Types Of Catechins Research Articles

Epigallocatechin Gallate Stabilized by Cyclodextrin Inactivates Influenza Virus and Human Coronavirus 229E.

Natural products are attractive antiviral agents because they are environment-friendly and mostly harmless. Epigallocatechin gallate (EGCg), a type of catechin, is a well-known natural antiviral agent that can inhibit various viruses. However, EGCg easily oxidizes and loses its physiological activity. Although this problem can be overcome by combining EGCg with cyclodextrin (CD-EGCg), which makes it stable in water at high concentrations, the antiviral effect of this compound remains unclear. Here, we show that in Madin–Darby canine kidney (MDCK) and MRC-5 cells, CD-EGCg is cytotoxic for 50% of cells at 85.61 and 65.34 ppm, respectively. Furthermore, CD-EGCg mainly shows its antiviral effect during the adsorption step for all four influenza virus strains (median effect concentration (EC50) was 0.93 to 2.78 ppm). Its antiviral effect post-adsorption is less intense, and no inhibitory effect is observed on influenza viruses pre-adsorption. Moreover, human coronavirus 229E (HCoV-229E) was inhibited at the adsorption step in short contact (EC50 = 2.5 ppm) and long contact conditions (EC50 = 0.5 ppm) by mixing CD-EGCg with HCoV-229E. These results suggest that CD-EGCg effectively inhibits various viruses that require an adsorption step, and is an effective tool for preventing infection.

Comprehensive profile of DNA adducts as both tissue and urinary biomarkers of exposure to acrylamide and chemo-preventive effect of catechins in rats

Two representative DNA adducts from acrylamide exposure, N7-(2-carbamoyl-2-hydroxyethyl) guanine (N7-GA-Gua) and N3-(2-carbamoyl-2-hydroxyethyl) adenine (N3-GA-Ade), are important long-term exposure biomarkers for evaluating genotoxicity of acrylamide. Catechins as natural antioxidants present in tea possess multiple health benefits, and may also have the potential to protect against acrylamide-induced DNA damage. The current study developed an ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC−MS/MS) method for simultaneous analysis of N7-GA-Gua and N3-GA-Ade in tissues and urine. The validated UHPLC−MS/MS method showed high sensitivity, with limit of detection and limit of quantification ranging 0.2–0.8 and 0.5–1.5 ng/mL, respectively, and achieved qualified precision (RSD<14.0%) and spiking recovery (87.2%–110.0%) with elution within 6 min, which was suitable for the analysis of the two DNA adducts in different matrices. The levels of N7-GA-Gua and N3-GA-Ade ranged 0.9–11.9 and 0.6–3.5 μg/g creatinine in human urine samples, respectively. To investigate the interventional effects of catechins on the two DNA adducts from acrylamide exposure, rats were supplemented with three types of catechins (tea polyphenols, epigallocatechin gallate, and epicatechin) 30 min before administration with acrylamide. Our results showed that catechins effectively inhibited the formation of DNA adducts from acrylamide exposure in both urine and tissues of rats. Among three catechins, epicatechin performed the best inhibitory effect. The current study provided evidence for the chemo-preventive effect of catechins, indicating that dietary supplement of catechins may contribute to health protection against exposure to acrylamide.

Effect of Acidified Ethanol on Antioxidant Properties of Morinda citrifolia Leaf Extract and Its Catechin Derivatives

