3,123 research outputs found
Saudi Rosmarinus offcinalis and Ocimum basilicum L. polyphenols and biological activities
Investigating the polyphenolic profile of natural Rosmarinus offcinalis and Ocimum basilicum
populations may reveal essential compounds that have biological activities. Natural populations
of R. offcinalis and O. basilicum in Northern Riyadh were investigated by HPLC-DAD analyses.
Several polyphenols, including rosmarinic acid, gentisic acid, 3,4-dihydroxyphenylacetic acid,
rutoside, and others, out of 38 screened were confirmed. Rosmarinic acid was the major polyphenol
in both of R. offcinalis and O. basilicum. R. offcinalis methanolic leaf extracts contained other
phenols such as gentisic acid while O. basilicum contained also 3,4-dihydroxyphenylacetic acid and
rutoside as well as others. R. o cinalis showed higher antioxidant activities than O. basilicum using
2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and -carotene
bleaching assays. These higher activities are associated with a higher composition of rosmarinic
acid in leaf extracts. The antioxidant activities of O. basilicum were attributed to identified phenols
of rosmarinic acid, 3,4-dihydroxyphenylacetic acid, and rutoside. There were antiproliferative
and cytotoxic activities of leaf extracts, as well as identified polyphenols, against several cancer
cells. These activities were attributed to the accumulation of necrotic and apoptotic cells in treated
cancer cells with leaf extracts as well as identified polyphenols. The antibacterial and antifungal
activities of leaf extracts were mainly attributed to 3,4-dihydroxyphenylacetic acid and rutoside in
O. basilicum and rosmarinic acid and caffeic acid in R. offcinalis. This study proved that R. offcinalis and
O. basilicum natural populations might be considered as promising sources of natural polyphenols
with biological activities
Low-molecular-weight components of olive oil mill wastewaters
A new lignan 1-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-6-(3-acetyl-4-hydroxy-5-methoxyphenyl)-3,7-dioxabicyclo[
3.3.0]octane, the secoiridoid 2H-pyran-4-acetic acid,3-hydroxymethyl-2,3-dihydro-5-(methoxycarbonyl)-2-
methyl-, methyl ester, the phenylglycoside 4-[β -D-xylopyranosyl-(1→6)]-β -D-glucopyranosyl-1,4-dihydroxy-2-
methoxybenzene and the lactone 3-[1-(hydroxymethyl)-1-propenyl] δ -glutarolactone were isolated and identified
on the basis of spectroscopic data including two-dimensional NMR, as components of olive oil mill waste-waters.
The known aromatic compounds catechol, 4-hydroxybenzoic acid, protocatechuic acid, vanillic acid, 4-hydroxy-
3,5-dimethoxybenzoic acid, 4-hydroxyphenylacetic acid, 3,4-dihydroxyphenylacetic acid, tyrosol, hydroxytyrosol,
2-(4-hydroxy-3-methoxy)phenylethanol, 2-(3,4-dihydroxy)phenyl-1,2-ethandiol, p-coumaric acid, caffeic acid,
ferulic acid, sinapic acid, 1-O-[2-(3,4-dihydroxy)phenylethyl]-(3,4-dihydroxy)phenyl-1,2-ethandiol, 1-O-[2-(4-
hydroxy)phenylethyl]-(3,4-dihydroxy)phenyl-1,2-ethandiol, D(+)-erythro-1-(4-hydroxy-3-methoxy)-phenyl-1,2,3-
propantriol, p-hydroxyphenethyl-β-D-glucopyranoside, 2(3,4-dihydroxyphenyl)ethanol 3β-D-glucopyranoside, and
2(3,4-dihydroxyphenyl)ethanol 4β-D-glucopyranoside were also confirmed as constituents of the waste-waters
The pharmacokinetics of anthocyanins and their metabolites in humans
Background and Purpose: Anthocyanins are phytochemicals with reported vasoactive bioactivity. However, given their instability at neutral pH, they are presumed to undergo significant degradation and subsequent biotransformation. The aim of the present study was to establish the pharmacokinetics of the metabolites of cyanidin-3-glucoside (C3G), a widely consumed dietary phytochemical with potential cardioprotective properties. Experimental Approach: A 500 mg oral bolus dose of 6,8,10,3′,5′-13C5-C3G was fed to eight healthy male participants, followed by a 48 h collection (0, 0.5, 1, 2, 4, 6, 24, 48 h) of blood, urine