Tea polyphenols dominate the short-term tea (Camellia sinensis) leaf litter decomposition*

PubMed Central

Fan, Dong-mei; Fan, Kai; Yu, Cui-ping; Lu, Ya-ting; Wang, Xiao-chang

2017-01-01

Polyphenols are one of the most important secondary metabolites, and affect the decomposition of litter and soil organic matter. This study aims to monitor the mass loss rate of tea leaf litter and nutrient release pattern, and investigate the role of tea polyphenols played in this process. High-performance liquid chromatography (HPLC) and classical litter bag method were used to simulate the decomposition process of tea leaf litter and track the changes occurring in major polyphenols over eight months. The release patterns of nitrogen, potassium, calcium, and magnesium were also determined. The decomposition pattern of tea leaf litter could be described by a two-phase decomposition model, and the polyphenol/N ratio effectively regulated the degradation process. Most of the catechins decreased dramatically within two months; gallic acid (GA), catechin gallate (CG), and gallocatechin (GC) were faintly detected, while others were outside the detection limits by the end of the experiment. These results demonstrated that tea polyphenols transformed quickly and catechins had an effect on the individual conversion rate. The nutrient release pattern was different from other plants which might be due to the existence of tea polyphenols. PMID:28124839

Tea polyphenols dominate the short-term tea (Camellia sinensis) leaf litter decomposition.

PubMed

Fan, Dong-Mei; Fan, Kai; Yu, Cui-Ping; Lu, Ya-Ting; Wang, Xiao-Chang

Polyphenols are one of the most important secondary metabolites, and affect the decomposition of litter and soil organic matter. This study aims to monitor the mass loss rate of tea leaf litter and nutrient release pattern, and investigate the role of tea polyphenols played in this process. High-performance liquid chromatography (HPLC) and classical litter bag method were used to simulate the decomposition process of tea leaf litter and track the changes occurring in major polyphenols over eight months. The release patterns of nitrogen, potassium, calcium, and magnesium were also determined. The decomposition pattern of tea leaf litter could be described by a two-phase decomposition model, and the polyphenol/N ratio effectively regulated the degradation process. Most of the catechins decreased dramatically within two months; gallic acid (GA), catechin gallate (CG), and gallocatechin (GC) were faintly detected, while others were outside the detection limits by the end of the experiment. These results demonstrated that tea polyphenols transformed quickly and catechins had an effect on the individual conversion rate. The nutrient release pattern was different from other plants which might be due to the existence of tea polyphenols.

Assessment of the polyphenolic composition of the organic extracts of Mauritian black teas: a potential contributor to their antioxidant functions.

PubMed

Luximon-Ramma, Amitabye; Neergheen, Vidushi S; Bahorun, Theeshan; Crozier, Alan; Zbarsky, Virginia; Datla, Krishna P; Dexter, David T; Aruoma, Okezie I

2006-01-01

There is increasing interest in the emerging view that tea improves the antioxidant status in vivo and thereby helps to lower risk of certain types of cancer, coronary heart disease and stroke and its component biofactors could provide prophylactic potential for these diseases. The polyphenolic composition and the antioxidant properties of organic extracts (acetone/methanol) of Mauritian commercial black teas were evaluated. HPLC data of the individual compounds revealed remarkably high levels (+)-Catechin ((+)-C), (-)-epicatechin ((-)-EC), (-)-epicatechin 3-gallate ((-)-ECG), (-)-epigallocatechin ((-)-EGC), (-)-epigallocatechin 3-gallate ((-)-EGCG) and gallic acid. Analysis of hydrolysed extracts indicated that quercetin was the dominant flavonol aglycone with traces of myricetin and kaempferol. Based on the Ferric Reducing Antioxidant Power (FRAP) and the Trolox Equivalent Antioxidant Capacity (TEAC) assays Extra tea from Bois Chéri exhibited the highest antioxidant potential. Linear regression analyses showed that the antioxidant capacities of the organic extracts are strongly influenced by total phenols (TEAC: r=0.95 and FRAP: r=0.96) and to a lesser extent by total proanthocyanidin and total flavonoid contents. Catechins and gallic acid seem to add up to the overall antioxidant capacity of black tea extracts. The fresh tea leaves had high levels of total phenols, total flavonoids, total proanthocyanidin and exhibited greater antioxidant potential when compared with black teas. Organic extracts of endemic teas represent useful source of phenolic antioxidants supplements for prophylactic use.

Chemistry of Secondary Polyphenols Produced during Processing of Tea and Selected Foods

PubMed Central

Tanaka, Takashi; Matsuo, Yosuke; Kouno, Isao

2010-01-01

This review will discuss recent progress in the chemistry of secondary polyphenols produced during food processing. The production mechanism of the secondary polyphenols in black tea, whisky, cinnamon, and persimmon fruits will be introduced. In the process of black tea production, tea leaf catechins are enzymatically oxidized to yield a complex mixture of oxidation products, including theaflavins and thearubigins. Despite the importance of the beverage, most of the chemical constituents have not yet been confirmed due to the complexity of the mixture. However, the reaction mechanisms at the initial stages of catechin oxidation are explained by simple quinone–phenol coupling reactions. In vitro model experiments indicated the presence of interesting regio- and stereoselective reactions. Recent results on the reaction mechanisms will be introduced. During the aging of whisky in oak wood barrels, ellagitannins originating from oak wood are oxidized and react with ethanol to give characteristic secondary ellagitannins. The major part of the cinnamon procyanidins is polymerized by copolymerization with cinnamaldehyde. In addition, anthocyanidin structural units are generated in the polymer molecules by oxidation which accounts for the reddish coloration of the cinnamon extract. This reaction is related to the insolubilization of proanthocyanidins in persimmon fruits by condensation with acetaldehyde. In addition to oxidation, the reaction of polyphenols with aldehydes may be important in food processing. PMID:20161999

Simplified recovery of enzymes and nutrients in sweet potato wastewater and preparing health black tea and theaflavins with scrap tea.

PubMed

Li, Qing-Rong; Luo, Jia-Ling; Zhou, Zhong-Hua; Wang, Guang-Ying; Chen, Rui; Cheng, Shi; Wu, Min; Li, Hui; Ni, He; Li, Hai-Hang

2018-04-15

The industry discards generous organic wastewater in sweet potato starch factory and scrap tea in tea production. A simplified procedure to recover all biochemicals from the wastewater of sweet potato starch factory and use them to make health black tea and theaflavins from scrap green tea was developed. The sweet potato wastewater was sequentially treated by isoelectric precipitation, ultrafiltration and nanofiltration to recover polyphenol oxidase (PPO), β-amylase, and small molecular fractions, respectively. The PPO fraction can effectively transform green tea extracts into black tea with high content of theaflavins through the optimized fed-batch feeding fermentation. The PPO transformed black tea with sporamins can be used to make health black tea, or make theaflavins by fractionation with ethyl acetate. This work provides a resource- and environment-friendly approach for economically utilizing the sweet potato wastewater and the scrap tea, and making biochemical, nutrient and health products. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Study on adsorption of tea polyphenol and caffine with polyamide resin].

PubMed

Tang, Ke-wen; Zhou, Chun-shan; Zhong, Shi-an; Zhu, Jie-ding

2003-02-01

The performance of adsorption of tea polyphenol and caffine with polyamide resin was investigated. The results obtained by spectrophotometry and HPLC show that the ability of adsorption of tea polyphenol with polyamide is stronger than that of caffine, in which hydrogen bond plays a very important role. The adsorption amount of caffine is 2.65 mg.g-1 with 7.5% adsorption ratio when 100 mL of 0.71 g.L-1 caffine is adsorbed on polyamide resine, but the adsorption amount of tea polyphenol is up to 148.13 mg.g-1 with 85% adsorption ratio when 700 mL of 1.98 g.L-1 tea polyphenol is adsorbed on polyamide resine. The dilution ratios of caffine and tea polyphenol are 74% and 90%, respectively, when they are diluted by 85% alcohol. The static adsorptions of caffine and tea polyphenol on polyamide resine reach equilibrium quickly in 80 min, and the plots of adsorption kinetics are nearly linear. Tea polyphenol and caffine are successfully separated on polyamide resine, and the obtained product contains more than 96% of tea polyphenol and 80% of EGCC with caffine less than 2.8%.

Analytical separation of tea catechins and food-related polyphenols by high-speed counter-current chromatography.

PubMed

Yanagida, Akio; Shoji, Atsushi; Shibusawa, Yoichi; Shindo, Heisaburo; Tagashira, Motoyuki; Ikeda, Mitsuo; Ito, Yoichiro

2006-04-21

High-speed counter-current chromatography (HSCCC) using the type-J coil planet centrifuge was applied to compositional analysis of tea catechins and separation of other food-related polyphenols. The HSCCC separation of nine different standard compounds and those from extracts of commercial tea leaves was performed with a two-phase solvent system composed of tert-butyl methyl ether-acetonitrile-0.1% aqueous trifluoroacetic acid (TFA) (2:2:3, v/v/v) by eluting the upper organic phase at a flow rate of 2 ml/min. The main compounds in the extract of non-fermented green tea were found to be monomeric catechins, their galloylated esters and caffeine. In addition to these compounds, oxidized pigments, such as hydrophobic theaflavins (TFs) and polar thearubigins (TRs) were also separated and detected from the extracts of semi-fermented oolong tea and fermented black tea. Furthermore, several food-related polyphenols, such as condensed catechin oligomers (procyanidins), phenolic acids and flavonol glycosides were clearly separated under the same HSCCC condition. These separation profiles of HSCCC provide useful information about the hydrophobic diversity of these bioactive polyphenols present in various types of teas and food products.

The enhanced inhibition of water extract of black tea under baking treatment on α-amylase and α-glucosidase.

PubMed

Tong, Da-Peng; Zhu, Ke-Xue; Guo, Xiao-Na; Peng, Wei; Zhou, Hui-Ming

2018-02-01

This paper studied the inhibition of water extract of natural or baked black tea on the activity of α-amylase and α- glucosidase. Baking treatment was found to be one effective way to enhance the inhibition of black tea on both α-amylase and α- glucosidase, and IC 50 of water extract of baked black tea (BBTWE) were 1.213mg/mL and 4.190mg/mL, respectively, while IC 50 of water extract of black tea (BTWE) were 1.723mg/mL and 6.056mg/mL, respectively. This study further studied the mechanism of the effect of water extract on α-amylase and α- glucosidase using HPLC, circular dichroism, and synchronous fluorescence. HPLC analysis of tea polyphenols showed that the content of tea polyphenols with low polarity increased after baking. In addition, BBTWE had higer abilty on decreasing the hydrophobicity of tryptophan residues than BTWE for both α-amylase and α- glucosidase.The increase of α-helix proportion of α-amylase when treated with BBTWE was more obvious than that when treated with BTWE. In a word, thermal process of baked foods may be beneficial for tea polyphenols to reduce the rate of starch digestion. Copyright © 2017 Elsevier B.V. All rights reserved.

Microwave-assisted water extraction of green tea polyphenols.

PubMed

Nkhili, Ezzohra; Tomao, Valerie; El Hajji, Hakima; El Boustani, Es-Seddik; Chemat, Farid; Dangles, Olivier

2009-01-01

Green tea, a popular drink with beneficial health properties, is a rich source of specific flavanols (polyphenols). There is a special interest in the water extraction of green tea polyphenols since the composition of the corresponding extracts is expected to reflect the one of green tea infusions consumed worldwide. To develop a microwave-assisted water extraction (MWE) of green tea polyphenols. MWE of green tea polyphenols has been investigated as an alternative to water extraction under conventional heating (CWE). The experimental conditions were selected after consideration of both temperature and extraction time. The efficiency and selectivity of the process were determined in terms of extraction time, total phenolic content, chemical composition (HPLC-MS analysis) and antioxidant activity of the extracts. By MWE (80 degrees C, 30 min), the flavanol content of the extract reached 97.46 (+/- 0.08) mg of catechin equivalent/g of green tea extract, vs. only 83.06 (+/- 0.08) by CWE (80 degrees C, 45 min). In particular, the concentration of the most bioactive flavanol EGCG was 77.14 (+/- 0.26) mg of catechin equivalent/g of green tea extract obtained by MWE, vs 64.18 (+/- 0.26) mg/g by CWE. MWE appears more efficient than CWE at both 80 and 100 degrees C, particularly for the extraction of flavanols and hydroxycinnamic acids. Although MWE at 100 degrees C typically affords higher yields in total phenols, MWE at 80 degrees C appears more convenient for the extraction of the green tea-specific and chemically sensitive flavanols.

Cancer Prevention by Tocopherols and Tea Polyphenols

PubMed Central

Yang, Chung S.; Li, Guangxun; Yang, Zhihong; Guan, Fei; Chen, Amber; Ju, Jihyeung

2013-01-01

Tocopherols (vitamin E) and tea polyphenols have been reported to have cancer preventive activities. Large-scale human trials with high doses of alpha-tocopherol, however, have produced disappointing results. This review presents data showing that γ- and δ-tocopherols inhibit colon, lung, mammary and prostate carcinogenesis in animal models, whereas α-tocopherol is ineffective in animal and human studies. Possible mechanisms of action are discussed. A broad cancer preventive activity of green tea polyphenols has been demonstrated in animal models, and many mechanisms have been proposed. The cancer preventive activity of green tea in humans, however, has not been conclusively demonstrated and remains to be further investigated. PMID:23403075

Comparison of Antioxidative Effects of Insect Tea and Its Raw Tea (Kuding Tea) Polyphenols in Kunming Mice.

PubMed

Zhao, Xin; Song, Jia-Le; Yi, Ruokun; Li, Guijie; Sun, Peng; Park, Kun-Young; Suo, Huayi

2018-01-19

Kudingcha is a traditional Chinese tea, and insect tea is a special drink produced by the metabolism of insect larvae using the raw Kuding tea. Insect tea polyphenols (ITP) and its raw tea (Kuding tea) polyphenols (KTP) are high-purity polyphenols extracted by centrifuge precipitation. The present study was designed to compare the antioxidative effects of insect tea polyphenols (ITP) and its raw tea (Kuding tea) polyphenols (KTP) on d-galactose-induced oxidation in Kunming (KM) mice. KM mice were treated with ITP (200 mg/kg) and KTP (200 mg/kg) by gavage, and vitamin C (VC, 200 mg/kg) was also used as a positive control by gavage. After determination in serum, liver and spleen, ITP-treated mice showed higher superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and glutathione (GSH) activities and lower nitric oxide (NO), malonaldehyde (MDA) activities than VC-treated mice, KTP-treated mice and untreated oxidation mice (control group). By H&E section observation, the mice induced by d-galactose-induced oxidation showed more changes than normal mice, and oxidative damage appeared in liver and spleen tissues; ITP, VC and KTP improved oxidative damage of liver and spleen tissues, and the effects of ITP were better than VC and KTP. Using quantitative polymerase chain reaction (qPCR) and western blot experiments, it was observed that ITP could increase the mRNA and protein expression of neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), manganese superoxide dismutase (Mn-SOD), cupro/zinc superoxide dismutase (Cu/Zn-SOD), catalase (CAT), heme oxygenase-1 (HO-1), nuclear factor erythroid 2 related factor 2 (Nrf2), gamma glutamylcysteine synthetase (γ-GCS), and NAD(P)H:quinone oxidoreductase 1 (NQO1) and reduce inducible nitric oxide synthase (iNOS) expression in liver and spleen tissues compared to the control group. These effects were stronger than for VC and KTP. Both ITP and KTP had good antioxidative effects, and after the

Immobilized tannase treatment alters polyphenolic composition in teas and their potential anti-obesity and hypoglycemic activities in vitro.

PubMed

Roberto, Bruna Sampaio; Macedo, Gabriela Alves; Macedo, Juliana Alves; Martins, Isabela Mateus; Nakajima, Vânia Mayumi; Allwood, J William; Stewart, Derek; McDougall, Gordon J

2016-09-14

The aim of this work was to assess the effect of immobilized-tannase treatment on black, green, white and mate tea components and on their bioactivities relevant to obesity. Tannase treatment caused predictable changes in polyphenol composition with substantial reduction in galloylated catechins in green, white and black tea. Mate tea, which is rich in chlorogenic acids, was much less affected by tannase treatment although some degradation of caffeoyl quinic acid derivatives was noted. The original tea samples were effective in inhibiting digestive enzymes in vitro. They inhibited amylase activity, some with IC50 values ∼70 μg mL(-1), but were much less effective against α-glucosidase. They also inhibited lipase activity in vitro and caused dose-dependent reductions in lipid accumulation in cultured adipocytes. The bio-transformed tea samples generally matched the effectiveness of the original samples but in some cases they were markedly improved. In particular, tannase treatment reduced the IC50 value for amylase inhibition for green tea and white tea by 15- and 6-fold respectively. In addition, the bio-transformed samples were more effective than the original samples in preventing lipid accumulation in adipocytes. These in vitro studies indicate that bio-transformed tea polyphenols could assist in the management of obesity through improvement in energy uptake and lipid metabolism and also indicate that biotechnological modification of natural food molecules can improve the benefits of a common beverage such as tea.

Addition of whole, semiskimmed, and skimmed bovine milk reduces the total antioxidant capacity of black tea.

PubMed

Ryan, Lisa; Petit, Sébastien

2010-01-01

Epidemiological studies have shown that populations consuming fruits, vegetables, tea, cocoa, and red wine have lower incidences of cardiovascular disease, certain cancers, and eye disease. These health effects have largely been attributed to the polyphenol content of the foods and drinks studied. Black tea is rich in a range of polyphenolic compounds that could potentially have health-promoting properties. The scale of consumption of tea in the United Kingdom means that it could be an appropriate vehicle for increasing the antioxidant activity and polyphenol content of human plasma. However, it is common practice in the United Kingdom to add milk to tea, and some studies have suggested that this may decrease the overall antioxidant capacity. The objective of the present study was to analyze and compare the antioxidant capacity of 5 brands of tea and to test the hypothesis that the addition of different volumes of whole milk, semiskimmed, and skimmed milk may affect the antioxidant capacity. Each of the teas analyzed was a significant source of antioxidants. The addition of 10, 15, and 20 mL of whole, semiskimmed, and skimmed bovine milk to a 200-mL tea infusion decreased the total antioxidant capacity of all the brands of tea. Skimmed milk decreased the total antioxidant capacity of the tea infusion significantly (P < .05) more than either whole milk or semiskimmed milk. We conclude that black tea is a valuable source of antioxidants and that the effect of milk on the total antioxidant capacity may be related to the fat content of the milk. 2010 Elsevier Inc. All rights reserved.

Simultaneous Determination of Black Tea-Derived Catechins and Theaflavins in Tissues of Tea Consuming Animals Using Ultra-Performance Liquid-Chromatography Tandem Mass Spectrometry

PubMed Central

Ganguly, Souradipta; G., Taposh Kumar; Mantha, Sudarshan

2016-01-01

The bioavailability, tissue distribution and metabolic fate of the major tea polyphenols, catechins and theaflavins as well as their gallated derivatives are yet to be precisely elucidated on a single identification platform for assessment of their relative bioefficacy in vivo. This is primarily due to the lack of suitable analytical tools for their simultaneous determination especially in an in vivo setting, which continues to constrain the evaluation of their relative health beneficiary potential and therefore prospective therapeutic application. Herein, we report a rapid and sensitive Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS) based method for the simultaneous determination of the major catechins and theaflavins in black tea infusions as well as in different vital tissues and body fluids of tea-consuming guinea pigs. This method allowed efficient separation of all polyphenols within seven minutes of chromatographic run and had a lower limit of quantification (LLOQ) of ~5 ng/ml. Using this method, almost all bioactive catechins and theaflavins could be simultaneously detected in the plasma of guinea pigs orally administered 5% black tea for 14 days. Our method could further detect the majority of these polyphenols in the lung and kidney as well as identify the major catechin metabolites in the urine of the tea-consuming animals. Overall, our study presents a novel tool for simultaneous detection and quantitation of both catechins and theaflavins in a single detection platform that could potentially enable precise elucidation of their relative bioavailability and bioefficacy as well as true health beneficiary potential in vivo. Such information would ultimately facilitate the accurate designing of therapeutic strategies utilizing high efficacy formulations of tea polyphenols for effective mitigation of oxidative damage and inflammation in humans as well as prevention of associated diseases. PMID:27695123

Physiological activity of irradiated green tea polyphenol on the human skin.

PubMed

An, Bong-Jeun; Kwak, Jae-Hoon; Son, Jun-Ho; Park, Jung-Mi; Lee, Jin-Young; Park, Tae Soon; Kim, So-Yeun; Kim, Yeoung-Sun; Jo, Cheorun; Byun, Myung-Woo

2005-01-01

Physiological activity of irradiated green tea polyphenol on the human skin was investigated for further industrial application. The green tea polyphenol was separated and irradiated at 40 kGy by y-ray. For an anti-wrinkle effect, the collagenase inhibition effect was higher in the irradiated sample (65.3%) than that of the non-irradiated control (56.8%) at 200 ppm of the concentration (p < 0.05). Collagen biosynthesis rates using a human fibroblast were 19.4% and 16.3% in the irradiated and the non-irradiated polyphenols, respectively. The tyrosinase inhibition effect, which is related to the skin-whitening effect, showed a 45.2% and 42.9% in the irradiated and the non-irradiated polyphenols, respectively, at a 100 ppm level. A higher than 90% growth inhibition on skin cancer cells (SK-MEL-2 and G361) was demonstrated in both the irradiated and the non-irradiated polyphenols. Thus, the irradiation of green tea polyphenol did not change and even increased its anti-wrinkle, skin-whitening and anticancer effects on the human skin. The results indicated that irradiated green tea polyphenol can be used as a natural ingredient with excellent physiological functions for the human skin through cosmetic or food composition.

Green tea and its major polyphenol EGCG increase the activity of oral peroxidases.

PubMed

Narotzki, Baruch; Levy, Yishai; Aizenbud, Dror; Reznick, Abraham Z

2013-01-01

Oral peroxidases (OPO) consist mainly of salivary peroxidase and myeloperoxidase and are involved in oral defense mechanisms. Salivary peroxidase is synthesized and secreted by salivary glands, whereas myeloperoxidase is found in polymorphonuclear leukocytes, which migrate into the oral cavity at gingival crevices. Green tea is the world's second most popular drink after water. Polyphenols are the most biologically active group of tea components. The purpose of our study was to elucidate the interaction between green tea & EGCG (Epigallocatechin 3-gallate), its main polyphenol and OPO. In previous studies we have shown that elderly trained people who drink green tea for 3 months, have a higher level of OPO activity compared to non-drinkers. Thus, we decided to extend our project in order to understand the above observations by studying the interaction of green tea and OPO both in vitro and in vivo. Addition of green tea and black tea infusions (50 μl/ml) and EGCG (50 μM) to saliva, resulted in a sharp rise of OPO activity +280% (p = 0.009), 54% (p = 0.04) and 42% (p = 0.009), respectively. The elevation of OPO activity due to addition of green tea and EGCG was in a dose dependent manner: r = 0.91 (p = 0.001) and r = 0.637 (p = 0.019), respectively. Also, following green tea infusion mouth rinsing, a rise of OPO activity was observed: +268% (p = 0.159). These results may be of great clinical importance, as tea consumer's oral epithelium may have better protection against the deleterious effects of hydroxyl radicals, produced by not removed hydrogen peroxides in the presence of metal ions. Higher OPO activity upon green tea drinking may provide an extra protection against oxidative stress in the oral cavity.

Inhibition of non-haem iron absorption in man by polyphenolic-containing beverages.

PubMed

Hurrell, R F; Reddy, M; Cook, J D

1999-04-01

The effects of different polyphenol-containing beverages on Fe absorption from a bread meal were estimated in adult human subjects from the erythrocyte incorporation of radio-Fe. The test beverages contained different polyphenol structures and were rich in either phenolic acids (chlorogenic acid in coffee), monomeric flavonoids (herb teas, camomile (Matricaria recutita L.), vervain (Verbena officinalis L.), lime flower (Tilia cordata Mill.), pennyroyal (Mentha pulegium L.) and peppermint (Mentha piperita L.), or complex polyphenol polymerization products (black tea and cocoa). All beverages were potent inhibitors of Fe absorption and reduced absorption in a dose-dependent fashion depending on the content of total polyphenols. Compared with a water control meal, beverages containing 20-50 mg total polyphenols/serving reduced Fe absorption from the bread meal by 50-70%, whereas beverages containing 100-400 mg total polyphenols/serving reduced Fe absorption by 60-90%. Inhibition by black tea was 79-94%, peppermint tea 84%, pennyroyal 73%, cocoa 71%, vervain 59%, lime flower 52% and camomile 47%. At an identical concentration of total polyphenols, black tea was more inhibitory than cocoa, and more inhibitory than herb teas camomile, vervain, lime flower and pennyroyal, but was of equal inhibition to peppermint tea. Adding milk to coffee and tea had little or no influence on their inhibitory nature. Our findings demonstrate that herb teas, as well as black tea, coffee and coca can be potent inhibitors of Fe absorption. This property should be considered when giving dietary advice in relation to Fe nutrition.

Interaction of green tea polyphenols with dairy matrices in a simulated gastrointestinal environment.

PubMed

Lamothe, Sophie; Azimy, Naheed; Bazinet, Laurent; Couillard, Charles; Britten, Michel

2014-10-01

The consumption of polyphenols in green tea has been associated with beneficial health effects. Although polyphenols are unstable in the intestinal environment, they may be protected by interactions with dairy proteins during digestion. The objectives of this study were to evaluate the effect of a green tea extract on the digestibility of different dairy matrices and to monitor the antioxidant activity of these matrices with or without the green tea extract during digestion in a simulated gastrointestinal environment. Milk, yogurt and cheese with similar fat-to-protein ratios were subjected to simulated digestion. Matrix degradation, protein and fat hydrolysis, polyphenol concentration and radical scavenging activity were analyzed during gastric and intestinal digestion phases. Cheese was the matrix most resistant to protein and fat digestion. The addition of the green tea extract significantly decreased proteolysis in the gastric phase but had no effect in the intestinal phase. The kinetics of fatty acid release was reduced by the presence of the green tea extract. Transition from the gastric phase to the intestinal phase induced a 50% decrease in the antioxidant activity of the control (tea extract dispersed in water) due to the degradation of polyphenols. The presence of dairy matrices significantly improved polyphenol stability in the intestinal phase and increased the antioxidant activity by 29% (cheese) to 42% (milk) compared to the control. These results suggest that simultaneous consumption of green tea and dairy products helps to maintain the integrity and antioxidant activity of polyphenols during digestion.

Green Tea Polyphenols Attenuated Glutamate Excitotoxicity via Antioxidative and Antiapoptotic Pathway in the Primary Cultured Cortical Neurons.

PubMed

Cong, Lin; Cao, Chang; Cheng, Yong; Qin, Xiao-Yan

2016-01-01

Green tea polyphenols are a natural product which has antioxidative and antiapoptotic effects. It has been shown that glutamate excitotoxicity induced oxidative stress is linked to neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. In this study we explored the neuroprotective effect of green teen polyphenols against glutamate excitotoxicity in the primary cultured cortical neurons. We found that green tea polyphenols protected against glutamate induced neurotoxicity in the cortical neurons as measured by MTT and TUNEL assays. Green tea polyphenols were then showed to inhibit the glutamate induced ROS release and SOD activity reduction in the neurons. Furthermore, our results demonstrated that green tea polyphenols restored the dysfunction of mitochondrial pro- or antiapoptotic proteins Bax, Bcl-2, and caspase-3 caused by glutamate. Interestingly, the neuroprotective effect of green tea polyphenols was abrogated when the neurons were incubated with siBcl-2. Taken together, these results demonstrated that green tea polyphenols protected against glutamate excitotoxicity through antioxidative and antiapoptotic pathways.

Preparation of organogel with tea polyphenols complex for enhancing the antioxidation properties of edible oil.

PubMed

Shi, Rong; Zhang, Qiuyue; Vriesekoop, Frank; Yuan, Qipeng; Liang, Hao

2014-08-20

Food-grade organogels are semisolid systems with immobilized liquid edible oil in a three-dimensional network of self-assembled gelators, and they are supposed to have a broad range of potential applications in food industries. In this work, an edible organogel with tea polyphenols was developed, which possesses a highly effective antioxidative function. To enhance the dispersibility of the tea polyphenols in the oil phase, a solid lipid-surfactant-tea polyphenols complex (organogel complex) was first prepared according to a novel method. Then, a food-grade organogel was prepared by mixing this organogel complex with fresh peanut oil. Compared with adding free tea polyphenols, the organogel complex could be more homogeneously distributed in the prepared organogel system, especially under heating condition. Furthermore, the organogel loading of tea polyphenols performed a 2.5-fold higher antioxidation compared with other chemically synthesized antioxidants (butylated hydroxytoluene and propyl gallate) by evaluating the peroxide value of the fresh peanut oil based organogel in accelerated oxidation conditions.

Total polyphenols, catechin profiles and antioxidant activity of tea products from purple leaf coloured tea cultivars.

PubMed

Kerio, L C; Wachira, F N; Wanyoko, J K; Rotich, M K

2013-02-15

Black (aerated) and green (unaerated) tea products, processed from 10 green and 18 purple leaf coloured cultivars of Kenyan origin, and two tea products, from the Japanese cultivars, Yabukita and Yutakamidori, were assayed for total polyphenols (TP) content, individual catechin profiles and in vitro antioxidant capacity (AA). In addition, the phenolic content of the tea products was determined using the Folin-Ciocalteu phenol reagent. Catechin fractions were identified using reverse phase high performance liquid chromatography (HPLC) with a binary gradient elution system. The AA% of the tea products was determined using a 2,2'-diphenyl picrylhydrazyl (DPPH) radical assay method. The results showed that TPs, catechin profiles and antioxidant activities were significantly (p≤0.05) higher in unaerated than in aerated teas. Tea products from the purple leaf coloured tea cultivars had levels of TPs, total catechin (TC) and antioxidant activities similar to those from the green leaf coloured cultivars, except for teas from the Japanese cultivars that were very low in the assayed parameters. Caffeine content was significantly (p≤0.05) lower in products from the purple leaf coloured cultivars than in those from the green leaf coloured tea cultivars. Antioxidant activity (%) was higher in tea products from the Kenyan germplasm than in those from the Japanese cultivars. Antioxidant potency of tea products was significantly (r=0.789(∗∗), p≤0.01) influenced by the total anthocyanin content of the purple leaf coloured cultivars. Cyanidin-3-O-glucoside was the anthocyanin most highly correlated with AA% (r=0.843(∗∗), p≤0.01 in unaerated tea). Total catechins in the unaerated products from the green leaf coloured tea cultivars were also significantly correlated with antioxidant capacity (r=0.818(∗∗), p≤0.01). Results from this study suggest that the antioxidant potency of teas is dependent on the predominant flavonoid compound, the type of tea cultivar and

A novel convenient process to obtain a raw decaffeinated tea polyphenol fraction using a lignocellulose column.

PubMed

Sakanaka, Senji

2003-05-07

Lignocellulose prepared from sawdust was investigated for its potential application in obtaining a raw decaffeinated tea polyphenol fraction from tea extract. Tea polyphenols having gallate residues, namely, (-)epigallocatechin gallate (EGCg) and (-)epicatechin gallate (ECg), were adsorbed on the lignocellulose column, while caffeine was passed through it. Adsorbed polyphenols were eluted with 60% ethanol, and the elute was found to consist mainly of EGCg and ECg. The caffeine/EGCg ratio was 0.696 before lignocellulose column treatment, but it became 0.004 after the column treatment. These results suggest that the lignocellulose column provides a useful and convenient process of purification of tea polyphenol fraction accompanied by decaffeination.

Molecular mechanisms of green tea polyphenols with protective effects against skin photoaging.

PubMed

Roh, Eunmiri; Kim, Jong-Eun; Kwon, Jung Yeon; Park, Jun Seong; Bode, Ann M; Dong, Zigang; Lee, Ki Won

2017-05-24

Whereas green tea has historically been consumed in high quantities in Northeast Asia, its popularity is also increasing in many Western countries. Green tea is an abundant source of plant polyphenols exhibiting numerous effects that are potentially beneficial for human health. Accumulating evidence suggests that green tea polyphenols confer protective effects on the skin against ultraviolet (UV) irradiation-induced acceleration of skin aging, involving antimelanogenic, antiwrinkle, antioxidant, and anti-inflammatory effects as well as prevention of immunosuppression. Melanin pigmentation in the skin is a major defense mechanism against UV irradiation, but pigmentation abnormalities such as melasma, freckles, senile lentigines, and other forms of melanin hyperpigmentation can also cause serious health and aesthetic issues. Furthermore, UV irradiation initiates the degradation of fibrillar collagen and elastic fibers, promoting the process of skin aging through deep wrinkle formation and loss of tissue elasticity. UV irradiation-induced formation of free radicals also contributes to accelerated photoaging. Additionally, immunosuppression caused by UV irradiation plays an important role in photoaging and skin carcinogenesis. In this review, we summarize the current literature regarding the antimelanogenic, antiwrinkle, antioxidant, and immunosuppression preventive mechanisms of green tea polyphenols that have been demonstrated to protect against UV irradiation-stimulated skin photoaging, and gauge the quality of evidence supporting the need for clinical studies using green tea polyphenols as anti-photoaging agents in novel cosmeceuticals.

Reduction of Hexavalent Chromium by Green Tea Polyphenols and Green Tea Nano Zero-Valent Iron (GT-nZVI).

PubMed

Chrysochoou, M; Reeves, K

2017-03-01

This study reports on the direct reduction of hexavalent chromium [Cr(VI)] by green tea polyphenols, including a green tea solution and pure epigallocatechin gallate (EGCG) solution. A linear trend was observed between the amount of reduced Cr(VI) and the amount of added polyphenols. The green tea solution showed a continued decrease in the observed stoichiometry with increasing pH, from a maximum of 1.4 mol per gallic acid equivalent (GAE) of green tea at pH 2.5, to 0.2 mol/GAE at pH 8.8. The EGCG solution exhibited different behavior, with a maximum stoichiometry of 2 at pH 7 and minimum of 1.6 at pH 4.4 and 8.9. When green tea was used to first react with Fe 3+ and form GT-nZVI, the amount of Cr(VI) reduced by a certain volume of GT-nZVI was double compared to green tea, and 6 times as high considering that GT-nZVI only contains 33 % green tea.

Fermentation characteristics of some assamica clones and process optimization of black tea manufacturing.

PubMed

Baruah, Ananta Madhab; Mahanta, Pradip Kumar

2003-10-22

Changes in the specific activities of polyphenol oxidase (PPO), peroxidase (POD), and protease and in the relative amounts of flavan-3-ols for eight genetically derived cultivated teas at various stages of leaf maturity and in four succescive seasons were examined. A series of investigations were carried out to study the cross-reactivity of complex polyphenols and PPO-generated orange-yellow theaflavins, as well as of POD oxidized substrates, producing brown so-called thearubigins during fermented tea processing. From the estimation of five major catechins, PPO activities in young shoots, and theaflavin and thearubigin contents of crushed, torn, and curled (CTC) black teas, the superior variety and flavorful flush characteristics were refined. Notable protein hydrolysis by endogenous protease as measured from free amino acids and formation of tannin-protein complex (browning products) was obtained for cultivar character and product quality. Results showed that process optimization with respect to time, temperature, moisture, and pH maximizes PPO-catalyzed desirable theaflavin pigments, whereas POD-mediated chemical reaction produces dull color.

Controlled-release of tea polyphenol from gelatin films incorporated with different ratios of free/nanoencapsulated tea polyphenols into fatty food simulants

USDA-ARS?s Scientific Manuscript database

Gelatin films having controlled-release properties were developed by incorporation of different free/encapsulated tea polyphenol (TP) ratios through modifying the encapsulation efficiency (EE) of TP-loaded chitosan nanoparticles. Different EEs were obtained by adjusting the chitosan hydrochloride (C...

Potential protection of green tea polyphenols against 1800 MHz electromagnetic radiation-induced injury on rat cortical neurons.

PubMed

Liu, Mei-Li; Wen, Jian-Qiang; Fan, Yu-Bo

2011-10-01

Radiofrequency electromagnetic fields (EMF) are harmful to public health, but the certain anti-irradiation mechanism is not clear yet. The present study was performed to investigate the possible protective effects of green tea polyphenols against electromagnetic radiation-induced injury in the cultured rat cortical neurons. In this study, green tea polyphenols were used in the cultured cortical neurons exposed to 1800 MHz EMFs by the mobile phone. We found that the mobile phone irradiation for 24 h induced marked neuronal cell death in the MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl-tetrazolium bromide) and TUNEL (TdT mediated biotin-dUTP nicked-end labeling) assay, and protective effects of green tea polyphenols on the injured cortical neurons were demonstrated by testing the content of Bcl-2 Assaciated X protein (Bax) in the immunoprecipitation assay and Western blot assay. In our study results, the mobile phone irradiation-induced increases in the content of active Bax were inhibited significantly by green tea polyphenols, while the contents of total Bax had no marked changes after the treatment of green tea polyphenols. Our results suggested a neuroprotective effect of green tea polyphenols against the mobile phone irradiation-induced injury on the cultured rat cortical neurons.

Prooxidant property of green tea polyphenols epicatechin and epigallocatechin-3-gallate: implications for anticancer properties.

PubMed

Azam, S; Hadi, N; Khan, N U; Hadi, S M

2004-10-01

It is believed that anticancer and apoptosis inducing properties of green tea are mediated by it's polyphenolic constituents particularly catechins. A number of reports have shown that green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) is among the most effective chemopreventive and apoptosis-inducing agents present in the beverage. Plant polyphenols are naturally occurring antioxidants but they also exhibit prooxidant properties. Over the last several years we have shown that various classes of plant polyphenols including flavonoids, curcuminoids and tannins are capable of catalyzing oxidative DNA cleavage particularly in the presence of transition metal ions such as copper and iron. With a view to understand the chemical basis of various pharmacological properties of green tea, in this paper we have compared the prooxidant properties of green tea polyphenols--EGCG and EC ((-)-epicatechin). The rate of oxidative DNA degradation as well as hydroxyl radical and superoxide anion formation was found to be greater in the case of EGCG as compared with EC. It was also shown that copper mediated oxidation of EC and EGCG possibly leads to the formation of polymerized polyphenols. Further, it was indicated that copper oxidized catechins were more efficient prooxidants as compared with their unoxidized forms. These results correlate with the observation by others that EGCG is the most effective apoptosis inducing polyphenol present in green tea. They are also in support of our hypothesis that prooxidant action of plant polyphenols may be an important mechanism of their anticancer properties. A model for binding of Cu(II) to EC has been presented where the formation of quinone and a quinone methide has been proposed.

Optimization and validation of Folin-Ciocalteu method for the determination of total polyphenol content of Pu-erh tea.

PubMed

Musci, Marilena; Yao, Shicong

2017-12-01

Pu-erh tea is a post-fermented tea that has recently gained popularity worldwide, due to potential health benefits related to the antioxidant activity resulting from its high polyphenolic content. The Folin-Ciocalteu method is a simple, rapid, and inexpensive assay widely applied for the determination of total polyphenol content. Over the past years, it has been subjected to many modifications, often without any systematic optimization or validation. In our study, we sought to optimize the Folin-Ciocalteu method, evaluate quality parameters including linearity, precision and stability, and then apply the optimized model to determine the total polyphenol content of 57 Chinese teas, including green tea, aged and ripened Pu-erh tea. Our optimized Folin-Ciocalteu method reduced analysis time, allowed for the analysis of a large number of samples, to discriminate among the different teas, and to assess the effect of the post-fermentation process on polyphenol content.

MALDI-TOF mass spectrometry: avoidance of artifacts and analysis of caffeine-precipitated SII thearubigins from 15 commercial black teas.

PubMed

Drynan, J Warren; Clifford, Michael N; Obuchowicz, Jacek; Kuhnert, Nikolai

2012-05-09

Thearubigins are the quantitatively major phenolic compounds in black tea, accounting for some 60-70% of the solids in a typical black tea infusion. MALDI-TOF mass spectra for caffeine-precipitated SII thearubigins (SII CTRs) from 15 different commercial teas support previous conclusions that SII CTRs are polyhydroxylated oligomers (rather than polymers) of catechins and catechin gallates in redox equilibrium with their quinone counterparts. Some 4500 peaks were revealed in a mass range from m/z 500 to 2100. Polyphenols are redox-susceptible and readily generate artifacts during MALDI-TOF analysis when the matrix is also redox-susceptible. Of the nine matrices evaluated, 3',4',5'-trihydroxyacetophenone (F) provided the best compromise between signal intensity and redox artifact formation.

Green tea polyphenols avert chronic inflammation-induced myocardial fibrosis of female rats

USDA-ARS?s Scientific Manuscript database

Objective: Green tea proposes anti-inflammatory properties which may attenuate chronic inflammation-induced fibrosis of vessels. This study evaluated whether green tea polyphenols (GTP) can avert fibrosis or vascular disruption along with mechanisms in rats with chronic inflammation. Treatments: Fo...

Tea and Health: Studies in Humans

PubMed Central

Khan, Naghma; Mukhtar, Hasan

2014-01-01

Tea, next to water is the cheapest beverage humans consume. Drinking the beverage tea has been considered a health-promoting habit since ancient times. The modern medicinal research is providing a scientific basis for this belief. The evidence supporting the health benefits of tea drinking grows stronger with each new study that is published in the scientific literature. Tea plant Camellia sinensis has been cultivated for thousands of years and its leaves have been used for medicinal purposes. Tea is used as a popular beverage worldwide and its ingredients are now finding medicinal benefits. Encouraging data showing cancer-preventive effects of green tea from cell-culture, animal and human studies have emerged. Evidence is accumulating that black tea may have similar beneficial effects. Tea consumption has also been shown to be useful for prevention of many debilitating human diseases that include maintenance of cardiovascular and metabolic health. Various studies suggest that polyphenolic compounds present in green and black tea are associated with beneficial effects in prevention of cardiovascular diseases, particularly of atherosclerosis and coronary heart disease. In addition, anti-aging, antidiabetic and many other health beneficial effects associated with tea consumption are described. Evidence is accumulating that catechins and theaflavins, which are the main polyphenolic compounds of green and black tea, respectively, are responsible for most of the physiological effects of tea. This article describes the evidences from clinical and epidemiological studies in the prevention of chronic diseases like cancer and cardiovascular diseases and general health promotion associated with tea consumption. PMID:23448443

Heterogeneous photodegradation of methylene blue with iron and tea or coffee polyphenols in aqueous solutions.

PubMed

Morikawa, Claudio Kendi; Shinohara, Makoto

2016-01-01

Recently, we developed two new Fenton catalysts using iron (Fe) and spent tea leaves or coffee grounds as raw material. In this study, Fe-to-tea or Fe-to-coffee polyphenol complexes were successfully tested as heterogeneous photo-Fenton catalysts. The photodegradation efficiency of methylene blue solutions with Fe-to-polyphenol complexes was higher than that of homogeneous iron salts in the photo-Fenton process. Furthermore, the tested Fe-to-polyphenol complexes could be reused by simply adding H2O2 to the solutions. After three sequential additions of H2O2, the conventional catalysts FeCl2·4H2O and FeCl3 removed only 16.6% and 53.6% of the dye, while the catalysts made using spent coffee grounds and tea leaves removed 94.4% and 96.0% of the dye, respectively. These results showed that the complexes formed between Fe and chlorogenic acid, caffeic acid, gallic acid and catechin, which are the main polyphenols in tea and coffee, can be used to improve the photo-Fenton process.

Metabonomics approach to determine metabolic differences between green tea and black tea consumption.

PubMed

Van Dorsten, Ferdi A; Daykin, Clare A; Mulder, Theo P J; Van Duynhoven, John P M

2006-09-06

The purpose of this study was to compare the effects of black and green tea consumption on human metabolism. Seventeen healthy male volunteers consumed black tea, green tea, or caffeine in a randomized crossover study. Twenty-four-hour urine and blood plasma samples were analyzed by NMR-based metabonomics, that is, high-resolution 1H NMR metabolic profiling combined with multivariate statistics. Green and black tea consumption resulted in similar increases in urinary excretion of hippuric acid and 1,3-dihydroxyphenyl-2-O-sulfate, both of which are end products of tea flavonoid degradation by colonic bacteria. Several unidentified aromatic metabolites were detected in urine specifically after green tea intake. Interestingly, green and black tea intake also had a different impact on endogenous metabolites in urine and plasma. Green tea intake caused a stronger increase in urinary excretion of several citric acid cycle intermediates, which suggests an effect of green tea flavanols on human oxidative energy metabolism and/or biosynthetic pathways.

Black tea high-molecular-weight polyphenol stimulates exercise training-induced improvement of endurance capacity in mouse via the link between AMPK and GLUT4.

PubMed

Eguchi, Tomoaki; Kumagai, Chiaki; Fujihara, Takashi; Takemasa, Thoru; Ozawa, Tetsuo; Numata, Osamu

2013-01-01

Aerobic exercise can promote "fast-to-slow transition" in skeletal muscles, i.e. an increase in oxidative fibers, mitochondria, and myoglobin and improvement in glucose and lipid metabolism. Here, we found that mice administered Mitochondria Activation Factor (MAF) combined with exercise training could run longer distances and for a longer time compared with the exercise only group; MAF is a high-molecular-weight polyphenol purified from black tea. Furthermore, MAF intake combined with exercise training increased phosphorylation of AMPK and mRNA level of glucose transporter 4 (GLUT4). Thus, our data demonstrate for the first time that MAF activates exercise training-induced intracellular signaling pathways that involve AMPK, and improves endurance capacity.

Green Tea Polyphenols and Metabolites in Prostatectomy Tissue: Implications for Cancer Prevention

PubMed Central

Wang, Piwen; Aronson, William J.; Huang, Min; Zhang, Yanjun; Lee, Ru-Po; Heber, David; Henning, Susanne M.

2011-01-01

Epidemiologic, preclinical, and clinical trials suggest that green tea (GT) consumption may prevent prostate cancer via the action of green tea polyphenols including (-)-epigallocatechin-3-gallate (EGCG). In order to study the metabolism and bioactivity of green tea polyphenols in human prostate tissue, men with clinically localized prostate cancer consumed 6 cups of GT (n=8) daily or water (n=9) for 3-6 weeks prior to undergoing radical prostatectomy. Using high performance liquid chromatography 4″-O-methyl EGCG (4″-MeEGCG) and EGCG were identified in comparable amounts, and (-)-epicatechin-3-gallate (ECG) in lower amounts in prostatectomy tissue from men consuming GT (38.9 ± 19.5, 42.1 ± 32.4, and 17.8 ± 10.1 pmol/g tissue, respectively). The majority of EGCG and other green tea polyphenols were not conjugated. Green tea polyphenols were not detected in prostate tissue or urine from men consuming water preoperatively. In the urine of men consuming GT, 50-60% of both (-)-epigallocatechin (EGC) and (-)-epicatechin were present in methylated form with 4′-O-MeEGC being the major methylated form of EGC. When incubated with EGCG LNCaP prostate cancer cells were able to methylate EGCG to 4″-MeEGCG. The capacity of 4″-MeEGCG to inhibit proliferation and NF-κB activation and induce apoptosis in LNCaP cells was decreased significantly compared to EGCG. In summary, methylated and non-methylated forms of EGCG are detectable in prostate tissue following a short-term GT intervention and the methylation status of EGCG may potentially modulate its preventive impact on prostate cancer, possibly based on genetic polymorphisms of catechol O-methyltransferase. PMID:20628004

Consumption of coffee, but not black tea, is associated with decreased risk of premenopausal breast cancer.

PubMed

Baker, Julie A; Beehler, Gregory P; Sawant, Abhishek C; Jayaprakash, Vijayvel; McCann, Susan E; Moysich, Kirsten B

2006-01-01

Caffeine has been suggested as a possible risk factor for breast cancer, potentially through its effect of facilitating the development of benign breast disease. However, coffee and tea also contain polyphenols, which exhibit anticarcinogenic properties. A hospital-based, case-control study was conducted to evaluate the role of coffee, decaffeinated coffee, and black tea in breast cancer etiology. Study participants included 1932 cases with primary, incident breast cancer and 1895 hospital controls with nonneoplastic conditions. All participants completed a comprehensive epidemiological questionnaire. Among premenopausal women, consumption of regular coffee was associated with linear declines in breast cancer risk (P for trend = 0.03); consumers of >or=4 cups/d experienced a 40% risk reduction (odds ratio = 0.62, 95% CI 0.39-0.98). No clear associations between intake of black tea or decaffeinated coffee and breast cancer risk were noted among premenopausal women, although black tea was associated with a protective effect unique to a subsample of cases with lobular histology. Among postmenopausal women, breast cancer risk was not associated with consumption of coffee, tea, or decaffeinated coffee. Results among postmenopausal women did not differ by histologic subtype. Our findings support a protective effect of coffee intake on premenopausal, but not postmenopausal breast cancer risk. Further studies are warranted to confirm these findings.

Comprehensive Lipidome-Wide Profiling Reveals Dynamic Changes of Tea Lipids during Manufacturing Process of Black Tea.

PubMed

Li, Jia; Hua, Jinjie; Zhou, Qinghua; Dong, Chunwang; Wang, Jinjin; Deng, Yuliang; Yuan, Haibo; Jiang, Yongwen

2017-11-22

As important biomolecules in Camellia sinensis L., lipids undergo substantial changes during black tea manufacture, which is considered to contribute to tea sensory quality. However, limited by analytical capacity, detailed lipid composition and its dynamic changes during black tea manufacture remain unclear. Herein, we performed tea lipidome profiling using high resolution liquid chromatography coupled to mass spectrometry (LC-MS), which allows simultaneous and robust analysis of 192 individual lipid species in black tea, covering 17 (sub)classes. Furthermore, dynamic changes of tea lipids during black tea manufacture were investigated. Significant alterations of lipid pattern were revealed, involved with chlorophyll degradation, metabolic pathways of glycoglycerolipids, and other extraplastidial membrane lipids. To our knowledge, this report presented most comprehensive coverage of lipid species in black tea. This study provides a global and in-depth metabolic map of tea lipidome during black tea manufacture.

Application of microencapsulation for the safe delivery of green tea polyphenols in food systems: Review and recent advances.

PubMed

Massounga Bora, Awa Fanny; Ma, Shaojie; Li, Xiaodong; Liu, Lu

2018-03-01

Green tea has been associated with the prevention and reduction of a wide range of severe health conditions such as cancer, immune, and cardiovascular diseases. The health benefits associated with green tea consumption have been predominantly attributed to green tea polyphenols. The functional properties of green tea polyphenols are mainly anti-oxidative, antimutagenic, anticarcinogenic, anti-microbial, etc. These excellent properties have recently gained considerable attention in the food industry. However, their application is limited by their sensitivity to factors like temperature, light, pH, oxygen, etc. More, studies have reported the occurrence of unpleasant taste and color transfer during food processing. Lastly, the production of functional food requires to maintain the stability, bioactivity, and bioavailability of the active compounds. To tackle these obstacles, technological approaches like microencapsulation have been developed and applied for the formulation of green tea-enriched food products. The present review discusses the novelty in microencapsulation techniques for the safe delivery of green tea polyphenols in food matrices. After a literature on the green tea polyphenols composition, and their health attributes, the encapsulation methods and the coating materials are presented. The application of green tea encapsulates in food matrices as well as their effect on food functional and sensory properties are also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

The anti-obesity effect of green tea polysaccharides, polyphenols and caffeine in rats fed with a high-fat diet.

PubMed

Xu, Yan; Zhang, Min; Wu, Tao; Dai, ShengDong; Xu, Jinling; Zhou, Zhongkai

2015-01-01

Beneficial effects of green tea (Camellia sinensis, Theaceae) extracts against obesity have been reported; however, the anti-obesity ability of the major components of green tea, polysaccharides, polyphenols and caffeine is not clear. Therefore, experiments with total green tea extracts, polyphenols, polysaccharides, caffeine, and a complex of polysaccharide and polyphenol at a dose of 400 or 800 mg kg⁻¹ were conducted on high-fat diet fed rats for 6 weeks to investigate their anti-obesity effects. The results indicated that polyphenols and polysaccharides were responsible for the suppressive effect of green tea extracts on body weight increase and fat accumulation. Moreover, polyphenols, polysaccharides, or caffeine can improve blood lipid and antioxidant levels, and effectively reduce rat serum leptin levels, inhibit the absorption of fatty acids, and markedly reduce the expression levels of the IL-6 and TNF-α gene. Furthermore, it was shown that polysaccharides and polyphenols were synergistic in reduction of serum leptin levels and in anti-inflammatory activity. These results suggest that the polysaccharide combination with polyphenols might be a potential therapy against obesity.

Preservation of kombucha tea-effect of temperature on tea components and free radical scavenging properties.

PubMed

Jayabalan, Rasu; Marimuthu, Subbaiya; Thangaraj, Periyasamy; Sathishkumar, Muthuswamy; Binupriya, Arthur Raj; Swaminathan, Krishnaswami; Yun, Sei Eok

2008-10-08

Kombucha tea is sugared black tea fermented with a consortium of acetic acid bacteria and yeasts (tea fungus) for 14 days. The tea tastes slightly sweet and acidic. The formation of tea fungal biofilms during storage is a big problem when kombucha tea is being stored and commercialized. Various thermal treatments have been tried for long-term storage of kombucha tea. The present study revealed the influence of heat on the biochemical constituents and the free radical scavenging properties of kombucha tea. Heat treatment at 60, 65, and 68 degrees C for 1 min controlled biofilm formation in kombucha tea without changing its clarity, taste, and flavor. However, tea polyphenols and black tea quality parameters showed varying stability during the storage period. A decrease in free radical scavenging properties was also found during the storage period. Because the biological activities of kombucha tea depended on the biochemical constituents, it was concluded that heat treatment was not a suitable method for kombucha tea preservation.

Simultaneous determination of all polyphenols in vegetables, fruits, and teas.

PubMed

Sakakibara, Hiroyuki; Honda, Yoshinori; Nakagawa, Satoshi; Ashida, Hitoshi; Kanazawa, Kazuki

2003-01-29

Polyphenols, which have beneficial effects on health and occur ubiquitously in plant foods, are extremely diverse. We developed a method for simultaneously determining all the polyphenols in foodstuffs, using HPLC and a photodiode array to construct a library comprising retention times, spectra of aglycons, and respective calibration curves for 100 standard chemicals. The food was homogenized in liquid nitrogen, lyophilized, extracted with 90% methanol, and subjected to HPLC without hydrolysis. The recovery was 68-92%, and the variation in reproducibility ranged between 1 and 9%. The HPLC eluted polyphenols with good resolution within 95 min in the following order: simple polyphenols, catechins, anthocyanins, glycosides of flavones, flavonols, isoflavones and flavanones, their aglycons, anthraquinones, chalcones, and theaflavins. All the polyphenols in 63 vegetables, fruits, and teas were then examined in terms of content and class. The present method offers accuracy by avoiding the decomposition of polyphenols during hydrolysis, the ability to determine aglycons separately from glycosides, and information on simple polyphenol levels simultaneously.

The Galloyl Catechins Contributing to Main Antioxidant Capacity of Tea Made from Camellia sinensis in China

PubMed Central

Zhao, Chunjian; Li, Chunying; Liu, Shuaihua; Yang, Lei

2014-01-01

Total polyphenol content, catechins content, and antioxidant capacities of green, dark, oolong, and black teas made from Camellia sinensis in China were evaluated. The total polyphenol content of 20 samples of tea was in the range of 7.82–32.36%. Total catechins content was in the range of 4.34–24.27%. The antioxidant capacity of tea extract was determined by the oxygen radical absorbance capacity (ORAC) test and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging test. Total polyphenol content, catechins content, and antioxidant capacity decreased in the following order: green > oolong > black > dark tea. A positive correlation existed between the antioxidant capacity and total polyphenol content or catechins content (R 2 = 0.67–0.87). The antioxidant capacities of five major catechins (epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epicatechin, epigallocatechin, and catechin) were determined by online HPLC DPPH radical-scavenging; the antioxidant activity of tea was mainly attributed to the esterified catechins (EGCG or ECG). PMID:25243234

Corneal Staining and Hot Black Tea Compresses.

PubMed

Achiron, Asaf; Birger, Yael; Karmona, Lily; Avizemer, Haggay; Bartov, Elisha; Rahamim, Yocheved; Burgansky-Eliash, Zvia

2017-03-01

Warm compresses are widely touted as an effective treatment for ocular surface disorders. Black tea compresses are a common household remedy, although there is no evidence in the medical literature proving their effect and their use may lead to harmful side effects. To describe a case in which the application of black tea to an eye with a corneal epithelial defect led to anterior stromal discoloration; evaluate the prevalence of hot tea compress use; and analyze, in vitro, the discoloring effect of tea compresses on a model of a porcine eye. We assessed the prevalence of hot tea compresses in our community and explored the effect of warm tea compresses on the cornea when the corneal epithelium's integrity is disrupted. An in vitro experiment in which warm compresses were applied to 18 fresh porcine eyes was performed. In half the eyes a corneal epithelial defect was created and in the other half the epithelium was intact. Both groups were divided into subgroups of three eyes each and treated experimentally with warm black tea compresses, pure water, or chamomile tea compresses. We also performed a study in patients with a history of tea compress use. Brown discoloration of the anterior stroma appeared only in the porcine corneas that had an epithelial defect and were treated with black tea compresses. No other eyes from any group showed discoloration. Of the patients included in our survey, approximately 50% had applied some sort of tea ingredient as a solid compressor or as the hot liquid. An intact corneal epithelium serves as an effective barrier against tea-stain discoloration. Only when this layer is disrupted does the damage occur. Therefore, direct application of black tea (Camellia sinensis) to a cornea with an epithelial defect should be avoided.

