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Mass spectrometry in grape and wine chemistry. Part I: polyphenols.

Mass spectrometry, had and still has, a very important role for research and quality control in the viticulture and enology field, and its analytical power is relevant for structural studies on aroma and polyphenolic compounds. Polyphenols are responsible for the taste and color of wine, and confer astringency and structure to the beverage. The knowledge of the anthocyanic structure is very important to predict the aging attitude of wine, and to attempt to resolve problems about color stability. Moreover, polyphenols are the main compounds related to the benefits of wine consumption in the diet, because of their properties in the treatment of circulatory disorders such as capillary fragility, peripheral chronic venous insufficiency, and microangiopathy of the retina. Liquid Chromatography-Mass Spectrometry (LC-MS) techniques are nowadays the best analytical approach to study polyphenols in grape extracts and wine, and are the most effective tool in the study of the structure of anthocyanins. The MS/MS approach is a very powerful tool that permits anthocyanin aglycone and sugar moiety characterization. LC-MS allows the characterization of complex structures of grape polyphenols, such as procyanidins, proanthocyanidins, prodelphinidins, and tannins, and provides experimental evidence for structures that were previously only hypothesized. The matrix-assisted-laser-desorption-ionization-time-of-flight (MALDI-TOF) technique is suitable to determine the presence of molecules of higher molecular weight with high accuracy, and it has been applied with success to study procyanidin oligomers up to heptamers in the reflectron mode, and up to nonamers in the linear mode. The levels of resveratrol in wine, an important polyphenol well-known for its beneficial effects, have been determined by SPME and LC-MS, and the former approach led to the best results in terms of sensitivity.

Agriculture↗
PubMed2005

Polyphenol profiles of apple juices.

Focusing on 17 constituents, the polyphenol profiles of juices freshly made from various dessert (n = 4) and cider apple cultivars (n = 7) as well as commercially available apple juices (n = 24) were investigated using high-performance liquid chromatography-photodiode array detection (HPLC-DAD) and (HPLC)-electrospray ionization-tandem mass spectrometry (ESI(neg)-MS/MS) analyses. Significant differences in the total polyphenol content as well as the profiles of the apple cultivars under study were observed. For dessert apples the total polyphenol content ranged from 154 to 178 mg/L, whereas for 'old' German cider apple cultivars 261-970 mg/L were determined. Boskoop showed the highest (970 mg/L) and Granny Smith the lowest (154 mg/L) polyphenol content of the freshly prepared samples under study. Hydroxycinnamic acids, with chlorogenic acid as dominating constituent, ranged from 57 to 68 mg/L as well as from 134-593 mg/L in juices made from dessert apples and that from cider apples, respectively. Dessert apple juices showed lower contents of dihydrochalcones (10-35 mg/L) and flavan-3-ols (50-95 mg/L) compared to that of cider apples (34-171 mg/L and 70-393 mg/L, respectively). Quercetin and its derivatives were found from 0.4-4 mg/L and 0.4-27 mg/L in juices made from dessert apples and that of cider apples, respectively. Compared with freshly made juices, lower contents of polyphenols were determined in the commercial samples under study. Amounts ranging from 110-459 mg/L, dominated by chlorogenic acid with concentrations from 53-217 mg/L, were determined. Information about cultivar-typical apple polyphenol content and profile is important for bioactivity studies and, consequently, essential for the development of consumer-relevant products with particular nutritional functionalities.

Beverages↗
PubMed2006

Studies on apple and blueberry fruit constituents: do the polyphenols reach the colon after ingestion?

The aim of our studies was to determine the amount of polyphenols reaching the colon after oral intake of apple juice and blueberries. After a polyphenol-free diet healthy ileostomy volunteers consumed a polyphenol-rich cloudy apple juice while others consumed anthocyanin-rich blueberries. Ileostomy effluent was collected and polyphenols were identified using HPLC-DAD as well as HPLC-ESI-MS/MS; quantification was performed with HPLC-DAD. Most of the orally administered apple polyphenols were absorbed from or metabolized in the small intestine. Between 0 and 33% of the oral dose was recovered in the ileostomy bags with a maximum of excretion after 2 h. A higher amount of the blueberry anthocyanins under study (up to 85%, depending on the sugar moiety) were determined in the ileostomy bags and therefore would reach the colon under physiological circumstances. Such structure-related availability has to be considered when polyphenols are used in model systems to study potential preventive effects in colorectal diseases.

