The Effects of Epigallocatechin-3-Gallate on Thermogenesis and Fat Oxidation in Obese Men: A Pilot Study Epigallocatechin-3-gallate and postprandial fat oxidation in overweight/obese male volunteers: a pilot study Effects of encapsulated green tea and Guarana extracts containing a mixture of epigallocatechin-3-gallate and caffeine on 24 h energy expenditure and fat oxidation in men. Phase I pharmacokinetic study of tea polyphenols following single-dose administration of epigallocatechin gallate and polyphenon E. Epigallocatechin-3-gallate increases maximal oxygen uptake in adult humans. The effects of EGCG on fat oxidation and endurance performance in male cyclists. Combined epigallocatechin-3-gallate and resveratrol supplementation for 12 wk increases mitochondrial capacity and fat oxidation, but not insulin sensitivity, in obese humans: a randomized controlled trial. Blood and urine levels of tea catechins after ingestion of different amounts of green tea by human volunteers. Diet supplementation with green tea extract epigallocatechin gallate prevents progression to glucose intolerance in db/db mice Exercise but not (–)-epigallocatechin-3-gallate or β-alanine enhances physical fitness, brain plasticity, and behavioral performance in mice Chinese green tea ameliorates lung injury in cigarette smoke-exposed rats. Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans. Role of (−)-epigallocatechin gallate in the pharmacokinetic interaction between nadolol and green tea in healthy volunteers Antihypertensive effect of Benifuuki tea containing O-methylated EGCG. A Presurgical Study of Lecithin Formulation of Green Tea Extract in Women with Early Breast Cancer Pharmacokinetics and safety of green tea polyphenols after multiple-dose administration of epigallocatechin gallate and polyphenon E in healthy individuals. Effect of 2-Month Controlled Green Tea Intervention on Lipoprotein Cholesterol, Glucose, and Hormone Levels in Healthy Postmenopausal Women Randomized, Placebo-Controlled Trial of Green Tea Catechins for Prostate Cancer Prevention Recent findings of green tea extract AR25 (Exolise) and its activity for the treatment of obesity. Health effects of green tea catechins in overweight and obese men: a randomised controlled cross-over trial. Epigallocatechin-3-gallate increased the push out bond strength of an epoxy resin sealer to root dentin. Tea polyphenols and theaflavins are present in prostate tissue of humans and mice after green and black tea consumption. EGCG-rich green tea extract stimulates sRAGE secretion to inhibit S100A12-RAGE axis through ADAM10-mediated ectodomain shedding of extracellular RAGE in type 2 diabetes.
Objectives : The development of obesity is characterized by an increase in adipose tissue mass and by concomitant and profound changes in almost all organ functions leading to diseases such as hypertension , diabetes mellitus and coronary heart disease . Recent data from human studies indicate that the consumption of green tea and green tea extracts may help reduce body weight , mainly body fat , by increasing postpr and ial thermogenesis and fat oxidation . However , human studies investigating the metabolic effects of the most predominant tea catechin , EGCG , alone are absent . Methods : In a r and omized double blind , placebo-controlled , cross-over pilot study , six overweight men were given 300 mg EGCG/d for 2d . Fasting and postpr and ial changes in energy expenditure ( EE ) and substrate oxidation were assessed . Results : Resting EE did not differ significantly between EGCG and placebo treatments , although during the first postpr and ial monitoring phase , respiratory quotient ( RQ ) values were significantly lower with EGCG compared to the placebo . Conclusions : These findings suggest that EGCG alone has the potential to increase fat oxidation in men and may thereby contribute to the anti-obesity effects of green tea . However , more studies with a greater sample size and a broader range of age and BMI are needed to define the optimum dose Objectives : Drinking green tea is associated with many health benefits , including increased fat oxidation . We tested the hypothesis that epigallocatechin-3-gallate ( EGCG ) , the main green tea catechin , increases  fat oxidation in obese men . Methods : Ten healthy overweight/obese males ( body mass index 31.3±0.8 kg/m2 ) were studied in a r and omized , placebo-controlled , double-blind crossover trial . Study supplements were low EGCG ( 300 mg ) , high EGCG ( 600 mg ) , caffeine ( 200 mg ) , EGCG/caffeine ( 300 mg/200 mg ) or placebo and were taken orally for 3 days . At the third day of supplementation , O2 consumption and CO2 production was measured by indirect calorimetry to assess energy expenditure and fat oxidation over 4 h each after overnight fasting and after a st and ardized test meal . Results : Energy expenditure was not affected by any supplementation , neither after overnight fasting nor after the test meal . During the first 2 h after overnight fasting , fat oxidation increased by 7.7 ( not significant , NS ) , 15.2 ( NS ) , 26.3 ( P<0.05 vs