Green tea catechin enhances cholesterol 7α-hydroxylase gene expression in HepG2 cells

Green tea catechins are known to have hypocholesterolaemic effects in animals and human subjects. In the present study, we investigated the effects of green tea catechins on the mRNA level and promoter activity of hepatic cholesterol 7α-hydroxylase (CYP7A1), the rate-limiting enzyme in the conversion of cholesterol to bile acids, in human hepatoma cells. Real-time PCR assays showed that different catechins, ( − )-epicatechin gallate (ECG), ( − )-epigallocatechin-3-gallate (EGCG), ( − )-epigallocatechin (EGC) and ( − )-epicatechin (EC), up regulated the CYP7A1 mRNA level by 5·5-, 4·2-, 2·9- and 1·9-fold, respectively, compared with the control. The − 1312/+358 bp of the CYP7A1 promoter was subcloned into the pGL3 basic vector that includes luciferase as a reporter gene. ECG or EGCG significantly increased CYP7A1 promoter activity by 6·0- or 4·0-fold, respectively, compared with the control. Also, EGCG stimulated CYP7A1 at both mRNA level and promoter activity in a dose-dependent manner. These results suggest that the expression of the CYP7A1 gene may be directly regulated by green tea catechins at the transcriptional level.

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Beneficial Properties of Green Tea Catechins

International Journal of Molecular Sciences ◽

10.3390/ijms21051744 ◽

2020 ◽

Vol 21 (5) ◽

pp. 1744 ◽

Cited By ~ 12

Author(s):

Claudia Musial ◽

Alicja Kuban-Jankowska ◽

Magdalena Gorska-Ponikowska

Keyword(s):

Green Tea ◽

Antioxidant Properties ◽

Biologically Active ◽

Hydroxyl Groups ◽

Molecular Signaling ◽

Epicatechin Gallate ◽

Tea Catechins ◽

Green Tea Catechins ◽

Antioxidant Agents ◽

Anti Inflammatory

Green tea (Camellia sinesis) is widely known for its anticancer and anti-inflammatory properties. Among the biologically active compounds contained in Camellia sinesis, the main antioxidant agents are catechins. Recent scientific research indicates that the number of hydroxyl groups and the presence of characteristic structural groups have a major impact on the antioxidant activity of catechins. The best source of these compounds is unfermented green tea. Depending on the type and origin of green tea leaves, their antioxidant properties may be uneven. Catechins exhibit the strong property of neutralizing reactive oxygen and nitrogen species. The group of green tea catechin derivatives includes: epicatechin, epigallocatechin, epicatechin gallate and epigallocatechin gallate. The last of these presents the most potent anti-inflammatory and anticancer potential. Notably, green tea catechins are widely described to be efficient in the prevention of lung cancer, breast cancer, esophageal cancer, stomach cancer, liver cancer and prostate cancer. The current review aims to summarize the potential anticancer effects and molecular signaling pathways of major green tea catechins. It needs to be clearly emphasized that green tea as well as green tea catechols cannot replace the standard chemotherapy. Nonetheless, their beneficial effects may support the standard anticancer approach.

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Green Tea Catechin Association with Ultraviolet Radiation-Induced Erythema: A Systematic Review and Meta-Analysis

Molecules ◽

10.3390/molecules26123702 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3702

Author(s):

Mahendra P. Kapoor ◽

Masaaki Sugita ◽

Yoshitaka Fukuzawa ◽

Derek Timm ◽

Makoto Ozeki ◽

...

