alpha-activated HUVEC. The inhibition of endothelial CAM induction by flavones is mediated by their interference with the NF-kappa B-dependent transcription pathway. Thus, the flavones may hamper initial atherosclerotic events involving endothelial CAM induction.

KR‐31378 ameliorates atherosclerosis by blocking monocyte recruitment in hypercholestrolemic mice

The recruitment of monocytes into the artery wall is a crucial early step in atherogenesis. A novel compound, KR-31378, has been shown to be a neuroprotective agent for ischemia-reperfusion damage in rat brain via its potent antioxidant and antiapoptotic actions. Here, we report the effects of this compound on atherogenesis and possible mechanisms of action. In Ldlr knockout mice fed with a high-fat, high-cholesterol diet, treatment with KR-31378 significantly inhibited fatty streak formation and macrophage accumulation. To address the possibility that KR-31378 may influence the initial stages of atherogenesis, we examined its effect on the adhesion and migration of monocytes to endothelial cells stimulated with tumor necrosis factor-alpha. KR-31378 decreased the adhesion in a dose-dependent manner. The observed decreases in cell adhesion and migration correlated with KR-31378-mediated down-regulation of vascular cell adhesion molecule-1 (VCAM-1) and interleukin (IL)-8. Nuclear factor-kappaB (NF-kappaB) is known to regulate the expression of adhesive and chemotactic molecules including VCAM-1 and IL-8. Indeed, transient transfection experiments, electrophoretic mobility shift assay, and IkappaB degradation assay showed that KR-31378 decreased NF-kappaB activation. These results indicate that KR-31378 potently reduces fatty streak formation by inhibiting NF-kappaB-dependent cellular adhesion and chemotactic molecule expression, which are crucial to monocyte infiltration into the arterial wall during the early stages of atherogenesis.

Red wine polyphenolic compounds inhibit atherosclerosis in apolipoprotein E-deficient mice independently of effects on lipid peroxidation

BACKGROUND

Lipid peroxidation is thought to play an important role in the pathogenesis of atherosclerosis. Fatty acid peroxidation products such as hydroxyeicosatetraenoic acids and F(2)-isoprostanes have been found in advanced human atherosclerotic plaques. However, little is known about the formation of these products during lesion development.

OBJECTIVE

This study examined stable biomarkers of lipid oxidative damage in relation to atherosclerotic disease progression in apolipoprotein E-deficient (Apoe(-/-)) mice and retardation of the disease by red wine polyphenols.

DESIGN

One hundred male Apoe(-/-) mice and 50 male control (C57BL/6J) mice were given a high-fat, high-cholesterol diet for 20 wk. To examine the effect of the polyphenolic compounds on lesion development, 50 of the Apoe(-/-) mice were also given dealcoholized red wine for the duration of the study.

RESULTS

Aortic lipid deposition was significantly greater in the Apoe(-/-) mice than in the control mice (P < 0.01). Plasma and aortic F(2)-isoprostanes did not differ between the treatment groups. Plasma concentrations of monocyte chemoattractant protein 1, which has been implicated in the development of atherosclerosis, were significantly higher in the Apoe(-/-) mice than in the control mice up to 16 wk (P < 0.05). Hydroxyeicosatetraenoic acid concentrations increased significantly over time in all groups (P < 0.05). Red wine polyphenols had no effect on markers of lipid peroxidation or monocyte chemoattractant protein 1 concentrations, but lipid deposition in the aorta at age 26 wk was significantly less in the mice given red wine than in those not given red wine.

CONCLUSION

These results suggest that lipid deposition is independent of lipid oxidation and that the protective action of red wine polyphenols is independent of any antioxidant action of these compounds.

