tannins and myricetin

Pathogenic bacteria in drinking water threaten human health and life. In the work, antimicrobial films composed of myricetin@tannic acid (My@TA) nanoparticles (NPs) and chitosan derivation microgels were developed to kill pathogenic bacteria in drinking water. Hydrophobic My was first made into water soluble My@TA NPs using a solvent exchange method with TA as stabilizer. Polymeric microgels of carboxymethyl chitosan (CMCS)/hydroxypropyltrimethyl ammonium chloride chitosan (HACC) were then fabricated with a blending method. CMCS&HACC/My@TA multilayer films were further deposited on the internal surface of PET bottles by using a layer-by-layer (LbL) assembly technique. The PET bottles coated with the films could effectively kill pathogenic bacteria in water such as S. aureus, E. coli, Staphylococcus epidermidis, Pseudomonas fluorescens, Listeria monocytogenes and methicillin resistant Staphylococcus aureus (MRSA). In addition, CMCS&HACC/My@TA films displayed good antioxidant activity, water resistance, and in vivo biocompatibility with heart, liver, spleen, lung and kidney organs. We believe that the container coated with CMCS&HACC/My@TA films can be applied to prevent microbial contamination of drinking water.

Topics: Anti-Bacterial Agents; Anti-Infective Agents; Chitosan; Drinking Water; Escherichia coli; Humans; Methicillin-Resistant Staphylococcus aureus; Microgels; Nanoparticles; Staphylococcus aureus; Tannins

The perception of tastes is sensed by the receptors that stimulate sensory cells. We previously reported that TRPA1 and TRPV1 channels expressed in the oral cavity of mammals, are activated by the auto-oxidized product of epigallocatechin gallate (oxiEGCG), a major astringent catechin in green tea. Here, we investigated and compared the sensitivity of TRPA1 and TRPV1 from various animals to astringent polyphenols. We selected three polyphenols, oxiEGCG, tannic acid and myricetin. HEK293T cells expressing TRPA1 or TRPV1 from mammal, bird, reptile, amphibian, and fish, were analyzed for their activation by the Ca

Topics: Ambystoma mexicanum; Amphibians; Animals; Calcium; Catechin; Chickens; Flavonoids; HEK293 Cells; Humans; Mice; Neurons; Oryzias; Polyphenols; Rats; Snakes; Tannins; TRPA1 Cation Channel; TRPV Cation Channels; Zebrafish; Zebrafish Proteins

Topics: Antioxidants; Biflavonoids; Biological Availability; Catechin; Cicer; Correlation of Data; Flavonoids; Flavonols; Inhibitory Concentration 50; Iron Chelating Agents; Lens Plant; Mass Spectrometry; Metabolomics; Phenols; Polyphenols; Proanthocyanidins; Seeds; Tannins; Vicia faba

Liquidambar styraciflua L., ALTINGIACEAE, popularly known as sweet gum or alligator tree, is an aromatic tree with a natural distribution in North America and acclimated in Brazil. In traditional medicine, L. styraciflua L is used for the treatment of stomach disorders, wounds, and coughs. The present study was designed to investigate the biological potential and chemical profile of extracts obtained from aerial parts of L. styraciflua L. The chemical profile was established using liquid chromatography-mass spectrometry analysis and the extracts were tested for total phenolics, flavonoids, and tannins using spectrophotometric assays. The anti-inflammatory activity of L. styraciflua L was tested using an inhibition of hyaluronidase enzyme assay, and cytotoxic activities were tested by the 3-(4,5-dimethylthiazol-2 yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. The synergy between the plant extracts with ciprofloxacin and tetracycline was studied by the checkerboard assay method against eight bacterial strains.The phytochemical investigation showed that the leaves and stem are rich in phenolics compounds (1419.34-1614.02 mg GAE/g, 875.21-1557.57 mg GAE/g, respectively), mainly flavonoids and hydrolyzable tannins. The samples of the stem exhibited the best anti-inflammatory activity. The butanol fraction of the stem was better than the commercial propolis extract. The hydroalcoholic extract of the stem and the propolis did not exhibit significant differences (p < 0.05) at any of the concentrations tested. A synergistic interaction was observed against the Gram-positive bacterial Enterococcus faecalis (hydroalcoholic extract of leaves and tetracycline) and Staphylococcus aureus (hydroalcoholic extract of stem and tetracycline). The IC50 values obtained for the extracts indicate the absence of toxicity and moderate cytotoxic for the hydroalcoholic extract of the stem. On the basis of our findings, L. styaciflua may be considered as a potential therapeutic source with high anti-inflammatory activity and synergistic interactions with antibiotics against bacteria.