Application of tea polyphenols in combination with 6-gingerol on shrimp paste of during storage: biogenic amines formation and quality determination.

PubMed

Cai, Luyun; Liu, Shucheng; Sun, Lijun; Wang, Yaling; Ji, Hongwu; Li, Jianrong

2015-01-01

Tea polyphenols (TP) have shown antioxidant activity and antimicrobial properties in the food industry. Assessment of anti-oxidation potential of 6-gingerol (GR) has also been verified. As little is known about the use of tea polyphenols either individually or in combination with 6-gingerol in shrimp paste, we aimed to investigate the effect of tea polyphenols combined with 6-gingerol on the biogenic amines inhibition and quality of shrimp paste stored at 25°C for 160 days. The shrimp paste samples were assigned into four groups: (1) control; (2) tea polyphenols treatment (0.3%); (3) 6-gingerol treatment (0.3%); (4) tea polyphenols (0.15%) + 6-gingerol (0.15%). Samples with no addition were used as control. The results indicate that treatment with tea polyphenols + 6-gingerol (TPGR) maintained paste appearance, inhibited oxidation of protein and lipids, and reduced microorganism counts compared to control treatment. The efficiency was superior to that of tea polyphenols or 6-gingerol treatment. Furthermore, shrimp paste treated with TPGR also exhibited significantly higher inhibition of biogenic amines. Total amino acids determination proved the efficacy of TPGR by maintaining the more amino acids of shrimp paste during ambient temperature storage. Our study suggests that TPGR might be a promising candidate for fermented foods due to its synergistic effect to maintain products quality and extending their shelf-life.

Application of tea polyphenols in combination with 6-gingerol on shrimp paste of during storage: biogenic amines formation and quality determination

PubMed Central

Cai, Luyun; Liu, Shucheng; Sun, Lijun; Wang, Yaling; Ji, Hongwu; Li, Jianrong

2015-01-01

Tea polyphenols (TP) have shown antioxidant activity and antimicrobial properties in the food industry. Assessment of anti-oxidation potential of 6-gingerol (GR) has also been verified. As little is known about the use of tea polyphenols either individually or in combination with 6-gingerol in shrimp paste, we aimed to investigate the effect of tea polyphenols combined with 6-gingerol on the biogenic amines inhibition and quality of shrimp paste stored at 25°C for 160 days. The shrimp paste samples were assigned into four groups: (1) control; (2) tea polyphenols treatment (0.3%); (3) 6-gingerol treatment (0.3%); (4) tea polyphenols (0.15%) + 6-gingerol (0.15%). Samples with no addition were used as control. The results indicate that treatment with tea polyphenols + 6-gingerol (TPGR) maintained paste appearance, inhibited oxidation of protein and lipids, and reduced microorganism counts compared to control treatment. The efficiency was superior to that of tea polyphenols or 6-gingerol treatment. Furthermore, shrimp paste treated with TPGR also exhibited significantly higher inhibition of biogenic amines. Total amino acids determination proved the efficacy of TPGR by maintaining the more amino acids of shrimp paste during ambient temperature storage. Our study suggests that TPGR might be a promising candidate for fermented foods due to its synergistic effect to maintain products quality and extending their shelf-life. PMID:26441911

Decaffeinated green and black tea polyphenols decrease weight gain and alter microbiome populations and function in diet-induced obese mice.

PubMed

Henning, Susanne M; Yang, Jieping; Hsu, Mark; Lee, Ru-Po; Grojean, Emma M; Ly, Austin; Tseng, Chi-Hong; Heber, David; Li, Zhaoping

2017-09-30

Decaffeinated green tea (GT) and black tea (BT) polyphenols inhibit weight gain in mice fed an obesogenic diet. Since the intestinal microflora is an important contributor to obesity, it was the objective of this study to determine whether the intestinal microflora plays a role in the anti-obesogenic effect of GT and BT. C57BL/6J mice were fed a high-fat/high-sucrose diet (HF/HS, 32% energy from fat; 25% energy from sucrose) or the same diet supplemented with 0.25% GTP or BTP or a low-fat/high-sucrose (LF/HS, 10.6% energy from fat, 25% energy from sucrose) diet for 4 weeks. Bacterial composition was assessed by MiSeq sequencing of the 16S rRNA gene. GTP and BTP diets resulted in a decrease of cecum Firmicutes and increase in Bacteroidetes. The relative proportions of Blautia, Bryantella, Collinsella, Lactobacillus, Marvinbryantia, Turicibacter, Barnesiella, and Parabacteroides were significantly correlated with weight loss induced by tea extracts. BTP increased the relative proportion of Pseudobutyrivibrio and intestinal formation of short-chain fatty acids (SCFA) analyzed by gas chromatography. Cecum propionic acid content was significantly correlated with the relative proportion of Pseudobutyrivibrio. GTP and BTP induced a significant increase in hepatic 5'adenosylmonophosphate-activated protein kinase (AMPK) phosphorylation by 70 and 289%, respectively (P < 0.05) determined by Western blot. In summary, both BTP and GTP induced weight loss in association with alteration of the microbiota and increased hepatic AMPK phosphorylation. We hypothesize that BTP increased pAMPK through increased intestinal SCFA production, while GTPs increased hepatic AMPK through GTP present in the liver.

Inhibitory Effects of the Four Main Theaflavin Derivatives Found in Black Tea on Ovarian Cancer Cells.

PubMed

Gao, Ying; Rankin, Gary O; Tu, Youying; Chen, Yi Charlie

2016-02-01

Some polyphenols induce apoptosis and inhibit angiogenesis. Consumption of black tea, rich in polyphenols, has been found to reduce ovarian cancer risk. Theaflavin (TF1), theaflavin-3-gallate (TF2a), theaflavin-3'-gallate (TF2b) and theaflavin-3, 3'-digallate (TF3) are four main theaflavin derivatives found in black tea. Cell proliferation assay, Hoechst 33342 staining assay, Caspase-Glo Assay, western blot, human umbilical vein endothelial cell tube formation assay and vascular endothelial growth factor (VEGF) enzyme-linked immunosorbent assay were performed. All four theaflavin derivatives reduced viability of ovarian cancer cells at lower concentrations than with normal ovarian cells. TF1 mainly mediated apoptosis via the intrinsic pathway, while the others via the intrinsic and extrinsic pathways. TF1 inhibited tube formation via reducing VEGF secretion in a hypoxia-inducible factor 1α-independent manner, while the others in a HIF1α-dependent way. All four theaflavin derivatives inhibited ovarian cancer cells. Some of the effects and mechanisms of TF1 are different from those of the other three theaflavin derivatives. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Green Tea Polyphenols Stimulate Mitochondrial Biogenesis and Improve Renal Function after Chronic Cyclosporin A Treatment in Rats

PubMed Central

Rehman, Hasibur; Krishnasamy, Yasodha; Haque, Khujista; Lemasters, John J.; Schnellmann, Rick G.; Zhong, Zhi

2013-01-01

Our previous studies showed that an extract from Camellia sinenesis (green tea), which contains several polyphenols, attenuates nephrotoxicity caused by cyclosporine A (CsA). Since polyphenols are stimulators of mitochondrial biogenesis (MB), this study investigated whether stimulation of MB plays a role in green tea polyphenol protection against CsA renal toxicity. Rats were fed a powdered diet containing green tea polyphenolic extract (0.1%) starting 3 days prior to CsA treatment (25 mg/kg, i.g. daily for 3 weeks). CsA alone decreased renal nuclear DNA-encoded oxidative phosphorylation (OXPHOS) protein ATP synthase-β (AS-β) by 42%, mitochondrial DNA (mtDNA)-encoded OXPHOS protein NADH dehydrogenase-3 (ND3) by 87% and their associated mRNAs. Mitochondrial DNA copy number was also decreased by 78% by CsA. Immunohistochemical analysis showed decreased cytochrome c oxidase subunit IV (COX-IV), an OXPHOS protein, in tubular cells. Peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α, the master regulator of MB, and mitochondrial transcription factor-A (Tfam), the transcription factor that regulates mtDNA replication and transcription, were 42% and 90% lower, respectively, in the kidneys of CsA-treated than in untreated rats. These results indicate suppression of MB by chronic CsA treatment. Green tea polyphenols alone and following CsA increased AS-β, ND3, COX-IV, mtDNA copy number, PGC-1α mRNA and protein, decreased acetylated PGC-1α, and increased Tfam mRNA and protein. In association with suppressed MB, CsA increased serum creatinine, caused loss of brush border and dilatation of proximal tubules, tubular atrophy, vacuolization, apoptosis, calcification, and increased neutrophil gelatinase-associated lipocalin expression, leukocyte infiltration, and renal fibrosis. Green tea polyphenols markedly attenuated CsA-induced renal injury and improved renal function. Together, these results demonstrate that green tea polyphenols attenuate Cs

Tea enhances insulin activity.

PubMed

Anderson, Richard A; Polansky, Marilyn M

2002-11-20

The most widely known health benefits of tea relate to the polyphenols as the principal active ingredients in protection against oxidative damage and in antibacterial, antiviral, anticarcinogenic, and antimutagenic activities, but polyphenols in tea may also increase insulin activity. The objective of this study was to determine the insulin-enhancing properties of tea and its components. Tea, as normally consumed, was shown to increase insulin activity >15-fold in vitro in an epididymal fat cell assay. Black, green, and oolong teas but not herbal teas, which are not teas in the traditional sense because they do not contain leaves of Camellia senensis, were all shown to increase insulin activity. High-performance liquid chromatography fractionation of tea extracts utilizing a Waters SymmetryPrep C18 column showed that the majority of the insulin-potentiating activity for green and oolong teas was due to epigallocatechin gallate. For black tea, the activity was present in several regions of the chromatogram corresponding to, in addition to epigallocatechin gallate, tannins, theaflavins, and other undefined compounds. Several known compounds found in tea were shown to enhance insulin with the greatest activity due to epigallocatechin gallate followed by epicatechin gallate, tannins, and theaflavins. Caffeine, catechin, and epicatechin displayed insignificant insulin-enhancing activities. Addition of lemon to the tea did not affect the insulin-potentiating activity. Addition of 5 g of 2% milk per cup decreased the insulin-potentiating activity one-third, and addition of 50 g of milk per cup decreased the insulin-potentiating activity approximately 90%. Nondairy creamers and soy milk also decreased the insulin-enhancing activity. These data demonstrate that tea contains in vitro insulin-enhancing activity and the predominant active ingredient is epigallocatechin gallate.

Artificial neural network modeling and optimization of ultrahigh pressure extraction of green tea polyphenols.

PubMed

Xi, Jun; Xue, Yujing; Xu, Yinxiang; Shen, Yuhong

2013-11-01

In this study, the ultrahigh pressure extraction of green tea polyphenols was modeled and optimized by a three-layer artificial neural network. A feed-forward neural network trained with an error back-propagation algorithm was used to evaluate the effects of pressure, liquid/solid ratio and ethanol concentration on the total phenolic content of green tea extracts. The neural network coupled with genetic algorithms was also used to optimize the conditions needed to obtain the highest yield of tea polyphenols. The obtained optimal architecture of artificial neural network model involved a feed-forward neural network with three input neurons, one hidden layer with eight neurons and one output layer including single neuron. The trained network gave the minimum value in the MSE of 0.03 and the maximum value in the R(2) of 0.9571, which implied a good agreement between the predicted value and the actual value, and confirmed a good generalization of the network. Based on the combination of neural network and genetic algorithms, the optimum extraction conditions for the highest yield of green tea polyphenols were determined as follows: 498.8 MPa for pressure, 20.8 mL/g for liquid/solid ratio and 53.6% for ethanol concentration. The total phenolic content of the actual measurement under the optimum predicated extraction conditions was 582.4 ± 0.63 mg/g DW, which was well matched with the predicted value (597.2mg/g DW). This suggests that the artificial neural network model described in this work is an efficient quantitative tool to predict the extraction efficiency of green tea polyphenols. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Black tea increases hypertonic stress resistance in C. elegans.

PubMed

Yuan, Pei; Pan, Lian-Yun; Xiong, Li-Gui; Tong, Jie-Wen; Li, Juan; Huang, Jian-An; Gong, Yu-Shun; Liu, Zhong-Hua

2018-06-22

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.

Rapid, direct determination of polyphenols in tea by reversed-phase column liquid chromatography.

PubMed

Ding, M; Yang, H; Xiao, S

1999-07-23

Column liquid chromatography on a C18-bonded silica column with water-methanol-acetic acid as eluent was used to determine polyphenols and caffeine in tea. Without any pretreatment, catechin, epicatechin gallate, epigallocatechin gallate, epigallocatechin, epicatechin and caffeine were separated successfully within 15 min. The detection limits (S/N = 3) of polyphenols studied were 1.8-24 mg/l at a detection wavelength 270 nm. The linear range of the peak area calibration curves for the analytes were over two orders of magnitude with a correlation coefficient of 0.996-0.999. Using this method, some Chinese tea samples were analyzed with a good reproducibility (RSD are below 5%).

Degradation of bromothymol blue by 'greener' nano-scale zero-valent iron synthesized using tea polyphenols

EPA Science Inventory

A green single-step synthesis of iron nanoparticles using tea (Camellia sinensis) polyphenols is described that uses no added surfactants/polymers as a capping or reducing agents. The expeditious reaction between polyphenols and ferric nitrate occurs within few minutes at room te...

Evaluation of the anti-oxidative effect (in vitro) of tea polyphenols.

PubMed

Hashimoto, Fumio; Ono, Masateru; Masuoka, Chikako; Ito, Yasuyuki; Sakata, Yusuke; Shimizu, Keiichi; Nonaka, Gen-ichiro; Nishioka, Itsuo; Nohara, Toshihiro

2003-02-01

Forty-three polyphenols from tea leaves were evaluated for their anti-oxidative effect against lipid peroxidation by the ferric thiocyanate method in vitro. Among these, 1,4,6-tri-O-galloyl-beta-D-glucose (hydrolyzable tannin) showed the highest anti-oxidative activity against lipid peroxidation, even stronger than that of 3-tert.-butyl-4-hydroxyanisole (BHA). The assay demonstrates that tea polyphenols, except for desgalloylated dimeric proanthocyanidins that possess a catechin structure in the upper unit and desgalloylated flavan-3-ols, and excepting theaflavin 3,3'-di-O-gallate, had more anti-oxidative activity than that of alpha-tocopherol. The chemical structure-activity relationship shows that the anti-oxidative action advanced with the condensation of two molecules of flavan-3-ols as well as with 3-O-acylation in the flavan skeleton such as that by galloyl, (3'-O-methyl)-galloyl, and p-coumaroyl groups.

Green tea and black tea consumption and prostate cancer risk: an exploratory meta-analysis of observational studies.

PubMed

Zheng, Jusheng; Yang, Bin; Huang, Tao; Yu, Yinghua; Yang, Jing; Li, Duo

2011-01-01

Observational studies on tea consumption and prostate cancer (PCa) risk are still inconsistent. The authors conducted a meta-analysis to investigate the association between green tea and black tea consumption with PCa risk. Thirteen studies providing data on green tea or black tea consumption were identified by searching PubMed and ISI Web of Science databases and secondary referencing qualified for inclusion. A random-effects model was used to calculate the summary odds ratios (OR) and their corresponding 95% confidence intervals (CIs). For green tea, the summary OR of PCa indicated a borderline significant association in Asian populations for highest green tea consumption vs. non/lowest (OR = 0.62; 95% CI: 0.38-1.01); and the pooled estimate reached statistically significant level for case-control studies (OR = 0.43; 95% CI: 0.25-0.73), but not for prospective cohort studies (OR = 1.00; 95% CI: 0.66-1.53). For black tea, no statistically significant association was observed for the highest vs. non/lowest black tea consumption (OR = 0.99; 95% CI: 0.82-1.20). In conclusion, this meta-analysis supported that green tea but not black tea may have a protective effect on PCa, especially in Asian populations. Further research regarding green tea consumption across different regions apart from Asia is needed.

Tea polyphenols prevent lung from preneoplastic lesions and effect p53 and bcl-2 gene expression in rat lung tissues.

PubMed

Gu, Qihua; Hu, Chengping; Chen, Qiong; Xia, Ying

2013-01-01

Lung cancer is one of the cancers that have the highest incidence and the highest mortality rate, and it is of great interest to identify ways to prevent its occurrence. We had established an animal model by using 3,4-benzopyrene intra-pulmonary injection in our previous study, and had observed that the rats lung carcinoma incidence and multiplicity were significantly reduced by green tea administration. This study further investigated the effect of tea polyphenols on rat lung preneoplastic lesions using the lung carcinoma model established by 3,4-benzopyrene intra-pulmonary injection. Sprague-Dawley rats of the same age were randomly divided into 10 groups and treated with 3,4-benzopyrene by intra-pulmonary injection. Five groups were given 0.3% solution of tea polyphenols (equivalent to 1.2% of green tea) in drinking water, while the other 5 groups were given pure drinking water. The rats were sacrificed at 0, 1, 4, 8 and 16 weeks after carcinogen treatment. In the control groups of rats, local bronchial inflammation were observed at 1 week after 3,4-benzopyrene treatment. From 4 weeks to 16 weeks after carcinogen treatment, hyperplasia, cell hyperproliferation, heterogeneity were observed in the bronchial epithelium. Meanwhile, the expression of p53 mRNA and protein, as well as the level of bcl-2, increased in the bronchial epithelial lesion. Tea polyphenols treatment significantly alleviated the bronchial epithelial lesions. At the same time, tea polyphenols treatment enhanced p53 expression, but reduced bcl-2 expression. These results indicated that tea polyphenols may have preventive effect against lung preneoplasm lesions, possibly through regulating the expression of some critical genes such as p53 and bcl-2.

Flavor characteristics of seven grades of black tea produced in Turkey.

PubMed

Alasalvar, Cesarettin; Topal, Bahar; Serpen, Arda; Bahar, Banu; Pelvan, Ebru; Gökmen, Vural

2012-06-27

Seven grades of black tea [high-quality black tea (grades 1-3) and low-quality black tea (grades 4-7)], processed by ÇAYKUR Tea Processing Plant (Rize, Turkey), were compared for their differences in descriptive sensory analysis (DSA), aroma-active compounds (volatile compounds), and taste-active compounds (sugar, organic acid, and free amino acid compositions). Ten flavor attributes such as 'after taste', 'astringency', 'bitter', 'caramel-like', 'floral/sweet', 'green/grassy', 'hay-like', 'malty', 'roasty', and 'seaweed' were identified. Intensities for a number of flavor attributes ('after taste', 'caramel-like', 'malty', and 'seaweed') were not significantly different (p > 0.05) among seven grades of black tea. A total of 57 compounds in seven grades of black tea (14 aldehydes, eight alcohols, eight ketones, two esters, four aromatic hydrocarbons, five aliphatic hydrocarbons, nine terpenes, two pyrazines, one furan, two acids, and two miscellaneous compounds) were tentatively identified. Of these, aldeyhdes comprised more than 50% to the total volatile compounds identified. In general, high-grade quality tea had more volatiles than low-grade quality tea. With respect to taste-active compounds, five sugars, six organic acids, and 18 free amino acids were positively identified in seven grades of black tea, of which fructose, tannic acid, and theanine predominated, respectively. Some variations (p < 0.05), albeit to different extents, were observed among volatile compounds, sugars, organic acids, and free amino acids in seven grades of black tea. The present study suggests that a certain flavor attributes correlate well with taste- and aroma-active compounds. High- and low-quality black teas should not be distinguished solely on the basis of their DSA and taste- and aroma-active compounds. The combination of taste-active compounds together with aroma-active compounds renders combination effects that provide the characteristic flavor of each grade of black tea.

Fungal isolates from a Pu-erh type tea fermentation and their ability to convert tea polyphenols to theabrownins.

PubMed

Wang, Qiuping; Gong, Jiashun; Chisti, Yusuf; Sirisansaneeyakul, Sarote

2015-04-01

The natural microbiota involved in the fermentation influence the quality and taste of fully postfermented teas such as China's Pu-erh tea. Ten microbial isolates representing 6 species were recovered from a solid-state fermentation of a Pu-erh type tea. The isolates were Aspergillus tubingensis, Aspergillus marvanovae, Rhizomucor pusillus, Rhizomucor tauricus, Aspergillus fumigatus, and Candida mogii. With the exception of A. marvanovae and C. mogii, all these microorganisms have been previously reported in solid-state fermentations of native Pu-erh tea. The ability of the isolates for converting the tea polyphenols to bioactive theabrownins in infusions of sun-dried green tea leaves in a submerged fermentation process was subsequently investigated. All isolates except C. mogii TISTR 5938 effectively produced theabrownins in a 4-d fermentation in shake flasks at 40 °C, 250 rpm. A. tubingensis TISTR 3646, A. tubingensis TISTR 3647, A. marvanovae TISTR 3648, and A. fumigatus TISTR 3654 produced theabrownins at particularly high levels of 6.5, 12.4, 11.1, and 8.4 g/L, respectively. © 2015 Institute of Food Technologists®

Dietary supplementation with selenium yeast and tea polyphenols improve growth performance and nitrite tolerance of Wuchang bream (Megalobrama amblycephala).

PubMed

Long, Meng; Lin, Wang; Hou, Jie; Guo, Honghui; Li, Li; Li, Dapeng; Tang, Rong; Yang, Fan

2017-09-01

In order to explore the effects of dietary selenium yeast, tea polyphenols and their combination on growth of Wuchang bream (Megalobrama amblycephala) and its resistance to nitrite stress, 360 healthy Wuchang bream with initial body weight of (55.90 ± 2.60) g were randomly divided into four groups: a control group fed with basal diet and three treated groups fed with basal diets supplemented with 0.50 mg/kg selenium yeast, 50 mg/kg tea polyphenols, and the combination of 0.50 mg/kg selenium yeast and 50 mg/kg tea polyphenols, respectively. After 60 d of feeding, the growth performance of Wuchang bream was measured. Then 25 fish per tank were exposed to nitrite stress of 15.0 mg/L. The serum stress hormones, liver histology and hepatic antioxidant responses were evaluated before nitrite exposure (0 h) and at 6, 12, 24, 48 and 96 h after exposure. The results showed that before nitrite exposure, compared with the control, the weight gain, specific growth rate, liver total antioxidant capacity, the activities and transcriptional levels of hepatic antioxidant enzymes (superoxide dismutase and glutathione peroxidase) in the selenium yeast and combination groups were significantly increased, while feed conversion rate was decreased significantly, which suggested that the combined use of selenium yeast and tea polyphenols as well as the single selenium yeast supplementation improved growth performance and enhanced antioxidant capacity in fish. After nitrite exposure, compared with the control, liver total antioxidant capacity as well as the activities and transcription levels of catalase superoxide dismutase and glutathione peroxidase in three treatment groups were significantly increased in varying degrees whereas serum cortisol contents and liver malondialdehyde levels were decreased significantly. By contrast, the combined use of selenium yeast and tea polyphenols was more effective than the single supplementation with selenium yeast or tea polyphenols. In

Toxic and essential mineral elements content of black tea leaves and their tea infusions consumed in Iran.

PubMed

Salahinejad, Maryam; Aflaki, Fereydoon

2010-04-01

The metal contents of eleven black tea samples, four cultivated in Iran and seven imported, and their tea infusions were determined. Twelve elements consisting toxic metals (Al, As, Pb, Cr, Cd, and Ni) and essential mineral elements (Fe, Zn, Cu, Mn, Ca, and Mg) were analyzed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). Al, Ca, Mg, and Mn ranged in black tea leaves at mg g(-1) levels, while Cr, Fe, Ni, Cu, Zn were at microg g(-1) levels. Analysis of variance showed no statistically significant differences among most elements determined in cultivated and imported black teas in Iran except for Ni and Cu. The extraction efficiency of each element into tea infusions was evaluated. The solubility of measured metals in infusion extracts varied widely and ranged from 0 to 59.3%. Among the studied elements, Cr, Pb, and Cd showed the lowest rates of solubility and Ni had the highest rates of solubility. The amount of toxic metals and essential mineral elements that one may take up through consumption of black tea infusion was estimated. The amount of realizing each element into tea infusions and acceptable daily intake, for safety consumption of black tea, was compared.

Comparison of the Level of Boron Concentrations in Black Teas with Fruit Teas Available on the Polish Market

PubMed Central

Zioła-Frankowska, Anetta; Frankowski, Marcin; Novotny, Karel; Kanicky, Viktor

2014-01-01

The determination of boron by inductively coupled plasma-atomic emission spectrometry has been carried in water-soluble and acid soluble (total content) fractions of 36 samples of traditional black tea and fruit brew. The estimation of the impact of the type of tea on the concentration of boron in water-soluble and acid extracts and potential human health risk from the daily intake of boron was carried out in this study. The levels of boron differed significantly in black and fruit tea types. The mean total content of boron ranged from 8.31 to 18.40 mg/kg in black teas, from 12.85 to 15.13 mg/kg in black tea with fruit flavor, and from 12.09 to 22.77 mg/kg in fruit brews. The degree of extraction of boron in black tea ranged from 8% to 27% and for fruit tea from 17% to 69%. In addition, the values below 25% were of black teas with fruit flavors. The daily intake of B from tea infusions (three cups/day) is still within the average daily intake except for some of the fruit brews which exceed acceptable regulations of the daily intake of total boron by humans. Hence, it may not produce any health risks for human consumption, if other sources of metal contaminated food are not taken at the same time. PMID:25379551

Comparison of the level of boron concentrations in black teas with fruit teas available on the Polish market.

PubMed

Zioła-Frankowska, Anetta; Frankowski, Marcin; Novotny, Karel; Kanicky, Viktor

2014-01-01

The determination of boron by inductively coupled plasma-atomic emission spectrometry has been carried in water-soluble and acid soluble (total content) fractions of 36 samples of traditional black tea and fruit brew. The estimation of the impact of the type of tea on the concentration of boron in water-soluble and acid extracts and potential human health risk from the daily intake of boron was carried out in this study. The levels of boron differed significantly in black and fruit tea types. The mean total content of boron ranged from 8.31 to 18.40 mg/kg in black teas, from 12.85 to 15.13 mg/kg in black tea with fruit flavor, and from 12.09 to 22.77 mg/kg in fruit brews. The degree of extraction of boron in black tea ranged from 8% to 27% and for fruit tea from 17% to 69%. In addition, the values below 25% were of black teas with fruit flavors. The daily intake of B from tea infusions (three cups/day) is still within the average daily intake except for some of the fruit brews which exceed acceptable regulations of the daily intake of total boron by humans. Hence, it may not produce any health risks for human consumption, if other sources of metal contaminated food are not taken at the same time.

Antioxidant Capacity and Polyphenolic Composition as Quality Indicators for Aqueous Infusions of Salvia officinalis L. (sage tea).

PubMed

Walch, Stephan G; Tinzoh, Laura Ngaba; Zimmermann, Benno F; Stühlinger, Wolf; Lachenmeier, Dirk W

2011-01-01

Sage (Salvia officinalis L.) is used as an herbal medicinal product, with the most typical form of application as infusion with boiling water (sage tea). The well-established traditional uses include symptomatic treatment of mild dyspeptic complaints, the treatment of inflammations in the mouth and the throat, and relief of excessive sweating and relief of minor skin inflammations. In this study, sage teas prepared from commercially available products were chemically analyzed for polyphenolic content using liquid chromatography, for antioxidant potential using the oxygen radical absorbance capacity method, and for the Folin-Ciocalteu (FC) index. The sage teas showed a high variation for all parameters studied (up to 20-fold differences for rosmarinic acid). Univariate and multivariate analyses showed that the antioxidant potential, which varied between 0.4 and 1.8 mmol trolox equivalents/100 mL, was highly dependent on rosmarinic acid and its derivatives. The FC index also showed a high correlation to these polyphenols, and could therefore be used as a screening parameter for sage tea quality. The considerable differences in polyphenolic composition and antioxidant capacity between the brands lead to a demand for quality standardization, especially if these sage teas are to be used for therapeutic purposes. Further research also appears to be necessary to characterize the dose-benefit relationship, as sage may also contain a constituent (thujone) with potentially adverse effects.

Theaflavins in black tea and catechins in green tea are equally effective antioxidants.

PubMed

Leung, L K; Su, Y; Chen, R; Zhang, Z; Huang, Y; Chen, Z Y

2001-09-01

Green tea catechins, including (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG), are oxidized and dimerized during the manufacture of black tea and oolong tea to form orange-red pigments, theaflavins (TF), a mixture of theaflavin (TF1), theaflavin-3-gallate (TF2A), theaflavin-3'-gallate (TF2B) and theaflavin-3,3'-digallate (TF3). The present study was designed to compare the antioxidant activities of individual TF with that of each catechin using human LDL oxidation as a model. All catechins and TF tested inhibited Cu(+2)-mediated LDL oxidation. Analysis of the thiobarbituric acid-reactive substances (TBARS) and conjugated dienes produced during LDL oxidation revealed that the antioxidant activity was in the order: TF3 > ECG > EGCG > or = TF2B > or = TF2A > TF1 > or = EC > EGC. Four TF derivatives also demonstrated a dose-dependent antioxidant activity in Cu(+2)-mediated LDL oxidation at concentrations of 5-40 micromol/L. These results demonstrate that the TF present in black tea possess at least the same antioxidant potency as catechins present in green tea, and that the conversion of catechins to TF during fermentation in making black tea does not alter significantly their free radical-scavenging activity.

Ambient Profiling of Phenolic Content in Tea Infusions by Matrix-Assisted Ionization in Vacuum

NASA Astrophysics Data System (ADS)

Cody, Robert B.

2018-05-01

Matrix-assisted ionization in vacuum (MAIV) was used to analyze the polyphenol content of ten different tea infusions. Nine different Camellia sinensis infusions were analyzed including three green teas, two black teas, two oolong teas, jasmine tea, and white tea. An infusion of rooibos (Aspalathus linearis) tea was also analyzed. Each freshly brewed tea was diluted 1:1 with methanol, and 100 ppm of phenolphthalein was added as an internal standard. An excess of 3-nitrobenzonitrile (NBN) was added to each vial, and the solution containing NBN crystals was analyzed by aspiration directly into the mass spectrometer sampling orifice. A working curve constructed for dilutions of catechin with phenolphthalein internal standard showed good linearity for five replicates of each concentration. The measured relative abundances of flavonoid polyphenols in each tea were in good agreement with previously reported values. Polyphenol content in tea infusions varied from 19.2 to 108.6 mg 100 mL-1. In addition to the expected catechin flavonoids, abundant quinic acid and gallic acid was detected in the C. sinensis infusions. Characteristic A. linearis flavonoids were detected in the rooibos tea.

Black Tea Increases Circulating Endothelial Progenitor Cells and Improves Flow Mediated Dilatation Counteracting Deleterious Effects from a Fat Load in Hypertensive Patients: A Randomized Controlled Study

PubMed Central

Grassi, Davide; Draijer, Richard; Schalkwijk, Casper; Desideri, Giovambattista; D’Angeli, Anatolia; Francavilla, Sandro; Mulder, Theo; Ferri, Claudio

2016-01-01

(1) Background: Endothelial dysfunction predicts cardiovascular events. Circulating angiogenic cells (CACs) maintain and repair the endothelium regulating its function. Tea flavonoids reduce cardiovascular risk. We investigated the effects of black tea on the number of CACs and on flow-mediated dilation (FMD) before and after an oral fat in hypertensives; (2) Methods: In a randomized, double-blind, controlled, cross-over study, 19 patients were assigned to black tea (150 mg polyphenols) or a placebo twice a day for eight days. Measurements were obtained in a fasted state and after consuming whipping cream, and FMD was measured at baseline and after consumption of the products; (3) Results: Compared with the placebo, black tea ingestion increased functionally active CACs (36 ± 22 vs. 56 ± 21 cells per high-power field; p = 0.006) and FMD (5.0% ± 0.3% vs. 6.6% ± 0.3%, p < 0.0001). Tea further increased FMD 1, 2, 3, and 4 h after consumption, with maximal response 2 h after intake (p < 0.0001). Fat challenge decreased FMD, while tea consumption counteracted FMD impairment (p < 0.0001); (4) Conclusions: We demonstrated the vascular protective properties of black tea by increasing the number of CACs and preventing endothelial dysfunction induced by acute oral fat load in hypertensive patients. Considering that tea is the most consumed beverage after water, our findings are of clinical relevance and interest. PMID:27854314

Transfer of ochratoxin A from raw black tea to tea infusions prepared according to the Turkish tradition.

PubMed

Toman, Jakub; Malir, Frantisek; Ostry, Vladimir; Kilic, Mehmet Akif; Roubal, Tomas; Grosse, Yann; Pfohl-Leszkowicz, Annie

2018-01-01

Ochratoxin A (OTA) is a natural contaminant of food including tea with multiple toxic effects, which poses a threat to human health. In terms of lifestyle, the Turkish population is a frequent visitor of tearooms, and the traditional Turkish tea preparation is one of the most popular ways of preparing tea infusion. The aim of this study was to investigate OTA transfer from raw black tea to the tea infusion prepared according to the Turkish tradition. A high-performance liquid chromatography method with a limit of quantification of 0.35 ng g -1 was used for OTA determination. The OTA amount in raw black teas from Turkey ranged from ≤0.35 ng g -1 up to 56.7 ng g -1 . An homogenised sample of black tea naturally contaminated with 55.0 ng g -1 was used to prepare infusions. The OTA transfer from the black tea to the infusion was found to be 41.5% ± 7%. These data are important for the realisation of a 'Total Diet study' (TDS). The TDS can be a complementary tool to estimate the population dietary exposure to OTA across the entire diet by analysing main foods prepared 'as consumed' (tea infusions) and not 'as purchased' (raw tea). © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Effect of different brewing times on soluble oxalate content of loose-packed black teas and tea bags.

PubMed

Mahdavi, Reza; Lotfi Yagin, Neda; Liebman, Michael; Nikniaz, Zeinab

2013-02-01

Because of the postulated role of increased dietary oxalate intake in calcium oxalate stone formation, the effect of different brewing times on soluble oxalate contents of loose-packed black tea and tea bags was studied. The oxalate content of 25 different samples of loose-packed black teas after brewing at 5, 10, 15, 30, and 60 min and of ten brands of tea bags after infusion for 1, 2, 3, 4, and 5 min was measured by enzymatic assay. The oxalate concentration resulting from different brewing times ranged from 4.3 to 6.2 mg/240 ml for loose-packed black teas and from 2.7 to 4.8 mg/240 ml for tea bags. There was a stepwise increase in oxalate concentration associated with increased brewing times.

Polyphenols and Sunburn.

PubMed

Saric, Suzana; Sivamani, Raja K

2016-09-09

Polyphenols are antioxidant molecules found in many foods such as green tea, chocolate, grape seeds, and wine. Polyphenols have antioxidant, anti-inflammatory, and antineoplastic properties. Growing evidence suggests that polyphenols may be used for the prevention of sunburns as polyphenols decrease the damaging effects of ultraviolet A (UVA) and ultraviolet B (UVB) radiation on the skin. This review was conducted to examine the evidence for use of topically and orally ingested polyphenols in prevention of sunburns. The PubMed database was searched for studies that examined polyphenols and its effects on sunburns. Of the 27 studies found, 15 met the inclusion criteria. Seven studies were conducted on human subjects and eight on animals (mice and rats). Eleven studies evaluated the effects of topical polyphenols, two studies examined ingested polyphenols, and two studies examined both topical and ingested polyphenols. Polyphenol sources included the following plant origins: green tea, white tea, cocoa, Romanian propolis (RP), Calluna vulgaris (Cv), grape seeds, honeybush, and Lepidium meyenii (maca). Eight studies examined green tea. Overall, based on the studies, there is evidence that polyphenols in both oral and topical form may provide protection from UV damage and sunburn, and thus are beneficial to skin health. However, current studies are limited and further research is necessary to evaluate the efficacy, mechanism of action, and potential side effects of various forms and concentrations of polyphenols.

Polyphenols and Sunburn

PubMed Central

Saric, Suzana; Sivamani, Raja K.

2016-01-01

Polyphenols are antioxidant molecules found in many foods such as green tea, chocolate, grape seeds, and wine. Polyphenols have antioxidant, anti-inflammatory, and antineoplastic properties. Growing evidence suggests that polyphenols may be used for the prevention of sunburns as polyphenols decrease the damaging effects of ultraviolet A (UVA) and ultraviolet B (UVB) radiation on the skin. This review was conducted to examine the evidence for use of topically and orally ingested polyphenols in prevention of sunburns. The PubMed database was searched for studies that examined polyphenols and its effects on sunburns. Of the 27 studies found, 15 met the inclusion criteria. Seven studies were conducted on human subjects and eight on animals (mice and rats). Eleven studies evaluated the effects of topical polyphenols, two studies examined ingested polyphenols, and two studies examined both topical and ingested polyphenols. Polyphenol sources included the following plant origins: green tea, white tea, cocoa, Romanian propolis (RP), Calluna vulgaris (Cv), grape seeds, honeybush, and Lepidium meyenii (maca). Eight studies examined green tea. Overall, based on the studies, there is evidence that polyphenols in both oral and topical form may provide protection from UV damage and sunburn, and thus are beneficial to skin health. However, current studies are limited and further research is necessary to evaluate the efficacy, mechanism of action, and potential side effects of various forms and concentrations of polyphenols. PMID:27618035

Study of the Stereochemistry and Oxidation Mechanism of Plant Polyphenols, Assisted by Computational Chemistry.

PubMed

Matsuo, Yosuke

2017-01-01

In recent years, plant polyphenols have attracted great attention due to their wide range of biological activities. Certain kinds of polyphenols have complex structures; therefore, it is difficult to elucidate their total structure, including stereochemistry. In this study, we reinvestigated the stereostructures of two major C-glycosidic ellagitannins contained in Quercus plants, vescalagin and castalagin, and revised their stereostructures based on theoretical calculations of spectroscopic data. We also determined the structures of quercusnins A and B, isolated from the sapwood of Quercus crispula, based on theoretical calculations of NMR data. The oxidation mechanism of polyphenols has not been entirely elucidated. Therefore, we have also studied the oxidation mechanism of tea catechins during black tea production. Our investigation of the oxidation mechanism of black tea pigment theaflavins revealed that the difference in the position of the galloyl ester affords different oxidation products of theaflavins. In addition, oxidation products of pyrogallol-type catechins could be classified into three types-dehydrotheasinensins, theacitrins, and proepitheaflagallins; their detailed production and degradation mechanisms were also examined.

The effects of co-administration of butter on the absorption, metabolism and excretion of catechins in rats after oral administration of tea polyphenols.

PubMed

Zhang, Liang; Han, Yuhui; Xu, Liwei; Liang, Yuhong; Chen, Xin; Li, Junsong; Wan, Xiaochun

2015-07-01

In Southwest China, tea polyphenols are usually utilized by way of butter tea. Tea polyphenols inhibit the absorption and biosynthesis of fatty acids in vivo, but the effects of butter on the pharmacokinetics of tea polyphenols have drawn less concern. A rapid UHPLC-MS/MS method was used to quantitatively determine the catechins in the plasma, feces and bile of rats after the oral administration of tea polyphenol or its combination with butter. In comparison with the single tea polyphenol treatment, the maximum plasma concentrations (Cmax) of the free EGCG, EGC, EC, GCG, GC and ECG significantly decreased after the co-administration of butter. The mean residence times (MRT) of the free EGCG, EGC, EC, GC and ECG were also significantly prolonged. When the plasma samples were treated with β-glucuronidase and arylsulfatase, the pharmacokinetic parameters of the total catechins (free and conjugated forms) were not affected by the co-administration of butter. These results indicated that the total absorption of catechins was not affected by butter, but the metabolism of catechins had been changed. Furthermore, the fecal catechins were significantly increased by butter. The total fecal amount and excretion ratio of all catechins were increased highly. The biliary excretion of EGCG, EGC, EC, GCG and GC was significantly increased by the co-administration of butter. To sum up, the butter changed the metabolism of catechins in vivo by decreasing the plasma concentration of the free catechins but increasing the conjugated catechins.

Antibacterial Activity of Polyphenolic Fraction of Kombucha Against Enteric Bacterial Pathogens.

PubMed

Bhattacharya, Debanjana; Bhattacharya, Semantee; Patra, Madhu Manti; Chakravorty, Somnath; Sarkar, Soumyadev; Chakraborty, Writachit; Koley, Hemanta; Gachhui, Ratan

2016-12-01

The emergence of multi-drug-resistant enteric pathogens has prompted the scientist community to explore the therapeutic potentials of traditional foods and beverages. The present study was undertaken to investigate the efficacy of Kombucha, a fermented beverage of sugared black tea, against enterotoxigenic Escherichia coli, Vibrio cholerae, Shigella flexneri and Salmonella Typhimurium followed by the identification of the antibacterial components present in Kombucha. The antibacterial activity was evaluated by determining the inhibition zone diameter, minimal inhibitory concentration and minimal bactericidal concentration. Kombucha fermented for 14 days showed maximum activity against the bacterial strains. Its ethyl acetate extract was found to be the most effective upon sequential solvent extraction of the 14-day Kombucha. This potent ethyl acetate extract was then subjected to thin layer chromatography for further purification of antibacterial ingredients which led to the isolation of an active polyphenolic fraction. Catechin and isorhamnetin were detected as the major antibacterial compounds present in this polyphenolic fraction of Kombucha by High Performance Liquid Chromatography. Catechin, one of the primary antibacterial polyphenols in tea was also found to be present in Kombucha. But isorhamnetin is not reported to be present in tea, which may thereby suggest the role of fermentation process of black tea for its production in Kombucha. To the best of our knowledge, this is the first report on the presence of isorhamnetin in Kombucha. The overall study suggests that Kombucha can be used as a potent antibacterial agent against entero-pathogenic bacterial infections, which mainly is attributed to its polyphenolic content.

Antimutagenicity and catechin content of soluble instant teas.

PubMed

Constable, A; Varga, N; Richoz, J; Stadler, R H

1996-03-01

The antimutagenic properties of soluble instant teas were examined using the bacterial Ames assay. Inhibition of the numbers of revertants induced from a number of known mutagens indicates that aqueous extracts of instant teas have antimutagenic activity and antioxidative properties, and can inhibit nitrosation reactions. Despite a significant reduction in the amounts of major green tea catechins, quantified using reversed-phase HPLC with electro-chemical detection, no differences in antimutagenicity were observed between the instant teas, a black fermented tea and a green tea. Oxidation of polyphenolic compounds which occurs during the production of instant tea does not therefore decrease the antioxidant, free radical scavenging and antimutagenic properties. This suggests that catechins are not the only compounds responsible for the protective effects of teas.

Effect of black tea consumption on radial blood pulse spectrum and cognitive health.

PubMed

Chang, Chi-Wei; Wang, Sheng-Hung; Jan, Ming-Yie; Wang, Wei-Kung

2017-04-01

Black tea consumption has been proven to improve endothelial function and to lower the risk of stroke and cognitive impairment. Several effects of black tea on cardiovascular system had been surveyed. However, the black tea effect on pressure pulse spectrum remains unknown. The study was aimed to investigate the influence of black tea on radial blood pressure and Pulse Spectrum. Fourteen healthy subjects received water and single doses of black tea (0.05g/Kg) in separate weeks. The radial blood pressure and pulse wave were measured and the pressure pulses were evaluated using harmonic analysis. This report confirmed that black tea consumption (dose=0.05g/Kg) significantly increased third, fifth, (P<0.1), sixth, seventh, and eighth harmonics (p<0.05) of radial pressure wave comparing to water control. We proposed that black tea may increase cerebral blood flow (CBF), which was deduced from the results and from the conclusions of previous studies. The results also showed that the harmonic components of pressure pulse could be the vascular kinetic index that assessed the hemodynamic status in each time frame before and after consumption of black tea. Copyright © 2017 Elsevier Ltd. All rights reserved.

inhibitory effects of citral, cinnamaldehyde, and tea polyphenols on mixed biofilm formation by foodborne Staphylococcus aureus and Salmonella enteritidis.

PubMed

Zhang, Hongmei; Zhou, Wenyuan; Zhang, Wenyan; Yang, Anlin; Liu, Yanlan; Jiang, Yan; Huang, Shaosong; Su, Jianyu

2014-06-01

Biofilms are significant hazards in the food industry. In this study, we investigated the effects of food additive such as citral, cinnamaldehyde, and tea polyphenols on mixed biofilm formation by foodborne Staphylococcus aureus and Salmonella serotype Enteritidis. The adhesion rates of mixed strains in sub-MIC of additives were determined by a microtiter plate assay and bacterial communication signal autoinducer 2 (AI-2) production via a bioluminescence reporter Vibrio harveyi BB170. The structure of mixed biofilm was analyzed using scanning electron microscopy. The effect of the disinfectants hydrogen peroxide, sodium hypochlorite, and peracetic acid was tested on the mixed biofilm. Our results demonstrated that citral, cinnamaldehyde, and tea polyphenols were able to significantly inhibit mixed biofilm formation, while citral could reduce the synthesis of AI-2. Conversely, we observed a significant increase in AI-2 mediated by cinnamaldehyde. Tea polyphenols at lower concentrations induced AI-2 synthesis; however, AI-2 synthesis was significantly inhibited at higher concentrations (300 m g/ml). Food additives inhibited the adhesion of mixed bacteria on stainless steel chips and increased the sensitivity of the mixed biofilm to disinfectants. In conclusion, citral, cinnamaldehyde, and tea polyphenols had strong inhibitory effects on mixed biofilm formation and also enhanced the effect of disinfectant on mixed biofilm formation. This study provides a scientific basis for the application of natural food additives to control biofilm formation of foodborne bacteria.

Changes of Constituents and Activity to Apoptosis and Cell Cycle During Fermentation of Tea

PubMed Central

Zhao, Hang; Zhang, Min; Zhao, Lu; Ge, Ya-kun; Sheng, Jun; Shi, Wei

2011-01-01

Tea is believed to be beneficial for health, and the effects of the fermentation process on its contributions to apoptosis and cell cycle arrest of gastric cancer cells have not been completely investigated. In this study, the chemical components in green tea, black tea and pu-erh tea aqueous extracts were analyzed and compared. The polysaccharide and caffeine levels were substantially higher in the fermented black tea and pu-erh tea, while the polyphenol level was higher in the unfermented green tea. Hence, a treatment of tea aqueous extract and the components, which are emerging as promising anticancer agents, were pursued to determine whether this treatment could lead to enhance apoptosis and cell cycle arrest. In the human gastric cancer cell line SGC-7901, the cell viability and flow cytometry analysis for apoptotic cells indicated effects in a dose-dependent inhibition manner for the three tea treatment groups. The apoptosis rates were found to be elevated after 48 h of treatment with 31.2, 125, and 500 μg/mL of green tea extract, the higher catechins content may be involved in the mechanism. Cell cycle was arrested in S phase in the fermented black tea and pu-erh tea, and the populations were significantly decreased in G2/M phases, possibly due to the oxidation of tea polyphenols, which causes an increase of theabrownins. CCC-HEL-1 normal cells were not sensitive to tea extract. These findings suggest that the fermentation process causes changes of the compounds which might be involved in the changes of cell proliferation inhibition, apoptosis induction and cell cycle arrest. PMID:21673927

Changes of constituents and activity to apoptosis and cell cycle during fermentation of tea.

PubMed

Zhao, Hang; Zhang, Min; Zhao, Lu; Ge, Ya-Kun; Sheng, Jun; Shi, Wei

2011-01-01

Tea is believed to be beneficial for health, and the effects of the fermentation process on its contributions to apoptosis and cell cycle arrest of gastric cancer cells have not been completely investigated. In this study, the chemical components in green tea, black tea and pu-erh tea aqueous extracts were analyzed and compared. The polysaccharide and caffeine levels were substantially higher in the fermented black tea and pu-erh tea, while the polyphenol level was higher in the unfermented green tea. Hence, a treatment of tea aqueous extract and the components, which are emerging as promising anticancer agents, were pursued to determine whether this treatment could lead to enhance apoptosis and cell cycle arrest. In the human gastric cancer cell line SGC-7901, the cell viability and flow cytometry analysis for apoptotic cells indicated effects in a dose-dependent inhibition manner for the three tea treatment groups. The apoptosis rates were found to be elevated after 48 h of treatment with 31.2, 125, and 500 μg/mL of green tea extract, the higher catechins content may be involved in the mechanism. Cell cycle was arrested in S phase in the fermented black tea and pu-erh tea, and the populations were significantly decreased in G2/M phases, possibly due to the oxidation of tea polyphenols, which causes an increase of theabrownins. CCC-HEL-1 normal cells were not sensitive to tea extract. These findings suggest that the fermentation process causes changes of the compounds which might be involved in the changes of cell proliferation inhibition, apoptosis induction and cell cycle arrest.

In Vitro Biocompatibility of Nanoscale Zerovalent Iron Particles (NZVI) Synthesized using tea-polyphenols.

EPA Science Inventory

A “green” protocol was used for the rapid generation of nanoscale zerovalent iron (NZVI) particles using tea polyphenols. The NZVI particles were subsequently examined for in vitro biocompatibility using the human keratinocyte cell (HaCaT) line as a skin exposure model. The cell...

Application of enzymes in the production of RTD black tea beverages: a review.

PubMed

Kumar, Chandini S; Subramanian, R; Rao, L Jaganmohan

2013-01-01

Ready-to-drink (RTD) tea is a popular beverage in many countries. Instability due to development of haze and formation of tea cream is the common problem faced in the production of RTD black tea beverages. Thus decreaming is an important step in the process to meet the cold stability requirements of the product. Enzymatic decreaming approaches overcome some of the disadvantages associated with other conventional decreaming methods such as cold water extraction, chill decreaming, chemical stabilization, and chemical solubilization. Enzyme treatments have been attempted at three stages of black tea processing, namely, enzymatic treatment to green tea and conversion to black tea, enzymatic treatment to black tea followed by extraction, and enzymatic clarification of extract. Tannase is the most commonly employed enzyme (tannin acyl hydrolase EC 3.1.1.20) aiming at improving cold water extractability/solubility and decreasing tea cream formation as well as improving the clarity. The major enzymatic methods proposed for processing black tea having a direct or indirect bearing on RTD tea production, have been discussed along with their relative advantages and limitations.

Synergistic Effect of Green Tea Polyphenols and Vitamin D on Chronic Inflammation-Induced Bone Loss in Female Rats

USDA-ARS?s Scientific Manuscript database

Our recent study demonstrated a bone-protective role of green tea polyphenols (GTPs), extracted from green tea, in chronic inflammation-induced bone loss of female rats through reduction of inflammation and oxidative stress. This study further examines effects of GTPs in conjunction with vitamin D (...

Green tea polyphenols supplementation improves bone microstructure in orchidectomized middle-Aged rats

USDA-ARS?s Scientific Manuscript database

Our recent study shows that green tea polyphenols (GTP) attenuate trabecular bone loss in ovariectomized middle-aged female rats. To investigate whether GTP prevents bone loss in male rats, 40 rats with and without oriectomy (ORX) were assigned to 4 groups in a 2 (sham vs. ORX)× 2 (no GTP and 0.5% G...

Structural characteristics for superoxide anion radical scavenging and productive activities of green tea polyphenols including proanthocyanidin dimers.

PubMed

Sato, Masashi; Toyazaki, Hajime; Yoshioka, Yu; Yokoi, Nobutoshi; Yamasaki, Toru

2010-01-01

The purpose of this paper is to report structural characteristics for superoxide anion radical (O(2(-))) scavenging and productive activities of green tea polyphenols. (-)-Epicatechin 3-O-gallate (5), (-)-epigallocatechin (6), (-)-epigallocatechin 3-O-gallate (7), (+)-gallocatechin-(4alpha-->8')-epigallocatechin (8), and (-)-epigallocatechin-(2beta-->O-->7', 4beta-->8')-epicatechin 3'-O-gallate (9) were isolated from the tea plant Camellia sinensis L. (+)-Epigallocatechin-(2beta-->O-->7, 4beta-->8')-epicatechin (10) was prepared by hydrolyzing 9. The polyphenols, as well as commercially available pyrogallol (1), methyl gallate (2), (+)-catechin (3), (-)-epicatechin (4), and the flavonol myricetin (11), produced O(2(-)) in descending order 1, 6 asymptotically equal to11 asymptotically equal to8, 7, 10, 2 asymptotically equal to9, 5 asymptotically equal to4. In the polyphenols with the pyrogallol-type B-ring and/or galloyl group, electron-withdrawing substituents (carbonyl and ketal carbons) and/or intramolecular hydrogen bonding constituted structural characteristics against the autoxidation reaction. The O(2(-))-productive activity partially counteracted O(2(-))-scavenging activity. However, such structural characteristics appeared to enhance the scavenging activity, accordingly the polyphenols in effect served as O(2(-))-scavengers in descending order 9 asymptotically equal to7, 2, 11, 8, 10, 3 asymptotically equal to4. On the other hand, 6, having no such structural characteristic, acted as a O(2(-))-generator, as well as 1. Further assessments covering tannins (e.g., A-type proanthocyanidin dimer 9) are needed to identify which green tea polyphenols are the most desirable chemopreventive agents.

Laboratory, Epidemiological, and Human Intervention Studies Show That Tea (Camellia sinensis) May Be Useful in the Prevention of Obesity12

PubMed Central

Grove, Kimberly A.; Lambert, Joshua D.

2010-01-01

Tea (Camellia sinensis, Theaceae) and tea polyphenols have been studied for the prevention of chronic diseases, including obesity. Obesity currently affects >20% of adults in the United States and is a risk factor for chronic diseases such as type II diabetes, cardiovascular disease, and cancer. Given this increasing public health concern, the use of dietary agents for the prevention of obesity would be of tremendous benefit. Whereas many laboratory studies have demonstrated the potential efficacy of green or black tea for the prevention of obesity, the underlying mechanisms remain unclear. The results of human intervention studies are mixed and the role of caffeine has not been clearly established. Finally, there is emerging evidence that high doses of tea polyphenols may have adverse side effects. Given that the results of scientific studies on dietary components, including tea polyphenols, are often translated into dietary supplements, understanding the potential toxicities of the tea polyphenols is critical to understanding their potential usefulness in preventing obesity. In this review, we will critically evaluate the evidence for the prevention of obesity by tea, discuss the relevance of proposed mechanisms in light of tea polyphenol bioavailability, and review the reports concerning the toxic effects of high doses of tea polyphenols and the implication that this has for the potential use of tea for the prevention of obesity. We hope that this review will expose areas for further study and encourage research on this important public health issue. PMID:20089791

The potential role of polyphenols in the modulation of skin cell viability by Aspalathus linearis and Cyclopia spp. herbal tea extracts in vitro.

PubMed

Magcwebeba, Tandeka Unathi; Riedel, Sylvia; Swanevelder, Sonja; Swart, Pieter; De Beer, Dalene; Joubert, Elizabeth; Andreas Gelderblom, Wentzel Christoffel

2016-11-01

The relationship between polyphenol constituents, antioxidant properties of aqueous and methanol extracts of green tea (Camellia sinensis), the herbal teas, rooibos (Aspalathus linearis) and honeybush (Cyclopia spp.), against skin cell viability was investigated in vitro. The effect of extracts, characterised in terms of polyphenol content and antioxidant properties, on cell viability of premalignant, normal and malignant skin cells was determined. Phenolic composition, particularly high levels of potent antioxidants, of rooibos and green tea methanol extracts was associated with a strong reduction in cell viability specifically targeting premalignant cells. In contrast, the aqueous extracts of Cyclopia spp. were more effective in reducing cell viability. This correlated with a relatively high flavanol/proanthocyanidin content and ABTS radical cation scavenging capacity. The major green tea flavanol (epigallocatechin gallate) and rooibos dihydrochalcone (aspalathin) exhibited differential effects against cell viability, while the major honeybush xanthone (mangiferin) and flavanone (hesperidin) lacked any effect presumably due to a cytoprotective effect. The underlying mechanisms against skin cell viability are likely to involve mitochondrial dysfunction resulting from polyphenol-iron interactions. The polyphenol constituents and antioxidant parameters of herbal tea extracts are useful tools to predict their activity against skin cell survival in vitro and potential chemopreventive effects in vivo. © 2016 Royal Pharmaceutical Society.

Black tea aroma inhibited increase of salivary chromogranin-A after arithmetic tasks.