This study was conducted to investigate the effect of ethanol acidification on the antioxidant properties of Morinda citrifolia leaf (MCL) extract and its catechin derivatives. Four different ethanol (100%, 99.5%, 70%, 50%) with or without 0.5% acetic acid were used for extraction. The antioxidant profile was studied with DPPH radical scavenging activity, FRAP and TPC. The quantification of catechins in MCL was performed using HPLC, and the identification of catechins derivatives was performed with Ultra UPLC-TWIMS-QTOF. The results showed that an extraction solvent composed of 70% ethanol: 29.5% water: 0.5 % acetic acid exhibited the highest DPPH percentage of inhibition (86.12±2.96%) and highest TPC value with 97.80±0.25 mg GAE/g extract, while 100% ethanol acidified with 0.5% acetic acid showed highest FRAP antioxidant power with 1.31±0.05mg FSE/g extract. All eight types of catechins were identified in MCL and the most total catechins were quantified in 70% ethanol: 29.5% water: 0.5 % acetic acid at 153.57mg/g. The catechin derivatives identified included epigallocatechin-3-O-gallate (EGCG), epigallocatechin (4β, 8)-gallocatechin, gallocatechin (4α→8)-epicatechin, catechin-3-O-gallate (CG) and epigallocatechin (EGC). The results suggest that acidification improves the extraction of polyphenols as well as catechin content.

Study on varietal preference and nutritional indices of tea looper Hyposidra talaca (Lepidoptera: Geometridae) on ten selected tea varieties

To find out the varietal preference of H. talaca larvae, leaves of ten selected tea cultivars were provided separately to II, III, IV, and V instars. The food consumption by different larval instars was the maximum on TV20 followed by TV1 > K1/1 > TV22 > TV26 > TV16 > SNT8 > TS520 > HP12 > B157. The nutritional indices showed the highest ECD and ECI values on TV20 followed by other cultivars. However, AD values were inversely proportional to the ECI and ECD. Biochemical analysis of the host leaves indicated higher carbohydrate and lipid concentrations in TV20 which was positively correlated (r = 0.6351) with the mean food consumption, whereas, the lowest carbohydrate and lipid concentration was observed in TS520. The levels of secondary metabolites such as alkaloids (r = -0.6137) and flavonoids (r = -0.7403) showed a negative correlation with larval food consumption. Results of HPLC analysis showed the presence of different types of catechins like, EGC, Catechin, EC, EGCG, ECG, and caffeine in variable quantity in all cultivars that were positively correlated with larval feeding except the Gallic acid which showed a negative correlation (r = -0.5610). Based on the larval food consumption, the susceptible index of cultivars were categorized as ‘highly susceptible’ (TV20, TV1, K1/1, TV22, TV26, TV16, and SNT8), ‘susceptible’ (TS520 and HP12), and ‘moderately susceptible’ (B157). Based on cluster analysis A1 grouped (TS520 and HP12), A2 indicated B157 whereas sub-branches B1 grouped (TV22, TV16, TV26, and SNT8) and B2 grouped (TV1, TV20, and K1/1).

Health Benefits and Chemical Composition of Matcha Green Tea: A Review.

Japanese matcha is a type of powdered green tea, grown in a traditional way. Shading of the plants during the growth period enhances the processes of synthesis and accumulation of biologically active compounds, including theanine, caffeine, chlorophyll and various types of catechins. Green tea contains four main catechins, i.e., (−)-epicatechin (EC), (−)-epicatechin-3-gallate (ECG), (−)-epigallocatechin (EGC) and (−)-epigallocatechin-3-gallate (EGCG), of which the latter is the most active and abundant and matcha is their best condensed source. Due to its unique chemical composition and prized flavour, which sets it apart from other tea beverages, it is considered the highest quality tea. Its health-promoting properties are attributed to the high content of antioxidant and anti-inflammatory substances. Studies confirming the high antioxidant potential of tea beverages claim that it originates from the considerable content of catechins, a type of phenolic compound with beneficial effects on human health. Due to its potential for preventing many diseases and supporting cognitive function, regular consumption of matcha may have a positive effect on both physical and mental health. The aim of this review was to compile the health benefits of matcha tea. It is the first such review to be undertaken, and presents its main bioactive compounds in a systematic manner.

