PolyphenolMatching Summaries of Recent
Health Information Search Results
Peer Reviewed Scientific Research Reports
|<< Prev 50 ||Showing 1 to 50 of 647 Matches||Next 50 >>|
Match Strength: 10.376
The objective of this study was to create a French database on the polyphenol content of fruit and vegetables as uncooked fruits and vegetables and then to evaluate polyphenol intake through fruit and vegetable consumption in France. To achieve this, we used the Folin-Ciocalteu method adapted to fruit and vegetable polyphenol quantitation (1). Vegetables with the highest polyphenol concentration were artichokes, parsley, and brussels sprouts [>250 mg of gallic acid equivalent (GAE)/100 g fresh edible portion (FEP)]; fruits with the highest concentrations were strawberries, lychees, and ... Read More »
» Published in J Nutr. 2006 Sep;136(9):2368-73.
2. Excess boron reduces polyphenol oxidase activities in embryo and endosperm of maize seed during germination.
Match Strength: 9.527
The effects of increasing concentrations of boron (0, 0.1, 1, 10 and 20 mM) as boric acid on the rate of germination and polyphenol oxidase activities in embryo and endosperm tissues of maize seeds (Zea mays L. cv. Arifiye) were studied. The germination percentage of maize seeds was not affected by boron concentrations up to 10 mM, and decreased by 20 mM. Distilled water and lower boron concentrations (0.1 and 1 mM) increased polyphenol oxidase activities at the beginning of germination up to 12 h whereas its excess levels (10 and 20 mM) decreased polyphenol oxidase activities in embryos and ... Read More »
» Published in Z Naturforsch [C]. 2007 Jan-Feb;62(1-2):111-5.
3. Polyphenol contents and antioxidant activity of Maydis stigma extracts.
Match Strength: 9.426
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 ... Read More »
» Published in Bioresour Technol. 2005 May;96(8):873-7. Epub 2004 Nov 11.
4. Successful storage of peripheral nerves using University of Wisconsin solution with polyphenol.
Match Strength: 9.344
We have previously reported that green tea polyphenol can preserve peripheral nerve segments for up to 1 month. In this study, we investigated the effect on peripheral nerve preservation of adding polyphenol to the conventional University of Wisconsin solution (UW solution), which has been widely used for organ storage. Twenty millimeter-long sciatic nerve segments, harvested from Lewis rats, were immersed in UW solution containing polyphenol (1mg/mL) for 1 week and then in UW solution alone at 4 degrees C for 3 additional weeks before transplantation into recipient Lewis rats. Neural cell ... Read More »
» Published in J Neurosci Methods. 2007 Jan 15;159(1):57-65. Epub 2006 Aug 30.
5. Total polyphenol intake estimated by a modified Folin-Ciocalteu assay of urine.
Match Strength: 9.324
BACKGROUND: Plant polyphenols have been studied largely because of the possibility that they might underlie the protective effects afforded by fruit and vegetable intake against cancer and other chronic diseases. Measurement of polyphenol content excreted in urine as an indicator of polyphenol consumption may offer a routine screening method that could be used for these pathologies. METHODS: Thirty-six healthy volunteers each received 2 interventions, one with a polyphenol-rich food (cocoa beverage) and one with a polyphenol-free food (milk) as a control, in a randomized cross-over design with ... Read More »
» Published in Clin Chem. 2006 Apr;52(4):749-52. Epub 2006 Feb 9.
6. Physiological activity of irradiated green tea polyphenol on the human skin.
Match Strength: 9.201
Physiological activity of irradiated green tea polyphenol on the human skin was investigated for further industrial application. The green tea polyphenol was separated and irradiated at 40 kGy by y-ray. For an anti-wrinkle effect, the collagenase inhibition effect was higher in the irradiated sample (65.3%) than that of the non-irradiated control (56.8%) at 200 ppm of the concentration (p < 0.05). Collagen biosynthesis rates using a human fibroblast were 19.4% and 16.3% in the irradiated and the non-irradiated polyphenols, respectively. The tyrosinase inhibition effect, which is related to ... Read More »
» Published in Am J Chin Med. 2005;33(4):535-46.
7. Polyphenol-enriched oolong tea increases fecal lipid excretion.
Match Strength: 8.890
OBJECTIVE: To assess possibility of polyphenol-enriched oolong tea to reduce dietary lipid absorption in humans. DESIGN: Twelve healthy adult subjects, three males and nine females, aged (mean+/-s.d.) 22.0+/-1.8 years, respectively, were randomly divided into two groups. The participants were followed a double-blind placebo-controlled crossover design, including 7-day washout periods and 10-day treatment periods. During the treatment periods, subjects were given about 38 g of lipids from potato chips (19 g each within 30 min after lunch and dinner) and total 750 ml beverages (placebo- or ... Read More »
» Published in Eur J Clin Nutr. 2006 Nov;60(11):1330-6. Epub 2006 Jun 28.
