Polyphenols: From Theory to Practice.

BACKGROUND: The importance of polyphenols in human health is well known; these compounds are common in foods, such as fruits, vegetables, spices, extra virgin olive oil and wine. On the other hand, the different factors that modulate the biological activity of these compounds are less well known. Conceptualization of the work: In this review we took into account about 200 relevant and recent papers on the following topics: "polyphenols bioavailability", "polyphenols matrix effect", "food matrix effect", "polyphenols-cytochromes interaction", after having reviewed and updated information on chemical classification and main biological properties of polyphenols, such as the antioxidant, anti-radical and anti-inflammatory activity, together with the tricky link between in vitro tests and clinical trials. KEY FINDINGS: the issue of polyphenols bioavailability and matrix effect should be better taken into account when health claims are referred to polyphenols, thus considering the matrix effect, enzymatic interactions, reactions with other foods or genetic or gender characteristics that could interfere. We also discovered that in vitro studies often underrate the role of phytocomplexes and thus we provided practical hints to describe a clearer way to approach an investigation on polyphenols for a more resounding transfer to their use in medicine.

Association between taste receptor (TAS) genes and the perception of wine characteristics.

Several studies have suggested a possible relationship between polymorphic variants of the taste receptors genes and the acceptance, liking and intake of food and beverages. In the last decade investigators have attempted to link the individual ability to taste 6-n-propylthiouracil (PROP) and the sensations, such as astringency and bitterness, elicited by wine or its components, but with contradictory results. We have used the genotype instead of the phenotype (responsiveness to PROP or other tastants), to test the possible relation between genetic variability and the perception of wine characteristic in 528 subjects from Italy and the Czech Republic. We observed several interesting associations, among which the association between several TAS2R38 gene single nucleotide polymorphisms (P = 0.002) and the TAS2R16-rs6466849 polymorphism with wine sourness P = 0.0003). These associations were consistent in both populations, even though the country of origin was an important factor in the two models, thus indicating therefore that genetics alongside cultural factors also play a significant role in the individual liking of wine.

Caffeic acid, a phenol found in white wine, modulates endothelial nitric oxide production and protects from oxidative stress-associated endothelial cell injury.

INTRODUCTION: Several studies demonstrated that endothelium dependent vasodilatation is impaired in cardiovascular and chronic kidney diseases because of oxidant stress-induced nitric oxide availability reduction. The Mediterranean diet, which is characterized by food containing phenols, was correlated with a reduced incidence of cardiovascular diseases and delayed progression toward end stage chronic renal failure. Previous studies demonstrated that both red and white wine exert cardioprotective effects. In particular, wine contains Caffeic acid (CAF), an active component with known antioxidant activities. AIM OF THE STUDY: The aim of the present study was to investigate the protective effect of low doses of CAF on oxidative stress-induced endothelial injury. RESULTS: CAF increased basal as well as acetylcholine-induced NO release by a mechanism independent from eNOS expression and phosphorylation. In addition, low doses of CAF (100 nM and 1 µM) increased proliferation and angiogenesis and inhibited leukocyte adhesion and endothelial cell apoptosis induced by hypoxia or by the uremic toxins ADMA, p-cresyl sulfate and indoxyl sulfate. The biological effects exerted by CAF on endothelial cells may be at least in part ascribed to modulation of NO release and by decreased ROS production. In an experimental model of kidney ischemia-reperfusion injury in mice, CAF significantly decreased tubular cell apoptosis, intraluminal cast deposition and leukocyte infiltration. CONCLUSION: The results of the present study suggest that CAF, at very low dosages similar to those observed after moderate white wine consumption, may exert a protective effect on endothelial cell function by modulating NO release independently from eNOS expression and phosphorylation. CAF-induced NO modulation may limit cardiovascular and kidney disease progression associated with oxidative stress-mediated endothelial injury.

Anti-inflammatory effect of white wine in CKD patients and healthy volunteers.