placebo ) and 35.4 % ( P<0.01 vs placebo and low EGCG ) , for low EGCG , high EGCG , caffeine and EGCG/caffeine , respectively . During the first 2 h after the meal , the mean increase in fat oxidation was 33.3 ( P<0.05 vs placebo ) , 20.2 ( NS ) , 34.5 ( P<0.05 vs placebo ) and 49.4 % ( P<0.05 vs placebo ) for low EGCG , high EGCG , caffeine and EGCG/caffeine , respectively . Conclusions : Low EGCG increases postpr and ial fat oxidation  in obese men and this to the same extent as 200 mg caffeine , whereas high EGCG does not exert this effect . Fasting fat oxidation is increased only by caffeine ( with or without EGCG ) . There is no synergism of low EGCG and 200 mg caffeine . Energy expenditure is not affected by EGCG It has been reported that green tea has a thermogenic effect , due to its caffeine content and probably also to the catechin , epigallocatechin-3-gallate ( EGCG ) . The main aim of the present study was to compare the effect of a mixture of green tea and Guarana extracts containing a fixed dose of caffeine and variable doses of EGCG on 24 h energy expenditure and fat oxidation .  Fourteen subjects took part to this r and omized , placebo-controlled , double-blind , cross-over study . Each subject was tested five times in a metabolic chamber to measure 24 h energy expenditure , substrate oxidation and blood pressure . During each stay , the subjects ingested a capsule of placebo or capsules containing 200 mg caffeine and a variable dose of EGCG ( 90 , 200 , 300 or 400 mg ) three times daily , 30 min before st and ardized meals . Twenty-four hour energy expenditure increased significantly by about 750 kJ with all EGCG-caffeine mixtures compared with placebo . No effect of the EGCG-caffeine mixture was observed for lipid oxidation . Systolic and diastolic blood pressure increased by about 7 and 5 mmHg , respectively , with the EGCG-caffeine mixtures compared with placebo . This increase was significant only for 24 h diastolic blood pressure . The main finding of the study was the increase in 24 h energy expenditure with the EGCG-caffeine mixtures . However , this increase was similar with all doses of EGCG in the mixtures Green tea has been shown to exhibit cancer-preventive activities in pre clinical studies . Its principal active components include epigallocatechin gallate ( EGCG ) , epigallocatechin ( EGC ) , epicatechin ( EC ) , and epicatechin gallate , of which EGCG is the most abundant and possesses the most potent antioxidative activity . We performed a Phase I pharmacokinetic study to determine the systemic availability of green tea catechins after single oral dose administration of EGCG and Polyphenon E ( decaffeinated green tea catechin mixture ) .  Twenty healthy subjects ( five subjects/dose level ) were r and omly assigned to one of the dose levels ( 200 , 400 , 600 , and 800 mg based on EGCG content ) . All subjects were r and omly crossed-over to receive the two catechin formulations at the same dose level . Blood and urine sample s were collected for up to 24 h after oral administration of the study medication . Tea catechin concentrations in plasma and urine sample s were determined using high-performance liquid chromatography with the coulometric electrode array detection system . After EGCG versus Polyphenon E administration , the mean area under the plasma concentration-time curves ( AUC ) of unchanged EGCG were 22.5 versus 21.9 , 35.4 versus 52.2 , 101.9 versus 79.7 , and 167.1 versus 161.4 min x microg/ml at the 200- , 400- , 600- , and 800-mg dose levels , respectively . EGC and EC were not detected in plasma after EGCG administration and were present at low/undetectable levels after Polyphenon E administration . High concentrations of EGC and EC glucuronide/sulfate conjugates were found in plasma and urine sample s after Polyphenon E administration . There were no significant differences in the pharmacokinetic characteristics of EGCG between the two study medications . The AUC and maximum plasma concentration ( Cmax ) of EGCG after the 800-mg dose of EGCG were found to be significantly higher than those after the 200- and 400-mg dose . The AUC and Cmax of EGCG after the 800-mg dose of Polyphenon E were significantly higher than those after the three lower doses . We conclude that the two catechin formulations result ed in similar plasma EGCG levels . EGC and EC were present in the body after the Polyphenon E administration ; however , they were present predominantly in conjugated forms . The systemic availability of EGCG increased at higher doses , possibly due to saturable presystemic elimination of orally administered green tea polyphenols UNLABELLED Epigallocatechin-3-gallate ( EGCG ) , a component of green tea , increases endurance performance in animals and promotes fat oxidation during cycle ergometer exercise in adult humans . PURPOSE We have investigated the hypothesis that short-term consumption of EGCG delays the onset of the ventilatory threshold ( VT ) and increases maximal oxygen uptake ( VO2max ) . METHODS In this r and omized , repeated- measures , double-blind study , 19 healthy adults ( 11 males and 8 females , age = 26 ± 2 yr ( mean ± SE ) ) received seven placebo  or seven EGCG ( 135-mg ) pills . Forty-eight hours before data collection , participants began consuming three pills per day ; the last pill was taken 2 h before exercise testing . VT and VO2max were determined from breath-by-breath indirect calorimetry data collected during continuous incremental stationary cycle ergometer exercise ( 20 - 35 W·min(-1 ) ) , from rest until volitional fatigue . Each condition/exercise test was separated by a minimum of 14 d. RESULTS Compared with placebo , short-term EGCG consumption increased VO2max ( 3.123 ± 0.187 vs 3.259 ± 0.196 L·min(-1 ) , P = 0.04 ) . Maximal work rate ( 301 ± 15 vs 301 ± 16 W , P = 0.98 ) , maximal RER ( 1.21 ± 0.01 vs 1.22 ± 0.02 , P = 0.27 ) , and maximal HR were unaffected ( 180 ± 3 vs 180 ± 3 beats·min(-1 ) , P = 0.87 ) . In a subset of subjects ( n = 11 ) , maximal cardiac output ( determined via open-circuit acetylene breathing ) was also unaffected by EGCG ( 29.6 ± 2.2 vs 30.2 ± 1.4 L·min(-1 ) , P = 0.70 ) . Contrary to our hypothesis , EGCG  decreased VO2 at VT ( 1.57 ± 0.11 vs 1.48 ± 0.10 L·min(-1 ) ) , but this change was not significant ( P = 0.06 ) . CONCLUSIONS Short-term consumption of EGCG  increased VO2max without affecting maximal cardiac output , suggesting that EGCG may increase arterial-venous oxygen difference Research ers have long been investigating strategies that can increase athletes ' ability to oxidize fatty acids and spare carbohydrate , thus potentially improving endurance capacity .  Green-tea extract ( epigallocatechin-3-gallate ; EGCG ) has been shown to improve endurance capacity in mice . If a green-tea extract can stimulate fat oxidation and as a result spare glycogen stores , then athletes may benefit through improved endurance performance . Eight male cyclists completed a study incorporating a 3-way crossover , r and omized , placebo-controlled , double-blinded , diet-controlled research design . All participants received 3 different treatments ( placebo 270 mg , EGCG 270 mg , and placebo 270 mg + caffeine 3 mg/kg ) over a 6-day period and 1 hr before exercise testing . Each participant completed 3 exercise trials consisting of 60 min of cycling at 60 % maximum oxygen uptake ( VO2(max ) ) immediately followed by a self-paced 40-km cycling time trial . The study found little benefit in consuming green-tea extract on fat oxidation or cycling performance , unlike caffeine , which did benefit cycling performance . The physiological responses observed during submaximal cycling after caffeine ingestion were similar to those reported previously , including an increase in heart rate  ( EGCG 147 + /- 17 , caffeine 146 + /- 19 , and placebo 144 + /- 15 beats/min ) , glucose at the 40-min exercise time point ( placebo 5.0 + /- 0.8 , EGCG 5.4 + /- 1.0 , and caffeine 5.8 + /- 1.0 mmol/L ) , and resting plasma free fatty acids and no change in the amount of carbohydrate and fat being oxidized . Therefore , it was concluded that green-tea extract offers no additional benefit to cyclists over and above those achieved by using caffeine BACKGROUND The obese insulin-resistant state is characterized by impairments in lipid metabolism . We previously showed that 3-d supplementation of combined epigallocatechin-3-gallate and resveratrol ( EGCG+RES ) increased energy expenditure and improved the capacity to switch from fat toward carbohydrate oxidation with a high-fat mixed meal ( HFMM ) test in men . OBJECTIVE The present study aim ed to investigate the longer-term effect of EGCG+RES supplementation on metabolic profile , mitochondrial capacity , fat oxidation , lipolysis , and tissue-specific insulin sensitivity . DESIGN In this r and omized double-blind study , 38 overweight and obese subjects [ 18 men ; aged 38 ± 2 y ; body mass index ( kg/m(2 ) ) : 29.7 ± 0.5 ] received either EGCG+RES ( 282 and 80 mg/d , respectively ) or placebo for 12 wk . Before and after the intervention , oxidative capacity and gene expression were assessed in skeletal muscle . Fasting and postpr and ial ( HFMM ) lipid metabolism was assessed by using indirect calorimetry , blood sampling , and microdialysis . Tissue-specific insulin sensitivity was assessed by a hyperinsulinemic-euglycemic clamp with [6,6-(2)H2]-glucose infusion . RESULTS EGCG+RES supplementation did not affect the fasting plasma metabolic profile . Although whole-body fat mass was not affected , visceral adipose tissue mass tended to decrease after the intervention compared with placebo ( P-time × treatment = 0.09 ) . EGCG+RES supplementation significantly increased oxidative capacity in permeabilized muscle fibers ( P-time × treatment < 0.05 , P-EGCG+RES < 0.05 ) . Moreover , EGCG+RES  reduced fasting ( P-time × treatment = 0.03 ) and postpr and ial respiratory quotient ( P-time × treatment = 0.01 ) compared with placebo . Fasting and postpr and ial fat oxidation was not significantly affected by EGCG+RES ( P-EGCG+RES = 0.46 and 0.38 , respectively ) but declined after placebo ( P-placebo = 0.05 and 0.03 , respectively ) . Energy