Sample records for tea catechins gtcs

  1. Extraction and isolation of catechins from tea.

    PubMed

    Vuong, Quan V; Golding, John B; Nguyen, Minh; Roach, Paul D

    2010-11-01

    Tea is a major source of catechins, which have become well known for their antioxidant potential. Numerous human, animal, and in vitro studies have linked tea catechins with prevention of certain types of cancers, reduction of the risks for obesity, diabetes, and cardiovascular disease, and improvement of the immune system. Tea catechins are widely used in various neutraceuticals, pharmaceuticals, and cosmetics for either enhancing product shelf-life or for enhancing human health. Thus, the demand for catechins has increased considerably. Catechins have been extracted and isolated from tea leaves by numerous methods through several steps including: treatment of the tea leaves, extraction of catechins from teas into solvents, isolation of catechins from other extracted components, and drying the preparations to obtain catechin extracts in a powder form. This paper outlines the physical and chemical properties of the tea catechins and reviews the extraction steps of the various extraction methods, as a basis to improve and further develop the extraction and isolation of the tea catechins.

  2. Using tea stalk lignocellulose as an adsorbent for separating decaffeinated tea catechins.

    PubMed

    Ye, J H; Jin, J; Liang, H L; Lu, J L; Du, Y Y; Zheng, X Q; Liang, Y R

    2009-01-01

    Lignocelluloses prepared from woody tea stalk, pine sawdust and sugarcane bagasse were used as adsorbents to isolate decaffeinated catechins from tea extracts and compared with synthetic macroporous resin HPD 600. HPD 600 had the highest adsorption capacity to catechins, followed by tea stalk lignocellulose while lignocelluloses of pine sawdust and bagasse the least. Tea stalk lignocellulose absorbed preferentially tea catechins and showed a good selectivity. HPD 600 absorbed caffeine and tea catechins simultaneously. The kinetics data of tea stalk lignocellulose showed a good fit with the Langmuir isotherm model. It is considered that tea stalk lignocellulose is an alternative low-cost adsorbent for preparing decaffeinated tea catechins.

  3. Common tea formulations modulate in vitro digestive recovery of green tea catechins.

    PubMed

    Green, Rodney J; Murphy, Angus S; Schulz, Burkhard; Watkins, Bruce A; Ferruzzi, Mario G

    2007-09-01

    Epidemiological evidence suggests a role for tea catechins in reduction of chronic disease risk. However, stability of catechins under digestive conditions is poorly understood. The objective of this study was to characterize the effect of common food additives on digestive recovery of tea catechins. Green tea water extracts were formulated in beverages providing 4.5, 18, 23, and 3.5 mg per 100 mL epicatechin (EC), epigallocatechin (EGC), epigallocatechin-gallate (EGCG), and epicatechin-gallate (ECG), respectively. Common commercial beverage additives; citric acid (CA), BHT, EDTA, ascorbic acid (AA), milk (bovine, soy, and rice), and citrus juice (orange, grapefruit, lemon, and lime) were formulated into finished tea beverages at incremental dosages. Samples were then subjected to in vitro digestion simulating gastric and small intestinal conditions with pre- and post-digestion catechin profiles assessed by HPLC. Catechin stability in green tea was poor with <20% total catechins remaining post-digestion. EGC and EGCG were most sensitive with less, not double equals 10% recovery. Teas formulated with 50% bovine, soy, and rice milk increased total catechin recovery significantly to 52, 55, and 69% respectively. Including 30 mg AA in 250 mL of tea beverage significantly (p<0.05) increased catechin recovery of EGC, EGCG, EC, and ECG to 74, 54, 82, and 45% respectively. Juice preparation resulted in the highest recovery of any formulation for EGC (81-98%), EGCG (56-76%), EC (86-95%), and ECG (30-55%). These data provide evidence that tea consumption practices and formulation factors likely impact catechin digestive recovery and may result in diverse physiological profiles.

  4. Randomized, Placebo-Controlled Trial of Green Tea Catechins for Prostate Cancer Prevention

    PubMed Central

    Kumar, Nagi B.; Pow-Sang, Julio; Egan, Kathleen M.; Spiess, Philippe E.; Dickinson, Shohreh; Salup, Raoul; Helal, Mohamed; McLarty, Jerry; Williams, Christopher R.; Schreiber, Fred; Parnes, Howard L.; Sebti, Said; Kazi, Aslam; Kang, Loveleen; Quinn, Gwen; Smith, Tiffany; Yue, Binglin; Diaz, Karen; Chornokur, Ganna; Crocker, Theresa; Schell, Michael J.

    2015-01-01

    Preclinical, epidemiological and prior clinical trial data suggest that green tea catechins (GTCs) may reduce prostate cancer (PCa) risk. We conducted a placebo-controlled, randomized clinical trial of Polyphenon E® (PolyE), a proprietary mixture of GTCs, containing 400 mg (–)-epigallocatechin-3-gallate (EGCG) per day, in 97 men with high-grade prostatic intraepithelial neoplasia (HGPIN) and/or atypical small acinar proliferation (ASAP). The primary study endpoint was a comparison of the cumulative one-year PCa rates on the two study arms. No differences in the number of PCa cases were observed: 5/49 (PolyE) versus 9/48 (placebo), P=0.25. A secondary endpoint comparing the cumulative rate of PCa plus ASAP among men with HGPIN without ASAP at baseline, revealed a decrease in this composite endpoint: 3/26 (PolyE) versus 10/25 (placebo), P<0.024. This finding was driven by a decrease in ASAP diagnoses on the Poly E (0/26) compared to the placebo arm (5/25). A decrease in serum prostate specific antigen (PSA) was observed on the PolyE arm [−0.87 ng/ml (95%CI: −1.66, −0.09)]. Adverse events related to the study agent did not significantly differ between the two study groups. Daily intake of a standardized, decaffeinated catechin mixture containing 400 mg EGCG per day for 1 year accumulated in plasma and was well tolerated but did not reduce the likelihood of PCa in men with baseline HGPIN or ASAP. PMID:25873370

  5. Suppressive Effects of Tea Catechins on Breast Cancer

    PubMed Central

    Xiang, Li-Ping; Wang, Ao; Ye, Jian-Hui; Zheng, Xin-Qiang; Polito, Curt Anthony; Lu, Jian-Liang; Li, Qing-Sheng; Liang, Yue-Rong

    2016-01-01

    Tea leaf (Camellia sinensis) is rich in catechins, which endow tea with various health benefits. There are more than ten catechin compounds in tea, among which epigallocatechingallate (EGCG) is the most abundant. Epidemiological studies on the association between tea consumption and the risk of breast cancer were summarized, and the inhibitory effects of tea catechins on breast cancer, with EGCG as a representative compound, were reviewed in the present paper. The controversial results regarding the role of tea in breast cancer and areas for further study were discussed. PMID:27483305

  6. 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.

  7. Green tea catechins: defensive role in cardiovascular disorders.

    PubMed

    Bhardwaj, Pooja; Khanna, Deepa

    2013-07-01

    Green tea, Camellia sinensis (Theaceae), a major source of flavonoids such as catechins, has recently shown multiple cardiovascular health benefits through various experimental and clinical studies. These studies suggest that green tea catechins prevent the incidence of detrimental cardiovascular events, and also lower the cardiovascular mortality rate. Catechins present in green tea have the ability to prevent atherosclerosis, hypertension, endothelial dysfunction, ischemic heart diseases, cardiomyopathy, cardiac hypertrophy and congestive heart failure by decreasing oxidative stress, preventing inflammatory events, reducing platelet aggregation and halting the proliferation of vascular smooth muscle cells. Catechins afford an anti-oxidant effect by inducing anti-oxidant enzymes, inhibiting pro-oxidant enzymes and scavenging free radicals. Catechins present anti-inflammatory activity through the inhibition of transcriptional factor NF-κB-mediated production of cytokines and adhesion molecules. Green tea catechins interfere with vascular growth factors and thus inhibit vascular smooth muscle cell proliferation, and also inhibit thrombogenesis by suppressing platelet adhesion. Additionally, catechins could protect vascular endothelial cells and enhance vascular integrity and regulate blood pressure. In this review various experimental and clinical studies suggesting the role of green tea catechins against the markers of cardiovascular disorders and the underlying mechanisms for these actions are discussed. Copyright © 2013 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  8. Green tea (Camellia sinensis) catechins and vascular function.

    PubMed

    Moore, Rosalind J; Jackson, Kim G; Minihane, Anne M

    2009-12-01

    The health benefits of green tea (Camellia sinensis) catechins are becoming increasingly recognised. Amongst the proposed benefits are the maintenance of endothelial function and vascular homeostasis and an associated reduction in atherogenesis and CVD risk. The mounting evidence for the influential effect of green tea catechins on vascular function from epidemiological, human intervention and animal studies is subject to review together with exploration of the potential mechanistic pathways involved. Epigallocatechin-3-gallate, one of the most abundant and widely studied catechin found in green tea, will be prominent in the present review. Since there is a substantial inconsistency in the published data with regards to the impact of green tea catechins on vascular function, evaluation and interpretation of the inter- and intra-study variability is included. In conclusion, a positive effect of green tea catechins on vascular function is becoming apparent. Further studies in animal and cell models using physiological concentrations of catechins and their metabolites are warranted in order to gain some insight into the physiology and molecular basis of the observed beneficial effects.

  9. Diversity of Catechin in Northeast Indian Tea Cultivars

    PubMed Central

    Sabhapondit, Santanu; Karak, Tanmoy; Bhuyan, Lakshi Prasad; Goswami, Bhabesh Chandra; Hazarika, Mridul

    2012-01-01

    Tea (Camellia sinensis L.) leaf contains a large amount of catechins (a group of very active flavonoids) which contribute to major quality attributes of black tea. Based on morphological characters tea plants were classified as Assam, China, and Cambod varieties. The present study is an attempt for biochemical fingerprinting of the tea varieties based on catechin composition in green leaf of cultivars grown in Northeast India. Assam variety cultivars contained the highest level of catechins followed by Cambod and China. The average catechin contents were 231 ± 7 mg g−1, 202 ± 5 mg g−1, and 157 ± 4 mg g−1 of dry weight of green leaf for Assam, Cambod, and China cultivars, respectively. Among the individual catechins the variations in epigallocatechin gallate (EGCG) and epigallocatechin (EGC) were the most prominent among the varieties. High EGC content was found to be a characteristic of Assam variety which was further corroborated through multivariate analysis. PMID:22448135

  10. Stability of green tea catechins in commercial tea leaves during storage for 6 months.

    PubMed

    Friedman, Mendel; Levin, C E; Lee, S-U; Kozukue, N

    2009-03-01

    To help meet the needs of consumers, producers of dietary tea products, and researchers for information on health-promoting tea ingredients, we determined by HPLC 7 catechins [(-)-epigallocatechin (EGC), (-)-catechin (C), (+)-epicatechin (EC), (-)-epigallocatechin 3-gallate (EGCG), (-)-gallocatechin 3-gallate (GCG), (-)-epicatechin 3-gallate (ECG), and (-)-catechin 3-gallate (CG)] in samples of 8 commercial green tea leaves of unknown history sold as tea bags in the United States, Korea, and Japan. The samples were stored at 20 degrees C and sampled at 1 wk and 1, 2, 4, and 6 mo. The following ranges in the initial values (0 controls) were observed (in mg/g tea leaves): EGC and C, 0 to trace amounts; EC, 1.9 to 21.1; EGCG, 13.3 to 113.0; GCG, 0.2 to 1.6; ECG, 5.7 to 50.5; CG 0.5 to 3.7; total catechins 36.5 to 169.7. Statistical analysis of the results and plots of changes in individual and total catechin levels as a function of storage time indicate a progressive decrease in the content in the total levels, most of which is due to losses in the most abundant catechins, EGCG and ECG. Possible mechanisms of degradations of catechins during storage and the possible significance of the results to consumers of tea are discussed.

  11. Using Defatted Rice Bran as a Bioadsorbent for Carrying Tea Catechins.

    PubMed

    Shi, Meng; Yang, Ya-Ping; Jin, Jing; Huang, Long-Yue; Ye, Jian-Hui; Liang, Yue-Rong

    2015-10-01

    The potential of rice bran as a bioabsorbent for tea catechins was examined. Defatted rice bran had the highest adsorption capacity for tea catechins and the best selectivity for (-)-epigallocatechin gallate over total catechins among water-washed rice bran and untreated rice bran. The adsorption characteristics of tea catechins onto defatted rice bran were determined over a range of concentration (0.5 to 2.5 g/L) and temperatures (10, 25, and 45 °C). The adsorption of tea catechins onto defatted rice bran showed excellent fitness with the pseudo-second-order model at different temperature. Both the Langmuir and Freundlich models adequately describe the isothermal adsorption of tea catechins onto defatted rice bran. The adsorption of total catechins on rice bran decreased from 10 to 25 °C, whereas was greatly enhanced at 45 °C. The adsorption system of bioadsorbent with multiconstituents may not be as simple as the single-force-driving adsorption system. Protein and cellulose are the main contributors to the adsorption of tea catechins on defatted rice bran. Rice bran is regarded as a good fibre source that can be added to various food products and health supplements, which is a potential biocarrier for bioactives. Our study showed that defatted rice bran had a high affinity for tea catechins but caffeine, and provided a promising way for selective enrichment of catechins on defatted rice bran under practical condition. Protein and cellulose are the main contributors to the adsorption of tea catechins on defatted rice bran. © 2015 Institute of Food Technologists®

  12. 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.

  13. A History of Catechin Chemistry with Special Reference to Tea Leaves

    NASA Astrophysics Data System (ADS)

    Ryoyasu, Saijo; Katoh, Miyuki

    This review describes the history of the discovery of catechins, i.e., flavan 3-ols in the flavonoid compounds, with a special reference to tea leaves. 1. Catechin was first separated from gambier catechu and acacia catechu, and its molecular weight and chemical structure were proposed in 1902. By 1948 the six catechins,(+)-catechin,(-)-epicatechin,(-)-epicatechin 3-O-gallate,(-)-epigallocatechin,(+)-gallocatechin, and(-)-epigallocatechin 3-O-gallate, as shown in Table 1, had been found in a variety of plants, including tea. Table 1 summarizes each catechin, the plant associated with it, and the year and authorship of each first reporting.(-)-Epigallocatechin 3-gallate was isolated from tea leaves in 1948 as the last compound of the six catechins, even though it accounted for the largest proportion of total catechin content. The compound was not isolated and purified by traditional separation methods, such as the ethyl acetate extraction and lead acetate precipitation methods; instead, silica gel column chromatography was the key technique used to succeed in the separation and purification of the compound, from which the determination of the chemical structure followed. 2. The six catechins in fresh tea leaves are easily epimerized by heat treatment to form the corresponding epimerized catechins, as shown in Table 2. Observation indicates that the six natural and six epimerized catechins can be present in heat-treated dried tea leaves or green teas. 3. The chemical structures of the ten catechins, which include the compounds in Table 1, are shown in Table 3. As the contents of the catechins in fresh tea leaves have been reported many times in the literature, it is certain that these compounds are naturally present in tea leaves. 4. Table 4 summarizes the chemical structures of eight minor catechin derivatives found in tea leaves and oolong teas, the first reporting authors, and the year reported. Because the presence of these catechin derivatives in fresh tea

  14. [Determination of catechins and caffeine in tea and tea beverages by high-performance liquid chromatography].

    PubMed

    Ling, Yun; Zhao, Yun-feng; Li, Zhi-jun; Zhang, Gong; Wu, Yongning

    2005-03-01

    A high-performance liquid chromatography method was developed for the determination of total tea catechin and caffeine. The catechins needed to be determined are: (-)-catechin, (-)-epigallocatechin, (-)-epigallocatechin gallate, (-)-epicatechin, (-)-epicatechin gallate, (-)-gallocatechin, (-)-gallocatechin gallate, (-)-catechin gallate and caffeine. The catechins in the tea was extracted with water:ethanol (3:7) by sonication for 20 min. After the extraction solution was centrifuged, it was analyzed by HPLC. The column used was a CAPCELL PAK C18 MG (4.6mm I.D. x 150mm) and gradient elution at constant column temperature with 30 degrees C under UV detector with 210nm. Mobile phase A was 0.1% H3PO4 in water, mobile phase B was 0.1% H3PO4 in methanol with the flow rate 1ml/min. The results showed that the concentration of the catechins and caffeine and their peak areas achieved good linear relation, r > 0.999. The recoveries were between 61.7%-117.3%. RSD was below 10%. With this method, some tea samples were determined, the results were favorable. The method can be applied for determination of catechin and caffeine in tea and tea beverages.

  15. 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.

  16. 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.

  17. Determination of catechins in matcha green tea by micellar electrokinetic chromatography.

    PubMed

    Weiss, David J; Anderton, Christopher R

    2003-09-05

    Catechins in green tea are known to have many beneficial health properties. Recently, it has been suggested that matcha has greater potential health benefits than other green teas. Matcha is a special powdered green tea used in the Japanese tea ceremony. However, there has been no investigation to quantitate the catechin intake from matcha compared to common green teas. We have developed a rapid method of analysis of five catechins and caffeine in matcha using micellar electrokinetic chromatography. Results are presented for water and methanol extractions of matcha compared with water extraction of a popular green tea. Using a mg catechin/g of dry leaf comparison, results indicate that the concentration of epigallocatechin gallate (EGCG) available from drinking matcha is 137 times greater than the amount of EGCG available from China Green Tips green tea, and at least three times higher than the largest literature value for other green teas.

  18. Effects of green tea catechins with or without caffeine on glycemic control in adults: a meta-analysis of randomized controlled trials.

    PubMed

    Zheng, Xin-Xin; Xu, Yan-Lu; Li, Shao-Hua; Hui, Rutai; Wu, Yong-Jian; Huang, Xiao-Hong

    2013-04-01

    The effect of green tea catechins (GTCs) with or without caffeine on glycemic control is controversial. We aimed to identify and quantify the effects of GTCs or GTC-caffeine mixtures on glucose metabolism in adults. A comprehensive literature search was conducted to identify relevant trials of GTCs with or without caffeine on markers of glycemic control [fasting blood glucose (FBG), fasting blood insulin (FBI), glycated hemoglobin (Hb A1c), and homeostatic model assessment of insulin resistance (HOMA-IR)]. Weighted mean differences were calculated for net changes by using fixed-effects models. Prespecified subgroup analyses were performed to explore the influence of covariates on net changes in FBG and FBI concentrations. Twenty-two eligible randomized controlled trials with 1584 subjects were identified. Pooled analyses showed that FBG (-1.48 mg/dL; 95% CI: -2.57, -0.40 mg/dL) decreased significantly with GTCs with or without caffeine, whereas FBI (0.04 μU/mL; 95% CI: -0.36, 0.45 μU/mL), Hb A1c (-0.04%; 95% CI: -0.15, 0.08%), and HOMA-IR (-0.05; 95% CI: -0.37, 0.26) did not. Subgroup analyses indicated that the glucose-lowering effect was apparent when the duration of follow-up was over a median of 12 wk. Overall, no significant heterogeneity was detected for FBG, FBI, Hb A1c, or HOMA-IR. The meta-analysis showed that the administration of GTCs with or without caffeine resulted in a significant reduction in FBG. The limited data available on GTCs did not support a positive effect on FBI, Hb A1c, or HOMA-IR. Thus, more large and well-designed trials are needed in the future. This trial was registered at http://www.crd.york.ac.uk/prospero as CRD42012002139.

  19. A randomized controlled trial of green tea catechins in protection against ultraviolet radiation-induced cutaneous inflammation.

    PubMed

    Farrar, Mark D; Nicolaou, Anna; Clarke, Kayleigh A; Mason, Sarah; Massey, Karen A; Dew, Tristan P; Watson, Rachel E B; Williamson, Gary; Rhodes, Lesley E

    2015-09-01

    Safe systemic protection from the health hazards of ultraviolet radiation (UVR) in sunlight is desirable. Green tea is consumed globally and is reported to have anti-inflammatory properties, which may be mediated through the impact on cyclooxygenase and lipoxygenase pathways. Recent data suggest that green tea catechins (GTCs) reduce acute UVR effects, but human trials examining their photoprotective potential are scarce. We performed a double-blind, randomized, placebo-controlled trial to examine whether GTCs protect against clinical, histologic, and biochemical indicators of UVR-induced inflammation. Healthy adults (aged 18-65 y, phototypes I-II) were randomly allocated to 1350 mg encapsulated green tea extract (540 mg GTC) with 50 mg vitamin C or placebo twice daily for 3 mo. Impact on skin erythema, dermal leukocytic infiltration, and concentrations of proinflammatory eicosanoids was assessed after solar-simulated UVR challenge, and subject compliance was determined through assay of urinary GTC metabolite epigallocatechin glucuronide. Volunteers were assigned to the active (n = 25) or the placebo (n = 25) group. After supplementation, median (IQR) sunburn threshold (minimal erythema dose) was 28 (20-28) and 20 (20-28) mJ/cm(2) in the active and placebo groups, respectively (nonsignificant), with no difference in AUC analysis for measured erythema index after a geometric series of 10 UVR doses. Skin immunohistochemistry showed increased neutrophil and CD3(+) T-lymphocyte numbers post-UVR in both groups (P < 0.01) with no statistically significant differences between groups after supplementation. Cyclooxygenase and lipoxygenase metabolites prostaglandin E2 (vasodilator) and 12-hydroxyeicosatetraenoicacid (chemoattractant), respectively, increased after UVR (P < 0.05), with no differences between supplementation groups. Oral GTC (1080 mg/d) with vitamin C over 3 mo did not significantly reduce skin erythema, leukocyte infiltration, or eicosanoid response to UVR

  20. A randomized controlled trial of green tea catechins in protection against ultraviolet radiation–induced cutaneous inflammation12

    PubMed Central

    Farrar, Mark D; Nicolaou, Anna; Clarke, Kayleigh A; Mason, Sarah; Massey, Karen A; Dew, Tristan P; Watson, Rachel EB; Williamson, Gary; Rhodes, Lesley E

    2015-01-01

    Background: Safe systemic protection from the health hazards of ultraviolet radiation (UVR) in sunlight is desirable. Green tea is consumed globally and is reported to have anti-inflammatory properties, which may be mediated through the impact on cyclooxygenase and lipoxygenase pathways. Recent data suggest that green tea catechins (GTCs) reduce acute UVR effects, but human trials examining their photoprotective potential are scarce. Objective: We performed a double-blind, randomized, placebo-controlled trial to examine whether GTCs protect against clinical, histologic, and biochemical indicators of UVR-induced inflammation. Design: Healthy adults (aged 18–65 y, phototypes I–II) were randomly allocated to 1350 mg encapsulated green tea extract (540 mg GTC) with 50 mg vitamin C or placebo twice daily for 3 mo. Impact on skin erythema, dermal leukocytic infiltration, and concentrations of proinflammatory eicosanoids was assessed after solar-simulated UVR challenge, and subject compliance was determined through assay of urinary GTC metabolite epigallocatechin glucuronide. Results: Volunteers were assigned to the active (n = 25) or the placebo (n = 25) group. After supplementation, median (IQR) sunburn threshold (minimal erythema dose) was 28 (20–28) and 20 (20–28) mJ/cm2 in the active and placebo groups, respectively (nonsignificant), with no difference in AUC analysis for measured erythema index after a geometric series of 10 UVR doses. Skin immunohistochemistry showed increased neutrophil and CD3+ T-lymphocyte numbers post-UVR in both groups (P < 0.01) with no statistically significant differences between groups after supplementation. Cyclooxygenase and lipoxygenase metabolites prostaglandin E2 (vasodilator) and 12-hydroxyeicosatetraenoicacid (chemoattractant), respectively, increased after UVR (P < 0.05), with no differences between supplementation groups. Conclusion: Oral GTC (1080 mg/d) with vitamin C over 3 mo did not significantly reduce skin erythema

  1. Effect of Tea Theaflavins and Catechins on Microvascular Function

    PubMed Central

    Fuchs, Dagmar; de Graaf, Young; van Kerckhoven, Roeland; Draijer, Richard

    2014-01-01

    Beneficial effects of flavonoid-rich black and green tea on macrocirculation have been well established. Theaflavins are unique to black tea as they are formed from catechins during the enzymatic oxidation of tea leaves. The study was performed to gain more insight into the effects of theaflavins on microcirculation and to compare effects with another important flavonoid class, the green tea derived catechins, which have been reported to improve vascular function. Twenty-four healthy subjects were included in a double-blind, placebo-controlled, randomised, cross-over study. On six different days, subjects received capsules with a single dose of catechins (500 mg), four varying doses of theaflavins (100 to 500 mg) or placebo. Microcirculation was assessed after each treatment by Pulse Amplitude Tonometry (EndoPAT) at baseline and 2, 4 and 6 h after test product intake. The EndoPAT reactive hyperemia response was improved by 500 mg catechins (reactive hyperemia index (RHI): 0.2; p = 0.04) and by 500 mg theaflavins (RHI: 0.19; p = 0.06) compared to placebo. Also, 300 mg theaflavins increased the RHI (0.28; p = 0.02), but no effects were observed at lower doses. The study suggests moderate effects of single doses of catechins and theaflavins on peripheral microcirculation. PMID:25514559

  2. 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

  3. Green tea catechin intervention of reactive oxygen species-mediated ERK pathway activation and chronically induced breast cell carcinogenesis

    PubMed Central

    Rathore, Kusum; Choudhary, Shambhunath; Odoi, Agricola; Wang, Hwa-Chain R.

    2012-01-01

    Long-term exposure to low doses of environmental carcinogens contributes to sporadic human breast cancers. Epidemiologic and experimental studies indicate that green tea catechins (GTCs) may intervene with breast cancer development. We have been developing a chronically induced breast cell carcinogenesis model wherein we repeatedly expose non-cancerous, human breast epithelial MCF10A cells to bioachievable picomolar concentrations of environmental carcinogens, such as 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and benzo[a]pyrene (B[a]P), to progressively induce cellular acquisition of cancer-associated properties, as measurable end points. The model is then used as a target to identify non-cytotoxic preventive agents effective in suppression of cellular carcinogenesis. Here, we demonstrate, for the first time, a two-step strategy that initially used end points that were transiently induced by short-term exposure to NNK and B[a]P as targets to detect GTCs capable of blocking the acquisition of cancer-associated properties and subsequently used end points constantly induced by long-term exposure to carcinogens as targets to verify GTCs capable of suppressing carcinogenesis. We detected that short-term exposure to NNK and B[a]P resulted in elevation of reactive oxygen species (ROS), leading to Raf-independent extracellular signal-regulated kinase (ERK) pathway activation and subsequent induction of cell proliferation and DNA damage. These GTCs, at non-cytotoxic levels, were able to suppress chronically induced cellular carcinogenesis by blocking carcinogen-induced ROS elevation, ERK activation, cell proliferation and DNA damage in each exposure cycle. Our model may help accelerate the identification of preventive agents to intervene in carcinogenesis induced by long-term exposure to environmental carcinogens, thereby safely and effectively reducing the health risk of sporadic breast cancer. PMID:22045026

  4. Carboxymethyl- and carboxyl-catechins from ripe Pu-er tea.

    PubMed

    Tian, Li-Wen; Tao, Mu-Ke; Xu, Min; Hu, Jing; Zhu, Hong-Tao; Xiong, Wen-Yong; Wang, Dong; Yang, Chong-Ren; Zhang, Ying-Jun

    2014-12-17

    Ripe Pu-er tea, a special microbial postfermented tea originated from Yunnan Province, China, since ancient times, is made from green Pu-er tea prepared from the leaves of Camellia sinensis var. assamica (Theaceae). Chemical investigation on thearubigin (n-BuOH-soluble) fraction of the commercial ripe Pu-er tea, led to the identification of four new flavan-3-ol derivatives, 8-carboxymethyl-(+)-catechin (1), 8-carboxymethyl-(+)-catechin methyl ester (2), 6-carboxymethyl-(+)-catechin (3), and 6-carboxyl-(-)-gallocatechin (4), together with 18 known compounds, including other three flavan-3-ol derivatives (5-7), 10 flavonoid glycosides (8-17), two hydrolyzable tannins (18 and 19), two quinic acid derivatives (20-21), and a purine alkaloid (22). Flavonoid glycosides 8-11 are reported from tea plants for the first time. The thearubigin fraction of ripe Pu-er tea was qualitatively analyzed by HPLC, and gallic acid was found to be the major component. Compounds 4, 6-17, 21 and 22 were tested for their acute activities on insulin sensitivity in differentiated 3T3-L1 adipocytes, but none of them showed significant bioactivity at a concentration of 10 μM.

  5. Preparation of tea catechins using polyamide.

    PubMed

    Ye, Jian-Hui; Wang, Liu-Xiang; Chen, Hao; Dong, Jun-Jie; Lu, Jian-Liang; Zheng, Xin-Qiang; Wu, Ming-Yan; Liang, Yue-Rong

    2011-02-01

    An adsorption separation method using Polyamide-6 (PA) as an adsorbent was developed to separate catechins from green tea extract. The adsorption capacity of total catechins for PA was 193.128 mg g⁻¹ with an adsorption selectivity coefficient K(A)(B) of total catechins over caffeine 21.717, which was better than macroporous resin model HPD 600. The Langmuir model and the pseudo-second order mode were primely fitted to describe its equilibrium data and adsorption kinetics, respectively. PA column separation by two-step elution using water and 80% (v/v) aqueous ethanol was established to prepare catechins complex which contained 670.808 mg g⁻¹ total catechins and 1.828 mg g⁻¹ caffeine. It is considered that PA was a promising adsorbent for selective isolation of catechins. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  6. Biophysical Approach to Mechanisms of Cancer Prevention and Treatment with Green Tea Catechins.

    PubMed

    Suganuma, Masami; Takahashi, Atsushi; Watanabe, Tatsuro; Iida, Keisuke; Matsuzaki, Takahisa; Yoshikawa, Hiroshi Y; Fujiki, Hirota

    2016-11-18

    Green tea catechin and green tea extract are now recognized as non-toxic cancer preventives for humans. We first review our brief historical development of green tea cancer prevention. Based on exciting evidence that green tea catechin, (-)-epigallocatechin gallate (EGCG) in drinking water inhibited lung metastasis of B16 melanoma cells, we and other researchers have studied the inhibitory mechanisms of metastasis with green tea catechins using biomechanical tools, atomic force microscopy (AFM) and microfluidic optical stretcher. Specifically, determination of biophysical properties of cancer cells, low cell stiffness, and high deformability in relation to migration, along with biophysical effects, were studied by treatment with green tea catechins. The study with AFM revealed that low average values of Young's moduli, indicating low cell stiffness, are closely associated with strong potential of cell migration and metastasis for various cancer cells. It is important to note that treatments with EGCG and green tea extract elevated the average values of Young's moduli resulting in increased stiffness (large elasticity) of melanomas and various cancer cells. We discuss here the biophysical basis of multifunctions of green tea catechins and green tea extract leading to beneficial effects for cancer prevention and treatment.

  7. Recovery of catechin compounds from Korean tea by solvent extraction.

    PubMed

    Row, Kyung Ho; Jin, Yinzhe

    2006-03-01

    Catechin compounds from Korean green tea as potential sources of anticancer and antioxidant components were target materials in this work. The methodologies of solvent extraction and partition were utilized to recover catechin compounds from green tea. The optimum experimental condition was obtained by optimizing operating factors, such as, the extraction solvent, extraction time and operating temperature. After extracting the green tea with water at 80 degrees C for 40 min, the extract was partitioned with water/chloroform, which was best suited to remove caffeine impurity from the extract. Further, the resulting extract was partitioned water/ethyl acetate to deeply purify the catechin compounds of EGC, EC, EGCG and ECG. The experimental result in this work could be extended to preparative HPLC to obtain EGCG on commercial scale.

  8. Novel acetylcholinesterase inhibitors from Zijuan tea and biosynthetic pathway of caffeoylated catechin in tea plant.

    PubMed

    Wang, Wei; Fu, Xi-Wen; Dai, Xin-Long; Hua, Fang; Chu, Gang-Xiu; Chu, Ming-Jie; Hu, Feng-Lin; Ling, Tie-Jun; Gao, Li-Ping; Xie, Zhong-Wen; Wan, Xiao-Chun; Bao, Guan-Hu

    2017-12-15

    Zijuan tea is a special cultivar of Yunnan broad-leaf tea (Camellia sinensis var. assamica) with purple buds, leaves, and stems. Phytochemical study on this tea led to the discovery of three hydroxycinnamoylated catechins (HCCs) (1-3), seven other catechins (4-10), three proanthocyanidins (11-13), five flavones and flavone glycosides (14-18), two alkaloids (19, 20), one steroid (21), and one phenylpropanoid glycoside (22). The isolation and structural elucidation of the caffeoylated catechin (1) by means of spectroscopic techniques were described. We also provide the first evidence that 1 is synthesized via a two-step pathway in tea plant. The three HCCs (1-3) were investigated on their bioactivity through molecular modeling simulation and biochemical experiments. Our results show that they bind acetylcholinesterase (AChE) tightly and have strong AChE inhibitory activity with IC 50 value at 2.49, 11.41, 62.26μM, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. The protective activity of tea catechins against experimental infection by Vibrio cholerae O1.

    PubMed

    Toda, M; Okubo, S; Ikigai, H; Suzuki, T; Suzuki, Y; Hara, Y; Shimamura, T

    1992-01-01

    Tea catechins inhibited the fluid accumulation induced by cholera toxin in sealed adult mice. The catechins also reduced fluid accumulation by Vibrio cholerae O1 in ligated intestinal loops of rabbits. These findings suggest that tea catechins may possess protective activity against V. cholerae O1.

  10. 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

  11. Nutraceuticals for body-weight management: The role of green tea catechins.

    PubMed

    Janssens, Pilou L H R; Hursel, Rick; Westerterp-Plantenga, Margriet S

    2016-08-01

    Green tea catechins mixed with caffeine have been proposed as adjuvants for maintaining or enhancing energy expenditure and for increasing fat oxidation, in the context of prevention and treatment of obesity. These catechins-caffeine mixtures seem to counteract the decrease in metabolic rate that occurs during weight loss. Their effects are of particular importance during weight maintenance after weight loss. Other metabolic targets may be fat absorption and the gut microbiota composition, but these effects still need further investigation in combination with weight loss. Limitations for the effects of green tea catechins are moderating factors such as genetic predisposition related to COMT-activity, habitual caffeine intake, and ingestion combined with dietary protein. In conclusion, a mixture of green tea catechins and caffeine has a beneficial effect on body-weight management, especially by sustained energy expenditure, fat oxidation, and preservation of fat free body-mass, after energy restriction induced body-weight loss, when taking the limitations into account. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. [Effect of tea extracts, catechin and caffeine against type-I allergic reaction].

    PubMed

    Shiozaki, T; Sugiyama, K; Nakazato, K; Takeo, T

    1997-07-01

    The antiallergic effects of green tea, oolong tea, and black tea extracts by hot water were examined. These extracts inhibited the passive cutaneous anaphylaxis (PCA) reaction of rat after oral administration. Three tea catechins, (--)-epigallocatechin (EGC), (--)-epicatechin gallate (ECg), and (--)-epigallocatechin gallate (EGCg) isolated from green tea showed stronger inhibitory effects than that of a green tea extract on the PCA reaction. The inhibitory effects of EGC and EGCg on the PCA reaction were greater than that of ECg. Caffeine also showed a inhibitory effect on the PCA reaction. These results indicate that tea could provide a significant protection against the type-I allergic reaction. These findings also suggest that tea catechins and caffeine play an important role in having an inhibitory effect on the type-I allergic reaction.

  13. [Isolation and purification of seven catechin compounds from fresh tea leaves by semi-preparative liquid chromatography].

    PubMed

    Gong, Zhihong; Chen, Si; Gao, Jiangtao; Li, Meihong; Wang, Xiaxia; Lin, Jun; Yu, Xiaomin

    2017-11-08

    An effective and simple method was established to simultaneously purify seven tea catechins (gallocatechin (GC), epigallocatechin (EGC), catechin (C), epigallocatechin-3- O -gallate (EGCG), epicatechin (EC), epigallocatechin-3- O -(3- O -methyl)-gallate (EGCG3"Me) and epicatechin-3- O -gallate (ECG)) from fresh tea leaves by semi-preparative high performance liquid chromatography (HPLC). Fresh leaves of Tieguanyin tea were successively extracted with methanol and chloroform. Then crude catechins were precipitated from the aqueous fraction of chloroform extraction by adding lead subacetate. Crude catechins were used for the isolation of the seven target catechin compounds by semi-preparative HPLC. Methanol-water and acetonitrile-water were sequentially used as mobile phases. After two rounds of semi-preparative HPLC, all target compounds were achieved with high purities (>90%). The proposed method was tested on two additional tea cultivars and showed similar results. This method demonstrated a simple and efficient strategy based on solvent extraction, ion precipitation and semi-preparative HPLC for the preparation of multiple catechins from tea leaves.

  14. Factors influencing the antifolate activity of synthetic tea-derived catechins.

    PubMed

    Sáez-Ayala, Magalí; Fernández-Pérez, María Piedad; Chazarra, Soledad; Mchedlishvili, Nani; Tárraga-Tomás, Alberto; Rodríguez-López, José Neptuno

    2013-07-16

    Novel tea catechin derivatives have been synthesized, and a structure-activity study, related to the capacity of these and other polyphenols to bind dihydrofolate reductase (DHFR), has been performed. The data showed an effective binding between all molecules and the free enzyme, and the dissociation constants of the synthetic compounds and of the natural analogues were on the same order. Polyphenols with a catechin configuration were better DHFR inhibitors than those with an epicatechin configuration. Antiproliferative activity was also studied in cultured tumour cells, and the data showed that the activity of the novel derivatives was higher in catechin isomers. Derivatives with a hydroxyl group para on the ester-bonded gallate moiety presented a high in vitro binding to DHFR, but exhibited transport problems in cell culture due to ionization at physiologic pHs. The impact of the binding of catechins to serum albumin on their biological activity was also evaluated. The information provided in this study could be important for the design of novel medicinal active compounds derived from tea catechins. The data suggest that changes in their structure to avoid serum albumin interactions and to facilitate plasmatic membrane transport are essential for the intracellular functions of catechins.

  15. Application of a functional mathematical index for antibacterial and anticarcinogenic effects of tea catechins.

    PubMed

    Finotti, Enrico; Bersani, Enrico; Friedman, Mendel

    2011-02-09

    Tea leaves produce secondary metabolites that are involved in the defense of the plants against invading pathogens. In the case of green teas, these metabolites are polyphenolic compounds called catechins. Previous studies developed a mathematical formula called functional mathematical index (FMI) that was used to describe the quality of different olive oils and potatoes in terms of compositional parameters and antioxidative properties of individual components. This study extends the development of the FMI concept to define an "optimum tea" based on reported relationships between the content of structurally different catechins of a large number of teas and their dual beneficial effects: antimicrobial activities against a foodborne pathogen and inhibition of human cancer cell lines. The described mathematical approach may be useful for predicting relative beneficial effects of new teas based on their catechin content.

  16. Accumulation of catechins in tea in relation to accumulation of mRNA from genes involved in catechin biosynthesis.

    PubMed

    Eungwanichayapant, P D; Popluechai, S

    2009-02-01

    Catechins are a group of polyphenols found in tea (Camellia sinensis var. sinensis) at high levels. They are beneficial for health. From the study on accumulation of catechins in shoots and mature leaves of a tea cultivar, Oolong No. 17, using high-performance liquid chromatography (HPLC), it was found that the amounts of most catechins in the shoots were higher than those in the mature leaves, with an exception of catechins gallate (CG) that was found in trace amounts in both the shoots and mature leaves. mRNA accumulation of genes involved in catechin synthesis was studied using reverse transcriptase-polymerase chain reaction (RT-PCR). The results showed that the mRNA accumulation of the genes were higher in the shoots than in the mature leaves. These genes included genes of phenylalanine ammonia-lyase 1 (PAL1; EC 4.3.1.5), chalcone synthase (CHS; EC 2.3.1.74), dihydroflavonol 4-reductase (DFR; EC 1.1.1.219), leucoanthocyanidin reductase (LCR; EC 1.17.1.3), and flavanone 3-hydroxylase (F3H; EC 1.14.11.9).

  17. Efficient procedure for isolating methylated catechins from green tea and effective simultaneous analysis of ten catechins, three purine alkaloids, and gallic acid in tea by high-performance liquid chromatography with diode array detection.

    PubMed

    Hu, Bing; Wang, Lin; Zhou, Bei; Zhang, Xin; Sun, Yi; Ye, Hong; Zhao, Liyan; Hu, Qiuhui; Wang, Guoxiang; Zeng, Xiaoxiong

    2009-04-10

    Monomers of (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCG), (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin 3-O-(3-O-methyl) gallate (EGCG3''Me) and (-)-3-O-methyl epicatechin gallate (ECG3'Me) (purity, >97%) were successfully prepared from extract of green tea by two-time separation with Toyopearl HW-40S column chromatography eluted by 80% ethanol. In addition, monomers of (-)-catechin (C), (-)-gallocatechin (GC), (-)-gallocatechin gallate (GCG), and (-)-catechin gallate (CG) (purity, >98%) were prepared from EC, EGC, EGCG, and ECG by heat-epimerization and semi-preparative HPLC chromatography. With the prepared catechin standards, an effective and simultaneous HPLC method for the analysis of gallic acid, tea catechins, and purine alkaloids in tea was developed in the present study. Using an ODS-100Z C(18) reversed-phase column, fourteen compounds were rapidly separated within 15min by a linear gradient elution of formic acid solution (pH 2.5) and methanol. A 2.5-7-fold reduction in HPLC analysis time was obtained from existing analytical methods (40-105min) for gallic acid, tea catechins including O-methylated catechins and epimers of epicatechins, as well as purine alkaloids. Detection limits were generally on the order of 0.1-1.0ng for most components at the applied wavelength of 280nm. Method replication generally resulted in intraday and interday peak area variation of <6% for most tested components in green, Oolong, black, and pu-erh teas. Recovery rates were generally within the range of 92-106% with RSDs less than 4.39%. Therefore, advancement has been readily achievable with commonly used chromatography equipments in the present study, which will facilitate the analytical, clinical, and other studies of tea catechins.

  18. Green tea catechins and their metabolites in human skin before and after exposure to ultraviolet radiation.

    PubMed

    Clarke, Kayleigh A; Dew, Tristan P; Watson, Rachel E B; Farrar, Mark D; Osman, Joanne E; Nicolaou, Anna; Rhodes, Lesley E; Williamson, Gary

    2016-01-01

    Dietary flavonoids may protect against sunburn inflammation in skin. Preliminary reports using less complete analysis suggest that certain catechins and their metabolites are found in skin biopsies and blister fluid after consumption of green tea; however, it is not known if they are affected by solar-simulated ultraviolet radiation (UVR) or whether conjugated forms, with consequently altered bioactivity, are present. The present study tested the hypothesis that UVR affects the catechin levels in the skin of healthy volunteers after consumption of green tea and how catechins in the plasma are related to their presence in skin tissue samples. In an open oral intervention study, 11 subjects consumed green tea and vitamin C supplements daily for 3months. Presupplementation and postsupplementation plasma samples, suction blister fluid and skin biopsies were collected; the latter two samples were collected both before and after UVR. A sensitive high-performance liquid chromatography/mass spectrometric assay was used to measure the intact catechin metabolites, conjugates and free forms. Seven green tea catechins and their corresponding metabolites were identified postsupplementation in skin biopsies, 20 in blister fluid and 26 in plasma, with 15 green tea catechin metabolites present in both blister fluid and plasma. The valerolactone, O-methyl-M4-O-sulfate, a gut microbiota metabolite of catechins, was significantly increased 1.6-fold by UVR in blister fluid samples. In conclusion, there were some common catechin metabolites in the plasma and blister fluid, and the concentration was always higher in plasma. The results suggest that green tea catechins and metabolites are bioavailable in skin and provide a novel link between catechin metabolites derived from the skin and gut microbiota. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  19. [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.

  20. 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.

  1. Inhibition of proliferation of human lung cancer cells by green tea catechins is mediated by upregulation of let-7

    PubMed Central

    ZHONG, ZHIWEI; DONG, ZHUO; YANG, LIHUA; CHEN, XIAOQIANG; GONG, ZHAOHUI

    2012-01-01

    Green tea catechins are known to function as anticancer agents via inhibition of carcinogenesis during the initiation, promotion and progression stages. Many potential mechanisms have been proposed, yet the precise mechanism of lung cancer prevention by green tea catechins remains unclear. microRNAs (miRs) are a class of 21–24 nucleotide small non-coding RNAs and play critical roles throughout cellular development and regulation. Emerging evidence demonstrates that tea catechins influence the expression of miRs in human cancer cells to inhibit tumorigenesis. Both let-7a-1 and let-7g were detected in the human lung cancer cells treated with tea catechins. The cell viability and cell cycle were analyzed after tea catechins treatment. In the present study, we found that tea catechins upregulated the tumor-suppressor miRs, let-7a-1 and let-7g, in lung cancer cell lines. The upregulation of let-7a/7g repressed the expression of their targets, C-MYC and the regulatory protein of LIN-28, at the mRNA and protein levels. Moreover, the cell growth assay indicated that tea catechins significantly inhibited cell proliferation, and the flow cytometric analysis revealed an increase in the number of cells in the G2/M phase and a decrease in the number of cells in the S phase after treatment with tea catechins. These observations suggest that green tea catechins mediate the inhibition of proliferation of lung cancer cells through the let-7 signaling pathway. PMID:22970031

  2. The effects of tea catechins on fecal conditions of elderly residents in a long-term care facility.

    PubMed

    Goto, K; Kanaya, S; Ishigami, T; Hara, Y

    1999-01-01

    This study was carried out to evaluate the effects of tea catechins on fecal contents and metabolites of elderly people who were on a diet of solid food. The subjects were 35 residents in a long-term care facility who were all on the same diet, consisting of rice gruel and minced food. Tea catechins (300 mg), which were divided into 3 doses a day, were a meal supplement every day for 6 weeks. Fecal specimens were collected by the nursing staff, and their moisture content, pH, ammonia, sulfide, and oxidation-reduction potential (ORP) were determined before, during, and after the administration of tea catechins. In a comparison of values before the administration, all these fecal parameters decreased significantly during the tea catechin administration. After termination of the administration, these data tended to return toward the levels before administration. The reduction of such fecal parameters as moisture, pH, ammonia, sulfide, and ORP by tea catechin administration indicated very favorable improvements of the subjects' bowel conditions.

  3. Separation of catechin constituents from five tea cultivars using high-speed counter-current chromatography.

    PubMed

    Kumar, N Savitri; Rajapaksha, Maheshinie

    2005-08-12

    Catechins were extracted from five different tea (Camellia sinensis L.) cultivars. High-speed counter-current chromatography was found to be an efficient method for the separation of seven catechins from the catechin extracts. High-performance liquid chromatography was used to assess the purity of the catechins isolated. Epigallocatechin gallate (EGCG), epicatechin gallate (ECG) and epigallocatechin (EGC) of high purity (91-99%) were isolated in high yield after a single high-speed counter-current chromatography run. The two-phase solvent mixtures used for the separation of the catechin extracts were hexane:ethyl acetate:methanol:water (1:6:1:6 for TRI 2023); (1:7:1:7 for TRI 2025 and TRI 2043); (1:5:1:5 for TRI 3079) and (1:6.5:1:6.5 for TRI 4006). Fresh tea shoots from the tea cultivar TRI 2023 (150 g) gave 440 mg of 96% pure EGCG while TRI 2025 (235 g) gave 347 mg of 99% pure EGCG and 40 mg of 97% ECG, and TRI 3079 (225 g) gave 432 mg of 97% pure EGCG and 32 mg of 96% pure ECG. Tea cultivar TRI 4006 (160 g) gave EGCG (272 mg, 96% pure) and EGC (104 mg, 90% pure). 1H and 13C NMR chemical shifts for catechin gallate (CG), EGC, ECG, EGCG and epigallocatechin 3,5-di-O-gallate (EGCDG) in CD3OD were also recorded.

  4. 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.

  5. Simultaneous determination of twelve tea catechins by high-performance liquid chromatography with electrochemical detection.

    PubMed

    Sano, M; Tabata, M; Suzuki, M; Degawa, M; Miyase, T; Maeda-Yamamoto, M

    2001-06-01

    A high-performance liquid chromatographic method with electrochemical detection was developed for the determination of twelve tea catechins including four major catechins: epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG) and epigallocatechin gallate (EGCG); four of their epimers at the C-2 position, C, GC, CG and GCG; and four methylated catechin derivatives, epigallocatechin-3-O-(3-O-methyl)gallate, gallocatechin-3-O-(3-O-methyl)gallate, epigallocatechin-3-O-(4-O-methyl)gallate and epicatechin-3-O-(3-O-methyl)gallate. These catechins were separated on an ODS C18 reversed-phase column by isocratic elution with 0.1 M NaH2PO4 buffer (pH 2.5)-acetonitrile (87:13) containing 0.1 mM EDTA.2Na. The detection limits (S/N = 3) of these catechins were approximately 10-40 pmol ml-1 at an applied voltage of 600 mV. Extracting these catechins from tea leaf powder with H2O-acetonitrile (1:1) at 30 degrees C for 40 min inhibited the epimerization at C-2 significantly from these epicatechins compared to extraction with hot water at 90 degrees C. This analytical method is sensitive to and appropriate for the simultaneous determination of various biologically active catechins in green tea.

  6. UHPLC determination of catechins for the quality control of green tea.

    PubMed

    Naldi, Marina; Fiori, Jessica; Gotti, Roberto; Périat, Aurélie; Veuthey, Jean-Luc; Guillarme, Davy; Andrisano, Vincenza

    2014-01-01

    An ultra-high performance liquid chromatography (UHPLC) with UV detection method was developed for the fast quantitation of the most represented and biologically important green tea catechins and caffeine. UHPLC system was equipped with C18 analytical column (50mm×2.1mm, 1.8μm), utilizing a mobile phase composed of pH 2.5 triethanolamine phosphate buffer (0.1M) and acetonitrile in a gradient elution mode; under these conditions six major catechins and caffeine were separated in a 3min run. The method was fully validated in terms of precision, detection and quantification limits, linearity, accuracy, and it was applied to the identification and quantification of catechins and caffeine present in green tea infusions. In particular, commercially available green tea leaves samples of different geographical origin (Sencha, Ceylon Green and Lung Ching) were used for infusion preparations (water at 85°C for 15min). The selectivity of the developed UHPLC method was confirmed by comparison with UHPLC-MS/MS analysis. The recovery of the main six catechins and caffeine on the three analyzed commercial tea samples ranged from 94 to 108% (n=3). Limits of detection (LOD) were comprised in the range 0.1-0.4μgmL(-1). An orthogonal micellar electrokinetic (MEKC) method was applied for comparative purposes on selectivity and quantitative data. The combined use of the results obtained by the two techniques allowed for a fast confirmation on quantitative characterization of commercial samples. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Potential role of green tea catechins in the management of oxidative stress-associated infertility.

    PubMed

    Roychoudhury, Shubhadeep; Agarwal, Ashok; Virk, Gurpriya; Cho, Chak-Lam

    2017-05-01

    Reactive oxygen species (ROS) are present in low concentrations in the genital tracts of males and females. Excessive ROS lead to oxidative stress, which damages DNA, lipids and proteins. Such molecular changes result in compromised vitality, increased morphological defects and decreased sperm motility in the male. In the female, oxidative stress interferes with oocyte maturation, and may inhibit in-vitro maturation of the oocyte. Recently, green tea supplementation has been reported to possess properties that may improve the quality of male and female gametes largely due to the ability of catechin polyphenols to quench ROS. Epigallocatechin-3-gallate (EGCG) is considered the most promising bioactive compound in green tea due to its strong antioxidant activity. The unique property of green tea catechins may potentially improve reproductive health and pose an important research area. We present a comprehensive overview on the effects and potential roles of green tea catechins on oxidative stress in male and female reproduction and fertility. In this review, possible mechanisms of action are highlighted to better understand the potential use of green tea catechins in the reduction of oxidative stress and its associated beneficial effects in the clinical setting. Copyright © 2017 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  8. 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.

  9. Primary cancer prevention by green tea, and tertiary cancer prevention by the combination of green tea catechins and anticancer compounds.

    PubMed

    Fujiki, Hirota; Sueoka, Eisaburo; Watanabe, Tatsuro; Suganuma, Masami

    2015-03-01

    Green tea is a daily beverage, a non-oxidized non-fermented product containing at least four green tea catechins. Considering our first results when repeated applications of (-)-epigallocatechin gallate (EGCG) prevented tumor promotion in mouse skin, we have continued to look at green tea as a possible cancer preventive agent. 1) The 10-year prospective cohort study by Drs. K. Nakachi and K. Imai revealed that drinking 10 Japanese-size cups (120 mL/cup) of green tea per day delayed cancer onset in humans by 7.3 years among females and by 3.2 years among males. The delay of cancer onset is of course significant evidence of primary cancer prevention in humans. 2) In collaboration with Dr. H. Moriwaki's group we successfully presented a prototype of tertiary cancer prevention showing that 10 Japanese-size cups of green tea daily, supplemented with tablets of green tea extract (G.T.E), reduced recurrence of colorectal adenomas in polypectomy patients by 51.6% (from 31% to 15%). 3) In 1999, we first reported that the combination of green tea catechins and non-steroidal anti-inflammatory drugs showed synergistic anticancer effects in both in vitro and in vivo experiments, along with elucidation of the mechanism. 4) Further studies by other investigators have revealed that various combinations of EGCG or green tea extract and anticancer compounds inhibit tumor volume in xenograft mouse models implanted with various human cancer cell lines. Green tea is a cancer preventive, and green tea catechins act as synergists with anticancer compounds.

  10. Green tea catechins and their metabolites in human skin before and after exposure to ultraviolet radiation☆☆☆★

    PubMed Central

    Clarke, Kayleigh A.; Dew, Tristan P.; Watson, Rachel E.B.; Farrar, Mark D.; Osman, Joanne E.; Nicolaou, Anna; Rhodes, Lesley E.; Williamson, Gary

    2016-01-01

    Dietary flavonoids may protect against sunburn inflammation in skin. Preliminary reports using less complete analysis suggest that certain catechins and their metabolites are found in skin biopsies and blister fluid after consumption of green tea; however, it is not known if they are affected by solar-simulated ultraviolet radiation (UVR) or whether conjugated forms, with consequently altered bioactivity, are present. The present study tested the hypothesis that UVR affects the catechin levels in the skin of healthy volunteers after consumption of green tea and how catechins in the plasma are related to their presence in skin tissue samples. In an open oral intervention study, 11 subjects consumed green tea and vitamin C supplements daily for 3 months. Presupplementation and postsupplementation plasma samples, suction blister fluid and skin biopsies were collected; the latter two samples were collected both before and after UVR. A sensitive high-performance liquid chromatography/mass spectrometric assay was used to measure the intact catechin metabolites, conjugates and free forms. Seven green tea catechins and their corresponding metabolites were identified postsupplementation in skin biopsies, 20 in blister fluid and 26 in plasma, with 15 green tea catechin metabolites present in both blister fluid and plasma. The valerolactone, O-methyl-M4-O-sulfate, a gut microbiota metabolite of catechins, was significantly increased 1.6-fold by UVR in blister fluid samples. In conclusion, there were some common catechin metabolites in the plasma and blister fluid, and the concentration was always higher in plasma. The results suggest that green tea catechins and metabolites are bioavailable in skin and provide a novel link between catechin metabolites derived from the skin and gut microbiota. PMID:26454512

  11. Topical application of ointment containing 0.5% green tea catechins suppresses tongue oxidative stress in 5-fluorouracil administered rats.

    PubMed

    Miyai, Hisataka; Maruyama, Takayuki; Tomofuji, Takaaki; Yoneda, Toshiki; Azuma, Tetsuji; Mizuno, Hirofumi; Sugiura, Yoshio; Kobayashi, Terumasa; Ekuni, Daisuke; Morita, Manabu

    2017-10-01

    The purpose of this study was to investigate the preventive effects of topical application of green tea catechins on tongue oxidative stress induced by 5-fluorouracil (5-FU) administration in rats. Male Wistar rats (n=28, 8 weeks old) were divided into four groups of seven rats each: a negative control group (saline administration and application of ointment without green tea catechins), a positive control group (5-FU administration and application of ointment without green tea catechins), and two experimental groups (5-FU administration and application of ointment containing 0.1% or 0.5% green tea catechins). Topical application of each ointment to the ventral surface of the tongue was performed once a day for 5days. The level of 8-hydroxydeoxyguanosine (8-OHdG) was determined to evaluate oxidative stress. Fluorescence staining was also performed to confirm nuclear factor erythroid 2-related factor 2 (Nrf2) translocation to the nucleus. After the experimental period, the ratios of 8-OHdG-positive cells in the ventral tongue tissue were higher in the positive control group than in the negative control group (P<0.05). On the other hand, those in the 0.5% green tea catechin group, but not in the 0.1% green tea catechin group, were lower than the positive control group (P<0.05). In addition, Nrf2 translocation to the nucleus was greater in the 0.5% green tea catechin group than in the positive control group (P<0.05). Topical application of ointment containing 0.5% green tea catechins could prevent tongue oxidative stress in 5-FU administered rats, via up-regulation of the Nrf2 signaling pathway. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. 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.

  13. Simultaneous analysis of tea catechins, caffeine, gallic acid, theanine and ascorbic acid by micellar electrokinetic capillary chromatography.

    PubMed

    Aucamp, J P; Hara, Y; Apostolides, Z

    2000-04-21

    A micellar electrokinetic capillary chromatography (MEKC) method for the simultaneous analysis of five tea catechins, theanine, caffeine, gallic acid and ascorbic acid has been developed. The catechins are (-)-epicatechin, (+)-catechin, (-)-epigallocatechin, (-)-epicatechin gallate and (-)-epigallocatechin gallate. p-Nitrophenol serves as both reference and internal standard. All the components are separated within 13 min with a 57 cm uncoated fused-silica column. On-column detection was carried out at 200 nm. This method has been used to measure these compounds in fresh tea leaves and tea liquor. The limit of detection for all analytes ranged from 1 to 20 microg/ml.

  14. 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.

  15. Rapid tea catechins and caffeine determination by HPLC using microwave-assisted extraction and silica monolithic column.

    PubMed

    Rahim, A A; Nofrizal, S; Saad, Bahruddin

    2014-03-15

    A rapid reversed-phase high performance liquid chromatographic method using a monolithic column for the determination of eight catechin monomers and caffeine was developed. Using a mobile phase of water:acetonitrile:methanol (83:6:11) at a flow rate of 1.4 mL min(-1), the catechins and caffeine were isocratically separated in about 7 min. The limits of detection and quantification were in the range of 0.11-0.29 and 0.33-0.87 mg L(-1), respectively. Satisfactory recoveries were obtained (94.2-105.2 ± 1.8%) for all samples when spiked at three concentrations (5, 40 and 70 mg L(-1)). In combination with microwave-assisted extraction (MAE), the method was applied to the determination of the catechins and caffeine in eleven tea samples (6 green, 3 black and 2 oolong teas). Relatively high levels of caffeine were found in black tea, but higher levels of the catechins, especially epigallocatechin gallate (EGCG) were found in green teas. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Determination of green tea catechins in human plasma using liquid chromatography-electrospray ionization mass spectrometry.

    PubMed

    Masukawa, Yoshinori; Matsui, Yuji; Shimizu, Namii; Kondou, Naoki; Endou, Hidenori; Kuzukawa, Michiya; Hase, Tadashi

    2006-04-13

    A method for the sensitive and specific determination of eight green tea catechins, consisting of catechin (C), epicatechin (EC), gallocatechin (GC), epigallocatechin (EGC), catechin-3-gallate (CG), epicatechin-3-gallate (ECG), gallocatechin-3-gallate (GCG) and epigallocatechin-3-gallate (EGCG), in human plasma was established. For optimization of conditions for LC-ESIMS, the separation of the eight catechins was achieved chromatographically using Inertsil ODS-2 column combined with a gradient elution system of 0.1M aqueous acetic acid and 0.1M acetic acid in acetonitrile. Detection using a mass spectrometer was performed with selected ion monitoring at m/z=289 for E and EC, 305 for GC and EGC, 441 for CG and ECG, and 457 for GCG and EGCG under negative ESI. A preparative procedure, consisting of the addition of perchloric acid and acetonitrile to the plasma for deproteinizing and the subsequent addition of potassium carbonate solution to remove excess acid, was developed. In six different plasma with the eight catechins spiked at two different concentrations, the average recoveries were in the range between 72.7 and 84.1%, which resulted from the matrix effect and preparative loss, with coefficients of variance being 8.2-19.8% among individuals. The levels of the catechins in prepared plasma solutions that were kept at 5 degrees C within 24h were stable, which allows us to simply analyze many prepared plasma solutions using an autosampler overnight. When using this method to analyze the eight catechins in human plasma after oral ingestion of a commercial green tea beverage, we detected all the catechins absorbed into human blood for the first time. This also suggested that extremely small amounts of the eight catechins orally ingested may be absorbed based on each absorptive property for the catechins. The method should enable pharmacokinetic studies of green tea catechins in humans.

  17. Green Tea Catechin Metabolites Exert Immunoregulatory Effects on CD4(+) T Cell and Natural Killer Cell Activities.

    PubMed

    Kim, Yoon Hee; Won, Yeong-Seon; Yang, Xue; Kumazoe, Motofumi; Yamashita, Shuya; Hara, Aya; Takagaki, Akiko; Goto, Keiichi; Nanjo, Fumio; Tachibana, Hirofumi

    2016-05-11

    Tea catechins, such as (-)-epigallocatechin-3-O-gallate (EGCG), have been shown to effectively enhance immune activity and prevent cancer, although the underlying mechanism is unclear. Green tea catechins are instead converted to catechin metabolites in the intestine. Here, we show that these green tea catechin metabolites enhance CD4(+) T cell activity as well as natural killer (NK) cell activity. Our data suggest that the absence of a 4'-hydroxyl on this phenyl group (B ring) is important for the effect on immune activity. In particular, 5-(3',5'-dihydroxyphenyl)-γ-valerolactone (EGC-M5), a major metabolite of EGCG, not only increased the activity of CD4(+) T cells but also enhanced the cytotoxic activity of NK cells in vivo. These data suggest that EGC-M5 might show immunostimulatory activity.

  18. 28-Day oral (gavage) toxicity studies of green tea catechins prepared for beverages in rats.

    PubMed

    Chengelis, Christopher P; Kirkpatrick, Jeannie B; Regan, Karen S; Radovsky, Ann E; Beck, Melissa J; Morita, Osamu; Tamaki, Yasushi; Suzuki, Hiroyuki

    2008-03-01

    The beneficial health effects associated with drinking green tea are widely considered to be due primarily to tea catechins. Heat treatment of marketed green tea beverages for sterilization causes epimerization and/or polymerization of tea catechins. Safety studies on heat-treated tea catechins are limited. The objective of the present study was to evaluate potential adverse effects, if any, of two standardized green tea catechin (GTC) preparations: one that underwent heat sterilization (GTC-H) and one that was not heat-sterilized (GTC-UH). A decaffeinated preparation of the GTC-H (GTC-HDC) was also evaluated to ascertain if any effects were due to caffeine. The GTC preparations were administered to rats once daily at levels up to 2000 mg/kg/day for 28 days. There were no deaths attributable to the GTC preparations. The clinical condition of the animals, functional observational battery, motor activity, clinical pathology evaluations, organ weights, and gross necropsy findings were unaffected by any of the GTC preparations. GTC-HDC or GTC-UH dosing had no effects on body weights or microscopic findings, whereas lower body weights and food consumption were observed in the 1000 and 2000 mg/kg/day GTC-H group males. The no observed-adverse-effect level (NOAEL) for localized gastric effects for GTC-H was 1000 mg/kg/day. No other target organs were identified. Thus, the NOAEL for systemic toxicity following oral administration was 2000 mg/kg/day for GTC-H, GTC HDC, and GTC-UH under the conditions of this study.

  19. 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

  20. Physiologically based pharmacokinetic modeling of tea catechin mixture in rats and humans.

    PubMed

    Law, Francis C P; Yao, Meicun; Bi, Hui-Chang; Lam, Stephen

    2017-06-01

    Although green tea ( Camellia sinensis) (GT) contains a large number of polyphenolic compounds with anti-oxidative and anti-proliferative activities, little is known of the pharmacokinetics and tissue dose of tea catechins (TCs) as a chemical mixture in humans. The objectives of this study were to develop and validate a physiologically based pharmacokinetic (PBPK) model of tea catechin mixture (TCM) in rats and humans, and to predict an integrated or total concentration of TCM in the plasma of humans after consuming GT or Polyphenon E (PE). To this end, a PBPK model of epigallocatechin gallate (EGCg) consisting of 13 first-order, blood flow-limited tissue compartments was first developed in rats. The rat model was scaled up to humans by replacing its physiological parameters, pharmacokinetic parameters and tissue/blood partition coefficients (PCs) with human-specific values. Both rat and human EGCg models were then extrapolated to other TCs by substituting its physicochemical parameters, pharmacokinetic parameters, and PCs with catechin-specific values. Finally, a PBPK model of TCM was constructed by linking three rat (or human) tea catechin models together without including a description for pharmacokinetic interaction between the TCs. The mixture PBPK model accurately predicted the pharmacokinetic behaviors of three individual TCs in the plasma of rats and humans after GT or PE consumption. Model-predicted total TCM concentration in the plasma was linearly related to the dose consumed by humans. The mixture PBPK model is able to translate an external dose of TCM into internal target tissue doses for future safety assessment and dose-response analysis studies in humans. The modeling framework as described in this paper is also applicable to the bioactive chemical in other plant-based health products.

  1. Effect of Catechins, Green tea Extract and Methylxanthines in Combination with Gentamicin Against Staphylococcus aureus and Pseudomonas aeruginosa

    PubMed Central

    Fazly Bazzaz, Bibi Sedigheh; Sarabandi, Sahar; Khameneh, Bahman; Hosseinzadeh, Hossein

    2016-01-01

    Objectives: Bacterial resistant infections have become a global health challenge and threaten the society’s health. Thus, an urgent need exists to find ways to combat resistant pathogens. One promising approach to overcoming bacterial resistance is the use of herbal products. Green tea catechins, the major green tea polyphenols, show antimicrobial activity against resistant pathogens. The present study aimed to investigate the effect of catechins, green tea extract, and methylxanthines in combination with gentamicin against standard and clinical isolates of Staphylococcus aureus (S. aureus) and the standard strain of Pseudomonas aeruginosa (P. aeruginosa). Methods: The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) values of different agents against bacterial strains were determined. The interactions of green tea extract, epigallate catechin, epigallocatechin gallate, two types of methylxanthine, caffeine, and theophylline with gentamicin were studied in vitro by using a checkerboard method and calculating the fraction inhibitory concentration index (FICI). Results: The MICs of gentamicin against bacterial strains were in the range of 0.312 - 320 μg/mL. The MIC values of both types of catechins were 62.5 - 250 μg/ mL. Green tea extract showed insufficient antibacterial activity when used alone. Methylxanthines had no intrinsic inhibitory activity against any of the bacterial strains tested. When green tea extract and catechins were combined with gentamicin, the MIC values of gentamicin against the standard strains and a clinical isolate were reduced, and synergistic activities were observed (FICI < 1). A combination of caffeine with gentamicin did not alter the MIC values of gentamicin. Conclusion: The results of the present study revealed that green tea extract and catechins potentiated the antimicrobial action of gentamicin against some clinical isolates of S. aureus and standard P. aeruginosa strains. Therefore

  2. Determination of catechins in human urine subsequent to tea ingestion by high-performance liquid chromatography with electrochemical detection.

    PubMed

    Yang, B; Arai, K; Kusu, F

    2000-07-15

    The title determination was conducted by HPLC with electrochemical detection using an ODS column and a mobile phase of acetonitrile: 0.1 M phosphate buffer (pH 2.5) (15:85, v/v). The eight catechins, gallocatechin (GC), epigallocatechin (EGC), catechin (C), epicatechin (EC), epigallocatechin gallate (EGCg), gallocatechin gallate (GCg), epicatechin gallate (ECg), and catechin gallate (Cg), were detected at 0.6 V vs Ag/AgCl. Good linear relationships between current and amount were noted for 0.5-250 pmol of each catechin, with a correlation coefficient of 0.999 in each case. The detection limit for any one was 0.5 pmol (signal to noise ratio, S/N = 3). After the ingestion of 340 ml canned green tea, GC, EGC, C, and EC, mostly in conjugated form, were determined in urine samples. Conjugated catechins were hydrolyzed by enzymes using sulfatase and beta-glucuronidase. The time courses of the above four catechins showed a maxima at 1-3 h after tea ingestion. (+), (-)-EC and (+), (-)-C were present in canned tea.

  3. Effects of different brewing conditions on catechin content and sensory acceptance in Turkish green tea infusions.

    PubMed

    Saklar, Sena; Ertas, Erdal; Ozdemir, Ibrahim S; Karadeniz, Bulent

    2015-10-01

    The optimal brewing conditions for Turkish green tea were determined on the basis of extracted catechins and sensory attributes. Green tea infusions were prepared at 75, 85 and 95 °C with brewing times of 1, 2, 3, 5, 10, 20, 30 and 45 min. The amounts of epistructured catechins (EGCG, EGC, ECG, EC), non-epistructured catechins (C, GC, GCG) and caffeine in brewed tea samples were analysed. Sensory analyses were performed by nine trained panelists for infusion colour, taste, aroma and overall acceptability. Brewing at 85 °C for 3 min was found to be the optimal condition, where the EGCG content was at a maximum of 50.69 mg/100 ml with the highest sensory scores. It was observed that the yield of epistructured catechins increased rapidly for the first 3-5 min of brewing at 85 °C, and increased brewing time resulted in a decrease in the yield of epistructured catechins. The amount of nonepistructured catechins continued to increase with longer extraction times. Sensory scores for infusion colour, taste, aroma and overall acceptability were highest at 3 and 5 min brewing times at all temperatures. Sensory scores were very low for 30 and 45 min brewing at 85 and 95 °C due to the bitter taste and dark colour.

  4. Green Tea Catechin Consumption Enhances Exercise-Induced Abdominal Fat Loss

    USDA-ARS?s Scientific Manuscript database

    Aim: This study evaluated the influence of a green tea catechin beverage on body composition and fat distribution in overweight and obese adults during exercised-induced weight loss. Methods: Participants (N=132) were randomly assigned to receive a 500 mL beverage containing approximately 625 mg of...