BACKGROUND: Mediterranean-style diet has been considered for its important beneficial effects on the progression of CV disease. Wine is an important component of the Mediterranean diet, and moderate wine drinkers have lower mortality rates than nondrinkers and heavy drinkers in epidemiologic studies. The beneficial effects of red wine are thought to be dependent on the polyphenol compounds such as resveratrol that exhibit potent antioxidant activity. However, white wine, although lacking polyphenols, contains simple phenols, such as tyrosol (Tyr) and hydroxytyrosol (OH-Tyr), characteristic also of extra-virgin olive oil, which may share similar antioxidant and inflammatory properties. PATIENTS AND METHODS: The effect of white wine and extra-virgin olive oil on inflammatory markers was evaluated in 10 healthy volunteers and in 10 patients with CKD (chronic kidney disease) K-DOQI stage III-IV in a prospective, single blind, randomized, cross-over trial. After two weeks of wash-out from alcoholic beverages, subjects were randomized to a cross-over design A-B or B-A of a 2-week treatment with white wine (4 ml/kg body weight, 0.48 g/kg of alcohol 12%, corresponding to 2-3 glasses/daily) and extra-virgin olive oil (treatment A) or extra-virgin olive oil alone (treatment B). The two study periods were separated by a two-week wash-out period. At baseline and at the end of each treatment, plasma levels of inflammatory markers C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and interleukin-8 (IL-8) concentration were determined. Urinary levels of Tyr, OH-Tyr, and their metabolites were measured at the same time. RESULTS: During combined consumption of white wine and extra-virgin olive oil (treatment A), plasma levels of CRP and IL-6 decreased from 4.1 ± 1.8 to 2.4 ± 1.9 mg/l (p < 0.05) and from 5.3 ± 3.2 to 3.4 ± 2.3 mg/l (p < 0.05) in CKD patients. CRP decreased from 2.6 ± 1.2 to 1.9 ± 0.9 mg/l (p < 0.05), and IL-6 decreased from 2.2 ± 1.8 to 1.7 ± 1.3 mg/l (p = ns) in healthy volunteers. No significant variation versus baseline was observed during treatment B. A significant increase in urinary Tyr and OH-Tyr was observed during treatment A (white wine and extra-virgin olive oil). CONCLUSIONS: Plasma markers of chronic inflammation were significantly reduced in CKD patients during the combined consumption of white wine and olive oil, suggesting a possible anti-inflammatory effect of this nutritional intervention.

Wine, alcohol and pills: What future for the French paradox?

The present review discusses the acquisitions obtained to date on the subject of wine consumption, health and cardiovascular protection. We distinguished the cardiovascular effects related to the consumption of wine and other alcoholic beverages focusing on non-alcoholic wine fraction: polyphenols and especially resveratrol. In the second part of the review we have addressed the issue of resveratrol bioavailability and the importance of wine matrix and phytocomplex highlighting the biological effects that can be obtained with nutraceuticals and resveratrol pills compared to the daily consumption of a glass of red wine.

Resveratrol-poor red wines modulate SIRT1 in human renal cells.

The cardioprotective and anti-aging effects of red wine phenols, especially resveratrol (RSV), are well known. One of the most interesting biological properties of RSV and other naturally occurring phenols is the regulation of the expression and activity of SIRT1 (silent mating type information regulation 2 homolog). In view of the role of SIRT1 in acute and chronic renal diseases, we decided to study the effects of RSV-poor red wines on the expression of SIRT1 and HIF-2α (hypoxia-inducible factor 2α) to be compared with a nanomolar concentration of RSV or malvidin in proximal tubular cells of human kidneys (PTEC). Survival signaling systems activation (extracellular signal-regulated kinases, ERK and AMP-activated protein kinase, AMPK) was also investigated in PTEC incubated with wines. PTEC cells were incubated in the presence of RSV-poor wines diluted 1:1,000 for 30', 90', 120' and 24 h. Expression of SIRT1 and HIF-2α, and activation of ERK and AMPK were analyzed by Western Blot. The data obtained show that wine modulates the expression of anti-aging molecular systems even when RSV is present in very small amounts.

Grapes, wines, resveratrol, and heart health.