expenditure was not altered ( P-time × treatment = 0.96 ) . Furthermore , EGCG+RES supplementation attenuated the increase in plasma triacylglycerol concentrations during the HFMM test that was observed after placebo ( P-time × treatment = 0.04 , P-placebo = 0.01 ) . Finally , EGCG+RES had no effect on insulin-stimulated glucose disposal , suppression of endogenous glucose production , or lipolysis . CONCLUSION Twelve weeks of EGCG+RES supplementation increased mitochondrial capacity and stimulated fat oxidation compared with placebo , but this did not translate into increased tissue-specific insulin sensitivity in overweight and obese subjects . This trial was registered at clinical trials.gov as NCT02381145 The inhibitory activity of tea against tumorigenesis has been demonstrated in many animal models and has been suggested by some epidemiological studies . Such activity has generally been attributed to tea catechins . To underst and the bioavailability of tea catechins in humans , we gave 18 individuals different amounts of green tea  and measured the time-dependent plasma concentrations and urinary excretion of  tea catechins .  After taking 1.5 , 3.0 , and 4.5 g of decaffeinated green tea solids ( dissolved in 500 ml of water ) , the maximum plasma concentration ( Cmax ) of (-)-epigallocatechin-3-gallate ( EGCG ) was 326 ng/ml , the Cmax of (-)-epigallocatechin ( EGC ) was 550 ng/ml , and the Cmax of (-)-epicatechin ( EC ) was 190 ng/ml . These Cmax values were observed at 1.4 - 2.4 h after ingestion of the tea preparation . When the dosage was increased from 1.5 to 3.0 g , the Cmax values increased 2.7 - 3.4-fold , but increasing the dose to 4.5 g did not increase the Cmax values significantly , which suggested a saturation phenomenon . The half-life of EGCG ( 5.0 - 5.5 h ) seemed to be higher than the half-life of EGC or EC ( 2.5 - 3.4 h ) . EGC and EC , but not EGCG , were excreted in the urine . Over 90 % of the total urinary EGC and EC was excreted within 8 h. When the tea dosage was increased , the amount of EGC and EC excretion seemed to increase , but a clear dose-response relationship was not observed . The present study provides basic pharmacokinetic parameters of green tea catechins in humans ; these parameters may be used to estimate the levels of these compounds after drinking tea Background Green tea was suggested as a therapeutic agent for the treatment of diabetes more than 70 years ago , but the mechanisms behind its antidiabetic effect remains elusive . In this work , we address this issue by feeding a green tea extract ( TEAVIGO ™ ) with a high content of epigallocatechin gallate ( EGCG ) or the thiazolidinedione PPAR-γ agonist rosiglitazone , as positive control , to db/db mice , an animal model for diabetes . Methods Young ( 7 week-old ) db/db mice were r and omized and assigned to receive diets supplemented with or without EGCG or rosiglitazone for 10 weeks . Fasting blood glucose , body weight and food intake was measured along the treatment . Glucose and insulin levels were determined during an oral glucose tolerance test after 10 weeks of treatment . Pancreata were sample d at the end of the study for blinded histomorphometric analysis . Islets were isolated and their mRNA expression analyzed by quantitative RT-PCR . Results The results show that , in db/db mice , EGCG  improves glucose tolerance and increases glucose-stimulated insulin secretion . EGCG supplementation reduces the number of pathologically changed islets of Langerhans , increases the number and the size of islets , and heightens pancreatic endocrine area . These effects occurred in parallel with a reduction in islet endoplasmic reticulum stress markers , possibly linked to the antioxidative capacity of EGCG . Conclusions This study shows that the green tea extract EGCG markedly preserves islet structure and enhances glucose tolerance in genetically diabetic mice . Dietary supplementation with EGCG could potentially contribute to nutritional strategies for the prevention and treatment of type 2 diabetes Nutrition and physical exercise can enhance cognitive function but the specific combinations of dietary bioactives that maximize pro-cognitive effects are not known nor are the contributing neurobiological mechanisms . Epigallocatechin-3-gallate ( EGCG ) is a flavonoid constituent of many plants with high levels found in green tea . EGCG has anti-inflammatory and anti-oxidant properties and is known to cross the blood brain barrier where it can affect brain chemistry and physiology . β-Alanine ( B-ALA ) is a naturally occurring β-amino acid that could increase cognitive functioning by increasing levels of exercise via increased capacity of skeletal muscle , by crossing the blood brain barrier and acting as a neurotransmitter , or by free radical scavenging in muscle and brain after conversion into carnosine . The objective of this study was to determine the effects of EGCG ( ~250mg/kg/day ) , B-ALA ( ~550mg/kg/day ) , and their combination with voluntary wheel running exercise on the following outcome measures : body composition , time to fatigue , production of new cells in the granule layer of the dentate gyrus of the hippocampus as a marker for neuronal plasticity , and behavioral performance on the context ual and cued fear conditioning tasks , as measures of associative learning and memory . Young adult male BALB/cJ mice approximately 2months old were r and omized into 8 groups varying the nutritional supplement in their diet and access to running wheels over a 39day study period . Running increased food intake , decreased fat mass , increased time to exhaustive fatigue , increased numbers of new cells in the granule layer of the hippocampus , and enhanced retrieval of both context ual and cued fear memories . The diets had no effect on their own or in combination with exercise on any of the fitness , plasticity , and behavioral outcome measures other than B-ALA decreased percent body fat whereas EGCG  increased lean body mass slightly . Results suggest that , in young adult BALB/cJ mice , a 39day treatment of exercise but not dietary supplementation with B-ALA or EGCG enhances measures of fitness , neuroplasticity and cognition BACKGROUND Epigallocatechin-3-gallate ( EGCG ) , which has been shown to have potent antioxidant effect , comprises 80 % of catechins in Chinese green tea . This study was to investigate whether cigarette smoke ( CS ) exposure would induce lung morphological changes and oxidative stress in the CS-exposed rat model , and whether Chinese green tea ( Lung Chen tea with EGCG as its main active ingredient ) consumption would alter oxidative stress in sera and lung leading to protection of CS-induced lung damage . METHODS Sprague-Dawley rats were r and omly divided into four groups , i.e. sham air ( SA ) , 4 % CS , 2 % Lung Chen tea plus SA or 4 % CS . Exposure to SA or 4 % CS was performed for 1h/day for 56 days in ventilated smoking chambers . Sera and lung tissues were collected 24h after last CS exposure for histology and all biochemical assays . RESULTS Airspace enlargement and goblet cell hyperplasia were observed after 56-day CS exposure alone , which were abolished in the presence of green tea consumption . Serum 8-isoprostane level was significantly elevated ( p<0.01 ) as well as lung superoxide dismutase ( SOD ) and catalase activities in CS-exposed rats compared to SA-exposed rats ( p<0.05 ) , which returned to the levels of SA-exposed rats after Chinese green tea consumption . CONCLUSION These results indicate that increased levels of systemic oxidative stress after CS exposure play an important role in the induction of lung damage . Chinese green tea may have the ability to suppress CS-induced oxidative stress that leads to protection of lung injury BACKGROUND Current interest in the role of functional foods in weight control has focused on plant ingredients capable of interfering with the sympathoadrenal system . OBJECTIVE We investigated whether a green tea extract , by virtue of its high content of caffeine and catechin polyphenols , could increase 24-h energy expenditure ( EE ) and fat oxidation in humans . DESIGN Twenty-four-hour EE , the respiratory quotient ( RQ ) , and the urinary excretion of nitrogen and catecholamines were measured in a respiratory chamber in 10 healthy men . On 3 separate occasions , subjects were r and omly assigned among 3 treatments : green tea extract ( 50 mg caffeine and 90 mg epigallocatechin gallate ) , caffeine ( 50 mg ) , and placebo , which they ingested at breakfast , lunch , and dinner . RESULTS Relative to placebo , treatment with the green tea extract result ed in a significant increase in 24-h EE ( 4 % ; P < 0.01 ) and a significant decrease in 24-h RQ ( from 0.88 to 0.85 ; P < 0.001 ) without any change in urinary nitrogen . Twenty-four-hour urinary norepinephrine excretion was higher during treatment with the green tea extract than with the placebo ( 40 % , P < 0.05 ) . Treatment with caffeine in amounts equivalent to those found in the green tea extract had no effect on EE and RQ nor on urinary nitrogen or catecholamines . CONCLUSIONS Green tea has thermogenic properties and promotes fat oxidation beyond that explained by its caffeine content per se . The green tea extract may play a role in the control of body composition via sympathetic activation of thermogenesis , fat oxidation , or both Purpose 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 . Methods In a r and omized 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 . Results 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 Tmax , 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 Ki values of 21.6 and 19.4 μM , respectively . Conclusions 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 Benifuuki is a tea cultivar with an antiallergic effect stronger than that of Yabukita tea , the most popular green tea cultivar consumed in Japan . The effective compound is (-)-epigallocatechin-3-O-(3-O-methyl)gallate ( EGCG3''Me ) , an O-methylated derivative of EGCG . This study examined the antihypertensive effects of EGCG3''Me and Benifuuki tea . First , it was determined that EGCG3''Me has a significant inhibitory effect on the activity of angiotensin I-converting enzyme ( ACE ) . Second , clinical trials showed that Benifuuki tea suppressed high blood pressure to a greater extent than green tea that did not contain EGCG3''Me after equal amounts of tea catechins were consumed for 8 weeks . The effect of Benifuuki tea on human hypertension is mainly the result of the strong inhibitory effect of EGCG3''Me on ACE activity , its high rate of absorption , and its stability in the blood Epidemiologic data support an inverse association between green tea intake and breast cancer risk .  