PubMed

Yoto, Ai; Fukui, Natsuki; Kaneda, Chisa; Torita, Shoko; Goto, Keiichi; Nanjo, Fumio; Yokogoshi, Hidehiko

2018-01-24

Growing attention has been paid to the effects of food flavor components on alleviating negative brain functions caused by stressful lifestyles. In this study, we investigated the alleviating effect of two kinds of black tea aromas on physical and psychological stress induced by the Uchida-Kraepelin test, based on salivary chromogranin-A (CgA) levels as a stress marker and subjective evaluations (Profile of Mood States). Compared with the water exposure control, inhaling black tea aroma (Darjeeling and Assam in this study) induced lower salivary CgA concentration levels after 30 min of mental stress load tasks. This anti-stress effect of black tea aroma did not differ between the two tea types even though the concentration of the anti-stress components in the Darjeeling tea aroma was higher than that in the Assam aroma. However, Darjeeling tea aroma tended to decrease the tension and/or anxiety score immediately after the first exposure. Inhaling black tea aroma may diminish stress levels caused by arithmetic mental stress tasks, and Darjeeling tea aroma tended to improve mood before mental stress load.

Randomized Clinical Trial of Brewed Green and Black Tea in Men with Prostate Cancer Prior to Prostatectomy

PubMed Central

Henning, Susanne M.; Wang, Piwen; Said, Jonathan W.; Huang, Min; Grogan, Tristan; Elashoff, David; Carpenter, Catherine L.; Heber, David; Aronson, William J.

2014-01-01

Background Preclinical and epidemiologic studies suggest chemopreventive effects of green tea (GT) and black tea (BT) in prostate cancer. In the current study we determined the effect of GT and BT consumption on biomarkers related to prostate cancer development and progression. Methods In this exploratory, open label, phase II trial 113 men diagnosed with prostate cancer were randomized to consume six cups daily of brewed GT, BT or water (control) prior to radical prostatectomy (RP). The primary endpoint was prostate tumor markers of cancer development and progression determined by tissue immunostaining of proliferation (Ki67), apoptosis (Bcl-2, Bax, Tunel), inflammation [nuclear and cytoplasmic nuclear factor kappa B (NFκB)] and oxidation [8-hydroxydeoxy- guanosine (8OHdG)]. Secondary endpoints of urinary oxidation, tea polyphenol uptake in prostate tissue, and serum prostate specific antigen (PSA) were evaluated by high performance liquid chromatography and ELISA analysis. Results Ninety three patients completed the intervention. There was no significant difference in markers of proliferation, apoptosis and oxidation in RP tissue comparing GT and BT to water control. Nuclear staining of NFkB was significantly decreased in RP tissue of men consuming GT (p=0.013) but not BT (p=0.931) compared to water control. Tea polyphenols were detected in prostate tissue from 32 of 34 men consuming GT but not in the other groups. Evidence of a systemic antioxidant effect was observed (reduced urinary 8OHdG) only with GT consumption (p=0.03). GT, but not BT or water, also led to a small but statistically significant decrease in serum prostate-specific antigen (PSA) levels (p=0.04). Conclusion Given the GT-induced changes in NFkB and systemic oxidation, and uptake of GT polyphenols in prostate tissue, future longer-term studies are warranted to further examine the role of GT for prostate cancer prevention and treatment, and possibly for other prostate conditions such as

Supplementation with green tea polyphenols improves bone microstructure and quality in aged, orchidectomized rats

USDA-ARS?s Scientific Manuscript database

Recent studies show that green tea polyphenols (GTP) attenuate bone loss and microstructure deterioration in ovariectomized aged female rats, a model of postmenopausal osteoporosis. However, it is not known if such an osteo-protective role of GTP is demonstrable in androgen-deficient aged rats, a mo...

Effect of tea polyphenols on microbiological and biochemical quality of Collichthys fish ball.

PubMed

Yi, Shumin; Li, Jianrong; Zhu, Junli; Lin, Yi; Fu, Linglin; Chen, Wei; Li, Xuepeng

2011-07-01

Tea polyphenols (TP), as the most active constituents of tea, are considered natural food additives. This study examined the preservative properties of TP for Collichthys fish ball in well storage. Vacuum-packed Collichthys fish balls were treated with 0, 0.1, 0.15, 0.20, 0.25, and 0.30 g kg(-1) TP and stored at 0 °C for 17 days. Microbiological results were obtained using a biochemical test, API system kit, and 16S rDNA sequence analysis. Results confirmed that the dominant bacteria in Collichthys fish balls are the genera Serratia and Pseudomonas. Total viable counts dropped two orders of magnitude in Collichthys fish balls with 0.25 g kg(-1) TP compared with the control. The advantages of total volatile basic nitrogen value, 2-thiobarbituric acid value and texture value were clearly observed, whereas pH and whiteness value exhibited no significant decrease for the group treated with 0.25 g kg(-1) TP. More than 0.25 g kg(-1) TP added could retain excellent fish ball characteristics in terms of sensory assessment after 17 days. The shelf life of Collichthys fish balls supplemented with tea polyphenols can be prolonged for an additional 6 days in good condition at 0 °C storage. Copyright © 2011 Society of Chemical Industry.

Nutritional and functional characteristics of seven grades of black tea produced in Turkey.

PubMed

Serpen, Arda; Pelvan, Ebru; Alasalvar, Cesarettin; Mogol, Burçe Ataç; Yavuz, Havvana Tuba; Gökmen, Vural; Özcan, Nihat; Özçelik, Beraat

2012-08-08

Seven grades of black tea [high-quality black tea (grades 1-3) and low-quality black tea (grades 4-7)], processed by ÇAYKUR Tea Processing Plant (Rize, Turkey), were examined for their proximate composition, dietary fiber, minerals, and water-soluble vitamins as well as total phenolic content, various antioxidant assays, phenolics (flavanols, alkoloids, condensed phenolics, and phenolic acids), chlorophylls, and carotenoids. Some variations, albeit to different extents, were observed (p < 0.05) among these parameters in seven grades of black tea. With respect to proximate composition, dietary fiber was the predominant compound (ranging from 49.68 to 54.31 g/100 g), followed by protein, carbohydrate, and, to a lesser extent, ash, moisture, and fat. Thirteen minerals, four water-soluble vitamins, six flavanols, two alkoloids, three condensed phenolics, one phenolic acid, two chlorophylls, and two carotenoids were identified in the seven grades of black tea. Total phenol content ranged from 7.52 to 8.29 g of gallic acid equivalents (GAE)/100 g, being lowest in grade 6 and highest in grade 1. With regard to antioxidant activities, a large variation in oxygen radical absorbance capacity (ORAC) values was observed among all grades of black tea (ranging from 777 μmol of trolox equivalents (TE)/g in grade 7 to 1210 μmol of TE/g in grade 3). The present work suggests that high- and low-quality black teas should not be distinguished on the basis of their nutritional and functional characteristics. The combination of nutritional compounds together with functional characteristics renders combination effects that provide the characteristic quality of each grade of black tea.

Green tea polyphenols attenuate deterioration of bone microarchitecture in female rats with systemic chronic inflammation

USDA-ARS?s Scientific Manuscript database

Introduction: Our previous study demonstrated that green tea polyphenols (GTP) benefit bone health in female rats with chronic inflammation, because of GTP’s antioxidant capacity. The current study further evaluates whether GTP can restore bone microstructure along with related mechanism in rats wit...

Effect of tea polyphenols on lipid peroxidation and antioxidant activity of litchi (Litchi chinensis Sonn.) fruit during cold storage.

PubMed

Chen, Wenrong; Zhang, Zhenzhen; Shen, Yanwen; Duan, Xuewu; Jiang, Yuemin

2014-10-20

To understand the potential of application of tea polyphenols to the shelf life extension and quality maintenance of litchi (Litchi chinensis Sonn.) fruit, the fruits were dipped into a solution of 1% tea phenols for 5 min before cold storage at 4 °C. Changes in browning index, contents of anthocyanins and phenolic compounds, superoxide dismutase (SOD) and peroxidase (POD) activities, O2.- production rate and H2O2 content, levels of relative leakage rate and lipid peroxidation, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity were measured after 0, 10, 20 and 30 days of cold storage. The results showed that application of tea polyphenols markedly delayed pericarp browning, alleviated the decreases in contents of total soluble solids (TSS) and ascorbic acid, and maintained relatively high levels of total phenolics and anthocyanins of litchi fruit after 30 days of cold storage. Meanwhile, the treatment reduced the increases in relative leakage rate and lipid peroxidation content, delayed the increases in both O2.- production rate and H2O2 contents, and increased SOD activity but reduced POD activity throughout this storage period. These data indicated that the delayed pericarp browning of litchi fruit by the treatment with tea polyphenols could be due to enhanced antioxidant capability, reduced accumulations of reactive oxygen species and lipid peroxidation, and improved membrane integrity.

Green and black tea intake in relation to prostate cancer risk among Singapore Chinese

PubMed Central

Montague, Julia A.; Wu, Anna H.; Genkinger, Jeanine M.; Koh, Woon-Puay; Wong, Alvin S.; Wang, Renwei; Yuan, Jian-Min; Yu, Mimi C.

2013-01-01

Purpose Tea is one of the most commonly consumed beverages worldwide. To date, observational data from prospective cohort studies investigating the relationship between green and black tea intake and prostate cancer risk are sparse and equivocal. In a population-based, prospective cohort study of Chinese men in Singapore, we investigated the relationship between green and black tea intake and prostate cancer risk. Methods Tea consumption data for 27,293 men were collected at baseline (between 1993 and 1998) using a validated food frequency questionnaire. After an average of 11.2 years of follow-up, 298 men had developed prostate cancer. Proportional hazards regression methods were used to assess the associations between tea intake and prostate cancer risk. Results There was no association between daily green tea intake and prostate cancer risk, compared with no green tea intake [hazard ratio (HR) = 1.08; 95 % confidence interval (CI) 0.79, 1.47]. For black tea, a statistically significant positive association and trend were observed for daily intake compared with no black tea intake (HR = 1.41, 95 % CI 1.03, 1.92; p for trend <0.01) Conclusions Few prospective data are available from populations that have both a high level and wide range of black and green tea intake; this study represents a unique opportunity to evaluate their individual effects on prostate cancer risk. Our findings support the notion that green tea intake does not protect against prostate cancer and that black tea intake may increase prostate cancer risk. PMID:22864870

Green and black tea intake in relation to prostate cancer risk among Singapore Chinese.

PubMed

Montague, Julia A; Butler, Lesley M; Wu, Anna H; Genkinger, Jeanine M; Koh, Woon-Puay; Wong, Alvin S; Wang, Renwei; Yuan, Jian-Min; Yu, Mimi C

2012-10-01

Tea is one of the most commonly consumed beverages worldwide. To date, observational data from prospective cohort studies investigating the relationship between green and black tea intake and prostate cancer risk are sparse and equivocal. In a population-based, prospective cohort study of Chinese men in Singapore, we investigated the relationship between green and black tea intake and prostate cancer risk. Tea consumption data for 27,293 men were collected at baseline (between 1993 and 1998) using a validated food frequency questionnaire. After an average of 11.2 years of follow-up, 298 men had developed prostate cancer. Proportional hazards regression methods were used to assess the associations between tea intake and prostate cancer risk. There was no association between daily green tea intake and prostate cancer risk, compared with no green tea intake [hazard ratio (HR) = 1.08; 95 % confidence interval (CI) 0.79, 1.47]. For black tea, a statistically significant positive association and trend were observed for daily intake compared with no black tea intake (HR = 1.41, 95 % CI 1.03, 1.92; p for trend <0.01) Few prospective data are available from populations that have both a high level and wide range of black and green tea intake; this study represents a unique opportunity to evaluate their individual effects on prostate cancer risk. Our findings support the notion that green tea intake does not protect against prostate cancer and that black tea intake may increase prostate cancer risk.

Antigenotoxic and Apoptotic Activity of Green Tea Polyphenol Extracts on Hexavalent Chromium-Induced DNA Damage in Peripheral Blood of CD-1 Mice: Analysis with Differential Acridine Orange/Ethidium Bromide Staining

PubMed Central

García-Rodríguez, María del Carmen; Carvente-Juárez, Megumi Monserrat; Altamirano-Lozano, Mario Agustín

2013-01-01

This study was conducted to investigate the modulating effects of green tea polyphenols on genotoxic damage and apoptotic activity induced by hexavalent chromium [Cr (VI)] in CD-1 mice. Animals were divided into the following groups: (i) injected with vehicle; (ii) treated with green tea polyphenols (30 mg/kg) via gavage; (iii) injected with CrO3 (20 mg/kg) intraperitoneally; (iv) treated with green tea polyphenols in addition to CrO3. Genotoxic damage was evaluated by examining micronucleated polychromatic erythrocytes (MN-PCEs) obtained from peripheral blood at 0, 24, 48, and 72 h after treatment. Induction of apoptosis and cell viability were assessed by differential acridine orange/ethidium bromide (AO/EB) staining. Treatment of green tea polyphenols led to no significant changes in the MN-PCEs. However, CrO3 treatment significantly increased MN-PCEs at 24 and 48 h after injection. Green tea polyphenols treatment prior to CrO3 injection led to a decrease in MN-PCEs compared to the group treated with CrO3 only. The average of apoptotic cells was increased at 48 h after treatment compared to control mice, suggesting that apoptosis could contribute to eliminate the DNA damaged cells induced by Cr (VI). Our findings support the proposed protective effects of green tea polyphenols against the genotoxic damage induced by Cr (VI). PMID:24363823

Chemical compositions and antimicrobial activities of Athrixia phylicoides DC. (bush tea), Monsonia burkeana (special tea) and synergistic effects of both combined herbal teas.

PubMed

Tshivhandekano, Itani; Ntushelo, Khayalethu; Ngezimana, Wonder; Tshikalange, Thilivhali Emmanuel; Mudau, Fhatuwani Nixwell

2014-09-01

To determine the chemical compositions and evaluate the antimicrobial activity of bush tea (Athrixia phylicoides DC.), special tea (Monsonia burkeana) and synergy (combination of bush tea and special tea). Total polyphenols were determined using the methods reported by Singleton and Rossi (1965) and modified by Waterman and Mole (1994). Tannins were determined using vanillin HCL methods described by Prince et al. (1978). Total antioxidants were determined using the methods described by Awika et al. (2004). The micro dilution technique using 96-well micro-plates, as described by Eloff (1998) was used to obtain the minimum inhibition concentration (MIC) and minimum microbicidal concentration (MMC) values of the ethanol extracts against the microorganisms under study. The microbes strain used was Gram negative bacteria such as Escherichia coli, Klebsiella oxytoca, Proteus vulgaris, Serratia marcescens, Salmonella typhi, Klebsiella pneumonia; Gram positive bacteria such as Bacillus cereus, Staphylococcus aureus and a fungus Candida albicans. The results demonstrated that special tea contains significantly higher content of total polyphenols (8.34 mg/100 g) and total antioxidant (0.83 mg/100 g) as compared to bush tea [total polyphenols (6.41 mg/100g) and total antioxidant (0.63 mg/100g)] and combination of bush tea and special tea [total polyphenols (6.42 mg/100 g) and total antioxidant (0.64 mg/100 g)]. There was no significant difference in tannins between bush tea, special tea and synergy. The results of antimicrobial activity (MIC and MMC) demonstrated that the ethanol extracts of bush tea, special tea and synergy possessed antimicrobial activity against all microorganisms at different zones. The MIC of bush tea ranged from 1.56 to 12.50 mg/mL while the MMC ranged from 0.78 to 12.50 mg/mL. Special tea's MIC ranged from 0.39 to 12.50 mg/mL while the MMC ranged from 0.01 to 12.50 mg/mL. The MIC of synergy ranged from 3.13 to 12.50 mg/mL while the MMC ranged from 3

Tea and human health: biomedical functions of tea active components and current issues*

PubMed Central

Chen, Zong-mao; Lin, Zhi

2015-01-01

Originating in China, tea and tea planting have spread throughout the world since the middle of the Tang dynasty. Now people from 160 countries in the world are accustomed to tea drinking. A brief history of tea’s medicinal role in China and its spread to the world are introduced. The effectiveness of tea active components and tea drinking on major human diseases, including cancer, metabolic syndrome, cardiovascular disease, and neurodegenerative diseases, is discussed. Also presented are some related issues, such as the bioavailability of tea active components, the new formulations of tea polyphenols, and the safety for consumers of dietary supplements containing tea polyphenols. PMID:25644464

Profiling and quantification of phenolic compounds in Camellia seed oils: Natural tea polyphenols in vegetable oil.

PubMed

Wang, Xiaoqin; Zeng, Qiumei; Del Mar Contreras, María; Wang, Lijuan

2017-12-01

In Asia, tea seed oils (seed oils from Camellia oleifera, C. chekiangoleosa, and C. sinensis) are used in edible, medicinal, and cosmetic applications. However, these oils differ in their fatty acid contents, and there is little known about their phenolic compounds. Here we analyzed the phenolic compounds of seed oils from three species gathered from 15 regions of China. Twenty-four phenolic compounds were characterized by HPLC-Q-TOF-MS, including benzoic acids (6), cinnamic acids (6), a hydroxyphenylacetic acid, flavanols (4), flavonols (3), flavones (2), and dihydroflavonoids (2). Some of these phenolic compounds had not previously been reported from C. sinensis (20), C. oleifera (15), and C. chekiangoleosa (24) seed oils. Quantification was done by HPLC-QqQ-MS using 24 chemical standards. The total concentrations in the studied samples ranged from 20.56 to 88.56μg/g. Phenolic acids were the most abundant class, accounting for 76.2-90.4%, with benzoic acid, found at up to 18.87μg/g. The concentration of catechins, typical of tea polyphenols, ranged between 2.1% and 9.7%, while the other flavonoids varied from 4.2% to 17.8%. Although the cultivation region affected the phenolic composition of the Camellia seed oils, in our hierarchical clustering analysis, the samples clustered according to species. The phenolic composition of the seed oils from C. oleifera and C. chekiangoelosa were similar. We found that the phenolic categories in Camellia seed oils were similar to tea polyphenols, thereby identifying a source of liposoluble tea polyphenols and potentially accounting for some of the reported activities of these oils. In addition, this work provides basic data that allows distinction of various Camellia seed oils, as well as improvements to be made in their quality standards. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preparation of gelatin films incorporated with tea polyphenol nanoparticles for enhancing controlled-release antioxidant properties

USDA-ARS?s Scientific Manuscript database

Tea polyphenols (TP) were incorporated into edible gelatin films either alone or incorporated into nanoparticles in order to determine the physico-chemical properties of the film and the antioxidant properties of TP in a solid gelatin matrix. The TP containing nanoparticles were prepared by cross-li...

Potent suppressing activity of the non-polyphenolic fraction of green tea (Camellia sinensis) against genotoxin-induced umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002)--association with pheophytins a and b.

PubMed

Okai, Y; Higashi-Okai, K

1997-11-25

Antigenotoxic and antimutagenic activities of green tea extract and tea-derived polyphenols have been studied using in vitro and in vivo experiments. However, antigenotoxic substances in the non-polyphenolic fraction of green tea have been poorly elucidated. In the present study, the effect of the non-polyphenolic fraction of green tea on genotoxin-induced umu C gene expression was analyzed using a tester bacteria, and potent antigenotoxic substances in the non-polyphenolic fraction were identified. The non-polyphenolic fraction of green tea showed strong suppressive activities against umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002) induced by 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indol (Trp-P-1) or mitomycin C (MMC) in the presence or absence of S9 metabolizing enzyme mixture. The non-polyphenolic fraction of green tea exhibited major two-color bands in a silica gel TLC and they were identified as chlorophyll-related compounds, pheophytins a and b, judged by their specific colors, Rf values in silica gel TLC and absorption spectra. These pigments showed significant suppressive activities against umu C gene expression in tester bacteria induced by Trp-P- and MMC in a dose-dependent manner. These results suggest that the non-polyphenolic fraction of green tea contains pheophytins a and b as potent antigenotoxic substances.

Effects of gut microbiota and time of treatment on tissue levels of green tea polyphenols in mice.

PubMed

Liu, Anna B; Tao, Siyao; Lee, Mao-Jung; Hu, Qi; Meng, Xiaofeng; Lin, Yong; Yang, Chung S

2018-05-08

The previous studies have shown that tea polyphenols are metabolized by gut microbiota. This study investigated the effect of gut microbiota on the bioavailability, tissue levels, and degradation of tea polyphenols. Mice were treated with antibiotics (ampicillin/sulfamethoxazole/trimethoprim) in drinking water and the control mice received water for 11 days, and they were given an AIN93M diet enriched with 0.32% of Polyphenon E. The levels of catechins and their metabolites (if present) in the serum, liver, urine, and fecal samples were determined by high-performance liquid chromatography. The results showed that treatment with antibiotics significantly increased the levels of the major polyphenol, (-)-epigallocatechin-3-gallate (EGCG), in serum and liver samples. Antibiotics also raised the levels of some catechins in urine and fecal samples but decreased the levels of their metabolites. These results suggest that antibiotics eliminated gut microbes and increased the bioavailabilities of these tea catechins. In a second study, mice were given different concentrations of green tea infusions as the drinking fluid. The plasma levels of EGCG and (-)-epicatechin-3-gallate (ECG) at day 112 were significantly lower than those at day 5. The urine levels of EGCG and ECG increased in the first 4 or 5 days, and then decreased to much lower levels at day 23 and beyond. In contrast, the levels of (-)-epigallocatechin and (-)-epicatechin showed a trend of increase during the 112-day experiment, likely owing to microbial hydrolysis of EGCG and ECG. Both sets of experiments support the idea that the degradation of EGCG and ECG by gut microbiota decreases their bioavailabilities. © 2018 BioFactors, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

Anticariogenic Activity of Black Tea - An Invivo Study.

PubMed

Arya, Vishal; Taneja, Lavina; Srivastava, Ankit; Nandlal, Swati

2016-03-01

Teas is known for its anticariogenic properties and various mechanisms have been invoked to explain this effect. One such proposed mechanism is inhibition of salivary alpha amylase activity by endogenous tannins present in tea. The objective of the present study was to determine whether or not the ingestion of black tea decoction inhibits the enzyme salivary amylase and thus interferes with the release of maltose from intraoral entrapped particles of food. A total of 30 children in the age group of 12 - 15 years were selected for the study. After two hours of fasting subjects consumed two salted crackers for 60 second following which they rinsed with water (control solution) and then with 1.5% black tea decoction (test solution) next day. Retained food particles were recovered from buccal aspect of left mandibular premolar and salivary amylase activity was noted via chromatography. Paired t-test was applied for statistical analysis. Maltose to Sucrose ratio was used to evaluate the result. The average ratio was 3.27 for control solution and 1.82 for test solution. The results were statistically highly significant (p <0.005). Tea inhibited the activity of salivary amylase and this inhibition assumes a special significance when it is considered that the effect of tea could be manifested over a prolonged period of time, as in a real life situation.

Plasma tea polyphenol levels and subsequent risk of breast cancer among Japanese women: a nested case-control study.

PubMed

Iwasaki, Motoki; Inoue, Manami; Sasazuki, Shizuka; Miura, Tsutomu; Sawada, Norie; Yamaji, Taiki; Shimazu, Taichi; Willett, Walter C; Tsugane, Shoichiro

2010-12-01

Although many in vitro and animal studies have suggested a protective effect of green tea against breast cancer, findings from epidemiological studies have been inconsistent. No study has used prediagnostic biomarkers of tea polyphenols, which might play a protective role. A total of 24,226 women aged 40 to 69 years in the Japan Public Health Center-based Prospective Study who responded to the baseline questionnaire and provided blood in 1990-1995 were followed to December 2002. During a mean 10.6 years of follow-up, 144 newly diagnosed breast cancers were identified. Two matched controls for each case were selected from the cohort. Plasma levels of (-)-epigallocatechin (EGC), (-)-epicatechin (EC), (-)-epigallocatechin-3-gallate (EGCG), and (-)-epicatechin-3-gallate (ECG) were measured, and the odds ratio (OR) of breast cancer according to plasma level was estimated using a conditional logistic regression model. We found no statistically significant association between plasma tea polyphenol levels and breast cancer risk. Adjusted ORs for the highest versus lowest group were 0.90 (95% CI 0.42-1.96; P for trend = 0.98) for EGC, 0.95 (95% CI 0.43-2.08; P for trend = 0.86) for EC, 1.21 (95% CI 0.52-2.80; P for trend = 0.53) for EGCG, and 1.75 (95% CI 0.81-3.78; P for trend = 0.15) for ECG. Stratified analyses according to baseline menopausal status showed no remarkable difference between two strata. This nested case-control study found no overall association between plasma tea polyphenols and the risk of breast cancer in Japan.

Green Tea Polyphenols Extend the Lifespan of Male Drosophila melanogaster While Impairing Reproductive Fitness

PubMed Central

Lopez, Terry; Schriner, Samuel E.; Okoro, Michael; Lu, David; Chiang, Beatrice T.; Huey, Jocelyn

2014-01-01

Abstract Green tea is a popular beverage believed to have many health benefits, including a reduction in the risks of heart disease and cancer. Rich in polyphenolic compounds known as catechins, green tea and its components have been shown to increase the lifespan of various animal models, including Drosophila melanogaster. Here, we investigated the gender-specific effects of green tea on the lifespan of fruit flies and observed that green tea extended the lifespan of male flies only. This effect was found to be independent of typical aging interventions, such as dietary restriction, modulation of oxidative energy metabolism, and improved tolerance to environmental stresses. The one exception was that green tea did protect male flies against iron toxicity. Since there is an inverse correlation between lifespan and reproduction, the impact of green tea on male reproductive fitness was also investigated. We found that green tea negatively impacted male fertility as shown by a reduced number of offspring produced and increased mating latency. We further identified that the lifespan extension properties of green tea was only observed in the presence of females which alludes to a reproductive (or mating) dependent mechanism. Our findings suggest that green tea extends the lifespan of male flies by inhibiting reproductive potential, possibly by limiting iron uptake. To our knowledge, our study is the first to report the negative impact of green tea on Drosophila male reproduction. Our results also support previous studies that suggest that green tea might have a negative effect on reproductive fitness in humans. PMID:25058464

ORAC and DPPH assay comparison to assess antioxidant capacity of tea infusions: relationship between total polyphenol and individual catechin content.

PubMed

Roy, Molay K; Koide, Motoki; Rao, Theertham P; Okubo, Tsutomu; Ogasawara, Yutaka; Juneja, Lekh R

2010-03-01

Commercially available tea infusions are the major source of catechins for preparing bottled tea beverages and tea supplements available in the market today. In the present study, we analyzed five tea infusions to measure the total antioxidant capacity (TAC) by oxygen radical absorbance capacity (ORAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity (DRSC) assays, total polyphenol content by the colorimetric method and individual catechin content by high-performance liquid chromatography. Four major tea catechins were also analyzed for their TAC to reveal differential antioxidant behavior of the tea infusions, resulting in the ORAC and DRSC methods. The correlation coefficients between DRSC and the total polyphenol or total catechin content of the tea infusions were 1.0 and 0.99. However, the values fall to 0.73 and 0.69, respectively, while the ORAC activity was correlated with total polyphenol and total catechin content. Determining the TAC of individual tea catechins showed that ORAC of epicatechin was seven-fold higher than that of epigallocatechin gallate; on the contrary, epigallocatechin gallate showed significantly (P < 0.05) stronger DRSC activity than epicatechin. By evaluating the structure-activity relationship, this study further revealed that OH substitution at the 3' position in pyrogallol moieties contributes to the lower ORAC value of epigallocatechin and epigallocatechin gallate comparing with their non-3'-OH counterparts, such as epicatechin and epicatechin gallate, respectively. Also, numbers of OH substitutions were poorly correlated with the observed ORAC value unlike the DRSC. Overall, results of this study enabled us to hypothesize that substances having a lower TAC value in the ORAC assay compared with that in DPPH assays may pertain to a pro-oxidant effect by generating reactive oxygen species in an aqueous buffer, at a physiological pH. We also propose that substances exhibiting lower TAC value in the ORAC assay

Antioxidant effects of green tea

PubMed Central

FORESTER, SARAH C.; LAMBERT, JOSHUA D.

2013-01-01

Consumption of green tea (Camellia sinensis) may provide protection against chronic diseases, including cancer. Green tea polyphenols are believed to be responsible for this cancer preventive effect, and the antioxidant activity of the green tea polyphenols has been implicated as a potential mechanism. This hypothesis has been difficult to study in vivo due to metabolism of these compounds and poor understanding of the redox environment in vivo. Green tea polyphenols can be direct antioxidants by scavenging reactive oxygen species or chelating transition metals as has been demonstrated in vitro. Alternatively, they may act indirectly by up-regulating phase II antioxidant enzymes. Evidence of this latter effect has been observed in vivo, yet more work is required to determine under which conditions these mechanisms occur. Green tea polyphenols can also be potent pro-oxidants, both in vitro and in vivo, leading to the formation of hydrogen peroxide, the hydroxyl radical, and superoxide anion. The potential role of these pro-oxidant effects in the cancer preventive activity of green tea is not well understood. The evidence for not only the antioxidant, but also pro-oxidant, properties of green tea are discussed in the present review. PMID:21538850

Antimicrobial Traits of Tea- and Cranberry-Derived Polyphenols against Streptococcus mutans

PubMed Central

Yoo, S.; Murata, R.M.; Duarte, S.

2011-01-01

There are over 750 species of bacteria that inhabit the human oral cavity, but only a small fraction of those are attributed to causing plaque-related diseases such as caries. Streptococcus mutans is accepted as the main cariogenic agent and there is substantial knowledge regarding the specific virulence factors that render the organism a pathogen. There has been rising interest in alternative, target-specific treatment options as opposed to nonspecific mechanical plaque removal or application of broad-spectrum antibacterials that are currently in use. The impact of diet on oral health is undeniable, and this is directly observable in populations that consume high quantities of polyphenol-rich foods or beverages. Such populations have low caries incidence and better overall oral health. Camellia sinensis, the plant from which various forms of tea are derived, and Vaccinium macrocarpon (American cranberry fruit) have received notable attention both for their prevalence in the human diet as well as for their unique composition of polyphenols. The biologically active constituents of these plants have demonstrated potent enzyme-inhibitory properties without being bactericidal, a key quality that is important in developing therapies that will not cause microorganisms to develop resistance. The aim of this review is to consider studies that have investigated the feasibility of tea, cranberry, and other select plant derivatives as a potential basis for alternative therapeutic agents against Streptococcus mutans and to evaluate their current and future clinical relevance. PMID:21720161

Green tea: a promising natural product in oral health.

PubMed

Narotzki, Baruch; Reznick, Abraham Z; Aizenbud, Dror; Levy, Yishai

2012-05-01

Green tea is a leading beverage in the Far East for thousands of years; it is regarded for a long time as a health product. Green tea is important source of polyphenol antioxidants. Polyphenols including epigallocatechin 3 gallate (EGCG) constitute the most interesting components in green tea leaves. Green tea has the potential to protect against various malignant, cardiovascular and metabolic diseases. There is a growing body of evidence pointing a beneficial role of green tea and its polyphenols in oral health. Green tea protects against bacterial induced dental caries. Tea polyphenols possess antiviral properties, believed to help in protection from influenza virus. Additionally, green tea polyphenols can abolish halitosis through modification of odorant sulphur components. Oral cavity oxidative stress and inflammation, consequent to cigarette smoking and cigarettes' deleterious compounds nicotine and acrolein, may be reduced in the presence of green tea polyphenols. Generally, green tea defends healthy cells from malignant transformation and locally has the ability to induce apoptosis in oral cancer cells. All together, there is an increasing interest in the health benefits of green tea in the field of oral health. Nonetheless, there is still a need for more clinical and biological studies to support guidelines for green tea intake as part of prevention and treatment of specific oral pathologies. Copyright © 2011 Elsevier Ltd. All rights reserved.

Long-term preservation of chilled canine semen using vitamin C in combination with green tea polyphenol.

PubMed

Wittayarat, Manita; Kimura, Taichi; Kodama, Risa; Namula, Zhao; Chatdarong, Kaywalee; Techakumphu, Mongkol; Sato, Yoko; Taniguchi, Masayasu; Otoi, Takeshige

2012-01-01

Vitamin C and green tea polyphenol are known to have antioxidant effects. The aim of this study was to evaluate the quality of canine semen after preservation with diluents containing vitamin C and polyphenol at 5 degree C for 4 weeks. In experiment 1, we investigated the effects of vitamin C combined with polyphenol supplementation on chilled semen quality. The addition of vitamin C (0.5 or 1 mM) with 0.75 mg per mL polyphenol to semen extender provided significantly higher percentages of sperm motility and viability during cold storage compared to unsupplemented semen. In experiment 2, we determined the optimal working concentration of vitamin C in the semen extender by comparison of a range of concentrations between 0.1 and 20 mM. Supplementation of 0.5 mM vitamin C plus polyphenol yielded the highest percentages of sperm motility and viability; however, there was no beneficial effect on the plasma membrane and acrosomal integrity of the spermatozoa.

The scavenging reactions of nitrogen dioxide radical and carbonate radical by tea polyphenol derivatives: a pulse radiolysis study

NASA Astrophysics Data System (ADS)

Miao, Jin-Ling; Wang, Wen-Feng; Pan, Jing-Xi; Lu, Chang-Yuan; Li, Rong-Qun; Yao, Si-De

2001-02-01

The reactions of tea polyphenol derivatives, including epicatechin (EC) and epigallocatechin gallate (EGCG), with nitrogen dioxide radical (NO 2rad ) and carbonate radical (CO 3rad - ) have been studied in detail using time-resolved pulse radiolysis technique. In all the cases, the corresponding phenoxyl radical was formed through electron transfer reaction. From the build-up kinetics of the phenoxyl radicals and the decay kinetics of CO 3rad - radical, the reaction rate constants of EC, EGCG with NO 2rad and CO 3rad - were determined to be 9.0×10 7, 1.2×10 8 and 5.6×10 8, 6.6×10 8 dm 3 mol -1 s -1, respectively. Therefore, tea polyphenol derivatives proved to be efficient scavengers of NO 2rad and CO 3rad - radicals.

Green Tea Polyphenols Require the Mitochondrial Iron Transporter, mitoferrin, for Lifespan Extension in Drosophila melanogaster

PubMed Central

Lopez, Terry E.; Pham, Hoang M.; Nguyen, Benjamin V.; Tahmasian, Yerazik; Ramsden, Shannon; Coskun, Volkan; Schriner, Samuel E.; Jafari, Mahtab

2016-01-01

Green tea has been found to increase the lifespan of various experimental animal models including the fruit fly, Drosophila melanogaster. High in polyphenolic content, green tea has been shown to reduce oxidative stress in part by its ability to bind free iron, a micronutrient that is both essential for and toxic to all living organisms. Due to green tea’s iron-binding properties, we questioned whether green tea acts to increase the lifespan of the fruit fly by modulating iron regulators, specifically, mitoferrin, a mitochondrial iron transporter, and transferrin, found in the hemolymph of flies. Publicly available hypomorph mutants for these iron-regulators were utilized to investigate the effect of green tea on lifespan and fertility. We identified that green tea could not increase the lifespan of mitoferrin mutants but did rescue the reduced male fertility phenotype. The effect of green tea on transferrin mutant lifespan and fertility were comparable to w1118 flies, as observed in our previous studies, in which green tea increased male fly lifespan and reduced male fertility. Expression levels in both w1118 flies and mutant flies, supplemented with green tea, showed an up-regulation of mitoferrin but not transferrin. Total body and mitochondrial iron levels were significantly reduced by green tea supplementation in w1118 and mitoferrin mutants but not transferrin mutant flies. Our results demonstrate that green tea may act to increase the lifespan of Drosophila in part by the regulation of mitoferrin and reduction of mitochondrial iron. PMID:27696504

Reduction of facial redness with resveratrol added to topical product containing green tea polyphenols and caffeine.

PubMed

Ferzli, Georgina; Patel, Mital; Phrsai, Natasha; Brody, Neil

2013-07-01

Many topical formulations include antioxidants to improve the antioxidant capability of the skin. This study evaluated the ability of a unique combination of antioxidants including resveratrol, green tea polyphenols, and caffeine to reduce facial redness. Subjects (n=16) presenting with facial redness applied the resveratrol-enriched product twice daily to the entire face. Reduction in redness was evaluated by trained staff members and dermatology house staff officers. Evaluators compared clinical photographs and spectrally enhanced images taken before treatment and at 2-week intervals for up to 12 weeks. 16 of 16 clinical images showed improvement and 13 of 16 spectrally enhanced images were improved. Reduction in facial redness continued to evolve over the duration of the study period but was generally detectable by 6 weeks of treatment. Adverse effects were not observed in any subject. The skin product combination of resveratrol, green tea polyphenols, and caffeine safely reduces facial redness in most patients by 6 weeks of continuous treatment and may provide further improvement with additional treatment.

Fusion of Potentiometric & Voltammetric Electronic Tongue for Classification of Black Tea Taste based on Theaflavins (TF) Content

NASA Astrophysics Data System (ADS)

Bhattacharyya, Nabarun; Legin, Andrey; Papieva, Irina; Sarkar, Subrata; Kirsanov, Dmitry; Kartsova, Anna; Ghosh, Arunangshu; Bandyopadhyay, Rajib

2011-09-01

Black tea is an extensively consumed beverage worldwide with an expanding market. The final quality of black tea depends upon number of chemical compounds present in the tea. Out of these compounds, theaflavins (TF), which is responsible for astringency in black tea, plays an important role in determining the final taste of the finished black tea. The present paper reports our effort to correlate the theaflavins contents with the voltammetric and potentiometric electronic tongue (e-tongue) data. Noble metal-based electrode array has been used for collecting data though voltammetric electronic tongue where as liquid filled membrane based electrodes have been used for potentiometric electronic tongue. Black tea samples with tea taster score and biochemical results have been collected from Tea Research Association, Tocklai, India for the analysis purpose. In this paper, voltammetric and potentiometric e-tongue responses are combined to demonstrate improvement of cluster formation among tea samples with different ranges of TF values.

Study the influence factors to the adsorption process for separation of polyphenols from green tea

NASA Astrophysics Data System (ADS)

Phung, Lan Huong; Tran, Trung Kien; Van Quyet, Chu; Phi, Nguyen Thien

2017-09-01

The objective of this work is applying adsorption process for separation of polyphenols from extract solution of green tea by-product. The older leaves and stem of green tea tree are collected from Hiep Khanh Tea Company (Hoabinh province, Vietnam). In this study, two kinds of adsorbent (silicagel, active carbon) were applied for the adsorption process in batch stirring vessel. The factors that affected to the process productivity were investigated: temperature, solid/liquid ratio, duration time, stirring speed. The process has been empirically described with statistical models obtained by Design of Experiments. The results indicated that active carbon was verified to offer good adsorption productivity (more than 95%), much more effective than silicagel (with only about 20%). From the model, the most affected factor to the process could be seen as solid/liquid ratio.

Arrhythmogenic Risk Assessment Following Four-Week Pretreatment With Nicotine and Black Tea in Rat

PubMed Central

Joukar, Siyavash; Sheibani, Vahid; Koushesh, Faramarz; Ghasemipoor Afshar, Elham; Ghorbani Shahrbabaki, Soodabe

2015-01-01

Background: There is the controversy concerning the main component of tobacco, which is responsible for its arrhythmogenesis. In addition, there is the lack of adequate information about the influence of combination of black tea and nicotine on heart rhythm. Objectives: This study aimed to examine whether pretreatment with black tea and nicotine could modulate the susceptibility to lethal ventricular arrhythmias. Materials and Methods: Animals were randomized to control, black tea, nicotine, and black tea plus nicotine groups. Test groups were treated with black tea brewed (orally) and nicotine (2 mg/kg, subcutaneous), alone and in combination for four weeks. On day 29, aconitine was infused intravenously for induction of cardiac arrhythmia. Results: In comparison with the control group, each of tea and nicotine significantly decreased the duration of the ventricular tachycardia (VT) plus ventricular fibrillation (VF) and the score of arrhythmia severity (P < 0.05 and P < 0.01, respectively,). The latency for the first VT event was significantly longer in the all test groups, but VF latency was significant only in tea and nicotine groups compared with control group (P < 0.05 and P < 0.01, respectively).Threshold dose of aconitine for inducing VT and VF increased in all test groups, but only VT showed a significant difference in comparison to the control group (P < 0.001). Conclusions: The findings suggest that sub-chronic consumption of nicotine or black tea alone with appropriate doses could potentially be antiarrhythmic and its combination regimen does not increase the risk of fatal ventricular arrhythmias during four-week consumption period in rats. PMID:26436072

Regeneration of tert-butylhydroquinone by tea polyphenols.

PubMed

Guo, Yafang; Guo, Yahui; Xie, Yunfei; Cheng, Yuliang; Qian, He; Yao, Weirong

2017-05-01

To study the antioxidant capacity (AC) regeneration of tert-butylhydroquinone (TBHQ) by tea polyphenols (TPs), a separable system has been designed for its evaluation. The AC values of three natural food matrices (liquorice, oat, and ginger) and TBHQ regenerated by TPs were all higher than their controls, and similar to the initial values (p<0.05). The average regeneration efficiency (RE) value was 1.49 for these three natural food matrices, and 0.82 for TBHQ. Electron paramagnetic resonance spectroscopy analysis has revealed the synergistic effect of TBHQ and TPs, which arose from the regeneration of TBHQ by TPs. The RE value of TBHQ regeneration by TPs embedded in a gelatine membrane was 0.51. The results demonstrated that TPs showed a capacity for regenerating TBHQ, indicating a potential application in regenerative packaging, whereby one antioxidant would be added to the food matrix, with another one as the regenerator incorporated into the packaging material. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synergistic effects of green tea polyphenols and alphacalcidol on chronic inflammation-induced bone loss in female rats

USDA-ARS?s Scientific Manuscript database

Summary: Studies suggest that green tea polyphenols (GTP) or alphacalcidol is promising agent for preventing bone loss. Findings that GTP supplementation in the drinking water plus alphacalcidol administration resulted in increased bone mass via a decrease of oxidative stress and inflammation sugges...

Green tea and risk of breast cancer in Asian Americans.

PubMed

Wu, Anna H; Yu, Mimi C; Tseng, Chiu-Chen; Hankin, Jean; Pike, Malcolm C

2003-09-10

There is substantial in vitro and in vivo evidence implicating tea polyphenols as chemopreventive agents against various cancers. However, epidemiologic data obtained from mainly Western populations are not supportive of a protective role of tea, mainly black tea, in the etiology of breast cancer. Much less is known about the relationship between green tea and breast cancer risk. During 1995-1998, we conducted a population-based, case-control study of breast cancer among Chinese, Japanese and Filipino women in Los Angeles County and successfully interviewed 501 breast cancer patients and 594 control subjects. Detailed information on menstrual and reproductive factors; dietary habits, including intake of black and green tea; and other lifestyle factors was collected. Risk of breast cancer was not related to black tea consumption. In contrast, green tea drinkers showed a significantly reduced risk of breast cancer, and this was maintained after adjusting for age, specific Asian ethnicity, birthplace, age at menarche, parity, menopausal status, use of menopausal hormones, body size and intake of total calories and black tea. Compared to women who did not drink green tea regularly (i.e., less than once a month), there was a significant trend of decreasing risk with increasing amount of green tea intake, adjusted odds ratios being 1.00, 0.71 (95% confidence interval [CI] 0.51-0.99) and 0.53 (95% CI 0.35-0.78), respectively, in association with no, 0-85.7 and >85.7 ml of green tea per day. The significant inverse association between risk of breast cancer and green tea intake remained after further adjustment for other potential confounders, including smoking; alcohol, coffee and black tea intake; family history of breast cancer; physical activity; and intake of soy and dark green vegetables. While both green tea and soy intake had significant, independent protective effects on breast cancer risk, the benefit of green tea was primarily observed among subjects who were low

Investigation of free amino acid, total phenolics, antioxidant activity and purine alkaloids to assess the health properties of non-Camellia tea.

PubMed

Bi, Wu; He, Chunnian; Ma, Yunyun; Shen, Jie; Zhang, Linghua Harris; Peng, Yong; Xiao, Peigen

2016-03-01

To find novel functional beverages from folk teas, 33 species of frequently used non-Camellia tea (plants other than Camellia) were collected and compared with Camellia tea (green tea, pu-erh tea and black tea) for the first time. Data are reported here on the quantities of 20 free amino acids (FAAs) and three purine alkaloids (measured by UHPLC), total polyphenols (measured by Folin-Ciocalteu assay), and antioxidant activity (DPPH). The total amounts of FAAs in non-Camellia tea (0.62-18.99 mg/g) are generally less than that of Camellia tea (16.55-24.99 mg/g). However, for certain FAAs, the quantities were much higher in some non-Camellia teas, such as γ-aminobutyric acid in teas from Ampelopsis grossedentata, Isodon serra and Hibiscus sabdariffa. Interestingly, theanine was detected in tea from Potentilla fruticosa (1.16±0.81 mg/g). Furthermore, the content of polyphenols in teas from A. grossedentata, Acer tataricum subsp. ginnala are significantly higher than those from Camellia tea; teas from I. serra, Pistacia chinensis and A. tataricum subsp. ginnala have remarkable antioxidant activities similar to the activities from green tea (44.23 μg/mL). Purine alkaloids (caffeine, theobromine and theophylline) were not detected in non-Camellia teas. The investigation suggest some non-Camellia teas may be great functional natural products with potential for prevention of chronic diseases and aging, by providing with abundant polyphenols, antioxidants and specific FAAs.

Green and black tea consumption and risk of stroke: a meta-analysis.

PubMed

Arab, Lenore; Liu, Weiqing; Elashoff, David

2009-05-01

Experimental models of stroke provide consistent evidence of smaller stroke volumes in animals ingesting tea components or tea extracts. To assess whether a similar association of black or green tea consumption with reduced risk is evident in human populations, we sought to identify and summarize all human clinical and observational data on tea and stroke. We searched PubMed and Web of Science for all studies on stroke and tea consumption in humans with original data, including estimation or measurement of tea consumption and outcomes of fatal or nonfatal stroke. Data from 9 studies involving 4378 strokes among 194 965 individuals were pooled. The main outcome was the occurrence of fatal or nonfatal stroke. We tested for heterogeneity and calculated the summary effect estimate associated with consumption of >or=3 cups of tea (green or black) per day using random-effects and fixed-effects models for the homogeneous studies. Publication bias was also evaluated. Regardless of their country of origin, individuals consuming >or=3 cups of tea per day had a 21% lower risk of stroke than those consuming <1 cup per day (absolute risk reduction, 0.79; CI, 0.73 to 0.85). The proportion of heterogeneity not explained by chance alone was 23.8%. Although a randomized clinical trial would be necessary to confirm the effect, this meta-analysis suggests that daily consumption of either green or black tea equaling 3 cups per day could prevent the onset of ischemic stroke.

Cardiovascular effects of black tea and nicotine alone or in combination against experimental induced heart injury.

PubMed

Joukar, Siyavash; Bashiri, Hamideh; Dabiri, Shahriar; Ghotbi, Payam; Sarveazad, Arash; Divsalar, Kouros; Joukar, Farzin; Abbaszadeh, Mahsa

2012-06-01

The present study was designed to elucidate the outcome of subchronic co-administration of black tea and nicotine on cardiovascular performance and whether these substances could modulate the isoproterenol-induced cardiac injury. Animal groups were control, black tea, nicotine and black tea plus nicotine. Test groups received nicotine (2 mg/kg s.c.) and black tea brewed (p.o.) each alone and in combination for 4 weeks. On the 28th day, myocardial damage was induced by isoproterenol (50 mg/kg i.p.), and blood samples were taken. On day 29, after hemodynamic parameters recording, hearts were removed for histopathological evaluation. Tea or nicotine consumption had no significant effects on hemodynamic indices of animals without heart damage. When the cardiac injury was induced, tea consumption maintained the maximum dp/dt, and nicotine significantly decreased the pressure-rate product. Moreover, severity of heart lesions was lower in the presence of nicotine or black tea. Concomitant use of these materials did not show extra effects on mentioned parameters more than the effect of each of them alone. The results suggest that subchronic administration of black tea or nicotine for a period of 4 weeks may have a mild cardioprotective effect, while concomitant use of these materials cannot intensify this beneficial effect.

Separation of catechins and methylxanthines in tea samples by capillary electrochromatography.

PubMed

Uysal, Ulku Dilek; Aturki, Zeineb; Raggi, Maria Augusta; Fanali, Salvatore

2009-04-01

In this paper, the simultaneous separation of several polyphenols such as (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, theophylline, caffeine in green and black teas by capillary electrochromatography (CEC) was developed. Several experimental parameters such as stationary phase type, mobile phase composition, buffer and pH, inner diameter of the columns, sample injection, were evaluated to obtain the complete separation of the analysed compounds. Baseline resolution of the studied polyphenols was achieved within 30 min by using a capillary column (id 100 microm) packed with bidentate C(18) particles for 24.5 cm and a mobile phase composed of 5 mM ammonium acetate buffer pH 4 with H(2)O/ACN (80:20, v/v). The applied voltage and the temperature were set at 30 kV and 20 degrees C. Precision, detection and quantification limits, linearity, and accuracy were investigated. A good linearity (R(2) > 0.9992) was achieved over a concentration working range of 2-100 microg/mL for all the analytes. LOD and LOQ were 1 and 2 microg/mL, respectively, for all studied compounds. The CEC method was applied to the analysis of those polyphenols in green and black tea samples after an extraction procedure. Good recovery data from accuracy studies ranged between 90% and 112% for all analytes.

New insights into the mechanisms of polyphenols beyond antioxidant properties; lessons from the green tea polyphenol, epigallocatechin 3-gallate☆

PubMed Central

Kim, Hae-Suk; Quon, Michael J.; Kim, Jeong-a

2014-01-01

Green tea is rich in polyphenol flavonoids including catechins. Epigallocatechin 3-gallate (EGCG) is the most abundant and potent green tea catechin. EGCG has been extensively studied for its beneficial health effects as a nutriceutical agent. Based upon its chemical structure, EGCG is often classified as an antioxidant. However, treatment of cells with EGCG results in production of hydrogen peroxide and hydroxyl radicals in the presence of Fe (III). Thus, EGCG functions as a pro-oxidant in some cellular contexts. Recent investigations have revealed many other direct actions of EGCG that are independent from anti-oxidative mechanisms. In this review, we discuss these novel molecular mechanisms of action for EGCG. In particular, EGCG directly interacts with proteins and phospholipids in the plasma membrane and regulates signal transduction pathways, transcription factors, DNA methylation, mitochondrial function, and autophagy to exert many of its beneficial biological actions. PMID:24494192

The consumption of coffee and black tea and the risk of lung cancer.

PubMed

Pasquet, Romain; Karp, Igor; Siemiatycki, Jack; Koushik, Anita

2016-11-01

Coffee and black tea are among the most consumed beverages worldwide. Although their potential role in lung cancer occurrence has been investigated in several studies, results have been inconclusive. We investigated the associations between intake of coffee and black tea with lung cancer in a population-based case-control study in Montreal, Canada. These analyses included 1130 cases and 1483 controls. Adjusted odds ratios (ORs) were estimated between four metrics of coffee and black tea consumption (frequency, average daily amount, duration, and cumulative amount) and lung cancer, using unconditional logistic regression. The adjusted ORs (95% confidence intervals) for lung cancer comparing daily to never consumers were 0.73 (0.49-1.10) for coffee and 1.05 (0.85-1.31) for black tea. Analyses of other metrics did not reveal any clear patterns of increasing or decreasing risk with increasing amounts or duration of consumption. There was no strong evidence of OR modification by sex or smoking level. The OR estimates did not materially differ by histological subtype for either of the beverages. Our results do not provide strong support for associations between consumption of coffee and black tea and lung cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

Green Tea Polyphenols and Vitamin D3 Protect Bone Microarchitecture in Female Rats with Chronic Inflammation

USDA-ARS?s Scientific Manuscript database

Our recent study showed that green tea polyphenols (GTP) in conjunction with 1-a-OH¬vit-D3 (vitD3) treatment mitigates lipopolysaccharide (LPS)-induced bone mineral density loss in female rats. This study was undertaken to further explore the mechanism and bone microarchitecture of GTP plus vitD3 in...

Comparative assessment of antibacterial efficacy of aqueous extract of commercially available black, green, and lemon tea: an in vitro study

PubMed Central

Arun, S. Dodamani; Minal, M. Kshirsagar; Karibasappa, G. N.; Prashanth, V. K.; Girija, A. Dodamani; Harish, C. Jadhav

2017-01-01

Objectives: The objective of this study is to determine and compare antibacterial efficacy of aqueous extracts of black, green, and lemon tea of a commercially available brand. Materials and Methods: The well-diffusion method was used to evaluate the antibacterial efficacy of commercially available black tea, green tea, and lemon tea at three different concentrations (1.5 g, 5 g, and 7.5 g) against Streptococcus mutans and Lactobacillus acidophilus. After incubation in appropriate culture medium, diameter of zone of inhibition was measured to assess the antibacterial efficacy of tea. Results: Maximum zone of inhibition was found with lemon tea (27 mm) followed by green tea (26 mm) and black tea (13 mm) against S. mutans and L. acidophilus. Zone of inhibition was highest at 7.5 g concentration (1 and half tea spoon) for lemon tea followed by green tea and black tea. Results were statistically analyzed with the analysis of variance (ANOVA). For pairwise intergroup multiple comparisons, bonferroni test was applied. The difference between black tea, green tea, and lemon tea were statistically significant (P < 0.001) at 5% of level of significance. Conclusion: Lemon tea at 7.5 g concentration was more effective followed by green tea and black tea against S. mutans and L. acidophilus. PMID:29085267

[Study on the analytical methods of catechins in tea and green tea polyphenol samples by high performance liquid chromatography].

PubMed

Dai, J; Wang, H X; Chen, S W; Tang, J

2001-09-01

Hypersil BDS C18 and Zorbax SB C18, suitable to separate simultaneously seven kinds of catechins and caffeine, were screened out from seven brands of reversed-phase columns. Mobile phase was a solution of methanol-water-acetic acid (or trifluoro acetic acid). Seven kinds of catechins in tea samples from six places in China and three green tea polyphenol(GTP) samples from different producers were separated and determined in 30 min by isocratic and gradient elutions. The effects of mobile phase components and temperature of column on retention parameters of catechins and caffeine are reviewed. Chromatographic conditions and pretreatment methods of samples were optimized. Gallocatechin gallate(GCG) and (-)-catechin gallate(CG) were identified by electrospray ionization mass spectrometry(ESI-MS) and prepared by high performance liquid chromatography for quantitative analysis. The other catechins, (-)-epigallocatechin (EGC), (+)-catechin (D-C), (-)-epicatechin(EC), (-)-epigallocatechin gallate(EGCG), (-)-epicatechin gallate(ECG) were identified with standards.

Effect of delta-tocotrienols and green tea polyphenols on high-fat-diet-induced bone deterioration in male C57BL/6J mice

USDA-ARS?s Scientific Manuscript database

Our previous studies demonstrated an osteo-protective roles for tocotrienols (TT, extracted from annatto consisting of 90% delta-TT and 10% gamma TT) and green tea polyphenols (GTP, extracted from green tea) in obese animals. This study further examined the combined effects of TT with GTP on high-fa...

Green tea polyphenols mitigate bone loss of female rats in a chronic inflammation-induced bone loss model

USDA-ARS?s Scientific Manuscript database

The purpose of this study was to explore bioavailability, efficacy, and molecular mechanisms of green tea polyphenols (GTP) related to preventing bone loss in rats with chronic inflammation. A 2 (placebo vs. lipopolysaccharide, LPS) × 2 (no GTP vs. 0.5% GTP in drinking water) factorial design using ...

Potentiating effects of honey on antioxidant properties of lemon-flavoured black tea.

PubMed

Pereira, Carla; Barros, Lillian; Vilas-Boas, Miguel; Ferreira, Isabel C F R

2013-03-01

Health benefits including antioxidant potential of black tea (Camellia sinensis), lemon (Citrus limon) and honey bees (Apis mellifera) have been extensively reported. Nevertheless, nothing is reported about the effects of their concomitant use. Herein, those effects were evaluated in infusions of lemon-flavoured black tea with three different kinds of honey (light amber, amber and dark amber) from Lavandula stoechas, Erica sp. pl. and other indigenous floral species from north-east Portugal, a region with high amounts of this food product. Data obtained showed that the use of honey (dark amber>amber>light amber) potentiates the antioxidant activity of lemon-flavoured black tea, increasing the reducing power and lipid peroxidation inhibition properties, as also the antioxidant contents such as phenolics, flavonoids and organic acids including ascorbic acid.

The antioxidant property of chitosan green tea polyphenols complex induces transglutaminase activation in wound healing.

PubMed

Qin, Yao; Guo, Xing Wei; Li, Lei; Wang, Hong Wei; Kim, Wook

2013-06-01

The present study examined, for the first time, the in vitro wound healing potential of chitosan green tea polyphenols (CGP) complex based on the activation of transglutaminase (TGM) genes in epidermal morphogenesis. Response surface methodology was applied to determine the optimal processing condition that gave maximum extraction of green tea polyphenols. The antioxidant activity, scavenging ability, and chelating ability were studied and expressed as average EC50 values of CGP and other treatments. In silico analysis and gene coexpression network was subjected to the TGM sequences analysis. The temporal expressions of TGMs were profiled by semi-quantitative reverse transcription (RT)-PCR technology within 10 days after wounding and 2 days postwounding. CGP showed the effectiveness of antioxidant properties, and the observations of histopathological photography showed advanced tissue granulation and epithelialization formation by CGP treatment. In silico and coexpression analysis confirmed the regulation via TGM gene family in dermatological tissues. RT-PCR demonstrated increased levels of TGM1-3 expression induced by CGP treatment. The efficacy of CGP in wound healing based on these results may be ascribed to its antioxidant properties and activation of the expression of TGMs, and is, thus, essential for the facilitated repair of skin injury.

