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Polyphenolic Compounds (polyphenolic + compound)
Selected AbstractsPutative Mechanism for Anticancer and Apoptosis-Inducing Properties of Plant-Derived Polyphenolic CompoundsIUBMB LIFE, Issue 3 2000S. M. Hadi Abstract Several plant-derived polyphenolic compounds are considered to possess anticancer and apoptosis-inducing properties in cancer cells. Such compounds are recognized as naturally occurring antioxidants but also exhibit prooxidant properties under appropriate conditions. Evidence in the literature suggests that the antioxidant properties of polyphenolics such as gallotannins, curcumin, and resveratrol may not fully account for their chemopreventive effects. We propose a mechanism for the cytotoxic action of these compounds against cancer cells that involves mobilization of endogenous copper and the consequent prooxidant action. [source] Antioxidant Properties of Natural Plant Extracts Containing Polyphenolic Compounds in Cooked Ground BeefJOURNAL OF FOOD SCIENCE, Issue 4 2002J. Ahn ABSTRACT Thiobarbituric acid-reactive substances (TBARS) values, hexanal content, and sensory analysis were used to evaluate the effectiveness of selected natural antioxidants to reduce warmed-over flavor (WOF) development in cooked ground beef. The control without added antioxidant showed the highest TBARS value, hexanal content, and WOF scores. Grape seed extract (ActiVinTM) and pine bark extract (Pycnogenol®) significantly improved the oxidative stability of cooked beef. Compared to the control, ActiVinTM, Pycnogenol®, and oleoresin rosemary reduced the hexanal content by 97%, 94% and 73% after 3 d of refrigerated storage, respectively. WOF scores showed a similar pattern as TBARS values and hexanal contents. TBARS values, WOF scores, and hexanal contents were all well correlated. [source] Fluorescence Resonance Energy Transfer Between Polyphenolic Compounds and Riboflavin Indicates a Possible Accessory Photoreceptor Function for Some Polyphenolic CompoundsPHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 5 2006Kumar Chandrakuntal ABSTRACT The photoreceptive extreme tip of the wheat coleoptile exhibits intense green-yellow fluorescence under UV light, suggesting the presence of UV-absorbing materials. Fluorescence spectra of the intact coleoptile tip and tip homogenate showed the presence of the known photoreceptor pigments flavin and carotene, and a preponderance of phenolic compounds. Absorption spectra and fluorescence spectra of various phenolic compounds showed close overlap with the absorption and fluorescence spectra of the wheat coleoptile tip homogenate. Fluorescence spectra of several phenolic compounds showed close overlap with the absorption bands of flavin, carotene and pterine, suggesting possible energy transduction from phenols to these photoreceptors. Excitation of gentisic acid and ferulic acid with 340 nm light in the presence of flavin showed enhancement of flavin fluorescence in a concentration- and viscosity-dependent fashion, indicating fluorescence resonance energy transfer between them and riboflavin. Furthermore, several phenolic compounds tested generated superoxide anion on excitation at 340 nm, suggesting that superoxide-dependent signal cascades could operate in a polyphenol-mediated pathway. Phenolic compounds thus may act as accessory photoreceptors bringing about excitation energy transfer to the reactive photoreceptor molecules, or they may take over the function of the normal photoreceptor in genetic mutations lacking the system, or both processes may occur. The responses of plants to UV-B and UV-A light in mutants may be explained in terms of various phenolics acting as energy transducers in photoreceptor functioning. [source] Targeting the development of resveratrol as a chemopreventive agent,DRUG DEVELOPMENT RESEARCH, Issue 6 2010Nian-Guang Li Abstract Tumor development consists of several separate, but closely linked, stages: tumor initiation, promotion, and progression. This long and complex process provides opportunities for intervention both in preventing cancer initiation and in treating the neoplasm during its premalignant stages. Resveratrol, a polyphenolic compound found in many plant species, including grapes, peanuts, and various herbs, has recently been investigated intensely for its cancer chemopreventive property. The present work is an overview of the chemopreventive mechanisms of resveratrol in anti-initiation, anti-promotion, and anti-progression. These, together with the low toxicity of resveratrol, suggest promise for novel chemopreventive agents. However, the low bioavailability and rapid clearance of resveratrol from the circulation require the design of new resveratrol-like chemopreventive agents, the structural modifications and the structure,activity relationship of which are also discussed in this review. Drug Dev Res 71:335,350, 2010. © 2010 Wiley-Liss, Inc. [source] Modulatory potential of ellagic acid, a natural plant