The effect of alcohol consumption on endothelial adhesion molecule expression

Endothelial adhesion molecules (AM) play an important role in the pathogenesis of several diseases namely infections, neoplasms and chronic inflammatory diseases. Because alcoholic hepatitis and even atherosclerosis are considered as inflammatory diseases and ethanol may modulate inflammatory response, several researchers have investigated the link between ethanol consumption, endothelial AM and the development of both processes. In vitro, animal and human studies have analysed the effects of ethanol and non-alcoholic components of alcoholic beverages on inflammatory biomarkers of atherosclerosis such as monocyte and endothelial AM. These studies have shown that both ethanol and non-alcoholic components of alcoholic beverages, mainly polyphenols, reduce intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin expression of vascular endothelium, as well as monocyte adhesion to this endothelium. These data suggest that moderate alcohol intake has an anti-inflammatory effect on the cardiovascular system and reduces early serum markers of atherosclerosis. However, at higher doses ethanol may exert an inflammatory effect. In fact, chronic alcoholics exhibit significantly higher serum levels of endothelial AM than abstainers and moderate drinkers. In addition, an upregulation of E-selectin, ICAM-1 and VCAM-1 is also detected in liver biopsies obtained from patients with alcoholic hepatitis and cirrhosis. The clinical usefulness of the measurement of serum endothelial AM is discussed.

A novel mechanism for the inhibition of NF-kappaB activation in vascular endothelial cells by natural antioxidants

The activation of Nuclear Factor kappa B (NF-kappaB) in vascular endothelial cells, in response to biochemical or biomechanical stimuli, is associated with vascular pathologies such as atherosclerosis. The present manuscript studies the ability of the natural antioxidant-pomegranate wine (PW), to inhibit tumor necrosis factor alpha (TNF-alpha) or shear stress-mediated-NF-kappaB activation in vascular endothelial cells and compares it to that of red wine (RW) and N-acetyl cysteine (NAC). PW and RW act as potent antioxidants in vascular endothelial cells, inhibiting the oxidation of 2',7'-dichloroflurescin diacetate in TNF-alpha treated cells. PW (as well as RW and NAC) acted as potent inhibitors of NF-kappaB activation (migration into the nucleus and DNA binding activity) in vascular endothelial cells. Nevertheless, PW and NAC failed to inhibit TNF-a induced serine 32/36 phosphorylation and IkappaBalpha degradation. Surprisingly, these antioxidants alone induced enhanced IkappaB serine phosphorylation, which was not accompanied by IkappaBalpha degradation, or NF-kappaB nuclear translocation. This phosphorylation did not involve serine 32/36. Furthermore, we show for the first time that NAC inhibited TNF-alpha mediated phosphorylation of p65 (ser536), whereas PW had no effect on this phosphorylation. Thus, natural antioxidants may serve as potent NF-kappaB inhibitors in vascular endothelial cells, yet act through unique and divergent pathways.

Beneficial effects of tea catechins on diet-induced obesity: stimulation of lipid catabolism in the liver

OBJECTIVE

Obesity has increased at an alarming rate in recent years and is now a worldwide health problem. We investigated the effects of long-term feeding with tea catechins, which are naturally occurring polyphenolic compounds widely consumed in Asian countries, on the development of obesity in C57BL/6J mice.

DESIGN

We measured body weight, adipose tissue mass and liver fat content in mice fed diets containing either low-fat (5% triglyceride (TG)), high-fat (30% TG), or high-fat supplemented with 0.1-0.5% (w/w) tea catechins for 11 months. The beta-oxidation activities and related mRNA levels were measured after 1 month of feeding.

RESULTS

Supplementation with tea catechins resulted in a significant reduction of high-fat diet-induced body weight gain, visceral and liver fat accumulation, and the development of hyperinsulinemia and hyperleptinemia. Feeding with tea catechins for 1 month significantly increased acyl-CoA oxidase and medium chain acyl-CoA dehydrogenase mRNA expression as well as beta-oxidation activity in the liver.

CONCLUSION

The stimulation of hepatic lipid metabolism might be a factor responsible for the anti-obesity effects of tea catechins. The present results suggest that long-term consumption of tea catechins is beneficial for the suppression of diet-induced obesity, and it may reduce the risk of associated diseases including diabetes and coronary heart disease.

