E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Special Issue "Catechin in Human Health and Disease"

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Natural Products Chemistry".

Deadline for manuscript submissions: 31 July 2018

Special Issue Editor

Guest Editor
Prof. Dr. Mamoru Isemura

University of Shizuoka, Tea Science Center, Shizuoka, Japan
Website | E-Mail
Interests: green tea; Catechin; lectin; cancer

Special Issue Information

Dear Colleagues,

Catechins are natural polyphenolic compounds that are distributed in a variety of foods and herbs. Tea (Camellia sinensis) is a rich source of catechins, especially epigallocatechin-3-gallate (EGCG), which has many biological activities beneficial for human health. These include anti-cancer, anti-obesity, anti-diabetic, anti-cardiovascular, anti-infectious, hepatoprotective, and neuroprotective effects. A number of human epidemiological and clinical studies on tea have provided evidence for its health benefits and these results have been supported by cell-based and animal experiments, although studies to show conflicting results have also been reported. In addition, detailed molecular mechanisms have been proposed for the action mechanism of tea’s major catechin EGCG. One of the most attractive mechanisms is the one in which reactive oxygen species (ROS) is involved. EGCG is known to have dual actions in relation to ROS as an anti-oxidant and a pro-oxidant. Several lines of evidence have indicated that EGCG can both eliminate ROS by scavenging and enhance ROS production. However, it remains unclear what factor(s) can direct EGCG to act as an anti-oxidant or a pro-oxidant.    Catechins and their oligomeric derivatives are also found in apples, persimmons, cacaos, grapes, berries, and so on. However, less information on biological activities of other catechin compounds has been available as compared with EGCG.   This Special Issue is devoted to promotion of the understanding of association of catechins and human health. Research articles and reviews related to catechin compounds to reveal their health effects and their mechanistic aspects are welcomed for inclusion in this Special Issue of Molecules. Topics will include cell-based, animal studies, and human studies and special focus will be given to mechanistically-informative studies to be useful to concinnate the dual action of EGCG and other catechin compounds on ROS. 

Prof. Dr. Mamoru Isemura
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • catechin
  • catechin-derivatives
  • anti-oxidant
  • pro-oxidant
  • ROS
  • human health

Published Papers (9 papers)

View options order results:
result details:
Displaying articles 1-9
Export citation of selected articles as:

Research

Jump to: Review

Open AccessFeature PaperArticle Binding of Catechins to Staphylococcal Enterotoxin A
Molecules 2018, 23(5), 1125; https://doi.org/10.3390/molecules23051125
Received: 19 April 2018 / Revised: 6 May 2018 / Accepted: 7 May 2018 / Published: 9 May 2018
PDF Full-text (1450 KB) | HTML Full-text | XML Full-text
Abstract
Staphylococcal enterotoxin A (SEA) is a toxin protein, and is the most common cause of staphylococcal food poisoning. Polyphenols, such as catechins, are known to interact with proteins. In this study, we investigated the binding of catechins to SEA using SPR (Biacore), Fourier
[...] Read more.
Staphylococcal enterotoxin A (SEA) is a toxin protein, and is the most common cause of staphylococcal food poisoning. Polyphenols, such as catechins, are known to interact with proteins. In this study, we investigated the binding of catechins to SEA using SPR (Biacore), Fourier transform infrared spectroscopy (FT-IR), isothermal titration calorimetry (ITC), and protein-ligand docking. We found that (−)-epigallocatechin gallate (EGCG) could strongly bind to SEA. According to thermodynamic parameters, a negative ΔG indicated that the interaction between EGCG and SEA was spontaneous, and the electrostatic force accompanied by hydrophobic binding forces may play a major role in the binding. Data from Western blot analysis and docking simulation suggest that the hydroxyl group at position 3 of the galloyl group in the catechin structure was responsible for binding affinity with the Y91 of the A-6 region of SEA active sites. Our results provide further understanding of the binding interactions between catechins and SEA, and the inhibition of toxin activities by catechins. Full article
(This article belongs to the Special Issue Catechin in Human Health and Disease)
Figures

