Black Tea Extract Research Articles

Evaluation of cell toxicity and DNA and protein binding of green synthesized silver nanoparticles

Silver nanoparticles (AgNPs) were prepared by GREEN chemistry relying on the reduction of AgNO3 by phytochemicals present in black tea extract. AgNPs were fully characterized by transmission electron microscopy (TEM), ultraviolet-visible spectroscopy ((UV–vis)), X-ray diffraction (XRD) and energy dispersive absorption spectroscopy (EDS). The synthesized AgNPs induced a decrease of the cell viability in a dose-dependent manner with a low IC50 (0.5 ± 0.1 μM) for an ovarian carcinoma cell line (A2780) compared to primary human fibroblasts (IC50 5.0 ± 0.1 μM). The DNA binding capability of CT (calf thymus) DNA was investigated using electronic absorption and fluorescence spectroscopies, circular dichroism and viscosity titration methods. Additionally, the AgNPs strongly quench the intrinsic fluorescence of BSA, as determined by synchronous fluorescence spectra.

Electrochemical performance of nanosized MnO2 synthesized by redox route using biological reducing agents

For more than a century, manganese dioxides (MDOs) have been used as electrochemically active materials in energy storage and conversion applications. To reduce the cost and hazardous impact of synthesis, a redox method was used to prepare MnO2 using extracts of green (GT-MnO2) and black (BT-MnO2) tea as biological reducing agents. Polyphenols present in the extracts of tea not only reduce Mn7+ ions but also act as “capping agents” to stabilize and prevent the produced MnO2 nanoparticles from degradation and aggregation. Elemental, structural properties and morphology of nanosized α-KyMnO2 were studied by thermogravimetric analysis, X-ray powder diffraction and Raman spectroscopy, which revealed the different crystallinity between GT-MnO2 and BT-MnO2 due to the strength of the antioxidant species. Electrochemical investigations highlight the beneficial presence of K+ ions in (2 × 2) tunnels; with a higher concentration, α-K0.135MnO2 exhibits a discharge specific capacity of 155 mAh g−1 after 20 cycles at C/26 rate. Kinetics of Li+ ions in LixKyMnO2 is also examined by impedance spectroscopy.

A novel ionic liquid/polyoxomolybdate based sensor for ultra-high sensitive monitoring of Al(III): Optimization by Taguchi statistical design

A novel ionic liquid electrostatically supported Nano-Cs-polyoxomolybdate modified carbon paste electrode (Nano-IL-PMo12-CPE) has been developed by using 1-n-butyl-3-methylimidazolium tetrafluoroborate (Bmim.BF4) as a superconductive hydrophobic binder. The supramolecular gel (IL-PMo12) exhibits an ordered structure, various physicochemical properties, and specifically as a result of its substantial reversible self-assembly, it can be used as an intelligent ion-exchange smart platform in the carbon paste bulk of the electrode. The provided materials were characterized by XRD, FT-IR, UV–vis, and elemental analyses. As expected, a significant linear correspondence was found between the sensor output signal (emf/mV) and logarithm of Al(III) ion activity with a Nernstian slope of 19.9 (±0.2) mV decade−1 over a wide concentration range of 1.0 × 10−9 to 2.2 × 10−1 mol L−1 (R2 = 0.9997). The sensor considered, exploits an astounding lower limit of detection and short response time of 7.94 × 10−10 mol L−1 and 8 s respectively within the working pH range of 2.0 to 5.0. A statistical design of experimental (Taguchi method with Qualitek-4 software and L16 orthogonal array robust design) was implemented in this work to optimize the process to achieve the least number of experimental runs as much as possible. Ultimately, practical capability of the sensor was investigated successfully by assessment of Al(III) ion quantity in some aqueous samples namely mineral water, Al-Mg syrup, black tea extract, and ore samples (Basalt and Andesite), in perfect agreement with flame atomic absorption spectroscopy (FAAS).

Evaluation and application of prebiotic and probiotic ingredients for development of ready to drink tea beverage.