Beneficial impact of epigallocatechingallate on LDL-C through PCSK9/LDLR pathway by blocking HNF1\u03b1 and activating FoxO3a

BackgroundGreen tea drinking has been proven to lower lipid and exert cardiovascular protection, while the potential mechanism has not been fully determined. This study was to investigate whether the beneficial impact of epigallocatechingallate (EGCG), a type of catechin in green tea on lipids is associated with proprotein convertase subtilisin/kexin type 9 (PCSK9) pathways.MethodsWe studied the effects and underlying molecular mechanism of EGCG or green tea on regulating cholesterol from human, animal and in vitro.ResultsIn the age- and gender-matched case control observation, we found that individuals with frequent tea consumption (n = 224) had the lower plasma PCSK9 and low density lipoprotein cholesterol (LDL-C) levels compared with ones without tea consumption (n = 224, p < 0.05). In the high fat diet (HFD) fed rats, EGCG administration significantly lowered circulating PCSK9 concentration and liver PCSK9 expression, along with up-regulated LDL receptor (LDLR) expression but decreased level of LDL-C. In hepatic cell study, similar results were obtained regarding the impact of EGCG on LDLR and PCSK9 expression. The assay transposase-accessible chromatic with high-throughput sequencing (ATAC-seq) and subsequent results suggested that two transcription factors, hepatocyte nuclear factor-1α (HNF-1α) and forkhead box class O (FoxO) 3a involved in inhibitory action of EGCG on PCSK9 expression.ConclusionsThe present study demonstrates that EGCG suppresses PCSK9 production by promoting nuclear FoxO3a, and reducing nuclear HNF1α, resulting in up-regulated LDLR expression and LDL uptake in hepatocytes. Thereby inhibiting liver and circulating PCSK9 levels, and ultimately lowering LDL-C levels.

Elimination of hydrogen peroxide enhances tyrosinase-catalyzed synthesis of theaflavins

In this study, we found that hydrogen peroxide was generated during the separate incubation of four catechins, (-)-epicatechin, (-)-epigallocatechin, and their galloylated forms, in the absence or presence of mushroom tyrosinase (EC 1.14.18.1). In particular, autooxidation of (-)-epigallocatechin and enzymatic oxidation of (-)-epicatechin gallate contributed to the increase of hydrogen peroxide. We confirmed the hydrogen peroxide-induced inactivation of tyrosinase and found that hydrogen peroxide was also generated during the tyrosinase-catalyzed synthesis of theaflavins by selectively combining two types of catechins, diphenol- and pyrogallol-types. Elimination of hydrogen peroxide by co-incubation with bovine catalase (EC 1.11.1.6) increased the products in synthetic reactions for TF1, TF2A, TF2B, and TF3 by 15%, 16%, 45%, and 18%, respectively. Based on the prospective mechanism of the tyrosinase-catalyzed synthesis of theaflavins, the yield of TF2B increased by elevating the initial ratio of (-)-epigallocatechin/(-)-epicatechin gallate in the reaction media. Furthermore, under such conditions, there were clear ameliorative effects of catalase on the tyrosinase-catalyzed synthesis of TF2B, reaching 3.1-fold increase of the product compared to the reaction without catalase. These results support a novel strategy to use both tyrosinase and catalase for the efficient synthesis of theaflavins from catechins.

Catechin inhibits glycated phosphatidylethanolamine formation by trapping dicarbonyl compounds and forming quinone.

It is important to inhibit food-derived potentially hazardous glycated lipids with natural products. A model reaction inhibition system was established, and products were identified with high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) to study the inhibitory effects of four types of catechins on the formation of glycated 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE) products. The results show that the percentage inhibition of epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC) and epigallocatechin gallate (EGCG) on the formation of carboxymethyl 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (CM-DPPE) are 38.84%, 33.31%, 20.71% and 22.66%, respectively. The percentage inhibition of EC, ECG, EGC and EGCG on the formation of carboxyethyl 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (CE-DPPE) is 42.04%, 41.99%, 31.70% and 36.24%, respectively. In addition, catechin can capture glyoxal (GO) and methylglyoxal (MGO) to produce multiple products. O-Benzoquinone, the oxidation products of catechin, also captures DPPE to produce quinone-DPPE adducts. Therefore, there are two inhibitory mechanisms of tea-derived catechin for glycated DPPE: (1) catechin inhibits the formation of CM-DPPE and CE-DPPE by trapping reactive GO and MGO; and (2) catechin is oxidized to o-benzoquinone. O-Benzoquinone reacts with DPPE through nucleophilic substitution, which competes with the reaction between glucose and DPPE. This study will provide a theoretical basis for the use of natural products to inhibit the formation of food-derived glycated lipids.