Graphical abstract

Open AccessArticle Epigallocatechin Gallate-Modified Gelatin Sponges Treated by Vacuum Heating as a Novel Scaffold for Bone Tissue Engineering
Molecules 2018, 23(4), 876; https://doi.org/10.3390/molecules23040876
Received: 13 March 2018 / Revised: 5 April 2018 / Accepted: 9 April 2018 / Published: 11 April 2018
PDF Full-text (26139 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Chemical modification of gelatin using epigallocatechin gallate (EGCG) promotes bone formation in vivo. However, further improvements are required to increase the mechanical strength and bone-forming ability of fabricated EGCG-modified gelatin sponges (EGCG-GS) for practical applications in regenerative therapy. In the present study, we
[...] Read more.
Chemical modification of gelatin using epigallocatechin gallate (EGCG) promotes bone formation in vivo. However, further improvements are required to increase the mechanical strength and bone-forming ability of fabricated EGCG-modified gelatin sponges (EGCG-GS) for practical applications in regenerative therapy. In the present study, we investigated whether vacuum heating-induced dehydrothermal cross-linking of EGCG-GS enhances bone formation in critical-sized rat calvarial defects. The bone-forming ability of vacuum-heated EGCG-GS (vhEGCG-GS) and other sponges was evaluated by micro-computed tomography and histological staining. The degradation of sponges was assessed using protein assays, and cell morphology and proliferation were verified by scanning electron microscopy and immunostaining using osteoblastic UMR106 cells in vitro. Four weeks after the implantation of sponges, greater bone formation was detected for vhEGCG-GS than for EGCG-GS or vacuum-heated gelatin sponges (dehydrothermal cross-linked sponges without EGCG). In vitro experiments revealed that the relatively low degradability of vhEGCG-GS supports cell attachment, proliferation, and cell–cell communication on the matrix. These findings suggest that vacuum heating enhanced the bone forming ability of EGCG-GS, possibly via the dehydrothermal cross-linking of EGCG-GS, which provides a scaffold for cells, and by maintaining the pharmacological effect of EGCG. Full article
(This article belongs to the Special Issue Catechin in Human Health and Disease)
Figures

Graphical abstract

Open AccessArticle Antioxidant and Cytoprotective Effects of Tibetan Tea and Its Phenolic Components
Molecules 2018, 23(2), 179; https://doi.org/10.3390/molecules23020179
Received: 6 December 2017 / Revised: 22 January 2018 / Accepted: 23 January 2018 / Published: 24 January 2018
Cited by 1 | PDF Full-text (2820 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Tibetan tea (Kangzhuan) is an essential beverage of the Tibetan people. In this study, a lyophilized aqueous extract of Tibetan tea (LATT) was prepared and analyzed by HPLC. The results suggested that there were at least five phenolic components, including gallic
[...] Read more.
Tibetan tea (Kangzhuan) is an essential beverage of the Tibetan people. In this study, a lyophilized aqueous extract of Tibetan tea (LATT) was prepared and analyzed by HPLC. The results suggested that there were at least five phenolic components, including gallic acid, and four catechins (i.e., (+)-catechin, (−)-catechin gallate (CG), (−)-epicatechin gallate (ECG), and (−)-epigallocatechin gallate). Gallic acid, the four catechins, and LATT were then comparatively investigated by four antioxidant assays: ferric reducing antioxidant power, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical (PTIO•) scavenging, 1,1-diphenyl-2-picryl-hydrazl radical scavenging, and 2,2′-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) radical scavenging assays. In these assays, LATT, along with the five phenolic components, increased their antioxidant effects in a concentration-dependent manner; however, the half maximal scavenging concentrations of ECG were always lower than those of CG. Gallic acid and the four catechins were also suggested to chelate Fe2+ based on UV-visible spectral analysis. Ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC−ESI−Q−TOF−MS/MS) analysis suggested that, when mixed with PTIO•, the five phenolic components could yield two types of radical adduct formation (RAF) products (i.e., tea phenolic dimers and tea phenolic-PTIO• adducts). In a flow cytometry assay, (+)-catechin and LATT was observed to have a cytoprotective effect towards oxidative-stressed bone marrow-derived mesenchymal stem cells. Based on this evidence, we concluded that LATT possesses antioxidative or cytoprotective properties. These effects may mainly be attributed to the presence of phenolic components, including gallic acid and the four catechins. These phenolic components may undergo electron transfer, H+-transfer, and Fe2+-chelating pathways to exhibit antioxidative or cytoprotective effects. In these effects, two diastereoisomeric CG and ECG showed differences to which a steric effect from the 2-carbon may contribute. Phenolic component decay may cause RAF in the antioxidant process. Full article
(This article belongs to the Special Issue Catechin in Human Health and Disease)
Figures

