Inhibitory effects of 1,3-bis-(2-substituted-phenyl)-propane-1,3-dione, β-diketone structural analogues of curcumin, on chemical-induced tumor promotion and inflammation in mouse skin

Dibenzoylmethane (DBM), a β-diketone structural analogue of curcumin, has been reported to exhibit anti-tumorigenic and chemopreventive activities. Due to the structural resemblance of DBM to the anti-inflammatory curcumin and an aspirin-like skeleton of DBM derivatives, we tested the anti-inflammatory effects of DBM and its derivatives, 1,3-bis-(2-substituted-phenyl)-propane-1,3-dione, on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced tumor promotion as well as TPA- and arachidonic acid-induced mouse ear edema in skin of CD-1 mice. Topical application of 10 μmol DBM together with TPA on the back of mice previously treated with 7,12-dimethylbenz[α]anthracene (DMBA) inhibited TPA-induced skin tumor promotion significantly. In addition, 1,3-bis-(2-acetoxy phenyl)-propane-1,3-dione was a superior anti-inflammatory agent to aspirin (80% of inhibition), on TPA-induced mouse ear edema and reduced the production of prostaglandin E2 (PGE(2)), comparable to aspirin. Taken together, 1,3-bis-(2-acetoxyphenyl-propane-1,3-dione merits a valuable anti-inflammatory agent substituting aspirin in therapeutic treatment as well prevention of cancer.     

Analysis of the theaflavin composition in black tea (Camellia sinensis) for predicting the quality of tea produced in Central and Southern Africa

A parameter of black tea that correlates with quality is highly desired. Twenty good and 20 poor quality tea clones were selected from the breeding programme at the Tea Research Foundation (Central Africa) (TRF(CA)). The theaflavin (TF) composition of the black tea manufactured from each clone was analysed by capillary electrophoresis and correlated with total scores and valuation from two tea tasters with regression analysis. The significance of the differences between the 20 good and 20 poor quality tea clones was determined with the Student t‐test and the distribution‐free Kruskal–Wallis test. The sum of the TFs of the black tea correlated well (r = 0.785, P = 0.0002) with the value of the tea. Of the individual TFs determined in the black tea, the highest correlation was obtained with TF‐3′‐monogallate (TF‐B) (r = 0.788, P = 0.0016), TF‐3‐monogallate (TF‐A) (r = 0.741, P = 0.0004) and free TF (TF‐f) (r = 0.705, P = 0.0002). TF‐B (m = 24.90) followed by TF‐A (m = 12.48) showed the steepest slopes against value, making them good indicators for value. The TF‐digallate (TF‐dg) content did not show significant correlation with value (r = 0.316, P = 0.358). The individual TF content thus can be used for optimising the black tea manufacturing process in Central and Southern Africa. © 2002 Society of Chemical Industry     

Theaflavins,dimeric catechins,inhibit peptide transport across Caco-2 cell monolayers via down-regulation of AMP-activated protein kinase-mediated peptide transporter PEPT1

In the small intestine, peptide transporter 1 (PEPT1) plays a role in the transport of di- and tripeptides. In this study, we investigated whether theaflavins (TFs) affect the absorption of small peptides in human intestinal Caco-2 cells, since TFs do not penetrate through the cells and might be involved in intestinal transport systems. In transport experiments, the transport of glycyl-sarcosine (Gly-Sar, a model molecule for PEPT1 transport) and other dipeptides (Val-Tyr and Ile-Phe) were significantly reduced (P < 0.05) in TFs-pretreated cells. In TF 3′-O-gallate-pretreated cells, Western blot analysis revealed attenuated expression of PEPT1 transporter and Gly-Sar transport was completely ameliorated by 10 μM Compound C, an AMP-activated protein kinase (AMPK) inhibitor. In conclusion, the present study demonstrated that TFs inhibit peptide transport across Caco-2 cell monolayers, probably through suppression of AMPK-mediated PEPT1 expression, which should be considered a new bioactivity of TFs in black tea.     