Ready-to-drink (RTD) ice tea is a ready prepared tea, produced from green and black tea originating from same plant Camellia sinensis. The objective of this study was to determine the effect of prebiotics [galacto-oligosaccharide (GOS), fructo-oligosaccharide (FOS), and inulin] or synbiotic ingredients (GOS, FOS, inulin, and Lactobacillus acidophilus) on the sensory properties and consumer acceptability of RTD. The quality of green tea extract (GTE) and black tea extract (BTE) was improved with pretreatment of cellulase and pectinase enzymes. The combined enzymatic extraction amplified total extractives up to 76% in GTE and 72% in BTE. Total polyphenol was found to be enhanced to 24% in GTE and 19% in BTE. GTE was further selected for development of RTD in two different formats; synbiotic RTD and prebiotic RTD premix and analyzed for sensory attributes (colour, aroma, taste, and acceptability). Synbiotic RTD was also evaluated for stability over a period of 28days at 4°C. Synbiotic RTD developed an unpleasant flavor and aroma during the shelf life. Premix format of RTD developed using spray drying was reconstituted and found to be functionally and sensorially acceptable.

Contribution of tea (Camellia sinensis L.) to recommended daily intake of Mg, Mn, and Fe: An in vitro bioaccessibility assessment

This study outlines the determination of total elemental contents, time-dependent extractabilities, and bioaccessibilities of Mg, Mn, and Fe from nine tea samples, including black, earl grey, and green teas, using inductively coupled plasma mass spectrometry. Leachabilities and bioaccessibilities were evaluated using samples infused for 2, 5, and 10 min, and bioaccessible levels were determined after in vitro enzymatic digestion. Lemon juice, sugar, milk, calcium, and tannic acid were studied as additives, and found to increase or decrease the bioaccessibilities from black tea infusions. Drinking one cup of tea provided 0.16%, 0.01%, and 0.10% of the recommended dietary allowance of Mg for black, earl grey, and green teas infused for 2 min, respectively. The equivalent levels were 11%, 6%, and 7% for Mn, and 0.05%, 0.02%, and 0.02% for Fe in the same samples, respectively. Therefore, Mn was found to be the most bioaccessible element resulting from tea consumption, reaching 17%–24% of the recommended daily allowance in the 10-min infusion. Moreover, lemon juice was found to increase the bioaccessibility of Mn by up to 3.4-fold, even in tea samples infused for 2 min.

Metabolomics Study Reveals Enhanced Inhibition and Metabolic Dysregulation in Escherichia coli Induced by Lactobacillus acidophilus-Fermented Black Tea Extract

This study examined the ability of Lactobacillus acidophilus (LA) to ferment black tea extract (BTE) and the enhancement of Escherichia coli cellular uptake of phenolic compounds when these bacteria were incubated with fermented BTE. The inhibitory effects of BTE to E. coli bacteria with and without fermentation were compared. Several intracellular phenolic compounds as well as metabolic profiles of E. coli with and without treatments were also determined using a high-performance liquid chromatography-tandem mass spectrometry-based approach. Our results showed that of three concentrations from the non-fermented BTE treatment, only the extract from the 25 mg/mL tea leaves solution could inhibit E. coli survival, while LA-fermented BTE extract from 5, 10, and 25 mg/mL tea leaves solutions all inhibited E. coli growth significantly. Intracellular concentrations of (+)-catechin-3-gallate/(-)-epicatechin-3-gallate and (+)-catechin/(-)-epicatechin were significantly higher when E. coli was treated with fermented BTE in comparison to non-fermented BTE. Scanning electron microscopy images indicated that the intracellular phenolic compounds inhibited E. coli growth by increasing endogenous oxidative stress. Metabolic profiles of E. coli were also investigated to understand their metabolic response when treated with BTE, and significant metabolic changes of E. coli were observed. Metabolic profile data were further analyzed using partial least squares discriminant analysis to distinguish the fermented BTE treatment group from the control group and the non-fermented BTE treatment group. The results indicated a large-scale E. coli metabolic dysregulation induced by the fermented BTE. Our findings showed that LA fermentation can be an efficient approach to enhance phenolic inhibition of bacterial cells through increased endogenous oxidative stress and dysregulated metabolic activities.