Epidemiological and experimental studies have revealed that a mild to moderate drinking of wine, particularly red wine, attenuates the cardiovascular, cerebrovascular, and peripheral vascular risk. However, the experimental basis for such health benefits is not fully understood. The cardioprotective effect of wine has been attributed to both components of wine: the alcoholic portion and, more importantly, the alcohol-free portion containing antioxidants. Wines are manufactured from grapes, which also contain a large variety of antioxidants, including resveratrol, catechin, epicatechin, and proanthocyanidins. Resveratrol is mainly found in the grape skin, whereas proanthocyanidins are found only in the seeds. Recent studies have demonstrated that resveratrol and proanthocyanidin are the major compounds present in grapes and wines responsible for cardioprotection. The purpose of this review is to provide evidence that grapes, wines, and resveratrol are equally important in reducing the risk of morbidity and mortality due to cardiovascular complications. Both wines and grapes can attenuate cardiac diseases such as atherosclerosis and ischemic heart disease. Recently, wine was also found to increase life span by inducing longevity genes. It appears that resveratrol and proanthocyanidins, especially resveratrol, present in grapes and wines play a crucial role in cardioprotective abilities of grapes and wines.

Expression of the longevity proteins by both red and white wines and their cardioprotective components, resveratrol, tyrosol, and hydroxytyrosol.

Resveratrol increases longevity through SirT1, which is activated with NAD(+) supplied by an anti-aging enzyme PBEF. SirT1 interacts with an anti-aging transcription factor, FoxO1, which is negatively regulated by Akt. Since white wine could have similar health benefits as red wine, we determined if white wine and its cardioprotective components possess anti-aging properties by feeding rats with these compounds. The hearts expressed SirT, FoxO, and PBEF in the order of white wine>resveratrol>tyrosol>hydroxytyrosol>red wine, while cardioprotection shown by reduction of infarct size and cardiomyocyte apoptosis followed a different pattern: resveratrol>red wine>hydroxytyrosol>white wine>tyrosol, suggesting the existence of different signaling mechanisms for the induction of longevity and survival.

Does white wine qualify for French paradox? Comparison of the cardioprotective effects of red and white wines and their constituents: resveratrol, tyrosol, and hydroxytyrosol.

It is generally believed that the French paradox is related to the consumption of red wine and not other varieties of wine, including white wine or champagne. Some recent studies have indicated that white wine could also be as cardioprotective as red wine. The present investigation compares the cardioprotective abilities of red wine, white wine, and their principal cardioprotective constituents. Different groups of rats were gavaged with red wine, white wine, resveratrol, tyrosol, and hydroxytyrosol. Red wine and its constituent resveratrol and white wine and its constituents tyrosol and hydroxytyrosol all showed different degrees of cardioprotection as evidenced by their abilities to improve postischemic ventricular performance, reduce myocardial infarct size and cardiomyocyte apoptosis, and reduce peroxide formation. It was discovered in this study that although each of the wines and their components increased the enzymatic activities of the mitochondrial complex (I-IV) and citrate synthase, which play very important roles in oxidative phosphorylation and ATP synthesis, some of the groups were more complex-specific in inducing the activity compared to the other groups. Cardioprotective ability was further confirmed by increased expression of phospho-Akt, Bcl-2, eNOS, iNOS, COX-1, COX-2, Trx-1, Trx-2, and HO-1. The results of this study suggest that white wine can provide cardioprotection similar to red wine if it is rich in tyrosol and hydroxytyrosol.

White wine induced cardioprotection against ischemia-reperfusion injury is mediated by life extending Akt/FOXO3a/NFkappaB survival pathway.