Keyword(s):

Ultraviolet Radiation ◽

Green Tea ◽

Human Subjects ◽

Meta Analysis ◽

Random Effects Model ◽

Tea Catechins ◽

Oral Supplementation ◽

Green Tea Catechins ◽

Radiation Induced ◽

Green Tea Catechin

Catechins are a part of the chemical family of flavonoids, a naturally occurring antioxidant, and a secondary metabolite in certain plants. Green tea catechins are well recognized for their essential anti-inflammatory, photo-protective, antioxidant, and chemo-preventive functions. Ultraviolet radiation is a principal cause of damage to the skin. Studies observed that regular intake of green tea catechins increased the minimal dose of radiation required to induce erythema. The objectives of this systematic review and meta-analysis are to determine the effectiveness of green tea catechins in cutaneous erythema and elucidate whether green tea catechin consumption protects against erythema (sunburn) inflammation. A comprehensive literature search was conducted to identify the relevant studies. Two researchers carried out independent screening, data extraction, and quality assessment according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The pooled effect of green tea catechins on protection against erythema was assessed using approaches fixed-effects or random-effects model to quantify the effectiveness of green tea catechins in the erythema dose–response. Studies not be included in meta-analyses were summarized narratively. Six randomized controlled studies of enrolled studies regularly administrated green tea catechins orally for 6 to 12 weeks involving healthy volunteers comprising a total of 100 participants were included in the analysis. The results revealed green tea catechins have favorable protection against erythema inflammation even at increased minimal erythema dose (MED) of ultraviolet radiation. Meta-analysis results confirm oral supplementation of green tea catechins is highly effective at low-intensity ultraviolet radiation-induced erythema response (MED range; 1.25–1.30) compared to placebo, showing a significant pooling difference (p = 0.002) in erythema index (SMD: −0.35; 95% CI, −0.57 to −0.13; I2 = 4%, p = 0.40) in the random-effects model. The pro-inflammatory signaling pathways through oral supplementation with green tea catechins are an attractive strategy for photo-protection in healthy human subjects and could represent a complementary approach to topical sunscreens. Therefore, studies that involved green tea catechin in topical applications to human subjects were also evaluated separately, and their meta-analysis is presented as a reference. The evidence indicates that regular green tea catechin supplementation is associated with protection against UV-induced damage due to erythema inflammation.

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Green tea and obesity: Effects of catechins on the energetic metabolism

Postępy Higieny i Medycyny Doświadczalnej ◽

10.5604/01.3001.0014.8498 ◽

2021 ◽

Vol 75 ◽

pp. 265-271

Author(s):

Patrycja Gogga ◽

Monika Szałajda ◽

Agata Janczy

Keyword(s):

Green Tea ◽

Body Mass ◽

Significant Risk ◽

Biologically Active ◽

Acid Oxidation ◽

Dependent Manner ◽

Energetic Metabolism ◽

Tea Catechins ◽

Green Tea Catechins

Obesity is a metabolic disease which has now reached epidemic proportions, becoming a major health, social, and economic problem worldwide. Untreated obesity is associated with decreased quality of life and is a significant risk factor for the development of other serious health problems, such as diabetes and cardiovascular diseases. For this reason, new approaches to prevent excess body mass and to support its reduction if necessary are being examined. Catechins extracted from green tea – especially epigallocatechin gallate (EGCG) – are one of the most widely investigated biologically active substances. In addition to the antioxidant, anti-inflammatory, and anticarcinogenic properties of the catechins, they also exhibit a role in maintaining normal fat mass and body mass. There are numerous research studies showing that regular green tea consumption is associated with lower body mass, BMI, and waist circumference. In vitro and animal experiments confirm beneficial effects of catechins on the energetic metabolism. These compounds lower lipid and carbohydrates absorption in the intestine. Additionally, they affect the energetic metabolism, lowering the rate of lipogenesis and adipogenesis, while stimulating lipolysis and fatty acid oxidation, and increasing energy expenditure. Moreover, it has been established that green tea catechins have an effect on the glucose uptake in the insulin-dependent manner – by GLUT4. The aim of the following paper was to review and summarize the literature data concerning the role of green tea catechins in the prevention and treatment of obesity.

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Osteoprotective Roles of Green Tea Catechins

Antioxidants ◽

10.3390/antiox9111136 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1136

Author(s):

Hsuan-Ti Huang ◽

Tsung-Lin Cheng ◽

Sung-Yen Lin ◽

Cheng-Jung Ho ◽

Joanna Y. Chyu ◽

...