Polyphenols Extracted from Black Tea (Camellia sinensis) Residue by Hot‐Compressed Water and Their Inhibitory Effect on Pancreatic Lipase in vitro

Abstract: Polyphenols, retained in black tea wastes following the commercial production of tea beverages, represent an underutilized resource. The purpose of this study was to investigate the potential use of hot‐compressed water (HCW) for the extraction of pancreatic lipase‐inhibiting polyphenols from black tea residues. Black tea residues were treated with HCW at 10 °C intervals, from 100 to 200 °C. The resulting extracts were analyzed using high‐performance liquid chromatography‐mass spectrometry and assayed to determine their inhibitory effect on pancreatic lipase activity in vitro. Four theaflavins (TF), 5 catechins, 2 quercetin glycosides, quinic acid, gallic acid, and caffeine were identified. The total polyphenol content of extracts increased with increasing temperature but lipase inhibitors (TF, theaflavin 3‐O‐gallate, theaflavin 3′‐O‐gallate, theaflavin 3,3′‐O‐gallate, epigallocatechin gallate, and epicatechin gallate) decreased over 150 °C. All extracts inhibited pancreatic lipase but extracts obtained at 100 to 140 °C showed the greatest lipase inhibition (IC₅₀s of 0.9 to 1.3 μg/mL), consistent with the optimal extraction of TFs and catechins except catechin by HCW between 130 and 150 °C. HCW can be used to extract pancreatic lipase‐inhibiting polyphenols from black tea waste. These extracts have potential uses, as dietary supplements and medications, for the prevention and treatment of obesity. Practical Application: Active forms of lipase inhibitors can be recovered from black tea residues. They could be used as dietary supplements or medications.     

The anti-inflammatory effects of phlorotannins from Eisenia arborea on mouse ear edema by inflammatory inducers

The anti-allergic and anti-inflammatory effects of phlorotannins (seaweed polyphenols) from the brown alga Eisenia arborea using in vitro experiments has already been reported. Therefore, in this study, these effects were examined in vivo using mice. When ear edema was induced in ICR mice by three sensitizers (arachidonic acid (AA), 12-O-tetradecanoylphorbol-13-acetate (TPA) and oxazolone (OXA)), four phlorotannins tested (eckol, 8,8’-bieckol, phlorofucofuroeckol (PFF)-A and PFF-B) inhibited the ear edema after spreading of 0.01 or 0.1 mg onto the mouse ear. The effects of the phlorotannins on the ear edema after AA and OXA treatments tended to be stronger than after TPA treatment, and the inhibitory effects against each sensitizer were similar to epigallocatechin gallate, a typical inhibitor. This is the first report that phlorotannins exhibit anti-allergic and anti-inflammatory effects in in vivo experiments, and inhibit OXA-induced delayed-type (type IV) allergic reactions.     

Preventive effects of black tea theaflavins against mouse type IV allergy

BACKGROUND: Tea (Camellia sinensis L.), one of the most popular beverages, contains various beneficial constituents. We investigated the preventive effects of black tea theaflavins, theaflavin‐3‐gallate (3‐TF) and theaflavin‐3,3′‐digallate (TFDG), on oxazolone‐induced type IV allergy in male ICR mice. RESULTS: Percutaneous administration of both 3‐TF and TFDG at 0.2 mg ear^?1 showed significant preventive effects against mouse type IV allergy. Oral administration of these agents at 50 mg kg^?1 body weight also showed significant preventive effects against mouse type IV allergy. Oral administration of 3‐TF and TFDG at a dose of 50 mg kg^?1 body weight prevented the increases in levels of some proinflammatory cytokines, interleukin‐12 (IL‐12), interferon‐gamma (IFN‐γ), and tumour necrosis factor‐alpha (TNF‐α), in the sera and/or ears of mice with type IV allergy. Lowering of serum antioxidant activity in mice with allergic symptoms was also prevented by oral administration of these theaflavins at a dose of 50 mg kg^?1 body weight. The anti‐allergic mechanisms of action of theaflavins involve inhibition of the fluctuations of cytokines and maintenance of antioxidant status in allergic mice. CONCLUSION: These results suggest that the theaflavins as well as catechins contribute to the anti‐allergic effects of black tea. Copyright © 2010 Society of Chemical Industry     

高效液相色谱法同时测定工夫红茶中10种内含物成分

建立高效液相色谱法同时测定工夫红茶中咖啡碱、儿茶素、表儿茶素、表没食子儿茶素、表儿茶素没食子酸酯、表没食子儿茶素没食子酸酯、茶黄素、茶黄素-3-没食子酸酯、茶黄素-3’-没食子酸酯、茶黄素双没食子酸酯10 种内含物成分含量的方法。通过色谱条件优化,确定出工夫红茶中10 种内含物成分含量测定的最佳色谱条件为：色谱柱为Whatman Partisphere C18液相色谱柱（4.6 mm×125 mm,5 μm）、柱温32 ℃、流动相为0.035%三氟乙酸-5%乙腈溶液和0.025%三氟乙酸-50%乙腈溶液、流速1 mL/min、进样量10 μL、检测波长205 nm。在此条件下,上述10 种内含物成分得到很好的分离和测定。各种内含物的线性范围为0.05～500 μg/mL,标准曲线相关系数均在0.999 8以上,精密度检测相对标准偏差为0.72%～3.32%（n=5）,重复性检测相对标准偏差为1.87%～4.43%（n=5）,回收率在94.73%～102.38%之间。该方法简单、快捷、准确、重复性好,可应用于工夫红茶中10 种内含物质的同时快速测定。     