8. Effect of the Walnut Polyphenol Fraction on Oxidative Stress in Type 2 Diabetes Mice
Match Strength: 8.748
We examined the in vivo antioxidative effect of a polyphenol-rich walnut extract on oxidative stress in mice with type 2 diabetes. C57BL/KsJ-db/db mice were used as an accelerated oxidative animal model. The oral administration of the walnut polyphenol fraction at 200 mg/kg body weight for 4 weeks caused a significant decrease in the level of urinary 8-hydroxy-2'-deoxyguanosin, which is an in vivo marker of oxidative stress. These results imply that walnut polyphenols have both in vitro and in vivo antioxidant effects ... Read More »
» Published in Biofactors. 2004;21(1-4):251-3.
9. Inhibitory effect of topical application of a green tea polyphenol fraction on tumor initiation and promotion in mouse skin
Match Strength: 8.617
A green tea polyphenol fraction was evaluated for its ability to inhibit tumor initiation by polycyclic aromatic hydrocarbons and tumor promotion by a phorbol ester in the skin of CD-1 mice. Topical application of the green tea polyphenol fraction inhibited benzo[a]pyrene- and 7,12-dimethylbenz[a]-anthracene-induced tumor initiation as well as 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced tumor promotion. Topical application of the green tea polyphenol fraction also inhibited TPA-induced inflammation, ornithine decarboxylase activity, hyperplasia and hydrogen peroxide formation. Studies ... Read More »
» Published in Carcinogenesis. 1992 Jun;13(6):947-54.
10. Characterization of supramolecular polyphenol-chromium(III) clusters by molecular dynamics simulations.
Match Strength: 8.519
The binding of Cr(III) with (2R,3S,4R)-(+)-3,3',4,4',7-flavanpentol in aqueous solution is investigated by atomistic molecular dynamics simulations concentrating the analysis of the sampled data on the polyphenol ability to chelate metal ions and to form large noncovalently bonded molecular and supramolecular architectures ... Read More »
» Published in J Phys Chem B Condens Matter Mater Surf Interfaces Biophys. 2006 Jul 6;110(26):13227-34.
11. Effects of dietary apple polyphenol on adipose tissues weights in Wistar rats.
Match Strength: 8.273
In this study, we investigated whether dietary apple polyphenol (APP) had an effect on adipose weights.Twenty-four Wistar male rats (10 weeks of age) were assigned to three groups: (1) the 5%APP group (diet containing 5% APP, N=8); (2) the 0.5%APP group (diet containing 0.5% APP, N=8); and (3) the control group (N=8) so that average weights of the groups were the same. After a three-week experimental period, adipose tissue weights were measured. Pathological and plasma characteristics were also examined. Retroperitoneal and epididymal adipose tissue weights in the 5%APP group were ... Read More »
» Published in Exp Anim. 2006 Jul;55(4):383-9.
12. Kinetic Characterization of the Oxidation of Esculetin by Polyphenol Oxidase and Peroxidase.
Match Strength: 8.228
Esculetin has been described as an inhibitor of tyrosinase and polyphenol oxidase and, therefore, of melanogenesis. In this work, we demonstrate that esculetin is not an inhibitor but a substrate of mushroom polyphenol oxidase (PPO) and horseradish peroxidase (POD), enzymes which oxidize esculetin, generating its o-quinone. Since o-quinones are very unstable, the usual way of determining the enzymatic activity (slope of recordings) is difficult. For this reason, we developed a chronometric method to characterize the kinetics of this substrate, based on measurements of the lag period in the ... Read More »
» Published in Biosci Biotechnol Biochem. 2007 Feb 7;
13. Decolorization and removal of textile and non-textile dyes from polluted wastewater and dyeing effluent by using potato (Solanum tuberosum) soluble and immobilized polyphenol oxidase.
Match Strength: 8.121
Celite bound potato polyphenol oxidase preparation was employed for the treatment of wastewater/dye effluent contaminated with reactive textile and non-textile dyes, Reactive Blue 4 and Reactive Orange 86. The maximum decolorization was found at pH 3.0 and 4.0 in case of Reactive Blue 4 and Reactive Orange 86, respectively. Immobilized potato polyphenol oxidase was significantly more effective in decolorizing the individual dye and complex mixtures of dyes as compared to soluble enzyme. The absorption spectra of the treated and untreated dye mixture and dyeing effluent exhibited a marked ... Read More »
» Published in Bioresour Technol. 2007 Mar;98(5):1012-9. Epub 2006 Jun 9.