polyphenol on altered lipid profile and lipid peroxidation status during alcohol-induced toxicity: A pathohistological studyJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 2 2008Nagarajan Devipriya Abstract Polyphenol-rich dietary foodstuffs, consumed as an integral part of vegetables, fruits, and beverages have attracted attention due to their antioxidant and anticancer properties. Ellagic acid (EA), a polyphenolic compound widely distributed in fruits and nuts, has been reported to scavenge free radicals and inhibit lipid peroxidation. Chronic consumption of alcohol potentially results in serious illness including hepatitis, fatty liver, hypertriglyceridemia, and cirrhosis. A little is known about the influence of EA on alcohol toxicity in vivo. Accordingly, in the present study, we have evaluated the protective effects of EA on lipid peroxidation and lipid levels during alcohol-induced toxicity in experimental rats. Forty female albino Wistar rats, which were weighing between 150,170 g were used for the study. The toxicity was induced by administration of 20% alcohol orally (7.9 g/kg body wt.) for 45 days. Rats were treated with EA at three different doses (30, 60, and 90 mg/kg body wt.) via intragastric intubations together with alcohol. At the end of experimental duration, liver marker enzymes (i.e., aspartate transaminase, alanine transaminase), lipid peroxidative indices (i.e., thiobarbituriacid reactive substances and hydroperoxides) in plasma, and lipid levels (i.e., cholesterol, free fatty acids, triglycerides and phospholipids) in tissues were analyzed to evaluate the antiperoxidative and antilipidemic effects of EA. Liver marker enzymes, lipid peroxidative indices, and lipid levels, i.e., cholesterol, triglycerides and free fatty acids, were significantly increased whereas phospholipid levels were significantly decreased in the alcohol-administered group. EA treatment resulted in positive modulation of marker enzymes, peroxidative indices, and lipid levels. EA at the dose of 60 mg/kg body wt. was found to be more effective when compared to the other two doses. Histological changes observed were also inconsistent with the biochemical parameters. Our study suggests that EA exerts beneficial effects at the dosage of 60 mg/kg body wt. against alcohol-induced damage, and it can be used as a potential drug for the treatment of alcohol-abuse ailments in the near future. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:101,112, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20226 [source] Lipid-lowering efficacy of 3,4-di(OH)-phenylpropionic L -leucine in high-cholesterol fed ratsJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 1 2005Soon-Ja Kim Abstract A preliminary study revealed that 3,4-di(OH)-hydrocinnamate (HC), a polyphenolic compound, lowered the plasma lipids in high-cholesterol fed rats. Accordingly, this study was designed to test the lipid-lowering efficacy of a synthetic derivative, 3,4-di(OH)-phenylpropionic (L -leucine) amide (PPLA), in rats fed a high-cholesterol (1%, wt/wt) diet. As such, HC or PPLA was given as supplement to a high-cholesterol diet for 6 weeks at a dose of 0.137 mmol/100 g diet. The supplementation of HC and PPLA significantly lowered the plasma and hepatic cholesterol and triglyceride levels compared to the control group. The activities of hepatic HMG-CoA reductase (164 ± 9.12 and 124.74 ± 17.09 pmol/min/mg protein vs. 245.41 ± 13.01 pmol/min/mg protein, p < 0.05) and ACAT (411.49 ± 11.48 and 334.35 ± 17.68 pmol/min/mg protein vs. 490.41 ± 16.69 pmol/min/mg protein, p < 0.05) were significantly lower in the HC- and PPLA-supplemented groups than in the control group. However, PPLA was more effective in inhibiting the enzyme activities than HC. The excretion of neutral sterol was significantly higher in HC- and PPLA-supplemented groups than in the control group. Therefore, these results indicate that PPLA, a leucine-attached version of HC, exhibited a similar significant hypocholesterolemic effect to HC in rats fed a high-cholesterol diet. © 2005 Wiley Periodicals, Inc. J Biochem Mol Toxicol 19:25,31, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20054 [source] Molecular targets for the cancer preventive activity of tea polyphenolsMOLECULAR CARCINOGENESIS, Issue 6 2006Chung S. Yang Abstract Inhibition of carcinogenesis by tea and tea polyphenols has been demonstrated in many animal models. The mechanisms of action have been extensively investigated mostly in cell culture systems with (-)-epigallocatechin-3-gallate (EGCG), the most active and major polyphenolic compound from green tea. However, the mechanisms of cancer preventive activity by tea and tea polyphenols are not clearly understood. This article discusses some of the reported mechanisms and possible targets for the action of EGCG. The difficulties and major issues in extrapolating data from studies in cancer cell lines to cancer prevention mechanisms are discussed. Activities observed in cell culture