Hypertension, nitric oxide, oxidants, and dietary plant polyphenols.

PubMed

Galleano, Monica; Pechanova, Olga; Fraga, Cesar G

2010-12-01

Fruits and vegetables are key foods whose high ingestion is associated with the improvement of numerous pathological conditions, including hypertension. Such health promoting actions have been increasingly ascribed to the antioxidant characteristics of different polyphenols in fruits and vegetables. Consequently, based on this assumption, many beverages and foods rich in polyphenols, grape, tea, cocoa, and soy products and many of their chemical constituents purified, are being studied both, as antioxidants and antihypertensive agents. This paper reviews the current evidence linking high polyphenol consumption with reductions in blood pressure. Basic chemical aspects of flavanols, flavonols, isoflavones and stilbenes, as possible responsible for the observed effects of those foods on blood pressure are included. Human interventions studies by using grapes and wine, cocoa and chocolate, black and green tea, soy products, and purified compounds ((+)-catequin, quercetin, (-)-epigallocatechin gallate) are summarized. The discussed hypothesis, strongly supported by experimental data in animals, is that by regulating nitric oxide bioavailability, polyphenols present in fruits and vegetables affect endothelial function and as a consequence, blood pressure. Even when data are not definitive and many questions remain open, the whole evidence is encouraging to start considering diets that can provide a benefit to hypertensive subjects, and those benefits will be more significant in people that do not have controlled his/her elevated blood pressure.

Priority PAHs in orthodox black tea during manufacturing process.

PubMed

Grover, Inderpreet Singh; Singh, Satnam; Pal, Bonamali

2013-08-01

Orthodox black tea is obtained from fresh leaves followed by withering, rolling, fermentation and drying. The presence of 16 priority polycyclic aromatic hydrocarbons (PAHs) was studied in fresh leaves and at various stages of manufacturing. Benzo(a)pyrene (2A: probable human carcinogen) was found in dried tea leaves only whereas, naphthalene (2B: probable human carcinogen) was present during all the stages of manufacturing. Dry tea leaves showed higher content of total 16 PAHs (∑PAHs) about 3 and 211 times than present in withered and dried leaves, respectively. Chrysene, benzo[g,h,i]perylene, indendo[1,2,3-c,d]pyrene, dibenzo[a,h]pyrene and benzo[a]antracene were not found during manufacturing stages of tea.

Green tea polyphenol EGCG blunts androgen receptor function in prostate cancer

PubMed Central

Siddiqui, Imtiaz A.; Asim, Mohammad; Hafeez, Bilal B.; Adhami, Vaqar M.; Tarapore, Rohinton S.; Mukhtar, Hasan

2011-01-01

Androgen deprivation therapy is the major treatment for advanced prostate cancer (PCa). However, it is a temporary remission, and the patients almost inevitably develop hormone refractory prostate cancer (HRPC). HRPC is almost incurable, although most HRPC cells still express androgen receptor (AR) and depend on the AR for growth, making AR a prime drug target. Here, we provide evidence that epigallocatechin-3-gallate (EGCG), the major polyphenol in green tea, is a direct antagonist of androgen action. In silico modeling and FRET-based competition assay showed that EGCG physically interacts with the ligand-binding domain of AR by replacing a high-affinity labeled ligand (IC50 0.4 μM). The functional consequence of this interaction was a decrease in AR-mediated transcriptional activation, which was due to EGCG mediated inhibition of interdomain N-C termini interaction of AR. Treatment with EGCG also repressed the transcriptional activation by a hotspot mutant AR (T877A) expressed ectopically as well as the endogenous AR mutant. As the physiological consequence of AR antagonism, EGCG repressed R1881-induced PCa cell growth. In a xenograft model, EGCG was found to inhibit AR nuclear translocation and protein expression. We also observed a significant down-regulation of androgen-regulated miRNA-21 and up-regulation of a tumor suppressor, miRNA-330, in tumors of mice treated with EGCG. Taken together, we provide evidence that EGCG functionally antagonizes androgen action at multiple levels, resulting in inhibition of PCa growth.—Siddiqui, I. A., Asim, M., Hafeez, B. B., Adhami, V. M., Tarapore, R. S., Mukhtar, H. Green tea polyphenol EGCG blunts androgen receptor function in prostate cancer. PMID:21177307

A physiological model of tea-induced astringency.

PubMed

Nayak, A; Carpenter, G H

2008-10-20

The mechanism by which solutions containing polyphenols are perceived as astringent is not clearly understood. Salivary proline-rich proteins and histatins are products of salivary glands and rapidly bind polyphenols - thought to be the main astringent compound in such as tea and wine. However it is unclear how this interaction leads to the altered oral mouthfeel known as astringency which is characterised by a dry, puckered feeling all around the mouth. To determine the role of saliva in the perception of astringency a protocol was used to decrease the volume of saliva from the mouth (by washing with water) and then by chewing to increase the volume of saliva above resting levels. Following each of these conditions subjects tasted the same solution of black tea and were asked to rate the relative astringency. Compared to the astringency rating of black tea at rest the majority of subjects (10 out of 15) perceived an increase in astringency following washing the mouth with water. Most subjects then perceived a decrease in astringency following chewing compared to the previous state. In all subjects a reduction in salivary proteins was detected following water washout and an increase above resting levels detected following chewing although there was no change in oral mucosal wetness. A separate experiment revealed several of the proteins interacting following the water washout were salivary in origin. We conclude that salivary proteins in solution inhibit the mouthfeeling of astringency which is mediated, at least in part, by salivary proteins adhered to buccal mucosal cells.

Chitosan pretreatment for cotton dyeing with black tea

NASA Astrophysics Data System (ADS)

Campos, J.; Díaz-García, P.; Montava, I.; Bonet-Aracil, M.; Bou-Belda, E.

2017-10-01

Chitosan is used in a wide range of applications due to its intrinsic properties. Chitosan is a biopolymer obtained from chitin and among their most important aspects highlights its bonding with cotton and its antibacterial properties. In this study two different molecular weight chitosan are used in the dyeing process of cotton with black tea to evaluate its influence. In order to evaluate the effect of the pretreatment with chitosan, DSC and reflection spectrophotometer analysis are performed. The curing temperature is evaluated by the DSC analysis of cotton fabric treated with 15 g/L of chitosan, whilst the enhancement of the dyeing is evaluated by the colorimetric coordinates and the K/S value obtained spectrophotometrically. This study shows the extent of improvement of the pretreatment with chitosan in dyeing with natural products as black tea.

Antioxidant and antibacterial properties of green, black, and herbal teas of Camellia sinensis.

PubMed

Chan, Eric W C; Soh, Eu Ying; Tie, Pei Pei; Law, Yon Peng

2011-10-01

The role of non-polymeric phenolic (NP) and polymeric tannin (PT) constituents in the antioxidant and antibacterial properties of six brands of green, black, and herbal teas of Camellia sinensis were investigated. Total phenolic content (TPC) and ascorbic acid equivalent antioxidant capacity (AEAC) were assessed using the Folin-Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, respectively. Minimum inhibitory dose (MID) against Gram-positive Micrococcus luteus, Staphylococcus aureus, and Bacillus cereus, and Gram-negative. Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa was assessed using the disc-diffusion method. Teas were extracted with hot water successively three times for one hour each time. The extracts were fractionated using Sephadex LH-20 column chromatography to obtain the NP and PT constituents. Extraction yields ranged from 12 to 23%. Yields of NP fractions (70-81%) were much higher than those of PT fractions (1-11%), suggesting that the former are the major tea components. Ranking of antioxidant properties of extracts was green tea>black tea>herbal tea. For all six teas, antioxidant properties of PT fractions were significantly higher than extracts and NP fractions. Extracts and fractions of all six teas showed no activity against the three Gram-negative bacteria. Green teas inhibited all three Gram-positive bacteria with S. aureus being the least susceptible. Black and herbal teas inhibited the growth of M. luteus and B. cereus, but not S. aureus. The most potent were the PT fractions of Boh Cameron Highlands and Ho Yan Hor with MID of 0.01 and 0.03 mg/disc against M. luteus. Results suggested that NP constituents are major contributors to the antioxidant and antibacterial properties of teas of C. sinensis. Although PT constituents have stronger antioxidant and antibacterial properties, they constitute only a minor component of the teas.

Interfering Effect of Black Tea Consumption on Diagnosis of Pancreatic Cancer by CA 19-9.

PubMed

Al-Janabi, Ali Abdul Hussein S; Tawfeeq, Ekhlas F

2017-06-01

The study aims to determine the possible effects of black tea consumption on the level of CA 19-9 antigen in the human body. The level of CA 19-9 was measured in 270 healthy individuals who consumed heavy amounts of black tea. About 43.3 % of involved individuals were revealed to have elevated levels of CA 19-9. Males with high values of CA 19-9 represented the greatest number of involved individuals. The cutoff value of high levels of CA 19-9 in all individuals was ranged 69-105 U/ml. Consuming heavy amounts of black tea could be considered an important interfering factor that affects the levels of CA 19-9. The cutoff or predictive value of CA 19-9 in heavy-consuming people of black tea was determined.

Tea polyphenols can restrict benzo[a]pyrene-induced lung carcinogenesis by altered expression of p53-associated genes and H-ras, c-myc and cyclin D1.

PubMed

Manna, Sugata; Mukherjee, Sudeshna; Roy, Anup; Das, Sukta; Panda, Chinmay Kr

2009-05-01

The modulatory influence of tea polyphenols (epigallocatechin gallate, epicatechin gallate and theaflavin) on benzo[a]pyrene (B[a]P)-induced lung carcinogenesis in mice was analyzed using histopathological and molecular parameters. Progression of lung lesions was restricted at the hyperplastic stage by tea polyphenols. A significant reduction in cellular proliferative index and an increase in apoptotic index were noted in the restricted lung lesions. High expression of H-ras, c-myc, cyclin D1 and p53 genes was seen at the inflammatory stage (9th week) and in subsequent premalignant lesions, but down-regulation of H-ras at the hyperplastic stage (17th week). Expression of bcl-2 was high in hyperplastic lesions, whereas the expression of mdm2 and bcl-xl increased only at the moderately dysplastic stage (36th week). The tea polyphenols inhibited inflammatory response in the lung lesions on the 9th week, when decreased expression of H-ras and c-myc and increased expression of bax were noted. Prolonged treatment (>9th week) with tea polyphenols resulted in changes in the expression of some additional genes, such as reduced expression of cyclin D1 (from the 17th week), bcl-2 (from the 26th week; mild dysplasia) and p21 (on the 36th week), and high expression of p53 (from the 17th week) and p27 (on the 36th week). These observations indicate that the tea polyphenols can restrict B[a]P-induced lung carcinogenesis by differential modulation of the expression of p53 and its associated genes such as bax, bcl-2, mdm2, p21 and p27, along with H-ras, c-myc and cyclin D1, at different time points.

Tea and its consumption: benefits and risks.

PubMed

Hayat, Khizar; Iqbal, Hira; Malik, Uzma; Bilal, Uzma; Mushtaq, Sobia

2015-01-01

The recent convention of introducing phytochemicals to support the immune system or combat diseases is a centuries' old tradition. Nutritional support is an emerging advancement in the domain of diet-based therapies; tea and its constituents are one of the significant components of these strategies to maintain the health and reduce the risk of various malignancies. Tea is the most frequently consumed beverage worldwide, besides water. All the three most popular types of tea, green (unfermented), black (fully fermented), and oolong (semifermented), are manufactured from the leaves of the plant Camellia sinensis. Tea possesses significant antioxidative, anti-inflammatory, antimicrobial, anticarcinogenic, antihypertensive, neuroprotective, cholesterol-lowering, and thermogenic properties. Several research investigations, epidemiological studies, and meta-analyses suggest that tea and its bioactive polyphenolic constituents have numerous beneficial effects on health, including the prevention of many diseases, such as cancer, diabetes, arthritis, cardiovascular disease (CVD), stroke, genital warts, and obesity. Controversies regarding beneficialts and risks of tea consumption still exist but the limitless health-promoting benefits of tea outclass its few reported toxic effects. However, with significant rise in the scientific investigation of role of tea in human life, this review is intended to highlight the beneficial effects and risks associated with tea consumption.

Dietary green tea polyphenols do not affect vitamin E status, antioxidant capacity and meat quality of growing pigs.

PubMed

Augustin, K; Blank, R; Boesch-Saadatmandi, C; Frank, J; Wolffram, S; Rimbach, G

2008-12-01

Supplementation of pigs with vitamin E, the most important lipid-soluble antioxidant, has been shown to improve meat quality and animal health. Previous studies in cultured cells and laboratory animals indicate synergistic effects between polyphenols and vitamin E. The present feeding trial was undertaken to investigate the effects of dietary green tea polyphenols (GTP) on vitamin E status, antioxidative capacity and parameters of meat quality in growing pigs. Eighteen castrated, crossbred, male pigs received a flavonoid-poor diet based on corn starch, caseinate and rapeseed oil with a total vitamin E content of 17 IU/kg diet over a period of 5 weeks. This basal diet was supplemented with green tea extract to provide daily doses of 0 (control), 10 and 100 mg GTP/kg body weight. Dietary supplementation of growing pigs with GTP did not affect serum, liver, lung and muscle vitamin E (alpha- and gamma-tocopherol) concentrations, plasma antioxidant capacity (ferric reducing ability of plasma, trolox equivalent antioxidant capacity) or parameters of meat quality including meat temperature, pH, conductivity, colour and drip loss. In conclusion, supplementation of pig diets with green tea catechins is not associated with improved antioxidant status and meat quality under practice-oriented conditions.

Protective actions of green tea polyphenols and alfacalcidol on bone microstructure in female rats with chronic inflammation

USDA-ARS?s Scientific Manuscript database

This study investigated the effects of green tea polyphenols (GTP) and alfacalcidol on bone microstructure and strength along with possible mechanisms in rats with chronic inflammation. A 12-week study using a 2 (no GTP vs. 0.5%, w/v GTP in drinking water) × 2 (no alfacalcidol vs. 0.05 ug/kg alfacal...

A Critical Review on Polyphenols and Health Benefits of Black Soybeans

PubMed Central

Ganesan, Kumar; Xu, Baojun

2017-01-01

Polyphenols are plant secondary metabolites containing antioxidant properties, which help to protect chronic diseases from free radical damage. Dietary polyphenols are the subject of enhancing scientific interest due to their possible beneficial effects on human health. In the last two decades, there has been more interest in the potential health benefits of dietary polyphenols as antioxidant. Black soybeans (Glycine max L. Merr) are merely a black variety of soybean containing a variety of phytochemicals. These phytochemicals in black soybean (BSB) are potentially effective in human health, including cancer, diabetes, cardiovascular diseases, cerebrovascular diseases, and neurodegenerative diseases. Taking into account exploratory study, the present review aims to provide up-to-date data on health benefit of BSB, which helps to explore their therapeutic values for future clinical settings. All data of in vitro and in vivo studies of BSB and its impact on human health were collected from a library database and electronic search (Science Direct, PubMed, and Google Scholar). The different pharmacological information was gathered and orchestrated in a suitable spot on the paper. PMID:28471393

Phenolic promiscuity in the cell nucleus--epigallocatechingallate (EGCG) and theaflavin-3,3'-digallate from green and black tea bind to model cell nuclear structures including histone proteins, double stranded DNA and telomeric quadruplex DNA.

PubMed

Mikutis, Gediminas; Karaköse, Hande; Jaiswal, Rakesh; LeGresley, Adam; Islam, Tuhidul; Fernandez-Lahore, Marcelo; Kuhnert, Nikolai

2013-02-01

Flavanols from tea have been reported to accumulate in the cell nucleus in considerable concentrations. The nature of this phenomenon, which could provide novel approaches in understanding the well-known beneficial health effects of tea phenols, is investigated in this contribution. The interaction between epigallocatechin gallate (EGCG) from green tea and a selection of theaflavins from black tea with selected cell nuclear structures such as model histone proteins, double stranded DNA and quadruplex DNA was investigated using mass spectrometry, Circular Dichroism spectroscopy and fluorescent assays. The selected polyphenols were shown to display affinity to all of the selected cell nuclear structures, thereby demonstrating a degree of unexpected molecular promiscuity. Most interestingly theaflavin-digallate was shown to display the highest affinity to quadruplex DNA reported for any naturally occurring molecule reported so far. This finding has immediate implications in rationalising the chemopreventive effect of the tea beverage against cancer and possibly the role of tea phenolics as "life span essentials".

Spatial variability of theaflavins and thearubigins fractions and their impact on black tea quality.

PubMed

Bhuyan, Lakshi Prasad; Borah, Paban; Sabhapondit, Santanu; Gogoi, Ramen; Bhattacharyya, Pradip

2015-12-01

The spatial distribution of theaflavin and thearubigin fractions and their impact on black tea quality were investigated using multivariate and geostatistics techniques. Black tea samples were collected from tea gardens of six geographical regions of Assam and West Bengal, India. Total theaflavin (TF) and its four fractions of upper Assam, south bank and North Bank teas were higher than the other regions. Simple theaflavin showed highest significant correlation with tasters' quality. Low molecular weight thearubigins of south bank and North Bank were significantly higher than other regions. Total thearubigin (TR) and its fractions revealed significant positive correlation with tasters' organoleptic valuations. Tea tasters' parameters were significantly and positively correlated with each other. The semivariogram for quality parameters were best represented by gaussian models. The nugget/sill ratio indicated a strong/moderate spatial dependence of the studied parameters. Spatial variation of tea quality parameters may be used for quality assessment in the tea growing areas of India.

Population nutrikinetics of green tea extract.

PubMed

Scholl, Catharina; Lepper, Anna; Lehr, Thorsten; Hanke, Nina; Schneider, Katharina Luise; Brockmöller, Jürgen; Seufferlein, Thomas; Stingl, Julia Carolin

2018-01-01

Green tea polyphenols may contribute to the prevention of cancer and other diseases. To learn more about the pharmacokinetics and interindividual variation of green tea polyphenols after oral intake in humans we performed a population nutrikinetic study of standardized green tea extract. 84 healthy participants took green tea extract capsules standardized to 150 mg epigallocatechin-gallate (EGCG) twice a day for 5 days. On day 5 catechin plasma concentrations were analyzed using non-compartmental and population pharmacokinetic methods. A strong between-subject variability in catechin pharmacokinetics was found with maximum plasma concentrations varying more than 6-fold. The AUCs of EGCG, EGC and ECG were 877.9 (360.8-1576.5), 35.1 (8.0-87.4), and 183.6 (55.5-364.6) h*μg/L respectively, and the elimination half lives were 2.6 (1.8-3.8), 3.9 (0.9-10.7) and 1.8 (0.8-2.9) h, respectively. Genetic polymorphisms in genes of the drug transporters MRP2 and OATP1B1 could at least partly explain the high variability in pharmacokinetic parameters. The observed variability in catechin plasma levels might contribute to interindividual variation in benefical and adverse effects of green tea polyphenols. Our data could help to gain a better understanding of the causes of variability of green tea effects and to improve the design of studies on the effects of green tea polyphenols in different health conditions. ClinicalTrials.gov: NCT01360320.

Chronic Inflammatory Diseases and Green Tea Polyphenols

PubMed Central

Oz, Helieh S.

2017-01-01

Chronic inflammatory diseases affect millions of people globally and the incidence rate is on the rise. While inflammation contributes to the tissue healing process, chronic inflammation can lead to life-long debilitation and loss of tissue function and organ failure. Chronic inflammatory diseases include hepatic, gastrointestinal and neurodegenerative complications which can lead to malignancy. Despite the millennial advancements in diagnostic and therapeutic modalities, there remains no effective cure for patients who suffer from inflammatory diseases. Therefore, patients seek alternatives and complementary agents as adjunct therapies to relieve symptoms and possibly to prevent consequences of inflammation. It is well known that green tea polyphenols (GrTPs) are potent antioxidants with important roles in regulating vital signaling pathways. These comprise transcription nuclear factor-kappa B mediated I kappa B kinase complex pathways, programmed cell death pathways like caspases and B-cell lymphoma-2 and intervention with the surge of inflammatory markers like cytokines and production ofcyclooxygenase-2. This paper concisely reviews relevant investigations regarding protective effects of GrTPs and some reported adverse effects, as well as possible applications for GrTPs in the treatment of chronic and inflammatory complications. PMID:28587181

An emerging strategy for evaluating the grades of Keemun black tea by combinatory liquid chromatography-Orbitrap mass spectrometry-based untargeted metabolomics and inhibition effects on α-glucosidase and α-amylase.

PubMed

Guo, Xuemei; Long, Piaopiao; Meng, Qilu; Ho, Chi-Tang; Zhang, Liang

2018-04-25

Quantitative analysis and untargeted liquid chromatography mass spectrum (LC-MS) based metabolomics of different grades of Keemun black tea (KBT) were conducted. Quantitative analysis did not show tight correlation between tea grades and contents of polyphenols, but untargeted metabolomics analysis revealed that high-grades KBT were distinguished from the low-grades. S-plot and Variable Importance (VIP) analysis gave 28 marker compounds responsible for the discrimination of different grades of KBT. The inhibitory effects of KBT on α-amylase and α-glucosidase were positively correlated to tea grades, and the correlation coefficient between each marker compound and inhibitory rate were calculated. Thirteen compounds were positively related to the anti-glycemic activity, and theasinensin A, afzelechin gallate and kaempferol-glucoside were confirmed as grade-related bioactive marker compounds by chemical and bioassay in effective fractions. This study suggested that combinatory metabolomics and bioactivities assay provided a new strategy for the classification of tea grades. Copyright © 2017 Elsevier Ltd. All rights reserved.

Black Tea Source, Production, and Consumption: Assessment of Health Risks of Fluoride Intake in New Zealand

PubMed Central

Godfrey, Michael; Limeback, Hardy

2017-01-01

In countries with fluoridation of public water, it is imperative to determine other dietary sources of fluoride intake to reduce the public health risk of chronic exposure. New Zealand has one of the highest per capita consumption rates of black tea internationally and is one of the few countries to artificially fluoridate public water; yet no information is available to consumers on the fluoride levels in tea products. In this study, we determined the contribution of black tea as a source of dietary fluoride intake by measuring the fluoride content in 18 brands of commercially available products in New Zealand. Fluoride concentrations were measured by potentiometric method with a fluoride ion-selective electrode and the contribution of black tea to Adequate Intake (AI) and Tolerable Upper Intake Level (UL) was calculated for a range of consumption scenarios. We examined factors that influence the fluoride content in manufactured tea and tea infusions, as well as temporal changes in fluoride exposure from black tea. We review the international evidence regarding chronic fluoride intake and its association with chronic pain, arthritic disease, and musculoskeletal disorders and provide insights into possible association between fluoride intake and the high prevalence of these disorders in New Zealand. PMID:28713433

The mechanism of interactions between tea polyphenols and porcine pancreatic alpha‐amylase: Analysis by inhibition kinetics, fluorescence quenching, differential scanning calorimetry and isothermal titration calorimetry

PubMed Central

Sun, Lijun; Gidley, Michael J.

2017-01-01

Scope This study aims to use a combination of biochemical and biophysical methods to derive greater mechanistic understanding of the interactions between tea polyphenols and porcine pancreatic α‐amylase (PPA). Methods and results The interaction mechanism was studied through fluorescence quenching (FQ), differential scanning calorimetry (DSC) and isothermal titration calorimetry (ITC) and compared with inhibition kinetics. The results showed that a higher quenching effect of polyphenols corresponded to a stronger inhibitory activity against PPA. The red‐shift of maximum emission wavelength of PPA bound with some polyphenols indicated a potential structural unfolding of PPA. This was also suggested by the decreased thermostability of PPA with these polyphenols in DSC thermograms. Through thermodynamic binding analysis of ITC and inhibition kinetics, the equilibrium of competitive inhibition was shown to result from the binding of particularly galloylated polyphenols with specific sites on PPA. There were positive linear correlations between the reciprocal of competitive inhibition constant (1/K ic), quenching constant (K FQ) and binding constant (K itc). Conclusion The combination of inhibition kinetics, FQ, DSC and ITC can reasonably characterize the interactions between tea polyphenols and PPA. The galloyl moiety is an important group in catechins and theaflavins in terms of binding with and inhibiting the activity of PPA. PMID:28618113

Acute effect of tea, wine, beer, and polyphenols on ecto-alkaline phosphatase activity in human vascular smooth muscle cells.

PubMed

Negrão, Maria R; Keating, Elisa; Faria, Ana; Azevedo, Isabel; Martins, Maria J

2006-07-12

Alkaline phosphatase (ALP) is an ecto-enzyme widely distributed across species. It modulates a series of transmembranar transport systems, has an important role in bone mineralization, and can also be involved in vascular calcification. Polyphenol-rich diets seem to have protective effects on human health, namely, in the prevention of cardiovascular diseases. We aimed to investigate the effects of polyphenols and polyphenol-rich beverages upon membranar alkaline phosphatase (ecto-ALP) activity in intact human vascular smooth muscle cells (AALTR). The ecto-ALP activity was determined at pH 7.8, with p-nitrophenyl phosphate as the substrate, by absorbance spectrophotometry at 410 nm. Cell viability was assessed by the lactate dehydrogenase (LDH) method, and the polyphenol content of beverages was assessed using the Folin-Ciocalteu reagent. All polyphenols tested inhibited ecto-ALP activity, in a concentration-dependent way. Teas, wines, and beers also inhibited ecto-ALP activity, largely according to their polyphenol content. All tested compounds and beverages improved or did not change AALTR cell viability. Stout beer was an exception to the described behavior. Although more studies must be done, the inhibition of AALTR ecto-ALP activity by polyphenolic compounds and polyphenol-containing beverages may contribute to their cardiovascular protective effects.

Characterization of film-forming solutions and films incorporating free and nanoencapsulated tea polyphenol prepared by gelatins with different Bloom values

USDA-ARS?s Scientific Manuscript database

Gelatin film-forming solutions and their films incorporating tea polyphenol (TP) and chitosan nanoparticles (CSNs) were prepared from gelatins with different Bloom values (100, 150 and 225). Blank gelatin film-forming solutions and films were prepared as controls. Gelatins with higher Bloom values h...

[Induction of NAD(P)H: quinone reductase by anticarcinogenic ingredients of tea].

PubMed

Qi, L; Han, C

1998-09-30

By assaying the activity of NAD(P)H: quinone reductase (QR) in Hep G2 cells exposed to inducing agents, a variety of ingredients in tea, we compared their abilities on inducing QR and preventing cancer. The results showed that tea polyphenols, tea pigments and mixed tea were all able to induce the activity of QR significantly. The single-component ingredients of tea polyphenols and tea pigments, including thearubigens, EGCG and ECG, also enhanced the activity of QR. But EGC, EC, theaflavins, tea polysaccharide and tea caffeine, showed no apparent induction of QR. We found that among those tea ingredients studied, the multi-component ingredients were more effective than the single-component ones. So we thought that the abilities of antioxidation and cancer prevention of tea depended on the combined effects of several kinds of active ingredients, which mainly include tea polyphenols and tea pigments.

The role of polyphenols in modern nutrition.

PubMed

Williamson, G

2017-09-01

Polyphenols are found in plant-based foods and beverages, notably apples, berries, citrus fruit, plums, broccoli, cocoa, tea and coffee and many others. There is substantial epidemiological evidence that a diet high in polyphenol-rich fruit, vegetables, cocoa and beverages protects against developing cardiovascular disease and type 2 diabetes. The absorption and metabolism of these compounds have been well described and, for many, the gut microbiota play a critical role in absorption; taking into consideration the parent compound and the metabolites from colon bacteria catabolism, more than 80% of a dose can be absorbed and ultimately excreted in the urine. Common polyphenols in the diet are flavanols (cocoa, tea, apples, broad beans), flavanones (hesperidin in citrus fruit), hydroxycinnamates (coffee, many fruits), flavonols (quercetin in onions, apples and tea) and anthocyanins (berries). Many intervention studies, mechanistic in vitro data and epidemiological studies support a role for polyphenols against the development of chronic diseases. For example, flavanols decrease endothelial dysfunction, lower blood pressure and cholesterol, and modulate energy metabolism. Coffee and tea both reduce the risk of developing type 2 diabetes, through action of their constituent polyphenols. Despite extensive research, the exact mechanisms of action of polyphenols in the human body have not been decisively proven, but there is strong evidence that some targets such as nitric oxide metabolism, carbohydrate digestion and oxidative enzymes are important for health benefits. Consumption of polyphenols as healthy dietary components is consistent with the advice to eat five or more portions of fruit and vegetables per day, but it is currently difficult to recommend what 'doses' of specific polyphenols should be consumed to derive maximum benefit.

Estimation of Theaflavins (TF) and Thearubigins (TR) Ratio in Black Tea Liquor Using Electronic Vision System

NASA Astrophysics Data System (ADS)

Akuli, Amitava; Pal, Abhra; Ghosh, Arunangshu; Bhattacharyya, Nabarun; Bandhopadhyya, Rajib; Tamuly, Pradip; Gogoi, Nagen

2011-09-01

Quality of black tea is generally assessed using organoleptic tests by professional tea tasters. They determine the quality of black tea based on its appearance (in dry condition and during liquor formation), aroma and taste. Variation in the above parameters is actually contributed by a number of chemical compounds like, Theaflavins (TF), Thearubigins (TR), Caffeine, Linalool, Geraniol etc. Among the above, TF and TR are the most important chemical compounds, which actually contribute to the formation of taste, colour and brightness in tea liquor. Estimation of TF and TR in black tea is generally done using a spectrophotometer instrument. But, the analysis technique undergoes a rigorous and time consuming effort for sample preparation; also the operation of costly spectrophotometer requires expert manpower. To overcome above problems an Electronic Vision System based on digital image processing technique has been developed. The system is faster, low cost, repeatable and can estimate the amount of TF and TR ratio for black tea liquor with accuracy. The data analysis is done using Principal Component Analysis (PCA), Multiple Linear Regression (MLR) and Multiple Discriminate Analysis (MDA). A correlation has been established between colour of tea liquor images and TF, TR ratio. This paper describes the newly developed E-Vision system, experimental methods, data analysis algorithms and finally, the performance of the E-Vision System as compared to the results of traditional spectrophotometer.

Influence of regular black tea consumption on tobacco associated DNA damage and HPV prevalence in human oral mucosa.

PubMed

Pal, Debolina; Banerjee, Sarmistha; Indra, Dipanjana; Mandal, Shyamsundar; Dum, Anirudha; Bhowmik, Anup; Panda, Chinmay Kr; Das, Sukta

2007-01-01

Black tea is more widely consumed than green tea worldwide, particularly in India. Therefore, it is necessary to focus attention on black tea with respect to its health promoting and anti-cancer actions. In order to establish the concept that black tea is a potential candidate for cancer prevention, it is important to provide epidemiological evidence derived from investigations of human populations. In view of this, the objective of the present study was to determine the correlation between nature of black tea consumption and DNA damage in normal subjects with or without tobacco habit and oral cancer patients, taking the latter as positive controls. Much experimental evidence points to associations between tobacco habit and HPV 16 and HPV 18 (Human Papilloma virus) infection. But no studies have taken into account the possible confounding effect of black tea consumption on DNA damage along with HPV infection. A pilot study was therefore undertaken. Comet assay was used to evaluate the DNA damage among normal subjects including tobacco users (n = 86), non-tobacco users (n = 45) and Oral cancer patients (n = 37). Percentage of damaged cells was scored in the buccal squamous cells of all subjects mentioned above. HPV analysis was performed on 79 samples (including 37 oral cancer patients). The evaluation of various confounding factors like age, tenure of tobacco habit and tea habit showed significant associations with DNA damage. The observations strongly indicate that regular intake of black tea at least above four cups can reduce tobacco associated DNA damage among normal tobacco users. HPV prevalence was not seen to be associated with age, tenure of tobacco habit or the tea drinking habit.

Phenolic acid concentrations in plasma and urine from men consuming green or black tea and potential chemopreventive properties for colon cancer

PubMed Central

Henning, Susanne M.; Wang, Piwen; Abgaryan, Narine; Vicinanza, Roberto; de Oliveira, Daniela Moura; Zhang, Yanjun; Lee, Ru-Po; Carpenter, Catherine L.; Aronson, William J.; Heber, David

2013-01-01

Scope Tea polyphenols are metabolized by the colonic microflora yielding phenolic metabolites, which may contribute to the health benefits of tea. We determined the serum and urine concentrations of phenolic acids, hippuric acid and polyhydroxyphenyl-γ-valerolactones during green tea (GT) and black tea (BT) administration. The effects of (−)-epigallocatechin gallate (EGCG) and 3,4-dihydroxyphenylacetic acid (3,4-DHPAA) alone and in combination on bioavailability, intracellular metabolism, and antiproliferative activity was determined in HCT-116 colon cancer cells. Methods and Results The concentration of phenolic metabolites was quantified by HPLC with electrochemical detection and MS. Urine concentrations of 4-hydroxyphenylacetic acid (4-HPAA), 3-hydroxyphenylacetic acid (3-HPAA) and polyhydroxy-γ-valerolactones were increased significantly in men drinking GT compared to control. Urine concentration of 3-O-methylgallic acid (3OMGA) was significantly increased in men drinking BT compared to control. Serum 3,4-DHPAA was significantly increased after consumption of GT and BT and 4-HPAA after GT consumption. In vitro treatment of HCT-116 colon cancer cells with 3,4-DHPAA and EGCG exhibited an additive antiproliferative effect, while methylation of 3,4-DHPAA was significantly decreased. 3OMGA exhibited the strongest antiproliferative activity among the phenolic acids. Conclusions The consumption of both, GT and BT, was associated with a significant increase in urinary and serum phenolic acids. PMID:23319439

Mechanisms of Body Weight Reduction and Metabolic Syndrome Alleviation by Tea

PubMed Central

Yang, Chung S.; Zhang, Jinsong; Zhang, Le; Huang, Jinbao; Wang, Yijun

2016-01-01

Tea, a popular beverage made from leaves of the plant Camellia sinensis, has been shown to reduce body weight, alleviate metabolic syndrome, and prevent diabetes and cardiovascular diseases in animal models and humans. Such beneficial effects have generally been observed in most human studies when the level of tea consumption was 3 to 4 cups (600–900 mg tea catechins) or more per day. Green tea is more effective than black tea. In spite of numerous studies, the fundamental mechanisms for these actions still remain unclear. From a review of the literature, we propose that the two major mechanisms are: 1) decreasing absorption of lipids and proteins by tea constituents in the intestine, thus reducing calorie intake; and 2) activating AMPK by tea polyphenols that are bioavailable in the liver, skeletal muscle, and adipose tissues. The relative importance of these two mechanisms depends on the types of tea and diet consumed by individuals. The activated AMPK would decrease gluconeogenesis and fatty acid synthesis and increase catabolism, leading to body weight reduction and MetS alleviation. Other mechanisms and the health relevance of these beneficial effects of tea consumption remain to be further investigated. PMID:26577614

Tea intake, COMT genotype, and breast cancer in Asian-American women.

PubMed

Wu, Anna H; Tseng, Chiu-Chen; Van Den Berg, David; Yu, Mimi C

2003-11-01

There is substantial in vitro and in vivo evidence implicating tea polyphenols as chemopreventive agents against various cancers. In a case-control study conducted among Asian-American women in Los Angeles County, we reported a significant inverse relationship between intake of green tea and risk of breast cancer (A. H. Wu et al., Int. J. Cancer, 106: 574-579, 2003). Because catechol-containing tea polyphenols are very rapidly O-methylated by human catechol-O-methyltransferase (COMT), we are interested in determining whether the association between tea intake and breast cancer differed in women according to COMT genotype. We examined the interrelationships between tea intake, COMT genotype, and breast cancer risk in 589 incident cases and 563 population-based controls from a population-based case-control study of breast cancer in Chinese-, Japanese-, and Filipino-American women in Los Angeles County. Risk of breast cancer was influenced significantly by intake of tea, particularly green tea intake. However, the inverse association between tea intake and breast cancer risk was observed only among individuals who possessed at least one low-activity COMT allele. Among women who carried at least one low activity COMT allele, tea drinkers showed a significantly reduced risk of breast cancer (adjusted odds ratio, 0.48; 95% confidence interval, 0.29-0.77) compared with nontea drinkers after adjustment for relevant demographic, menstrual, reproductive, and dietary factors. This risk reduction was observed in relation to both green tea and black tea intake. In contrast, risk of breast cancer did not differ between tea drinkers and nontea drinkers among those who were homozygous for the high activity COMT allele (adjusted odds ratio, 1.02; 95% confidence interval, 0.66-1.60). In conclusion, tea catechins appeared to reduce breast cancer risk in this study of Asian-American women. Reduction in risk was strongest among persons who had the low activity COMT alleles, suggesting

Black tea extract and dental caries formation in hamsters.

PubMed

Linke, Harald A B; LeGeros, Racquel Z

2003-01-01

Several studies have suggested that green tea and Oolong tea extracts have antibacterial and anticariogenic properties in vitro and in vivo. The aim of the present study was to determine the effect of a standardized black tea extract (BTE) on caries formation in inbred hamsters on a regular and a cariogenic diet. Eighty hamsters were divided into four groups of 20 animals each. Two groups received a pelleted regular diet (LabChow) with water or BTE ad libitum. The other two groups received a powdered cariogenic diet (Diet 2000, containing 56% sucrose) with water or BTE ad libitum. The animals were kept for 3 months on their respective diets and then were sacrificed. The heads were retained, the jaws were prepared and stained using alizarin mordant red II, and were then scored for dental caries according to the Keyes method. This is the first study indicating that BTE, as compared with water, significantly decreased caries formation by 56.6% in hamsters on a regular diet and by 63.7% in hamsters on a cariogenic diet (P < 0.05). In the cariogenic diet group BTE, reduced the mandibular caries score of the hamsters slightly more than the maxillary caries score. The fluoride content of the standardized BTE solution was frequently monitored during the experiment; the mean fluoride concentration was found to be 4.22 ppm. A frequent intake of black tea can significantly decrease caries formation, even in the presence of sugars in the diet.

Protective effects of tea polyphenols and β-carotene against γ-radiation induced mutation and oxidative stress in Drosophila melanogaster.

PubMed

Nagpal, Isha; Abraham, Suresh K

2017-01-01

The commonly consumed antioxidants β-carotene and tea polyphenols were used to assess their protective effects against γ-radiation induced sex-linked recessive lethal (SLRL) mutation and oxidative stress in Drosophila melanogaster . Third instar larvae and adult males of wild-type Oregon-K (ORK) were fed on test agents for 24 and 72 h respectively before exposure to 10Gy γ-irradiation. The treated/control flies were used to assess the induction of SLRLs. We also evaluated antioxidant properties of these phytochemicals in the third instar larvae. Different stages of spermatogenesis in adult males showed a decrease in γ-radiation induced SLRL frequencies upon co-treatment with test agents. A similar trend was observed in larvae. Furthermore, a significant increase in antioxidant enzymatic activities with a decrease in malondialdehyde content was observed. β-carotene and tea polyphenols have exerted antigenotoxic and antioxidant effects in Drosophila . This study demonstrated the suitability of Drosophila as an alternative to mammalian testing for evaluating the antigenotoxic and antioxidant activity of natural products.

The effect of black tea and caffeine on regional cerebral blood flow measured with arterial spin labeling

PubMed Central

Vidyasagar, Rishma; Greyling, Arno; Draijer, Richard; Corfield, Douglas R; Parkes, Laura M

2013-01-01

Black tea consumption has been shown to improve peripheral vascular function. Its effect on brain vasculature is unknown, though tea contains small amounts of caffeine, a psychoactive substance known to influence cerebral blood flow (CBF). We investigated the effects on CBF due to the intake of tea components in 20 healthy men in a double-blinded, randomized, placebo-controlled study. On separate days, subjects received a single dose of 184 mg caffeine (equivalent to one strong espresso coffee), 2,820 mg black tea solids containing 184 mg caffeine (equivalent to 6 cups of tea), 2,820 mg decaffeinated black tea solids, or placebo. The CBF and cerebrovascular reactivity (CVR) to hypercapnia were measured with arterial spin labeled magnetic resonance imaging (MRI) before and 2 hours after administration. We found a significant global reduction with caffeine (20%) and tea (21%) in gray matter CBF, with no effect of decaffeinated tea, suggesting that only caffeine influences CBF acutely. Voxelwise analysis revealed the effect of caffeine to be regionally specific. None of the interventions had an effect on CVR. Additional research is required to conclude on the physiologic relevance of these findings and the chronic effects of caffeine and tea intake on CBF. PMID:23486295

Antibacterial activity of polyphenolic fraction of Kombucha against Vibrio cholerae: targeting cell membrane.

PubMed

Bhattacharya, D; Ghosh, D; Bhattacharya, S; Sarkar, S; Karmakar, P; Koley, H; Gachhui, R

2018-02-01

The present study was undertaken to determine the mechanism of antibacterial activity of a polyphenolic fraction, composed of mainly catechin and isorhamnetin, previously isolated from Kombucha, a 14-day fermented beverage of sugared black tea, against the enteropathogen Vibrio cholerae N16961. Bacterial growth was found to be seriously impaired by the polyphenolic fraction in a dose-dependent manner. Scanning Electron Microscopy demonstrated morphological alterations in bacterial cells when exposed to the polyphenolic fraction in a concentration-dependent manner. Permeabilization assays confirmed that the fraction disrupted bacterial membrane integrity in both time- and dose-dependent manners, which were proportional to the production of intracellular reactive oxygen species (ROS). Furthermore, each of the polyphenols catechin and isorhamnetin showed the ability to permeate bacterial cell membranes by generating oxidative stress, thereby suggesting their role in the antibacterial potential of Kombucha. Thus, the basic mechanism of antibacterial activity of the Kombucha polyphenolic fraction against V. cholerae involved bacterial membrane permeabilization and morphological changes, which might be due to the generation of intracellular ROS. To the best of our knowledge, this is the first report on the investigation of antibacterial mechanism of Kombucha, which is mostly attributed to its polyphenolic content. The emergence of multidrug-resistant Vibrio cholerae strains has hindered an efficient anti-Vibrio therapy. This study has demonstrated the membrane damage-mediated antibacterial mechanism of Kombucha, a popular fermented beverage of sugared tea, which is mostly attributed to its polyphenolic content. This study also implies the exploitation of Kombucha as a potential new source of bioactive polyphenols against V. cholerae. © 2017 The Society for Applied Microbiology.

Joint effects of citrus peel use and black tea intake on the risk of squamous cell carcinoma of the skin

PubMed Central

Hakim, Iman A; Harris, Robin B

2001-01-01

Background Differences in tea drinking habits and/or citrus peel use are likely to vary by populations and could contribute to the inconsistencies found between studies comparing their consumption and cancer risk. Methods A population-based case-control study was used to evaluate the relationships between citrus peel use and black tea intake and squamous cell carcinoma (SCC) of the skin. Moreover, we assessed the independent and interactive effects of citrus peel and black tea in the development of SCC. Results Hot and iced teas were consumed by 30.7% and 51.8% of the subjects, respectively. Peel consumption was reported by 34.5% of subjects. Controls were more likely than were cases to report citrus peel use (odds ratio (OR) = 0.67) and hot tea intake (OR = 0.79). After adjustment for hot and iced tea intake, the ORs associated with citrus peel use were 0.55 and 0.69, respectively, whereas the corresponding adjusted ORs for hot and iced tea intake after adjustment for citrus peel use were 0.87 and 1.22 respectively. Compared with those who did not consume hot black tea or citrus peel, the adjusted ORs associated with sole consumption of hot black tea or citrus peel were 0.60 and 0.30, respectively. Subjects who reported consumption of both hot black tea and citrus peel had a significant marked decrease (OR= 0.22; 95% CI = 0.10 – 0.51) risk of skin SCC. Conclusion These results indicate that both citrus peel use and strong (hot) black tea have independent potential protective effects in relation to skin SCC. PMID:11527506

Black Tea Lowers Blood Pressure and Wave Reflections in Fasted and Postprandial Conditions in Hypertensive Patients: A Randomised Study

PubMed Central

Grassi, Davide; Draijer, Richard; Desideri, Giovambattista; Mulder, Theo; Ferri, Claudio

2015-01-01

Hypertension and arterial stiffening are independent predictors of cardiovascular mortality. Flavonoids may exert some vascular protection. We investigated the effects of black tea on blood pressure (BP) and wave reflections before and after fat load in hypertensives. According to a randomized, double-blind, controlled, cross-over design, 19 patients were assigned to consume black tea (129 mg flavonoids) or placebo twice a day for eight days (13 day wash-out period). Digital volume pulse and BP were measured before and 1, 2, 3 and 4 h after tea consumption. Measurements were performed in a fasted state and after a fat load. Compared to placebo, reflection index and stiffness index decreased after tea consumption (p < 0.0001). Fat challenge increased wave reflection, which was counteracted by tea consumption (p < 0.0001). Black tea decreased systolic and diastolic BP (−3.2 mmHg, p < 0.005 and −2.6 mmHg, p < 0.0001; respectively) and prevented BP increase after a fat load (p < 0.0001). Black tea consumption lowers wave reflections and BP in the fasting state, and during the challenging haemodynamic conditions after a fat load in hypertensives. Considering lipemia-induced impairment of arterial function may occur frequently during the day, our findings suggest regular consumption of black tea may be relevant for cardiovascular protection. PMID:25658240

Changes in chlorophyll and polyphenols content in Camellia sinensis var. sinensis at different stage of leaf maturity

NASA Astrophysics Data System (ADS)

Prawira-Atmaja, M. I.; Shabri; Khomaini, H. S.; Maulana, H.; Harianto, S.; Rohdiana, D.

2018-03-01

Chlorophyll and polyphenols are chemical compound related to parameter quality of green tea. We studied the variation of chlorophyll and polyphenol in the development stage of tea leaves (bud, 1st, 2nd, 3rd, and 4th). Five clones of tea (Camelia sinensis var. sinensis) from Indonesia and a clone from Japan were used in this study. The results showed that total chlorophyll and total polyphenol content in bud between 1.59-2.15 mg/g (db) and 12.24-14.59% respectively. The concentration of chlorophyll increased significantly with developments stage of leaf while total polyphenol tended to decrease with leaf maturity. Pearson Correlation analysis showed that chlorophyll content was negatively correlated (r = -0.83; p = 0.05) with total polyphenol during developmental stage of tea leaves. Results suggests that five clones of tea from Indonesia have similar quality with tea clone from Japan in chlorophyll and polyphenol content. The present study also provides guidelines on application plucking standard to produce high quality of green tea.

Green Tea Polyphenols Decrease Strecker Aldehydes and Bind to Proteins in Lactose-Hydrolyzed UHT Milk.

PubMed

Jansson, Therese; Rauh, Valentin; Danielsen, Bente P; Poojary, Mahesha M; Waehrens, Sandra S; Bredie, Wender L P; Sørensen, John; Petersen, Mikael A; Ray, Colin A; Lund, Marianne N

2017-12-06

The effect of epigallocatechin gallate enriched green tea extract (GTE) on flavor, Maillard reactions and protein modifications in lactose-hydrolyzed (LH) ultrahigh temperature (UHT) processed milk was examined during storage at 40 °C for up to 42 days. Addition of GTE inhibited the formation of Strecker aldehydes by up to 95% compared to control milk, and the effect was similar when GTE was added either before or after UHT treatment. Release of free amino acids, caused by proteolysis, during storage was also decreased in GTE-added milk either before or after UHT treatment compared to control milk. Binding of polyphenols to milk proteins was observed in both fresh and stored milk samples. The inhibition of Strecker aldehyde formation by GTE may be explained by two different mechanisms; inhibition of proteolysis during storage by GTE or binding of amino acids and proteins to the GTE polyphenols.

Chemical composition, plant secondary metabolites, and minerals of green and black teas and the effect of different tea-to-water ratios during their extraction on the composition of their spent leaves as potential additives for ruminants.

PubMed

Ramdani, Diky; Chaudhry, Abdul Shakoor; Seal, Chris J

2013-05-22

This study characterized the chemical composition of green and black teas as well as their spent tea leaves (STL) following boiling in water with different tea-to-water ratios. The green and black tea leaves had statistically similar (g/kg dry matter (DM), unless stated otherwise) DM (937 vs 942 g/kg sample), crude protein (240 vs 242), and ash (61.8 vs 61.4), but green tea had significantly higher (g/kg DM) total phenols (231 vs 151), total tannins (204 vs 133), condensed tannins (176 vs 101), and total saponins (276 vs 86.1) and lower neutral detergent fiber (254 vs 323) and acid detergent fiber (211 vs 309) than the black tea leaves. There was no significant difference between the green and black tea leaves for most mineral components except Mn, which was significantly higher in green tea leaves, and Na and Cu, which were significantly higher in black tea leaves. A higher tea-to-water ratio during extraction significantly reduced the loss of soluble compounds into water and hence yielded more nutrient-rich STL. On the basis of these analyses it appears that the green and black tea leaves alongside their STL have the potential for use as sources of protein, fiber, secondary metabolites, and minerals in ruminant diets. The presence of high levels of plant secondary metabolites in either tea leaves or their STL suggests that they may have potential for use as natural additives in ruminant diets.

Honey and green/black tea consumption may reduce the risk of Helicobacter pylori infection.

PubMed

Boyanova, Lyudmila; Ilieva, Juliana; Gergova, Galina; Vladimirov, Borislav; Nikolov, Rossen; Mitov, Ivan

2015-05-01

The aim of the study was to evaluate the influence of dietary and demographic factors and some habits on the prevalence of Helicobacter pylori infection in 150 dyspeptic patients examined endoscopically and by the urea breath test. Positivity rate was lower (50.6%) in patients consuming honey ≥1 day weekly compared with the remainder (70.8%) and in those consuming green/black tea ≥1 day weekly (45.2%) compared with the other patients (64.8%). Logistic regression confirmed that the factors associated with significantly lower H. pylori positivity rate were the consumption of honey (odds ratio [OR], 0.38; 95% confidence interval [CI], 0.19-0.78) and green/black tea (OR, 0.45; 95% CI, 0.21-0.95). In conclusion, honey and green/black tea intake is associated with reduced prevalence of H. pylori infection. Copyright © 2015 Elsevier Inc. All rights reserved.

Aflatoxin-induced biochemical changes in liver of mice and its mitigation by black tea extract.

PubMed

Jha, Anamika; Shah, Komal; Verma, Ramtej J

2012-01-01

Aflatoxin belongs to the class of naturally occurring mycotoxins, food contaminants having potent carcinogenicity. We have evaluated the ameliorative role of black tea extract on aflatoxin-induced biochemical changes in the liver of albino male mice. Adult male mice were orally administered with 750 and 1500 pg of aflatoxin in 0.2 mL olive oil/kg b.w./day for 30 days. Oral administration of aflatoxin caused, as compared with controls, significant, dose-dependent reduction in DNA, RNA, protein and glycogen contents; however, cholesterol content and phsphorylase activity were significantly increased. Black tea is one of the most potent antioxidants containing numerous bioactive phytonurtients having therapeutic applications. Aflatoxin-induced changes in the liver of mice were significantly ameliorated on co-treatment of black tea extract (2% infusion in water).

Antioxidant potential of tea reduces arsenite induced oxidative stress in Swiss albino mice.

PubMed

Sinha, D; Roy, S; Roy, M

2010-04-01

Environmental arsenic (As) is a potent human carcinogen and groundwater As contamination is a major health concern in West Bengal, India. Oxidative stress has been one of the prime factors in As-induced carcinogenicity. Generation of reactive oxygen species (ROS), beyond the body's endogenous antioxidant balance cause a severe imbalance of the cellular antioxidant defence mechanism. Tea, a popular beverage has excellent chemopreventive and antioxidant properties. In this study it was investigated whether these flavonoids could ameliorate the arsenite (As III) induced oxidative stress in Swiss albino mice. Bio-monitoring with comet assay elicited that the increase in genotoxicity caused by As III was counteracted by both black tea and green tea. Elevated levels of lipid peroxides and protein carbonyl by As III were effectively reduced with green as well as black tea. They also exhibited protective action against the As III induced depletion of antioxidants like catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST) and glutathione (GSH) in mice liver tissue. Thus the tea polyphenols by virtue of their antioxidant potential may be used as an effective agent to reduce the As III induced oxidative stress in Swiss albino mice. 2010 Elsevier Ltd. All rights reserved.

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

PubMed

Itoh, Nobuya; Kurokawa, Junji; Isogai, Yasuhiro; Ogasawara, Masaru; Matsunaga, Takayuki; Okubo, Tsutomu; Katsube, Yuji

2017-12-06

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.

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

PubMed

Tewari, Shweta; Dubey, Kriti Kumari; Singhal, Rekha S

2018-04-01

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 28 days 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.

Brassinosteroids Improve Quality of Summer Tea (Camellia sinensis L.) by Balancing Biosynthesis of Polyphenols and Amino Acids.

PubMed

Li, Xin; Ahammed, Golam J; Li, Zhi-Xin; Zhang, Lan; Wei, Ji-Peng; Shen, Chen; Yan, Peng; Zhang, Li-Ping; Han, Wen-Yan

2016-01-01

Summer grown green tea is less popular due to bitterness and high astringency, which are attributed to high levels of tea polyphenols (TP) and low levels of amino acids (AA) in tea leaves (Camellia sinensis L.). Brassinosteroids (BRs), a group of steroidal plant hormones can regulate primary and secondary metabolism in a range of plant species under both normal and stress conditions. However, specific effects of BRs on the photosynthesis of tea plants and the quality of summer green tea are largely unknown. Here we show that 24-epibrassinolide (EBR), a bioactive BR, promoted photosynthesis in tea plants in a concentration-dependent manner. Stimulation in photosynthesis by EBR resulted in an increased summer tea yield. Although all tested concentrations (0.01, 0.05, 0.1, 0.5, and 1.0 ppm) of EBR increased concentrations of TP and AA, a moderate concentration (0.5 ppm) caused the highest decrease in TP to AA ratio, an important feature of quality tea. Time-course analysis using 0.5 ppm EBR as foliar spray revealed that TP or AA concentration increased as early as 3 h after EBR application, reaching the highest peak at 24 h and that remained more or less stable. Importantly, such changes in TP and AA concentration by EBR resulted in a remarkably decreased but stable TP to AA ratio at 24 h and onward. Furthermore, concentrations of catechins and theanine increased, while that of caffeine remained unaltered following treatment with EBR. EBR improved activity of phenylalanine ammonia-lyase (PAL) and glutamine: 2-oxoglutarate aminotransferase (GOGAT) enzymes involved in catechins and theanine biosynthesis, respectively. Transcript analysis revealed that transcript levels of CsPAL and CsGS peaked as early as 6 h, while that of CsGOGAT peaked at 12 h following application of EBR, implying that EBR increased the concentration of TP and AA by inducing their biosynthesis. These results suggest a positive role of BR in enhancing green tea quality, which might have potential

Brassinosteroids Improve Quality of Summer Tea (Camellia sinensis L.) by Balancing Biosynthesis of Polyphenols and Amino Acids

PubMed Central

Li, Xin; Ahammed, Golam J.; Li, Zhi-Xin; Zhang, Lan; Wei, Ji-Peng; Shen, Chen; Yan, Peng; Zhang, Li-Ping; Han, Wen-Yan

2016-01-01

Summer grown green tea is less popular due to bitterness and high astringency, which are attributed to high levels of tea polyphenols (TP) and low levels of amino acids (AA) in tea leaves (Camellia sinensis L.). Brassinosteroids (BRs), a group of steroidal plant hormones can regulate primary and secondary metabolism in a range of plant species under both normal and stress conditions. However, specific effects of BRs on the photosynthesis of tea plants and the quality of summer green tea are largely unknown. Here we show that 24-epibrassinolide (EBR), a bioactive BR, promoted photosynthesis in tea plants in a concentration-dependent manner. Stimulation in photosynthesis by EBR resulted in an increased summer tea yield. Although all tested concentrations (0.01, 0.05, 0.1, 0.5, and 1.0 ppm) of EBR increased concentrations of TP and AA, a moderate concentration (0.5 ppm) caused the highest decrease in TP to AA ratio, an important feature of quality tea. Time-course analysis using 0.5 ppm EBR as foliar spray revealed that TP or AA concentration increased as early as 3 h after EBR application, reaching the highest peak at 24 h and that remained more or less stable. Importantly, such changes in TP and AA concentration by EBR resulted in a remarkably decreased but stable TP to AA ratio at 24 h and onward. Furthermore, concentrations of catechins and theanine increased, while that of caffeine remained unaltered following treatment with EBR. EBR improved activity of phenylalanine ammonia-lyase (PAL) and glutamine: 2-oxoglutarate aminotransferase (GOGAT) enzymes involved in catechins and theanine biosynthesis, respectively. Transcript analysis revealed that transcript levels of CsPAL and CsGS peaked as early as 6 h, while that of CsGOGAT peaked at 12 h following application of EBR, implying that EBR increased the concentration of TP and AA by inducing their biosynthesis. These results suggest a positive role of BR in enhancing green tea quality, which might have potential

Perspectives on the recent developments with green tea polyphenols in drug discovery.

