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We investigated the combined effects of 'Benifuuki,' a tea cultivar that contains O-methylated catechins like epigallocatechin-3-O-(3-O-methyl) gallate, and quercetin on hepatic fat accumulation in male Sprague-Dawley rats fed a high-fat, high-cholesterol diet for 15 d. Rats given 'Benifuuki'+quercetin had synergistically lower liver triglyceride (TG) level compared with rats given 'Benifuuki' or quercetin alone. Compared with 'Benifuuki' or quercetin alone, supplementation with 'Benifuuki'+quercetin resulted in a low level of fatty acid synthase (FAS) and stearoyl-CoA desaturase1 (SCD1) gene expression levels. These results suggest that the combination of 'Benifuuki' and quercetin has greater liver lipid-lowing effects than that of 'Benifuuki' or quercetin alone. The liver TG-lowing effect of combination of 'Benifuuki' with quercetin may be partially mediated by the suppression of lipogenesis. The combination of 'Benifuuki' and quercetin suppresses hepatic fat accumulation in high fat high cholesterol diet fed rats, showing a new trend of 'Benifuuki' as synergist with quercetin.

Green tea and its major polyphenol epigallocatechin-3-O-gallate (EGCG) have suppressive effect on dietary obesity. However, it remains unsolved what type of diet on which they exhibit high or low anti-obesity effect. In the present study, we investigated whether anti-obesity effect of green tea differs depending on composition of fats or fatty acids that consist high-fat (HF) diet in mouse model. Green tea extract (GTE) intake dramatically suppressed weight gain and fat accumulation induced by olive oil-based HF diet, whereas the effects on those induced by beef tallow-based HF diet were weak. GTE also effectively suppressed obesity induced by unsaturated fatty acid-enriched HF diet with the stronger effect compared with that induced by saturated fatty acid-enriched HF diet. These differences would be associated with the increasing action of GTE on expression of PPARδ signaling pathway-related genes in the white adipose tissue. Expressions of genes relating to EGCG signaling pathway that is critical for exhibition of physiological effects of EGCG were also associated with the different effects of GTE. Here, we show that anti-obesity effect of GTE differs depending on types of fats or fatty acids that consist HF diet and could be attenuated by saturated fatty acid.

We conducted a systematic review of the literature for the ability of green tea epigallocatechin gallate (EGCG) to lower low-density lipoprotein cholesterol (LDL-C). Study subjects were limited to healthy individuals and randomized, controlled trials on human serum lipid levels, especially LDL-C, conducted. A total of 17 trials (n = 1356) met all of the inclusion criteria. According to weighted mean differences for changes from baseline with 95% confidence intervals (CI), 107-856 mg/d of EGCG for 4 to 14 weeks reduced LDL-C by -9.29 mg/dl (95% CI, -12.27 to -6.31). Sub-analysis was performed to compare the EGCG lowering effect on LDL-C between non-obese and obese subjects, EGCG dose, baseline of LDL-C levels, or BMI. We concluded that consumption of green tea EGCG resulted in a significant reduction of LDL-C at any baseline level and any dose between 107 and 856 mg/d, and the effect size was slightly dependent on the baseline lipid level of the subjects.

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.

Seven new O-methylated theaflavins (TFs) were synthesized by using O-methyltransferase from an edible mushroom. Using TFs and O-methylated TFs, metabolic stability in pooled human liver S9 fractions and inhibitory effect on H(2)O(2)-induced oxidative damage in human HepG2 cells were investigated. In O-methylation of theaflavin 3'-O-gallate (TF3'G), metabolic stability was potentiated by an increase in the number of introduced methyl groups. O-methylation of TF3,3'G did not affect metabolic stability, which was likely because of a remaining 3-O-galloyl group. The inhibitory effect on oxidative damage was assessed by measuring the viability of H(2)O(2)-damaged HepG2 cells treated with TFs and O-methylated TFs. TF3,3'G and O-methylated TFs increased cell viabilities significantly compared with DMSO, which was the compound vehicle (p < 0.05), and improved to approximately 100%. Only TF3'G did not significantly increase cell viability. It was suggested that the inhibitory effect on H(2)O(2)-induced oxidative damage was potentiated by O-methylation or O-galloylation of TFs.