  5. Inhibition of Catalase by Tea Catechins in Free and Cellular State: A Biophysical Approach

    PubMed Central

    Pal, Sandip; Dey, Subrata Kumar; Saha, Chabita

    2014-01-01

    Tea flavonoids bind to variety of enzymes and inhibit their activities. In the present study, binding and inhibition of catalase activity by catechins with respect to their structure-affinity relationship has been elucidated. Fluorimetrically determined binding constants for (−)-epigallocatechin gallate (EGCG) and (−)-epicatechin gallate (ECG) with catalase were observed to be 2.27×106 M−1 and 1.66×106 M−1, respectively. Thermodynamic parameters evidence exothermic and spontaneous interaction between catechins and catalase. Major forces of interaction are suggested to be through hydrogen bonding along with electrostatic contributions and conformational changes. Distinct loss of α-helical structure of catalase by interaction with EGCG was captured in circular dichroism (CD) spectra. Gallated catechins demonstrated higher binding constants and inhibition efficacy than non-gallated catechins. EGCG exhibited maximum inhibition of pure catalase. It also inhibited cellular catalase in K562 cancer cells with significant increase in cellular ROS and suppression of cell viability (IC50 54.5 µM). These results decipher the molecular mechanism by which tea catechins interact with catalase and highlight the potential of gallated catechin like EGCG as an anticancer drug. EGCG may have other non-specific targets in the cell, but its anticancer property is mainly defined by ROS accumulation due to catalase inhibition. PMID:25025898

  6. 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.

  7. Analysis of some selected catechins and caffeine in green tea by high performance liquid chromatography.

    PubMed

    El-Shahawi, M S; Hamza, A; Bahaffi, S O; Al-Sibaai, A A; Abduljabbar, T N

    2012-10-15

    Green tea seems to have a positive impact on health due to the catechins-found as flavanols. Thus, the present study was aimed to develop a low cost reversed phase high performance liquid chromatographic (HPLC) method for simultaneous determination of flavanol contents, namely catechin (C), epicatechin (EC), epigallocatechin (EGC), epicatechin 3-gallate (ECG) and epigallocatechin 3-gallate (EGCG) and caffeine in 29 commercial green tea samples available in a Saudi Arabian local market. A C-18 reversed-phase column, acetonitrile-trifluoroacetic acid as a mobile phase, coupled with UV detector at 205 nm, was successfully used for precise analysis of the tested analytes in boiled water of digested tea leaves. The average values of N (No. of theoretical plates), HETP (height equivalent of theoretical plates) and R(s) (separation factor) (at 10 μg ml(-1) of the catechins EC, EGC, EGCG and ECG) were 2.6×10(3)±1.2×10(3), 1.7×10(-3)±4.7×10(-4) cm and 1.7±5.53×10(-2), respectively. The developed HPLC method demonstrated excellent performance, with low limits of detection (LOD) and quantification (LOQ) of the tested catechins of 0.004-0.05 μg ml(-1) and 0.01-0.17 μg ml(-1), respectively, and recovery percentages of 96-101%. The influence of infusion time (5-30 min) and temperature on the content of the flavanols was investigated by HPLC. After a 5 min infusion of the tea leaves, the average concentrations of caffeine, catechin, EC, EGC, ECG and EGCG were found to be in the ranges 0.086-2.23, 0.113-2.94, 0.58-10.22, 0.19-24.9, 0.22-13.9 and 1.01-43.3 mg g(-1), respectively. The contents of caffeine and catechins followed the sequence: EGCG>EGC>ECG>EC>C>caffeine. The method was applied satisfactorily for the analysis of (+)-catechin, even at trace and ultra trace concentrations of catechins. The method was rapid, accurate, reproducible and ideal for routine analysis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. [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.

  9. Grape seed and tea extracts and catechin 3-gallates are potent inhibitors of α-amylase and α-glucosidase activity.

    PubMed

    Yilmazer-Musa, Meltem; Griffith, Anneke M; Michels, Alexander J; Schneider, Erik; Frei, Balz

    2012-09-12

    This study evaluated the inhibitory effects of plant-based extracts (grape seed, green tea, and white tea) and their constituent flavan-3-ol monomers (catechins) on α-amylase and α-glucosidase activity, two key glucosidases required for starch digestion in humans. To evaluate the relative potency of extracts and catechins, their concentrations required for 50 and 90% inhibition of enzyme activity were determined and compared to the widely used pharmacological glucosidase inhibitor, acarbose. Maximum enzyme inhibition was used to assess relative inhibitory efficacy. Results showed that grape seed extract strongly inhibited both α-amylase and α-glucosidase activity, with equal and much higher potency, respectively, than acarbose. Whereas tea extracts and catechin 3-gallates were less effective inhibitors of α-amylase, they were potent inhibitors of α-glucosidase. Nongallated catechins were ineffective. The data show that plant extracts containing catechin 3-gallates, in particular epigallocatechin gallate, are potent inhibitors of α-glucosidase activity and suggest that procyanidins in grape seed extract strongly inhibit α-amylase activity.

  10. Content Variation of Catechin Markers, Total Phenolics and Caffeine in Green Tea Dietary Supplements.

    PubMed

    Abourashed, Ehab A; Roberson, Cindy Leslie A; Elsharkawy, Nancy

    2016-01-01

    Green tea (Camellia sinensis) preparations are among the top selling products in the United States dietary supplements market. Numerous manufacturers claim different levels of specific catechin markers in their products while many others use total phenolic concentration instead, or not at all. Limited quality control results have been published for green tea dietary supplements over the past seven years. Thus, the goal of this work was to correlate determined levels of phenolics, catechins, and caffeine with manufacturer label claims for selected dietary supplement products (26 total) purchased in the United States. The Folin-Ciocalteu (FC) method was used to determine the total phenolic content while reversed-phase (RP) HPLC was used to quantify the major catechins: epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG), epigallocatechin gallate (EGCG). The developed HPLC method was validated for accuracy and precision. It utilized a C8 column with gradient elution of acetonitrile in 0.1% aqueous formic acid over 11 min total run time. Peak detection was performed at 280 nm. Caffeine was also included in the HPLC method as another non-phenolic alkaloid marker commonly found in green tea. Both methods showed a good correlation between the content of catechins and polyphenolic compounds in the selected products. The ranges of total catechins and polyphenol concentrations were 3.8-70.2% and 3.6-95.8%, respectively, while that of caffeine was 0.8-11.2%. The selected products displayed a wide range of marker levels. A lack of conformity in disclosing the actual levels of marker compounds was also noticed in the labeling of many products.

  11. Elevated plasma and urinary concentrations of green tea catechins associated with improved plasma lipid profile in healthy Japanese women.

    PubMed

    Takechi, Ryusuke; Alfonso, Helman; Hiramatsu, Naoko; Ishisaka, Akari; Tanaka, Akira; Tan, La'Belle; Lee, Andy H

    2016-03-01

    This study investigated green tea catechins in plasma and urine and chronic disease biomarkers. We hypothesized that plasma and urinary concentration of green tea catechins are associated with cardiovascular disease and diabetes biomarkers. First void urine and fasting plasma samples were collected from 57 generally healthy females aged 38 to 73 years (mean, 52 ± 8 years) recruited in Himeji, Japan. The concentrations of plasma and urinary green tea catechins were determined by liquid chromatography coupled with mass tandem spectrometer. Low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglyceride, glucose, insulin, glycated hemoglobin, and C-reactive protein in plasma/serum samples were analyzed by a commercial diagnostic laboratory. Statistical associations were assessed using Spearman correlation coefficients. The results showed weak associations between plasma total catechin and triglyceride (r = -0.30) and LDL cholesterol (r = -0.28), whereas plasma (-)-epigallocatechin-3-gallate, (-)-epigallocatechin, (-)-epicatechin-3-gallate, and (-)-epicatechin exhibited weak to moderate associations with triglyceride or LDL cholesterol, but little associations with HDL cholesterol, body fat, and body mass index were evident. Urinary total catechin was weakly associated with triglyceride (r = -0.19) and LDL cholesterol (r = -0.15), whereas urinary (-)-epigallocatechin-3-gallate (r = -0.33), (-)-epigallocatechin (r = -0.23), and (-)-epicatechin-3-gallate (r = -0.33) had weak to moderate correlations with triglyceride and similarly with body fat and body mass index. Both plasma (r = -0.24) and urinary (r = -0.24) total catechin, as well as individual catechins, were weakly associated with glycated hemoglobin. Plasma total and individual catechins were weakly to moderately associated with C-reactive protein, but not the case for urinary catechins. In conclusion, we found weak to moderate associations between plasma and urinary green tea

  12. Construction of a SSR-Based Genetic Map and Identification of QTLs for Catechins Content in Tea Plant (Camellia sinensis)

    PubMed Central

    Ma, Chun-Lei; Wang, Xin-Chao; Jin, Ji-Qiang; Wang, Xue-Min; Chen, Liang

    2014-01-01

    Catechins are the most important bioactive compounds in tea, and have been demonstrated to possess a wide variety of pharmacological activities. To characterize quantitative trait loci (QTLs) for catechins content in the tender shoots of tea plant, we constructed a moderately saturated genetic map using 406 simple sequence repeat (SSR) markers, based on a pseudo-testcross population of 183 individuals derived from an intraspecific cross of two Camellia sinensis varieties with diverse catechins composition. The map consisted of fifteen linkage groups (LGs), corresponding to the haploid chromosome number of tea plant (2n = 2x = 30). The total map length was 1,143.5 cM, with an average locus spacing of 2.9 cM. A total of 25 QTLs associated with catechins content were identified over two measurement years. Of these, nine stable QTLs were validated across years, and clustered into four main chromosome regions on LG03, LG11, LG12 and LG15. The population variability explained by each QTL was predominantly at moderate-to-high levels and ranged from 2.4% to 71.0%, with an average of 17.7%. The total number of QTL for each trait varied from four to eight, while the total population variability explained by all QTLs for a trait ranged between 38.4% and 79.7%. This is the first report on the identification of QTL for catechins content in tea plant. The results of this study provide a foundation for further cloning and functional characterization of catechin QTLs for utilization in improvement of tea plant. PMID:24676054

  13. Biotransformation of catechin and extraction of active polysaccharide from green tea leaves via simultaneous treatment with tannase and pectinase.

    PubMed

    Baik, Joo Hyun; Shin, Kwang-Soon; Park, Yooheon; Yu, Kwang-Won; Suh, Hyung Joo; Choi, Hyeon-Son

    2015-08-30

    Green tea is a dietary source of bioactive compounds for human health. Enzymatic treatments induce the bioconversion of bioactive components, which can improve biological activities. In this study, we investigated the effect of simultaneous treatment with tannase and Rapidase on biotransformation of catechins and extraction of polysaccharide from green tea extract (GTE). Tannase and pectinase treatments induced the biotransformation of catechins and altered tea polysaccharide () content. The addition of GTE to the enzyme reaction resulted in a significant increase in degallated catechins, including gallic acid, a product of the tannase reaction (314.5-4076.0 µg mL(-1)) and a reduction in epigallocatechin gallate (EGCG). Biotransformation of catechins improved the radical scavenging activity of GTE. Pectinase treatment led to change of TPS composition in GTE by hydrolyzing polysaccharides. In addition, pectinase-driven hydrolysis in polysaccharides significantly increased TPS-induced Interleukin 6 (IL-6) production in macrophages. In particular, treatment of Rapidase (TPS-Ra) led to the highest IL-6 production among TPS samples, similar to treatment of highly purified pectinase (TPS-GTE), a positive control. Simultaneous processing with tannase and Rapidase can be an efficient method for the extraction of bioactive polysaccharides and biotransformation of catechins with enhanced radical scavenging activity from green tea. © 2014 Society of Chemical Industry.

  14. Complexing of Green Tea Catechins with Food Constituents and Degradation of the Complexes by Lactobacillus plantarum

    PubMed Central

    HAYASHI, Taeko; UEDA, Shuhei; TSURUTA, Hiroki; KUWAHARA, Hiroshige; OSAWA, Ro

    2012-01-01

    Complexing of green tea catechins with food constituents and their hydrolysis by tannase-producing Lactobacillus plantarum strains, were investigated. Our observations indicated that 1) epigallocatechin gallate (EGCg) and other catechin galloyl esters bound with food ingredients (i.e., proteins) to form a complex that is likely to be unabsorbable through the intestinal wall, whereas most catechins not esterified with gallic acid (GA) remain in free form, not complexing with food ingredients; 2) tannase activity of L. plantarum is strain dependent, possibly grouped into those with high tannase activity hydrolyzing EGCg to epigallocatechin and GA and those with the low activity; and 3) L. plantarum strains with high tannase activity are capable of hydrolyzing not only intact EGCg but also EGCg and other catechin galloyl esters complexed with dietary proteins to free non-galloyl ester catechins and GA. The evidence suggests that L. plantarum with high tannase activity, if it colonizes the human intestine, would release free non-galloyl-ester catechins and GA that are readily absorbed through the human intestinal epithelia from the complexes, thereby ensuring maximum delivery of the bioactive polyphenols of green tea to the host. PMID:24936346

  15. A novel functional full-fat hard cheese containing liposomal nanoencapsulated green tea catechins: manufacture and recovery following simulated digestion.

    PubMed

    Rashidinejad, Ali; Birch, E John; Everett, David W

    2016-07-13

    (+)-Catechin or green tea extract were encapsulated in soy lecithin nanoliposomes and incorporated into a full-fat cheese, then ripened at 8 °C for 90 days. Cheese samples were subjected to simulated gastrointestinal digestion to measure total phenolic content (TPC) and antioxidant activity of the cheese digesta, and to determine the catechin recovery after digestion by high performance liquid chromatography (HPLC). Addition of catechin or green tea extract significantly (P ≤ 0.05) increased TPC and antioxidant activity (measured by ferric reducing antioxidant power and oxygen radical absorbance capacity) of the full-fat cheese without affecting pH or proximate composition. HPLC analysis confirmed retention of encapsulated catechins in the cheese curd; however, individual catechins were recovered in differing amounts (15-52%) from cheese digesta after 6 h of digestion. Transmission electron microscopy and Fourier transform infrared spectroscopy provided evidence for association of nanoliposomes with the surface of milk fat globules inside the cheese matrix. The study shows the potential for using cheese as a delivery vehicle for green tea antioxidants.

  16. 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

  17. Antiproliferative activity of tea catechins associated with casein micelles, using HT29 colon cancer cells.

    PubMed

    Haratifar, S; Meckling, K A; Corredig, M

    2014-02-01

    Numerous studies have shown that green tea polyphenols display anticancer activities in many organ sites by using different experimental models in rodents and in cultured cell lines in vitro. The present study tested the ability of casein micelles to deliver biologically active concentrations of polyphenols to HT-29 colon cancer cells. Epigallocatechin gallate (EGCG), the major catechin found in green tea, was used as the model molecule, as it has been shown to have antiproliferative activity on colon cancer cells. In the present work, we hypothesized that due to the binding of caseins with EGCG, casein micelles may be an ideal platform for the delivery of this bioactive molecule and that the binding would not affect the bioaccessibility of EGCG. The cytotoxicity and proliferation behavior of HT-29 colon cancer cells when exposed to free EGCG was compared with that of nanoencapsulated EGCG in casein micelles of skim milk. Epigallocatechin gallate-casein complexes were able to decrease the proliferation of HT-29 cancer cells, demonstrating that bioavailability may not be reduced by the nanoencapsulation. As casein micelles may act as protective carriers for EGCG in foods, it was concluded that nanoencapsulation of tea catechins in casein micelles may not diminish their antiproliferative activity on colon cancer cells compared with free tea catechins. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  18. Role of catechins in the antioxidant capacity of an active film containing green tea, green coffee, and grapefruit extracts.

    PubMed

    Colon, M; Nerin, C

    2012-10-03

    The oxygen radical absorbance capacity (ORAC) method was used to characterize the antioxidant capacity of natural extracts of green tea, green coffee, and grapefruit. These natural extracts were incorporated into a plastic film layer, which was subsequently subjected to a free radical gas stream in order to determine the antioxidant capacity directly in the active film. The green tea extract (GTE) afforded the strongest antioxidant activity. To identify the active compounds in the extract, concentration of the diverse catechins in samples were determined by HPLC-UV analysis. The results showed that the content of catechins in the GTE is around 77% (w/w), the major components being (-)-epigallocatechin gallate, (-)-epicatechin gallate, and (-)-epicatechin. A variation in the concentration profile of catechins was detected during the oxidation process. The chromatographic study demonstrated that (-)-gallocatechin, (-)- epigallocatechin, (+)-catechin, and (-)-catechin gallate exhibited the most radical scavenging.

  19. Formulation with ascorbic acid and sucrose modulates catechin bioavailability from green tea

    PubMed Central

    Peters, Catrina M.; Green, Rodney J.; Janle, Elsa M.; Ferruzzi, Mario G.

    2009-01-01

    In order to investigate the impact of common food ingredients on catechin absorption, green tea (GT) extract (50 mg) was formulated plain, with sucrose (GT+S), with ascorbic acid (GT+AA) and with sucrose and ascorbic acid (GT+S+AA). Bioavailability and bioaccessibility were assessed in Sprague Dawley rats and an in vitro digestion/Caco-2 cell model respectively. Absorption of epigallocatechin (EGC) and epigallocatechin gallate (EGCG) was significantly (P<0.05) enhanced in GT+S+AA formulations (AUC0-6h= 3237.0 and 181.8 pmol*h/L plasma respectively) relative to GT control (AUC0-6h = 1304.1 and 61.0 pmol*h/L plasma respectively). In vitro digestive recovery was higher for EGC and epicatechin (EC) (∼51-53%) relative to EGCG and epicatechin gallate (ECG) (< 20%) and was modestly enhanced in GT+S and GT+S+AA formulations. Accumulation of EGC, EGCG and ECG by Caco-2 cells was significantly (P<0.05) higher from GT+S+AA compared to other formulations while retention of catechins was enhanced in presence of ascorbic acid. These data suggest that formulation with sucrose and ascorbic acid may improve catechin bioavailability by enhancing bioaccessibility and intestinal uptake from tea. PMID:20161530

  20. Separation of major catechins from green tea by ultrahigh pressure extraction.

    PubMed

    Jun, Xi; Shuo, Zhao; Bingbing, Lu; Rui, Zhang; Ye, Li; Deji, Shen; Guofeng, Zhou

    2010-02-15

    This study presents a novel extraction technique, ultrahigh pressure extraction, to obtain major catechins from green tea leaves. The effects of various high pressure level (100, 200, 300, 400, 500, 600 MPa) on the extract are examined. HPLC chromatographic analyses determine the concentration of four major catechins and caffeine. The extraction yields of active ingredients with ultrahigh pressure extraction (400 MPa pressure) for only 15 min were given the same as those of organic solvent extraction for 2h. These excellent results for the ultrahigh pressure extraction are promising for the future separation of active ingredients from traditional Chinese herbal medicine. Copyright 2009 Elsevier B.V. All rights reserved.

  1. Chiral analysis of theanine and catechin in characterization of green tea by cyclodextrin-modified micellar electrokinetic chromatography and high performance liquid chromatography.

    PubMed

    Fiori, Jessica; Pasquini, Benedetta; Caprini, Claudia; Orlandini, Serena; Furlanetto, Sandra; Gotti, Roberto

    2018-08-10

    Monomeric catechins are important compounds in green tea accounting for potential bioactivity against a wide range of diseases. Besides catechins, l-Theanine (γ-glutamylethylamide), a characteristic amino acid in tea leaves, has become a further focus of the phytochemical research for the reported beneficial effects mainly on cognitive performance, emotional state and sleep quality. In the present study has been developed a CD-MEKC method based on sodium dodecyl sulfate (SDS) and Heptakis (2,6-di-O-methyl)-β-cyclodextrin for the separation of six major green tea catechins and enantiomers of theanine. The latter, because of the poor detectability was derivatized prior analysis by o-phthaldialdehyde in the presence of N-acetyl-l-cysteine which, under mild conditions (neutral pH, in two minutes) allowed two diastereomers isoindole derivatives to be obtained. The derivatization reaction was directly carried out on tea infusion and derivatized samples were analysed by CD-MEKC involving 65 mM SDS and 28 mM cyclodextrin in acidic buffer (pH 2.5). The separation of six major green tea catechins including enantioresolution of (±)-Catechin and d/l-Theanine was obtained in about 5 min allowing d-Theanine to be quantified at least at 0.5% m/m level with respect to l-Theanine. Since (-)-Catechin and d-Theanine can be considered as non-native enantiomers (distomers), their presence in real samples provides an indication of tea leaves treatments (thermal treatment, fermentation, etc.) and could represent an opportunity for grading tea. The obtained results were confirmed by a RP-HPLC approach; even though the chromatography was developed in achiral conditions, the derivatization approach applied to theanine (diastereomers formation), allowed for d/l-Theanine chiral analysis. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Effects of green tea catechins on gramicidin channel function and inferred changes in bilayer properties

    PubMed Central

    Ingólfsson, Helgi I.; Koeppe, Roger E.; Andersen, Olaf S.

    2011-01-01

    Green tea's health benefits have been attributed to its major polyphenols, the catechins: (−)-epigallocatechin gallate (EGCG), (−)-epicatechin gallate (ECG), (−)-epigallocatechin (EGC), and epicatechin (EC). Catechins (especially EGCG) modulate a wide range of biologically important molecules, including many membrane proteins. Yet, little is known about their mechanism(s) of action. We tested the catechins' bilayer-modifying potency using gramicidin A (gA) channels as molecular force probes. All the catechins alter gA channel function and modify bilayer properties, with a 500-fold range in potency (EGCG > ECG >> EGC > EC). Additionally, the gallate group causes current block, as evident by brief downward current transitions (flickers). PMID:21896274

  3. On-chip sample pretreatment using a porous polymer monolithic column for solid-phase microextraction and chemiluminescence determination of catechins in green tea.

    PubMed

    Lin, Ling; Chen, Hui; Wei, Huibin; Wang, Feng; Lin, Jin-Ming

    2011-10-21

    A porous polymer monolithic column for solid-phase microextraction and chemiluminescence detection was integrated into a simple microfluidic chip for the extraction and determination of catechins in green tea. The porous polymer was prepared by poly(glycidyl methacrylate-co-ethylene dimethacrylate) and modified with ethylenediamine. Catechins can be concentrated in the porous polymer monolithic column and react with potassium permanganate to give chemiluminescence. The microfluidic chip is reusable with high sensitivity and very low reagent consumption. The on-line preconcentration and detection can be realized without an elution step. The enrichment factor was calculated to be about 20 for catechins. The relative chemiluminescence intensity increased linearly with concentration of catechin from 5.0 × 10(-9) to 1.0 × 10(-6) M and the limit of detection was 1.0 × 10(-9) M. The proposed method was applied to determine catechin in green tea. The recoveries are from 90% to 110% which benefits the actual application for green tea samples.

  4. Interaction of Environmental Moisture with Powdered Green Tea Formulations: Relationship between Catechin Stability and Moisture-Induced Phase Transformations

    PubMed Central

    Ortiz, Julieta; Kestur, Umesh S.; Taylor, Lynne S.; Mauer, Lisa J.

    2009-01-01

    This study investigated the effect of phase transformations of amorphous and deliquescent ingredients on catechin stability in green tea powder formulations. Blends of amorphous green tea and crystalline sucrose, citric acid, and/or ascorbic acid were analyzed by X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), dynamic water vapor sorption, water activity measurements, and high-performance liquid chromatography (HPLC) after storage for up to 12 weeks at 0–75% relative humidity (RH) and 22 °C. The glass transition temperature (Tg) of green tea was reduced to below room temperature (<22 °C) at 68% RH. Dissolution of deliquescent ingredients commenced at RH values below deliquescence points in blends with amorphous green tea, and these blends had greater water uptake than predicted by an additive model of individual ingredient moisture sorption. Catechin degradation was affected by Tg of green tea powder and both dissolution and deliquescence of citric and ascorbic acids. PMID:19489621

  5. Preparation of catechin extracts and nanoemulsions from green tea leaf waste and their inhibition effect on prostate cancer cell PC-3

    PubMed Central

    Tsai, Yin-Jieh; Chen, Bing-Huei

    2016-01-01

    Green tea is one of the most commonly consumed natural health beverages in Taiwan’s market, with the major functional component catechin being shown to possess several biological activities such as antioxidation, anticancer, and prevention of cardiovascular disease. The objectives of this study were to develop a high-performance liquid chromatography–mass spectrometry method to determine the variety and content of catechins in green tea leaf waste, a by-product obtained during processing of tea beverage. In addition, catechin nanoemulsion was prepared to study its inhibition effect on prostate cancer cell PC-3. Results showed that a total of eight catechin standards were separated within 25 minutes by using a Gemini C18 column and a gradient mobile phase of 0.1% formic acid (A) and acetonitrile (B) with flow rate at 1 mL/min, column temperature at 30°C, and detection wavelength at 280 nm. Among various extraction solvents, 50% ethanol generated the highest yield of total catechins from tea leaf waste, of which five catechins were identified and quantified. The catechin nanoemulsion was composed of catechin extract, lecithin, Tween 80, and deionized water in an appropriate proportion, with the mean particle size being 11.45 nm, encapsulation efficiency 88.1%, and zeta potential −66.3 mV. A high stability of catechin nanoemulsion was shown over a storage period of 120 days at 4°C. Both catechin extract and nanoemulsion could inhibit growth of PC-3 tumor cells, with the half maximal inhibitory concentration being 15.4 μg/mL and 8.5 μg/mL, respectively. The PC-3 cell cycle was arrested at S phase through elevation of P27 expression and decline of cyclin A, cyclin B, cyclin-dependent kinase 2, and cyclin-dependent kinase 1 expression. In addition, both catechin extract and nanoemulsion could induce apoptosis of PC-3 cells through decrease in B-cell lymphoma 2 (bcl-2) expression and increase in cytochrome c expression for activation of caspase-3, caspase-8, and

  6. Determination of volatile organic compounds, catechins, caffeine and theanine in Jukro tea at three growth stages by chromatographic and spectrometric methods.

    PubMed

    Jeon, Dong Bok; Hong, Young Shin; Lee, Ga Hyun; Park, Yu Min; Lee, Cheong Mi; Nho, Eun Yeong; Choi, Ji Yeon; Jamila, Nargis; Khan, Naeem; Kim, Kyong Su

    2017-03-15

    Tea contains characteristic volatile organic compounds, polyphenols, caffeine and catechins, and is therefore among the most widely consumed beverages all over the world. In this study, fresh Jukro tea leaves collected from Damyang-gun (Jeollanam-do) at 40, 60 and 90day growth stages, were semi-fermented. The volatile organic compounds (VOCs) were extracted by simultaneous distillation-solvent extraction (SDE) and analyzed by gas chromatography/mass spectrometry (GC/MS). Catechins, caffeine and theanine were analyzed by high performance liquid chromatography (HPLC). A total of 159 VOCs were identified in the analyzed Jukro tea leaves. Comparatively, the increase in the concentrations of VOCs was high in 60day leaves. The content of catechins increased along the three growth stages, whereas caffeine, compared to 90day leaves, was higher for 40 and 60day leaves. Based on the results, the 60day leaves were found to be the most suitable and useful for making semi-fermented Jukro tea. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Tea Catechin Auto-oxidation Dimers are Accumulated and Retained by Caco-2 Human Intestinal Cells

    PubMed Central

    Neilson, Andrew P.; Song, Brian J.; Sapper, Teryn N.; Bomser, Joshua A.; Ferruzzi, Mario G.

    2010-01-01

    Despite the presence of bioactive catechin B-ring auto-oxidation dimers in tea, little is known regarding their absorption in humans. Our hypothesis for this research is that catechin auto-oxidation dimers are present in teas and are absorbable by human intestinal epithelial cells. Dimers [theasinensins (THSNs) and P-2 analogs) were quantified in commercial teas by HPLC-MS. (−)-Epigallocatechin (EGC) and (−)-epigallocatechin gallate (EGCG) homodimers were present at 10–43 and 0–62 µmol/g leaf, respectively. EGC-EGCG heterodimers were present at 0–79 µmol/g. The potential intestinal absorption of these dimers was assessed using Caco-2 intestinal cells. Catechin monomers and dimers were detected in cells exposed to media containing monomers and preformed dimers. Accumulation of dimers was significantly greater than monomers from test media. Three h accumulation of EGC and EGCG was 0.19– 0.55% and 1.24–1.35% respectively. Comparatively, 3h accumulation of the EGC P-2 analog, and THSNs C/E was 0.89 ± 0.28% and 1.53 ± 0.36%. Accumulation of P-2, and THSNs A/D was 6.93 ± 2.1%, and 10.1 ± 3.6%. EGCG-EGC heterodimer P-2 analog, and THSN B 3h accumulation was 4.87 ± 2.2%, and 4.65 ± 2.8% respectively. One h retention of P-2, and THSNs A/D was 171 ± 22%, and 29.6 ± 9.3% of accumulated amount suggesting intracellular oxidative conversion of THSNs to P-2. These data suggest that catechin dimers present in the gut lumen may be readily absorbed by intestinal epithelium. PMID:20579525

  8. Systemic Absorption of Catechins after Intraruminal or Intraduodenal Application of a Green Tea Extract in Cows

    PubMed Central

    Wein, Silvia; Beyer, Birgit; Gohlke, Annika; Blank, Ralf; Metges, Cornelia C.; Wolffram, Siegfried

    2016-01-01

    Green tea catechins have various potential health benefits in humans including anti-inflammatory, anti-oxidative and hepato-protective effects. If present in the circulation, they might have similar effects in ruminants, which are exposed to oxidative stress and fatty liver disease such as dairy cows during the periparturient phase. However, the bioavailability of a substance is a prerequisite for any post absorptive effect in vivo. This study aimed to investigate the appearance of catechins from a green tea extract (GTE) in cattle plasma after intraruminal and intraduodenal administration because absorption is of major importance regarding the bioavailability of catechins. The studies were performed in 5 rumen-fistulated non-lactating heifers and 6 duodenally fistulated lactating dairy cows, respectively, equipped with indwelling catheters placed in a jugular vein. The GTE was applied intraruminally (10 and 50 mg/kg BW, heifers) or duodenally (10, 20 and 30 mg/kg BW, dairy cows) in a cross‐over design with a 2 d washout period between different dosages. Blood samples were drawn following the GTE administration at various pre-defined time intervals. The concentration of the major GTE catechins (gallocatechin, epigallocatechin, catechin, epicatechin, epigallocatechin-gallate, epicatechin-gallate) in plasma samples were analysed by HPLC with electrochemical detection. Irrespective of the dose, almost none of the catechins originally contained in the GTE were detected in plasma samples after intraruminal application. In contrast, intraduodenal administration of GTE resulted in increased plasma concentrations of epicatechin, epigallocatechin, epigallocatechin gallate in a dose‐dependent manner. Thus, we can conclude that intraruminally or orally administered catechins are intensively metabolized by ruminal microorganisms. PMID:27427946

  9. Comparison of effects of green tea catechins on apicomplexan hexose transporters and mammalian orthologues.

    PubMed

    Slavic, Ksenija; Derbyshire, Elvira T; Naftalin, Richard J; Krishna, Sanjeev; Staines, Henry M

    2009-11-01

    Here we have investigated the inhibitory properties of green tea catechins on the Plasmodium falciparum hexose transporter (PfHT), the Babesia bovis hexose transporter 1 (BboHT1) and the mammalian facilitative glucose transporters, GLUT1 and GLUT5, expressed in Xenopus laevis oocytes. (-)-Epicatechin-gallate (ECG) and (-)-epigallocatechin-gallate (EGCG) inhibited D-glucose transport by GLUT1 and PfHT, and D-fructose transport by GLUT5, with apparent K(i) values between 45 and 117 microM. BboHT1 was more potently inhibited by the ungallated catechins (-)-epicatechin (EC) and (-)-epigallocatechin (EGC), with apparent K(i) values of 108 and 168 microM, respectively. Site-directed mutagenesis experiments provided little further support for previously reported models of catechin binding to hexose transporters. Furthermore, P. falciparum growth inhibition by catechins was not affected by the external D-glucose concentration. Our results provide new data on the inhibitory action of catechins against sugar transporters but were unable to elucidate the antimalarial mechanism of action of these agents.

  10. Comparison of effects of green tea catechins on apicomplexan hexose transporters and mammalian orthologues

    PubMed Central

    Slavic, Ksenija; Derbyshire, Elvira T.; Naftalin, Richard J.; Krishna, Sanjeev; Staines, Henry M.

    2009-01-01

    Here we have investigated the inhibitory properties of green tea catechins on the Plasmodium falciparum hexose transporter (PfHT), the Babesia bovis hexose transporter 1 (BboHT1) and the mammalian facilitative glucose transporters, GLUT1 and GLUT5, expressed in Xenopus laevis oocytes. (−)-Epicatechin-gallate (ECG) and (−)-epigallocatechin-gallate (EGCG) inhibited d-glucose transport by GLUT1 and PfHT, and d-fructose transport by GLUT5, with apparent Ki values between 45 and 117 μM. BboHT1 was more potently inhibited by the ungallated catechins (−)-epicatechin (EC) and (−)-epigallocatechin (EGC), with apparent Ki values of 108 and 168 μM, respectively. Site-directed mutagenesis experiments provided little further support for previously reported models of catechin binding to hexose transporters. Furthermore, P. falciparum growth inhibition by catechins was not affected by the external d-glucose concentration. Our results provide new data on the inhibitory action of catechins against sugar transporters but were unable to elucidate the antimalarial mechanism of action of these agents. PMID:19577593

  11. Combination of curcumin and green tea catechins prevents dimethylhydrazine-induced colon carcinogenesis.

    PubMed

    Xu, Gang; Ren, Guijie; Xu, Xia; Yuan, Huiqing; Wang, Zhenzheng; Kang, Ludong; Yu, Wenguang; Tian, Keli

    2010-01-01

    The chemopreventive effects of curcumin and green tea catechins individually and in combination on 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis were studied in male Wister rats following 32 weeks of dietary treatment. The incidence, number and size of colorectal cancer were measured. Colorectal aberrant crypt foci (ACF) were analyzed by methylene blue staining. Proliferation indices and apoptotic indices were determined by PCNA immunostaining and TUNEL assay, respectively. The results showed that dietary curcumin, catechins and combination administration significantly inhibited the total number of ACF per rat. The combination treatment displayed the most potent inhibitory effect, while there was no difference of inhibition between curcumin and catechins-treated groups. The incidence of colorectal cancer in the treated groups was significantly lower than that of positive control group. Compared with the positive control group, the proliferation index was significantly decreased and the apoptotic index was significantly increased in all treatment groups, while the effect of the combination was the greatest among the treated groups. Our findings suggest that the combination of curcumin and catechins may produce a synergistic colon cancer-preventative effect that would be more potent than each of the compounds alone. Copyright 2009 Elsevier Ltd. All rights reserved.

  12. Designed polar cosolvent-modified supercritical CO2 removing caffeine from and retaining catechins in green tea powder using response surface methodology.

    PubMed

    Huang, Kuo-Jong; Wu, Jia-Jiuan; Chiu, Yung-Ho; Lai, Cheng-Yung; Chang, Chieh-Ming J

    2007-10-31

    This study examines cosolvent-modified supercritical carbon dioxide (SC-CO2) to remove caffeine from and to retain catechins in green tea powder. The response surface method was adopted to determine the optimal operation conditions in terms of the extraction efficiencies and concentration factors of caffeine and catechins during the extractions. When SC-CO2 was used at 333 K and 300 bar, 91.5% of the caffeine was removed and 80.8% of catechins were retained in the tea: 3600 g of carbon dioxide was used in the extraction of 4 g of tea soaked with 1 g of water. Under the same extraction conditions, 10 g of water was added to <800 g of carbon dioxide in an extraction that completely removed caffeine (that is, the caffeine extraction efficiency was 100%). The optimal result as predicted by three-factor response surface methodology and supported by experimental data was that in 1.5 h of extraction, 640 g of carbon dioxide at 323 K and 275 bar with the addition of 6 g of water extracted 71.9% of the caffeine while leaving 67.8% of the catechins in 8 g of tea. Experimental data indicated that supercritical carbon dioxide decaffeination increased the concentrations of caffeine in the SC-CO2 extracts at 353 K.

  13. GREEN TEA CATECHINS ARE POTENT SENSITIZERS OF RYANODINE RECEPTOR TYPE 1 (RYR1)

    PubMed Central

    Feng, Wei; Cherednichenko, Gennady; Ward, Chris W.; Padilla, Isela T.; Cabrales, Elaine; Lopez, José R.; Eltit, José M.; Allen, Paul D.; Pessah, Isaac N.

    2010-01-01

    Catechins, polyphenols extracted from green tea leaves, have a broad range of biological activities although the specific molecular mechanisms responsible are not known. At the high experimental concentrations typically used polyphenols bind to membrane phospholipid and also are easily auto-oxidized to generate superoxide anion and semiquinones, and can adduct to protein thiols. We report that the type 1 ryanodine receptor (RyR1) is a molecular target that responds to nanomolar (−)-epigallocatechin-3-gallate (EGCG) and (−)-epicatechin-3-gallate (ECG). Single channel analyses demonstrate EGCG (5-10nM) increases channel open probability (Po) 2-fold, by lengthening open dwell time. The degree of channel activation is concentration dependent and is rapidly and fully reversible. Four related catechins, EGCG, ECG, EGC ((−)-epigallocatechin) and EC ((−)-epicatechin) showed a rank order of activity toward RyR1 (EGCG>ECG>>EGC>>>EC). EGCG and ECG enhance the sensitivity of RyR1 to activation by ≤100μM cytoplasmic Ca2+ without altering inhibitory potency by >100μM Ca2+. EGCG as high as 10μM in the extracellular medium potentiated Ca2+ transient amplitudes evoked by electrical stimuli applied to intact myotubes and adult FDB fibers, without eliciting spontaneous Ca2+ release or slowing Ca2+ transient recovery. The results identify RyR1 as a sensitive target for the major tea catechins EGCG and ECG, and this interaction is likely to contribute to their observed biological activities. PMID:20471964

  14. Erythrocyte membrane transporters during human ageing: modulatory role of tea catechins.

    PubMed

    Pandey, Kanti Bhooshan; Jha, Rashmi; Rizvi, Syed Ibrahim

    2013-02-01

    Ageing is associated with many physiological and cellular changes, many of which are due to alterations in the plasma membrane. The functions of membrane transporter proteins are crucial for the maintenance of ionic homeostasis between the extra- and intracellular environments. The aim of the present study was to determine the status of erythrocyte membrane transporters, specifically Ca(2+) -ATPases, Na(+) /K(+) -ATPases and the Na(+) /H(+) exchanger (NHE), during ageing in humans. Furthermore, because tea catechins have been reported to possess strong anti-oxidant potential, the study was extended to evaluate the effect of (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), (-)-epigallocatechin (EGC) and (-)-epigallocatechin-3-gallate (EGCG) on these transporters as a function of human age. The study was performed on 97 normal healthy subjects (62 men, 35 women; 16-80 years old). To investigate the effects of tea catechins, subjects were divided into three groups: young (<40 years old; n = 34); middle-aged (40-60 years old; n = 32); and old (>60 years old; n = 31). Erythrocyte ghosts/cell suspension from each group were incubated with ECG, EGCG, EGC and EC (10 μmol/L) for 30 min at 37°C prior to assay. Ageing significantly increased NHE activity and decreased Ca(2+) -ATPase activity. There were no significant changes in Na(+) /K(+) -ATPase activity during the ageing process. (-)-Epigallocatechin-3-gallate, EGC, ECG and EC effectively mitigated the changes in membrane transporter activity in erythrocytes from all age groups; however, the effect was more pronounced in the old age group. We hypothesize that impairment in -bound transporters may be one of the possible mechanisms underlying the pathological events during ageing. A higher intake of catechin-rich food may provide some protection against age-dependent diseases. © 2012 The Authors Clinical and Experimental Pharmacology and Physiology © 2012 Wiley Publishing Asia Pty Ltd.

  15. Interaction between Ester-Type Tea Catechins and Neutrophil Gelatinase-Associated Lipocalin: Inhibitory Mechanism.

    PubMed

    Zhang, Wei; Li, Xiao; Hua, Fang; Chen, Wei; Wang, Wei; Chu, Gang-Xiu; Bao, Guan-Hu

    2018-02-07

    Tea is thought to alleviate neurotoxicity due to the antioxidative effect of ester-type tea catechins (ETC). Neutrophil gelatinase-associated lipocalin (NGAL) can sensitize β-amyloid (Aβ) induced neurotoxicity, and inhibitors of NGAL may relieve associated symptoms. As such, the interactions of ETC with NGAL were investigated by fluorescence spectrometry and molecular simulation. NGAL fluorescence is quenched regularly when being added with six processing types of tea infusion (SPTT) and ETC. Thermodynamic analyses suggest that ETC with more catechol moieties has a stronger binding capacity with NGAL especially in the presence of Fe 3+ . (-)-Epicatechin 3-O-caffeoate (ECC), a natural product isolated from Zijuan green tea, shows the strongest binding ability with NGAL (K d = 15.21 ± 8.68 nM in the presence of Fe 3+ ). All ETC are effective in protecting nerve cells against H 2 O 2 or Aβ 1-42 induced injury. The inhibitory mechanism of ETC against NGAL supports its potential use in attenuation of neurotoxicity.

  16. Molecular insights into the differences in anti-inflammatory activities of green tea catechins on IL-1β signaling in rheumatoid arthritis synovial fibroblasts.

    PubMed

    Fechtner, Sabrina; Singh, Anil; Chourasia, Mukesh; Ahmed, Salahuddin

    2017-08-15

    In this study, we found that catechins found in green tea (EGCG, EGC, and EC) differentially interfere with the IL-1β signaling pathway which regulates the expression of pro-inflammatory mediators (IL-6 and IL-8) and Cox-2 in primary human rheumatoid arthritis synovial fibroblasts (RASFs). EGCG and EGC inhibited IL-6, IL-8, and MMP-2 production and selectively inhibited Cox-2 expression. EC did not exhibit any inhibitory effects. When we looked at the expression of key signaling proteins in the IL-1β signaling pathway, we found all the tested catechins could inhibit TAK-1 activity. Therefore, the consumption of green tea offers an overall anti-inflammatory effect. Molecular docking analysis confirms that EGCG, EGC, and EC all occupy the active site of the TAK1 kinase domain. However, EGCG occupies the majority of the TAK1 active site. In addition to TAK1 inhibition, EGCG can also inhibit P38 and nuclear NF-κB expression whereas EC and EGC were not effective inhibitors. Our findings suggest one of the main health benefits associated with the consumption of green tea are due to the activity of EGCG and EGC which are both present at higher amounts. Although EGCG is the most effective catechin at inhibiting downstream inflammatory signaling, its effectiveness could be hindered by the presence of EC. Therefore, varying EC content in green tea may reduce the anti-inflammatory effects of other potential catechins in green tea. Copyright © 2017. Published by Elsevier Inc.

  17. Effect of green tea catechins and hydrolyzable tannins on benzo[a]pyrene-induced DNA adducts and structure-activity relationship.

    PubMed

    Cao, Pengxiao; Cai, Jian; Gupta, Ramesh C

    2010-04-19

    Green tea catechins and hydrolyzable tannins are gaining increasing attention as chemopreventive agents. However, their mechanism of action is poorly understood. We investigated the effects of four green tea catechins and two hydrolyzable tannins on microsome-induced benzo[a]pyrene (BP)-DNA adducts and the possible structure-activity relationship. BP (1 microM) was incubated with rat liver microsomes and DNA in the presence of the test compound (1-200 microM) or vehicle. The purified DNA was analyzed by (32)P-postlabeling. The inhibitory activity of the catechins was in the following descending order: epigallocatechin gallate (IC(50) = 16 microM) > epicatechin gallate (24 microM) > epigallocatechin (146 microM) > epicatechin (462 microM), suggesting a correlation between the number of adjacent aromatic hydroxyl groups in the molecular structure and their potencies. Tannic acid (IC(50) = 4 microM) and pentagalloglucose (IC(50) = 26 microM) elicited as much DNA adduct inhibitory activity as the catechins or higher presumably due to the presence of more functional hydroxyl groups. To determine if the activity of these compounds was due to direct interaction of phenolic groups with electrophilic metabolite(s) of BP, DNA was incubated with anti-benzo[a]pyrene-7,8-diol-9,10-epoxide (anti-BPDE) (0.5 microM) in the presence of test compounds (200 microM) or vehicle. Significant inhibition of DNA adduct formation was found (tannic acid > pentagalloglucose > epigallocatechin gallate > epicatechin gallate). This notion was confirmed by analysis of the reaction products of anti-BPDE with the catechins and pentagalloglucose by electrospray ionization mass spectrometry and liquid chromatography-mass spectrometry. In conclusion, our data demonstrate that green tea catechins and the hydrolyzable tannins are highly effective in inhibiting BP-DNA adduct formation at least, in part, due to direct interaction of adjacent hydroxyl groups in their structures and that the activity is

  18. Effect of Green Tea Catechins and Hydrolyzable Tannins on Benzo[a]pyrene-Induced DNA Adducts and Structure–Activity Relationship

    PubMed Central

    Cao, Pengxiao; Cai, Jian; Gupta, Ramesh C.

    2016-01-01

    Green tea catechins and hydrolyzable tannins are gaining increasing attention as chemopreventive agents. However, their mechanism of action is poorly understood. We investigated the effects of four green tea catechins and two hydrolyzable tannins on microsome-induced benzo[a]pyrene (BP)–DNA adducts and the possible structure–activity relationship. BP (1 μM) was incubated with rat liver microsomes and DNA in the presence of the test compound (1–200 μM) or vehicle. The purified DNA was analyzed by 32P-postlabeling. The inhibitory activity of the catechins was in the following descending order: epigallocatechin gallate (IC50 = 16 μM) > epicatechin gallate (24 μM) > epigallocatechin (146 μM) > epicatechin (462 μM), suggesting a correlation between the number of adjacent aromatic hydroxyl groups in the molecular structure and their potencies. Tannic acid (IC50 = 4 μM) and pentagalloglucose (IC50 = 26 μM) elicited as much DNA adduct inhibitory activity as the catechins or higher presumably due to the presence of more functional hydroxyl groups. To determine if the activity of these compounds was due to direct interaction of phenolic groups with electrophilic metabolite(s) of BP, DNA was incubated with anti-benzo[a]pyrene-7,8-diol-9,10-epoxide (anti-BPDE) (0.5 μM) in the presence of test compounds (200 μM) or vehicle. Significant inhibition of DNA adduct formation was found (tannic acid > pentagalloglucose > epigallocatechin gallate > epicatechin gallate). This notion was confirmed by analysis of the reaction products of anti-BPDE with the catechins and pentagalloglucose by electrospray ionization mass spectrometry and liquid chromatography–mass spectrometry. In conclusion, our data demonstrate that green tea catechins and the hydrolyzable tannins are highly effective in inhibiting BP–DNA adduct formation at least, in part, due to direct interaction of adjacent hydroxyl groups in their structures and that the activity is higher with an increasing

  19. Anticandidal synergistic activity of green tea catechins, antimycotics and copper sulphate as a mean of combinational drug therapy against candidiasis.

    PubMed

    Anand, J; Rai, N

    2017-03-01

    The present investigation aims at evaluating synergistic herbal based composition of purified catechins with fluconazole, amphotericin B and copper sulphate against Candida albicans (MTCC 3017) and Candida glabrata (MTCC 3019). The catechins were isolated from green tea leaves of Assam, Himachal Pradesh and Uttarakhand regions of India. The synergistic activity of combinations against Candida species was assessed following microdilution checkerboard technique and time kill assay. The inhibitory action of most significant combination on treated Candida cells was assessed by scanning electron microscopy. Cytotoxicity of synergistic compositions was further analyzed by performing MTT assay on Vero cell lines. Purified catechins of Assam and Himachal Pradesh green tea showed synergistic activity with fluconazole and amphotericin B against Candida species. Time kill assay depicted synergistic activity at minimum inhibitory concentration and twice of minimum inhibitory concentration of purified catechins and antimycotics. Further, Copper sulphate increased anticandidal efficacy of synergistic combinations by 0.4% to 6.63%. SEM analysis revealed morphological distortions of treated Candida cells. Cytotoxicity analysis of synergistic composition depicted high percentage viability (≥91.4% to≥100%) of Vero cell line, which suggests non-cytotoxic activity of proposed composition on healthy cells. It can be inferred that present evaluated synergistic composition can confer promising anticandidal efficacy and requires further investigation of safety and translational guidelines for effective and safer green tea based potent therapeutic drug. Copyright © 2016. Published by Elsevier Masson SAS.

  20. Direct enantioseparation of catechin and epicatechin in tea drinks by 6-O-alpha-D-glucosyl-beta-cyclodextrin-modified micellar electrokinetic chromatography.

    PubMed

    Kodama, Shuji; Yamamoto, Atsushi; Matsunaga, Akinobu; Yanai, Hiroko

    2004-08-01

    Cyclodextrin-modified micellar electrokinetic chromatography was applied to the enantioseparation of catechin and epicatechin using 6-O-alpha-D-glucosyl-beta-cyclodextrin together with sodium dodecyl sulfate and borate-phosphate buffer. Factors affecting chiral resolution and migration time of catechin and epicatechin were studied. The optimum running conditions were found to be 200 mM borate-20 mM phosphate buffer (pH 6.4) containing 25 mM 6-O-alpha-D-glucosyl-beta-cyclodextrin and 240 mM sodium dodecyl sulfate with an effective voltage of +25 kV at 20 degrees C using direct detection at 210 nm. Under these conditions, the resolution (Rs) of racemic catechin and epicatechin were 4.15 and 1.92, respectively. With this system, catechin and epicatechin enantiomers along with other four catechins ((-)-catechin gallate, (-)-epicatechin gallate, (-)-epigallocatechin, (-)-epigallocatechin gallate) and caffeine in tea samples were analyzed successfully. The difference of migration time between catechin and epicatechin is discussed.

  1. Catechin prodrugs and analogs: a new array of chemical entities with improved pharmacological and pharmacokinetic properties.

    PubMed

    Bansal, Sumit; Vyas, Sandeep; Bhattacharya, Shoumyo; Sharma, Manu

    2013-10-11

    Extensive research on tea catechins, mainly (-)-epigallocatechin gallate, has shown numerous health promoting effects. However, various clinical studies demonstrated several issues associated with tea catechins which account for their poor systemic bioavailability. In order to improve pharmacological activity and bioavailability of natural tea catechins, two major strategies have been adopted to date which include synthesizing catechin analogs/prodrugs and the development of novel drug delivery systems. In this review, we provide a detailed account of novel synthetic analogs/prodrugs as well as novel drug delivery approaches used for natural tea catechins to make them therapeutically potent drug-like molecules.

  2. 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

  3. The efficacy of early treatment of seasonal allergic rhinitis with benifuuki green tea containing O-methylated catechin before pollen exposure: an open randomized study.

    PubMed

    Maeda-Yamamoto, Mari; Ema, Kaori; Monobe, Manami; Shibuichi, Ikuo; Shinoda, Yuki; Yamamoto, Tomohiro; Fujisawa, Takao

    2009-09-01

    We previously reported that 'benifuuki' green tea containing O-methylated catechin significantly relieved the symptoms of perennial or seasonal rhinitis compared with a placebo green tea that did not contain O-methylated catechin in randomized double-blind clinical trials. In this study we assessed the effects of 'benifuuki' green tea on clinical symptoms of seasonal allergic rhinitis. An open-label, single-dose, randomized, parallel-group study was performed on 38 subjects with Japanese cedar pollinosis. The subjects were randomly assigned to long-term (December 27, 2006-April 8, 2007, 1.5 months before pollen exposure) or short-term (February 15, 2007: after cedar pollen dispersal--April 8, 2007) drinking of a 'benifuuki' tea drink containing 34 mg O-methylated catechin per day. Each subject recorded their daily symptom scores in a diary. The primary efficacy variable was the mean weekly nasal symptom medication score during the study period. The nasal symptom medication score in the long-term intake group was significantly lower than that of the short-term intake group at the peak of pollen dispersal. The symptom scores for throat pain, nose-blowing, tears, and hindrance to activities of daily living were significantly better in the long-term group than the short-term group. In particular, the differences in the symptom scores for throat pain and nose-blowing between the 2 groups were marked. We conclude that drinking 'benifuuki' tea for 1.5 months prior to the cedar pollen season is effective in reducing symptom scores for Japanese cedar pollinosis.

  4. The Powdering Process with a Set of Ceramic Mills for Green Tea Promoted Catechin Extraction and the ROS Inhibition Effect.

    PubMed

    Fujioka, Kouki; Iwamoto, Takeo; Shima, Hidekazu; Tomaru, Keiko; Saito, Hideki; Ohtsuka, Masaki; Yoshidome, Akihiro; Kawamura, Yuri; Manome, Yoshinobu

    2016-04-11

    For serving green tea, there are two prominent methods: steeping the leaf or the powdered leaf (matcha style) in hot water. The purpose of the present study was to reveal chemical and functional differences before and after the powdering process of green tea leaf, since powdered green tea may contribute to expanding the functionality because of the different ingesting style. In this study, we revealed that the powdering process with a ceramic mill and stirring in hot water increased the average extracted concentration of epigallocatechin gallate (EGCG) by more than three times compared with that in leaf tea using high-performance liquid chromatography (HPLC) and liquid chromatography-tandem mass Spectrometry (LC-MS/MS) analyses. Moreover, powdered green tea has a higher inhibition effect of reactive oxygen species (ROS) production in vitro compared with the same amount of leaf tea. Our data suggest that powdered green tea might have a different function from leaf tea due to the higher catechin contents and particles.

  5. Protection of brain and pancreas from high-fat diet: effects of catechin and caffeine.

    PubMed

    Unno, Keiko; Yamamoto, Hiroyuki; Maeda, Ken-Ichi; Takabayashi, Fumiyo; Yoshida, Hirotoshi; Kikunaga, Naomi; Takamori, Nina; Asahina, Shunsuke; Iguchi, Kazuaki; Sayama, Kazutoshi; Hoshino, Minoru

    2009-02-16

    To investigate the effect of a high-fat diet on brain and pancreas functions, we used SAMP10 mice that have characteristics of brain atrophy and cognitive dysfunction with aging. Simultaneously, we investigated the effect of green tea catechin consumption on high-fat diet feeding, because green tea catechin has been reported to improve brain atrophy, brain dysfunction and obesity. The body weight of mice fed a high-fat diet from 2 to 12 months was higher than that of the control, although the calorie intake was not. The high-fat diet also increased insulin secretion; however, the hypersecretion of insulin and obesity were suppressed when mice were fed a high-fat diet with green tea catechin and caffeine. Furthermore, brain atrophy was suppressed and the working memory, tested using Y-maze, improved in mice fed a high-fat diet containing green tea catechin and caffeine. The secretion of insulin might affect both obesity and brain function. A strong correlation was found between working memory and insulin release in mice fed a high-fat diet with green tea catechin and/or caffeine. The results indicate the protective effect of green tea catechin and caffeine on the functions of brain and pancreas in mice fed a high-fat diet.

  6. Effect of green tea catechin, a local drug delivery system as an adjunct to scaling and root planing in chronic periodontitis patients: A clinicomicrobiological study

    PubMed Central

    Kudva, Praveen; Tabasum, Syeda Tawkhira; Shekhawat, Nirmal Kanwar

    2011-01-01

    Background: Evaluate the adjunctive use of locally delivered green tea catechin with scaling and root planing, as compared to scaling and root planing alone in the management of chronic periodontitis. Materials and Methods: Fourteen patients with two sites in the contralateral quadrants with probing pocket depth of 5–8mm were selected. Each of the sites was assessed for the plaque index, gingival index, and probing pocket depth at baseline and 21 days and for microbiological analysis at baseline, 1 week and 21 days. Test sites received scaling and root planing along with green tea catechin strips and control sites received scaling and root planning alone. Results: The result showed intercomparison of the plaque index and gingival index for test and control groups at 21 days was not significant with P>0.05, whereas the probing depth at 21 days was significant with P<0.001. Intercomparison between microbial results demonstrated a considerable reduction of occurrence of Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Fusobacterium species and Capnocytophaga in test. Conclusion: Green tea catechin local delivery along with scaling and root planing is more effective than scaling and root planing alone. PMID:21772720

  7. Dynamic calibration approach for determining catechins and gallic acid in green tea using LC-ESI/MS.

    PubMed

    Bedner, Mary; Duewer, David L

    2011-08-15

    Catechins and gallic acid are antioxidant constituents of Camellia sinensis, or green tea. Liquid chromatography with both ultraviolet (UV) absorbance and electrospray ionization mass spectrometric (ESI/MS) detection was used to determine catechins and gallic acid in three green tea matrix materials that are commonly used as dietary supplements. The results from both detection modes were evaluated with 14 quantitation models, all of which were based on the analyte response relative to an internal standard. Half of the models were static, where quantitation was achieved with calibration factors that were constant over an analysis set. The other half were dynamic, with calibration factors calculated from interpolated response factor data at each time a sample was injected to correct for potential variations in analyte response over time. For all analytes, the relatively nonselective UV responses were found to be very stable over time and independent of the calibrant concentration; comparable results with low variability were obtained regardless of the quantitation model used. Conversely, the highly selective MS responses were found to vary both with time and as a function of the calibrant concentration. A dynamic quantitation model based on polynomial data-fitting was used to reduce the variability in the quantitative results using the MS data.

  8. Quantitative comparison of cancer and normal cell adhesion using organosilane monolayer templates: an experimental study on the anti-adhesion effect of green-tea catechins.

    PubMed

    Sakamoto, Rumi; Kakinuma, Eisuke; Masuda, Kentaro; Takeuchi, Yuko; Ito, Kosaku; Iketaki, Kentaro; Matsuzaki, Takahisa; Nakabayashi, Seiichiro; Yoshikawa, Hiroshi Y; Yamamoto, Hideaki; Sato, Yuko; Tanii, Takashi

    2016-09-01

    The main constituent of green tea, (-)-Epigallocatechin-3-O-gallate (EGCG), is known to have cancer-specific chemopreventive effects. In the present work, we investigated how EGCG suppresses cell adhesion by comparing the adhesion of human pancreatic cancer cells (AsPC-1 and BxPC-3) and their counterpart, normal human embryonic pancreas-derived cells (1C3D3), in catechin-containing media using organosilane monolayer templates (OMTs). The purpose of this work is (1) to evaluate the quantitativeness in the measurement of cell adhesion with the OMT and (2) to show how green-tea catechins suppress cell adhesion in a cancer-specific manner. For the first purpose, the adhesion of cancer and normal cells was compared using the OMT. The cell adhesion in different type of catechins such as EGCG, (-)-Epicatechin-3-O-gallate (ECG) and (-)-Epicatechin (EC) was also evaluated. The measurements revealed that the anti-adhesion effect of green-tea catechins is cancer-specific, and the order is EGCG≫ECG>EC. The results agree well with the data reported to date, showing the quantitativeness of the new method. For the second purpose, the contact area of cells on the OMT was measured by reflection interference contrast microscopy. The cell-OMT contact area of cancer cells decreases with increasing EGCG concentration, whereas that of normal cells remains constant. The results reveal a twofold action of EGCG on cancer cell adhesion-suppressing cell attachment to a candidate adhesion site and decreasing the contact area of the cells-and validates the use of OMT as a tool for screening cancer cell adhesion.

  9. A green tea-containing starch confection increases plasma catechins without protecting against postprandial impairments in vascular function in normoglycemic adults.

    PubMed

    Sapper, Teryn N; Mah, Eunice; Ahn-Jarvis, Jennifer; McDonald, Joshua D; Chitchumroonchokchai, Chureeporn; Reverri, Elizabeth J; Vodovotz, Yael; Bruno, Richard S

    2016-09-14

    Postprandial hyperglycemia (PPH) increases cardiovascular disease risk regardless of glucose intolerance by transiently impairing vascular endothelial function (VEF) by limiting nitric oxide bioavailability in an oxidative stress-dependent manner. Preclinical studies show that green tea catechins attenuate PPH by inhibiting starch digestion. We hypothesized that a starch-based confection containing catechin-rich green tea extract (GTE) would limit PPH-mediated impairments in VEF in normoglycemic adults. We formulated a unique GTE confection and then conducted a double-blind, randomized, controlled, crossover study in healthy men (n = 15; 25.3 ± 1.0 years; 22.4 ± 1.8 kg m(-2)) in which they ingested starch confections (50 g carbohydrate) formulated with or without GTE (1 g) prior to evaluating sensory characteristics of confections and plasma glucose, biomarkers of lipid peroxidation and nitric oxide homeostasis, and brachial artery flow-mediated dilation (FMD) at 30 min intervals for 3 h. Sensory evaluation of confections indicated acceptable consumer appeal and an inability to distinguish between confections regardless of GTE. Plasma catechins concentrations increased following ingestion of the GTE confection. However, plasma glucose peaked at 60 min (P < 0.05) following confection ingestion and was unaffected throughout the postprandial period by the GTE confection (P > 0.05). FMD was significantly decreased only at 60 min regardless of confections containing GTE. Also at 60 min, both confections similarly increased plasma malondialdehyde while decreasing arginine and increasing asymmetric dimethylarginine/arginine. The successfully formulated GTE-containing confection effectively delivered catechins, but without mitigating PPH-mediated impairments in VEF in association with oxidative stress that likely limits nitric oxide bioavailability.

  10. 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.

  11. 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

  12. 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.

  13. Evaluation of the inhibitory effects of quercetin-related flavonoids and tea catechins on the monoamine oxidase-A reaction in mouse brain mitochondria.

    PubMed

    Bandaruk, Yauhen; Mukai, Rie; Kawamura, Tomoyuki; Nemoto, Hisao; Terao, Junji

    2012-10-17

    Quercetin, a typical dietary flavonoid, is thought to exert antidepressant effects by inhibiting the monoamine oxidase-A (MAO-A) reaction, which is responsible for regulation of the metabolism of the neurotransmitter 5-hydroxytryptamine (5-HT) in the brain. This study compared the MAO-A inhibitory activity of quercetin with those of O-methylated quercetin (isorhamnetin, tamarixetin), luteolin, and green tea catechins ((-)-epicatechin, (-)-epicatechin gallate, (-)-epigallocatechin, and (-)-epigallocatechin gallate) by measuring the formation of the oxidative deamination product of 5-HT, 5-hydroxyindole aldehyde (5-HIAL), in mouse brain mitochondria. Quercetin was inferior to luteolin in the inhibition of MAO-A activity, whereas isorhamnetin, tamarixetin, and tea catechins scarcely exerted inhibitory activity. Quercetin did not affect MAO-A activity in mouse intestinal mitochondria, indicating that it does not evoke side effects on the metabolism of dietary monoamines in the gut. These data suggest that quercetin is a weak (but safe) MAO-A inhibitor in the modulation of 5-HT levels in the brain.

  14. Green Tea Catechins Quench the Fluorescence of Bacteria-Conjugated Alexa Fluor Dyes

    PubMed Central

    Zhao, Lin; Li, Wei; Zhu, Shu; Tsai, Sheena; Li, Jianhua; Tracey, Kevin J.; Wang, Ping; Fan, Saijun; Sama, Andrew E.; Wang, Haichao

    2013-01-01

    Accumulating evidence suggests that Green tea polyphenolic catechins, especially the (-)-epigallocatechin gallate (EGCG), can be cross-linked to many proteins, and confer a wide range of anti-bacterial activities possibly by damaging microbial cytoplasmic lipids and proteins. At the doses that conferred protection against lethal polymicrobial infection (induced by cecal ligation and puncture), EGCG significantly reduced bacterial loads particularly in the liver and lung. To elucidate its bactericidal mechanisms, we determined whether EGCG affected the fluorescence intensities of bacteria-conjugated Alexa Fluor 488 or 594 dyes. When mixed with unconjugated Alexa Fluor 488 or 594 dyes, EGCG or analogs did not affect the fluorescence intensity of these dyes. In a sharp contrast, EGCG and some analogs (e.g., Catechin Gallate, CG), markedly reduced the fluorescence intensity of Gram-positive Staphylococcus aureus-conjugated Alexa 594 and Gram-negative Escherichia coli-conjugated Alexa 488. Interestingly, co-treatment with ethanol impaired the EGCG-mediated fluorescence quenching of the G+ S. aureus, but not of the G- E. coli-conjugated Alexa Flour dyes. In light of the notion that Alexa Fluor dyes can be quenched by aromatic amino acids, it is plausible that EGCG exerts anti-microbial activities possibly by altering microbial protein conformations and functions. This possibility can now be explored by screening other fluorescence-quenching agents for possible antimicrobial activities. PMID:24011199

  15. Green tea epigallo-catechin-galleate ameliorates the development of obliterative airway disease.

    PubMed

    Liang, Olin D; Kleibrink, Bjoern E; Schuette-Nuetgen, Katharina; Khatwa, Umakanth U; Mfarrej, Bechara; Subramaniam, Meera

    2011-09-01

    Lung transplantation has the worst outcome compared to all solid organ transplants due to chronic rejection known as obliterative bronchiolitis (OB). Pathogenesis of OB is a complex interplay of alloimmune-dependent and -independent factors, which leads to the development of inflammation, fibrosis, and airway obliteration that have been resistant to therapy. The alloimmune-independent inflammatory pathway has been the recent focus in the pathogenesis of rejection, suggesting that targeting this may offer therapeutic benefits. As a potent anti-inflammatory agent, epigallo-catechin-galleate (EGCG), a green tea catechin, has been very effective in ameliorating inflammation in a variety of diseases, providing the rationale for its use in this study in a murine heterotopic tracheal allograft model of OB. Mice treated with EGCG had reduced inflammation, with significantly less neutrophil and macrophage infiltration and significantly reduced fibrosis. On further investigation into the mechanisms, inflammatory cytokines keratinocyte (KC), interleukin-17 (IL-17), and tumor necrosis factor-α (TNF-α), involved in neutrophil recruitment, were reduced in the EGCG-treated mice. In addition, monocyte chemokine monocyte chemoattractant protein-1 (MCP-1) was significantly reduced by EGCG treatment. Antifibrotic cytokine interferon-γ-inducible protein-10 (IP-10) was increased and profibrotic cytokine transforming growth factor-β (TGF-β) was reduced, further characterizing the antifibrotic effects of EGCG. These findings suggest that EGCG has great potential in ameliorating the development of obliterative airway disease.

  16. Metabolic dependence of green tea on plucking positions revisited: a metabolomic study.

    PubMed

    Lee, Jang-Eun; Lee, Bum-Jin; Hwang, Jeong-Ah; Ko, Kwang-Sup; Chung, Jin-Oh; Kim, Eun-Hee; Lee, Sang-Jun; Hong, Young-Shick

    2011-10-12

    The dependence of global green tea metabolome on plucking positions was investigated through (1)H nuclear magnetic resonance (NMR) analysis coupled with multivariate statistical data set. Pattern recognition methods, such as principal component analysis (PCA) and orthogonal projection on latent structure-discriminant analysis (OPLS-DA), were employed for a finding metabolic discrimination among fresh green tea leaves plucked at different positions from young to old leaves. In addition to clear metabolic discrimination among green tea leaves, elevations in theanine, caffeine, and gallic acid levels but reductions in catechins, such as epicatechin (EC), epigallocatechin (EGC), epicatechin-3-gallate (ECG), and epigallocatechin-3-gallate (EGCG), glucose, and sucrose levels were observed, as the green tea plant grows up. On the other hand, the younger the green tea leaf is, the more theanine, caffeine, and gallic acid but the lesser catechins accumlated in the green tea leaf, revealing a reverse assocation between theanine and catechins levels due to incorporaton of theanine into catechins with growing up green tea plant. Moreover, as compared to the tea leaf, the observation of marked high levels of theanine and low levels of catechins in green tea stems exhibited a distinct tea plant metabolism between the tea leaf and the stem. This metabolomic approach highlights taking insight to global metabolic dependence of green tea leaf on plucking position, thereby providing distinct information on green tea production with specific tea quality.

  17. Green tea: A boon for periodontal and general health

    PubMed Central

    Chatterjee, Anirban; Saluja, Mini; Agarwal, Gunjan; Alam, Mahtab

    2012-01-01

    Green tea is particularly rich in health-promoting flavonoids (which account for 30% of the dry weight of a leaf), including catechins and their derivatives. The most abundant catechin in green tea is epigallocatechin-3-gallate, which is thought to play a pivotal role in the green tea's anticancer and antioxidant effects. Catechins should be considered right alongside of the better-known antioxidants like vitamins E and C as potent free radical scavengers and health-supportive for this reason. It has been suggested that green tea also promotes periodontal health by reducing inflammation, preventing bone resorption and limiting the growth of certain bacteria associated with periodontal diseases. PMID:23055579

  18. Effect of girdling at various positions of 'Huang Zhi Xiang' tea tree (Camellia sinensis) on the contents of catechins and starch in fresh leaf.

    PubMed

    Chen, Yulong; Jiang, Yueming; Shi, John; Xu, Xinlan; Yang, Shaoyu; Duan, Jun

    2011-06-01

    The contents of starch and catechins in the fresh leaf of 'Huang Zhi Xiang' Oolong tea trees girdled at the bottom, middle (on the big branches) and top (on the small branches) were determined. The study demonstrated that the starch contents from girdled trees were significantly higher (p<0.05) than that from non-girdled ones. Furthermore, the contents of (-)-epicatechin (EC), (-)-epigallocatechin (EGC), total catechins (TC) and simple catechins (SC) from girdled trees were significantly higher (p<0.05) than those from non-girdled ones. Especially, the contents of (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG) and catechin gallate (CG) from girdled at the middle were also significantly higher (p<0.05) than those from the non-girdled. The starch contents were negatively correlated with the contents of (-)-gallocatechin (GC), EC, SC, TC and EGC, while positively correlated with the contents of EGCG and CG in fresh shoots.

  19. Molecular binding of catechins to biomembranes:Relationship to biolgical activity

    USDA-ARS?s Scientific Manuscript database

    Molecular dynamics simulations were used to study the interactions of four catechins commonly found in tea with lipid bilayers of cell membranes. Experimental studies in the literature have shown that catechins are linked to beneficial health effects, specifically as they are related to interaction...

