tannins and caffeic-acid

The binding interactions between young apple polyphenols and porcine pancreatic α-amylase were investigated through isothermal titration calorimetry (ITC), differential scanning calorimetry (DSC) and molecular docking. The results obtained were compared with those obtained through inhibition kinetics and fluorescence quenching. It was found that binding of tannic acid, chlorogenic acid, caffeic acid and epicatechin with α-amylase is an exothermal process, with the binding constants in the order of tannic acid > chlorogenic acid > caffeic acid > epicatechin. This is consistent with the orders of reciprocal of competitive inhibition constant and fluorescence quenching constant. The binding energy obtained through molecular docking showed the same order, except for epicatechin. These results are consistent with the inhibition of α-amylase being caused by the binding of the polyphenols with the enzyme. In addition, from the fluorescence quenching and DSC data, total polyphenols, tannic acid, chlorogenic acid and caffeic acid were found to partially unfold the enzyme structure.

Topics: Animals; Binding Sites; Caffeic Acids; Calorimetry; Catalytic Domain; Chlorogenic Acid; Malus; Molecular Docking Simulation; Pancreatic alpha-Amylases; Polyphenols; Swine; Tannins; Thermodynamics

Previously, we reported that coffee extract and its constituents, caffeic acid (CA) and p-coumaric acid, inhibit infection by the hepatitis C virus (HCV). In the present report, we identified another coffee-related compound, tannic acid (TA), which also inhibits HCV infection. We systematically evaluated which steps of the viral lifecycle were affected by CA and TA. TA substantially inhibits HCV RNA replication and egression, while CA does not. The infectivity of the HCV pretreated with CA or TA was almost lost. Cellular attachment of HCV particles and their interaction with apolipoprotein E, which is essential for HCV infectivity, were significantly reduced by CA. These results indicate that CA inhibits HCV entry via its direct effect on viral particles and TA inhibits HCV RNA replication and particle egression as well as entry into host cells. Taken together, our findings may provide insights into CA and TA as potential anti-HCV strategies.

Topics: Antiviral Agents; Apolipoproteins E; Caffeic Acids; Cell Line, Tumor; Hepacivirus; Hepatitis C; Humans; RNA, Viral; Tannins

We evaluated the antioxidant activity of natural polyphenols which gives high oxidative stability to the pecan oil. The in vitro DPPH radical scavenging, reducing power and total antioxidant activity of tested antioxidants demonstrated that tannic acid displayed the highest DPPH scavenging activity and provided the largest reducing power. During storage of pecan oil, based on oxidative stability tests, we further evaluated the protective effect of polyphenols and synthetic antioxidants on the oxidative stability of pecan oil. The results showed that caffeic acid inhibited oxidation of pecan oil effectively. Sesamol and catechin showed slight improvement in oxidative stability, while ferulic acid, erucic acid and rutin had no effect. Taken together, compared with synthetic antioxidants (TBHQ, BHT, BHA), caffeic acid was observed to be stronger than BHT and BHA and was close to TBHQ.

Topics: Antioxidants; Biphenyl Compounds; Caffeic Acids; Carya; Gas Chromatography-Mass Spectrometry; Oxidation-Reduction; Picrates; Plant Oils; Polyphenols; Tannins; Thiobarbituric Acid Reactive Substances

We searched for inhibitors against prolyl isomerase Pin1 in order to develop functional foods to prevent and cure various Pin1 related diseases such as cancer, diabetes, cardiovascular disease, Alzheimers's disease, and so on. We created a polyphenol library consisting of ingredients in healthy foods and beverages, since polyphenols like epigallocatechin gallate (EGCG) in green tea and 974B in brown algae had been identified as its Pin1 inhibitors. Several polyphenols such as EGCG derivatives, caffeic acid derivatives and tannic acid inhibited Pin1 activity. These results provide a first step in development of the functional foods and beverage targeting Pin1 and its related diseases.

