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Population nutrikinetics of green tea extract.
Scholl, C, Lepper, A, Lehr, T, Hanke, N, Schneider, KL, Brockmöller, J, Seufferlein, T, Stingl, JC
PloS one. 2018;(2):e0193074
Abstract
UNLABELLED 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. TRIAL REGISTRATION ClinicalTrials.gov: NCT01360320.
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ProDiet: A Phase II Randomized Placebo-controlled Trial of Green Tea Catechins and Lycopene in Men at Increased Risk of Prostate Cancer.
Lane, JA, Er, V, Avery, KNL, Horwood, J, Cantwell, M, Caro, GP, Crozier, A, Smith, GD, Donovan, JL, Down, L, et al
Cancer prevention research (Philadelphia, Pa.). 2018;(11):687-696
Abstract
Epidemiologic studies suggest that diet can alter prostate cancer risk. This study aimed to establish the feasibility and acceptability of dietary modification in men at increased risk of prostate cancer. Men were invited with a PSA level of 2.0-2.95 ng/mL or 3.0-19.95 ng/mL with negative prostate biopsies. Randomization (3 × 3 factorial design) to daily green tea and lycopene: green tea drink (3 cups, unblinded) or capsules [blinded, 600 mg flavan-3-ol ()-epigallocatechin-3-gallate (EGCG) or placebo] and lycopene-rich foods (unblinded) or capsules (blinded, 15 mg lycopene or placebo) for 6 months. Primary endpoints were randomization rates and intervention adherence (blinded assessment of metabolites) at 6 months with secondary endpoints of acceptability (from interviews), safety, weight, blood pressure, and PSA. A total of 133 of 469 (28.4%) men approached agreed to be randomized and 132 were followed-up (99.2%). Mean lycopene was 1.28 [95% confidence intervals (CI), 1.09-1.50, P = 0.003] times higher in the lycopene capsule group and 1.42 (95% CI, 1.21-1.66; P < 0.001) times higher in the lycopene-enriched diet group compared with placebo capsules. Median EGCG was 10.7 nmol/L (95% CI, 7.0-32.0) higher in in the active capsule group and 20.0 nmol/L (95% CI, 0.0-19.0) higher in the green tea drink group compared with placebo capsules (both P < 0.001). All interventions were acceptable and well tolerated although men preferred the capsules. Dietary prevention is acceptable to men at risk of prostate cancer. This intervention trial demonstrates that a chemoprevention clinical trial is feasible. Cancer Prev Res; 11(11); 687-96. ©2018 AACR.
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Effect of green tea catechins in patients with high-grade prostatic intraepithelial neoplasia: Results of a short-term double-blind placebo controlled phase II clinical trial.
Micali, S, Territo, A, Pirola, GM, Ferrari, N, Sighinolfi, MC, Martorana, E, Navarra, M, Bianchi, G
Archivio italiano di urologia, andrologia : organo ufficiale [di] Societa italiana di ecografia urologica e nefrologica. 2017;(3):197-202
Abstract
BACKGROUND AND STUDY OBJECTIVE Several studies suggest a protective role of green tea catechins against prostate cancer (PCa). In order to evaluate the efficacy of green tea catechins for chemoprevention of PCa in patients with high-grade prostate intraepithelial neoplasia (HG-PIN) we performed a phase II clinical trial. METHODS Sixty volunteers with HG-PIN were enrolled to carry out a double-blind randomized placebo-controlled phase II clinical trial. Treated group took daily 600 mg of green tea catechins (Categ Plus®) for 1 year. Patients were screened at 6 and 12 months through prostatic biopsy and measurements of prostate-specific antigen (PSA). RESULTS Despite the statistically significant reduction of PSA observed in subjects who received green tea catechins for 6 and 12 months, we did not find any statistical difference in PCa incidence between the experimental groups neither after 6 nor after 12 months. However, throughout the one-year follow- up we observed very limited adverse effects induced by green tea catechins and a not significant improvement in lower urinary tract symptoms and quality of life. CONCLUSIONS Although the small number of patients enrolled in our study and the relatively short duration of intervention, our findings seems to deny the efficacy of green tea catechins. However, results of our clinical study, mainly for its low statistical strength, suggest that the effectiveness of green tea catechins should be evaluated in both a larger cohort of men and longer trial.