Topics: Animals; Anti-Bacterial Agents; Anti-Inflammatory Agents; Antioxidants; Chlorocebus aethiops; Enterococcus faecalis; Flavonoids; Gallic Acid; Hydrolysis; Inhibitory Concentration 50; Liquidambar; Medicine, Traditional; Microbial Sensitivity Tests; Phenols; Phytochemicals; Plant Extracts; Plant Leaves; Plant Stems; Quercetin; Staphylococcus aureus; Tannins; Tetracycline; Vero Cells

Etlingera elatior is a well-known herb in Malaysia with various pharmaceutical properties.. E. elatior flowers grown in three different locations of Malaysia (Kelantan, Pahang and Johor), were investigated for differences in their content of secondary metabolites (total phenolics [TPC], total flavonoids [TFC], and total tannin content [TTC]) as well as for their antioxidant, anticancer, and antibacterial properties. Phenolic acids and flavonoids were isolated and identified using ultra-high performance liquid chromatography (UHPLC). Ferric reducing antioxidant potential (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays were used to evaluate the antioxidant activities. The anticancer activity of extracts was evaluated using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay.. When extracted with various solvents (aqueous and ethanolic), samples from the different locations yielded significantly different results for TPC, TFC, and TTC as well as antioxidant activity. Aqueous extracts of E. elatior flowers collected from Kelantan exhibited the highest values: TPC (618.9 mg/100 g DM), TFC (354.2 mg/100 g DM), TTC (129.5 mg/100 g DM), DPPH (76.4 %), and FRAP (6.88 mM of Fe (II)/g) activity with a half-maximal inhibitory concentration (IC50) of 34.5 μg/mL compared with extracts of flowers collected from the other two locations. The most important phenolic compounds isolated in this study, based on concentration, were: gallic acid > caffeic acid > tannic acid > chlorogenic acid; and the most important flavonoids were: quercetin > apigenin > kaempferol > luteolin > myricetin. Extracts of flowers from Kelantan exhibited potent anticancer activity with a IC50of 173.1 and 196.2 μg/mL against the tumor cell lines MCF-7 and MDA-MB-231 respectively, compared with extracts from Pahang (IC50 = 204.5 and 246.2 μg/mL) and Johor samples (IC50 = 277.1 and 296.7 μg/mL). Extracts of E. elatior flowers also showed antibacterial activities against Staphylococcus aureus, Bacillus subtilis, Listeria monocytogenes, Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa with minimal inhibitory concentrations (MIC) ranging from 30 to >100 μg/mL.. In general, therefore, based on the potent antioxidant and anticancer activity of flower extracts, it appears that E. elatior grown in the North-east of Malaysia (Kelantan) is a potential source of therapeutic compounds with anti-cancer activity.

Topics: Animals; Anti-Bacterial Agents; Antioxidants; Biphenyl Compounds; Flavonoids; Flowers; Gallic Acid; Humans; Hydroxybenzoates; Magnoliopsida; Malaysia; Microbial Sensitivity Tests; Phenols; Picrates; Plant Extracts; Quercetin; Staphylococcus aureus; Tannins

MALDI-TOF MS suggested that the high molecular weight proanthocyanidin (condensed tannin) from persimmon (Diospyros kaki L.) pulp comprised a heteropolyflavanol series with flavan-3-O-galloylated extenders, flavan-3-ol and flavonol terminal units, and A-type interflavan linkages. Thiolysis-HPLC-ESI-MS with DAD, electrochemical, and ESI-MS detection confirmed a previously unreported terminal unit, the flavonol myricetin, in addition to the typical flavan-3-ols catechin and epigallocatechin gallate. The extender units were epicatechin, epigallocatechin, (epi)gallocatechin-3-O-gallate, and (epi)catechin-3-O-gallate. The crude tannin had a high prodelphinidin content (65%) and a high degree of 3-O-galloylation (72%). The material was fractionated on Toyopearl TSK-HW-50-F to yield fractions distinguished by degree of polymerization (DP). Thiolysis suggested that the persimmon tannin was composed of polymers ranging from 7 to 20 kDa (DP 19-47), but sizes estimated by GPC were 50-70% smaller. The crude material was chemically degraded with acid to yield products that were amenable to NMR and ESI-MS analysis, which were used to establish for the first time that persimmon tannin has a mixture of B-type and A-type linkages.