Topics: Caffeic Acids; Catechin; Food; HCT116 Cells; Humans; NIMA-Interacting Peptidylprolyl Isomerase; Polyphenols; Quercetin; Rutin; Tannins

Young apple polyphenols (YAP) and nine types of phenolic compounds were investigated regarding the inhibitory activity against porcine pancreatic α-amylase (PPA) in vitro. Tannic acid, chlorogenic acid and caffeic acid in YAP showed relatively high inhibition with the IC50 values of 0.30, 1.96 and 3.69mg/mL, respectively. A detailed kinetics of inhibition study revealed that YAP and tannic acid were competitive inhibitors of PPA, whereas chlorogenic acid and caffeic acid were mixed inhibitors, exhibiting both competitive and uncompetitive characteristics. The fluorescence of PPA could be significantly quenched by YAP and the three polyphenols, and their quenching constants were determined. The results showed that for the polyphenols investigated, the order of the apparent static quenching constants (KFQ) was in agreement with that of the reciprocal competitive inhibition constants (1/Kic) (tannic acid>chlorogenic acid>caffeic acid>epicatechin); both of the parameters were contrary to the order of the IC50 values. Thus, combining detailed kinetics and fluorescence quenching studies can be applied to characterise the interactions between polyphenols in young apples and α-amylase.

Topics: Animals; Caffeic Acids; Catechin; Chlorogenic Acid; Fluorescence; Malus; Pancreas; Pancreatic alpha-Amylases; Phenols; Polyphenols; Swine; Tannins

Currently, no effective crosslinking reagents are available to treat xenogenic decellularized heart valve matrices. The study aim was to evaluate the crosslinking effect of quercetin, catechin, caffeic acid and tannic acid on porcine aortic valve matrices.. Cytotoxicity of the different crosslinkers was evaluated. The mechanical properties of crosslinked porcine matrices and control matrices (non-fixed) were examined by tensile strength testing, as was the cytocompatibility of the fixed matrices. Crosslinked and control matrices were implanted subcutaneously in Wistar rats (n = 9) and, after two weeks, their calcium contents were determined using inductively coupled plasma-mass spectrometry. The antibody reaction against porcine tissue in rat serum was also determined.. Cytotoxicity studies showed that crosslinkers, even at high concentrations, did not inhibit cell viability. All crosslinkers except tannic acid improved the mechanical strength of acellular porcine matrices. Moreover, the tensile strength of quercetin-fixed matrices was comparable with that of glutaraldehyde (GTA)-fixed leaflets. Light microscopic evaluation showed that crosslinked matrices caused only a mild lymphocytic inflammatory reaction. Furthermore, quercetin-fixed leaflets exhibited a well-preserved matrix without infiltration of CD3+ cells. After two weeks, calcium levels were 206.33 µg/mg for controls (non-fixed), and 151.33 µg/mg, 181 µg/mg and 163.66 µg/mg for quercetin-, catechin-, and caffeic acid-fixed matrices, respectively. At two weeks after implantation the quercetin-crosslinked matrices also elicited the lowest levels of IgG antibodies.. The study results identified quercetin as the most suitable crosslinker for heart valve tissue engineering, and a possible alternative to GTA. Further studies are essential to determine whether quercetin crosslinking will allow autologous cell repopulation in order to create a viable heart valve.

Topics: Animals; Aortic Valve; Bioprosthesis; Caffeic Acids; Catechin; Cell Proliferation; Cell Survival; Cells, Cultured; Cross-Linking Reagents; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Prosthesis Design; Quercetin; Rats, Wistar; Swine; Tannins; Tensile Strength; Time Factors; Tissue Engineering

Phytochemical analysis of lyophilised aqueous extract of the stem bark of Scutia buxifolia (SBSB) was carried out by determining total phenolics (0.280 ± 0.02 mg of gallic acid equivalents/g of extract), flavonoids (17.42 ± 2.95 mg of quercetin equivalents/g of extract) and tannins (1.28 ± 0.15 mg of catechin equivalents/g of extract) contents followed by a high-performance liquid chromatography/diode array detection (HPLC/DAD) analysis. The HPLC profile showed caffeic acid, being the major constituent of SBSB (247.21 ± 2.17 mg g⁻¹ of extract). The antioxidant scavenging capacity of SBSB was determined by 2,2-diphenyl-2-picrylhydrazyl (DPPH) assay. The antioxidant power of SBSB was comparable with that of the antioxidant ascorbic acid. Acute toxicity was assayed in rats whereas catalase activity and malondialdehyde production were determined in rats' liver. The SBSB showed safety in the dose tested. This report is the first realised in animals for S. buxifolia.