Anthocyanins↗
PubMed2006

Intervention with polyphenol-rich fruit juices results in an elevation of glutathione S-transferase P1 (hGSTP1) protein expression in human leucocytes of healthy volunteers.

Polyphenols are probably antigenotoxic on account of their antioxidant activities and might alter phase I and II enzymes in a way that results in chemoprotection. We investigated the hypothesis that polyphenols enhance expression of glutathione S-transferases (GSTs), which increases carcinogen detoxification and thereby provides protection against oxidative stress. HGSTP1 protein expression and GST polymorphisms were determined in leucocytes obtained during an intervention study with healthy subjects consuming two fruit juices in an 8 wk trial (polyphenol-free run in phase, juice intervention phase, washout phase, second juice intervention phase, each treatment regime lasted for 2 wk). The study had originally shown that juice intervention significantly reduced oxidative DNA damage in leucocytes at week 8 (Bub, A., Watzl, B., Blockhaus, M., Briviba, K. et al., J. Nutr. Biochem. 2003, 14, 90-98). We reanalysed the levels of DNA damage based on GST genotypes. We also treated leucocytes in vitro with mixtures of polyphenols and determined cytotoxicity and expression of 96 genes related to drug metabolism. Key results with leucocytes of the intervention study were that the initial content of hGSTP1 protein was first suppressed at weeks 4 and 6. At week 8, however, hGSTP1 protein expression was significantly increased. HGSTP1 protein levels and DNA damage were inversely correlated (p = 0.005), but there was no difference for cells obtained from subjects with hGSTM1*1 and hGSTM1*0 genotypes, nor was there any difference between cells from subjects consuming the two different juices. The treatment of leucocytes with polyphenol mixtures in vitro did not result in modulated GST gene expression or total GST activity, but in an up-regulation of other biotransformation enzymes (e. g., members of the cytochrome P450 and the sulphotransferase family). In conclusion, in vitro treatment of leucocytes led to a modulated mRNA expression of selected genes, not directly related to oxidative defence systems. In vivo, however, we observed a delayed enhancement of hGSTP1, which could be associated with an initial repression of oxidative DNA damage in leucocytes from human subjects, consuming juices with high levels of polyphenols.

Adult↗
PubMed2003

Anti-obesity action of Salix matsudana leaves (Part 1). Anti-obesity action by polyphenols of Salix matsudana in high fat-diet treated rodent animals.

In preliminary experiments, polyphenol fractions prepared from the leaves of Salix matsudana reduced the elevation of the rat plasma triacylglycerol level at 3 and 4 h after oral administration of a lipid emulsion containing corn oil, at a dose of 570 mg/kg. The present study examined the anti-obesity action of polyphenol fractions of S. matsudana leaves by testing whether the polyphenol fractions prevented the obesity induced by feeding a high-fat diet to female mice for 9 weeks. Body weights at 2-9 weeks and the fi nal parametrial adipose tissue weights were significantly lower in mice fed the high-fat diet with 5% polyphenols of S. matsudana leaves than in those fed the high-fat diet alone. The polyphenols of S. matsudana leaves also significantly reduced the hepatic total cholesterol content, which was elevated in mice fed the high-fat diet alone. In addition, the polyphenol fractions of S. matsudana leaves inhibited palmitic acid uptake into brush border membrane vesicles prepared from rat jejunum and alpha-amylase activity, and their fractions enhanced norepinephrine-induced lipolysis in fat cells. In conclusion, it is suggested that the inhibitory effects of the flavonoid glycoside fraction of S. matsudana leaves on high-fat diet-induced obesity might be due to the inhibition of carbohydrate and lipid absorption from small intestine through the inhibition of alpha-amylase and palmitic acid uptake into small intestinal brush border membrane or by accelerating fat mobilization through enhancing norepinephrine-induced lipolysis in fat cells.