14. Polyphenol profiles of apple juices.
Match Strength: 8.112
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 ... Read More »
» Published in Mol Nutr Food Res. 2005 Aug;49(8):797-806.
15. Stabilization of collagen using plant polyphenol: role of catechin.
Match Strength: 8.002
Collagen, a unique connective tissue protein finds extensive application as biocompatible biomaterial in wound healing, as drug carriers, cosmetics, etc. A work has been undertaken to study the stabilization of type I collagen using the plant polyphenol catechin. Catechin treated collagen fibres showed a shrinkage temperature around 70 degrees C implying that catechin is able to impart thermal stability to collagen. Catechin treated collagen fibres has been found to be stable even after treatment with high concentration of the secondary structural destabilizer, urea. Circular dichroism studies ... Read More »
» Published in Int J Biol Macromol. 2005 Oct 30;37(1-2):47-53. Epub 2005 Sep 23.
16. Evidence for a tetrameric form of iceberg lettuce (Lactuca sativa L.) polyphenol oxidase: purification and characterization.
Match Strength: 7.983
Polyphenol oxidase from iceberg lettuce (Lactuca sativa L.) chloroplasts was released from the thylakoid-membrane by sonication, and it was extensively purified to homogeneity as judged by SDS-PAGE. Purification was achieved by ammonium sulfate fractionation, gel-filtration chromatography, and ion-exchange chromatography. Two molecular forms were separated by gel-filtration chromatography with apparent molecular masses of 188 and 49 kDa. Both forms were characterized by sedimentation analysis with S(20,W) values of 10.2 and 4.1 S, respectively. For the high-molecular-weight form purified to ... Read More »
» Published in J Agric Food Chem. 2001 Oct;49(10):4870-5.
17. Determination of phenolic compounds by a polyphenol oxidase amperometric biosensor and artificial neural network analysis.
Match Strength: 7.947
The determination of phenolic compounds is significant given its toxicity, even at very low concentration levels. Amperometric determination of phenols is a simple technique available. Direct oxidation of phenols can be used, but another possibility is the use of polyphenol oxidase (tyrosinase) enzyme biosensors that oxidises the phenolic compounds into their corresponding quinones. Reduction of the resulting quinones accomplishes the amplification of the amperometric signal, as long as the result of the reduction process is the corresponding cathecol, this being able to be oxidised again by ... Read More »
» Published in Biosens Bioelectron. 2005 Feb 15;20(8):1668-73.
18. Enhancement of inward Ca(2+) currents in bovine chromaffin cells by green tea polyphenol extracts.
Match Strength: 7.857
Green tea contains four major polyphenol compounds: they are (-)-epigallocatechin-3-gallate (EGCG), (-)-epigallocatechin (EGC), (-)-epicatechin-3-gallate (ECG), and (-)-epicatechin (EC). Although all four polyphenol compounds are known to affect tumor suppression, little is known about whether they alter membrane properties. In this study, we examined the effects of ECG and EGCG on ionic currents and secretion. Membrane capacitance changes were used to monitor secretion in bovine chromaffin cells. ECG had the ability to reversibly enhance the inward Ca(2+) current by 21%, and inhibited the ... Read More »
» Published in Neurochem Int. 2002 Feb;40(2):131-7.
19. Various applications of immobilized glucose oxidase and polyphenol oxidase in a conducting polymer matrix.
Match Strength: 7.831
In this study, glucose oxidase and polyphenol oxidase were immobilized in conducting polymer matrices; polypyrrole and poly(N-(4-(3-thienyl methylene)-oxycarbonyl phenyl) maleimide-co-pyrrole) via electrochemical method. Fourier transform infrared and scanning electron microscope were employed to characterize the copolymer of (N-(4-(3-thienyl methylene)-oxycarbonyl phenyl) maleimide) with pyrrole. Kinetic parameters, maximum reaction rate and Michealis-Menten constant, were determined. Effects of temperature and pH were examined for immobilized enzymes. Also, storage and operational ... Read More »
» Published in Int J Biol Macromol. 2006 Dec 30;
20. Acute effect of tea, wine, beer, and polyphenols on ecto-alkaline phosphatase activity in human vascular smooth muscle cells.
Match Strength: 7.798
Alkaline phosphatase (ALP) is an ecto-enzyme widely distributed across species. It modulates a series of transmembranar transport systems, has an important role in bone mineralization, and can also be involved in vascular calcification. Polyphenol-rich diets seem to have protective effects on human health, namely, in the prevention of cardiovascular diseases. We aimed to investigate the effects of polyphenols and polyphenol-rich beverages upon membranar alkaline phosphatase (ecto-ALP) activity in intact human vascular smooth muscle cells (AALTR). The ecto-ALP activity was determined at pH 7.8, ... Read More »
» Published in J Agric Food Chem. 2006 Jul 12;54(14):4982-8.