  20. Insight into Catechins Metabolic Pathways of Camellia sinensis Based on Genome and Transcriptome Analysis.

    PubMed

    Wang, Wenzhao; Zhou, Yihui; Wu, Yingling; Dai, Xinlong; Liu, Yajun; Qian, Yumei; Li, Mingzhuo; Jiang, Xiaolan; Wang, Yunsheng; Gao, Liping; Xia, Tao

    2018-04-25

    Tea is an important economic crop with a 3.02 Gb genome. It accumulates various bioactive compounds, especially catechins, which are closely associated with tea flavor and quality. Catechins are biosynthesized through the phenylpropanoid and flavonoid pathways, with 12 structural genes being involved in their synthesis. However, we found that in Camellia sinensis the understanding of the basic profile of catechins biosynthesis is still unclear. The gene structure, locus, transcript number, transcriptional variation, and function of multigene families have not yet been clarified. Our previous studies demonstrated that the accumulation of flavonoids in tea is species, tissue, and induction specific, which indicates that gene coexpression patterns may be involved in tea catechins and flavonoids biosynthesis. In this paper, we screened candidate genes of multigene families involved in the phenylpropanoid and flavonoid pathways based on an analysis of genome and transcriptome sequence data. The authenticity of candidate genes was verified by PCR cloning, and their function was validated by reverse genetic methods. In the present study, 36 genes from 12 gene families were identified and were accessed in the NCBI database. During this process, some intron retention events of the CsCHI and CsDFR genes were found. Furthermore, the transcriptome sequencing of various tea tissues and subcellular location assays revealed coexpression and colocalization patterns. The correlation analysis showed that CsCHIc, CsF3'H, and CsANRb expression levels are associated significantly with the concentration of soluble PA as well as the expression levels of CsPALc and CsPALf with the concentration of insoluble PA. This work provides insights into catechins metabolism in tea and provides a foundation for future studies.

  1. Safety assessment of green tea based beverages and dried green tea extracts as nutritional supplements.

    PubMed

    Dekant, Wolfgang; Fujii, Kenkichi; Shibata, Eiichiro; Morita, Osamu; Shimotoyodome, Akira

    2017-08-05

    The safety of green tea infusions and green tea extract (GTE)-based products is reviewed regarding catechins. Epigallocatechin 3-gallate (EGCG), the major catechin present in green tea, is suspected of being responsible for liver toxicity reported in humans consuming food supplements. Intake of EGCG with green tea infusions and GTE-based beverages is up to about 450mg EGCG/person/day in Europe and higher in Asia. Consumption of green tea is not associated with liver damage in humans, and green tea infusion and GTE-based beverages are considered safe in the range of historical uses. In animal studies, EGCG's potency for liver effects is highly dependent on conditions of administration. Use of NOAELs from bolus administration to derive a tolerable upper intake level applying the margin of safety concept results in acceptable EGCG-doses lower than those from one cup of green tea. NOAELs from toxicity studies applying EGCG with diet/split of the daily dose are a better point of departure for risk characterization. In clinical intervention studies, liver effects were not observed after intakes below 600mg EGCG/person/day. Thus, a tolerable upper intake level of 300mg EGCG/person/day is proposed for food supplements; this gives a twofold safety margin to clinical studies that did not report liver effects and a margin of safety of 100 to the NOAELs in animal studies with dietary administration of green tea catechins. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Green Tea as Inhibitor of the Intestinal Absorption of Lipids: Potential Mechanism for its Lipid-Lowering Effect1

    PubMed Central

    Koo, Sung I.; Noh, Sang K.

    2007-01-01

    Animal and epidemiological studies suggest that green tea catechins may reduce the risk of cardiovascular diseases (CHD). The health benefit of green tea has been attributed to its antioxidant and anti-inflammatory properties; however, considerable evidence suggests that green tea and its catechins may reduce the risk of CHD by lowering the plasma levels of cholesterol and triglyceride. Although the mechanism underlying such effect of green tea is yet to be determined, it is evident from in vitro and in vivo studies that green tea or catechins inhibit the intestinal absorption of dietary lipids. Studies in vitro indicate that green tea catechins, particularly EGCG, interfere with the emulsification, digestion, and micellar solubilization of lipids, critical steps involved in the intestinal absorption of dietary fat, cholesterol, and other lipids. Based on the observations, it is likely that green tea or its catechins lower the absorption and tissue accumulation of other lipophilic organic compounds. The available information strongly suggests that green tea or its catechins may be used as safe and effective lipid-lowering therapeutic agents. PMID:17296491

  3. Plasma pharmacokinetics of catechin metabolite 4'-O-Me-EGC in healthy humans.

    PubMed

    Renouf, Mathieu; Redeuil, Karine; Longet, Karin; Marmet, Cynthia; Dionisi, Fabiola; Kussmann, Martin; Williamson, Gary; Nagy, Kornél

    2011-10-01

    Tea is an infusion of the leaves of the Camellia sinensis plant and is the most widely consumed beverage in the world after water. Green tea contains significant amounts of polyphenol catechins and represents a promising dietary component to maintain health and well-being. Epidemiological studies indicate that polyphenol intake may have potential health benefits, such as, reducing the incidence of coronary heart disease, diabetes and cancer. While bioavailability of green tea bioactives is fairly well understood, some gaps still remain to be filled, especially the identification and quantification of conjugated metabolites in plasma, such as, sulphated, glucuronidated or methylated compounds. In the present study, we aimed to quantify the appearance of green tea catechins in plasma with particular emphasis on their methylated forms. After feeding 400 mL of green tea, 1.25% infusion to 9 healthy subjects, we found significant amounts of EC, EGC and EGCg in plasma as expected. EGC was the most bioavailable catechin, and its methylated form (4'-O-Me-EGC) was also present in quantifiable amounts. Its kinetics followed that of its parent compound. However, the relative amount of the methylated form of EGC was lower than that of the parent compound, an important aspect which, in the literature, has been controversial so far. The quantitative results presented in our study were confirmed by co-chromatography and accurate mass analysis of the respective standards. We show that the relative abundance of 4'-O-Me-EGC is ~40% compared to the parent EGC. 4'-O-Me-EGC is an important metabolite derived from catechin metabolism. Its presence in significant amounts should not be overlooked when assessing human bioavailability of green tea.

  4. Inhibitory effect of six green tea catechins and caffeine on the growth of four selected human tumor cell lines.

    PubMed

    Valcic, S; Timmermann, B N; Alberts, D S; Wächter, G A; Krutzsch, M; Wymer, J; Guillén, J M

    1996-06-01

    Green tea is an aqueous infusion of dried unfermented leaves of Camellia sinensis (family Theaceae) from which numerous biological activities have been reported including antimutagenic, antibacterial, hypocholesterolemic, antioxidant, antitumor and cancer preventive activities. From the aqueous-alcoholic extract of green tea leaves, six compounds (+)-gallocatechin (GC), (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin gallate (EGCG) and caffeine, were isolated and purified. Together with (+)-catechin, these compounds were tested against each of four human tumor cells lines (MCF-7 breast carcinoma, HT-29 colon carcinoma, A-427 lung carcinoma and UACC-375 melanoma). The three most potent green tea components against all four tumor cell lines were EGCG, GC and EGC. EGCG was the most potent of the seven green tea components against three out of the four cell lines (i.e. MCF-7 breast cancer, HT-29 colon cancer and UACC-375 melanoma). On the basis of these extensive in vitro studies, it would be of considerable interest to evaluate all three of these components in comparative preclinical in vivo animal tumor model systems before final decisions are made concerning which of these potential chemopreventive drugs should be taken into broad clinical trials.

  5. Catechin concentrates of garden tea leaves (Camellia sinensis L.): extraction/isolation and evaluation of chemical composition.

    PubMed

    Gadkari, Pravin Vasantrao; Kadimi, Udaya Sankar; Balaraman, Manohar

    2014-11-01

    Solid-liquid (SLE) and liquid-liquid (LLE) extraction techniques were applied to extract catechins and caffeine from quick mechanically expelled tea leaf juice (QMETLJ) and freeze-dried (FD)-QMETLJ of Camellia sinensis L. The concentrates obtained were analyzed for total polyphenol content and antioxidant activity (DPPH(•) inhibition, FRAP and phosphomolybdenum assay). Catechins were identified and quantified using HPLC. Overall, 95% (v/v) ethanol was the best solvent system for extracting total polyphenols (355.26 ± 23.68 to 457.89 ± 28.94 g GAE kg(-1) extractable solid yield (ESY)) and antioxidants (DPPH(•) inhibition, 16.97 ± 0.52 to 20.83 ± 3.11%; FRAP, 4.15 ± 0.32 to 6.38 ± 0.57 mmol TE g(-1) ESY; Mo(V) reduction, 2.47 ± 0.19 to 3.84 ± 0.39 mmol AAE g(-1) ESY) from FD-QMETLJ. Similarly, in LLE, ethyl acetate showed the best results for recovering polyphenols (960.52 ± 7.89 g GAE kg(-1) ESY) and antioxidants (DPPH(•) inhibition, 42.39 ± 0.91%; FRAP, 11.39 ± 0.83 mmol TE g(-1) ESY; Mo(V) reduction, 6.71 ± 1.14 mmol AAE g(-1) ESY) from QMETLJ. It was found that 95% ethanol can be used to increase the total polyphenols and antioxidants in extracts from FD-QMETLJ, while ethyl acetate can be effectively employed for concentrating catechins from QMETLJ. © 2014 Society of Chemical Industry.

  6. Metabolic Flux Redirection and Transcriptomic Reprogramming in the Albino Tea Cultivar ‘Yu-Jin-Xiang’ with an Emphasis on Catechin Production

    PubMed Central

    Liu, Guo-Feng; Han, Zhuo-Xiao; Feng, Lin; Gao, Li-Ping; Gao, Ming-Jun; Gruber, Margaret Y.; Zhang, Zhao-Liang; Xia, Tao; Wan, Xiao-Chun; Wei, Shu

    2017-01-01

    In this study, shade-induced conversion from a young pale/yellow leaf phenotype to a green leaf phenotype was studied using metabolic and transcriptomic profiling and the albino cultivar ‘Yu-Jin-Xiang’ (‘YJX’) of Camellia sinensis for a better understanding of mechanisms underlying the phenotype shift and the altered catechin and theanine production. Shaded leaf greening resulted from an increase in leaf chlorophyll and carotenoid abundance and chloroplast development. A total of 1,196 differentially expressed genes (DEGs) were identified between the ‘YJX’ pale and shaded green leaves, and these DEGs affected ‘chloroplast organization’ and ‘response to high light’ besides many other biological processes and pathways. Metabolic flux redirection and transcriptomic reprogramming were found in flavonoid and carotenoid pathways of the ‘YJX’ pale leaves and shaded green leaves to different extents compared to the green cultivar ‘Shu-Cha-Zao’. Enhanced production of the antioxidant quercetin rather than catechin biosynthesis was correlated positively with the enhanced transcription of FLAVONOL SYNTHASE and FLAVANONE/FLAVONOL HYDROXYLASES leading to quercetin accumulation and negatively correlated to suppressed LEUCOANTHOCYANIDIN REDUCTASE, ANTHOCYANIDIN REDUCTASE and SYNTHASE leading to catechin biosynthesis. The altered levels of quercetin and catechins in ‘YJX’ will impact on its tea flavor and health benefits. PMID:28332598

  7. A population-based, case–control study of green tea consumption and leukemia risk in southwestern Taiwan

    PubMed Central

    Yu, Chu-Ling; Liu, Chen-Yu; Wang, Su-Fen; Pan, Pi-Chen; Wu, Ming-Tsang; Ho, Chi-Kung; Lo, Yu-Shing; Li, Yi; Christiani, David C.

    2011-01-01

    Objective This study investigated the association between green tea consumption and leukemia. Methods A total of 252 cases (90.3% response) and 637 controls (53.4% response) were enrolled. Controls were matched for cases on age and gender. Information was collected on participants’ living habits, including tea consumption. Green tea was used as a standard to estimate the total amount of individual catechin consumption. We stratified individual consumption of catechins into four levels. Conditional logistic regression models were fit to subjects aged 0–15 and 16–29 years to evaluate separate associations between leukemia and catechin consumption. Results A significant inverse association between green tea consumption and leukemia risk was found in individuals aged 16–29 years, whereas no significant association was found in the younger age groups. For the older group with higher amounts of tea consumption (>550 units of catechins), the adjusted odds ratio (OR) compared with the group without tea consumption was 0.47 [95% confidence interval (CI) = 0.23–0.97]. After we adjusted for smoking status and medical irradiation exposure, the overall OR for all participants was 0.49 (95% CI = 0.27–0.91), indicating an inverse relation between large amounts of catechins and leukemia. Conclusion Drinking sufficient amounts of tea, especially green tea, which contains more catechins than oolong tea and black tea, may reduce the risk of leukemia. PMID:18752033

  8. Hyaluronic acid-green tea catechin micellar nanocomplexes: Fail-safe cisplatin nanomedicine for the treatment of ovarian cancer without off-target toxicity.

    PubMed

    Bae, Ki Hyun; Tan, Susi; Yamashita, Atsushi; Ang, Wei Xia; Gao, Shu Jun; Wang, Shu; Chung, Joo Eun; Kurisawa, Motoichi

    2017-12-01

    The green tea catechin, (-)-epigallocatechin-3-O-gallate (EGCG), has gained significant attention as a potent adjuvant to enhance the antitumor efficacy of cisplatin while mitigating its harmful side effects. Herein we report the development of a fail-safe cisplatin nanomedicine constructed with hyaluronic acid-EGCG conjugate for ovarian cancer therapy. A simple mixing of this conjugate and cisplatin induces spontaneous self-assembly of micellar nanocomplexes having a spherical core-shell structure. The surface-exposed hyaluronic acid enables efficient delivery of cisplatin into CD44-overexpressing cancer cells via receptor-mediated endocytosis whereas the internally packed EGCG moieties offer an environment favorable for the encapsulation of cisplatin. In addition, the antioxidant effect of EGCG moieties ensures fail-safe protection against off-target organ toxicity originating from cisplatin-evoked oxidative stress. Pharmacokinetic and biodistribution studies reveal the prolonged blood circulation and preferential tumor accumulation of intravenously administered nanocomplexes. Moreover, the nanocomplexes exhibit superior antitumor efficacy over free cisplatin while displaying no toxicity in both a subcutaneous xenograft model and peritoneal metastatic model of human ovarian cancer. Our findings demonstrate proof of concept for the feasibility of green tea catechin-based micellar nanocomplexes as a safe and effective cisplatin nanomedicine for ovarian cancer treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Preventive effects of C-2 epimeric isomers of tea catechins on mouse type I allergy.

    PubMed

    Yoshino, Kyoji; Miyase, Toshio; Sano, Mitsuaki

    2010-01-01

    The preventive effects of C-2 epimeric isomers of (-)-epigallocatechin-3-O-gallate (EGCG) and the O-methylated derivative, (-)-epigallocatechin-3-O-(3-O-methyl)gallate (EGCG3''Me), against ovalbumin-induced type I allergy in male mice were investigated. EGCG and EGCG3''Me exhibited strong antiallergic effects by oral administration at doses of 25 and 50 mg/kg body weight. The antiallergic effects of their C-2 epimers, (-)-gallocatechin-3-O-gallate and (-)-gallocatechin-3-O-(3-O-methyl)gallate (GCG3''Me), on mouse type I allergy were almost equivalent to and/or as strong as those of the corresponding original catechins, respectively. Oral administration of these compounds at a dose of 50 mg/kg body weight tended to suppress the increases in interleukin-4 levels in the abdominal walls of allergic mice and immunoglobulin E levels in the serum of allergic mice. In particular, the administration of GCG3''Me exhibited significant effects on the production and/or release of these parameters stimulating type 2 T helper cells and mast cells in the type I allergic process. These results indicated that C-2 epimerization of tea catechins, which are produced during heat processing at high temperatures, would not be disadvantageous for preventive effects on type I allergy.

  10. [Effectiveness of green tea catechines for the correction of the alimentary obesity in the experiment].

    PubMed

    Chanadiri, T; Sanikidze, T; Esaishvili, M; Chkhikvishvili, I; Datunashvili, I

    2005-09-01

    Obesity is one of the most important problems of the modern medicine. The immobile life-style and consumption of high-calorie food are the most remarkable risk-factors of the obesity, which in presence of genetic predisposition contribute to the increasing of the body weight. In the modern literature there are numerous data about the important role of free radical oxidation in the pathogenesis of the obesity. In this relation application of natural antioxidants for the purpose of the correction of excess weight has gained an active research interest. Numerous researches showed natural antioxidants to be effective in correction of elevated blood cholesterol, triglycerides and LDL levels. In this relation the purpose of our research was to investigate effectiveness of green tea catechizes on lipid metabolism disorder, antioxidant status and excess body weight during experimental alimentary obesity. Experiment was conducted on rats kept on high-calorie diet for 7 weeks. Simultaneously one group of animals had been administered catechines in addition to the high-calorie diet during last 4 weeks. The experiment established corrective effect of catechines on the parameters of lipid metabolism (blood cholesterol, triglyceride and LDL levels), epididymal fat mass and antioxidant enzymes activity. Obtained results may be important for the development of weight losing diets.

  11. [Chemical studies on plant polyphenols and formation of black tea polyphenols].

    PubMed

    Tanaka, Takashi

    2008-08-01

    Recent biological and pharmacological studies strongly suggested that plant polyphenols in foods, beverages and crude drugs have various health benefits. However, still there are chemically uncharacterized polyphenols, especially those with large molecular weights. The typical example is black tea polyphenols. Four tea catechins of fresh tea leaves are enzymatically oxidized in tea fermentation process of black tea manufacture to give a complex mixture of the oxidation products. Despite many efforts since 1950's, major part of the black tea polyphenols has not been clarified yet. We have investigated the oxidation mechanism of each catechin by employing a newly developed in vitro model fermentation system. The oxidation was initiated by enzymatic dehydrogenation of catechins, and subsequent intermolecular quinone-phenol coupling reactions followed by cascade-type degradation of the unstable products resulted in the formation of complex black tea polyphenols. Besides black tea polyphenols, this review introduces the chemistry of insolubilization of persimmon proanthocyanidins, wood polyphenols in connection with whisky polyphenols, and co-polymerization of cinnamaldehyde and proanthocyanidins in cinnamon bark.

  12. 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.

  13. Orthogonal analytical methods for botanical standardization: Determination of green tea catechins by qNMR and LC-MS/MS

    PubMed Central

    Napolitano, José G.; Gödecke, Tanja; Lankin, David C.; Jaki, Birgit U.; McAlpine, James B.; Chen, Shao-Nong; Pauli, Guido F.

    2013-01-01

    The development of analytical methods for parallel characterization of multiple phytoconstituents is essential to advance the quality control of herbal products. While chemical standardization is commonly carried out by targeted analysis using gas or liquid chromatography-based methods, more universal approaches based on quantitative 1H NMR (qHNMR) measurements are being used increasingly in the multi-targeted assessment of these complex mixtures. The present study describes the development of a 1D qHNMR-based method for simultaneous identification and quantification of green tea constituents. This approach utilizes computer-assisted 1H iterative Full Spin Analysis (HiFSA) and enables rapid profiling of seven catechins in commercial green tea extracts. The qHNMR results were cross-validated against quantitative profiles obtained with an orthogonal LC-MS/MS method. The relative strengths and weaknesses of both approaches are discussed, with special emphasis on the role of identical reference standards in qualitative and quantitative analyses. PMID:23870106

  14. Spontaneously Assembled Nano-aggregates in Clear Green Tea Infusions from Camellia ptilophylla and Camellia sinensis.

    PubMed

    Lin, Xiaorong; Gao, Xiong; Chen, Zhongzheng; Zhang, Yuanyuan; Luo, Wei; Li, Xiaofei; Li, Bin

    2017-05-10

    Tea nano-aggregates spontaneously assembled in clear tea infusions are considered as the precursors of tea cream, although their molecular basis remains obscure. Here, we characterized nano-aggregates in green tea infusions from Camellia ptilophylla, a peculiar tea variety with 6.0% of theobromine, and Camellia sinensis as the control for comparative purpose. Numerous negatively charged spherical colloidal particles of 50-100 nm in diameter were primarily found in both green tea infusions. Catechins, proteins, and carbohydrates were confirmed as the dominant components in green tea nano-aggregates. In addition, iron, copper, nickel, proteins, and gallated catechins exhibited higher aggregating affinity than other components, whereas methylxanthines and calcium contributed to the transformation of nano-aggregates into tea cream. Green tea nano-aggregates were partly destroyed by simulated gastrointestinal digestion, and removing theses peculiar particles dramatically attenuated the bioaccessibility of methylxanthines, theanine, and some catechin monomers in green tea infusions. This study enhanced our knowledge of molecular interactions in the formation of green tea cream and provided insight into physicochemical profiles, phytochemical nature, and functional effects of green tea nano-aggregates.

  15. The safety of green tea and green tea extract consumption in adults - Results of a systematic review.

    PubMed

    Hu, Jiang; Webster, Donna; Cao, Joyce; Shao, Andrew

    2018-06-01

    A systematic review of published toxicology and human intervention studies was performed to characterize potential hazards associated with consumption of green tea and its preparations. A review of toxicological evidence from laboratory studies revealed the liver as the target organ and hepatotoxicity as the critical effect, which was strongly associated with certain dosing conditions (e.g. bolus dose via gavage, fasting), and positively correlated with total catechin and epigallocatechingallate (EGCG) content. A review of adverse event (AE) data from 159 human intervention studies yielded findings consistent with toxicological evidence in that a limited range of concentrated, catechin-rich green tea preparations resulted in hepatic AEs in a dose-dependent manner when ingested in large bolus doses, but not when consumed as brewed tea or extracts in beverages or as part of food. Toxico- and pharmacokinetic evidence further suggests internal dose of catechins is a key determinant in the occurrence and severity of hepatotoxicity. A safe intake level of 338 mg EGCG/day for adults was derived from toxicological and human safety data for tea preparations ingested as a solid bolus dose. An Observed Safe Level (OSL) of 704 mg EGCG/day might be considered for tea preparations in beverage form based on human AE data. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  16. The Tea Tree Genome Provides Insights into Tea Flavor and Independent Evolution of Caffeine Biosynthesis.

    PubMed

    Xia, En-Hua; Zhang, Hai-Bin; Sheng, Jun; Li, Kui; Zhang, Qun-Jie; Kim, Changhoon; Zhang, Yun; Liu, Yuan; Zhu, Ting; Li, Wei; Huang, Hui; Tong, Yan; Nan, Hong; Shi, Cong; Shi, Chao; Jiang, Jian-Jun; Mao, Shu-Yan; Jiao, Jun-Ying; Zhang, Dan; Zhao, Yuan; Zhao, You-Jie; Zhang, Li-Ping; Liu, Yun-Long; Liu, Ben-Ying; Yu, Yue; Shao, Sheng-Fu; Ni, De-Jiang; Eichler, Evan E; Gao, Li-Zhi

    2017-06-05

    Tea is the world's oldest and most popular caffeine-containing beverage with immense economic, medicinal, and cultural importance. Here, we present the first high-quality nucleotide sequence of the repeat-rich (80.9%), 3.02-Gb genome of the cultivated tea tree Camellia sinensis. We show that an extraordinarily large genome size of tea tree is resulted from the slow, steady, and long-term amplification of a few LTR retrotransposon families. In addition to a recent whole-genome duplication event, lineage-specific expansions of genes associated with flavonoid metabolic biosynthesis were discovered, which enhance catechin production, terpene enzyme activation, and stress tolerance, important features for tea flavor and adaptation. We demonstrate an independent and rapid evolution of the tea caffeine synthesis pathway relative to cacao and coffee. A comparative study among 25 Camellia species revealed that higher expression levels of most flavonoid- and caffeine- but not theanine-related genes contribute to the increased production of catechins and caffeine and thus enhance tea-processing suitability and tea quality. These novel findings pave the way for further metabolomic and functional genomic refinement of characteristic biosynthesis pathways and will help develop a more diversified set of tea flavors that would eventually satisfy and attract more tea drinkers worldwide. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Nε-(carboxymethyl)lysine and Nε-(carboxyethyl)lysine in tea and the factors affecting their formation.

    PubMed

    Jiao, Ye; He, Jialiang; Li, Fengli; Tao, Guanjun; Zhang, Shuang; Zhang, Shikang; Qin, Fang; Zeng, Maomao; Chen, Jie

    2017-10-01

    The levels of N ε -(carboxymethyl)lysine (CML) and N ε -(carboxyethyl)lysine (CEL) in 99 tea samples from 14 geographic regions, including 44 green, 7 oolong, 41 black, and 7 dark teas were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The CML and CEL contents varied from 11.0 to 1701μg/g tea and 4.6 to 133μg/g tea, respectively. Dark tea presented the highest levels of CML and CEL, whereas green and oolong teas presented the lowest levels. Five kinds of catechins in the tea were also analyzed, and spearman's correlation coefficients showed that all the catechins negatively correlated with CML and CEL. The results suggested that withering, fermentation and pile fermentation may facilitate the formation of CML and CEL. Catechins might inhibit the formation of CML and CEL, but their inhibitory effects may be affected by tea processing. The results of this study are useful for the production of healthier tea. Copyright © 2017. Published by Elsevier Ltd.

  18. Interactions of tea tannins and condensed tannins with proteins.

    PubMed

    Frazier, Richard A; Deaville, Eddie R; Green, Rebecca J; Stringano, Elisabetta; Willoughby, Ian; Plant, John; Mueller-Harvey, Irene

    2010-01-20

    Binding parameters for the interactions of four types of tannins: tea catechins, grape seed proanthocyanidins, mimosa 5-deoxy proanthocyanidins, and sorghum procyanidins (mDP=17), with gelatin and bovine serum albumin (BSA) have been determined from isothermal titration calorimetry data. Equilibrium binding constants determined for the interaction with gelatin were in the range 10(4) to 10(6) M(-1) and in the order: sorghum procyanidins > grape seed proanthocyanidins > mimosa 5-deoxy proanthocyanidins > tea catechins. Interaction with BSA was generally weaker, with equilibrium binding constants of < or =10(3)M(-1) for grape seed proanthocyanidins, mimosa 5-deoxy proanthocyanidins and tea catechins, and 10(4)M(-1) for the sorghum procyanidins. In all cases the interactions with proteins were exothermic and involved multiple binding sites on the protein. The data are discussed in relation to the structures and the known nutritional effects of the condensed tannins.

  19. 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

  20. [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.

  1. 'Benifuuki' green tea containing o-methylated catechin reduces symptoms of Japanese cedar pollinosis: a randomized, double-blind, placebo-controlled trial.

    PubMed

    Masuda, Sawako; Maeda-Yamamoto, Mari; Usui, Satoko; Fujisawa, Takao

    2014-06-01

    Methylated catechin, one of the active ingredients in green tea, has been reported to ameliorate allergic reactions. We evaluated the efficacy of 'Benifuuki' green tea, which contains O-methylated epigallocatechin-3-O-[3-O-methyl] gallate (O-methylated EGCG), in alleviating Japanese cedar pollinosis (JCP). The study was a double-blind, randomized, placebo-controlled trial. The subjects with JCP were randomly assigned to drink 700ml of 'Benifuuki' green tea containing O-methylated EGCG or 'Yabukita' green tea (not containing O-methylated EGCG) as a placebo every day from December 2007 through March 2008, which includes the pollen season. The primary outcome was the area under the curve (AUC) of symptom scores during the peak pollen season. Fifty-one adults with JCP participated in the study. Twenty-six subjects were assigned to 'Benifuuki' and 25 to 'Yabukita'. The AUC of symptom score during the peak pollen season in the 'Benifuuki' group was significantly smaller than in the 'Yabukita' group for each of runny nose, itchy eyes, tearing, total nasal symptom score, total ocular symptom score, nasal symptom-medication score and ocular symptom-medication score. The total QOL-related questionnaire score for one week in the peak pollen season was significantly better in the 'Benifuuki' group. Increase in the peripheral eosinophil count in response to pollen exposure was suppressed in the 'Benifuuki' group. No adverse events were reported in either group. 'Benifuuki' green tea containing a large amount of O-methylated EGCG reduced the symptoms of JCP and has potential as a complementary/alternative medicine for treating seasonal allergic rhinitis.

  2. Quantitative analysis of major constituents in green tea with different plucking periods and their antioxidant activity.

    PubMed

    Lee, Lan-Sook; Kim, Sang-Hee; Kim, Young-Boong; Kim, Young-Chan

    2014-07-01

    The objective of this study was to determine the relationship between the plucking periods and the major constituents and the antioxidant activity in green tea. Green tea was prepared from leaves plucked from the end of April 2013 to the end of May 2013 at intervals of one week or longer. The contents of theanine, theobromine, caffeine, catechin (C), and gallocatechin gallate (GCg) were significantly decreased, whereas those of epicatechin (EC), epigallocatechin gallate (EGCg) and epigallocatechin (EGC) were significantly increased along with the period of tea leaf plucking. In addition, antioxidant activity of green tea and standard catechins was investigated using ABTS, FRAP and DPPH assays. The highest antioxidant activity was observed in relatively the oldest leaf, regardless of the assay methods used. Additionally, the order of antioxidant activity of standard catechins was as follows: EGCg≥GCg≥ECg>EGC≥GC≥EC≥C. Moreover, the cis-catechins contents were the key factor affecting the antioxidant activity of green tea in all assays employed (ABTS, r=0.731, p<0.01; FRAP, r=0.886, p<0.01; DPPH, r=0.778, p<0.01).

  3. Polyphenolic chemistry of tea and coffee: a century of progress.

    PubMed

    Wang, Yu; Ho, Chi-Tang

    2009-09-23

    Tea and coffee, the most popular beverages in the world, have been consumed for thousands of years for their alluring flavors and health benefits. Polyphenols, particularly flavonoids and phenolic acids, are of great abundance in tea and coffee and contribute a lot to their flavor and health properties. This paper reviews the polyphenol chemistry of tea and coffee, specifically their stability, and scavenging ability of reactive oxygen species (ROS) and reactive carbonyl species (RCS). During the manufacturing and brewing process, green tea and black tea polyphenols undergo epimerization and oxidation, respectively. Meanwhile, the lactonization and the polymerization of chlorogenic acid are the major causes for the degradation of polyphenols in coffee. Tea catechins, besides having antioxidant properties, have the novel characteristic of trapping reactive carbonyl species. The A ring of the catechins is the binding site for RCS trapping, whereas the B ring is the preferred site for antioxidation.

  4. Safety and anti-hyperglycemic efficacy of various tea types in mice

    PubMed Central

    Han, Manman; Zhao, Guangshan; Wang, Yijun; Wang, Dongxu; Sun, Feng; Ning, Jingming; Wan, Xiachun; Zhang, Jinsong

    2016-01-01

    Tea, a beverage consumed worldwide, has proven anti-hyperglycemic effects in animal models. Better efficacies of tea beverages are frequently associated with high-dose levels, whose safety attracts considerable attention. Based on the inherent nature of tea catechin oxidation, fresh tea leaves are manufactured into diverse tea types by modulating the oxidation degree of catechins. The present study aimed to assess various tea types for their safety properties and anti-hyperglycemic effects. Mice were allowed free access to tea infusion (1:30, w/v) for one week, and the rare smoked tea caused salient adverse reactions, including hepatic and gastrointestinal toxicities; meanwhile, the widely-consumed green and black teas, unlike the rare yellow tea, suppressed growth in fast-growing healthy mice. When mice were fed a high-fat diet and allowed free access to tea infusion (1:30, w/v) for 25 days, only yellow tea significantly reduced blood glucose. Therefore, various teas showed different safety profiles as well as anti-hyperglycemic efficacy strengths. To achieve an effective and safe anti-hyperglycemic outcome, yellow tea, which effectively suppressed high-fat diet-induced early elevation of hepatic thioredoxin-interacting protein, is an optimal choice. PMID:27531374

  5. Effect of the type of brewing water on the chemical composition, sensory quality and antioxidant capacity of Chinese teas.

    PubMed

    Xu, Yong-Quan; Zou, Chun; Gao, Ying; Chen, Jian-Xin; Wang, Fang; Chen, Gen-Sheng; Yin, Jun-Feng

    2017-12-01

    The physicochemical characteristics, sensory quality, and antioxidant activity of tea infusions prepared with purified water (PW), mineral water (MW), mountain spring water (MSW), and tap water (TW) from Hangzhou were investigated. The results showed that the taste quality, catechin concentration, and antioxidant capacity of green, oolong, and black tea infusions prepared using MW and TW were significantly lower than those prepared using PW. Extraction of catechins and caffeine was reduced with high-conductivity water, while high pH influenced the stability of catechins. PW and MSW were more suitable for brewing green and oolong teas, while MSW, with low pH and moderate ion concentration, was the most suitable water for brewing black tea. Lowering the pH of mineral water partially improved the taste quality and increased the concentration of catechins in the infusions. These results aid selection of the most appropriate water for brewing Chinese teas. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Alkaloid and polyphenol analysis by HPLC in green and black tea powders and their potential use as additives in ruminant diets

    NASA Astrophysics Data System (ADS)

    Ramdani, Diky; Chaudhry, Abdul S.; Seal, Chris J.

    2018-02-01

    We used HPLC to examine the bioactive compounds such as alkaloids and polyphenols in green and black tea powders and their use as potential additives in ruminant diets. Caffeine was the highest alkaloid in both green and black teas. Green tea had significantly higher concentrations of alkaloids and catechins but lower theaflavins than black tea. Epigallocatechin gallate, epicatechin gallate and epigallocatechin were the major catechins in green tea while theaflavin-3, 3'-digallate and theaflavin-3-gallate were the major theaflavins in black tea. Tea powders in ruminant diets decreased in vitro rumen ammonia and methane production without affecting volatile fatty acid profiles and the degradability of the diets. The tea powders containing variable amounts of alkaloids, catechins and theaflavins can potentially be used to decrease rumen ammonia and methane productions without any detrimental effect on rumen functions in vitro and perhaps ruminant productive efficiency.

  7. Determination of catechins and caffeine in camillia sinensis raw materials, extracts, and dietary supplements by HPLC-uv: single-laboratory validation.

    PubMed

    Roman, Mark C

    2013-01-01

    A rapid method has been developed to quantify seven catechins and caffeine in green tea (Camillia sinensis) raw material and powdered extract, and dietary supplements containing green tea extract. The method utilizes RP HPLC with a phenyl-based stationary phase and gradient elution. Detection is by UV absorbance. The total run time, including column re-equilibration, is 13 min. Single-laboratory validation (SLV) has been performed on the method to determine the repeatability, accuracy, selectivity, LOD, LOQ, ruggedness, and linearity for (+)-catechin, (-)-epicatechin, (-)-epicatechin gallate, (-)-epigallocatechin, (-)-gallocatechin gallate, (-)-epigallocatechin gallate, and (+)-gallocatechin, as well as caffeine. Repeatability precision and recovery results met AOAC guidelines for SLV studies for all catechins and caffeine down to a level of approximately 20 mg/g. Finished products containing high concentrations of minerals require the use of EDTA to prevent decomposition of the catechins.

  8. Antioxidant and Cytoprotective Effects of Tibetan Tea and Its Phenolic Components.

    PubMed

    Xie, Hong; Li, Xican; Ren, Zhenxing; Qiu, Weimin; Chen, Jianlan; Jiang, Qian; Chen, Ban; Chen, Dongfeng

    2018-01-24

    Tibetan tea (Kangzhuan) is an essential beverage of the Tibetan people. In this study, a lyophilized aqueous extract of Tibetan tea ( LATT ) was prepared and analyzed by HPLC. The results suggested that there were at least five phenolic components, including gallic acid, and four catechins (i.e., (+)-catechin, (-)-catechin gallate ( CG ), (-)-epicatechin gallate ( ECG ), and (-)-epigallocatechin gallate). Gallic acid, the four catechins, and LATT were then comparatively investigated by four antioxidant assays: ferric reducing antioxidant power, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical (PTIO•) scavenging, 1,1-diphenyl-2-picryl-hydrazl radical scavenging, and 2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) radical scavenging assays. In these assays, LATT, along with the five phenolic components, increased their antioxidant effects in a concentration-dependent manner; however, the half maximal scavenging concentrations of ECG were always lower than those of CG . Gallic acid and the four catechins were also suggested to chelate Fe 2+ based on UV-visible spectral analysis. Ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) analysis suggested that, when mixed with PTIO•, the five phenolic components could yield two types of radical adduct formation (RAF) products (i.e., tea phenolic dimers and tea phenolic-PTIO• adducts). In a flow cytometry assay, (+)-catechin and LATT was observed to have a cytoprotective effect towards oxidative-stressed bone marrow-derived mesenchymal stem cells. Based on this evidence, we concluded that LATT possesses antioxidative or cytoprotective properties. These effects may mainly be attributed to the presence of phenolic components, including gallic acid and the four catechins. These phenolic components may undergo electron transfer, H⁺-transfer, and Fe 2+ -chelating pathways to exhibit antioxidative or

  9. Bactericidal catechins damage the lipid bilayer.

    PubMed

    Ikigai, H; Nakae, T; Hara, Y; Shimamura, T

    1993-04-08

    The mode of antibacterial action of, the green tea (Camellia sinensis) extracts, (-)-epigallocatechin gallate (EGCg) and (-)-epicatechin (EC) was investigated. Strong bactericidal EGCg caused leakage of 5,6-carboxyfluorescein from phosphatidylcholine liposomes (PC), but EC with very weak bactericidal activity caused little damage to the membrane. Phosphatidylserine and dicetyl phosphate partially protected the membrane from EGCg-mediated damage when reconstituted into the liposome membrane with PC. EGCg, but not EC, caused strong aggregation and NPN-fluorescence quenching of PC-liposomes and these actions were markedly lowered in the presence of negatively charged lipids. These results show that bactericidal catechins primarily act on and damage bacterial membranes. The observation that Gram-negative bacteria are more resistant to bactericidal catechins than Gram-positive bacteria can be explained to some extent by the presence of negatively charged lipopolysaccharide.

  10. Green tea flavour determinants and their changes over manufacturing processes.

    PubMed

    Han, Zhuo-Xiao; Rana, Mohammad M; Liu, Guo-Feng; Gao, Ming-Jun; Li, Da-Xiang; Wu, Fu-Guang; Li, Xin-Bao; Wan, Xiao-Chun; Wei, Shu

    2016-12-01

    Flavour determinants in tea infusions and their changes during manufacturing processes were studied using Camellia sinensis cultivars 'Bai-Sang Cha' ('BAS') possessing significant floral scents and 'Fuding-Dabai Cha' ('FUD') with common green tea odour. Metabolite profiling based on odour activity threshold revealed that 'BAS' contained higher levels of the active odorants β-ionone, linalool and its two oxides, geraniol, epoxylinalool, decanal and taste determinant catechins than 'FUD' (p<0.05). Enhanced transcription of some terpenoid and catechin biosynthetic genes in 'BAS' suggested genetically enhanced production of those flavour compounds. Due to manufacturing processes, the levels of linalool and geraniol decreased whereas those of β-ionone, linalool oxides, indole and cis-jasmone increased. Compared with pan-fire treatment, steam treatment reduced the levels of catechins and proportion of geraniol, linalool and its derivatives, consequently, reducing catechin-related astringency and monoterpenol-related floral scent. Our study suggests that flavour determinant targeted modulation could be made through genotype and manufacturing improvements. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. 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.

  12. 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.

  13. Functional characterization of proanthocyanidin pathway enzymes from tea and their application for metabolic engineering.

    PubMed

    Pang, Yongzhen; Abeysinghe, I Sarath B; He, Ji; He, Xianzhi; Huhman, David; Mewan, K Mudith; Sumner, Lloyd W; Yun, Jianfei; Dixon, Richard A

    2013-03-01

    Tea (Camellia sinensis) is rich in specialized metabolites, especially polyphenolic proanthocyanidins (PAs) and their precursors. To better understand the PA pathway in tea, we generated a complementary DNA library from leaf tissue of the blister blight-resistant tea cultivar TRI2043 and functionally characterized key enzymes responsible for the biosynthesis of PA precursors. Structural genes encoding enzymes involved in the general phenylpropanoid/flavonoid pathway and the PA-specific branch pathway were well represented in the library. Recombinant tea leucoanthocyanidin reductase (CsLAR) expressed in Escherichia coli was active with leucocyanidin as substrate to produce the 2R,3S-trans-flavan-ol (+)-catechin in vitro. Two genes encoding anthocyanidin reductase, CsANR1 and CsANR2, were also expressed in E. coli, and the recombinant proteins exhibited similar kinetic properties. Both converted cyanidin to a mixture of (+)-epicatechin and (-)-catechin, although in different proportions, indicating that both enzymes possess epimerase activity. These epimers were unexpected based on the belief that tea PAs are made from (-)-epicatechin and (+)-catechin. Ectopic expression of CsANR2 or CsLAR led to the accumulation of low levels of PA precursors and their conjugates in Medicago truncatula hairy roots and anthocyanin-overproducing tobacco (Nicotiana tabacum), but levels of oligomeric PAs were very low. Surprisingly, the expression of CsLAR in tobacco overproducing anthocyanin led to the accumulation of higher levels of epicatechin and its glucoside than of catechin, again highlighting the potential importance of epimerization in flavan-3-ol biosynthesis. These data provide a resource for understanding tea PA biosynthesis and tools for the bioengineering of flavanols.

  14. Volatile and non-volatile compounds in green tea affected in harvesting time and their correlation to consumer preference.

    PubMed

    Kim, Youngmok; Lee, Kwang-Geun; Kim, Mina K

    2016-10-01

    Current study was designed to find out how tea harvesting time affects the volatile and non-volatile compounds profiles of green tea. In addition, correlation of instrumental volatile and non-volatile compounds analyses to consumer perception were analyzed. Overall, earlier harvested green tea had stronger antioxidant capacity (~61.0%) due to the polyphenolic compounds from catechin (23,164 mg/L), in comparison to later harvested green teas (11,961 mg/L). However, high catechin content in green tea influenced negatively the consumer likings of green tea, due to high bitterness (27.6%) and astringency (13.4%). Volatile compounds drive consumer liking of green tea products were also identified, that included linalool, 2,3-methyl butanal, 2-heptanone, (E,E)-3,5-Octadien-2-one. Finding from current study are useful for green tea industry as it provide the difference in physiochemical properties of green tea harvested at different intervals.

  15. Draft genome sequence of Camellia sinensis var. sinensis provides insights into the evolution of the tea genome and tea quality

    PubMed Central

    Wei, Chaoling; Yang, Hua; Wang, Songbo; Zhao, Jian; Liu, Chun; Gao, Liping; Xia, Enhua; Lu, Ying; Tai, Yuling; She, Guangbiao; Sun, Jun; Cao, Haisheng; Tong, Wei; Gao, Qiang; Li, Yeyun; Deng, Weiwei; Jiang, Xiaolan; Wang, Wenzhao; Chen, Qi; Zhang, Shihua; Li, Haijing; Wu, Junlan; Wang, Ping; Li, Penghui; Shi, Chengying; Zheng, Fengya; Jian, Jianbo; Huang, Bei; Shan, Dai; Shi, Mingming; Fang, Congbing; Yue, Yi; Li, Fangdong; Li, Daxiang; Wei, Shu; Han, Bin; Jiang, Changjun; Yin, Ye; Xia, Tao; Zhang, Zhengzhu; Bennetzen, Jeffrey L.; Zhao, Shancen; Wan, Xiaochun

    2018-01-01

    Tea, one of the world’s most important beverage crops, provides numerous secondary metabolites that account for its rich taste and health benefits. Here we present a high-quality sequence of the genome of tea, Camellia sinensis var. sinensis (CSS), using both Illumina and PacBio sequencing technologies. At least 64% of the 3.1-Gb genome assembly consists of repetitive sequences, and the rest yields 33,932 high-confidence predictions of encoded proteins. Divergence between two major lineages, CSS and Camellia sinensis var. assamica (CSA), is calculated to ∼0.38 to 1.54 million years ago (Mya). Analysis of genic collinearity reveals that the tea genome is the product of two rounds of whole-genome duplications (WGDs) that occurred ∼30 to 40 and ∼90 to 100 Mya. We provide evidence that these WGD events, and subsequent paralogous duplications, had major impacts on the copy numbers of secondary metabolite genes, particularly genes critical to producing three key quality compounds: catechins, theanine, and caffeine. Analyses of transcriptome and phytochemistry data show that amplification and transcriptional divergence of genes encoding a large acyltransferase family and leucoanthocyanidin reductases are associated with the characteristic young leaf accumulation of monomeric galloylated catechins in tea, while functional divergence of a single member of the glutamine synthetase gene family yielded theanine synthetase. This genome sequence will facilitate understanding of tea genome evolution and tea metabolite pathways, and will promote germplasm utilization for breeding improved tea varieties. PMID:29678829

  16. [Antibacterial and anti-hemolysin activities of tea catechins and their structural relatives].

    PubMed

    Toda, M; Okubo, S; Ikigai, H; Shimamura, T

    1990-03-01

    Among catechins tested, (-)epigallocatechin (EGC), (-)epicatechin gallate (ECg), (-) epigallocatechin gallate (EGCg) inhibited the growth of Staphylococcus aureus, Vibrio cholerae O1 classical Inaba 569B and El Tor Inaba V86. S. aureus was more sensitive than V. cholerae O1 to these compounds. EGCg showed also a bactericidal activity against V. cholerae O1 569B. Pyrogallol showed a stronger antibacterial activity against S. aureus and V. cholerae O1 than tannic and gallic acid. Rutin or caffein had no effect on them. ECg and EGCg showed the most potent anti-hemolysin activity against S. aureus alpha-toxin, Vibrio parahaemolyticus thermostable direct hemolysin (Vp-TDH) and cholera hemolysin. Among catechin relatives, only tannic acid had a potent anti-hemolysin activity against alpha-toxin. These results suggest that the catechol and pyrogallol groups are responsible for the antibacterial and bactericidal activities, while the conformation of catechins might play an important role in the anti-hemolysin activity.

  17. 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...

  18. A combination of (+)-catechin and (-)-epicatechin underlies the in vitro adipogenic action of Labrador tea (Rhododendron groenlandicum), an antidiabetic medicinal plant of the Eastern James Bay Cree pharmacopeia.

    PubMed

    Eid, Hoda M; Ouchfoun, Meriem; Saleem, Ammar; Guerrero-Analco, Jose A; Walshe-Roussel, Brendan; Musallam, Lina; Rapinski, Michel; Cuerrier, Alain; Martineau, Louis C; Arnason, John T; Haddad, Pierre S

    2016-02-03

    Rhododendron groenlandicum (Oeder) Kron & Judd (Labrador tea) was identified as an antidiabetic plant through an ethnobotanical study carried out with the close collaboration of Cree nations of northern Quebec in Canada. In a previous study the plant showed glitazone-like activity in a 3T3-L1 adipogenesis bioassay. The current study sought to identify the active compounds responsible for this potential antidiabetic activity using bioassay guided fractionation based upon an in vitro assay that measures the increase of triglycerides content in 3T3-L1 adipocyte. Isolation and identification of the crude extract's active constituents was carried out. The 80% ethanol extract was fractionated using silica gel column chromatography. Preparative HPLC was then used to isolate the constituents. The identity of the isolated compounds was confirmed by UV and mass spectrometry. Nine chemically distinct fractions were obtained and the adipogenic activity was found in fraction 5 (RGE-5). Quercetins, (+)-catechin and (-)-epicatechin were detected and isolated from this fraction. While (+)-catechin and (-)-epicatechin stimulated adipogenesis (238±26% and 187±21% relative to vehicle control respectively) at concentrations equivalent to their concentrations in the active fraction RGE-5, none afforded biological activity similar to RGE-5 or the plant's crude extract when used alone. When cells were incubated with a mixture of the two compounds, the adipogenic activity was close to that of the crude extract (280.7±27.8 vs 311± 30%). Results demonstrate that the mixture of (+)-catechin and (-)-epicatechin is responsible for the adipogenic activity of Labrador tea. This brings further evidence for the antidiabetic potential of R. groenlandicum and provides new opportunities to profile active principles in biological fluids or in traditional preparations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Nutraceutical Approach for Preventing Obesity-Related Colorectal and Liver Carcinogenesis

    PubMed Central

    Shimizu, Masahito; Kubota, Masaya; Tanaka, Takuji; Moriwaki, Hisataka

    2012-01-01

    Obesity and its related metabolic abnormalities, including insulin resistance, alterations in the insulin-like growth factor-1 (IGF-1)/IGF-1 receptor (IGF-1R) axis, and the state of chronic inflammation, increase the risk of colorectal cancer (CRC) and hepatocellular carcinoma (HCC). However, these findings also indicate that the metabolic disorders caused by obesity might be effective targets to prevent the development of CRC and HCC in obese individuals. Green tea catechins (GTCs) possess anticancer and chemopreventive properties against cancer in various organs, including the colorectum and liver. GTCs have also been known to exert anti-obesity, antidiabetic, and anti-inflammatory effects, indicating that GTCs might be useful for the prevention of obesity-associated colorectal and liver carcinogenesis. Further, branched-chain amino acids (BCAA), which improve protein malnutrition and prevent progressive hepatic failure in patients with chronic liver diseases, might be also effective for the suppression of obesity-related carcinogenesis because oral supplementation with BCAA reduces the risk of HCC in obese cirrhotic patients. BCAA shows these beneficial effects because they can improve insulin resistance. Here, we review the detailed relationship between metabolic abnormalities and the development of CRC and HCC. We also review evidence, especially that based on our basic and clinical research using GTCs and BCAA, which indicates that targeting metabolic abnormalities by either pharmaceutical or nutritional intervention may be an effective strategy to prevent the development of CRC and HCC in obese individuals. PMID:22312273

  20. 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.

  1. Plasma appearance and correlation between coffee and green tea metabolites in human subjects.

    PubMed

    Renouf, Mathieu; Guy, Philippe; Marmet, Cynthia; Longet, Karin; Fraering, Anne-Lise; Moulin, Julie; Barron, Denis; Dionisi, Fabiola; Cavin, Christophe; Steiling, Heike; Williamson, Gary

    2010-12-01

    Coffee and green tea are two of the most widely consumed hot beverages in the world. Their respective bioavailability has been studied separately, but absorption of their respective bioactive phenolics has not been compared. In a randomised cross-over design, nine healthy subjects drank instant coffee and green tea. Blood samples were collected over 12 h and at 24 h to assess return to baseline. After green tea consumption, (-)-epigallocatechin (EGC) was the major catechin, appearing rapidly in the plasma; (-)-EGC gallate (EGCg) and (-)-epicatechin (EC) were also present, but (-)-EC gallate and C were not detected. Dihydroferulic acid and dihydrocaffeic acid were the major metabolites that appeared after coffee consumption with a long time needed to reach maximum plasma concentration, suggesting metabolism and absorption in the colon. Other phenolic acid equivalents (caffeic acid (CA), ferulic acid (FA) and isoferulic acid (iFA)) were detected earlier, and they peaked at lower concentrations. Summations of the plasma area under the curves (AUC) for the measured metabolites showed 1.7-fold more coffee-derived phenolic acids than green tea-derived catechins (P = 0.0014). Furthermore, we found a significant correlation between coffee metabolites based on AUC. Inter-individual differences were observed, but individuals with a high level of CA also showed a correspondingly high level of FA. However, no such correlation was observed between the tea catechins and coffee phenolic acids. Correlation between AUC and maximum plasma concentration was also significant for CA, FA and iFA and for EGCg. This implies that the mechanisms of absorption for these two classes of compounds are different, and that a high absorber of phenolic acids is not necessarily a high absorber of catechins.

  2. Blood brain barrier permeability of (-)-epigallocatechin gallate, its proliferation-enhancing activity of human neuroblastoma SH-SY5Y cells, and its preventive effect on age-related cognitive dysfunction in mice.

    PubMed

    Pervin, Monira; Unno, Keiko; Nakagawa, Aimi; Takahashi, Yuu; Iguchi, Kazuaki; Yamamoto, Hiroyuki; Hoshino, Minoru; Hara, Aya; Takagaki, Akiko; Nanjo, Fumio; Minami, Akira; Imai, Shinjiro; Nakamura, Yoriyuki

    2017-03-01

    The consumption of green tea catechins (GTCs) suppresses age-related cognitive dysfunction in mice. GTCs are composed of several catechins, of which epigallocatechin gallate (EGCG) is the most abundant, followed by epigallocatechin (EGC). Orally ingested EGCG is hydrolyzed by intestinal biota to EGC and gallic acid (GA). To understand the mechanism of action of GTCs on the brain, their permeability of the blood brain barrier (BBB) as well as their effects on cognitive function in mice and on nerve cell proliferation in vitro were examined. The BBB permeability of EGCG, EGC and GA was examined using a BBB model kit. SAMP10, a mouse model of brain senescence, was used to test cognitive function in vivo . Human neuroblastoma SH-SY5Y cells were used to test nerve cell proliferation and differentiation. The in vitro BBB permeability (%, in 30 min) of EGCG, EGC and GA was 2.8±0.1, 3.4±0.3 and 6.5±0.6, respectively. The permeability of EGCG into the BBB indicates that EGCG reached the brain parenchyma even at a very low concentration. The learning ability of SAMP10 mice that ingested EGCG (20 mg/kg) was significantly higher than of mice that ingested EGC or GA. However, combined ingestion of EGC and GA showed a significant improvement comparable to EGCG. SH-SY5Y cell growth was significantly enhanced by 0.05 µM EGCG, but this effect was reduced at higher concentrations. The effect of EGC and GA was lower than that of EGCG at 0.05 µM. Co-administration of EGC and GA increased neurite length more than EGC or GA alone. Cognitive dysfunction in mice is suppressed after ingesting GTCs when a low concentration of EGCG is incorporated into the brain parenchyma via the BBB. Nerve cell proliferation/differentiation was enhanced by a low concentration of EGCG. Furthermore, the additive effect of EGC and GA suggests that EGCG sustains a preventive effect after the hydrolysis to EGC and GA.

  3. Draft genome sequence of Camellia sinensis var. sinensis provides insights into the evolution of the tea genome and tea quality.

    PubMed

    Wei, Chaoling; Yang, Hua; Wang, Songbo; Zhao, Jian; Liu, Chun; Gao, Liping; Xia, Enhua; Lu, Ying; Tai, Yuling; She, Guangbiao; Sun, Jun; Cao, Haisheng; Tong, Wei; Gao, Qiang; Li, Yeyun; Deng, Weiwei; Jiang, Xiaolan; Wang, Wenzhao; Chen, Qi; Zhang, Shihua; Li, Haijing; Wu, Junlan; Wang, Ping; Li, Penghui; Shi, Chengying; Zheng, Fengya; Jian, Jianbo; Huang, Bei; Shan, Dai; Shi, Mingming; Fang, Congbing; Yue, Yi; Li, Fangdong; Li, Daxiang; Wei, Shu; Han, Bin; Jiang, Changjun; Yin, Ye; Xia, Tao; Zhang, Zhengzhu; Bennetzen, Jeffrey L; Zhao, Shancen; Wan, Xiaochun

    2018-05-01

    Tea, one of the world's most important beverage crops, provides numerous secondary metabolites that account for its rich taste and health benefits. Here we present a high-quality sequence of the genome of tea, Camellia sinensis var. sinensis (CSS), using both Illumina and PacBio sequencing technologies. At least 64% of the 3.1-Gb genome assembly consists of repetitive sequences, and the rest yields 33,932 high-confidence predictions of encoded proteins. Divergence between two major lineages, CSS and Camellia sinensis var. assamica (CSA), is calculated to ∼0.38 to 1.54 million years ago (Mya). Analysis of genic collinearity reveals that the tea genome is the product of two rounds of whole-genome duplications (WGDs) that occurred ∼30 to 40 and ∼90 to 100 Mya. We provide evidence that these WGD events, and subsequent paralogous duplications, had major impacts on the copy numbers of secondary metabolite genes, particularly genes critical to producing three key quality compounds: catechins, theanine, and caffeine. Analyses of transcriptome and phytochemistry data show that amplification and transcriptional divergence of genes encoding a large acyltransferase family and leucoanthocyanidin reductases are associated with the characteristic young leaf accumulation of monomeric galloylated catechins in tea, while functional divergence of a single member of the glutamine synthetase gene family yielded theanine synthetase. This genome sequence will facilitate understanding of tea genome evolution and tea metabolite pathways, and will promote germplasm utilization for breeding improved tea varieties. Copyright © 2018 the Author(s). Published by PNAS.

  4. Validation of AN Hplc-Dad Method for the Classification of Green Teas

    NASA Astrophysics Data System (ADS)

    Yu, Jingbo; Ye, Nengsheng; Gu, Xuexin; Liu, Ni

    A reversed phase high performance liquid chromatography (RP-HPLC) separation coupled with diode array detection (DAD) and electrospray ionization mass spectrometer (ESI/MS) was developed and optimized for the classification of green teas. Five catechins [epigallocatechin (EGC), epigallocatechin gallate (EGCG), epicatechin (EC), gallocatechin gallate (GCG), epicatechin gallate (ECG)] had been identified and quantified by the HPLC-DAD-ESI/MS/MS method. The limit of detection (LOD) of five catechins was within the range of 1.25-15 ng. All the analytes exhibited good linearity up to 2500 ng. These compounds were considered as chemical descriptors to define groups of green teas. Chemometric methods including principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied for the purpose. Twelve green tea samples originating from different regions were subjected to reveal the natural groups. The results showed that the analyzed green teas were differentiated mainly by provenance; HCA afforded an excellent performance in terms of recognition and prediction abilities. This method was accurate and reproducible, providing a potential approach for authentication of green teas.

  5. Metabolic phenotyping of various tea (Camellia sinensis L.) cultivars and understanding of their intrinsic metabolism.

    PubMed

    Ji, Hyang-Gi; Lee, Yeong-Ran; Lee, Min-Seuk; Hwang, Kyeong Hwan; Kim, Eun-Hee; Park, Jun Seong; Hong, Young-Shick

    2017-10-15

    Recently, we selected three tea (Camellia sinensis) cultivars that are rich in taste, epigallocatechin-3-O-gallate (EGCG) and epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG3″Me) and then cultivated them through asexual propagation by cutting in the same region. In the present study, proton nuclear magnetic resonance ( 1 H NMR)-based metabolomics was applied to characterize the metabotype and to understand the metabolic mechanism of these tea cultivars including wild type tea. Of the tea leaf metabolite variations, reverse associations of amino acid metabolism with catechin compound metabolism were found in the rich-taste, and EGCG- and EGCG3″Me-rich tea cultivars. Indeed, the metabolism of individual catechin compounds in the EGCG3″Me-rich cultivar differed from those of other tea cultivars. The current study highlights the distinct metabolism of various tea cultivars newly selected for cultivation and the important role of metabolomics in understanding the metabolic mechanism. Thus, comprehensive metabotyping is a useful method to assess and then develop a new plant cultivar. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. 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.

  7. Regulation of matrix metalloproteinase secretion by green tea catechins in a three-dimensional co-culture model of macrophages and gingival fibroblasts.

    PubMed

    Morin, Marie-Pierre; Grenier, Daniel

    2017-03-01

    Elevated levels of matrix metalloproteinases (MMPs) have been associated with the active phases of tissue and bone destruction in periodontitis, an inflammatory disease characterized by a significant breakdown of tooth support. In the present study, we used a three-dimensional (3D) co-culture model of macrophages and gingival fibroblasts to investigate the ability of a green tea extract and its major constituent epigallocatechin-3-gallate (EGCG) to regulate the secretion of MMP-3, -8, and -9. The 3D co-culture model was composed of gingival fibroblasts embedded in a type I collagen matrix overlaid with macrophages. Two arbitrary ratios were tested. The ratio composed of 1 macrophage to 10 fibroblasts was used to mimic a slightly inflamed periodontal site while the ratio composed of 10 macrophages to 1 fibroblast was used to mimic a severely inflamed periodontal site. The 3D co-culture model was pre-treated for 2h with either the green tea extract or EGCG. It was then stimulated with Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS). The model was also first stimulated with LPS for 2h and then incubated with the green tea extract or EGCG. The concentrations of secreted MMP-3, -8, and -9 were quantified by enzyme-linked immunoassays. When the 3D co-culture model was stimulated with A. actinomycetemcomitans LPS, the 10:1 ratio of macrophages to gingival fibroblasts was associated with a highest secretion of MMP-3 and -9 and, to a lesser extent, MMP-8, than the 1:10 ratio. Non-cytotoxic concentrations of the green tea extract or EGCG reduced the basal secretion levels of all three MMPs. A 2-h treatment with the green tea extract or EGCG prior to the stimulation with LPS resulted in a dose-dependent decrease in MMP secretion, with MMP-9 showing the most significant decrease. A decrease in MMP secretion was also observed when the green tea extract or EGCG was added following a 2-h stimulation with LPS. Our results suggested that green tea catechins, and more

  8. Preparative isolation and purification of theaflavins and catechins by high-speed countercurrent chromatography.

    PubMed

    Wang, Kunbo; Liu, Zhonghua; Huang, Jian-an; Dong, Xinrong; Song, Lubing; Pan, Yu; liu, Fang

    2008-05-15

    High-speed countercurrent chromatography (HSCCC) has been applied for the separation of theaflavins and catechins. The HSCCC run was carried out with a two-phase solvent system composed of hexane-ethyl acetate-methanol-water-acetic acid (1:5:1:5:0.25, v/v) by eluting the lower aqueous phase at 2 ml/min at 700 rpm. The results indicated that pure theaflavin, theaflavins-3-gallate, theaflavins-3'-gallate and theaflavin-3,3'-digallate could be obtained from crude theaflavins sample and black tea. The structures of the isolated compounds were positively confirmed by (1)H NMR and (13)C NMR, MS analysis, HPLC data and TLC data. Meanwhile, catechins including epigallocatechin gallate, gallocatechin gallate, epicatechin gallate and epigallocatechin were isolated from the aqueous extract of green tea by using the same solvent system. This study developed a modified method combined with enrichment theaflavins method by using HSCCC for separation of four individual theaflavins, especially for better separation of theaflavins monogallates.

  9. Functional Characterization of Proanthocyanidin Pathway Enzymes from Tea and Their Application for Metabolic Engineering1[W][OA

    PubMed Central

    Pang, Yongzhen; Abeysinghe, I. Sarath B.; He, Ji; He, Xianzhi; Huhman, David; Mewan, K. Mudith; Sumner, Lloyd W.; Yun, Jianfei; Dixon, Richard A.

    2013-01-01

    Tea (Camellia sinensis) is rich in specialized metabolites, especially polyphenolic proanthocyanidins (PAs) and their precursors. To better understand the PA pathway in tea, we generated a complementary DNA library from leaf tissue of the blister blight-resistant tea cultivar TRI2043 and functionally characterized key enzymes responsible for the biosynthesis of PA precursors. Structural genes encoding enzymes involved in the general phenylpropanoid/flavonoid pathway and the PA-specific branch pathway were well represented in the library. Recombinant tea leucoanthocyanidin reductase (CsLAR) expressed in Escherichia coli was active with leucocyanidin as substrate to produce the 2R,3S-trans-flavan-ol (+)-catechin in vitro. Two genes encoding anthocyanidin reductase, CsANR1 and CsANR2, were also expressed in E. coli, and the recombinant proteins exhibited similar kinetic properties. Both converted cyanidin to a mixture of (+)-epicatechin and (−)-catechin, although in different proportions, indicating that both enzymes possess epimerase activity. These epimers were unexpected based on the belief that tea PAs are made from (−)-epicatechin and (+)-catechin. Ectopic expression of CsANR2 or CsLAR led to the accumulation of low levels of PA precursors and their conjugates in Medicago truncatula hairy roots and anthocyanin-overproducing tobacco (Nicotiana tabacum), but levels of oligomeric PAs were very low. Surprisingly, the expression of CsLAR in tobacco overproducing anthocyanin led to the accumulation of higher levels of epicatechin and its glucoside than of catechin, again highlighting the potential importance of epimerization in flavan-3-ol biosynthesis. These data provide a resource for understanding tea PA biosynthesis and tools for the bioengineering of flavanols. PMID:23288883

  10. Association of (+)-catechin and catechin-(4a-8)-catechin with oligopeptides

    Treesearch

    Tsutomu Hatano; Richard W. Hemingway

    1996-01-01

    NOE studies on the complexation of (poly)flavanoids with peptides containing proline residues in aqueous solutions reveal site specific approach directed by hydrophobic interaction of the aromatic rings of catechin and its dimer, catechin-(4α→8)-catechin, to conformationally accessible regions of peptides without strong preferencef or interaction...

  11. Evaluation of New Cleanup Agents for Analysis of Pesticide Residues in Tea.

    PubMed

    Ueda, Yuko; Honda, Katsuhisa

    2017-01-01

    We evaluated the effectiveness of new cleanup agents (S-NH 2 and S-Si) compared with other previously reported cleanup agents (octadecylsilane, graphitized carbon, aminopropyl and silica gel) for removal of interfering substances such as catechin and caffeine prior to analysis of pesticide residues in tea. S-NH 2 and S-Si were highly efficient in removal of catechin and caffeine, respectively. Recoveries of 80 pesticides using S-NH 2 and S-Si were tested, and more than 70% of pesticides showed recovery greater than 70%. These results indicate that S-NH 2 and S-Si agents will be useful for analysis of pesticide residues in tea.

  12. Green tea supplementation affects body weight, lipids, and lipid peroxidation in obese subjects with metabolic syndrome.

    PubMed

    Basu, Arpita; Sanchez, Karah; Leyva, Misti J; Wu, Mingyuan; Betts, Nancy M; Aston, Christopher E; Lyons, Timothy J

    2010-02-01

    To compare the effects of supplementation of green tea beverage or green tea extracts with controls on body weight, glucose and lipid profile, biomarkers of oxidative stress, and safety parameters in obese subjects with metabolic syndrome. Randomized, controlled prospective trial. General Clinical Research Center (GCRC) at University of Oklahoma Health Sciences Center (OUHSC). Thirty-five subjects with obesity and metabolic syndrome were recruited in age- and gender-matched trios and were randomly assigned to the control (4 cups water/d), green tea (4 cups/d), or green tea extract (2 capsules and 4 cups water/d) group for 8 weeks. The tea and extract groups had similar dosing of epiogallocatechin-3-gallate (EGCG), the active compound in green tea. Anthropometrics, blood pressure, fasting glucose and lipids, nuclear magnetic resonance (NMR)-based lipid particle size, safety parameters, biomarkers of oxidative stress (oxidized low-density lipoprotein [LDL], myeloperoxidase [MPO], malondialdehyde and hydroxynonenals [MDA and HNE]), and free catechins were analyzed at screen and at 4 and 8 weeks of the study. Pairwise comparisons showed green tea beverage and green tea extracts caused a significant decrease in body weight and body mass index (BMI) versus controls at 8 weeks (-2.5 +/- 0.7 kg, p < 0.01, and -1.9 +/- 0.6, p < 0.05, respectively). Green tea beverage showed a decreasing trend in LDL-cholesterol and LDL/high-density lipoprotein (HDL) versus controls (p < 0.1). Green tea beverage also significantly decreased MDA and HNE (-0.39 +/- 0.06 microM, p < 0.0001) versus controls. Plasma free catechins were detectable in both beverage and extract groups versus controls at screen and at 8 weeks, indicating compliance and bioavailability of green tea catechins. Green tea beverage consumption (4 cups/d) or extract supplementation (2 capsules/d) for 8 weeks significantly decreased body weight and BMI. Green tea beverage further lowered lipid peroxidation versus age- and

  13. Efficient extraction strategies of tea (Camellia sinensis) biomolecules.

    PubMed

    Banerjee, Satarupa; Chatterjee, Jyotirmoy

    2015-06-01

    Tea is a popular daily beverage worldwide. Modulation and modifications of its basic components like catechins, alkaloids, proteins and carbohydrate during fermentation or extraction process changes organoleptic, gustatory and medicinal properties of tea. Through these processes increase or decrease in yield of desired components are evident. Considering the varied impacts of parameters in tea production, storage and processes that affect the yield, extraction of tea biomolecules at optimized condition is thought to be challenging. Implementation of technological advancements in green chemistry approaches can minimize the deviation retaining maximum qualitative properties in environment friendly way. Existed extraction processes with optimization parameters of tea have been discussed in this paper including its prospects and limitations. This exhaustive review of various extraction parameters, decaffeination process of tea and large scale cost effective isolation of tea components with aid of modern technology can assist people to choose extraction condition of tea according to necessity.

  14. [Progress in research for pharmacological effects of Pu-erh tea].

    PubMed

    Gu, Xiao-Pan; Pan, Bo; Wu, Zhen; Zhao, Yun-Fang; Tu, Peng-Fei; Zheng, Jiao

    2017-06-01

    Pu-erh tea has gradually aroused general concern with social development and people's enhanced awareness of health. Pu-erh tea is rich in multiple active constitute such as flavonoids, catechins, phenolic acids, flavanols polymer, purine alkaloids, and hydrolysable tannin as a microbial-fermented tea.It is reported that Pu-erh tea have a variety of pharmacologically activities, such as anti-hyperlipidemic, anti-diabetic, anti-oxidative, anti-tumor, anti-bacterial, anti-inflammatory, and anti-viral effects. In this paper, the main pharmacological effects of Pu-erh tea are reviewed. We wish this work will provide some references and clues for further research of Pu-erh tea. Copyright© by the Chinese Pharmaceutical Association.

  15. Enrichment of Biscuits with Matcha Green Tea Powder: Its Impact on Consumer Acceptability and Acute Metabolic Response

    PubMed Central

    Phongnarisorn, Benjapor; Orfila, Caroline; Holmes, Melvin; Marshall, Lisa J.

    2018-01-01

    Matcha green tea powder (MGTP) is made with finely ground green tea leaves that are rich in phytochemicals, most particularly catechins. Shortbread biscuits were enriched with MGTP and evaluated for consumer acceptability and potential functional health properties. Baking decreased the content of total catechins by 19% compared to dough, although epimerization increased the amount of (+)-gallocatechin gallate at the expense of other catechins such as (−)-epigallocatechin gallate. Consumer acceptability tests using a 9-point hedonic scale showed that consumers preferred enriched biscuits with low content of MGTP (2 g of MGTP 100 g−1 of flour), and an increase of sugar content did not significantly improve the acceptability of MGTP-enriched biscuits. Overall, enrichment of biscuits with MGTP did not significantly affect the postprandial glucose or triglyceride response (area under curve) compared to non-enriched biscuits consumed with water or MGTP drink. Enriching biscuits with Matcha green tea is acceptable to consumers, but may not bring significant postprandial effects. PMID:29389844

  16. Enrichment of Biscuits with Matcha Green Tea Powder: Its Impact on Consumer Acceptability and Acute Metabolic Response.

    PubMed

    Phongnarisorn, Benjapor; Orfila, Caroline; Holmes, Melvin; Marshall, Lisa J

    2018-02-01

    Matcha green tea powder (MGTP) is made with finely ground green tea leaves that are rich in phytochemicals, most particularly catechins. Shortbread biscuits were enriched with MGTP and evaluated for consumer acceptability and potential functional health properties. Baking decreased the content of total catechins by 19% compared to dough, although epimerization increased the amount of (+)-gallocatechin gallate at the expense of other catechins such as (-)-epigallocatechin gallate. Consumer acceptability tests using a 9-point hedonic scale showed that consumers preferred enriched biscuits with low content of MGTP (2 g of MGTP 100 g -1 of flour), and an increase of sugar content did not significantly improve the acceptability of MGTP-enriched biscuits. Overall, enrichment of biscuits with MGTP did not significantly affect the postprandial glucose or triglyceride response (area under curve) compared to non-enriched biscuits consumed with water or MGTP drink. Enriching biscuits with Matcha green tea is acceptable to consumers, but may not bring significant postprandial effects.