Figure 1

Open AccessFeature PaperArticle Liposomal TriCurin, A Synergistic Combination of Curcumin, Epicatechin Gallate and Resveratrol, Repolarizes Tumor-Associated Microglia/Macrophages, and Eliminates Glioblastoma (GBM) and GBM Stem Cells
Molecules 2018, 23(1), 201; https://doi.org/10.3390/molecules23010201
Received: 20 November 2017 / Revised: 3 January 2018 / Accepted: 15 January 2018 / Published: 18 January 2018
Cited by 2 | PDF Full-text (10006 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Glioblastoma (GBM) is a deadly brain tumor with a current mean survival of 12–15 months. Despite being a potent anti-cancer agent, the turmeric ingredient curcumin (C) has limited anti-tumor efficacy in vivo due to its low bioavailability. We have reported earlier a strategy
[...] Read more.
Glioblastoma (GBM) is a deadly brain tumor with a current mean survival of 12–15 months. Despite being a potent anti-cancer agent, the turmeric ingredient curcumin (C) has limited anti-tumor efficacy in vivo due to its low bioavailability. We have reported earlier a strategy involving the use two other polyphenols, epicatechin gallate (E) from green tea and resveratrol (R) from red grapes at a unique, synergistic molar ratio with C (C:E:R: 4:1:12.5, termed TriCurin) to achieve superior potency against HPV+ tumors than C alone at C:E:R (μM): 32:8:100 (termed 32 μM+ TriCurin). We have now prepared liposomal TriCurin (TrLp) and demonstrated that TrLp boosts activated p53 in cultured GL261 mouse GBM cells to trigger apoptosis of GBM and GBM stem cells in vitro. TrLp administration into mice yielded a stable plasma concentration of 210 nM C for 60 min, which, though sub-lethal for cultured GL261 cells, was able to cause repolarization of M2-like tumor (GBM)-associated microglia/macrophages to the tumoricidal M1-like phenotype and intra-GBM recruitment of activated natural killer cells. The intratumor presence of such tumoricidal immune cells was associated with concomitant suppression of tumor-load, and apoptosis of GBM and GBM stem cells. Thus, TrLp is a potential onco-immunotherapeutic agent against GBM tumors. Full article
(This article belongs to the Special Issue Catechin in Human Health and Disease)
Figures

Figure 1

Open AccessArticle Dietary Copper Reduces the Hepatotoxicity of (−)-Epigallocatechin-3-Gallate in Mice
Received: 27 November 2017 / Revised: 22 December 2017 / Accepted: 23 December 2017 / Published: 23 December 2017
PDF Full-text (2021 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
We developed Cu-deficient, -sufficient and -super nutrition mice models by feeding them with diet containing 1.68, 11.72 or 51.69 mg of Cu/kg for 28 days, respectively. Then, the mice were treated to (−)-epigallocatechin-3-gallate (EGCG, 750 mg/kg BW) by oral in order to assess
[...] Read more.
We developed Cu-deficient, -sufficient and -super nutrition mice models by feeding them with diet containing 1.68, 11.72 or 51.69 mg of Cu/kg for 28 days, respectively. Then, the mice were treated to (−)-epigallocatechin-3-gallate (EGCG, 750 mg/kg BW) by oral in order to assess the acute toxicity of the drug. Following EGCG treatment, the survival rates were 12.5%, 50% and 100% in the Cu-deficient, -sufficient and Cu-super nutrition groups of mice, respectively. Cu level and ceruloplasmin activity in serum were significantly increased with the increase of dietary Cu. However, the Cu supplementation did not produce any obvious impact on serum superoxide dismutase activity. Furthermore, ceruloplasmin, in vitro, significantly promotes EGCG oxidation accompanied with increasing oxidation products and decreasing levels of reactive oxygen species. These results, therefore, suggest that Cu can relieve EGCG hepatotoxicity, possibly by up-regulating ceruloplasmin activity, which can be used to promote EGCG applications. Full article
(This article belongs to the Special Issue Catechin in Human Health and Disease)
Figures

