Heat-Epimerized Tea Catechins Rich in Gallocatechin Gallate and Catechin Gallate Are More Effective To Inhibit Cholesterol Absorption than Tea Catechins Rich in Epigallocatechin Gallate and Epicatechin Gallate

2003 ◽  
Vol 51 (25) ◽  
pp. 7303-7307 ◽  
Author(s):  
Ikuo Ikeda ◽  
Makoto Kobayashi ◽  
Tadateru Hamada ◽  
Koichi Tsuda ◽  
Hitomi Goto ◽  
...  
Keyword(s):  
Epigallocatechin Gallate ◽  
Cholesterol Absorption ◽  
Epicatechin Gallate ◽  
Tea Catechins ◽  
Gallocatechin Gallate

scholarly journals Anti-Trypanosoma cruzi Activity of Green Tea (Camellia sinensis) Catechins

2004 ◽  
Vol 48 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Cristina Paveto ◽  
María C. Güida ◽  
Mónica I. Esteva ◽  
Virginia Martino ◽  
Jorge Coussio ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Green Tea ◽  
Camellia Sinensis ◽  
Developmental Stages ◽  
Arginine Kinase ◽  
Epigallocatechin Gallate ◽  
Array Detector ◽  
Epicatechin Gallate ◽  
Active Compounds ◽  
Gallocatechin Gallate

ABSTRACT The trypanocidal action of green tea catechins against two different developmental stages of Trypanosoma cruzi is reported for the first time. This activity was assayed with the nonproliferative bloodstream trypomastigote and with the intracellular replicative amastigote parasite forms. An ethyl acetate fraction from Camellia sinensis green tea leaves, which contains most of the polyphenolic compounds and the maximal trypanocidal activity, was obtained by fractionation of the aqueous extract with organic solvents. The active compounds present in this extract were further purified by LH-20 column chromatography and were identified by high-performance liquid chromatography analysis with a photo diode array detector and gas chromatography coupled to mass spectroscopy. The following flavan-3-ols derivatives, known as catechins, were identified: catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, and epigallocatechin gallate. The purified compounds lysed more than 50% of the parasites present in the blood of infected BALB/c mice at concentrations as low as 0.12 to 85 pM. The most active compounds were gallocatechin gallate and epigallocatechin gallate, with minimal bactericidal concentrations that inhibited 50% of isolates tested of 0.12 and 0.53 pM, respectively. The number of amastigotes in infected Vero cells decreased by 50% in the presence of each of these compounds at 100 nM. The effects of the catechins on the recombinant T. cruzi arginine kinase, a key enzyme in the energy metabolism of the parasite, were assayed. The activity of this enzyme was inhibited by about 50% by nanomolar concentrations of catechin gallate or gallocatechin gallate, whereas the other members of the group were less effective. On the basis of these results, we suggest that these compounds could be used to sterilize blood and, eventually, as therapeutic agents for Chagas' disease.

scholarly journals Effect of Stereochemical Configuration on the Transport and Metabolism of Catechins from Green Tea across Caco-2 Monolayers

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1185
Author(s):  
Zeyi Ai ◽  
Shuyuan Liu ◽  
Fengfeng Qu ◽  
Haojie Zhang ◽  
Yuqiong Chen ◽  
...  
Keyword(s):  
Green Tea ◽  
Epigallocatechin Gallate ◽  
Dimensional Structure ◽  
Cancer Resistance ◽  
Epicatechin Gallate ◽  
Efflux Transport ◽  
Transcellular Transport ◽  
P Glycoprotein ◽  
Gallocatechin Gallate ◽  
Resistance Protein

The transcellular transport and metabolism of eight green tea catechins (GTCs) were studied in Caco-2 monolayers, with the aim of investigating the effect of cis–trans isomerism on the membrane permeability and biotransformation of GTCs. The results showed that the catechin stereochemistry significantly affects the efflux transport rather than the absorption transport in the Caco-2 monolayers. The trans catechins showed a better transcellular permeability than their corresponding cis (epi) catechins in the efflux transport, as the efflux amount of trans catechins were all significantly higher than that of the cis (epi) catechins at each concentration and each time point tested. Moreover, the relative contents of the (+)-catechin (C)-O-sulfate, (+)-gallocatechin (GC)-O-sulfate, (−)-catechin gallate (CG)-O-sulfate, and (−)-gallocatechin gallate (GCG)-O-sulfate in the efflux transport were 2.67, 16.08, 50.48, and 31.54 times higher than that of the (−)-epicatechin (EC)-O-sulfate, (−)-epigallocatechin (EGC)-O-sulfate, (−)-epicatechin gallate (ECG)-O-sulfate, and (−)-epigallocatechin gallate (EGCG)-O-sulfate, respectively. It indicated that more metabolites were observed after the transcellular efflux of trans catechins. Furthermore, after two hours of incubation, the GTCs could significantly increase the expression of multidrug resistance-associated protein 2 (MRP2) and breast cancer-resistance protein (BCRP), and decrease the expression of P-glycoprotein in the Caco-2 cells. The regulation of GTCs on P-glycoprotein, MRP2, and BCRP could also be significantly influenced by the chemical and dimensional structure. In a conclusion, catechin stereochemistry significantly affects the transport and metabolism of GTCs when refluxed in the Caco-2 monolayers.

scholarly journals Molecular Rescue of Dyrk1A Overexpression Alterations in Mice with Fontup® Dietary Supplement: Role of Green Tea Catechins