Peptide inhibitors of chloride channels for treating secretory diarrhea.

Morbidity and mortality associated with diarrheal diseases remain significant burdens on global health. In the developing world, the major sources of secretory diarrhea are infectious, including those caused by bacteria such as enterotoxic Escherichia coli, and viruses such as rotavirus. In many cases of secretory diarrhea, activation of pathways for cyclic nucleotides and/or Ca2+ signaling in the apical membrane of enterocytes increases the conductance of Cl- channels at the enterocyte lumen-facing membrane. Those channels include the cystic fibrosis transmembrane conductance regulator (CFTR) and Ca2+-activated Cl- channel (CaCC). Inhibition of enterocyte Cl- channels is an effective strategy for anti-secretory drug therapy. Small molecules and natural peptides with Cl- channel inhibitory activity have shown efficacy in diarrhea models. Screening of natural peptides via the patch-clamp technique provides evidence that such channel inhibition by an extract of black tea may be responsible for its anti-diarrhea benefits.

Study on tea leaves extract as green corrosion inhibitor of mild steel in hydrochloric acid solution

Corrosion inhibitor from extraction of plant has been considered as the most preferable and most chosen technique to prevent corrosion of metal in acidic medium because of the environmental friendly factor. In this study, black tea leaves extraction was tested as corrosion inhibitor for mild steel in 0.1M of hydrochloric acid (HCl) with the absence and presence of corrosion inhibitor. The efficiency and effectiveness of black tea as corrosion inhibitor was tested by using corrosion weight loss measurement experiment was carried out with varies parameters which with different concentration of black tea extract solution. The extraction of black tea solution was done by using aqueous solvent method. The FT-IR result shows that black tea extract containing compounds such as catechin, caffeine and tannins that act as anti-corrosive reagents and responsible to enhance the effectiveness of black tea extract as corrosion inhibitor by forming the hydrophobic thin film through absorption process. As a result of weight loss measurement, it shows that loss in weight of mild steel reduces as the concentration of inhibitor increases. The surface analysis was done on the mild steel samples by using SEM.

Black tea increases hypertonic stress resistance in C. elegans.

Here we identified that BTE (black tea extract), within the studied concentration range, is more effective than GTE (green tea extract) in protecting C. elegans against hypertonic stress, by enhancing survival after exposure to various salts, and alleviating suffered motility loss and body shrinkage. The mechanism of such protection may be due to the ability of black tea to induce the conserved WNK/GCK signaling pathway and down-regulation of the expression levels of nlp-29. Intriguingly, black tea does not relieve hypertonicity-induced protein damage. The findings implicate the potential health benefits of black tea consumed worldwide.

Inhibitory activity of a green and black tea blend on Streptococcus mutans

ABSTRACT Through the years, tea consumption has been associated with good health, and some publications are related to oral health. The bioactive components of green tea are thought to be able to influence the process of caries formation through inhibition of proliferation of the streptococcal agent, interference with the process of bacterial adhesion to tooth enamel, and inhibition of glucosyl transferase and amylase; however, little is known about black tea and oral health. The aim of the present in- vitro study was to determine the inhibitory activity of a novel, patent-pending and proprietary blend of green and black tea aqueous extracts on Streptococcus mutans, a bacterium widely associated with plaque development and tooth decay. A minimum inhibitory concentration (MIC) of 12.5 mg/mL and a minimum bactericidal concentration (MBC) of 12.5 mg/mL was established against S. mutans, meaning that at concentrations of 12.5 mg/mL and higher, the proprietary tea blend is effective against the growth of S. mutans. This MIC concentration is lower than the ones reported in the literature for alcoholic black tea and green tea extracts tested separately. As a promising natural ingredient for oral health, this finding is a good indicator for the use of this proprietary blend of black and green tea water extracts.

