Effect on the epigallocatechin gallate/epigallocatechin ratio in a green tea (Camellia sinensis L.) extract of different extraction temperatures and its effect on IgA production in mice

We found that the epigallocatechin gallate (EGCG)/epigallocatechin (EGC) ratio in a green tea (Camellia sinensis L.) extract was affected by the extraction temperature. The EGCG/EGC ratio in the 4 °C extract was around 1:3-4, whereas in the 100 °C extract, it was around 1:0.7. Oral administration of the mixture with a high EGC ratio (1:2-3 = EGCG/EGC) resulted in greater IgA production by murine Peyer's patch cells.     

Inhibitory Effects of Persimmon (Diospyros kaki) Extract and Related Polyphenol Compounds on Growth of Human Lymphoid Leukemia Cells

We have investigated the effects of persimmon (Diospyros kaki) extract (PS) and related polyphenol compounds such as catechin (C), epicatechin (EC), epicatechingallate (ECG), epigallocatechin (EGC), and epigallocatechingallate (EGCG) on the growth of human lymphoid leukemia Molt 4B cells. We found that PS, ECG, EGC, and EGCG strongly inhibited the growth of the cells in a dose-dependent manner, while C and EC inhibited the growth of the cells only moderately. Ornithine decarboxylase (ODC), a rate-limiting enzyme of polyamine biosynthesis, was inhibited by 10–20% by these polyphenol compounds. The morphology of the Molt 4B cells indicated severe damage 3 days after treatment with PS, ECG, EGC, and EGCG. Irregular shape of the cells and DNA fragmentation were observed in PS, ECG, EGC, or EGCG-treated cells. These results suggest that PS, ECG, EGC, and EGCG induce apoptosis (programmed cell death) of Molt 4B cells.     

Structure-activity relationship of the tocopherol-regeneration reaction by catechins

The reaction rates (k(r)) of 5,7-diisopropyl-tocopheroxyl radical (Toc) with catechins (epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), epigallocatechin gallate (EGCG)) and related compounds (methyl gallate (MG), 4-methylcatechol (MC), and 5-methoxyresorcinol (MR)) have been measured by stopped-flow spectrophotometer. The k(r) values increased in the order of MR < < MG < EC < MC approximately ECG < EGC < EGCG in ethanol and 2-propanol/H(2)O (5/1, v/v) solutions, indicating that the reactivity of the OH groups in catechins increased in the order of resorcinol A-ring < < gallate G-ring < catechol B-ring < pyrogallol B-ring. The catechins which have lower oxidation potentials show higher reactivities. The rate constants for catechins in micellar solution showed notable pH dependence with one or two peaks around pH 9-11, because of the dissociation of various phenolic hydroxyl protons in catechins. The structure-activity relationship in the free-radical-scavenging reaction by catechins has been clarified by the detailed analyses of the pH dependence of k(r) values. The reaction rates increased remarkably with increasing the anionic character of catechins, that is, the electron-donating capacity of catechins. The mono anion form at catechol B-and resorcinol A-rings and dianion form at pyrogallol B-and gallate G-rings show the highest activity for free-radical-scavenging. It was found that catechins (EC, ECG, EGC, and EGCG) have activity similar to or higher than that of vitamin C in vitamin E regeneration at pH 7-12 in micellar solution.     

Effect of epigallocatechin gallate on growth performance and antioxidant capacity in heat-stressed broilers