Oxygen radicals trigger activation of NF-kappaB and AP-1 and upregulation of ICAM-1 in reperfused canine heart

We investigated whether oxygen radicals generated during ischemia-reperfusion trigger postischemic inflammation in the heart. Closed-chest dogs underwent 90-min coronary artery occlusion, followed by 1- or 3-h reperfusion: 10 dogs received the cell-permeant oxygen radical scavenger N-(2-mercaptopropionyl)-glycine (MPG; 8 mg x kg(-1) x h(-1) intracoronary) beginning 5 min before reperfusion, and 9 dogs received vehicle. Blood flow (microspheres), intercellular adhesion molecule (ICAM)-1 protein expression (immunohistochemistry), ICAM-1 gene activation (Northern blotting), nuclear DNA binding activity of nuclear factor (NF)-kappaB and AP-1 (electrophoretic mobility shift assays), and neutrophil (PMN) accumulation (myeloperoxidase activity) were assessed in myocardial tissue samples. ICAM-1 protein expression was high in vascular endothelium after ischemia-reperfusion but was markedly reduced by MPG. MPG treatment also markedly decreased expression of ICAM-1 mRNA and tissue PMN accumulation. Nuclear DNA binding activities of NF-kappaB and AP-1, increased by ischemia-reperfusion, were both markedly decreased by MPG at 1 h of reperfusion. However, by 3 h, AP-1 activity was only modestly reduced by MPG and NF-kappaB activity was not significantly different from ischemic-reperfused controls. These results suggest that oxygen radicals generated in vivo during reperfusion trigger early activation of NF-kappaB and AP-1, resulting in upregulation of the ICAM-1 gene in vascular endothelium and subsequent tissue accumulation of activated PMNs.

Potential role of dietary flavonoids in reducing microvascular endothelium vulnerability to oxidative and inflammatory insults ( small star, filled)

Although antioxidant systems help control the level of reactive oxygen species they may be overwhelmed during periods of oxidative stress. Evidence suggests that oxidative stress components as well as inflammatory mediators may be involved in the pathogenesis of vascular disorders, where localized markers of oxidative damage have been found. In this regard we investigated the putative antioxidant and anti-inflammatory effects of blueberry and cranberry anthocyanins and hydroxycinnamic acids against H(2)O(2) and TNFalpha induced damage to human microvascular endothelial cells. Polyphenols from both berries were able to localize into endothelial cells subsequently reducing endothelial cells vulnerability to increased oxidative stress at both the membrane and cytosol level. Furthermore, berry polyphenols also reduced TNFalpha induced up-regulation of various inflammatory mediators (IL-8, MCP-1 and ICAM-1) involved in the recruitment of leukocytes to sites of damage or inflammation along the endothelium. In conclusion, polyphenols isolated from both blueberry and cranberry were able to afford protection to endothelial cells against stressor induced up-regulation of oxidative and inflammatory insults. This may have beneficial actions against the initiation and development of vascular diseases and be a contributing factor in the reduction of age-related deficits in neurological impairments previously reported by us.

Effect of red wine polyphenols on vascular smooth muscle cell function--molecular mechanism of the 'French paradox'

Red wine polyphenols (RWP) have been shown to have an anti-atherogenic activity mainly through anti-oxidative effects on low-density lipoprotein (LDL) oxidation. Though proliferation of vascular smooth muscle cells (VSMC) is critical to atherosclerosis formation, the effect of RWP on VSMC proliferation has not been elucidated. In this study, we investigated whether RWP, which extracted from red wine using column chromatography, could affect the 10% serum-stimulated VSMC proliferation. Treatment with RWP showed a potent inhibitory effect on the proliferation and DNA syntheses is in cultured rat VSMC. In contrast, the inhibitory effect of RWP on the proliferation of bovine vascular endothelial cells (EC) was only observed at much higher doses. Moreover, RWP significantly inhibited the proliferation and DNA synthesis of human VSMC but no human vascular EC in a dose-dependent manner. To elucidate the molecular mechanisms of these anti-proliferative effects of RWP on VSMC, but not on vascular EC, we investigated the effects of RWP on the cell cycle regulation. RWP downregulated the expression and promoter activity of cyclin A gene, one of cell cycle regulators. In addition, RWP inhibited the binding of nuclear proteins to the activating transcription factor (ATF) site in the cyclin A promoter, and downregulated the expression of transcription factors, cyclic AMP-responsive element binding protein (CREB) and ATF-1. In conclusion, these results demonstrate one possible finding that the anti-proliferative effect of RWP on VSMC may be associated with the downregulation of cyclin A gene expression through the inhibition of transcription factor expression.