  17. Simultaneous preparation of naturally abundant and rare catechins by tannase-mediated biotransformation combining high speed counter current chromatography.

    PubMed

    Xia, Guobin; Hong, Shan; Liu, Songbai

    2014-05-15

    Simultaneous preparation of naturally rare catechins, EGC and EC, has been realized by tannase-mediated biotransformation combining high speed counter current chromatography. In addition, simultaneous preparation of the four catechins, EGCG, ECG, EGC, and EC in green tea extract has also been achieved by HSCCC under the normal phase and the reversed phase modes. The identity of the catechins was determined by HPLC-DAD-ESI-MS and quantification of the catechins was performed by HPLC-DAD. In a typical HSCCC separation, 27.2 mg 98.8% EGCG, 14.1 mg 94.7% EGC, and 9.3 mg 97.5% EC were obtained. This new method is efficient, time-saving and valuable for biological studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Pulse radiolysis study of the reactions of catechins with nitrogen dioxide

    NASA Astrophysics Data System (ADS)

    Gebicki, Jerzy L.; Meisner, Piotr; Stawowska, Katarzyna; Gebicka, Lidia

    2012-12-01

    Nitrogen dioxide (•NO2), one of the oxidizing radicals formed in vivo is suspected to play a role in various pathophysiological processes. The reactions of •NO2 with dietary catechins, the group of flavonoids present in high amounts in green tea and red wine, have been investigated by pulse radiolysis method. The kinetics of the reaction of •NO2 with gallic acid have been also studied for comparison. The spectra of transient intermediates are presented. The rate constants of the reaction of •NO2 with catechin, epigallocatechin, epigallocatechin gallate and gallic acid determined by the competition method with 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonate) at pH 7.0 and room temperature have been found to be 0.9, 1.0, 2.3 and 0.5×108 M-1 s-1, respectively. The values for catechins are among the highest reported for the reactions of •NO2 with non-radical compounds.

  19. Effect of emulsification on the skin permeation and UV protection of catechin.

    PubMed

    Yoshino, Sachie; Mitoma, Tomoaki; Tsuruta, Keiko; Todo, Hiroaki; Sugibayashi, Kenji

    2014-06-01

    An anti-aging effect may be obtained by skin application of tea catechins (Camellia sinensis) since they have high ultraviolet (UV)-protection activity. In this study, the skin permeation of catechin (C), epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECg) and epigallocatechin gallate (EGCg) was determined and compared, and the effect of emulsification on the skin permeation of C was measured. The UV-protective effect of C was also determined. The in vitro skin permeability of each catechin derivative was determined using side-by-side diffusion of cells. The UV-protective effect of C was determined by applying different concentrations of C to the solution or emulsion on a three-dimensional cultured human skin model or normal human epidermal keratinocytes with UV-irradiation. ECg and EGCg with gallate groups showed lower skin permeability than C, EC and EGC without gallate groups, suggesting that the skin permeability of catechin derivatives may be dependent on the existence of a gallate group. Interestingly, the skin permeation of C was increased by an o/w emulsification. In addition, the C emulsion showed a significantly higher UV-protective effect by C than that with its aqueous solution. These results suggest that the o/w emulsion of catechin derivatives is probably useful as a cosmetic formulation with anti-aging efficacy.

  20. Fast gradient HPLC/MS separation of phenolics in green tea to monitor their degradation.

    PubMed

    Šilarová, Petra; Česlová, Lenka; Meloun, Milan

    2017-12-15

    The degradation of catechins and other phenolics in green tea infusions were monitored using fast HPLC/MS separation. The final separation was performed within 2.5min using Ascentis Express C18 column (50mm×2.1mm i.d.) packed with 2μm porous shell particles. Degradation was studied in relation to the temperature of water (70, 80, 90°C) and the standing time of the infusion (up to 6h). Along with chromatographic separation, the antioxidant properties of the infusions were monitored using two spectrophotometric methods. During staying of green tea infusion, the degradation of some catechins probably to gallic acid was observed. Finally, the influence of tea bag storage on antioxidant properties of green tea was evaluated. Rapid degradation of antioxidants after 3weeks was observed. The principal component analysis, factor analysis and discriminant analysis were used for the statistical evaluation of obtained experimental data. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Urinary Biomarkers of Catechins and Risk of Hepatocellular Carcinoma in the Shanghai Cohort Study

    PubMed Central

    Butler, Lesley M.; Huang, Joyce Yongxu; Wang, Renwei; Lee, Mao-Jun; Yang, Chung S.; Gao, Yu-Tang; Yuan, Jian-Min

    2015-01-01

    Dietary catechins are phytochemicals with both antioxidative and prooxidative stress properties. Green tea is a major source of catechins and may be associated with hepatocellular carcinoma (HCC) risk, but the catechin-HCC relationship has not been evaluated using a biomarker-based approach. A nested case-control study of HCC (211 cases and 1,067 matched controls) was conducted within the Shanghai Cohort Study, which enrolled 18,244 men between 1986 and 1989. Concentrations of specific catechins, including epicatechin, epigallocatechin (EGC), and 4′-O-methyl-epigallocatechin, were measured in urine specimens that had been collected prior to HCC diagnosis. None of the catechins measured were associated with HCC risk. In stratified analyses, there was a statistically significant trend for an association of higher urinary EGC with increased HCC risk among subjects with positive serology for hepatitis B surface antigen (P for trend = 0.02). This positive EGC-HCC association became stronger for hepatitis B surface antigen–positive persons who also had low serum retinol levels (for detectable levels vs. undetectable levels, odds ratio = 2.62, 95% confidence interval: 1.25, 5.51). There was no evidence supporting a protective role of catechins in the development of HCC. Instead, exposure to high levels of catechins may increase the risk of developing HCC for high-risk individuals. PMID:25713334

  2. Biochemical evaluation of triploid progenies of diploid × tetraploid breeding populations of Camellia for genotypes rich in catechin and caffeine.

    PubMed

    Das, Sourabh Kumar; Sabhapondit, Santanu; Ahmed, Giasuddin; Das, Sudripta

    2013-06-01

    To verify the quality of triploid varieties of Camellia tea species at the secondary metabolite level, we tested caffeine and catechin profiles of 97 F(1) segregating progenies in two breeding populations with a common tetraploid parent and diploid parents of two geographic and varietal origins. Catechin and caffeine levels of the triploid progenies were quantified and compared against their diploid parent. Some of the progenies showed better performance than their diploid parent. Most of the progenies of the diploid C. sinensis × tetraploid cross showed heterosis for caffeine and EGCG. Progenies of the C. assamica subsp. lasiocalyx × tetraploid cross showed heterosis for +C, EC, EGC, and TC. The genomic contributions of the diploid parent seem to be the main factor in the variation between the two populations. Our studies showed quantitative enhancement of some of the quality-related parameters in tea, providing a platform to refocus on this classical breeding approach for developing quality cultivars in tea.

  3. Antioxidative capacity and binding affinity of the complex of green tea catechin and beta-lactoglobulin glycated by the Maillard reaction.

    PubMed

    Perusko, Marija; Al-Hanish, Ayah; Mihailovic, Jelena; Minic, Simeon; Trifunovic, Sara; Prodic, Ivana; Cirkovic Velickovic, Tanja

    2017-10-01

    Major green tea catechin, epigallocatechin-3-gallate (EGCG), binds non-covalently to numerous dietary proteins, including beta-lactoglobulin of cow's milk. The effects of glycation of proteins via Maillard reaction on the binding capacity for polyphenols and the antiradical properties of the formed complexes have not been studied previously. Binding constant of BLG glycated by milk sugar lactose to EGCG was measured by the method of fluorophore quenching. Binding of EGCG was confirmed by CD and FTIR. The antioxidative properties of the complexes were examined by measuring ABTS radical scavenging capacity, superoxide anion scavenging capacity and total reducing power assay. Glycation of BLG does not significantly influence the binding constant of EGCG for the protein. Conformational changes were observed for both native and glycated BLG upon complexation with EGCG. Masking effect of polyphenol complexation on the antioxidative potential of the protein was of the similar degree for both glycated BLG and native BLG. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Tannase-converted green tea catechins and their anti-wrinkle activity in humans.

    PubMed

    Hong, Yang-Hee; Jung, Eun Young; Shin, Kwang-Soon; Yu, Kwang-Won; Chang, Un Jae; Suh, Hyung Joo

    2013-06-01

    This study was performed to investigate the anti-wrinkle effects of topical applications of green tea extract with high antioxidant activity by tannase treatment. Increases in gallic acid (GA), (-)-epigallocatechin (EGC), and (-)-epicatechin (EC) were observed in the green tea extract after tannase treatment. This study was performed to investigate the anti-wrinkle effects of topical applications of green tea extract exhibiting high antioxidant activity after tannase treatment. Subjects, randomly divided into two groups, received the application of either tannase-converted green tea extract (TGE) or normal green tea extract (NGE) on their crow's feet for 8 weeks. The anti-wrinkle effects were evaluated with two methods: (i) self-assessment; and (ii) average roughness of skin surface (R(a), R(z), and R(t) value) using skin replica and Skin-Visiometer SV 600. The scavenging abilities of TGE against radicals were significantly higher compared to NGE. The evaluation of skin wrinkle index values after 8 weeks of treatment showed that reductions of R(a), R(z), and R(t) values in the TGE group were significantly greater than in the NGE group, which indicated that tannase treatment improved the anti-wrinkle effects of green tea extract. According to the overall ratings for wrinkle treatment by applying the formulations, most of the TGE group (63.60%) reported marked or moderate improvement in wrinkles compared with only 36.30% of the NGE group. Tannase treatment can improve the antioxidant activity of green tea extract, conferring anti-wrinkle activities. These results suggest that TGE may have beneficial properties as an anti-wrinkle agent. © 2013 Wiley Periodicals, Inc.

  5. 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

  6. Influence of brewing conditions on taste components in Fuding white tea infusions.

    PubMed

    Zhang, Haihua; Li, Yulin; Lv, Yangjun; Jiang, Yulan; Pan, Junxian; Duan, Yuwei; Zhu, Yuejin; Zhang, Shikang

    2017-07-01

    White tea has received increasing attention of late as a result of its sweet taste and health benefits. During the brewing of white tea, many factors may affect the nutritional and sensory quality of the resulting infusions. The present study aimed to investigate the effect of various infusion conditions on the taste components of Fuding white tea, including infusion time, ratio of tea and water, number of brewing steps, and temperature. Brewing conditions had a strong effect on the taste compound profile and sensory characteristics. The catechin, caffeine, theanine and free amino acid contents generally increased with increasing infusion time and temperature. Conditions comprising an infusion time of 7 min, a brewing temperature of 100 °C, a tea and water ratio of 1:30 or 1:40, and a second brewing step, respectively, were shown to obtain the highest contents of most compounds. Regarding tea sensory evaluation, conditions comprising an infusion time of 3 min, a brewing temperature of 100 °C, a tea and water ratio of 1:50, and a first brewing step, resulted in the highest sensory score for comprehensive behavior of color, aroma and taste. The results of the present study reveal differences in the contents of various taste compounds, including catechins, caffeine, theanine and free amino acids, with respect to different brewing conditions, and sensory scores also varied with brewing conditions. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  7. Cloning and Characterization of a Flavonoid 3′-Hydroxylase Gene from Tea Plant (Camellia sinensis)

    PubMed Central

    Zhou, Tian-Shan; Zhou, Rui; Yu, You-Ben; Xiao, Yao; Li, Dong-Hua; Xiao, Bin; Yu, Oliver; Yang, Ya-Jun

    2016-01-01

    Tea leaves contain abundant flavan-3-ols, which include dihydroxylated and trihydroxylated catechins. Flavonoid 3′-hydroxylase (F3′H: EC 1.14.13.21) is one of the enzymes in the establishment of the hydroxylation pattern. A gene encoding F3′H, designated as CsF3′H, was isolated from Camellia sinensis with a homology-based cloning technique and deposited in the GenBank (GenBank ID: KT180309). Bioinformatic analysis revealed that CsF3′H was highly homologous with the characterized F3′Hs from other plant species. Four conserved cytochrome P450-featured motifs and three F3′H-specific conserved motifs were discovered in the protein sequence of CsF3′H. Enzymatic analysis of the heterologously expressed CsF3′H in yeast demonstrated that tea F3′H catalyzed the 3′-hydroxylation of naringenin, dihydrokaempferol and kaempferol. Apparent Km values for these substrates were 17.08, 143.64 and 68.06 μM, and their apparent Vmax values were 0.98, 0.19 and 0.44 pM·min−1, respectively. Transcription level of CsF3′H in the new shoots, during tea seed germination was measured, along with that of other key genes for flavonoid biosynthesis using real-time PCR technique. The changes in 3′,4′-flavan-3-ols, 3′,4′,5′-flavan-3-ols and flavan-3-ols, were consistent with the expression level of CsF3′H and other related genes in the leaves. In the study of nitrogen supply for the tea plant growth, our results showed the expression level of CsF3′H and all other tested genes increased in response to nitrogen depletion after 12 days of treatment, in agreement with a corresponding increase in 3′,4′-catechins, 3′,4′,5′-catechins and flavan 3-ols content in the leaves. All these results suggest the importance of CsF3′H in the biosynthesis of 3′,4′-catechins, 3′,4′,5′-catechins and flavan 3-ols in tea leaves. PMID:26907264

  8. 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.

  9. Metabolite Profiling of 14 Wuyi Rock Tea Cultivars Using UPLC-QTOF MS and UPLC-QqQ MS Combined with Chemometrics.

    PubMed

    Chen, Si; Li, Meihong; Zheng, Gongyu; Wang, Tingting; Lin, Jun; Wang, Shanshan; Wang, Xiaxia; Chao, Qianlin; Cao, Shixian; Yang, Zhenbiao; Yu, Xiaomin

    2018-01-24

    Wuyi Rock tea, well-recognized for rich flavor and long-lasting fragrance, is a premium subcategory of oolong tea mainly produced in Wuyi Mountain and nearby regions of China. The quality of tea is mainly determined by the chemical constituents in the tea leaves. However, this remains underexplored for Wuyi Rock tea cultivars. In this study, we investigated the leaf metabolite profiles of 14 major Wuyi Rock tea cultivars grown in the same producing region using UPLC-QTOF MS and UPLC-QqQ MS with data processing via principal component analysis and cluster analysis. Relative quantitation of 49 major metabolites including flavan-3-ols, proanthocyanidins, flavonol glycosides, flavone glycosides, flavonone glycosides, phenolic acid derivatives, hydrolysable tannins, alkaloids and amino acids revealed clear variations between tea cultivars. In particular, catechins, kaempferol and quercetin derivatives were key metabolites responsible for cultivar discrimination. Information on the varietal differences in the levels of bioactive/functional metabolites, such as methylated catechins, flavonol glycosides and theanine, offers valuable insights to further explore the nutritional values and sensory qualities of Wuyi Rock tea. It also provides potential markers for tea plant fingerprinting and cultivar identification.

  10. Effects of Tea Phenolics on Iron Uptake from Different Fortificants by Caco-2 cells

    USDA-ARS?s Scientific Manuscript database

    The in vitro effects of tea phenolics on Fe uptake from different fortificants (FeSO4, FeCl3, FeEDTA) by Caco-2 cells were compared. Cell cultures were exposed to catechin, tannic acid, green or black tea solutions added within Fe-containing solution, or used to pre-treat cell cultures before Fe-exp...

  11. 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.

  12. 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.

  13. The effects of catechin rich teas and caffeine on energy expenditure and fat oxidation: a meta-analysis

    USDA-ARS?s Scientific Manuscript database

    Different outcomes of the effect of catechin-caffeine mixtures and caffeine-only supplementation on energy expenditure and fat oxidation have been reported in short-term studies. Therefore, a meta-analysis was conducted to elucidate whether catechin-caffeine mixtures and caffeine-only supplementatio...

  14. 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.

  15. Green Tea Catechin-Based Complex Micelles Combined with Doxorubicin to Overcome Cardiotoxicity and Multidrug Resistance

    PubMed Central

    Cheng, Tangjian; Liu, Jinjian; Ren, Jie; Huang, Fan; Ou, Hanlin; Ding, Yuxun; Zhang, Yumin; Ma, Rujiang; An, Yingli; Liu, Jianfeng; Shi, Linqi

    2016-01-01

    Chemotherapy for cancer treatment has been demonstrated to cause some side effects on healthy tissues and multidrug resistance of the tumor cells, which greatly limits therapeutic efficacy. To address these limitations and achieve better therapeutic efficacy, combination therapy based on nanoparticle platforms provides a promising approach through delivering different agents simultaneously to the same destination with synergistic effect. In this study, a novel green tea catechin-based polyion complex (PIC) micelle loaded with doxorubicin (DOX) and (-)-Epigallocatechin-3-O-gallate (EGCG) was constructed through electrostatic interaction and phenylboronic acid-catechol interaction between poly(ethylene glycol)-block-poly(lysine-co-lysine-phenylboronic acid) (PEG-PLys/PBA) and EGCG. DOX was co-loaded in the PIC micelles through π-π stacking interaction with EGCG. The phenylboronic acid-catechol interaction endowed the PIC micelles with high stability under physiological condition. Moreover, acid cleavability of phenylboronic acid-catechol interaction in the micelle core has significant benefits for delivering EGCG and DOX to same destination with synergistic effects. In addition, benefiting from the oxygen free radicals scavenging activity of EGCG, combination therapy with EGCG and DOX in the micelle core could protect the cardiomyocytes from DOX-mediated cardiotoxicity according to the histopathologic analysis of hearts. Attributed to modulation of EGCG on P-glycoprotein (P-gp) activity, this kind of PIC micelles could effectively reverse multidrug resistance of cancer cells. These results suggested that EGCG based PIC micelles could effectively overcome DOX induced cardiotoxicity and multidrug resistance. PMID:27375779

  16. Green Tea Catechin-Based Complex Micelles Combined with Doxorubicin to Overcome Cardiotoxicity and Multidrug Resistance.

    PubMed

    Cheng, Tangjian; Liu, Jinjian; Ren, Jie; Huang, Fan; Ou, Hanlin; Ding, Yuxun; Zhang, Yumin; Ma, Rujiang; An, Yingli; Liu, Jianfeng; Shi, Linqi

    2016-01-01

    Chemotherapy for cancer treatment has been demonstrated to cause some side effects on healthy tissues and multidrug resistance of the tumor cells, which greatly limits therapeutic efficacy. To address these limitations and achieve better therapeutic efficacy, combination therapy based on nanoparticle platforms provides a promising approach through delivering different agents simultaneously to the same destination with synergistic effect. In this study, a novel green tea catechin-based polyion complex (PIC) micelle loaded with doxorubicin (DOX) and (-)-Epigallocatechin-3-O-gallate (EGCG) was constructed through electrostatic interaction and phenylboronic acid-catechol interaction between poly(ethylene glycol)-block-poly(lysine-co-lysine-phenylboronic acid) (PEG-PLys/PBA) and EGCG. DOX was co-loaded in the PIC micelles through π-π stacking interaction with EGCG. The phenylboronic acid-catechol interaction endowed the PIC micelles with high stability under physiological condition. Moreover, acid cleavability of phenylboronic acid-catechol interaction in the micelle core has significant benefits for delivering EGCG and DOX to same destination with synergistic effects. In addition, benefiting from the oxygen free radicals scavenging activity of EGCG, combination therapy with EGCG and DOX in the micelle core could protect the cardiomyocytes from DOX-mediated cardiotoxicity according to the histopathologic analysis of hearts. Attributed to modulation of EGCG on P-glycoprotein (P-gp) activity, this kind of PIC micelles could effectively reverse multidrug resistance of cancer cells. These results suggested that EGCG based PIC micelles could effectively overcome DOX induced cardiotoxicity and multidrug resistance.

  17. Design, formulation and evaluation of green tea chewing gum

    PubMed Central

    Aslani, Abolfazl; Ghannadi, Alireza; Khalafi, Zeinab

    2014-01-01

    Background: The main purpose of this study is to design, formulate and evaluate the green tea gums with a suitable taste and quality in order to produce an anti-oxidant chewing gum. Materials and Methods: Fresh green tea leaves obtained from Northern Iran for extraction. Maceration is the extraction method that is used in this study. The contents of caffeine, catechin and flavonoids of the hydro alcoholic extract were measured. Various formulations of the 120 mg green tea extract chewing gums with different sweeteners, flavoring agents and various gum bases were prepared afterward release pattern, content uniformity, organoleptic results and other properties were characterized. Results: The contents of caffeine, catechin and flavonoid of the hydro alcoholic extraction were 207.32 mg/g, 130.00 mg/g and 200.82 mg/g, respectively. Release pattern of green tea chewing gum with different gum base ratios and various sweeteners in phosphate buffer were prepared. A total of 60 persons who were 20-30 years of age, participated in our panel test for organoleptic properties such as taste, stiffness, stickiness, etc., Acceptable gum was the one with the same ratio of the used rubber bases. Cinnamon selected as the preferred taste by volunteers. Combination of aspartame, sugar and maltitol has appropriate taste. The effect of various sweetener on release pattern was negligible, on the other hand rubber bases ratio variation, changed the release pattern obviously. Conclusion: The green tea chewing gum with sugar, maltitol and aspartame sweeteners and cinnamon flavor, using the same rubber bases ratio may be a desirable antioxidant product. PMID:25161989

  18. 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

  19. Inhibition of mammary gland carcinogenesis by green tea catechins and other naturally occurring antioxidants in female Sprague-Dawley rats pretreated with 7,12-dimethylbenz[alpha]anthracene.

    PubMed

    Hirose, M; Hoshiya, T; Akagi, K; Futakuchi, M; Ito, N

    1994-08-15

    Effects of the naturally occurring antioxidants on mammary gland carcinogenesis were examined in female Sprague-Dawley rats pretreated with 7,12-dimethylbenz[alpha]anthracene (DMBA). Groups of 15-16 7-week-old rats received a 50 mg/kg body weight intra-gastric dose of DMBA, and starting one week thereafter placed on diet containing 0.4% catechol, 1.0% gamma-oryzanol, 2.0% phytic acid, 1.0% green tea catechins (GTC), 1.0% tannic acid or basal diet alone for 35 weeks. Although the final incidences and multiplicities of mammary tumors were not significantly different between DMBA-treated groups, the numbers of survivors in the antioxidant-treated groups at the end of the experiment at week 36 were significantly higher than in the basal diet group. In particular, the survival rate of the GTC group at 93.8% strongly contrasted with that of only 33.3% for rats on the basal diet. At the end of week 18, when all the animals were still alive, the average size of palpable mammary tumors was significantly smaller in the catechol, phytic acid and catechins groups. These results indicate that antioxidants, and GTC in particular, inhibit rat mammary gland carcinogenesis after DMBA initiation.

  20. 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

  1. 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…

  2. Antioxidants from steamed used tea leaves and their reaction behavior.

    PubMed

    Nomizu, Kayoko; Hashida, Koh; Makino, Rei; Ohara, Seiji

    2008-07-01

    The most efficient steaming conditions below 200 degrees C for extracting antioxidants from used tea leaves and their reaction behavior during the steaming treatment were investigated. The antioxidative activity of the steamed extracts increased with increasing steaming temperature, and the yield of the ethyl acetate extract fraction from each steamed extract showing the greatest antioxidative activity also increased. Caffeine, (-)-catechin, (-)-epicatechin, (-)-gallocatechin, (-)-epigallocatechin, (-)-catechin gallate, (-)-epicatechin gallate, (-)-gallocatechin gallate, (-)-epigallocatechin gallate and gallic acid were identified from the ethyl acetate extract fraction. Quantitative analyses demonstrated that the catechins with a 2,3-cis configuration decreased with increasing steaming temperature, whereas the corresponding epimers at the C-2 position increased. Each pair of epimers showed similar antioxidative activity to each other, indicating that the epimerization reaction did not contribute to the improved antioxidative activity. It is concluded from these results that the improvement in antioxidative activity at higher steaming temperatures was due to the increased yield of catechins and other antioxidants.

  3. Application of Green Tea Catechin for Inducing the Osteogenic Differentiation of Human Dedifferentiated Fat Cells in Vitro

    PubMed Central

    Kaida, Koji; Honda, Yoshitomo; Hashimoto, Yoshiya; Tanaka, Masahiro; Baba, Shunsuke

    2015-01-01

    Despite advances in stem cell biology, there are few effective techniques to promote the osteogenic differentiation of human primary dedifferentiated fat (DFAT) cells. We attempted to investigate whether epigallocatechin-3-gallate (EGCG), the main component of green tea catechin, facilitates early osteogenic differentiation and mineralization on DFAT cells in vitro. DFAT cells were treated with EGCG (1.25–10 μM) in osteogenic medium (OM) with or without 100 nM dexamethasone (Dex) for 12 days (hereafter two osteogenic media were designated as OM(Dex) and OM). Supplementation of 1.25 μM EGCG to both the media effectively increased the mRNA expression of collagen 1 (COL1A1) and runt-related transcription factor 2 (RUNX2) and also increased proliferation and mineralization. Compared to OM(Dex) with EGCG, OM with EGCG induced earlier expression for COL1A1 and RUNX2 at day 1 and higher mineralization level at day 12. OM(Dex) with 10 μM EGCG remarkably hampered the proliferation of the DFAT cells. These results suggest that OM(without Dex) with EGCG might be a preferable medium to promote proliferation and to induce osteoblast differentiation of DFAT cells. Our findings provide an insight for the combinatory use of EGCG and DFAT cells for bone regeneration and stem cell-based therapy. PMID:26602917

  4. Augmented cellular uptake of nanoparticles using tea catechins: effect of surface modification on nanoparticle-cell interaction

    NASA Astrophysics Data System (ADS)

    Lu, Yi-Ching; Luo, Pei-Chun; Huang, Chun-Wan; Leu, Yann-Lii; Wang, Tzu-Hao; Wei, Kuo-Chen; Wang, Hsin-Ell; Ma, Yunn-Hwa

    2014-08-01

    Nanoparticles may serve as carriers in targeted therapeutics; interaction of the nanoparticles with a biological system may determine their targeting effects and therapeutic efficacy. Epigallocatechin-3-gallate (EGCG), a major component of tea catechins, has been conjugated with nanoparticles and tested as an anticancer agent. We investigated whether EGCG may enhance nanoparticle uptake by tumor cells. Cellular uptake of a dextran-coated magnetic nanoparticle (MNP) was determined by confocal microscopy, flow cytometry or a potassium thiocyanate colorimetric method. We demonstrated that EGCG greatly enhanced interaction and/or internalization of MNPs (with or without polyethylene glycol) by glioma cells, but not vascular endothelial cells. The enhancing effects are both time- and concentration-dependent. Such effects may be induced by a simple mix of MNPs with EGCG at a concentration as low as 1-3 μM, which increased MNP uptake 2- to 7-fold. In addition, application of magnetic force further potentiated MNP uptake, suggesting a synergetic effect of EGCG and magnetic force. Because the effects of EGCG were preserved at 4 °C, but not when EGCG was removed from the culture medium prior to addition of MNPs, a direct interaction of EGCG and MNPs was implicated. Use of an MNP-EGCG composite produced by adsorption of EGCG and magnetic separation also led to an enhanced uptake. The results reveal a novel interaction of a food component and nanocarrier system, which may be potentially amenable to magnetofection, cell labeling/tracing, and targeted therapeutics.

  5. Green Tea Leaves Extract: Microencapsulation, Physicochemical and Storage Stability Study.

    PubMed

    Zokti, James A; Sham Baharin, Badlishah; Mohammed, Abdulkarim Sabo; Abas, Faridah

    2016-07-26

    Green tea polyphenols have been reported to possess many biological properties. Despite the many potential benefits of green tea extracts, their sensitivity to high temperature, pH and oxygen is a major disadvantage hindering their effective utilization in the food industry. Green tea leaves from the Cameron Highlands Malaysia were extracted using supercritical fluid extraction (SFE). To improve the stability, green tea extracts were encapsulated by spray-drying using different carrier materials including maltodextrin (MD), gum arabic (GA) and chitosan (CTS) and their combinations at different ratios. Encapsulation efficiency, total phenolic content and antioxidant capacity were determined and were found to be in the range of 71.41%-88.04%, 19.32-24.90 (g GAE/100 g), and 29.52%-38.05% respectively. Further analysis of moisture content, water activity, hygroscopicity, bulk density and mean particles size distribution of the microparticles were carried out and the results ranged from; 2.31%-5.11%, 0.28-0.36, 3.22%-4.71%, 0.22-0.28 g/cm³ and 40.43-225.64 µm respectively. The ability of the microparticles to swell in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) was determined as 142.00%-188.63% and 207.55%-231.77%, respectively. Release of catechin polyphenol from microparticles in SIF was higher comparable to that of SGF. Storage stability of encapsulated catechin extracts under different temperature conditions was remarkably improved compared to non-encapsulated extract powder. This study showed that total catechin, total phenolic content (TPC) and antioxidant activity did not decrease significantly (p ≥ 0.05) under 4 °C storage conditions. The half-life study results were in the range of 35-60, 34-65 and 231-288 weeks at storage temperatures of 40 °C, 25 °C and 4 °C respectively, therefore, for improved shelf-life stability we recommend that microparticles should be stored at temperatures below 25 °C.

  6. The impact of the catechol-O-methyltransferase genotype on vascular function and blood pressure after acute green tea ingestion.

    PubMed

    Miller, Rosalind J; Jackson, Kim G; Dadd, Tony; Mayes, Andrew E; Brown, A Louise; Lovegrove, Julie A; Minihane, Anne M

    2012-06-01

    Evidence for the benefits of green tea catechins on vascular function is inconsistent, with genotype potentially contributing to the heterogeneity in response. Here, the impact of the catechol-O-methyltransferase (COMT) genotype on vascular function and blood pressure (BP) after green tea extract ingestion are reported. Fifty subjects (n = 25 of the proposed low-activity [AA] and of the high-activity [GG] COMT rs4680 genotype), completed a randomized, double-blind, crossover study. Peripheral arterial tonometry, digital volume pulse (DVP), and BP were assessed at baseline and 90 min after 1.06 g of green tea extract or placebo. A 5.5 h and subsequent 18.5 h urine collection was performed to assess green tea catechin excretion. A genotype × treatment interaction was observed for DVP reflection index (p = 0.014), with green tea extract in the AA COMT group attenuating the increase observed with placebo. A tendency for a greater increase in diastolic BP was evident at 90 min after the green tea extract compared to placebo (p = 0.07). A genotypic effect was observed for urinary methylated epigallocatechin during the first 5.5 h, with the GG COMT group demonstrating a greater concentration (p = 0.049). Differences in small vessel tone according to COMT genotype were evident after acute green tea extract. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Self-assembly of green tea catechin derivatives in nanoparticles for oral lycopene delivery.

    PubMed

    Li, Weikun; Yalcin, Murat; Lin, Qishan; Ardawi, Mohammed-Salleh M; Mousa, Shaker A

    2017-02-28

    Lycopene is a natural anti-oxidant that has attracted much attention due to its varied applications such as protection against loss of bone mass, chronic diseases, skin cancer, prostate cancer, and cardiovascular disease. However, high instability and extremely low oral bioavailability limit its further clinical development. We selected a green tea catechin derivative, oligomerized (-)-epigallocatechin-3-O-gallate (OEGCG) as a carrier for oral lycopene delivery. Lycopene-loaded OEGCG nanoparticles (NPs) were prepared by a nano-precipitation method, followed by coating with chitosan to form a shell. This method not only can easily control the size of the NP to be around 200nm to improve its bioavailability, but also can effectively protect the lycopene against degradation due to EGCG's anti-oxidant property. OEGCG was carefully characterized with nuclear magnetic resonance spectroscopy and mass spectrometry. Lycopene-loaded polylactic-co-glycolic acid (PLGA) NPs were prepared by the same method. Chitosan-coated OEGCG/lycopene NPs had a diameter of 152±32nm and a ζ-potential of 58.3±4.2mv as characterized with transmission electron microscopy and dynamic light scattering. The loading capacity of lycopene was 9% and encapsulation efficiency was 89%. FT-IR spectral analysis revealed electrostatic interaction between OEGCG and chitosan. Freeze drying of the NPs was also evaluated as a means to improve shelf life. Dynamic light scattering data showed that no aggregation occurred, and the size of the NP increased 1.2 times (S f /S i ratio) in the presence of 10% sucrose after freeze drying. The in vitro release study showed slow release of lycopene in simulated gastric fluid at acidic pH and faster release in simulated intestinal fluid. In an in vivo study in mice, lycopene pharmacokinetic parameters were improved by lycopene/OEGCG/chitosan NPs, but not improved by lycopene/PLGA/chitosan NPs. The self-assembled nanostructure of OEGCG combined with lycopene may be a

  8. Microwave heating of tea residue yields polysaccharides, polyphenols, and plant biopolyester.

    PubMed

    Tsubaki, Shuntaro; Iida, Hiroyuki; Sakamoto, Masahiro; Azuma, Jun-ichi

    2008-12-10

    Microwave heating was used to produce aqueous-soluble components from green, oolong, and black tea residues. Heating at 200-230 degrees C for 2 min extracted 40-50% of polysaccharides and 60-70% of the polyphenols. Solubilization of arabinose and galactose by autohydrolysis occurred with heating above 170 degrees C, whereas heating above 200 degrees C was necessary to solubilize xylose. Catechins were soluble in water by heating at low temperature (110 degrees C); however, new polyphenols having strong antioxidant activity were produced above 200 degrees C. The amount of solubilized materials and antioxidant activity increased with increased fermentation of harvested tea leaves (green tea < oolong tea < black tea). Cutin, a plant biopolyester, remained in the residue after heating as did cellulose and lignin/tannin. The predominant cutin monomer that was recovered was 9,10-epoxy-18-hydroxyoctadecanoic acid, followed by dihydroxyhexadecanoic acid and 9,10,18-trihydroxyoctadecanoic acid.

  9. Theagalloflavic Acid, a New Pigment Derived from Hexahydroxydiphenoyl Group, and Lignan Oxidation Products Produced by Aerobic Microbial Fermentation of Green Tea.

    PubMed

    Matsuo, Yosuke; Matsuda, Tomoko; Sugihara, Keisuke; Saito, Yoshinori; Zhang, Ying-Jun; Yang, Chong-Ren; Tanaka, Takashi

    2016-01-01

    Chinese ripe pu-erh tea is produced by aerobic microbial fermentation of green tea. To clarify the microbial degradation of tea polyphenols, Japanese commercial green tea was mixed with Chinese ripe pu-erh tea, which retains microorganisms, and fermented for 5 d. Chromatographic separation yielded a novel water-soluble yellow pigment termed theagalloflavic acid. Spectroscopic and chemical evidence suggested that this pigment was produced by oxidative ring cleavage of hexahydroxydiphenoyl esters. In addition, two new oxygenated lignin metabolites, (+)-5,5'-dihydroxypinoresinol and 5-hydroxydihydrodehydrodiconiferyl alcohol, were also isolated together with known degradation products of quercetin and tea catechins.

  10. 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

  11. A Non-targeted Approach to Chemical Discrimination Between Green Tea Dietary Supplements and Green Tea Leaves by HPLC/MS

    PubMed Central

    Sun, Jianghao; Chen, Pei; Lin, Long-Ze; Harnly, James M.

    2013-01-01

    Green tea-based dietary supplements (GTDSs) have gained popularity in the U.S. market in recent years. This study evaluated the phytochemical composition difference of GTDS in comparison with green tea leaves using an HPLC/MS fingerprinting technique coupled with chemometric analysis. Five components that are most responsible for class separation among samples were identified as (−) epicatechin gallate, strictinin, trigalloylglucose, quercetin-3-O-glucosylrhamnosylglucoside, and kaempferol-3-O-galactosyl-rhamnosylglucoside, according to the accurate mass measurements and MS/MS data. The similarity coefficients between the GTDSs in solid form with green tea were 0.55 to 0.91, while for the GTDSs in liquid form they were 0.12 to 0.89, which suggested that chemical composition variance across the GTDSs was significant. Flavonol aglycone concentrations were higher in GTDSs than in tea leaves, indicating the degradation of flavonol glycosides or the oxidation of catechin during the manufacturing and storage processes. In some GTDS samples, compounds were identified that were on the label. The results demonstrate the urgency of QC for GTDS products. PMID:21563682

  12. 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.

  13. Obesity and thermogenesis related to the consumption of caffeine, ephedrine, capsaicin, and green tea.

    PubMed

    Diepvens, Kristel; Westerterp, Klaas R; Westerterp-Plantenga, Margriet S

    2007-01-01

    The global prevalence of obesity has increased considerably in the last decade. Tools for obesity management, including caffeine, ephedrine, capsaicin, and green tea have been proposed as strategies for weight loss and weight maintenance, since they may increase energy expenditure and have been proposed to counteract the decrease in metabolic rate that is present during weight loss. A combination of caffeine and ephedrine has shown to be effective in long-term weight management, likely due to different mechanisms that may operate synergistically, e.g., respectively inhibiting the phosphodiesterase-induced degradation of cAMP and enhancing the sympathetic release of catecholamines. However, adverse effects of ephedrine prevent the feasibility of this approach. Capsaicin has been shown to be effective, yet when it is used clinically it requires a strong compliance to a certain dosage, that has not been shown to be feasible yet. Also positive effects on body-weight management have been shown using green tea mixtures. Green tea, by containing both tea catechins and caffeine, may act through inhibition of catechol O-methyl-transferase, and inhibition of phosphodiesterase. Here, the mechanisms may also operate synergistically. In addition, tea catechins have antiangiogenic properties that may prevent development of overweight and obesity. Furthermore, the sympathetic nervous system is involved in the regulation of lipolysis, and the sympathetic innervation of white adipose tissue may play an important role in the regulation of total body fat in general.

  14. Bioefficacy of tea catechins encapsulated in casein micelles tested on a normal mouse cell line (4D/WT) and its cancerous counterpart (D/v-src) before and after in vitro digestion.

    PubMed

    Haratifar, Sanaz; Meckling, Kelly A; Corredig, Milena

    2014-06-01

    Numerous studies have demonstrated that tea catechins form complexes with milk proteins, especially caseins. Much less work has been conducted to understand the metabolic conversions of tea-milk complexes during gastro-duodenal digestion. The objective of this study was to determine the significance of this association on the digestibility of the milk proteins and on the bioaccessibility of the tea polyphenol epigallocatechin gallate (EGCG). An in vitro digestion model mimicking the gastric and duodenal phases of the human gastrointestinal tract was employed to follow the fate of the milk proteins during digestion and determine the bioefficacy of EGCG isolated or encapsulated with the caseins. The samples, before and after digestion, were tested using two parallel colonic epithelial cell lines, a normal line (4D/WT) and its cancerous transformed counterpart (D/v-src). EGCG caused a decrease in proliferation of cancer cells, while in normal cells, neither isolated nor encapsulated EGCG affected cell proliferation, at concentrations <0.15 mg ml(-1). At higher concentrations, both isolated and encapsulated produced similar decreases in proliferation. On the other hand, the bioefficacy on the cancer cell line showed some differences at lower concentrations. The results demonstrated that regardless of the extent of digestion of the nanoencapsulated EGCG, the bioefficacy of EGCG was not diminished, confirming that casein micelles are an appropriate delivery system for polyphenols.

  15. Inhibition of pectin methyl esterase activity by green tea catechins.

    PubMed

    Lewis, Kristin C; Selzer, Tzvia; Shahar, Chen; Udi, Yael; Tworowski, Dmitry; Sagi, Irit

    2008-10-01

    Pectin methyl esterases (PMEs) and their endogenous inhibitors are involved in the regulation of many processes in plant physiology, ranging from tissue growth and fruit ripening to parasitic plant haustorial formation and host invasion. Thus, control of PME activity is critical for enhancing our understanding of plant physiological processes and regulation. Here, we report on the identification of epigallocatechin gallate (EGCG), a green tea component, as a natural inhibitor for pectin methyl esterases. In a gel assay for PME activity, EGCG blocked esterase activity of pure PME as well as PME extracts from citrus and from parasitic plants. Fluorometric tests were used to determine the IC50 for a synthetic substrate. Molecular docking analysis of PME and EGCG suggests close interaction of EGCG with the catalytic cleft of PME. Inhibition of PME by the green tea compound, EGCG, provides the means to study the diverse roles of PMEs in cell wall metabolism and plant development. In addition, this study introduces the use of EGCG as natural product to be used in the food industry and agriculture.

  16. Catechin secretion and phytotoxicity

    PubMed Central

    Kaushik, Shail

    2010-01-01

    Research indicates that the invasiveness of Centaurea stoebe is attributed to the stronger allelopathic effects on the native North American species than on the related European species, which is one of the unquestionable aspects of the “novel weapons hypothesis (NWH).” Studies originating from controlled to field conditions have shown that C. stoebe utilizes its biochemical potential to exert its invasiveness. The roots of C. stoebe secrete a potent phytotoxin, catechin, which has a detrimental effect on the surrounding plant species. Although, studies on catechin secretion and phytotoxicity represent one of the most well studied systems describing negative plant-plant interactions, it has also sparked controversies lately due to its phytotoxicity dosages and secretion effluxes. Previous reports negate the phytotoxic and pro-oxidant nature of catechin.1–3 In our recent study we have shown that catechin is highly phytotoxic against Arabidopsis thaliana and Festuca idahoensis. We also show that (±) catechin applied to roots of A. thaliana induces reactive oxygen species (ROS) confirming the pro-oxidant nature of catechin. In addition, activation of signature cell death genes such as acd2 and cad1 post catechin treatment in A. thaliana ascertains the phytotoxic nature of catechin. PMID:21057643

  17. Effects of catechins and caffeine on the development of atherosclerosis in mice.

    PubMed

    Liu, Litong; Nagai, Izumi; Gao, Ying; Matsushima, Yoshibumi; Kawai, Yoshichika; Sayama, Kazutoshi

    2017-10-01

    Atherosclerosis is one of the diseases related to metabolic syndrome which is caused by obesity. Previous reports have shown that green tea and its components have anti-obesity effect. We examined whether catechins and caffeine can prevent the development of atherosclerosis by oral administration, singly or in combination to the atherosclerosis model mice. Results demonstrated that the number of atherosclerotic regions in the aorta was significantly reduced by the combined treatment, and the atherosclerotic area was also improved. Serum HDL-C increased by caffeine single treatment, but no effect on the TG and TC by any treatments. Moreover, ECG illuviated to atheromatous lesions in aorta and the illuviation was enhanced by caffeine. The mRNA expression levels of LOX-1 and TNF-α showed a tendency to suppress by the combined treatment. These results indicated that the combined administration of catechins and caffeine has the inhibitory effect on the development of atherosclerosis in mice.

  18. Diabetes and Alzheimer's Disease: Can Tea Phytochemicals Play a Role in Prevention?

    PubMed

    Fernando, Warnakulasuriya M A D B; Somaratne, Geeshani; Goozee, Kathryn G; Williams, Shehan; Singh, Harjinder; Martins, Ralph N

    2017-01-01

    Dementia and diabetes mellitus are prevalent disorders in the elderly population. While recognized as two distinct diseases, diabetes has more recently recognized as a significant contributor to risk for developing dementia, and some studies make reference to type 3 diabetes, a condition resulting from insulin resistance in the brain. Alzheimer's disease, the most common form of dementia, and diabetes, interestingly, share underlying pathological processes, commonality in risk factors, and, importantly, pathways for intervention. Tea has been suggested to possess potent antioxidant properties. It is rich in phytochemicals including, flavonoids, tannins, caffeine, polyphenols, boheic acid, theophylline, theobromine, anthocyanins, gallic acid, and finally epigallocatechin-3-gallate, which is considered to be the most potent active ingredient. Flavonoid phytochemicals, known as catechins, within tea offer potential benefits for reducing the risk of diabetes and Alzheimer's disease by targeting common risk factors, including obesity, hyperlipidemia, hypertension, cardiovascular disease, and stroke. Studies also show that catechins may prevent the formation of amyloid-β plaques and enhance cognitive functions, and thus may be useful in treating patients who have Alzheimer's disease or dementia. Furthermore, other phytochemicals found within tea offer important antioxidant properties along with innate properties capable of modulating intracellular neuronal signal transduction pathways and mitochondrial function.

  19. Chemometrics-enhanced high performance liquid chromatography-diode array detection strategy for simultaneous determination of eight co-eluted compounds in ten kinds of Chinese teas using second-order calibration method based on alternating trilinear decomposition algorithm.

    PubMed

    Yin, Xiao-Li; Wu, Hai-Long; Gu, Hui-Wen; Zhang, Xiao-Hua; Sun, Yan-Mei; Hu, Yong; Liu, Lu; Rong, Qi-Ming; Yu, Ru-Qin

    2014-10-17

    In this work, an attractive chemometrics-enhanced high performance liquid chromatography-diode array detection (HPLC-DAD) strategy was proposed for simultaneous and fast determination of eight co-eluted compounds including gallic acid, caffeine and six catechins in ten kinds of Chinese teas by using second-order calibration method based on alternating trilinear decomposition (ATLD) algorithm. This new strategy proved to be a useful tool for handling the co-eluted peaks, uncalibrated interferences and baseline drifts existing in the process of chromatographic separation, which benefited from the "second-order advantages", making the determination of gallic acid, caffeine and six catechins in tea infusions within 8 min under a simple mobile phase condition. The average recoveries of the analytes on two selected tea samples ranged from 91.7 to 103.1% with standard deviations (SD) ranged from 1.9 to 11.9%. Figures of merit including sensitivity (SEN), selectivity (SEL), root-mean-square error of prediction (RMSEP) and limit of detection (LOD) have been calculated to validate the accuracy of the proposed method. To further confirm the reliability of the method, a multiple reaction monitoring (MRM) method based on LC-MS/MS was employed for comparison and the obtained results of both methods were consistent with each other. Furthermore, as a universal strategy, this new proposed analytical method was applied for the determination of gallic acid, caffeine and catechins in several other kinds of Chinese teas, including different levels and varieties. Finally, based on the quantitative results, principal component analysis (PCA) was used to conduct a cluster analysis for these Chinese teas. The green tea, Oolong tea and Pu-erh raw tea samples were classified successfully. All results demonstrated that the proposed method is accurate, sensitive, fast, universal and ideal for the rapid, routine analysis and discrimination of gallic acid, caffeine and catechins in Chinese tea

  20. 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.

  1. Persistence of thiacloprid and deltamethrin residues in tea grown at different locations of North-East India.

    PubMed

    Sharma, Nitesh; Banerjee, Hemanta; Pal, Srikumar; Sharma, K K

    2018-07-01

    In order to examine the residues of thiacloprid (90 and 180 g a.i./ha) and deltamethrin (10 and 20 g a.i./ha) in fresh tea leaves, made tea and tea infusion, field experiments were conducted at three different locations viz. Kamalpur tea estate, Darjeeling; West Bengal, Teok tea Estate and AAU, Jorhat; Assam in India. Regardless of location and doses, residues of both the insecticides dissipated following first order kinetics. The half-life of Thiacloprid (4.93-5.38 days) was longer than that of deltamethrin (1.78-1.94 days). Processing of green tea leaves reduced the residue level of thiacloprid and deltamethrin in made tea. No residues of both these insecticides could be detected in tea infusion. With respect to the phenolic distribution in tea, a marked increase in total catechin monomers with thiacloprid and greater accumulation of EGCG and ECG (indices of phenol quality) with deltamethrin were observed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Chemopreventive potential of the tannase-mediated biotransformation of green tea.

    PubMed

    Macedo, J A; Ferreira, L R; Camara, L E; Santos, J C; Gambero, A; Macedo, G A; Ribeiro, M L

    2012-07-15

    Green tea (Camellia sinensis) is one of the most widely consumed beverages in the world. The cancer chemopreventive qualities of green tea have been well documented. Epigallocatechin gallate (EGCG) is often described as the most potently chemopreventive green tea catechin; however, the low bioavailability of EGCG is a limiting factor for its biological effect. Thus, the aim of this work was to test the chemopreventive potential of green tea extract and EGCG after tannase-mediated hydrolysis. The results showed that the biotransformed compounds retained most of the beneficial properties of the original compounds, and some beneficial properties were improved in the biotransformed compounds. Biotransformation of EGCG decreased its toxicity without affecting its antiproliferative effects. Furthermore, human cells gene expression profiling showed that the biotransformed compounds modulated the expression of several genes related to carcinogenesis. These results demonstrate the benefits of the biotechnological modification of natural food molecules, allowing the improvement of the nutraceutical potential of a beverage as green tea. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. 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

  4. Anti-stress effects of drinking green tea with lowered caffeine and enriched theanine, epigallocatechin and arginine on psychosocial stress induced adrenal hypertrophy in mice.

    PubMed

    Unno, Keiko; Hara, Ayane; Nakagawa, Aimi; Iguchi, Kazuaki; Ohshio, Megumi; Morita, Akio; Nakamura, Yoriyuki

    2016-11-15

    Theanine, an amino acid in tea, has significant anti-stress effects on animals and humans. However, the anti-stress effects of drinking green tea have not yet been elucidated. The present study aimed to explore anti-stress effects of green tea and roles of tea components in a mouse model of psychosocial stress. We examined anti-stress effects of three types of green teas, theanine-rich "Gyokuro", standard "Sencha", and Sencha with lowered caffeine (low-caffeine green tea). Furthermore, the roles of tea components such as caffeine, catechins, and other amino acids in anti-stress effects were examined. To prepare low-caffeine green tea, plucked new tea leaves were treated with a hot-water spray. Mice were psychosocially stressed from a conflict among male mice under confrontational housing. Mice consumed each tea that was eluted with room temperature water ad libitum. As a marker for the stress response, adrenal hypertrophy was compared with mice that ingested water. Caffeine was significantly lowered by spraying hot-water on tea leaves. While epigallocatechin gallate (EGCG) is the main catechin in tea leaves, epigallocatechin (EGC) was mainly infused into water at room temperature. Adrenal hypertrophy was significantly suppressed in mice that ingested theanine-rich and low-caffeine green tea that were eluted with water at room temperature. Caffeine and EGCG suppressed the anti-stress effects of theanine while EGC and arginine (Arg) retained these effects. These results suggest that drinking green tea exhibits anti-stress effects, where theanine, EGC and Arg cooperatively abolish the counter-effect of caffeine and EGCG on psychosocial stress induced adrenal hypertrophy in mice. Copyright © 2016 Elsevier GmbH. All rights reserved.

  5. Direct scavenging of nitric oxide and superoxide by green tea.

    PubMed

    Nakagawa, T; Yokozawa, T

    2002-12-01

    In the present study, we investigated the free radical scavenging effects of green tea extract and green tea tannin mixture and its components using a nitric oxide (NO) and superoxide (O(2)(-)) generating system in vitro. Green tea extract showed direct scavenging activity against NO and O(2)(-) and green tea tannin mixture, at the same concentration, showed high scavenging activity. Comparison of the activities of seven pure compounds isolated from green tea tannin mixture showed that (-)-epigallocatechin 3-O-gallate (EGCg), (-)-gallocatechin 3-O-gallate (GCg) and (-)-epicatechin 3-O-gallate (ECg) had higher scavenging activities than (-)-epigallocatechin (EGC), (+)-gallocatechin (GC), (-)-epicatechin (EC) and (+)-catechin (C), showing the importance of the structure of flavan-3-ol linked to gallic acid for this activity. Among the gallate-free tannins, EGC and GC were more effective O(2)(-) scavengers than EC and C, indicating the O-trihydroxy structure in the B ring is an important determinant of such activity. However, this structure did not affect the NO scavenging activity. These findings confirm that green tea tannin has excellent antioxidant properties, which may be involved in the beneficial effect of this compound.

  6. Catechins activate muscle stem cells by Myf5 induction and stimulate muscle regeneration.

    PubMed

    Kim, A Rum; Kim, Kyung Min; Byun, Mi Ran; Hwang, Jun-Ha; Park, Jung Il; Oh, Ho Taek; Kim, Hyo Kyeong; Jeong, Mi Gyeong; Hwang, Eun Sook; Hong, Jeong-Ho

    2017-07-22

    Muscle weakness is one of the most common symptoms in aged individuals and increases risk of mortality. Thus, maintenance of muscle mass is important for inhibiting aging. In this study, we investigated the effect of catechins, polyphenol compounds in green tea, on muscle regeneration. We found that (-)-epicatechin gallate (ECG) and (-)-epigallocatechin-3-gallate (EGCG) activate satellite cells by induction of Myf5 transcription factors. For satellite cell activation, Akt kinase was significantly induced after ECG treatment and ECG-induced satellite cell activation was blocked in the presence of Akt inhibitor. ECG also promotes myogenic differentiation through the induction of myogenic markers, including Myogenin and Muscle creatine kinase (MCK), in satellite and C2C12 myoblast cells. Finally, EGCG administration to mice significantly increased muscle fiber size for regeneration. Taken together, the results suggest that catechins stimulate muscle stem cell activation and differentiation for muscle regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. 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

  8. Phenolic antioxidants from green tea produced from Camellia taliensis.

    PubMed

    Gao, Da-Fang; Zhang, Ying-Jun; Yang, Chong-Ren; Chen, Ke-Ke; Jiang, Hong-Jian

    2008-08-27

    The chemical constituents of green tea prepared from the leaves of Camellia taliensis (W. W. Smith) Melchior (Theaceae) were investigated for the first time. Of these, 19 phenolic compounds including 8 hydrolyzable tannins (1-8), 6 catechin derivatives (9-14), 3 quinic acid aromatic esters (15-17), and 2 simple phenolics (18, 19) were identified, along with caffeine (20). Their antioxidant activities were evaluated by DPPH radical scavenging and tyrosinase inhibitory assays. Moreover, the chemical composition was compared with that in the cultivated tea plant, C. sinensis var. assamica, by HPLC analysis. It was noted that C. taliensis has similar chemical features with the cultivated tea plant; that is, both of them contain rich flavan-3-ols and caffeine. In addition, there are abundant hydrolyzable tannins as specific characteristic constituents contained in the leaves of C. taliensis. Therein, 1,2-di-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-beta-D-glucopyranose (8), as a major compound in C. taliensis, showed remarkable antioxidant activity. The results suggested that C. taliensis could be a valuable plant resource for the production of tea.

  9. Striking changes in tea metabolites due to elevational effects.

    PubMed

    Kfoury, Nicole; Morimoto, Joshua; Kern, Amanda; Scott, Eric R; Orians, Colin M; Ahmed, Selena; Griffin, Timothy; Cash, Sean B; Stepp, John Richard; Xue, Dayuan; Long, Chunlin; Robbat, Albert

    2018-10-30

    Climate effects on crop quality at the molecular level are not well-understood. Gas and liquid chromatography-mass spectrometry were used to measure changes of hundreds of compounds in tea at different elevations in Yunnan Province, China. Some increased in concentration while others decreased by 100's of percent. Orthogonal projection to latent structures-discriminant analysis revealed compounds exhibiting analgesic, antianxiety, antibacterial, anticancer, antidepressant, antifungal, anti-inflammatory, antioxidant, anti-stress, and cardioprotective properties statistically (p = 0.003) differentiated high from low elevation tea. Also, sweet, floral, honey-like notes were higher in concentration in the former while the latter displayed grassy, hay-like aroma. In addition, multivariate analysis of variance showed low elevation tea had statistically (p = 0.0062) higher concentrations of caffeine, epicatechin gallate, gallocatechin, and catechin; all bitter compounds. Although volatiles represent a small fraction of the total mass, this is the first comprehensive report illustrating how normal variations in temperature, 5 °C, due to elevational effects impact tea quality. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Synergistic anticancer activity of curcumin and catechin: an in vitro study using human cancer cell lines.

    PubMed

    Manikandan, R; Beulaja, M; Arulvasu, C; Sellamuthu, S; Dinesh, D; Prabhu, D; Babu, G; Vaseeharan, B; Prabhu, N M

    2012-02-01

    The most practical approach to reduce morbidity and mortality of cancer is to delay the process of carcinogenesis by usage of anticancer agents. This necessitates that safer compounds are to be critically examined for anticancer activity especially, those derived from natural sources. A spice commonly found in India and the surrounding regions, is turmeric, derived from the rhizome of Curcuma longa and the major active component is a phytochemical termed curcumin. Green tea is one of the most popular beverages used worldwide, produced from the leaves of evergreen plant Camellia sinensis and the major active ingredients are polyphenolic compounds known as catechins. In this study, synergistic anticancer activity of curcumin and catechin was evaluated in human colon adenocarcinoma HCT 15, HCT 116, and human larynx carcinoma Hep G-2 cell lines. Although, both curcumin or catechin inhibited the growth of above cell lines, interestingly, in combination of both these compounds highest level of growth control was observed. The anticancer activity shown is due to cytotoxicity, nuclear fragmentation as well as condensation, and DNA fragmentation associated with the appearance of apoptosis. These results suggest that curcumin and catechin in combination can inhibit the proliferation of HCT 15, HCT 116, as well as Hep G-2 cells efficiently through induction of apoptosis. Copyright © 2011 Wiley Periodicals, Inc.

  11. 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

  12. 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

  13. 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.

  14. Xanthine-Catechin Mixture Enhances Lithium-Induced Anti-Inflammatory Response in Activated Macrophages In Vitro

    PubMed Central

    Barbisan, Fernanda; Azzolin, Verônica Farina; Teixeira, Cibele Ferreira; Mastella, Moisés Henrique; Ribeiro, Euler Esteves; do Prado-Lima, Pedro Antonio Schmidt; Praia, Raquel de Souza; Medeiros Frescura Duarte, Marta Maria

    2017-01-01

    Lithium (Li) is a chemical element used for treating and preventing bipolar disorder (BD) and exerts positive effects such as anti-inflammatory effects as well as undesirable side effects. These effects of Li can be influenced by interaction with some nutritional elements. Therefore, we investigated the potential effects of xanthine (caffeine and theobromine) and catechin molecules present in some food beverages broadly consumed worldwide, such as coffee and tea, on Li-induced anti-inflammatory effects. In the present study, we concomitantly exposed RAW 264.7 macrophages to Li, isolated xanthine and catechin molecules, and a xanthine-catechin mixture (XC mixture). We evaluated the effects of these treatments on cell proliferation, cell cycle progression, oxidative and antioxidant marker expression, cytokine levels, gene expression, and GSK-3β enzyme expression. Treatment with the XC mixture potentialized Li-induced anti-inflammatory effects by intensification of the following: GSK-3β inhibitory action, lowering effect on proinflammatory cytokines (IL-1β, IL-6, and TNFα), and increase in the levels of IL-10 that is an anti-inflammatory cytokine. Despite the controversial nature of caffeine consumption by BD patients, these results suggested that consumption of caffeine, in low concentrations, mixed with other bioactive molecules along with Li may be safe. PMID:29250539

  15. Investigation of epigallocatechin-3-O-caffeoate and epigallocatechin-3-O-p-coumaroate in tea leaves by LC/MS-MS analysis.

    PubMed

    Umehara, Masahiro; Yanae, Koji; Maruki-Uchida, Hiroko; Sai, Masahiko

    2017-12-01

    (-)-Epigallocatechin-3-O-gallate (EGCG), the major catechin present in green tea, exhibits potent antioxidant activity. We thereby investigated the presence of unknown components bearing the (-)-epigallocatechin (EGC) moiety in fresh tea leaf samples. Initially, liquid chromatography tandem mass spectrometry (LC-MS/MS) was employed to examine fresh tea leaves of the Yabukita, the most popular tea cultivar in Japan, which suggested the presence of the EGC phenylpropanoid derivatives, (-)-epigallocatechin-3-O-p-coumaroate (EGCpCA) and (-)-epigallocatechin-3-O-caffeoate (EGCCA). The structures of the detected EGCpCA and EGCCA were then confirmed by LC-MS/MS using synthesized EGCpCA and EGCCA as standards. In addition, EGCpCA and EGCCA were evaluated for their antioxidant activity in the ORAC (oxygen radical antioxidant capacity) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assays, where EGCCA (8.60μmolTE/μmol, TE=Trolox equivalents) exhibited a stronger antioxidant activity than EGCG (5.52μmolTE/μmol) in the ORAC assay. Finally, EGCpCA and EGCCA were quantitated in several tea leaf samples using LC-MS/MS, and it was found that these compounds were present in lower quantities (EGCpCA, 16.8-345.8μg/g, EGCCA, 4.3-75.1μg/g in the dry tea leaves) than the major catechins. In this study, we found the potent antioxidant EGCCA using LC-MS/MS and revealed its wide existence in various tea leaves. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Development of new antioxidant active packaging films based on ethylene vinyl alcohol copolymer (EVOH) and green tea extract.

    PubMed

    Lopez de Dicastillo, Carol; Nerin, Cristina; Alfaro, Pilar; Catala, Ramon; Gavara, Rafael; Hernandez-Munoz, Pilar

    2011-07-27

    Ethylene vinyl alcohol copolymer (EVOH) films containing green tea extract were successfully produced by extrusion. The films were brown and translucent, and the addition of the extract increased the water and oxygen barrier at low relative humidity but increased the water sensitivity, the glass transition temperature, and the crystallinity of the films and improved their thermal resistance. An analysis by HPLC revealed that the antioxidant components of the extract suffered partial degradation during extrusion, reducing the content of catechin gallates and increasing the concentration of free gallic acid. Exposure of the films to various food simulants showed that the liquid simulants increased their capacity to reduce DPPH(•) and ABTS(•+) radicals. The release of green tea extract components into the simulant monitored by HPLC showed that all compounds present in the green tea extract were partially released, although the extent and kinetics of release were dependent on the type of food. In aqueous food simulants, gallic acid was the main antioxidant component released with partition coefficient values ca. 200. In 95% ethanol (fatty food simulant) the K value for gallic acid decreased to 8 and there was a substantial contribution of catechins (K in the 1000 range) to a greatly increased antioxidant efficiency. Kinetically, gallic acid was released more quickly than catechins, owing to its faster diffusivity in the polymer matrix as a consequence of its smaller molecular size, although the most relevant effect is the plasticization of the matrix by alcohol, increasing the diffusion coefficient >10-fold. Therefore, the materials here developed with the combination of antioxidant substances that constitute the green tea extract could be used in the design of antioxidant active packaging for all type of foods, from aqueous to fatty products, the compounds responsible for the protection being those with the higher compatibility with the packaged product.

  17. Effects of green tea catechin extract on serum lipids in postmenopausal women: a randomized, placebo-controlled clinical trial12

    PubMed Central

    Samavat, Hamed; Newman, April R; Wang, Renwei; Yuan, Jian-Min; Wu, Anna H; Kurzer, Mindy S

    2016-01-01

    Background: Green tea has been suggested to improve cardiovascular disease risk factors, including circulating lipid variables. However, current evidence is predominantly based on small, short-term randomized controlled trials conducted in diverse populations. Objective: The aim of this study was to examine the efficacy and impact of green tea extract (GTE) supplementation high in epigallocatechin gallate (EGCG) on blood lipids in healthy postmenopausal women. Design: This was an ancillary study of a double-blind, randomized, placebo-controlled, parallel-arm trial investigating the effects of a GTE supplement containing 1315 mg catechins (843 mg EGCG) on biomarkers of breast cancer risk. Participants were randomly assigned to receive GTE (n = 538) or placebo (n = 537) and were stratified by catechol-O-methyltransferase (COMT) genotype activity (high COMT compared with low or intermediate COMT genotype activity). They consumed either 4 GTE or identical placebo capsules daily for 12 mo. A total of 936 women completed this substudy. Circulating lipid panels including total cholesterol (TC), HDL cholesterol, and triglycerides were measured at baseline and at months 6 and 12. Results: Compared with placebo, 1-y supplementation with GTE capsules resulted in a significant reduction in circulating TC (−2.1% compared with 0.7%; P = 0.0004), LDL cholesterol (−4.1% compared with 0.9%; P < 0.0001) and non-HDL cholesterol (−3.1% compared with 0.4%; P = 0.0032). There was no change in HDL-cholesterol concentration, but triglyceride concentrations increased by 3.6% in the GTE group, whereas they decreased by 2.5% in the placebo group (P = 0.046). A significant reduction in TC was observed only among women with high (i.e., ≥200 mg/dL) baseline TC concentrations (P-interaction = 0.01) who consumed GTE capsules. The effect of GTE on the increase in triglycerides was mainly observed among obese women and statin users (P-interaction = 0.06). Conclusion: Supplementation with

  18. Green-Tea and Epigallocatechin-3-Gallate are Bactericidal against Bacillus anthracis

    DTIC Science & Technology

    2017-06-13

    EGCG, catechins such 245 as epigallocatechin and epicatechin gallate are also antibacterial agents. Moreover, the 246 bactericidal activity of green...Sharma A, Gupta S, Sarethy IP, Dang S, Gabrani R. 2012. Green tea extract: possible mechanism 285 and antibacterial activity on skin pathogens. Food...was shown to be responsible for this activity , against 30 both the attenuated B. anthracis ANR and the virulent, encapsulated strain B. anthracis

  19. Phytochemical profiles and antioxidant activity of 27 cultivars of tea.

    PubMed

    Zeng, Liang; Luo, Liyong; Li, Hongjun; Liu, Ruihai

    2017-08-01

    Tea, rich in phytochemicals, has been suggested to have human health benefits. The phenolic profiles, antioxidant and antiproliferative activities of 27 tea cultivars were determined. Wide ranges of variation were found in analyzed cultivars for the contents of water-soluble phenolics (121.6-223.7 mg/g dry weight (DW)), total catechins (TC) (90.5-177.2 mg/g DW), antioxidant activities (PSC values 627.3-2332.3 μmol of vitamin C equiv/g DW, ORAC values (1865.1-3489.3 μmol of vitamin C equiv/g DW), CAA values (37.7-134.3 μmol of QE/g DW without PBS wash and 25.3-75.4 μmol of QE/g DW with PBS wash) and antiproliferative activity (53.0-90.8% at the concentration of 400 μg/mL extracts). The PSC, ORAC and CAA values were significantly correlated with phenolics, epicatechin gallate (ECG), CC and TC. Knowledge of specific differences among tea cultivars is important for breeding tea cultivars and gives sights to its potential application to promote health.

  20. Effective Subcritical Butane Extraction of Bifenthrin Residue in Black Tea.

    PubMed

    Zhang, Yating; Gu, Lingbiao; Wang, Fei; Kong, Lingjun; Qin, Guangyong

    2017-03-30

    As a natural and healthy beverage, tea is widely enjoyed; however, the pesticide residues in tea leaves affect the quality and food safety. To develop a highly selective and efficient method for the facile removal of pesticide residues, the subcritical butane extraction (SBE) technique was employed, and three variables involving temperature, time and extraction cycles were studied. The optimum SBE conditions were found to be as follows: extraction temperature 45 °C, extraction time 30 min, number of extraction cycles 1, and in such a condition that the extraction efficiency reached as high as 92%. Further, the catechins, theanine, caffeine and aroma components, which determine the quality of the tea, fluctuated after SBE treatment. Compared with the uncrushed leaves, pesticide residues can more easily be removed from crushed leaves, and the practical extraction efficiency was 97%. These results indicate that SBE is a useful method to efficiently remove the bifenthrin, and as appearance is not relevant in the production process, tea leaves should first be crushed and then extracted in order that residual pesticides are thoroughly removed.

  1. The effect of copper(II), iron(II) sulphate, and vitamin C combinations on the weak antimicrobial activity of (+)-catechin against Staphylococcus aureus and other microbes.

    PubMed

    Holloway, Andrew C; Mueller-Harvey, Irene; Gould, Simon W J; Fielder, Mark D; Naughton, Declan P; Kelly, Alison F

    2012-12-01

    Few attempts have been made to improve the activity of plant compounds with low antimicrobial efficacy. (+)-Catechin, a weak antimicrobial tea flavanol, was combined with putative adjuncts and tested against different species of bacteria. Copper(II) sulphate enhanced (+)-catechin activity against Pseudomonas aeruginosa but not Staphylococcus aureus, Proteus mirabilis or Escherichia coli. Attempts to raise the activity of (+)-catechin against two unresponsive species, S. aureus and E. coli, with iron(II) sulphate, iron(III) chloride, and vitamin C, showed that iron(II) enhanced (+)-catechin against S. aureus, but not E. coli; neither iron(III) nor combined iron(II) and copper(II), enhanced (+)-catechin activity against either species. Vitamin C enhanced copper(II) containing combinations against both species in the absence of iron(II). Catalase or EDTA added to active samples removed viability effects suggesting that active mixtures had produced H(2)O(2)via the action of added metal(II) ions. H(2)O(2) generation by (+)-catechin plus copper(II) mixtures and copper(II) alone could account for the principal effect of bacterial growth inhibition following 30 minute exposures as well as the antimicrobial effect of (+)-catechin-iron(II) against S. aureus. These novel findings about a weak antimicrobial flavanol contrast with previous knowledge of more active flavanols with transition metal combinations. Weak antimicrobial compounds like (+)-catechin within enhancement mixtures may therefore be used as efficacious agents. (+)-Catechin may provide a means of lowering copper(II) or iron(II) contents in certain crop protection and other products.