This study investigated the effects of epigallocatechin gallate (EGCG) on the growth performance and antioxidant capacity of 35-d-old broilers exposed to heat stress. Broilers, 14 d of age, were divided into four groups with six replicates per group (eight chickens/replicate). Thermoneutral group (Group TN) was fed the basal diet and maintained at 28°C for 24 h/d. The heat-stressed groups were housed at 35°C for 12 h/d and 28°C for 12 h/d and fed the basal diet supplemented with EGCG at 0, 300 and 600 mg/kg diet (Groups HS0, HS 300 and HS600, respectively). Compared with Group TN, heat-stressed groups showed significantly reduced gain, feed intake and serum total protein and glucose levels; inhibited serum alkaline phosphatase activities; and increased serum levels of uric acid, cholesterol and triglycerides and the activity of serum creatine kinase, lactate dehydrogenase and aspartate aminotransferase (p < 0.05). Compared with Group HS0, Group HS600 exhibited an increased gain and feed intake; and normalised blood parameters and enzyme activities. Compared with Group TN, the expression of antioxidant-related liver proteins was decreased in Group HS0 and increased in Groups HS300 and HS600 (p < 0.05). The results suggest that EGCG can improve the growth performance and alleviate the oxidant damage by modulating the antioxidant properties of broilers.     

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

BackgroundThe 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.MethodsThe 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.ResultsThe 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.ConclusionCognitive 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.     

Catechins delay lipid oxidation and alpha-tocopherol and beta-carotene depletion following ascorbate depletion in human plasma

Blood plasma was incubated with 50 mM AAPH [2, 2'-azobis-(2-amidinopropane) hydrochloride] in the absence or presence of catechins (5-100 microM). Lipid oxidation was evaluated by measuring the formation of 2-thiobarbituric acid reactive substances (TBARS). The concentration of alpha-tocopherol (AT), beta-carotene (BC), ascorbic acid (AA), and catechins was determined by reverse phase high performance liquid chromatography (HPLC) with electrochemical detection. All the assayed catechins inhibited plasma TBARS formation. Based on the calculated IC50, the order of effectiveness was: epicatechin gallate (ECG) > epigallocatechin gallate (EGCG) > epigallocatechin (EGC) > epicatechin (EC) > catechin (C). Catechins protected plasma AT and BC from AAPH-mediated oxidation. The order of effectiveness for AT protection was ECG > EGCG > EC = C > EGC; and for BC protection, the order was EGCG > ECG > EGC > > EC > C. The addition of catechins modified the kinetics of TBARS formation and AT depletion, but the rate of AA depletion was not affected. Catechin oxidation did not start until the complete depletion of AA, and it preceded AT depletion. These results indicate that catechins are effective antioxidants in human blood plasma, delaying the lipid oxidation and depletion of endogenous lipid-soluble antioxidants (AT and BC).     

Enhancement of phagocytic activity of macrophage-like cells by pyrogallol-type green tea polyphenols through caspase signaling pathways

We investigated the phagocytosis-enhancing activity of green tea polyphenols, such as epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG), epicatechin (EC) catechin (+C) and strictinin, using VD3-differentiated HL60 cells. EGCG, EGC, ECG and strictinin, but not EC and +C, increased the phagocytic activity of macrophage-like cells, and a caspase inhibitor significantly inhibited phagocytic activities. These results suggest that the pyrogallol-type structure in green tea polyphenols may be important for enhancement of the phagocytic activity through caspase signaling pathways.     

Inhibition of interleukin-1beta-stimulated collagenase and stromelysin expression in human tendon fibroblasts by epigallocatechin gallate ester.

The medicinal benefits of green tea (Camellia sinensis) consumption have been attributed to bioavailable polyphenols, notably epigallocatechin gallate (EGCG). We have assessed the effects of EGCG and its non-esterified counterpart EGC on the expression of the collagenases, matrix metalloproteinases (MMP)-1 and -13, and the stromelysin, MMP-3, in human tendon-derived fibroblasts. Interleukin (IL)-1beta increased MMP-1, -3 and -13 mRNA and output at least 30-fold. EGCG reduced this stimulation, by 20-30% at 2.5 microM and more than 80% at 25 microM, and had a smaller effect on MMP-2 mRNA expression, which was not stimulated by IL-1beta. In all experiments EGCG was at least 10-fold more potent than EGC. EGCG reduced the stimulation of p54 JNK/SAPK phosphorylation by IL-1beta but did not affect p38 MAPK phosphorylation, the degradation of IkappaB or the activating phosphorylation of NFkappaB. We conclude that EGCG reduces the IL-1-stimulated expression of both collagenase and stromelysin mRNA species, an effect which may be mediated by inhibition of the JNK/SAPK pathway. Taken together with previous reports of EGCG effects on the expression and/or activity of gelatinases and aggrecanases, our results underline the importance of extracellular matrix breakdown as a potential target for the actions of green tea polyphenols.     