A known O-methylated theaflavin, theaflavin 3-O-(3-O-methyl)gallate (3MeTF3G), and the new theaflavin 3-O-(3,5-di-O-methyl)gallate (3,5diMeTF3G) were synthesized via the O-methylation of theaflavin 3-O-gallate (TF3G). Both 3MeTF3G and 3,5diMeTF3G are more stable than TF3G at pH 7.5 in the order 3,5diMeTF3G > 3MeTF3G > TF3G. The inhibitory effects of these compounds on the intracellular accumulation of triglycerides from terminally differentiated human visceral adipocytes were investigated. Compound 3MeTF3G exhibited an inhibitory effect similar to that of TF3G at 3 μM and a slightly lower effect than that of TF3G at 10 μM. The result suggested that the degradants and oxidatively polymerized products of TF3G may also have inhibitory effects. For cells treated with 3,5diMeTF3G at 3 and 10 μM, intracellular triglyceride accumulation was dose dependent and significantly lower compared with that for other compounds. It was suggested that the higher effect of 3,5diMeTF3G was due to its higher stability and likely improved absorption owing to di-O-methylation.

Japan is a major tea producing country, and green tea is known for its health benefits which are believed to be due to catechins. However, difficulties in maintaining an adequate amount of catechins in the blood have been reported. Another important health-promoting activity among the Japanese is bathing in hot springs. This pilot study examined whether the combined effects of green tea consumption and hot spring bathing improved absorption of green tea catechins. The study, with a comparative within-subject design involving two different intervention trials--green tea consumption with hot spring bathing and only green tea consumption--was conducted on 2 separate days. Plasma levels of catechin; (-)-epigallocatechin-3-O-gallate (EGCG) were analyzed from four volunteers. Plasma EGCG concentration was found to be higher for the combined trial of green tea consumption and hot spring bathing., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

We investigated the effects of extracts of Benifuuki (a tea cultivar that contains methylated catechins such as epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3"Me)) in mice fed a high-fat/high-sucrose (HF/HS) diet. This tea cultivar was then compared with an extract of Yabukita (a popular tea cultivar that lacks methylated catechins). For 6 weeks, C57BL/6J mice were fed either HF/HS diet with or without tea extracts from tea cultivars, which contained almost identical ingredients except for methylated catechins (i.e., Yabukita (0.2% and 1%) or Benifuuki (0.2% and 1%) extract powders). Supplementation with Benifuuki 0.2% markedly lowered plasma levels of TG and NEFAs compared with mice supplemented with Yabukita 0.2%. The diet containing Benifuuki 1% decreased adipose tissue weights, liver TG, and expression of lipogenic genes in the liver. These results suggested that Benifuuki had much greater lipid-lowering effects than Yabukita. Taken together, these data suggest that methylated catechins direct the strong lipid-lowering activity of Benifuuki.

Delphinidin-3-O-galactoside (D3G) is a water-soluble anthocyanin with antioxidant activity. (-)-Epigallocatechin-3-gallate (EGCG) is also known as a powerful antioxidant but concomitantly possesses a prooxidative property. We hypothesized that D3G is capable of protecting the EGCG-induced cytotoxicity and endoplasmic reticulum (ER) stress via inducing self-protective proteins and antioxidant enzymes. (-)-Epigallocatechin-3-gallate (200-500 μM) dose dependently decreased the viability of hepa1c1c-7 mouse hepatocytes, whereas D3G (50-500 μM) did not change it. Pretreatment with D3G significantly suppressed EGCG-induced cytotoxicity in a time-dependent manner (0, 6, and 24 hours). (-)-Epigallocatechin-3-gallate drastically decreased heme oxygenase-1 and heat shock protein 70 messenger RNA (mRNA) levels, whereas, pretreatment with D3G markedly attenuated their down-regulations. Delphinidin-3-O-galactoside remarkably decreased EGCG-induced ER stress responses such as C/EBP-homologus protein mRNA expression and X-box-binding protein-1 mRNA splicing. Taken together, our data suggest that D3G is capable of masking the EGCG-induced cytotoxicity and ER stress, presumably through up-regulation of antioxidant enzymes and heat shock proteins., (Copyright © 2012 Elsevier Inc. All rights reserved.)

We attempted to improve the bioavailability of green tea catechins by using food ingredients. The catechin bioavailability of a green tea extract administered to mice was significantly (p<0.05) increased by supplementing with steamed rice. This enhanced bioavailability was due to the increased concentration of plasma non-gallated catechins, especially epigallocatechin (EGC).