21. Kinetic Characterization of the Oxidation of Chlorogenic Acid by Polyphenol Oxidase and Peroxidase. Characteristics of the o-Quinone.
Match Strength: 7.651
Chlorogenic acid is the major diphenol of many fruits, where it is oxidized enzymatically by polyphenol oxidase (PPO) or peroxidase (POD) to its o-quinone. In spectrophotometric studies of chlorogenic acid oxidation with a periodate ratio of [CGA]0/[IO4-]0 < 1 and [CGA]0/[IO4-]0 > 1, the o-quinone was characterized as follows: lambdamax at 400 nm and epsilon = 2000 and 2200 M-1 cm-1 at pH 4.5 and 7.0, respectively. In studies of o-quinone generated by the oxidation of chlorogenic acid using a periodate at ratio of [CGA]0/[IO4-]0 > 1, a reaction with the remaining substrate was ... Read More »
» Published in J Agric Food Chem. 2007 Feb 7;55(3):920-928.
22. Polyphenol interaction with the T47D human breast cancer cell line.
Match Strength: 7.617
Experimental and epidemiological studies indicate that antioxidant food polyphenols could have antimitotic activities, interfering with cancer initiation, progression or mortality. Circulating polyphenols are far lower than the nominal value in foods. In the rare studies dealing with polyphenol bioavailability, it was noted that their active concentrations in the blood are <1% of their food concentration. In the present study we investigated the effect of four polyphenols (resveratrol, and the flavonoids quercetin, catechin and epicatechin, major constituents of wine) in the hormone ... Read More »
» Published in J Dairy Res. 2005;72 Spec No:44-50.
23. High nitrogen availability reduces polyphenol content in Sphagnum peat.
Match Strength: 7.507
Peat mosses of the genus Sphagnum constitute the bulk of living and dead biomass in bogs. These plants contain peculiar polyphenols which hamper litter peat decomposition through their inhibitory activity on microbial breakdown. In the light of the increasing availability of biologically active nitrogen in natural ecosystems, litter derived from Sphagnum mosses is an ideal substrate to test the potential effects of increased atmospheric nitrogen deposition on polyphenol content in litter peat. To this aim, we measured total nitrogen and soluble polyphenol concentration in Sphagnum litter peat ... Read More »
» Published in Sci Total Environ. 2007 May 15;377(2-3):439-43. Epub 2007 Mar 26.
24. Correlation between the in vitro antioxidant activity and polyphenol content of aqueous extracts from Bulgarian herbs.
Match Strength: 7.382
The water phase antioxidant activity of extracts from 23 Bulgarian medicinal plants was studied in relation to their polyphenol content in comparison with mate, black tea, honeybush and rooibos foreign species. Antioxidant activity was measured by the ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)) cation radical decolorization assay, and the total polyphenol content was assayed according to the Folin-Ciocalteu method. Five Bulgarian plant extracts exhibited higher antioxidant activity than that of mate, which is 21.7% of all Bulgarian herbs included in this study. These were ... Read More »
» Published in Phytother Res. 2006 Nov;20(11):961-5.
25. Cinnamaldehyde inhibits phenylalanine ammonia-lyase and enzymatic browning of cut lettuce.
Match Strength: 7.295
Stored cut lettuce gradually turns brown on the cut section after several days of storage, because cutting induces phenylalanine ammonia-lyase (PAL) activity, the biosynthesis of polyphenol is promoted, and the polyphenols are oxidized by polyphenol oxidase. In this study, we screened for inhibitors of PAL derived from fermented broths of microbes and from foods and found that a cinnamon extract definitely inhibited PLA of cut lettuce. An active component was isolated by chromatographic procedures and was identified as trans-cinnamaldehyde. Browning of cut lettuce immersed in a solution ... Read More »
» Published in Biosci Biotechnol Biochem. 2006 Mar;70(3):672-6.
26. Electrofocusing of methanolic extracts for identification of individual flavonol biomolecules in Camellia species.
Match Strength: 7.280
An effort has been made to isolate individual catechin compounds from green tea leaves in their pure form by electrophoresis. In the present study total polyphenol extraction was carried out initially and estimated through spectrophotometric and HPLC methods. Extracted polyphenol was separated on 0.7% agarose gel and visualized at 360 nm. Fragmented individual compounds were gel eluted with methanol and confirmed as (-)-epigallocatechin (EGC), (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG) by HPLC. The method developed describes a suitable method ... Read More »
» Published in J Agric Food Chem. 2006 Apr 19;54(8):2828-31.