Green tea decoction improves glucose tolerance and reduces weight gain of rats fed normal and high-fat diet

Green tea containing polyphenols exerts antidiabetic and antiobesity effects, but the mechanisms involved are not fully understood. In this study, we first analyzed and compared polyphenol compounds [epigallocatechin gallate (EGCG), epigallocatechin (EGC)] in decoction of green tea leaves versus usual green tea extracts. Second, the effects of acute (30 min) or chronic (6 weeks) oral administration of green tea decoction (GTD) on intestinal glucose absorption were studied in vitro in Ussing chamber, ex vivo using isolated jejunal loops and in vivo through glucose tolerance tests. Finally, we explore in rat model fed normal or high-fat diet the effects of GTD on body weight, blood parameters and on the relative expression of glucose transporters SGLT-1, GLUT2 and GLUT4. GTD cooked for 15 min contained the highest amounts of phenolic compounds. In fasted rats, acute administration of GTD inhibited SGLT-1 activity, increased GLUT2 activity and improved glucose tolerance. Similarly to GTD, acute administration of synthetic phenolic compounds (2/3 EGCG+1/3 EGC) inhibited SGLT-1 activity. Chronic administration of GTD in rat fed high-fat diet reduced body weight gain, circulating triglycerides and cholesterol and improved glucose tolerance. GTD-treated rats for 6 weeks display significantly reduced SGLT-1 and increased GLUT2 mRNA levels in the jejunum mucosa. Moreover, adipose tissue GLUT4 mRNA levels were increased. These results indicate that GTD, a traditional beverage rich in EGCG and EGC reduces intestinal SGLT-1/GLUT2 ratio, a hallmark of regulation of glucose absorption in enterocyte, and enhances adipose GLUT4 providing new insights in its possible role in the control of glucose homeostasis.     

Dietary supplementation of a high-temperature-processed green tea extract attenuates cognitive impairment in PS2 and Tg2576 mice

ABSTRACT

Green tea intake is generally recognized as an effective supplement that promotes mental clarity and cognitive function. These health benefits of green tea have been attributed mainly to its effective component, epigallocatechin gallate (EGCG). Because various catechin derivatives potently enhance these health benefits, we manipulated the extraction process with a high-temperature intervention. High-temperature-processed green tea extract (HTP-GTE) showed an elevated proportion of gallocatechin gallate (GCG) content. To investigate the preventive effects of HTP-GTE on cognitive decline, we found its neuroprotective effects against amyloid β (Aβ)-induced neurotoxicity in neurons and clarified that GCG significantly inhibited Aβ aggregation in vitro. Moreover, we showed that HTP-GTE intake attenuated several cognitive-decline phenotypes in a model mouse of Alzheimer’s disease. These beneficial effects of HTP-GTE against cognitive decline were due to the distinctive composition of the extract and suggest the possibility that HTP-GTE supplementation could attenuate cognitive decline of Alzheimer’s disease.     

Inhibition by green tea catechins of metabolic activation of procarcinogens by human cytochrome P450