Graphical abstract

Review

Jump to: Research

Open AccessReview A Review on the Weight-Loss Effects of Oxidized Tea Polyphenols
Molecules 2018, 23(5), 1176; https://doi.org/10.3390/molecules23051176
Received: 23 April 2018 / Revised: 6 May 2018 / Accepted: 9 May 2018 / Published: 14 May 2018
PDF Full-text (318 KB) | HTML Full-text | XML Full-text
Abstract
The mechanistic systems in the body through which tea causes weight loss are complex and multi-dimensional. Additionally, the bioactive components in tea such as catechins, caffeine, and products of tea polyphenol oxidation vary greatly from one major tea type to the next. Green
[...] Read more.
The mechanistic systems in the body through which tea causes weight loss are complex and multi-dimensional. Additionally, the bioactive components in tea such as catechins, caffeine, and products of tea polyphenol oxidation vary greatly from one major tea type to the next. Green tea has been the primary subject of consideration for investigation into the preventative health effects of tea because it contains the highest levels of phenolic compounds and retains the highest antioxidant capabilities of any major tea type. However, recent research suggests decreasing body fat accumulation has little to do with antioxidant activity and more to do with enzyme inhibition, and gut microbiota interactions. This paper reviews several different tea polyphenol-induced weight-loss mechanisms, and purposes a way in which these mechanisms may be interrelated. Our original ‘short-chain fatty acid (SCFA) hypothesis’ suggests that the weight-loss efficacy of a given tea is determined by a combination of carbohydrate digestive enzyme inhibition and subsequent reactions of undigested carbohydrates with gut microbiota. These reactions among residual carbohydrates, tea polyphenols, and gut microbiota within the colon produce short-chain fatty acids, which enhance lipid metabolism through AMP-activated protein kinase (AMPK) activation. Some evidence suggests the mechanisms involved in SCFA generation may be triggered more strongly by teas that have undergone fermentation (black, oolong, and dark) than by non-fermented (green) teas. We discussed the mechanistic differences among fermented and non-fermented teas in terms of enzyme inhibition, interactions with gut microbiota, SCFA generation, and lipid metabolism. The inconsistent results and possible causes behind them are also discussed. Full article
(This article belongs to the Special Issue Catechin in Human Health and Disease)
Open AccessReview The Role of Catechins in Cellular Responses to Oxidative Stress
Molecules 2018, 23(4), 965; https://doi.org/10.3390/molecules23040965
Received: 30 March 2018 / Revised: 17 April 2018 / Accepted: 18 April 2018 / Published: 20 April 2018
PDF Full-text (4568 KB) | HTML Full-text | XML Full-text
Abstract
Catechins are polyphenolic compounds—flavanols of the flavonoid family found in a variety of plants. Green tea, wine and cocoa-based products are the main dietary sources of these flavanols. Catechins have potent antioxidant properties, although in some cases they may act in the cell
[...] Read more.
Catechins are polyphenolic compounds—flavanols of the flavonoid family found in a variety of plants. Green tea, wine and cocoa-based products are the main dietary sources of these flavanols. Catechins have potent antioxidant properties, although in some cases they may act in the cell as pro-oxidants. Catechins are reactive oxygen species (ROS) scavengers and metal ion chelators, whereas their indirect antioxidant activities comprise induction of antioxidant enzymes, inhibition of pro-oxidant enzymes, and production of the phase II detoxification enzymes and antioxidant enzymes. Oxidative stress and ROS are implicated in aging and related dysfunctions, such as neurodegenerative disease, cancer, cardiovascular diseases, and diabetes. Due to their antioxidant properties, catechins may be beneficial in preventing and protecting against diseases caused by oxidative stress. This article reviews the biochemical properties of catechins, their antioxidant activity, and the mechanisms of action involved in the prevention of oxidative stress-caused diseases. Full article
(This article belongs to the Special Issue Catechin in Human Health and Disease)
Figures