Adipocytes↗
PubMed2003

Anti-obesity action of Salix matsudana leaves (Part 2). Isolation of anti-obesity effectors from polyphenol fractions of Salix matsudana.

Previously, it was reported that polyphenol fractions prepared from the leaves of Salix matsudana reduced the elevation of the rat plasma triacylglycerol level at 3 and 4 h after oral administration of a lipid emulsion containing corn oil, at a dose of 570 mg/kg. Moreover, body weights at 2-9 weeks and the fi nal parametrial adipose tissue weights were significantly lower in mice fed the high-fat diet with 5% polyphenol fractions of S. matsudana leaves than in those fed the high-fat diet alone. The polyphenol fractions of S. matsudana leaves also significantly reduced the hepatic total cholesterol content, which was elevated in mice fed the high-fat diet alone. In addition, the polyphenol fractions of S. matsudana leaves inhibited palmitic acid uptake into brush border membrane vesicles prepared from rat jejunum and alpha-amylase activity, and their fractions enhanced norepinephrine-induced lipolysis in fat cells. To clarify the active substances inhibiting the palmitic acid uptake into small intestinal brush border membrane, the alpha-amylase activity or enhancing the norepinephrine-induced lipolyis in fat cells, the isolation of the active substances from polyphenol fraction was attempted using the above three assay systems. Compounds 1, 2 and 3 were isolated from the polyphenol fractions and identified as apigenin-7-O-d-glucoside, luteolin-7-O-d-glucoside and chrysoeriol-7-O-d-glucoside, respectively. Among three flavonoids, apigenin-7-O-d-glucoside inhibited alpha-amylase activity, and luteolin-7-O-d-glucoside and chrysoeriol-7-O-d-glucoside inhibited palmitic acid uptake into small intestinal brush border membrane. Furthermore, three flavonoid glucosides enhanced norepinephrine-induced lipolysis in fat cells.

Adipocytes↗
PubMed2003

Antiproliferative effect of antioxidant polyphenols from grape in murine Hepa-1c1c7.

BACKGROUND: Grapes and wine contain high concentrations of polyphenolic compounds. Although their cancer protective effect has been well documented, their activity as anticarcinogens should be cautiously considered since the molecular bases of action and their applicability to human cancer prevention are still unclear. AIM OF THE STUDY: We studied the antioxidant/antiradical activity and the antiproliferative effect in vitro of different polyphenolic mixtures, extracted from grapes and fractionated through RP-HPLC. METHODS: The polyphenolic fractions were chemically characterized and their antioxidant/antiradical activity was determined by the DPPH assay. Mouse hepatoma Hepa-1c1c7 cells were used to study the cell growth inhibition capacity of these fractions by MTT assay. Their capacity of altering cell cycle and possible induction of apoptosis was examined using FACS analysis. RESULTS: The original polyphenolic fraction OW, which contained gallic acid (GA), (+)-catechin (Cat), (-)-epicatechin (Ec), glycosylated flavonols (F) and procyanidin oligomers was fractionated into fraction I, composed of monomers and small oligomers, and fraction II that included flavonols and procyanidin oligomers of higher molecular weight. The three polyphenolic fractions tested showed quite similar antiradical activity, although fraction I was the most potent antiradical agent (lowest ED(50) value: 9 microg). Fraction II was the least potent cell growth inhibitor (highest IC(50) value: 100 microg/ml) but showed the strongest effect on the cell cycle of Hepa-1c1c7, inducing apoptosis in those cells. The original fraction OW was demonstrated to have the most potent cell growth inhibition effect (lowest IC(50) value: 43 microg/ml). However, it only appeared to alter cell cycle of Hepa-1c1c7 at concentrations higher than its IC(50) and did not induce apoptosis in those cells. A similar effect on cell cycle and apoptosis was encountered for fraction I. CONCLUSIONS: The polyphenolic fractions tested in this study were potent antiradical agents and exerted an antiproliferative effect in mouse hepatoma Hepa-1c1c7 cells; the fraction with the highest degree of polimerization and galloylation (fraction II) had the most influence on the cell cycle and induction of apoptosis on Hepa-1c1c7.

Animals↗
PubMed2004

Effect of polyphenolic extracts from red wine and 4-OH-coumaric acid on 1,2-dimethylhydrazine-induced colon carcinogenesis in rats.