Antiobesity and lipid lowering effects of theaflavins on high-fat diet induced obese rats

Theaflavins are major polyphenols in black tea. This study investigated antiobesity and lipid lowering effects of black tea extract (BTE), a highly purified theaflavins mixture (TFs, 83.84%) and theaflavin (TF1, 93.25%) on high-fat diet (HFD) induced obese rats. The body weight was slightly reduced by BTE and TFs (p > 0.05), and was significantly decreased by TF1 (p < 0.05) relative to the HFD control group. All samples remarkably decreased the food intake, adiposity index and the serum levels of total cholesterol (TC), triacylglycerol (TG) and low-density lipoprotein cholesterol (LDL-C) (p < 0.05), except that BTE and TF1 insignificantly decreased the TC concentration (p > 0.05). Moreover, administration of BTE, TFs and TF1 all significantly decreased atherogenic index (AI), enhanced insulin sensitive index (ISI), inhibited the hepatic lipase (HL) activity (p < 0.05), and slightly reduced leptin level in liver, decreased serum alanine transaminase (ALT) activity and increased serum superoxide dismutase (SOD) activity (p > 0.05) as compared to that of the HFD controls. These results indicated that theaflavins were one of the functional components which contributed to the antiobesity and lipid lowering effects of black tea, and might reduce the risk of type 2 diabetes and cardiovascular disease (CVD) in obese patients.     

Antimicrobial activities of tea catechins and theaflavins and tea extracts against Bacillus cereus

We evaluated the antimicrobial activities of seven green tea catechins and four black tea theaflavins, generally referred to as flavonoids, as well as the aqueous extracts (infusions) of 36 commercial black, green, oolong, white, and herbal teas against Bacillus cereus (strain RM3190) incubated at 21 degrees C for 3, 15, 30, and 60 min. The results obtained demonstrate that (i) (-)-gallocatechin-3-gallate, (-)-epigallocatechin-3-gallate, (-)-catechin-3-gallate, (-)-epicatechin-3-gallate, theaflavin-3, 3'-digallate, theaflavin-3'-gallate, and theaflavin-3-gallate showed antimicrobial activities at nanomolar levels; (ii) most compounds were more active than were medicinal antibiotics, such as tetracycline or vancomycin, at comparable concentrations; (iii) the bactericidal activities of the teas could be accounted for by the levels of catechins and theaflavins as determined by high-pressure liquid chromatography; (iv) freshly prepared tea infusions were more active than day-old teas; and (v) tea catechins without gallate side chains, gallic acid and the alkaloids caffeine and theobromine also present in teas, and herbal (chamomile and peppermint) teas that contain no flavonoids are all inactive. These studies extend our knowledge about the antimicrobial effects of food ingredients.     

Phenolic composition and biological activities of Salvia halophila and Salvia virgata from Turkey

The aerial parts of Salvia halophila and Salvia virgata were subjected to Soxhlet extraction with different solvents such as n-hexane, ethyl acetate, methanol, and aqueous methanol (50%). Plants were also extracted with water under reflux. The effects of the extracts were studied in p-benzoquinone-induced abdominal constriction test for the assessment of antinociceptive activity and carrageenan-induced hind paw edema and 12-O-tetradecanoyl-13-acetate (TPA)-induced ear edema models in mice for the anti-inflammatory activity. The extracts were analysed using a HPLC–PDA method. Results showed that methanol extract of S. virgata significantly inhibited carrageenan-induced paw edema and p-benzoquinone-induced abdominal constriction at 100 mg/kg dose, while it showed no effect in the TPA-induced ear edema. On the other hand, the other extracts did not show any inhibitory antinociceptive and anti-inflammatory activities in these in vivo models. Rosmarinic acid was found as main constituent in the extracts, while caffeic acid and luteolin derivatives were also detected.     