Topics: Animals; Antioxidants; Ascorbic Acid; Caffeic Acids; Catechin; Chromatography, High Pressure Liquid; Flavonoids; Liver; Phenols; Plant Bark; Plant Extracts; Plant Stems; Rats; Rhamnaceae; Tannins

We examined the free radical scavenging activity of Sasa veitchii extract (Hoshi's Striped Bamboo Extract(®), HSBE), well known in folk medicine as an efficient drug and antioxidant in detail. To evaluate the free radical scavenging activity of HSBE, its reactivity as hydrogen atom donor toward the 1, 1-diphenyl-2-picrylhydrazyl has been measured using stopped-flow spectrophotometry. It was found that the second-order rate constant, k(2), obtained at 25 °C was 1.4 (g/L)(-1) s(-1) for HSBE. To compare different chain-breaking antioxidants quantitatively, we obtained the second-order rate constant, k(2)', on the molar basis of active hydroxyl groups in the tested substances. As a result, the k(2)' values for HSBE, 6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (Trolox), caffeic acid, and (+)-catechin were 2.6 × 10(3), 2.0 × 10(3), 2.3 × 10(2), and 6.0 × 10(2) M(-1) s(-1), respectively. These results show that HSBE and Trolox exerted the same free radical scavenging activity under these conditions. In addition, HSBE significantly inhibited the oxidation of methyl linoleate micelles in aqueous dispersions at 30 °C and its antioxidant activity (k(inh)) was more effective than those of caffeic acid and (+)-catechin. This is the first study on bamboo extracts in the context of radical scavenging activity that reports kinetic results.. We determined the stoichiometric number and the rate constants of bamboo extracts using the method that was devised in determining the antioxidant activity of mixtures. This is the first study of bamboo extracts as an antioxidant that reports the stoichiometric and kinetic results.

Topics: Biphenyl Compounds; Caffeic Acids; Catechin; Chromans; Flavonoids; Free Radical Scavengers; Kinetics; Linoleic Acids; Micelles; Oxidation-Reduction; Phenol; Picrates; Plant Extracts; Sasa; Tannins

Solanum guaraniticum is a shrub belonging to the Solanaceae family popularly known in Brazil as jurubeba or false-jurubeba. The aim of this study was to evaluate the antioxidant activity of crude extract and chloroform, ethyl acetate and n-butanol fractions from its leaves, verifying the ability to remove reactive species and identify and quantify phenolic compounds. The ethyl acetate fraction showed the highest amount of total polyphenols (546.57 ± 2.35 mg gallic acid equivalent/g) and the lowest IC(50) (9.11 ± 0.75 µg/mL) by the DPPH method. Furthermore, the chloroform fraction presented the highest content of flavonoids (75.73 ± 0.34 mg rutin equivalents/g), tannins (56.03 ± 0.68 mg catechin equivalents/g) and alkaloids (10.79 ± 0.06 mg/g). This fraction was effective in the scavenging of reactive species by 2',7'-dichlorofluorescein diacetate assay, in addition to completely reducing protein carbonyl content and reducing lipid peroxidation at basal levels even at low concentrations. Chlorogenic, caffeic and rosmarinic acids were identified and quantified by HPLC/DAD. These results show that S. guaraniticum is rich in phenolic compounds and has potential as an antioxidant.