BACKGROUND: Total polyphenolic extracts from red wine protect against azoxymethane (AOM)-induced colon carcinogenesis in rats. Since red wine contains more than 200 different polyphenolic compounds, it is still unclear which substances are responsible for this effect. AIM OF THE STUDY: We investigated the effect of high molecular weight polyphenols (HMWP), low molecular weight polyphenols (LMWP) and total polyphenolic extracts from red wine (WE) on colon carcinogenesis. We also tested the effect of 4-OH-coumaric acid, a potent phenolic antioxidant present in wine and fruit. METHODS: F344 rats were treated weekly with 1,2-dimethylhydrazine (DMH) (30 mg/kg b.w. subcutaneously x 10 times). One week after the final DMH injection rats were divided into five groups and fed: a) a high fat (HF) diet containing 23% corn oil (w/w), as control or the same basal diet supplemented with b) 0.11 % (w/w) WE; c) 0.027% (w/w) HMWP d) 0.083% (w/w) LMWP or e) 0.1 % (w/w) 4-OH-coumaric acid. The dietary treatments continued until sacrifice, 16 weeks after the last DMH injection. RESULTS: WE treated rats had significantly fewer (p < 0.05) colorectal adenomas than controls, while rats in other treatment groups did not differ significantly from controls (colorectal adenomas/rat were: 2.2 +/- 0.3; 1.4 +/- 0.2; 2.9 +/- 0.5; 2.6 +/- 0.4; 2.3 +/- 0.3; in controls, WE, HMWP, LMWP and 4-OH-coumaric acid groups, respectively; means +/- SE). The mean number of colorectal carcinomas per rat was similar among all experimental groups. Proliferative activity in the normal colon mucosa did not vary among experimental groups. CONCLUSIONS: Total polyphenolic extracts (WE) from red wine, but neither the HMWP nor the LMWP, have some inhibitory effect on the process of colon carcinogenesis by DMH reducing the number of adenomas.

1,2-Dimethylhydrazine↗
PubMed2006

Radioprotective properties of apple polyphenols: an in vitro study.

Present study was undertaken to evaluate the radioprotective ability of total polyphenols extracted from edible portion (epicarp and mesocarp) of apple. Prior administration of apple polyphenols to murine thymocytes significantly countered radiation induced DNA damage (evaluated by alkaline halo assay) and cell death (trypan blue exclusion method) in a dose dependent manner maximally at a concentration of 2 and 0.2 mg/ml respectively. Apple polyphenols in a dose dependent fashion inhibited both radiation or Fenton reaction mediated 2-deoxyribose (2-DR) degradation indicating its ability to scavenge hydroxyl radicals and this activity was found to be unaltered in presence of simulated gastric juice. Similarly apple polyphenols in a dose dependent fashion scavenged DPPH radicals (maximum 69% at 1 mg/ml), superoxide anions (maximum 88% at 2 mg/ml), reduced Fe(3 +) to Fe(2 +) (maximum at 1 mg/ml) and inhibited Fenton reaction mediated lipid peroxidation (maximum 66% at 1.5 mg/ml) further establishing its antioxidative properties. Studies carried out with plasmid DNA revealed the ability of apple polyphenols to inhibit radiation induced single as well as double strand breaks. The results clearly indicate that apple polyphenols have significant potential to protect cellular system from radiation induced damage and ability to scavenge free radicals might be playing an important role in its radioprotective manifestation.

Animals↗
PubMed2005

Quantitative structure-activity relationships in prooxidant cytotoxicity of polyphenols: role of potential of phenoxyl radical/phenol redox couple.