The gene of a novel O-methyltransferase was isolated from tea cultivars (Camellia sinensis L.). Using the recombinant enzyme, O-methylated (-)-epigallocatechin-3-O-gallate (EGCG) in all cases were synthesized. EGCG and the synthesized O-methylated EGCGs including (-)-epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG3''Me), (-)-epigallocatechin-3-O- (4-O-methyl)-gallate(EGCG4''Me), (-)-epigallocatechin-3-O-(3,5-O-dimethyl)-gallate (EGCG3'',5''diMe), and (-)-3-O-methyl-epigallocatechin-3-O-(3,5-O-dimethyl)-gallate (EGCG3',3'',5''triMe) were assayed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and antibacterial activity. EGCG was the most effective of the O-methylated EGCGs. The antiallergic effects of EGCG and the other O-methylated EGCGs were measured by conducting histamine release assays using bone marrow-derived mouse mast cells, and the order of potency was EGCG3',3'',5''triMe = EGCG3'',5''diMe > EGCG3''Me > EGCG. These results indicated that reducing the number of hydroxyl groups decreases the effectiveness of DPPH radical scavenging and antibacterial activity. In contrast, the inhibition of histamine release was potentiated by an increase in the number of methyl groups in EGCG, especially in the galloyl moiety.

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.

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.

Background: 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., Methods: 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., Results: 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., Conclusions: 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.

Green tea extract is well-known to reduce the risk of a variety of diseases. Here, we investigated the immunostimulating activity of tea polysaccharide (TPS), one of the main components in green tea extract. The water extracts from mature or immature tea leaves were precipitated by using ethanol at room temperature. The sediment was washed with ethanol and acetone alternately and then dried. We used the phagocytic activity of macrophage-like cells as an indicator of immune function activation. Chemical components were analyzed by HPLC. The immunostimulating activity of TPS from immature leaves extract was higher than that of TPS from mature leaves, and its activities were dependent on the content of strictinin in the leaf extract. Futhermore, a mixture of catechin and TPS that removed polyphenols did not increase the immunostimulating activity. These results suggest that the catechin-polysaccharide complex is a very important molecule in the immunomodulating activity of tea extracts.

Previously we have reported that the O-methylated derivative of (-)-epigallocatechin-3-O-gallate (EGCG), (-)-epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3"Me), possesses anti-allergic activities such as inhibition of histamine release and suppression of the high-affinity IgE receptor (FcepsilonRI) expression. However, the underlying mechanism is still unclear. Recently we have identified the 67kDa laminin receptor (67LR) as a cell-surface receptor that can mediate biological activities of EGCG. Here we show that the suppression of myosin II regulatory light chain (MRLC) phosphorylation through the cell-surface binding to the 67 LR contributes to the inhibitory effect of EGCG3"Me on the histamine release from the human basophilic KU812 cells. The 67LR also mediated the EGCG3"Me-induced suppression of FcepsilonRI expression by reducing ERK1/2 phosphorylation. These results suggest that anti-allergic effects of EGCG3"Me may be triggered by the inhibition of MRLC or ERK1/2 phosphorylation mediated through the cell-surface 67LR.

Tea contains a variety of bioactive compounds. In this study, we show that two O-methylated catechins, (-)-epigallocatechin-3-O-(3-O-methyl) gallate and (-)-epigallocatechin-3-O-(4-O-methyl) gallate, inhibit in vivo mast cell-dependent allergic reactions more potently than their nonmethylated form, (-)-epigallocatechin-3-O-gallate. Consistent with this, these O-methylated catechins inhibit IgE/Ag-induced activation of mouse mast cells: histamine release, leukotriene release, and cytokine production and secretion were all inhibited. As a molecular basis for the catechin-mediated inhibition of mast cell activation, Lyn, Syk, and Bruton's tyrosine kinase, the protein tyrosine kinases, known to be critical for early activation events, are shown to be inhibited by the O-methylated catechins. In vitro kinase assays using purified proteins show that the O-methylated catechins can directly inhibit the above protein tyrosine kinases. These catechins inhibit IgE/Ag-induced calcium response as well as the activation of downstream serine/threonine kinases such as Akt and c-Jun N-terminal kinase. These observations for the first time have revealed the molecular mechanisms of antiallergic effects of tea-derived catechins.