Topics: Alkaloids; Animals; Biphenyl Compounds; Blood Proteins; Brain; Caffeic Acids; Chlorogenic Acid; Cinnamates; Depsides; Flavonoids; Fluoresceins; Free Radical Scavengers; Inhibitory Concentration 50; Lipid Peroxidation; Male; Oxidative Stress; Picrates; Plant Extracts; Plant Leaves; Plants, Medicinal; Protein Carbonylation; Rats; Rats, Wistar; Rosmarinic Acid; Solanum; Tannins; Thiobarbituric Acid Reactive Substances

Cross-linking gelatin with natural phenolic compound caffeic acid (CA) or tannic acid (TA) above pH 9 resulted in formation of insoluble hydrogels. The cross-linking reactivity was controlled by variation of pH, the concentration of the gelatin solution, or the amount of CA or TA used in the reaction. The cross-linking chemistry was studied by high-resolution NMR technique in both solution and solid state via investigation on small molecular model systems or using (13)C enriched caffeic acid (LCA) in the reaction with gelatin. Direct evidence was obtained to confirm the chemical reactions occurring between the phenolic reactive sites of the phenolic compounds and the amino groups in gelatin to form C-N covalent bonds as cross-linking linkages in gelatin matrix. The cross-linked network was homogeneous on a scale of 2-3 nm. The cross-linking resulted in a significant decrease in the molecular mobility of the hydrogels, while the modulus of the films remained at high values at high temperatures.

Topics: Caffeic Acids; Cross-Linking Reagents; Gelatin; Hydrogels; Magnetic Resonance Spectroscopy; Materials Testing; Models, Molecular; Molecular Structure; Tannins

Ethanolic extracts of 30 Thai medicinal plants, traditionally used as alternative treatments in diabetes, were evaluated for antioxidative activity by the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) method. They were evaluated in vitro for oxidative stress by thiobarbituric acid-reactive substance (TBARS) assay in pooled plasma of diabetic patients compared to without treatment of the extracts (control). The extracts were also assayed for protein glycation. The results showed that five plants had strong antioxidant activity: Phyllanthus emblica Linn. (PE), Terminalia chebula Retz. (TC), Morinda citrifolia Linn. (MC), Kaempferia parviflora Wall. (KP) and Houttuynia cordata Thunb.(HC), respectively. Thirty plant extracts were good correlation between total antioxidant activity and antiradical activity by TBARS as well as by glycation (r = 0.856, p<0.01 and r = 0.810, p<0.01). PE had stronger antioxidative activity as well as inhibition of TBARS and glycation than the other plants. The investigation showed that total polyphenol and tannin content of PE and the flavonoid content of HC were the highest. The results imply that these plants are potential sources of natural antioxidants which have free radical scavenging activity and might be used for reducing oxidative stress in diabetes.

Topics: Antioxidants; Benzothiazoles; Caffeic Acids; Catechin; Diabetes Mellitus, Type 2; Flavonoids; Free Radicals; Gallic Acid; Glycation End Products, Advanced; Humans; Lipid Peroxidation; Medicine, Traditional; Molecular Structure; Oxidative Stress; Phenols; Plant Extracts; Plants, Medicinal; Polyphenols; Pyrogallol; Rutin; Sulfonic Acids; Tannins; Thailand; Thiobarbituric Acid Reactive Substances

The inhibitory effect of some plant oil aromatics against three strains of Arcobacter butzleri, two strains of Arcobacter cryaerophilus, and one strain of Arcobacter skirrowii was evaluated. When MICs were determined using the broth macrodilution method, cinnamaldehyde was most inhibitory followed by thymol, carvacrol, caffeic acid, tannic acid, and eugenol (P < 0.001). Sublethal concentrations of the three most potent plant oil aromatics also were examined. Overall, cinnamaldehyde was the most bacteriostatic against all arcobacters tested except A. butzleri when these strains were exposed to the MIC25 of this aromatic aldehyde. The bacteriostatic activities of thymol and carvacrol were concentration and species dependent.