The aim of this work was to characterize the role of the potential of phenoxyl radical/phenol redox couple, E(7)(2), in the cytotoxicity of polyphenols. The cytotoxicity of polyphenols in bovine leukemia virus-transformed lamb kidney fibroblasts (line FLK), and human promyelocytic leukemia cells (line HL-60) was partly inhibited by catalase, by the antioxidant N,N'-diphenyl-p-phenylene diamine and desferrioxamine, and potentiated by 1,3-bis-(2-chloro-ethyl)-1-nitrosourea, thus showing its prooxidant character. Dapsone, an inhibitor of myeloperoxidase, did not affect the cytotoxicity of polyphenols in HL-60 cells, whereas dicumarol, an inhibitor of DT-diaphorase, showed controversial effects on their cytotoxicity in FLK cells. Inhibitors of cytochromes P-450, alpha-naphthoflavone and izoniazide, decreased the cytotoxicity of several polyphenols, whereas 3,5-dinitrocatechol, an inhibitor of catechol-o-methyltransferase (COMT), increased it. The cytotoxicity of 13 polyhydroxybenzenes was described by the equations: logcL50 (microM) = -0.67 + 5.46E(7)(2) (V) - 0.16 logD (FLK), and logcL50 (microM) = -1.39 + 6.90E(7)(2) (V) - 0.20logD (HL-60), where cL50 is compound concentration for 50% cell survival, and D is octanol/water distribution coefficient at pH 7.0. The flavonoids comprise a separate series of compounds with lower cytotoxicity. The correlations obtained quantitatively confirm the parallelism between the polyphenol cytotoxicity and the rates of their single-electron oxidation, and point to the leading role of formation of the reactive oxygen species in their cytotoxicity. Depending on the examined system, this parallelism may be distorted due to the cytochrome P-450 and COMT-catalyzed transformation of polyphenols.

Animals↗
PubMed2005

Role of peptide primary sequence in polyphenol-protein recognition: an example with neurotensin.

Polyphenols are known for their impact on health and one of their major properties is the formation of complexes with proteins. To investigate the involvement of polyphenol-protein complexes in health, the interactions between bioactive polyphenols and neurotensin were examined by structural NMR and molecular modeling. Neurotensin is a linear bioactive tridecapeptide and polyphenols seem to affect the NT metabolism. We studied the polyphenols resveratrol and its glucoside the piceid in order to observe the possible role of glucose group and the penta-O-galloyl-D-glucopyranose (PGG). NMR data and molecular modeling showed that interaction occurred with the three polyphenols involving hydrophobic stacking and hydrogen bonds. Moreover, the peptide primary sequence plays a role in the specificity of complex formation.

Amino Acid Sequence↗
PubMed2004

Polyphenol contents and antioxidant activity of Maydis stigma extracts.

The antioxidant activity and contents of various polyphenol classes in the silks of fifteen maize hybrids with economic importance in Serbia were evaluated. Total polyphenols, tannins and proanthocyanidins were determined spectrophotometrically, after extraction of plant material with 70% aqueous acetone under sonication at room temperature. In addition, flavonoid content was determined. Antioxidant activity of aqueous acetone extracts was evaluated by FRAP assay. A positive linear correlation between antioxidant activity and contents of all investigated polyphenol classes was established. The highest antioxidant activity was observed in the extract of NS 640 hybrid, which had high levels of all polyphenol classes examined. Results suggested strongly that polyphenol content should be considered as an important feature of the herbal drug Maydis stigma. For that reason, the biological source of this herbal drug needs to be more precisely defined, as observed activities and polyphenol contents were greatly dependent on plant material source.

Antioxidants↗
PubMed2006

Red wine polyphenols prevent angiotensin II-induced hypertension and endothelial dysfunction in rats: role of NADPH oxidase.

OBJECTIVE: Chronic administration of moderate amounts of red wine has been associated with a protective effect on the cardiovascular system. This study examined whether red wine polyphenols prevent the angiotensin II (Ang II)-induced hypertension and endothelial dysfunction in rats, and, if so, to elucidate the underlying mechanism. METHODS: Hypertensive rats were obtained by a 14-day infusion of Ang II. Red wine polyphenols were administered in the drinking water one week before and during the Ang II infusion. Arterial pressure was measured in conscious rats. Ex vivo vascular relaxation was assessed in organ chambers, vascular superoxide anion production by dihydroethidine and vascular NADPH oxidase expression by immunohistochemistry. RESULTS: Ang II-induced hypertension was associated with decreased relaxation to acetylcholine but not to red wine polyphenols. The Ang II treatment also increased vascular superoxide anion production and expression of nox1 and p22phox NADPH oxidase subunits. Intake of red wine polyphenols prevented the Ang II-induced hypertension and endothelial dysfunction and normalized vascular superoxide anion production and NADPH oxidase subunit expression. Red wine polyphenol treatment alone did not affect blood pressure. CONCLUSION: Intake of red wine polyphenols prevents Ang II-induced hypertension and endothelial dysfunction. Prevention of vascular NADPH oxidase induction and preservation of arterial nitric oxide availability during Ang II administration likely contribute to this effect.