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Effect of Green Tea Supplements on Liver Enzyme Elevation: Results from a Randomized Intervention Study in the United States.
Yu, Z, Samavat, H, Dostal, AM, Wang, R, Torkelson, CJ, Yang, CS, Butler, LM, Kensler, TW, Wu, AH, Kurzer, MS, et al
Cancer prevention research (Philadelphia, Pa.). 2017;(10):571-579
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Liver injury effects of green tea-based products have been reported in sporadic case reports. However, no study has examined systematically such adverse effects in an unbiased manner. We examined the potential effects of a high, sustained oral dose of green tea extract (GTE) on liver injury measures in a randomized, placebo-controlled, double-blinded phase II clinical trial, which enrolled 1,075 women with the original aim to assess the effect of daily GTE consumption for 12 months on biomarkers of breast cancer risk. The current analysis examined the effect of GTE consumption on liver injury in 1,021 participants (513 in GTE and 508 in placebo arm) with normal baseline levels of liver enzymes. Among women in the GTE arm, alanine aminotransferase (ALT) increased by 5.4 U/L [95% confidence interval (CI), 3.6-7.1] and aspartate aminotransferase increased by 3.8 U/L (95% CI, 2.5-5.1), which were significantly higher than those among women in the placebo arm (both P < 0.001). Overall, 26 (5.1%) women in GTE developed moderate or more severe abnormalities in any liver function measure during the intervention period, yielding an OR of 7.0 (95% CI, 2.4-20.3) for developing liver function abnormalities as compared with those in the placebo arm. ALT returned to normal after dechallenge and increased again after one or more rechallenges with GTE. The rise-fall pattern of liver enzyme values following the challenge-dechallenge cycles of GTE consumption strongly implicates the effect of high-dose GTE on liver enzyme elevations. Cancer Prev Res; 10(10); 571-9. ©2017 AACR.
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Identification of Targets of a New Nutritional Mixture for Osteoarthritis Management Composed by Curcuminoids Extract, Hydrolyzed Collagen and Green Tea Extract.
Comblain, F, Dubuc, JE, Lambert, C, Sanchez, C, Lesponne, I, Serisier, S, Henrotin, Y
PloS one. 2016;(6):e0156902
Abstract
OBJECTIVE We have previously demonstrated that a mixture of curcuminoids extract, hydrolyzed collagen and green tea extract (COT) inhibited inflammatory and catabolic mediator's synthesis by osteoarthritic human chondrocytes. The objective of this study was to identify new targets of COT using genomic and proteomic approaches. DESIGN Cartilage specimens were obtained from 12 patients with knee osteoarthritis. Primary human chondrocytes were cultured in monolayer until confluence and then incubated for 24 or 48 hours in the absence or in the presence of human interleukin(IL)-1β (10-11M) and with or without COT, each compound at the concentration of 4 μg/ml. Microarray gene expression profiling between control, COT, IL-1β and COT IL-1β conditions was performed. Immunoassays were used to confirm the effect of COT at the protein level. RESULTS More than 4000 genes were differentially expressed between conditions. The key regulated pathways were related to inflammation, cartilage metabolism and angiogenesis. The IL-1β stimulated chemokine ligand 6, matrix metalloproteinase-13, bone morphogenetic protein-2 and stanniocalcin1 gene expressions and protein productions were down-regulated by COT. COT significantly decreased stanniocalcin1 production in basal condition. Serpin E1 gene expression and protein production were down-regulated by IL-1β. COT reversed the inhibitory effect of IL-1β. Serpin E1 gene expression was up-regulated by COT in control condition. CONCLUSION The COT mixture has beneficial effect on osteoarthritis physiopathology by regulating the synthesis of key catabolic, inflammatory and angiogenesis factors. These findings give a scientific rationale for the use of these natural ingredients in the management of osteoarthritis.