THE SUPPLEMENTARY EFFECT OF BLACK AND GREEN TEA INFUSION ON ANTIMICROBIAL ACTIVITIES OF KEFIR

The influence of supplementation with green and black tea on microbiological properties and antimicrobial activities of kefir was investigated during 21 days of storage. The samples supplemented with 2% either green or black tea had higher viable counts of both kefir cultures than those of supplemented with the ratio of 4%. Both green and black tea extracts showed antimicrobial activity on Esch­erichia coli, Bacillus cereus, Staphylococcus aureus, Candida albicans however this effect was detected higher in samples containing

Black Tea Extract Attenuates Sodium Fluoride-Induced Neurotoxicity in Adult Male Rats

Black Tea Extract Attenuates Sodium Fluoride-Induced Neurotoxicity in Adult Male Rats

Antioxidant Properties of the Artist's Conk Medicinal Mushroom, Ganoderma applanatum (Agaricomycetes), upon Cultivation with para-Substituted Phenolic Compounds and Tea Leaf Extracts.

In this study we elucidate antioxidative properties of the mushroom Ganoderma applanatum (Pers.) Pat. enhanced by submerged culture with para-hydroxyphenolic compounds and tea leaf extracts. The tea extract has been shown to increase to different extents the antioxidative efficiency of para-substituted phenolics, with the most profound effect for 2-(4-hydroxyphenyl)ethane-1-ol (tyrosol). Within the range of physiological concentrations, the symbatic correlation of the antioxidative action of the fungal samples with the volume of tea extract in the submerged culture medium was observed. We propose an approach to obtain, through the use of black tea extracts as the nutrient medium component, large amounts of G. applanatum seeding mycelia; the extract exerts a profound positive effect on the level of phenolic-type antioxidants.

Our Tea-Drinking Habits: Effects of Brewing Cycles and Infusion Time on Total Phenol Content and Antioxidants of Common Teas

ABSTRACTThis study determined the total phenolic content (TPC) and antioxidant activities of common teas in response to our tea drinking habits. Selected green and black tea (Chinese black and green tea, Lipton black and green tea, Twining black and green tea) were infused with water for 3, 5, 7, and 10 min, and the teabags were rebrewed for two cycles (an hour interval each). Results showed that the TPC and antioxidant activities increased throughout the infusion time, suggesting that the longer the infusion time, the higher the concentrations of antioxidants. On the contrary, the TPC and antioxidants activities decreased throughout the three brewing cycles, suggesting that the teabags are most suitably used only once. This study therefore revealed that 10 min is recommended for the infusion of green and black tea to derive optimum benefits, and rebrewing of teabags is not recommended.

Functional Characterization of Epitheaflagallin 3-O-Gallate Generated in Laccase-Treated Green Tea Extracts in the Presence of Gallic Acid.

Epitheaflagallin (ETFG) and epitheaflagallin 3-O-gallate (ETFGg) are minor polyphenols in black tea extract that are enzymatically synthesized from epigallocatechin (EGC) and epigallocatechin gallate (EGCg), respectively, in green tea extract via laccase oxidation in the presence of gallic acid. The constituents of laccase-treated green tea extract in the presence of gallic acid are thus quite different from those of nonlaccase-treated green tea extract: EGC and EGCg are present in lower concentrations, and ETFG and ETFGg are present in higher concentrations. Additionally, laccase-treated green tea extract contains further polymerized catechin derivatives, comparable with naturally fermented teas such as oolong tea and black tea. We found that ETFGg and laccase-treated green tea extracts exhibit versatile physiological functions in vivo and in vitro, including antioxidative activity, pancreatic lipase inhibition, Streptococcus sorbinus glycosyltransferase inhibition, and an inhibiting effect on the activity of matrix metalloprotease-1 and -3 and their synthesis by human gingival fibroblasts. We confirmed that these inhibitory effects of ETFGg in vitro match well with the results obtained by docking simulations of the compounds with their target enzymes or noncatalytic protein. Thus, ETFGg and laccase-treated green tea extracts containing ETFGg are promising functional food materials with potential antiobesity and antiperiodontal disease activities.