27. Identification of Antidiabetic Effect of Iridoid Glycosides and Low Molecular Weight Polyphenol Fractions of Corni Fructus, a Constituent of Hachimi-jio-gan, in Streptozotocin-Induced Diabetic Rats.
Match Strength: 7.196
In our previous study, Corni Fructus (Cornus officinalis SIEB. et ZUCC.), a component crude drug of the Chinese prescription Hachimi-jio-gan, was reported to reduce glucotoxicities, up-regulate renal function, and consequently ameliorate glycation-associated renal damage as well as Hachimi-jio-gan. Based upon these facts, we prepared Corni Fructus fractions and evaluated which fraction contained the effective components against diabetes, using one iridoid glycoside and three polyphenol fractions, which were expected to possess stronger activities than Corni Fructus, administered orally at a ... Read More »
» Published in Biol Pharm Bull. 2007 Jul;30(7):1289-96.
28. Polyphenol Content and Antioxidative Activity in Some Species of Freshly Consumed Salads.
Match Strength: 7.111
Ten genotypes belonging to Lactuca sativa, Cicorium intybus, Plantago coronopus, Eruca sativa, and Diplotaxis tenuifolia and used in fresh mixed salads were investigated for their polyphenol contents. Flavonoids and hydroxycinnamic acids were characterized by high-performance liquid chromatography (HPLC)/diode array detection/mass spectrometry. Quercetin, kaempferol, luteolin, apigenin, and crysoeriol derivatives were identified; hydroxycinnamic acids were all caffeoyl derivatives. The total polyphenol content was obtained through the Folin-Ciocalteu test and from the HPLC data. The amounts ... Read More »
» Published in J Agric Food Chem. 2007 Feb 6;
29. Concentrations and characteristics of procyanidins and other phenolics in apples during fruit growth.
Match Strength: 7.100
Apples (Malus domestica Borkh.) of two table and two cider cultivars were collected during fruit growth and maturation from the end of cell proliferation. Concentrations of flavonoids (flavan-3-ols, dihydrochalcones and flavonols) in the fruit flesh decreased sharply between circa 35 and circa 100 days after flowering. For hydroxycinnamic acids, the decrease appeared slower. In a second experiments apples of the cider cultivars Kermerrien and Avrolles were sampled every 2 weeks from 40 days after flowering to overripeness for a detailed characterisation of polyphenol accumulation kinetics in ... Read More »
» Published in Phytochemistry. 2007 Apr;68(8):1128-38. Epub 2007 Apr 2.
30. Factors affecting the bioavailability of soy isoflavones in humans.
Match Strength: 7.083
To fully evaluate the potential risks and benefits of isoflavones to human health, an understanding of the physiological behavior of these compounds following ingestion is required. Numerous researchers have investigated the kinetics and extent of polyphenol absorption by measuring plasma concentrations and/or urinary excretion among adults after the ingestion of a single dose of polyphenol, provided as either a pure compound, plant extract, or whole food/beverage. Available data suggest isoflavones are more bioavailable than other flavonoid subclasses. This review will focus on our current ... Read More »
» Published in J AOAC Int. 2006 Jul-Aug;89(4):1182-8.
31. Dietary non-tocopherol antioxidants present in extra virgin olive oil increase the resistance of low density lipoproteins to oxidation in rabbits.
Match Strength: 7.079
Consumption of a range of dietary antioxidants may be beneficial in protecting low density lipoprotein (LDL) against oxidative modification, as studies have demonstrated that antioxidants other than vitamin E may also function against oxidation of LDL in vitro. In the present study, the effect of polyphenol antioxidants on the susceptibility of LDL to copper-mediated oxidation was investigated after feeding semi-purified diets to 3 groups of New Zealand white (NZW) rabbits. All diets comprised 40% energy as fat with 17% energy as oleic acid. Dietary fatty acid compositions were identical. Oils ... Read More »
» Published in Atherosclerosis. 1996 Feb;120(1-2):15-23.
32. Activation of endothelial nitric oxide synthase by red wine polyphenols: impact of grape cultivars, growing area and the vinification process.
Match Strength: 7.072
OBJECTIVE: Accumulating data document protective effects of red wine in cardiovascular disease by improved nitric oxide bioavailability. Not all wines, however, seem to be equally effective. The aim of the present study was to elucidate the impact of grape cultivars, growing area and the vinification/fermentation process on the ability of red wine polyphenol extracts to increase human endothelial nitric oxide synthase (eNOS) promotor and enzyme activity. METHODS: We produced polyphenol extracts from a variety of red wines from all over the world and tested their influence on eNOS promotor ... Read More »
» Published in J Hypertens. 2007 Mar;25(3):541-9.