  2. Effects of Exogenous Enzymatic Treatment During Processing on the Sensory Quality of Summer Tieguanyin Oolong Tea from the Chinese Anxi County

    PubMed Central

    Zhang, Xue-Bo

    2015-01-01

    Summary In order to attenuate the bitter taste and improve the aroma of the summer tieguanyin oolong tea from the Chinese Anxi county, the effects of processing treatment with exogenous laccase and α-galactosidase on tea sensory quality and related compounds were investigated. The solutions of laccase and/or α-galactosidase were sprayed on the tea leaves before the first drying process. The sensory evaluation results showed that the sensory quality of the tea was significantly enhanced with the enzymatic treatment. The combined application of laccase at 8.25 and α-galactosidase at 22 U per kg of fresh tea shoots achieved the most satisfying sensory quality. Further analysis of flavour-related constituents was carried out by HPLC and GC-MS. The HPLC analysis showed that the contents of catechins and total polyphenols were reduced, compared to the untreated group, by 11.9 and 13.3% respectively, and the total soluble sugars and water extract content were increased by 19.4 and 6.6% respectively, after the treatment with both enzymes. The decrease of catechins and total polyphenols reduced the bitterness and astringency of the summer tea, while the increase of total soluble sugars and water extract content improved the sweetness and mellow taste. The aromatic compound data from GC-MS showed that the total essential oil content in these tea samples co-treated with laccase and α-galactosidase increased significantly, in which aldehydes, alcohols, esters and alkenes increased by 23.28, 37.05, 20.10 and 38.99%, respectively. Our data suggest that the exogenous enzymatic treatment can enhance the summer oolong tea quality, especially its taste and aroma. PMID:27904347

  3. Tea catechins and flavonoids from the leaves of Camellia sinensis inhibit yeast alcohol dehydrogenase.

    PubMed

    Manir, Md Maniruzzaman; Kim, Jeong Kee; Lee, Byeong-Gon; Moon, Surk-Sik

    2012-04-01

    Four new quercetin acylglycosides, designated camelliquercetisides A-D, quercetin 3-O-[α-L-arabinopyranosyl(1→3)][2-O″-(E)-p-coumaroyl][β-D-glucopyranosyl(1→3)-α-L-rhamnopyranosyl(1→6)]-β-D-glucoside (17), quercetin 3-O-[2-O″-(E)-p-coumaroyl][β-D-glucopyranosyl(1→3)-α-L-rhamnopyranosyl(1→6)]-β-D-glucoside (18), quercetin 3-O-[α-L-arabinopyranosyl(1→3)][2-O″-(E)-p-coumaroyl][α-L-rhamnopyranosyl(1→6)]-β-d-glucoside (19), and quercetin 3-O-[2-O″-(E)-p-coumaroyl][α-L-rhamnopyranosyl(1→6)]-β-D-glucoside (20), together with caffeine and known catechins, and flavonoids (1-16) were isolated from the leaves of Camellia sinensis. Their structures were determined by spectroscopic (1D and 2D NMR, IR, and HR-TOF-MS) and chemical methods. The catechins and flavonoidal glycosides exhibited yeast alcohol dehydrogenase (ADH) inhibitory activities in the range of IC(50) 8.0-70.3μM, and radical scavenging activities in the range of IC(50) 1.5-43.8 μM, measured by using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. 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.

  5. Effect of teapot materials on the chemical composition of oolong tea infusions.

    PubMed

    Liao, Zih-Hui; Chen, Ying-Jie; Tzen, Jason Tze-Cheng; Kuo, Ping-Chung; Lee, Maw-Rong; Mai, Fu-Der; Rairat, Tirawat; Chou, Chi-Chung

    2018-01-01

    The flavor and quality of tea are widely believed to be associated with the pot in which the tea is made. However, this claim is mostly by experiences and lacks solid support from scientific evidence. The current study investigated and compared the chemical compositions of oolong tea made with six different teapot materials, namely Zisha, Zhuni, stainless steel, ceramic, glass and plastic. For each tea sample, polyphenols and caffeine were examined by HPLC-UV, volatile compounds by GC/MS, amino acids by LC/MS and minerals by ICP-MS. The results suggested that tea infusions from Zisha and Zhuni pots contain higher levels of EGC, EGCG and total catechins and less caffeine than those from ceramic, glass and plastic pots and tend to have the lowest total mineral contents, potassium and volatile compounds in tea soup. The statistical differences were not all significant among Zisha, Zhuni and stainless steel pots. Based on the overall chemical composition of the tea infusion, Yixing clay pots (Zisha and Zhuni) produce tea infusions that are presumably less bitter and more fragrant and tend to contain more healthful compounds than tea infusions from other pots. The results could partially explain why Yixing clay pots are among the most popular teapots. The beneficial effects of long-term repeated use of these teapots warrants further study. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  6. 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.

  7. Implications of Green Tea and Its Constituents in the Prevention of Cancer via the Modulation of Cell Signalling Pathway

    PubMed Central

    Rahmani, Arshad H.; Al shabrmi, Fahad M.; Allemailem, Khaled S.; Aly, Salah M.; Khan, Masood A.

    2015-01-01

    Green tea is commonly used as a beverage worldwide, especially in China, Japan, Morocco, and Saudi Arabia. Green tea and its constituents have been considered very effective in the prevention and treatment of various diseases. It contains a variety of catechins, which show a pivotal role in the modulation of biological activities and also act as chemopreventive agents. Earlier studies have confirmed that green tea and its chief constituent epigallocatechin gallate (EGCG) have a potential role in the management of cancer through the modulation of cell signaling pathways. In this review, we focused on the beneficial effects of green tea and its constituents in the cancer prevention and treatment and its impact on modulation of molecular pathways. PMID:25977926

  8. Variations of Antioxidant Properties and NO Scavenging Abilities during Fermentation of Tea

    PubMed Central

    Xu, Yang; Zhao, Hang; Zhang, Min; Li, Chun-Jie; Lin, Xue-Zhen; Sheng, Jun; Shi, Wei

    2011-01-01

    Tea is known as one of the most popular beverages in the world, which is believed to be beneficial for health. The main components in tea will change a lot depending on the different processes of fermentation, and thus the effects of different teas on human health may differ. The aim of this study is to explore the varied abilities of reactive oxygen species (ROS) and nitric oxide (NO) scavenging during the fermentation of tea. In this study, we conducted the in vitro experiments which involved some reaction systems indicating the abilities of scavenging ROS and NO. We also investigated the effects of tea and their components (catechins, theabrownins, caffeine) on the intracellular levels of ROS and NO, using Raw 264.7 cells as the model. We found that regardless of whether it was out of cell system or in Raw 264.7 cells, the abilities of scavenging ROS would decrease during the fermentation of tea. Further, the post-fermented pu-erh tea showed the best effect on inhibiting the lipopolysaccharide (LPS)-induced production of NO. These findings indicated that the fermentation process caused a change of the components which might be due to the changes of their antioxidant properties and NO scavenging abilities. PMID:21845097

  9. Comparison of the nutrient and chemical contents of traditional Korean Chungtaejeon and green teas.

    PubMed

    Park, Yong-Seo; Lee, Mi-Kyung; Heo, Buk-Gu; Ham, Kyung-Sik; Kang, Seong-Gook; Cho, Ja-Yong; Gorinstein, Shela

    2010-06-01

    This study was conducted in order to compare the nutrient and chemical contents of two Korean teas: traditional Chungtaejeon tea (CTJ) with that of green tea (GT). Main bioactive compounds and the antioxidant activities using four radical scavenging assays (ABTS, CUPRAC, FRAP and DPPH) in methanol and acetone extracts of both teas were determined. It was found that the contents of vitamin C, amino acids and total nitrogen in CTJ were lower than that of GT (p < 0.05). Caffeine, reducing sugar and chlorophyll contents in CTJ were similar to GT. Catechin (C), epicatechin (EC), and epigallocatechin (EGC) contents were lower in CTJ than in green tea (p < 0.05), but gallocatechin (GC), epicatechin gallate (ECG), epigallocatechin gallate (EGCG) and catechin gallate (CG) showed no significant differences between CTJ and GT (p >/= 0.05). The contents of polyphenols, flavonoids, flavanols and tannins in CTJ methanol were 229.30 +/- 11.3 mg GAE/g dry weight (DW), 15.24 +/- 0.8 mg CE/g DW, 109.10 +/- 5.1 mg CE/g DW and 25.68 +/- 1.2 mg CE/g DW, respectively, and significantly higher than in acetone extracts (p < 0.05). Flavonoids (quercetin and kaempferol) were higher in GT than in CTJ and myricetin was higher in CTJ (p < 0.05). Threonine and aspartic acid was lower, and glutamic acid was higher in CTJ compared with GT (p < 0.05). Free amino acid content in CTJ and GT showed no significant difference. Potassium and magnesium in CTJ were lower compared to GT, but no significant difference was found for iron, manganese and calcium. Also, the level of the antioxidant activity by all four used assays was significantly higher in CTJ and in methanol was higher than in acetone extracts (p < 0.05). In conclusion, traditional fermented Korean tea Chungtaejeon contains high quantities of bioactive compounds and possesses high antioxidant activity. The contents of the bioactive compounds and the levels of antioxidant activities are significantly higher in methanol than in acetone

  10. Metabolomic unveiling of a diverse range of green tea (Camellia sinensis) metabolites dependent on geography.

    PubMed

    Lee, Jang-Eun; Lee, Bum-Jin; Chung, Jin-Oh; Kim, Hak-Nam; Kim, Eun-Hee; Jung, Sungheuk; Lee, Hyosang; Lee, Sang-Jun; Hong, Young-Shick

    2015-05-01

    Numerous factors such as geographical origin, cultivar, climate, cultural practices, and manufacturing processes influence the chemical compositions of tea, in the same way as growing conditions and grape variety affect wine quality. However, the relationships between these factors and tea chemical compositions are not well understood. In this study, a new approach for non-targeted or global analysis, i.e., metabolomics, which is highly reproducible and statistically effective in analysing a diverse range of compounds, was used to better understand the metabolome of Camellia sinensis and determine the influence of environmental factors, including geography, climate, and cultural practices, on tea-making. We found a strong correlation between environmental factors and the metabolome of green, white, and oolong teas from China, Japan, and South Korea. In particular, multivariate statistical analysis revealed strong inter-country and inter-city relationships in the levels of theanine and catechin derivatives found in green and white teas. This information might be useful for assessing tea quality or producing distinct tea products across different locations, and highlights simultaneous identification of diverse tea metabolites through an NMR-based metabolomics approach. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. 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

  12. Optimizing the orosensory properties of model functional beverages: the influence of novel sweeteners, odorants, bitter blockers, and their mixtures on (+)-catechin.

    PubMed

    Gaudette, Nicole J; Pickering, Gary J

    2012-06-01

    The use of flavor-modifying strategies are important to improving the sensory profile of some excessively bitter and astringent functional ingredients, such as (+)-catechin (CAT). Two bitter blockers (ß-cyclodextrin [CYCLO], homoeriodictyol sodium salt [HED]), two sweeteners (sucrose [SUC], rebaudioside A [REB]), and two odorants (vanillin [VAN], black tea aroma [TEA]) were assessed for their efficacy at modifying the bitterness and astringency of CAT in model aqueous solutions. The intensity of oral sensations elicited by CAT was determined in duplicate in binary, ternary, and quaternary mixtures of these stimuli by a trained panel (n = 15) using a 15 cm visual analogue scale. Overall, bitterness and astringency were most effectively reduced by ternary solutions containing CYCLO + REB or CYCLO + SUC (68%, 60%, and 45%, 43% for bitterness and astringency, respectively). Odorants were not effective at modifying the bitterness or astringency of CAT. We conclude that the use of select bitter blockers and sweeteners may be of value in optimizing the flavor and acceptance of functional food and beverages fortified with phenolic compounds. (+)-Catechin is a bitter-tasting plant-derived health-promoting phenolic compound of interest to functional food and beverage manufacturers. We investigated the efficacy of bitter blockers, plant-based sweeteners, and odorants in decreasing the bitterness and astringency elicited by (+)-catechin. Some of these additives, both alone and in combination, reduced bitterness and astringency, and may therefore assist in optimizing the flavor and consumer acceptance of some phenolic-based functional foods and beverages. © 2012 Institute of Food Technologists®

  13. 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%).

  14. Effects of γ-radiation on microbial load and antioxidant proprieties in green 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.

    2015-02-01

    The aim of this paper is to study the effect of gamma radiation on green tea irradiated with different water activities. The green tea samples had their Aw adjusted to three values (0.93, 0.65, and 0.17) 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. Despite the irradiation with 5.0 kGy with high water activity has a small decrease in phenolic compounds and in some catechins content, this condition is recommended once was the dose to ensure microbiological safety without interfering in the main catechins and the antioxidant activity.

  15. Metabolomics analysis reveals the metabolic and functional roles of flavonoids in light-sensitive tea leaves.

    PubMed

    Zhang, Qunfeng; Liu, Meiya; Ruan, Jianyun

    2017-03-20

    As the predominant secondary metabolic pathway in tea plants, flavonoid biosynthesis increases with increasing temperature and illumination. However, the concentration of most flavonoids decreases greatly in light-sensitive tea leaves when they are exposed to light, which further improves tea quality. To reveal the metabolism and potential functions of flavonoids in tea leaves, a natural light-sensitive tea mutant (Huangjinya) cultivated under different light conditions was subjected to metabolomics analysis. The results showed that chlorotic tea leaves accumulated large amounts of flavonoids with ortho-dihydroxylated B-rings (e.g., catechin gallate, quercetin and its glycosides etc.), whereas total flavonoids (e.g., myricetrin glycoside, epigallocatechin gallate etc.) were considerably reduced, suggesting that the flavonoid components generated from different metabolic branches played different roles in tea leaves. Furthermore, the intracellular localization of flavonoids and the expression pattern of genes involved in secondary metabolic pathways indicate a potential photoprotective function of dihydroxylated flavonoids in light-sensitive tea leaves. Our results suggest that reactive oxygen species (ROS) scavenging and the antioxidation effects of flavonoids help chlorotic tea plants survive under high light stress, providing new evidence to clarify the functional roles of flavonoids, which accumulate to high levels in tea plants. Moreover, flavonoids with ortho-dihydroxylated B-rings played a greater role in photo-protection to improve the acclimatization of tea plants.

  16. Differentiation of tea varieties using UV-Vis spectra and pattern recognition techniques

    NASA Astrophysics Data System (ADS)

    Palacios-Morillo, Ana; Alcázar, Ángela.; de Pablos, Fernando; Jurado, José Marcos

    2013-02-01

    Tea, one of the most consumed beverages all over the world, is of great importance in the economies of a number of countries. Several methods have been developed to classify tea varieties or origins based in pattern recognition techniques applied to chemical data, such as metal profile, amino acids, catechins and volatile compounds. Some of these analytical methods become tedious and expensive to be applied in routine works. The use of UV-Vis spectral data as discriminant variables, highly influenced by the chemical composition, can be an alternative to these methods. UV-Vis spectra of methanol-water extracts of tea have been obtained in the interval 250-800 nm. Absorbances have been used as input variables. Principal component analysis was used to reduce the number of variables and several pattern recognition methods, such as linear discriminant analysis, support vector machines and artificial neural networks, have been applied in order to differentiate the most common tea varieties. A successful classification model was built by combining principal component analysis and multilayer perceptron artificial neural networks, allowing the differentiation between tea varieties. This rapid and simple methodology can be applied to solve classification problems in food industry saving economic resources.

  17. (+/-)-catechin: chemical weapon, antioxidant, or stress regulator?

    PubMed

    Chobot, Vladimir; Huber, Christoph; Trettenhahn, Guenter; Hadacek, Franz

    2009-08-01

    (+/-)-Catechin is a flavan-3-ol that occurs in the organs of many plant species, especially fruits. Health-beneficial effects have been studied extensively, and notable toxic effects have not been found. In contrast, (+/-)-catechin has been implicated as a 'chemical weapon' that is exuded by the roots of Centaurea stoebe, an invasive knapweed of northern America. Recently, this hypothesis has been rejected based on (+/-)-catechin's low phytotoxicity, instability at pH levels higher than 5, and poor recovery from soil. In the current study, (+/-)-catechin did not inhibit the development of white and black mustard to an extent that was comparable to the highly phytotoxic juglone, a naphthoquinone that is allegedly responsible for the allelopathy of the walnut tree. At high stress levels, caused by sub-lethal methanol concentrations in the medium, and a 12 h photoperiod, (+/-)-catechin even attenuated growth retardation. A similar effect was observed when (+/-)-catechin was assayed for brine shrimp mortality. Higher concentrations reduced the mortality caused by toxic concentrations of methanol. Further, when (+/-)-catechin was tested in variants of the deoxyribose degradation assay, it was an efficient scavenger of reactive oxygen species (ROS) when they were present in higher concentrations. This antioxidant effect was enhanced when iron was chelated directly by (+/-)-catechin. Conversely, if iron was chelated to EDTA, pro-oxidative effects were demonstrated at higher concentrations; in this case (+/-)-catechin reduced molecular oxygen and iron to reagents required by the Fenton reaction to produce hydroxyl radicals. A comparison of cyclic voltammograms of (+/-)-catechin with the phytotoxic naphthoquinone juglone indicated similar redox-cycling properties for both compounds although juglone required lower electrochemical potentials to enter redox reactions. In buffer solutions, (+/-)-catechin remained stable at pH 3.6 (vacuole) and decomposed at pH 7.4 (cytoplasm

  18. 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.

  19. Estimated daily intake of phenolics and antioxidants from green tea consumption in the Korean diet.

    PubMed

    Lee, Bong Han; Nam, Tae Gyu; Park, Na Young; Chun, Ock K; Koo, Sung I; Kim, Dae-Ok

    2016-01-01

    To estimate daily intake of total phenolics and flavonoids from green tea and the contribution of green tea to the antioxidant intake from the Korean diet, 24 commercial brands of green tea were selected and analyzed. Data from the Korea National Health and Nutrition Examination Survey (KNHANES) from 2008 and 2011 indicate that the green tea consumption in these 2 years was 2.8 g/tea drinker/day and 2.9 g/tea drinker/day, respectively. Based on data derived from direct measurements of green tea phenolics and the dataset of the 2008 KNHANES, we estimated the daily per tea drinker phenolics intake to be 172 mg gallic acid equivalents (GAE), the total flavonoids to be 43 mg catechin equivalents (CE) and the total antioxidants to be 267 mg vitamin C equivalents (VCE; 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay) and 401 mg VCE (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assay). In 2011, we estimated the daily per tea drinker total phenolics intake to be 246 mg GAE, the total flavonoids to be 60 mg CE and the antioxidants to be 448 mg VCE (DPPH assay) and 630 mg VCE (ABTS assay). The daily intake of total phenolics, total flavonoids and antioxidants from green tea consumption increased from 2008 to 2011.

  20. Catechin secretion and phytotoxicity: Fact not fiction.

    PubMed

    Bais, Harsh P; Kaushik, Shail

    2010-09-01

    Research indicates that the invasiveness of Centaurea stoebe is attributed to the stronger allelopathic effects on the native North American species than on the related European species, which is one of the unquestionable aspects of the "novel weapons hypothesis (NWH)." Studies originating from controlled to field conditions have shown that C. stoebe utilizes its biochemical potential to exert its invasiveness. The roots of C. stoebe secrete a potent phytotoxin, catechin, which has a detrimental effect on the surrounding plant species. Although, studies on catechin secretion and phytotoxicity represent one of the most well studied systems describing negative plant-plant interactions, it has also sparked controversies lately due to its phytotoxicity dosages and secretion effluxes. Previous reports negate the phytotoxic and pro-oxidant nature of catechin.1-3 In our recent study we have shown that catechin is highly phytotoxic against Arabidopsis thaliana and Festuca idahoensis. We also show that (±) catechin applied to roots of A. thaliana induces reactive oxygen species (ROS) confirming the pro-oxidant nature of catechin. In addition, activation of signature cell death genes such as acd2 and cad1 post catechin treatment in A. thaliana ascertains the phytotoxic nature of catechin.

  1. Investigation on biochemical compositional changes during the microbial fermentation process of Fu brick tea by LC-MS based metabolomics.

    PubMed

    Xu, Jie; Hu, Feng-Lin; Wang, Wei; Wan, Xiao-Chun; Bao, Guan-Hu

    2015-11-01

    Fu brick tea (FBT) is a unique post-fermented tea product which is fermented with fungi during the manufacturing process. In this study, we investigated the biochemical compositional changes occurring during the microbial fermentation process (MFP) of FBT based on non-targeted LC-MS, which was a comprehensive and unbiased methodology. Our data analysis took a two-phase approach: (1) comparison of FBT with other tea products using PCA analysis to exhibit the characteristic effect of MFP on the formation of Fu brick tea and (2) comparison of tea samples throughout the MFP of FBT to elucidate the possible key metabolic pathways produced by the fungi. Non-targeted LC-MS analysis clearly distinguished FBT with other tea samples and highlighted some interesting metabolic pathways during the MFP including B ring fission catechin. Our study demonstrated that those fungi had a significant influence on the biochemical profiles in the FBT and consequently contributed to its unique quality. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Synthesis and structural characterization of oaklin-catechins.

    PubMed

    Sousa, André; Fernandes, Ana; Mateus, Nuno; De Freitas, Victor

    2012-02-15

    Condensation reactions of procyanidin dimer B4 with two representative oak wood cinnamic aldehydes (coniferaldehyde and sinapaldehyde) were conducted in winelike model solutions. Coniferaldehyde led to the formation of guaiacylcatechin-pyrylium-catechin (GCP-catechin, 737 m/z), whereas sinapaldehyde led to the formation of syringylcatechin-pyrylium-catechin (SCP-catechin, 767 m/z). The former was also structurally characterized by 1D and 2D NMR, allowing an elucidation of the formation mechanism of these oaklin-catechin adducts and demonstrating the importance of procyanidins in the formation of colored compounds through the reaction with cinnamic aldehydes extracted from oaks during storage.

  3. In vitro electrocardiographic and cardiac ion channel effects of (-)-epigallocatechin-3-gallate, the main catechin of green tea.

    PubMed

    Kang, Jiesheng; Cheng, Hsien; Ji, Junzhi; Incardona, Josephine; Rampe, David

    2010-08-01

    Epigallocatechin-3-gallate (EGCG) is the major catechin found in green tea. EGCG is also available for consumption in the form of concentrated over-the-counter nutritional supplements. This compound is currently undergoing clinical trials for the treatment of a number of diseases including multiple sclerosis, and a variety of cancers. To date, few data exist regarding the effects of EGCG on the electrophysiology of the heart. Therefore, we examined the effects of EGCG on the electrocardiogram recorded from Langendorff-perfused guinea pig hearts and on cardiac ion channels using patch-clamp electrophysiology. EGCG had no significant effects on the electrocardiogram at concentrations of 3 and 10 microM. At 30 microM, EGCG prolonged PR and QRS intervals, slightly shortened the QT interval, and altered the shape of the ST-T-wave segment. The ST segment merged with the upstroke of the T wave, and we noted a prolongation in the time from the peak of the T wave until the end. Patch-clamp studies identified the KvLQT1/minK K(+) channel as a target for EGCG (IC(50) = 30.1 microM). In addition, EGCG inhibited the cloned human cardiac Na(+) channel Na(v)1.5 in a voltage-dependent fashion. The L-type Ca(2+) channel was inhibited by 20.8% at 30 microM, whereas the human ether-a-go-go-related gene and Kv4.3 cardiac K(+) channels were less sensitive to inhibition by EGCG. ECGC has a number of electrophysiological effects in the heart, and these effects may have clinical significance when multigram doses of this compound are used in human clinical trials or through self-ingestion of large amounts of over-the-counter products enriched in EGCG.

  4. Quantitative Analysis of Major Phytochemicals in Orthodox tea (Camellia sinensis), Oxidized under Compressed Air Environment.

    PubMed

    Panda, Brajesh Kumar; Datta, Ashis Kumar

    2016-04-01

    This study describes major changes in phytochemical composition of orthodox tea (Camellia sinensis var. Assamica) oxidized under compressed air (CA). The experiments for oxidation were conducted under air pressure (101, 202, and 303 kPa) for 150 min. Relative change in the concentrations of caffeine, catechins, theaflavins (TF), and thearubigins (TR) were analyzed. Effect of CA pressure was found to be nonsignificant in regulating caffeine concentration during oxidation. But degradation in different catechins as well as formation of different TF was significantly affected by CA pressure. At high CA pressure, TF showed highest peak value. TR was found to have slower rate of formation during initial phase of oxidation than TF. Even though the rate of TR formation was significantly influenced by CA, a portion of catechins remained unoxidized at end of oxidation. Except caffeine, the percent change in rate of formation or degradation were more prominent at 202 kPa. © 2016 Institute of Food Technologists®

  5. Anti-stress Effect of Green Tea with Lowered Caffeine on Humans: A Pilot Study.

    PubMed

    Unno, Keiko; Yamada, Hiroshi; Iguchi, Kazuaki; Ishida, Hitoshi; Iwao, Yasunori; Morita, Akio; Nakamura, Yoriyuki

    2017-01-01

    Theanine, an amino acid in tea, has significant anti-stress effects on animals and humans. However, the effect of theanine was blocked by caffeine and gallate-type catechins, which are the main components in tea. We examined the anti-stress effect of green tea with lowered caffeine, low-caffeine green tea, on humans. The study design was a single-blind group comparison and participants (n=20) were randomly assigned to low-caffeine or placebo tea groups. These teas (≥500 mL/d), which were eluted with room temperature water, were taken from 1 week prior to pharmacy practice and continued for 10 d in the practice period. The participants ingested theanine (ca. 15 mg/d) in low-caffeine green tea. To assess the anxiety of participants, the state-trait anxiety inventory test was used before pharmacy practice. The subjective stress of students was significantly lower in the low-caffeine-group than in the placebo-group during pharmacy practice. The level of salivary α-amylase activity, a stress marker, increased significantly after daily pharmacy practice in the placebo-group but not in the low-caffeine-group. These results suggested that the ingestion of low-caffeine green tea suppressed the excessive stress response of students. This study was registered at the University Hospital Medical Information Network (ID No. UMIN14942).

  6. Highly Selective and Considerable Subcritical Butane Extraction to Separate Abamectin in Green Tea.

    PubMed

    Zhang, Yating; Gu, Lingbiao; Wang, Fei; Kong, Lingjun; Pang, Huili; Qin, Guangyong

    2017-06-01

    We specially carried out the subcritical butane extraction to separate abamectin from tea leaves. Four parameters, such as extraction temperature, extraction time, number of extraction cycles, and solid-liquid ratio were studied and optimized through the response surface methodology with design matrix developed by Box-Behnken. Seventeen experiments with three various factors and three variable levels were employed to investigate the effect of these parameters on the extraction of abamectin. Besides, catechins, theanine, caffeine, and aroma components were determined by both high-performance liquid chromatography and gas chromatography-mass spectrometry to evaluate the tea quality before and after the extraction. The results showed that the extraction temperature was the uppermost parameter compared with others. The optimal extraction conditions selected as follows: extraction temperature, 42°C; number of extraction cycles and extraction time, 1 and 30 min, respectively; and solid-liquid ratio, 1:10. Based on the above study, the separation efficiency of abamectin was up to 93.95%. It is notable that there has a quite low loss rate, including the negligible damage of aroma components, the bits reduce of catechins within the range of 0.7%-13.1%, and a handful lessen of caffeine and theanine of 1.81% and 2.6%, respectively. The proposed method suggested subcritical butane possesses solubility for lipid-soluble pesticides, and since most of the pesticides are attached to the surfaces of tea, thus the as-applied method was successfully effective to separate abamectin because of the so practical and promising method.

  7. Concentrations of the Allelochemical (+/-)-catechin IN Centaurea maculosa soils.

    PubMed

    Perry, Laura G; Thelen, Giles C; Ridenour, Wendy M; Callaway, Ragan M; Paschke, Mark W; Vivanco, Jorge M

    2007-12-01

    The phytotoxin (+/-)-catechin has been proposed to mediate invasion and autoinhibition by the Eurasian plant Centaurea maculosa (spotted knapweed). The importance of (+/-)-catechin to C. maculosa ecology depends in part on whether sufficient catechin concentrations occur at appropriate times and locations within C. maculosa soil to influence neighboring plants. Previous research on catechin in C. maculosa soils has yielded conflicting results, with some studies finding high soil catechin concentrations and other, more recent studies finding little or no catechin in field soils. Here, we report the most extensive study of soil catechin concentrations to date. We examined soil catechin concentrations in 402 samples from 11 C. maculosa sites in North America sampled in consecutive months over 1 yr, excluding winter months. One site was sampled on seven dates, another was sampled twice, and the remaining nine sites were each sampled once on a range of sampling dates. Methods used were similar to those with which we previously measured high soil catechin concentrations. We detected catechin only in the site that was sampled on seven dates and only on one sampling date in that site (May 16 2006), but in all samples collected on that date. The mean soil catechin concentration on that date was 0.65 +/- 0.45 (SD) mg g(-1), comparable to previously reported high concentrations. There are a number of possible explanations for the infrequency with which we detected soil catechin in this work compared to previous studies. Differences in results could reflect spatial and temporal variation in catechin exudation or degradation, as we examined different sites in a different year from most previous studies. Also, large quantities of catechin were detected in blanks for two sampling periods in the present study, leading us to discard those data. This contamination suggests that previous reports of high catechin concentrations that did not include blanks should be viewed with caution

  8. 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

  9. 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.

  10. Effect of brewing time and temperature on antioxidant capacity and phenols of white tea: Relationship with sensory properties.

    PubMed

    Pérez-Burillo, S; Giménez, R; Rufián-Henares, J A; Pastoriza, S

    2018-05-15

    White tea is highly consumed due to its sensory properties and health benefits, although most scientific reports don't include the analysis of both properties. Therefore, the objective of the present study was to unravel the best brewing conditions for optimal extraction of the bioactive compounds and antioxidant capacity, while realising the best sensory properties. Infusions of eighty commercial teas (sold in bags or leaves) were obtained at different time-temperature ratios, studying bioactive compounds (caffeine and individual catechins), antioxidant capacity and sensory analysis. Brewing at 98 °C for 7 min was the best condition to obtain a high content of antioxidant polyphenols and pleasant sensory properties. Those teas sold in bags give rise to tea brews with almost double antioxidant capacity. In conclusion, it is very important to link sensory and chemical data to obtain optimal sensorial quality and the highest healthy properties in white tea infusions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Long-Term Green Tea Supplementation Does Not Change the Human Gut Microbiota

    PubMed Central

    Janssens, Pilou L. H. R.; Penders, John; Hursel, Rick; Budding, Andries E.; Savelkoul, Paul H. M.; Westerterp-Plantenga, Margriet S.

    2016-01-01

    Background Green tea catechins may play a role in body weight regulation through interactions with the gut microbiota. Aim We examined whether green tea supplementation for 12 weeks induces changes in composition of the human gut microbiota. Methods 58 Caucasian men and women were included in a randomized, placebo-controlled design. For 12 weeks, subjects consumed either green tea (>0.56 g/d epigallocatechin-gallate + 0.28 ∼ 0.45 g/d caffeine) or placebo capsules. Fecal samples were collected twice (baseline, vs. week 12) for analyses of total bacterial profiles by means of IS-profiling, a 16S-23S interspacer region-based profiling method. Results No significant changes between baseline and week 12 in subjects receiving green tea or placebo capsules, and no significant interactions between treatment (green tea or placebo) and time (baseline and week 12) were observed for body composition. Analysis of the fecal samples in subjects receiving green tea and placebo showed similar bacterial diversity and community structures, indicating there were no significant changes in bacterial diversity between baseline and week 12 in subjects receiving green tea capsules or in subjects receiving placebo capsules. No significant interactions were observed between treatment (green tea or placebo) and time (baseline and week 12) for the gut microbial diversity. Although, there were no significant differences between normal weight and overweight subjects in response to green tea, we did observe a reduced bacterial alpha diversity in overweight as compared to normal weight subjects (p = 0.002). Conclusion Green tea supplementation for 12 weeks did not have a significant effect on composition of the gut microbiota. Trial Registration ClinicalTrials.gov NCT01556321 PMID:27054321

  12. 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

  13. Pine Bark and Green Tea Concentrated Extracts: Antioxidant Activity and Comprehensive Characterization of Bioactive Compounds by HPLC–ESI-QTOF-MS

    PubMed Central

    Cádiz-Gurrea, María de la Luz; Fernández-Arroyo, Salvador; Segura-Carretero, Antonio

    2014-01-01

    The consumption of polyphenols has frequently been associated with low incidence of degenerative diseases. Most of these natural antioxidants come from fruits, vegetables, spices, grains and herbs. For this reason, there has been increasing interest in identifying plant extract compounds. Polymeric tannins and monomeric flavonoids, such as catechin and epicatechin, in pine bark and green tea extracts could be responsible for the higher antioxidant activities of these extracts. The aim of the present study was to characterize the phenolic compounds in pine bark and green tea concentrated extracts using high-performance liquid chromatography coupled to electrospray ionization mass spectrometry (HPLC–ESI-QTOF-MS). A total of 37 and 35 compounds from pine bark and green tea extracts, respectively, were identified as belonging to various structural classes, mainly flavan-3-ol and its derivatives (including procyanidins). The antioxidant capacity of both extracts was evaluated by three complementary antioxidant activity methods: Trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC). Higher antioxidant activity values by each method were obtained. In addition, total polyphenol and flavan-3-ol contents, which were determined by Folin–Ciocalteu and vanillin assays, respectively, exhibited higher amounts of gallic acid and (+)-catechin equivalents. PMID:25383680

  14. Pine bark and green tea concentrated extracts: antioxidant activity and comprehensive characterization of bioactive compounds by HPLC-ESI-QTOF-MS.

    PubMed

    de la Luz Cádiz-Gurrea, María; Fernández-Arroyo, Salvador; Segura-Carretero, Antonio

    2014-11-06

    The consumption of polyphenols has frequently been associated with low incidence of degenerative diseases. Most of these natural antioxidants come from fruits, vegetables, spices, grains and herbs. For this reason, there has been increasing interest in identifying plant extract compounds. Polymeric tannins and monomeric flavonoids, such as catechin and epicatechin, in pine bark and green tea extracts could be responsible for the higher antioxidant activities of these extracts. The aim of the present study was to characterize the phenolic compounds in pine bark and green tea concentrated extracts using high-performance liquid chromatography coupled to electrospray ionization mass spectrometry (HPLC-ESI-QTOF-MS). A total of 37 and 35 compounds from pine bark and green tea extracts, respectively, were identified as belonging to various structural classes, mainly flavan-3-ol and its derivatives (including procyanidins). The antioxidant capacity of both extracts was evaluated by three complementary antioxidant activity methods: Trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC). Higher antioxidant activity values by each method were obtained. In addition, total polyphenol and flavan-3-ol contents, which were determined by Folin-Ciocalteu and vanillin assays, respectively, exhibited higher amounts of gallic acid and (+)-catechin equivalents.

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

    NASA Astrophysics Data System (ADS)

    Hamdan, A. B.; Suryanto; Haider, F. I.

    2018-01-01

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

  16. Effects of single dose and regular intake of green tea (Camellia sinensis) on DNA damage, DNA repair, and heme oxygenase-1 expression in a randomized controlled human supplementation study.

    PubMed

    Ho, Cyrus K; Choi, Siu-wai; Siu, Parco M; Benzie, Iris F F

    2014-06-01

    Regular intake of green tea (Camellia sinensis) lowers DNA damage in humans, but molecular mechanisms of genoprotection are not clear. Protection could be via direct antioxidant effects of tea catechins, but, paradoxically, catechins have pro-oxidant activity in vitro, and it is hypothesized that mechanisms relate to redox-sensitive cytoprotective adaptations. We investigated this hypothesis, focusing particularly on effects on the DNA repair enzyme human oxoguanine glycosylase 1 (hOGG1), and heme oxygenase-1, a protein that has antioxidant and anti-inflammatory effects. A randomized, placebo-controlled, human supplementation study of crossover design was performed. Subjects (n = 16) took a single dose (200 mL of 1.5%, w/v) and 7-days of (2 × 200 mL 1%, w/v per day) green tea (with water as control treatment). Lymphocytic DNA damage was ∼30% (p < 0.001) lower at 60 and 120 min after the single dose and in fasting samples collected after 7-day tea supplementation. Lymphocytic hOGG1 activity was higher (p < 0.0001) at 60 and 120 min after tea ingestion. Significant increases (p < 0.0005) were seen in hOGG1 activity and heme oxygenase-1 after 7 days. Results indicate that molecular triggering of redox-sensitive cytoprotective adaptations and posttranslational changes affecting hOGG1 occur in vivo in response to both a single dose and regular intake of green tea, and contribute to the observed genoprotective effects of green tea. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Removal of caffeine from green tea by microwave-enhanced vacuum ice water extraction.

    PubMed

    Lou, Zaixiang; Er, Chaojuan; Li, Jing; Wang, Hongxin; Zhu, Song; Sun, Juntao

    2012-02-24

    In order to selectively remove caffeine from green tea, a microwave-enhanced vacuum ice water extraction (MVIE) method was proposed. The effects of MVIE variables including extraction time, microwave power, and solvent to solid radio on the removal yield of caffeine and the loss of total phenolics (TP) from green tea were investigated. The optimized conditions were as follows: solvent (mL) to solid (g) ratio was 10:1, microwave extraction time was 6 min, microwave power was 350 W and 2.5 h of vacuum ice water extraction. The removal yield of caffeine by MVIE was 87.6%, which was significantly higher than that by hot water extraction, indicating a significant improvement of removal efficiency. Moreover, the loss of TP of green tea in the proposed method was much lower than that in the hot water extraction. After decaffeination by MVIE, the removal yield of TP tea was 36.2%, and the content of TP in green tea was still higher than 170 mg g(-1). Therefore, the proposed microwave-enhanced vacuum ice water extraction was selective, more efficient for the removal of caffeine. The main phenolic compounds of green tea were also determined, and the results indicated that the contents of several catechins were almost not changed in MVIE. This study suggests that MVIE is a new and good alternative for the removal of caffeine from green tea, with a great potential for industrial application. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. 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.

  19. [Fast Detection of Camellia Sinensis Growth Process and Tea Quality Informations with Spectral Technology: A Review].

    PubMed

    Peng, Ji-yu; Song, Xing-lin; Liu, Fei; Bao, Yi-dan; He, Yong

    2016-03-01

    The research achievements and trends of spectral technology in fast detection of Camellia sinensis growth process information and tea quality information were being reviewed. Spectral technology is a kind of fast, nondestructive, efficient detection technology, which mainly contains infrared spectroscopy, fluorescence spectroscopy, Raman spectroscopy and mass spectroscopy. The rapid detection of Camellia sinensis growth process information and tea quality is helpful to realize the informatization and automation of tea production and ensure the tea quality and safety. This paper provides a review on its applications containing the detection of tea (Camellia sinensis) growing status(nitrogen, chlorophyll, diseases and insect pest), the discrimination of tea varieties, the grade discrimination of tea, the detection of tea internal quality (catechins, total polyphenols, caffeine, amino acid, pesticide residual and so on), the quality evaluation of tea beverage and tea by-product, the machinery of tea quality determination and discrimination. This paper briefly introduces the trends of the technology of the determination of tea growth process information, sensor and industrial application. In conclusion, spectral technology showed high potential to detect Camellia sinensis growth process information, to predict tea internal quality and to classify tea varieties and grades. Suitable chemometrics and preprocessing methods is helpful to improve the performance of the model and get rid of redundancy, which provides the possibility to develop the portable machinery. Future work is to develop the portable machinery and on-line detection system is recommended to improve the further application. The application and research achievement of spectral technology concerning about tea were outlined in this paper for the first time, which contained Camellia sinensis growth, tea production, the quality and safety of tea and by-produce and so on, as well as some problems to be solved

  20. 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.

  1. 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.

  2. Effects of oolong tea on plasma antioxidative capacity in mice loaded with restraint stress assessed using the oxygen radical absorbance capacity (ORAC) assay.

    PubMed

    Kurihara, Hiroshi; Fukami, Harukazu; Asami, Sumio; Toyoda, Yoshiko; Nakai, Masaaki; Shibata, Hiroshi; Yao, Xin-Sheng

    2004-07-01

    In the present study, we investigated the antioxidative effect of oolong tea in vitro and in vivo using the oxygen radical absorbance capacity (ORAC) assay. An oolong tea extract, catechin and related compounds suppressed the oxidation of fluorescence induced by AAPH in a dose-dependent manner, that is, they prolonged the antioxidant time in vitro. Oral administration of the oolong tea extract to mice treated with restraint stress increased ORAC activity in plasma as compared with a stress control group. The extract also increased plasma vitamin C levels, and there was a good relationship between ORAC activity and the vitamin C level in plasma. The elevation of plasma ORAC and vitamin C level may have been related to the stress-relieving effect of oolong tea. These effects are probably due to the antioxidative properties of the tea. Thus, these findings suggested that oolong tea has beneficial effects on health related to its antioxidative action.

  3. Electrospun polyvinylpyrrolidone (PVP)/green tea extract composite nanofiber mats and their antioxidant activities

    NASA Astrophysics Data System (ADS)

    Pusporini, Pusporini; Edikresnha, Dhewa; Sriyanti, Ida; Suciati, Tri; Miftahul Munir, Muhammad; Khairurrijal, Khairurrijal

    2018-05-01

    Electrospinning was employed to make PVP (polyvinylpyrrolidone)/GTE (green tea extract) composite nanofiber mats. The electrospun PVP nanofiber mat as well as the PVP/GTE nanofiber mats were uniform. The average fiber diameter of PVP/GTE composite nanofiber mat decreased with increasing the GTE weight fraction (or decreasing the PVP weight fraction) in the PVP/GTE solution because the PVP/GTE solution concentration decreased. Then, the broad FTIR peak representing the stretching vibrations of O–H in hydroxyl groups of phenols and the stretching of N–H in amine groups of the GTE paste shifted to higher wavenumbers in the PVP/GTE composite nanofiber mats. These peak shifts implied that PVP and catechins of GTE in the PVP/GTE composite nanofiber mats had intermolecular interactions via hydrogen bonds between carbonyl groups of PVP and hydroxyl groups of catechins in GTE. Lastly, the antioxidant activity of the PVP/GTE composite nanofiber mat increased with reducing the average fiber diameter because the amount of catechins in the composite nanofiber mat increased with the increase of surface area due to the reduction of the average fiber diameter.

  4. Lack of pharmacokinetic interaction between fluvastatin and green tea in healthy volunteers.

    PubMed

    Misaka, Shingen; Abe, Osamu; Sato, Hideyuki; Ono, Tomoyuki; Shikama, Yayoi; Onoue, Satomi; Yabe, Hirooki; Kimura, Junko

    2018-05-01

    The objective of this study is to assess the effects of green tea and its major catechin component, (-)-epigallocatechin gallate (EGCG), on CYP2C9-mediated substrate metabolism in vitro, and the pharmacokinetics of fluvastatin in healthy volunteers. The metabolism of diclofenac and fluvastatin in human recombinant CYP2C9 was investigated in the presence of EGCG. In a randomized three-phase crossover study, 11 healthy volunteers ingested a single 20-mg dose of fluvastatin with green tea extract (GTE), containing 150 mg of EGCG, along with water (300 mL), brewed green tea (300 mL), or water (300 mL) after overnight fasting. Plasma concentrations of fluvastatin and EGCG were measured by ultra-performance liquid chromatography with fluorescence detection and a single mass spectrometer. EGCG inhibited diclofenac 4'-hydroxylation and fluvastatin degradation with IC 50 of 2.23 and 48.04 μM, respectively. Brewed green tea used in the clinical study also dose-dependently inhibited the metabolism of diclofenac and fluvastatin in vitro. However, no significant effects of GTE and brewed green tea were observed in plasma concentrations of fluvastatin. The geometric mean ratios with 90% CI for area under the plasma concentration-time curve (AUC 0-∞ ) of fluvastatin were 0.993 (0.963-1.024, vs. brewed green tea) and 0.977 (0.935-1.020, vs. GTE). Although in vitro studies indicated that EGCG and brewed green tea produce significant inhibitory effects on CYP2C9 activity, the concomitant administration of green tea and fluvastatin in healthy volunteers did not influence the pharmacokinetics of fluvastatin.

  5. Matcha Green Tea Drinks Enhance Fat Oxidation During Brisk Walking in Females.

    PubMed

    Willems, Mark Elisabeth Theodorus; Şahin, Mehmet Akif; Cook, Matthew David

    2018-01-18

    Intake of the catechin epigallocatechin gallate and caffeine has been shown to enhance exercise-induced fat oxidation. Matcha green tea powder contains catechins and caffeine and is consumed as a drink. We examined the effect of Matcha green tea drinks on metabolic, physiological and perceived intensity responses during brisk walking. Thirteen females (age: 27±8 yr, body mass: 65±7 kg, height: 166±6 cm) volunteered. Resting metabolic equivalent (1-MET) was measured using Douglas bags (1-MET: 3.4±0.3 ml·kg -1 ·min -1 ). Participants completed an incremental walking protocol to establish the relationship between walking speed and oxygen uptake and individualize the walking speed at 5- or 6-MET. A randomized cross-over design was used with participants tested between day 9 and 11 of the menstrual cycle (follicular phase). Participants consumed 3 drinks (each drink made with 1 gram of Matcha premium grade, OMGTea Ltd UK) the day before, and 1 drink 2 hours before the 30-min walk at 5- (n=10) or 6-METs (walking speed: 5.8±0.4 km·h -1 ) with responses measured at 8-10, 18-20 and 28-30 min. Matcha had no effect on physiological and perceived intensity responses. Matcha resulted in lower respiratory exchange ratio (control: 0.84±0.04; Matcha: 0.82±0.04) (P < 0.01) and enhanced fat oxidation during a 30-min brisk walk (control: 0.31±0.10; Matcha: 0.35±0.11 g·min -1 ) (P < 0.01). Matcha green tea drinking can enhance exercise-induced fat oxidation in females. However, when regular brisk walking with 30-min bouts is being undertaken as part of a weight loss program, the metabolic effects of Matcha should not be overstated.

  6. Electrophilic aromatic substitution of catechins: Bromination and benzylation

    Treesearch

    G.W. McGraw; Richard W. Hemingway

    1982-01-01

    Relative yields of C-6, C-8. and C-6 and C-8 substituted catechins obtained from the reaction of (+)-catechin or 3',4',5-7-tetra-O-methyl-(+)-catechin with pyridinium hydrobromide-perbromide, bromine, p-hydroxybenzyl alcohol, or o-hydroxybenzyl alcohol showed differing selectivities depending upon the...

  7. 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.

  8. Punicalagin and catechins contain polyphenolic substructures that influence cell viability and can be monitored by radical chemosensors sensitive to electron transfer.

    PubMed

    Carreras, Anna; Mateos-Martín, María Luisa; Velázquez-Palenzuela, Amado; Brillas, Enric; Sánchez-Tena, Susana; Cascante, Marta; Juliá, Luis; Torres, Josep Lluís

    2012-02-22

    Plant polyphenols may be free radical scavengers or generators, depending on their nature and concentration. This dual effect, mediated by electron transfer reactions, may contribute to their influence on cell viability. This study used two stable radicals (tris(2,3,5,6-tetrachloro-4-nitrophenyl)methyl (TNPTM) and tris(2,4,6-trichloro-3,5-dinitrophenyl)methyl (HNTTM)) sensitive only to electron transfer reduction reactions to monitor the redox properties of polyphenols (punicalagin and catechins) that contain phenolic hydroxyls with different reducing capacities. The use of the two radicals reveals that punicalagin's substructures consisting of gallate esters linked together by carbon-carbon (C-C) bonds are more reactive than simple gallates and less reactive than the pyrogallol moiety of green tea catechins. The most reactive hydroxyls, detected by TNPTM, are present in the compounds that affect HT-29 cell viability the most. TNPTM reacts with C-C-linked gallates and pyrogallol and provides a convenient way to detect potentially beneficial polyphenols from natural sources.

  9. Dietary catechins and procyanidins modulate zinc homeostasis in human HepG2 cells.

    PubMed

    Quesada, Isabel M; Bustos, Mario; Blay, Mayte; Pujadas, Gerard; Ardèvol, Anna; Salvadó, M Josepa; Bladé, Cinta; Arola, Lluís; Fernández-Larrea, Juan

    2011-02-01

    Catechins and their polymers procyanidins are health-promoting flavonoids found in edible vegetables and fruits. They act as antioxidants by scavenging reactive oxygen species and by chelating the redox-active metals iron and copper. They also behave as signaling molecules, modulating multiple cell signalling pathways and gene expression, including that of antioxidant enzymes. This study aimed at determining whether catechins and procyanidins interact with the redox-inactive metal zinc and at assessing their effect on cellular zinc homeostasis. We found that a grape-seed procyanidin extract (GSPE) and the green tea flavonoid (-)-epigallocatechin-3-gallate (EGCG) bind zinc cations in solution with higher affinity than the zinc-specific chelator Zinquin, and dose-dependently prevent zinc-induced toxicity in the human hepatocarcinoma cell line HepG2, evaluated by the lactate dehydrogenase test. GSPE and EGCG hinder intracellular accumulation of total zinc, measured by atomic flame absorption spectrometry, concomitantly increasing the level of cytoplasmic labile zinc detectable by Zinquin fluorescence. Concurrently, GSPE and EGCG inhibit the expression, evaluated at the mRNA level by quantitative reverse transcriptase-polymerase chain reaction, of zinc-binding metallothioneins and of plasma membrane zinc exporter ZnT1 (SLC30A1), while enhancing the expression of cellular zinc importers ZIP1 (SLC39A1) and ZIP4 (SLC39A4). GSPE and EGCG also produce all these effects when HepG2 cells are stimulated to import zinc by treatment with supplemental zinc or the proinflammatory cytokine interleukin-6. We suggest that extracellular complexation of zinc cations and the elevation of cytoplasmic labile zinc may be relevant mechanisms underlying the modulation of diverse cell signaling and metabolic pathways by catechins and procyanidins. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Impact of (+/-)-catechin on soil microbial communities.

    PubMed

    Inderjit; Kaur, Rajwant; Kaur, Surinder; Callaway, Ragan M

    2009-01-01

    Catechin is a highly studied but controversial allelochemical reported as a component of the root exudates of Centaurea maculosa. Initial reports of high and consistent exudation rates and soil concentrations have been shown to be highly inaccurate, but the chemical has been found in root exudates at and much less frequently in soil but sporadically at high concentrations. Part of the problem of detection and measuring phytotoxicity in natural soils may be due to the confounding effect of soil microbes, and little is known about interactions between catechin and soil microbes. Here we tested the effect of catechin on soil microbial communities and the feedback of these effects to two plant species. We found that catechin inhibits microbial activity in the soil we tested, and by doing so appears to promote plant growth in the microbe-free environment. This is in striking contrast to other in vitro studies, emphasizing the highly conditional effects of the chemical and suggesting that the phytotoxic effects of catechin may be exerted through the microbes in some soils.

  11. 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.

  12. [Simultaneous determination of 16 flavonoids in the ginkgo dietary supplement tea by high performance liquid chromatography-tandem mass spectrometry].

    PubMed

    Jiang, Yalan; Huang, Fang; Wu, Fuhai; Wu, Huiqin; Huang, Xiaolan; Deng, Xin

    2015-10-01

    A method for the determination of 16 functional components of ginkgo dietary supplement tea such as catechin, vitexin, puerarin, isoflavoues aglycone, silymarin, quercetin, luteolin, apigenin, naringenin, hesperitin dihydrochalcone, kaempferol, hesperitin, isorhamnetin, baicalein, nobiletin and tangeretin by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was proposed. The conditions of chromatography and mass spectrometry were optimized. The 16 flavonoids were separated on a C18 chromatographic column with acetonitrile and water (additional 0.1% formic acid) as mobile phases under gradient elution at a flow rate of 0.25 mL/min. The determination was conducted by tandem mass spectrometry in positive ESI mode under multiple reaction monitoring (MRM) mode. Good linearities for all the compounds, with correlation coefficients over 0.996, were acquired. The recoveries were in the range of 70.9% to 100.0% (n = 6), while the relative standard deviations (RSDs) were less than 10%. The results showed that the nine flavonoids, which were kaempferol, quercetin, hesperitin, vitexin, luteolin, catechin, apigenin, naringenin and isorhamnetin, were higher in contents among the 16 flavonoids in real samples, and they constituted up to 99.6% of the total flavonoids. The contents of these nine flavonoids can be considered as the quality control index of the ginkgo dietary supplement tea. The method proved to be rapid, selective, sensitive and stable, and it can be applied to control the quality of the ginkgo dietary supplement tea.

  13. Mineral and metabolic profiles in tea leaves and flowers during flower development.

    PubMed

    Jia, Sisi; Wang, Yu; Hu, Jianhui; Ding, Zhaotang; Liang, Qing; Zhang, Yinfei; Wang, Hui

    2016-09-01

    Tea [Camellia sinensis (L.) O. Kuntze] is one of the most popular non-alcoholic beverage crops in the world, and the physiological processes and gene regulations involved in development in tea plants have been well characterized. However, relatively little is known about the metabolic changes combined with mineral distributions that occur during flower development. Here we detected the contents of 11 elements in tea leaves and flowers and found that, some of them, especially phosphorus, sulfur and copper, showed significant changes during tea flowering. We also detected 122 metabolites in tea leaves and flowers and found that, 72 of them showed significant differences between flowers and leaves, of which sugars, organic acids, and flavonoids dominated. The sugars, such as trehalose and galactose, all accumulated in tea flowers, and the organic acids, such as malic acid, citric acid and fumaric acid involved in TCA cycle. The flavonoids, like epicatechin, catechin gallate and epigallocatechin, were more abundant in leaves. Furthermore, we found that the contents of 33 metabolites changed during the development of flowers. Especially, citric acid, phenylalanine and most flavonoids decreased while fructose and galactose increased during flowering stages in flowers. We also analyzed the correlations between the ions and metabolites and found that, some mineral nutrients including phosphorus, sulfur, manganese and zinc had close relations to organic acids, flavonoids, sugars and several amino acids during flowering. We mapped the metabolic pathway according to the KEGG database. This work will serve as the foundation for a systems biology approach to the understanding of mineral metabolism. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  14. Identification of Intestinal UDP-Glucuronosyltransferase Inhibitors in Green Tea (Camellia sinensis) Using a Biochemometric Approach: Application to Raloxifene as a Test Drug via In Vitro to In Vivo Extrapolation.

    PubMed

    Tian, Dan-Dan; Kellogg, Joshua J; Okut, Neşe; Oberlies, Nicholas H; Cech, Nadja B; Shen, Danny D; McCune, Jeannine S; Paine, Mary F

    2018-05-01

    Green tea ( Camellia sinensis ) is a popular beverage worldwide, raising concern for adverse interactions when co-consumed with conventional drugs. Like many botanical natural products, green tea contains numerous polyphenolic constituents that undergo extensive glucuronidation. As such, the UDP-glucuronosyltransferases (UGTs), particularly intestinal UGTs, represent potential first-pass targets for green tea-drug interactions. Candidate intestinal UGT inhibitors were identified using a biochemometrics approach, which combines bioassay and chemometric data. Extracts and fractions prepared from four widely consumed teas were screened (20-180 μ g/ml) as inhibitors of UGT activity (4-methylumbelliferone glucuronidation) in human intestinal microsomes; all demonstrated concentration-dependent inhibition. A biochemometrics-identified fraction rich in UGT inhibitors from a representative tea was purified further and subjected to second-stage biochemometric analysis. Five catechins were identified as major constituents in the bioactive subfractions and prioritized for further evaluation. Of these catechins, (-)-epicatechin gallate and (-)-epigallocatechin gallate showed concentration-dependent inhibition, with IC 50 values (105 and 59 μ M, respectively) near or below concentrations measured in a cup (240 ml) of tea (66 and 240 μ M, respectively). Using the clinical intestinal UGT substrate raloxifene, the K i values were ∼1.0 and 2.0 μ M, respectively. Using estimated intestinal lumen and enterocyte inhibitor concentrations, a mechanistic static model predicted green tea to increase the raloxifene plasma area under the curve up to 6.1- and 1.3-fold, respectively. Application of this novel approach, which combines biochemometrics with in vitro-in vivo extrapolation, to other natural product-drug combinations will refine these procedures, informing the need for further evaluation via dynamic modeling and clinical testing. Copyright © 2018 by The American Society for

  15. 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.

  16. Synthesis and Property of Ag(NP)/catechin/Gelatin Nanofiber

    NASA Astrophysics Data System (ADS)

    Nasir, Muhamad; Apriani, Dita

    2017-12-01

    Nanomaterial play important role future industry such as for the medical, food, pharmaceutical and cosmetic industry. Ag (NP) and catechin exhibit antibacterial property. Ag(NP) with diameter around 15 nm was synthesis by microwaved method. We have successfully produce Ag(NP)/catechin/gelatin nanofiber composite by electrospinning process. Ag(NP)/catechin/gelatin nanofiber was synthesized by using gelatin from tuna fish, polyethylene oxide (PEO), acetic acid as solvent and silver nanoparticle(NP)/catechin as bioactive component, respectively. Morphology and structure of bioactive catechin-gelatin nanofiber were characterized by scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR), respectively. SEM analysis showed that morphology of nanofiber composite was smooth and had average diameter 398.97 nm. FTIR analysis results were used to confirm structure of catechin-gelatin nanofiber. It was confirmed by FTIR that specific vibration band peak amide A (N-H) at 3286,209 cm-1, amide B (N-H) 3069,396 cm-1, amide I (C=O) at 1643,813 cm-1, amide II (N-H and CN) at 1538,949 cm-1, amide III (C-N) at 1276,789 cm-1, C-O-C from polyethylene oxide at 1146,418 cm-1, respectively. When examined to S. Aureus bacteria, Ag/catechin/gelatin nanofiber show inhabitation performance around 40.44%. Ag(NP)/catechin/gelatin nanofiber has potential application antibacterial medical application.

  17. Green Tea Consumption after Intense Taekwondo Training Enhances Salivary Defense Factors and Antibacterial Capacity

    PubMed Central

    Lin, Shiuan-Pey; Li, Chia-Yang; Suzuki, Katsuhiko; Chang, Chen-Kang; Chou, Kuei-Ming; Fang, Shih-Hua

    2014-01-01

    The aim of this study was to investigate the short-term effects of green tea consumption on selected salivary defense proteins, antibacterial capacity and anti-oxidation activity in taekwondo (TKD) athletes, following intensive training. Twenty-two TKD athletes performed a 2-hr TKD training session. After training, participants ingested green tea (T, caffeine 6 mg/kg and catechins 22 mg/kg) or an equal volume of water (W). Saliva samples were collected at three time points: before training (BT-T; BT-W), immediately after training (AT-T; AT-W), and 30 min after drinking green tea or water (Rec-T; Rec-W). Salivary total protein, immunoglobulin A (SIgA), lactoferrin, α-amylase activity, free radical scavenger activity (FRSA) and antibacterial capacity were measured. Salivary total protein, lactoferrin, SIgA concentrations and α-amylase activity increased significantly immediately after intensive TKD training. After tea drinking and 30 min rest, α-amylase activity and the ratio of α-amylase to total protein were significantly higher than before and after training. In addition, salivary antibacterial capacity was not affected by intense training, but green tea consumption after training enhanced salivary antibacterial capacity. Additionally, we observed that salivary FRSA was markedly suppressed immediately after training and quickly returned to pre-exercise values, regardless of which fluid was consumed. Our results show that green tea consumption significantly enhances the activity of α-amylase and salivary antibacterial capacity. PMID:24498143

  18. Identification of epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG3''Me) and amino acid profiles in various tea (Camellia sinensis L.) cultivars.

    PubMed

    Ji, Hyang-Gi; Lee, Yeong-Ran; Lee, Min-Seuk; Hwang, Kyeng Hwan; Kim, Eun-Hee; Park, Jun Seong; Hong, Young-Shick

    2017-10-01

    This article includes experimental data on the identification of epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG3''Me) by 2-dimensional (2D) proton ( 1 H) NMR analysis and on the information of amino acid and catechin compound profiles by HPLC analysis in leaf extracts of various tea cultivars. These data are related to the research article " Metabolic phenotyping of various tea (Camellia sinensis L.) cultivars and understanding of their intrinsic metabolism " (Ji et al., 2017) [1]. The assignment for EGCG3x''Me by 1 H NMR analysis was also confirmed with spiking experiment of its pure chemical.

  19. Determination of catechins and catechin gallates in tissues by liquid chromatography with coulometric array detection and selective solid phase extraction.

    PubMed

    Chu, Kai On; Wang, Chi Chiu; Chu, Ching Yan; Rogers, Michael Scott; Choy, Kwong Wai; Pang, Chi Pui

    2004-10-25

    Catechins levels in organ tissues, particularly liver, determined by published methods are unexpectedly low, probably due to the release of oxidative enzymes, metal ions and reactive metabolites from tissue cells during homogenization and to the pro-oxidant effects of ascorbic acid during sample processing in the presence of metal ions. We describe a new method for simultaneous analysis of eight catechins in tissue: (+)-catechin (C), (-)-epicatechin (EC), (-)-gallocatechin (GC), (-)-epigallocatechin (EGC), (-)-catechin gallate (CG), (-)-epicatechin gallate (ECG), (-)-gallocatechin gallate (GCG) and (-)-epigallocatechin gallate (EGCG) (Fig. 1). The new extraction procedure utilized a methanol/ethylacetate/dithionite (2:1:3) mixture during homogenization for simultaneous enzyme precipitation and antioxidant protection. Selective solid phase extraction was used to remove most interfering bio-matrices. Reversed phase HPLC with CoulArray detection was used to determine the eight catechins simultaneously within 25 min. Good linearity (>0.9922) was obtained in the range 20-4000 ng/g. The coefficients of variance (CV) were less than 5%. Absolute recovery ranged from 62 to 96%, accuracy 92.5 +/- 4.5 to 104.9 +/- 6%. The detection limit was 5 ng/g. This method is capable for determining catechins in rat tissues of liver, brain, spleen, and kidney. The method is robust, reproducible, with high recovery, and has been validated for both in vitro and in vivo sample analysis.

  20. Green tea extracts reduce leukocyte cell-Derived chemotaxin 2 and selenoprotein P levels in the livers of C57BL/6J mice fed a high-fat diet.

    PubMed

    Onishi, Shintaro; Kitazawa, Hidefumi; Meguro, Shinichi; Tokimitsu, Ichiro

    2018-05-31

    Epidemiological studies suggest that green tea extracts (GTEs), including catechins such as epigallocatechin gallate and epicatechin gallate, have a beneficial effect on obesity, hyperglycemia, insulin resistance, endothelial dysfunction, and inflammation. Although several studies have shown that catechins directly modulate the cellular and molecular alterations in the liver tissue, the contributions of indirect mechanisms underlying these systemic effects of catechins remain unclear. In this study, we report that, in the C57BL/6J mouse liver, GTEs reduce high-fat diet-induced increases in the levels of hepatokines, liver-derived secretary proteins such as leukocyte cell-derived chemotaxin 2 and selenoprotein P production, which have been shown to induce systemic adverse effects, including several metabolic diseases. These findings suggest that the systemic effects of GTEs involve the regulation of hepatokine production as an indirect mechanism.

  1. [Study on extraction process of available components of tea].

    PubMed

    Bai, Qing-Qing; Liu, Yong-Feng; Guo, Mei; Zhao, Jian-Xi; Zhang, Tian-Cai; Di, Duo-Long

    2011-09-01

    To investigate the optimum ethanol extraction process conditions for the available components in the tea - Catechines (CT) including Epigallo catechin gallate (EGCG) and Caffeine (CF). The content of EGCG, CT and CF, extraction rate, DPPH * Free radical scavenging capacity were chosen as the assessment indexes. With the alcohol ratio (A), solid-liquid ratio (B) and reflux time (C) as investigation factors, the optimum ethanol extraction process of the available components from tea was determined by L9 (3(4)) orthogonal experimental design. It would obtain different extraction conditions to analyze the assessment indexes depending on the different extraction purposes. For the purpose of CT, the contents of EGCG and CT, extraction rate and DPPH * Free radical scavenging capacity were chosen as the assessment indexes, the optimum extraction conditions were selected as follows: the ratio of raw material to 75% alcohol was 1: 12, the reflux time was 30 minutes and extraction times were three; For the purpose of CF, the content of CF and extraction rate were chosen as the assessment indexes, the optimum extraction conditions were selected as follows: the ratio of raw material to 60% alcohol was 1: 12, the reflux time was 30 minutes and extraction times were three; For the purpose of integrated extraction, the contents of CT and CF, extraction rate and DPPH * Free radical scavenging capacity were chosen as the assessment indexes, the optimum extraction conditions were selected as follows: the ratio of raw material to 60% alcohol was 1: 8, the reflux time was 30 minutes and extraction times were three. The optimum extraction process in order to attain different purposes can give a reference to the research of a new medicine and industry production.

  2. Anti-proliferative and differentiation-inducing activities of the green tea catechin epigallocatechin-3-gallate (EGCG) on the human eosinophilic leukemia EoL-1 cell line.

    PubMed

    Lung, H L; Ip, W K; Wong, C K; Mak, N K; Chen, Z Y; Leung, K N

    2002-12-06

    A novel approach for the treatment of leukemia is the differentiation therapy in which immature leukemia cells are induced to attain a mature phenotype when exposed to differentiation inducers, either alone or in combinations with other chemotherapeutic or chemopreventive drugs. Over the past decade, numerous studies indicated that green tea catechins (GTC) could suppress the growth and induce apoptosis on a number of human cancer cell lines. However, the differentiation-inducing activity of GTC on human tumors remains poorly understood. In the present study, the effect of the major GTC epigallocatechin-3-gallate (EGCG) on the proliferation and differentiation of a human eosinophilc leukemic cell line, EoL-1, was examined. Our results showed that EGCG suppressed the proliferation of the EoL-1 cells in a dose-dependent manner, with an estimated IC(50) value of 31.5 microM. On the other hand, EGCG at a concentration of 40 microM could trigger the EoL-1 cells to undergo morphological differentiation into mature eosinophil-like cells. Using RT-PCR and flow cytometry, it was found that EGCG upregulated the gene and protein expression of two eosinophil-specific granule proteins, the major basic protein (MBP) and eosinophil peroxidase (EPO), in EoL-1 cells. Taken together, our findings suggest that EGCG can exhibit anti-leukemic activity on a human eosinophilic cell line EoL-1 by suppressing the proliferation and by inducing the differentiation of the leukemia cells.

  3. Impact of (±)-catechin on soil microbial communities

    PubMed Central

    Kaur, Rajwant; Kaur, Surinder

    2009-01-01

    Catechin is a highly studied but controversial allelochemical reported as a component of the root exudates of Centaurea maculosa. Initial reports of high and consistent exudation rates and soil concentrations have been shown to be highly inaccurate, but the chemical has been found in root exudates at and much less frequently in soil but sporadically at high concentrations. Part of the problem of detection and measuring phytotoxicity in natural soils may be due to the confounding effect of soil microbes, and little is known about interactions between catechin and soil microbes. Here we tested the effect of catechin on soil microbial communities and the feedback of these effects to two plant species. We found that catechin inhibits microbial activity in the soil we tested, and by doing so appears to promote plant growth in the microbe-free environment. This is in striking contrast to other in vitro studies, emphasizing the highly conditional effects of the chemical and suggesting that the phytotoxic effects of catechin may be exerted through the microbes in some soils. PMID:19704908

  4. Antioxidative activity of green tea treated with radical initiator 2, 2'-azobis(2-amidinopropane) dihydrochloride.

    PubMed

    Yokozawa, T; Cho, E J; Hara, Y; Kitani, K

    2000-10-01

    This study investigated the antioxidative activity of green tea extract, and a green tea tannin mixture and its components, under conditions of radical generation using the hydrophilic azo compound, 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) to generate peroxyl radicals at a constant and measurable rate in the cultured renal epithelial cell line, LLC-PK(1), which is susceptible to oxidative damage. Treatment with AAPH decreased cell viability and increased the formation of thiobarbituric acid-reactive substances. However, green tea extract, and the tannin mixture and its components, comprising (-)-epigallocatechin 3-O-gallate (EGCg), (-)-gallocatechin 3-O-gallate (GCg), (-)-epicatechin 3-O-gallate (ECg), (-)-epigallocatechin (EGC), (+)-gallocatechin (GC), (-)-epicatechin (EC), and (+)-catechin (C), showed protective activity against AAPH-induced cellular damage. The tannin mixture and its components exhibited higher antioxidative activity than the green tea extract. Furthermore, EGCg and GCg had higher activity than EGC and GC, respectively. In particular, EGCg exerted the most significant cellular protective activity against AAPH. These results indicate that green tea tannin may inhibit cellular loss and lipid peroxidation resulting from the peroxyl radical generated by AAPH, and that the chemical structure of tannin is also involved in the activity, suggesting that the O-dihydroxy structure in the B ring and the galloyl groups are important determinants for radical scavenging and antioxidative potential.

  5. Total phenolic content, antioxidant activity, and cross-cultural consumer rejection threshold in white and red wines functionally enhanced with catechin-rich extracts.

    PubMed

    Yoo, Yung J; Saliba, Anthony J; Prenzler, Paul D; Ryan, Danielle

    2012-01-11

    White and red wines spiked with catechin-rich green tea extract and grape seed extract were assessed for phenolic content, antioxidant activity, and cross-cultural consumer rejection thresholds in relation to wine as a functional food. Health functionality is an important factor in functional foods, and spiking pure compounds or plant extracts is an effective method to increase or control functionality. The total phenolic content and antioxidant activity were measured in wines spiked to different extract concentrations, namely, control and 50, 100, 200, 400, and 800 mg/L, to confirm the dose-response curves in both white and red wines. Consumer rejection thresholds (CRTs) were established for spiked wines in a Korean and in an Australian population. Our results showed that the green tea extract and grape seed extract increased the antioxidant activity dose dependently, and the CRTs varied considerably between the Korean and the Australian groups, with Koreans preferring wines spiked with green tea extract and Australians showing a preference for wines spiked with grape seed extract. These results have implications for producing wine products that are enhanced in phenolic compounds and targeted to different cultural groups.

  6. The Minnesota Green Tea Trial (MGTT), a randomized controlled trial of the efficacy of green tea extract on biomarkers of breast cancer risk: Study rationale, design, methods, and participant characteristics

    PubMed Central

    Samavat, Hamed; Dostal, Allison M.; Wang, Renwei; Bedell, Sarah; Emory, Tim H.; Ursin, Giske; Torkelson, Carolyn J.; Gross, Myron D.; Le, Chap T.; Yu, Mimi C.; Yang, Chung S.; Yee, Douglas; Wu, Anna H.; Yuan, Jian-Min; Kurzer, Mindy S.

    2015-01-01

    Purpose The Minnesota Green Tea Trial (MGTT) was a randomized, placebo-controlled, double-blinded trial investigating the effect of daily green tea extract consumption for 12 months on biomarkers of breast cancer risk. Methods Participants were healthy postmenopausal women at high risk of breast cancer due to dense breast tissue with differing catechol-O-methyltransferase (COMT) genotypes. The intervention was a green tea catechin extract containing 843.0 ± 44.0 mg/day epigallocatechin gallate or placebo capsules for one year. Annual digital screening mammograms were obtained at baseline and month 12, and fasting blood and 24-hour urine samples were provided at baseline, months 6, and 12. Primary endpoints included changes in percent mammographic density, circulating endogenous sex hormones and insulin-like growth factor axis proteins; secondary endpoints were changes in urinary estrogens and estrogen metabolites and circulating F2-isoprostanes, a biomarker of oxidative stress. Results The MGTT screened more than 100,000 mammograms and randomized 1075 participants based on treatment (green tea extract vs. placebo), stratified by COMT genotype activity (high COMT vs. low/intermediate COMT genotype activity). 937 women successfully completed the study and 138 dropped out (overall dropout rate= 12.8%). Conclusions In this paper we report the rationale, design, recruitment, participant characteristics, and methods for biomarker and statistical analyses. PMID:26206423

  7. Tea Catechins Protect Goat Skeletal Muscle against H₂O₂-Induced Oxidative Stress by Modulating Expression of Phase 2 Antioxidant Enzymes.