Acetylcholine↗
PubMed2006

Antiproliferative effect of polyphenols and sterols of virgin argan oil on human prostate cancer cell lines.

BACKGROUND: The aim of our study has to evaluate the antiproliferative effect of polyphenols and sterols extracted from the virgin argan oil on three human prostatic cell lines (DU145, LNCaP, and PC3). METHODS: Cytotoxicity, anti-proliferative effects and nuclear morphological changes of cells were analyzed after treatment with sterols and polyphenols. The results were compared to 2-methoxyestradiol (2ME(2)) as positive control. RESULTS: Polyphenols and sterols of virgin argan oil and 2ME(2) exhibited a dose-response cytotoxic effect and antiproliferative action on the three tested cell lines. The antiproliferative effect of polyphenols was similar for the DU145 and LNCaP cell lines; the GI(50) (defined as the concentration inhibiting growth by 50% in comparison with the control) was respectively 73 and 70microg/ml. The antiproliferative effect of sterols was 46 and 60microg/ml as GI(50) for the DU145 and LNCaP cell lines. For the PC3 cell line, the best antiproliferative effect was obtained by argan sterols with GI(50)=43microg/ml. On the other hand, the nuclear morphology analyses have shown an increased proportion of pro-apoptotic of nuclei in LNCaP cell treated with IC(50) of polyphenols or sterols compared to control cells. Our results show for the first time the antiproliferative and pro-apoptotic effects of polyphenols and sterols extracted from virgin argan oil and confirm the antiproliferative and pro-apoptotic effects of 2ME(2) on prostate cancer cell lines. CONCLUSION: These data suggest that argan oil may be interesting in the development of new strategies for prostate cancer prevention.

2-Methoxyestradiol↗
PubMed2004

Black tea polyphenol theaflavins inhibit aromatase activity and attenuate tamoxifen resistance in HER2/neu-transfected human breast cancer cells through tyrosine kinase suppression.

The aromatase enzyme, which converts androstenedione to oestrone, regulates the availability of oestrogen to support the growth of hormone-dependent breast tumours. In this study, we investigated the inhibitory effects of black tea polyphenols on aromatase activities. We found that black tea polyphenols, TF-1, TF-2 and TF-3, significantly inhibited rat ovarian and human placental aromatase activities. In addition, using an in vivo model, these black tea polyphenols also inhibited the proliferation induced by 100 nM dehydroepiandrosterone (DHEA) in MCF-7 cells. Transfection of HER2/neu in MCF-7 breast cancer cells appeared to be associated with an increased resistance of the cells to hormonal therapy. Interestingly, unlike the selective oestrogen receptor modulator (SERM) tamoxifen, black tea polyphenols had antiproliferation effects in breast cancer cells with hormonal resistance. The inhibitory effect of black tea polyphenols on hormone-resistant breast cancer cells suppressed the basal receptor tyrosine phosphorylation in HER2/neu-overexpressing MCF-7 cells. These findings suggest the use of black tea polyphenols may be beneficial in the chemoprevention of hormone-dependent breast tumours and represent a possible remedy to overcome hormonal resistance of hormone-independent breast tumours.

Animals↗
PubMed2004

Vascular protection by dietary polyphenols.