with high concentrations of EGCG may not be relevant because of the limited systemic bioavailability of EGCG. In addition, possible artifacts due to the auto-oxidation of EGCG may complicate this issue. Some recent studies revealed high-affinity EGCG binding proteins as possible direct targets for the action of EGCG. Validating the related cancer preventive mechanisms found in in vitro studies in animal models and human samples would be exciting. © 2006 Wiley-Liss, Inc. [source] Protective effect of resveratrol on markers of oxidative stress in human erythrocytes subjected to in vitro oxidative insultPHYTOTHERAPY RESEARCH, Issue S1 2010Kanti Bhooshan Pandey Abstract Resveratrol is a natural polyphenolic compound found largely in the skin of red grapes. Growing evidence suggests that resveratrol may play an important role in the prevention of many human diseases. Many of the biological actions of this polyphenol have been attributed to its antioxidant properties. The present study was undertaken to evaluate the effect of resveratrol on intracellular reduced glutathione (GSH) and membrane sulphydryl groups in erythrocytes subjected to oxidative stress in vitro by incubating with t-BHP (10 µm). The study was aimed to test the efficacy of the antioxidant effect of resveratrol on human erythrocytes. Subjecting erythrocytes to oxidative stress (in vitro) by incubating them with t-BHP (10 µm) caused a significant decrease in the intracellular GSH level and membrane ,SH content compared with basal values. Incubation of erythrocytes/membranes with resveratrol (1,100 µm final conc) resulted in significant protection against the t-BHP-induced oxidative stress as evidenced by the increase in GSH level and membrane ,SH content. It was observed that the effect of resveratrol is dose/concentration and time-dependent. Since resveratrol is naturally present in many fruits and vegetables, a diet rich in resveratrol may provide protection against degenerative diseases. Copyright © 2009 John Wiley & Sons, Ltd. [source] Lowering seed gossypol content in glanded cotton (Gossypium hirsutum L.) linesPLANT BREEDING, Issue 6 2008G. B. Romano Abstract Cottonseed is a rich source of high quality protein, but its value as an animal feed is limited by gossypol, a toxic polyphenolic compound contained in glands located throughout the plant. This compound helps protect the plant from pests. Totally glandless varieties have been developed, but not adopted as these plants are left vulnerable to pests. This study describes a breeding strategy to decrease the levels of gossypol in the seed while maintaining a high enough concentration of toxin in vegetative plant parts to offer protection from pests. Preliminary studies indicated that crosses between varieties with different gland densities and distributions produced a range of glanding patterns. By selecting within the resulting progeny, we have identified F7 generation progeny that have <0.30% total gossypol in the seed, while still possessing glands at critical locations on the vegetative plant parts. These new lines will be a valuable source of germplasm for developing low seed gossypol varieties. Seed from these varieties would provide a new source of inexpensive protein for animal feeding rations. [source] Electroanalytical Approach to Evaluate Antioxidant Capacity in Honeys: Proposal of an Antioxidant IndexELECTROANALYSIS, Issue 18 2006Mónica Ávila Abstract A novel electrochemical route to estimate the antioxidant capacity in honey samples is proposed just using flow injection analysis. The analytical strategy involved the selective oxidation of polyphenolic compounds using two different target potentials, +0.8 and +0.5,V, at two different pHs. An oxidation current obtained at the fixed potential was used as an analytical guide of the antioxidant activity of the target honeys. Chemometrics (correlation and principal component analysis, PCA) demonstrated the significance of the electrochemical protocol versus the traditional spectrophotometric ones in the evaluation of antioxidant capacity and revealed the role of detection potential as a screening variable. The proposed protocol is very simple and fast. However, the most relevant merit of the electrochemical procedure is its inherent versatility which allows the evaluation of the antioxidant activity under predesigned controlled oxidation conditions. In addition, since intercept was statistically zero, its corresponding antioxidant content using just a calibration factor is proposed thus simplifying the calibration-analysis process. As a result, an electrochemical antioxidant index (EAI) is proposed. [source] "In-gel patch electrophoresis:" A,new method for environmental DNA purificationELECTROPHORESIS, Issue 16 2005Changhyun Roh Abstract Most of the microorganism species are largely untapped and could represent an interesting reservoir of genes useful for biotechnological applications. Unfortunately, a major difficulty associated with the methods used to