Influence of fermentation time on the development of compounds responsible for quality in black tea

The compounds responsible for tea quality, such as theaflavins (TFs) and thearubigins were found to increase with fermentation time. However, TF reached a maximum, declining subsequently. The water extract of black tea decreased with fermentation time. Caffeine concentration remained unchanged. The digallate equivalent of theaflavin, colour index and briskness index were found to peak at the optimum fermentation time. Polyphenols declined more quickly during the initial stages, followed by a steadily declining trend. Fermentation time had little impact on the gallic acid concentration. Among the catechins, epigallocatechin oxidized fastest, followed by epigallocatechin gallate and epicatechin gallate.     

The relationship between some chemical parameters and sensory evaluations for plain black tea (Camellia sinensis) produced in Kenya and comparison with similar teas from Malawi and South Africa

Reliable and accurately measurable chemical parameters that can be used to estimate black tea quality are desirable in trade, research and breeding programmes. Using plain Kenyan black tea from 11 cultivars, which gave some significant differences in their plain black tea quality parameters, the individual theaflavins composition, total theaflavins, thearubigins, theaflavin digallate equivalent, total colour and brightness were determined. The parameters were regressed against sensory evaluation scores of two tasters A and B. The theaflavin digallate equivalent (TDE) showed the strongest relationship (r = 0.71 (P ? 0.01) and r = 0.80 (P ? 0.001)) for A and B′, respectively. The simple (non gallated) theaflavin and thearubigins did not show significant relationships with sensory evaluation. Of the liquor characteristics, there were significant relationships between liquor brightness and sensory evaluation by A and B (r = 0.58 (P ? 0.06) and r = 0.59 (P ? 0.05)), respectively. In consequence, TDE and brightness can be used in tea breeding programmes as quality indicators or to estimate plain black tea quality potential in the tea trade. Optimising their levels can also help to produce good quality Kenyan black teas during processing. Comparison of these results with work published earlier indicates that, of the individual theaflavins, theaflavin-3,3′-digallate correlates best with tea taster scores for the 11 Kenyan cultivars, whereas the simple theaflavin correlates best with tea tasters’ scores for 40 Malawian cultivars. However, the derived parameter, TDE correlates very well with tea tasters’ scores for all of the above cultivars.     

Distribution of Catechins, Theaflavins, Caffeine, and Theobromine in 77 Teas Consumed in the United States

ABSTRACT: To help define the composition of commercial teas consumed in the United States, we have developed and validated an high-performance liquid chromatography (HPLC) method to analyze levels of catechins, theaflavins, and alkaloids in 77 commercial black, green, specialty (brown rice, white, oolong), and herbal teas extracted with hot water to simulate home use. The following 13 compounds were separated in a single analysis on an Inertsil ODS-3v column with acetonitrile/potassium dihydrogen phosphate as the mobile phase: (−)-epigallocatechin, (+)-catechin, (−)-epicatechin, (−)-epigallocatechin-3-gallate, (−)-gallocatechin-3-gallate, (−)-epicatechin-3-gallate, (−)-catechin-3-gallate, theaflavin, theaflavin-3-gallate, theaflavin-3'-gallate, theaflavin-3, 3'-digallate, caffeine, and theobromine. The data show that (1) extraction time from 3 min to 20 min did not significantly affect measured levels of tea compounds and (2) there was a wide variation in the composition of the tea compounds both within each tea category and among categories: black teas contained both theaflavins and catechins, green and white teas contained catechins and trace amounts of theaflavins, herbal teas contained very low amounts of all tea compounds. A statistical profile of the distribution of catechins, theaflavins, caffeine, and theobromine in the evaluated teas offers consumers a choice of teas containing high levels of health-promoting compounds.     

Quality evaluation of black CTC teas based upon seasonal variations

Effects of seasonal variations on the colour and chemical constituents of Indian black tea were investigated. The experimentation involved collection of different black tea samples that were cultivated at the same tea garden but harvested in three different seasons. Measurement of moisture content was done along with theaflavins (TFs), thearubigins (TRs) and colour (CIE La*b* values) of the brewed tea liquor using spectrophotometric approach. The correlation analysis between chemical constituents, that is, TFs and TRs, moisture content, colour and quality grading was done by using principal component analysis (PCA). The results suggest that quality of tea is dependent upon seasonal variations in terms of chemical changes such as TFs, TRs and moisture content, which also correlate well with colour. The efficacy of the colour of brewed tea liquor in explaining the changes in tea quality due to seasonal variations can be beneficial for scientific fixation of prices at tea auction centres.     