Geography and the therapeutic effect of matcha tea in drinks

Camellia sinensis belonging to family Theaceae, commonly called as tea is the most widely used refreshing beverage accepted globally. It has two variety such as Green tea and black depending upon its method of cultivation. Green teas are non-fermented minimally oxidized variety of tea. Green tea has also attracted the research limelight because of its variety of Phenols with versatile pharmacology and health effects. There are wide range of green tea some are Biluochun, Gunpowder, Genmaicha, Matcha, Sencha. Matcha which commonly originates in Japan and is a type of powdered green tea, cultivated and produced in a traditional way. Shading of the plants during the growth period enhances the processes of accumulation and synthesis of biologically active compounds, including caffeine, theanine, chlorophyll and various types of catechins. Retention of chlorophyll results in soothing green colour of tea and theanine for it non bitter taste. Green tea contains four main catechins, i.e., (−)-epicatechin-3-gallate (ECG), (−)-epicatechin (EC), (−)-epigallocatechin-3-gallate (EGCG) and (−)-epigallocatechin (EGC), of which (−)-epigallocatechin-3-gallate (EGCG) is the most active and is present in abundance and matcha is their best condensed source. Matcha tea is considered as highest quality tea Due to its unique chemical composition and texture, which also sets it apart from other tea beverages. Its high content of antioxidant and anti-inflammatory substances attributes the various health-promoting properties. Due to its potential for preventing many diseases and illness, regular consumption of matcha may have a positive effect on both physical and mental health. The aim of this review was to compile the native origin and health benefits of matcha tea along with its side effects.

Effects of Green Tea (Sliming Herbal Tea) and Role of Dietary Practice to Reduce Obesity

Obesity is a cluster of non-transmissible diseases creating a massive socioeconomic and civil health burden in both developed and developing countries. The prevalence of obesity is increased in an alarming rate and one-third of the world’s population carrying obesity. Phenolic compounds from plant sources play a great role on obesity. Green tea or herbal tea that contains four types of catechins reduced cholesterol level through the modulation of bile acid absorption and metabolism.&#x0D; Objectives: the aim of this study was to monitor the effects of green tea and nutritional education about dietary habit on obese persons.&#x0D; Methods: A randomized control trial (n=20) of obese persons were selected as baseline study and a sliming herbal tea (green tea) with nutritional counseling was prescribed for 12 weeks to take regularly for twice in a day. Results: This study showed a positive impact on obese individuals. After 12 weeks intervention, BMI was decreased from 30.94 to 30.57, body weight, body fat and body fat mass were reduced from 72.50 to 71.36 kg, 32.06 to 30.18% and 27.38 to 25.52 kg respectively. Moreover, a dietary practice of high protein diet with low calorie and low fat diet was developed through nutrition counseling at the baseline study. Conclusion: Obesity management is a combined process. So, green tea with planned diet might be a fruitful effort to reduce body weight, body fat and overall BMI of an obese person.

EGCG promotes cell growth inhibition and reprograms mesenchymal‐epithelial transition by restoring CCN5/WISP2 in triple negative breast cancer cells in vitro and in vivo