and faecal samples. Samples were analysed by HPLC-ESI-MS/MS with elimination kinetics established using non-compartmental pharmacokinetic modelling. Key Results: Seventeen 13C-labelled compounds were identified in the serum, including 13C5-C3G, its degradation products, protocatechuic acid (PCA) and phloroglucinaldehyde (PGA), 13 metabolites of PCA and 1 metabolite derived from PGA. The maximal concentrations of the phenolic metabolites (Cmax) ranged from 10 to 2000 nM, between 2 and 30 h (tmax) post-consumption, with half-lives of elimination observed between 0.5 and 96 h. The major phenolic metabolites identified were hippuric acid and ferulic acid, which peaked in the serum at approximately 16 and 8 h respectively. Conclusions and Implications: Anthocyanins are metabolized to a structurally diverse range of metabolites that exhibit dynamic kinetic profiles. Understanding the elimination kinetics of these metabolites is key to the design of future studies examining their utility in dietary interventions or as therapeutics for disease risk reduction
Protein–phenolic interactions and inhibition of glycation – combining a systematic review and experimental models for enhanced physiological relevance
Background: While antiglycative capacity has been attributed to (poly)phenols, the exact mechanism of action remains unclear. Studies so far are often relying on supra-physiological concentrations and use of non-bioavailable compounds.<p></p> Methods: To inform the design of a physiologically relevant in-vitro study, we carried out a systematic literature review of dietary interventions reporting plasma concentrations polyphenol metabolites. Bovine Serum Albumin (BSA) was pre-treated prior to in vitro glycation: either no treatment (native), pre-oxidised (incubated with 10nM H2O2, for 8 hours) or incubated with a mixture of phenolic acids at physiologically relevant concentrations, for 8 hours). In-vitro glycation was carried out in presence of i) glucose only (0, 5 or 10mM), ii) glucose (0, 5 or 10mM) plus H2O2 (10nM), or iii) glucose (0, 5 or 10mM) plus phenolic acids (10-160nM). Fructosamine was measured using the nitroblue tetrazolium method.<p></p> Results: Following (high) dietary polyphenol intake, 3-hydroxyphenylacetic acid is the most abundant phenolic acid in peripheral blood (up to 338μM) with concentrations for other phenolic acids ranging from 13nM-200μM. Presence of six phenolic acids with BSA during in-vitro glycation did not lower fructosamine formation. However, when BSA was pre-incubated with phenolic acids, significantly lower concentration of fructosamine was detected under glycoxidative conditions (glucose 5 or 10mM plus H2O2 10nM) (p<0.001 vs. native BSA).<p></p> Conclusion: Protein pre-treatment, either with oxidants or phenolic acids, is an important regulator of subsequent glycation in a physiologically relevant system. High quality in-vitro studies under conditions closer to physiology are feasible and should be employed more frequently.<p></p>
Identification and characterization of cytochrome P450 1232A24 and 1232F1 from Arthrobacter sp. and their role in the metabolic pathway of papaverine
Cytochrome P450 monooxygenases (P450s) play crucial roles in the cell metabolism and provide an unsurpassed diversity of catalyzed reactions. Here, we report the identification and biochemical characterization of two P450s from Arthrobacter sp., a gram-positive organism known to degrade the opium alkaloid papaverine. Combining phylogenetic and genomic analysis suggested physiological roles for P450s in metabolism, and revealed potential gene clusters with redox partners facilitating the reconstitution of the P450 activities in vitro. CYP1232F1 catalyzes the para demethylation of 3,4-dimethoxyphenylacetic acid to homovanillic acid while CYP1232A24 continues demethylation to 3,4-dihydroxyphenylacetic acid. Interestingly, the latter enzyme is also able to perform both demethylation steps with