Recent studies on the protection afforded by moderate wine consumption against cardiovascular diseases have focused mainly on the activity of red wine in view of its high content of antioxidants, especially polyphenols. White wine lacks polyphenols, but it contains other compounds such as hydroxycinnamic acids (caffeic acid) and monophenols (tyrosol), which are known to have antioxidant properties. Therefore, this study was designed to examine the effect of white wine in myocardial ischemic-reperfusion injury. The experimental rats were gavaged with white wine (Soave Suavia "Le Rive" 2004) at a dosage of 6.5 mL/(kg.rat.day) for 30 days. Rats were divided into four groups: control sham (CS), wine-treated sham (WS), control ischemia (I)/reperfusion (R) (CIR), and wine + IR (WIR). All the rats in both IR groups underwent 30 min occlusion of the left anterior descending coronary artery followed by 8, 24 h, and 30 days of reperfusion (R). Significant reduction in infarct size (21 vs 39%, n = 6), cardiomyocyte (274 vs 384 counts/100 HPF, n = 6), and endothelial cell apoptosis (387 vs 587 counts/100 HPF) was observed in WIR as compared with CIR after 24 h of reperfusion. Echocardiography demonstrated significant increased fractional shortening (32 vs 22%) and ejection fraction (60 vs 44%) following 30 days of reperfusion in WIR rats compared to CIR ( n = 6). In addition, increased phosphorylation of AKT, Foxo3a, and eNOS were found in WS and WIR, as compared to their respective controls. The gel-shift analysis demonstrated significant upregulation of DNA binding activity of NF-kappaB in the white wine-treated groups. This report demonstrated for the first time that the white wine mediated cardioprotection in ischemic reperfused myocardium is through the PI-3kinase/Akt/FOXO3a/e-NOS/NF-kappaB survival pathway.

Wine, research and cardiovascular disease: instructions for use.

The results of studies on the role of appropriate wine consumption in the prevention of cardiovascular disease are inconsistent, suggesting that the general approach to the issue needs to be revisited before further research is conducted. A number of points for consideration are raised: (1) the necessity to characterize wine analytically, as the content in important components of wine, such as resveratrol, is influenced considerably by regional factors, such as climate and local oenological procedures; (2) the bioavailability of the components of wine, which appears to be adequate as a broad range of biological effects have been documented at low concentrations that can be achieved by moderate chronic wine consumption; (3) the lack of importance of wine color, as also white wine consumption affords benefit, thanks to its content in the antioxidants caffeic acid, tyrosol and hydroxytyrosol, which are also found in olive oil; (4) the recommendation by WHO to "investigate the possible protective effects of ingredients other than alcohol in alcoholic beverages".

Early cytotoxic effects of ochratoxin A in rat liver: a morphological, biochemical and molecular study.

We characterized the overall early effect of chronic ochratoxin A (OTA) treatment on rat liver, analyzing different aspects related to: (i) fibrosis, by measuring collagen content and turnover, and alpha-smooth muscle actin (alphaSMA); (ii) oxidative stress and stress response, by analyzing protein carbonylation, superoxide dismutase (SOD) and heat shock protein (HSP70) gene expression; (iii) the possible tumor promoter effect, evaluating cadherin and connexin (CX) mRNA levels. Light microscopy analysis showed no histological differences in OTA-treated and control (CT) rats. Collagen content, determined by computer analysis of Sirius red-stained liver sections, was similar in both groups. In liver homogenates COL-I, COL-III, TIMP-1 and TGF-beta1 mRNA levels and alphaSMA were unaffected by OTA. Matrix metalloproteinase (MMP)-1, MMP-2 and MMP-9 protein levels were also similar in the two groups. Protein carbonylation, a marker of severe oxidative stress, was not evident in the homogenates of OTA-treated livers; superoxide dismutase (SOD) mRNA tended to be lower and HSP70 was strongly down-regulated. OTA reduced E-cadherin and DSC-2 transcription, and down-regulated liver CX26, CX32 and CX43. In conclusion, these in vivo results show that OTA-induced liver injury involves a reduction in the ability to counterbalance oxidative stress, maybe leading to altered gap junction intercellular communication and loss of cell adhesion and polarity. This suggests that mild oxidative damage might be a key factor, in combination with other cytotoxic effects, in triggering the promotion of liver tumors after exposure to OTA.

Effect of Ukrain on matrix metalloproteinase-2 and Secreted Protein Acidic and Rich in Cysteine (SPARC) expression in human glioblastoma cells.