Background and ObjectiveCCN5/WISP‐2, a matricellular secretory protein that is localized in both cytoplasm and nucleus, is mainly expressed in luminal cells rather than basal cell types in breast cancer tumors. Endogenous CCN5 plays critical role in promoting growth arrest and reprograming Mesenchymal to Epithelial Transition(MET), inhibition of migration and invasion, overall inducing the invasive to non‐invasive phenotypes. Thus, we hypothesize that targeting endogenous CCN5 restoration in Triple‐negative‐breast cancer (TNBC) cells could be an ideal strategy to prevent the progression of TNBC. To test the hypothesis, we set out to identify a molecule that has the capability to restore CCN5 in TNBC cells. Here we report that CCN5, which is normally absent in TNBC cells can be restored by a common dietary supplement epigallocatechin‐3‐gallate (EGCG), an ester of epigallocatechin and gallic acid, and is a type of catechin, to promote growth arrest and reverse EMT.MethodsEffect of EGCG on breast cancer cells were characterized by in vitro protein and gene expression profilings, cytotoxic assays, colony formation assays, migration assays, anchorage independent growth assays. In vivo effect of EGCG on tumorigenesis was investigated in xenograft model of immunosuppressive mice.Result and ConclusionEGCG treatment in breast cancer cells significantly elevated and restored CCN5 expression in TNBC cells along with inhibition of cell proliferation, migration and colony formation and induction of apoptosis. Reprogramming of mesenchymal to epithelial transition(MET) was also observed in EGCG‐treated TNBC cells. Oral administration of EGCG resulted in drastic inhibition of tumor growth and propagation in immunosuppressive mouse xenografts of MDA‐MB‐231 cells, along with restoration of CCN5 expression. Altogether, these studies clearly indicate that EGCG is an ideal molecule to restore CCN5 in TNBC cells in preventing the TNBC growth, progression and possibly make these cells susceptible to anti‐estrogen treatment, as restoration of CCN5 causes estrogen receptor(ER)‐α in TNBC cells. Moreover, it is reasonable to speculate that the CCN5 pathways probably play an important part in the anti‐tumorigenic role of EGCG in TNBC cells.Support or Funding InformationSupported by Midwest Biomedical Research Foundation and VA Merit Grant.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

(-)-Epigallocatechin-3-gallate and EZH2 inhibitor GSK343 have similar inhibitory effects and mechanisms of action on colorectal cancer cells.

Epigallocatechin-3-gallate (EGCG) is a type of catechin. It exhibits excellent antioxidant effects and anti-tumour activities for cancer chemoprevention. The mechanism of anti-tumour effects of EGCG on different cancers has been studied for the past few decades, but remains controversial. To investigate the potential role that EGCG may play in the epigenetic regulation of colorectal cancer (CRC) cell line, we integrated bioinformatics analysis with experimental validation. We found that levels of the enhancer of zeste homologue 2 (EZH2) were significantly higher in CRC tissues compared to normal adjacent tissues, based on the Genomic Data Commons (GDC) data portal. Different human CRC cell lines exhibited differing expression of levels of the EZH2 protein. In RKO cells, EGCG and the EZH2 inhibitor GSK343 exhibited similar inhibitory efficacy on the proliferation, invasion and migration abilities of the cells, and suppressed protein expression of trimethylated lysine 27 on histone H3 (H3K27me3), which may be caused by the loss of the enzymatic function of EZH2. EGCG and GSK343 were found to have a synergistic effect on the growth of RKO cells in lower concentrations. EZH2-correlated genes were enriched in the cell cycle pathway, the top-ranking up-regulated pathway in tumour tissues, based on pathway analyses using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Set Enrichment Analysis (GSEA). In accord with this, we confirmed that EGCG and GSK343 could both significantly arrest the G0/G1 phase in RKO cell cycle, suggesting EGCG and EZH2 inhibitor share a common mechanism of action in RKO cells.

Simultaneous Determination of Catechins and Caffeine in Green Tea-Based Beverages and Foods for Specified Health Uses