Keyword(s):

Green Tea ◽

Large Scale ◽

Human Subjects ◽

Safety Data ◽

Common Disease ◽

Tea Catechins ◽

Green Tea Catechins ◽

Anti Oxidant ◽

In Vitro Effects

Osteoporosis is the second most common disease only secondary to cardiovascular disease, with the risk of fracture increasing with age. Osteoporosis is caused by an imbalance between osteoblastogenesis and osteoclastogenesis processes. Osteoclastogenesis may be enhanced, osteoblastogenesis may be reduced, or both may be evident. Inflammation and high reactive oxygen enhance osteoclastogenesis while reducing osteoblastogenesis by inducing osteoblast apoptosis and suppressing osteoblastic proliferation and differentiation. Catechins, the main polyphenols found in green tea with potent anti-oxidant and anti-inflammatory properties, can counteract the deleterious effects of the imbalance of osteoblastogenesis and osteoclastogenesis caused by osteoporosis. Green tea catechins can attenuate osteoclastogenesis by enhancing apoptosis of osteoclasts, hampering osteoclastogenesis, and prohibiting bone resorption in vitro. Catechin effects can be directly exerted on pre-osteoclasts/osteoclasts or indirectly exerted via the modulation of mesenchymal stem cells (MSCs)/stromal cell regulation of pre-osteoclasts through activation of the nuclear factor kB (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) system. Catechins also can enhance osteoblastogenesis by enhancing osteogenic differentiation of MSCs and increasing osteoblastic survival, proliferation, differentiation, and mineralization. The in vitro effects of catechins on osteogenesis have been confirmed in several animal models, as well as in epidemiological observational studies on human subjects. Even though randomized control trials have not shown that catechins provide anti-fracture efficacy, safety data in the trials are promising. A large-scale, placebo-controlled, long-term randomized trial with a tea regimen intervention of optimal duration is required to determine anti-fracture efficacy.

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

International Journal of Molecular Sciences ◽

10.3390/ijms21041404 ◽

2020 ◽

Vol 21 (4) ◽

pp. 1404 ◽

Cited By ~ 4

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.

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Computational Molecular Docking and X-ray Crystallographic Studies of Catechins in New Drug Design Strategies

Molecules ◽

10.3390/molecules23082020 ◽

2018 ◽

Vol 23 (8) ◽

pp. 2020 ◽

Cited By ~ 16

Author(s):

Shogo Nakano ◽

Shin-ichi Megro ◽

Tadashi Hase ◽

Takuji Suzuki ◽

Mamoru Isemura ◽

...

Keyword(s):

Green Tea ◽

Protein Interactions ◽

Crystallographic Analysis ◽

New Drugs ◽

Hydroxyl Groups ◽

Epicatechin Gallate ◽

Tea Catechins ◽

Computational Docking ◽

X Ray ◽

Green Tea Catechins

Epidemiological and laboratory studies have shown that green tea and green tea catechins exert beneficial effects on a variety of diseases, including cancer, metabolic syndrome, infectious diseases, and neurodegenerative diseases. In most cases, (−)-epigallocatechin gallate (EGCG) has been shown to play a central role in these effects by green tea. Catechins from other plant sources have also shown health benefits. Many studies have revealed that the binding of EGCG and other catechins to proteins is involved in its action mechanism. Computational docking analysis (CMDA) and X-ray crystallographic analysis (XCA) have provided detailed information on catechin-protein interactions. Several of these studies have revealed that the galloyl moiety anchors it to the cleft of proteins through interactions with its hydroxyl groups, explaining the higher activity of galloylated catechins such as EGCG and epicatechin gallate than non-galloylated catechins. In this paper, we review the results of CMDA and XCA of EGCG and other plant catechins to understand catechin-protein interactions with the expectation of developing new drugs with health-promoting properties.

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

Biosciences Biotechnology Research Asia ◽

10.13005/bbra/2787 ◽

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.

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