isolate environmental DNA is related to the contamination of the extracted material with humic substances. These polyphenolic compounds inhibit the DNA processing reactions and severely impede cloning procedures. In this work, we describe a rapid, simple, and efficient method for the purification of genomic DNA from environmental samples: we added a chromatography step directly embedded into an agarose gel electrophoresis. This strategy enabled the DNA extraction from various environmental samples and it appeared that the purity grade was compatible with digestion by restriction enzymes and polymerase chain reaction (PCR) amplifications. [source] Nonaqueous capillary electrophoretic separation of polyphenolic compounds in wine using coated capillaries at high pH in methanolELECTROPHORESIS, Issue 24 2003Zuzana Demianová Abstract Nonaqueous capillary electrophoretic separation of a group of flavonoids (quercetin, myricetin, catechin, epicatechin) and resveratrol in wine was investigated in methanol at high pH. Malonate background electrolyte (pH* 13.5, ionic strength I = 14.2 mmol/L) provided highly repeatable separations of the analytes. Tests of untreated and coated (poly(glycidylmethacrylate- co - N -vinylpyrrolidone)) capillaries showed the analysis to be faster (6.5 min vs. 25 min) and the repeatability better in the coated capillaries. The coating procedure was simple and highly repeatable and the coating was stable during 40,45 runs. Determination of the last migrating peaks (epicatechin, resveratrol and catechin) was achieved merely by evaporating the wine samples and reconstituting the residue in methanol. For determination of the first migrating peaks (quercetin and myricetin) the samples were submitted to solid-phase extraction in C8 cartridges. [source] Antimutagenicity of green tea polyphenols in the liver of transgenic medakaENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 2 2005Richard N. Winn Abstract We examined the ability of a mixture of the predominant green tea polyphenolic compounds (GTP) to reduce benzo[a]pyrene (B[a]P)-induced mutations in the cII gene of the , transgenic medaka. Fish were treated with 50 ppb B[a]P for 24 hr, followed by exposure to 2 ppm or 10 ppm GTP for 28 days. cII mutations in livers of fish exposed to B[a]P were increased significantly, 2.6-fold above controls. In contrast, the addition of GTP significantly reduced the frequency of cII mutants by 84%, comparable to that of controls. The frequencies of mutations at G:C basepairs, mutations that are highly characteristic of B[a]P exposure, were elevated significantly in treated fish. By comparison, B[a]P-exposed fish also treated with GTP showed reductions in these mutations, demonstrating a protective effect of GTP against B[a]P-induced mutagenesis. The antioxidant mechanism of GTP possibly played an important role in the reduction of B[a]P mutagenicity. These results corroborate findings from rodent models, showing that the protective effects of green tea extend to different species, and suggesting that similar mechanisms of B[a]P mutagenesis and GTP antimutagenesis are shared among the models. These studies illustrate the utility of , transgenic medaka for in vivo mutation analyses and suggest that this fish may be a valuable model in chemoprevention studies. Environ. Mol. Mutagen., 2005. © 2005 Wiley-Liss, Inc. [source] Free radicals, antioxidants, and soil organic matter recalcitranceEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2006D. L. Rimmer Summary Highly reactive, and potentially damaging, free radicals are readily generated in our oxygen-rich environment, and are ubiquitous in biological systems. However, plants and animals have evolved protection against them with a range of antioxidant molecules, such as vitamins C and E, many of which are phenolic compounds. These stop the destructive chain reaction of free radical formation by being transformed into unreactive, stable free radicals. The biodegradation of food involves oxidation by free radicals, and is retarded by antioxidants. Similarly, the biodegradation of plant residues in soils involves free radicals; so the questions arise: (i) do soils have antioxidants, and (ii) what function might they have? The evidence suggests that they probably do have antioxidants. First, plant and animal remains added to soils will contain antioxidants. These are likely to persist for a time, particularly tannins, which are polyphenolic compounds with known antioxidant properties and which are relatively resistant to degradation. Second, studies using electron spin resonance spectroscopy have shown that humic materials contain stable semiquinone free radicals, and that their concentration increases as humification progresses. These semiquinone species are most likely to be derived from the reaction of phenolic compounds with reactive radicals. If this is the case, the phenolics are acting as antioxidants, because they are scavenging the reactive free radicals and terminating