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Randomized clinical trial of brewed green and black tea in men with prostate cancer prior to prostatectomy.
Henning, SM, Wang, P, Said, JW, Huang, M, Grogan, T, Elashoff, D, Carpenter, CL, Heber, D, Aronson, WJ
The Prostate. 2015;(5):550-9
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BACKGROUND Preclinical and epidemiologic studies suggest chemopreventive effects of green tea (GT) and black tea (BT) in prostate cancer. In the current study we determined the effect of GT and BT consumption on biomarkers related to prostate cancer development and progression. METHODS In this exploratory, open label, phase II trial 113 men diagnosed with prostate cancer were randomized to consume six cups daily of brewed GT, BT or water (control) prior to radical prostatectomy (RP). The primary endpoint was prostate tumor markers of cancer development and progression determined by tissue immunostaining of proliferation (Ki67), apoptosis (Bcl-2, Bax, Tunel), inflammation (nuclear and cytoplasmic nuclear factor kappa B [NFκB]) and oxidation (8-hydroxydeoxy-guanosine [8OHdG]). Secondary endpoints of urinary oxidation, tea polyphenol uptake in prostate tissue, and serum prostate specific antigen (PSA) were evaluated by high performance liquid chromatography and ELISA analysis. RESULTS Ninety three patients completed the intervention. There was no significant difference in markers of proliferation, apoptosis and oxidation in RP tissue comparing GT and BT to water control. Nuclear staining of NFκB was significantly decreased in RP tissue of men consuming GT (P = 0.013) but not BT (P = 0.931) compared to water control. Tea polyphenols were detected in prostate tissue from 32 of 34 men consuming GT but not in the other groups. Evidence of a systemic antioxidant effect was observed (reduced urinary 8OHdG) only with GT consumption (P = 0.03). GT, but not BT or water, also led to a small but statistically significant decrease in serum prostate-specific antigen (PSA) levels (P = 0.04). CONCLUSION Given the GT-induced changes in NFκB and systemic oxidation, and uptake of GT polyphenols in prostate tissue, future longer-term studies are warranted to further examine the role of GT for prostate cancer prevention and treatment, and possibly for other prostate conditions such as prostatitis.
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'Benifuuki' green tea containing o-methylated catechin reduces symptoms of Japanese cedar pollinosis: a randomized, double-blind, placebo-controlled trial.
Masuda, S, Maeda-Yamamoto, M, Usui, S, Fujisawa, T
Allergology international : official journal of the Japanese Society of Allergology. 2014;(2):211-7
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BACKGROUND 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). METHODS 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. RESULTS 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. CONCLUSIONS '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.
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Combined topical application of lotus and green tea improves facial skin surface parameters.
Mahmood, T, Akhtar, N
Rejuvenation research. 2013;(2):91-7
Abstract
No study has yet determined the anti-wrinkle efficacy of green tea plus lotus in Asian subjects using skin image analysis technique. In this study, the efficacy of two cosmetic active formulations intended for the treatment of facial wrinkles (green tea and lotus extract) has been evaluated in healthy subjects using a non-invasive device, the Visioscan(®) VC, and software for surface evaluation of living skin (SELS). Thirty-three healthy Asian subjects, all men, were enrolled after consent in a placebo-controlled comparative study with a split face design. One group applied multiple emulsions with green tea. The second group applied multiple emulsions with lotus extract, while a third group applied a multiple emulsion with a combination of both extracts. In all three groups, active formulations were applied to one side of the face and the placebo to the other side, once daily over the 60-day treatment course. Non-invasive measurements were performed at baseline and on days 30 and 60. Interesting and significant improvements were observed for the treatment effects on skin roughness (SEr), scaliness (SEsc), smoothness (SEsm), and wrinkling (SEw). For example, a 49.99% improvement in skin smoothness (SEsm) from baseline value and -23.22% and perfection in facial wrinkles (SEw) substantiated that combined treatment is superior over single treatments. Green tea and lotus combined in multiple emulsions brought a superior synergistic anti-aging effect. We conclude that diverse anti-oxidant constituents in both plants have a potential influence on skin surface parameters, thus indicating these plants as the future of new anti-aging products.