Catechins, major polyphenol constituents of green tea, are potent chemopreventive agents against cancers caused by chemical carcinogens in rodents. The effects of four epicatechin derivatives, epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epigallocatechin (EGC) and epicatechin (EC), on the metabolic activation of benzo[a]pyrene (B[a]P), 2-amino-1-methyl-6-phenylimidazo-[4,5-b]pyridine (PhIP) and aflatoxin B(1) (AFB(1)) by human cytochrome P450 (CYP) were examined. B[a]P, PhIP and AFB(1) were activated by respective human CYP1A1, CYP1A2 and CYP3A4 expressed in the membrane fraction of genetically engineered Salmonella typhimurium (S. typhimurium) TA1538 cells harboring the human CYP and human NADPH-CYP reductase (OR), when the membrane fraction was added to S. typhimurium TA98. Galloylated catechins, ECG and EGCG inhibited the mutagenic activation potently, while EGC and EC showed relatively weak inhibitory effects. Catechins also inhibited the oxidations of typical substrates catalyzed by human CYPs, namely ethoxycoumarin O-deethylation by CYP1A1, ethoxyresorufin O-deethylation by CYP1A2 and midazolam 1'-hydroxylation by CYP3A4. The IC(50) values of catechins for the inhibition of human CYP were roughly the same as those seen in the mutagenic activation. EGCG inhibited other forms of human CYP such as CYP2A6, CYP2C19 and CYP2E1, indicating the non-specific inhibitory effects of EGCG toward human CYPs. Furthermore, EGCG inhibited human NADPH-cytochrome CYP reductase (OR) with a K(i) value of 2.5 microM. These results suggest that the inhibition of the enzyme activity of CYP is accounted for partially by the inhibition of OR.     

Dose-dependent Incorporation of Tea Catechins, (–)-Epigallocatechin-3-gallate and (–)-Epigallocatechin,into Human Plasma

Tea catechins, (–)-epigallocatechin-3-gallate (EGCg) and (–)-epigallocatechin (EGC), have been reported to suppress oxidation of plasma low density lipoprotein (LDL) in vitro. If dietary catechins can be efficiently incorporated into human blood plasma, anti-atherosclerotic effects in preventing oxidative modification of LDL would be expected. In this study, a newly developed chemiluminescence detection-high pressure liquid chromatography (CL-HPLC) method for measuring plasma catechins was used and the incorporation of EGCg and EGC into human plasma was investigated. Healthy subjects orally ingested 3, 5, or 7 capsules of green tea extract (corresponding to 225, 375, and 525 mg EGCg and 7.5, 12.5, and 17.5 mg EGC, respectively). The plasma EGCg and EGC concentrations before the administration were all below the detection limit (< 2 pmol/ml), but 90 min after, significantly and dose-dependently increased to 657, 4300, and 4410 pmol EGCg/ml, and 35, 144, and 255 pmol EGC/ml, in the subjects who received 3, 5, and 7 capsules, respectively. Both EGCg and EGC levels detected in plasma corresponded to 0.2–2.0% of the ingested amount. Catechin intake had no effect on the basal level of endogenous antioxidants (α-tocopherol, β-carotene, and lycopene) or of lipids in plasma. These results suggested that drinking green tea daily would contribute to maintain plasma catechin levels sufficient to exert antioxidant activity against oxidative modification of lipoproteins in blood circulation systems.     

Modulation of tea and tea polyphenols on benzo(a)pyrene-induced DNA damage in Chang liver cells

The protective effects of three tea extracts (green tea, GTE; oolong tea, OTE; and black tea, BTE) and five tea polyphenols (epicatechin, EC; epicatechin gallate, ECG; epigallocatechin, EGC; epigallocatechin gallate, EGCG; and theaflavins, THFs) on benzo[a]pyrene (B[a]P)-induced DNA damage in Chang liver cells were evaluated using the comet assay. B[a]P-induced DNA damage in Chang liver cells was significantly (p < 0.05) inhibited by GTE and OTE at a concentration of 10 microg/ml and by BTE at 25 microg/ml. At a concentration of 100 microg/ml, the % tail DNA was reduced from 33% (B[a]P treated only) to 10, 9, 13%, by GTE, OTE and BTE, respectively. EC and ECG did not cause DNA damage in cells according to the results of the comet assay; however, EGC, EGCG and theaflavins caused DNA damage in cells at a concentration of 100 microM. The results indicated that EC and ECG had protective effects against B[a]P-induced DNA damage in cells at a concentration of 10-100 microM. Although EGC, EGCG and the theaflavins caused DNA damage at a high concentration, but they had protective effects against B[a]P-induced DNA damage in cells at a low concentration of 10-50 microM. The results also showed that the DNA damage in cells induced by EGC, EGCG, and the theaflavins was due to the generation of superoxide during incubation with cells at a higher concentration. Therefore, tea catechins and THFs play an important role in enabling tea extracts to inhibit DNA damage in Chang liver cells.     