Greenselect Phytosome ( GSP ) is a lecithin formulation of a caffeine-free green tea catechin extract . The purpose of the study was to determine the tissue distribution of epigallocatechin-3-O-gallate ( EGCG ) and its effect on cell proliferation and circulating biomarkers in breast cancer patients . Twelve early breast cancer patients received GSP 300 mg , equivalent to 44.9 mg of EGCG , daily for 4 weeks prior to surgery . The EGCG levels were measured before ( free ) and after ( total ) enzymatic hydrolysis by HPLC-MS/MS in plasma , urine , breast cancer tissue , and surrounding normal breast tissue . Fasting blood sample s were taken at baseline , before the last administration , and 2 hours later . Repeated administration of GSP achieved levels of total EGCG ranging from 17 to 121 ng/mL in plasma . Despite a high between-subject variability , total EGCG was detectable in all tumor tissue sample s collected up to 8 ng/g . Median total EGCG concentration was higher in the tumor as compared with the adjacent normal tissue ( 3.18 ng/g vs. 0 ng/g , P = 0.02 ) . Free EGCG concentrations ranged from 8 to 65.8 ng/mL in plasma ( P between last administration and 2 hours after < 0.001 ) . Free EGCG plasma levels showed a significant positive correlation with the Ki-67 decrease in tumor tissue ( P = 0.02 ) . No change in any other biomarkers was noted , except for a slight increase in testosterone levels after treatment . Oral GSP increases bioavailability of EGCG , which is detectable in breast tumor tissue and is associated with antiproliferative effects on breast cancer tissue . Cancer Prev Res ; 10(6 ) ; 363–9 . © 2017 AACR PURPOSE Green tea and green tea polyphenols have been shown to possess cancer preventive activities in pre clinical model systems . In preparation for future green tea intervention trials , we have conducted a clinical study to determine the safety and pharmacokinetics of green tea polyphenols after 4 weeks of daily p.o . administration of epigallocatechin gallate ( EGCG ) or Polyphenon E ( a defined , decaffeinated green tea polyphenol mixture ) . In an exploratory fashion , we have also determined the effect of chronic green tea polyphenol administration on UV-induced erythema response . EXPERIMENTAL DESIGN Healthy participants with Fitzpatric skin type II or III underwent a 2-week run-in period and were r and omly assigned to receive one of the five treatments for 4 weeks : 800 mg EGCG once/day , 400 mg EGCG twice/day , 800 mg EGCG as Polyphenon E once/day , 400 mg EGCG as Polyphenon E twice/day , or a placebo once/day  ( 8 subjects/group ) . Sample s were collected and measurements performed before and after the 4-week treatment period for determination of safety , pharmacokinetics , and biological activity of green tea polyphenol treatment . RESULTS Adverse events reported during the 4-week treatment period include excess gas , upset stomach , nausea , heartburn , stomach ache , abdominal pain , dizziness , headache , and muscle pain . All of the reported events were rated as mild events . For most events , the incidence reported in the polyphenol-treated groups was not more than that reported in the placebo group . No significant changes were observed in blood counts and blood chemistry profiles after repeated administration of green tea polyphenol products . There was a > 60 % increase in the area under the plasma EGCG concentration-time curve after 4 weeks of green tea polyphenol treatment at a dosing schedule of 800 mg once daily . No significant changes were observed in the pharmacokinetics of EGCG after repeated green tea polyphenol treatment at a regimen of 400 mg twice daily . The pharmacokinetics of the conjugated metabolites of epigallocatechin and epicatechin were not affected by repeated green tea polyphenol treatment . Four weeks of green tea polyphenol treatment at the selected dose and dosing schedule did not provide protection against UV-induced erythema . CONCLUSIONS We conclude that it is safe for healthy individuals to take green tea polyphenol products in amounts equivalent to the EGCG content in 8 - 16 cups of green tea once a day or in divided doses twice a day for 4 weeks . There is a > 60 % increase in the systemic availability of free EGCG  after chronic green tea polyphenol administration at a high daily bolus dose ( 800 mg EGCG or Polyphenon E once daily ) There have been no controlled intervention studies to investigate the effects of green tea on circulating hormone levels , an established breast cancer risk factor . We conducted a