Amplification of the antioxidant properties of myricetin, fisetin, and morin following their oxidation.

Quercetin oxidation leads to the formation of a metabolite, 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone, whose antioxidant potency was recently reported to be a 1000-fold higher than that of its precursor. The formation of similar metabolites (BZF) is limited to certain flavonols (FL), among which are myricetin, fisetin, and morin. Here we addressed the consequences of inducing the auto-oxidation of these flavonols in terms of their antioxidant properties (assessed in ROS-exposed Caco-2 cells).

Chemical characterization and microencapsulation of extracellular fungal pigments.

In this work, extracellular colored metabolites obtained from the filamentous fungi Talaromyces australis and Penicillium murcianum, isolated in the Andean-Patagonian native forests of Chile, were studied as prospect compounds to increase the sustainability of cosmetic products. The chemical and antioxidant properties of these natural pigments were characterized and strategies for their microencapsulation were also studied. UHPLC/MS-MS analyses indicated that the predominant metabolites detected in the cultures of P.

Improvement of endothelial function by Gunnera tinctoria extract with antioxidant properties.

Background: Gunnera tinctoria has been collected by Mapuche-Pewenche people for food and medicinal purposes. The high polyphenol content of methanolic extract from G. tinctoria leaves with chemical constituents such as ellagic acid and quercetin derivatives suggests its application to prevent endothelial dysfunction and oxidative stress.

Metabolomic Analysis, Fast Isolation of Phenolic Compounds, and Evaluation of Biological Activities of the Bark From Cav. (Cunoniaceae).

Cav. (Cunoniaceae) (local name, tineo; Mapuche names, madén, mëdehue) is an endemic species of Chile and Argentina used in Mapuche traditional medicine in the treatment of chronic diarrhea, inflammation, and wound healing. This study focused on the isolation, analysis, and characterization of the biological activity of compounds and bark extracts from this plant for the first time.

N-Acetyl Cysteine and Catechin-Derived Polyphenols: A Path Toward Multi-Target Compounds Against Alzheimer's Disease.

Background: Alzheimer's disease (AD) is a multifactorial disease, that involves neuroinflammatory processes in which microglial cells respond to "damage signals". The latter includes oligomeric tau, iron, oxidative free radicals, and other molecules that promotes neuroinflammation in the brain, promoting neuronal death and cognitive impairment. Since AD is the first cause of dementia in the elderly, and its pharmacotherapy has limited efficacy, novel treatments are critical to improve the quality of life of AD patients.

Low nanomolar concentrations of a quercetin oxidation product, which naturally occurs in onion peel, protect cells against oxidative damage.

The occurrence of the quercetin oxidation metabolite 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (BZF), whose antioxidant potency is notably higher than the antioxidant potency of quercetin, was investigated in twenty quercetin-rich plant foods. BZF was identified (HPLC-DAD-ESI-MS/MS) only in the dry outer scales of onions and shallots. Aqueous extracts of onions (OAE) and shallots (SAE) were evaluated for their antioxidant and cytoprotective properties.

Protective Effect of an Avocado Peel Polyphenolic Extract Rich in Proanthocyanidins on the Alterations of Colonic Homeostasis Induced by a High-Protein Diet.

Avocado peel, a byproduct from the avocado pulp industry, is a promising source of polyphenolic compounds. We evaluated the effect of a proanthocyanidin-rich avocado peel polyphenol extract (AvPPE) on the composition and metabolic activity of human fecal microbiota cultured for 24 h in a bioreactor in the presence of high protein (HP) amounts and the effect of the resulting culture supernatants (CSs) on HT-29Glc and Caco-2 cells. AvPPE decreased the HP-induced production of ammonia, HS, propionate, and isovalerate and increased that of indole and butyrate.

Effect of a proanthocyanidin-rich polyphenol extract from avocado on the production of amino acid-derived bacterial metabolites and the microbiota composition in rats fed a high-protein diet.

The consumption of high-protein diets (HPDs) increases the flux of undigested proteins moving to the colon. These proteins are hydrolyzed by bacterial proteases and peptidases, releasing amino acids, which in turn are metabolized by the intestinal microbiota (IM) for protein synthesis and production of various metabolites that can exert positive or deleterious effects, depending on their concentrations, at the colonic or systemic level. On the other hand, proanthocyanidins are polymers of flavan-3-ols which cannot be absorbed at the intestinal level, accumulating in the colon where they are fermented by the IM producing metabolites that appear beneficial for colonocytes and also at the peripheral level.