Procyanidin dimer B1 and trimer C1 impair inflammatory response signalling in human monocytes

Abstract

The way specific procyanidins exert their anti-inflammatory effects is not fully understood. This study has investigated the capacity of different procyanidins to modulate lipopolysaccharide (LPS)-induced reactive oxygen species (ROS) production in THP1 human monocytes and their effects on the redox regulated protein kinases activity: IkB kinase beta (IKKb) and the extracellular signal-regulated kinase (ERK). LPS-triggered increase of ROS was prevented by cell pre-incubation with procyanidins. LPS induced ERK1/2 activation through phosphorylation, which was inhibited by all the compounds tested, the most active being epigallocatechin (EG), followed by epigallocatechin gallate (EGCG) and C1. Procyanidins inhibited IKKb activity in vitro. C1 and procyanidin extract (PE) exerted the maximal IKKb inhibition, followed by EGCG and dimer B1. Catechin exerted a slight but significant IKKb inhibition, in contrast to epicatechin, which was ineffective. In conclusion, procyanidins reduce the LPS-induced production of ROS and they exert their anti-inflammatory effects by inhibiting ERK1/2 and IKKb activity.     

Epigallocatechin gallate protects U937 cells against nitric oxide-induced cell cycle arrest and apoptosis

Ingesting phenolic phytochemicals in many plant products may promote health, but the effects of phenolic phytochemicals at the cellular level have not been fully examined. Thus, it was determined if the tea phenolic phytochemical, epigallocatechin gallate (EGCG), protects U937 human pro-monocytic cells against the nitrogen free radical, nitric oxide (*NO). Cells were incubated for 4-6 h with 500 microM S-nitrosoglutathione (GSNO), which generates *NO, but this did not induce single-strand breaks in DNA. Nevertheless, 82 +/- 4% of GSNO-treated cells, compared to only 39 +/- 1% of untreated cells, were arrested in the G(1)-phase of the cell cycle. However, dosing the GSNO-treated cells with 9, 14, or 18 microg/ml of EGCG resulted in only 74 +/- 8%, 66 +/- 1%, and 43 +/- 3% of the cells, respectively, in the G(1)-phase. Exposing cells to GSNO also resulted in the emergence of a sub-G(1) apoptotic cell population numbering 14 +/- 3%, but only 5 +/- 2%, 5 +/- 1%, and 2 +/- 0% upon dosing of the GSNO-treated cells with 9, 14, and 18 microg/ml of EGCG, respectively. Furthermore, exposing cells to GSNO resulted in greater cell surface binding of annexin V-FITC, but binding was 41-89% lower in GSNO-treated cells dosed with EGCG. Collectively, these data suggest that *NO or downstream products induced cell cycle arrest and apoptosis that was not due to single-strand breaks in DNA, and that EGCG scavenged cytotoxic *NO or downstream products, thus reducing the number of cells in a state of cell cycle arrest or apoptosis.     

人工接种冠突散囊菌对白茶主要呈味物质的影响

本文为了排除其他微生物的干扰,首次以人工接种的方式研究了冠突散囊菌Eurotium cristatum对白茶主要呈味物质的作用。采用高效液相色谱、分光光度计等方法,分析表明冠突散囊菌能够显著降低白茶中呈苦涩味的表没食子儿茶素没食子酸酯（EGCG）和表儿茶素没食子酸酯（ECG）,并提高表没食子儿茶素（EGC）、Asp、His、咖啡碱和山奈酚的含量;灭菌压制的过程中EGCG可能异构化成为更稳定的没食子儿茶素没食子酸酯（GCG）,且二者以相近的含量共存。冠突散囊菌可以降低人工发花白茶饼中呈苦涩味的化合物含量,从而达到减少白茶饼苦涩味的效果;灭菌压制过程也能够降低白茶饼的苦涩味物质的含量。“发花”处理为白茶带来了新的风味,可以丰富白茶产品种类,同时为促进粗老原料白茶的综合利用提供新思路。     