PubMed

Li, Feng; Wang, Yongli; Li, Dapeng; Chen, Yilun; Qiao, Xuguang; Fardous, Rania; Lewandowski, Ashton; Liu, Jinbao; Chan, Tak-Hang; Dou, Q Ping

2018-04-24

Increasing evidence has expanded the role of green tea from a traditional beverage to a source of pharmacologically active molecules with diverse health benefits. However, conclusive clinical results are needed to better elucidate the cancer-preventive and therapeutic effects of green tea polyphenols (GTPs). Areas covered: The authors describe GTPs' chemical compositions and metabolic biotransformations, and their recent developments in drug discovery, focusing on their cancer chemopreventive and therapeutic effects. They then review the recent development of GTP-loaded nanoparticles and GTP prodrugs. Expert opinion: GTPs possess potent anticarcinogenic activities through interfering with the initiation, development and progression phases of cancer. There are several challenges (e.g. poor bioavailability) in developing GTPs as therapeutic agents. Use of nanoparticle-based delivery systems has provided unique advantages over purified GTPs. However, there is still a need to determine the actual magnitude and pharmacological mechanisms of GTPs encapsulated in nanoparticles, in order to address newly emerging safety issues associated with the potential 'local overdose' effect. The use of Pro- epigallocatechin gallate (Pro-EGCG) as a prodrug appears to offer improved in vitro stability as well as better in vivo bioavailability and efficacies in a number of animal studies, suggesting its potential as a therapeutic agent for further study and development.

Green tea extract for periodontal health

PubMed Central

Venkateswara, Babu; Sirisha, K.; Chava, Vijay K.

2011-01-01

Tea, the commonly consumed beverage, is gaining increased attention in promoting overall health. In specific, green tea is considered a healthful beverage due to the biological activity of its polyphenols namely catechins. Among the polyphenols Epigallo catechin 3 gallate and Epicatechin 3 Gallate are the most predominant catechins. The antioxidant, antimicrobial, anticollagenase, antimutagenic, and c hemopreventive properties of these catechins proved to be helpful in the treatment of chronic diseases like periodontal disease. Studies have demonstrated that the type of processing mainly effects the concentration of catechins. Several epidemiological studies have proved that green tea also has some general health benefitting properties like antihypertensive, reduction of cardiovascular risk, antibacterial, antiviral, and antifungal activity. The present review concentrates on the effects of green tea in periodontal and general health. PMID:21772716

Bioavailability and activity of phytosome complexes from botanical polyphenols: the silymarin, curcumin, green tea, and grape seed extracts.

PubMed

Kidd, Parris M

2009-09-01

Plant-derived polyphenols are increasingly receiving attention as dietary supplements for the homeostatic management of inflammation, to support detoxication, and for anticancer, weight loss, and other benefits. Their pro-homeostatic effects on genes, transcription factors, enzymes, and cell signaling pathways are being intensively explored, but the poor bioavailability of some polyphenols likely contributes to poor clinical trial outcomes. This review covers four polyphenol preparations with poor bioavailability and their complexation into phytosomes to bypass this problem. Silybin and the other silymarin flavonolignans from milk thistle conserve tissue glutathione, are liver-protective, and have anticancer potential. Curcumin and its related diphenolic curcuminoids have potent antioxidant, anti-inflammatory, and anti-carcinogenic properties. The green tea flavan-3-ol catechins have antioxidant, anti-inflammatory, cardio- and neuro-protective effects, and anti-carcinogenic benefits, with fat oxidation effects coupled to weight loss. The complex grape seed proanthocyanidin mix (including catechin and epicatechin monomers and oligomers) counters oxidative stress and protects the circulatory system. For each of these preparations, conversion into phytosomes has improved efficacy without compromising safety. The phytosome technology creates intermolecular bonding between individual polyphenol molecules and one or more molecules of the phospholipid, phosphatidylcholine (PC). Molecular imaging suggests that PC molecule(s) enwrap each polyphenol; upon oral intake the amphipathic PC molecules likely usher the polyphenol through the intestinal epithelial cell outer membrane, subsequently accessing the bloodstream. PC itself has proven clinical efficacy that contributes to phytosome in vivo actions. As a molecular delivery vehicle, phytosome technology substantially improves the clinical applicabilities of polyphenols and other poorly absorbed plant medicinals.

Both phenolic and non-phenolic green tea fractions inhibit migration of cancer cells

USDA-ARS?s Scientific Manuscript database

Green tea consumption is associated with chemoprevention of many cancer types. Fresh tea leaves are rich in polyphenolic catechins, which can constitute up to 30% of the dry leaf weight. While the polyphenols of green tea have been well investigated, it is still largely unknown, whether or not non-p...

Combinatorial effect of nicotine and black tea on heart rate variability: Useful or harmful?

PubMed

Joukar, S; Sheibani, M

2017-06-01

The effect of nicotine on heart rate variability (HRV) is controversial. Autonomic nervous system is the main regulator of heart rhythm, and heart rate variability is an appropriate index to assessment of the effects of the autonomic system on heart. In this study, the combination effect of nicotine and black tea consumption on sympatho-vagal balance and heart rate variability was investigated in rats. Male Wistar rats were randomized into four groups as control, tea (2.5 g/100 cc, daily), nicotine (2 mg/kg/d) and tea plus nicotine groups which treated for 28 days, and in the 29th day, their electrocardiograms (lead II) were recorded. The mean of high-frequency power (HF) in tea, nicotine and tea plus nicotine groups was significantly more than control group (P < .05), and low-frequency power/high-frequency power (LF/HF) ratio in the nicotine and tea + nicotine groups was significantly less than control group (P < .05). LF values did not differ significantly among groups. Mean of standard deviation of normal RR intervals (SDNN) and square root of the mean squared differences of successive RR intervals (RMSSD) increased significantly in tea, nicotine and tea + nicotine groups in comparison with control group (P < .05) Overall, 4-week administration of black tea, nicotine or their combination with dosages used in this study can increase the heart rate variability and improve the sympatho-vagal balance in rat. © 2017 John Wiley & Sons Ltd.

Tracking residual organochlorine pesticides (OCPs) in green, herbal, and black tea leaves and infusions of commercially available tea products marketed in Poland.

PubMed

Witczak, Agata; Abdel-Gawad, Hassan; Zalesak, Michal; Pohoryło, Anna

2018-03-01

The content of residual organochlorine pesticides (OCPs) was examined in green, herbal, and black tea leaves as well as in their infusions prepared from tea products marketed in the main supermarkets in Poland. It was found that the detected mean levels of organochlorine residues in tea leaves ranged from tea occurred in the highest concentrations. Among dichlorodiphenyltrichloroethane (DDT) metabolites the highest level of p,p'DDT (1.96 ng g -1 dw) was in green tea samples. The transfer of OCPs from tea leaves to brew was investigated. The present study revealed that during the infusion process, a significant percentage of the residues, particularly pesticides with high water solubility, were transferred to the infusions. The obtained results show that the percentage transfer of each pesticides from tea to the tea infusions ranged from 6.74% (heptachlor) to 86.6% (endrin). The detected residues were below current MRLs for these pesticides.

Oolong tea increases energy metabolism in Japanese females.

PubMed

Komatsu, Tatsushi; Nakamori, Masayo; Komatsu, Keiko; Hosoda, Kazuaki; Okamura, Mariko; Toyama, Kenji; Ishikura, Yoshiyuki; Sakai, Tohru; Kunii, Daisuke; Yamamoto, Shigeru

2003-08-01

Oolong tea is a traditional Chinese tea that has long been believed to be beneficial to health such as decreasing body fat. We were interested in this assertion and tried to evaluate the effect of oolong tea on energy expenditure (EE) in comparison with green tea. The subjects were eleven healthy Japanese females (age 20+/-1 y; body mass index (BMI) 21.2+/-2.5 kg/m2) who each consumed of three treatments in a crossover design: 1) water, 2) oolong tea, 3) green tea. Resting energy expenditure (REE) and EE after the consumption of the test beverage for 120 min were measured using an indirect calorimeter. The cumulative increases of EE for 120 min were significantly increased 10% and 4% after the consumption of oolong tea and green tea, respectively. EE at 60 and 90 min were significantly higher after the consumption of oolong tea than that of water (P<0.05). In comparison with green tea, oolong tea contained approximately half the caffeine and epigallocatechin galate, while polymerized polyphenols were double. These results suggest that oolong tea increases EE by its polymerized polyphenols.

Polyphenol levels in human urine after intake of six different polyphenol-rich beverages.

PubMed

Ito, Hideyuki; Gonthier, Marie-Paule; Manach, Claudine; Morand, Christine; Mennen, Louise; Rémésy, Christian; Scalbert, Augustin

2005-10-01

Dietary polyphenols are suggested to participate in the prevention of CVD and cancer. It is essential for epidemiological studies to be able to compare intake of the main dietary polyphenols in populations. The present paper describes a fast method suitable for the analysis of polyphenols in urine, selected as potential biomarkers of intake. This method is applied to the estimation of polyphenol recovery after ingestion of six different polyphenol-rich beverages. Fifteen polyphenols including mammalian lignans (enterodiol and enterolactone), several phenolic acids (chlorogenic, caffeic, m-coumaric, gallic, and 4-O-methylgallic acids), phloretin and various flavonoids (catechin, epicatechin, quercetin, isorhamnetin, kaempferol, hesperetin, and naringenin) were simultaneously quantified in human urine by HPLC coupled with electrospray ionisation mass-MS (HPLC-electrospray-tandem mass spectrometry) with a run time of 6 min per sample. The method has been validated with regard to linearity, precision, and accuracy in intra- and inter-day assays. It was applied to urine samples collected from nine volunteers in the 24 h following consumption of either green tea, a grape-skin extract, cocoa beverage, coffee, grapefruit juice or orange juice. Levels of urinary excretion suggest that chlorogenic acid, gallic acid, epicatechin, naringenin or hesperetin could be used as specific biomarkers to evaluate the consumption of coffee, wine, tea or cocoa, and citrus juices respectively.

Bioavailability of catechins from tea: the effect of milk.

PubMed

van het Hof, K H; Kivits, G A; Weststrate, J A; Tijburg, L B

1998-05-01

To assess the blood concentration of catechins following green or black tea ingestion and the effect of addition of milk to black tea. Twelve volunteers received a single dose of green tea, black tea and black tea with milk in a randomized cross-over design with one-week intervals. Blood samples were drawn before and up to eight hours after tea consumption. The study was performed at the Unilever Research Vlaardingen in The Netherlands. Twelve healthy adult volunteers (7 females, 5 males) participated in the study. They were recruited among employees of Unilever Research Vlaardingen. Green tea, black tea and black tea with semi-skimmed milk (3 g tea solids each). Consumption of green tea (0.9 g total catechins) or black tea (0.3 g total catechins) resulted in a rapid increase of catechin levels in blood with an average maximum change from baseline (CVM) of 0.46 micromol/l (13%) after ingestion of green tea and 0.10 micromol/l (13%) in case of black tea. These maximum changes were reached after (mean (s.e.m.)) t=2.3 h (0.2) and t=2.2 h (0.2) for green and black tea respectively. Blood levels rapidly declined with an elimination rate (mean (CVM)) of t1/2=4.8 h (5%) for green tea and t1/2=6.9 h (8%) for black tea. Addition of milk to black tea (100 ml in 600 ml) did not significantly affect the blood catechin levels (areas under the curves (mean (CVM) of 0.53 h. micromol/l (11%) vs 0.60 h. micromol/l (9%) for black tea and black tea with milk respectively. Catechins from green tea and black tea are rapidly absorbed and milk does not impair the bioavailability of tea catechins.

Berry components inhibit α-glucosidase in vitro: synergies between acarbose and polyphenols from black currant and rowanberry.

PubMed

Boath, Ashley S; Stewart, Derek; McDougall, Gordon J

2012-12-01

Polyphenol-rich extracts from certain berries inhibited α-glucosidase activity in vitro. The two most effective berry extracts, from black currant and rowanberry, inhibited α-glucosidase with IC(50) values respectively of 20 and 30μg GAE/ml and were as effective as the pharmaceutical inhibitor, acarbose. These berry extracts differed greatly in their polyphenol composition: black currant was dominated by anthocyanins (∼70% of total) whereas rowanberry was enriched in chlorogenic acids (65% total) and had low levels of anthocyanins. Both black currant and rowanberry extracts potentiated the inhibition caused by acarbose and could replace the inhibition lost by reducing the acarbose dose. However, no additive effects were noted when black currant and rowanberry extracts were added in combination. The mechanisms underlying the synergy between acarbose and the berry polyphenols and the lack of synergy between the berry components are discussed. These extracts exhibited the potential to replace acarbose (or reduce the dose required) in its current clinical use in improving post-prandial glycaemic control in type 2 diabetics. As a result, these polyphenols may offer a dietary means for type 2 diabetics to exercise glycaemic control. Copyright © 2012 Elsevier Ltd. All rights reserved.

Reorganisation of the Salivary Mucin Network by Dietary Components: Insights from Green Tea Polyphenols

PubMed Central

Davies, Heather S.; Pudney, Paul D. A.; Georgiades, Pantelis; Waigh, Thomas A.; Hodson, Nigel W.; Ridley, Caroline E.; Blanch, Ewan W.; Thornton, David J.

2014-01-01

The salivary mucins that include MUC5B (gel-forming) and MUC7 (non-gel-forming) are major contributors to the protective mucus barrier in the oral cavity, and it is possible that dietary components may influence barrier properties. We show how one dietary compound, the green tea polyphenol epigallocatechin gallate (EGCG), can substantially alter the properties of both the polymeric MUC5B network and monomeric MUC7. Using rate-zonal centrifugation, MUC5B in human whole saliva and MUC5B purified from saliva sedimented faster in the presence of EGCG. The faster sedimentation by EGCG was shown to be greater with increasing MUC5B concentration. Particle tracking microrheology was employed to determine the viscosity of purified MUC5B solutions and showed that for MUC5B solutions of 200–1600 µg/mL, EGCG caused a significant increase in mucin viscosity, which was greater at higher MUC5B concentrations. Visualisation of the changes to the MUC5B network by EGCG was performed using atomic force microscopy, which demonstrated increased aggregation of MUC5B in a heterogeneous manner by EGCG. Using trypsin-resistant, high-molecular weight oligosaccharide-rich regions of MUC5B and recombinant N-terminal and C-terminal MUC5B proteins, we showed that EGCG causes aggregation at the protein domains of MUC5B, but not at the oligosaccharide-rich regions of the mucin. We also demonstrated that EGCG caused the majority of MUC7 in human whole saliva to aggregate. Furthermore, purified MUC7 also underwent a large increase in sedimentation rate in the presence of EGCG. In contrast, the green tea polyphenol epicatechin caused no change in the sedimentation rate of either MUC5B or MUC7 in human whole saliva. These findings have demonstrated how the properties of the mucin barrier can be influenced by dietary components. In the case of EGCG, these interactions may alter the function of MUC5B as a lubricant, contributing to the astringency (dry puckering sensation) of green tea. PMID

Polyphenols in foods are more complex than often thought.

PubMed

Cheynier, Véronique

2005-01-01

Dietary polyphenols show a great diversity of structures, ranging from rather simple molecules (monomers and oligomers) to polymers. Higher-molecular-weight structures (with molecular weights of > 500) are usually designated as tannins, which refers to their ability to interact with proteins. Among them, condensed tannins (proanthocyanidins) are particularly important because of their wide distribution in plants and their contributions to major food qualities. All phenolic compounds are highly unstable and rapidly transformed into various reaction products when the plant cells are damaged (for instance, during food processing), thus adding to the complexity of dietary polyphenol composition. The polyphenol composition of plant-derived foods and beverages depends on that of the raw material used but also on the extraction process and subsequent biochemical and chemical reactions of plant polyphenols. The occurrence of specific tannin-like compounds (ie, thearubigins and theaflavins) arising from enzymatic oxidation is well documented in black tea. Various chemical reactions involving anthocyanins and/or flavanols have been demonstrated to occur during red wine aging. Current knowledge regarding the reaction mechanisms involved in some of these processes and the structures of the resulting products is reviewed. Their effects on organoleptic and nutritional quality are also discussed.

The synergistic potential of various teas, herbs and therapeutic drugs in health improvement: a review.

PubMed

Malongane, Florence; McGaw, Lyndy J; Mudau, Fhatuwani N

2017-11-01

Tea is one of the most widely consumed non-alcoholic beverages in the world next to water. It is classified as Camellia sinensis and non-Camellia sinensis (herbal teas). The common bioactive compounds found mainly in green teas are flavan-3-ols (catechins) (also called flavanols), proanthocyanidins (tannins) and flavonols. Black tea contains theaflavins and thearubigins and white tea contains l-theanine and gamma-aminobutyric acid (GABA), while herbal teas contain diverse polyphenols. Phytochemicals in tea exhibit antimicrobial, anti-diabetic and anti-cancer activities that are perceived to be helpful in managing chronic diseases linked to lifestyle. Many of these phytochemicals are reported to be biologically active when combined. Knowledge of the synergistic interactions of tea with other teas or herbs in terms of biological activities will be of benefit for therapeutic enhancement. There is evidence that various types of teas act synergistically in exhibiting health benefits to humans, improving consumer acceptance and economic value. Similar observations have been made when teas and herbs or medicinal drugs were combined. The aim of this review is to highlight potential beneficial synergies between combinations of different types of teas, tea and herbs, and tea and medicinal drugs. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Short- and long-term black tea consumption reverses endothelial dysfunction in patients with coronary artery disease.

PubMed

Duffy, S J; Keaney , J F; Holbrook, M; Gokce, N; Swerdloff, P L; Frei, B; Vita, J A

2001-07-10

Epidemiological studies suggest that tea consumption decreases cardiovascular risk, but the mechanisms of benefit remain undefined. Endothelial dysfunction has been associated with coronary artery disease and increased oxidative stress. Some antioxidants have been shown to reverse endothelial dysfunction, and tea contains antioxidant flavonoids. Methods and Results-- To test the hypothesis that tea consumption will reverse endothelial dysfunction, we randomized 66 patients with proven coronary artery disease to consume black tea and water in a crossover design. Short-term effects were examined 2 hours after consumption of 450 mL tea or water. Long-term effects were examined after consumption of 900 mL tea or water daily for 4 weeks. Vasomotor function of the brachial artery was examined at baseline and after each intervention with vascular ultrasound. Fifty patients completed the protocol and had technically suitable ultrasound measurements. Both short- and long-term tea consumption improved endothelium- dependent flow-mediated dilation of the brachial artery, whereas consumption of water had no effect (P<0.001 by repeated-measures ANOVA). Tea consumption had no effect on endothelium-independent nitroglycerin-induced dilation. An equivalent oral dose of caffeine (200 mg) had no short-term effect on flow-mediated dilation. Plasma flavonoids increased after short- and long-term tea consumption. Short- and long-term black tea consumption reverses endothelial vasomotor dysfunction in patients with coronary artery disease. This finding may partly explain the association between tea intake and decreased cardiovascular disease events.

Effect of black tea on enteral feeding tolerance in ICU patients

PubMed Central

Mojdeh, Soheila; Shahin, Samire; Khalili, Gholamreza

2010-01-01

BACKGROUND: Tea consumption has been known mostly as a well-drink after water in the world. Tea drink can affect balance of fluids and renal function. In addition, it can cause loss of many viruses in the stomach and can increase or decrease gastrointestinal movements. This research was done to determine the effect of tea on increasing enteral feeding tolerance in ICU patients in Alzahra Hospital. METHODS: In this clinical trial study, 45 patients were enrolled in two groups, tea consumption group and the standard method of nutrition as control group. Tea gavage was performed two times in the morning; 100 cc tea used for the study group and the same volume of water was used for the control group. Residual volume was measured before gavage. Data collected for one week. Information sheet had two pages; the first page described how to complete the form and the method of tea gavage and the second page was for data collection. Data were analyzed by t-student test, chi-square, and analysis of variance. RESULTS: In two groups, 92% of patients tolerated liquid gavage. Their difference by chi-square test was not significant. Average urine volume after black tea gavage was 783.3 L in the study group and 802.2 L in the control group. ANOVA test showed no significant difference. CONCLUSIONS: Although the difference was not statistically significant between the two groups, but in study group consumption of tea was acceptable by patients. PMID:21589775

Black and white teas as potential agents to combine with amphotericin B and protect red blood cells from amphotericin B-mediated toxicity.

PubMed

Oliveira, V M; Khalil, N M; Carraro, E

2018-02-01

Amphotericin B is a fungicidal substance that is treatment of choice for most systemic fungal infections affecting immunocompromised patients. However, severe side effects have limited the utility of this drug. The aim of this study was to evaluate the antifungal effect of the combination of amphotericin B with black tea or white tea and protective of citotoxic effect. The present study shows that white and black teas have additive effects with amphotericin B against some species Candida. In addition, the combination of white and black tea with amphotericin B may reduce the toxicity of amphotericin B to red blood cells. Our results suggest that white and black tea is a potential agent to combine with amphotericin for antifungal efficacy and to reduce the amphotericin dose to lessen side effects.

Potential anthelmintics: polyphenols from the tea plant Camellia sinensis L. are lethally toxic to Caenorhabditis elegans.

PubMed

Mukai, Daisuke; Matsuda, Noriko; Yoshioka, Yu; Sato, Masashi; Yamasaki, Toru

2008-04-01

A novel gallate of tannin, (-)-epigallocatechin-(2 beta-->O-->7',4 beta-->8')-epicatechin-3'-O-gallate (8), together with (-)-epicatechin-3-O-gallate (4), (-)-epigallocatechin (5), (-)-epigallocatechin-3-O-gallate (6), and (+)-gallocatechin-(4 alpha-->8')-epigallocatechin (7), were isolated from the tea plant Camellia sinensis (L.) O. Kuntze var. sinensis (cv., Yabukita). The structure of 8, including stereochemistry, was elucidated by spectroscopic methods and hydrolysis. The compounds, along with commercially available pyrogallol (1), (+)-catechin (2), and (-)-epicatechin (3), were examined for toxicity towards egg-bearing adults of Caenorhabditis elegans. The anthelmintic mebendazole (9) was used as a positive control. Neither 2 nor 3 were toxic but the other compounds were toxic in the descending order 8, 7 approximately 6, 9, 4, 5, 1. The LC(50) (96 h) values of 8 and 9 were evaluated as 49 and 334 micromol L(-1), respectively. These data show that many green tea polyphenols may be potential anthelmintics.

Effect of Black Tea Intake on Blood Cholesterol Concentrations in Individuals with Mild Hypercholesterolemia: A Diet-Controlled Randomized Trial

PubMed Central

Troup, Rasa; Hayes, Jennifer H.; Raatz, Susan K.; Thyagarajan, Bharat; Khaliq, Waseem; Jacobs, David R.; Key, Nigel S.; Morawski, Bozena M.; Kaiser, Daniel; Bank, Alan J.; Gross, Myron

2014-01-01

Habitual intake of black tea has been associated with relatively lower serum cholesterol concentrations in observational studies. However, clinical trial results evaluating the effects of black tea on serum cholesterol have been inconsistent. Several factors could explain these mixed results, in particular, uncontrolled confounding caused by lifestyle factors, e.g. diet. This diet-controlled clinical trial estimates the effect of black tea flavonoid consumption on cholesterol concentrations in 57 borderline hypercholesterolemic individuals (total cholesterol concentrations between 190 and 260 mg/dl (4.9 and 6.7 mmol/L)). A double blind, randomized crossover trial was conducted in Minneapolis, MN from April 2002 through April 2004, wherein key conditions were tightly controlled to minimize possible confounding. Participants consumed a controlled low-flavonoid diet plus 5 cups per day of black tea or tea-like placebo over two 4-week treatment periods. The flavonoid-free caffeinated placebo matched the tea in color and taste. Differences in cholesterol concentrations at the end of each treatment period were evaluated via linear mixed models. Differences (95% CI) in mg/dl among those treated with tea versus placebo were 3.43 (−7.08, 13.94) for total cholesterol, −1.02 (−11.34, 9.30) for low-density lipoprotein cholesterol (LDL-C), 0.58 (−2.98, 4.14) for high-density lipoprotein cholesterol (HDL-C), 15.22 (−40.91, 71.35) for triglycerides, and −0.39 (−11.16, 10.38) for LDL plus HDL cholesterol fraction. The LCL-C/HDL-C ratio decreased by −0.1 units (95% CI −0.41, 0.21). No results were statistically or clinically significant. Thus, the intake of 5 cups of black tea per day did not significantly alter the lipid profile of borderline hypercholesterolemic subjects. PMID:25266246

The green tea polyphenol (-)-epigallocatechin gallate precipitates salivary proteins including alpha-amylase: biochemical implications for oral health.

PubMed

Hara, Kumiko; Ohara, Masaru; Hayashi, Ikue; Hino, Takamune; Nishimura, Rumi; Iwasaki, Yoriko; Ogawa, Tetsuji; Ohyama, Yoshihiko; Sugiyama, Masaru; Amano, Hideaki

2012-04-01

Green tea is a popular drink throughout the world, and it contains various components, including the green tea polyphenol (-)-epigallocatechin gallate (EGCG). Tea interacts with saliva upon entering the mouth, so the interaction between saliva and EGCG interested us, especially with respect to EGCG-protein binding. SDS-PAGE revealed that several salivary proteins were precipitated after adding EGCG to saliva. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) peptide mass fingerprinting indicated that the major proteins precipitated by EGCG were alpha-amylase, S100, and cystatins. Surface plasmon resonance revealed that EGCG bound to alpha-amylase at dissociation constant (K(d)) = 2.74 × 10(-6) M, suggesting that EGCG interacts with salivary proteins with a relatively strong affinity. In addition, EGCG inhibited the activity of alpha-amylase by non-competitive inhibition, indicating that EGCG is effective at inhibiting the formation of fermentable carbohydrates involved in caries formation. Interestingly, alpha-amylase reduced the antimicrobial activity of EGCG against the periodontal bacterium Aggregatibacter actinomycetemcomitans. Therefore, we considered that EGCG-salivary protein interactions might have both protective and detrimental effects with respect to oral health. © 2012 Eur J Oral Sci.

[Separation of catechins and caffeine in tea polyphenol by isocratic elution high performance liquid chromatography].

PubMed

Tang, G Y; Wu, H J; Wu, L; Li, Z J; Yao, Y G

2001-05-01

The catechins, particularly in green tea, have been found to possess anti-mutagenic and anti-tumorigenic properties. As each catechin possesses distinct properties, a simple and rapid method that could be used for analysis of individual catechins in a complex mixture would be necessary. A relatively simple and rapid method for simultaneous separation of five catechins and caffeine in tea polyphenol by isocratic elution high performance liquid chromatography has been developed. The analysis could be finished within 30 min. They were measured using Resolve C18 column (at 43 degrees C) and UV detector (at 280 nm), water-85% phosphoric acid aqueous solution-acetonitrile-dimethyl formamide(DMF) (859:1:120:20, V/V) as mobile phase. There was a good linear relationship between the content of component and its peak area for catechins and caffeine, with the correlation coefficients of 0.9992-0.9999. The average recoveries (n = 5) were 83.33%-104.42%, and the relative standard deviations (n = 6) were 0.74%-1.43%. The effect of concentration of DMF in mobile phase was studied.

Green tea and the skin.

PubMed

Hsu, Stephen

2005-06-01

Plant extracts have been widely used as topical applications for wound-healing, anti-aging, and disease treatments. Examples of these include ginkgo biloba, echinacea, ginseng, grape seed, green tea, lemon, lavender, rosemary, thuja, sarsaparilla, soy, prickly pear, sagebrush, jojoba, aloe vera, allantoin, feverwort, bloodroot, apache plume, and papaya. These plants share a common character: they all produce flavonoid compounds with phenolic structures. These phytochemicals are highly reactive with other compounds, such as reactive oxygen species and biologic macromolecules, to neutralize free radicals or initiate biological effects. A short list of phenolic phytochemicals with promising properties to benefit human health includes a group of polyphenol compounds, called catechins, found in green tea. This article summarizes the findings of studies using green tea polyphenols as chemopreventive, natural healing, and anti-aging agents for human skin, and discusses possible mechanisms of action.

Enhancement of fermentation process in Pu-erh tea by tea-leaf extract.

PubMed

Hou, C W; Jeng, K C; Chen, Y S

2010-01-01

Pu-erh tea is known as a fermented tea and longer storage enhances its flavor and taste. Recently, Aspergillus, Blastobotrys, and Streptomyces are found to play important roles in nutritional enhancement of Pu-erh tea by fermentation. Since water and temperature affect the microbial growth, we therefore explored the factors that might enhance the Pu-erh tea fermentation. The results showed that the addition of fresh tea-leaf extract (TLE) enhanced the withered tea fermentation (at 37 degrees C, 80 to 85% RH) as compared with the water only. Contents of statin, GABA, gallic acid, DPPH scavenging and polyphenol oxidase (PPO) activities were increased, whereas polyphenols and caffeine were decreased over 6 mo. TLE dose-dependently enhanced some of the qualities (that is, statin, PPO) of Pu-erh tea significantly as compared with the water only. The effect was related to the increase population of A. niger and A. carbonarius at 6 mo (from 7.6 +/- 1.2 x 10(1) and 3.2 +/- 1.3 x 10(1) to 3.1 +/- 1.2 x 10(6) and 2.4 +/- 1.1 x 10(5) colony forming units [CFU]/g, respectively). After drying process (90 degrees C, 30 min), the total microbial count from these samples returned to background level (3 +/- 0.5 x 10(2) CFU/g). None of ochratoxin and fumonisin, toxins from Aspergillus, was detected in the final products. The flavor and taste were also enhanced by treatment with TLE. The inoculation with S. cinereus Y11 with 2% TLE further enhanced these functional contents (about 2-fold increase of statin level) in the experimental Pu-erh tea. Therefore, this result may add a new process for Pu-erh tea manufacture.

Reducing Breast Cancer Recurrence: The Role of Dietary Polyphenolics.

PubMed

Braakhuis, Andrea J; Campion, Peta; Bishop, Karen S

2016-09-06

Evidence from numerous observational and clinical studies suggest that polyphenolic phytochemicals such as phenolic acids in olive oil, flavonols in tea, chocolate and grapes, and isoflavones in soy products reduce the risk of breast cancer. A dietary food pattern naturally rich in polyphenols is the Mediterranean diet and evidence suggests those of Mediterranean descent have a lower breast cancer incidence. Whilst dietary polyphenols have been the subject of breast cancer risk-reduction, this review will focus on the clinical effects of polyphenols on reducing recurrence. Overall, we recommend breast cancer patients consume a diet naturally high in flavonol polyphenols including tea, vegetables (onion, broccoli), and fruit (apples, citrus). At least five servings of vegetables and fruit daily appear protective. Moderate soy protein consumption (5-10 g daily) and the Mediterranean dietary pattern show the most promise for breast cancer patients. In this review, we present an overview of clinical trials on supplementary polyphenols of dietary patterns rich in polyphenols on breast cancer recurrence, mechanistic data, and novel delivery systems currently being researched.

Reducing Breast Cancer Recurrence: The Role of Dietary Polyphenolics

PubMed Central

Braakhuis, Andrea J.; Campion, Peta; Bishop, Karen S.

2016-01-01

Evidence from numerous observational and clinical studies suggest that polyphenolic phytochemicals such as phenolic acids in olive oil, flavonols in tea, chocolate and grapes, and isoflavones in soy products reduce the risk of breast cancer. A dietary food pattern naturally rich in polyphenols is the Mediterranean diet and evidence suggests those of Mediterranean descent have a lower breast cancer incidence. Whilst dietary polyphenols have been the subject of breast cancer risk-reduction, this review will focus on the clinical effects of polyphenols on reducing recurrence. Overall, we recommend breast cancer patients consume a diet naturally high in flavonol polyphenols including tea, vegetables (onion, broccoli), and fruit (apples, citrus). At least five servings of vegetables and fruit daily appear protective. Moderate soy protein consumption (5–10 g daily) and the Mediterranean dietary pattern show the most promise for breast cancer patients. In this review, we present an overview of clinical trials on supplementary polyphenols of dietary patterns rich in polyphenols on breast cancer recurrence, mechanistic data, and novel delivery systems currently being researched. PMID:27608040

Anti-Fatigue Effect of Green Tea Polyphenols (-)-Epigallocatechin-3-Gallate (EGCG).

PubMed

Teng, Yu-Song; Wu, Di

2017-01-01

(-)-Epigallocatechin-3-gallate (EGCG) is the most abundant of the green tea polyphenols that exhibit a variety of bioactivities. The objective of this study was to evaluate the anti-fatigue effect of EGCG by forced swimming exercise. The mice were divided into one control group and three EGCG-treated groups. The control group was administered with distilled water and EGCG-treated groups were administered with different dose of EGCG (50, 100, and 200 mg/kg) by oral gavage for 28 days. On the last day of experiment, the forced swimming exercise was performed and corresponding biochemical parameters were measured. The data showed that EGCG prolonged exhaustive swimming time, decreasing the levels of blood lactic acid, serum urea nitrogen, serum creatine kinase and malondialdehyde, which were accompanied by corresponding increase in liver and muscle glycogen contents, and superoxide dismutase, catalase, and glutathione peroxidase activities. This study indicated that EGCG had an anti-fatigue effect. EGCG significantly prolonged exhaustive swimming time and decreased the levels of BLA, SUN, SCK and MDA, which were accompanied by corresponding increases in liver and muscle glycogen contents, and SOD, CAT, and GPx activities.EGCG can be used to design nutraceutical supplements aimed to facilitate recovery from fatigue and attenuate exhaustive exercise-induced oxidative damage. Abbreviations used: EGCG: (-)-Epigallocatechin-3-gallate, ROS: reactive oxygen species, BLA: blood lactic acid, SUN: serum urea nitrogen, SOD: superoxide dismutase, GPx: glutathione peroxidase, CAT: catalase, SCK: serum creatine kinase, MDA: malondialdehyde, C: control, LET: Low-dose EGCG-treated, MET: Middle-dose EGCG-treated, HET: High-dose EGCG-treated, GTE: green tea extract.

Tea Drinking and Its Association with Active Tuberculosis Incidence among Middle-Aged and Elderly Adults: The Singapore Chinese Health Study

PubMed Central

Soh, Avril Zixin; Pan, An; Chee, Cynthia Bin Eng; Wang, Yee-Tang; Yuan, Jian-Min; Koh, Woon-Puay

2017-01-01

Experimental studies showed that tea polyphenols may inhibit growth of Mycobacterium tuberculosis. However, no prospective epidemiologic study has investigated tea drinking and the risk of active tuberculosis. We investigated this association in the Singapore Chinese Health Study, a prospective population-based cohort of 63,257 Chinese aged 45–74 years recruited between 1993 and 1998 in Singapore. Information on habitual drinking of tea (including black and green tea) and coffee was collected via structured questionnaires. Incident cases of active tuberculosis were identified via linkage with the nationwide tuberculosis registry up to 31 December 2014. Cox proportional hazard models were used to estimate the relation of tea and coffee consumption with tuberculosis risk. Over a mean 16.8 years of follow-up, we identified 1249 incident cases of active tuberculosis. Drinking either black or green tea was associated with a dose-dependent reduction in tuberculosis risk. Compared to non-drinkers, the hazard ratio (HR) (95% confidence interval (CI)) was 1.01 (0.85–1.21) in monthly tea drinkers, 0.84 (0.73–0.98) in weekly drinkers, and 0.82 (0.71–0.96) in daily drinkers (p for trend = 0.003). Coffee or caffeine intake was not significantly associated with tuberculosis risk. In conclusion, regular tea drinking was associated with a reduced risk of active tuberculosis. PMID:28587081

Tea Drinking and Its Association with Active Tuberculosis Incidence among Middle-Aged and Elderly Adults: The Singapore Chinese Health Study.

PubMed

Soh, Avril Zixin; Pan, An; Chee, Cynthia Bin Eng; Wang, Yee-Tang; Yuan, Jian-Min; Koh, Woon-Puay

2017-05-25

Experimental studies showed that tea polyphenols may inhibit growth of Mycobacterium tuberculosis . However, no prospective epidemiologic study has investigated tea drinking and the risk of active tuberculosis. We investigated this association in the Singapore Chinese Health Study, a prospective population-based cohort of 63,257 Chinese aged 45-74 years recruited between 1993 and 1998 in Singapore. Information on habitual drinking of tea (including black and green tea) and coffee was collected via structured questionnaires. Incident cases of active tuberculosis were identified via linkage with the nationwide tuberculosis registry up to 31 December 2014. Cox proportional hazard models were used to estimate the relation of tea and coffee consumption with tuberculosis risk. Over a mean 16.8 years of follow-up, we identified 1249 incident cases of active tuberculosis. Drinking either black or green tea was associated with a dose-dependent reduction in tuberculosis risk. Compared to non-drinkers, the hazard ratio (HR) (95% confidence interval (CI)) was 1.01 (0.85-1.21) in monthly tea drinkers, 0.84 (0.73-0.98) in weekly drinkers, and 0.82 (0.71-0.96) in daily drinkers ( p for trend = 0.003). Coffee or caffeine intake was not significantly associated with tuberculosis risk. In conclusion, regular tea drinking was associated with a reduced risk of active tuberculosis.

Contamination of Tea and Tea Infusion with Polycyclic Aromatic Hydrocarbons

PubMed Central

Zachara, Alicja; Gałkowska, Dorota; Juszczak, Lesław

2017-01-01

The aim of this work was to validate the method of determination of polycyclic aromatic hydrocarbons (PAHs), i.e., benzo(a)pyrene and sum of benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthene and chrysene in different types of tea, as well as to assess the transfer of these contaminants from tea to tea infusion. The research materials were popular types of black, green, red and white tea. Quantitative and qualitative determination of PAHs was performed by High Performance Liquid Chromatography with fluorimetric detection (HPLC-FLD). The samples were prepared by QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) technique followed by cleaning-up by dispersion solid-phase extraction (d-SPE). Values of limit of detection and limit of quantification obtained in the validation of the method were lower than the respective maximum values given in Commission Regulation (EU) No. 836/2011. The level of contamination of popular teas commercially available on the Polish market with PAHs is similar to that of teas available in other countries, with a very large variation in the concentration of each of the compounds. The highest benzo(a)pyrene and Σ4PAHs contents (209 ± 42 μg/kg and 756 ± 151 μg/kg, respectively) were found for black tea leaves. The transfer of Σ4PAHs from black tea to tea infusions was 0.48%, while it was 1.55–1.72% for red, white and green teas. PMID:29283369

Black tea theaflavins inhibit formation of toxic amyloid-β and α-synuclein fibrils.

PubMed

Grelle, Gerlinde; Otto, Albrecht; Lorenz, Mario; Frank, Ronald F; Wanker, Erich E; Bieschke, Jan

2011-12-13

Causal therapeutic approaches for amyloid diseases such as Alzheimer's and Parkinson's disease targeting toxic amyloid oligomers or fibrils are still emerging. Here, we show that theaflavins (TF1, TF2a, TF2b, and TF3), the main polyphenolic components found in fermented black tea, are potent inhibitors of amyloid-β (Aβ) and α-synuclein (αS) fibrillogenesis. Their mechanism of action was compared to that of two established inhibitors of amyloid formation, (-)-epigallocatechin gallate (EGCG) and congo red (CR). All three compounds reduce the fluorescence of the amyloid indicator dye thioflavin T. Mapping the binding regions of TF3, EGCG, and CR revealed that all three bind to two regions of the Aβ peptide, amino acids 12-23 and 24-36, albeit with different specificities. However, their mechanisms of amyloid inhibition differ. Like EGCG but unlike congo red, theaflavins stimulate the assembly of Aβ and αS into nontoxic, spherical aggregates that are incompetent in seeding amyloid formation and remodel Aβ fibrils into nontoxic aggregates. When compared to EGCG, TF3 was less susceptible to air oxidation and had an increased efficacy under oxidizing conditions. These findings suggest that theaflavins might be used to remove toxic amyloid deposits.

Chemical characterization of heteropolysaccharides from green and black teas (Camellia sinensis) and their anti-ulcer effect.

PubMed

Scoparo, Camila T; Souza, Lauro M; Dartora, Nessana; Sassaki, Guilherme L; Santana-Filho, Arquimedes P; Werner, Maria Fernanda P; Borato, Débora G; Baggio, Cristiane H; Iacomini, Marcello

2016-05-01

In order to obtain polysaccharides from green and black teas (Camellia sinensis), commercial leaves were submitted to infusion and then to alkaline extraction. The extracts were fractionated by freeze-thawing process, giving insoluble and soluble fractions. Complex arabinogalactan protein from the soluble fractions of both teas (GTPS and BTPS) were determined by methylation analysis and (1)H/(13)C-HSQC spectroscopy, showing a main chain of (1→3)-β-Galp, substituted at O-6 by (1→6)-linked β-Galp with side chains of α-Araf and terminal units of α-Araf, α-Fucp and α-Rhap. A highly branched heteroxylan from the insoluble fractions (GTPI and BTPI) showed in methylation analysis and (1)H/(13)C-HSQC spectroscopy the main chain of (1→4)-β-Xylp, substituted in O-3 by α-Araf, β-Galp and α-Glcp units. Evaluating their gastroprotective activity, the fractions containing the soluble heteropolysaccharides from green (GTPS) and black teas (BTPS) reduced the gastric lesions induced by ethanol. Furthermore, the fraction of insoluble heteropolysaccharides of green (GTPI) and black (BTPI) teas also protected the gastric mucosa. In addition, the maintenance of gastric mucus and reduced glutathione (GSH) levels was involved in the polysaccharides gastroprotection. Copyright © 2016 Elsevier B.V. All rights reserved.

Tea Polyphenol-Reduced Graphene Oxide Deposition on Titanium Surface Enhances Osteoblast Bioactivity.

PubMed

Liu, Mengting; Hao, Liying; Huang, Qian; Zhao, Dan; Li, Qianshun; Cai, Xiaoxiao

2018-05-01

Graphene, a novel carbon-based material, has been widely used as osteogenic agent for the potential effect on the promotion of osteoblast proliferation. Tea polyphenol-reduced graphene oxide (TPG) is a simple and environmental-friendly raw material to obtain graphene. In this study, TPG was deposited on the Ti substrate to promote the bone regeneration. We prepared a honeycomb-like structure by acid and alkali pretreatment and immobilized the TPG layer (Ti-TPG) on the surface via electrochemical deposition. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD) were used to identify the immobilization of TPG on the titanium (Ti) successfully. Furthermore, the biological response of the Ti-TPG surface to rat osteoblast was evaluated. We also studied the cell adhesion, proliferation and expression of ossification genes on the sample. The results revealed that Ti-TPG had an advantage over Ti alloys in modulating cellular activity and Ti-TPG may be a promising coating for biological materials.

Anti-Fatigue Effect of Green Tea Polyphenols (-)-Epigallocatechin-3-Gallate (EGCG)

PubMed Central

Teng, Yu-song; Wu, Di

2017-01-01

Background: (-)-Epigallocatechin-3-gallate (EGCG) is the most abundant of the green tea polyphenols that exhibit a variety of bioactivities. The objective of this study was to evaluate the anti-fatigue effect of EGCG by forced swimming exercise. Materials and Methods: The mice were divided into one control group and three EGCG-treated groups. The control group was administered with distilled water and EGCG-treated groups were administered with different dose of EGCG (50, 100, and 200 mg/kg) by oral gavage for 28 days. On the last day of experiment, the forced swimming exercise was performed and corresponding biochemical parameters were measured. Results: The data showed that EGCG prolonged exhaustive swimming time, decreasing the levels of blood lactic acid, serum urea nitrogen, serum creatine kinase and malondialdehyde, which were accompanied by corresponding increase in liver and muscle glycogen contents, and superoxide dismutase, catalase, and glutathione peroxidase activities. Conclusions: This study indicated that EGCG had an anti-fatigue effect. SUMMARY EGCG significantly prolonged exhaustive swimming time and decreased the levels of BLA, SUN, SCK and MDA, which were accompanied by corresponding increases in liver and muscle glycogen contents, and SOD, CAT, and GPx activities.EGCG can be used to design nutraceutical supplements aimed to facilitate recovery from fatigue and attenuate exhaustive exercise-induced oxidative damage. Abbreviations used: EGCG: (-)-Epigallocatechin-3-gallate, ROS: reactive oxygen species, BLA: blood lactic acid, SUN: serum urea nitrogen, SOD: superoxide dismutase, GPx: glutathione peroxidase, CAT: catalase, SCK: serum creatine kinase, MDA: malondialdehyde, C: control, LET: Low-dose EGCG-treated, MET: Middle-dose EGCG-treated, HET: High-dose EGCG-treated, GTE: green tea extract. PMID:28539729

A study on toxicity of gasoline and GM-10 on liver of mice and it's amelioration by black tea extract.

PubMed

Verma, Ramtej Jayram; Dave, Manjeet; Mathuria, Neeta

2008-01-01

The aim of present study is to investigate the ameliorative effect of black tea extract on gasoline and GM-10 induced toxicity in liver of mice. Eighty healthy male mice weighing 38-40 g approximately were divided into eight groups which included untreated control and various treated groups. Mice were treated with Gasoline 462 mg/kg/day and GM-10 low dose (206 mg/kg/day) and high dose (412 mg/kg/day) subcutaneously for 30 days. Black tea extract was given as 2 g/100 mL drinking water (2% w/v) instead of pure drinking water. All the animals were sacrificed on 31st day by cervical dislocation and livers were isolated and weighed. Parameters such as lipid peroxidation, catalase, superoxide dismutase, glutathione peroxidase, glutathione and total ascorbic acid were studied. The results revealed dose-dependent toxicity of gasoline and GM-10 on liver. Administration of black tea extract ameliorates this toxicity of gasoline and GM-10 in liver of mice. This proves the effective ameliorative effect of black tea extract.

Cancer prevention by green tea: evidence from epidemiologic studies.

PubMed

Yuan, Jian-Min

2013-12-01

In contrast to the consistent results of an inhibitory effect of green tea extracts and tea polyphenols on the development and growth of carcinogen-induced tumors in experimental animal models, results from human studies are mixed. Both observational and intervention studies have provided evidence in support of a protective role of green tea intake in the development of oral-digestive tract cancer or an inhibitory role of oral supplementation of green tea extract on a precancerous lesion of oral cavity. Evidence in support of green tea intake against the development of liver cancer risk is limited and inconsistent. An inverse association between green tea intake and lung cancer risk has been observed among never smokers but not among smokers. Although observational studies do not support a beneficial role of tea intake against the development of prostate cancer, several phase 2 clinical trials have shown an inhibitory effect of green tea extract against the progression of prostate premalignant lesions to malignant tumors. Prospective epidemiologic studies so far have not provided evidence for a protective effect of green tea consumption on breast cancer development. Current data neither confirm nor refute a definitive cancer-preventive role of green tea intake. Large randomized intervention trials on the efficacy of green tea polyphenols or extracts are required before a recommendation for green tea consumption for cancer prevention should be made.

Polyphenols, Inflammation, and Cardiovascular Disease

PubMed Central

Tangney, Christy; Rasmussen, Heather E.

2013-01-01

Polyphenols are compounds found in foods such as tea, coffee, cocoa, olive oil, and red wine and have been studied to determine if their intake may modify cardiovascular disease (CVD) risk. Historically, biologic actions of polyphenols have been attributed to antioxidant activities, but recent evidence suggests that immunomodulatory and vasodilatory properties of polyphenols may also contribute to CVD risk reduction. These properties will be discussed, and recent epidemiological evidence and intervention trials will be reviewed. Further identification of polyphenols in foods and accurate assessment of exposures through measurement of biomarkers (i.e., polyphenol metabolites) could provide the needed impetus to examine the impact of polyphenol-rich foods on CVD intermediate outcomes (especially those signifying chronic inflammation) and hard endpoints among high risk patients. Although we have mechanistic insight into how polyphenols may function in CVD risk reduction, further research is needed before definitive recommendations for consumption can be made. PMID:23512608

Highly selective defluoridation of brick tea infusion by tea waste supported aluminum oxides.

PubMed

Peng, Chuanyi; Xi, Junjun; Chen, Guijie; Feng, Zhihui; Ke, Fei; Ning, Jingming; Li, Daxiang; Ho, Chi-Tang; Cai, Huimei; Wan, Xiaochun

2017-03-01

Brick tea usually contains very high fluoride, which may affect human health. Biosorbents have received much attention for selective removal of fluoride because of low cost, environmental friendliness, and relative safeness. In the present study, a highly selective fluoride tea waste based biosorbent, namely, aluminum (Al) oxide decorated tea waste (Tea-Al), was successfully prepared. The Tea-Al biosorbent was characterized by energy-dispersive spectrometry, Fourier transform infrared spectroscopy, powder X-ray diffraction and X-ray photoelectron spectroscopic analysis. The Tea-Al sample exhibited remarkably selective adsorption for fluoride (52.90%), but a weaker adsorption for other major constituents of brick tea infusion, such as catechins, polyphenols and caffeine, under the same conditions. Fluoride adsorption by Tea-Al for different times obeyed the surface reaction and adsorption isotherms fit the Freundlich model. In addition, the fluoride adsorption mechanism appeared to be an ion exchange between hydroxyl and fluoride ions. Results from this study demonstrated that Tea-Al is a promising biosorbent useful for the removal of fluoride in brick tea infusion. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Free radicals generated during oxidation of green tea polyphenols: electron paramagnetic resonance spectroscopy combined with density functional theory calculations.

PubMed

Severino, Joyce Ferreira; Goodman, Bernard A; Kay, Christopher W M; Stolze, Klaus; Tunega, Daniel; Reichenauer, Thomas G; Pirker, Katharina F

2009-04-15

Electron paramagnetic resonance spectroscopy and density functional theory calculations have been used to investigate the redox properties of the green tea polyphenols (GTPs) (-)-epigallocatechin gallate (EGCG), (-)-epigallocatechin (EGC), and (-)-epicatechin gallate (ECG). Aqueous extracts of green tea and these individual phenols were autoxidized at alkaline pH and oxidized by superoxide anion (O(2)(-)) radicals in dimethyl sulfoxide. Several new aspects of the free radical chemistry of GTPs were revealed. EGCG can be oxidized on both the B and the D ring. The B ring was the main oxidation site during autoxidation, but the D ring was the preferred site for O(2)(-) oxidation. Oxidation of the D ring was followed by structural degradation, leading to generation of a radical identical to that of oxidized gallic acid. Alkaline autoxidation of green tea extracts produced four radicals that were related to products of the oxidation of EGCG, EGC, ECG, and gallic acid, whereas the spectra from O(2)(-) oxidation could be explained solely by radicals generated from EGCG. Assignments of hyperfine coupling constants were made by DFT calculations, allowing the identities of the radicals observed to be confirmed.

Modelling and simulation of a moving interface problem: freeze drying of black tea extract

NASA Astrophysics Data System (ADS)

Aydin, Ebubekir Sıddık; Yucel, Ozgun; Sadikoglu, Hasan

2017-06-01

The moving interface separates the material that is subjected to the freeze drying process as dried and frozen. Therefore, the accurate modeling the moving interface reduces the process time and energy consumption by improving the heat and mass transfer predictions during the process. To describe the dynamic behavior of the drying stages of the freeze-drying, a case study of brewed black tea extract in storage trays including moving interface was modeled that the heat and mass transfer equations were solved using orthogonal collocation method based on Jacobian polynomial approximation. Transport parameters and physical properties describing the freeze drying of black tea extract were evaluated by fitting the experimental data using Levenberg-Marquardt algorithm. Experimental results showed good agreement with the theoretical predictions.

The erosive effect of herbal tea on dental enamel.

PubMed

Brunton, P A; Hussain, A

2001-11-01

The aim of this study was to determine whether conventional black tea and a herbal tea were capable of eroding dental enamel. A further aim was to investigate whether herbal tea of the type tested eroded dental hard tissues to a greater or lesser extent than conventional black tea. Three groups of 21 teeth were exposed to a conventional black tea Typhoo (Group A), a herbal tea Twinings Blackcurrant, Ginsing and Vanilla (Group B) and water, which acted as a control (Group C). Sequential profilometric tracings of the specimens were taken, superimposed and the degree of enamel loss calculated as the area of disparity between the tracings before and after exposure. Conventional black tea and herbal tea, of the type tested, both resulted in tooth surface loss. Tooth surface loss, which resulted from exposure to herbal tea (mean 0.05mm(2), s.d. 0.02), however, was significantly greater (P=0.00) than that which resulted from exposure to conventional black tea (mean 0.01mm(2), s.d. 0.00) and water (mean 0.00mm(2), s.d. 0.00). It was concluded that herbal tea and conventional black tea of the type tested result in erosion of dental enamel. The erosive effect of the herbal tea of the type tested was five times more severe than that of the conventional black tea tested. The cumulative effects of regular consumption of herbal tea of the type tested are likely, therefore, to be of clinical significance.

Comparative healing property of kombucha tea and black tea against indomethacin-induced gastric ulceration in mice: possible mechanism of action.

PubMed

Banerjee, Debashish; Hassarajani, Sham A; Maity, Biswanath; Narayan, Geetha; Bandyopadhyay, Sandip K; Chattopadhyay, Subrata

2010-12-01

The healing activity of black tea (BT) and BT fermented with Candida parapsilosis and kombucha culture, designated as CT and KT respectively against the indomethacin-induced stomach ulceration has been studied in a mouse model. The KT sample (KT4) produced by fermenting BT for four days, showed the best DPPH radical scavenging capacity and phenolics contents. Hence the ulcer-healing activity of KT4 was compared with those of CT4 and BT. All the tea extracts (15 mg kg(-1)) could effectively heal the gastric ulceration as revealed from the histopathological and biochemical studies, with relative efficacy as KT4 > CT4 ∼ BT. The healing capacities of the tea extracts could be attributed to their antioxidant activity as well as the ability to protect the mucin content of the gastric tissues. In addition, the ability of KT4 to reduce gastric acid secretion might also contribute to its ulcer-healing activity. The tea preparation KT4 (15 mg kg(-1)) was as effective as the positive control, omeprazole (3 mg kg(-1)) in ulcer healing.

Research on the effect of culture time on the kombucha tea beverage's antiradical capacity and sensory value.

PubMed

Gramza-Michałowska, Anna; Kulczyński, Bartosz; Xindi, Yuan; Gumienna, Małgorzata

2016-01-01

Recent consumption trends shows high consumer acceptability and growing medicinal interest in the biological value of kombucha tea. This tea is a sweetened tea leaf brew fermented with a layer containing mainly acetic acid bacteria, yeast and lactic acid bacteria. The main antioxidants in tea leaves are polyphenols, the consumption of which is proven to be beneficial for human health, e.g. protecting from reactive oxygen species (ROS). The aim of the present research was to evaluate antiradical activity, total polyphenol content (TPC) and sensory value of kombucha tea brews. In the present study, Kombucha tea beverages were analyzed for TPC content, DPPH radical scavenging method and sensory value. The highest TPC content and DPPH radical scavenging capacity values were evaluated in yellow tea samples, both unfermented and kombucha, which did not differ within the storage time. The results of sensory evaluations of kombucha tea brews depend on the tea leaf variety used for preparing the drink. Research indicates that the fermentation process of tea brews with kombucha microbiota does not affect significantly its polyphenol content and antiradical capacity, and retains its components' biological activity.

Fermentation Characteristics, Tannin Contents and In vitro Ruminal Degradation of Green Tea and Black Tea By-products Ensiled at Different Temperatures

PubMed Central

Kondo, Makoto; Hirano, Yoshiaki; Kita, Kazumi; Jayanegara, Anuraga; Yokota, Hiro-omi

2014-01-01

Green and black tea by-products, obtained from ready-made tea industry, were ensiled at 10°C, 20°C, and 30°C. Green tea by-product silage (GTS) and black tea by-product silage (BTS) were opened at 5, 10, 45 days after ensiling. Fermentation characteristics and nutrient composition, including tannins, were monitored and the silages on day 45 were subjected to in vitro ruminal fermentation to assess anti-nutritive effects of tannins using polyethylene glycol (PEG) as a tannin-binding agent. Results showed that the GTS and BTS silages were stable and fermented slightly when ensiled at 10°C. The GTS stored at 20°C and 30°C showed rapid pH decline and high acetic acid concentration. The BTS was fermented gradually with moderate change of pH and acid concentration. Acetic acid was the main acid product of fermentation in both GTS and BTS. The contents of total extractable phenolics and total extractable tannins in both silages were unaffected by storage temperatures, but condensed tannins in GTS were less when stored at high temperature. The GTS showed no PEG response on in vitro gas production, and revealed only a small increase by PEG on NH3-N concentration. Storage temperature of GTS did not affect the extent of PEG response to both gas production and NH3-N concentration. On the other hand, addition of PEG on BTS markedly increased both the gas production and NH3-N concentration at any ensiled temperature. It can be concluded that tannins in both GTS and BTS suppressed rumen fermentation, and tannins in GTS did more weakly than that in BTS. Ensiling temperature for both tea by-products did not affect the tannin’s activity in the rumen. PMID:25050034

Fermentation Characteristics, Tannin Contents and In vitro Ruminal Degradation of Green Tea and Black Tea By-products Ensiled at Different Temperatures.