Figure 1

Open AccessFeature PaperReview Synthesis of Theaflavins and Their Functions
Molecules 2018, 23(4), 918; https://doi.org/10.3390/molecules23040918
Received: 9 March 2018 / Revised: 11 April 2018 / Accepted: 12 April 2018 / Published: 16 April 2018
PDF Full-text (3439 KB) | HTML Full-text | XML Full-text
Abstract
Numerous epidemiological and interventional clinical studies have consistently reported that black tea is good for human health. The polyphenolic compound, theaflavin, and its galloyl esters (theaflavins) are the primary red pigments in black tea that possess several health benefits, including fat-reducing and glucose-lowering
[...] Read more.
Numerous epidemiological and interventional clinical studies have consistently reported that black tea is good for human health. The polyphenolic compound, theaflavin, and its galloyl esters (theaflavins) are the primary red pigments in black tea that possess several health benefits, including fat-reducing and glucose-lowering capabilities and lifestyle-related disease prevention related to anti-obesity, anticancer, anti-atherosclerotic, anti-inflammatory, antiviral, antibacterial, anti-osteoporotic, and anti-dental caries properties. These compounds are produced by key enzymes, such as polyphenol oxidase and peroxidase, from parent green tea catechins present in fresh green tea leaves during the production of black tea leaves or the fermentation of green tea. However, theaflavins are only present in low concentrations in black tea; thus, their extraction from black tea leaves at sufficient levels for use in medical studies has been difficult. To circumvent this issue, different procedures for the synthesis of theaflavins using chemical oxidizing reagents or enzymes have been studied; however, low yields have limited their utility. Recently, however, several biosynthetic methods have been developed for the mass production of theaflavins. Using these methods, the physiological functions of theaflavins in lifestyle-related diseases in mice and humans have also been studied. In this review, we present the synthesis of theaflavins and their health benefits. Full article
(This article belongs to the Special Issue Catechin in Human Health and Disease)
Figures

Figure 1

Open AccessReview Food-Grade Encapsulation Systems for (−)-Epigallocatechin Gallate
Molecules 2018, 23(2), 445; https://doi.org/10.3390/molecules23020445
Received: 2 February 2018 / Revised: 12 February 2018 / Accepted: 15 February 2018 / Published: 17 February 2018
Cited by 2 | PDF Full-text (726 KB) | HTML Full-text | XML Full-text
Abstract
(−)-Epigallocatechin gallate (EGCG) has attracted significant research interest due to its health-promoting effects such as antioxidation, anti-inflammation and anti-cancer activities. However, its instability and poor bioavailability have largely limited its efficacy and application. Food-grade materials such as proteins, carbohydrates and lipids show biodegradability,
[...] Read more.
(−)-Epigallocatechin gallate (EGCG) has attracted significant research interest due to its health-promoting effects such as antioxidation, anti-inflammation and anti-cancer activities. However, its instability and poor bioavailability have largely limited its efficacy and application. Food-grade materials such as proteins, carbohydrates and lipids show biodegradability, biocompatibility and biofunctionality properties. Food-grade encapsulation systems are usually used to improve the bioavailability of EGCG. In the present paper, we provide an overview of materials and techniques used in encapsulating EGCG, in which the adsorption mechanisms of food-grade systems during in vitro digestion are reviewed. Moreover, the potential challenges and future work using food-grade encapsulates for delivering EGCG are also discussed. Full article
(This article belongs to the Special Issue Catechin in Human Health and Disease)
Figures

Figure 1

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title: Effects of catechins on Alzheimer’s disease: Recent updates and perspectives
Authors: Kazuki Ide 1,2,3, Norihiro Matsuoka 4, Hiroshi Yamada 3, Daisuke Furushima 3, Koji Kawakami 1, 2
Affiliations: 1 Department of Pharmacoepidemiology, Graduate School of Medicine and Public Health, Kyoto University; Kyoto 606–8501, Japan
2 Center for the Promotion of Interdisciplinary Education and Research, Kyoto University; Kyoto
606–8501, Japan
3 Department of Drug Evaluation and Informatics, Graduate School of Pharmaceutical Sciences, University of Shizuoka; Shizuoka 422–8526, Japan
4 Jyoto Hospital, 11-22 Hanatenhigashi 2-chome, Tsurumi-ku Osaka-shi, Osaka, 538-0044, Japan
Abstract: Alzheimer’s disease (AD) is one of the most frequent neurodegenerative disorders worldwide. Its incidence is gradually increasing because of demographic aging. Therefore, AD prevention and modification is important to improve the elderly health status. Oxidative stress is a component of pathological mechanisms underlying AD. It is caused by a disruption of the balance between reactive oxygen species and antioxidant molecules. This imbalance also causes neuroinflammation. Catechins, which are bioactive components of tea, have antioxidative and anti-inflammatory effects. Moreover, their other potential properties related to AD prevention and modification have been reported in in vitro and in vivo studies. Several clinical studies have also been conducted to date. The current review summarizes recent updates and perspectives of the effects of catechins on AD based on the molecular mechanisms and related clinical studies.
Keywords: Alzheimer’s disease, catechins, molecular mechanisms, clinical study