    PubMed

    Zhong, Rong-Zhen; Fang, Yi; Qin, Gui-Xin; Li, Hao-Yang; Zhou, Dao-Wei

    2015-09-16

    To study the mechanisms of tea catechins (TCs) in goat muscles against oxidative stress, skeletal muscle cells (SMCs) induced by H2O2 or not were incubated with TCs or 3H-1,2-dithiole-3-thione (D3T) and were defined as H2O2, H2O2D3T, H2O2TC, D3T, and TC treatments, respectively. Results showed that, similar to effects of D3T, TCs regulated mRNA and protein expression of antioxidant enzymes by suppressing Keap1 protein expression in SMCs from 1.58 ± 0.12 to 0.71 ± 0.21 and 1.03 ± 0.11 in H2O2TC and TC groups, respectively; however, effects differed in oxidative condition of cells and among enzymes. In stressed cells, TCs increased catalase and glutathione S-transferases (GST) activities (P < 0.001), whereas both enzymes' activities decreased (P < 0.001) to 2.97 ± 0.37 U/mg protein or 42.1 ± 1.85 mU/mg protein, respectively, in unstressed SMCs. Subsequently, an in vivo experiment in goats fed grain supplemented with TCs or D3T following infusion with H2O2 was conducted to further verify mechanisms of TC action. As seen in vitro, TCs reduced Keap1 protein expression (P < 0.001) from 2.11 ± 0.37 to 1.34 ± 0.13 and 1.43 ± 0.23 in H2O2TC and TC groups, respectively, in muscle. However, dietary TCs increased plasma CuZn superoxide dismutase and GST activities (P < 0.001) regardless of oxidative stress. Moreover, feeding TCs to goats under both conditions increased meat color and tenderness (P ≤ 0.001). In conclusion, TCs protected goat muscles against oxidative stress and subsequently improved meat quality by modulating phase 2 antioxidant enzymes and Keap1 expression.

  8. Inhibition of FLT3 Expression by Green Tea Catechins in FLT3 Mutated-AML Cells

    PubMed Central

    Ly, Bui Thi Kim; Chi, Hoang Thanh; Yamagishi, Makoto; Kano, Yasuhiko; Hara, Yukihiko; Nakano, Kazumi; Sato, Yuko; Watanabe, Toshiki

    2013-01-01

    Acute myeloid leukemia (AML) is a heterogeneous disease characterized by a block in differentiation and uncontrolled proliferation. FLT3 is a commonly mutated gene found in AML patients. In clinical trials, the presence of a FLT3-ITD mutation significantly correlates with an increased risk of relapse and dismal overall survival. Therefore, activated FLT3 is a promising molecular target for AML therapies. In this study, we have shown that green tea polyphenols including (−)-epigallocatechin-3-gallate (EGCG), (−)-epigallocatechin (EGC), and (−)-epicatechin-3-gallate (ECG) suppress the proliferation of AML cells. Interestingly, EGCG, EGC and ECG showed the inhibition of FLT3 expression in cell lines harboring FLT3 mutations. In the THP-1 cells harboring FLT3 wild-type, EGCG showed the suppression of cell proliferation but did not suppress the expression of FLT3 even at the concentration that suppress 100% cell proliferation. Moreover, EGCG-, EGC-and ECG-treated cells showed the suppression of MAPK, AKT and STAT5 phosphorylation. Altogether, we suggest that green tea polyphenols could serve as reagents for treatment or prevention of leukemia harboring FLT3 mutations. PMID:23840454

  9. Comparative Transcriptome Analysis of Chinary, Assamica and Cambod tea (Camellia sinensis) Types during Development and Seasonal Variation using RNA-seq Technology

    NASA Astrophysics Data System (ADS)

    Kumar, Ajay; Chawla, Vandna; Sharma, Eshita; Mahajan, Pallavi; Shankar, Ravi; Yadav, Sudesh Kumar

    2016-11-01

    Tea quality and yield is influenced by various factors including developmental tissue, seasonal variation and cultivar type. Here, the molecular basis of these factors was investigated in three tea cultivars namely, Him Sphurti (H), TV23 (T), and UPASI-9 (U) using RNA-seq. Seasonal variation in these cultivars was studied during active (A), mid-dormant (MD), dormant (D) and mid-active (MA) stages in two developmental tissues viz. young and old leaf. Development appears to affect gene expression more than the seasonal variation and cultivar types. Further, detailed transcript and metabolite profiling has identified genes such as F3‧H, F3‧5‧H, FLS, DFR, LAR, ANR and ANS of catechin biosynthesis, while MXMT, SAMS, TCS and XDH of caffeine biosynthesis/catabolism as key regulators during development and seasonal variation among three different tea cultivars. In addition, expression analysis of genes related to phytohormones such as ABA, GA, ethylene and auxin has suggested their role in developmental tissues during seasonal variation in tea cultivars. Moreover, differential expression of genes involved in histone and DNA modification further suggests role of epigenetic mechanism in coordinating global gene expression during developmental and seasonal variation in tea. Our findings provide insights into global transcriptional reprogramming associated with development and seasonal variation in tea.

  10. Comparative Transcriptome Analysis of Chinary, Assamica and Cambod tea (Camellia sinensis) Types during Development and Seasonal Variation using RNA-seq Technology.

    PubMed

    Kumar, Ajay; Chawla, Vandna; Sharma, Eshita; Mahajan, Pallavi; Shankar, Ravi; Yadav, Sudesh Kumar

    2016-11-17

    Tea quality and yield is influenced by various factors including developmental tissue, seasonal variation and cultivar type. Here, the molecular basis of these factors was investigated in three tea cultivars namely, Him Sphurti (H), TV23 (T), and UPASI-9 (U) using RNA-seq. Seasonal variation in these cultivars was studied during active (A), mid-dormant (MD), dormant (D) and mid-active (MA) stages in two developmental tissues viz. young and old leaf. Development appears to affect gene expression more than the seasonal variation and cultivar types. Further, detailed transcript and metabolite profiling has identified genes such as F3'H, F3'5'H, FLS, DFR, LAR, ANR and ANS of catechin biosynthesis, while MXMT, SAMS, TCS and XDH of caffeine biosynthesis/catabolism as key regulators during development and seasonal variation among three different tea cultivars. In addition, expression analysis of genes related to phytohormones such as ABA, GA, ethylene and auxin has suggested their role in developmental tissues during seasonal variation in tea cultivars. Moreover, differential expression of genes involved in histone and DNA modification further suggests role of epigenetic mechanism in coordinating global gene expression during developmental and seasonal variation in tea. Our findings provide insights into global transcriptional reprogramming associated with development and seasonal variation in tea.

  11. Green tea: a novel functional food for the oral health of older adults.

    PubMed

    Gaur, Sumit; Agnihotri, Rupali

    2014-04-01

    Functional foods are foods with positive health effects that extend beyond their nutritional value. They affect the function of the body and help in the management of specific health conditions. Green tea, a time-honoured Chinese herb, might be regarded as a functional food because of its inherent anti-oxidant, anti-inflammatory, antimicrobial and antimutagenic properties. They are attributed to its reservoir of polyphenols, particularly the catechin, epigallocatechin-3-gallate. Owing to these beneficial actions, this traditional beverage was used in the management of chronic systemic diseases including cancer. Recently, it has been emphasized that the host immuno-inflammatory reactions destroy the oral tissues to a greater extent than the microbial activity alone. Green tea with its wide spectrum of activities could be a healthy alternative for controlling these damaging reactions seen in oral diseases, specifically, chronic periodontitis, dental caries and oral cancer, which are a common occurrence in the elderly population. © 2013 Japan Geriatrics Society.

  12. Tea Derived Galloylated Polyphenols Cross-Link Purified Gastrointestinal Mucins

    PubMed Central

    Georgiades, Pantelis; Pudney, Paul D. A.; Rogers, Sarah; Thornton, David J.; Waigh, Thomas A.

    2014-01-01

    Polyphenols derived from tea are thought to be important for human health. We show using a combination of particle tracking microrheology and small-angle neutron scattering that polyphenols acts as cross-linkers for purified gastrointestinal mucin, derived from the stomach and the duodenum. Both naturally derived purified polyphenols, and green and black tea extracts are shown to act as cross-linkers. The main active cross-linking component is found to be the galloylated forms of catechins. The viscosity, elasticity and relaxation time of the mucin solutions experience an order of magnitude change in value upon addition of the polyphenol cross-linkers. Similarly small-angle neutron scattering experiments demonstrate a sol-gel transition with the addition of polyphenols, with a large increase in the scattering at low angles, which is attributed to the formation of large scale (>10 nm) heterogeneities during gelation. Cross-linking of mucins by polyphenols is thus expected to have an impact on the physicochemical environment of both the stomach and duodenum; polyphenols are expected to modulate the barrier properties of mucus, nutrient absorption through mucus and the viscoelastic microenvironments of intestinal bacteria. PMID:25162539

  13. Development and validation of a high throughput assay for the quantification of multiple green tea-derived catechins in human plasma.

    PubMed

    Mawson, Deborah H; Jeffrey, Keon L; Teale, Philip; Grace, Philip B

    2018-06-19

    A rapid, accurate and robust method for the determination of catechin (C), epicatechin (EC), gallocatechin (GC), epigallocatechin (EGC), catechin gallate (Cg), epicatechin gallate (ECg), gallocatechin gallate (GCg) and epigallocatechin gallate (EGCg) concentrations in human plasma has been developed. The method utilises protein precipitation following enzyme hydrolysis, with chromatographic separation and detection using reversed-phase liquid chromatography - tandem mass spectrometry (LC-MS/MS). Traditional issues such as lengthy chromatographic run times, sample and extract stability, and lack of suitable internal standards have been addressed. The method has been evaluated using a comprehensive validation procedure, confirming linearity over appropriate concentration ranges, and inter/intra batch precision and accuracies within suitable thresholds (precisions within 13.8% and accuracies within 12.4%). Recoveries of analytes were found to be consistent between different matrix samples, compensated for using suitable internal markers and within the performance of the instrumentation used. Similarly, chromatographic interferences have been corrected using the internal markers selected. Stability of all analytes in matrix is demonstrated over 32 days and throughout extraction conditions. This method is suitable for high throughput sample analysis studies. This article is protected by copyright. All rights reserved.

  14. [Relationship between the anti-hemolysin activity and the structure of catechins and theaflavins].

    PubMed

    Ikigai, H; Toda, M; Okubo, S; Hara, Y; Shimamura, T

    1990-11-01

    We examined the corresponding isomers of catechins and theaflavins for anti-hemolysin activities against Staphylococcus aureus alpha-toxin and Vibrio cholerae O1 hemolysin. Catechins and theaflavins showed anti-hemolysin activities in a dose-dependent manner. Among the catechins tested, (-)catechin gallate, (-)epicatechin gallate and (-)epigallocatechin gallate having galloyl groups in their molecules showed more potent anti-hemolysin activities against both toxins. On the other hand, free catechins, i. e. (-)catechin, (-)gallocatechin, (-) epicatechin and (-)epigallocatechin had low anti-hemolysin activities against alpha-toxin. Although (-)catechin or (-)gallocatechin had no effect on cholera hemolysin, (-) epicatechin and (-)epigallocatechin were slightly inhibitory. Among dextrocatechins, (+) epicatechin and (+)epigallocatechin proved to be more effective than (+)catechin and (+) gallocatechin. The anti-hemolysin activities of theaflavins against alpha-toxin and cholera hemolysin were dependent on the number of the galloyl group in their structure. These results suggest that the tertiary structure of the catechin or theaflavin and the active site of hemolysin, that affects the interaction between them, plays an important role in the anti-hemolysin activity.

  15. An Integrated Metagenomics/Metaproteomics Investigation of the Microbial Communities and Enzymes in Solid-state Fermentation of Pu-erh tea

    PubMed Central

    Zhao, Ming; Zhang, Dong-lian; Su, Xiao-qin; Duan, Shuang-mei; Wan, Jin-qiong; Yuan, Wen-xia; Liu, Ben-ying; Ma, Yan; Pan, Ying-hong

    2015-01-01

    Microbial enzymes during solid-state fermentation (SSF), which play important roles in the food, chemical, pharmaceutical and environmental fields, remain relatively unknown. In this work, the microbial communities and enzymes in SSF of Pu-erh tea, a well-known traditional Chinese tea, were investigated by integrated metagenomics/metaproteomics approach. The dominant bacteria and fungi were identified as Proteobacteria (48.42%) and Aspergillus (94.98%), through pyrosequencing-based analyses of the bacterial 16S and fungal 18S rRNA genes, respectively. In total, 335 proteins with at least two unique peptides were identified and classified into 28 Biological Processes and 35 Molecular Function categories using a metaproteomics analysis. The integration of metagenomics and metaproteomics data demonstrated that Aspergillus was dominant fungus and major host of identified proteins (50.45%). Enzymes involved in the degradation of the plant cell wall were identified and associated with the soft-rotting of tea leaves. Peroxiredoxins, catalase and peroxidases were associated with the oxidation of catechins. In conclusion, this work greatly advances our understanding of the SSF of Pu-erh tea and provides a powerful tool for studying SSF mechanisms, especially in relation to the microbial communities present. PMID:25974221

  16. Magnetic catechin-dextran conjugate as targeted therapeutic for pancreatic tumour cells.

    PubMed

    Vittorio, Orazio; Voliani, Valerio; Faraci, Paolo; Karmakar, Biswajit; Iemma, Francesca; Hampel, Silke; Kavallaris, Maria; Cirillo, Giuseppe

    2014-06-01

    Catechin-dextran conjugates have recently attracted a lot of attention due to their anticancer activity against a range of cancer cells. Magnetic nanoparticles have the ability to concentrate therapeutically important drugs due to their magnetic-spatial control and provide opportunities for targeted drug delivery. Enhancement of the anticancer efficiency of catechin-dextran conjugate by functionalisation with magnetic iron oxide nanoparticles. Modification of the coating shell of commercial magnetic nanoparticles (Endorem) composed of dextran with the catechin-dextran conjugate. Catechin-dextran conjugated with Endorem (Endo-Cat) increased the intracellular concentration of the drug and it induced apoptosis in 98% of pancreatic tumour cells placed under magnetic field. The conjugation of catechin-dextran with Endorem enhances the anticancer activity of this drug and provides a new strategy for targeted drug delivery on tumour cells driven by magnetic field. The ability to spatially control the delivery of the catechin-dextran by magnetic field makes it a promising agent for further application in cancer therapy.

  17. The green tea catechin epigallocatechin gallate induces cell cycle arrest and shows potential synergism with cisplatin in biliary tract cancer cells.

    PubMed

    Mayr, Christian; Wagner, Andrej; Neureiter, Daniel; Pichler, Martin; Jakab, Martin; Illig, Romana; Berr, Frieder; Kiesslich, Tobias

    2015-06-23

    The green tea catechin epigallocatechin gallate (EGCG) was shown to effectively inhibit tumor growth in various types of cancer including biliary tract cancer (BTC). For most BTC patients only palliative therapy is possible, leading to a median survival of about one year. Chemoresistance is a major problem that contributes to the high mortality rates of BTC. The aim of this study was to investigate the cytotoxic effect of EGCG alone or in combination with cisplatin on eight BTC cell lines and to investigate the cellular anti-cancer mechanisms of EGCG. The effect of EGCG treatment alone or in combination with the standard chemotherapeutic cisplatin on cell viability was analyzed in eight BTC cell lines. Additionally, we analyzed the effects of EGCG on caspase activity, cell cycle distribution and gene expression in the BTC cell line TFK-1. EGCG significantly reduced cell viability in all eight BTC cell lines (p < 0.05 or p < 0.01, respectively, for most cell lines and EGCG concentrations > 5 μM). Combined EGCG and cisplatin treatment showed a synergistic cytotoxic effect in five cell lines and an antagonistic effect in two cell lines. Furthermore, EGCG reduced the mRNA levels of various cell cycle-related genes, while increasing the expression of the cell cycle inhibitor p21 and the apoptosis-related death receptor 5 (p < 0.05). This observation was accompanied by an increase in caspase activity and cells in the sub-G1 phase of the cell cycle, indicating induction of apoptosis. EGCG also induced a down-regulation of expression of stem cell-related genes and genes that are associated with an aggressive clinical character of the tumor, such as cd133 and abcg2. EGCG shows various anti-cancer effects in BTC cell lines and might therefore be a potential anticancer drug for future studies in BTC. Additionally, EGCG displays a synergistic cytotoxic effect with cisplatin in most tested BTC cell lines. Graphical abstract Summary illustration.

  18. Tunneling in green tea: understanding the antioxidant activity of catechol-containing compounds. A variational transition-state theory study.

    PubMed

    Tejero, Ismael; Gonzalez-García, Núria; Gonzalez-Lafont, Angels; Lluch, José M

    2007-05-09

    The catechol functionality present in the catechins is responsible for the protective effects exerted by green tea against a wide range of human diseases. High-level electronic structure calculations and canonical variational transition-state theory including multidimensional tunneling corrections have allowed us to understand the key factors of the antioxidant effectiveness of the catechol group. This catechol group forms two hydrogen bonds with the two oxygen atoms of the lipid peroxyl radical, leading to a very compact reactant complex. This fact produces an extremely narrow adiabatic potential-energy profile corresponding to the hydrogen abstraction by the peroxyl radical, which makes it possible for a huge tunneling contribution to take place. So, quantum-mechanical tunneling highly increases the corresponding rate constant value, in such a way that catechins become able to trap the lipid peroxyl radicals in a dominant competition with the very damaging free-radical chain-lipid peroxidation reaction.

  19. Conventional and Accelerated-Solvent Extractions of Green Tea (Camellia sinensis) for Metabolomics-based Chemometrics

    PubMed Central

    Kellogg, Joshua J.; Wallace, Emily D.; Graf, Tyler N.; Oberlies, Nicholas H.; Cech, Nadja B.

    2018-01-01

    Metabolomics has emerged as an important analytical technique for multiple applications. The value of information obtained from metabolomics analysis depends on the degree to which the entire metabolome is present and the reliability of sample treatment to ensure reproducibility across the study. The purpose of this study was to compare methods of preparing complex botanical extract samples prior to metabolomics profiling. Two extraction methodologies, accelerated solvent extraction and a conventional solvent maceration, were compared using commercial green tea [Camellia sinensis (L.) Kuntze (Theaceae)] products as a test case. The accelerated solvent protocol was first evaluated to ascertain critical factors influencing extraction using a D-optimal experimental design study. The accelerated solvent and conventional extraction methods yielded similar metabolite profiles for the green tea samples studied. The accelerated solvent extraction yielded higher total amounts of extracted catechins, was more reproducible, and required less active bench time to prepare the samples. This study demonstrates the effectiveness of accelerated solvent as an efficient methodology for metabolomics studies. PMID:28787673

  20. Laboratory Studies on Weight Control and Prevention of Metabolic Syndrome by Green Tea1

    PubMed Central

    Sudathip, Sae-tan; Grove, Kimberly A.; Lambert, Joshua D.

    2011-01-01

    Green tea (Camellia sinensis, Theaceace) is the second most popular beverage in the world and has been extensively studied for its putative disease preventive effects. Green tea is characterized by the presence of a high concentrations of polyphenolic compounds known as catechins, with (−)-epigallocatechin-3-gallate (EGCG) being the most abundant and most well-studied. Metabolic syndrome (MetS) is a complex condition that is defined by the presence of elevated waist circumference, dysglycemia, elevated blood pressure, decrease serum high density lipoprotein-associated cholesterol, and increased serum triglycerides. Studies in both in vitro and laboratory animal models have examined the preventive effects of green tea and EGCG against the symptoms of MetS. Overall, the results of these studies have been promising and demonstrate that green tea and EGCG have preventive effects in both genetic and dietary models of obesity, insulin resistance, hypertension, and hypercholesterolemia. Various mechanisms have been proposed based on these studies and include: modulation of dietary fat absorption and metabolism, increased glucose utilization, decreased de novo lipogenesis, enhanced vascular responsiveness, and antioxidative effects. In the present review, we discuss the current state of the science with regard to laboratory studies on green tea and MetS. We attempt to critically evaluate the available data and point out areas for future research. Although there is a considerable amount of data available, questions remain in terms of the primary mechanism(s) of action, the dose-response relationships involved, and the best way to translate the results to human intervention studies. PMID:21193040

  1. Comparison of the bioavailability of quercetin and catechin in rats.

    PubMed

    Manach, C; Texier, O; Morand, C; Crespy, V; Régérat, F; Demigné, C; Rémésy, C

    1999-12-01

    Quercetin and catechin are present in noticeable amounts in human diet and these polyphenolic compounds are supposed to exert beneficial effects on human health. However, their metabolic fates in the organism have never been compared. In the present study, rats were fed a 0.25% quercetin or a 0.25% catechin diet. Quercetin and catechin metabolites were analyzed in plasma and liver samples by high-performance liquid chromatography coupled to an ultraviolet or a multielectrode coulometric detection. All plasma metabolites were present as conjugated forms, but catechin metabolites were mainly constituted by glucuronidated derivatives, whereas quercetin metabolites were sulfo- and glucurono-sulfo conjugates. Quercetin was more intensively methylated than catechin in plasma. The plasma quercetin metabolites are well maintained during the postabsorptive period (approximately 50 microM), whereas the concentration of catechin metabolites dropped dramatically between 12- and 24-h after an experimental meal (from 38.0 to 4.5 microM). In the liver, the concentrations of quercetin and catechin derivatives were lower than in plasma, and no accumulation was observed when the rats were adapted for 14 d to the supplemented diets. The hepatic metabolites were intensively methylated (90-95%), but in contrast to plasma, some free aglycones could be detected. Thus, it clearly appears that studies dealing with the biological impact of these polyphenols should take into account the feature of their bioavailability, particularly the fact that their circulating metabolites are conjugated derivatives.

  2. Green tea catechin plus caffeine supplementation to a high-protein diet has no additional effect on body weight maintenance after weight loss.

    PubMed

    Hursel, Rick; Westerterp-Plantenga, Margriet S

    2009-03-01

    Green tea (epigallocatechin gallate + caffeine) and protein each were shown to improve body weight maintenance after weight loss. We investigated the effect of a green tea-caffeine mixture added to a high-protein (HP) diet on weight maintenance (WM) after body weight loss in moderately obese subjects. A randomized, placebo-controlled, double-blind parallel trial was conducted in 80 overweight and moderately obese subjects [age (mean +/- SD): 44 +/- 2 y; body mass index (BMI; in kg/m(2)): 29.6 +/- 2.0] matched for sex, age, BMI, height, body mass, and with a habitually low caffeine intake. A very-low-energy diet intervention during 4 wk was followed by 3 mo of WM; during the WM period, the subjects received a green tea-caffeine mixture (270 mg epigallocatechin gallate + 150 mg caffeine/d) or placebo, both in addition to an adequate protein (AP) diet (50-60 g protein/d) or an HP diet (100-120 g protein/d). Subjects lost 7.0 +/- 1.6 kg, or 8.2 +/- 2.0%, body weight (P < 0.001). During the WM phase, WM, resting energy expenditure, and fat-free mass (FFM) increased relatively in both the HP groups and in the AP + green tea-caffeine mixture group (P < 0.05), whereas respiratory quotient and body fat mass decreased, all compared with the AP + placebo group. Satiety increased only in both HP groups (P < 0.05). The green tea-caffeine mixture was only effective with the AP diet. The green tea-caffeine mixture, as well as the HP diet, improved WM independently through thermogenesis, fat oxidation, sparing FFM, and, for the HP diet, satiety; a possible synergistic effect failed to appear.

  3. Investigate the Binding of Catechins to Trypsin Using Docking and Molecular Dynamics Simulation

    PubMed Central

    Cui, Fengchao; Yang, Kecheng; Li, Yunqi

    2015-01-01

    To explore the inhibitory mechanism of catechins for digestive enzymes, we investigated the binding mode of catechins to a typical digestive enzyme-trypsin and analyzed the structure-activity relationship of catechins, using an integration of molecular docking, molecular dynamics simulation and binding free energy calculation. We found that catechins with different structures bound to a conservative pocket S1 of trypsin, which is comprised of residues 189–195, 214–220 and 225–228. In the trypsin-catechin complexes, Asp189 by forming strong hydrogen bonding, and Gln192, Trp215 and Gly216 through hydrophobic interactions, all significantly contribute to the binding of catechins. The number and the position of hydroxyl and aromatic groups, the structure of stereoisomers, and the orientation of catechins in the binding pocket S1 of trypsin all affect the binding affinity. The binding affinity is in the order of Epigallocatechin gallate (EGCG) > Epicatechin gallate (ECG) > Epicatechin (EC) > Epigallocatechin (EGC), and 2R-3R EGCG shows the strongest binding affinity out of other stereoisomers. Meanwhile, the synergic conformational changes of residues and catechins were also analyzed. These findings will be helpful in understanding the knowledge of interactions between catechins and trypsin and referable for the design of novel polyphenol based functional food and nutriceutical formulas. PMID:25938485

  4. [Morphologic studies of the protective role of catechin on kanamycin otoneurotoxicity in SD rats].

    PubMed

    Liu, Guo-hui; Xie, Ding-hua; Wu, Wei-jing

    2002-12-28

    To determine the protection of catechin on aminoglycoside antibiotics otoneurotoxicity in SD rats, and observe the morphologic changes of cochlear efferent nerve terminals and outer hair cells after the injection of kanamycin and the feeding of catechin by the stomach tube. Thirty-eight SD rats were randomly assigned into three experimental groups (KM-treated, catechin-treated, KM and catechin in combination) and one control group. The KM-treated group was given kanamycin in a dose of 500 mg.(kg.d)-1 for 14 days. The catechin-treated group was given catechin once by the stomach tube in a dose of 400 mg.(kg.d)-1. Two kinds of medicine were simultaneously given in the KM+ catechin group. Transmission electron microscopy was utilized to observe the subcellular structure of efferent nerve fibers and outer hair cells. The densities of efferent nerve fibers and terminals were examined and the numbers of efferent nerve fibers and terminals were numerated by the surface preparation using modified histochemical staining for acetylcholinesterase (AchE). The damage in the group protected by catechin was relieved compared with the unprotected group. No damage was found in the catechin-treated alone group and controls. The densities and numbers of efferent nerve fibers and terminals were obviously fewer in the unprotected group than in the protected group and controls(P < 0.05). There was no significant difference in the numbers of efferent nerve fibers and terminals of the group protected by catechin compared with the controls and the catechin-treated group (P > 0.05). Catechin significantly protects MOC efferent nerves in kanamycin otoneurotoxicity.

  5. Determination of catechin in lotus rhizomes by high-performance liquid chromatography.

    PubMed

    Yan, Shou-Lei; Wang, Qing-Zhang; Peng, Guang-Hua

    2009-08-01

    A novel method was developed to analyze lotus rhizome polyphenolic catechin using high-performance liquid chromatography (HPLC). The retain time of catechin was 14.72 min under the optimized condition. Mass spectrometry was further employed to qualify and quantify the purity of the catechin peak. Good linearity (R=0.9997) was obtained within the range of 50-1,000 ng. The coefficient of variance was determined as 5.2%, with a recovery rate of 97%. The detection and quantification limitations of catechin were 23 ng and 50 ng, respectively. The catechin level was 0.0025% in the lotus rhizome, and 0.011% in the knot of the lotus rhizome (Nelumbo nucifera cv. 'damao jie'). The optimized conditions of HPLC for catechin detection in the lotus rhizome matrix were as follows: the SuperlcosIL™ LC-18 analytical column (150 mm×4.6 mm, 5 µm), methanol-water-acetic acid (10:90:1, volume ratio) as the mobile phase, an UV detector at 280 nm, a flow rate of 0.8 ml/min, column temperature at 30°C, and an injection volume of 10 µl.

  6. [Effect of green tea or green tea extract consumption on body weight and body composition; systematic review and meta-analysis].

    PubMed

    Baladia, Eduard; Basulto, Julio; Manera, María; Martínez, Rodrigo; Calbet, David

    2014-03-01

    Caffeine and catechins contained in green tea may have a thermogenic effect favoring weight and body fat loss. The aim of this study is to evaluate the magnitude of the effect of green tea or its extracts (caffeine and catechins) on body weight and body composition. A systematic review and meta-analysis was conducted to determine the magnitude of the effect of green tea or its extracts on body weight (kg), body mass index (BMI) (kg/m2), fat mass (%), and waist and hip circumference (cm). We included studies published between 2000 and 2013, retrieved from PubMed/Medline with the following characteristics: randomized controlled trials (RCTs) of parallel groups (intervention and placebo), randomized, double-blind, and a minimum 12-week follow-up, in healthy individuals of either gender, 18 years or older, with a BMI of 25-40 kg/m2. Quality and risk of bias was assessed for every included study, and the statistical analysis was performed with the Crochrane Collaboration RevMan 5.1.6 software, according to the random effects model with a confidence interval of 95% (95%). It was established that the effect was statistically significant at p < 0.05, and the homogeneity of the studies was assessed using the I2 index. The search strategy retrieved 154 studies, of which only five could be included in the quantitative analysis. The analysis revealed a not statistically significant mean difference (MD) in weight loss in the analyzed sample and subgroups: Asian individuals -0.81 kg (95% CI: -2.76 to 1.13; P = 0.41; I2 = 0%, n = 210), Caucasians -0.73 kg (95% CI: -3.22 to 1.75; P = 0.45; I2 = 0%; n = 91), as well as in the sample as a whole: -0.78 kg (95% CI: -2.31 to 0.75; P = 0.32; I2 = 0%; n = 301). No statistically significant decrease was revealed in BMI in the analyzed sample and subgroups: Asian individuals -0.65 (95% CI: -1.85 to 0.54; P = 0.29; I2 = 0%; n = 71), -0.21 Caucasians (95% CI: -0.96 to 0.53; P = 0.58; I2 = 22%; n = 91), as well as in the sample as a whole: -0

  7. Oolong tea prevents cardiomyocyte loss against hypoxia by attenuating p-JNK mediated hypertrophy and enhancing P-IGF1R, p-akt, and p-Badser136 activity and by fortifying NRF2 antioxidation system.

    PubMed

    Shibu, Marthandam Asokan; Kuo, Chia-Hua; Chen, Bih-Cheng; Ju, Da-Tong; Chen, Ray-Jade; Lai, Chao-Hung; Huang, Pei-Jane; Viswanadha, Vijaya Padma; Kuo, Wei-Wen; Huang, Chih-Yang

    2018-02-01

    Tea, the most widely consumed natural beverage has been associated with reduced mortality risk from cardiovascular disease. Oolong tea is a partially fermented tea containing high levels of catechins, their degree of oxidation varies between 20%-80% causing differences in their active metabolites. In this study we examined the effect of oolong tea extract (OTE) obtained by oxidation at low-temperature for short-time against hypoxic injury and found that oolong tea provides cyto-protective effects by suppressing the JNK mediated hypertrophic effects and by enhancing the innate antioxidant mechanisms in neonatal cardiomyocytes and in H9c2 cells. OTE effectively attenuates 24 h hypoxia-triggered cardiomyocyte loss by suppressing caspase-3-cleavage and apoptosis in a dose-dependent manner. OTE also enhances the IGFIR/p-Akt associated survival-mechanism involving the elevation of p-Bad ser136 in a dose-dependent manner to aid cellular adaptations against hypoxic challenge. The results show the effects and mechanism of Oolong tea to provide cardio-protective benefits during hypoxic conditions. © 2017 Wiley Periodicals, Inc.

  8. Facile synthesis of amine-functional reduced graphene oxides as modified quick, easy, cheap, effective, rugged and safe adsorbent for multi-pesticide residues analysis of tea.

    PubMed

    Ma, Guicen; Zhang, Minglu; Zhu, Li; Chen, Hongping; Liu, Xin; Lu, Chengyin

    2018-01-05

    Amine-functional reduced graphene oxide (amine-rGO) with different carbon chain length amino groups were successfully synthesized. The graphene oxides (GO) reduction as well as amino grafting were achieved simultaneously in one step via a facile solvothermal synthetic strategy. The obtained materials were characterized by X-ray diffraction, Raman spectroscopy, Fourier-transform infrared spectrometry and X-ray photoelectron spectroscopy to confirm the modification of GO with different amino groups. The adsorption performance of catechins and caffeine from tea acetonitrile extracts on different amine functional rGO samples were evaluated. It was found that tributylamine-functional rGO (tri-BuA-rGO) exhibited the highest adsorption ability for catechins and caffeine compared to GO and other amino group functional rGO samples. It was worth to note that the adsorption capacity of catechins on tri-BuA-rGO was 11 times higher than that of GO (203.7mgg -1 vs 18.7mgg -1 ). Electrostatic interaction, π-π interaction and surface hydrophilic-hydrophobic properties of tri-BuA-rGO played important roles in the adsorption of catechins as well as caffeine. The gravimetric analysis confirmed that the tri-BuA-rGO achieved the highest efficient cleanup preformance compared with traditional dispersive solid phase extraction (dSPE) adsorbents like primary-secondary amine (PSA), graphitized carbon black (GCB) or C18. A multi-pesticides analysis method based on tri-BuA-rGO is validated on 33 representative pesticides in tea using gas chromatography coupled to tandem mass spectrometry or high-performance liquid chromatography coupled with tandem mass spectrometry. The analysis method gave a high coefficient of determination (r 2 >0.99) for each pesticide and satisfactory recoveries in a range of 72.1-120.5%. Our study demonstrated that amine functional rGO as a new type of QuEChERS adsorbent is expected to be widely applied for analysis of pesticides at trace levels. Copyright © 2017

  9. Evaluation of green tea extract as a safe personal hygiene against viral infections.

    PubMed

    Lee, Yun Ha; Jang, Yo Han; Kim, Young-Seok; Kim, Jinku; Seong, Baik Lin

    2018-01-01

    Viral infections often pose tremendous public health concerns as well as economic burdens. Despite the availability of vaccines or antiviral drugs, personal hygiene is considered as effective means as the first-hand measure against viral infections. The green tea catechins, in particular, epigallocatechin-3-gallate (EGCG), are known to exert potent antiviral activity. In this study, we evaluated the green tea extract as a safe personal hygiene against viral infections. Using the influenza virus A/Puerto Rico/8/34 (H1N1) as a model, we examined the duration of the viral inactivating activity of green tea extract (GTE) under prolonged storage at various temperature conditions. Even after the storage for 56 days at different temperatures, 0.1% GTE completely inactivated 10 6 PFU of the virus (6 log 10 reduction), and 0.01% and 0.05% GTE resulted in 2 log 10 reduction of the viral titers. When supplemented with 2% citric acid, 0.1% sodium benzoate, and 0.2% ascorbic acid as anti-oxidant, the inactivating activity of GTE was temporarily compromised during earlier times of storage. However, the antiviral activity of the GTE was steadily recovered up to similar levels with those of the same concentrations of GTE without the supplements, effectively prolonging the duration of the virucidal function over extended period. Cryo-EM and DLS analyses showed a slight increase in the overall size of virus particles by GTE treatment. The results suggest that the virucidal activity of GTE is mediated by oxidative crosslinking of catechins to the viral proteins and the change of physical properties of viral membranes. The durability of antiviral effects of GTE was examined as solution type and powder types over extended periods at various temperature conditions using human influenza A/H1N1 virus. GTE with supplements demonstrated potent viral inactivating activity, resulting in greater than 4 log 10 reduction of viral titers even after storage for up to two months at a wide range of

  10. THE EFFECT OF GREEN TEA ON OXIDATIVE DAMAGE AND TUMOUR FORMATION IN LOBUND-WISTAR RATS

    PubMed Central

    O'Sullivan, Jacintha; Sheridan, Juliette; Mulcahy, Hugh; Tenniswood, Martin; Morrissey, Colm

    2014-01-01

    A number of epidemiological studies suggest that the consumption of green tea reduces the incidence of prostate cancer. Since the major catechins present in green tea are potent anti-oxidants, we hypothesized that genetic and cellular damage induced by oxygen free radicals could be significantly reduced by potent anti-oxidants in green tea, thus reducing the cumulative genetic and cellular damage with age, and slowing or preventing tumour formation. Long-term administration of a decaffeinated green tea extract to Lobund-Wistar rats for periods up to 26 months almost halved the incidence of primary tumours in the genitourinary tract when compared to an aged-matched cohort receiving just water. We observed no inhibition of DNA adduct formation or lipid peroxidation in animals consuming green tea compared to animals consuming de-ionized water. The decrease in tumour formation was associated with an increase in 8-hydroxy-2’deoxyguanosine (8-OH-dG) and 4-hydroxynonenal (4-HNE) content (markers of DNA adduct formation and lipid peroxidation respectively) in the epithelium of the ventral prostate in aging animals. There was also an increase in 8-OH-dG expression, but no change in 4-HNE expression in the seminal vesicles of older animals. There was an age associated increase in expression of the anti-oxidant enzymes MnSOD and catalase in the epithelium of the ventral prostate of aging animals. There was also an increase in MnSOD expression, but no change in catalase expression in the seminal vesicles of older animals. These data demonstrate that consumption of green tea decreases the incidence of genitourinary tract tumours in the Lobund-Wistar rat, but has no effect on age associated DNA adduct formation and lipid peroxidation in the aging rat ventral prostate and seminal vesicles. PMID:18941371

  11. 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.

  12. Inhibition of Ca2+-activated Cl- channels by gallotannins as a possible molecular basis for health benefits of red wine and green tea.

    PubMed

    Namkung, Wan; Thiagarajah, Jay R; Phuan, Puay-Wah; Verkman, A S

    2010-11-01

    TMEM16A was found recently to be a calcium-activated Cl(-) channel (CaCC). CaCCs perform important functions in cell physiology, including regulation of epithelial secretion, cardiac and neuronal excitability, and smooth muscle contraction. CaCC modulators are of potential utility for treatment of hypertension, diarrhea, and cystic fibrosis. Screening of drug and natural product collections identified tannic acid as an inhibitor of TMEM16A, with IC(50) ∼ 6 μM and ∼100% inhibition at higher concentrations. Tannic acid inhibited CaCCs in multiple cell types but did not affect CFTR Cl(-) channels. Structure-activity analysis indicated the requirement of gallic or digallic acid substituents on a macromolecular scaffold (gallotannins), as are present in green tea and red wine. Other polyphenolic components of teas and wines, including epicatechin, catechin, and malvidin-3-glucoside, poorly inhibited CaCCs. Remarkably, a 1000-fold dilution of red wine and 100-fold dilution of green tea inhibited CaCCs by >50%. Tannic acid, red wine, and green tea inhibited arterial smooth muscle contraction and intestinal Cl(-) secretion. Gallotannins are thus potent CaCC inhibitors whose biological activity provides a potential molecular basis for the cardioprotective and antisecretory benefits of red wine and green tea.

  13. Microemulsion formulation design and evaluation for hydrophobic compound: Catechin topical application.

    PubMed

    Lin, Yu-Hsiang; Tsai, Ming-Jun; Fang, Yi-Ping; Fu, Yaw-Syan; Huang, Yaw-Bin; Wu, Pao-Chu

    2018-01-01

    The aim of the present study was to design a microemulsion for catechin topical application. A mixture experimental design with five independent variables (X 1 : oil, X 2 : surfactant, X 3 : catechin, X 4 : cosurfactant and X 5 : water) was developed, and the response surface methodology was used to study the effect of formulation components on physiochemical characteristics and penetration capacity of a catechin-loaded microemulsion, and to obtain an optimal microemulsion formulation. The results showed that the drug-loaded microemulsion formation and characteristics were related to many parameters of the components. The transdermal amounts in receiver cells and skin deposition amount remarkably increased about 4.1-111.6-fold and 0.6-7.6-fold respectively. The lag time was significantly shortened from 10h to 1.0-6.7h. The optimal formulation with 20% surfactant, 30% cosurfactant and 2.6% Catechin was subjected to stability and irritation tests. The results showed that the physicochemical characteristics and catechin level of the drug-loaded microemulsion did not show significant degradation after 3 months of storage at 25°C.The catechin-loaded microemulsion did not cause significant irritation compared to the water-treated group. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Size-exclusion chromatography of tea tannins and intercepting potentials of peptides for the inhibition of trypsin-caseinolytic activity by tea tannins.

    PubMed

    Kasai, Naoya; Nakatsubo, Genki

    2006-07-12

    Molecular-weight distribution and characterization of tea tannin were investigated by high-performance liquid chromatography and the equivalent preparative exclusion gel chromatography using Sephadex G-25. The characteristics of the fractions were studied regarding the amounts of terminal catechin, sugar, and gallic acid, the color reaction of the Folin-Chiocalteu reagent, the UV absorbance, and the inhibition activity for the trypsin-caseinolytic activity per weight. Furthermore, we investigated the intercepting activities of the inhibition by the amino acids, peptides, their analogues, poly(ethylene glycol)s (PEGs), and histatin 5 using the inhibition of trypsin-caseinolytic activity by tea. Arg, Lys, and their peptides had strong intercepting activities for the inhibition, but only a weak activity was detected in the Pro peptides or gelatin-like peptides of (Pro-Pro-Gly)(n) (n = 5 or 10). The guanidyl group of Arg and the amino methylene group of Lys were important for the intercepting activity, but the activity was weakly dependent upon the peptide bond formation. The intercepting activity of the peptides or PEG exponentially increased with the number of polymerizations. Histatin 5 did not have a remarkably strong intercepting activity considering the peptide length. The activity of the synthetic histatin 5 in which all of the Lys and Arg were substituted by Ala was at the same level as histatin 5.

  15. Changes in the structural and gel properties of pork myofibrillar protein induced by catechin modification.

    PubMed

    Jia, Na; Wang, Letian; Shao, Junhua; Liu, Dengyong; Kong, Baohua

    2017-05-01

    Different concentrations of catechin (0, 10, 50, 100 and 200μmol/g protein) were added to pork myofibrillar protein (MP) suspensions, and the related changes in protein conformational and gel properties were investigated. The results showed that catechin at 200μmol/g protein led to the greatest increase in the surface hydrophobicity of MP. A significant loss of thiols (SH) content was observed in MP in the presence of catechin. The low concentration of catechin of 10μmol/g led to slight changes in the MP gel strength and water-holding capacity. However, catechin at higher concentrations (50, 100 and 200μmol/g protein) caused severe deterioration of MP gelation. The microstructure and dynamic rheological properties confirmed the unfavorable effect of catechin on the MP gel properties. The results indicate that catechin caused changes in MP conformational and gel properties, which may be due to the catechin-MP covalent interactions and the exposure of hydrophobic domains caused by catechin. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Enhanced uptake and transport of (+)-catechin and (−)-epigallocatechin gallate in niosomal formulation by human intestinal Caco-2 cells

    PubMed Central

    Song, Qinxin; Li, Danhui; Zhou, Yongzhi; Yang, Jie; Yang, Wanqi; Zhou, Guohua; Wen, Jingyuan

    2014-01-01

    The aim of this study was to evaluate (+)-catechin and (−)-epigallocatechin gallate (EGCG) cellular uptake and transport across human intestinal Caco-2 cell monolayer in both the absence and presence of niosomal carrier in variable conditions. The effect of free drugs and drug-loaded niosomes on the growth of Caco-2 cells was studied. The effects of time, temperature, and concentration on drug cellular uptake in the absence or presence of its niosomal delivery systems were investigated. The intestinal epithelial membrane transport of the drug-loaded niosomes was examined using the monolayer of the human Caco-2 cells. The kinetics of transport, and the effect of temperature, adenosine triphosphate inhibitor, permeability glycoprotein inhibitor, multidrug resistance-associated protein 2 inhibitor, and the absorption enhancer on transport mechanism were investigated. It was found that the uptake of catechin, EGCG, and their niosomes by Caco-2 cells was 1.22±0.16, 0.90±0.14, 3.25±0.37, and 1.92±0.22 μg/mg protein, respectively (n=3). The apparent permeability coefficient values of catechin, EGCG, and their niosomes were 1.68±0.16, 0.88±0.09, 2.39±0.31, and 1.42±0.24 cm/second (n=3) at 37°C, respectively. The transport was temperature- and energy-dependent. The inhibitors of permeability glycoprotein and multidrug resistance-associated protein 2 and the absorption enhancer significantly enhanced the uptake amount. Compared with the free drugs, niosomal formulation significantly enhanced drug absorption. Additionally, drug-loaded niosomes exhibited stronger stability and lower toxicity. These findings showed that the oral absorption of tea flavonoids could be improved by using the novel drug delivery systems. PMID:24855353

  17. Conventional and accelerated-solvent extractions of green tea (camellia sinensis) for metabolomics-based chemometrics.

    PubMed

    Kellogg, Joshua J; Wallace, Emily D; Graf, Tyler N; Oberlies, Nicholas H; Cech, Nadja B

    2017-10-25

    Metabolomics has emerged as an important analytical technique for multiple applications. The value of information obtained from metabolomics analysis depends on the degree to which the entire metabolome is present and the reliability of sample treatment to ensure reproducibility across the study. The purpose of this study was to compare methods of preparing complex botanical extract samples prior to metabolomics profiling. Two extraction methodologies, accelerated solvent extraction and a conventional solvent maceration, were compared using commercial green tea [Camellia sinensis (L.) Kuntze (Theaceae)] products as a test case. The accelerated solvent protocol was first evaluated to ascertain critical factors influencing extraction using a D-optimal experimental design study. The accelerated solvent and conventional extraction methods yielded similar metabolite profiles for the green tea samples studied. The accelerated solvent extraction yielded higher total amounts of extracted catechins, was more reproducible, and required less active bench time to prepare the samples. This study demonstrates the effectiveness of accelerated solvent as an efficient methodology for metabolomics studies. Copyright © 2017. Published by Elsevier B.V.

  18. Catechin is a phytotoxin and a pro-oxidant secreted from the roots of Centaurea stoebe

    PubMed Central

    Kaushik, Shail; Biedrzycki, Meredith L; Venkatachalam, Lakshmannan

    2010-01-01

    When applied to the roots of Arabidopsis thaliana, the phytotoxin (±)-catechin triggers a wave of reactive oxygen species (ROS), leading to a cascade of genome-wide changes in gene expression and, ultimately, death of the root system. Biochemical links describing the root secreted phytotoxin, (±)-catechin, represent one of most well studied systems to describe biochemically based negative plant-plant interactions, but of late have also sparked controversies on phytotoxicity and pro-oxidant behavior of (±)-catechin. The studies originating from two labs1–3 maintained that (±)-catechin is not at all phytotoxic but has strong antioxidant activity. The step-wise experiments performed and the highly correlative results reported in the present study clearly indicate that (±)-catechin indeed is phytotoxic against A. thaliana and Festuca idahoensis. Our results show that catechin dissolved in both organic and aqueous phase inflicts phytotoxic activity against both A. thaliana and F. idahoensis. We show that the deviation in results highlighted by the two labs1–3 could be due to different media conditions and a group effect in catechin treated seedlings. We also determined the presence of catechin in the growth medium of C. stoebe to support the previous studies. One of the largest functional categories observed for catechin-responsive genes corresponded to gene families known to participate in cell death and oxidative stress. Our results showed that (±)-catechin treatment to A. thaliana plants resulted in activation of signature cell death genes such as accelerated cell death (acd2) and constitutively activated cell death 1 (cad1). Further, we confirmed our earlier observation of (±)-catechin induced ROS mediated phytotoxicity in A. thaliana. We also provide evidence that (±)-catechin induced ROS could be aggravated in the presence of divalent transition metals. These observations have significant impact on our understanding regarding catechin phytotoxicity and

  19. Effects of extreme climate events on tea (Camellia sinensis) functional quality validate indigenous farmer knowledge and sensory preferences in tropical China.

    PubMed

    Ahmed, Selena; Stepp, John Richard; Orians, Colin; Griffin, Timothy; Matyas, Corene; Robbat, Albert; Cash, Sean; Xue, Dayuan; Long, Chunlin; Unachukwu, Uchenna; Buckley, Sarabeth; Small, David; Kennelly, Edward

    2014-01-01

    Climate change is impacting agro-ecosystems, crops, and farmer livelihoods in communities worldwide. While it is well understood that more frequent and intense climate events in many areas are resulting in a decline in crop yields, the impact on crop quality is less acknowledged, yet it is critical for food systems that benefit both farmers and consumers through high-quality products. This study examines tea (Camellia sinensis; Theaceae), the world's most widely consumed beverage after water, as a study system to measure effects of seasonal precipitation variability on crop functional quality and associated farmer knowledge, preferences, and livelihoods. Sampling was conducted in a major tea producing area of China during an extreme drought through the onset of the East Asian Monsoon in order to capture effects of extreme climate events that are likely to become more frequent with climate change. Compared to the spring drought, tea growth during the monsoon period was up to 50% higher. Concurrently, concentrations of catechin and methylxanthine secondary metabolites, major compounds that determine tea functional quality, were up to 50% lower during the monsoon while total phenolic concentrations and antioxidant activity increased. The inverse relationship between tea growth and concentrations of individual secondary metabolites suggests a dilution effect of precipitation on tea quality. The decrease in concentrations of tea secondary metabolites was accompanied by reduced farmer preference on the basis of sensory characteristics as well as a decline of up to 50% in household income from tea sales. Farmer surveys indicate a high degree of agreement regarding climate patterns and the effects of precipitation on tea yields and quality. Extrapolating findings from this seasonal study to long-term climate scenario projections suggests that farmers and consumers face variable implications with forecasted precipitation scenarios and calls for research on management

  20. Effects of Extreme Climate Events on Tea (Camellia sinensis) Functional Quality Validate Indigenous Farmer Knowledge and Sensory Preferences in Tropical China

    PubMed Central

    Ahmed, Selena; Stepp, John Richard; Orians, Colin; Griffin, Timothy; Matyas, Corene; Robbat, Albert; Cash, Sean; Xue, Dayuan; Long, Chunlin; Unachukwu, Uchenna; Buckley, Sarabeth; Small, David; Kennelly, Edward

    2014-01-01

    Climate change is impacting agro-ecosystems, crops, and farmer livelihoods in communities worldwide. While it is well understood that more frequent and intense climate events in many areas are resulting in a decline in crop yields, the impact on crop quality is less acknowledged, yet it is critical for food systems that benefit both farmers and consumers through high-quality products. This study examines tea (Camellia sinensis; Theaceae), the world's most widely consumed beverage after water, as a study system to measure effects of seasonal precipitation variability on crop functional quality and associated farmer knowledge, preferences, and livelihoods. Sampling was conducted in a major tea producing area of China during an extreme drought through the onset of the East Asian Monsoon in order to capture effects of extreme climate events that are likely to become more frequent with climate change. Compared to the spring drought, tea growth during the monsoon period was up to 50% higher. Concurrently, concentrations of catechin and methylxanthine secondary metabolites, major compounds that determine tea functional quality, were up to 50% lower during the monsoon while total phenolic concentrations and antioxidant activity increased. The inverse relationship between tea growth and concentrations of individual secondary metabolites suggests a dilution effect of precipitation on tea quality. The decrease in concentrations of tea secondary metabolites was accompanied by reduced farmer preference on the basis of sensory characteristics as well as a decline of up to 50% in household income from tea sales. Farmer surveys indicate a high degree of agreement regarding climate patterns and the effects of precipitation on tea yields and quality. Extrapolating findings from this seasonal study to long-term climate scenario projections suggests that farmers and consumers face variable implications with forecasted precipitation scenarios and calls for research on management

  1. 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.

  2. Capsule shell material impacts the in vitro disintegration and dissolution behaviour of a green tea extract☆

    PubMed Central

    Glube, Natalie; Moos, Lea von; Duchateau, Guus

    2013-01-01

    Purpose In vitro disintegration and dissolution are routine methods used to assess the performance and quality of oral dosage forms. The purpose of the current work was to determine the potential for interaction between capsule shell material and a green tea extract and the impact it can have on the release. Methods A green tea extract was formulated into simple powder-in-capsule formulations of which the capsule shell material was either of gelatin or HPMC origin. The disintegration times were determined together with the dissolution profiles in compendial and biorelevant media. Results All formulations disintegrated within 30 min, meeting the USP criteria for botanical formulations. An immediate release dissolution profile was achieved for gelatin capsules in all media but not for the specified HPMC formulations. Dissolution release was especially impaired for HPMCgell at pH 1.2 and for both HPMC formulations in FeSSIF media suggesting the potential for food interactions. Conclusions The delayed release from studied HPMC capsule materials is likely attributed to an interaction between the catechins, the major constituents of the green tea extract, and the capsule shell material. An assessment of in vitro dissolution is recommended prior to the release of a dietary supplement or clinical trial investigational product to ensure efficacy. PMID:25755998

  3. Capsule shell material impacts the in vitro disintegration and dissolution behaviour of a green tea extract.

    PubMed

    Glube, Natalie; Moos, Lea von; Duchateau, Guus

    2013-01-01

    In vitro disintegration and dissolution are routine methods used to assess the performance and quality of oral dosage forms. The purpose of the current work was to determine the potential for interaction between capsule shell material and a green tea extract and the impact it can have on the release. A green tea extract was formulated into simple powder-in-capsule formulations of which the capsule shell material was either of gelatin or HPMC origin. The disintegration times were determined together with the dissolution profiles in compendial and biorelevant media. All formulations disintegrated within 30 min, meeting the USP criteria for botanical formulations. An immediate release dissolution profile was achieved for gelatin capsules in all media but not for the specified HPMC formulations. Dissolution release was especially impaired for HPMCgell at pH 1.2 and for both HPMC formulations in FeSSIF media suggesting the potential for food interactions. The delayed release from studied HPMC capsule materials is likely attributed to an interaction between the catechins, the major constituents of the green tea extract, and the capsule shell material. An assessment of in vitro dissolution is recommended prior to the release of a dietary supplement or clinical trial investigational product to ensure efficacy.

  4. Antioxidant and protective effect of inulin and catechin grafted inulin against CCl4-induced liver injury.

    PubMed

    Liu, Jun; Lu, Jian-feng; Wen, Xiao-yuan; Kan, Juan; Jin, Chang-hai

    2015-01-01

    In this study, the antioxidant activity and hepatoprotective effect of inulin and catechin grafted inulin (catechin-g-inulin) against carbon tetrachloride (CCl4)-induced acute liver injury were investigated. Results showed that both inulin and catechin-g-inulin had moderate scavenging activity on superoxide radical, hydroxyl radical and H2O2, as well as lipid peroxidation inhibition effect. The antioxidant activity decreased in the order of Vc > catechin >catechin-g-inulin > inulin. Administration of inulin and catechin-g-inulin could significantly reduce the elevated levels of serum aspartate transaminase, alanine transaminase and alkaline phosphatase as compared to CCl4 treatment group. Moreover, inulin and catechin-g-inulin significantly increased the levels of hepatic superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione and total antioxidant capacity, whereas markedly decreased the malondialdehyde level when compared with CCl4 treatment group. Notably, catechin-g-inulin showed higher hepatoprotective effect than inulin. In addition, the hepatoprotective effect of catechin-g-inulin was comparable to positive standard of silymarin. Our results suggested that catechin-g-inulin had potent antioxidant activity and potential protective effect against CCl4-induced acute liver injury. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Inhibition of Ca2+-activated Cl− channels by gallotannins as a possible molecular basis for health benefits of red wine and green tea

    PubMed Central

    Namkung, Wan; Thiagarajah, Jay R.; Phuan, Puay-Wah; Verkman, A. S.

    2010-01-01

    TMEM16A was found recently to be a calcium-activated Cl− channel (CaCC). CaCCs perform important functions in cell physiology, including regulation of epithelial secretion, cardiac and neuronal excitability, and smooth muscle contraction. CaCC modulators are of potential utility for treatment of hypertension, diarrhea, and cystic fibrosis. Screening of drug and natural product collections identified tannic acid as an inhibitor of TMEM16A, with IC50 ∼ 6 μM and ∼100% inhibition at higher concentrations. Tannic acid inhibited CaCCs in multiple cell types but did not affect CFTR Cl− channels. Structure-activity analysis indicated the requirement of gallic or digallic acid substituents on a macromolecular scaffold (gallotannins), as are present in green tea and red wine. Other polyphenolic components of teas and wines, including epicatechin, catechin, and malvidin-3-glucoside, poorly inhibited CaCCs. Remarkably, a 1000-fold dilution of red wine and 100-fold dilution of green tea inhibited CaCCs by >50%. Tannic acid, red wine, and green tea inhibited arterial smooth muscle contraction and intestinal Cl− secretion. Gallotannins are thus potent CaCC inhibitors whose biological activity provides a potential molecular basis for the cardioprotective and antisecretory benefits of red wine and green tea.—Namkung, W., Thiagarajah, J. R., Phuan, P.-W., Verkman, A. S. Inhibition of Ca2+-activated Cl− channels by gallotannins as a possible molecular basis for health benefits of red wine and green tea. PMID:20581223

  6. In vitro antioxidant activity of phenolic-enriched extracts from Zhangping Narcissus tea cake and their inhibition on growth and metastatic capacity of 4T1 murine breast cancer cells* #

    PubMed Central

    Ying, Le; Kong, De-dong; Gao, Yuan-yuan; Yan, Feng; Wang, Yue-fei; Xu, Ping

    2018-01-01

    Phenolics, as the main bioactive compounds in tea, have been suggested to have potential in the prevention of various human diseases. However, little is known about phenolics and their bioactivity in Zhangping Narcissue tea cake which is considered the most special kind of oolong tea. To unveil its bioactivity, three phenolic-enriched extracts were obtained from Zhangping Narcissue tea cake using ethyl acetate, n-butanol, and water. Their main chemical compositions and in vitro bioactivity were analyzed by high-performance liquid chromatography (HPLC) and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). The ethyl acetate fraction (ZEF) consisted of higher content of phenolics, flavonoids, procyanidins, and catechin monomers (including epigallocatechin gallate (EGCG), epicatechin gallate (ECG), and gallocatechin gallate (GCG)) than n-butanol fraction (ZBF) and water fraction (ZWF). ZEF exhibited the strongest antioxidant capacity in vitro due to its abundant bioactive compounds. This was validated by Pearson correlation and hierarchical clustering analyses. ZEF also showed a remarkable inhibition on the growth, migration, and invasion of 4T1 murine breast cancer cells. PMID:29504313

  7. Stimulation or Inhibition: Conflicting evidence for (+/-)-catechin's role as a chemical facilitator and disease protecting agent.

    PubMed

    Bais, Harsh P; Venkatachalam, L; Biedrzycki, Meredith L

    2010-03-01

    The occurrence of plant hormesis is a poorly understood phenomenon, wherein low doses of phytotoxins unusually promote growth responses in higher plants. In contrast, negative plant-plant interactions mediated through secreted small molecular weight compounds initiate growth inhibitory responses. Studies related to (+/-)-catechin mediated allelopathy have transpired both novel information and generated significant controversy. Specifically, studies related to the phytotoxicity responses mediated by (+/-)-catechins have been seriously debated. The pronged opinion that (+/-)-catechin is phytotoxic versus non-phytotoxic relies more on the target plant systems and the conditions used to test phytotoxic responses. It is reported that lower than MIC dosage supplementation of (+/-)-catechin could promote growth responses in the model plant Arabidopsis thaliana. Furthermore, it was shown that sub-MIC levels of (+/-)-catechin supplementation leads to elicitation of disease resistance against Pseudomonas syringae DC3000 (hereafter DC3000). Intrigued by the unique hormesis response observed, we tested whether (+/-)-catechin indeed promotes growth responses in A. thaliana. In our hands, we observed no growth promotion responses of (+/-)-catechin against A. thaliana under in vitro or in soil conditions. We also evaluated the previously reported disease protecting properties of (+/-)-catechin in A. thaliana against DC3000. The systematic observations to evaluate disease protecting properties entailing colony counts, disease incidences and loss of chlorophyll studies showed no disease protecting properties of (+/-)-catechin. The transcriptional response for a marker pathogenesis related PR1 defense gene showed no induction post (+/-)-catechin supplementation. The cell death genes (ACD2 and CAD1) associated with programmed cell death revealed unchanged expression levels in plants treated with sub-MIC levels of (+/-)-catechin. Further, we report supplementation of sub-MIC levels of

  8. Effect of catechin and its derivatives on inhibition of polyphenoloxidase and melanosis of Pacific white shrimp.

    PubMed

    Sae-Leaw, Thanasak; Benjakul, Soottawat; Simpson, Benjamin K

    2017-04-01

    This study aimed to investigate the effect of tea catechin (C) and 4 of its derivatives on the Pacific white shrimp PPO inhibition and melanosis during refrigerated storage. Epigallocatechin gallate (EGCG) exhibited the highest inhibition towards PPO, followed by C. Inhibitory activity of all compounds tested was in a dose dependent manner (0.1-2.0 mM). Based on activity staining, EGCG most effectively inhibited PPO. For inhibition kinetic studies, C and epicatechin (EC) showed uncompetitive type, whereas epicatechin gallate (ECG), epigallocatechin (EGC) and EGCG exhibited mixed type inhibition. When whole shrimps were treated with EGCG solution at various concentrations (0.25-0.75%), those treated with 0.5 or 0.75% EGCG had lower melanosis scores throughout storage for 10 days at 4 °C, compared with the control and the 1.25% sodium metabisulfite treated samples ( P  < 0.05). Therefore, EGCG could be used as a potential inhibitor for melanosis in raw Pacific white shrimp during refrigerated storage.

  9. Influence of green tea catechins on oxidative stress metabolites at rest and during exercise in healthy humans.

    PubMed

    Sugita, Masaaki; Kapoor, Mahendra P; Nishimura, Akinobu; Okubo, Tsutomu

    2016-03-01

    The aim of this study was to investigate the effects of green tea catechins (GTC) on oxidative stress metabolites in healthy individuals while at rest and during exercise. The effects investigated included response to fat metabolism, blood lactate concentrations, and rating of perceived exertion. In a paralleled, crossover, randomized controlled study, 16 trained male gymnastic students were randomly divided into two groups. The rest group (n = 8; GTC-NEX) received a single dose of 780 mg GTC with water but no exercise; the exercise group (n = 8; GTC-EX) received a similar dose of GTC but were instructed to exercise. This was followed by a crossover study with similar exercise regime as a placebo group (PL-EX) that received water only. Blood samples were collected at baseline and after 60 and 120 min of GTC intake. Oxidative stress blood biomarkers using the diacron reactive oxygen metabolite (d-ROMs) and biological antioxidant potential (BAP) tests; urinary 8-hydroxydeoxyguanosine (8-OHdG); 8-OHdG/creatinine; and blood lactate concentrations were analyzed. During the cycle ergometer exercise, volume of maximal oxygen uptake, volume of oxygen consumption, volume of carbon dioxide, and respiratory exchange ratio were measured from a sample of respiratory breath gas collected during low, moderate, and high intensity exercising, and the amount of fat burning and sugar consumption were calculated. Analysis of variance was used to determine statistical significance (P < 0.05) between and among the groups. Levels of postexercise oxidative stress metabolites BAP and d-ROMs were found significant (P < 0.0001) in the PL-EX and GTC-EX groups, and returned to pre-exercise levels after the recovery period. Levels of d-ROMs showed no significant difference from baseline upon GTC intake followed by resting and a resting recovery period in the GTC-NEX group. BAP levels were significant upon GTC intake followed by resting (P = 0.04), and after a resting recovery period (P = 0

  10. Protective effect of catechin in type I Gaucher disease cells by reducing endoplasmic reticulum stress

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, Yea-Jin; Kim, Sung-Jo, E-mail: sungjo@hoseo.edu; Heo, Tae-Hwe, E-mail: thhur92@catholic.ac.kr

    Highlights: {yields} Catechin reduces the expression level of ER stress marker protein in type I Gaucher disease cells. {yields} Catechin induces the proliferation rate of GD cells similar levels to normal cells. {yields} Catechin improves wound healing activity. {yields} Catechin-mediated reductions in ER stress may be associated with enhanced cell survival. {yields} We identified catechin as a protective agent against ER stress in GD cells. -- Abstract: Gaucher disease (GD) is the most common lysosomal storage disorder (LSD) and is divided into three phenotypes, I, II, and III. Type I is the most prevalent form and has its onset inmore » adulthood. The degree of endoplasmic reticulum (ER) stress is one of the factors that determine GD severity. It has recently been reported that antioxidants reduce ER stress and apoptosis by scavenging the oxidants that cause oxidative stress. For this report, we investigated the possibility that catechin can act on type I GD patient cells to alleviate the pathogenic conditions of GD. We treated GD cells with catechin and examined the expression level of GRP78/BiP (an ER stress marker) by western blots and fluorescence microscopy, the proliferation rate of GD cells, and scratch-induced wound healing activity. Our results show that catechin reduces the expression level of GRP78/BiP, leads to cell proliferation rates of GD cells similar levels to normal cells, and improves wound healing activity. We conclude that catechin protects against ER stress in GD cells and catechin-mediated reductions in ER stress may be associated with enhanced cell survival.« less

  11. Anti-infective properties of epigallocatechin-3-gallate (EGCG), a component of green tea

    PubMed Central

    Steinmann, J; Buer, J; Pietschmann, T; Steinmann, E

    2013-01-01

    The consumption of green tea (Camellia sinensis) has been shown to have many physiological and pharmacological health benefits. In the past two decades several studies have reported that epigallocatechin-3-gallate (EGCG), the main constituent of green tea, has anti-infective properties. Antiviral activities of EGCG with different modes of action have been demonstrated on diverse families of viruses, such as Retroviridae, Orthomyxoviridae and Flaviviridae and include important human pathogens like human immunodeficiency virus, influenza A virus and the hepatitis C virus. Furthermore, the molecule interferes with the replication cycle of DNA viruses like hepatitis B virus, herpes simplex virus and adenovirus. Most of these studies demonstrated antiviral properties within physiological concentrations of EGCG in vitro. In contrast, the minimum inhibitory concentrations against bacteria were 10–100-fold higher. Nevertheless, the antibacterial effects of EGCG alone and in combination with different antibiotics have been intensively analysed against a number of bacteria including multidrug-resistant strains such as methicillin-resistant Staphylococcus aureus or Stenotrophomonas maltophilia. Furthermore, the catechin EGCG has antifungal activity against human-pathogenic yeasts like Candida albicans. Although the mechanistic effects of EGCG are not fully understood, there are results indicating that EGCG binds to lipid membranes and affects the folic acid metabolism of bacteria and fungi by inhibiting the cytoplasmic enzyme dihydrofolate reductase. This review summarizes the current knowledge and future perspectives on the antibacterial, antifungal and antiviral effects of the green tea constituent EGCG. PMID:23072320

  12. Quantification of the predominant monomeric catechins in baking chocolate standard reference material by LC/APCI-MS.

    PubMed

    Nelson, Bryant C; Sharpless, Katherine E

    2003-01-29

    Catechins are polyphenolic plant compounds (flavonoids) that may offer significant health benefits to humans. These benefits stem largely from their anticarcinogenic, antioxidant, and antimutagenic properties. Recent epidemiological studies suggest that the consumption of flavonoid-containing foods is associated with reduced risk of cardiovascular disease. Chocolate is a natural cocoa bean-based product that reportedly contains high levels of monomeric, oligomeric, and polymeric catechins. We have applied solid-liquid extraction and liquid chromatography coupled with atmospheric pressure chemical ionization-mass spectrometry to the identification and determination of the predominant monomeric catechins, (+)-catechin and (-)-epicatechin, in a baking chocolate Standard Reference Material (NIST Standard Reference Material 2384). (+)-Catechin and (-)-epicatechin are detected and quantified in chocolate extracts on the basis of selected-ion monitoring of their protonated [M + H](+) molecular ions. Tryptophan methyl ester is used as an internal standard. The developed method has the capacity to accurately quantify as little as 0.1 microg/mL (0.01 mg of catechin/g of chocolate) of either catechin in chocolate extracts, and the method has additionally been used to certify (+)-catechin and (-)-epicatechin levels in the baking chocolate Standard Reference Material. This is the first reported use of liquid chromatography/mass spectrometry for the quantitative determination of monomeric catechins in chocolate and the only report certifying monomeric catechin levels in a food-based Standard Reference Material.

  13. In vitro and in vivo anti-allergic effects of ‘benifuuki’ green tea containing O-methylated catechin and ginger extract enhancement

    PubMed Central

    Ema, Kaori; Shibuichi, Ikuo

    2007-01-01

    ‘Benifuuki’, a tea (Camellia Sinensis L.) cultivar in Japan, is rich in anti-allergic epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3″Me). ‘Benifuuki’ green tea and simultaneous addition of ginger extract remarkably suppressed cytokine (TNF-α and MIP-1α) secretion from mouse bone marrow-derived mast cells after antigen stimulation and, as expected, suppressed delay-type allergy. After drinking ‘benifuuki’ green tea containing 43.5 mg of EGCG and 8.5 mg of EGCG3″Me, the AUC (area under the drug concentration time curve; min μg/ml) of EGCG was 6.72 ± 2.87 and EGCG3″Me was 8.48 ± 2.54 in healthy human volunteers. Though the dose of EGCG was 5.1 times the dose of EGCG3″Me, the AUC of EGCG3″Me was higher than that of EGCG. A double blind clinical study on subjects with Japanese cedar pollinosis was carried out. At the 11th week after starting the study, in the most severe cedar pollen scattering period, symptoms, i.e., blowing the nose and itching eyes, were significantly relieved in the ‘benifuuki’ intake group compared with the placebo group, and blowing the nose, itching eyes and nasal symptom score, and at the 11th and 13th weeks, stuffy nose, throat pain and the nasal symptom medication score were significantly relieved in the ‘benifuuki’ containing ginger extract group compared with the placebo group. These results suggested that over one consecutive month, drinking ‘benifuuki’ green tea was useful to reduce some of the symptoms from Japanese cedar pollinosis, and did not affect any normal immune response in subjects with seasonal rhinitis, and the ginger extract enhanced the effect of ‘benifuuki’ green tea. PMID:19003003

  14. Phytotoxic Effects of (±)-Catechin In vitro, in Soil, and in the Field

    PubMed Central

    Inderjit; Pollock, Jarrod L.; Callaway, Ragan M.; Holben, William

    2008-01-01

    Background Exploring the residence time of allelochemicals released by plants into different soils, episodic exposure of plants to allelochemicals, and the effects of allelochemicals in the field has the potential to improve our understanding of interactions among plants. Methodology/Principal Findings We conducted experiments in India and the USA to understand the dynamics of soil concentrations and phytotoxicity of (±)-catechin, an allelopathic compound exuded from the roots of Centaurea maculosa, to other plants in vitro and in soil. Experiments with single and pulsed applications into soil were conducted in the field. Experimental application of (±)-catechin to soils always resulted in concentrations that were far lower than the amounts added but within the range of reported natural soil concentrations. Pulses replenished (±)-catechin levels in soils, but consistently at concentrations much lower than were applied, and even pulsed concentrations declined rapidly. Different natural soils varied substantially in the retention of (±)-catechin after application but consistent rapid decreases in concentrations over time suggested that applied experimental concentrations may overestimate concentrations necessary for phytotoxicity by over an order of magnitude. (±)-Catechin was not phytotoxic to Bambusa arundinacea in natural Indian soil in a single pulse, but soil concentrations at the time of planting seeds were either undetectable or very low. However, a single dose of (±)-catechin suppressed the growth of bamboo in sand, in soil mixed with organic matter, and Koeleria macrantha in soils from Montana and Romania, and in field applications at 40 µg l−1. Multiple pulses of (±)-catechin were inhibitory at very low concentrations in Indian soil. Conclusions/Significance Our results demonstrate that (±)-catechin is highly dynamic in natural soils, but is phytotoxic well below natural concentrations measured in some soils and applied at low concentrations in

  15. 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.