PubMed

Kondo, Makoto; Hirano, Yoshiaki; Kita, Kazumi; Jayanegara, Anuraga; Yokota, Hiro-Omi

2014-07-01

Green and black tea by-products, obtained from ready-made tea industry, were ensiled at 10°C, 20°C, and 30°C. Green tea by-product silage (GTS) and black tea by-product silage (BTS) were opened at 5, 10, 45 days after ensiling. Fermentation characteristics and nutrient composition, including tannins, were monitored and the silages on day 45 were subjected to in vitro ruminal fermentation to assess anti-nutritive effects of tannins using polyethylene glycol (PEG) as a tannin-binding agent. Results showed that the GTS and BTS silages were stable and fermented slightly when ensiled at 10°C. The GTS stored at 20°C and 30°C showed rapid pH decline and high acetic acid concentration. The BTS was fermented gradually with moderate change of pH and acid concentration. Acetic acid was the main acid product of fermentation in both GTS and BTS. The contents of total extractable phenolics and total extractable tannins in both silages were unaffected by storage temperatures, but condensed tannins in GTS were less when stored at high temperature. The GTS showed no PEG response on in vitro gas production, and revealed only a small increase by PEG on NH3-N concentration. Storage temperature of GTS did not affect the extent of PEG response to both gas production and NH3-N concentration. On the other hand, addition of PEG on BTS markedly increased both the gas production and NH3-N concentration at any ensiled temperature. It can be concluded that tannins in both GTS and BTS suppressed rumen fermentation, and tannins in GTS did more weakly than that in BTS. Ensiling temperature for both tea by-products did not affect the tannin's activity in the rumen.

Polyphenols and Glycemic Control

PubMed Central

Kim, Yoona; Keogh, Jennifer B.; Clifton, Peter M.

2016-01-01

Growing evidence from animal studies supports the anti-diabetic properties of some dietary polyphenols, suggesting that dietary polyphenols could be one dietary therapy for the prevention and management of Type 2 diabetes. This review aims to address the potential mechanisms of action of dietary polyphenols in the regulation of glucose homeostasis and insulin sensitivity based on in vitro and in vivo studies, and to provide a comprehensive overview of the anti-diabetic effects of commonly consumed dietary polyphenols including polyphenol-rich mixed diets, tea and coffee, chocolate and cocoa, cinnamon, grape, pomegranate, red wine, berries and olive oil, with a focus on human clinical trials. Dietary polyphenols may inhibit α-amylase and α-glucosidase, inhibit glucose absorption in the intestine by sodium-dependent glucose transporter 1 (SGLT1), stimulate insulin secretion and reduce hepatic glucose output. Polyphenols may also enhance insulin-dependent glucose uptake, activate 5′ adenosine monophosphate-activated protein kinase (AMPK), modify the microbiome and have anti-inflammatory effects. However, human epidemiological and intervention studies have shown inconsistent results. Further intervention studies are essential to clarify the conflicting findings and confirm or refute the anti-diabetic effects of dietary polyphenols. PMID:26742071

Green tea polyphenol tailors cell adhesivity of RGD displaying surfaces: multicomponent models monitored optically

PubMed Central

Peter, Beatrix; Farkas, Eniko; Forgacs, Eniko; Saftics, Andras; Kovacs, Boglarka; Kurunczi, Sandor; Szekacs, Inna; Csampai, Antal; Bosze, Szilvia; Horvath, Robert

2017-01-01

The interaction of the anti-adhesive coating, poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) and its Arg-Gly-Asp (RGD) functionalized form, PLL-g-PEG-RGD, with the green tea polyphenol, epigallocatechin-gallate (EGCg) was in situ monitored. After, the kinetics of cellular adhesion on the EGCg exposed coatings were recorded in real-time. The employed plate-based waveguide biosensor is applicable to monitor small molecule binding and sensitive to sub-nanometer scale changes in cell membrane position and cell mass distribution; while detecting the signals of thousands of adhering cells. The combination of this remarkable sensitivity and throughput opens up new avenues in testing complicated models of cell-surface interactions. The systematic studies revealed that, despite the reported excellent antifouling properties of the coatings, EGCg strongly interacted with them, and affected their cell adhesivity in a concentration dependent manner. Moreover, the differences between the effects of the fresh and oxidized EGCg solutions were first demonstrated. Using a semiempirical quantumchemical method we showed that EGCg binds to the PEG chains of PLL-g-PEG-RGD and effectively blocks the RGD sites by hydrogen bonds. The calculations supported the experimental finding that the binding is stronger for the oxidative products. Our work lead to a new model of polyphenol action on cell adhesion ligand accessibility and matrix rigidity. PMID:28186133

Green tea polyphenol tailors cell adhesivity of RGD displaying surfaces: multicomponent models monitored optically.

PubMed

Peter, Beatrix; Farkas, Eniko; Forgacs, Eniko; Saftics, Andras; Kovacs, Boglarka; Kurunczi, Sandor; Szekacs, Inna; Csampai, Antal; Bosze, Szilvia; Horvath, Robert

2017-02-10

The interaction of the anti-adhesive coating, poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) and its Arg-Gly-Asp (RGD) functionalized form, PLL-g-PEG-RGD, with the green tea polyphenol, epigallocatechin-gallate (EGCg) was in situ monitored. After, the kinetics of cellular adhesion on the EGCg exposed coatings were recorded in real-time. The employed plate-based waveguide biosensor is applicable to monitor small molecule binding and sensitive to sub-nanometer scale changes in cell membrane position and cell mass distribution; while detecting the signals of thousands of adhering cells. The combination of this remarkable sensitivity and throughput opens up new avenues in testing complicated models of cell-surface interactions. The systematic studies revealed that, despite the reported excellent antifouling properties of the coatings, EGCg strongly interacted with them, and affected their cell adhesivity in a concentration dependent manner. Moreover, the differences between the effects of the fresh and oxidized EGCg solutions were first demonstrated. Using a semiempirical quantumchemical method we showed that EGCg binds to the PEG chains of PLL-g-PEG-RGD and effectively blocks the RGD sites by hydrogen bonds. The calculations supported the experimental finding that the binding is stronger for the oxidative products. Our work lead to a new model of polyphenol action on cell adhesion ligand accessibility and matrix rigidity.

Green tea polyphenol tailors cell adhesivity of RGD displaying surfaces: multicomponent models monitored optically

NASA Astrophysics Data System (ADS)

Peter, Beatrix; Farkas, Eniko; Forgacs, Eniko; Saftics, Andras; Kovacs, Boglarka; Kurunczi, Sandor; Szekacs, Inna; Csampai, Antal; Bosze, Szilvia; Horvath, Robert

2017-02-01

The interaction of the anti-adhesive coating, poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) and its Arg-Gly-Asp (RGD) functionalized form, PLL-g-PEG-RGD, with the green tea polyphenol, epigallocatechin-gallate (EGCg) was in situ monitored. After, the kinetics of cellular adhesion on the EGCg exposed coatings were recorded in real-time. The employed plate-based waveguide biosensor is applicable to monitor small molecule binding and sensitive to sub-nanometer scale changes in cell membrane position and cell mass distribution; while detecting the signals of thousands of adhering cells. The combination of this remarkable sensitivity and throughput opens up new avenues in testing complicated models of cell-surface interactions. The systematic studies revealed that, despite the reported excellent antifouling properties of the coatings, EGCg strongly interacted with them, and affected their cell adhesivity in a concentration dependent manner. Moreover, the differences between the effects of the fresh and oxidized EGCg solutions were first demonstrated. Using a semiempirical quantumchemical method we showed that EGCg binds to the PEG chains of PLL-g-PEG-RGD and effectively blocks the RGD sites by hydrogen bonds. The calculations supported the experimental finding that the binding is stronger for the oxidative products. Our work lead to a new model of polyphenol action on cell adhesion ligand accessibility and matrix rigidity.

Tea polyphenols inactivate Cronobacter sakazakii isolated from powdered infant formula.

PubMed

Li, R; Fei, P; Man, C X; Lou, B B; Niu, J T; Feng, J; Sun, L H; Li, M Y; Jiang, Y J

2016-02-01

This study evaluated the antimicrobial activity of tea polyphenols (TP) against 4 Cronobacter sakazakii strains with different sequence types (ST) isolated from powdered infant formula (PIF). The results showed that in normal saline, 5mg/mL of TP (pH 3.44) could eliminate approximately 7.0 log cfu/mL of C. sakazakii within 1 h; in rehydrated PIF, after acidification with HCl (pH 3.55), TP showed a stronger antibacterial activity compared with the controls (malic acid, ascorbic acid, and citric acid). Further, some differences were obvious in tolerance to TP between C. sakazakii strains with different ST. The tolerance of C. sakazakii CE1 (ST4) to TP was found to be greater than that of the other 3 C. sakazakii strains (ST1, ST8, and ST64). The results of recovered test and transmission electron microscope analysis revealed that the action of TP against C. sakazakii was an irreversible bactericidal process caused by leakage of cytoplasm. Taken together, these results indicated that TP had an effective bactericidal effect against C. sakazakii, and provided a new idea for preventing and inactivating C. sakazakii in PIF. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Inhibitory effect of black tea and its combination with acarbose on small intestinal α-glucosidase activity.

PubMed

Satoh, Takashi; Igarashi, Masaki; Yamada, Shogo; Takahashi, Natsuko; Watanabe, Kazuhiro

2015-02-23

It is said that black tea is effective against type 2 diabetes mellitus because it can help modulate postprandial hyperglycemia. However, the mechanism underlying its therapeutic and preventive effects on type 2 diabetes mellitus is unclear. In this study, we focused on the effect of black tea on the carbohydrate digestion and absorption process in the gastrointestinal tract. We examined whether black tea can modulate postprandial hyperglycemia. The freeze-dried powder of the aqueous extract of black tea leaves (JAT) was used for in vitro studies of α-amylase activity, α-glucosidase activity, and glucose uptake by glucose transporters in Caco-2 cells; ex vivo studies of small intestinal α-glucosidase activity; and in vivo studies of oral sugar tolerance in GK rats, an animal model of nonobese type 2 diabetes mellitus. Half maximal inhibitory concentration values indicated that JAT significantly reduced α-glucosidase activity, but weakly reduced α-amylase activity. Kinetic studies of rat small intestinal α-glucosidase activity revealed that the combination of JAT and the α-glucosidase inhibitor, acarbose, showed a mixed-type inhibition. JAT had no effect on the uptake of 2'-deoxy-d-glucose by glucose transporter 2 (GLUT2) and the uptake of α-methyl-d-glucose by sodium-dependent glucose transporter 1 (SGLT1). In the oral sucrose tolerance test in GK rats, JAT reduced plasma glucose levels in a dose-dependent manner compared with the control group. The hypoglycemic action of JAT was also confirmed: JAT, in combination with acarbose, produced a synergistic inhibitory effect on plasma glucose levels in vivo. In contrast to the oral sucrose tolerance test, JAT showed no effect in the oral glucose tolerance test. JAT was demonstrated to inhibit the degradation of disaccharides into monosaccharides by α-glucosidase in the small intestine. Thereby indirectly preventing the absorption of the dietary source of glucose mediated by SGLT1 and GLUT2 transporters

Estimating Biochemical Parameters of Tea (camellia Sinensis (L.)) Using Hyperspectral Techniques

NASA Astrophysics Data System (ADS)

Bian, M.; Skidmore, A. K.; Schlerf, M.; Liu, Y.; Wang, T.

2012-07-01

Tea (Camellia Sinensis (L.)) is an important economic crop and the market price of tea depends largely on its quality. This research aims to explore the potential of hyperspectral remote sensing on predicting the concentration of biochemical components, namely total tea polyphenols, as indicators of tea quality at canopy scale. Experiments were carried out for tea plants growing in the field and greenhouse. Partial least squares regression (PLSR), which has proven to be the one of the most successful empirical approach, was performed to establish the relationship between reflectance and biochemical concentration across six tea varieties in the field. Moreover, a novel integrated approach involving successive projections algorithms as band selection method and neural networks was developed and applied to detect the concentration of total tea polyphenols for one tea variety, in order to explore and model complex nonlinearity relationships between independent (wavebands) and dependent (biochemicals) variables. The good prediction accuracies (r2 > 0.8 and relative RMSEP < 10 %) achieved for tea plants using both linear (partial lease squares regress) and nonlinear (artificial neural networks) modelling approaches in this study demonstrates the feasibility of using airborne and spaceborne sensors to cover wide areas of tea plantation for in situ monitoring of tea quality cheaply and rapidly.

Estimated Dietary Polyphenol Intake and Major Food and Beverage Sources among Elderly Japanese.

PubMed

Taguchi, Chie; Fukushima, Yoichi; Kishimoto, Yoshimi; Suzuki-Sugihara, Norie; Saita, Emi; Takahashi, Yoshinari; Kondo, Kazuo

2015-12-09

Estimating polyphenol intake contributes to the understanding of polyphenols' health benefits. However, information about human polyphenol intake is scarce, especially in the elderly. This study aimed to estimate the dietary intake and major sources of polyphenols and to determine whether there is any relationship between polyphenol intake and micronutrient intake in healthy elderly Japanese. First, 610 subjects (569 men, 41 women; aged 67.3 ± 6.1 years) completed food frequency questionnaires. We then calculated their total polyphenol intake using our polyphenol content database. Their average total polyphenol intake was 1492 ± 665 mg/day, the greatest part of which was provided by beverages (79.1%). The daily polyphenol intake differed largely among individuals (183-4854 mg/day), also attributable mostly to beverage consumption. Coffee (43.2%) and green tea (26.6%) were the major sources of total polyphenol; the top 20 food items accounted for >90%. The polyphenol intake did not strongly correlate with the intake of any micronutrient, suggesting that polyphenols may exert health benefits independently of nutritional intake. The polyphenol intake in this elderly population was slightly higher than previous data in Japanese adults, and beverages such as coffee and green tea contributed highly to the intake.

Spray drying of lipid-based systems loaded with Camellia sinensis polyphenols.

PubMed

Secolin, Vanessa A; Souza, Claudia R F; Oliveira, Wanderley P

2017-03-01

In this work, spray-dried lipid systems based on soy phosphatidylcholine, cholesterol and lauroyl polyoxylglycerides for entrapping Green tea polyphenols were produced. The aim was to study the effects of the encapsulating composition and spray drying conditions on the system performance and physicochemical product properties. The spray dryer powder production yield falls around 50.7 ± 2.8%, which is typical for lab scale spray dryers. Wrinkled and rounded particles, with low surface porosities were generated, independent of the drying carriers (trehalose or lactose) used. The product showed high encapsulation efficiency of Green tea polyphenols, which was promptly redispersible in water. It presented low density, and good compressive and flow properties. The results herein reported confirm the feasibility of the entrapment of Green tea polyphenols in lipid-based compositions by spray drying in presence of the drying carriers evaluated. The spray-dried microparticles show high potential to be used as additive in food, nutraceutical and pharmaceutical products.

Antimicrobial effect and membrane-active mechanism of tea polyphenols against Serratia marcescens.

PubMed

Yi, Shumin; Wang, Wei; Bai, Fengling; Zhu, Junli; Li, Jianrong; Li, Xuepeng; Xu, Yongxia; Sun, Tong; He, Yutang

2014-02-01

In this study, we investigated the antimicrobial effect of tea polyphenols (TP) against Serratia marcescens and examined the related mechanism. Morphology changes of S. marcescens were first observed by transmission electron microscopy after treatment with TP, which indicated that the primary inhibition action of TP was to damage the bacterial cell membranes. The permeability of the outer and inner membrane of S. marcescens dramatically increased after TP treatment, which caused severe disruption of cell membrane, followed by the release of small cellular molecules. Furthermore, a proteomics approach based on two-dimensional gel electrophoresis and MALDI-TOF/TOF MS analysis was used to study the difference of membrane protein expression in the control and TP treatment S. marcescens. The results showed that the expression of some metabolism enzymes and chaperones in TP-treated S. marcescens significantly increased compared to the untreated group, which might result in the metabolic disorder of this bacteria. Taken together, our results first demonstrated that TP had a significant growth inhibition effect on S. marcescens through cell membrane damage.

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

PubMed

Koch, Wojciech; Kukula-Koch, Wirginia; Głowniak, Kazimierz

2017-11-01

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.

Role of dietary polyphenols in attenuating brain edema and cell swelling in cerebral ischemia

USDA-ARS?s Scientific Manuscript database

Polyphenols are natural substances with variable phenolic structures and are enriched in vegetables, fruits, grains, bark, roots, tea, and wine. There are over 8000 polyphenolic structures identified in plants, but edible plants contain only several hundred polyphenolic structures. Recent interest...

Dietary polyphenols exert neuroprotective effects by attenuating neuronal and astrocytic damage in cerebral ischemia

USDA-ARS?s Scientific Manuscript database

Polyphenols are natural substances with variable phenolic structures and are found in vegetables, fruits, grains, bark, roots, tea, and wine. There are over 8000 polyphenolic structures identified in plants, but edible plants contain only several hundred polyphenolic structures. Recent interest in...

Updated bioavailability and 48 h excretion profile of flavan-3-ols from green tea in humans.

PubMed

Calani, Luca; Del Rio, Daniele; Luisa Callegari, Maria; Morelli, Lorenzo; Brighenti, Furio

2012-08-01

Green tea is a popular beverage, prepared with infusion of unfermented dried leaves of Camellia sinensis, and is one of the most relevant sources of polyphenolic compounds in the human diet. This study reports green tea flavan-3-ol absorption, metabolism and complete urinary excretion up to 48 h in 20 healthy volunteers. Urinary and tea samples were analysed by high-performance liquid chromatography coupled with tandem mass spectrometry. Green tea contained monomeric flavan-3-ols and proanthocyanidins with a total polyphenol content of 728 μmol. A total of 41 metabolites were identified in urines, all present in conjugated forms. Among these, six colonic metabolites of green tea flavan-3-ols were identified for the first time after green tea consumption in humans. The average 48 h bioavailability was close to 62%, major contributors being microbial metabolites. Some volunteer showed a 100% absorption/excretion, whereas some others were unable to efficiently absorb/excrete this class of flavonoids. This suggests that colonic ring fission metabolism could be relevant in the putative bioactivity of green tea polyphenols.

Estimated Dietary Polyphenol Intake and Major Food and Beverage Sources among Elderly Japanese

PubMed Central

Taguchi, Chie; Fukushima, Yoichi; Kishimoto, Yoshimi; Suzuki-Sugihara, Norie; Saita, Emi; Takahashi, Yoshinari; Kondo, Kazuo

2015-01-01

Estimating polyphenol intake contributes to the understanding of polyphenols’ health benefits. However, information about human polyphenol intake is scarce, especially in the elderly. This study aimed to estimate the dietary intake and major sources of polyphenols and to determine whether there is any relationship between polyphenol intake and micronutrient intake in healthy elderly Japanese. First, 610 subjects (569 men, 41 women; aged 67.3 ± 6.1 years) completed food frequency questionnaires. We then calculated their total polyphenol intake using our polyphenol content database. Their average total polyphenol intake was 1492 ± 665 mg/day, the greatest part of which was provided by beverages (79.1%). The daily polyphenol intake differed largely among individuals (183–4854 mg/day), also attributable mostly to beverage consumption. Coffee (43.2%) and green tea (26.6%) were the major sources of total polyphenol; the top 20 food items accounted for >90%. The polyphenol intake did not strongly correlate with the intake of any micronutrient, suggesting that polyphenols may exert health benefits independently of nutritional intake. The polyphenol intake in this elderly population was slightly higher than previous data in Japanese adults, and beverages such as coffee and green tea contributed highly to the intake. PMID:26690212

Antidiabetic Effects of Tea.

PubMed

Fu, Qiu-Yue; Li, Qing-Sheng; Lin, Xiao-Ming; Qiao, Ru-Ying; Yang, Rui; Li, Xu-Min; Dong, Zhan-Bo; Xiang, Li-Ping; Zheng, Xin-Qiang; Lu, Jian-Liang; Yuan, Cong-Bo; Ye, Jian-Hui; Liang, Yue-Rong

2017-05-20

Diabetes mellitus (DM) is a chronic endocrine disease resulted from insulin secretory defect or insulin resistance and it is a leading cause of death around the world. The care of DM patients consumes a huge budget due to the high frequency of consultations and long hospitalizations, making DM a serious threat to both human health and global economies. Tea contains abundant polyphenols and caffeine which showed antidiabetic activity, so the development of antidiabetic medications from tea and its extracts is increasingly receiving attention. However, the results claiming an association between tea consumption and reduced DM risk are inconsistent. The advances in the epidemiologic evidence and the underlying antidiabetic mechanisms of tea are reviewed in this paper. The inconsistent results and the possible causes behind them are also discussed.

Using UV-Vis spectroscopy for simultaneous geographical and varietal classification of tea infusions simulating a home-made tea cup.

PubMed

Diniz, Paulo Henrique Gonçalves Dias; Barbosa, Mayara Ferreira; de Melo Milanez, Karla Danielle Tavares; Pistonesi, Marcelo Fabián; de Araújo, Mário César Ugulino

2016-02-01

In this work we proposed a method to verify the differentiating characteristics of simple tea infusions prepared in boiling water alone (simulating a home-made tea cup), which represents the final product as ingested by the consumers. For this purpose we used UV-Vis spectroscopy and variable selection through the Successive Projections Algorithm associated with Linear Discriminant Analysis (SPA-LDA) for simultaneous classification of the teas according to their variety and geographic origin. For comparison, KNN, CART, SIMCA, PLS-DA and PCA-LDA were also used. SPA-LDA and PCA-LDA provided significantly better results for tea classification of the five studied classes (Argentinean green tea; Brazilian green tea; Argentinean black tea; Brazilian black tea; and Sri Lankan black tea). The proposed methodology provides a simpler, faster and more affordable classification of simple tea infusions, and can be used as an alternative approach to traditional tea quality evaluation as made by skilful tasters, which is evidently partial and cannot assess geographic origins. Copyright © 2015 Elsevier Ltd. All rights reserved.

Xerophilic aflatoxigenic black tea fungi and their inhibition by Elettaria cardamomum and Syzygium aromaticum extracts

PubMed Central

Al-Sohaibani, Saleh; Murugan, K.; Lakshimi, G.; Anandraj, K.

2011-01-01

Black tea is consumed worldwide and is believed to play a role in cancer prevention. Xerophilic aflatoxigenic fungi are highly hazardous contaminants of tea since they are associated with tea quality impairment and human health risk. The present study reports isolation of such xerophilic and aflatoxigenic fungi associated with marketed tea. Twenty different tea samples collected from the local markets of Tamilnadu, India were investigated for fungal contamination. The results indicated contamination by 0.38% Aspergillus flavus. Other common contaminant fungi including Penicillium spp. (0.30%), Pacelomyces spp. (0.14%), and Mucor spp. (0.19%) were also isolated. Amongst the fungi isolated Aspergillus niger ML01 and A. flavus ML02 were found to be xerophilic aflatoxigenic mycoflora. Phylogenetic analysis based on 28S rRNA revealed their close ancestry. The chloroform and acetone extracts of spices Elettaria cardamomum and Syzygium aromaticum exhibited antifungal inhibitory activity on growth and toxin elaboration of both these xerophilic tea contaminants A. niger ML01 and A. flavus ML02. The results advocate the use of these spices plant or their extracts as novel antimicrobials which may add preservation and flavour in marketed tea. PMID:23961151

Therapeutic properties of green tea against environmental insults

PubMed Central

Chen, Lixia; Mo, Huanbiao; Zhao, Ling; Gao, Weimin; Wang, Shu; Cromie, Meghan M; Lu, Chuanwen; Wang, Jia-Sheng; Shen, Chwan-Li

2016-01-01

Pesticides, smoke, mycotoxins, polychlorinated biphenyls, and arsenic are the most common environmental toxins and toxicants to humans. These toxins and toxicants may impact on human health at the molecular (DNA, RNA, or protein), organelle (mitochondria, lysosome, or membranes), cellular (growth inhibition or cell death), tissue, organ, and systemic levels. Formation of reactive radicals, lipid peroxidation, inflammation, genotoxicity, hepatotoxicity, embryotoxicity, neurological alterations, apoptosis, and carcinogenic events are some of the mechanisms mediating the toxic effects of the environmental toxins and toxicants. Green tea, the non-oxidized and non-fermented form of tea that contains several polyphenols, including green tea catechins, exhibits protective effects against these environmental toxins and toxicants in preclinical studies and to a much-limited extent, in clinical trials. The protective effects are collectively mediated by antioxidant, anti-inflammatory, anti-mutagenic, hepato- and neuroprotective, and anti-carcinogenic activities. In addition, green tea modulates signaling pathway including NFκB and ERK pathways, preserves mitochondrial membrane potential, inhibits caspase-3 activity, down-regulates pro-apoptotic proteins, and induces the phase II detoxifying pathway. The bioavailability and metabolism of green tea and its protective effects against environmental insults induced by pesticides, smoke, mycotoxins, polychlorinated biphenyls, and arsenic are reviewed in this paper. Future studies with emphasis on clinical trials should identify biomarkers of green tea intake, examine the mechanisms of action of green tea polyphenols, and investigate potential interactions of green tea with other toxicant-modulating dietary factors. PMID:27723473

Black soybean seed coat polyphenols prevent AAPH-induced oxidative DNA-damage in HepG2 cells

PubMed Central

Yoshioka, Yasukiyo; Li, Xiu; Zhang, Tianshun; Mitani, Takakazu; Yasuda, Michiko; Nanba, Fumio; Toda, Toshiya; Yamashita, Yoko; Ashida, Hitoshi

2017-01-01

Black soybean seed coat extract (BE), which contains abundant polyphenols such as procyanidins, cyanidin 3-glucoside, (+)-catechin, and (−)­epicatechin, has been reported on health beneficial functions such as antioxidant activity, anti-inflammatory, anti-obesity, and anti-diabetic activities. In this study, we investigated that prevention of BE and its polyphenols on 2,2'-azobis(2-methylpropionamide) dihydrochloride (AAPH)-induced oxidative DNA damage, and found that these polyphenols inhibited AAPH-induced formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a biomarker for oxidative DNA damage in HepG2 cells. Under the same conditions, these polyphenols also inhibited AAPH-induced accumulation of reactive oxygen species (ROS) in the cells. Inhibition of ROS accumulation was observed in both cytosol and nucleus. It was confirmed that these polyphenols inhibited formation of AAPH radical using oxygen radical absorbance capacity assay under the cell-free conditions. These results indicate that polyphenols in BE inhibit free radical-induced oxidative DNA damages by their potent antioxidant activity. Thus, BE is an effective food material for prevention of oxidative stress and oxidative DNA damages. PMID:28366989

Slow digestion property of octenyl succinic anhydride modified waxy maize starch in the presence of tea polyphenols.

PubMed

Peng, Shanli; Xue, Lei; Leng, Xue; Yang, Ruobing; Zhang, Genyi; Hamaker, Bruce R

2015-03-18

The in vivo slow digestion property of octenyl succinic anhydride modified waxy corn starch (OSA-starch) in the presence of tea polyphenols (TPLs) was studied. Using a mouse model, the experimental results showed an extended and moderate postprandial glycemic response with a delayed and significantly decreased blood glucose peak of OSA-starch after cocooking with TPLs (5% starch weight base). Further studies revealed an increased hydrodynamic radius of OSA-starch molecules indicating an interaction between OSA-starch and TPLs. Additionally, decreased gelatinization temperature and enthalpy and reduced viscosity and emulsifiability of OSA-starch support their possible complexation to form a spherical OSA-starch-TPLs (OSAT) complex. The moderate and extended postprandial glycemic response is likely caused by decreased activity of mucosal α-glucosidase, which is noncompetitively inhibited by tea catechins released from the complex during digestion. Meanwhile, a significant decrease of malondialdehyde (MDA) and increased DPPH free radical scavenging activity in small intestine tissue demonstrated the antioxidative functional property of the OSAT complex. Thus, the complex of OSAT, acting as a functional carbohydrate material, not only leads to a flattened and prolonged glycemic response but also reduces the oxidative stress, which might be beneficial to health.

Tea polyphenols as an antivirulence compound Disrupt Quorum-Sensing Regulated Pathogenicity of Pseudomonas aeruginosa

PubMed Central

Yin, Honging; Deng, Yifeng; Wang, Huafu; Liu, Wugao; Zhuang, Xiyi; Chu, Weihua

2015-01-01

Green tea, a water extract of non-fermented leaves of Camellia sinensis L., is one of the nonalcoholic beverages in China. It is becoming increasingly popular worldwide, because of its refreshing, mild stimulant and medicinal properties. Here we examined the quorum sensing inhibitory potentials of tea polyphenols (TP) as antivirulence compounds both in vitro and in vivo. Biosensor assay data suggested minimum inhibitory concentrations (MICs) of TP against selected pathogens were 6.25 ~ 12.5 mg/mL. At sub-MIC, TP can specifically inhibit the production of violacein in Chromobacterium violaceum 12472 with almost 98% reduction at 3.125 mg/mL without affecting its growth rate. Moreover, TP exhibited inhibitory effects on virulence phenotypes regulated by QS in Pseudomonas aeruginosa. The total proteolytic activity, elastase, swarming motility and biofilm formation were reduced in a concentration-dependent manner. In vivo, TP treatment resulted in the reduction of P. aeruginosa pathogenicity in Caenorhabditis elegans. When its concentration was 3.125 mg/mL, the survival rate reached 63.3%. In the excision wound infection model, the wound contraction percentage in treatment groups was relatively increased and the colony-forming units (CFU) in the wound area were significantly decreased. These results suggested that TP could be developed as a novel non-antibiotic QS inhibitor without killing the bacteria but as an antivirulence compound to control bacterial infection. PMID:26548447

In vitro and in vivo antioxidant and antimutagenic activities of polyphenols extracted from hops (Humulus lupulus L.).

PubMed

Wang, Xuping; Yang, Lei; Yang, Xiaolan; Tian, Yanhua

2014-06-01

Hops (Humulus lupulus L.) contain 40-140 mg g(-1) polyphenols. The objective of this study was to determine the phenolic composition of a high-purity (total phenolic content = 887 mg g(-1) ) hop polyphenol extract (HPE) and evaluate its antioxidant activities in vivo and in vitro and its antimutagenic activity. The antioxidant activity of HPE was compared with the activity of green tea polyphenols. The phenolic compositions of HPE were more than 55% proanthocyanidins and more than 28% flavonoid glycosides. In vitro, HPE effectively scavenged α,α-diphenyl-β-picrylhydrazyl, hydroxyl and superoxide anion radicals, and inhibited DNA oxidative damage. In vivo, oral HPE at a polyphenol dose of 200-800 mg kg(-1) body weight significantly prevented a bromobenzene-induced decrease in liver superoxide dismutase and glutathione peroxidase activity, and decreased levels of liver thiobarbituric acid reactive substances in bromobenzene-treated mice. An oral dose of 20-80 mg kg(-1) body weight HPE significantly reduced the frequency of bone marrow micronuclei induced by cyclophosphamide. The antioxidant activities of hop polyphenols in vitro and in vivo were higher than green tea polyphenols at the same concentration. Hop polyphenols had the same or higher antioxidant activity than tea polyphenols. Hop polyphenols might be useful as natural antioxidants and antimutagens. © 2013 Society of Chemical Industry.

Cooking and co-ingested polyphenols reduce in vitro methylmercury bioaccessibility from fish and may alter exposure in humans.

PubMed

Girard, Catherine; Charette, Tania; Leclerc, Maxime; Shapiro, B Jesse; Amyot, Marc

2018-03-01

Fish consumption is a major pathway for mercury exposure in humans. Current guidelines and risk assessments assume that 100% of methylmercury (MeHg) in fish is absorbed by the human body after ingestion. However, a growing body of literature suggests that this absorption rate may be overestimated. We used an in vitro digestion method to measure MeHg bioaccessibility in commercially-purchased fish, and investigated the effects of dietary practices on MeHg bioaccessibility. Cooking had the greatest effect, decreasing bioaccessibility on average to 12.5±5.6%. Polyphenol-rich beverages also significantly reduced bioaccessibility to 22.7±3.8% and 28.6±13.9%, for green and black tea respectively. We confirmed the suspected role of polyphenols in tea as being a driver of MeHg's reduced bioaccessibility, and found that epicatechin, epigallocatechin gallate, rutin and cafeic acid could individually decrease MeHg bioaccessibility by up to 55%. When both cooking and polyphenol-rich beverage treatments were combined, only 1% of MeHg remained bioaccessible. These results call for in vivo validation, and suggest that dietary practices should be considered when setting consumer guidelines for MeHg. More realistic risk assessments could promote consumption of fish as a source of fatty acids, which can play a protective role against cardiovascular disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Iron bioavailability and weight gains to iron-deficient rats fed a commonly consumed Tunisian meal 'bean seeds ragout' with or without beef and with green or black tea decoction.

PubMed

Hamdaoui, Mohamed Hédi; Chabchoub, Soufia; Hédhili, Abderrazek

2003-01-01

The Fe bioavailability and the weight gains were evaluated in rats fed a commonly consumed Tunisian meal 'bean seeds ragout' (BSR), with or without beef and with black or green tea decoction. The Fe bioavailability was evaluated in Fe-deficient rats by the hemoglobin repletion method and the Fe stored in the liver. The addition of beef to the BSR significantly increased the Fe bioavailability from this meal by 147% and the reserve of Fe stored in the liver by 77% (P < 0.001). In contrast, both black and green tea decoctions caused a significant decrease of the Fe bioavailability from BSR meal (-19.6 +/- 4.9% and -14.9 +/- 4.1%, respectively). The reserve of Fe stored in the liver was significantly lower in the BSR, the black and the green tea groups than in the positive control group (FeSO4). The weight gains were significantly lower in the black and the green tea groups (3.9 +/- 5.7 g, 13 +/- 1.9 g, respectively) than in the BSR group (24.9 +/- 6 g). The addition of beef to BSR meal counteracted the inhibitory effect of the kidney bean and considerably improved the Fe bioavailability and the Fe stored in the liver of rats. The green tea decoction, which constitutes an important source of antioxidant factors, had the same inhibitory effect as the black tea decoction on the Fe bioavailability from BSR meal. In addition, both black and green teas significantly reduced the weight gains, where the black tea decoction has the most effect.

Separation of polyphenols and caffeine from the acetone extract of fermented tea leaves (Camellia sinensis) using high-performance countercurrent chromatography.

PubMed

Choi, Soo Jung; Hong, Yong Deog; Lee, Bumjin; Park, Jun Seong; Jeong, Hyun Woo; Kim, Wan Gi; Shin, Song Seok; Yoon, Kee Dong

2015-07-21

Leaves from Camellia sienensis are a popular natural source of various beverage worldwide, and contain caffeine and polyphenols derived from catechin analogues. In the current study, caffeine (CAF, 1) and three tea polyphenols including (-)-epigallocatechin 3-O-gallate (EGCg, 2), (-)-gallocatechin 3-O-gallate (GCg, 3), and (-)-epicatechin 3-O-gallate (ECg, 4) were isolated and purified by flow-rate gradient high-performance countercurrent chromatography (HPCCC) using a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:9:1:9, v/v). Two hundred milligrams of acetone-soluble extract from fermented C. sinensis leaves was separated by HPCCC to give 1 (25.4 mg), 2 (16.3 mg), 3 (11.1 mg) and 4 (4.4 mg) with purities over 98%. The structures of 1-4 were elucidated by QTOF-MS, as well as 1H- and 13C-NMR, and the obtained data were compared to the previously reported values.

Transfer of Ochratoxin A into Tea and Coffee Beverages

PubMed Central

Malir, Frantisek; Ostry, Vladimir; Pfohl-Leszkowicz, Annie; Toman, Jakub; Bazin, Ingrid; Roubal, Tomas

2014-01-01

Ochratoxin A (OTA) is nephrotoxic, hepatotoxic, immunotoxic, neurotoxic, reprotoxic, teratogenic, and carcinogenic (group 2B), being characterized by species and sex differences in sensitivity. Despite the fact that OTA is in some aspects a controversial topic, OTA is the most powerful renal carcinogen. The aim of this study was to make a small survey concerning OTA content in black tea, fruit tea, and ground roasted coffee, and to assess OTA transfer into beverages. OTA content was measured using a validated and accredited HPLC-FLD method with a limit of quantification (LOQ) of 0.35 ng/g. The OTA amount ranged from LOQ up to 250 ng/g in black tea and up to 104 ng/g in fruit tea. Black tea and fruit tea, naturally contaminated, were used to prepare tea infusions. The transfer from black tea to the infusion was 34.8% ± 1.3% and from fruit tea 4.1% ± 0.2%. Ground roasted coffee naturally contaminated at 0.92 ng/g was used to prepare seven kinds of coffee beverages. Depending on the type of process used, OTA transfer into coffee ranged from 22.3% to 66.1%. OTA intakes from fruit and black tea or coffee represent a non-negligible human source. PMID:25525684

Stability and immunogenicity of hypoallergenic peanut protein-polyphenol complexes during in vitro pepsin digestion.

PubMed

Plundrich, Nathalie J; White, Brittany L; Dean, Lisa L; Davis, Jack P; Foegeding, E Allen; Lila, Mary Ann

2015-07-01

Allergenic peanut proteins are relatively resistant to digestion, and if digested, metabolized peptides tend to remain large and immunoreactive, triggering allergic reactions in sensitive individuals. In this study, the stability of hypoallergenic peanut protein-polyphenol complexes was evaluated during simulated in vitro gastric digestion. When digested with pepsin, the basic subunit of the peanut allergen Ara h 3 was more rapidly hydrolyzed in peanut protein-cranberry or green tea polyphenol complexes compared to uncomplexed peanut flour. Ara h 2 was also hydrolyzed more quickly in the peanut protein-cranberry polyphenol complex than in uncomplexed peanut flour. Peptides from peanut protein-cranberry polyphenol complexes and peanut protein-green tea polyphenol complexes were substantially less immunoreactive (based on their capacity to bind to peanut-specific IgE from patient plasma) compared to peptides from uncomplexed peanut flour. These results suggest that peanut protein-polyphenol complexes may be less immunoreactive passing through the digestive tract in vivo, contributing to their attenuated allergenicity.

Effect of black tea consumption on brachial artery flow-mediated dilation and ischaemia-reperfusion in humans.

PubMed

Schreuder, Tim H A; Eijsvogels, Thijs M H; Greyling, Arno; Draijer, Richard; Hopman, Maria T E; Thijssen, Dick H J

2014-02-01

Tea consumption is associated with reduced cardiovascular risk. Previous studies found that tea flavonoids work through direct effects on the vasculature, leading to dose-dependent improvements in endothelial function. Cardioprotective effects of regular tea consumption may relate to the prevention of endothelial ischaemia-reperfusion (IR) injury. Therefore, we examined the effect of black tea consumption on endothelial function and the ability of tea to prevent IR injury. In a randomized, crossover study, 20 healthy subjects underwent 7 days of tea consumption (3 cups per day) or abstinence from tea. We examined brachial artery (BA) endothelial function via flow-mediated dilation (FMD), using high resolution echo-Doppler, before and 90 min after tea or hot water consumption. Subsequently, we followed a 20-min ischaemia and 20-min reperfusion protocol of the BA after which we measured FMD to examine the potential of tea consumption to protect against IR injury. Tea consumption resulted in an immediate increase in FMD% (pre-consumption: 5.8 ± 2.5; post-consumption: 7.2 ± 3.2; p < 0.01), whilst no such change occurred after ingestion of hot water. The IR protocol resulted in a significant decrease in FMD (p < 0.005), which was also present after tea consumption (p < 0.001). This decline was accompanied by an increase in the post-IR baseline diameter. In conclusion, these data indicate that tea ingestion improves BA FMD. However, the impact of the IR protocol on FMD was not influenced by tea consumption. Therefore, the cardioprotective association of tea ingestion relates to a direct effect of tea on the endothelium in humans in vivo.

Fabrication and characterization of tea polyphenols loaded pullulan-CMC electrospun nanofiber for fruit preservation.

PubMed

Shao, Ping; Niu, Ben; Chen, Hangjun; Sun, Peilong

2018-02-01

Edible packaging films using polymer for food preservation have been developed for a long time. In this study, the effects of different concentrations (0.5%, 1%, 1.5%, w/v) of tea polyphenols incorporated into pullulan-Carboxymethylcellulose sodium (Pul-CMC) solutions on electrospun nanofiber films were evaluated. The fiber size distribution was characterized by scanning electron microscopy. The morphological features of nanofibers were modulated through adjusting process parameters (e.g. concentration of polymer solution, applied voltage and feeding rate). Increasing the applied voltage from 19 to 21kV and the feed rate from 0.36 to 0.6mL/h leads to a reduction in mean fiber diameter. Fruit packaging potential was evaluated using strawberry. The pullulan-CMC-TP nanofibers significantly decreased weight loss and maintained the firmness of the strawberries, and improved the quality of the fruit during storage. The findings demonstrate a facile packaging route to improve food sustainability and reduce waste. Copyright © 2017 Elsevier B.V. All rights reserved.

The Effect of Different Tea Varieties on Iron Chelation

NASA Astrophysics Data System (ADS)

Truong, S. K.; Karim, R.

2016-12-01

The chief objectives of this experiment are to distinguish which type of tea of four variants, pomegranate blackberry green, green, lemon chamomile (herbal), and earl grey (black), are capable of chelating the most iron (III) chloride (FeCl3) through titration. We hypothesized that if each tea variety chelates differing amounts of iron chloride, and if we conduct an experiment in which four different teas are mixed in the same amount of water, iron chloride, and iron chloride indicator EDTA, then the pomegranate blackberry green tea will bind to the most iron due to its large amount of fruit antioxidants. To summarize our methodology, we prepared three solutions of each tea, dissolved with 1 gram of FeCl3 to test three trials per tea variety. The chelation process took place overnight as teas cooled. Six drops of iron chloride indicator added to each solution began the titration. The necessary amount of 0.1M EDTA (ethylenediaminetetraacetic acid) drops required for each solution to turn to a universal amber color from its original dark tone indicates how many free iron molecules were left unbound by the tea solution. After careful analysis of the data, we discovered that blackberry pomegranate green tea possessed the best chelating abilities with 97.48% of FeCl3 adsorbed. Green tea followed with 96.67%. Herbal tea chelated 94.24% of the iron while earl grey absorbed the least amount at 93.43%. From our conclusion, we drew that since blackberry pomegranate green tea contained the highest amount of polyphenols and antioxidants as well as epigallocatechin gallate (EGCG) found in green teas, it was able to chelate the most amount of iron. The substances mentioned in blackberry pomegranate green tea possess the ability to form strong bonds with multiple heavy metals, such as iron (III) chloride atoms. Overall, each variety of tea contains different organic substances. Each of these substances possesses a unique chelating ability, determining how well the type of tea can

Chemical composition and hepatoprotective effects of polyphenol-rich extract from Houttuynia cordata tea.

PubMed

Tian, Lingmin; Shi, Xiaolong; Yu, Linhong; Zhu, Jiao; Ma, Rui; Yang, Xingbin

2012-05-09

This study was designed to investigate the antioxidant activity, hepatoprotective effect, and phenolic composition of the ethyl acetate fraction (EAF) extracted from Houttuynia cordata tea. EAF was shown to exhibit strong ferric-reducing antioxidant power (FRAP) and scavenging activity against DPPH radical in vitro, and the antioxidant effects were further verified by suppressing CCl₄-induced oxidative stress in mouse liver at three tested doses of EAF (250, 500, and 1000 mg/kg bw). Pretreatment with EAF (1000 mg/kg bw) prior to CCl₄ administration significantly (p < 0.001) decreased the CCl₄-elevated levels of serum AST, ALT, alkaline phosphatase, total bilirubin, and hepatic MDA in mice and prevented the increases in GSH, SOD, and CAT caused by CCl₄. HPLC analysis revealed that three predominantly polyphenolic compounds present in EAF were quercitrin (111.7 μg/mg), quercetin (43.8 μg/mg), and hyperoside (29.1 μg/mg). These results combined with liver histopathology indicate that EAF possesses a significant protective effect against acute hepatotoxicity induced by CCl₄, which may be due to the strong antioxidant activity of phenolic components.

Evaluation of polyphenols and anthocyanins contents in black chockeberry--Photinia melanocarpa (Michx.) fruits extract.

PubMed

Symonowicz, Marzena; Sykuła-Zajac, Anna; Łodyga-Chruścińska, Elzbieta; Rumora, Ivana; Straukas, Martinas

2012-01-01

An evaluation of total polyphenols and anthocyanins contents in dietary supplements is important analysis in medical aspect of human and animal diets. The content of the mentioned compounds should be higher in 100 g of solid extracts than in 100 g of fruits. Thus, the presented work concerns the evaluation of total polyphenols and anthocyanins contents in black chockeberry--Photinia melanocarpa (Michx.) extract--dietary supplement (DS) available on market. The spectrophotometric analysis of DS were performed. The usage of certain conditions of measurements such as dilution factor, storage conditions and filtration, has the significance in the determination of the analyzed compounds in the extract.

Total phenolics and antioxidant activities of fenugreek, green tea, black tea, grape seed, ginger, rosemary, gotu kola, and ginkgo extracts, vitamin E, and tert-butylhydroquinone.

PubMed

Rababah, Taha M; Hettiarachchy, Navam S; Horax, Ronny

2004-08-11

The total phenolics and antioxidant activities of fenugreek, green tea, black tea, grape seed, ginger, rosemary, gotu kola, and ginkgo extracts, vitamin E, and tert-butylhydroquinone, were determined. Grape seed and green tea were analyzed for their phenolic constituents using high-performance liquid chromatography. The total phenolics of the plant extracts, determined by the Folin-Ciocalteu method, ranged from 24.8 to 92.5 mg of chlorogenic acid equivalent/g dry material. The antioxidant activities of methanolic extracts determined by conjugated diene measurement of methyl linoleate were 3.4-86.3%. The antioxidant activity of the extracts using chicken fat by an oxidative stability instrument (4.6-10.2 h of induction time) followed a similar trend in antioxidant activity as determined by the Folin-Ciocalteu method. Seven phenolics in grape seed and green tea extracts were identified that ranged from 15.38 to 1158.49 and 18.3 to 1087.02 mg/100 g of extract, respectively. Plant extracts such as green tea and grape seed extracts can be used to retard lipid oxidation in a variety of food products.

Serum gamma-glutamyltransferase is inversely associated with dietary total and coffee-derived polyphenol intakes in apparently healthy Japanese men.

PubMed

Taguchi, Chie; Kishimoto, Yoshimi; Kondo, Kazuo; Tohyama, Kazushige; Goda, Toshinao

2017-10-07

Serum γ-glutamyltransferase (GGT) has been proposed as a marker of oxidative stress. Here, we examined the association between serum GGT and the dietary intake of polyphenols, which have antioxidant properties. A cross-sectional survey including 7960 apparently healthy Japanese men (aged 22-86 years) who participated in health checkups was conducted in Shizuoka, Japan. We analyzed these subjects' clinical serum parameters and lifestyle factors, including dietary polyphenol intake, which was evaluated by a self-administered questionnaire and by matching the subjects' food consumption data with our original polyphenol content database. The average intake of polyphenols was 1157 ± 471 mg/day, and green tea was the largest source of polyphenols at 40%, followed by coffee at 36%. Dividing the population according to quintiles of total polyphenol intake, the difference in polyphenol intake from coffee between the groups was much greater than the difference in polyphenol intake from green tea. The analysis of the association between polyphenol intake and biological parameters showed a significant negative association between polyphenol intake and the levels of systolic and diastolic blood pressure (SBP and DBP), GGT, and alanine aminotransferase (ALT) after adjusting for age, smoking habit, energy intake and alcohol intake. The GGT levels were inversely associated with the polyphenol intake from coffee, but not with that from green tea. Multivariable linear regression analyses demonstrated that the subjects' GGT levels were negatively and independently associated with their polyphenol intake. The intake of total polyphenol including coffee as a major contributor is inversely associated with the serum GGT concentration in Japanese males.

Prediction of Moisture Content for Congou Black Tea Withering Leaves Using Image Features and Nonlinear Method.

PubMed

Liang, Gaozhen; Dong, Chunwang; Hu, Bin; Zhu, Hongkai; Yuan, Haibo; Jiang, Yongwen; Hao, Guoshuang

2018-05-18

Withering is the first step in the processing of congou black tea. With respect to the deficiency of traditional water content detection methods, a machine vision based NDT (Non Destructive Testing) method was established to detect the moisture content of withered leaves. First, according to the time sequences using computer visual system collected visible light images of tea leaf surfaces, and color and texture characteristics are extracted through the spatial changes of colors. Then quantitative prediction models for moisture content detection of withered tea leaves was established through linear PLS (Partial Least Squares) and non-linear SVM (Support Vector Machine). The results showed correlation coefficients higher than 0.8 between the water contents and green component mean value (G), lightness component mean value (L * ) and uniformity (U), which means that the extracted characteristics have great potential to predict the water contents. The performance parameters as correlation coefficient of prediction set (Rp), root-mean-square error of prediction (RMSEP), and relative standard deviation (RPD) of the SVM prediction model are 0.9314, 0.0411 and 1.8004, respectively. The non-linear modeling method can better describe the quantitative analytical relations between the image and water content. With superior generalization and robustness, the method would provide a new train of thought and theoretical basis for the online water content monitoring technology of automated production of black tea.

Green and black tea inhibit cytokine-induced IL-8 production and secretion in AGS gastric cancer cells via inhibition of NF-κB activity.

PubMed

Gutierrez-Orozco, Fabiola; Stephens, Brian R; Neilson, Andrew P; Green, Rodney; Ferruzzi, Mario G; Bomser, Joshua A

2010-10-01

Consumption of tea is associated with a reduced risk for several gastrointestinal cancers. Inflammatory processes, such as secretion of IL-8 from the gastric epithelium in response to chronic chemokine or antigen exposure, serve both as a chemoattractant for white blood cells and a prerequisite for gastric carcinogenesis. In this study, the gastric adenocarcinoma cell line AGS was used to investigate the effect of green tea extract, black tea extract, and epigallocatechin gallate (EGCG), the most abundant catechin in tea, on cytokine-induced inflammation. AGS cells were stimulated with interleukin-1β (IL-1β) to initiate inflammation, followed by exposure to either tea extracts or EGCG. We found that both green and black tea extracts at concentrations of 20 and 2 µM total catechins, respectively, significantly (p < 0.05) inhibited IL-1β-induced IL-8 production and secretion to a similar extent. Treatment of AGS cells with EGCG (8 µM) produced similar reductions in IL-1β-induced IL-8 production and secretion. Inhibition of NF-κB activity was found to be responsible, in part, for these observed effects. Our findings demonstrate that both green and black tea extracts with distinctly different catechin profiles, are capable of disrupting the molecular link between inflammation and carcinogenesis via inhibition of NF-κB activity in AGS cells. © Georg Thieme Verlag KG Stuttgart · New York.

Dietary polyphenols and colorectal cancer risk: The Fukuoka colorectal cancer study

PubMed Central

Wang, Zhen-Jie; Ohnaka, Keizo; Morita, Makiko; Toyomura, Kengo; Kono, Suminori; Ueki, Takashi; Tanaka, Masao; Kakeji, Yoshihiro; Maehara, Yoshihiko; Okamura, Takeshi; Ikejiri, Koji; Futami, Kitaroh; Maekawa, Takafumi; Yasunami, Yohichi; Takenaka, Kenji; Ichimiya, Hitoshi; Terasaka, Reiji

2013-01-01

AIM: To investigate the associations between dietary intake of polyphenols and colorectal cancer. METHODS: The study subjects were derived from the Fukuoka colorectal cancer study, a community-based case-control study. The study subjects were 816 cases of colorectal cancer and 815 community-based controls. The consumption of 148 food items was assessed by a computer-assisted interview. We used the consumption of 97 food items to estimate dietary intakes of total, tea and coffee polyphenols. The Phenol-Explorer database was used for 92 food items. Of the 5 foods which were not listed in the Phenol-Explorer Database, polyphenol contents of 3 foods (sweet potatoes, satoimo and daikon) were based on a Japanese study and 2 foods (soybeans and fried potatoes) were estimated by ORAC-based polyphenol contents in the United States Department of Agriculture Database. Odds ratios (OR) and 95%CI of colorectal cancer risk according to quintile categories of intake were obtained by using logistic regression models with adjustment for age, sex, residential area, parental history of colorectal cancer, smoking, alcohol consumption, body mass index 10 years before, type of job, leisure-time physical activity and dietary intakes of calcium and n-3 polyunsaturated fatty acids. RESULTS: There was no measurable difference in total or tea polyphenol intake between cases and controls, but intake of coffee polyphenols was lower in cases than in controls. The multivariate-adjusted OR of colorectal cancer according to quintile categories of coffee polyphenols (from the first to top quintile) were 1.00 (referent), 0.81 (95%CI: 0.60-1.10), 0.65 (95%CI: 0.47-0.89), 0.65 (95%CI: 0.46-0.89) and 0.82 (95%CI: 0.60-1.10), respectively (Ptrend = 0.07). Similar, but less pronounced, decreases in the OR were also noted for the third and fourth quintiles of total polyphenol intake. Tea polyphenols and non-coffee polyphenols showed no association with colorectal cancer risk. The site-specific analysis

Determination of some selected secondary metabolites and their invitro antioxidant activity in commercially available Ethiopian tea (Camellia sinensis).

PubMed

Bizuayehu, Dereje; Atlabachew, Minaleshewa; Ali, Mirtachew Tihar

2016-01-01

Eight brands of tea (Camellia sinensis),which are cultivated and commercially available in Ethiopian market, were analyzed for estimation of their total secondary metabolites (polyphenols, flavonoids and tannins) content and free radical scavenging activity which is expressed on dry weight basis. In this present study, the total polyphenols, tannin and flavonoid contents were studied spectrophotometrically using Folin-Dennis, Folin-Dennis/protein precipitation and aluminium chloride methods respectively. The free radical scavenging activity was determined by using DPPH radical assay. Results of the analysis revealed that the total polyphenol content varied from 21.3 ± 0.24 to 31.6 ± 0.31 mg of gallic acid equivalent/g of dry matter. Total flavonoids content in the tea samples varied from 8.17 ± 0.68 to 23.2 ± 0.68 mg of catechin equivalent/g of dry weight and tannin content varied from 5.64 ± 0.39 7.45 ± 0.27 mg tannic acid equivalent/g of dry weight basis. The free radical scavenging activity among the tea brand samples ranged from 28.8 ± 1.86 to 80.0 ± 0.63 mg ascorbic acid equivalent/g and the half maximal inhibitory concentration (IC50%) values varied from 7.3 ± 1.35 to 64.0 ± 2.81 µg/mL of extract. The correlation between the antioxidant activity with total polyphenol content (R = 0.91325), with flavonoids (R = 0.80658) and with tannin (R = 0.73125) was calculated and maximum correlation value was found between polyphenol content and the free radical scavenging activity of the tea samples. The results in this study also revealed that green tea had the higher polyphenolic content and found to have the most promising antioxidant activity. This study further confirmed that Ethiopia tea is reach in phenolic compounds as compared to some overseas tea cultivars/varieties.

Green tea and its anti-angiogenesis effects.

PubMed

Rashidi, Bahman; Malekzadeh, Mehrnoush; Goodarzi, Mohammad; Masoudifar, Aria; Mirzaei, Hamed

2017-05-01

The development of new blood vessels from a pre-existing vasculature (also known as angiogenesis) is required for many physiological processes including embryogenesis and post-natal growth. However, pathological angiogenesis is also a hallmark of cancer and many ischaemic and inflammatory diseases. The pro-angiogenic members of the VEGF family (vascular endothelial growth factor family), VEGF-A, VEGF-B, VEGF-C, VEGF-D and placental growth factor (PlGF), and the related receptors, VEGFR-1, VEGFR-2 and VEGFR-3 have a central and decisive role in angiogenesis. Indeed, they are the targets for anti-angiogenic drugs currently approved. Green tea (from the Camellia sinensis plant) is one of the most popular beverages in the world. It is able to inhibit angiogenesis by different mechanisms such as microRNAs (miRNAs). Green tea and its polyphenolic substances (like catechins) show chemo-preventive and chemotherapeutic features in various types of cancer and experimental models for human cancers. The tea catechins, including (-)-epigallocatechin-3-gallate (EGCG), have multiple effects on the cellular proteome and signalome. Note that the polyphenolic compounds from green tea are able to change the miRNA expression profile associated with angiogenesis in various cancer types. This review focuses on the ability of the green tea constituents to suppress angiogenesis signaling and it summarizes the mechanisms by which EGCG might inhibit the VEGF family. We also highlighted the miRNAs affected by green tea which are involved in anti-angiogenesis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Synergistic effects of green tea polyphenols and alphacalcidol on chronic inflammation-induced bone loss in female rats

PubMed Central

Yeh, J. K.; Cao, J. J.; Tatum, O. L.; Dagda, R. Y.; Wang, J.-S.