Glioblastoma is a highly malignant brain tumor with a highly invasive phenotype and hence an unfavorable prognosis even in response to multidisciplinary treatment strategies. Ukrain, a semi-synthetic thiophosphoric acid derivative of the purified alkaloid chelidonine, has been used in the therapy of several solid tumors, but little is known about its effect on glioblastoma and, in general, about the molecular mechanisms responsible for its effects. We used RT-PCR, Western blot and SDS-zymography to investigate the effects of three doses of Ukrain (0.1, 1 and 10 micromol/l) on the expression of genes and proteins involved in the extracellular matrix remodeling associated with tumor invasion in human cultured glioblastoma cells treated for 24, 48 and 72 h. We analyzed the expression of matrix metalloproteinase-2 and -9, the main mediators of glioblastoma invasiveness, and secreted protein acidic and rich in cysteine (SPARC), involved in the regulation of cell-matrix interactions. There was a significant, dose-related decrease of glioblastoma cell proliferation and a tendency to downregulation of SPARC at the protein level 72 h after 10 micromol/l Ukrain, suggesting the drug may be a useful therapeutic tool for brain tumors.

Effect of resveratrol on matrix metalloproteinase-2 (MMP-2) and Secreted Protein Acidic and Rich in Cysteine (SPARC) on human cultured glioblastoma cells.

INTRODUCTION: Glioblastoma is a highly malignant brain tumor with a high-invasive phenotype, so the prognosis is unfavorable, even in response to multidisciplinary treatment strategies. Obviously, therefore, a better therapeutic strategy is needed. Resveratrol has been reported to be one of the most potent chemopreventive agents inhibiting the cellular processes associated with tumor development, including initiation, promotion, and progression. MATERIALS AND METHODS: In this study we used RT-PCR, western blot and SDS-zymography to investigate the effect of resveratrol on the expression of genes and proteins involved in the extracellular matrix remodeling associated with tumor invasion in human cultured glioblastoma cells treated for 24, 48 and 72 h. We analyzed the expression of matrix metalloproteinase-2 (MMP-2), the main mediator of glioblastoma invasiveness, and the Secreted Protein Acidic and Rich in Cysteine (SPARC), involved in the regulation of cell-matrix interactions. RESULTS: Our results show a dose-related decrease of MMP-2 mRNA and protein levels 72 h after resveratrol treatment, and lower SPARC gene and protein expression 72 h after resveratrol treatment. This indicates that resveratrol may influence the two major factors in the ECM remodeling occurring with tumor invasion, suggesting it may have uses as a therapeutic agent for brain tumors.

Effect of ethanol and red wine on ochratoxin a-induced experimental acute nephrotoxicity.

Ochratoxin A (OTA), is a nephrotoxic mycotoxin present in wine, which is nephrotoxic in humans. Our working hypothesis is that natural substances in wine may counteract OTA toxicity. Thirty-six rats were randomized to OTA dissolved in saline, red wine, or 13.5% ethanol or to OTA-free wine, ethanol, or saline. OTA (289 microg/kg of body weight/48 h) was administered by gastric gavage for 2 weeks. Serum creatinine, tubular enzymuria, renal lipohydroperoxides (LOOH), reduced (GSH) and oxidized (GSSG) glutathione, and renal superoxide dismutase activity (SOD) were determined in renal tissue. OTA alone produced significant increases in renal lipoperoxides and significant decreases in SOD and GSH/GSSG ratio. In red wine or ethanol, OTA was less nephrotoxic, reducing oxidative damage as revealed by LOOH. In OTA-wine and OTA-ethanol groups, SOD activity was higher than in the OTA-treated one, suggesting that both ethanol and nonalcoholic fractions may preserve antioxidant reserve. GSH/GSSG ratio was significantly preserved only in the OTA-wine group and not in OTA-ethanol. Red wine may exert a protective effect against OTA nephrotoxicity by limiting oxidative damage. The ostensible protection afforded by ethanol deserves further investigation.