Consumption of polyphenol-rich foods, such as fruits and vegetables, and beverages derived from plants, such as cocoa, red wine and tea, may represent a beneficial diet in terms of cardiovascular protection. Indeed, epidemiological studies demonstrate a significant inverse correlation between polyphenol consumption and cardiovascular risk. Among the numerous plausible mechanisms by which polyphenols may confer cardiovascular protection, improvement of the endothelial function and inhibition of angiogenesis and cell migration and proliferation in blood vessels have been the focus of recent studies. These studies have indicated that, in addition to and independently from their antioxidant effects, plant polyphenols (1) enhance the production of vasodilating factors [nitric oxide (NO), endothelium-derived hyperpolarizing factor (EDHF) and prostacyclin] and inhibit the synthesis of vasoconstrictor endothelin-1 in endothelial cells; and (2) inhibit the expression of two major pro-angiogenic factors, vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2 (MMP-2) in smooth muscle cells. The mechanisms of these effects involve: (1) in endothelial cells, increased Ca(2+) level and redox-sensitive activation of the phosphoinositide 3 (PI3)-kinase/Akt pathway (leading to rapid and sustained activation of nitric oxide synthase and formation of EDHF) and enhanced expression of nitric oxide synthase; and (2) in smooth muscle cells, both redox-sensitive inhibition of the p38 mitogen-activated protein kinase (p38 MAPK) pathway activation (leading to inhibition of platelet-derived growth factor (PDGF)-induced VEGF gene expression) and redox-insensitive mechanisms (leading to inhibition of thrombin-induced MMP-2 formation). The current evidence suggests that all these mechanisms are triggered by polyphenols with specific structures, although the structural requirements may be different from one effect to the other, and that they all contribute to the vasoprotective, anti-angiogenic, anti-atherogenic, vasorelaxant and anti-hypertensive effects of acute or chronic administration of plant polyphenols found in vivo in animals and in patients.

Angiogenesis Inhibitors↗
PubMed2005

Apoptotic effect of red wine polyphenols on human colon cancer SNU-C4 cells.

Polyphenols in fruits, soybean, vegetables, herbs, roots and leaves act as bioactive components related with prevention of cancer, heart diseases and diabetes. We investigated the apoptotic effects of polyphenols from red wine on human colon cancer cells SNU-C4 using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, reverse transcription-polymerase chain reaction (RT-PCR) expressions of Bcl-2, Bax and Caspase-3 genes, and Caspase-3 enzyme activity. Polyphenols (100 microg/ml) increased the apoptosis of SNU-C4 cells with apparent apoptotic characteristics including morphological changes of chromatin condensation and apoptotic body formation from DAPI staining and TUNEL assay. Compared with untreated control group, polyphenols (100 microg/ml) reduced the expression of Bcl-2 whereas those of Bax and Caspase-3 were increased. The Caspase-3 activity in the polyphenols treated group was significantly increased compared to those in control group (P<0.05). These results suggest that polyphenols have a strong potential for development as an anti-colon cancer agent.

Apoptosis↗
PubMed2004

Polyphenols from Camellia sinenesis prevent primary graft failure after transplantation of ethanol-induced fatty livers from rats.

Fatty liver caused by ethanol decreases survival after liver transplantation in rats. This study investigated if antioxidant polyphenols from Camellia sinenesis (green tea) prevent failure of fatty grafts from ethanol-treated rats. Donor rats were given ethanol intragastrically (6 g/kg). After 20 h, livers were explanted and stored in University of Wisconsin solution for 24 h. Prior to implantation, the explanted grafts were rinsed with lactated Ringer's solution containing 0 to 60 microg/ml polyphenols. Alanine aminotransferase (ALT) release after liver transplantation was 4.5-fold higher in recipients receiving ethanol-induced fatty grafts than in those receiving normal grafts. Liver grafts from ethanol-treated donors also developed severe focal necrosis. Graft survival was 11% in the ethanol group versus 88% for normal grafts. Polyphenol treatment at 60 microg/ml blunted ALT release by 66%, decreased necrotic areas by 84%, and increased survival to 75%. Ethanol increased alpha-(4-pyridyl-1-oxide)-N-tert.-butylnitrone free radical adducts in bile by 2.5-fold, as measured by electron spin resonance spectroscopy, and caused accumulation of 4-hydroxynonenal in liver sections, effects blunted by polyphenols. Epicatechin gallate, a major polyphenol from C. sinenesis, also decreased enzyme release, minimized pathological changes, and decreased free radical adduct formation. In conclusion, polyphenols scavenged free radicals in ethanol-induced fatty livers and decreased injury after liver transplantation.

Alanine Transaminase↗