33. Oxidation of polyphenols in phytate-reduced high-tannin cereals: effect on different phenolic groups and on in vitro accessible iron.
Match Strength: 7.062
After reduction of phytate with phytase, water slurries of two high-tannin cereal flours were incubated with polyphenol oxidase (mushroom tyrosinase), and the effects on different phenolic groups and on in vitro accessible iron were studied. Enzyme incubation was also performed after cooking, soaking, and germination of the cereals. Phytase incubation significantly decreased the phytate content, and incubation with polyphenol oxidase had a reducing effect on the total phenol content, as well as on the amount of catechol and resorcinol groups. The in vitro accessible iron increased when the ... Read More »
» Published in J Agric Food Chem. 2001 Nov;49(11):5630-8.
34. Enzymology of aurone biosynthesis.
Match Strength: 7.035
Aurones belong to a class of plant flavonoids that provides the bright yellow color of some important ornamental flowers, such as snapdragon (Antirrhinum majus). Despite the potential significance of the enzyme(s) and gene(s) responsible for aurone biosynthesis in biotechnology, the enzymological details of aurone biosynthesis were not established until recently. During the past two years, however, the biosynthetic pathway of aurones in yellow snapdragon has been elucidated, and a key enzyme of the pathway, aureusidin synthase, and its cDNA have been isolated. This enzyme was identified as a ... Read More »
» Published in J Biosci Bioeng. 2002;94(6):487-91.
35. Imaging of hydroperoxide and hydrogen peroxide-scavenging substances by photon emission.
Match Strength: 7.003
An imaging system for the hydroperoxide and hydrogen donor was developed by photon emission from the reactive oxygen species-hydrogen donor-KHCO(3)-MeCHO system. Photon intensity (luminance, cd/m(2)) showed a linear correlation with the concentration of some hydroperoxides [hydrogen peroxide (H(2)O(2)), tert-butyl hydroperoxide and methyl ethyl ketone peroxide] and that of hydrogen donors (catechins and anthocyanins). The linear relationship between photon intensity and concentration was observed in polyphenol-rich samples, such as teas, berries and currants. Photon intensity from the H(2)O(2) ... Read More »
» Published in Luminescence. 2001 Sep-Oct;16(5):327-35.
36. Effect of flash release treatment on phenolic extraction and wine composition.
Match Strength: 6.985
The flash release (FR) process, consisting of rapidly heating the grapes and then applying strong vacuum, has been proposed to increase the polyphenol content of red wines. Its impact on polyphenol extraction kinetics and on the polyphenol composition of red juice and wines was studied over two seasons on different grape varieties (Grenache, Mourvedre, Carignan). The FR process allows fast extraction of all phenolic compounds (hydroxycinnamic acids, flavonols, anthocyanins, catechins, proanthocyanidins) and can be used to produce polyphenol-enriched grape juices. However, the concentration of ... Read More »
» Published in J Agric Food Chem. 2006 Jun 14;54(12):4270-6.
37. The effect of cocoa polyphenols on the growth, metabolism, and biofilm formation by Streptococcus mutans and Streptococcus sanguinis.
Match Strength: 6.983
The aim of this study was to determine if cocoa polyphenols could interfere with biofilm formation by Streptococcus mutans or Streptococcus sanguinis, and reduce acid production from sucrose by S. mutans. The antimicrobial activity of cocoa polyphenols was assessed against cariogenic (S. mutans) and health-associated (S. sanguinis) species by minimum inhibitory concentration assays. Cocoa polyphenol dimer, tetramer, and pentamer inhibited the growth of S. sanguinis, whereas the growth of S. mutans was unaffected. However, pretreatment of surfaces with cocoa polyphenol pentamer (35 microM) ... Read More »
» Published in Eur J Oral Sci. 2006 Aug;114(4):343-8.
38. Bioavailability and bioefficacy of polyphenols in humans. I. Review of 97 bioavailability studies.
Match Strength: 6.962
Polyphenols are abundant micronutrients in our diet, and evidence for their role in the prevention of degenerative diseases is emerging. Bioavailability differs greatly from one polyphenol to another, so that the most abundant polyphenols in our diet are not necessarily those leading to the highest concentrations of active metabolites in target tissues. Mean values for the maximal plasma concentration, the time to reach the maximal plasma concentration, the area under the plasma concentration-time curve, the elimination half-life, and the relative urinary excretion were calculated for 18 major ... Read More »
» Published in Am J Clin Nutr. 2005 Jan;81(1 Suppl):230S-242S.
39. No evidence for modulation of endothelial nitric oxide synthase by the olive oil polyphenol hydroxytyrosol in human endothelial cells.