Topics: Acrolein; Arcobacter; Caffeic Acids; Colony Count, Microbial; Consumer Product Safety; Cymenes; Dose-Response Relationship, Drug; Eugenol; Food Preservation; Food Preservatives; Humans; Microbial Sensitivity Tests; Monoterpenes; Plant Oils; Species Specificity; Tannins; Thymol

Twenty varieties of ber (Zizyphus mouritiana), namely umaran, katha, bilayati, kaithli, ZG-3, gola, safeda rohtak, takadi, tikari, banarasi karaka, seo, sonaur-2, sonaur-3, ilaichi, mundia murahra, pathan, kakrola gola, seb, golden yellow and chhuhara, were investigated for the presence of phenolic acids in stem bark, leaves and fruits using high performance liquid chromatograph. Results indicated the presence of tannic (retention time (Rt.) 2.76 min), gallic (Rt. 2.86 min), caffeic (Rt. 3.12 min), vanillic (Rt. 3.26 min), ferulic (Rt. 3.42 min), chlorogenic (Rt. 4.16 min) and cinnamic acids (Rt. 4.45 min) in varying amounts in different parts in of these varieties. In fruits of seven varieties, namely, kaithly, sonaur-2, sonaur-3, mundia murahra, pathan, golden yellow and chhuhara, oxalic acid (Rt. 3.00 min) was also detected. Pharmacological properties of phenolic acids of fruits in relation to human health and the possible implications of different phenolic acids in chemotaxonomy of different varieties of ber are discussed.

Topics: Antioxidants; Caffeic Acids; Chromatography, High Pressure Liquid; Coumaric Acids; Gallic Acid; Humans; Hydroxybenzoates; India; Plant Bark; Plant Extracts; Species Specificity; Tannins; Vanillic Acid; Ziziphus

Foliar spray and micro-injection of plant growth-promoting rhizobacterial species, viz. Pseudomonas fluorescens and P. aeruginosa on chickpea induced synthesis of phenylalanine ammonia-lyase (PAL) when tested against Sclerotinia sclerotiorum. Induction of PAL was also associated with increased synthesis of phenolic compounds such as tannic, gallic, caffeic, chlorogenic and cinnamic acids. Treatment with P. fluorescens was found to be more effective in inducing phenolic compounds as compared to P. aeruginosa. However, persistence of PAL activity was observed more with P. aeruginosa. Although both the inoculation methods were effective, foliar application was found to be superior to micro-injection in terms of rapid PAL activity leading to the synthesis of phenolic compounds.

Topics: Antibiosis; Ascomycota; Caffeic Acids; Chlorogenic Acid; Cicer; Cinnamates; Gallic Acid; Pest Control, Biological; Phenylalanine Ammonia-Lyase; Plant Diseases; Plant Roots; Pseudomonas aeruginosa; Pseudomonas fluorescens; Tannins

Saccharomyces cerevisiae served as a model fungal system to examine functional genomics of oxidative stress responses and reactions to test antioxidant compounds. Twenty-two strains of S. cerevisiae, including a broad spectrum of singular gene deletion mutants, were exposed to hydrogen peroxide (H2O2) to examine phenotypic response to oxidative stress. Responses of particular mutants treated with gallic, tannic or caffeic acids, or methyl gallate, during H2O2 exposure, indicated that these compounds alleviated oxidative stress. These compounds are also potent inhibitors of aflatoxin biosynthesis in Aspergillus flavus. To gain further insights into a potential link between oxidative stress and aflatoxin biosynthesis, 43 orthologs of S. cerevisiae genes involved in gene regulation, signal transduction (e.g., SHO1, HOG1, etc.) and antioxidation (e.g., CTT1, CTA1, etc.) were identified in an A. flavus expressed sequence tag library. A successful exemplary functional complementation of an antioxidative stress gene from A. flavus, mitochondrial superoxide dismutase (sodA), in a sod2Delta yeast mutant further supported the potential of S. cerevisiae deletion mutants to serve as a model system to study A. flavus. Use of this system to further examine functional genomics of oxidative stress in aflatoxigenesis and reduction of aflatoxin biosynthesis by antioxidants is discussed.