Antibacterial Substances in Japanese Green Tea Extract against Streptococcus mutans,a Cariogenic Bacterium

An extract of Japanese green tea, one of the most popular drinks in Japan, was an inhibitor of the growth of Streptococcus mutans, a bacterium responsible for causing dental caries. The analysis of the extract revealed that the main antibacterial components of the extract were several polyphenolic compounds, especially gallocatechin (GC), epigallocatechin (EGC), and epigallocatechin gallate (EGCg). GC was the most active component and its minimum inhibitory concentration against the bacterium was around 250 μg per ml.     

Enzymatic production of epigallocatechin by using an epigallocatechin gallate hydrolase induced from Aspergillus oryzae

Catechins are a group of polyphenolic compounds that are antioxidants having beneficial biological activities. There are four main catechins in green tea, and each has its own biological features. In order to fully exploit prominent biological activities of specific catechins and to develop new medicine from catechins, it is necessary to obtain pure catechin preparations by isolation from natural sources, by chemical synthesis, or by biotransformation reactions with high yield and specificity. In this study epigallocatechin gallate (EGCG) can be hydrolyzed to epigallocatechin (EGC) by a hydrolase from Aspergillus oryzae after induction by addition of EGCG to the cultures. However, cultures without EGCG induction did not show any EGCG hydrolysis activity. The yield of EGC could reach at least 70%. Thin layer chromatography and high performance liquid chromatography were applied to separate and quantify EGCG and EGC.     

Radical chemistry of epigallocatechin gallate and its relevance to protein damage

The radical chemistry of the plant polyphenolics epigallocatechin gallate (EGCG) and epigallocatechin (EGC) were investigated using electron paramagnetic resonance spectroscopy. Radical species formed spontaneously in aqueous solutions at low pH without external oxidant and were spin stabilized with Zn(II). The spectra were assigned to the gallyl radical and the anion gallyl radical, with only 10% of the signal assigned to a radical from the galloyl ester. Spectral simulations were used to establish a pK(a) of 4.8 for the EGCG radical and a pK(a) of 4.4 for the EGC radical. The electrochemical redox potentials of EGCG and EGC varied from 1000 mV at pH 3 to 400 mV at pH 8. The polyphenolics did not produce hydroxyl radicals unless reduced metal ions such as iron(II) were added to the system. Zinc(II)-stabilized EGCG radicals were more effective protein-precipitating agents than unoxidized EGCG and produced irreversibly complexed protein. EGCG and other naturally occurring polyphenolics are effective radical scavengers but their radical products have the potential to damage biological molecules such as proteins.     

(-)-Epigallocatechin-3-gallate Inhibits Pancreatic Lipase and Reduces Body Weight Gain in High Fat-Fed Obese Mice

Tea (Camellia sinensis, Theaceae) has been shown to have obesity preventive effects in laboratory studies. We hypothesized that dietary epigallocatechin‐3‐gallate (EGCG) could reverse metabolic syndrome in high fat‐fed obese C57bl/6J mice, and that these effects were related to inhibition of pancreatic lipase (PL). Following treatment with 0.32% EGCG for 6 weeks, a 44% decrease in body weight (BW) gain in high fat‐fed, obese mice (P < 0.01) was observed compared to controls. EGCG treatment increased fecal lipid content by 29.4% (P < 0.05) compared to high fat‐fed control, whereas in vitro, EGCG dose‐dependently inhibited PL (IC₅₀ = 7.5 µmol/l) in a noncompetitive manner with respect to substrate concentration. (?)?Epicatechin‐3‐gallate exhibited similar inhibitory activity, whereas the nonester‐containing (?)?epigallocatechin did not. In conclusion, EGCG supplementation reduced final BW and BW gain in obese mice, and some of these effects may be due to inhibition of PL by EGCG.