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Effect of increasing levels of zinc fortificant on the iron absorption of bread co-fortified with iron and zinc consumed with a black tea.
Olivares, M, Castro, C, Pizarro, F, de Romaña, DL
Biological trace element research. 2013;(3):321-5
Abstract
Iron (Fe) and zinc's (Zn) interaction at the absorptive level can have an effect on the success of co-fortification of wheat flour with both minerals on iron deficiency prevention. The aim of the study was to determine the effect of increasing levels of zinc fortificant on the iron absorption of bread co-fortified with iron and zinc consumed with a black tea. Twelve women aged 33-42 years participated in the study. They received on four different days 200 mL of black tea and 100 g of bread made with wheat flour (70% extraction) fortified with either 30 mg Fe/kg alone, as ferrous sulfate (A), or with the same Fe-fortified flour, but with graded levels of Zn, as zinc sulfate: 30 mg/kg (B), 60 mg/kg (C), or 90 mg/kg (D). Fe radioisotopes ((59)Fe and (55)Fe) of high specific activity were used as tracers, and Fe absorption iron was measured by the incorporation of radioactive Fe into erythrocytes. The geometric mean and range of ±1 SD of Fe absorption were as follows: A = 6.5% (2.2-19.3%), B = 4.6% (1.0-21.0%), C = 2.1% (0.9-4.9%), and D = 2.2% (0.7-6.6%), respectively; ANOVA for repeated measures F = 10.9, p < 0.001 (Scheffè's post hoc test: A vs. C, A vs. D, B vs. C, and B vs. D; p < 0.05). We can conclude that Fe absorption of bread made from low-extraction flour fortified with 30 mg/kg of Fe, as ferrous sulfate, and co-fortified with zinc, as zinc sulfate consumed with black tea is significantly decreased at a zinc fortification level of ≥60 mg/kg flour.
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The effects of green tea consumption and resistance training on body composition and resting metabolic rate in overweight or obese women.
Cardoso, GA, Salgado, JM, Cesar, Mde C, Donado-Pestana, CM
Journal of medicinal food. 2013;(2):120-7
Abstract
Green tea has been shown to have thermogenic and antiobesity properties. Therefore, it is important to investigate its effect on weight loss in humans, especially in women. We investigated the effects of green tea consumption combined with resistance training on the body composition and the resting metabolic rate (RMR) in women who were overweight or obese (grade I). After 4 weeks on an adaptive diet, 36 women were divided into four groups (group 1 green tea; group 2 placebo; group 3 green tea plus resistance training; group 4 placebo plus resistance training). The study was double-blinded and placebo-controlled. The RMR and body composition were ascertained for each volunteer, blood tests were performed, and subjects in groups 3 and 4 were tested for their one repetition maximum. Each subject followed the protocol and continued the diet for eight additional weeks, and periodic evaluations were administered. The mean RMR of group 1 decreased significantly and was accompanied by weight loss, maintenance of lean body mass, and decreases in both waist circumference and body mass index. Group 2 showed no variations in anthropometric or blood variables and significantly decreased their mean RMR. Group 3 showed significant increases in RMR, lean body mass, and muscle strength, and significant decreases in body fat, triglycerides, and waist circumference as compared to group 4. Green tea combined with resistance training its potential is increased with decreasing body fat, waist circumference, and triacylglyceride levels and by increasing lean body mass and muscle strength.