Matrix metalloproteinases (MMPs) play a crucial role in the process of cancer invasion and metastasis. Previous findings suggested that epigallocatechin gallate (EGCG), a main flavanol of green tea, caused decreased levels of MMP-2 and MMP-9 activities to be secreted into culture medium. To obtain further information on EGCG-mediated regulation of these MMPs, the effects of EGCG on enzyme activity, mRNA expression, and mitogen-activated protein kinase (MAPK) activities in human fibrosarcoma HT1080 cells were examined. EGCG was confirmed to suppress the gelatin-degrading activities due to MMP-2 and MMP-9 in the culture medium. This suppression of enzyme activities by EGCG was consistent with the decreased levels of MMP-2 and MMP-9 mRNAs. EGCG-mediated suppression was also observed for MT1-MMP mRNA. EGCG-mediated suppression of the level of MMP-9 transcript was correlated with its suppression of MMP-9 promoter activity. EGCG inhibited the phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), which are the members of an MAPK family necessary for MMP-9 up-regulation. EGCG also suppressed p38 MAPK activity but gave no effects on stress-activated protein kinase/c-Jun N-terminal kinase activity. These findings suggest that suppression of ERK phosphorylation by EGCG is involved in the inhibition of expression for MMP-2 and MMP-9 mRNAs, leading to the reduction of their enzyme activities of the cancer cells. Methyl derivatives, epigallocatechin-3-O-(3-O-methyl) gallate and epigallocatechin-3-O-(4-O-methyl) gallate, exhibited effects similar to, but weaker than, those of EGCG, suggesting the important role of an unsubstituted triphenolic ester structure in these activities.

Epimerization at C-2 of O-methylated catechin derivatives and four major tea catechins were investigated. The epimeric isomers of (-)-epicatechin (I), (-)-epicatechin-3-O-gallate (II), (-)-epigallocatechin (III), (-)-epigallocatechin-3-O-gallate (IV), and (-)-epigallocatechin-3-O-(3-O-methyl)gallate (V) in green tea extracts increased time-dependently at 90 degrees C. The epimerization rates of authentic tea catechins in distilled water are much lower than those in tea infusion or in pH 6.0 buffer solution. The addition of tea infusion to the authentic catechin solution accelerated the epimerization, and the addition of ethylenediaminetetraacetic acid, disodium salt (Na(2)EDTA) decreased the epimerization in the pH 6.0 buffer solution. Therefore, the metal ions in tea infusion may affect the rate of epimerization. The proportions of the epimers to authentic tea catechins [III, IV, V, and (-)-epigallocatechin-3-O-(4-O-methyl)gallate (VI)] in pH 6.0 buffer solution after heating at 90 degrees C for 30 min were 42.4%, 37.0%, 41.7%, and 30.4%, respectively. These values were higher than those of I and II (23.5% and 23.6%, respectively). The O-methylated derivatives at the 4'-position on the B ring of IV and VI were hardly epimerized. These results suggest that the hydroxyl moiety on the B ring of catechins plays an important role in the epimerization in the order 3',4',5'-triol type > 3',4'-diol type >> 3',5'-diol type.

We previously found that the O-methylated derivative of (-)-epigallocatechin-3-O-gallate (EGCg), (-)-epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG' '3Me), has potent antiallergic activity. The high-affinity IgE receptor, FcepsilonRI, is found at high levels on basophils and mast cells and plays a key role in a series of acute and chronic human allergic reactions. To understand the mechanism of action for the antiallergic EGCG' '3Me, the effect of EGCG' '3Me on the cell surface expression of FcepsilonRI in human basophilic KU812 cells was examined. Flow cytometric analysis showed that EGCG' '3Me was able to decrease the cell surface expression of FcepsilonRI. Moreover, immunoblot analysis revealed that total cellular expression of the FcepsilonRI alpha chain decreased upon treatment with EGCG' '3Me. FcepsilonRI is a tetrameric structure comprising one alpha chain, one beta chain, and two gamma chains. The level of mRNA production of each subunit in KU812 cells was investigated. EGCG' '3Me reduced FcepsilonRI alpha and gamma mRNA levels. The cross-linkage of FcepsilonRI causes the activation of basophils, which leads to the secretion of inflammatory mediators including histamine. EGCG' '3Me treatment inhibited the FcepsilonRI cross-linking-induced histamine release. These results suggested that EGCG' '3Me can negatively regulate basophil activation through the suppression of FcepsilonRI expression.

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.