double-blind , r and omized , placebo-controlled intervention study to investigate the effect of the main green tea catechin , epigallocatechin gallate ( EGCG ) , taken in a green tea extract , polyphenon E ( PPE ) . Postmenopausal women ( n = 103 ) were r and omized into three arms : placebo , 400-mg EGCG as PPE , or 800-mg EGCG as PPE as capsules per day for 2 months . Urinary tea catechin and serum estrogen , and rogen , lipid , glucose-related markers , adiponectin , and growth factor levels were measured at baseline and at the end of months 1 and 2 of intervention . On the basis of urinary tea catechin concentrations , compliance was excellent . Supplementation with PPE did not produce consistent patterns of changes in estradiol ( E2 ) , estrone ( E1 ) , or testosterone ( T ) levels . Low-density lipoprotein (LDL)-cholesterol decreased significantly in both PPE groups but was unchanged in the placebo group ; the change in LDL-cholesterol differed between the placebo and PPE groups ( P = 0.02 ) . Glucose and insulin levels decreased nonsignificantly in the PPE groups but increased in the placebo group ; statistically significant differences in changes in glucose ( P = 0.008 ) and insulin ( P = 0.01 ) were found . In summary , green tea ( 400- and 800-mg EGCG as PPE ; ∼5–10 cups ) supplementation for 2 months had suggestive beneficial effects on LDL-cholesterol concentrations and glucose-related markers . Cancer Prev Res ; 5(3 ) ; 393–402 . © 2012 AACR Pre clinical , epidemiologic , and prior clinical trial data suggest that green tea catechins ( GTC ) may reduce prostate cancer risk . We conducted a placebo-controlled , r and omized 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 prostate cancer rates on the two study arms . No differences in the number of prostate cancer cases were observed : 5 of 49 ( PolyE ) versus 9 of 48 ( placebo ) , P = 0.25 . A secondary endpoint comparing the cumulative rate of prostate cancer plus ASAP among men with HGPIN without ASAP at baseline , revealed a decrease in this composite endpoint : 3 of 26 ( PolyE ) versus 10 of 25 ( placebo ) , P < 0.024 . This finding was driven by a decrease in ASAP diagnoses on the Poly E ( 0/26 ) compared with the placebo arm ( 5/25 ) . A decrease in serum prostate-specific antigen ( PSA ) was observed on the PolyE arm [ −0.87 ng/mL ; 95 % confidence intervals ( CI ) , −1.66 to −0.09 ] . Adverse events related to the study agent did not significantly differ between the two study groups . Daily intake of a st and ardized , 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 prostate cancer in men with baseline HGPIN or ASAP . Cancer Prev Res ; 8(10 ) ; 879–87 . © 2015 AACR The green tea extract AR25 is an 80 % ethanolic dry extract st and ardized at 25 % catechins expressed as epigallocatechin gallate ( EGCG ) . In vitro , green tea extract AR25 exerts a direct inhibition of gastric and pancreatic lipases and a stimulation of thermogenesis . In an open study , the effects of extract AR25 were evaluated in moderately obese patients . After 3 months , body weight was decreased by 4.6 % and waist circumference by 4.48 % . These results suggest the green tea extract AR25 to be a natural product for the treatment of obesity , which exerts its activity by several ways : inhibition of lipases and stimulation of thermogenesis Regular consumption of green tea may be cardioprotective . In the present study we investigated the health effects of dietary supplementation with green tea catechins and the potential modifying effect of the catechol-O-methyltransferase ( COMT ) Val/Met genotype . Subjects ( sedentary males , aged 40 - 69 years , with BMI ≥ 28 and ≤ 38 kg/m(2 ) ) were r and omly assigned to consume decaffeinated green tea extract ( DGT ; 530 mg containing about 400 mg total catechins/capsule , twice daily ) and placebo in a complete cross-over design . Ambulatory blood pressure and biomarkers of metabolic function ( cholesterol , TAG , glucose and insulin ) were measured at weeks 0 and 6 . Although a marked increase in the concentration of plasma epigallocatechin gallate ( EGCG ) , urinary epigallocatechin ( EGC ) and urinary 4'-O-methyl EGC was found after DGT treatment , no effect on blood pressure or biomarkers of metabolic function was observed . However , a period × treatment interaction ( P < 0·05 ) was detected for body-weight change . Despite a similar increase in estimated energy intake during intervention period 1 , body weight decreased by 0·64 ( sd 2·2 ) kg and increased by 0·53 ( sd 1·9 ) kg in the DGT and placebo groups , respectively ( P = 0·025 ) , suggesting a protective effect of green tea catechins on weight gain . Additionally , the COMT Val/Met genotype influenced urinary accumulation of EGC and 4'-O-methyl EGC ( P < 0·01 ) . Mean concentrations were lower in individuals homozygous for the high-activity G-allele , possibly reflecting increased metabolic flux and a more rapid conversion to downstream metabolic species , compared with individuals carrying at least one copy of the low-activity A-allele . Additional studies are needed to confirm