Catechins in green tea have various useful features including antioxidant activity and preventive effects on metabolic syndrome. Various beverages that are enriched with tea catechins are marketed as Foods for Specified Health Uses (FOSHU) in Japan. However, recent reports have indicated that excessive consumption of green tea extracts as a dietary supplement are associated with adverse health effects such as liver disorders. Various catechins and caffeine are constituents of FOSHU tea-based beverages. The amount of catechins in FOSHU products is displayed on labels as total catechin content, but the content of individual catechins are not provided. Although health hazards of FOSHU products have rarely been reported, precise information about the content and types of catechins in FOSHU products is needed to ensure safety. We used high-performance liquid chromatography with a photodiode array (HPLC/PDA) to simultaneously identify and quantify catechins and caffeine in green tea-based popular beverages and FOSHU beverages. This technique allowed simultaneous quantitation of five types of catechins and caffeine in green tea without complicated sample preparation. Epigallocatechin gallate (EGCG) and epigallocatechin EGC were the main catechins in various FOSHU beverages and the concentrations of almost all catechins were higher in FOSHU, than in popular green tea-based beverages. The concentrations of EGCG in green tea-based popular beverages and in FOSHU beverages were 5.4 - 7.3 and 10.2 - 41.9 mg/100mL, respectively, with the highest concentration being in a product named Healthya (approximately 147 mg/bottle). The simultaneous determination of compounds such as catechins and caffeine in FOSHU beverages can help to estimate beneficial and adverse effects to prevent deleterious effects on health and the excessive consumption of FOSHU beverages containing high concentrations of tea catechins should be avoided.

Interactions of digestive enzymes and milk proteins with tea catechins at gastric and intestinal pH

SummaryThe interactions of digestive enzymes (pepsin, pancreatin) and milk proteins (β‐casein, β‐lactoglobulin (β‐Lg)) with (−)‐epigallocatechin gallate (EGCG), (−)‐epigallocatechin (EGC) and (−)‐epicatechin (EC) at gastric and intestinal pH were investigated by fluorescence spectroscopy. The results indicated that in the gastric environment, all three tea catechins showed binding affinities in descending order of strength with β‐casein first, followed by β‐Lg and then pepsin. The highest affinity was observed for EGCG–β‐casein, with a binding constant (KA) of 2.502(±0.201) × 105 m−1. In the intestinal environment, the binding strengths of the proteins with EGCG and EGC were in the order β‐Lg &gt; pancreatin &gt; β‐casein; for binding with EC, the strength order was β‐casein &gt; β‐Lg &gt; pancreatin. The combination EGCG–β‐Lg had the strongest binding affinity, with a KA of 14.300(±0.997) × 105 m−1. Thermodynamic analysis revealed that tea catechins complexed with milk proteins and digestive enzymes via different hydrophilic and hydrophobic interactions depending on the different digestion environments and types of catechins, proteins and enzymes.

The cosmetic dose: how much are you getting?

One of the biggest differences between drugs and cosmetics is the amount of information available to determine the constituents of the product. Drugs are explicitly labeled with the number of milligrams contained in the pill. Tight quality control is enforced globally by government regulatory agencies to insure that manufacturers adhere to ingredient purity and formulation accuracy. While there are many rules that apply globally to cosmetics, dose is an issue that has not been felt to be pertinent. Now with the development of active cosmetics, better known to dermatologists as cosmeceuticals, the amount of the active ingredient in the formulation has become more important. It is necessary to recognize that the concept of dose is foreign to cosmeceuticals because cosmeceuticals is a regulatory unrecognized term and unrecognized category in the United States. Many cosmeceuticals use botanical ingredients to provide skin benefits such as antioxidant, anti-inflammatory, emolliency, and moisturization. While cosmetics are required to disclose ingredients in order of decreasing concentration, it is not possible to determine the exact amount of any individual ingredient. Even the cosmetic manufacturer may not know the exact concentration and type of catechin in a green tea extract. Raw material suppliers develop and manufacture extracts, but characterization is difficult, given the variability of substances grown in an outdoor environment. The amount of sun, water, and soil nutrients can affect the amount of catechins present in a green tea. Further, the location of the farm and the season of harvesting can have additional effects. It would be challenging to standardize plant materials in the same manner as drugs. It is my belief, however, that cosmeceuticals cannot scientifically advance until the dose is better characterized and standardized. The development of plant bioreactors has made the ability to determine the “dose” for plant extracts within reach. Plant bioreactors use stem cells as living machines to generate botanicals in a controlled environment allowing more accuracy in the characterization of these plant materials. Stem cells are pluripotential cells that can differentiate into many different structures derived from many different plant parts including berries, leaves, stems, twigs, and roots. Antioxidant botanicals are commonly derived from plant leaves, as the leaves are the site of photosynthesis and require excellent oxidative stress protection. Plant materials obtained from outdoor cultivation may contain a variety of contaminants to include heavy metals, pesticides, and fungal toxins. When the plant material is concentrated, so are the contaminants. One of the biggest concerns with frequent green tea consumption is the possibility of pesticide intake, as pesticides are used to prevent leaf damage in the fields. It is not possible to remove the pesticides completely from the leaves, and tea represents a concentrated use of the dried leaves. Utilizing stem cells eliminates this type of concern by allowing the plant material to grow under controlled laboratory conditions increasing purity. Stem cell-derived materials also have greater consistency of contents. The plant materials are cultured under optimal conditions to yield a more standard composition than those grown outdoors that may vary based on weather, soil condition, fertilizer application, etc. Consistency is key to obtaining botanical materials that have a standardized dose of ingredients. This is an important step in moving the science of cosmeceuticals forward. This new technology will be very important to cosmetic dermatology as active cosmetics advance in their efficacy and safety. Only through this type of ingredient development can dermatologists better understand how much patients are getting by using botanical extracts in skin care products.