the oxidative chain reaction responsible for soil organic matter (SOM) degradation. Thus the soil's antioxidant capacity could control the rate of breakdown of organic matter in the more labile pools and could provide a chemical mechanism for the recalcitrance of SOM. Current available evidence for the nature of the recalcitrant pool in SOM is discussed in the light of this hypothesis, and the experimental approaches necessary for testing it are outlined. [source] Role of laccase in the biology and virulence of Cryptococcus neoformansFEMS YEAST RESEARCH, Issue 1 2004Xudong Zhu Abstract Laccase is an important virulence factor for the human pathogen, Cryptococcus neoformans. In this review, we examine the structural, biological and genetic features of the enzyme and its role in the pathogenesis of cryptococcosis. Laccase is expressed in C. neoformans as a cell wall enzyme that possesses a broad spectrum of activity oxidizing both polyphenolic compounds and iron. Two paralogs, CNLAC1 and CNLAC2, are present in the fungus, of which the first one expresses the dominant enzyme activity under glucose starvation conditions. Regulation of the enzyme is in response to various environmental signals including nutrient starvation, the presence of multivalent cations and temperature stress, and is mediated through multiple signal transduction pathways. Study of the function and regulation of this important virulence factor has led to further understanding of mechanisms of fungal pathogenesis and the regulation of stress response in the host cell environment. [source] The combination of epigallocatechin gallate and curcumin suppresses ER,-breast cancer cell growth in vitro and in vivoINTERNATIONAL JOURNAL OF CANCER, Issue 9 2008Tiffany J. Somers-Edgar Abstract Both epigallocatechin gallate (EGCG) and curcumin have shown efficacy in various in vivo and in vitro models of cancer. This study was designed to determine the efficacy of these naturally derived polyphenolic compounds in vitro and in vivo, when given in combination. Studies in MDA-MB-231 cells demonstrated that EGCG + curcumin was synergistically cytotoxic and that this correlated with G2/M-phase cell cycle arrest. After 12 hr, EGCG (25 ,M) + curcumin (3 ,M) increased the proportion of cells in G2/M-phase to 263 ± 16% of control and this correlated with a 50 ± 4% decrease in cell number compared to control. To determine if this in vitro result would translate in vivo, athymic nude female mice were implanted with MDA-MB-231 cells and treated with curcumin (200 mg/kg/day, po), EGCG (25 mg/kg/day, ip), EGCG + curcumin, or vehicle control (5 ml/kg/day, po) for 10 weeks. Tumor volume in the EGCG + curcumin treated mice decreased 49% compared to vehicle control mice (p < 0.05), which correlated with a 78 ± 6% decrease in levels of VEGFR-1 protein expression in the tumors. Curcumin treatment significantly decreased tumor protein levels of EGFR and Akt, however the expression of these proteins was not further decreased following combination treatment. Therefore, these results demonstrate that the combination of EGCG and curcumin is efficacious in both in vitro and in vivo models of ER,- breast cancer and that regulation of VEGFR-1 may play a key role in this effect. © 2007 Wiley-Liss, Inc. [source] Putative Mechanism for Anticancer and Apoptosis-Inducing Properties of Plant-Derived Polyphenolic CompoundsIUBMB LIFE, Issue 3 2000S. M. Hadi Abstract Several plant-derived polyphenolic compounds are considered to possess anticancer and apoptosis-inducing properties in cancer cells. Such compounds are recognized as naturally occurring antioxidants but also exhibit prooxidant properties under appropriate conditions. Evidence in the literature suggests that the antioxidant properties of polyphenolics such as gallotannins, curcumin, and resveratrol may not fully account for their chemopreventive effects. We propose a mechanism for the cytotoxic action of these compounds against cancer cells that involves mobilization of endogenous copper and the consequent prooxidant action. [source] Red wine polyphenolic compounds inhibit tracheal smooth muscle contraction during allergen-induced hyperreactivity of the airwaysJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 5 2007Sona Franova The aims of the study were to investigate the short and long-term effects of Provinol (red wine polyphenolic compounds) on tracheal smooth muscle reactivity using an in-vitro model of ovalbumin-induced airway inflammation in guinea-pig trachea, and to evaluate the role of nitric oxide (NO) in the bronchodilatory effect of Provinol. The amplitude of tracheal smooth muscle contraction in response to mediators of bronchoconstriction ,histamine (10 nM-1 mM), acetylcholine (10 nM-1 mM) and to allergen (ovalbumin 10,5 -10,3 g mL,1) was used as a parameter of tracheal smooth muscle reactivity. To test the short-term effects of Provinol, isolated tracheal strips were pre-treated for 30 min with Provinol (10,4mg mL,1) alone or