these findings and further explore the modifying effect of genotype This study aim ed to investigate the effect of epigallocatechin-3-gallate ( EGCG ) from green tea extract on the push out bond strength of an epoxy resin sealer to root dentin . Seventy single root canal premolars were decoronated and instrumented . The roots were r and omly irrigated with different final irrigation protocol s ( n=16 ) : 17%EDTA ( EDTA ) , 17%EDTA followed by 2.5%NaOCl ( EDTA+NaOCl ) , 17%EDTA followed by 1 mg/mL EGCG ( EDTA+EGCG ) and 1 mg/mL EGCG ( EGCG ) . Other six root canals were received only 2.5%NaOCl as a control group . One root from each group ( n=1 ) was excluded and prepared for SEM investigation . All root canals were then obturated and horizontally sectioned to perform the push out test . EDTA+EGCG group had the highest bond strength ( p<0.05 ) . EGCG group showed higher bond strength than EDTA group ( p<0.05 ) . The use of EGCG as a final irrigant significantly increased the push out bond strength of an epoxy resin sealer to root dentin Green and black tea have shown promise in the chemoprevention of prostate cancer . The objective of this study was to determine the bioavailability and bioactivity of tea polyphenols ( PP ) and theaflavins in human serum and human and mouse tissues . A decaffeinated black tea diet was administered to C57BL/6 mice . PPs and theaflavins were found in the small and large intestine , liver , and prostate in conjugated and free forms . The relative prostate bioavailability of theaflavin was 70 % higher than that of epigallocatechin gallate ( EGCG ) . In the second mouse study , a green tea ( GT ) diet was administered followed by the control diet for 1 - 5 d. Epicatechin ( EC ) , EGCG , and epicatechin gallate ( ECG ) concentrations in prostate tissue were significantly decreased after 1 d of consuming the control diet . Epigallocatechin gallate ( EGC ) , however , did not decrease significantly . For the human study , 20 men scheduled for surgical prostatectomy were r and omly assigned to consume 1.42 L daily of GT , BT , or a caffeine-matched soda control ( SC ) for 5 d before radical prostatectomy . Tea PPs were greater in prostate sample s from men consuming BT and GT than in men consuming SC ( P = 0.0025 ) . Although tea PP were not detectable in serum , ex vivo LNCaP prostate cancer cell proliferation was less when cells were grown in media containing patient serum collected after BT ( P < 0.001 ) and GT ( P = 0.025 ) consumption relative to baseline serum This is the first human study to show that tea polyphenols and theaflavins are bioavailable in the prostate where they may be active in the prevention of prostate cancer The receptor for advanced glycation of end products ( RAGE ) plays a critical role in the progression of type 2 diabetes ( T2D ) . Soluble RAGE ( sRAGE ) is one of the RAGE variants , which acts as a decoy domain receptor and competes with RAGE , thus contributing to prevention of T2D . In this study , we conducted clinical trials of (-)-epigallocatechin-3-gallate ( EGCG ) rich green tea extract ( 300 - 900 mg/day ) to investigate the effect of EGCG on relationship between S100A12 RAGE lig and and diverse sRAGE in T2D . Moreover , mechanism of sRAGE production also confirmed in vitro . Our data indicated that EGCG could stimulate sRAGE circulation but inhibited RAGE lig and in T2D , and ADAM10-mediated ectodomain shedding of extracellular RAGE was mainly involved in EGCG-stimulated sRAGE circulation . The present evidence indicates that EGCG has a potential to block S100A12-RAGE axis by stimulating sRAGE production through ADAM10-mediated ectodomain shedding of extracellular RAGE . Therefore , EGCG contributes to nutritional strategies for diabetes , not only because of its efficient antioxidant activity to scavenge free radicals , but also because of its ability stimulating sRAGE release in the circulation . Additionally , ADAM10-induced ectodomain shedding of extracellular RAGE leading to sRAGE circulation should be a potential of passive mechanism of sRAGE production to block S100A12-RAGE axis-related pathogenesis of proinflammation and diabetes
Changes in FOX did not reach the level of statistical significance .
Finding showed that EGCG intake moderately accelerates EE and reduces RQ .
The analyses revealed that the EGCG result ed in difference in RQ and EE but the effect on the other measures of energy metabolism was relatively mild .
Possibly , EGCG alone has the potential to increase metabolic rate at 300 mg dose .
Collectively , the outcome supports the findings that EGCG has an effect on metabolic parameters .
Green tea catechins ( GTCs ) are known to improve fat oxidation ( FOX ) during fasted , rested and exercise conditions wherein epigallocatechin-3-gallate ( EGCG ) is thought to be the most pharmacologically active and has been studied extensively .
From the available data of r and omized controlled trials ( RCTs ) on EGCG , we carried out a systematic review and meta- analysis to eluci date whether EGCG consumption indeed increase energy expenditure ( EE ) and promote FOX .