PURPOSE: The green tea polyphenol (GTPP) has been known to exert antioxidant activity as a radical scavenger as well as cancer preventive and cancer growth inhibition effect. The aim of this study was to identify whether GTPP not only potentiate the growth inhibition effect in gamma-irradiated human cancer cell but also exert protection action for irradiated human normal cell. MATERIALS AND METHODS: GTPP (80% catechin including > 45% EGCG) added in the HL60, human leukemia, and NC37, human lymphoblast, before irradiation. After establishing the amount of GTPP and the dose of radiation, the cells were treated with the GTPP for 6 hours and irradiated with the determined doses. RESULTS: Viability when 10 mug/ml GTPP added before gamma-irradiation with 1 Gy to NC37 cells was not different in comparison with control but it when was irradiated with 3 Gy significantly different (1 Gy; P=0.126, 3 Gy; P=0.010). 20 mug/ml GTPP did not show significant difference in both NC37 cells irradiated with 1 Gy and 3 Gy (1 Gy; P=0.946, 3 Gy; P=0.096). Viabilities were significantly decreased with concentration of additional GTPP in HL60 with 1 or 3 Gy (1 Gy; 69.0+/-1.7% vs 42.4+/-1.3%, 3 Gy; 66.9+/-3.9% vs 44.2+/-1.6 %). CONCLUSION: In vitro study, we certified that when the cells were irradiated with dose below 3 Gy, GTPP provide not only anticancerous effect against cancer cells but also radioprotective effect in normal cells simultaneously. Theses results suggest the possibility that consumption of green tea could give the radioprotective effect and maximize the effect on internal radiation such as radioiodine therapy concomitantly.
Catechin ; Humans* ; Leukemia ; Tea*

Aims: Infectious bronchitis virus (IBV) is a highly contagious, acute viral respiratory disease that mostly affects chickens. The poultry sector has suffered enormous losses as a result of IBV. Currently, live attenuated vaccines are routinely used to prevent and control IBV. However, due to the enormous genetic variety, vaccinations are becoming ineffective, with low cross-protection effects among vaccine serotypes. The present study aimed at investigating the possible antiviral effects of curcumin, epigallocatechin gallate (EGCG) and their mixtures against IBV in vivo. Methodology and results: Curcumin, EGCG and their combinations were administered to infected and uninfected chicken groups and viral load titers were determined by real-time PCR. The clinical symptoms of both the negative and positive control groups were also compared. Finally, the trachea tissues of each group were examined histopathologically. According to our findings, the viral titer and the clinical signs dropped significantly during the pretreatment infection procedure. Curcumin, EGCG and their combinations also show significant antiviral activities. Conclusion, significance and impact of study This study clearly shown that natural compounds and their combinations, such as curcumin or/and ECGC can reduce viral pathogenicity in vivo, suggesting that they might have therapeutic implications in the poultry sector.
Infectious bronchitis virus--physiology ; Curcumin ; Catechin

A method for simultaneously identifying antioxidative compounds was developed using time-based LC-MS coupled with DPPH assay regardless of the time consuming process. The methanolic extract of Polygonum aviculare (Polygonaceae) showed significant DPPH radical scavenging activity. Time-based DPPH assay for simultaneous identification of active compounds from the extracts of P. aviculare was used. Major peaks of ethyl acetate fraction of P. aviculare showed high DPPH radical scavenging activity. A simple phenolic compound (1) and six flavonoids (2-7) were isolated from the ethyl acetate fraction of P. aviculare by silica gel and sephadex LH-20 column chromatography. The structures of seven compounds were determined to be protocatechuic acid (1), catechin (2), myricitrin (3), epicatechin-3-O-gallate (4), avicularin (5), quercitrin (6), and juglanin (7) based on the analysis of the 1H-NMR, 13C-NMR and ESI-MS data. All compounds exhibited significant antioxidant activity on DPPH assay and active compounds were well correlated with predicted one.
Catechin ; Chromatography ; Flavonoids ; Methanol ; Phenol ; Polygonum* ; Silica Gel