Match Strength: 6.955
Reduced nitric oxide (NO) availability is associated with the development of atherosclerosis. Upregulation of endothelial nitric oxide synthase (eNOS) activity is pursued as a strategy for the prevention of cardiovascular diseases. The polyphenol hydroxytyrosol (HT) which is present in olive oil and red wine, is regarded to be partly responsible for the beneficial effects associated with olive oil consumption and has shown antiatherogenic activity in vitro and in vivo. To elucidate the underlying molecular mechanisms, we investigated possible effects of HT on the endothelial nitric oxide ... Read More »
» Published in Atherosclerosis. 2007 Mar 29;
40. Spray-dried propolis extract. I: physicochemical and antioxidant properties.
Match Strength: 6.899
The effect of spray drying on the chemical and biological properties of alcoholic extract of green propolis was investigated. The total polyphenol and flavonoid contents in spray-dried propolis extract were determined by the Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively. The antioxidant activity of the dry extract was assessed by the membrane lipid peroxidation inhibition method, using quercetin as reference. The polyphenol content was shown to depend on the drying air outlet temperature and its square at the 0.5% significance level, while the flavonoid content ... Read More »
» Published in Pharmazie. 2006 Apr;61(4):325-30.
41. Multivariate analysis of antioxidant power and polyphenolic composition in red wines.
Match Strength: 6.890
It has been demonstrated that the dietary intake of compounds having antioxidant activity is very important, and various chemical, biological, and electrochemical methods have been proposed to evaluate the antioxidant power of compounds such as polyphenols. Wine, although nonessential, has a high polyphenol content up to 2-3 g/L in red wines obtained by traditional maceration. The polyphenol content of wines is usually evaluated by the Folin reagent, which provides an appropriate response to the requirements of wine manufacturers. Because the presence of individual polyphenols may be evaluated ... Read More »
» Published in J Agric Food Chem. 2001 Oct;49(10):4841-4.
42. Polyphenol Oxidase from Yacon Roots (Smallanthus sonchifolius).
Match Strength: 6.876
Polyphenol oxidase (E.C. 18.104.22.168) (PPO) extracted from yacon roots (Smallanthus sonchifolius) was partially purified by ammonium sulfate fractionation and separation on Sephadex G-100. The enzyme had a molecular weight of 45 490 +/- 3500 Da and Km values of 0.23, 1.14, 1.34, and 5.0 mM for the substrates caffeic acid, chlorogenic acid, 4-methylcatechol, and catechol, respectively. When assayed with resorcinol, dl-DOPA, pyrogallol, protocatechuic, p-coumaric, ferulic, and cinnamic acids, catechin, and quercetin, the PPO showed no activity. The optimum pH varied from 5.0 to 6.6, depending on ... Read More »
» Published in J Agric Food Chem. 2007 Feb 23;
43. Biologically active constituents of a polyphenol extract from Geranium sanguineum L. with anti-influenza activity.
Match Strength: 6.865
From the aerial roots of the medicinal plant Geranium sanguineum L. a polyphenol-rich extract with strong anti-influenza activity has been isolated. To investigate its active fractions, the extract was partitioned by solvents with increasing polarity. The n-BuOH fraction contained the majority of the in vitro antiviral activity; the EtOAc fraction was the most effective one in vivo. A bioassay-directed fractionation of the n-BuOH and EtOAc fractions was performed to obtain information about the nature of the chemical components of the plant extract, responsible for the antiviral effect. The ... Read More »
» Published in Z Naturforsch [C]. 2006 Jul-Aug;61(7-8):508-16.
44. Factors affecting the caffeine and polyphenol contents of black and green tea infusions.
Match Strength: 6.836
The effects of product and preparation variables on the in-cup chemical composition of tea extracts is of interest because the appearance and taste characteristics and the possible health effects of a tea liquor arise from the chemical components extracted from the leaf during tea preparation. A comprehensive study was therefore undertaken to determine the contributions of product and preparation variables on the total soluble solids, caffeine, and polyphenol contents of tea extracts. The results of this study show that the variety, growing environment, manufacturing conditions, and grade ... Read More »
» Published in J Agric Food Chem. 2001 Nov;49(11):5340-7.
45. Immobilization of polyphenol oxidase on chitosan-SiO(2) gel for removal of aqueous phenol.
Match Strength: 6.828
A partially purified potato polyphenol oxidase (PPO) was immobilized in a cross-linked chitosan-SiO(2) gel and used to treat phenol solutions. Under optimized conditions (formaldehyde 20 mg/ml, PPO 4 mg/ml and pH 7.0), the activity of immobilized PPO was 1370 U/g and its K (m) value for catechol was 12 mM: at 25 degrees C. The highest activity of immobilized enzyme was at pH 7.4. Immobilization stabilized the enzyme with 73 and 58% retention of activity after 10 and 20 days, respectively, at 30 degrees C whereas most of the free enzyme was inactive after 7 days. The efficiency of removing ... Read More »
» Published in Biotechnol Lett. 2007 Jun;29(6):901-5. Epub 2007 Apr 7.