Effect of EGCG on Expression of Neurogenin 3 via the MAP Kinase Signaling Pathway in AR42J Cells, a Rat Pancreatic Tumor Cell Line

Epigallocatechin gallate (EGCG), or epigallocatechin 3-gallate. is the ester of epigallocatcchin and gallic acid, and is a type of catec hin. EGCG may be therapeutic for many disorders including diabetic s and some types of cancer. Howev-er it is unknown whet her EGCG ca n induce transdifferentiation of pancreatic cells in pancreatitis. The aim of this study was to investigate the effects of EGCG on the expression of pancreatic regenerating related markers in pancreatic AR42J cells, a model of pancreatic progenitor cells. AR42J cells. differentiated with betacellulin and activin A, were cultured with/without EGCG in a time-dependent manner. Cell growth rate, levels of mRNA. and protein expression were examined with the MTT assay, quantitative PCR, and Western blots, respectively. The results showed that AR42J cell growth rates were inhibited by EGCG in a dose-dependent manner. mRNA and protein expression of amylase, insulin and neurogenin 3 (ngn 3) increased in AR42J cells treated with EGCG. Additionally, we demonstrated that the signal transduction pathway of mitogen-activated protein (MA P) kinase is active in EGCG-treated AR42J cells. ERK and JNK phosphorylation decreased in cells treated with EGCG but not p38 phosphorylation. Activation of the p38 MAP kinase pathway was confirmed by specific MAP kinase pathways inhibitors: U0126 for ERK, SP600126 for INK, and SB203580 for p38. Activated p38 phosphorylation was inhibited by the specific p38 inhibitor SB203580 but p38 phosphorylation was inhibit ed with increased EGCG treatment. The ERK and JNK MAP kinase pathways were not affected by EGCG treatment. Although further studies are needed, these result s suggest that EGCG affects the induction of pancreatic cell regeneration by increasing the ngn 3 protein and mRNA expression and activating the p38 MAP kinase pathway.

Estimation of Catechins Concentration of Green Tea Using Hyperspectral Remote Sensing

Models for the estimation of the concentration of catechins concentration in new green tea shoots were established using ground-based hyperspectral remote sensing. The coefficient of determination (R2) was determined to be more than 0.913, the root mean squared error of prediction (RMSEP) was determined to be less than 0.617 % and the relative error of prediction (REP) was determined to be less than 6.17%, except in the EGC model (R2=0.512, RMSEP=0.272%, and REP=15.7%). The regression coefficients of the green, red edge and near infrared regions were all changed, indicating that those regions were important for the estimation of catechin concentration. A similar trend was noted for the regression coefficients of ECg and EGCg. Therefore, the X -loadings of the first latent variables of ECg and EGCg (ester-type catechins) and EC and EGC (free-type catechins) were compared and the similarities between each type of catechin were determind. Therefore, each type of PLS regression model was designed based on date of the ester- and free-type catechins. The accuracy of the free-type model was as follows: R2=0.774, RMSEP=0.273% and REP=7.85%. The accuracy of ester-type model was as follows: R2=0.869, RMSEP=0.991% and REP=6.99%. The regression coefficients of the free-type catechins differed from those of the ester-type catechins. Large changes to the regression coefficients of the green to red, and red edge regions were also demonstrated.