Natural products as targeted modulators of the nuclear factor-kappaB pathway

The use of plant extracts to alleviate inflammatory diseases is centuries old and continues to this day. This review assesses the current understanding of the use of such plants and natural products isolated from them in terms of their action against the ubiquitous transcription factor, nuclear factor kappa B (NF-kappaB). As an activator of many pro-inflammatory cytokines and inflammatory processes the modulation of the NF-kappaB transduction pathway is a principal target to alleviate the symptoms of such diseases as arthritis, inflammatory bowel disease and asthma. Two pathways of NF-kappaB activation will first be summarised, leading to the IKK (IkappaB kinase) complex, that subsequently initiates phosphorylation of the NF-kappaB inhibitory protein (IKB). Natural products and some extracts are reviewed and assessed for their activity and potency as NF-kappaB inhibitors. A large number of compounds are currently known as NF-kappaB modulators and include the isoprenoids, most notably kaurene diterpenoids and members of the sesquiterpene lactones class, several phenolics including curcumin and flavonoids such as silybin. Additional data on cellular toxicity are also highlighted as an exclusion principle for pursuing such compounds in clinical development. In addition, where enough data exists some conclusions on structure-activity relationship are provided.

Hamamelitannin from Hamamelis virginiana inhibits the tumour necrosis factor-alpha (TNF)-induced endothelial cell death in vitro

The tumour necrosis factor-alpha (TNF) inhibitory activity of hamamelitannin from Hamamelis virginiana was investigated by assessing the TNF-mediated EAhy926 endothelial cell death and adhesiveness to monocytes. Treatment of the cells by TNF (25 ng/ml) and actinomycin D (0.1ng/ml) resulted in significant DNA fragmentation (34+/-0.6, n=4) and cytotoxicity (97+/-4.5%, n=6) following treatment for 8 and 24h, respectively. One to 100 microM concentrations of hamamelitannin inhibited the TNF-mediated endothelial cell death and DNA fragmentation in a dose-dependent manner. One hundred % protection against TNF-induced DNA fragmentation and cytotoxicity was obtained for hamamelitannin concentrations higher than 10 microM. The protective effect of hamamelitannin was comparable with that of a related compound epigallocatechin gallate while gallic acid was a weak protective agent (<40% protection). EAhy926 endothelial cells upregulated (by 4- to 7-fold) the surface expression of intercellular adhesion molecule-1 (ICAM-1) and adhesiveness to monocytic U937 cells after treatment with TNF (0.5ng/ml) for 6 or 24h. Concentrations (1-100 microM) of hamamelitannin that inhibited the TNF-mediated cell death and DNA fragmentation, however, failed to inhibit the TNF-induced ICAM-1 expression and EAhy926 cell adhesiveness to U937 cells. Thus, hamamelitannin inhibits the TNF-mediated endothelial cell death without altering the TNF-induced upregulation of endothelial adhesiveness. The observed anti-TNF activity of hamamelitannin may explain the antihamorrhaegic use of H. virginiana in traditional medicine and its claimed use as a protective agent for UV radiation.

Inhibition of cytokine-induced vascular cell adhesion molecule-1 expression; possible mechanism for anti-atherogenic effect of Agastache rugosa

Adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1) play an important role during the early stages of atherogenesis. Agastache rugosa has an anti-atherogenic effect in low density lipoprotein receptor -/- mice. Moreover, A. rugosa reduced macrophage infiltration and VCAM-1 expression has been localized in aortic endothelium that overlies early foam cell lesions. This study ascertained that tilianin (100 microM), a major component of A. rugosa, inhibits the tumor necrotic factor-alpha (TNF-alpha)-induced expression of VCAM-1 by 74% in cultured human umbilical vein endothelial cells (HUVECs). Also, tilianin (100 microM) reduced TNF-alpha-induced activation of nuclear factor-kappaB in HUVECs.