in combination with N, -nitro-L-arginine methyl ester (L-NAME; 10,6mol L,1). To test the long-term effects of Provinol, isolated tracheal strips were prepared from guinea pigs that had been treated for 14 days with Provinol (20mg kg,1 per day) alone or in combination with L-NAME (40 mg kg,1 per day). Incubation of tracheal smooth muscle with Provinol decreased the amplitude of contraction in response to ovalbumin, histamine and acetylcholine. The non-selective NO synthase inhibitor L-NAME partially abolished the effect of Provinol on acetylcholine and ovalbumin-induced but not histamine-induced bronchoconstriction. A similar profile was observed after 14 days' oral administration of Provinol. In conclusion, Provinol inhibited the allergen- and spasmogen-induced contraction of tracheal smooth muscle in ovalbumin-sensitized guinea pigs via a mechanism that was mediated at least partially through the metabolism of NO. [source] The intake of dietary fiber from grape seeds modifies the antioxidant status in rat cecumJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2005Isabel Gońi Abstract The aim of this study was to measure the antioxidant activity and polyphenolic compounds in cecum and feces of rats fed with a grape seed concentrate. The grape concentrate was rich in indigestible compounds (dietary fiber, polyphenols and other associated compounds) which presented significant antioxidant activity. Polyphenols extracted by aqueous,organic solvents (extractable polyphenols, EPs) and non-extractable polyphenols (NEPs) exhibited high antioxidant capacity as measured by the ABTS method. High correlations were found between antioxidant capacity values and EP (r2 = 0.9608) and NEP content (r2 = 0.9179). EPs and NEPs exhibited considerable antioxidant activity within the large intestine. Significant antioxidant activity was also found in feces derived from excreted EPs and NEPs. The grape fiber concentrate enhanced the antioxidant status in the large intestine. The antioxidant activity in the intestinal content should be considered when assessing the effects of dietary components on bowel diseases. Copyright © 2005 Society of Chemical Industry [source] Persistence of the gelatinous layer within altered tension-wood fibres of beech degraded by Ustulina deustaNEW PHYTOLOGIST, Issue 2 2000S. BAUM The gelatinous layer (G-layer) of tension-wood fibres in reaction wood of beech showed alterations as a result of the physiological processes involved in the conversion of sapwood into false heartwood or reaction-zone tissue. Using transmitted-light, fluorescence and UV microscopy, polyphenolic compounds were found to infiltrate and encrust the cellulose microfibrils within the G-layer. Experiments with naturally infected and artificially inoculated wood showed that these processes affect the rate and mode of degradation by wood-decaying fungi. Thus, although the ascomycete Ustulina deusta was able to degrade the G-layer from within the lumina of tension-wood fibres in unaltered sapwood, it failed to do so for a prolonged period within false heartwood and reaction zones. In both situations, however, there was some degradation of the underlying secondary wall in the form of erosion troughs which can be attributed to soft rot ,type II', and internal cavity formation typical for ,type I' attack. The present study indicates that not only cell type, but also alterations in the cell wall structure, affect the activity and degradation mode of decay fungi in beech. [source] Dietary polyphenols can modulate the intestinal inflammatory responseNUTRITION REVIEWS, Issue 7 2009Béatrice Romier Inflammatory bowel diseases (IBD) arise from multiple causes, including environmental factors, gut microflora, immunity, and genetic predispositions. In the course of IBD, immune homeostasis and intestinal mucosa barrier integrity are impaired. Among natural preventive treatments that have been identified to date, polyphenols appear as promising candidates. They have been shown to protect against several diseases, including cardiovascular diseases and cancers, and they have anti-inflammatory properties in non-intestinal models. This paper will review the literature that has described to date some effects of polyphenols on intestinal inflammation. Studies, conducted using in vivo and in vitro models, provide evidence that pure polyphenolic compounds and natural polyphenolic plant extracts can modulate intestinal inflammation. [source] Olive Oil as a Functional Food: Epidemiology and Nutritional ApproachesNUTRITION REVIEWS, Issue 6 2002Aliza H. Stark Ph.D. Olive oil is an integral ingredient of the Mediterranean diet and accumulating evidence suggests that it may have health benefits that include reduction of risk factors of coronary heart disease, prevention of several varieties of cancers, and modification of immune and inflammatory responses. Olive oil appears to be an example of a functional food, with varied components that may contribute to its overall therapeutic