Topics: Aflatoxins; Antioxidants; Aspergillus flavus; Caffeic Acids; Expressed Sequence Tags; Gallic Acid; Gene Targeting; Genes, Bacterial; Genes, Fungal; Genetic Complementation Test; Hydrogen Peroxide; Mutation; Oxidative Stress; Saccharomyces cerevisiae; Superoxide Dismutase; Tannins

A Chardonnay white wine enriched in polyphenols was obtained by modification of winemaking and characterized by its enrichment in total polyphenolic content (1346 mg/L as compared to 316 mg/L for traditional Chardonnay) and in various individual polyphenols (catechin, epicatechin, procyanidins dimers B1-B4, gallic acid, cafeic acid, and caftaric acid), as determined from HPLC coupled to a diode array detector. The polyphenols-enriched white wine (W) or its ethanol-free derivative (EFW) was then administered by gavage (10 mL/kg, twice a day) for 6 weeks to rats that have been rendered diabetic by a single iv injection of streptozotocin (55 mg/kg). Treatments had no effect on the symptoms associated with hyperglycemia. However, while a reduction in plasma antioxidant capacity was associated with the diabetic state, administration of W or EFW restored plasma antioxidant capacities to a level not significantly different from that of nondiabetic control animals. In addition, the effect of both treatments was manifested by the enlargement of mesenteric arteries, as determined by quantitative histomorphometry. In summary, our study indicates that white wine, when enriched in polyphenols, is able to induce ethanol-independent in vivo effects in a model of insulin-deficient diabetes characterized by a major oxidative stress.

Topics: Animals; Anthocyanins; Antioxidants; Biflavonoids; Caffeic Acids; Catechin; Chromatography, High Pressure Liquid; Diabetes Mellitus, Experimental; Flavonoids; Gallic Acid; Male; Mesenteric Arteries; Oxidative Stress; Phenols; Polymers; Proanthocyanidins; Rats; Rats, Wistar; Tannins; Wine

Topics: Adjuvants, Immunologic; Animals; Antineoplastic Agents, Phytogenic; Antioxidants; Benzopyrans; Caffeic Acids; Cell Survival; Drug Screening Assays, Antitumor; Female; Flavonoids; Hydrolyzable Tannins; Mice; Mice, Inbred BALB C; Neoplasms, Experimental; Phenols; Polymers; Polyphenols; Sarcoma 180; Spleen; Structure-Activity Relationship; Tannins; Tumor Cells, Cultured

Crude extracts of dried leaves of Hyssop officinalis showed strong anti-HIV activity as measured by inhibition of syncytia formation, HIV reverse transcriptase (RT), and p17 and p24 antigen expression, but were non-toxic to the uninfected Molt-3 cells. Ether extracts from direct extraction (Procedure I), after removal of tannins (Procedure II), or from the residue after dialysis of the crude extract (Procedure III), showed good antiviral activity. Methanol extracts, subsequent to ether, chloroform and chloroform ethanol extractions, derived from procedure I or II, but not III, also showed very strong anti-HIV activity. In addition, the residual material after methanol extractions still showed strong activity. Caffeic acid was identified in the ether extract of procedure I by HPLC and UV spectroscopy. Commercial caffeic acid showed good antiviral activity in the RT assay and high to moderate activity in the syncytia assay and the p17 and p24 antigen expression. Tannic acid and gallic acid, common to other teas, could not be identified in our extracts. When commercial products of these two acids were tested in our assay systems, they showed high to moderate activity against HIV-1. Hyssop officinalis extracts contain caffeic acid, unidentified tannins, and possibly a third class of unidentified higher molecular weight compounds that exhibit strong anti-HIV activity, and may be useful in the treatment of patients with AIDS.

Topics: Antiviral Agents; Caffeic Acids; Cell Fusion; Cells, Cultured; Chromatography, High Pressure Liquid; HIV; HIV Antigens; Humans; In Vitro Techniques; Plant Extracts; Plants, Medicinal; RNA-Directed DNA Polymerase; Spectrophotometry, Ultraviolet; Tannins; Virus Replication

Topics: Animals; Caffeic Acids; Chlorogenic Acid; Cinnamates; Corn Oil; Lipid Metabolism; Lipid Peroxides; Liver; Male; Oils; Plant Extracts; Plants, Medicinal; Rats; Rats, Inbred Strains; Tannins