Search results for "polyphenols"
showing 10 items of 293 documents
Polyphenol Characterization, Antioxidant and Skin Whitening Properties of Alnus cordata Stem Bark
2019
In this study, we investigated the phenolic composition of the crude extract (MeOH 80 %) of Alnus cordata (Loisel.) Duby stem bark (ACE) and its antioxidant and skin whitening properties. RP-LC-DAD analysis showed a high content of hydroxycinnamic acids (47.64 %), flavanones (26.74 %) and diarylheptanoids (17.69 %). Furthermore, ACE exhibited a dose-dependent antioxidant and free-radical scavenging activity, expressed as half-maximal inhibitory concentration (IC50 ): Oxygen radical absorbance capacity (ORAC, IC50 1.78 μg mL-1 )>Trolox equivalent antioxidant capacity (TEAC, IC50 3.47 μg mL-1 )>2,2-Diphenyl-1-picrylhydrazyl (DPPH, IC50 5.83 μg mL-1 )>β-carotene bleaching (IC50 11.58 μg mL-1 )…
Inhibition of induced DNA oxidative damage by beers: correlation with the content of polyphenols and melanoidins.
2005
Beers are a source of dietary flavonoids; however, there exist differences in composition, alcohol concentration, and beneficial activities. To characterize these differences, three kinds of lager beer of habitual consumption in Spain, dark, blond, and alcohol-free, were assayed for total phenolic content, antioxidant activity, superoxide and hydroxyl radical scavenging activities, and in vitro inhibitory effect on DNA oxidative damage. Furthermore, their melanoidin content and correlation with antioxidant activity were evaluated. Dark beer contained the highest total phenolic (489 +/- 52 mg/L) and melanoidin (1.49 +/- 0.02 g/L) contents with a 2-fold difference observed when compared to th…
Nanosponges for the protection and release of the natural phenolic antioxidants quercetin, curcumin and phenethyl caffeate
2020
The inclusion of polyphenols into nanoporous materials may significantly improve their application as radical trapping agents for therapeutic purposes. In the present work, nanosponges based on hypercross- linked cyclodextrins and calixarenes (NS1–NS3) were used as carriers of three natural phenolic antioxidants: quercetin (Que), curcumin (Cur) and phenethyl caffeate (Phec). Good w/w loadings, namely 7.3% for the Que–NS1 composite, 17.3% for Cur–NS2 and 12.9% for Phec–NS3, were achieved. The release kinetics and the inhibition rate constants (kinh) of the reaction with alkylperoxyl radicals (ROO.) in 0.1 M phosphate buffer solutions at pH 7.4 were studied and indicated better antioxidant ac…
Use of Saccharomyces cerevisiae and Caenorhabditis elegans as model organisms to study the effect of cocoa polyphenols in the resistance to oxidative…
2011
Developing functional foods to improve the quality of life for elderly people has great economic and social impact. Searching for and validating ingredients with in vivo antioxidant effects is one of the key steps in developing this kind of food. Here we describe the combined use of simple biological models and transcriptomics to define the functional intracellular molecular targets of a polyphenol-enriched cocoa powder. Cocoa powder supplemented culture medium led to increased resistance to oxidative stress, in both the budding yeast Saccharomyces cerevisiae and the nematode Caenorhabditis elegans, and, in the latter, lifespan was also increased. These effects are fully dependent on the po…
Polyphenols pattern and correlation with antioxidant activities of berries extracts from four different populations of SicilianSambucus nigraL.
2014
Sambucus nigra L. (Caprifoliaceae) is wide spread in temperate and sub-tropical zones. The consumption of its berries has been associated with health benefits especially for its high content of natural antioxidants such as polyphenols, in particular anthocyanins. In this work we investigated the polyphenolic composition and the in vitro antioxidant activities (ABTS, DPPH, BCB and FRAP-ferrozine (FRAP-FZ) assays) of S. nigra berries, collected in four different Sicilian areas (Italy). Elderberries are considered one of the fruits with highest anthocyanins content, the amount of phenolic compounds, other than anthocyanins, is approximately 1.5 times greater than the latter. The LC–MS analyses…
Coffee components and cardiovascular risk: beneficial and detrimental effects
2014
Coffee consists of several biological active compounds, such as caffeine, diterpenes, chlorogenic acids, and melanoidins, which may affect human health. The intake of each compound depends on the variety of coffee species, roasting degree, type of brewing method and serving size. The bioavailability and the distribution of each compound and its metabolites also contribute to coffee mechanisms of action. The health benefits of coffee consumption regarding cardiovascular system and metabolism mostly depend on its antioxidant compounds. In contrast, diterpenes and caffeine may produce harmful effects by raising lipid fraction and affecting endothelial function, respectively. Studying the mecha…
Extraction of polyphenols in Himanthalia elongata and determination by high performance liquid chromatography with diode array detector prior to its …
2016
Abstract Several studies have demonstrated the antioxidant capacity of seaweeds, which can be used for the development of biopharmaceuticals with extensive medical application. Antioxidant therapies appear to attenuate the organic deterioration originated by an excessive oxidative stress, which could prevent the harmful effects of various injuries such as ischemia-reperfusion (I/R) among others. Marine brown seaweeds play a significant role, as they are the only organisms on earth producing phlorotannins, which are polyphenols that exhibit important biological activity. To ensure obtaining an extract with the greatest antioxidant activity, some variables that affect the extraction of polyph…
Wine Consumption and Oral Cavity Cancer: Friend or Foe, Two Faces of Janus
2020
The health benefits of moderate wine consumption have been extensively studied during the last few decades. Some studies have demonstrated protective associations between moderate drinking and several diseases including oral cavity cancer (OCC). However, due to the various adverse effects related to ethanol content, the recommendation of moderate wine consumption has been controversial. The polyphenolic components of wine contribute to its beneficial effects with different biological pathways, including antioxidant, lipid regulating and anti-inflammatory effects. On the other hand, in the oral cavity, ethanol is oxidized to form acetaldehyde, a metabolite with genotoxic properties. This rev…
Phytochemical, ecological and antioxidant evaluation of wild Sicilian thyme: Thymbra capitata (L.) Cav.
2016
In a broad survey conducted throughout the Sicily region, 45 different sites were identified where thyme grows wild. All the biotypes collected were classified as Thymbra capitata (L.) Cav. (syn. Thymus capitatus (L.) Hoffmanns. & Link). Cluster analysis based on the main morphological characteristics of the plant led to the division of the biotypes into 3 major groups. All samples were analyzed for their secondary phytochemical metabolites identified in the extracts and the essential oils. LC-UV-DAD/ESI-MS and GC-FID/GC-MS have been applied to characterize the extracts and the essential oils, respectively. In the extracts, 15 flavonoid derivatives with taxifolin-di-O-glucoside and thymusin…
Evaluation of fermentation assisted by Lactobacillus brevis POM, and Lactobacillus plantarum (TR-7, TR-71, TR-14) on antioxidant compounds and organi…
2020
Abstract The impact of fermentation assisted by four different lactic acid bacteria (LAB) on polyphenols, carotenoids, organic acids, and antioxidant capacity of orange-juice milk based beverages was evaluated. Lactobacillus brevis POM, and Lactobacillus plantarum (TR-7, TR-71, TR-14) were used to promote the fermentation of the beverages for 72 h at 37 °C. The bacteria population increased with the elapse of fermentation period, except for beverages inoculated with L. plantarum TR-7. After fermentation period, total polyphenols, total carotenoids and total antioxidant capacity were increased compared to the control ones (non-fermented). Two phenolic acids (DL-3-phenylactic acid and 3–4-dih…