2010-01-01

Summary Studies suggest that green tea polyphenols (GTP) or alphacalcidol is promising agent for preventing bone loss. Findings that GTP supplementation plus alphacalcidol administration increased bone mass via a decrease of oxidative stress and inflammation suggest a significant role of GTP plus alphacalcidol in bone health of patients with chronic inflammation. Introduction Studies have suggested that green tea polyphenols (GTP) or alphacalcidol are promising dietary supplements for preventing bone loss in women. However, the mechanism(s) related to the possible osteo-protective role of GTP plus D3 in chronic inflammation-induced bone loss is not well understood. Methods This study evaluated bioavailability, efficacy, and related mechanisms of GTP in combination with alphacalcidol in conserving bone loss in rats with chronic inflammation. A 12-week study of 2 (no GTP vs. 0.5% GTP in drinking water) × 2 (no alphacalcidol vs. 0.05 μg/kg alphacalcidol, 5×/week) factorial design in lipopolysaccharide-administered female rats was performed. In addition, a group receiving placebo administration was used to compare with a group receiving lipopolysaccharide administration only to evaluate the effect of lipopolysaccharide. Results Lipopolysaccharide administration resulted in lower values for bone mass, but higher values for serum tartrate-resistant acid phosphatase (TRAP), urinary 8-hydroxy-2′-deoxyguanosine, and mRNA expression of tumor necrosis factor-α and cyclooxygenase-2 in spleen. GTP supplementation increased urinary epigallocatechin and epicatechin concentrations. Both GTP supplementation and alphacalcidol administration resulted in a significant increase in bone mass, but a significant decrease in serum TRAP levels, urinary 8-hydroxydeoxyguanosine levels, and mRNA expression of tumor necrosis factor-α and cyclooxygenase-2 in spleen. A synergistic effect of GTP and alphacalcidol was observed in these parameters. Neither GTP nor alphacalcidol affected

Green synthesis of iron nanoparticles by various tea extracts: comparative study of the reactivity.

PubMed

Huang, Lanlan; Weng, Xiulan; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravendra

2014-09-15

Iron nanoparticles (Fe NPs) are often synthesized using sodium borohydride with aggregation, which is a high cost process and environmentally toxic. To address these issues, Fe NPs were synthesized using green methods based on tea extracts, including green, oolong and black teas. The best method for degrading malachite green (MG) was Fe NPs synthesized by green tea extracts because it contains a high concentration of caffeine/polyphenols which act as both reducing and capping agents in the synthesis of Fe NPs. These characteristics were confirmed by a scanning electron microscope (SEM), UV-visible (UV-vis) and specific surface area (BET). To understand the formation of Fe NPs using various tea extracts, the synthesized Fe NPs were characterized by SEM, X-ray energy-dispersive spectrometer (EDS), and X-ray diffraction (XRD). What emerged were different sizes and concentrations of Fe NPs being synthesized by tea extracts, leading to various degradations of MG. Furthermore, kinetics for the degradation of MG using these Fe NPs fitted well to the pseudo first-order reaction kinetics model with more than 20 kJ/mol activation energy, suggesting a chemically diffusion-controlled reaction. The degradation mechanism using these Fe NPs included adsorption of MG to Fe NPs, oxidation of iron, and cleaving the bond that was connected to the benzene ring. Copyright © 2014 Elsevier B.V. All rights reserved.

Extractability of polyphenols from black currant, red currant and gooseberry and their antioxidant activity.

PubMed

Laczkó-Zöld, Eszter; Komlósi, Andrea; Ülkei, Timea; Fogarasi, Erzsébet; Croitoru, Mircea; Fülöp, Ibolya; Domokos, Erzsébet; Ştefănescu, Ruxandra; Varga, Erzsébet

2018-06-01

In this study, we analyzed extracts of Ribes (black currant, red currant and gooseberry) fruits obtained with methanol, methanol 50% and water. For each extract total polyphenol content, total flavonoid content and total anthocyanin content was assessed. The antioxidant activity of extracts was evaluated by 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging capacity and by the photo-chemiluminescence (PCL) method. Identification and quantification of individual phenolic compounds was performed by means of high performance liquid chromatograph coupled with diode array detector (HPLC-DAD) analyses. From each fruit, best extraction of polyphenols was obtained with methanol 50%. In case of red currants and gooseberry there was no significant difference in flavonoids and anthocyanins extraction rate by the different extraction solvents. For black currants the methanol and methanol 50% extract presented the highest antioxidant activity. For red currants extracts with methanol 50% showed stronger antioxidant activity (IC 50 = 5.71 mg/ml for DPPH, IC 50 = 1.17 mg/ml for ABTS) than those with methanol or water. In case of gooseberry by the DPPH test the water extract proved to be the most active (IC 50 = 5.9 mg/ml). In the PCL test black currants methanol 50% extract was over 6 times more powerful as the ones from red currants. In case of gooseberries, water extract presented the highest antioxidant activity (41.84 μmol AAE/g). In black currant cyanidin-3-glucoside was the major compound. Quercetin 3-O-glucoside was identified in each sample. From cinnamic acid derivatives neochlorogenic acid was present in black currants in the highest amount (356.33 μg/g).

Comparison of Catechins and Antioxidant Activity in Four kinds of Sichuan tea

NASA Astrophysics Data System (ADS)

Li, Jianhua; Chen, Shengxiang; Zhu, Mingzhu; Meng, Xueli

2017-11-01

Absract:Catechins of the nine representative teas produced in Sichuan, which belonged to green tea, yellow tea, dark tea and black tea, were determined by UHPLC. Their antioxidant activity was determined by the hydroxyl radical scavenging. The results showed that: the total amount of their catechins was between 0.45(Qingzhuan) ˜ 121.21 mg/g (Mengding ganlu), and the order for theirs was green tea > yellow tea > dark tea (black tea); except Qingzhuan, their EGCG contents were between 1.07 ± 0.01 (Chuanhong gongfu) ˜ 76.16 ±0.43 mg/g (Mengding ganlu), and the order for theirs was green tea > yellow tea> dark tea (black tea); EGCG3“Me, which only remained in green and yellow tea, their contents were between 0.05±0.02 (Mengding Huangya) ˜ 0.39±0.04 mg/g (Mengding ganlu); their hydroxyl radical scavenging was between 48.37±0.20 (Fuzhuan) ˜75.51±0.63% (Mengding Huangya) and their IC50 was between 3.31±0.028 ˜5.18±0.012 mg/mL, the order for their clear rates was yellow tea> green tea> dark tea (black tea). Mengding Huangya showed the highest antioxidant activity in sichuan tea.

Effects of tea polyphenols on the post-mortem integrity of large yellow croaker (Pseudosciaena crocea) fillet proteins.

PubMed

Zhao, Jin; Lv, Weijin; Wang, Jinlin; Li, Jianrong; Liu, Xiaoxiang; Zhu, Junli

2013-12-01

Tea polyphenols (TP) are known to be important for the post-mortem deterioration of fish muscle and can enhance food quality. To shed light on the influence of TP on the status of large yellow croaker muscle proteins, control and treated fillets (0.1% TP, 0.2% TP and 0.3% TP, w/v) were analysed periodically for myofibrillar protein functional properties (Ca(2+)-ATPase activity, surface hydrophobicity, total sulfhydryl content, emulsion stability index and rheological behaviour). Degradation of the myofibrillar protein myosin could be clearly observed; several proteins were also observed to vary in abundance following post-mortem storage for 25 days. The present study offers new evidence that TP have an effective impact on muscle protein integrity post-mortem. Copyright © 2013 Elsevier Ltd. All rights reserved.

Synergistic effects and related bioactive mechanisms of Potentilla fruticosa Linn. leaves combined with green tea polyphenols studied with microbial test system (MTS).

PubMed

Liu, Ze-Hua; Luo, Zi-Wen; Li, Deng-Wu; Wang, Dong-Mei; Ji, Xia

2018-06-01

Previous research found Potentilla fruticosa leaf extracts (PFE) combined with green tea polyphenols (GTP) showed obvious synergistic effects based on chemical mechanisms. This study further confirmed the synergy of PFE + GTP viewed from bioactivities using the microbial test system (MTS). The MTS antioxidant activity results showed the combination of PFE + GTP exhibited synergistic effect and the ratio 3:1 showed the strongest synergy, which were in accordance with the results in H 2 O 2 production rate. The combination of PFE + GTP promoted CAT and SOD enzyme activity and their gene expression especially at the ratio 3:1. Therefore, the synergism of PFE + GTP may be due to the promotion of CAT and SOD genes expression which enhanced the CAT and SOD enzyme activities. These results confirmed the synergy of PFE + GTP and could provide theoretical basis to produce a compounded tea made of a mixture of leaves from Potentilla species.

Whitening Effect of Black Tea Water Extract on Brown Guinea Pig Skin

PubMed Central

Choi, So-Young

2011-01-01

To evaluate the whitening effect of black tea water extract (BT), BT was topically applied to artificially hyperpigmented spots on the back skins of brown guinea-pigs (weight: 450~500 g) induced by 1,500 mJ/ cm2 of ultraviolet B (UVB) irradiation. The test compounds of 30 μl were applied twice a day, six days a week, for four weeks. The artificially hyperpigmented spots were divided into 5 groups: control (UVB + saline, C), vehicle control [UVB + propylene glycol: ethanol: water (5 : 3 : 2), VC], positive control (UVB + 2% hydroquinone, PC), experimental 1 (UVB + 1% BT), experimental 2 (UVB + 2% BT). After 4-week application, the spots were removed by biopsy punch under anesthetic condition and used as specimens for the histological examination. The total polyphenol and flavonoid contents of BT were 104 and 91 mg/g, respectively. The electron-donating ability of BT revealed a dose-dependent response, showing the excellent capacities of 86% at 800 μg/ml. The artificially hyperpigmented spots treated with the PC and BT were obviously lightened compared to the C and VC groups. At the fourth week, the melanin indices for the PC and BT groups were significantly lower (p < 0.00l) than those of the C and VC groups. In histological examination, PC and BT groups were significantly reduced in the melanin pigmentation, the proliferation of melanocytes and the synthesis of melanosomes compared to the C and VC groups. It is found that BT inhibits the proliferation of melanocytes and synthesis of melanosomes in vivo using brown guinea pigs, thereby showing a definite skin whitening effect. PMID:24278566

Associations between black tea and coffee consumption and risk of lung cancer among current and former smokers.

PubMed

Baker, Julie A; McCann, Susan E; Reid, Mary E; Nowell, Susan; Beehler, Gregory P; Moysich, Kirsten B

2005-01-01

Although cigarette smoking is a clear risk factor for lung cancer, the other determinants of lung cancer risk among smokers are less clear. Tea and coffee contain catechins and flavonoids, which have been shown to exhibit anticarcinogenic properties. Conversely, caffeine may elevate cancer risk through a variety of mechanisms. The current study investigated the effects of regular consumption of black tea and coffee on lung cancer risk among 993 current and former smokers with primary incident lung cancer and 986 age-, sex-, and smoking-matched hospital controls with non-neoplastic conditions. Results indicated that lung cancer risk was not different for those with the highest black tea consumption (>or=2 cups/day) compared with nondrinkers of tea [adjusted odds ratio (aOR)=0.90; 95% confidence interval (CI)=0.66-1.24]. However, elevated lung cancer risk was observed for participants who consumed 2-3 cups of regular coffee daily (aOR=1.34; 95% CI=0.99-1.82) or >or=4 cups of regular coffee daily (aOR=1.51, 95% CI=1.11-2.05). In contrast, decaffeinated coffee drinking was associated with decreased lung cancer risk for both participants who consumed or=2 cups/day (aOR=0.64; 95% CI=0.51-0.80). These results suggest that any chemoprotective effects of phytochemicals in coffee and tea may be overshadowed by the elevated risk associated with caffeine in these beverages.

Noni leaf and black tea enhance bone regeneration in estrogen-deficient rats.

PubMed

Shalan, Nor Aijratul Asikin Mohd; Mustapha, Noordin M; Mohamed, Suhaila

2017-01-01

Black tea and Nonileaf are among the dietary compounds that can benefit patients with bone resorption disorders. Their bone regeneration effects and their mechanisms were studied in estrogen-deficient rats. Noni leaves (three doses) and black tea water extracts were fed to ovariectomized rats for 4 mo, and their effects (analyzed via mechanical measurements, micro-computed tomography scan, and reverse transcriptase polymerase chain reaction mRNA) were compared with Remifemin (a commercial phytoestrogen product from black cohosh). The water extracts (dose-dependently for noni leaves) increased bone regeneration biomarker (runt-related transcription factor 2, bone morphogenetic protein 2, osteoprotegerin, estrogen receptor 1 [ESR1], collagen type I alpha 1A) expressions and reduced the inflammatory biomarkers (interleukin-6, tumor necrosis factor-α, nuclear factor [NF]-κB, and receptor activator of NF-κB ligand) mRNA expressions/levels in the rats. The extracts also improved bone physical and mechanical properties. The extracts demonstrated bone regeneration through improving bone size and structure, bone mechanical properties (strength and flexibility), and bone mineralization and density. The catechin-rich extract favored bone regeneration and suppressed bone resorption. The mechanisms involved enhancing osteoblast generation and survival, inhibiting osteoclast growth and activities, suppressing inflammation, improving bone collagen synthesis and upregulating ESR1 expression to augment phytoestrogenic effects. Estrogen deficiency bone loss and all extracts studied (best effect from Morinda leaf at 300 mg/kg body weight) mitigated the loss, indicating benefits for the aged and menopausal women. Copyright © 2016 Elsevier Inc. All rights reserved.

Annotation of Different Dehydrocatechin Oligomers by MS/MS and Their Occurrence in Black Tea.

PubMed

Verloop, Annewieke J W; Gruppen, Harry; Vincken, Jean-Paul

2016-08-03

Dehydrocatechins (DhC's), oligomeric oxidation products of (epi)catechins, were formed in model incubations of epicatechin with mushroom tyrosinase. DhC oligomers up to tetramers were detected by reversed-phase ultrahigh-performance liquid chromatography mass spectrometry (RP-UHPLC-MS) analysis. Measurements with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) showed formation of oligomers up to at least 15 catechin subunits. Isomeric DhC's were obtained, and a method based on MS(2) fragment ratios was set up to distinguish between the different interflavanic configurations of the isomers. In the model incubation, 8 dehydrodicatechins (DhC2's) and 22 dehydrotricatechins (DhC3's) were tentatively annotated by their MS(2) signature fragments. Three different interflavanic configuration types were determined for the DhC2's. DhC2's and DhC3's were shown to occur in a black tea extract for the first time. For the DhC2's, at least two isomeric types, i.e., DhC β and DhC ε, could be annotated in black tea.

White and green teas (Camellia sinensis var. sinensis): variation in phenolic, methylxanthine, and antioxidant profiles.

PubMed

Unachukwu, Uchenna J; Ahmed, Selena; Kavalier, Adam; Lyles, James T; Kennelly, Edward J

2010-08-01

Recent investigations have associated white teas with anti-carcinogenic, immune-boosting, and antioxidative properties that may impact human health in a manner comparable to green teas. An in-depth chemical analysis of white tea types was conducted to quantify polyphenols and antioxidant potential of 8 commercially available white teas, and compare them to green tea. Extraction and HPLC protocols were optimized and validated for the quantification of 9 phenolic and 3 methylxanthine compounds to examine inter- and intra-variation in white and green tea types and subtypes. A sampling strategy was devised to assess various subtypes procured from different commercial sources. Variation in antioxidant activity and total phenolic content (TPC) of both tea types was further assessed by the 1-1-diphenyl-2-picrylhydrazyl (DPPH) and Folin-Ciocalteau (F-C) assays, respectively. Total catechin content (TCC) for white teas ranged widely from 14.40 to 369.60 mg/g of dry plant material for water extracts and 47.16 to 163.94 mg/g for methanol extracts. TCC for green teas also ranged more than 10-fold, from 21.38 to 228.20 mg/g of dry plant material for water extracts and 32.23 to 141.24 mg/g for methanol extracts. These findings indicate that statements suggesting a hierarchical order of catechin content among tea types are inconclusive and should be made with attention to a sampling strategy that specifies the tea subtype and its source. Certain white teas have comparable quantities of total catechins to some green teas, but lesser antioxidant capacity, suggesting that white teas have fewer non-catechin antioxidants present. Practical Application: In this investigation white and green teas were extracted in ways that mimic common tea preparation practices, and their chemical profiles were determined using validated analytical chemistry methods. The results suggest certain green and white tea types have comparable levels of catechins with potential health promoting qualities

[Short-term screening of anticarcinogenic ingredients of tea by cell biology assays].

PubMed

Liu, L; Han, C; Chen, J

1998-01-01

By using a panel of short term cell biology assays, several ingredients of tea (tea pigments, caffeine, tea polysaccharide, tea polyphenols tablet and mixed tea) were screened in order to investigate their anticarcinogenic effects. The cytokinesis block micronuclei test in V79 cells induced by mitomycin, the test of metabolic cooperation between V79 and M cells and the test of growth ability of Hela cells in soft agar were used in the screening. The results showed that the six kinds of tea ingredients tested were effective in the test involved in different stages of carcinogenesis, i.e. initiation, promotion and progression. The effects of mixed tea and tea pigments were the strongest among the ingredients tested.

Polyphenolic profile and biological activities of black carrot crude extract (Daucus carota L. ssp. sativus var. atrorubens Alef.).

PubMed

Smeriglio, A; Denaro, M; Barreca, D; D'Angelo, V; Germanò, M P; Trombetta, D

2018-01-01

Black carrot (Daucus carota L. ssp. sativus var. atrorubens Alef.) is a valuable source of carbohydrates, minerals and vitamins and contains also high amounts of anthocyanins giving the characteristic deep-purple color. These latter compounds are known as natural dyes used in the food and pharmaceutical industry that have recently attracted much attention for their healthful properties. The aim of this work was to investigate for the first time the polyphenolic profile and biological properties of a black carrot crude extract (BCCE) through an in-depth analysis of the main polyphenolic classes evaluating its antioxidant, cytoprotective and anti-angiogenic properties. Twenty five polyphenols were quantified by LC-DAD-FLD-MS/MS analysis (anthocyanins 78.06%, phenolic acids 17.89% and other flavonoids 4.06%) with polyglycosylated cyanidins as major components. In addition, BCCE showed a strong antioxidant and free radical scavenging activity particularly in the hydrogen transfer-based assays (ORAC and β-carotene bleaching) and a significant increase in the cell viability. Furthermore, BCCE exhibited a strong anti-angiogenic activity at the highest concentration assayed on the chick chorioallantoic membrane (50μg/egg). In conclusion, the obtained results demonstrated the antioxidant, cytoprotective and anti-angiogenic properties of BCCE, which highlight that the higher biological activity of BCCE is probably due to the synergic effects exerted by various polyphenolic classes. Copyright © 2017 Elsevier B.V. All rights reserved.

Green tea polyphenol treatment attenuates atherosclerosis in high-fat diet-fed apolipoprotein E-knockout mice via alleviating dyslipidemia and up-regulating autophagy

PubMed Central

Jiang, Jinjin; Yu, Pengxin; Zhang, Guofu; Zhang, Guanghui; Liu, Xiaoting

2017-01-01

Background: Green tea polyphenol (GTP) is a polyphenol source from green tea that has drawn wide attention owing to epidemiological evidence of its beneficial effects in the prevention of cardiovascular disease; the underlying molecular mechanisms of these effects are not well understood. This study aimed to investigate the effects of GTP treatment on autophagy regulation in the vessel wall and lipid metabolism of HFD-fed male ApoE-knockout mice. Methods: Adult male ApoE-knockout mice (n = 30) fed with a high-fat diet (HFD) were treated with either vehicle or GTP (3.2 or 6.4 g/L) administered via drinking water for 15 weeks, and C57BL/6J mice fed with standard chow diet (STD) were used as the control group. Metabolic parameters, expression of key mRNAs and proteins of hepatic lipid metabolism and autophagy in the vessel wall of mice were determined after the 15-week treatment. Results: A HFD induced atherosclerosis formation and lipid metabolism disorders as well as reduced autophagy expression in the vessel wall of ApoE-knockout mice, but GTP treatment alleviated the lipid metabolism disorders, decreased the oxLDL levels in serum, and increased the mRNA and protein expressions of hepatic PPARα and autophagy markers (LC3, Beclin1 and p62) in the vessel wall of ApoE-knockout mice. Conclusions: Our findings suggest that GTP supplementation showed marked suppression of atherogenesis through improved lipid metabolism as well as through a direct impact on oxLDL and autophagy flux in the vessel wall. PMID:28777810

An EPR study on tea: Identification of paramagnetic species, effect of heat and sweeteners

NASA Astrophysics Data System (ADS)

Bıyık, Recep; Tapramaz, Recep

2009-10-01

Tea ( Camellia Sinensis) is the most widely consumed beverage in the world, and is known to be having therapeutic, antioxidant and nutritional effects. Electron paramagnetic resonance (EPR) spectral studies made on the tea cultivated along the shore of Black Sea, Turkey, show Mn 2+ and Fe 3+ centers in green tea leaves and in black tea extract. Dry black tea flakes and dry extract show additional sharp line attributed to semiquinone radical. The origins of the paramagnetic species in black tea are defined and discussed. Effect of humidity and heat are investigated. It is observed that dry extract of black tea melts at 100 °C and the semiquinone radical lives up to 140 °C while Mn 2+ sextet disappears just above 100 °C in tea extract. Natural and synthetics sweeteners have different effects on the paramagnetic centers. White sugar (sucrose) quenches the Mn 2+ and semiquinone lines in black tea EPR spectrum, and glucose, fructose, lactose and maltose quench Fe 3+ line while synthetic sweeteners acesulfam potassium, aspartame and sodium saccharine do not have any effect on paramagnetic species in tea.

An EPR study on tea: identification of paramagnetic species, effect of heat and sweeteners.

PubMed

Biyik, Recep; Tapramaz, Recep

2009-10-15

Tea (Camellia Sinensis) is the most widely consumed beverage in the world, and is known to be having therapeutic, antioxidant and nutritional effects. Electron paramagnetic resonance (EPR) spectral studies made on the tea cultivated along the shore of Black Sea, Turkey, show Mn(2+) and Fe(3+) centers in green tea leaves and in black tea extract. Dry black tea flakes and dry extract show additional sharp line attributed to semiquinone radical. The origins of the paramagnetic species in black tea are defined and discussed. Effect of humidity and heat are investigated. It is observed that dry extract of black tea melts at 100 degrees C and the semiquinone radical lives up to 140 degrees C while Mn(2+) sextet disappears just above 100 degrees C in tea extract. Natural and synthetics sweeteners have different effects on the paramagnetic centers. White sugar (sucrose) quenches the Mn(2+) and semiquinone lines in black tea EPR spectrum, and glucose, fructose, lactose and maltose quench Fe(3+) line while synthetic sweeteners acesulfam potassium, aspartame and sodium saccharine do not have any effect on paramagnetic species in tea.

PLGA-encapsulated tea polyphenols enhance the chemotherapeutic efficacy of cisplatin against human cancer cells and mice bearing Ehrlich ascites carcinoma

PubMed Central

Singh, Madhulika; Bhatnagar, Priyanka; Mishra, Sanjay; Kumar, Pradeep; Shukla, Yogeshwer; Gupta, Kailash Chand

2015-01-01

The clinical success of the applicability of tea polyphenols awaits efficient systemic delivery and bioavailability. Herein, following the concept of nanochemoprevention, which uses nanotechnology for enhancing the efficacy of chemotherapeutic drugs, we employed tea polyphenols, namely theaflavin (TF) and epigallocatechin-3-gallate (EGCG) encapsulated in a biodegradable nanoparticulate formulation based on poly(lactide-co-glycolide) (PLGA) with approximately 26% and 18% encapsulation efficiency, respectively. It was observed that TF/EGCG encapsulated PLGA nanoparticles (NPs) offered an up to ~7-fold dose advantage when compared with bulk TF/EGCG in terms of exerting its antiproliferative effects and also enhanced the anticancer potential of cisplatin (CDDP) in A549 (lung carcinoma), HeLa (cervical carcinoma), and THP-1 (acute monocytic leukemia) cells. Cell cycle analysis revealed that TF/EGCG-NPs were more efficient than bulk TF/EGCG in sensitizing A549 cells to CDDP-induced apoptosis, with a dose advantage of up to 20-fold. Further, TF/EGCG-NPs, alone or in combination with CDDP, were more effective in inhibiting NF-κB activation and in suppressing the expression of cyclin D1, matrix metalloproteinase-9, and vascular endothelial growth factor, involved in cell proliferation, metastasis, and angiogenesis, respectively. EGCG and TF-NPs were also found to be more effective than bulk TF/EGCG in inducing the cleavage of caspase-3 and caspase-9 and Bax/Bcl2 ratio in favor of apoptosis. Further, in vivo evaluation of these NPs in combination with CDDP showed an increase in life span (P<0.05) in mice bearing Ehrlich’s ascites carcinoma cells, with apparent regression of tumor volume in comparison with mice treated with bulk doses with CDDP. These results indicate that EGCG and TF-NPs have superior cancer chemosensitization activity when compared with bulk TF/EGCG. PMID:26586942

Immunochemical detection of food-derived polyphenols in the aorta: macrophages as a major target underlying the anti-atherosclerotic activity of polyphenols.

PubMed

Kawai, Yoshichika

2011-01-01

It has been suggested that polyphenol-rich diets decrease the risk of cardiovascular diseases. Although studies of the bioavailability of polyphenols, particularly their absorption and metabolism, have been reported recently, the tissue and cellular distributions underlying their biological mechanisms remain unknown. It is difficult to evaluate the specific localization of tissue and/or cellular polyphenols, because the method is limited to chromatography. To overcome these difficulties, we have developed anti-polyphenol antibodies to characterize immunohistochemically the localization of polyphenols and their metabolites in vivo. Two novel monoclonal antibodies were raised against quercetin and tea catechins, which represent flavonoid-type polyphenols distributed in foods and beverages, and are expected to exhibit anti-oxidative and anti-inflammatory activities in vivo. Using these antibodies, we identified activated macrophages as a specific target of these flavonoids during the development of atherosclerotic lesions. This review describes recent findings on the molecular actions of flavonoids that underly their anti-atherosclerotic activity in vivo.

Effect of polyphenols on oxidative stress and mitochondrial dysfunction in neuronal death, brain edema, and cell swelling in cerebral ischemia

USDA-ARS?s Scientific Manuscript database

Polyphenols are natural substances with variable phenolic structures and are elevated in vegetables, fruits, grains, bark, roots, tea, and wine. while there are over 8000 polyphenolic structures identified in plants, edible plants contain only several hundred polyphenolic structures. In addition t...

Effect of theanine and polyphenols enriched fractions from decaffeinated tea dust on the formation of Maillard reaction products and sensory attributes of breads.

PubMed

Culetu, Alina; Fernandez-Gomez, Beatriz; Ullate, Monica; del Castillo, Maria Dolores; Andlauer, Wilfried

2016-04-15

The antiglycoxidative properties of theanine (TEF) and polyphenols enriched fractions (PEF) prepared from tea dust were tested in a model system composed of bovine serum albumin (BSA) and methylglyoxal (MGO). PEF caused a decrease in available free amino groups of BSA in presence and absence of MGO, suggesting the simultaneous occurrence of glycoxidation reaction and phenols-protein interaction. The presence of PEF and TEF inhibited formation of fluorescent advanced glycation end-products (AGEs). Moreover, theanine (TB) and polyphenol-enriched bread (PB) were formulated. A significant increase in free amino groups was observed in TBs with a dose-response effect, while addition of PEF in bread produced a significant decrease (p<0.05). PEF efficiently reduced fluorescent AGE formation in breads compared with TEF. The results are in line with the simplified model systems. PEF used as food ingredient allows obtaining a tasty food possessing health promoting properties and lower content of potential harmful compounds (AGEs). Copyright © 2015 Elsevier Ltd. All rights reserved.

Polyphenols and Prostate Cancer Chemoprevention

DTIC Science & Technology

2005-03-01

ABSTRACT (Maximum 200 Words) The goal of this research is to Investigate the potential of (-)- epigallocatechin -3- gallate ( EGCG ), genistein and resveratrol...prostate chemoprevention are the soy isoflavone, genistein, and the tea catechin, (-)- epigallocatechin -3- gallate ( EGCG ). Another polyphenol that has...adenocarcinoma (TRAMP)). The specific aims are 1) to investigate the potential of genistein, EGCG and resveratrol, alone and in combination, to

Interactions between tea catechins and casein micelles and their impact on renneting functionality.

PubMed

Haratifar, Sanaz; Corredig, Milena

2014-01-15

Many studies have shown that tea catechins bind to milk proteins. This research focused on the association of tea polyphenols with casein micelles, and the consequences of the interactions on the renneting behaviour of skim milk. It was hypothesized that epigallocatechin-gallate (EGCG), the main catechin present in green tea, forms complexes with the casein micelles and that the association modifies the processing functionality of casein micelles. The binding of EGCG to casein micelles was quantified using HPLC. The formation of catechin-casein micelles complexes affected the rennet induced gelation of milk, and the effect was concentration dependent. Both the primary as well as the secondary stage of gelation were affected. These experiments clearly identify the need for a better understanding of the effect of tea polyphenols on the processing functionality of casein micelles, before milk products can be used as an appropriate platform for delivery of bioactive compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

Phytochemical Screening and Antimicrobial Properties of a Common Brand of Black Tea (Camellia sinensis) Marketed in Nigerian Environment.

PubMed

Olosunde, O Funmilayo; Abu-Saeed, Kamaldeen; Abu-Saeed, Muhammad Buhari

2012-01-01

This study is aimed at determining chemical constituents and antimicrobial activities of a common brand of black tea (Lipton®) in Nigeria. Standard methods were employed for testing carbohydrates, tannins, saponins, flavonoids, alkaloids, steroids and terpenes in the tea. Antimicrobial activities of methanolic and aqueous extracts of the tea on four standard strains of organisms: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis were also determined by standard methods. RESULTs showed that the tea contains tannin and reducing sugar. Concentrations of 1%, 2%, 4%, 6%, 8% and 10% aqueous and methanolic extract of black tea were prepared and their zones of inhibition determined against the four test organisms using the cup plate method. This was compared with zones for standard disc Gentamicin (10 µg) and Erythromycin (15 µg). Pseudomonas aeruginosa was sensitive to 2% to 10% aqueous extracts and intermediate to 6%, 8% and 10% methanolic extracts. E. coli was intermediately sensitive to 6%, 8% and 10% aqueous extract and 2% to 10% methanolic extracts. B. subtilis was intermediately sensitive to 4%, 6% and 8% aqueous extract and 4% to 10% methanolic extract but sensitive to 10% aqueous extract. Staph.aureus was intermediately sensitive to 4% to 10% aqueous extracts and 2% to 10% methanolic extracts. B. subtilis had the lowest MIC values of both aqueous and methanolic extracts. In conclusion, this study has shown that Lipton® has antimicrobial properties on E.coli, Staph.aureus, B.subtilis and Ps.aeruginosa and contains tannin and reducing sugar.

Intelligent evaluation of color sensory quality of black tea by visible-near infrared spectroscopy technology: A comparison of spectra and color data information

NASA Astrophysics Data System (ADS)

Ouyang, Qin; Liu, Yan; Chen, Quansheng; Zhang, Zhengzhu; Zhao, Jiewen; Guo, Zhiming; Gu, Hang

2017-06-01

Instrumental test of black tea samples instead of human panel test is attracting massive attention recently. This study focused on an investigation of the feasibility for estimation of the color sensory quality of black tea samples using the VIS-NIR spectroscopy technique, comparing the performances of models based on the spectra and color information. In model calibration, the variables were first selected by genetic algorithm (GA); then the nonlinear back propagation-artificial neural network (BPANN) models were established based on the optimal variables. In comparison with the other models, GA-BPANN models from spectra data information showed the best performance, with the correlation coefficient of 0.8935, and the root mean square error of 0.392 in the prediction set. In addition, models based on the spectra information provided better performance than that based on the color parameters. Therefore, the VIS-NIR spectroscopy technique is a promising tool for rapid and accurate evaluation of the sensory quality of black tea samples.

Effects of plant polyphenols and a-tocopherol on lipid oxidation, microbiological characteristics, and biogenic amines formation in dry-cured bacons

USDA-ARS?s Scientific Manuscript database

Effects of plant polyphenols (tea polyphenol, grape seed extract, and gingerol) and a-tocopherol on physicochemical parameters, microbiological counts, and biogenic amines were determined in dry-cured bacons at the end of ripening. Results showed that plant polyphenols and a-tocopherol significantly...

Antioxidant-mediated preventative effect of Dragon-pearl tea crude polyphenol extract on reserpine-induced gastric ulcers.

PubMed

Yi, Ruokun; Wang, Rui; Sun, Peng; Zhao, Xin

2015-07-01

Dragon-pearl tea is a type of green tea commonly consumed in Southwest China. In the present study, the antioxidative and anti-gastric ulcer effects of Dragon-pearl tea crude polyphenols (DTCP) were determined in vitro and in vivo . Treatment with 25, 50 or 100 µg/ml DTCP resulted in notable antioxidant effects in vitro , which manifested as 2,2-diphenyl-1-picrylhydrazyl and OH radical-scavenging activity. Furthermore, using an in vivo mouse model, DTCP was shown to reduce the gastric ulcer area in the stomach, in which the 200 mg/kg DTCP dose exhibited the most marked effect, with a gastric ulcer index inhibitory rate of 72.63%. In addition, DTCP was demonstrated to improve stomach acidity conditions in vivo by increasing the pH and reducing the level of gastric juice, as compared with the reserpine-induced gastric ulcer control mice. Furthermore, DTCP altered the serum levels of a number of oxidation-related biomolecules, including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), lipid peroxidation (LPO) and catalase (CAT), to subsequently exert an anti-gastric ulcer effect. Treatment with 50, 100 and 200 mg/kg DTCP increased the SOD, GSH-Px and CAT levels and reduced the MDA and LPO levels in the mouse model of gastric ulcers. These serum level alterations resulted in the modified serum levels of prostaglandin E2 (PGE2) and nitric oxide (NO), which are associated with gastric mucosal protection. A reverse transcription-quantitative polymerase chain reaction (RT-PCR) assay is a molecular biology experiment which could determine the changes of mRNA in tissues. Using the RT-PCR assay, DTCP was observed to increase the mRNA expression levels of certain genes associated with gastric ulcers: Epidermal growth factor, epidermal growth factor receptor, vascular endothelial growth factor and vascular endothelial growth factor receptor 1, while reducing gastrin expression levels. Therefore, the results indicated that DTCP induced a

Residues and contaminants in tea and tea infusions: a review.

PubMed

Abd El-Aty, A M; Choi, Jeong-Heui; Rahman, Md Musfiqur; Kim, Sung-Woo; Tosun, Alev; Shim, Jae-Han

2014-01-01

Consumers are very aware of contaminants that could pose potential health hazards. Most people drink tea as an infusion (adding hot water); however, in some countries, including India, China and Egypt, tea is drunk as a decoction (tea and water are boiled together). An infusion usually brings the soluble ingredients into solution, whereas a decoction brings all soluble and non-soluble constituents together. Therefore, a cup of tea may contain various kinds of contaminants. This review focuses on green and black tea because they are most commonly consumed. The target was to examine the transfer rate of contaminants - pesticides, environmental pollutants, mycotoxins, microorganisms, toxic heavy metals, radioactive isotopes (radionuclides) and plant growth regulators - from tea to infusion/brewing, factors contributing to the transfer potential and contaminants degradation, and residues in or on the spent leaves. It is concluded that most contaminants leaching into tea infusion are not detected or are detected at a level lower than the regulatory limits. However, the traditional practice of over-boiling tea leaves should be discouraged as there may be a chance for more transfer of contaminants from the tea to the brew.

The Microbiota Is Essential for the Generation of Black Tea Theaflavins-Derived Metabolites

PubMed Central

Chen, Huadong; Hayek, Saeed; Rivera Guzman, Javier; Gillitt, Nicholas D.; Ibrahim, Salam A.; Jobin, Christian; Sang, Shengmin

2012-01-01

Background Theaflavins including theaflavin (TF), theaflavin-3-gallate (TF3G), theaflavin-3′-gallate (TF3′G), and theaflavin-3,3′-digallate (TFDG), are the most important bioactive polyphenols in black tea. Because of their poor systemic bioavailability, it is still unclear how these compounds can exert their biological functions. The objective of this study is to identify the microbial metabolites of theaflavins in mice and in humans. Methods and Findings In the present study, we gavaged specific pathogen free (SPF) mice and germ free (GF) mice with 200 mg/kg TFDG and identified TF, TF3G, TF3′G, and gallic acid as the major fecal metabolites of TFDG in SPF mice. These metabolites were absent in TFDG- gavaged GF mice. The microbial bioconversion of TFDG, TF3G, and TF3′G was also investigated in vitro using fecal slurries collected from three healthy human subjects. Our results indicate that TFDG is metabolized to TF, TF3G, TF3′G, gallic acid, and pyrogallol by human microbiota. Moreover, both TF3G and TF3′G are metabolized to TF, gallic acid, and pyrogallol by human microbiota. Importantly, we observed interindividual differences on the metabolism rate of gallic acid to pyrogallol among the three human subjects. In addition, we demonstrated that Lactobacillus plantarum 299v and Bacillus subtilis have the capacity to metabolize TFDG. Conclusions The microbiota is important for the metabolism of theaflavins in both mice and humans. The in vivo functional impact of microbiota-generated theaflavins-derived metabolites is worthwhile of further study. PMID:23227227

Tea polyphenols induce S phase arrest and apoptosis in gallbladder cancer cells

PubMed Central

Wang, Jiaqi; Pan, Yixuan; Hu, Jiacheng; Ma, Qiang; Xu, Yi; Zhang, Yijian; Zhang, Fei; Liu, Yingbin

2018-01-01

Gallbladder cancer (GBC) is the most common malignancy in the biliary tract. Without effective treatment, its prognosis is notoriously poor. Tea polyphenols (TPs) have many pharmacological and health benefits, including antioxidant, anti-inflammatory, anti-tumor, anti-thrombotic, antibacterial, and vasodilatory properties. However, the anti-cancer effect of TPs in human gallbladder cancer has not yet been determined. Cell viability and colony formation assay were used to investigate the cell growth. Cell cycle and apoptosis were evaluated by flow cytometry analysis. Western blot assay was used to detect the expression of proteins related to cell cycle and apoptosis. Human tumor xenografts were used to examine the effect of TPs on gallbladder cancer cells in vivo. TPs significantly inhibited cell growth of gallbladder cancer cell lines in a dose- and time-dependent manner. Cell cycle progression in GBC cells was blocked at the S phase by TPs. TPs also induced mitochondrial-related apoptosis in GBC cells by upregulating Bax, cleaved caspase-3, and cleaved PARP expressions and downregulating Bcl-2, cyclin A, and Cdk2 expressions. The effects of TPs on GBC were further proven in vivo in a mouse xenograft model. Our study is the first to report that TPs inhibit GBC cell growth and these compounds may have potential as novel therapeutic agents for treating gallbladder cancer. PMID:29513793

Quercetin increased bioavailability and decreased methylation of green tea polyphenols in vitro and in vivo

PubMed Central

Wang, Piwen; Heber, David; Henning, Susanne M.

2013-01-01

The extensive methylation of green tea polyphenols (GTPs) in vivo may limit their chemopreventive potential. We investigated whether quercetin, a natural inhibitor of catechol-O-methyltransferase (COMT) and multidrug resistance proteins (MRPs), will differentially increase the intracellular concentration and decrease the methylation of GTPs in different cancer cell lines. Intrinsic COMT activity was lowest in lung cancer A549 cells, intermediate in kidney 786-O cells and highest in liver HepG2 cells. Quercetin increased the cellular absorption of epigallocatechin gallate (EGCG) four-fold in A549 cells with a decreased methylation rate from 63% to 19%, 2-fold in 786-O cells with a decreased methylation from 97% to 56%, while no significant effect was observed in HepG2 cells. The combination significantly decreased the activity and protein expression of COMT and decreased the protein expression of MRP1 compared to individual treatments. The combination exhibited the strongest increase in antiproliferation in A549 cells, an intermediate effect in 786-O cells and lowest effect in HepG2 cells. The effect of quercetin on bioavailability and metabolism of GTPs was confirmed in vivo. SCID mice were administered brewed green tea (GT) and a diet supplemented with 0.4% quercetin alone or in combination for 2 weeks. We observed a 2 to 3-fold increase of total and non-methylated EGCG in lung and kidney and a trend to increase in liver. In summary, combining quercetin with GT provides a promising approach to enhance the chemoprevention of GT. Responses of different cancers to the combination may vary by tissue depending on the intrinsic COMT and MRP activity. PMID:22438067

Metabolic variation and antioxidant potential of Malus prunifolia (wild apple) compared with high flavon-3-ol containing fruits (apple, grapes) and beverage (black tea).

PubMed

Maria John, K M; Enkhtaivan, Gansukh; Kim, Ju Jin; Kim, Doo Hwan

2014-11-15

Secondary metabolic variation of wild apple (Malus prunifolia) was compared with fruits that contained high flavan-3-ol like grapes (GR), apple (App) and the beverage, black tea (BT). The polyphenol contents in wild apple was higher than in GR and App but less than BT. The identified phenolic acids (gallic, protocatechuic, chlorogenic, p-coumaric and ferulic acids) and flavonoids (quercetin and myricetin) indicate that wild apple was higher than that of App. Among all the samples, BT had highest antioxidant potential in terms of 2,2'-Azinobis (3-thylbenzothiazoline-6-sulfonic acid) diammonium salt (95.36%), metal chelating (45.36%) and phosphomolybdenum activity (95.8 mg/g) because of the high flavan-3-ol content. The gallic acid and epigallocatechin gallate were highly correlated with antioxidant potential and these metabolites levels are higher in wild apple than that of App. Wild apples being a non-commercial natural source, a detailed study of this plant will be helpful for the food additive and preservative industry. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of a foot bath containing green tea polyphenols on interdigital tinea pedis.

PubMed

Ikeda, Sugako; Kanoya, Yuka; Nagata, Shigeki

2013-01-01

It has been shown that green tea polyphenols (GTP) can directly kill Trichophyton in vitro; however, there are no published clinical studies that show anti-fungal activity of GTP. To identify the effects of GTP on interdigital tinea pedis in elderly patients. Ninety-four patients with interdigital tinea pedis were enrolled and were either given a lukewarm water foot bath containing GTP or placebo treatment. Effects of GTP were assessed based on changes in the size of the affected area, the rate of recurrence, microscopy findings, and overall assessment of skin changes. After 12 weeks of treatment with either GTP or placebo, a significant reduction in the size of the affected area was observed (p<0.001). There were no significant differences between the GTP or placebo groups in the size of the affected area (p=0.638), the recurrence rate (p=0.172), or the microscopy findings (p=1.000). However, the overall assessment demonstrated significant improvements (p=0.010) in the GTP group. These results show that GTP was effective in improving the symptoms of tinea pedis in comparison to only lukewarm water. Our results suggest that GTP could have anti-fungal activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

The cupric ion reducing antioxidant capacity and polyphenolic content of some herbal teas.

PubMed

Apak, Reşat; Güçlü, Kubilay; Ozyürek, Mustafa; Esin Karademir, Saliha; Erçağ, Erol

2006-01-01

The total antioxidant capacity of the aqueous extracts of some endemic herbs-prepared as infusions by steeping these herbs in hot water--was assayed with bis(neocuproine)copper(II) chloride, also known as the cupric ion reducing antioxidant capacity (CUPRAC) reagent, which was easily accessible, rapid, stable and responsive to both hydrophilic and lipophilic antioxidants. The highest antioxidant capacities of some herbal teas available in the Turkish market were observed for scarlet pimpernel (Anagallis arvensis), sweet basil (Ocimum basilicum), green tea (Camellia sinensis) and lemon balm (Melissa officinalis), in this order (1.63, 1.18, 1.07, and 0.99 mmol trolox equivalent (TR)/g, respectively). For infusions prepared from ready-to-use tea bags, the CUPRAC values were highest for Ceylon blended ordinary tea (4.41), green tea with lemon (1.61), English breakfast ordinary tea (1.26) and green tea (0.94), all of which were manufactured types of C. sinensis. Following the strongest antioxidant herbs with capacities close to or slightly exceeding 1.0 mmol TR/g, sage, thyme, coriander, coltsfoot, blackberry and immortelle (Helichrysum) exhibited capacities around 0.5 mmol TR/g. The correlation of the Folin total phenolic content of herbal teas with their CUPRAC and ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) total antioxidant capacities gave linear curves with correlation coefficients of 0.966 and 0.936, respectively, showing that the CUPRAC assay results better correlated with total phenolic content of herbal teas. Absorbance versus concentration data at different dilutions and upon standard additions of model antioxidant compounds (trolox and quercetin) to herbal tea infusions showed that the absorbances (at 450 nm of the CUPRAC method) due to different antioxidant compounds in herbal tea infusions were additive; that is, the tested antioxidants did not chemically interact to cause apparent deviations from Beer's law.

Determination of theanine, GABA, and other amino acids in green, oolong, black, and Pu-erh teas with dabsylation and high-performance liquid chromatography.

PubMed

Syu, Kai-Yang; Lin, Chih-Li; Huang, Hsiu-Chen; Lin, Jen-Kun

2008-09-10

Dabsyl chloride (dimethylaminoazobenzene sulfonyl chloride), a useful chromophoric labeling reagent for amino acids and amines, was developed in this laboratory in 1975. Although several methods have been developed to determine various types of amino acids, a quick and easy method of determining theanine, GABA, and other amino acids has not been developed in one HPLC system. In this paper are analyzed the free amino acid contents of theanine and GABA in different teas (green tea, black tea, oolong tea, Pu-erh tea, and GABA tea) with a dabsylation and reverse phase high-performance liquid chromatography (HPLC) system coupled with a detector at 425 nm absorbance. Two reverse phase columns, Hypersil GOLD and Zorbax ODS, were used and gave different resolutions of dabsyl amino acids in the gradient elution program. The data suggest that the tea source or the steps of tea-making may contribute to the theanine contents variations. High theanine contents of high-mountain tea were observed in both green tea and oolong tea. Furthermore, the raw (natural fermented) Pu-erh tea contained more theanine than ripe (wet fermented) Pu-erh tea, and the GABA contents in normal teas were generally lower than that in GABA tea.

Epigallocatechin-3-gallate (EGCG), a green tea polyphenol, stimulates hepatic autophagy and lipid clearance.

PubMed

Zhou, Jin; Farah, Benjamin Livingston; Sinha, Rohit Anthony; Wu, Yajun; Singh, Brijesh Kumar; Bay, Boon-Huat; Yang, Chung S; Yen, Paul Michael

2014-01-01

Epigallocatechin gallate (EGCG) is a major polyphenol in green tea that has been shown to have anti-inflammatory, anti-cancer, anti-steatotic effects on the liver. Autophagy also mediates similar effects; however, it is not currently known whether EGCG can regulate hepatic autophagy. Here, we show that EGCG increases hepatic autophagy by promoting the formation of autophagosomes, increasing lysosomal acidification, and stimulating autophagic flux in hepatic cells and in vivo. EGCG also increases phosphorylation of AMPK, one of the major regulators of autophagy. Importantly, siRNA knockdown of AMPK abrogated autophagy induced by EGCG. Interestingly, we observed lipid droplet within autophagosomes and autolysosomes and increased lipid clearance by EGCG, suggesting it promotes lipid metabolism by increasing autophagy. In mice fed with high-fat/western style diet (HFW; 60% energy as fat, reduced levels of calcium, vitamin D3, choline, folate, and fiber), EGCG treatment reduces hepatosteatosis and concomitantly increases autophagy. In summary, we have used genetic and pharmacological approaches to demonstrate EGCG induction of hepatic autophagy, and this may contribute to its beneficial effects in reducing hepatosteatosis and potentially some other pathological liver conditions.

Addition of milk to tea infusions: Helpful or harmful? Evidence from in vitro and in vivo studies on antioxidant properties.

PubMed

Rashidinejad, Ali; Birch, E John; Sun-Waterhouse, Dongxiao; Everett, David W

2017-10-13

Tea consumption is practised as a tradition, and has shown potential to improve human health. Maximal uptake of tea antioxidants and milk proteins without a negative impact on tea flavor is highly desired by consumers. There is a conflicting evidence of the effect of milk addition to tea on antioxidant activity. Differences in the type of tea, the composition, type and amount of milk, preparation method of tea-milk infusions, the assays used to measure antioxidant activity, and sampling size likely account for different findings. Interactions between tea polyphenols and milk proteins, especially between catechins and caseins, could account for a decrease in antioxidant activity, although other mechanisms are also possible, given the similar effects between soy and bovine milk. The role of milk fat globules and the milk fat globule membrane surface is also important when considering interactions and loss of polyphenolic antioxidant activity, which has not been addressed in the literature.

The effect of green, black and white tea on the level of alpha and gamma tocopherols in free radical-induced oxidative damage of human red blood cells.

PubMed

Gawlik, Małgorzata; Czajka, Aneta

2007-01-01

The present study was undertaken to investigate the effect of aqueous tea extracts on lipid peroxidation and alpha and gamma tocopherols concentration in the oxidative damage of human red blood cells (RBC). RBC was taken as the model for study of the oxidative damage was induced by cumene hydroperoxide (cumOOH). The antioxidative property of leaf green tea, leaf and granulate of black tea and white tea at levels 1, 2, 4 g/150 mL of water were evaluated. The correlation was observed between reducing power of tea extract and formation of malondialdehyde--MDA (an indicator of lipid peroxidation) in oxidative damage of RBC. All tea extracts at level of 4 g/150 mL of water significantly decreased concentration of MDA. The extract of green tea in comparison to black and white tea extracts at the same levels seems to be a better protective agent against oxidative stress. The antioxidant synergism between components extracted from leaves of green tea and endogenous alpha tocopherol in the oxidative damage of red blood cells was observed. The consumption of alpha tocopherol in oxidative damage of RBC was the lowest after treatment with the highest dose of green tea extract. All tea extracts did not protect against decrease of gamma tocopherol in human erythrocytes treated with cumOOH.

Determination of catechins and flavonol glycosides in Chinese tea varieties.

PubMed

Wu, Chunyan; Xu, Hairong; Héritier, Julien; Andlauer, Wilfried

2012-05-01

A standardised profiling method based on high performance liquid chromatography combined with ultraviolet (UV) and mass spectrometric detection (MS) was established to analyse the phenolic compounds of selected tea varieties used for manufacturing of green, black and oolong teas. The composition and content of 24 tea constituents were analysed, including catechins, flavonol and flavones glycosides, phenolic acids and purine alkaloids. Each tea variety had a unique chemical profile. The compositions of catechins were lower in the tea varieties for green tea manufacturing, while the content of myricetin glycosides was the lowest in the tea variety for oolong tea manufacturing. The content of individual phenolic compounds in the selected tea varieties is highly variable. However, the content of total catechins is proposed to be helpful to classify tea according to the future application as non fermented green and fermented oolong or black tea. Copyright © 2011 Elsevier Ltd. All rights reserved.

Polyphenolic compounds appear to limit the nutritional benefit of biofortified higher iron black bean (Phaseolus vulgaris L.)

PubMed Central

2014-01-01

Background Our objective was to determine if a biofortified variety of black bean can provide more bioavailable-iron (Fe) than a standard variety. Two lines of black beans (Phaseolus-vulgaris L.), a standard (DOR500; 59μg Fe/g) and biofortified (MIB465; 88μg Fe/g) were used. The DOR500 is a common commercial variety, and the MIB465 is a line developed for higher-Fe content. Given the high prevalence of Fe-deficiency anemia worldwide, it is important to determine if Fe-biofortified black beans can provide more absorbable-Fe. Methods Black bean based diets were formulated to meet the nutrient requirements for the broiler (Gallus-gallus) except for Fe (dietary Fe-concentrations were 39.4±0.2 and 52.9±0.9 mg/kg diet, standard vs. biofortified, respectively). Birds (n=14) were fed the diets for 6-weeks. Hemoglobin-(Hb), liver-ferritin and Fe-related transporter/enzyme gene-expression were measured. Hemoglobin-maintenance-efficiency and total-body-Hb-Fe values were used to estimate Fe-bioavailability. Results Hemoglobin-maintenance-efficiency values were higher (P<0.05) in the group consuming the standard-Fe beans on days 14, 21 and 28; indicating a compensatory response to lower dietary-Fe. Final total-Hb-Fe body content was higher in the biofortified vs. the standard group (26.6±0.9 and 24.4±0.8 mg, respectively; P<0.05). There were no differences in liver-ferritin or in expression of DMT-1, Dcyt-B, and ferroportin. In-vitro Fe-bioavailability assessment indicated very low Fe-bioavailability from both diets and between the two bean varieties (P>0.05). Such extremely-low in-vitro Fe-bioavailability measurement is indicative of the presence of high levels of polyphenolic-compounds that may inhibit Fe-absorption. High levels of these compounds would be expected in the black bean seed-coats. Conclusions The parameters of Fe-status measured in this study indicate that only a minor increase in absorbable-Fe was achieved with the higher-Fe beans. The results also raise

Inhibition of green tea polyphenol EGCG((-)-epigallocatechin-3-gallate) on the proliferation of gastric cancer cells by suppressing canonical wnt/β-catenin signalling pathway.

PubMed

Yang, Chenggang; Du, Wenfeng; Yang, Daogui

2016-11-01

(-)-Epigallocatechin-3-gallate (EGCG), the major polyphenol in green tea, could affect carcinogenesis and development of many cancers. However, the effects and underlying mechanisms of EGCG on gastric cancer remain unclear. We found that EGCG significantly inhibited proliferation and increased apoptosis of SGC-7901 cells in vitro. The decreased expressions of p-β-catenin(Ser552), p-GSK3β(S9) and β-catenin target genes were detected in SGC-7901 cells after treated by EGCG. XAV939 and β-catenin plasmid were further used to demonstrate the inhibition of EGCG on canonical Wnt/β-catenin signalling. Moreover, EGCG significantly inhibited gastric tumour growth in vivo by inhibiting Wnt/β-catenin signalling. Taken together, our findings establish that EGCG suppressed gastric cancer cell proliferation and demonstrate that this inhibitory effect is related to canonical Wnt/β-catenin signalling. This study raises a new insight into gastric cancer prevention and therapy, and provides evidence that green tea could be used as a nutraceutical beverage.

Improvement of green tea polyphenol with milk on skin with respect to antioxidation in healthy adults: a double-blind placebo-controlled randomized crossover clinical trial.

PubMed

Chiu, Hui-Fang; Lin, Tung-Yi; Shen, You-Cheng; Venkatakrishnan, Kamesh; Wang, Chin-Kun

2016-02-01

Green tea polyphenols (GTP) have been widely tested for their effects on several metabolic syndromes and degenerative diseases such as cancer, cardiovascular diseases, and diabetes. The present study was formulated to assess the physiological efficacy of green tea polyphenol infused with milk (GTPM) on skin integrity in correlation with antioxidative status in healthy adults. Forty-four healthy voluntary subjects were recruited and assigned to two groups, who drank 240 ml of mineral water mixed with either an experimental (GTPM) or placebo package (2 packs per day) for the following 6 months. The experimental group then switched to the placebo package, and vice versa, for a further 6 months, with one month of washout period in between. During the initial, 3(rd), 6(th), 10(th), and 13(th) month anthropometric measurements were performed and fasting blood samples were withdrawn for various biochemical assays. Skin examination was performed at the initial, 6(th) and 13(th) month. No significant alterations were observed in any of the anthropometric measurements. Administration of GTPM significantly increased (p < 0.05) the antioxidant index and antioxidant enzyme activities when compared with the placebo group, whereas a concomitant decrease in the levels of lipid peroxidation were noted. Moreover, GTPM intake notably improved skin integrity and texture by markedly lowering (p < 0.05) skin wrinkles and roughness in elderly subjects. GTPM proved to be an effective antioxidant by lowering oxidative stress and thereby ameliorating skin texture and integrity.

Effect of Kombucha, a fermented black tea in attenuating oxidative stress mediated tissue damage in alloxan induced diabetic rats.