Catechin Composition and Antioxidant Activity of Black Teas in Relation to Brewing Time

Black tea infusions are one of the most popular beverages across the world. Their extract composition depends on several factors, brewing time being one of the most important determinants. The aim of the present study was to determine the catechin composition of different black tea infusions using a validated LC electrospray ionization time-of-flight MS method. Additionally, total phenolic content (TPC) and antioxidant activity of infusions were evaluated using Folin-Ciocalteu reagent and stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). An optimized LC-MS method enabled the precise identification of the studied catechins [epicatechin (EC), EC gallate (ECG), epigallocatechin (EGC), and epigallocatechin-3-gallate (EGCG)] and gallic acid (GA). The major catechin in all investigated teas was EGC (25.6 mg/100 cm3 after 4 min of brewing). EC was present at the lowest concentration in all extracts. TPC and antiradical scavenging activity were in a good agreement with catechins and GA content. In general, the longer the brewing time, the higher the concentration of catechin, TPC, and antioxidant activity values. However, it should be noted that after 2 min brewing, most phenolics had already been extracted, and extract composition did not significantly change at a prolonged extraction time.

Depigmentation Effects of Black, Green, and White Tea Extracts on Brownish Guinea Pig Skins

Depigmentation Effects of Black, Green, and White Tea Extracts on Brownish Guinea Pig Skins

Effective multivariate data presentation and modeling in distinction of the tea infusions

In this work a review of multivariate data visualization and unsupervised modeling methods was presented, applied to DPV and LAPV signals of black, green, red and white tea infusions of China and Vietnam origin. It proves that graphical presentation by diagrams and charts has a number of advantages in comparison to analysis of the measured signals or numerical datasheets. The same data presented and modeled by different methods may deliver various, complementary conclusions and also the strategy verifies the quality of the experiments. Insight to the experimental data and extraction of the useful information were done applying Chernoff faces, star plots, radar plot and matrix scatterplot. Using SOMs and PCA it was demonstrated that DPV data enabled distinction of the tea kinds with some problems with separation of the green and white ones, while LAPV signals distinguished the origin of the infusions. Successful separation of the 8 different types of objects were done by polar dendrogram, first time applied in voltammetry.

Swimming endurance of mice administered black tea extract and chicken egg powder

Research of swimming endurance on mice administered black tea extract and chicken egg powder was carried out. The aim of this research was to evalute natatory exhaustion mice administered black tea extract, chicken egg powder and its combinated. The result of this research shown that mice administered of black tea extract and chicken egg powder have a swimming endurance 3.25 minutes and 3.01 minutes. Mice which administered combination of black tea extract and chicken egg powder have a swimming endurance 4.80 minutes. Generally, mice which administered combination of black tea extract and chicken egg powder have a swimming endurance more better than mice which administered of black tea extract and chicken egg powder individually.

Phytochemical-rich foods inhibit the growth of pathogenic trichomonads

BackgroundPlants produce secondary metabolites that often possess widespread bioactivity, and are then known as phytochemicals. We previously determined that several phytochemical-rich food-derived preparations were active against pathogenic foodborne bacteria. Trichomonads produce disease (trichomoniasis) in humans and in certain animals. Trichomonads are increasingly becoming resistant to conventional modes of treatment. It is of interest to test bioactive, natural compounds for efficacy against these pathogens.MethodsUsing a cell assay, black tea, green tea, grape, pomegranate, and jujube extracts, as well as whole dried jujube were tested against three trichomonads: Trichomonas vaginalis strain G3 (found in humans), Tritrichomonas foetus strain D1 (found in cattle), and Tritrichomonas foetus-like organism strain C1 (found in cats). The most effective of the test substances was subsequently tested against two metronidazole-resistant Trichomonas vaginalis strains, and on normal mucosal flora.ResultsBlack tea extract inhibited all the tested trichomonads, but was most effective against the T. vaginalis organisms. Inhibition by black tea was correlated with the total and individual theaflavin content of the two tea extracts determined by HPLC. Metronidazole-resistant Trichomonas vaginalis strains were also inhibited by the black tea extract. The response of the organisms to the remaining preparations was variable and unique. We observed no effect of the black tea extract on common normal flora bacteria.ConclusionsThe results suggest that the black tea, and to a lesser degree green tea, grape seed, and pomegranate extracts might present possible natural alternative therapeutic agents to treat Trichomonas vaginalis infections in humans and the related trichomonad infections in animals, without negatively affecting the normal flora.