  16. Gallic Acid Content in Taiwanese Teas at Different Degrees of Fermentation and Its Antioxidant Activity by Inhibiting PKCδ Activation: In Vitro and in Silico Studies.

    PubMed

    Kongpichitchoke, Teeradate; Chiu, Ming-Tzu; Huang, Tzou-Chi; Hsu, Jue-Liang

    2016-10-12

    Teas can be classified according to their degree of fermentation, which has been reported to affect both the bioactive components in the teas and their antioxidative activity. In this study, four kinds of commercial Taiwanese tea at different degrees of fermentation, which include green (non-fermented), oolong (semi-fermented), black (fully fermented), and Pu-erh (post-fermented) tea, were profiled for catechin levels by using high performance liquid chromatography (HPLC). The result indicated that the gallic acid content in tea was directly proportional to the degree of fermentation in which the lowest and highest gallic acid content were 1.67 and 21.98 mg/g from green and Pu-erh tea, respectively. The antioxidative mechanism of the gallic acid was further determined by in vitro and in silico analyses. In vitro assays included the use of phorbol ester-induced macrophage RAW264.7 cell model for determining the inhibition of reactive oxygen species (ROS) production, and PKCδ and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit (p47) activations. The results showed that only at a concentration of 5.00 μM could gallic acid significantly ( p < 0.05) reduce ROS levels in phorbol ester-activated macrophages. Moreover, protein immunoblotting expressed similar results in which activations of PKCδ and p47 were only significantly ( p < 0.05) attenuated by 5.00 μM treatment. Lastly, in silico experiments further revealed that gallic acid could block PKCδ activation by occupying the phorbol ester binding sites of the protein.

  17. Role of (-)-epigallocatechin gallate in the pharmacokinetic interaction between nadolol and green tea in healthy volunteers.

    PubMed

    Abe, Osamu; Ono, Tomoyuki; Sato, Hideyuki; Müller, Fabian; Ogata, Hiroshi; Miura, Itaru; Shikama, Yayoi; Yabe, Hirooki; Onoue, Satomi; Fromm, Martin F; Kimura, Junko; Misaka, Shingen

    2018-06-01

    The aim of the present study is to investigate a possible role of a single dose of (-)-epigallocatechin gallate (EGCG), the major catechin in green tea, for the pharmacokinetic interaction between green tea and nadolol in humans. In a randomized three-phase crossover study, 13 healthy volunteers received single doses of 30 mg nadolol orally with water (control), or an aqueous solution of EGCG-concentrated green tea extract (GTE) at low or high dose. Plasma concentrations and urinary excretion of nadolol were determined up to 48 h. In addition, blood pressure and pulse rate were monitored. In vitro transport kinetic experiments were performed using human embryonic kidney 293 cells stably expressing organic anion transporting polypeptide (OATP)1A2 to evaluate the inhibitory effect of EGCG on OATP1A2-mediated substrate transport. Single coadministration of low and high dose GTE significantly reduced the plasma concentrations of nadolol. The geometric mean ratios with 90% CI for area under the plasma concentration-time curves from 0 to infinity of nadolol were 0.72 (0.56-0.87) for the low and 0.60 (0.51-0.69) for the high dose. There were no significant differences in T max , elimination half-life, and renal clearance between GTE and water phases. No significant changes were observed for blood pressure and pulse rate between phases. EGCG competitively inhibited OATP1A2-mediated uptake of sulphobromophthalein and nadolol with K i values of 21.6 and 19.4 μM, respectively. EGCG is suggested to be a key contributor to the interaction of green tea with nadolol. Moreover, even a single coadministration of green tea may significantly affect nadolol pharmacokinetics.

  18. Proteomic evaluation of myofibrillar carbonylation in chilled fish mince and its inhibition by catechin.

    PubMed

    Pazos, Manuel; Maestre, Rodrigo; Gallardo, José M; Medina, Isabel

    2013-01-01

    The present study investigates the susceptibility of individual myofibrillar proteins from mackerel (Scomber scombrus) mince to undergo carbonylation reactions during chilled storage, and the antioxidant capacity of (+)-catechin to prevent oxidative processes of proteins. The carbonylation of each particular protein was quantified by combining the labelling of protein carbonyls by fluorescein-5-thiosemicarbazide (FTSC) with 1-D or 2-D gel electrophoresis. Alpha skeletal actin, glycogen phosphorylase, unnamed protein product (UNP) similar to enolase, pyruvate kinase, isoforms of creatine kinase, aldolase A and an isoform of glyceraldehyde 3-phosphate dehydrogenase (G3PDH) showed elevated oxidation in chilled non-supplemented mince. Myosin heavy chain (MHC) was not carbonylated in chilled muscle, but an extensive MHC degradation was observed in those samples. The supplementation of catechin reduced protein oxidation and lipid oxidation in a concentration-dependent manner: control>25>100≈200ppm. Therefore, the highest catechin concentrations (100 and 200ppm) exhibited the strongest antioxidant activity. Catechin (200ppm) reduced significantly carbonylation of protein spots identified as glycogen phosphorylase, pyruvate kinase muscle isozyme, isoforms of creatine kinase. Conversely, catechin was ineffective to inhibit the oxidation of actin and UNP similar to enolase. These results draw attention to the inefficiency of catechin to prevent actin oxidation, in contrast to the extremely high efficiency of catechin in inhibiting oxidation of lipids and other proteins. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Dextran-Catechin: An anticancer chemically-modified natural compound targeting copper that attenuates neuroblastoma growth

    PubMed Central

    Vittorio, Orazio; Brandl, Miriam; Cirillo, Giuseppe; Kimpton, Kathleen; Hinde, Elizabeth; Gaus, Katharina; Yee, Eugene; Kumar, Naresh; Duong, Hien; Fleming, Claudia; Haber, Michelle; Norris, Murray; Boyer, Cyrille; Kavallaris, Maria

    2016-01-01

    Neuroblastoma is frequently diagnosed at advanced stage disease and treatment includes high dose chemotherapy and surgery. Despite the use of aggressive therapy survival rates are poor and children that survive their disease experience long term side effects from their treatment, highlighting the need for effective and less toxic therapies. Catechin is a natural polyphenol with anti-cancer properties and limited side effects, however its mechanism of action is unknown. Here we report that Dextran-Catechin, a conjugated form of catechin that increases serum stability, is preferentially and markedly active against neuroblastoma cells having high levels of intracellular copper, without affecting non-malignant cells. Copper transporter 1 (CTR1) is the main transporter of copper in mammalian cells and it is upregulated in neuroblastoma. Functional studies showed that depletion of CTR1 expression reduced intracellular copper levels and led to a decrease in neuroblastoma cell sensitivity to Dextran-Catechin, implicating copper in the activity of this compound. Mechanistically, Dextran-Catechin was found to react with copper, inducing oxidative stress and decreasing glutathione levels, an intracellular antioxidant and regulator of copper homeostasis. In vivo, Dextran-Catechin significantly attenuated tumour growth in human xenograft and syngeneic models of neuroblastoma. Thus, Dextran-Catechin targets copper, inhibits tumour growth, and may be valuable in the treatment of aggressive neuroblastoma and other cancers dependent on copper for their growth. PMID:27374085

  20. 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.

  1. Delineating the anti-cytotoxic and anti-genotoxic potentials of catechin hydrate against cadmium toxicity in human peripheral blood lymphocytes.

    PubMed

    Alshatwi, Ali A; Hasan, Tarique N; Alqahtani, Ali M; Syed, Naveed A; Shafi, Gowhar; Al-Assaf, Abdullah H; Al-Khalifa, Abdulrahmann S

    2014-09-01

    Catechins (flavan-3-ol) are a type of natural phenol and well-studied antioxidants. Catechin hydrate, also known as taxifolin; is non-mutagenic, low in toxicity compared to other immunomodulator antioxidants. We aimed to determine the potential of catechin hydrate to prevent the cyto-genotoxic effects of cadmium in lymphocytes; demonstrate the immuno-protective activity of catechin hydrate. Our previous study indicated that cadmium is apoptogenic. Lymphocytes were treated with catechin hydrate or cadmium and catechine hydrate combinations (range 0.1-100μM) to determine their effects on cell viability. Lymphocytes treated with 100μM catechin hydrate and 100μM cadmium showed cell viability 70.65±6.92% and 5.69±2.27%, respectively. In our previous study cadmium (10 and 20μM) induced apoptosis in 31.8% and 44.4% of lymphocytes, respectively. However, the percentage of apoptotic cells after treatment with the combination of cadmium and catechin hydrate was not significantly different from that of catechin hydrate (P>0.05). Only 7.3% and 10.5% of the lymphocytes were apoptotic after treatment with 10μM cadmium+10μM catechin hydrate and 20μM cadmium+20μM catechin hydrate, respectively. The anti-geno-cytotoxic and immuno-protective potential of catechin hydrate was also demonstrated by the non-significant expression of apoptosis-related genes after treatment with catechin hydrate. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. [Simultaneous extraction of tea-polyphenols and caffeine from green tea].

    PubMed

    Hai, L; Sun, H; Li, Z

    1998-05-01

    Tea-polyphenols and caffeine were extracted simultaneously from green tea. The factors influencing on the process of impregnation and extraction were studied. The result indicated that the content of tea-polyphenols and caffeine in tea was increased with the duration of extraction and decreased with the frequency of extraction. The authors discuss the effect of pH on the precipition of calcium-tea-polyphenols.

  3. [Characteristics of the composition of Caucasian blackberry (Rubus caucasicus L.) leaves as a raw material for tea production].

    PubMed

    Melkadze, R G; Chichkovani, N Sh; Kakhniashvili, E Z

    2008-01-01

    The composition of Caucasian blackberry (Rubus caucasicus L.) six-leaf shoot was studied. The weight of the stem reached 50% of the total weight of the shoot. The content of moisture, extractive substances, and phenolic compounds was minimal at the beginning and end of the vegetation season. Phenolic compounds were represented by catechins, leukoanthocyanidins, and flavonols. The most abundant phenolic compounds in all parts of the blackberry shoot were leukoanthocyanidins, which accounted for approximately 50% of all compounds of this class. Phenolic compounds accumulated most actively in July and August. The average content of free amino acids in the blackberry leaf during the vegetation season was 26.68 mg/g. Among the total free amino acids, eleven have been identified, five of which proved to be essential (His, Arg, Met, Leu, Val) and accounted for 40% of the total amount of amino acids. The oxidability of acetone extract of the blackberry leaf was compared to the oxidability of total phenolic compounds and tea tannin. The tea product obtained from the blackberry leaf had good organoleptic parameters and a saturated extractive complex.

  4. Effects of green tea gargling on the prevention of influenza infection in high school students: a randomized controlled study.

    PubMed

    Ide, Kazuki; Yamada, Hiroshi; Matsushita, Kumi; Ito, Miki; Nojiri, Kei; Toyoizumi, Kiichiro; Matsumoto, Keiji; Sameshima, Yoichi

    2014-01-01

    The anti-influenza virus activity of green tea catechins has been demonstrated in experimental studies, but clinical evidence has been inconclusive. School-aged children play an important role in the infection and spread of influenza in the form of school-based outbreaks. Preventing influenza infection among students is essential for reducing the frequency of epidemics and pandemics. As a non-pharmaceutical intervention against infection, gargling is also commonly performed in Asian countries but has not yet been extensively studied. A randomized, open label, 2-group parallel study of 757 high school students (15 to 17 years of age) was conducted for 90 days during the influenza epidemic season from December 1st, 2011 to February 28th, 2012, in 6 high schools in Shizuoka Prefecture, Japan. The green tea gargling group gargled 3 times a day with bottled green tea, and the water gargling group did the same with tap water. The water group was restricted from gargling with green tea. The primary outcome measure was the incidence of laboratory-confirmed influenza using immunochromatographic assay for antigen detection. 757 participants were enrolled and 747 participants completed the study (384 in the green tea group and 363 in the water group). Multivariate logistic regression indicated no significant difference in the incidence of laboratory-confirmed influenza between the green tea group (19 participants; 4.9%) and the water group (25 participants; 6.9%) (adjusted OR, 0.69; 95%CI, 0.37 to 1.28; P = 0.24). The main limitation of the study is the adherence rate among high school students was lower than expected. Among high school students, gargling with green tea three times a day was not significantly more efficacious than gargling with water for the prevention of influenza infection. In order to adequately assess the effectiveness of such gargling, additional large-scale randomized studies are needed. ClinicalTrials.gov NCT01225770.

  5. Tea production characteristics of tea growers (plantations and smallholdings) and livelihood dimensions of tea workers in Assam, India.

    PubMed

    Biggs, Eloise M; Gupta, Niladri; Saikia, Sukanya D; Duncan, John M A

    2018-04-01

    This article provides summary data regarding tea production in Assam, India. Questionnaires were completed by tea producers and focus group discussions undertaken with tea workers. These data are presented for the four main tea growing regions of the state (Cachar, North Bank, South Bank and Upper Assam). Tables detail tea production characteristics of the tea plantations for both large- (> 10 ha) and small- (< 10 ha) holders. Figures provide supplementary information for research by Biggs et al. [1] regarding fertilizer application, landscape management strategies, healthcare provisioning and educational facilities within plantations, as well as detailing the livelihood dimensions of tea workers. The questions posed to producers are also included. For further context underpinning the research for which these data were collated, see 'The tea landscape of Assam: multi-stakeholder insights into sustainable livelihoods under a changing climate' by Biggs et al. [1].

  6. 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.

  7. 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.

  8. Anti-inflammatory activity of green versus black tea aqueous extract in a rat model of human rheumatoid arthritis.

    PubMed

    Ramadan, Gamal; El-Beih, Nadia M; Talaat, Roba M; Abd El-Ghffar, Eman A

    2017-02-01

    Recently, there has been an increasing interest in tea (Camellia sinensis) as a protective agent against inflammatory diseases. Here, we evaluated/compared the anti-inflammatory activity of two different doses (0.5 and 1.0 g/kg body weight) of green tea aqueous extract (GTE, rich in catechins) and black tea aqueous extract (BTE, rich in theaflavins and thearubigins) in rat adjuvant-induced arthritis (AIA). Adjuvant-induced arthritis rat model received orally/daily distilled water as vehicle, indomethacin (1.0 mg/kg body weight; a non-steroidal/anti-inflammatory drug), or tea aqueous extracts (for 28 or 14 consecutive days starting from day 0 or 14 of arthritis induction, respectively). The present study showed that only the high dose of GTE (from day 0) significantly alleviated (P < 0.05-0.001) all complications shown in arthritic rats, including synovial joint inflammation, elevation in erythrocyte sedimentation rate, blood leukocytosis (due to lymphocytosis and neutrocytosis), and changes in weight/cellularity of lymphoid organs. The anti-arthritic activity of the high dose of GTE (from day 0) was comparable (P > 0.05) with that of indomethacin (12.9-53.8 vs. 9.5-48.4%, respectively) and mediated by significantly decreasing and down-regulating (P < 0.001) the systemic production of pro-inflammatory cytokines and the expression of chemokine receptor-5 in synovial tissues, respectively. Moreover, the anti-arthritic activity of tea aqueous extracts was in the following order: high dose of GTE > low dose of GTE ≥ high dose of BTE > low dose of BTE. The present study proved the anti-inflammatory activity of GTE over BTE and equal to that of indomethacin in AIA rat model. © 2015 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  9. Co-delivery of hydrophobic curcumin and hydrophilic catechin by a water-in-oil-in-water double emulsion.

    PubMed

    Aditya, N P; Aditya, Sheetal; Yang, Hanjoo; Kim, Hye Won; Park, Sung Ook; Ko, Sanghoon

    2015-04-15

    Curcumin and catechin are naturally occurring phytochemicals with extreme sensitivity to oxidation and low bioavailability. We fabricated a water-in-oil-in-water (W/O/W) double emulsion encapsulating hydrophilic catechin and hydrophobic curcumin simultaneously. The co-loaded emulsion was fabricated using a two-step emulsification method, and its physicochemical properties were characterised. Volume-weighted mean size (d43) of emulsion droplets was ≈3.88 μm for blank emulsions, whereas it decreased to ≈2.8-3.0 μm for curcumin and/or catechin-loaded emulsions, which was attributed to their capacity to act as emulsifiers. High entrapment efficiency was observed for curcumin and/or catechin-loaded emulsions (88-97%). Encapsulation of catechin and curcumin within an emulsion increased their stability significantly in simulated gastrointestinal fluid, which resulted in a four-fold augmentation in their bioaccessibility compared to that of freely suspended curcumin and catechin solutions. Co-loading of curcumin and catechin did not have adverse effects on either compound's stability or bioaccessibility. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Analyzing organic tea certification and traceability system within the Taiwanese tea industry.

    PubMed

    Wang, Mao-Chang; Yang, Chin-Ying

    2015-04-01

    We applied game theory to the organic tea certification process and traceability system used by the Taiwanese tea industry to elucidate the strategic choices made by tea farmers and organic tea certification agencies. Thus, this paper clarifies how relevant variables affect the organic certification process and traceability system used within the tea industry. The findings indicate that farmers who generate high revenues experience failures regarding tea deliveries, cash outflow, damage compensation, and quasi-rent. An additional problem included the high costs yielded when tea farmers colluded with or switched organic tea certification agencies. Furthermore, there could be decreasing levels of personal interest in planting non-organic tea and lowering the costs of planting organic tea and the managerial accounting costs of building comprehensive traceability systems; thus, the analysis yielded strong results and a superior equilibrium. This research is unprecedented, using an innovative model and providing a novel analysis structure for use in the tea industry. These results contribute to the field of literature and should serve as a valuable reference for members of the tea industry, government, and academia. © 2014 Society of Chemical Industry.

  11. Identification, quantitation, and method validation for flavan-3-ols in fermented ready-to-drink teas from the Italian market using HPLC-UV/DAD and LC-MS/MS.

    PubMed

    Cordero, Chiara; Canale, Francesca; Del Rio, Daniele; Bicchi, Carlo

    2009-11-01

    The present study is focused on flavan-3-ols characterizing the antioxidant properties of fermented tea (Camellia sinensis). These bioactive compounds, object of nutritional claims in commercial products, should be quantified with rigorous analytical procedures whose accuracy and precision have been stated with a certain level of confidence. An HPLC-UV/DAD method, able to detect and quantify flavan-3-ols in infusions and ready-to-drink teas, has been developed for routine analysis and validated by characterizing several performance parameters. The accuracy assessment has been run through a series of LC-MS/MS analyses. Epigallocatechin, (+)-catechin, (-)-epigallocatechingallate, (-)-epicatechin, (-)-gallocatechingallate, (-)-epicatechingallate, and (-)-catechingallate were chosen as markers of the polyphenolic fraction. Quantitative results showed that samples obtained from tea leaves infusion were richer in polyphenolic antioxidants than those obtained through other industrial processes. The influence of shelf-life and packaging material on the flavan-3-ols content was also considered; markers decreased, with an exponential trend, as a function of time within the shelf life while packaging materials demonstrated to influence differently the flavan-3-ol fraction composition over time. The method presented here provides quantitative results with a certain level of confidence and is suitable for a routine quality control of iced teas whose antioxidant properties are object of nutritional claim.

  12. 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

  13. Development of polymethacrylate nanospheres as targeted delivery systems for catechin within the gastrointestinal tract

    NASA Astrophysics Data System (ADS)

    Pool, Hector; Luna-Barcenas, Gabriel; McClements, David Julian; Mendoza, Sandra

    2017-09-01

    In this study, pH-sensitive nanospheres were fabricated using a polymethacrylate-based copolymer to encapsulate, protect, and release catechin, and thereby overcome its poor water solubility and low oral bioaccessibility. The polymer used was a polymethacrylic acid-co-ethyl acrylate 1:1 copolymer that dissolves above pH 5.5, and so can be used to retain and protect bioactives within the stomach but releases them in the small intestine. Catechin-loaded nanospheres were fabricated using the solvent displacement method. Physicochemical characterization of the nanospheres indicated that they were relatively small ( d = 160 nm) and had a high negative charge ( ζ = - 36 mV), which meant that they had good stability to aggregation under physiological conditions (pH 7.2). Catechin was trapped within the nanospheres at an encapsulation efficiency of about 51% in an amorphous state. A simulated gastrointestinal study showed that catechin was slowly released under gastric conditions (pH 2.5), but rapidly released under small intestine conditions (pH 7.2). The observed improvement in the antioxidant activity and bioaccessibility of catechin after encapsulation was attributed to the fact that it was in an amorphous state and had good water dispersibility. This study provides useful information for the formulation of novel delivery systems to improve the dispersibility, bioaccessibility, and bioactivity of catechin and potentially other active components. These delivery systems could be used to improve the efficacy of bioactive components in foods, supplements, and pharmaceutical products.

  14. 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.

  15. 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

  16. 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.

  17. Condensed tannins: The formation of a diarylpropanol-catechinic acid dimer from base-catalyzed reactions of (+)-catechin

    Treesearch

    Seiji Ohara; Richard W. Hemingway

    1991-01-01

    Reaction of (+ )-catechin at pH 12 and 40 DC results in the stereoselective (if not stereospecific) formation of an enolic form of 1-[6-(3',4'-dihydroxyphenyl)-7-hydroxybicyclo[3.3.1]nonane-2,4,9-trione-3-yl]-1-(3,4-dihyroxyphenyl)-3-(2,-4,6-trihydroxyphenyl)-propan-2-ol. The n.m.r. chemical shift assignments determined by a variety of two-dimensional...

  18. 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.

  19. Self-assembled micellar nanocomplexes comprising green tea catechin derivatives and protein drugs for cancer therapy

    NASA Astrophysics Data System (ADS)

    Chung, Joo Eun; Tan, Susi; Gao, Shu Jun; Yongvongsoontorn, Nunnarpas; Kim, Soon Hee; Lee, Jeong Heon; Choi, Hak Soo; Yano, Hirohisa; Zhuo, Lang; Kurisawa, Motoichi; Ying, Jackie Y.

    2014-11-01

    When designing drug carriers, the drug-to-carrier ratio is an important consideration, because the use of high quantities of carriers can result in toxicity as a consequence of poor metabolism and elimination of the carriers. However, these issues would be of less concern if both the drug and carrier had therapeutic effects. (-)-Epigallocatechin-3-O-gallate (EGCG), a major ingredient of green tea, has been shown, for example, to possess anticancer effects, anti-HIV effects, neuroprotective effects and DNA-protective effects. Here, we show that sequential self-assembly of the EGCG derivative with anticancer proteins leads to the formation of stable micellar nanocomplexes, which have greater anticancer effects in vitro and in vivo than the free protein. The micellar nanocomplex is obtained by complexation of oligomerized EGCG with the anticancer protein Herceptin to form the core, followed by complexation of poly(ethylene glycol)-EGCG to form the shell. When injected into mice, the Herceptin-loaded micellar nanocomplex demonstrates better tumour selectivity and growth reduction, as well as longer blood half-life, than free Herceptin.

  20. 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.

  1. The Impact of Microbial Biotransformation of Catechin in Enhancing the Allelopathic Effects of Rhododendron formosanum

    PubMed Central

    Wang, Chao-Min; Li, Tsai-Chi; Jhan, Yun-Lian; Weng, Jen-Hsien; Chou, Chang-Hung

    2013-01-01

    Rhododendron formosanum is distributed widely in the central mountains in Taiwan and the major allelopathic compound in the leaves has been identified as (-)-catechin, which is also a major allelochemical of an invasive spotted knapweed in North America. Soil microorganisms play key roles in ecosystems and influence various important processes, including allelopathy. However, no microorganism has been identified as an allelochemical mediator. This study focused on the role of microorganisms in the allelopathic effects of R. formosanum. The microorganism population in the rhizosphere of R. formosanum was investigated and genetic analysis revealed that the predominant genera of microorganisms in the rhizosphere of R. formosanum were Pseudomonas, Herbaspirillum, and Burkholderia. The dominant genera Pseudomonas utilized (-)-catechin as the carbon source and catalyzed the conversion of (-)-catechin into protocatechuic acid in vitro. The concentrations of allelochemicals in the soil were quantified by liquid chromatography-electrospray ionization/tandem mass spectrometry. The concentration of (-)-catechin in the soil increased significantly during the extreme rainfall in the summer season and suppressed total bacterial populations. Protocatechuic acid accumulation was observed while total bacterial populations increased abundantly in both laboratory and field studies. Allelopathic interactions were tested by evaluating the effects of different allelochemicals on the seed germination, radicle growth, and photosynthesis system II of lettuce. Protocatechuic acid exhibited higher phytotoxicity than (-)-catechin did and the effect of (-)-catechin on the inhibition of seed germination was enhanced by combining it with protocatechuic acid at a low concentration. This study revealed the significance of the allelopathic interactions between R. formosanum and microorganisms in the rhizosphere. These findings demonstrate that knowledge regarding the precise biotransformation

  2. The impact of microbial biotransformation of catechin in enhancing the allelopathic effects of Rhododendron formosanum.

    PubMed

    Wang, Chao-Min; Li, Tsai-Chi; Jhan, Yun-Lian; Weng, Jen-Hsien; Chou, Chang-Hung

    2013-01-01

    Rhododendron formosanum is distributed widely in the central mountains in Taiwan and the major allelopathic compound in the leaves has been identified as (-)-catechin, which is also a major allelochemical of an invasive spotted knapweed in North America. Soil microorganisms play key roles in ecosystems and influence various important processes, including allelopathy. However, no microorganism has been identified as an allelochemical mediator. This study focused on the role of microorganisms in the allelopathic effects of R. formosanum. The microorganism population in the rhizosphere of R. formosanum was investigated and genetic analysis revealed that the predominant genera of microorganisms in the rhizosphere of R. formosanum were Pseudomonas, Herbaspirillum, and Burkholderia. The dominant genera Pseudomonas utilized (-)-catechin as the carbon source and catalyzed the conversion of (-)-catechin into protocatechuic acid in vitro. The concentrations of allelochemicals in the soil were quantified by liquid chromatography-electrospray ionization/tandem mass spectrometry. The concentration of (-)-catechin in the soil increased significantly during the extreme rainfall in the summer season and suppressed total bacterial populations. Protocatechuic acid accumulation was observed while total bacterial populations increased abundantly in both laboratory and field studies. Allelopathic interactions were tested by evaluating the effects of different allelochemicals on the seed germination, radicle growth, and photosynthesis system II of lettuce. Protocatechuic acid exhibited higher phytotoxicity than (-)-catechin did and the effect of (-)-catechin on the inhibition of seed germination was enhanced by combining it with protocatechuic acid at a low concentration. This study revealed the significance of the allelopathic interactions between R. formosanum and microorganisms in the rhizosphere. These findings demonstrate that knowledge regarding the precise biotransformation

  3. Tea polyphenols for health promotion

    PubMed Central

    Khan, Naghma; Mukhtar, Hasan

    2011-01-01

    People have been consuming brewed tea from the leaves of the Camellia sinensis plant for almost 50 centuries. Although health benefits have been attributed to tea, especially green tea consumption since the beginning of its history, scientific investigations of this beverage and its constituents have been underway for less than three decades. Currently, tea, in the form of green or black tea, next to water, is the most widely consumed beverage in the world. In vitro and animal studies provide strong evidence that polyphenols derived from tea may possess the bioactivity to affect the pathogenesis of several chronic diseases. Among all tea polyphenols, epigallocatechin-3-gallate has been shown to be responsible for much of the health promoting ability of green tea. Tea and tea preparations have been shown to inhibit tumorigenesis in a variety of animal models of carcinogenesis. However, with increasing interest in the health promoting properties of tea and a significant rise in scientific investigation, this review covers recent findings on the medicinal properties and health benefits of tea with special reference to cancer and cardiovascular diseases. PMID:17655876

  4. 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

  5. Impact of fermentation, drying, roasting, and Dutch processing on epicatechin and catechin content of cacao beans and cocoa ingredients.

    PubMed

    Payne, Mark J; Hurst, W Jeffrey; Miller, Kenneth B; Rank, Craig; Stuart, David A

    2010-10-13

    Low molecular weight flavan-3-ols are thought to be responsible, in part, for the cardiovascular benefits associated with cocoa powder and dark chocolate. The levels of epicatechin and catechin were determined in raw and conventionally fermented cacao beans and during conventional processing, which included drying, roasting, and Dutch (alkali) processing. Unripe cacao beans had 29% higher levels of epicatechin and the same level of catechin compared to fully ripe beans. Drying had minimal effect on the epicatechin and catechin levels. Substantial decreases (>80%) in catechin and epicatechin levels were observed in fermented versus unfermented beans. When both Ivory Coast and Papua New Guinea beans were subjected to roasting under controlled conditions, there was a distinct loss of epicatechin when bean temperatures exceeded 70 °C. When cacao beans were roasted to 120 °C, the catechin level in beans increased by 696% in unfermented beans, by 650% in Ivory Coast beans, and by 640% in Papua New Guinea fermented beans compared to the same unroasted beans. These results suggest that roasting in excess of 70 °C generates significant amounts of (-)-catechin, probably due to epimerization of (-)-epicatechin. Compared to natural cocoa powders, Dutch processing caused a loss in both epicatechin (up to 98%) and catechin (up to 80%). The epicatechin/catechin ratio is proposed as a useful and sensitive indicator for the processing history of cacao beans.

  6. Long-term supplementation of decaffeinated green tea extract does not modify body weight or abdominal obesity in a randomized trial of men at high risk for prostate cancer

    PubMed Central

    Kumar, Nagi B.; Patel, Roshni; Pow-Sang, Julio; Spiess, Philippe E.; Salup, Raoul; Williams, Christopher R.; Schell, Michael J.

    2017-01-01

    Background Evidence continues to demonstrate the role of obesity in prostate carcinogenesis and prognosis, underscoring the need to identify and continue to evaluate the effective interventions to reduce obesity in populations at high risk. The aim of the study was to determine the effect of daily consumption of decaffeinated green tea catechins (GTC) formulation (Polyphenon E® (PolyE)) for 1 year on biomarkers of obesity in men who are at high risk for prostate cancer. Materials and Methods A randomized, double-blinded trial was conducted targeting 97 men diagnosed with HGPIN or ASAP. Subjects were randomized to receive GTC (PolyE) (n = 49) or placebo (n = 48) for 1 year. Anthropometric data were collected at baseline, 6 and 12 months and data analyzed to observe change in weight, body mass index (indicator of obesity) and waist: hip ratio (indicator of abdominal obesity). Results Decaffeinated GTC containing 400 mgs of the bioactive catechin, EGCG administered for 1 year to men diagnosed with ASAP and HGPIN appears to be bioavailable, well tolerated but not effective in reducing biomarkers of obesity including body weight, body mass index and waist: hip ratio. Conclusions The results of our trial demonstrates that men who are obese and at high risk for prostate cancer should resort to effective weight management strategies to reduce obesity and not resort to ineffective measures such as taking supplements of green tea to reduce biomarkers of obesity. Changes in body mass index and abdominal obesity seen in other studies were potentially due to caffeine and not GTC. PMID:29228755

  7. 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.

  8. Tissue-Specific, Development-Dependent Phenolic Compounds Accumulation Profile and Gene Expression Pattern in Tea Plant [Camellia sinensis

    PubMed Central

    Li, Weiwei; Zhao, Lei; Meng, Fei; Wang, Yunsheng; Tan, Huarong; Yang, Hua; Wei, Chaoling; Wan, Xiaochun; Gao, Liping; Xia, Tao

    2013-01-01

    Phenolic compounds in tea plant [Camellia sinensis (L.)] play a crucial role in dominating tea flavor and possess a number of key pharmacological benefits on human health. The present research aimed to study the profile of tissue-specific, development-dependent accumulation pattern of phenolic compounds in tea plant. A total of 50 phenolic compounds were identified qualitatively using liquid chromatography in tandem mass spectrometry technology. Of which 29 phenolic compounds were quantified based on their fragmentation behaviors. Most of the phenolic compounds were higher in the younger leaves than that in the stem and root, whereas the total amount of proanthocyanidins were unexpectedly higher in the root. The expression patterns of 63 structural and regulator genes involved in the shikimic acid, phenylpropanoid, and flavonoid pathways were analyzed by quantitative real-time polymerase chain reaction and cluster analysis. Based on the similarity of their expression patterns, the genes were classified into two main groups: C1 and C2; and the genes in group C1 had high relative expression level in the root or low in the bud and leaves. The expression patterns of genes in C2-2-1 and C2-2-2-1 groups were probably responsible for the development-dependent accumulation of phenolic compounds in the leaves. Enzymatic analysis suggested that the accumulation of catechins was influenced simultaneously by catabolism and anabolism. Further research is recommended to know the expression patterns of various genes and the reason for the variation in contents of different compounds in different growth stages and also in different organs. PMID:23646127

  9. Evaluation of green tea extract as a glazing material for shrimp frozen by cryogenic freezing.

    PubMed

    Sundararajan, Srijanani; Prudente, Alfredo; Bankston, J David; King, Joan M; Wilson, Paul; Sathivel, Subramaniam

    2011-09-01

    Solutions of green tea (Camellia sinensis) extract (GTE) in distilled water were evaluated as a glazing material for shrimp frozen by cryogenic freezing. Total of 2%, 3%, and/or 5% GTE solutions (2GTE, 3GTE, 5GTE) were used for glazing. Distilled water glazed (GDW) and nonglazed shrimp (NG) served as controls. The GTE was characterized by measuring color, pH, (o) Brix, total phenols, and % antiradical activity. Individual catechins were identified by HPLC. The freezing time, freezing rate, and energy removal rate for freezing shrimp by cryogenic freezing process were estimated. The frozen shrimp samples were stored in a freezer at -21 °C for 180 d. Samples were analyzed for pH, moisture content, glazing yield, thaw yield, color, cutting force, and thiobarbituric acid reactive substances (TBARS) after 1, 30, 90, and 180 d. The HPLC analysis of GTE revealed the presence of catechins and their isomers and the total polyphenol content was 148.10 ± 2.49 g/L. The freezing time (min) and energy removal rate (J/s) were 48.67 ± 2.3 and 836.67 ± 78.95, respectively. Glazed samples had higher moisture content compared to NG shrimp after 180 d storage. GTE was effective in controlling the lipid oxidation in shrimp. Glazing with GTE affected a* and b* color values, but had no significant effect on the L* values of shrimp. © 2011 Institute of Food Technologists®

  10. Aroma changes of black tea prepared from methyl jasmonate treated tea plants*

    PubMed Central

    Shi, Jiang; Wang, Li; Ma, Cheng-ying; Lv, Hai-peng; Chen, Zong-mao; Lin, Zhi

    2014-01-01

    Methyl jasmonate (MeJA) was widely applied in promoting food quality. Aroma is one of the key indicators in judging the quality of tea. This study examined the effect of exogenous MeJA treatment on tea aroma. The aroma components in black tea prepared from MeJA-treated fresh tea leaves were extracted using headspace solid-phase microextraction (HS-SPME) and were analyzed using gas chromatography-mass spectrometry (GC-MS) and GC-olfactometry (GC-O). Forty-five volatile compounds were identified. The results revealed that the MeJA-treated black tea had higher levels of terpene alcohols and hexenyl esters than the untreated tea. Moreover, several newly components, including copaene, cubenol, and indole, were induced by the MeJA treatment. The activities of polyphenol oxidase and β-glucosidase in fresh tea leaves changed after the MeJA treatment. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis indicated that the gene expression levels of polyphenol oxidase and β-primeverosidase were upregulated by two and three folds, respectively, by the MeJA treatment (P<0.01); however, the gene expression of β-glucosidase was downregulated to a half level. In general, the aroma quality of the MeJA-treated black tea was clearly improved. PMID:24711352

  11. Mechanical properties of a Gelidium corneum edible film containing catechin and its application in sausages.

    PubMed

    Ku, K-J; Hong, Y-H; Song, K B

    2008-04-01

    We prepared an edible Gelidium corneum (GC) film containing catechin and examined the microbial growth and quality change during storage of sausages packaged with the film. Incorporation of catechin in the film improved film tensile strength and water vapor permeability. The film's antimicrobial activity against Eschericha coli O157:H7 increased with increasing catechin concentrations and resulted in a decrease in the populations of the bacteria by 1.93 log CFU/g at 150 mg of catechin. For the sausage samples inoculated with E. coli O157:H7 and Listeria monocytogenes, the samples packed with the GC film showed a decrease in populations of E. coli O157:H7 and L. monocytogenes by 1.81 and 1.44 log CFU/g, respectively, compared to the control after 5 d of storage. In addition, the sausage samples packed with the GC film had lower degrees of lipid oxidation. The results suggest that sausages can be packed with GC film to extend shelf life.

  12. Role of chlorogenic acid quinone and interaction of chlorogenic acid quinone and catechins in the enzymatic browning of apple.

    PubMed

    Amaki, Kanako; Saito, Eri; Taniguchi, Kumiko; Joshita, Keiko; Murata, Masatsune

    2011-01-01

    Chlorogenic acid (CQA) is one of the major polyphenols in apple and a good substrate for the polyphenol oxidase (PPO) in apple. Apple contains catechins as well as CQA, and the role of CQA quinone and its interaction with catechins in the enzymatic browning of apple were examined. Browning was repressed and 2-cysteinyl-CQA was formed when cysteine was added to apple juice. CQA quinone was essential for browning to occur. Although catechins and CQA were oxidized by PPO, some catechins seemed to be non-enzymatically oxidized by CQA quinone.

  13. Proteomic analysis of tea plants (Camellia sinensis) with purple young shoots during leaf development

    PubMed Central

    Zhou, Qiongqiong; Chen, Zhidan; Lee, Jinwook; Li, Xinghui; Sun, Weijiang

    2017-01-01

    Tea products made from purple leaves are highly preferred by consumers due to the health benefits. This study developed a proteome reference map related to color changes during leaf growth in tea (Camellia sinensis) plant with purple young shoots using two-dimensional electrophoresis (2-DE). Forty-six differentially expressed proteins were detected in the gel and successfully identified by using MALDI-TOF/TOF-MS. The pronounced changes in the proteomic profile between tender purple leaves (TPL) and mature green leaves (MGL) included: 1) the lower activity of proteins associated with CO2 assimilation, energy metabolism and photo flux efficiency and higher content of anthocyanins in TPL than those in MGL may protect tender leaves against photo-damage; 2) the higher abundance of chalcone synthase (CHS), chalcone isomerase (CHI) and flavonol synthase (FLS) likely contributes to the synthesis of anthocyanins, catechins and flavonols in TPL tissues; 3) higher abundance of stress response proteins, such as glutathione S-transferases (GST) and phospholipid hydroperoxide glutathione peroxidase (PHGPx), could enhance the tolerance of TPL tissues to adverse condition in; and 4) the increased abundance of proteins related to protein synthesis, nucleic acids and cell wall proteins should be beneficial for the proliferation and expansion of leaf cell in TPL tissues. qPCR analysis showed that the expression of differentially abundant proteins was regulated at the transcriptional level. Therefore, the results indicated that higher abundance of CHI and CHS may account for the production of the purple-shoot phenotype in Wuyiqizhong 18 and thereby, enhancing the anthocyanin biosynthesis. The higher abundance of glutamine synthetase (GS) proteins related to the theanine biosynthesis may improve the flavor of tea products from TPL materials. Thus, this work should help to understand the molecular mechanisms underlying the changes in leaf color alteration. PMID:28520776

  14. Identification of proanthocyanidin dimers and trimers, flavone C-Glycosides, and antioxidants in Ficus deltoidea , a malaysian herbal tea.

    PubMed

    Omar, Maizatul Hasyima; Mullen, William; Crozier, Alan

    2011-02-23

    Phenolic compounds in an aqueous infusion of leaves of Ficus deltoidea (Moraceae), a well-known herbal tea in Malaysia, were analyzed by HPLC coupled to photodiode array and fluorescence detectors and an electrospray ionization tandem mass spectrometer. Following chromatography of extracts on a reversed phase C(12) column, 25 flavonoids were characterized and/or tentatively identified with the main constituents being flavan-3-ol monomers, proanthocyanidins, and C-linked flavone glycosides. The proanthocyanidins were dimers and trimers comprising (epi)catechin and (epi)afzelechin units. No higher molecular weight proanthocyanidin polymers were detected. The antioxidant activity of F. deltoidea extract was analyzed using HPLC with online antioxidant detection. This revealed that 85% of the total antioxidant activity of the aqueous F. deltoidea infusion was attributable to the flavan-3-ol monomers and the proanthocyanidins.

  15. Absorption kinetics of vitamin E nanoemulsion and green tea microstructures by intestinal in situ single perfusion technique in rats.

    PubMed

    Saratale, Rijuta Ganesh; Lee, Hee-Seok; Koo, Yong Eui; Saratale, Ganesh Dattatraya; Kim, Young Jun; Imm, Jee Young; Park, Yooheon

    2018-04-01

    The absorption kinetics of food ingredients such as nanoemulsified vitamin E and green tea microstructures were evaluated by the intestinal in situ single perfusion technique. Absorption rate, sub-acute oral toxicity and organ morphology in a rat model were examined. The intestinal in situ single perfusion technique and HPLC analysis were applied to investigate the absorption rate of selected materials by examining time-dependent changes in the serum levels of catechin and dl-α-tocopherol. The acute toxicity test and histopathological evaluation were applied to analyze the safety of microsized green tea and nanosized vitamin E in a rat model. Total serum dl-α-tocopherol levels significantly increased with nanosized vitamin E administration (P<0.05). Rats treated to nanosized vitamin E until 90min after administration showed significantly increased absorption rate of serum dl-α-tocopherol levels at each time point (10min interval) (P<0.001). Rats administered 2000mg/kg of nanosized vitamin E and microsized green tea did not show signs of acute toxicity or death after 14days of observation. In addition, macroscopic analysis showed that there were no changes in representative organ sections of rats following the oral administration of food-related nanoscale materials. We successfully demonstrated that using nanosized vitamin E increased absorption rate to a greater extent than normal food-related material, and these results occurs via safety analyses on food-related nanoscale materials for human consumption. These results could be useful for the design and development of novel nanoemulsified vitamin E and microsized green tea formulations that can overcome the problem of their bioavailability and improve their efficacy while still maintaining their essential therapeutic efficacies. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. 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.

  17. 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

  18. (-)-Catechin in cocoa and chocolate: occurrence and analysis of an atypical flavan-3-ol enantiomer.

    PubMed

    Kofink, Michael; Papagiannopoulos, Menelaos; Galensa, Rudolf

    2007-07-04

    Cocoa contains high levels of different flavonoids. In the present study, the enantioseparation of catechin and epicatechin in cocoa and cocoa products by chiral capillary electrophoresis (CCE) was performed. A baseline separation of the catechin and epicatechin enantiomers was achieved by using 0.1 mol x L(-1) borate buffer (pH 8.5) with 12 mmol x L(-1) (2-hydroxypropyl)-gamma-cyclodextrin as chiral selector, a fused-silica capillary with 50 cm effective length (75 microm I.D.), +18 kV applied voltage, a temperature of 20 degrees C and direct UV detection at 280 nm. To avoid comigration or coelution of other similar substances, the flavan-3-ols were isolated and purified using polyamide-solid-phase-extraction and LC-MS analysis. As expected, we found (-)-epicatechin and (+)-catechin in unfermented, dried, unroasted cocoa beans. In contrast, roasted cocoa beans and cocoa products additionally contained the atypical flavan-3-ol (-)-catechin. This is generally formed during the manufacturing process by an epimerization which converts (-)-epicatechin to its epimer (-)-catechin. High temperatures during the cocoa bean roasting process and particularly the alkalization of the cocoa powder are the main factors inducing the epimerization reaction. In addition to the analysis of cocoa and cocoa products, peak ratios were calculated for a better differentiation of the cocoa products.

  19. Plasticized poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends incorporated with catechin intended for active food-packaging applications.

    PubMed

    Arrieta, Marina Patricia; Castro-López, María del Mar; Rayón, Emilio; Barral-Losada, Luis Fernando; López-Vilariño, José Manuel; López, Juan; González-Rodríguez, María Victoria

    2014-10-15

    Active biobased packaging materials based on poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends were prepared by melt blending and fully characterized. Catechin incorporation, as antioxidant compound, enhanced the thermal stability, whereas its release was improved by the addition of acetyl(tributyl citrate) (ATBC) as plasticizer. Whereas the incorporation of ATBC resulted in a reduction of elastic modulus and hardness, catechin addition produced more rigid materials due to hydrogen-bonding interactions between catechin hydroxyl groups and carbonyl groups of PLA and PHB. The quantification of catechin released into a fatty food simulant and the antioxidant effectiveness after the release process were demonstrated. The effect of the materials' exposure to a food simulant was also investigated. PHB-added materials maintained their structural and mechanical properties after 10 days in a test medium that represents the worst foreseeable conditions of the intended use. Thus, plasticized PLA-PHB blends with catechin show their potential as biobased active packaging for fatty food.

  20. Non-classic androgen actions in Sertoli cell membrane in whole seminiferous tubules: effects of nandrolone decanoate and catechin.

    PubMed

    Cavalari, Fernanda Carvalho; de Castro, Alexandre Luz; Fracasso, Bianca de Moraes; Loss, Eloísa da Silveira

    2012-01-01

    Studies show a mechanism of action of testosterone, nandrolone and catechin as agonists of the membrane androgen receptor. The aim of this work is to investigate the non-classical effect of androgens and catechin in Sertoli cells from immature rats. The membrane potential of Sertoli cells in whole seminiferous tubules was recorded using a standard single microelectrode technique. It was performed a topical application of testosterone (1 μM), nandrolone (0.1, 0.5 and 1 μM) and the flavonoid catechin (0.1, 0.5 and 1 μM) alone and also after infusion with flutamide (1 μM), diazoxide (100 μM) or U73122 (1 μM). The immature testes were incubated for 5 min in KRb with (45)Ca(2+), with or without nandrolone (1 μM). The results were given as mean±SEM. The data were analyzed using ANOVA for repeated measures with Bonferroni post-test. Testosterone produces a depolarization in the membrane potential at 120 s after application. Catechin (1 μM) and nandrolone (1 μM) have shown a similar response to testosterone: depolarization at 120 s after the application. The same response of catechin and nandrolone was observed at different doses. The effects of testosterone, catechin and nandrolone were not affected after perfusion with flutamide. Perfusion with diazoxide and U73122 nullified the effect of nandrolone (1 μM) and catechin (1 μM). Nandrolone and testosterone increased (45)Ca(2+) uptake with or without flutamide within 5min. These results indicate that nandrolone and catechin act through a receptor on the plasmatic membrane, as well as testosterone, showing a non-classical pathway in Sertoli cells from immature rat testes. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. 9,10-Anthraquinone deposit in tea plantation might be one of the reasons for contamination in tea.

    PubMed

    Wang, Xuan; Zhou, Li; Luo, Fengjian; Zhang, Xinzhong; Sun, Hezhi; Yang, Mei; Lou, Zhengyun; Chen, Zongmao

    2018-04-01

    9,10-Anthraquinone (AQ) was a new contaminant, with unknown sources, occurred globally in tea. European Union (EU) fixed the maximum residue limit (MRL) of 0.02mg/kg. The pollution source of AQ in tea was traced from the view of AQ deposit on tea crop by simulation. The possible contamination pathway and main factors to decrease AQ were explored in tea cultivation- tea manufacture- tea infusion, on the basis of AQ analytical methods by using solvent extraction and gas chromatography-tandem mass spectrometry (GC-MS/MS) quantification. 58.8-84.6% of AQ degraded in tea processing, and drying played a key role to reduce the AQ contamination. Certain concentration of AQ deposited on tea shoots could resulted in AQ beyond the MRL of 0.02mg/kg in tea. AQ leaching into tea brew (about 10%) could lead to the possible health risk. AQ deposit on tea crop during the tea cultivation might cause the AQ contamination in tea. Copyright © 2017. Published by Elsevier Ltd.

  2. 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.

  3. Tea-induced calmness: Sugar-sweetened tea calms consumers exposed to acute stressor

    PubMed Central

    Samant, Shilpa. S.; Wilkes, Katherine; Odek, Zephania; Seo, Han-Seok

    2016-01-01

    The food and beverage industry has been increasingly replacing sugar with non-nutritive sweeteners in their sweetened products to control or reduce total calories. Research comparing the effect of nutritive and non-nutritive sweeteners on emotional state of participants exposed to acute stressors is still limited. This study aimed to determine the effect of drinking tea sweetened with either a nutritive sweetener (sugar) or a non-nutritive sweetener (sucralose or stevia) on emotional state, in terms of calmness and pleasantness, of participants exposed to an acute stressor. Effects of acute stress on sweetness intensity and overall liking of tea beverages were also determined. Results showed that the possibility of tea-induced calmness, calculated as the difference between calmness ratings after and before drinking a tea sample, was established on stress session in the sugar-sweetened tea. Overall liking, but not the sweetness intensity, of the sugar-sweetened tea was affected by acute stress. In conclusion, this study provides empirical evidence that the consumption of tea sweetened with nutritive sweetener, but not with non-nutritive sweetener, has calming effect on consumers with acute stress, suggesting that this effect may not be due to the sweet taste of sugar, but due to the caloric nature of the sweetener. PMID:27848976

  4. Tea-induced calmness: Sugar-sweetened tea calms consumers exposed to acute stressor.

    PubMed

    Samant, Shilpa S; Wilkes, Katherine; Odek, Zephania; Seo, Han-Seok

    2016-11-16

    The food and beverage industry has been increasingly replacing sugar with non-nutritive sweeteners in their sweetened products to control or reduce total calories. Research comparing the effect of nutritive and non-nutritive sweeteners on emotional state of participants exposed to acute stressors is still limited. This study aimed to determine the effect of drinking tea sweetened with either a nutritive sweetener (sugar) or a non-nutritive sweetener (sucralose or stevia) on emotional state, in terms of calmness and pleasantness, of participants exposed to an acute stressor. Effects of acute stress on sweetness intensity and overall liking of tea beverages were also determined. Results showed that the possibility of tea-induced calmness, calculated as the difference between calmness ratings after and before drinking a tea sample, was established on stress session in the sugar-sweetened tea. Overall liking, but not the sweetness intensity, of the sugar-sweetened tea was affected by acute stress. In conclusion, this study provides empirical evidence that the consumption of tea sweetened with nutritive sweetener, but not with non-nutritive sweetener, has calming effect on consumers with acute stress, suggesting that this effect may not be due to the sweet taste of sugar, but due to the caloric nature of the sweetener.

  5. Catechin-3-0-rhamoside chain procyanidins from mangrove bark

    Treesearch

    Suminar Achmadi; Gustini Syahbirin; Elvin T. Chonng; Richard W. Hemingway

    1994-01-01

    Acid-catalysed cleavage of 'purified' condensed tannin isolates from Bruguiera gymnorrhiza (tancang) bark in the presence of phloroglucinol as a capture nucleophile gave, in addition to the expected procyanidin- and prodelphinidin-phloroglucinol adducts, 3-O-α-L-rhamnopyranosyl-(+)-catechin-(4α...

  6. Killing K channels with TEA+.

    PubMed

    Khodakhah, K; Melishchuk, A; Armstrong, C M

    1997-11-25

    Tetraethylammonium (TEA+) is widely used for reversible blockade of K channels in many preparations. We noticed that intracellular perfusion of voltage-clamped squid giant axons with a solution containing K+ and TEA+ irreversibly decreased the potassium current when there was no K+ outside. Five minutes of perfusion with 20 mM TEA+, followed by removal of TEA+, reduced potassium current to < 5% of its initial value. The irreversible disappearance of K channels with TEA+ could be prevented by addition of > or = 10 mM K+ to the extracellular solution. The rate of disappearance of K channels followed first-order kinetics and was slowed by reducing the concentration of TEA+. Killing is much less evident when an axon is held at -110 mV to tightly close all of the channels. The longer-chain TEA+ derivative decyltriethylammonium (C10+) had irreversible effects similar to TEA+. External K+ also protected K channels against the irreversible action of C10+. It has been reported that removal of all K+ internally and externally (dekalification) can result in the disappearance of K channels, suggesting that binding of K+ within the pore is required to maintain function. Our evidence further suggests that the crucial location for K+ binding is external to the (internal) TEA+ site and that TEA+ prevents refilling of this location by intracellular K+. Thus in the absence of extracellular K+, application of TEA+ (or C10+) has effects resembling dekalification and kills the K channels.

  7. Green tea extract induces protective autophagy in A549 non-small lung cancer cell line.

    PubMed

    Izdebska, Magdalena; Klimaszewska-Wiśniewska, Anna; Hałas, Marta; Gagat, Maciej; Grzanka, Alina

    2015-12-31

    For many decades, polyphenols, including green tea extract catechins, have been reported to exert multiple anti-tumor activities. However, to date the mechanisms of their action have not been completely elucidated. Thus, the aim of this study was to assess the effect of green tea extract on non-small lung cancer A549 cells. A549 cells following treatment with GTE were analyzed using the inverted light and fluorescence microscope. In order to evaluate cell sensitivity and cell death, the MTT assay and Tali image-based cytometer were used, respectively. Ultrastructural alterations were assessed using a transmission electron microscope. The obtained data suggested that GTE, even at the highest dose employed (150 μM), was not toxic to A549 cells. Likewise, the treatment with GTE resulted in only a very small dose-dependent increase in the population of apoptotic cells. However, enhanced accumulation of vacuole-like structures in response to GTE was seen at the light and electron microscopic level. Furthermore, an increase in the acidic vesicular organelles and LC3-II puncta formation was observed under the fluorescence microscope, following GTE treatment. The analysis of the functional status of autophagy revealed that GTE-induced autophagy may provide self-protection against its own cytotoxicity, since we observed that the blockage of autophagy by bafilomycin A1 decreased the viability of A549 cells and potentiated necrotic cell death induction in response to GTE treatment. Collectively, our results revealed that A549 cells are insensitive to both low and high concentrations of the green tea extract, probably due to the induction of cytoprotective autophagy. These data suggest that a potential utility of GTE in lung cancer therapy may lie in its synergistic combinations with drugs or small molecules that target autophagy, rather than in monotherapy.

  8. The green tea modulates large intestinal microbiome and exo/endogenous metabolome altered through chronic UVB-exposure.

    PubMed

    Jung, Eun Sung; Park, Hye Min; Hyun, Seung Min; Shon, Jong Cheol; Singh, Digar; Liu, Kwang-Hyeon; Whon, Tae Woong; Bae, Jin-Woo; Hwang, Jae Sung; Lee, Choong Hwan

    2017-01-01

    The attenuating effects of green tea supplements (GTS) against the ultraviolet (UV) radiation induced skin damages are distinguished. However, the concomitant effects of GTS on the large intestinal microbiomes and associated metabolomes are largely unclear. Herein, we performed an integrated microbiome-metabolome analysis to uncover the esoteric links between gut microbiome and exo/endogenous metabolome maneuvered in the large intestine of UVB-exposed mice subjected to dietary GTS. In UVB-exposed mice groups (UVB), class Bacilli and order Bifidobacteriales were observed as discriminant taxa with decreased lysophospholipid levels compared to the unexposed mice groups subjected to normal diet (NOR). Conversely, in GTS fed UVB-exposed mice (U+GTS), the gut-microbiome diversity was greatly enhanced with enrichment in the classes, Clostridia and Erysipelotrichia, as well as genera, Allobaculum and Lachnoclostridium. Additionally, the gut endogenous metabolomes changed with an increase in amino acids, fatty acids, lipids, and bile acids contents coupled with a decrease in nucleobases and carbohydrate levels. The altered metabolomes exhibited high correlations with GTS enriched intestinal microflora. Intriguingly, the various conjugates of green tea catechins viz., sulfated, glucuronided, and methylated ones including their exogenous derivatives were detected from large intestinal contents and liver samples. Hence, we conjecture that the metabolic conversions for the molecular components in GTS strongly influenced the gut micro-environment in UVB-exposed mice groups, ergo modulate their gut-microbiome as well as exo/endogenous metabolomes.

  9. Residue pattern of polycyclic aromatic hydrocarbons during green tea manufacturing and their transfer rates during tea brewing.

    PubMed

    Gao, Guanwei; Chen, Hongping; Liu, Pingxiang; Hao, Zhenxia; Ma, Guicen; Chai, Yunfeng; Wang, Chen; Lu, Chengyin

    2017-06-01

    Residues of polycyclic aromatic hydrocarbons (PAHs) in green tea and tea infusion were determined using gas chromatography-tandem mass spectrometry to study their dissipation pattern during green tea processing and infusion. Concentration and evaporation of PAHs during tea processing were the key factors affecting PAH residue content in product intermediates and in green tea. PAH residues in tea leaves increased by 2.4-3.1 times during the manufacture of green tea using the electric heating model. After correction to dry weight, PAH residue concentrations decreased by 33.5-48.4% during green tea processing because of PAH evaporation. Moreover, spreading and drying reduced PAH concentrations. The transfer rates of PAH residues from green tea to infusion varied from 4.6% to 7.2%, and PAH leaching was higher in the first infusion than in the second infusion. These results are useful for assessing exposure to PAHs from green tea and in formulating controls for the maximum residue level of PAHs in green tea.

  10. Anti-allergic activity of standardized extract of Albizia lebbeck with reference to catechin as a phytomarker.

    PubMed

    Venkatesh, Pichairajan; Mukherjee, Pulok K; Kumar, Nanjappan Satheesh; Bandyopadhyay, Arun; Fukui, Hiroyuki; Mizuguchi, Hiroyuki; Islam, Nurul

    2010-06-01

    The major groups of phytonutrients found in plants include polyphenols, flavonoids, terpenes, amines, etc., all of which are observed to have potential anti-allergic activity. In this study, we evaluated the anti-allergic activity of the standardized extract of Albizia lebbeck with respect to the catechin, a polyphenolic phytomarker. The percentage of catechin in the ethanolic extract was found to be 14.72 mg/g. We administered Albizia lebbeck (50-300 mg/kg) and 50 mg/kg of catechin to mice to evaluate the mast cell stabilization and estimation of histamine elevation in the plasma. Results support the conclusion that Albizia lebbeck at different concentrations has got potent mast cell stabilizing property and the IC(50) value of Albizia lebbeck was found to be 85 microg/ml. This inhibitory potential of catechin from Albizia lebbeck is perhaps due to modulation of two important effector's functions, histamine release and cytokine expression of antigen -IgE activated mast cells.

  11. 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.

  12. Formulation of a dry green tea-apple product: study on antioxidant and color stability.

    PubMed

    Lavelli, Vera; Vantaggi, Claudia; Corey, Mark; Kerr, William

    2010-03-01

    A dry apple product enriched with green tea (GT) extract was designed as a novel food to deliver relevant amounts of catechins. The target water activity (a(w)) range between 0.11 and 0.32 was chosen for the GT-fortified apple, since it corresponds to low water mobility and, consequently, maximum stability of dehydrated apples. The GT-fortified product and a control dehydrated apple product were stored in air, at 30 degrees C, and evaluated for color, antioxidant contents (monomeric flavan 3-ols, total procyanidins, ascorbic acid, chlorogenic acid and dihydrochalcones), ferric reducing/antioxidant power (FRAP), and 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl radical (DPPH) scavenging capacity. After 1 mo of storage at the lowest a(w) level (0.11), the GT-fortified product retained 80 and 100% of the initial contents of the monomeric flavan 3-ols and total procyanidins, respectively. With increasing a(w) level to 0.32, the stability of antioxidants slowly decreased. The addition of GT to the apple product increased the FRAP value and the DPPH scavenging capacity by 3.6-fold and 4.6-fold respectively, which remained almost unchanged during storage. The GT-fortified product was similar in color to commercially available dehydrated apples. Results highlighted some advantages of using dehydrated apples as a target for green tea fortification, which deserve further trials to investigate potential applications for fortification of other dehydrated fruits.

  13. The case against (-)-catechin involvement in allelopathy of Centaurea stoebe (spotted knapweed)

    PubMed Central

    Dayan, Franck E; Bajsa, Joanna; Meepagala, Kumudini M; Hufbauer, Ruth A; Blair, Amy C

    2009-01-01

    Proving allelopathic chemical interference is a daunting endeavor, in that production and movement of a phytotoxin from a donor plant to a receiving plant must be demonstrated in the substrate in which the plants grow, which is usually a complex soil matrix. The soil levels or soil flux levels of the compound generated by the donor must be proven to be sufficient to adversely affect the receiving plant. Reports of (-)-catechin to be the novel weapon used by Centaurea stoebe (spotted knapweed) to invade new territories are not supported by the paper featured in this Addendum, nor by papers produced by two other laboratories. These papers find that (-)-catechin levels in soil in which C. stoebe grows are orders of magnitude below levels that cause only minor growth effects on reported sensitive species. Furthermore, the claim that (-)-catechin acts as a phytotoxin through causing oxidative damage is refuted by the fact that the molecule is a strong antioxidant and is quickly degraded by extracellular root enzymes. PMID:19816095

  14. Antioxidant activity and diffusion of catechin and epicatechin from antioxidant active films made of poly(L-lactic acid).

    PubMed

    Iñiguez-Franco, Fabiola; Soto-Valdez, Herlinda; Peralta, Elizabeth; Ayala-Zavala, J Fernando; Auras, Rafael; Gámez-Meza, Nohemí

    2012-07-04

    Active membranes and food packaging containing antioxidants like catechin and epicatechin, combined with the use of materials made of biopolymers obtained from renewable sources, could create a novel alternative to reduce oxidation in food, pharmaceutical, and cosmetic products. Poly(94% L-lactic acid) films containing 1.28% catechin and 1.50% epicatechin were extruded in a pilot plant-scale extrusion machine. The diffusion kinetics of catechin and epicatechin into 95% ethanol at 20, 30, 40, and 50 °C and 50% ethanol at 40 °C displayed Fickian release behavior and diffusion coefficients between 0.5 and 50 × 10(-11) cm(2)/s. According to the Arrhenius equation, the energy of activation for the diffusion of catechin and epicatechin in the films was 110.43 and 98.92 kJ/mol, respectively. The antioxidant activity of the films was measured in methanol extracts containing 46.42 μg/mL of catechin and 57.52 μg/mL of epicatechin as 32.90 and 36.68% of scavenging the 2,2-diphenyl-1-picrylhydrazyl radical, respectively.

  15. Hybrid catechin silica nanoparticle influence on Cu(II) toxicity and morphological lesions in primary neuronal cells.

    PubMed

    Halevas, E; Nday, C M; Salifoglou, A

    2016-10-01

    Morphological alterations compromising inter-neuronal connectivity may be directly linked to learning-memory deficits in Central Nervous System neurodegenerative processes. Cu(II)-mediated oxidative stress plays a pivotal role in regulating redox reactions generating reactive oxygen species (ROS) and reactive nitrogen species (RNS), known contributors to Alzheimer's disease (AD) pathology. The antioxidant properties of flavonoid catechin have been well-documented in neurodegenerative processes. However, the impact that catechin encapsulation in nanoparticles may have on neuronal survival and morphological lesions has been poorly demonstrated. To investigate potential effects of nano-encapsulated catechin on neuronal survival and morphological aberrations in primary rat hippocampal neurons, poly(ethyleneglycol) (PEG) and cetyltrimethylammonium bromide (CTAB)-modified silica nanoparticles were synthesized. Catechin was loaded on silica nanoparticles in a concentration-dependent fashion, and release studies were carried out. Further physicochemical characterization of the new nano-materials included elemental analysis, particle size, z-potential, FT-IR, Brunauer-Emmett-Teller (BET), thermogravimetric (TGA), and scanning electron microscopy (SEM) analysis in order to optimize material composition linked to the delivery of loaded catechin in the hippocampal cellular milieu. The findings reveal that, under Cu(II)-induced oxidative stress, the loading ability of the PEGylated/CTAB silica nanoparticles was concentration-dependent, based on their catechin release profile. The overall bio-activity profile of the new hybrid nanoparticles a) denoted their enhanced protective activity against oxidative stress and hippocampal cell survival compared to previously reported quercetin, b) revealed that morphological lesions affecting neuronal integrity can be counterbalanced at high copper concentrations, and c) warrants in-depth perusal of molecular events underlying neuronal

  16. Structure-dependent phytotoxicity of catechins and other flavonoids: flavonoid conversions by cell-free protein extracts of Centaurea maculosa (spotted knapweed) roots.

    PubMed

    Bais, Harsh Pal; Walker, Travis S; Kennan, Alan J; Stermitz, Frank R; Vivanco, Jorge M

    2003-02-12

    Invasive plants are believed to succeed in part by secretion of allelochemicals, thus displacing competing plant species. Centaurea maculosa (spotted knapweed) provides a classic example of this process. We have previously reported that spotted knapweed roots secrete (+/-)-catechin and that (-)-catechin, but not (+)-catechin, is phytotoxic and hence may be a major contributor to C. maculosa's invasive behavior in the rhizosphere. In this communication, we explore both structure/activity relationships for flavonoid phytotoxicity and possible biosynthetic pathways for root production of (+/-)-catechin. Kaempferol and dihydroquercetin were shown to be phytotoxic, while quercetin was not. Kaempferol was converted to dihydroquercetin and (+/-)-catechin when treated with total root protein extracts from C. maculosa, but quercetin was not. This finding suggests an alteration in the standard flavonoid biosynthetic pathway in C. maculosa roots, whereby kaempferol is not a dead-end product but serves as a precursor to dihydroquercetin, which in turn leads to (+/-)-catechin production.

  17. Quantitative analysis of catechins in Saraca asoca and correlation with antimicrobial activity

    PubMed Central

    Shirolkar, Amey; Gahlaut, Anjum; Chhillar, Anil K.; Dabur, Rajesh

    2013-01-01

    Herbal medicines are highly complex and have unknown mechanisms in diseases treatment. Saraca asoca (Roxb.), De. Wild has been recommended to treat gynecological disorders and used in several commercial polyherbal formulations. In present study, efforts have been made to explore antimicrobial activity and its co-relation with the distributions of catechins in the organs of S. asoca using targeted MS/MS. Eight extracts (cold and hot water) from four different organs of S. asoca and two drugs were prepared and antimicrobial activity was assessed by microbroth dilution assay. Quantitative and qualitative analysis of catechins in crude extracts was done by using targeted and auto-MS/MS and correlated with antimicrobial activity. (+)-Catechin and (+)-epicatechin and their biosynthesis related compound were found to be up-regulated in regenerated bark and leaves extracts. (−)-Epigallocatechin was found to be significantly higher in bark water extract as compared to others but showed low antimicrobial activity. Result showed down-regulation of (−)-epigallocatechin and up-regulation of (+)-catechin and (+)-epicatechin in the regenerated bark and leaves of S. asoca. It might be the contributing factor in the antimicrobial activity of regenerated bark and leaves of the plant. The concentration of (+)-epicatechin in processed drugs (Ashokarishta) from Baidyanath was found to be seven times higher than that of Dabur Pvt. Ltd., but no antimicrobial activity was observed, indicating the variations among the plant based drugs. This will be helpful in rational use of S. asoca parts. Furthermore, the analytical method developed is sensitive, repeatable and reliable; therefore, it is suitable for quality control of herbal drugs. PMID:29403849

  18. Monomeric cocoa catechins enhance β-cell function by increasing mitochondrial respiration.

    PubMed

    Rowley, Thomas J; Bitner, Benjamin F; Ray, Jason D; Lathen, Daniel R; Smithson, Andrew T; Dallon, Blake W; Plowman, Chase J; Bikman, Benjamin T; Hansen, Jason M; Dorenkott, Melanie R; Goodrich, Katheryn M; Ye, Liyun; O'Keefe, Sean F; Neilson, Andrew P; Tessem, Jeffery S

    2017-11-01

    A hallmark of type 2 diabetes (T2D) is β-cell dysfunction and the eventual loss of functional β-cell mass. Therefore, mechanisms that improve or preserve β-cell function could be used to improve the quality of life of individuals with T2D. Studies have shown that monomeric, oligomeric and polymeric cocoa flavanols have different effects on obesity, insulin resistance and glucose tolerance. We hypothesized that these cocoa flavanols may have beneficial effects on β-cell function. INS-1 832/13-derived β-cells and primary rat islets cultured with a monomeric catechin-rich cocoa flavanol fraction demonstrated enhanced glucose-stimulated insulin secretion, while cells cultured with total cocoa extract and with oligomeric or polymeric procyanidin-rich fraction demonstrated no improvement. The increased glucose-stimulated insulin secretion in the presence of the monomeric catechin-rich fraction corresponded with enhanced mitochondrial respiration, suggesting improvements in β-cell fuel utilization. Mitochondrial complex III, IV and V components are up-regulated after culture with the monomer-rich fraction, corresponding with increased cellular ATP production. The monomer-rich fraction improved cellular redox state and increased glutathione concentration, which corresponds with nuclear factor, erythroid 2 like 2 (Nrf2) nuclear localization and expression of Nrf2 target genes including nuclear respiratory factor 1 (Nrf1) and GA binding protein transcription factor alpha subunit (GABPA), essential genes for increasing mitochondrial function. We propose a model by which monomeric cocoa catechins improve the cellular redox state, resulting in Nrf2 nuclear migration and up-regulation of genes critical for mitochondrial respiration, glucose-stimulated insulin secretion and ultimately improved β-cell function. These results suggest a mechanism by which monomeric cocoa catechins exert their effects as an effective complementary strategy to benefit T2D patients. Copyright

  19. In Vitro and In Silico Studies of the Molecular Interactions of Epigallocatechin-3-O-gallate (EGCG) with Proteins That Explain the Health Benefits of Green Tea.