茶黄素双没食子酸酯的生物活性及其作用机制

文章综述了近年来国内外有关茶黄素双没食子酸酯(theaflavin-3,3’-digallate,TFDG)在抗氧化、抗癌、抗炎、抗病毒以及治疗代谢综合征等方面生物活性及其作用机制研究进展,同时展望了中国红茶资源的深层次研究和健康功能性产品开发这一研究领域的发展前景和方向。     

Biological and chemical factors affecting the valuation of North East Indian plains teas. III. Statistical Evaluation of the Biochemical Constituents and their Effects on Colour,Brightness and Strength of Black Teas

Regardless of tasters and methods of manufacture five biochemical factors, total oxygen uptake of unprocessed tea shoots and theaflavins (TF), thearubigins (TR), (?)-epigallocatechin gallate (EGCE) and theogallin (TG), of black tea are the main contributing factors of colour of North East India plains tea. Similarly, three constituents, TF, TR and (?)-epicatechin gallate (ECG) of black tea, are main the factors for brightness. Four factors, total oxygen uptake and ECG of unprocessed tea shoots and TF and moisture of black tea are the main contributing factors of strength of North East Indian plains tea.     

Analysis of caffeine and flavan‐3‐ol composition in the fresh leaf of Camellia sinesis for predicting the quality of the black tea produced in Central and Southern Africa

A parameter of fresh tea leaf that correlates with black tea quality is highly desired. Twenty good and 20 poor quality tea clones were selected from the breeding programme at the Tea Research Foundation (Central Africa) (TRF(CA)). The flavan‐3‐ol profile of fresh tea leaves was analysed by capillary electrophoresis while total theaflavin (TF) content was determined in the black tea manufactured from the same leaves for each clone. The above parameters were correlated with total scores and valuation from two tea tasters with regression analysis. The significance of the differences between the 20 good and 20 poor quality tea clones was determined with the Student's t‐test. The total TF content of the black tea correlated (r = 0.63, P = 0.0001) well with the value of the tea. Of all the parameters determined in the fresh leaves, the highest correlation was obtained with (−)‐epicatechin (EC) (r = 0.65, P = 0.0001). This may facilitate early selection of good quality TRF(CA) clones in the future. © 2000 Society of Chemical Industry     

ENZYMATIC SYNTHESIS OF THEAFLAVINS AND EPITHEAFLAVIC ACID FROM TEA CATECHINS AND THEIR ANTIOXIDANT ACTIVITY

A number of in vitro and in vivo studies have demonstrated that black tea polyphenols have significant biological activities, including antioxidant, antiinflammatory and anticancer activity. The theaflavins have received attention as one of responsible components for biological activities of black tea. However, little information is available for the biological activity of individual theaflavins and minor components in black tea. In the present study, theaflavins and epitheqflavic acid were synthesized from their parent flavan-3-ols catechins using an enzymatic oxidation method and employing crude polyphenol oxidase from banana fruit. The compounds were isolated using column chromatographic methods, and their structures confirmed by ¹H-NMR and APCI-MS. The peroxyl radical scavenging activities of theaflavins and epitheaflavic acids were measured using a modified ORAC method. The results indicated that theaflavins have higher peroxyl radical scavenging activity than EGCG. The hierarchy of radical scavenging activity of theaflavins, epitheaflavic acid and related compounds were in the order of: theaflavin-3, 3'-digallate ∼ theflavin-3-gallate ∼ theaflavin-3'-gallate ∼ theaflavin > epitheaflavic acid > EGCG > purpurogallin.     

Trapping reactions of reactive carbonyl species with tea polyphenols in simulated physiological conditions

The carbonyl stress that leads to the formation of advanced glycation end products (AGEs) in diabetes mellitus has drawn much attention recently. Reactive alpha-dicarbonyl compounds, such as glyoxal (GO) and methylglyoxal (MGO), have been shown to be a high potential glycation agent in vitro and in vivo. In this study, epicatechins in green tea and theaflavins in black tea were found to be able to reduce the concentration of MGO in physiological phosphate buffer conditions. Modified MGO derivatization for GC/flame ionization detector (FID) method in quantification was systematically conducted. In molar ratio of 3 (MGO/polyphenol), theaflavin-3,3'-digallate (TF3) in theaflavins and (-)-epigallocatechin (EGC) in epicatechins showed the highest MGO reduction at 66.65 and 45.74%, respectively, after 1 h of incubation. In kinetic study (molar ratio of MGO/polyphenol = 1:1), rapid MGO reduction occurred within 10 min. Identities of primary adducts between (-)-epigallocatechin gallate (EGCG) and MGO were determined. Newly generated stereoisomers at the C8 position of EGCG A-ring were isolated with a chiral column, and structurally confirmed by 2-D NMR analyses.