Hematein inhibits tumor necrotic factor-alpha-induced vascular cell adhesion molecule-1 and NF-kappaB-dependent gene expression in human vascular endothelial cells

Monocyte adhesion to the endothelium via adhesion molecules is one of the earliest events in atherogenesis. It has been suggested that vascular cell adhesion molecule-1 (VCAM-1) plays a very important role in the recruitment of monocytes in atherosclerosis. The aim of our study was to evaluate whether hematein can influence the expression of VCAM-1 and the transcription of nuclear factor-kappaB (NF-kappaB)-dependent genes. Immunohistochemistry revealed that mouse aortic artery endothelial cells express VCAM-1 after feeding a high cholesterol diet for 8 weeks. Hematein dose dependently suppressed TNF-alpha-induced VCAM-1 in both surface (30.8%) and soluble protein (65%) production in HUVECs. The transcription level of VCAM-1 was measured by Northern blot analysis, and decreased VCAM-1 protein expression was associated with a reduction of VCAM-1 mRNA expression. Transient transfection study of NF-kappaB promoter construct and electrophoretic mobility shift assay suggested that hematein inhibited both NF-kappaB-dependent gene expression and NF-kappaB activation induced by TNF-alpha. Our results suggest that the down-regulation of VCAM-1 expression by hematein may in part be due to the inhibition of NF-kappaB-dependent gene expression.

The health benefits of wine

Epidemiologic studies from numerous disparate populations reveal that individuals with the habit of daily moderate wine consumption enjoy significant reductions in all-cause and particularly cardiovascular mortality when compared with individuals who abstain or who drink alcohol to excess. Researchers are working to explain this observation in molecular and nutritional terms. Moderate ethanol intake from any type of beverage improves lipoprotein metabolism and lowers cardiovascular mortality risk. The question now is whether wine, particularly red wine with its abundant content of phenolic acids and polyphenols, confers additional health benefits. Discovering the nutritional properties of wine is a challenging task, which requires that the biological actions and bioavailability of the >200 individual phenolic compounds be documented and interpreted within the societal factors that stratify wine consumption and the myriad effects of alcohol alone. Further challenge arises because the health benefits of wine address the prevention of slowly developing diseases for which validated biomarkers are rare. Thus, although the benefits of the polyphenols from fruits and vegetables are increasingly accepted, consensus on wine is developing more slowly. Scientific research has demonstrated that the molecules present in grapes and in wine alter cellular metabolism and signaling, which is consistent mechanistically with reducing arterial disease. Future research must address specific mechanisms both of alcohol and of polyphenolic action and develop biomarkers of their role in disease prevention in individuals.

Humic acid suppresses the LPS-induced expression of cell-surface adhesion proteins through the inhibition of NF-kappaB activation

Humic acid (HA), a potential toxin when penetrating the drinking well water of blackfoot disease-endemic areas in Taiwan, has been implicated as one of the etiological factors of this disease. In this study, we investigated the effects of HA on the expression of human vascular endothelial-leukocyte adhesion molecules and the activation of nuclear factor kappa B (NF-kappaB) in cultured human umbilical vein endothelial cells (HUVECs). The expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin was monitored by flow cytometry. Pretreatment of HUVECs with HA inhibited the lipopolysaccharide (LPS)-induced expression of these three adhesion molecules in a dose- and time-dependent manner. Since NF-kappaB can regulate the expression of these adhesion molecules, NF-kappaB activation was assessed by electrophoretic mobility shift assay (EMSA). Our results reveal that the activation of NF-kappaB by LPS is suppressed by HA in a dose- and time-dependent manner. Furthermore, HA reduces NF-kappaB binding to DNA slightly, but completely inhibits the degradation of IkappaBalpha at a concentration of 100 microg/ml. Thus, all our data demonstrate that HA can inhibit the LPS-induced expression of adhesion molecules through the inhibition of NF-kappaB activation. HA may also suppress the immune or inflammatory reaction of HUVECs responsible for endotoxin, which could be one possible explanation for the causes of the infection and inflammation observed for patients with blackfoot disease. Our results also suggest that immune or inflammatory disturbance occurs for patients with blackfoot disease and that NF-kappaB may be a critical molecule in the pathogenesis of this disease.

Black and green tea and heart disease: a review

Tea is the second most consumed beverage around the world behind water. Epidemiological evidence points to both green and black tea consumption being protective with respect to heart disease. However, epidemiological evidence does not prove cause and effect and is potentially flawed by confounding variables. The recent evidence with respect to teas' beneficial effects from in vitro and in vivo studies in both animals and humans will be covered in this review. The comparative benefits of green vs. black tea will be considered. Articles published through December, 1999 will be included.