Ochratoxin A-induced renal cortex fibrosis and epithelial-to-mesenchymal transition: molecular mechanisms of ochratoxin A-injury and potential effects of red wine.

We characterized the effect of chronic ochratoxin A (OTA) on rat kidney cortex, analyzing collagen content and collagen turnover and the major markers of epithelial-to-mesenchymal transition (EMT), such as alpha-smooth muscle actin (alphaSMA), cadherins, and MMP-9. Because OTA nephrotoxicity is mediated by free radicals, we also investigated whether antioxidants in red wine provided protection for the kidney and attenuated OTA-induced EMT. Collagen content, determined by computerized analysis of Sirius red-stained kidney sections, increased in OTA, OTA-wine, and OTA-EtOH treated rats. In kidney cortex homogenates, COL-I and COL-III mRNA levels tended to rise in OTA treated rats, but were similar to CT after OTA-wine and OTA-EtOH administration. TIMP-1 gene expression was up-regulated in OTA, OTA-wine, and OTA-EtOH treated rats. LH2b mRNA/COL-I mRNA was significantly up-regulated in OTA-wine and OTA-EtOH treated rats, compared with CT and OTA alone. TGF-beta1 signaling tended to dominate after OTA, OTA-wine, and OTA-EtOH. MMP-1 protein levels were not affected. OTA induced proMMP-9 and alphaSMA overexpression, decreases of E-cadherin and N-cadherin, and DSC-2 up-regulation. OTA-wine caused a further, unexpected decrease of E- and N-cadherins and further up-regulation of OTA-induced DSC-2, while strongly reducing the OTA-induced increases of alphaSMA and proMMP-9. Posttranslational collagen modifications, such as decreased collagen degradation through MMP inhibition and increased collagen cross-links, seem to be key mechanisms leading to OTA-induced kidney cortex fibrosis. This mechanism was not affected by red wine in these conditions. Red wine seems to have some protective role against OTA-induced EMT, although without completely blocking the process and determining a condition in which abundant cells display an intermediate translational phenotype, but there are no alphaSMA or epithelial markers.

Different short- and long-term effects of resveratrol on nuclear factor-kappaB phosphorylation and nuclear appearance in human endothelial cells.

BACKGROUND: Resveratrol (a naturally occurring phytoalexin found in grapes and wine) has cardiovascular protective effects that suggest the antiatherogenic (ie, antiinflammatory) activities of the compound on endothelial cells. OBJECTIVE: The antiinflammatory activity of resveratrol could be mediated by its interference with nuclear factor-kappaB (NF-kappaB)-dependent transcription. Thus, we studied the in vitro influence of physiologic concentrations of resveratrol (

Resveratrol provides late-phase cardioprotection by means of a nitric oxide- and adenosine-mediated mechanism.

We used two experimental models to prove that resveratrol (trans-3,4',5-trihydroxystilbene) reduces cardiac ischemic-reperfusion injury by means of a nitric oxide- and adenosine-dependent mechanism. (1). ACUTE EX VIVO: resveratrol (10 microM, 10 min) infusion in Langendorff-perfused normoxic rat hearts significantly increased adenosine release and coronary flow compared with baseline. After 30-min low-flow ischemia, vasodilation, still present at reperfusion, was completely abolished by resveratrol plus adenosine antagonist 8-(p-sulfophenyl)theophylline (SPT, 50 microM) administration. (2). CHRONIC IN VIVO: rats received tap water containing 25 mg/l resveratrol for 15 days or normal water. Twenty-four hours after, their hearts were Langendorff-perfused and submitted to 60-min low-flow ischemia and reperfusion. The resveratrol-treated hearts showed better functional recovery at reperfusion and significant vasodilation, but no variation in high-energy phosphates (31P Nuclear Magnetic Resonance). N(G)-nitro-L-arginine methyl ester (L-NAME, 30 microM), a nonselective nitric oxide synthase inhibitor, or SPT (50 microM) administered for 10 min prior to the low-flow ischemia cancelled the effects. This suggests that long-term moderate resveratrol consumption could play an important role in late cardioprotective effects.