characteristics. Olive oil is known for its high levels of monounsaturated fatty acids and is also a good source of phytochemicals including polyphenolic compounds, squalene, and ,-tocopherol. [source] An effective DNA extraction protocol for brown algaePHYCOLOGICAL RESEARCH, Issue 2 2001Naomi Phillips SUMMARY Successful extraction of total DNA from brown algae, which are generally polysaccharide and polyphenol rich, is often problematic using current methods. Persistent polysaccharide and polyphenolic compounds can hinder further application of modern molecular techniques requisite to molecular-based evolutionary studies. Our broad and long-term research goals with fucalean taxa, especially Sargassum, and problems with existing DNA extraction methods were an impetus to develop a reliable DNA extraction method. Initial research established hexadecyltrimethylammonium bromide (CTAB) based total-DNA methods as the most viable for further empirical development. Several constituents effective at either complexing secondary compounds or creating a reductive extraction environment were increased in concentration or added to the extraction buffer. These seemingly minor changes resulted in the creation of a highly reductive extraction buffer and effective total- DNA harvesting technique. We detail these modifications and demonstrate the reliability of the modified protocol with a variety of brown algae and tissue preservation methods. Such DNA is shown to be suitable for a variety of molecular techniques. [source] High-performance liquid chromatographic separation and identification of polyphenolic compounds from the infusion of Davilla elliptica St. HillPHYTOCHEMICAL ANALYSIS, Issue 1 2008Clenilson M. Rodrigues Abstract The isolation of polyphenolic compounds from an infusion of the Brazilian plant Davilla elliptica (Dilleniaceae), used as tea by virtue of its digestive properties, is described. An improved preparative HPLC method was used in order to isolate pure polyphenols from the complex mixture. Liquid,liquid extraction and solid-phase extraction were employed to minimise the interference of polymeric compounds and to provide an enriched fraction of the compounds of interest. The identification of the isolated compounds was performed using analytical HPLC as well as direct injection electrospray ionisation ion trap tandem mass spectrometry (ESI-IT-MS/MS). The high flavonoid content suggests that D. elliptica may be a promising source of compounds to produce natural phytomedicines. Copyright © 2007 John Wiley & Sons, Ltd. [source] Concentration-dependent effect of (,) epicatechin in hypertensive patientsPHYTOTHERAPY RESEARCH, Issue 10 2010Navneet Kumar Abstract Non-vitamin polyphenolic compounds are ubiquitous in food plants and therefore potentially present in human plasma in a diet-dependent concentration. The aim of this study was to evaluate the concentration-dependent effect of (,) epicatechin, a polyphenol present in green tea with antioxidant activity, on various biomarkers of oxidative stress. The current study examined the in vitro concentration-dependent (10,4,M to 10,7,M) effects of (,) epicatechin on biomarkers of oxidative stress viz. malondialdehyde (MDA), reduced glutathione (GSH), membrane sulfhydryl (-SH) group and protein carbonyl content in hypertensive patients and normal ones. This effect seems to be due to ability of (,) epicatechin to reduce MDA and protein carbonyl content while increase in GSH and membrane -SH group in hypertensive patients. It can be concluded that (-) epicatechin exerts an antioxidant action inside the cell, responsible for the observed modulation of cellular response to oxidative challenges. Copyright © 2010 John Wiley & Sons, Ltd. [source] Effect of polyphenols on the perception of key aroma compounds from Sauvignon Blanc wineAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 1 2009C.M. LUND Abstract Background and Aims:, Sensory wine research has mainly focused on the role of volatile compounds and their contribution to the aroma profile. Wines also contain polyphenolic compounds, which are not volatile. This research begins to investigate the interactions of volatile and non-volatile wine compounds and the consequential effects on sensory perception of aroma. Methods and Results:, Trained panellists of this study measured the perception of four aroma compounds (isobutyl methoxypyrazine, 3-mercaptohexanol, 3-mercaptohexanol acetate and ethyl decanoate) in wine. Panellists assessed the four compounds in combinations with three polyphenols (catechin, caffeic acid and quercetin) commonly found in white wine. The perception of isobutyl methoxypyrazine, 3-mercaptohexanol and ethyl decanoate was largely suppressed by the added polyphenols, while the perception of 3-mercaptohexanol was accentuated with the addition of caffeic acid. Of the three polyphenols, only catechin had a slight effect of accentuating the mercaptohexanol acetate perception. Conclusions:, Results showed each polyphenol