Pharmacokinetics of low molecular weight phenolic compounds in gerbil plasma after the consumption of calafate berry (Berberis microphylla) extract.

Calafate is a berry with high concentration of anthocyanins and hydroxycinnamic acids that grows in South Patagonia. To date, no metabolism studies of phenolic compounds using calafate have been carried out. A calafate extract was characterized by HPLC-DAD-ESI-MS/MS.

Application of a JA-Ile Biosynthesis Inhibitor to Methyl Jasmonate-Treated Strawberry Fruit Induces Upregulation of Specific MBW Complex-Related Genes and Accumulation of Proanthocyanidins.

Fleshy fruits are an important source of anthocyanins and proanthocyanidins (PAs), which protect plants against stress, and their consumption provides beneficial effects for human health. In strawberry fruit, the application of exogenous methyl jasmonate (MeJA) upregulates anthocyanin accumulation, although the relationship between the jasmonate pathway and anthocyanin and PA biosynthesis in fruits remains to be understood. Anthocyanin and PA accumulation is mainly regulated at the transcriptional level through R2R3-MYB and bHLH transcription factors in different plant species and organs.

Oligostilbenoids in Vitis vinifera L. Pinot Noir grape cane extract: Isolation, characterization, in vitro antioxidant capacity and anti-proliferative effect on cancer cells.

The following oligostilbenoids were isolated from extracts of Vitis vinifera L. Pinot Noir grape canes produced at a pilot-plant scale: (E)-ε-viniferin, (E)-resveratrol, (E)-piceatannol, ampelopsin A, vitisin B, pallidol, (E)-δ-viniferin, (E)-ω-viniferin, (E)-trans-cis-miyabenol C, isorhapontigenin, scirpusin A, and a new isomer named isoscirpusin A. The antioxidant capacity of the isolated stilbenoids was studied by three different assays, and their 50% inhibition concentration (IC) against cancer cells was determined by MTT reduction assay.

Proanthocyanidin-containing polyphenol extracts from fruits prevent the inhibitory effect of hydrogen sulfide on human colonocyte oxygen consumption.

Hydrogen sulfide (HS), a metabolic end product synthesized by the microbiota from L-cysteine, has been shown to act at low micromolar concentration as a mineral oxidative substrate in colonocytes while acting as an inhibitor of oxygen consumption at higher luminal concentrations (65 µM and above). From the previous works showing that polyphenols can bind volatile sulfur compounds, we hypothesized that different dietary proanthocyanidin-containing polyphenol (PACs) plant extracts might modulate the inhibitory effect of HS on colonocyte respiration. Using the model of human HT-29 Glc-/+ cell colonocytes, we show here that pre-incubation of 65 µM of the HS donor NaHS with the different polyphenol extracts markedly reduced the inhibitory effect of NaHS on colonocyte oxygen consumption.

Quercetin Oxidation Paradoxically Enhances its Antioxidant and Cytoprotective Properties.

Quercetin oxidation is generally believed to ultimately result in the loss of its antioxidant properties. To test this assertion, quercetin oxidation was induced, and after each of its major metabolites was identified and isolated by HPLC-DAD-ESI-MS/MS, the antioxidant (dichlorodihydrofluorescein oxidation-inhibiting) and cytoprotective (LDH leakage-preventing) properties were evaluated in Hs68 and Caco2 cells exposed to indomethacin. Compared to quercetin, the whole mixture of metabolites (Q) displayed a 20-fold greater potency.

Evaluation of microextraction by packed sorbent, liquid-liquid microextraction and derivatization pretreatment of diet-derived phenolic acids in plasma by gas chromatography with triple quadrupole mass spectrometry.

Miniaturized sample pretreatments for the analysis of phenolic metabolites in plasma, involving protein precipitation, enzymatic deconjugation, extraction procedures, and different derivatization reactions were systematically evaluated. The analyses were conducted by gas chromatography with mass spectrometry for the evaluation of 40 diet-derived phenolic compounds. Enzyme purification was necessary for the phenolic deconjugation before extraction.

[Pediculicide effect of a Eucaliptus globulus L formulation].

Introduction: Pediculosis capitis is a public health problem with a high prevalence. The emergence of parasite resistance to conventional pediculicide is of great concern worldwide.