Epicatechins Purified from Green Tea (Camellia sinensis) Differentially Suppress Growth of Gender‐Dependent Human Cancer Cell Lines

The anticancer potential of catechins derived from green tea is not well understood, in part because catechin-related growth suppression and/or apoptosis appears to vary with the type and stage of malignancy as well as with the type of catechin. This in vitro study examined the biological effects of epicatechin (EC), epigallocatechin (EGC), EC 3-gallate (ECG) and EGC 3-gallate (EGCG) in cell lines from human gender-specific cancers. Cell lines developed from organ-confined (HH870) and metastatic (DU145) prostate cancer, and from moderately (HH450) and poorly differentiated (HH639) epithelial ovarian cancer were grown with or without EC, EGC, ECG or EGCG. When untreated cells reached confluency, viability and doubling time were measured for treated and untreated cells. Whereas EC treatment reduced proliferation of HH639 cells by 50%, EGCG suppressed proliferation of all cell lines by 50%. ECG was even more potent: it inhibited DU145, HH870, HH450 and HH639 cells at concentrations of 24, 27, 29 and 30 µM, whereas EGCG inhibited DU145, HH870, HH450 and HH639 cells at concentrations 89, 45, 62 and 42 µM. When compared with EGCG, ECG more effectively suppresses the growth of prostate cancer and epithelial ovarian cancer cell lines derived from tumors of patients with different stages of disease.

Dietary catechins in relation to coronary heart disease death among postmenopausal women.

Catechins, one of the major groups of flavonoids, are bioactive compounds present in a variety of plant foods and beverages. Experimental data suggest that they might prevent chronic diseases in humans. We studied whether the intake of catechins was inversely associated with the risk of coronary heart disease death in a prospective study of postmenopausal women from Iowa. Between 1986 and 1998, 767 of 34,492 participants initially free of cardiovascular diseases died from coronary heart disease. There was a strong inverse association between the intake of (+)-catechin and (-)-epicatechin and coronary heart disease death, which was somewhat attenuated after multivariate adjustment (risk ratios from lowest to highest quintile: 1.00, 0.95, 0.97, 0.77, 0.76). This inverse association was most pronounced in women at low risk of coronary heart disease (non-smokers, free of diabetes mellitus and cardiovascular diseases). A high intake of "gallates," catechins typical of tea, was not associated with coronary heart disease death. Of the major catechin sources, apples and wine were inversely associated with coronary heart disease death. Our data suggest that preventive effects might be limited to certain types of catechins, or that these are indicators of other dietary components or a healthy lifestyle in general.

NMR Analytical Approach To Clarify the Antioxidative Molecular Mechanism of Catechins Using 1,1-Diphenyl-2-picrylhydrazyl.

Each tea catechin was reacted with 1,1-diphenyl-2-picrylhydrazyl (DPPH), and the reaction mixture was subjected to NMR analysis. The antioxidation mechanism of (+)-catechin [(+)-C] is considered to be due to the change of the B-ring to an o-quinone structure at first because of the appearance of two carbonyl signals. This is substantiated by trapping the compound as an adduct of a 1,2-phenylenediamine to an o-quinone. (-)-Epicatechin [(-)-EC] was also confirmed to give a similar result, but in the case of (-)-epigallocatechin [(-)-EGC] and ethyl gallate (EG) no carbonyl signals were observed. The antioxidation mechanisms of (-)-EGC and EG are different from those of (+)-C and (-)-EC. This may be one of the reasons for the differences of the antioxidative activities between the two types of catechins.