The inhibitory effects of tea catechins, the O-methylated derivatives of (-)-epigallocatechin-3-O-gallate (EGCG), and the polyphenol extracts from tea leaves (Camellia sinensis L.) on oxazolone-induced type IV allergy in male ICR mice were investigated. Four major tea catechins and two O-methylated derivatives, (-)-epigallocatechin-3-O-(3-O-methyl)gallate (EGCG3' 'Me) and (-)-epigallocatechin-3-O-(4-O-methyl)gallate (EGCG4' 'Me), showed significant inhibitory effects on mouse type IV allergy after a percutaneous administration at a dose of 0.13 mg/ear. Among tea catechins, the compounds including galloyl moieties, such as EGCG and (-)-epicatechin-3-O-gallate (ECG), showed the strongest inhibitory activities on mouse type IV allergy. The inhibitory activities of EGCG3' 'Me and EGCG4' 'Me were higher than that of EGCG at a dose of 0.05 mg/ear. Polyphenol extract from tea leaves of Benihomare cultivar, which includes EGCG3' 'Me, strongly inhibited mouse type IV allergy after percutaneous administration in comparison with that from Yabukita cultivar, which does not include EGCG3' 'Me, at doses of 0.05 and 0.13 mg/ear. EGCG3' 'Me is thought to contribute, at least in part, to the inhibitory ability of Benihomare tea leaves on mouse type IV allergy. EGCG and the polyphenol extracts from Benihomare and Yabukita tea leaves also inhibited mouse type IV allergy by oral administration at 1 h before the sensitization and at 1 h before the challenge with oxazolone. Therefore, daily intake of tea drinks could have potential to prevent type IV allergy.

We examined the constituents of tea that had an inhibitory effect on the degranulation process in the human basophilic cell line, KU812. Among the constituents purified from a extract of 'Benihomare' oolong tea by column chromatography, a methylated (-)-epigallocatechin gallate ((-)-epigallocatechin 3-O-(3-O-methyl) gallate) was found to inhibit the degranulation of KU812 cells that had been stimulated with calcium ionophore A23187. The inhibitory effect of this methylated (-)-epigallocatechin gallate on degranulation was greater than that of (-)-epigallocatechin gallate. This result indicates that methylation of (-)-epigallocatechin gallate may be an effective modification for the catechin to inhibit degranulation from human basophils.

The effects of tea polyphenols on the invasion of highly metastatic human fibrosarcoma HT1080 cells through a monolayer of human umbilical vein endothelial cells (HUVECs) and the accompanying basal membrane were investigated. Among the tea polyphenols tested, epicatechin gallate (ECg), epigallocatechin gallate (EGCg), and theaflavin strongly suppressed the invasion of HT1080 cells into the monolayer of HUVECs/gelatin membrane, whereas epicatechin, epigallocatechin, tea flavonols, tea flavones, and gallate derivatives had no effect. Both theaflavin-digallate and theasinensin D showed a weak invasion inhibitory effect. ECg significantly inhibited the invasion without cytotoxicity against cancer cells and HUVECs. Ester-type catechins (ECg and EGCg) and theaflavin strongly suppressed the gelatin degradation mediated by matrix metalloproteinase (MMP) 2 and MMP-9, which were secreted into the conditioned medium of HT1080 cells. In conclusion, among the tea polyphenols tested, ECg was considered to be the agent with the most potential antimetastasis activity because it inhibited invasion in the absence of cytotoxicity.

Two catechin derivatives (C-1 and C-2) with potent antiallergic activity were isolated from Taiwanese oolong tea by HPLC techniques. From NMR and FAB-MS analyses, the structures of C-1 and C-2 were elucidated as (-)-epigallocatechin 3-O-(3-O-methyl)gallate and (-)-epigallocatechin 3-O-(4-O-methyl)gallate, respectively. The oolong tea leaves contained 0.34% (dry weight) C-1 and 0.20% C-2. Traces of C-2 were detected in only 1 of 15 varieties of green tea tested. C-1 was detected in 13 of 15 green tea varieties; C-1 was most concentrated in tea cultivars classified as Assam hybrids (0. 50-0.82% of dry weight). Quantitative analyses of green tea, oolong tea, and black tea manufactured from same batches of tea leaves showed that neither catechin derivative was produced during the fermentation process. Oral doses of C-1 and C-2 (5-50 mg/kg) significantly inhibited type I allergic (anaphylactic) reactions in mice sensitized with ovalbumin and Freund's incomplete adjuvant. These inhibitory effects exceeded that of the major tea catechin, (-)-epigallocatechin 3-O-gallate, which has known antiallergic properties.