46. Induction of apoptosis in human leukemia cells by black tea and its polyphenol theaflavin.
Match Strength: 6.828
Treatment of human leukemic cell lines HL-60 and K-562 with extracts of green and black tea and their polyphenols epigallocatechin gallate and theaflavins, respectively, showed a dose dependent inhibition of growth as a result of cytotoxicity and suppression of cell proliferation. Based on the IC50 values obtained from cytotoxicity data it was clearly evident that black tea was as efficient as green tea. Analysis of polyphenol contents of tea extracts revealed that not only epigallocatechin gallate, which is a predominant polyphenol of green tea, but also theaflavin that is abundantly present ... Read More »
» Published in Cancer Lett. 2005 Dec 8;230(1):111-21.
47. High-throughput profiling of dietary polyphenols and their metabolites by HPLC-ESI-MS-MS in human urine.
Match Strength: 6.779
Polyphenols in biological fluids are generally estimated by HPLC with UV, electrochemical or fluorimetric detection. We describe herein a method specially developed to estimate biomarkers of polyphenol consumption in human urine. We simultaneously quantified 15 polyphenols and their related compounds in human urine using an HPLC coupled with electrospray ionization mass-mass (HPLC-ESI-MS-MS) method with an analytical run time of 6 min. The method has been validated with respect to linearity, precision, and accuracy in intra- and inter-day assays. It has been applied to human urine samples ... Read More »
» Published in Biofactors. 2004;22(1-4):241-3.
48. Inhibitory effect of polyphenol-enriched apple extracts on mast cell degranulation in vitro targeting the binding between IgE and FcepsilonRI.
Match Strength: 6.733
Extracts from immature fruit of the apple (Rosaceae, Malus sp.), which contain procyanidins (polymers of catechins) as the major ingredients, are known to inhibit histamine release from mast cells. We analyzed in this study the mechanism for the anti-allergic activity of two polyphenol-enriched apple extracts. These extracts, termed "crude apple polyphenol (CAP)" and "apple condensed tannin (ACT)", reduced the degranulation of mast cells caused by cross-linking of the high-affinity receptor for IgE (FcepsilonRI) with IgE and the antigen in a dose-dependent manner. Furthermore, western blotting ... Read More »
» Published in Biosci Biotechnol Biochem. 2005 Oct;69(10):1974-7.
49. Identification of novel polyphenol oxidase inhibitors by enzymatic one-pot synthesis and deconvolution of combinatorial libraries.
Match Strength: 6.587
The feasibility of enzymatic synthesis of combinatorial libraries using multifunctional starting materials [i.e., 2,4-dihydroxy-N-(2-hydroxyethyl)benzamide, 1; 4-hydroxyphenethyl alcohol, 2; 3,5-dihydroxybenzyl alcohol, 3; and 4-hydroxybenzyl alcohol, 4] with six vinyl esters, in a one-pot reaction, was investigated. Candida antarctica lipase was employed as a biocatalyst. The resulting 24-compound library contained all the expected species with no significant bias toward particular combinations of substrates. As expected, the library contained a substance(s) that showed significant inhibition ... Read More »
» Published in Biotechnol Bioeng. 2001 Oct 5;75(1):93-9.
50. Characterization of polyphenol oxidase and peroxidase and influence on browning of cold stored strawberry fruit.
Match Strength: 6.563
Polyphenol oxidase and peroxidase were extracted from two different varieties of strawberry fruit (Fragaria x ananassa D, cv. 'Elsanta' and Fragaria vesca L, cv. 'Madame Moutot') and characterized using reliable spectrophotometric methods. In all cases, the enzymes followed Michaelis-Menten kinetics, showing different values of peroxidase kinetics parameters between the two cultivars: Km = 50.68 +/- 2.42 mM ('Elsanta') and 18.18 +/- 8.79 mM ('Madame Moutot') mM and Vmax = 0.14 +/- 0.03 U/g ('Elsanta') and 0.05 +/- 0.01 U/g ('Madame Moutot'). The physiological pH of fruit at the red ripe stage ... Read More »
» Published in J Agric Food Chem. 2007 May 2;55(9):3469-76. Epub 2007 Apr 4.
|<< Prev 50 ||Showing results 1 to 50 of 647||Next 50 >>|
* All information on Level1Diet.com is for educational purposes only. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease. Before changing your diet, or adding supplements to your diet, or beginning an exercise program, everyone should consult a qualified and licensed health practitioner; a physician, dietician or similar professional.