preference for the meta position. The crystal structure of CYP1232A24, which shares only 29% identity to previous published structures of P450s helped to rationalize the preferred demethylation specificity for the meta position and also the broader substrate specificity profile. In addition to the detailed characterization of the two P450s using their physiological redox partners, we report the construction of a highly-active whole-cell E. coli biocatalyst expressing CYP1232A24, which formed up to 1.77 g l-1 3,4-dihydroxyphenylacetic acid. Our results revealed the P450s' role in the metabolic pathway of papaverine enabling further investigation and application of these biocatalysts
Synergism Effect between Phenolic Metabolites and Endogenous Antioxidants in Terms of Antioxidant Activity
Polyphenolic compounds, widely distributed in plant kingdom, have been exhaustively studied for their bioactive properties specially antioxidant activity. However, they are extensively metabolized by human organism and the resulting metabolites are largely responsible for their effects. Furthermore, they may interact with the endogenous antioxidant network being this possibility scarcely studied. Plasma antioxidant network encompasses antioxidant enzymes and other substances such as uric acid. In addition, ascorbic acid is the major compound representing water soluble compartment both in foods and human body. The interaction of this vitamin with phenolic compound is largely unexplored. This work aims to study if there is a synergic effect between phenolic metabolites and main antioxidants (uric and ascorbic acid). For this purpose, the antioxidant activity was evaluated in terms of ORAC (oxygen radical absorbance capac
ity) and FRAP (ferricreducing antioxidant power) as these tests involved
either HAT (Hydrogen Atom Transfer) or SET (Single Electron Transfer) mechanisms. Additionally, a kinetic studied was developed to test if the rate constant presented a synergic effect. Protocatechuic acid, 3, 4 -dihydroxyphenylacetic acid, 3,4 -dihydroxyphenylpropionic acid and 3
-hydroxyphenylacetic acid were selected as they were metabolites of polyphenol compounds such as anthocyanins, quercetin, neohesperidin, chlorogenic acid and hesperetin present in wines, orange and strawberries. A synergic effect was proved for the combination of ascorbic acid with 3,4
-dihydroxyphenylacetic acid, both in terms of antioxidant activity and potent increase of velocity of the antioxidant reaction that took place.Ministerio de Economía y Competitividad AGL-2010-22152-C03-0
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Moderate Champagne consumption promotes an acute improvement in acute endothelial-independent vascular function in healthy human volunteers
Epidemiological studies have suggested an inverse correlation between red wine consumption and the incidence of CVD. However, Champagne wine has not been fully investigated for its cardioprotective potential. In order to assess whether acute and moderate Champagne wine consumption is capable of modulating vascular function, we performed a randomised, placebo-controlled, cross-over intervention trial. We show that consumption of Champagne wine, but not a control matched for alcohol, carbohydrate and fruit-derived acid content, induced an acute change in endothelium-independent vasodilatation at 4 and 8 h post-consumption. Although both Champagne wine and the control also induced an increase in endothelium-dependent vascular reactivity at 4 h, there was no significant difference between the vascular effects induced by Champagne or the control at any time point. These effects were accompanied by an acute decrease in the concentration of matrix metalloproteinase (MMP-9), a significant decrease in plasma levels of oxidising species and an increase in urinary excretion of a number of phenolic metabolites. In particular, the mean total excretion of hippuric acid, protocatechuic acid and isoferulic acid were all significantly greater following the Champagne wine intervention compared with the control intervention. Our data suggest that a daily moderate consumption of Champagne wine may improve vascular performance via the delivery of phenolic constituents capable of improving NO bioavailability and reducing matrix metalloproteinase activity