PubMed

Bhattacharya, Semantee; Gachhui, Ratan; Sil, Parames C

2013-10-01

Diabetic complications associated with increased oxidative stress can be suppressed by antioxidants. In the present study we investigated the antidiabetic and antioxidant effects of Kombucha (KT), a fermented black tea, in comparison to that of unfermented black tea (BT), in ALX-induced diabetic rats. ALX exposure lowered the body weight and plasma insulin by about 28.12% and 61.34% respectively and elevated blood glucose level and glycated Hb by about 3.79 and 3.73 folds respectively. The oxidative stress related parameters like lipid peroxidation end products (increased by 3.38, 1.7, 1.65, 1.94 folds respectively), protein carbonyl content (increased by 2.5, 2.35, 1.8, 3.26 folds respectively), glutathione content (decreased by 59.8%, 47.27%, 53.69%, 74.03% respectively), antioxidant enzyme activities were also altered in the pancreatic, hepatic, renal and cardiac tissues of diabetic animals. Results showed significant antidiabetic potential of the fermented beverage (150 mg lyophilized extract/kg bw for 14 days) as it effectively restored ALX-induced pathophysiological changes. Moreover, it could ameliorate DNA fragmentation and caspase-3 activation in the pancreatic tissue of diabetic rats. Although unfermented black tea is effective in the above pathophysiology, KT was found to be more efficient. This might be due to the formation of some antioxidant molecules during fermentation period. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Relevance of Dietary Polyphenols in Cardiovascular Protection.

PubMed

Murillo, Ana G; Fernandez, Maria L

2017-01-01

The chemical structure of polyphenols consisting of aromatic rings, capable of quenching free radicals, makes them ideal candidates to protect against oxidation. Polyphenols are present in a variety of foods including grapes, berries, dark chocolate, coffee and tea to mention a few. A number of studies have shown that dietary polyphenols exert a protective effect against hypertension, dyslipidemias, inflammation, endothelial function and atherosclerosis, conditions associated with increased risk for cardiovascular disease. Studies indicate that by decreasing cholesterol absorption, polyphenols alter hepatic cholesterol homeostasis resulting in decreases in plasma lipids and reduction in atherogenic lipoproteins thus having a protective effect against atherosclerosis; polyphenols have also been shown to decrease the activity of enzymes involved in the renin-angiotensinaldosterone system and improve blood pressure. Further, they have been recognized to increase nitric oxide production and to improve endothelial function. In this review we will present some of the evidence derived from epidemiological studies, clinical interventions as well as animal and cell studies supporting the cardioprotective effects of dietary polyphenols. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Effects of γ-radiation on microbial load and antioxidant proprieties in black tea irradiated with different water activities

NASA Astrophysics Data System (ADS)

Fanaro, G. B.; Hassimotto, N. M. A.; Bastos, D. H. M.; Villavicencio, A. L. C. H.

2014-04-01

The aim of this paper is to study the effect of gamma radiation on black tea irradiated with different water activities. The black tea samples had their Aw adjusted to three values (0.92, 0.65, and 0.18) and were irradiated in 60Co source at doses of 0, 1.0, 1.5, 2.0, 2.5, 5.0, 7.5, and 10.0 kGy. The methods used were: microbiology, total phenolic compounds quantification, antioxidant activity by ORAC, and quantification of the main antioxidants. It was observed that the greater the amount of free water present in the samples, lower was the dose to achieve microbiological control. Regardless the water activity used, there was no difference in content of the phenolic compounds and at the mainly theaflavins, as well in the antioxidant activity at doses up to 5.0 kGy.

Intelligent evaluation of color sensory quality of black tea by visible-near infrared spectroscopy technology: A comparison of spectra and color data information.

PubMed

Ouyang, Qin; Liu, Yan; Chen, Quansheng; Zhang, Zhengzhu; Zhao, Jiewen; Guo, Zhiming; Gu, Hang

2017-06-05

Instrumental test of black tea samples instead of human panel test is attracting massive attention recently. This study focused on an investigation of the feasibility for estimation of the color sensory quality of black tea samples using the VIS-NIR spectroscopy technique, comparing the performances of models based on the spectra and color information. In model calibration, the variables were first selected by genetic algorithm (GA); then the nonlinear back propagation-artificial neural network (BPANN) models were established based on the optimal variables. In comparison with the other models, GA-BPANN models from spectra data information showed the best performance, with the correlation coefficient of 0.8935, and the root mean square error of 0.392 in the prediction set. In addition, models based on the spectra information provided better performance than that based on the color parameters. Therefore, the VIS-NIR spectroscopy technique is a promising tool for rapid and accurate evaluation of the sensory quality of black tea samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Tea polyphenol epigallocatechin 3-gallate impedes the anti-apoptotic effects of low-grade repetitive stress through inhibition of Akt and NFkappaB survival pathways.

PubMed

Sen, Prosenjit; Chakraborty, Prabir Kumar; Raha, Sanghamitra

2006-01-09

V79 Chinese Hamster lung fibroblasts were subjected to repetitive low-grade stress through multiple exposures to 30 microM H2O2 in culture for 4 weeks. Akt/protein kinase B became phosphorylated at serine473 and threonine308 during this period of repetitive stress. Concurrent exposure of the cells to LY294002 (5 microM), a phosphoinositide-3 kinase inhibitor or 4.5 microM epigallocatechin 3-gallate (EGCG), a tea polyphenol almost completely blocked Akt activation by repetitive stress. Phosphorylation of I kappa B kinase (IKK) and transcriptional activity driven by nuclear factor kappa B (NFkappaB) were significantly enhanced by repetitive oxidative stress. These increases were largely abolished by simultaneous exposure to EGCG. The repetitively stressed cells demonstrated a significant resistance to apoptosis by subsequent acute stress in the form of ultraviolet radiation at 5 J/m2 or H2O2 (7.5 mM). The resistance to apoptosis conferred by repetitive stress was drastically reduced (>80%) by constant exposure to EGCG during the stress period while the presence of LY294002 or the NFkappaB inhibitor SN50 brought about a relatively moderate effect (about 50-65%). Our data indicate that activation of Akt and NFkappaB pro-survival pathways by repetitive low-grade stress results in a strong inhibition of the normal apoptotic response after subsequent acute stress. The tea polyphenol EGCG impedes the activation of both Akt and NFkappaB by repetitive stress and as a result preserves the normal apoptotic response during subsequent acute stress.

The role of dietary polyphenols in the management of inflammatory bowel disease.

PubMed

Farzaei, Mohammad H; Rahimi, Roja; Abdollahi, Mohammad

2015-01-01

Inflammatory bowel disease (IBD) is an idiopathic chronic, relapsing inflammation of the bowel which is caused by dysregulation of the mucosal immune system. Polyphenols as the secondary plant metabolites universally present in vegetables and fruits and are the most abundant antioxidants in the human diet. There is evidence demonstrating the beneficial health effects of dietary polyphenols. This review criticizes the potential of commonly used polyphenols including apple polyphenol, bilberry anthocyanin, curcumin, epigallocatechin-3-gallate (EGCG) and green tea polyphenols, naringenin, olive oil polyphenols, pomegranate polyphenols and ellagic acid, quercetin, as well as resveratrol specifically in IBD with an emphasis on cellular mechanisms and pharmaceutical aspects. Scientific research confirmed that dietary polyphenols possess both protective and therapeutic effects in the management of IBD mediated via down-regulation of inflammatory cytokines and enzymes, enhancing antioxidant defense, and suppressing inflammatory pathways and their cellular signaling mechanisms. Further preclinical and clinical studies are needed in order to understand safety, bioavailability and bioefficacy of dietary polyphenols in IBD patients.

Separation and identification of twelve catechins in tea using liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry.

PubMed

Zeeb, D J; Nelson, B C; Albert, K; Dalluge, J J

2000-10-15

A method has been developed for the direct microscale determination of 12 catechins in green and black tea infusions. The method is based on liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (LC/APCI-MS). Standard catechin mixtures and tea infusions were analyzed by LC/APCI-MS with detection of protonated molecular ions and characteristic fragment ions for each compound. The identities of eight major catechins and caffeine in tea were established based on LC retention times and simultaneously recorded mass spectra. In addition, monitoring of the catechin-specific retro Diels-Alder fragment ion at m/z 139 throughout the chromatogram provided a unique fingerprint for catechin content in the samples that led to the identification of four minor chemically modified catechin derivatives in the infusions. This report is the first to describe the comprehensive determination of all 12 reported catechins in a single analysis. The utility of LC/APCI-MS for providing routine separation and identification of catechins at femtomole to low-picomole levels without extraction or sample pretreatment, and its potential as a standard analytical tool for the determination of polyphenols in natural products and biological fluids, are discussed.

Polyphenols as potential therapeutical agents against cardiovascular diseases.

PubMed

Curin, Yann; Andriantsitohaina, Ramaroson

2005-01-01

Increasing evidence suggests that polyphenols from fruits, vegetables and beverages such as wine and tea may exert protective effects on the cardiovascular system. Indeed, research in the field of polyphenols points out their antioxidant and free radical scavenging properties, leading to lower low-density lipoprotein (LDL) oxidation and platelet aggregation. These compounds are also able to modulate the generation of nitric oxide (NO) from vascular endothelium and to interfere with the mechanisms leading to inflammation and endothelial apoptosis, contributing to the prevention of the endothelial dysfunction, known to play a central role in the pathogenesis of cardiovascular diseases. This article reviews the potential targets of polyphenols involved in the complex pathophysiological events occurring in cardiovascular diseases, such as hypertension, atherosclerosis and stroke.

[Direct determination of purine bases in tea by reversed-phase high performance liquid chromatography].

PubMed

Ding, M; Yang, H; Xiao, S; Chen, P

1999-09-01

A reversed-phase high performance liquid chromatographic(RP-HPLC) method for the direct determination of three purine bases(theobromin, theophyllin and caffeine) in tea was developed. An ODS column with Zorbax SB-C18(4.6 mm i.d. x 250 mm, 5 microns) was employed. The aqueous solution of methanol containing 0.05% of acetic acid and 0.25% of N,N-dimethylformamide(DMF) was used as eluent with a flow rate of 0.8 mL/min. In this method, the aqueous extract of tea can be injected into HPLC directly, but in current HPLC methods for purine bases the coexisted tea polyphenols must be pre-separated. The three purine bases in tea were separated without any interference from the coexisted tea polyphenols. This method is simple (without any special sample pretreatment) and sensitive with detection limits (S/N = 3) of 0.7, 0.9 and 1.8 mg/L for theobromin, theophyllin and caffeine respectively. The linear range of the calibration curve of peak area for the three purine bases were from 6 mg/L to 1,000 mg/L with a correlation coefficient (r) of 0.998-0.999.

Phytochemical profiles and antioxidant activities of Chinese dark teas obtained by different processing technologies.

PubMed

Lv, Hai-Peng; Zhang, Yue; Shi, Jiang; Lin, Zhi

2017-10-01

Dark teas are rich in secondary metabolites, such as phenolics and flavonoids, which have been suggested to be associated with their health benefits. In this study, the concentrations of tea polyphenols, tea pigments, catechins, flavonoids, alkaloid, and volatile components in 44 dark tea samples, including Pu-erh, Fuzhuan and Liubao teas, were systematically examined. Among the samples tested, Pu-erh tea contained the highest total flavonoid content (5.24±0.05%), followed by Liubao (4.45±0.61%) and Fuzhuan teas (3.33±0.23%). The tea polyphenols levels in the dark teas were approximately 10%, and no statistically significant differences (p>0.05) were found among the different types. Hexadecanoic acid was the most abundant aroma component in the dark teas, accounting for 15-20% of the total volatile oils. Moreover, the antioxidant activities of these dark teas were analyzed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) assay, ferric reducing antioxidant power (FRAP) assay, and cellular antioxidant activity (CAA) assay (HepG2 cells). The fat metabolism modulation activities (FMMA) of the dark teas were tested using a high-throughput screening method (SMMC-7221 cells). The results indicated that the different dark teas had diverse antioxidant activities, and the variation in the activities was significant. Correlation analysis showed that there was a significant positive correlation between the levels of EGCG and antioxidant activities measured using the ABTS (r=0.916) and FRAP (r=0.853) assays, and the levels of total flavonoids and theabrownins correlated well with the values determined using the CAA (r=0.845 and 0.865, respectively) assay. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quality components and antidepressant-like effects of GABA green tea.

PubMed

Teng, Jie; Zhou, Wen; Zeng, Zhen; Zhao, Wenfang; Huang, Yahui; Zhang, Xu

2017-09-20

Gamma (γ)-aminobutyric acid (GABA) green tea, with high GABA content, is a kind of special green tea. The goals of this study are to analyze the changes in quality components of green tea during anaerobic treatment, and to investigate whether or not the extract of GABA present in green tea can prevent depression or improve the depressive state of animals. Results showed that GABA content in green tea had increased significantly after anaerobic treatment. The contents of tea polysaccharides, total free amino acids, and water extracts were also increased whereas tea polyphenols were reduced. More importantly, the extract of GABA green tea could alleviate mouse depression and stress from desperate environments through the forced swim test (FST), tail suspension test (TST), mRNA and protein expression levels of GABA A receptors. Therefore, these results indicate that GABA green tea may have a health effect on prevention and alleviation of depression, and it works on the GABAergic neurotransmission of mouse cerebral cortex via up-regulating expression of the GABA A receptor α1 subunit, thus ameliorating depression.

Pyrrolizidine and tropane alkaloids in teas and the herbal teas peppermint, rooibos and chamomile in the Israeli market.

PubMed

Shimshoni, Jakob Avi; Duebecke, Arne; Mulder, Patrick P J; Cuneah, Olga; Barel, Shimon

2015-01-01

Dehydro pyrrolizidine alkaloids (dehydro PAs) are carcinogenic phytotoxins prevalent in the Boraginaceae, Asteraceae and Fabaceae families. Dehydro PAs enter the food and feed chain by co-harvesting of crops intended for human and animal consumption as well as by carry-over into animal-based products such as milk, eggs and honey. Recently the occurrence of dehydro PAs in teas and herbal teas has gained increasing attention from the EU, due to the high levels of dehydro PAs found in commercially available teas and herbal teas in Germany and Switzerland. Furthermore, several tropane alkaloids (TAs, e.g. scopolamine and hyoscyamine) intoxications due to the consumption of contaminated herbal teas were reported in the literature. The aim of the present study was to determine the dehydro PAs and TAs levels in 70 pre-packed teabags of herbal and non-herbal tea types sold in supermarkets in Israel. Chamomile, peppermint and rooibos teas contained high dehydro PAs levels in almost all samples analysed. Lower amounts were detected in black and green teas, while no dehydro PAs were found in fennel and melissa herbal teas. Total dehydro PAs concentrations in chamomile, peppermint and rooibos teas ranged from 20 to 1729 μg/kg. Except for black tea containing only mono-ester retrorsine-type dehydro PAs, all other teas and herbal teas showed mixed patterns of dehydro PA ester types, indicating a contamination by various weed species during harvesting and/or production. The TA levels per teabag were below the recommended acute reference dose; however, the positive findings of TAs in all peppermint tea samples warrant a more extensive survey. The partially high levels of dehydro PAs found in teas and herbal teas present an urgent warning letter to the regulatory authorities to perform routine quality control analysis and implement maximum residual levels for dehydro PAs.

The potential protective effect of green, black, red and white tea infusions against adverse effect of cadmium and lead during chronic exposure - A rat model study.

PubMed

Winiarska-Mieczan, Anna

2015-11-01

The protective effect of green (GT), black (BT), red (RT) and white (WT) tea infusions on the lungs, brains, hearts, livers and kidneys of adult Wistar rats exposed to Cd (7 mg/kg) and Pb (50 m/kg) was studied. The degree of reduction in the absorption of Cd and Pb in the organs compared to control group and the activity of SOD, CAT and GPx as well as GSH level was evaluated. It was determined that tea significant reduced the accumulation of Cd in the tissues. A significant reduction in the accumulation of Pb was recorded in the brain (WT), liver (GT, WT) and kidneys (BT, GT, RT, WT). A significant increase was observed in the activity of SOD, CAT and GPx in the organs of all rats from tea groups. It was found that the results obtained in rats receiving black, red and white tea were overall not worse than those recorded for rats receiving green tea. The obtained results suggest that drinking tea could be an effective method of reducing the adverse effect of environmental Cd and Pb pollution on the human body. Copyright © 2015 Elsevier Inc. All rights reserved.

Evaluation of Macro- and Microelement Levels in Black Tea in View of Its Geographical Origin.

PubMed

Brzezicha-Cirocka, Justyna; Grembecka, Małgorzata; Ciesielski, Tomasz; Flaten, Trond Peder; Szefer, Piotr

2017-04-01

The aim of this study was to evaluate the elemental composition of black tea samples and their infusions in view of their geographical origin. In total, 14 elements were analyzed, 13 (Ca, K, Mg, Na, Mn, Fe, Zn, Cu, Cr, Ni, Co, Cd, and Pb) by flame atomic absorption spectrometry, and P by UV-Vis spectrometry, after mineralization of samples. It was found that K was the most abundant macroelement in the analyzed samples, whereas among microelements, the highest concentration was found for Mn. Based on the obtained data, the percentage of elements leached into the infusions as well as the daily elemental intake from tea were calculated. The daily intake from tea was compared to the recommended daily allowances (RDAs), and the highest percentages of the RDAs were found for Mn (15 %) and Co (10 %). To study the relations between elemental composition and country of origin of samples, factor analysis and cluster analysis were applied. These multivariate techniques proved to be efficient tools able to differentiate samples according to their provenance as well as plantation within the common regions.

Bioassay-guided purification and identification of antimicrobial components in Chinese green tea extract.

PubMed

Si, Weiduo; Gong, Joshua; Tsao, Rong; Kalab, Milosh; Yang, Raymond; Yin, Yulong

2006-09-01

The Chinese green tea extract was found to strongly inhibit the growth of major food-borne pathogens, Escherichia coli O157:H7, Salmonella Typhimurium DT104, Listeria monocytogenes, Staphylococcus aureus, and a diarrhoea food-poisoning pathogen Bacillus cereus, by 44-100% with the highest activity found against S. aureus and lowest against E. coli O157:H7. A bioassay-guided fractionation technique was used for identifying the principal active component. A simple and efficient reversed-phase high-speed counter-current chromatography (HSCCC) method was developed for the separation and purification of four bioactive polyphenol compounds, epicatechin gallate (ECG), epigallocatechin gallate (EGCG), epicatechin (EC), and caffeine (CN). The structures of these polyphenols were confirmed with mass spectrometry. Among the four compounds, ECG and EGCG were the most active, particularly EGCG against S. aureus. EGCG had the lowest MIC90 values against S. aureus (MSSA) (58 mg/L) and its methicilin-resistant S. aureus (MRSA) (37 mg/L). Scanning electron microscopy (SEM) studies showed that these two compounds altered bacterial cell morphology, which might have resulted from disturbed cell division. This study demonstrated a direct link between the antimicrobial activity of tea and its specific polyphenolic compositions. The activity of tea polyphenols, particularly EGCG on antibiotics-resistant strains of S. aureus, suggests that these compounds are potential natural alternatives for the control of bovine mastitis and food poisoning caused by S. aureus.

In vitro assay to estimate tea astringency via observing flotation of artificial oil bodies sheltered by caleosin fused with histatin 3.

PubMed

Shih, Yu-En; Lin, Yu-Chih; Chung, Tse-Yu; Liu, Mei-Chun; Chen, Guan-Heng; Wu, Chia-Chang; Tzen, Jason T C

2017-10-01

Astringency, a sensory characteristic of food and beverages rich in polyphenols, mainly results from the formation of complexes between polyphenols and salivary proteins, causing a reduction of the lubricating properties of saliva. To develop an in vitro assay to estimate the astringency of oolong tea infusion, artificial oil bodies were constituted with sesame oil sheltered by a modified caleosin fused with histatin 3, one of the human salivary small peptides. Aggregation of artificial oil bodies was induced when they were mixed with oolong tea infusion or its major polyphenolic compound, (-)-epigallocatechin gallate (EGCG) of 100μM as observed in light microscopy. The aggregated artificial oil bodies gradually floated on top of the solution and formed a visible milky layer whose thickness was in proportion to the concentrations of tea infusion. This assay system was applied to test four different oolong tea infusions with sensory astringency corresponding to their EGCG contents. The result showed that relative astringency of the four tea infusions was correlated to the thickness of floated artificial oil bodies, and could be estimated according to the standard curve generated by simultaneously observing a serial dilution of the tea infusion with the highest astringency. Copyright © 2016. Published by Elsevier B.V.

[Preparation and component analysis of tea pigments].

PubMed

Li, Daxiang; Wan, Xiaochun; Xia, Tao

2004-11-01

To prepare tea pigments. Tea pigments are prepared by solvent extraction from Sri lanka black tea. Tea pigments contains the components as follows: caffeine 1.77%, epigallocatechin 1.37%, catechin 1.20%, epicatechin 9.55%, epigallocatechin gallate 10.52%, epicatechin gallate 9.94%, theaflavin 10.34%, theaflavin monogallate 9.57%, theaflavin digallate 4.81%, thearubigin about 40.93%. The best proportions of the compound that are obtained with HPLC analysis.

Coffee and tea: perks for health and longevity?

PubMed

Bhatti, Salman K; O'Keefe, James H; Lavie, Carl J

2013-11-01

Tea and coffee, after water, are the most commonly consumed beverages in the world and are the top sources of caffeine and antioxidant polyphenols in the American diet. The purpose of this review is to assess the health effects of chronic tea and/or coffee consumption. Tea consumption, especially green tea, is associated with significantly reduced risks for stroke, diabetes and depression, and improved levels of glucose, cholesterol, abdominal obesity and blood pressure. Habitual coffee consumption in large epidemiological studies is associated with reduced mortality, both for all-cause and cardiovascular deaths. In addition, coffee intake is associated with risks of heart failure, stroke, diabetes mellitus and some cancers in an inverse dose-dependent fashion. Surprisingly, coffee is associated with neutral to reduced risks for both atrial and ventricular arrhythmias. However, caffeine at high doses can increase anxiety, insomnia, calcium loss and possibly the risk of fractures. Coffee and tea can generally be recommended as health-promoting additions to an adult diet. Adequate dietary calcium intake may be particularly important for tea and coffee drinkers.

Effect of Cinnamon Tea on Postprandial Glucose Concentration.

PubMed

Bernardo, Maria Alexandra; Silva, Maria Leonor; Santos, Elisabeth; Moncada, Margarida Maria; Brito, José; Proença, Luis; Singh, Jaipaul; de Mesquita, Maria Fernanda

2015-01-01

Glycaemic control, in particular at postprandial period, has a key role in prevention of different diseases, including diabetes and cardiovascular events. Previous studies suggest that postprandial high blood glucose levels (BGL) can lead to an oxidative stress status, which is associated with metabolic alterations. Cinnamon powder has demonstrated a beneficial effect on postprandial glucose homeostasis in animals and human models. The purpose of this study is to investigate the effect of cinnamon tea (C. burmannii) on postprandial capillary blood glucose level on nondiabetic adults. Participants were given oral glucose tolerance test either with or without cinnamon tea in a randomized clinical trial. The data revealed that cinnamon tea administration slightly decreased postprandial BGL. Cinnamon tea ingestion also results in a significantly lower postprandial maximum glucose concentration and variation of maximum glucose concentration (p < 0.05). Chemical analysis showed that cinnamon tea has a high antioxidant capacity, which may be due to its polyphenol content. The present study provides evidence that cinnamon tea, obtained from C. burmannii, could be beneficial for controlling glucose metabolism in nondiabetic adults during postprandial period.

A polyphenolic extract from green tea leaves activates fat browning in high-fat-diet-induced obese mice.

PubMed

Neyrinck, Audrey M; Bindels, Laure B; Geurts, Lucie; Van Hul, Matthias; Cani, Patrice D; Delzenne, Nathalie M

2017-11-01

Fat browning has emerged as an attractive target for the treatment of obesity and related metabolic disorders. Its activation leads to increased energy expenditure and reduced adiposity, thus contributing to a better energy homeostasis. Green tea extracts (GTEs) were shown to attenuate obesity and low-grade inflammation and to induce the lipolytic pathway in the white adipose tissue (WAT) of mice fed a high-fat diet. The aim of the present study was to determine whether the antiobesity effect of an extract from green tea leaves was associated with the activation of browning in the WAT and/or the inhibition of whitening in the brown adipose tissue (BAT) in HF-diet induced obese mice. Mice were fed a control diet or an HF diet supplemented with or without 0.5% polyphenolic GTE for 8 weeks. GTE supplementation significantly reduced HF-induced adiposity (WAT and BAT) and HF-induced inflammation in WAT. Histological analysis revealed that GTE reduced the adipocyte size in the WAT and the lipid droplet size in the BAT. Markers of browning were induced in the WAT upon GTE treatment, whereas markers of HF-induced whitening were reduced in the BAT. These results suggest that browning activation in the WAT and whitening reduction in the BAT by the GTE could participate to the improvement of metabolic and inflammatory disorders mediated by GTE upon HF diet. Our study emphasizes the importance of using GTE as a nutritional tool to activate browning and to decrease fat storage in all adipose tissues, which attenuate obesity. Copyright © 2017 Elsevier Inc. All rights reserved.

Antiviral effects of black raspberry (Rubus coreanus) seed extract and its polyphenolic compounds on norovirus surrogates.

PubMed

Lee, Ji-Hye; Bae, Sun Young; Oh, Mi; Seok, Jong Hyeon; Kim, Sella; Chung, Yeon Bin; Gowda K, Giri; Mun, Ji Young; Chung, Mi Sook; Kim, Kyung Hyun

2016-06-01

Black raspberry seeds, a byproduct of wine and juice production, contain large quantities of polyphenolic compounds. The antiviral effects of black raspberry seed extract (RCS) and its fraction with molecular weight less than 1 kDa (RCS-F1) were examined against food-borne viral surrogates, murine norovirus-1 (MNV-1) and feline calicivirus-F9 (FCV-F9). The maximal antiviral effect was achieved when RCS or RCS-F1 was added simultaneously to cells with MNV-1 or FCV-F9, reaching complete inhibition at 0.1-1 mg/mL. Transmission electron microscopy (TEM) images showed enlarged viral capsids or disruption (from 35 nm to up to 100 nm) by RCS-F1. Our results thus suggest that RCS-F1 can interfere with the attachment of viral surface protein to host cells. Further, two polyphenolic compounds derived from RCS-F1, cyanidin-3-glucoside (C3G) and gallic acid, identified by liquid chromatography-tandem mass spectrometry, showed inhibitory effects against the viruses. C3G was suggested to bind to MNV-1 RNA polymerase and to enlarge viral capsids using differential scanning fluorimetry and TEM, respectively.

Human clinical studies of tea polyphenols in allergy or life style-related diseases.

PubMed

Maeda-Yamamoto, Mari

2013-01-01

Many previous epidemiological studies have revealed that green tea or green tea catechins contributed to the preveintion of lifestyle-related diseases. Several cohort studies on the relationship between green tea consumption and cardiovascular disease (CVD) risk/type 2 diabetes mellitus risk have been conducted. The results showed that green tea consumption (5 or more cups/day) was inversely associated with mortality from CVD and all causes. Within CVD mortality, the strongest inverse association was observed for stroke mortality. Furthermore, consumption of green tea, coffee, and total caffeine was associated with a reduced risk for type 2 diabetes. On the other hand, the analysis of randomized clinical trial (RCT) studies showed that the administration of green tea beverages or extracts resulted in significant reductions in serum total cholesterol and LDL-cholesterol concentrations, but had no apparent effect on HDL-cholesterol. Green tea reduced fasting blood glucose levels in a small intervention trial, although no improvements in HbA1c levels were seen. Continuous intake of green tea containing catechins and caffeine (5 or more cups per day) may be beneficial for body weight management, vascular disease risk reduction via LDL-cholesterol improvement, and type 2 diabetes risk reduction through the lowering of fasting blood glucose levels. Epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3"Me) isolated from cv. "Benifuuki" green tea has been shown to strongly inhibit mast cell activation and histamine release after FcepsilonRI cross-linking through the suppression of tyrosine phosphorylation (Lyn) of cellular protein kinase, and the suppression of myosin light chain phosphorylation and high-affinity IgE receptor expression via the binding to 67 kDa laminin receptors. A double-blind clinical study on subjects with Japanese cedar pollinosis was carried out. At the eleventh week after starting intake, which was coincident with the most severe period of cedar pollen

An Improved Weighted Partial Least Squares Method Coupled with Near Infrared Spectroscopy for Rapid Determination of Multiple Components and Anti-Oxidant Activity of Pu-Erh Tea.

PubMed

Liu, Ze; Xie, Hua-Lin; Chen, Lin; Huang, Jian-Hua

2018-05-02

Background: Pu-erh tea is a unique microbially fermented tea, which distinctive chemical constituents and activities are worthy of systematic study. Near infrared spectroscopy (NIR) coupled with suitable chemometrics approaches can rapidly and accurately quantitatively analyze multiple compounds in samples. Methods: In this study, an improved weighted partial least squares (PLS) algorithm combined with near infrared spectroscopy (NIR) was used to construct a fast calibration model for determining four main components, i.e., tea polyphenols, tea polysaccharide, total flavonoids, theanine content, and further determine the total antioxidant capacity of pu-erh tea. Results: The final correlation coefficients R square for tea polyphenols, tea polysaccharide, total flavonoids content, theanine content, and total antioxidant capacity were 0.8288, 0.8403, 0.8415, 0.8537 and 0.8682, respectively. Conclusions : The current study provided a comprehensive study of four main ingredients and activity of pu-erh tea, and demonstrated that NIR spectroscopy technology coupled with multivariate calibration analysis could be successfully applied to pu-erh tea quality assessment.

Potential Health Benefits of Olive Oil and Plant Polyphenols

PubMed Central

Gorzynik-Debicka, Monika; Przychodzen, Paulina; Cappello, Francesco; Kuban-Jankowska, Alicja; Marino Gammazza, Antonella; Knap, Narcyz; Wozniak, Michal; Gorska-Ponikowska, Magdalena

2018-01-01

Beneficial effects of natural plant polyphenols on the human body have been evaluated in a number of scientific research projects. Bioactive polyphenols are natural compounds of various chemical structures. Their sources are mostly fruits, vegetables, nuts and seeds, roots, bark, leaves of different plants, herbs, whole grain products, processed foods (dark chocolate), as well as tea, coffee, and red wine. Polyphenols are believed to reduce morbidity and/or slow down the development of cardiovascular and neurodegenerative diseases as well as cancer. Biological activity of polyphenols is strongly related to their antioxidant properties. They tend to reduce the pool of reactive oxygen species as well as to neutralize potentially carcinogenic metabolites. A broad spectrum of health-promoting properties of plant polyphenols comprises antioxidant, anti-inflammatory, anti-allergic, anti-atherogenic, anti-thrombotic, and anti-mutagenic effects. Scientific studies present the ability of polyphenols to modulate the human immune system by affecting the proliferation of white blood cells, and also the production of cytokines or other factors that participate in the immunological defense. The aim of the review is to focus on polyphenols of olive oil in context of their biological activities. PMID:29495598

Potential Health Benefits of Olive Oil and Plant Polyphenols.

PubMed

Gorzynik-Debicka, Monika; Przychodzen, Paulina; Cappello, Francesco; Kuban-Jankowska, Alicja; Marino Gammazza, Antonella; Knap, Narcyz; Wozniak, Michal; Gorska-Ponikowska, Magdalena

2018-02-28

Beneficial effects of natural plant polyphenols on the human body have been evaluated in a number of scientific research projects. Bioactive polyphenols are natural compounds of various chemical structures. Their sources are mostly fruits, vegetables, nuts and seeds, roots, bark, leaves of different plants, herbs, whole grain products, processed foods (dark chocolate), as well as tea, coffee, and red wine. Polyphenols are believed to reduce morbidity and/or slow down the development of cardiovascular and neurodegenerative diseases as well as cancer. Biological activity of polyphenols is strongly related to their antioxidant properties. They tend to reduce the pool of reactive oxygen species as well as to neutralize potentially carcinogenic metabolites. A broad spectrum of health-promoting properties of plant polyphenols comprises antioxidant, anti-inflammatory, anti-allergic, anti-atherogenic, anti-thrombotic, and anti-mutagenic effects. Scientific studies present the ability of polyphenols to modulate the human immune system by affecting the proliferation of white blood cells, and also the production of cytokines or other factors that participate in the immunological defense. The aim of the review is to focus on polyphenols of olive oil in context of their biological activities.

Recent advances in tea polysaccharides: Extraction, purification, physicochemical characterization and bioactivities.

PubMed

Chen, Guijie; Yuan, Qingxia; Saeeduddin, Muhammad; Ou, Shiyi; Zeng, Xiaoxiong; Ye, Hong

2016-11-20

Tea has a long history of medicinal and dietary use. Tea polysaccharide (TPS) is regarded as one of the main bioactive constituents of tea and is beneficial for health. Over the last decades, considerable efforts have been devoted to the studies on TPS: extraction, structural feature and bioactivity of TPS. However, it has been received much less attention compared with tea polyphenols. In order to provide new insight for further development of TPS in functional foods, in present review we summarize the recent literature, update the information and put forward future perspectives on TPS covering its extraction, purification, quantitative determination techniques as well as physicochemical characterization and bioactivities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hepatoprotective and curative properties of Kombucha tea against carbon tetrachloride-induced toxicity.

PubMed

Murugesan, G S; Sathishkumar, M; Jayabalan, R; Binupriya, A R; Swaminathan, K; Yun, S E

2009-04-01

Kombucha tea (KT) is sugared black tea fermented with a symbiotic culture of acetic acid bacteria and yeasts, which is said to be tea fungus. KT is claimed to have various beneficial effects on human health, but there is very little scientific evidence available in the literature. In the present study, KT along with black tea (BT) and black tea manufactured with tea fungus enzymes (enzyme-processed tea, ET) was evaluated for hepatoprotective and curative properties against CCl4-induced toxicity, using male albino rats as an experimental model by analyzing aspartate transaminase, alanine transaminase, and alkaline phosphatase in plasma and malondialdehyde content in plasma and liver tissues. Histopathological analysis of liver tissue was also included. Results showed that BT, ET, and KT have the potential to revert the CCl4-induced hepatotoxicity. Among the three types of teas tried, KT was found to be more efficient than BT and ET. Antioxidant molecules produced during the fermentation period could be the reason for the efficient hepatoprotective and curative properties of KT against CCI4-induced hepatotoxicity.

Assessment of Anti-nutritive Activity of Tannins in Tea By-products Based on In vitro Rumen Fermentation.

PubMed

Kondo, Makoto; Hirano, Yoshiaki; Ikai, Noriyuki; Kita, Kazumi; Jayanegara, Anuraga; Yokota, Hiro-Omi

2014-11-01

Nutritive values of green and black tea by-products and anti-nutritive activity of their tannins were evaluated in an in vitro rumen fermentation using various molecular weights of polyethylene glycols (PEG), polyvinyl pyrrolidone (PVP) and polyvinyl polypyrrolidone as tannin-binding agents. Significant improvement in gas production by addition of PEG4000, 6000 and 20000 and PVP was observed only from black tea by-product, but not from green tea by-product. All tannin binding agents increased NH3-N concentration from both green and black tea by-products in the fermentation medium, and the PEG6000 and 20000 showed relatively higher improvement in the NH3-N concentration. The PEG6000 and 20000 also improved in vitro organic matter digestibility and metabolizable energy contents of both tea by-products. It was concluded that high molecular PEG would be suitable to assess the suppressive activity of tannins in tea by-products by in vitro fermentation. Higher responses to gas production and NH3-N concentration from black tea by-product than green tea by-product due to PEG indicate that tannins in black tea by-product could suppress rumen fermentation more strongly than that in green tea by-product.

Theaflavin-3,3'-digallate, a component of black tea: an inducer of oxidative stress and apoptosis.

PubMed

Schuck, Alyssa G; Ausubel, Miriam B; Zuckerbraun, Harriet L; Babich, Harvey

2008-04-01

Treatment of human oral squamous carcinoma HSC-2 cells and normal GN46 fibroblasts with theaflavin-3,3'-digallate (TF-3), a polyphenol in black tea, showed a concentration and time dependent inhibition of growth, with the tumor cells more sensitive than the fibroblasts. In buffer and in cell culture medium, TF-3 generated reactive oxygen species, with lower levels detected in buffer amended with catalase and superoxide dismutase, indicating the generation of hydrogen peroxide and superoxide, respectively, and suggesting that TF-3 may be an inducer of oxidative stress. The toxicity of TF-3 was decreased in the presence of catalase, pyruvate, and divalent cobalt, all scavengers of reactive oxygen species, but was potentiated in the presence of diethyldithiocarbamate, an inhibitor of superoxide dismutase. The intracellular level of glutathione in HSC-2 cells was lessened after a 4-h exposure to 250 and 500 microM TF-3. However, for GN46 fibroblasts, a 4-h exposure to 250 microM TF-3 stimulated, but to 500 microM TF-3 lessened, intracellular glutathione. Treatment of the cells with the glutathione depleters, 1,3-bis(2-chloroethyl)-N-nitrosourea, 1-chloro-2,4-dinitrobenzene, and d,l-buthionine-[S,R]-sulfoximine potentiated the toxicity of TF-3. Induction of apoptotic cell death in HSC-2 cells treated with TF-3 was noted by apoptotic cell morphologies, by TUNEL staining, by PARP cleavage, and by elevated activity of caspase-3. Apoptosis was not noted in GN46 fibroblasts treated with TF-3.

Biophysical characteristics of proteins and living cells exposed to the green tea polyphenol epigallocatechin-3-gallate (EGCg): review of recent advances from molecular mechanisms to nanomedicine and clinical trials.

PubMed

Peter, Beatrix; Bosze, Szilvia; Horvath, Robert

2017-01-01

Herbs and traditional medicines have been applied for thousands of years, but researchers started to study their mode of action at the molecular, cellular and tissue levels only recently. Nowadays, just like in ancient times, natural compounds are still determining factors in remedies. To support this statement, the recently won Nobel Prize for an anti-malaria agent from the plant sweet wormwood, which had been used to effectively treat the disease, could be mentioned. Among natural compounds and traditional Chinese medicines, the green tea polyphenol epigallocatechin gallate (EGCg) is one of the most studied active substances. In the present review, we summarize the molecular scale interactions of proteins and EGCg with special focus on its limited stability and antioxidant properties. We outline the observed biophysical effects of EGCg on various cell lines and cultures. The alteration of cell adhesion, motility, migration, stiffness, apoptosis, proliferation as well as the different impacts on normal and cancer cells are all reviewed. We also handle the works performed using animal models, microbes and clinical trials. Novel ways to develop its utilization for therapeutic purposes in the future are discussed too, for instance, using nanoparticles and green tea polyphenols together to cure illnesses and the combination of EGCg and anticancer compounds to intensify their effects. The limitations of the employed experimental models and criticisms of the interpretation of the obtained experimental data are summarized as well.

Formation of enriched black tea extract loaded chitosan nanoparticles via electrospraying

NASA Astrophysics Data System (ADS)

Hammond, Samuel James

Creating nanoparticles of beneficial nutraceuticals and pharmaceuticals has had a large surge of research due to the enhancement of absorption and bioavailability by decreasing their size. One of these ways is by electrohydrodynamic atomization, also known as electrospraying. In general, this novel process is done by forcing a liquid through a capillary nozzle and which is subjected to an electrical field. While there are different ways to create nanoparticles, the novel method of electrospraying can be beneficial over other types of nanoparticle formation. Reasons include high control over particle size and distribution by altering electrospray parameters (voltage, flow rate, distance, and time), higher encapsulation efficiency than other methods, and also it is a one step process without exposure to extreme conditions (Gomez-Estaca et. al. 2012, Jaworek and Sobcyzk 2008). The current study aimed to create a chitosan encapsulated theaflavin-2 enriched black tea extract (BTE) nanoparticles via electrospraying. The first step of this process was to create the smallest chitosan nanoparticles possible by altering the electrospray parameters and the chitosan-acetic acid solution parameters. The solution properties altered include chitosan molecular weight, acetic acid concentration, and chitosan concentration. Specifically, the electrospray parameters such as voltage, flow rate and distance from syringe to collector are the most important in determining particle size. After creating the smallest chitosan particles, the TF-2 enriched black tea extract was added to the chitosan-acetic acid solution to be electrosprayed. The particles were assessed with the following procedures: Atomic force microscopy (AFM) and scanning electron microscopy (SEM) for particle morphology and size, and loading efficiency with ultraviolet--visible spectrophotometer (UV-VIS). Chitosan-BTE nanoparticles were successfully created in a one step process. Diameter of the particles on average

Effect of complex polyphenols and tannins from red wine on DNA oxidative damage of rat colon mucosa in vivo.

PubMed

Giovannelli, L; Testa, G; De Filippo, C; Cheynier, V; Clifford, M N; Dolara, P

2000-10-01

Dietary polyphenols have been reported to have a variety of biological actions, including anti-carcinogenic, antioxidant and anti-inflammatory activities. In the present study we have evaluated the effect of an oral treatment with complex polyphenols and tannins from red wine and tea on DNA oxidative damage in the rat colon mucosa. Isolated colonocytes were prepared from the colon mucosa of rats treated for ten days with either wine complex polyphenols (57.2 mg/kg/d) or thearubigin (40 mg/kg/d) by oral gavage. Colonocyte oxidative DNA damage was analysed at the single cell level using a modification of the comet assay technique. The results show that wine complex polyphenols and tannins induce a significant decrease (-62% for pyrimidine and -57% for purine oxidation) in basal DNA oxidative damage in colon mucosal cells without affecting the basal level of single-strand breaks. On the other hand, tea polyphenols, namely a crude extract of thearubigin, did not affect either strand breaks or pyrimidine oxidation in colon mucosal cells. Our experiments are the first demonstration that dietary polyphenols can modulate in vivo oxidative damage in the gastrointestinal tract of rodents. These data support the hypothesis that dietary polyphenols might have both a protective and a therapeutic potential in oxidative damage-related pathologies.

Changes in free-radical scavenging ability of kombucha tea during fermentation.

PubMed

Jayabalan, R; Subathradevi, P; Marimuthu, S; Sathishkumar, M; Swaminathan, K

2008-07-01

Kombucha tea is a fermented tea beverage produced by fermenting sugared black tea with tea fungus (kombucha). Free-radical scavenging abilities of kombucha tea prepared from green tea (GTK), black tea (BTK) and tea waste material (TWK) along with pH, phenolic compounds and reducing power were investigated during fermentation period. Phenolic compounds, scavenging activity on DPPH radical, superoxide radical (xanthine-xanthine oxidase system) and inhibitory activity against hydroxyl radical mediated linoleic acid oxidation (ammonium thiocyanate assay) were increased during fermentation period, whereas pH, reducing power, hydroxyl radical scavenging ability (ascorbic acid-iron EDTA) and anti-lipid peroxidation ability (thiobarbituric assay) were decreased. From the present study, it is obvious that there might be some chances of structural modification of components in tea due to enzymes liberated by bacteria and yeast during kombucha fermentation which results in better scavenging performance on nitrogen and superoxide radicals, and poor scavenging performance on hydroxyl radicals. Copyright © 2007 Elsevier Ltd. All rights reserved.

Preparation and Oxidation Stability Evaluation of Tea Polyphenols-Loaded Inverse Micro-Emulsion.

PubMed

Lan, Xiaohong; Sun, Jingjing; Yang, Ying; Chen, Mengjie; Liu, Jianhua; Wu, Jinhong; Wang, Zhengwu

2017-05-01

Compared to synthetic antioxidants, tea polyphenols (TPs) has its own advantages in edible oil industry, however, the hydrophilic properties have restricted its applications. In this study, the ternary phase diagram of TPs-loaded micro-emulsion (ME) system was constructed, in which glyceryl monooleate (GMO), Tween80, linoleic acid as the surfactants, ethanol as the co-surfactant and soybean, corn, sunflower oil as the oil phase, have been used for the preparation of ME. The results indicated that a composition of ME (57.5% oil, 18% Tween80, 18% GMO, 4% Linolic acid, and 2.5% water+ethanol) could dissolve maximum water and could stable for 2 mo at room temperature with an average diameter of 6 to 7 nm, as detected by means of dynamic light scattering (DLS). The loaded of TPs into ME led to an increase of particle size to 15 to 16 nm, due to increased polarity of the water phase. The antioxidant capacity of TPs in ME was characterized by the peroxide value (POV) method. The addition of 1% water phase with 0.1 g/mL TPs could retain the POV at low value for 30 d at accelerating temperature 50 °C. Meanwhile, comparing the three edible oil, ME with corn oil has lower conductivity and higher value of POV during the storage. This work provides an efficient and environmentally friendly approach for the preparation of TPs-loaded ME, which is beneficial to the application of TPs in edible oil. © 2017 Institute of Food Technologists®.

Green Tea Polyphenols, Mimicking the Effects of Dietary Restriction, Ameliorate High-Fat Diet-Induced Kidney Injury via Regulating Autophagy Flux

PubMed Central

Xie, Xiao; Yi, Weijie; Zhang, Piwei; Wu, Nannan; Yan, Qiaoqiao; Yang, Hui; Tian, Chong; Xiang, Siyun; Du, Miying; Getachew Assefa, Eskedar; Zuo, Xuezhi; Ying, Chenjiang

2017-01-01

Epidemiological and experimental studies reveal that Western dietary patterns contribute to chronic kidney disease, whereas dietary restriction (DR) or dietary polyphenols such as green tea polyphenols (GTPs) can ameliorate the progression of kidney injury. This study aimed to investigate the renal protective effects of GTPs and explore the underlying mechanisms. Sixty Wistar rats were randomly divided into 6 groups: standard diet (STD), DR, high-fat diet (HFD), and three diets plus 200 mg/kg(bw)/day GTPs, respectively. After 18 weeks, HFD group exhibited renal injuries by increased serum cystatin C levels and urinary N-acetyl-β-d-glucosaminidase activity, which can be ameliorated by GTPs. Meanwhile, autophagy impairment as denoted by autophagy-lysosome related proteins, including LC3-II, Beclin-1, p62, cathepsin B, cathepsin D and LAMP-1, was observed in HFD group, whereas DR or GTPs promoted renal autophagy activities and GTPs ameliorated HFD-induced autophagy impairment. In vitro, autophagy flux suppression was detected in palmitic acid (PA)-treated human proximal tubular epithelial cells (HK-2), which was ameliorated by epigallocatechin-3-gallate (EGCG). Furthermore, GTPs (or EGCG) elevated phosphorylation of AMP-activated protein kinase in the kidneys of HFD-treated rats and in PA-treated HK-2 cells. These findings revealed that GTPs mimic the effects of DR to induce autophagy and exert a renal protective effect by alleviating HFD-induced autophagy suppression. PMID:28505110

A comparative evaluation of Morinda citrifolia, green tea polyphenols, and Triphala with 5% sodium hypochlorite as an endodontic irrigant against Enterococcus faecalis: An in vitro study.

PubMed

Divia, A R; Nair, Mali G; Varughese, Jolly Mary; Kurien, Shobha

2018-01-01

Endodontic infections require effective removal of microorganisms from the root canal system for long-term prognosis. Sodium hypochlorite (NaOCl) is the most effective irrigant currently, but potential complications due to its toxicity warrant search for newer alternatives. In this study, the antimicrobial efficacy of Morinda citrifolia (MC), green tea polyphenols and Triphala was compared with 5% NaOCl against Enterococcus faecalis . In this in vitro study sixty extracted human premolar teeth were infected with E. faecalis , a Group D Streptococci for 48 h. At the end of 48 h, the vital bacterial population was assessed by counting the number of colony-forming units (CFUs) on blood agar plate. Samples were divided into five groups; Group I (distilled water), Group II (NaOCl), Group III (MC), Group IV (Triphala), and Group V (green tea polyphenols). The samples were irrigated with individual test agents and CFUs were recorded. Kruskal-Wallis test was performed as the parametric test to compare different groups. Student's t -test was used to compare mean values between groups before and after treatment with test agents ( P < 0.001). NaOCl was the most effective irrigant the elimination of E. faecalis reinforcing its role as the best irrigant available currently and a gold standard for comparison of the experimental groups. Its antibacterial effect was comparable to Triphala. Among the experimental groups, MC showed the minimum antibacterial effect. The use of herbal alternatives as a root canal irrigant might prove to be advantageous considering the several undesirable characteristics of NaOCl.

A comparative evaluation of Morinda citrifolia, green tea polyphenols, and Triphala with 5% sodium hypochlorite as an endodontic irrigant against Enterococcus faecalis: An in vitro study

PubMed Central

Divia, A. R.; Nair, Mali G.; Varughese, Jolly Mary; Kurien, Shobha

2018-01-01

Background: Endodontic infections require effective removal of microorganisms from the root canal system for long-term prognosis. Sodium hypochlorite (NaOCl) is the most effective irrigant currently, but potential complications due to its toxicity warrant search for newer alternatives. In this study, the antimicrobial efficacy of Morinda citrifolia (MC), green tea polyphenols and Triphala was compared with 5% NaOCl against Enterococcus faecalis. Materials and Methods: In this in vitro study sixty extracted human premolar teeth were infected with E. faecalis, a Group D Streptococci for 48 h. At the end of 48 h, the vital bacterial population was assessed by counting the number of colony-forming units (CFUs) on blood agar plate. Samples were divided into five groups; Group I (distilled water), Group II (NaOCl), Group III (MC), Group IV (Triphala), and Group V (green tea polyphenols). The samples were irrigated with individual test agents and CFUs were recorded. Kruskal–Wallis test was performed as the parametric test to compare different groups. Student's t-test was used to compare mean values between groups before and after treatment with test agents (P < 0.001). Results: NaOCl was the most effective irrigant the elimination of E. faecalis reinforcing its role as the best irrigant available currently and a gold standard for comparison of the experimental groups. Its antibacterial effect was comparable to Triphala. Among the experimental groups, MC showed the minimum antibacterial effect. Conclusion: The use of herbal alternatives as a root canal irrigant might prove to be advantageous considering the several undesirable characteristics of NaOCl. PMID:29576775

Effect of tea on iron absorption from the typical Tunisian meal 'couscous' fed to healthy rats.

PubMed

Hamdaoui, M; Hedhili, A; Doghri, T; Tritar, B

1994-01-01

Black and green tea decoctions are popular beverages in Tunisia, especially after eating. Our study was performed to examine the effect of graded amounts of black and green tea decoction prepared under realistic Tunisian conditions on nonheme iron absorption from a typical Tunisian meal, 'couscous', by extrinsic radioiron labeling in rats. Concentrations of 300, 200 and 100 micrograms/ml of black tea decreased dramatically nonheme iron bioavailability from couscous, but 50 micrograms/ml did not influence iron absorption. The inhibition of nonheme iron from couscous varied from 36 to 61% with black tea and 30.5% with green tea. Taken together, our findings show that the tea decoction in Tunisia has a great inhibitory power and may constitute an important factor for the development of iron deficiency anemia throughout Tunisia.

Tea, coffee, and cocoa as ultraviolet radiation protectants for the beet armyworm nucleopolyhedrovirus.

PubMed

El-Salamouny, S; Ranwala, D; Shapiro, M; Shepard, B M; Farrar, Robert R

2009-10-01

The addition of 1% (wt:vol) aqueous extracts of cocoa (Theobroma cacao L.) (Malvales: Malvaceae), coffee (Coffea arabica L.) (Gentianales: Rubiaceae), and green and black tea (Camellia sinensis L.) (Ericales: Theaceae) provided excellent UV radiation protection for the beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), nucleopolyhedrovirus under laboratory conditions. Aqueous extracts of coffee, green tea, and black tea at 0.5% provided 85-100% UV protection, whereas cocoa provided 50% UV protection. Epigallocatechin gallate (EGCG), a component of green tea, and caffeine, a component of tea and coffee, also were tested as UV protectants. Both compounds were ineffective when tested alone. When EGCG and caffeine were combined, UV protection increased in a synergistic manner, but <35% of the original virus activity was maintained. This study demonstrated that coffee was comparable to green tea and black tea as a UV protectant. Further studies should be conducted to optimize their use in biopesticide formulations.

Potential role of naturally derived polyphenols and their nanotechnology delivery in cancer.

PubMed

Khushnud, Tasnima; Mousa, Shaker A

2013-09-01

Polyphenols are natural compounds found in plants, fruits, chocolate, and beverages such as tea and wine. To date, the majority of polyphenol research shows them to have anticancer activity in cell lines and animal models. Some human clinical trials also indicate possible anticancer benefits are associated with polyphenols. A problem with polyphenols is their short half-life and low bioavailability; thus the use of nanoparticles to enhance their delivery is a new research field. A Pubmed search was conducted to find in vitro, in vivo, and human clinical trials done within the past 10 years involving the use of polyphenols against different cancer types, and for studies done within the past 5 years on the use of nanoparticles to enhance polyphenol delivery. Based on the studies found, it is observed that polyphenols may be a potential alternative or additive therapy against cancer, and the use of nanoparticles to enhance their delivery to tumors is a promising approach. However, further human clinical trials are necessary to better understand the use of polyphenols as well as their nanoparticle-mediated delivery.

Assessment of Anti-nutritive Activity of Tannins in Tea By-products Based on In vitro Rumen Fermentation

PubMed Central

Kondo, Makoto; Hirano, Yoshiaki; Ikai, Noriyuki; Kita, Kazumi; Jayanegara, Anuraga; Yokota, Hiro-omi

2014-01-01

Nutritive values of green and black tea by-products and anti-nutritive activity of their tannins were evaluated in an in vitro rumen fermentation using various molecular weights of polyethylene glycols (PEG), polyvinyl pyrrolidone (PVP) and polyvinyl polypyrrolidone as tannin-binding agents. Significant improvement in gas production by addition of PEG4000, 6000 and 20000 and PVP was observed only from black tea by-product, but not from green tea by-product. All tannin binding agents increased NH3-N concentration from both green and black tea by-products in the fermentation medium, and the PEG6000 and 20000 showed relatively higher improvement in the NH3-N concentration. The PEG6000 and 20000 also improved in vitro organic matter digestibility and metabolizable energy contents of both tea by-products. It was concluded that high molecular PEG would be suitable to assess the suppressive activity of tannins in tea by-products by in vitro fermentation. Higher responses to gas production and NH3-N concentration from black tea by-product than green tea by-product due to PEG indicate that tannins in black tea by-product could suppress rumen fermentation more strongly than that in green tea by-product. PMID:25358316

Anti-oxidative effects of rooibos tea extract on autoxidation and thermal oxidation of lipids.

PubMed

Fukasawa, Ryo; Kanda, Ayato; Hara, Setsuko

2009-01-01

Powdered rooibos tea extract (RTE), which is rich in polyphenols, is made from rooibos tea by freeze-drying. "Rooibos" is Afrikaans for "red bush," and the scientific name is "Aspalathus linearis." It is a broom-like member of the legume family of plants and is used to make an herbal tea which has been popular in South Africa for generations and is now consumed in many countries. In the present work, the anti-oxidative effect of RTE on oils and fats in autoxidation or thermal oxidation was studied, and it was confirmed that RTE has a very strong anti-oxidative effect on emulsifying oils owing to the water-soluble polyphenols such as rutin and quercetin contained in RTE. RTE was found to have a strong ability to quench radicals generated in the water phase, and to confer higher thermal stability against deep fat frying than tocopherol. But RTE showed little anti-oxidative effect on frying oil because of its lower oil-solubility.

Quantification of Tea Flavonoids by High Performance Liquid Chromatography

ERIC Educational Resources Information Center

Freeman, Jessica D.; Niemeyer, Emily D.

2008-01-01

We have developed a laboratory experiment that uses high performance liquid chromatography (HPLC) to quantify flavonoid levels in a variety of commercial teas. Specifically, this experiment analyzes a group of flavonoids known as catechins, plant-derived polyphenolic compounds commonly found in many foods and beverages, including green and black…

Safety Evaluation of Green Tea Polyphenols Consumption in Middle-aged Ovariectomized Rat Model.

PubMed

Shen, Chwan-Li; Brackee, Gordon; Song, Xiao; Tomison, Michael D; Finckbone, VelvetLee; Mitchell, Kelly T; Tang, Lili; Chyu, Ming-Chien; Dunn, Dale M; Wang, Jia-Sheng

2017-09-01

This work evaluates chronic safety in middle-aged ovariectomized rats supplemented with different dosages of green tea polyphenols (GTP) in drinking water. The experiment used 6-mo-old sham (n = 39) and ovariectomized (OVX, n = 143) female rats. All sham (n = 39) and 39 of the OVX animals received no GTP treatment and their samples were collected for outcome measures at baseline, 3 mo, and 6 mo (n = 13 per group for each). The remaining OVX animals were randomized into 4 groups receiving 0.15%, 0.5%, 1%, and 1.5% (n = 26 for each) of GTP (wt/vol), respectively, in drinking water for 3 and 6 mo. No mortality or abnormal treatment-related findings in clinical observations or ophthalmologic examinations were noted. No treatment-related macroscopic or microscopic findings were noted for animals administered 1.5% GTP supplementation. Throughout the study, there was no difference in the body weight among all OVX groups. In all OVX groups, feed intake and water consumption significantly decreased with GTP dose throughout the study period. At 6 mo, GTP intake did not affect hematology, clinical chemistry, and urinalysis, except for phosphorus and blood urea nitrogen (increased), total cholesterol, lactate dehydrogenase, and urine pH (decreased). This study reveals that the no-observed-adverse-effect level (NOAEL) of GTP is 1.5% (wt/vol) in drinking water, the highest dose used in this study. © 2017 Institute of Food Technologists®.

Tea and coffee intake in relation to risk of breast cancer in the Black Women’s Health Study