2020 ◽  
Vol 21 (4) ◽  
pp. 1404 ◽  
Author(s):  
Yuchen Gu ◽  
Gautier Moroy ◽  
Jean-Louis Paul ◽  
Anne-Sophie Rebillat ◽  
Mara Dierssen ◽  
...  
Keyword(s):  
Green Tea ◽  
Epigallocatechin Gallate ◽  
Nutritional Supplement ◽  
Green Tea Extract ◽  
Epicatechin Gallate ◽  
Tea Catechins ◽  
Green Tea Catechins ◽  
Tea Extract ◽  
Vitro Effect

Epigallocatechin gallate (EGCG) is an inhibitor of DYRK1A, a serine/threonine kinase considered to be a major contributor of cognitive dysfunctions in Down syndrome (DS). Two clinical trials in adult patients with DS have shown the safety and efficacy to improve cognitive phenotypes using commercial green tea extract containing EGCG (45% content). In the present study, we performed a preclinical study using FontUp®, a new nutritional supplement with a chocolate taste specifically formulated for the nutritional needs of patients with DS and enriched with a standardized amount of EGCG in young mice overexpressing Dyrk1A (TgBACDyrk1A). This preparation is differential with previous one used, because its green tea extract has been purified to up 94% EGCG of total catechins. We analyzed the in vitro effect of green tea catechins not only for EGCG, but for others residually contained in FontUp®, on DYRK1A kinase activity. Like EGCG, epicatechin gallate was a noncompetitive inhibitor against ATP, molecular docking computations confirming these results. Oral FontUp® normalized brain and plasma biomarkers deregulated in TgBACDyrk1A, without negative effect on liver and cardiac functions. We compared the bioavailability of EGCG in plasma and brain of mice and have demonstrated that EGCG had well crossed the blood-brain barrier.

scholarly journals Exploring Inhibitory Mechanisms of Green Tea Catechins as Inhibitors of a Cancer Therapeutic Target, Nuclear Factor-κB (NF-κB)

2019 ◽  
Vol 16 (04) ◽  
pp. 715-723
Author(s):  
Mohd Suhail ◽  
Asma parveen ◽  
Amjad Husain ◽  
Mohd Rehan
Keyword(s):  
Transcription Factor ◽  
Green Tea ◽  
Therapeutic Target ◽  
Epigallocatechin Gallate ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Epicatechin Gallate ◽  
Tea Catechins ◽  
Green Tea Catechins ◽  
Cancer Types

Nuclear factor kappa B (NF-κB), a transcription factor is a well-established cancer therapeutic target. NF-κB’s linkage with cancer is known through the constitutive activation of NF-κB in several cancer types. The most important role of NF-κB as a transcription factor is its ability to promote cell survival through the induction of transcription of target pro-survival genes and thus inhibition of programmed cell death (PCD) by resulting proteins in both malignant and normal cells. Current findings have unveiled that green tea catechins exert anticancer effect by inhibiting the activity of various receptors including NF-κB. The current study is designed to gain the structural insights for inhibitory mechanism of catechin derivatives against NF-κB. The major green tea catechins include (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG) and are included in the current study. The study explored the binding pose, interacting residues, molecular interactions, and predicted binding energy and dissociation constant for the catechin derivatives. Our results showed that the catechin derivatives bound well in the DNA binding site with adequate binding strength scores. The study suggested that the four catechin derivatives may act as potential inhibitors of NF-κB and thus, may inhibit the progression of various cancer types.

Search for Compounds Suppressing Intestinal α-Glucosidase Expression in Caco-2 Cells

2019 ◽  
Vol 2 (2) ◽  
pp. 96-101
Author(s):  
Kota Noda ◽  
Eisuke Kato ◽  
Jun Kawabata
Keyword(s):  
Blood Glucose ◽  
Intestinal Tract ◽  
Cell Model ◽  
Epigallocatechin Gallate ◽  
Calluna Vulgaris ◽  
Active Principle ◽  
Intestinal Epithelial ◽  
Mrna Expression Level ◽  
Epicatechin Gallate ◽  
Control Post

Diabetes is a chronic disease characterized by elevated blood glucose level.Reducing carbohydrate absorption from the intestinal tract is an effective strategy to control post-meal blood glucose level. Inhibition of intestinal α-glucosidase, involved in digestion of carbohydrates, is known as an approach to accomplish this. On the other hand, reduction of α-glucosidase amount is expected to work in the similar manner. However, none of the previousstudy pursues this approach. A convenient assay was developed to evaluate α-glucosidase amount employing Caco-2 cells, the intestinal epithelial cell model reported to express α-glucosidase. Sixty plants were screened and two candidate plants, Calluna vulgaris and Perilla frutescens var. crispa were found to reduce α-glucosidase expression. C. vulgaris extract was subjected to activity guided isolation. Proanthocyanidin was identified as the active principle which was analyzed by thiol decomposition to reveal the components as a mixture ofcatechin, epicatechin, epigallocatechin, and A type procyanidin dimer. The proanthocyanidin suppressed about 30% of α-glucosidase amount evaluated through convenient assay, and suppressed bulk of mRNA expression level of sucrase-isomaltase (SI) at 0.125 mg/mL. Several flavan-3-ol monomers were also tested, and epicatechin gallate and epigallocatechin gallate were found to suppress α-glucosidase amount significantly.

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