had a unique effect when blended with a specific aroma compound, either suppressing, accentuating or showing little effect on the perception of the aroma compounds. Significance of the Study:, Understanding these interactions can assist winemakers in managing polyphenol levels to optimize selected volatile compounds to achieve desirable aroma profiles. [source] An integrated database of flavonoidsBIOFACTORS, Issue 3 2006Takashi Kinoshita Abstract Flavonoids are polyphenolic compounds that occur ubiquitously in foods of plant origin. Some of these molecules exhibit various physiological activities. Among existing drugs, there are a huge number of compounds bearing a flavonoid-related skeleton. Because of the relevance for pharmaceutical research, it would be beneficial to collect these compounds into a database. Recently, various databases of chemicals were compiled to help biological and/or chemical research, but no comprehensive database of flavonoids with chemical structures and physicochemical parameters, supposedly related to their activity, is available yet. The aim of this research was to merge the information about flavonoids of plant origin and flavonoids used as medicines into a database. Moreover, predictions of activities against various targets were performed using a virtual screening procedure to demonstrate a possible application of the database for pharmaceutical research. [source] Concord grape juice supplementation reduces blood pressure in Korean hypertensive men: Double-blind, placebo controlled intervention trialBIOFACTORS, Issue 1-4 2004Yoo Kyoung Park Abstract Many of the flavonoids found in grapes and grape products such as juice or wine have been known to exert antioxidant, anti-inflammatory, platelet inhibitory and arterial relaxing effects either in vitro, in animal studies and in human trials. This study was designed to test the effect of Concord grape juice consumption on altering blood pressure in hypertensive patients. Forty subjects were given 5.5 ml/kg body weight/day of either Concord grape juice (CGJ) or a calorie-matched placebo drink every day for 8 weeks. Blood pressure (BP) was measured on weeks 0, 4 and 8. Compared to baseline, in the CGJ group systolic BP was reduced on average by 7.2 mm Hg (p = 0.005) and diastolic BP was reduced on average by 6.2 mm Hg (p = 0.001) at the end of 8 weeks. Comparable changes in the group getting the placebo product were -3.5 mm Hg (NS) and -3.2 mm Hg (p = 0.05) Consuming Concord grape juice, which is high in polyphenolic compounds, may favorably affect BP in hypertensive individuals. [source] Pharmacological Effects of Xanthones as Cardiovascular Protective AgentsCARDIOVASCULAR THERAPEUTICS, Issue 2 2004De-Jian Jiang ABSTRACT Many epidemiological studies indicate that consumption of dietary polyphenolic compounds is beneficial in the prevention of cardiovascular diseases. Xanthones are a class of polyphenolic compounds that commonly occur in plants and have been shown to have extensive biological and pharmacological activities. Recently, the pharmacological properties of xanthones in the cardiovascular system have attracted great interest. Xanthones and xanthone derivatives have been shown to have beneficial effects on some cardiovascular diseases, including ischemic heart disease, atherosclerosis, hypertension and thrombosis. The protective effects of xanthones in the cardiovascular system may be due to their antioxidant, antiinflammatory, platelet aggregation inhibitory, antithrombotic and/or vasorelaxant activities. In particular, the antagonism of endogenous nitric oxide synthase inhibitors by xanthones may represent the basis for improved endothelial function and for reduction of events associated with atherosclerosis. [source] Polyphenols from Polygala spp. and Their Antioxidant ActivityCHEMISTRY & BIODIVERSITY, Issue 3 2004Rinaldo Cervellati Members of Polygalaceae are known to contain a variety of different polyphenolic compounds such as xanthones, flavonoids, and biphenyl derivatives. Here, we report the isolation and structural characterization of two new phenol derivatives, named alpestrin (=3,3,,5,-trimethoxy[1,1,-biphenyl]-4-ol; 10) and alpestriose,A (=6- O -benzoyl-1- O -{6- O -acetyl-3- O -[(4-hydroxy-3,5-dimethoxyphenyl)prop-2-enoyl]- , - D -fructofuranosyl}- , - D -glucopyranoside; 11), and of four known compounds (12,15) from the MeOH extract of Polygala alpestris. The relative in vitro antioxidant activities of these compounds, in comparison with other phenolic substances from Polygala vulgaris, were evaluated by means of the BriggsRauscher (BR) oscillating reaction, a method based on the inhibitory effects of antioxidant free-radical scavengers. The experimental antioxidant-activity values (relative to resorcinol as a standard) were compared with those calculated on the basis of the bond-dissociation enthalpies. The structure/activity relationships for the compounds examined are also discussed. [source] | ||||||||||||||||||||||||||||