Topics: Chromatography, Gel; Chromatography, High Pressure Liquid; Diospyros; Flavonoids; Flavonols; Molecular Weight; Proanthocyanidins; Spectrometry, Mass, Electrospray Ionization; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Tannins

The pH dependence of the complexes was determined by both potentiometric and spectrophotometric studies. Stability constants and stoichiometries of the formed complexes were determined using slope ratio method. Fe(III) was formed complexes with tannic acid of various stoichiometries, which in the 1:1 molar ratio at pH<3, in the 2:1 molar ratio at pH 3-7 and in the 4:1 molar ratio at pH>7. Fe(III) was formed complexes with myricetin in the 1:2 molar ratio at pH 4 and 5 and in the 1:1 molar ratio at pH 6. Stability constant values were found to be 10(5) to 10(17) and 10(5) to 10(9) for Fe(III)-tannic acid complexes and Fe(III)-myricetin complexes. Both tannic acid and myricetin were possessed minimum affinities to Cu(II) and Zn(II). They had less affinity for Al(III) than for Fe(III).

Topics: Flavonoids; Iron; Potentiometry; Spectrum Analysis; Tannins

Inhibition of the accumulation of amyloid beta-peptide (Abeta) and the formation of beta-amyloid fibrils (fAbeta) from Abeta, as well as the destabilization of preformed fAbeta in the CNS would be attractive therapeutic targets for the treatment of Alzheimer's disease (AD). We previously reported that nordihydroguaiaretic acid (NDGA) and wine-related polyphenols inhibit fAbeta formation from Abeta(1-40) and Abeta(1-42) as well as destabilizing preformed fAbeta(1-40) and fAbeta(1-42) dose-dependently in vitro. Using fluorescence spectroscopic analysis with thioflavin T and electron microscopic studies, we examined the effects of polymeric polyphenol, tannic acid (TA) on the formation, extension, and destabilization of fAbeta(1-40) and fAbeta(1-42) at pH 7.5 at 37 degrees C in vitro. We next compared the anti-amyloidogenic activities of TA with myricetin, rifampicin, tetracycline, and NDGA. TA dose-dependently inhibited fAbeta formation from Abeta(1-40) and Abeta(1-42), as well as their extension. Moreover, it dose-dependently destabilized preformed fAbetas. The effective concentrations (EC50) of TA for the formation, extension and destabilization of fAbetas were in the order of 0-0.1 microM. Although the mechanism by which TA inhibits fAbeta formation from Abeta as well as destabilizes preformed fAbeta in vitro is still unclear, it could be a key molecule for the development of therapeutics for AD.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Flavonoids; Kinetics; Masoprocol; Microscopy, Electron; Rifamycins; Tannins; Tetracycline; Thermodynamics

Our recent studies have shown that naturally occurring dietary plant phenols such as tannic acid, quercetin, myricetin, and anthraflavic acid are capable of inhibiting polycyclic aromatic hydrocarbon (PAH) metabolism and subsequent PAH-DNA adduct formation in epidermis of SENCAR mice (M. Das, et al., Cancer Res., 47: 760-766, 1987, and 47: 767-773, 1987). In this study these plant phenols were tested for their effects against PAHs and N-methyl-N-nitrosourea-induced skin tumorigenesis in mice. Each plant phenol was evaluated as a possible anticarcinogen in an initiation and promotion and a complete skin tumorigenesis protocol. In the two-stage tumor protocol in SENCAR mice using 7,12-dimethylbenz(a)anthracene, benzo(a)pyrene, and N-methyl-N-nitrosourea as the initiating agent followed by twice weekly applications of 12-O-tetradecanoylphorbol-13-acetate as tumor promoter each plant phenol afforded significant protection against skin tumorigenicity. The protective effects were verified both by prolongation of latency period and by subsequent tumor development. In the complete carcinogenesis protocol in BALB/c mice using 3-methylcholanthrene as a tumorigen the applications of each of the plant phenols 30 min prior to each PAH application afforded significant protection by delaying the onset and the subsequent development of skin tumors. Our results suggest that these plant phenols have substantial though variable potential for modifying the risk of skin tumorigenicity induced by a wide variety of chemicals and of these tannic acid was shown to have maximal chemoprotective effects.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Administration, Topical; Animals; Anthraquinones; Benzo(a)pyrene; DNA; Female; Flavonoids; Hydrolyzable Tannins; Methylcholanthrene; Methylnitrosourea; Mice; Mice, Inbred BALB C; Quercetin; Skin Neoplasms; Tannins