Antiproliferative, antimicrobial, and antifungal activities of polyphenol extracts from Ferocactus species
Polyphenols, obtained from natural resources, may possess important pharmacological
effects. The polyphenolic profiles of the stem extracts of six Ferocactus species (sp.): F. gracilis, F. pottsii,
F. herrerae, F. horridus, F. glaucescens, and F. emoryi, were measured using high-performance liquid
chromatography (HPLC) with diode-array detection (DAD). Additionally, anticancer, antibacterial,
and antifungal activities were examined. Results showed the presence of high to moderate amounts
of polyphenols in the extracts (phenolic acids: Protocatechuic acid, 3,4-dihydroxyphenylacetic
acid, cffeic acid, and vanillic acid; flavonoids: Rutoside and quercitrin). The highest amounts of
3,4-dihydroxyphenylacetic acid were found in F. glaucescens ((132.09 mg 100 dry weight (DW)),
F. pottsii (75.71 mg 100 DW), and F. emoryi (69.14 mg 100 DW) while rutoside content was
highest in F. glaucescens (107.66 mg 100 DW). Maximum antiproliferative activities were observed
against HeLa and Jurkat cancer cells, with F. glaucescens, F. emoryi, and F. pottsii showing the highest
anticancer activity. Most bacteria were sensitive to Ferocactus sp. stem extracts. Escherichia coli and
Staphylococcus aureus were the most sensitive. Excellent antifungal effects were observed against
Aspergillus ochraceus and A. niger. However, Penicillium funiculosum, P. ochrochloron, and Candida
albicans were relatively resistant. This is the first study reporting novel sources of polyphenols in
Ferocactus sp. with anticancer and antimicrobial activities
Human metabolism and elimination of the anthocyanin, cyanidin-3-glucoside: a 13C-tracer study
BACKGROUND: Evidence suggests that the consumption of anthocyanin-rich foods beneficially affects cardiovascular health; however, the absorption, distribution, metabolism, and elimination (ADME) of anthocyanin-rich foods are relatively unknown. OBJECTIVE: We investigated the ADME of a (13)C5-labeled anthocyanin in humans. DESIGN: Eight male participants consumed 500 mg isotopically labeled cyanidin-3-glucoside (6,8,10,3',5'-(13)C5-C3G). Biological samples were collected over 48 h, and (13)C and (13)C-labeled metabolite concentrations were measured by using isotope-ratio mass spectrometry and liquid chromatography-tandem mass spectrometry. RESULTS: The mean +/- SE percentage of (13)C recovered in urine, breath, and feces was 43.9 +/- 25.9% (range: 15.1-99.3% across participants). The relative bioavailability was 12.38 +/- 1.38% (5.37 +/- 0.67% excreted in urine and 6.91 +/- 1.59% in breath). Maximum rates of (13)C elimination were achieved 30 min after ingestion (32.53 +/- 14.24 mug(13)C/h), whereas (13)C-labeled metabolites peaked (maximum serum concentration: 5.97 +/- 2.14 mumol/L) at 10.25 +/- 4.14 h. The half-life for (13)C-labeled metabolites ranged between 12.44 +/- 4.22 and 51.62 +/- 22.55 h. (13)C elimination was greatest between 0 and 1 h for urine (90.30 +/- 15.28 mug/h), at 6 h for breath (132.87 +/- 32.23 mug/h), and between 6 and 24 h for feces (557.28 +/- 247.88 mug/h), whereas the highest concentrations of (13)C-labeled metabolites were identified in urine (10.77 +/- 4.52 mumol/L) and fecal samples (43.16 +/- 18.00 mumol/L) collected between 6 and 24 h. Metabolites were identified as degradation products, phenolic, hippuric, phenylacetic, and phenylpropenoic acids. CONCLUSION: Anthocyanins are more bioavailable than previously perceived, and their metabolites are present in the circulation fo
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