OBJECTIVES: The aim of this study was to determine the effect of epigallocatechin gallate (EGCG) on the shear bond strength of composite resin to bleached enamel. MATERIALS AND METHODS: Ninety enamel surfaces of maxillary incisors were randomly divided into 9 groups as follows: G1: control (no bleaching); G2: bleaching; G3: bleaching and storage for seven days; G4 - 6: bleaching and application of 600, 800 and 1,000 micromol of EGCG-containing solution for 10 minutes, respectively; G7 - 9: bleaching and application of 600, 800 and 1,000 micromol of EGCG-containing solution for 20 minutes, respectively. The specimens were bleached with 30% hydrogen peroxide gel and a composite resin cylinder was bonded on each specimen using a bonding agent. Shear bond strength of the samples were measured in MPa. Data was analyzed using the two-way ANOVA and Tukey HSD tests (alpha = 0.05). RESULTS: The maximum and minimum mean shear bond strength values were observed in G1 and G2, respectively. Time and concentration of EGCG showed no significant effects on bond strength of the groups (p > 0.05). Multiple comparison of groups did not reveal any significant differences between the groups except for G2 and all the other groups (p < 0.05). CONCLUSIONS: There is a significant decrease in bond strength of composite resin to enamel immediately after bleaching. A delay of one week before bonding and the use of EGCG increased bond strength of composite resin to bleached enamel.
Catechin ; Dental Enamel* ; Hydrogen Peroxide ; Incisor ; Tooth Bleaching

Content analysis of flavonoids (epicatechin, epicatechin gallate, and rutin) present in the leaves of Boehmeria nivea (originating from Geumsan-myeon, Biin-myeon, Hansan-myeon, and Baeksu-eup) and their commercial products (ramie tteok, ramie songpyeon, ramie bory-tteok, and ramie tea) was conducted by HPLC. The content of epicatechin, epicatechin gallate, and rutin was highest in the leaves of B. nivea from Geumsanmyeon (0.138 mg/g), Baeksu-eup (1.654 mg/g) and Geumsan-myeon (12.205 mg/g), respectively. With respect to commercial products, the content of epicatechin and epicatechin gallate was highest in ramie tea, with concentrations of 1.879 and 1.090 mg/g, respectively. Given these flavonoid concentrations, B. nivea leaf extracts have the potential to be used as additives in natural medicinal products, health supplements, and beverages.
Beverages ; Boehmeria* ; Catechin ; Chromatography, High Pressure Liquid ; Flavonoids ; Rutin ; Tea

Diospyros burmanica Kurz. is an evergreen deciduous tree distributed in Mandalay of Myanmar, which belongs to the family of Ebenaceae. In Myanmar, it has been used to treat diarrhea, diabetes, diabetes and also as lumbers. In this study, seven flavonoids (1 - 7), a phenolic compound (8), and five triterpenes (9 - 13) were isolated from the barks of D. burmanica and their chemical structures were elucidated. Isolates were identified to be (+)-catechin (1), (+)-catechin 3-O-alpha-L-rhamnopyranoside (2), (+)-catechin 3-O-gallate (3), (-)-epicatechin (4), (-)-epicatechin 3-O-gallate (5), (+)-afzelechin 3-O-alpha-L-rhamnopyranoside (6), (+)-2,3-trans-dihydrokaempferol 3-O-alpha-L-rhamnopyranoside (7), methyl gallate (8), lupeol (9), methyl lup-20(29)-en-3-on-28-oate (10), beta-amyrin (11), alpha-amyrin (12), 3beta-hydroxy-D:B-friedo-olean-5-ene (13) through MS, 1H NMR and 13C NMR spectroscopic evidences.
Catechin ; Diarrhea ; Diospyros* ; Ebenaceae ; Flavonoids ; Humans ; Myanmar ; Phenol* ; Trees ; Triterpenes*

OBJECTIVEIn situ, real timely and dynamically monitoring the processes of theaflavin (TF), curcumin (Cur) and cyanidin (Cy) binding to human whole saliva (WS) surface has been investigated by surface plasmon resonance (SPR) technique at the molecular level.