    PubMed

    Saeki, Koichi; Hayakawa, Sumio; Nakano, Shogo; Ito, Sohei; Oishi, Yumiko; Suzuki, Yasuo; Isemura, Mamoru

    2018-05-28

    Green tea has been shown to have beneficial effects on many diseases such as cancer, obesity, inflammatory diseases, and neurodegenerative disorders. The major green tea component, epigallocatechin-3- O -gallate (EGCG), has been demonstrated to contribute to these effects through its anti-oxidative and pro-oxidative properties. Furthermore, several lines of evidence have indicated that the binding affinity of EGCG to specific proteins may explain its mechanism of action. This review article aims to reveal how EGCG-protein interactions can explain the mechanism by which green tea/EGCG can exhibit health beneficial effects. We conducted a literature search, using mainly the PubMed database. The results showed that several methods such as dot assays, affinity gel chromatography, surface plasmon resonance, computational docking analyses, and X-ray crystallography have been used for this purpose. These studies have provided evidence to show how EGCG can fit or occupy the position in or near functional sites and induce a conformational change, including a quaternary conformational change in some cases. Active site blocking, steric hindrance by binding of EGCG near an active site or induced conformational change appeared to cause inhibition of enzymatic activity and other biological activities of proteins, which are related to EGCG's biological oligomer and formation of their toxic aggregates, leading to the prevention of neurodegenerative diseases and amyloidosis. In conclusion, these studies have provided useful information on the action of green tea/catechins and would lead to future studies that will provide further evidence for rational EGCG therapy and use EGCG as a lead compound for drug design.

  20. Backyard Teas.

    ERIC Educational Resources Information Center

    Young, Darrell D.

    1996-01-01

    Describes plants commonly found in residential areas that can be used for making tea: chicory, chickweed, red clover, goldenrod, gill-over-the-ground, pineapple weed, plantain, self-heal, sheep sorrel, and wild strawberry. Includes proper plant name, areas where the plant grows, identifying plant features, what part is used in making tea, and tea…

  1. 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.

  2. Development of CAPS markers based on three key genes of the phenylpropanoid pathway in tea, Camellia sinensis (L.) O. Kuntze, and differentiation between assamica and sinensis varieties.

    PubMed

    Kaundun, Shiv Shankhar; Matsumoto, Satoru

    2003-02-01

    The genetic diversity of tea, Camellia sinensis (L.) O. Kuntze, including the two main cultivated sinensis and assamica varieties, was investigated based on PCR-RFLP analysis of PAL, CHS2 and DFR, three key genes involved in catechin and tannin synthesis and directly responsible for tea taste and quality. Polymorphisms were of two types: amplicon length polymorphism (ALP) due to the presence of indels in two introns of PAL and DFR, and point mutations detected after restriction of amplified fragments with appropriate enzymes. A progeny test showed that all markers segregated in a Mendelian fashion and that polymorphisms were exclusively co-dominant. CHS2, which belongs to a multi-gene family, allowed for greater variation than the single-copy PAL gene. Based on Nei's gene diversity index, var. sinensis was revealed to be more variable than var. assamica, and that a higher proportion of overall diversity resided within varieties as compared to between varieties. Even though no specific DNA profile was found for either tea varieties following any single PCR-RFLP analysis, a factorial correspondence analysis carried out on all genotypes and markers separated the tea samples into two distinct groups according to their varietal status. This reflects the large difference between var. sinensis and var. assamica in their polyphenolic profiles. The STS-based markers developed in this study will be very useful in future mapping, population genetics and fingerprinting studies of this important crop species and other Camellia species, as the primers have also proven successful in the three other subgenera of this genus.

  3. Recent advances on tea polyphenols

    PubMed Central

    Kanwar, Jyoti; Taskeen, Mujtaba; Mohammad, Imthiyaz; Huo, Congde; Chan, Tak Hang; Dou, Qing Ping

    2012-01-01

    Over the past decade many scientific and medical studies have focused on green tea for its long-purported health benefits. There is convincing evidence that tea is a cup of life. It has multiple preventive and therapeutic effects. This review thus focuses on the recent advances of tea polyphenols and their applications in the prevention and treatment of human cancers. Of the various polyphenols in tea, (−)-Epigallocatechin-3-gallate (EGCG) is the most abundant, and active compound studied in tea research. EGCG inhibits several molecular targets to inhibit cancer initiation and modulates several essential survival pathways to block cancer progression. Herein, we describe the various mechanisms of action of EGCG and also discuss previous and current ongoing clinical trials of EGCG and green tea polyphenols in different cancer types. PMID:22201858

  4. Tea and Cancer Prevention: Strengths and Limits of the Evidence

    MedlinePlus

    ... mg catechins (experimental group) or 75 mg catechins (control group) for 24 weeks with no adverse effects ( 19 ). ... intakes of up to 400 mg per day (equivalent to 6 mg per kilogram [kg] body weight) ...

  5. Hypotriacylglycerolemic and antiobesity properties of a new fermented tea product obtained by tea-rolling processing of third-crop green tea (Camellia sinensis) leaves and loquat (Eriobotrya japonica) leaves.

    PubMed

    Tanaka, Kazunari; Tamaru, Shizuka; Nishizono, Shoko; Miyata, Yuji; Tamaya, Kei; Matsui, Toshiro; Tanaka, Takashi; Echizen, Yoshie; Ikeda, Ikuo

    2010-01-01

    We manufactured a new fermented tea by tea-rolling processing of third-crop green tea (Camellia sinensis) leaves and loquat (Eriobotrya japonica) leaves. The mixed fermented tea extract inhibited pancreatic lipase activity in vitro, and effectively suppressed postprandial hypertriacylglycerolemia in rats. Rats fed a diet containing 1% freeze-dried fermented tea extract for 4 weeks had a significantly lower liver triacylglycerol concentration and white adipose tissue weight than those fed the control diet lacking fermented tea extract. The activity of fatty acid synthase in hepatic cytosol markedly decreased in the fermented tea extract group as compared to the control group. The serum and liver triacylglycerol- and body fat-lowering effects of the mixed fermented tea extract were strong relative to the level of dietary supplementation. These results suggest that the new fermented tea product exhibited hypotriacylglycerolemic and antiobesity properties through suppression of both liver fatty acid synthesis and postprandial hypertriacylglycerolemia by inhibition of pancreatic lipase.

  6. Brewing and volatiles analysis of three tea beers indicate a potential interaction between tea components and lager yeast.

    PubMed

    Rong, Lei; Peng, Li-Juan; Ho, Chi-Tang; Yan, Shou-He; Meurens, Marc; Zhang, Zheng-Zhu; Li, Da-Xiang; Wan, Xiao-Chun; Bao, Guan-Hu; Gao, Xue-Ling; Ling, Tie-Jun

    2016-04-15

    Green tea, oolong tea and black tea were separately introduced to brew three kinds of tea beers. A model was designed to investigate the tea beer flavour character. Comparison of the volatiles between the sample of tea beer plus water mixture (TBW) and the sample of combination of tea infusion and normal beer (CTB) was accomplished by triangular sensory test and HS-SPME GC-MS analysis. The PCA of GC-MS data not only showed a significant difference between volatile features of each TBW and CTB group, but also suggested some key compounds to distinguish TBW from CTB. The results of GC-MS showed that the relative concentrations of many typical tea volatiles were significantly changed after the brewing process. More interestingly, the behaviour of yeast fermentation was influenced by tea components. A potential interaction between tea components and lager yeast could be suggested. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. 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.

  8. Green tea for weight loss and weight maintenance in overweight or obese adults.

    PubMed

    Jurgens, Tannis M; Whelan, Anne Marie; Killian, Lara; Doucette, Steve; Kirk, Sara; Foy, Elizabeth

    2012-12-12

    Preparations of green tea are used as aids in weight loss and weight maintenance. Catechins and caffeine, both contained in green tea, are each believed to have a role in increasing energy metabolism, which may lead to weight loss. A number of randomised controlled trials (RCTs) evaluating the role of green tea in weight loss have been published; however, the efficacy of green tea preparations in weight loss remains unclear. To assess the efficacy and safety of green tea preparations for weight loss and weight maintenance in overweight or obese adults. We searched the following databases from inception to specified date as well as reference lists of relevant articles: The Cochrane Library (Issue 12, 2011), MEDLINE (December 2011), EMBASE (December 2011), CINAHL (January 2012), AMED (January 2012), Biological Abstracts (January 2012), IBIDS (August 2010), Obesity+ (January 2012), IPA (January 2012) and Web of Science (December 2011). Current Controlled Trials with links to other databases of ongoing trials was also searched. RCTs of at least 12 weeks' duration comparing green tea preparations to a control in overweight or obese adults. Three authors independently extracted data, assessed studies for risk of bias and quality, with differences resolved by consensus. Heterogeneity of included studies was assessed visually using forest plots and quantified using the I(2) statistic. We synthesised data using meta-analysis and descriptive analysis as appropriate; subgroup and sensitivity analyses were conducted. Adverse effects reported in studies were recorded. Due to the level of heterogeneity among studies, studies were divided into two groups; those conducted in Japan and those conducted outside Japan. Study length ranged between 12 and 13 weeks. Meta-analysis of six studies conducted outside Japan showed a mean difference (MD) in weight loss of -0.04 kg (95% CI -0.5 to 0.4; P = 0.88; I(2) = 18%; 532 participants). The eight studies conducted in Japan were not similar

  9. Development of an isocratic HPLC method for catechin quantification and its application to formulation studies.

    PubMed

    Li, Danhui; Martini, Nataly; Wu, Zimei; Wen, Jingyuan

    2012-10-01

    The aim of this study was to develop a simple, rapid and accurate isocratic HPLC analytical method to qualify and quantify five catechin derivatives, namely (+)-catechin (C), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), (-)-epicatechin (EC) and (-)-epigallocatechin gallate (EGCG). To validate the analytical method, linearity, repeatability, intermediate precision, sensitivity, selectivity and recovery were investigated. The five catechin derivatives were completely separated by HPLC using a mobile phase containing 0.1% TFA in Milli-Q water (pH 2.0) mixed with methanol at the volume ratio of 75:25 at a flow rate of 0.8 ml/min. The method was shown to be linear (r²>0.99), repeatable with instrumental precision<2.0 and intra-assay precision<2.5 (%CV, percent coefficient of variation), precise with intra-day variation<1 and inter-day variation<2.5 (%CV, percent coefficient of variation) and sensitive (LOD<1 μg/mL and LOQ<3 μg/mL) over the calibration range for all five derivatives. Derivatives could be fully recovered in the presence of niosomal formulation (recovery rates>91%). Selectivity of the method was proven by the forced degradation studies, which showed that under acidic, basic, oxidation temperature and photolysis stresses, the parent drug can be separated from the degradation products by means of this analytical method. The described method was successfully applied in the in vitro release studies of catechin-loaded niosomes to manifest its utility in formulation characterization. Obtained results indicated that the drug release from niosomal formulations was a biphasic process and a diffusion mechanism regulated the permeation of catechin niosomes. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Molecular Docking Studies of Catechin and Its Derivatives as Anti-bacterial Inhibitor for Glucosamine-6-Phosphate Synthase

    NASA Astrophysics Data System (ADS)

    Fikrika, H.; Ambarsari, L.; Sumaryada, T.

    2016-01-01

    Molecular docking simulation of catechin and its derivatives on Glucosamine-6- Phosphate Synthase (GlmS) has been performed in this research. GlmS inhibition by a particular ligand will suppress the production of bacterial cell wall and significantly reduce the population of invading bacteria. In this study, catechin derivatives i.e epicatechin, galloatechin and epigalloatechin were found to have stronger binding affinities as compared to natural ligand of GlmS, Fructose-6-Phosphate (F6P). Those three ligands were docked on the same pocket in GlmS target as F6P, with 70% binding sites similarity. Based on the docking results, gallocatechin turns out to be the most potent ligand for anti-bacterial agent with ΔG= -8.00 kcal/mol. The docking between GlmS and catechin derivatives are characterized by a constant present of a strong hydrogen bond between functional group O3 and Ser-349. This hydrogen bond most likely plays a significant role in the docking mechanism and binding modes selection. The surprising result is catechin itself exhibited a quite strong binding with GlmS (ΔG= -7.80 kcal.mol), but docked on a completely different pocket compared to other ligands. This results suggest that catechin might still have a curing effect but with a completely different pathway and mechanism as compared to its derivatives.

  11. Preparative separation and purification of epigallocatechin gallate from green tea extracts using a silica adsorbent containing β-cyclodextrin.

    PubMed

    Lai, Shih-Ming; Gu, Jhe-Yu; Huang, Bing-Hao; Chang, Chieh-Ming J; Lee, Wen-Lung

    2012-03-01

    A silica adsorbent containing β-cyclodextrin (β-CD) has been developed and used for the separation and purification of epigallocatechin gallate (EGCG) from the green tea extracts. The batch adsorption experiments demonstrated that, the β-CD bonded silica adsorbent possessed excellent adsorption equilibrium capacity (> 55 mg/g adsorbent) and adsorption ratio (>95%) for EGCG compared to the other tea catechins and caffeine. The excellent adsorption capacity and selectivity for EGCG are attributed to the specific interactions between β-CD and EGCG. The preparative separation and purification performance of EGCG on the β-CD bonded silica column (220 mm L × 15 mm i.d., 40-63 μm) was then evaluated. The column was operated in the polar organic mode using methanol/acetonitrile/acetic acid as the mobile phase and eluted under a three-step gradient elution program. The sample was dissolved in acetonitrile and loaded on a preparative scale of about 0.8 mg/g adsorbent. Under the optimal chromatographic conditions, the target compound, EGCG, being the most retained species, was obtained at a purity of about 90% with a recovery of about 90%. The productivity of EGCG was about 6 mg per injection, which can be further increased by scaling-up the chromatographic system. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Intraspecific and interspecific interactions mediated by a phytotoxin, (-)-catechin, secreted by the roots of Centaurea maculosa (spotted knapweed).

    PubMed

    Weir, Tiffany L; Bais, Harsh Pal; Vivanco, Jorge M

    2003-11-01

    Centarea maculosa Lam. (spotted knapweed) is one of the most destructive invasive weeds in the western United States, particularly in pastures and rangelands. One of the components that may contribute to its invasiveness is the naturally produced, root-secreted allelochemical (-)-catechin. This compound has been shown to have broad-spectrum phytotoxic activity, possibly assisting C. maculosa in displacing native plant communities. As a recently characterized phytochemical, little is known about the specific effect of (-)-catechin on either C. maculosa or other plant species. We have found that, in vitro, C. maculosa begins to secrete phytotoxic levels of (-)-catechin within 2-3 weeks of seedling emergence. Furthermore, (-)-catechin concentrations consistent with those naturally secreted by C. maculosa were sufficient to inhibit germination in all species tested, including C. maculosa. These concentrations were also often either phytotoxic or growth inhibitory to seedlings in a range of plant species, while having no negative effects on the growth of C. maculosa seedlings. However, our results also indicate that different levels of resistance and susceptibility to (-)-catechin exist in plant populations, suggesting that the capability of C. maculosa to invade an area through allelochemistry may be dependent on the age and species composition of plants in that area.

  13. 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

  14. 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.

  15. 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.

  16. New Drugs for Prevention of Breast Cancer Metastases

    DTIC Science & Technology

    1999-07-01

    the principal anticancer catechin, epigallocatechin gallate ( EGCg ). A 3-way mixture of epicatechin (EC), EGCg and glaucarubolone was more effective...DAPI, 4’,6-diamidino-2-phenylindole; DMSO, dimethyl sulfoxide; EGF, epidermal growth factor; EGCg , epigallocatechin gallate . ABSTRACT A drug...preferentially in HeLa and human and mouse mammary adenocarcinoma by the naturally-occurring catechin of green tea, epigallocatechin gallate ( EGCg ). With

  17. Formation of (E)-nerolidol in tea (Camellia sinensis) leaves exposed to multiple stresses during tea manufacturing.

    PubMed

    Zhou, Ying; Zeng, Lanting; Liu, Xiaoyu; Gui, Jiadong; Mei, Xin; Fu, Xiumin; Dong, Fang; Tang, Jingchi; Zhang, Lingyun; Yang, Ziyin

    2017-09-15

    (E)-Nerolidol is a volatile sesquiterpene that contributes to the floral aroma of teas (Camellia sinensis). The unique manufacturing process for oolong tea involves multiple stresses, resulting in a high content of (E)-nerolidol, which is not known to form in tea leaves. This study aimed to determine the formation mechanism of (E)-nerolidol in tea exposed to multiple stresses during tea manufacture. C. sinensis (E)-nerolidol synthase (CsNES) recombinant protein, found in the cytosol, was found to transform farnesyl diphosphate into (E)-nerolidol. CsNES was highly expressed during the oolong tea turn over process, resulting in (E)-nerolidol accumulation. Continuous mechanical damage, simulating the turn over process, significantly enhanced CsNES expression level and (E)-nerolidol content. The combination of low temperature stress and mechanical damage had a synergistic effect on (E)-nerolidol formation. This is the first evidence of (E)-nerolidol formation mechanism in tea leaves and a characteristic example of plant volatile formation in response to dual stresses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. A case of Kombucha tea toxicity.

    PubMed

    SungHee Kole, Alison; Jones, Heather D; Christensen, Russell; Gladstein, Jay

    2009-01-01

    Kombucha "mushroom'' tea is touted to have medicinal properties. Here, we present a case of hyperthermia, lactic acidosis, and acute renal failure within 15 hours of Kombucha tea ingestion. A 22 year old male, newly diagnosed with HIV, became short of breath and febrile to 103.0F, within twelve hours of Kombucha tea ingestion. He subsequently became combative and confused, requiring sedation and intubation for airway control. Laboratories revealed a lactate of 12.9 mmol/L, and serum creatinine of 2.1 mg/dL. Kombucha tea is black tea fermented in a yeast-bacteria medium. Several case reports exist of serious, and sometimes fatal, hepatic dysfunction and lactic acidosis within close proximity to ingestion. While Kombucha tea is considered a healthy elixir, the limited evidence currently available raises considerable concern that it may pose serious health risks. Consumption of this tea should be discouraged, as it may be associated with life-threatening lactic acidosis.

  19. Identification and quantitation of alkaloids in coca tea

    PubMed Central

    Jenkins, Amanda J.; Llosa, Teobaldo; Montoya, Ivan

    2008-01-01

    The consumption of coca tea is a common occurrence in many South American countries. The tea is often packaged in individual servings as tea bags which contain approximately 1 g of plant material. The consumption of coca tea leads to ingestion of cocaine and other alkaloids: however, there is little information available regarding the pharmacological or toxicological effects that result from consumption of coca tea. We performed a series of studies with coca tea bags from two South American countries, Peru and Bolivia. The alkaloidal content of the ‘coca leaf’ in coca tea bags was determined by two different extraction methods: Soxhlet extraction with methanol (exhaustive extraction), and mechanical agitation with methanol. Extracts were purified by solid-phase extraction (SPE) followed by analysis by gas chromatography/mass spectrometry (GC/MS). Coca tea prepared from Peruvian and Bolivian coca tea bags was also analyzed by SPE-GC/MS assay. In addition, urine specimens were analyzed from an individual who consumed one cup of Peruvian coca tea and one cup of Bolivian coca tea on separate occasions. Urine samples were analyzed by immunoassay (TDxR) and SPE-GC/MS. Analysis of coca tea bags and coca tea indicated that cocaine, benzoylecgonine, ecgonine methyl ester and trans-cinnamoylcocaine were present in varying quantities. With exhaustive extraction, an average of 5.11 mg, and 4.86 mg of cocaine per tea bag were found in coca leaf from Peru and Bolivia, respectively. The average amounts of benzoylecgonine and ecgonine methyl ester in Peruvian coca leaf were 0.11 and 1.15 mg, and in Bolivian coca leaf were 0.12 and 2.93 mg per tea bag, respectively. trans-Cinnamoylcocaine was found in trace amounts in Peruvian tea bags and 0.16 mg/tea bag of Bolivian tea. When tea was prepared, an average of 4.14 mg of cocaine was present in a cup of Peruvian coca tea and 4.29 mg of cocaine was present in Bolivian tea. Following the consumption of a cup of Peruvian tea by one

  20. 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.

  1. Occurrence and Residue Pattern of Phthalate Esters in Fresh Tea Leaves and during Tea Manufacturing and Brewing.

    PubMed

    Liu, Pingxiang; Chen, Hongping; Gao, Guanwei; Hao, Zhenxia; Wang, Chen; Ma, Guicen; Chai, Yunfeng; Zhang, Lin; Liu, Xin

    2016-11-23

    The residues of 16 phthalate esters (PAEs) in fresh tea leaves and made tea were determined via gas chromatography-tandem mass spectrometry to study their distribution and degradation characteristics during tea planting and processing. Five PAEs were detected in all fresh tea leaves, and higher concentrations were detected in mature leaves. The distribution of PAEs in fresh tea leaves ranged from 69.7 to 2244.0 μg/kg. The degradative percentages of ∑ 5 PAEs during green tea manufacturing ranged from 61 to 63% and were significantly influenced by the drying process. The transfer rates of PAEs-D 4 ranged from 5.2 to 100.6%. PAEs with a high water solubility showed the highest transfer coefficient in the range of 91.8-100.6%, whereas PAEs with a high log K ow showed a low leaching efficiency below 11.9%. These results benefit the risk evaluation and establishment of a maximum residue limit for PAEs in tea.

  2. [Retrospect of Chinese herbs taken as tea drinking].

    PubMed

    Zhu, J N; Zhang, X L; Guo, H

    2017-01-28

    Tea and wine are time-honored drinks in China. Along with coffee and cocoa, tea, as one of the non-alcoholic plant beverages, is prevailing the world. Tea and Chinese medicine has a very close relationship. Chinese herbs taken as tea forming the tea-like medicinal tea, can be taken frequently at anytime. The application of Chinese herbs taken as tea drinking begins from the Tang Dynasty, flourishes in the Song Dynasty and matures in the Qing Dynasty. The review of its history provides ample evidence of Chinese herbs taken as tea drinking in treating and preventing diseases, as well as providing the clues and references of developing new Chinese herbs taking as tea.

  3. Prevention of carcinogenesis of mouse mammary epithelial cells RIII/MG by epigallocatechin gallate.

    PubMed

    Yanaga, Hiroshi; Fujii, Teruhiko; Koga, Toshihiro; Araki, Ruriko; Shirouzu, Kazuo

    2002-09-01

    The chemopreventive effect of the polyphenols abundant in green tea on carcinogenesis has been attracting attention in recent years. Among tea polyphenols, epigallocatechin gallate (EGCG) has been studied as a preventive substance for carcinogenesis. We investigated the chemopreventive effect in a group treated with EGCG in vitro and in vivo using mouse mammary epithelial cells RIII/MG. In the in vitro experiment, crude catechin (catechin) containing 50% or more EGCG significantly inhibited the growth of RIII/MG cells, which were precancerous cultured cells. Many cells died, and a DNA ladder was observed. In the in vivo experiment, RIII/MG cells formed a tumor after 13 weeks in a group without catechin treatment, and the tumor formation rate in the 20th week was 40%. In a group treated with 0.1% catechin, a tumor began to grow in the 13th week, and the tumor formation rate in the 20th week was 20%. In a group treated with 1% catechin, no tumor was detected even in the 20th week. There was no significant difference in the change in body weight between the catechin treatment groups and the non-treatment group during the observation period. Tissue samples were stained by the nick-end-labeling method and apoptosis was observed in many cells. Based on the above findings, EGCG inhibited growth in the mouse viral mammary epithelial carcinogenesis model RIII/MG, and induced apoptosis, suggesting a clinical usefulness of EGCG as a chemopreventive substance.

  4. 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.

  5. 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.

  6. Travelling with tea: a Tuckerella’s tale

    USDA-ARS?s Scientific Manuscript database

    Tuckerella japonica appears strongly associated with tea (Camellia sinensis (L.) Kuntze., Theaceae) and, due to certain cultural practices in tea production, has in fact become a world traveller, accompanying the greatly coveted tea plant as it spread across the planet. The history of tea productio...

  7. 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.

  8. 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.

  9. Probable Gastrointestinal Toxicity of Kombucha Tea

    PubMed Central

    Srinivasan, Radhika; Smolinske, Susan; Greenbaum, David

    1997-01-01

    Kombucha tea is a health beverage made by incubating the Kombucha “mushroom” in tea and sugar. Although therapeutic benefits have been attributed to the drink, neither its beneficial effects nor adverse side effects have been reported widely in the scientific literature. Side effects probably related to consumption of Kombucha tea are reported in four patients. Two presented with symptoms of allergic reaction, the third with jaundice, and the fourth with nausea, vomiting, and head and neck pain. In all four, use of Kombucha tea in proximity to onset of symptoms and symptom resolution on cessation of tea drinking suggest a probable etiologic association. PMID:9346462

  10. Functional testing of topical skin formulations using an optimised ex vivo skin organ culture model.

    PubMed

    Sidgwick, G P; McGeorge, D; Bayat, A

    2016-07-01

    A number of equivalent-skin models are available for investigation of the ex vivo effect of topical application of drugs and cosmaceuticals onto skin, however many have their drawbacks. With the March 2013 ban on animal models for cosmetic testing of products or ingredients for sale in the EU, their utility for testing toxicity and effect on skin becomes more relevant. The aim of this study was to demonstrate proof of principle that altered expression of key gene and protein markers could be quantified in an optimised whole tissue biopsy culture model. Topical formulations containing green tea catechins (GTC) were investigated in a skin biopsy culture model (n = 11). Punch biopsies were harvested at 3, 7 and 10 days, and analysed using qRT-PCR, histology and HPLC to determine gene and protein expression, and transdermal delivery of compounds of interest. Reduced gene expression of α-SMA, fibronectin, mast cell tryptase, mast cell chymase, TGF-β1, CTGF and PAI-1 was observed after 7 and 10 days compared with treated controls (p < 0.05). Histological analysis indicated a reduction in mast cell tryptase and chymase positive cell numbers in treated biopsies compared with untreated controls at day 7 and day 10 (p < 0.05). Determination of transdermal uptake indicated that GTCs were detected in the biopsies. This model could be adapted to study a range of different topical formulations in both normal and diseased skin, negating the requirement for animal models in this context, prior to study in a clinical trial environment.

  11. Tea, coffee and prostate cancer.

    PubMed

    Lee, Andy H; Fraser, Michelle L; Binns, Colin W

    2009-02-01

    Worldwide, prostate cancer has the second highest incidence of all cancers in males with incidence and mortality being much higher in affluent developed countries. Risk and progression of the disease may be linked to both genetic and environmental factors, especially dietary factors. Tea and coffee are two of the most popular beverages in the world and have been investigated for possible effects on health outcomes, including cancer. However, very little dietary advice for their consumption exists. The evidence for a relationship between coffee or tea consumption and prostate cancer is reviewed in this paper. While current evidence indicates that coffee is a safe beverage, its consumption probably has no relationship with prostate cancer. Tea, especially green tea, has shown some potential in the prevention of prostate cancer. While evidence from epidemiologic studies is currently inconclusive, strong evidence has emerged from animal and in vitro studies. We also consider what level of evidence is required to make recommendations for preventive measures to the public. Although evidence on the relationship between coffee, tea and prostate cancer is not complete, we consider it strong enough to recommend tea as a healthier alternative to coffee.

  12. Catechin treatment improves cerebrovascular flow-mediated dilation and learning abilities in atherosclerotic mice

    PubMed Central

    Drouin, Annick; Bolduc, Virginie; Thorin-Trescases, Nathalie; Bélanger, Élisabeth; Fernandes, Priscilla; Baraghis, Edward; Lesage, Frédéric; Gillis, Marc-Antoine; Villeneuve, Louis; Hamel, Edith; Ferland, Guylaine; Thorin, Eric

    2013-01-01

    Severe dyslipidemia and the associated oxidative stress could accelerate the age-related decline in cerebrovascular endothelial function and cerebral blood flow (CBF), leading to neuronal loss and impaired learning abilities. We hypothesized that a chronic treatment with the polyphenol catechin would prevent endothelial dysfunction, maintain CBF responses, and protect learning abilities in atherosclerotic (ATX) mice. We treated ATX (C57Bl/6-LDLR−/− hApoB+/+; 3 mo old) mice with catechin (30 mg·kg−1·day−1) for 3 mo, and C57Bl/6 [wild type (WT), 3 and 6 mo old] mice were used as controls. ACh- and flow-mediated dilations (FMD) were recorded in pressurized cerebral arteries. Basal CBF and increases in CBF induced by whisker stimulation were measured by optical coherence tomography and Doppler, respectively. Learning capacities were evaluated with the Morris water maze test. Compared with 6-mo-old WT mice, cerebral arteries from 6-mo-old ATX mice displayed a higher myogenic tone, lower responses to ACh and FMD, and were insensitive to NOS inhibition (P < 0.05), suggesting endothelial dysfunction. Basal and increases in CBF were lower in 6-mo-old ATX than WT mice (P < 0.05). A decline in the learning capabilities was also observed in ATX mice (P < 0.05). Catechin 1) reduced cerebral superoxide staining (P < 0.05) in ATX mice, 2) restored endothelial function by reducing myogenic tone, improving ACh- and FMD and restoring the sensitivity to nitric oxide synthase inhibition (P < 0.05), 3) increased the changes in CBF during stimulation but not basal CBF, and 4) prevented the decline in learning abilities (P < 0.05). In conclusion, catechin treatment of ATX mice prevents cerebrovascular dysfunctions and the associated decline in learning capacities. PMID:21186270

  13. 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.

  14. 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.

  15. Localized shape abnormalities in the thalamus and pallidum are associated with secondarily generalized seizures in mesial temporal lobe epilepsy.

    PubMed

    Yang, Linglin; Li, Hong; Zhu, Lujia; Yu, Xinfeng; Jin, Bo; Chen, Cong; Wang, Shan; Ding, Meiping; Zhang, Minming; Chen, Zhong; Wang, Shuang

    2017-05-01

    Mesial temporal lobe epilepsy (mTLE) is a common type of drug-resistant epilepsy and secondarily generalized tonic-clonic seizures (sGTCS) have devastating consequences for patients' safety and quality of life. To probe the mechanism underlying the genesis of sGTCS, we investigated the structural differences between patients with and without sGTCS in a cohort of mTLE with radiologically defined unilateral hippocampal sclerosis. We performed voxel-based morphometric analysis of cortex and vertex-wise shape analysis of subcortical structures (the basal ganglia and thalamus) on MRI of 39 patients (21 with and 18 without sGTCS). Comparisons were initially made between sGTCS and non-sGTCS groups, and subsequently made between uncontrolled-sGTCS and controlled-sGTCS subgroups. Regional atrophy of the ipsilateral ventral pallidum (cluster size=450 voxels, corrected p=0.047, Max voxel coordinate=107, 120, 65), medial thalamus (cluster size=1128 voxels, corrected p=0.049, Max voxel coordinate=107, 93, 67), middle frontal gyrus (cluster size=60 voxels, corrected p<0.05, Max voxel coordinate=-30, 49.5, 6), and contralateral posterior cingulate cortex (cluster size=130 voxels, corrected p<0.05, Max voxel coordinate=16.5, -57, 27) was found in the sGTCS group relative to the non-sGTCS group. Furthermore, the uncontrolled-sGTCS subgroup showed more pronounced atrophy of the ipsilateral medial thalamus (cluster size=1240 voxels, corrected p=0.014, Max voxel coordinate=107, 93, 67) than the controlled-sGTCS subgroup. These findings indicate a central role of thalamus and pallidum in the pathophysiology of sGTCS in mTLE. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. EPIGALLOCATECHIN-3-GALLATE (EGCG), A GREEN TEA POLYPHENOL, SUPPRESSES HEPATIC GLUCONEOGENESIS THROUGH 5′-AMP-ACTIVATED PROTEIN KINASE

    PubMed Central

    Collins, Qu Fan; Liu, Hui-Yu; Pi, Jingbo; Liu, Zhenqi; Quon, Michael J.; Cao, Wenhong

    2008-01-01

    Epigallocatechin-3-gallate (EGCG), a main catechin of green tea, has been suggested to inhibit hepatic gluconeogenesis. However, the exact role and related mechanism have not been established. In this study, we examined the role of EGCG in hepatic gluconeogenesis at concentrations that are reachable by ingestion of pure EGCG or green tea, and are not toxic to hepatocytes. Our results show in isolated hepatocytes that EGCG at relatively low concentrations (≤ 1 μM) inhibited glucose production via gluconeogenesis and expression of key gluconeogenic genes. EGCG was not toxic at these concentrations while demonstrating significant cytotoxicity at 10 μM and higher concentrations. EGCG at 1 μM or lower concentrations effective in suppressing hepatic gluconeogenesis did not activate the insulin signaling pathway, but activated 5′-AMP-activated protein kinase (AMPK). The EGCG suppression of hepatic gluconeogenesis was prevented by blockade of AMPK activity. In defining the mechanism by which EGCG activates AMPK, we found that the EGCG activation of AMPK was mediated by the Ca2+/calmodulin-dependent protein kinase kinase (CaMKK). Furthermore, our results show that the EGCG activation of AMPK and EGCG suppression of hepatic gluconeogenesis were both dependent on production of reactive oxygen species (ROS), which was a known activator of CaMKK. Together, our results demonstrate an inhibitory role for EGCG in hepatic gluconeogenesis and shed new light on the mechanism by which EGCG suppresses gluconeogenesis. PMID:17724029

  17. Anti-pandemic influenza A (H1N1) virus potential of catechin and gallic acid.

    PubMed

    You, Huey-Ling; Huang, Chao-Chun; Chen, Chung-Jen; Chang, Cheng-Chin; Liao, Pei-Lin; Huang, Sheng-Teng

    2018-05-01

    The pandemic influenza A (H1N1) virus has spread worldwide and infected a large proportion of the human population. Discovery of new and effective drugs for the treatment of influenza is a crucial issue for the global medical community. According to our previous study, TSL-1, a fraction of the aqueous extract from the tender leaf of Toonasinensis, has demonstrated antiviral activities against pandemic influenza A (H1N1) through the down-regulation of adhesion molecules and chemokine to prevent viral attachment. The aim of the present study was to identify the active compounds in TSL-1 which exert anti-influenza A (H1N1) virus effects. XTT assay was used to detect the cell viability. Meanwhile, the inhibitory effect on the pandemic influenza A (H1N1) virus was analyzed by observing plaque formation, qRT-PCR, neuraminidase activity, and immunofluorescence staining of influenza A-specific glycoprotein. Both catechin and gallic acid were found to be potent inhibitors in terms of influenza virus mRNA replication and MDCK plaque formation. Additionally, both compounds inhibited neuraminidase activities and viral glycoprotein. The 50% effective inhibition concentration (EC 50 ) of catechin and gallic acid for the influenza A (H1N1) virus were 18.4 μg/mL and 2.6 μg/mL, respectively; whereas the 50% cytotoxic concentrations (CC 50 ) of catechin and gallic acid were >100 μg/mL and 22.1 μg/mL, respectively. Thus, the selectivity indexes (SI) of catechin and gallic acid were >5.6 and 22.1, respectively. The present study demonstrates that catechin might be a safe reagent for long-term use to prevent influenza A (H1N1) virus infection; whereas gallic acid might be a sensitive reagent to inhibit influenza virus infection. We conclude that these two phyto-chemicals in TSL-1 are responsible for exerting anti-pandemic influenza A (H1N1) virus effects. Copyright © 2017. Published by Elsevier Taiwan LLC.

  18. 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

  19. 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.

  20. Tea Tells All

    ERIC Educational Resources Information Center

    Roever, Carol

    2007-01-01

    A beverage, as well as the way it is served, can be a window into the soul of a culture. For the author and her husband, Turkish tea helped them understand and enjoy the culture of Turkey. They learned that the broad nuances of culture can be as instructive as a classroom experience. The tea story begins in Chicago in the spring of 2005 when the…

  1. Metaphysics of the tea ceremony: a randomized trial investigating the roles of intention and belief on mood while drinking tea.

    PubMed

    Shiah, Yung-Jong; Radin, Dean

    2013-01-01

    This study explored whether drinking tea "treated" with good intentions would enhance mood more than drinking ordinary tea, under double-blind, randomized conditions. Each evening, for seven days in a row, volunteers recorded their mood using the Profile of Mood States (POMS) questionnaire. On days three, four, and five of the test, each participant drank 600 mL of oolong tea in the morning and again in the afternoon. One randomly assigned group blindly received tea that had been intentionally treated by three Buddhist monks; the other group blindly received untreated tea from the same source. On the last day of the test, each person indicated what type of tea he/she believed he/she had been drinking. Stratified, random sampling was used to assign 189 adults into two groups matched by age, gender, the psychological trait of neuroticism, and the amount of tea consumed on average per day. All participants were Taiwanese and lived in Kaohsiung, Taiwan, and the test was conducted over the course of one week to reduce mood fluctuations due to changes in local weather and other common influences. Those who drank treated tea showed a greater increase in mood than those who drank untreated tea (Cohen's d = 0.65, P = .02, two-tailed). Change in mood in those who believed that they were drinking treated tea was much better than those who did not believe (Cohen's d = 1.45, P = .00002, two-tailed). Tea treated with good intentions improved mood more than ordinary tea derived from the same source. Belief that one was drinking treated tea produced a large improvement in mood, but only if one was actually drinking the treated tea, indicating that belief and intentional enhancement interact. This also suggests that the esthetic and intentional qualities associated with the traditional tea ceremony may have subtle influences that extend beyond the ritual itself. © 2013 Elsevier Inc. All rights reserved.

  2. 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.

  3. Formation and emission of linalool in tea (Camellia sinensis) leaves infested by tea green leafhopper (Empoasca (Matsumurasca) onukii Matsuda).

    PubMed

    Mei, Xin; Liu, Xiaoyu; Zhou, Ying; Wang, Xiaoqin; Zeng, Lanting; Fu, Xiumin; Li, Jianlong; Tang, Jinchi; Dong, Fang; Yang, Ziyin

    2017-12-15

    Famous oolong tea (Oriental Beauty), which is manufactured by tea leaves (Camellia sinensis) infected with tea green leafhoppers, contains characteristic volatile monoterpenes derived from linalool. This study aimed to determine the formation mechanism of linalool in tea exposed to tea green leafhopper attack. The tea green leafhopper responsible for inducing the production of characteristic volatiles was identified as Empoasca (Matsumurasca) onukii Matsuda. E. (M.) onukii attack significantly induced the emission of linalool from tea leaves (p<0.05) as a result of the up-regulation of the linalool synthases (CsLIS1 and CsLIS2) (p<0.05). Continuous mechanical damage significantly enhanced CsLIS1 and CsLIS2 expression levels and linalool emission (p<0.05). Therefore, continuous wounding was a key factor causing the formation and emission of linalool from tea leaves exposed to E. (M.) onukii attack. This information should prove helpful for the future use of stress responses of plant secondary metabolism to improve quality components of agricultural products. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Catechins and procyanidins of Ginkgo biloba show potent activities towards the inhibition of β-amyloid peptide aggregation and destabilization of preformed fibrils.

    PubMed

    Xie, Haiyan; Wang, Jing-Rong; Yau, Lee-Fong; Liu, Yong; Liu, Liang; Han, Quan-Bin; Zhao, Zhongzhen; Jiang, Zhi-Hong

    2014-04-22

    Catechins and procyanidins, together with flavonoid glycosides and terpene trilactones, are three important categories of components in the standard extract of Ginkgo biloba leaves (EGb761). In this research, catechins and proanthocyanidins were found to exist in both the extract of Ginkgo leaves and Ginkgo products. By comparing with reference compounds, six of them were identified as (+)-catechin, (-)-epicatechin, (-)-gallocatechin, (-)-epigallocatechin and procyanidins B1 and B3. The activities of these polyphenols in the inhibition of Aβ42 aggregation and the destabilization of preformed fibrils were evaluated using biochemical assays, which showed that all six of the polyphenols, as well as a fraction of the extract of Ginkgo biloba leaves (EGb) containing catechins and procyanidins, exerted potent inhibitory activities towards Aβ42 aggregation and could also destabilize the performed fibrils. Catechins and procyanidins can therefore be regarded as the potent active constituents of EGb761 in terms of their inhibition of Aβ42 aggregation and destabilization of the fibrils. Although quantitative mass spectroscopic analysis revealed that the catechins and procyanidins are only present in low concentrations in EGb761, these components should be studied in greater detail because of their potent inhibitory effects towards Aβ42 aggregation and their ability to destabilize preformed fibrils, especially during the quality control of Ginkgo leaves and the manufacture of Ginkgo products.

  5. Tea and Cardiovascular Disease

    PubMed Central

    Deka, Apranta; Vita, Joseph A.

    2011-01-01

    There is increasing evidence for a protective effect of tea consumption against cardiovascular disease. This review summarizes the available epidemiological data providing evidence for and against such an effect. We also review observational and intervention studies that investigated an effect of tea and tea extracts on cardiovascular risk factors, including blood pressure, serum lipids, diabetes mellitus, and obesity. Finally, we review potential mechanisms of benefit, including anti-inflammatory, anti-oxidant, and anti-proliferative effects, as well as favorable effects on endothelial function. Overall, the observational data suggest a benefit, but results are mixed and likely confounded by lifestyle and background dietary factors. The weight of evidence indicates favorable effects on risk factors and a number of plausible mechanisms have been elucidated in experimental and translational human studies. Despite the growing body evidence, it remains uncertain whether tea consumption should be recommended to the general population or to patients as a strategy to reduce cardiovascular risk. PMID:21477653

  6. Transcripts of Anthocyanidin Reductase and Leucoanthocyanidin Reductase and Measurement of Catechin and Epicatechin in Tartary Buckwheat

    PubMed Central

    Kim, Yeon Bok; Thwe, Aye Aye; Kim, YeJi; Li, Xiaohua; Cho, Jin Woong; Park, Phun Bum; Valan Arasu, Mariadhas; Abdullah Al-Dhabi, Naif; Kim, Sun-Ju; Suzuki, Tastsuro; Hyun Jho, Kwang; Park, Sang Un

    2014-01-01

    Anthocyanidin reductase (ANR) and leucoanthocyanidin reductase (LAR) play an important role in the monomeric units biosynthesis of proanthocyanidins (PAs) such as catechin and epicatechin in several plants. The aim of this study was to clone ANR and LAR genes involved in PAs biosynthesis and examine the expression of these two genes in different organs under different growth conditions in two tartary buckwheat cultivars, Hokkai T8 and T10. Gene expression was carried out by quantitative real-time RT-PCR, and catechin and epicatechin content was analyzed by high performance liquid chromatography. The expression pattern of ANR and LAR did not match the accumulation pattern of PAs in different organs of two cultivars. Epicatechin content was the highest in the flowers of both cultivars and it was affected by light in only Hokkai T8 sprouts. ANR and LAR levels in tartary buckwheat might be regulated by different mechanisms for catechin and epicatechin biosynthesis under light and dark conditions. PMID:24605062

  7. 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.

  8. TEA: A Code Calculating Thermochemical Equilibrium Abundances

    NASA Astrophysics Data System (ADS)

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver

    2016-07-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature-pressure pairs. We tested the code against the method of Burrows & Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows & Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

  9. 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

  10. Fluoride content in caffeinated, decaffeinated and herbal teas.

    PubMed

    Chan, J T; Koh, S H

    1996-01-01

    The fluoride contents of infusions prepared from 44 different brands and types of teas were measured. Fluoride concentrations ranged from 0.34 to 3.71 ppm (mean = 1.50 ppm) in caffeinated tea infusions, 0.02-0.14 ppm (mean = 0.05 ppm) in herbal tea infusions, and 1.01-5.20 ppm (mean = 3.19) in decaffeinated tea infusions. This is the first report of the fluoride content of decaffeinated teas. The mean fluoride content of decaffeinated tea infusions is significantly (p < 0.01) higher than the corresponding caffeinated tea. The use of mineral water containing a naturally high fluoride level during the process of decaffeination is the most likely explanation of the above observation.

  11. (-)Epigallocatechin-3-gallate decreases the stress-induced impairment of learning and memory in rats.

    PubMed

    Soung, Hung-Sheng; Wang, Mao-Hsien; Tseng, Hsiang-Chien; Fang, Hsu-Wei; Chang, Kuo-Chi

    2015-08-18

    Stress induces reactive oxygen species (ROS) and causes alterations in brain cytoarchitecture and cognition. Green tea has potent antioxidative properties especially the tea catechin (-) epigallocatechin-3-gallate (EGCG). These powerful antioxidative properties are able to protect against various oxidative damages. In this study we investigated the impact of stress on rats' locomotor activity, learning and memory. Many tea catechins, including EGCG, were examined for their possible therapeutic effects in treating stress-induced impairment. Our results indicated that locomotor activity was decreased, and the learning and memory were impaired in stressed rats (SRs). EGCG treatment was able to prevent the decreased locomotor activity as well as improve the learning and memory in SRs. EGCG treatment was also able to reduce the increased oxidative status in SRs' hippocampi. The above results suggest a therapeutic effect of EGCG in treating stress-induced impairment of learning and memory, most likely by means of its powerful antioxidative properties. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Synthesis of modified proanthocyanidins: introduction of acyl substituents at C-8 of catechin. Selective synthesis of a C-4-->O-->C-3 ether-linked procyanidin-like dimer.

    PubMed

    Beauhaire, Josiane; Es-Safi, Nour-Eddine; Boyer, François-Didier; Kerhoas, Lucien; Guernevé, Christine le; Ducrot, Paul-Henri

    2005-02-01

    The regioselective introduction of substituents at C-8 of (+)-catechin is described, leading to the synthesis of several catechin derivatives with various substitution patterns to be used for the further synthesis of modified proanthocyanidins. Thereafter, a new 3-O-4 ether-linked procyanidin-like derivative was synthesized. Its formation was selectively achieved through TiCl(4)-catalyzed condensation of 4-(2-hydroxyethoxy)tetra-O-benzyl catechin with the 8-trifluoroacetyl adduct of tetra-O-benzyl catechin.

  13. Dissipation kinetics of beta-cyfluthrin and imidacloprid in tea and their transfer from processed tea to infusion.

    PubMed

    Paramasivam, M; Deepa, M; Selvi, C; Chandrasekaran, S

    2017-10-01

    Dissipation kinetics of mixed formulation consisting beta-cyfluthrin and imidacloprid in tea crop under an open field ecosystem was investigated. The mixed formulation was applied on tea plant at recommended (27 + 63) and double the recommended (54 + 126g a.i./ha) dose and residues were determined using gas chromatography-electron capture detector and high performance liquid chromatography-photodiode array detector for beta-cyfluthrin and imidacloprid, respectively. The limit of quantification of analytical method was 0.05µg/g and the average recoveries were ranged from 88.36% to 103.49% with relative standard deviations of less than 6% at three spiked levels. The experimental results showed that in the green tea leaves imidacloprid dissipated faster than beta-cyfluthrin with the half-life ranging between 1.20-1.39 and 2.89-3.15days, respectively. The beta-cyfluthrin residues present in the processed tea not transferred into the tea infusion during the infusion process and imidacloprid transferred in the range 43.12-49.7%. On the basis of the transfer of residues from processed tea to infusion, a waiting period of 17 days for tea plucking after pesticide application at recommended dose may be suggested. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Antioxidative and anti-carcinogenic activities of tea polyphenols.

    PubMed

    Yang, Chung S; Lambert, Joshua D; Sang, Shengmin

    2009-01-01

    Tea (Camellia sinensis, Theaceace), a popular beverage consumed world-wide, has been studied for its preventive effects against cancer as well as cardiovascular, neurodegenerative, and other diseases. Most of the proposed beneficial effects have been attributed to the polyphenolic compounds in tea, but the nature of these activities and the molecular mechanisms of their actions remain unclear. Tea polyphenols are known to be strong antioxidants. Prevention of oxidative stress, modulation of carcinogen metabolism, and prevention of DNA damage have been suggested as possible cancer preventive mechanisms for tea and tea polyphenols. In this chapter, we discuss these topics in the light of biotransformation and bioavailability of tea polyphenols. We also review the preventive effects of tea polyphenols in animal models of carcinogenesis and some of the possible post-initiation mechanisms of action. Finally, we discuss the effects of tea consumption on cancer risk in humans. It is our aim to raise some of the unanswered questions regarding cancer prevention by tea and to stimulate further research in this area.

  15. Green Tea (Camellia Sinensis): Chemistry and Oral Health.

    PubMed

    Khurshid, Zohaib; Zafar, Muhammad S; Zohaib, Sana; Najeeb, Shariq; Naseem, Mustafa

    2016-01-01

    Green tea is a widely consumed beverage worldwide. Numerous studies have suggested about the beneficial effects of green tea on oral conditions such as dental caries, periodontal diseases and halitosis. However, to date there have not been many review articles published that focus on beneficial effects of green tea on oral disease. The aim of this publication is to summarize the research conducted on the effects of green tea on oral cavity. Green tea might help reduce the bacterial activity in the oral cavity that in turn, can reduce the aforementioned oral afflictions. Furthermore, the antioxidant effect of the tea may reduce the chances of oral cancer. However, more clinical data is required to ascertain the possible benefits of green tea consumption on oral health.

  16. 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.

  17. Chapter 8. Tea and Cancer Prevention: Epidemiological Studies

    PubMed Central

    Yuan, Jian-Min; Sun, Canlan; Butler, Lesley M.

    2011-01-01

    Experimental studies have consistently shown the inhibitory activities of tea extracts on tumorigenesis in multiple model systems. Epidemiologic studies, however, have produced inconclusive results in humans. A comprehensive review was conducted to assess the current knowledge on tea consumption and risk of cancers in humans. In general, consumption of black tea was not associated with lower risk of cancer. High intake of green tea was consistently associated with reduced risk of upper gastrointestinal tract cancers after sufficient control for confounders. Limited data support a protective effect of green tea on lung and hepatocellular carcinogenesis. Although observational studies do not support a beneficial role of tea intake on prostate cancer risk, phase II clinical trials have demonstrated an inhibitory effect of green tea extract against the progression of prostate pre-malignant lesions. Green tea may exert beneficial effects against mammary carcinogenesis in premenopausal women and recurrence of breast cancer. There is no sufficient evidence that supports a protective role of tea intake on the development of cancers of the colorectum, pancreas, urinary tract, glioma, lymphoma, and leukemia. Future prospective observational studies with biomarkers of exposure and phase III clinical trials are required to provide definitive evidence for the hypothesized beneficial effect of tea consumption on cancer formation in humans. PMID:21419224

  18. TEA: A CODE CALCULATING THERMOCHEMICAL EQUILIBRIUM ABUNDANCES

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver, E-mail: jasmina@physics.ucf.edu

    2016-07-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature–pressure pairs. We tested the code against the method of Burrows and Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows and Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but withmore » higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.« less

  19. 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.

  20. Quantitative Determination of Catechin as Chemical Marker in Pediatric Polyherbal Syrup by HPLC/DAD.

    PubMed

    Sheikh, Zeeshan A; Siddiqui, Zafar A; Naveed, Safila; Usmanghani, Khan

    2016-09-01

    Vivabon syrup is a balanced composition of dietary ingredients of phytopharmaceutical nature for maintaining the physique, vigor, vitality and balanced growth of children. The herbal ingredients of pediatric syrup are rich in bioflavonoid, proteins, vitamins, glycosides and trace elements. Vivabon is formulated with herbal drugs such as Phoenix sylvestris, Emblica officinalis, Withania somnifera, Centella asiatica, Amomum subulatum, Zingiber officinalis, Trigonella foenum-graecum, Centaurea behen and Piper longum Catechins are flavan-3-ols that are found widely in the medicinal herbs and are utilized for anti-inflammatory, cardio protective, hepato-protective, neural protection and other biological activities. In general, the dietary intake of flavonoids has been regarded traditionally as beneficial for body growth. Standardization of Vivabon syrup dosage form using HPLC/DAD has been developed for quantitative estimation of Catechin as a chemical marker. The method was validated as per ICH guidelines. Validation studies demonstrated that the developed HPLC method is quite distinct, reproducible as well as quick and fast. The relatively high recovery and low comparable standard deviation confirm the suitability of the developed method for the determination of Catechin in syrup. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Effects of water-soluble natural antioxidants on photosensitized oxidation of conjugated linoleic acid in an oil-in-water emulsion system.

    PubMed

    Liu, T-T; Yang, T-S

    2008-05-01

    The effect of photosensitized oxidation of conjugated linoleic acid in an oil-in-water (o/w) emulsion system was studied. Water-soluble natural antioxidants, including apple polyphenols from apple extract, green tea extract, 4-hydroxy-2(or 5)-ethyl-5(or2)-methyl-3(2H)-furanone(HEMF), 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF), and ascorbic acid, were tested for antioxidant activity in this system. The green tea extract showed the highest antioxidant activity followed by ascorbic acid. Apple polyphenols did not give significant antioxidant activity. HEMF and HDMF exhibited a prooxidant effect. The antioxidant activity of tea catechins was also investigated. Of them, EGCG and ECG exhibited antioxidant activity at 50 ppm, but the antioxidant activity between them was not significantly different (P < 0.05). Comparatively, EC, EGC, and GCG showed no significant antioxidative effect at 50 ppm. When the concentration increased to 100 ppm, the antioxidant activity of ECG and EGCG significantly increased compared with that at 50 ppm, and EGCG had higher antioxidant activity than ECG. GCG also showed significant antioxidant activity at 100 ppm. EGCG exhibited the highest antioxidant activity among the tea catechins in the emulsion system at 100 ppm.

  2. Influence of formulation and processing on absorption and metabolism of flavan-3-ols from tea and cocoa.

    PubMed

    Neilson, Andrew P; Ferruzzi, Mario G

    2011-01-01

    Flavan-3-ols are a major subclass of the class of plant phytochemicals known as flavonoids. Flavan-3-ols are commonly found in fruit, vegetable, and botanical products, including tea, cocoa, grapes, and apples. Both monomeric catechins and polymeric procyanidins are common in the diet, along with several derivatives produced by degradation of these species during processing. Both epidemiological and biological evidence suggests a health-protective role for dietary flavan-3-ols, leading to increased interest in the bioavailability of these compounds from foods. Flavan-3-ol bioavailability depends on numerous factors, including digestive release, absorption, metabolism, and elimination. In addition to these in vivo factors, the complexity of whole-food systems (physical form, flavan-3-ol form and dose, macronutrient and micronutrient profile, processing, etc.) influences the absorption efficiency and circulating profile of flavan-3-ols. An understanding of how food matrices may influence flavan-3-ol absorption will provide a framework to design and develop functional products that positively affect flavan-3-ol absorption and, by extension, potential bioactivity.

  3. 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.

  4. 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.

  5. Association between tea consumption and osteoporosis

    PubMed Central

    Sun, Kang; Wang, Le; Ma, Qingping; Cui, Qiaoyun; Lv, Qianru; Zhang, Wenzheng; Li, Xinghui

    2017-01-01

    Abstract Background: Previous reports have suggested a potential association of tea consumption with the risk of osteoporosis. As such association is controversial, we conducted a meta-analysis to assess the relationship between tea consumption and osteoporosis. Methods and Findings: We systematically searched PubMed, EMBASE and WanFang databases until March 30, 2016, using the keywords “tea and osteoporosis,” without limits of language. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were derived by using random-effects models throughout the analyses. We conducted the analysis of the statistical heterogeneity using Cochrane I2. The funnel plot was used to speculate the publication bias, while the subgroup analysis and multiround elimination method were employed. Results: Our study was based on 17 journal articles, including 2 prospective cohort studies, 4 case–control studies, and 11 cross-sectional studies. In the present study, the total OR of osteoporosis for the highest versus the lowest categories of tea consumption was 0.62 (95% CI, 0.46–0.83), with significant heterogeneity among studies (I2 = 94%, P < .01). There was, however, no publication bias of the meta-analysis about tea consumption and osteoporosis. Subgroup analysis showed that tea consumption could reduce the risk of osteoporosis in all examined subgroups. Conclusion: In the present study, it can be concluded from the results that tea consumption can reduce the risk of osteoporosis. PMID:29245297

  6. Effect of a single dose of green tea polyphenols on the blood markers of exercise-induced oxidative stress in soccer players.

    PubMed

    Jówko, Ewa; Sacharuk, Jaroslaw; Balasinska, Bozena; Wilczak, Jacek; Charmas, Malgorzata; Ostaszewski, Piotr; Charmas, Robert

    2012-12-01

    To evaluate the effect of acute ingestion of green tea polyphenols (GTP) on blood markers of oxidative stress and muscle damage in soccer players exposed to intense exercise. This randomized, double-blinded study was conducted on 16 players during a general preparation period, when all athletes participated in a strength-training program focused on the development of strength endurance. After ingestion of a single dose of GTP (640 mg) or placebo, all athletes performed an intense muscle-endurance test consisting of 3 sets of 2 strength exercises (bench press, back squat) performed to exhaustion, with a load at 60% 1-repetition maximum and 1-min rests between sets. Blood samples were collected preexercise, 5 min after the muscle-endurance test, and after 24 hr of recovery. Blood plasma was analyzed for the concentrations of thiobarbituric acid-reacting substances (TBARS), uric acid (UA), total catechins, total antioxidant status (TAS), and activity of creatine kinase (CK); at the same time, erythrocytes were assayed for the activity of superoxide dismutase (SOD). In both groups, plasma TBARS, UA, and TAS increased significantly postexercise and remained elevated after a 24-hr recovery period. SOD activity in erythrocytes did not change significantly in response to the muscle-endurance test, whereas in both groups plasma CK activity increased significantly after 24 hr of recovery. Acute intake of GTP cased a slight but significant increase in total plasma catechins. However, GTP was found not to exert a significant effect on measured parameters. Acute ingestion of GTP (640 mg) does not attenuate exercise-induced oxidative stress and muscle damage.

  7. Polymeric proanthocyanidins: Interflavanoid linkage isomerism in (epicatechin-4)-(epicatechin-4)-catechin procyanidins

    Treesearch

    Richard W. Hemingway; L. Yeap Foo; L. J. Porter

    1981-01-01

    Procyanidin trimers have been isolated from a variety of plants,1-3 but their structures remain unresolved. We have now isolated three configurational isomers of (epicatechin-4)-(epicatechin-4)-catechin from Pinus taeda L. (loblolly pine) phloem which exhibit isomerism of the interflavanoid linkages.

  8. Profiling elements in Puerh tea from Yunnan province, China.

    PubMed

    Zhang, Jianyang; Ma, Guicen; Chen, Liyan; Liu, Ting; Liu, Xin; Lu, Chengyin

    2017-09-01

    Puerh tea, as the most representative Chinese dark tea, has attracted global interest in recent years. Profiling the levels of metal elements in Puerh tea is very important since its presence is related to human health. In this study, 41 elements in 98 Puerh tea samples from Yunnan province, China including Puerh raw tea and Puerh ripe tea were evaluated by microwave digestion combined with inductively coupled plasma mass spectrometry . The content of toxic elements, essential elements and rare earth elements of Puerh tea from different regions was discussed in detail. The concentrations of Ba, Cr, As, Pb, Bi, Fe, Zn, V, Mn, Be, Ag and Tl showed significant differences (p < 0.05) by ANOVA analysis. Principal component analysis and linear discriminant analysis were used to describe the relationship of Puerh tea from different regions. This study provided a comprehensive database for Puerh tea quality control and intake risk assessment.

  9. Tea Consumption and Mortality Among Oldest-Old Chinese

    PubMed Central

    Ruan, Rongping; Feng, Lei; Li, Jialiang; Ng, Tze-Pin; Zeng, Yi

    2013-01-01

    Objectives To investigate the association between tea consumption and mortality among oldest-old Chinese. Design Population-based longitudinal data from The Chinese Longitudinal Healthy Longevity Survey (CLHLS) was analyzed using Cox semi-parametric proportional hazard model. Setting 631 randomly selected counties and cities of China’s 22 provinces. Participants 9,093 old adults aged 80 and above who provided complete data at baseline survey (year 1998). Measurements Self-reported current frequency of tea drinking and past frequency around age 60 were ascertained at baseline survey, and follow-up survey was conducted respectively in years 2000, 2002 and 2005. Results Among oldest-old Chinese, tea consumption was associated with reduced risk of mortality after adjusting for demographic characteristics, socioeconomic status, health practices, and health status. Compared with non-tea drinkers, the adjusted hazard ratio (HR) was 0.90 (95% CI 0.84–0.96) for daily tea drinkers (at the baseline survey, 1998) and 1.00 (95% CI 1.01–1.07) for occasional tea drinkers respectively (P for linear trend=0.003). Similar results were found when tea drinking status around age 60 was used in analysis. Further analysis showed that compared to consistently infrequent tea drinkers, subjects who reported frequent tea drinking at both age 60 and at baseline survey had a 10% reduction in mortality (HR=0.90, 95%CI 0.84–0.97). Conclusion Tea consumption is associated reduced risk of mortality among oldest-old Chinese. PMID:24117374

  10. 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®

  11. Kombucha fermentation test used for various types of herbal teas

    NASA Astrophysics Data System (ADS)

    Novi Primiani, C.; Pujiati; Mumtahanah, Mahda; Ardhi, Waskitho

    2018-05-01

    Tea is a common drink in the community, the benefits of tea can be improved by processing fermented tea called kombucha. Kombucha is a refreshing drink made from tea water plus sugar, obtained through the fermentation process by acetic acid bacteria and fungi, is consumed for its health benefits. The common Kombucha starter is called SCOOBY (Simbyotic of Bacteri and Yeast). Kombucha research using herbal tea is very rarely done, it is necessary kombucha research using a variety of herbal teas to determine the quality of its inhibitory power against bacteria and its quality compared with kombucha berkomposisi tea Camelia sinensis in general. The purpose of this research was to know kombucha quality with ph parameter, thickness of nata, total acid and its inhibitory power to Escherchia coli and Staphylococcus aureus bacteria. This research used Randomized Block Design (RAK) method using 1 tea type treatment, with 3 replications. The first type of green tea (P1), roselle tea (P2), mangosteen peel tea (P3), soursop leaf tea (P4), moringa leaf tea (P5) and yellow leaf tea (P6), so there are 18 treatment combinations. Based on statistical analysis, there was influence of tea type to kombucha quality. Treatments of P1 and P2 were found to have an optimum and significant effect for kombucha. the results in level of acidity [pH] on green tea (P1) was 3.05, nata thickness of 4.63 and total acid of 0.69. Acidity in roselle tea (P2) was 2.86, nata thickness of 3.83, and total acid of 0.71. While the lowest quality was found in the treatment of mangosteen peel (P3) tea with pH 2.57, nata thickness of 0.35, and total acid of 0.79.

  12. Simultaneous determination of theobromine, (+)-catechin, caffeine, and (-)-epicatechin in standard reference material baking chocolate 2384, cocoa, cocoa beans, and cocoa butter.

    PubMed

    Risner, Charles H

    2008-01-01

    A reverse-phase liquid chromatography analysis is used to access the quantity of theobromine, (+)-catechin, caffeine, and (-)-epicatechin in Standard Reference Material 2384 Baking Chocolate, cocoa, cocoa beans, and cocoa butter using water or a portion of the mobile phase as the extract. The procedure requires minimal sample preparation. Theobromine, (+)-catechin, caffeine, and (-)-epicatechin are detected by UV absorption at 273 nm after separation using a 0.3% acetic acid-methanol gradient (volume fractions) and quantified using external standards. The limit of detection for theobromine, (+)-catechin, caffeine, and (-)-epicatechin averages 0.08, 0.06, 0.06, and 0.06 microg/mL, respectively. The method when applied to Standard Reference Material 2384 Baking Chocolate; baking chocolate reference material yields results that compare to two different, separate procedures. Theobromine ranges from 26000 mg/kg in cocoa to 140 mg/kg in cocoa butter; (+)-catechin from 1800 mg/kg in cocoa to below detection limits of < 32 mg/kg in cocoa butter; caffeine from 2400 mg/kg in cocoa to 400 mg/kg in cocoa butter, and (-)-epicatechin from 3200 mg/kg in cocoa to BDL, < 27 mg/kg, in cocoa butter. The mean recoveries from cocoa are 102.4 +/- 0.6% for theobromine, 100.0 +/- 0.6 for (+)-catechin, 96.2 +/- 2.1 for caffeine, and 106.2 +/- 1.7 for (-)-epicatechin.

  13. Migration and Accumulation of Octachlorodipropyl Ether in Soil-Tea Systems in Young and Old Tea Gardens.

    PubMed

    Liao, Min; Shi, Yan-Hong; Cao, Hai-Qun; Fang, Qing-Kui; Xiao, Jin-Jing; Hua, Ri-Mao

    2017-09-08

    The migration and accumulation of octachlorodipropyl ether (OCDPE) in soil-tea systems were investigated using a gas chromatography-electron capture detector (GC-ECD) method in young and old tea gardens. When the residual concentration of OCDPE was 100 g a.i. hm -2 in soils, the peak concentrations of OCDPE in fresh leaves of young and old tea plants were 0.365 mg/kg and 0.144 mg/kg, taking 45 days and 55 days, respectively. Equations for the accumulation curves of OCDPE in fresh leaves of young and old tea plants were C t = 0.0227e 0.0566t (R² = 0.9154) and C t = 0.0298e -0.0306t (R² = 0.7156), and were C t = 3.8435e 0.055t (R² = 0.9698) and C t = 1.5627e -0.048t (R² = 0.9634) for dissipation curves, with a half-life of 14.4 days and 12.6 days, respectively. These results have practical guiding significance for controlling tea food safety.

  14. 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

  15. Inhibition of attachment of oral bacteria to immortalized human gingival fibroblasts (HGF-1) by tea extracts and tea components

    PubMed Central

    2013-01-01

    Background Tea has been suggested to promote oral health by inhibiting bacterial attachment to the oral cavity. Most studies have focused on prevention of bacterial attachment to hard surfaces such as enamel. Findings This study investigated the effect of five commercial tea (green, oolong, black, pu-erh and chrysanthemum) extracts and tea components (epigallocatechin gallate and gallic acid) on the attachment of five oral pathogens (Streptococcus mutans ATCC 25175, Streptococcus mutans ATCC 35668, Streptococcus mitis ATCC 49456, Streptococcus salivarius ATCC 13419 and Actinomyces naeslundii ATCC 51655) to the HGF-1 gingival cell line. Extracts of two of the teas (pu-erh and chrysanthemum) significantly (p < 0.05) reduced attachment of all the Streptococcus strains by up to 4 log CFU/well but effects of other teas and components were small. Conclusions Pu-erh and chrysanthemum tea may have the potential to reduce attachment of oral pathogens to gingival tissue and improve the health of oral soft tissues. PMID:23578062

  16. Inhibition of attachment of oral bacteria to immortalized human gingival fibroblasts (HGF-1) by tea extracts and tea components.

    PubMed

    Wang, Yi; Chung, Felicia F L; Lee, Sui M; Dykes, Gary A

    2013-04-11

    Tea has been suggested to promote oral health by inhibiting bacterial attachment to the oral cavity. Most studies have focused on prevention of bacterial attachment to hard surfaces such as enamel. This study investigated the effect of five commercial tea (green, oolong, black, pu-erh and chrysanthemum) extracts and tea components (epigallocatechin gallate and gallic acid) on the attachment of five oral pathogens (Streptococcus mutans ATCC 25175, Streptococcus mutans ATCC 35668, Streptococcus mitis ATCC 49456, Streptococcus salivarius ATCC 13419 and Actinomyces naeslundii ATCC 51655) to the HGF-1 gingival cell line. Extracts of two of the teas (pu-erh and chrysanthemum) significantly (p < 0.05) reduced attachment of all the Streptococcus strains by up to 4 log CFU/well but effects of other teas and components were small. Pu-erh and chrysanthemum tea may have the potential to reduce attachment of oral pathogens to gingival tissue and improve the health of oral soft tissues.

  17. Insulin mimetic impact of Catechin isolated from Cassia fistula on the glucose oxidation and molecular mechanisms of glucose uptake on Streptozotocin-induced diabetic Wistar rats.

    PubMed

    Daisy, P; Balasubramanian, K; Rajalakshmi, M; Eliza, J; Selvaraj, J

    2010-01-01

    Diabetes mellitus is the most common and serious metabolic disorder among people all over the world. Many plants have successfully been used to overcome this problem. Cassia fistula, an ethnomedicnal plant, is widely used in Indian medicine to treat diabetes. Methanol extract of stem of plant, reduced the blood glucose levels in Streptozotocin-induced diabetic rats. Bioassay guided fractionation was followed to isolate Catechin from methanol extract. Catechin was administered to Streptozotocin (60mg/kg b.w.)-induced diabetic male Wistar rats at different doses (5, 10, 20mg/kg b.w.) for 6 weeks to assess its effect on fasting plasma glucose. The plasma glucose was significantly (p<0.05) reduced when compared to the control. Oral administration of Catechin (20mg/kg b.w.) markedly increased tissue glycogen, and (14)C-glucose oxidation without any change in plasma insulin and C-peptide. Catechin restored the altered Glucokinase, glucose-6 Phosphatase, Glycogen Synthase and Glycogen Phosphorylase levels to near normal. GLUT4 mRNA and protein expression were enhanced after Catechin treatment. The results of this experimental study indicated that Catechin possesses hypo-glycemic, Glucose oxidizing and insulin mimetic activities and hence it could be used as a drug for treating diabetes.

  18. 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.

  19. Does oolong tea (Camellia sinensis) made from a combination of leaf and stem smell more aromatic than leaf-only tea? Contribution of the stem to oolong tea aroma.

    PubMed

    Zeng, Lanting; Zhou, Ying; Fu, Xiumin; Mei, Xin; Cheng, Sihua; Gui, Jiadong; Dong, Fang; Tang, Jinchi; Ma, Shengzhou; Yang, Ziyin

    2017-12-15

    The raw materials used to make oolong tea (Camellia sinensis) are a combination of leaf and stem. Oolong tea made from leaf and stem is thought to have a more aromatic smell than leaf-only tea. However, there is no available evidence to support the viewpoint. In this study, sensory evaluation and detailed characterization of emitted and internal volatiles (not readily emitted, but stored in samples) of dry oolong teas and infusions indicated that the presence of stem did not significantly improve the total aroma characteristics. During the enzyme-active processes, volatile monoterpenes and theanine were accumulated more abundantly in stem than in leaf, while jasmine lactone, indole, and trans-nerolidol were lower in stem than in leaf. Tissue-specific aroma-related gene expression and availability of precursors of aroma compounds resulted in different aroma distributions in leaf and stem. This study presents the first determination of the contribution of stem to oolong tea aroma. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Towards generating caffeine-free tea by metabolic engineering.

    PubMed

    Yadav, Sudesh Kumar; Ahuja, Paramvir Singh

    2007-12-01

    Tea is a rich source of antioxidants which are contributing substantially to the promotion of health and the prevention of various chronic diseases. Despite the fact that tea has various important compounds, it also contains a purine alkaloid, caffeine. High intake of tea leads to an increase in level of caffeine in addition to its important antioxidant constituents. Increased level of caffeine causes several health related problems. Therefore, tea can become a most useful source of beneficial compounds, if only its caffeine level is either decreased or eliminated all together from the plant itself. This could be achieved through either of the techniques; overexpressing caffeine degradative pathway genes or silencing caffeine biosynthesis pathway gene. The identification and cloning of caffeine biosynthesis in tea and degradative genes in microorganisms opens up the possibility of using genetic engineering to produce naturally decaffeinated tea. Here we review these different strategies which can be employed to make caffeine-free tea, a human health beneficial drink.