Objective: To develop alternatives pediculicide, effective and safe, based on the essential oil of Eucaliptus globulus.

Deleterious Effect of p-Cresol on Human Colonic Epithelial Cells Prevented by Proanthocyanidin-Containing Polyphenol Extracts from Fruits and Proanthocyanidin Bacterial Metabolites.

The protective effect of proanthocyanidin-containing polyphenol extracts from apples, avocados, cranberries, grapes, or proanthocyanidin microbial metabolites was evaluated in colonic epithelial cells exposed to p-cresol, a deleterious compound produced by the colonic microbiota from l-tyrosine. In HT29 Glc(-/+) cells, p-cresol significantly increased LDH leakage and decreased ATP contents, whereas in Caco-2 cell monolayers, it significantly decreased the transepithelial electrical resistance and increased the paracellular transport of FITC-dextran. The alterations induced by p-cresol in HT29 Glc(-/+) cells were prevented by the extracts from cranberries and avocados, whereas they became worse by extracts from apples and grapes.

Catechin-based procyanidins from Peumus boldus Mol. aqueous extract inhibit Helicobacter pylori urease and adherence to adenocarcinoma gastric cells.

In this work, the anti-Helicobacter pylori effect of an aqueous extract from dried leaves of Peumus boldus Mol. (Monimiaceae) was evaluated. This extract displayed high inhibitory activity against H.

Stimulation of cytosolic and mitochondrial calcium mobilization by indomethacin in Caco-2 cells: modulation by the polyphenols quercetin, resveratrol and rutin.

Background: The effect of indomethacin (INDO) on Ca(2+) mobilization, cytotoxicity, apoptosis and caspase activation and the potential protective effect of quercetin (QUE), resveratrol (RES) and rutin (RUT) were determined in Caco-2 cells.

Methods: Caco-2 cells were incubated with INDO in the presence or absence of QUE, RES or RUT. The concentrations of Ca(2+) in the cytosol (Fluo-3 AM) and mitochondria (Rhod-2 AM) were determined as well as the cytotoxicity (MTT reduction and LDH leakage), apoptosis (TUNEL) and caspase-3 and 9 activities.

Apple peel polyphenols protect against gastrointestinal mucosa alterations induced by indomethacin in rats.

The stability of an apple peel polyphenol extract (APPE) with powerful antioxidant activity was evaluated under acidic conditions in vitro, and its protective effect against gastrointestinal damage was investigated in rats treated with indomethacin. The antioxidant activity of APPE remained stable at pH 2.0 for 4 h.

In vitro and in vivo effects of apple peel polyphenols against Helicobacter pylori.

The inhibitory effects of a standarized apple peel polyphenol-rich extract (APPE) against Helicobacter pylori infection and vacuolating bacterial toxin (VacA) induced vacuolation were investigated. Apple peel polyphenols significantly prevented vacuolation in HeLa cells with an IC(50) value of 390 microg of gallic acid equivalents (GAE)/mL. APPE also displayed an in vitro antiadhesive effect against H.

In vitro inhibitory effect of apple peel extract on the growth of Helicobacter pylori and respiratory burst induced on human neutrophils.

In the present work, the in vitro effect of a standardized extract of apple peel APPE (60% of total polyphenols; 58% of flavonoids; 30% of flavan-3-ols and procyanidins) was evaluated with regard to the viability of Helicobacter pylori. The cytotoxic effect of APPE on H. pylori was also evaluated through the resazurin assay and ATP level determination.

Association between polymerization degree of apple peel polyphenols and inhibition of Helicobacter pylori urease.

Apple peel extracts and their fractions pooled according to their molecular size were prepared and evaluated for their inhibitory activity against Helicobacter pylori and Jack bean ureases. Urease Inhibitory effect of apple peel polyphenols (APPE) extracted from the Granny Smith variety was concentration-dependent and reversible. High molecular weight polyphenols (HMW) were more active against Helicobacter pylori and Jack bean ureases than low molecular weight polyphenols with IC50 values of 119 and 800 microg GAE/mL, respectively.

Cu(I)-glutathione complex: a potential source of superoxide radicals generation.

Cu(2+) ions and GSH molecules interact swiftly to form the complex Cu(I)-glutathione. We investigated the potential capacity of such complex to reduce molecular oxygen. The addition of SOD to a solution containing Cu(I)-glutathione led to a sustained decline of the basal oxygen level.