METHODSThe affinity between pigments and WS, association rate constant (k(a)), dissociation rate constant (k(d)), association equilibrium constant (K(A)) and dissociation equilibrium constant (K(D)) of pigments binding on WS surface had been determined by SPR and the Langmuir model as well as the Freundlich model. The data were analyzed by one-way ANOVA and SNK-q test.

RESULTSThere were significant differences among TF, Cur and Cy in k(a), k(d), K(A) and K(D) (P<0.05). Our results showed that the adsorption isotherm of pigments on WS surface could be better described by the Freundlich model than the Langmuir model. The pigments adsorption on WS surface was dominant by specific interactions, such as hydrogen bonding. The affinity of pigments to WS were TF> Cur>Cy (P<0.05), as evidenced by the rate constants and equilibrium constants.

CONCLUSIONCompared with Cur and Cy, TF shows much higher adsorption capacity on WS surface, suggesting the importance of the hydroxyl group in pigment/protein interactions.

OBJECTIVETo observe the effect of green tea extractive epigallocatechin-3-gallate (EGCG) on degradation of collagen in dental erosion.

METHODSSixty-four volunteers with dental erosion were randomly divided into two groups. The custom fitted trays were made from the heat curable braces and were injected with carboxymethyl cellulose sodium (CMC) hydrogel in one group (control group) or CMC hydrogel with EGCG added in another (experimental group). These trays were used during sleep and removed from oral cavity in the next morning. The content of carboxy-terminal telopeptide of type I collagen (ICTP) were determined by radioimmunoassay kit at 1 d before the experiment, and 1, 2, 3, 4 weeks after the experiment.

RESULTSBoth the types and time showed significant effects on ICTP. The incubation in EGCG resulted in relatively rapid and significant (P < 0.05) decrease in the expression level of ICTP compared with the control group.

CONCLUSIONEGCG can inhibit collagen degradation and improve the antierosive effect of dentine.

The present study investigated the chemical constituents from the leaves of Craibiodendron yunnanense. The compounds were isolated and purified from the leaves of C. yunnanense by a combination of various chromatographic techniques including column chromatography over polyamide, silica gel, Sephadex LH-20, and reversed-phase HPLC. Their structures were identified by extensive spectroscopic analyses including MS and NMR data. As a result, 10 compounds, including melionoside F(1), meliosmaionol D(2), naringenin(3), quercetin-3-O-α-L-arabinopyranoside(4), epicatechin(5), quercetin-3'-glucoside(6), corbulain Ib(7), loliolide(8), asiatic acid(9), and ursolic acid(10), were isolated. Compounds 1 and 2 were two new compounds, and compound 7 was isolated from this genus for the first time. All compounds showed no significant cytotoxic activity by MTT assay.
Quercetin ; Ericaceae ; Plant Leaves ; Catechin ; Chromatography, High Pressure Liquid

This paper aimed to study the chemical constituents from the root bark of Schisandra sphenanthera. Silica, Sephadex LH-20 and RP-HPLC were used to separate and purify the 80% ethanol extract of S. sphenanthera. Eleven compounds were identified by ~1H-NMR, ~(13)C-NMR, ESI-MS, etc., which were 2-[2-hydroxy-5-(3-hydroxypropyl)-3-methoxyphenyl]-propane-1,3-diol(1), threo-7-methoxyguaiacylglycerol(2),4-O-(2-hydroxy-1-hydroxymethylethyl)-dihydroconiferylalcohol(3), morusin(4), sanggenol A(5), sanggenon I(6), sanggenon N(7), leachianone G(8),(+)-catechin(9), epicatechin(10), and 7,4'-dimethoxyisoflavone(11). Among them, compound 1 was a new compound, and compounds 2-9 were isolated from S. sphenanthera for the first time. Compounds 2-11 were subjected to cell viability assay, and the results revealed that compounds 4 and 5 had potential cytotoxicity, and compound 4 also had potential antiviral activity.
Schisandra ; Plant Bark ; Antiviral Agents ; Biological Assay ; Catechin ; Phenols