Title: Lipid peroxidation diminishing perspective of isolated oxidized catechins (theaflavins and thearubigins) from black tea in arginine induced renal malfunctional Rats.
Author: Ali Imran
Abstract: Background: Recently oxidative stress induced maladies have amplified owing to sedentary lifestyle and monotonous diet. Introduction of plant based biomolecules may be a suitable strategy to cope with the lipid peroxidation. In this context, black tea polyphenols (theaflavin & thearubigins) are in fame among the scientific community as cost effective therapeutic agents owing to their safety, economics, structural diversity and ability to modulate various lipid peroxidation responses by halting the expression of different metabolic targets. Methods: The mandate of present investigation was to test the synergism among theaflavins & thearubigins against lipid peroxidative indicators both in vitro and in vivo. Purposely, theaflavins and thearubigins were isolated from black tea through solvent partition methods by using different solvents (Aqueous ethanol, Aqueous methanol & Water) and time intervals (30, 60 & 90 minutes) and subjected to in vitro characterization through different antioxidant indices to access the in vitro lipid peroxidation shooting effect of these bioactive moieties. Moreover, individual theaflavins contents also estimate through HPLC. For evaluation of in vivo antioxidant effect, renal malfunction was induced through arginine and forty rats were divided in four groups (10 each after power analysis) and 04 types of diets were given i.e. T0 (control diet without supplementation), T1 (Basic experimental Diet+ theaflavins supplementation @ 1g), T2 (Basic experimental Diet+ Thearubigins supplementation @ 1g) & T3 (Basic experimental Diet+ Supplementation of theaflavins+ thearubigins @ 0.5+0.5 g, respectively) for the period of 56 days. The body weight, lipid profile, glycemic responses, Renal function test, liver function test, antioxidant indices and hematological parameters were estimated at the termination of study.
Results: The results indicated that theaflavins and thearubigins isolation was significantly affected by time of extraction and solvent. In this context, aqueous ethanol at 60 minute extraction interval caused maximum extraction. Likewise, theaflavins isolate exhibited more antioxidant activity as compared to thearubigins. Moreover, the theaflavins and thearubigins based experimental diets imparted significant reduction in Lipid profile, glucose content, renal function tests and TBARS with enhancement in insulin, HDL and hematological parameters. In this context, theaflavin based diet caused maximum reduction in lipid profile and TBARS better as compared to thearubigins and theaflavins + thearubigins based. However, theaflavin+ thearubigins based diet caused highest glucose, urea & creatinine decline and maximum insulin increase & antioxidant indices as compared to other nutraceuticals.
Conclusions: it was deduced that theaflavins & thearubigins have strong antioxidative potential both in in vitro as well as in vivo to tackle the menace associated with lipid peroxidation.

Title: Probing the in vitro antioncogenic potential of isolated oxidized black tea polyphenols(theaflavins and thearubigins) against HCT-116 and HT 460 Colon and lung cancer cells"
Authors: Ali Imran1, Masood sadiq Butt2 and Hang Xiao3
Abstract: Theaflavins and thearubigins are the flavanols-3-ols found in black tea and have promising antioncogenic potential.  In current research, these fractions were isolated from black tea and probe for their in vitro inhibitory effect against colon and lung cancer cell lines. Results indicated that theaflavin, thearubigins and their combination caused significant inhibition in cell viability in dose dependent manner however, theaflavin imparted maximum reduction in cell viability of HCT 116 & HT460. The flow cytometry results indicated that theaflavin, thearubigins and their combination caused substantial cell arrest at G2/M phase. The effect was more obvious in lung cancer cells (HT 460) as compared to colon cells (HCT 116). Likewise, all treatments caused apoptosis however, the combination of theaflavin and thearubigins showed highest apoptotic ability in comparison of their alone treatments.  Conclusively, it was revealed that theaflavin and thearubigins showed synergistic effect and significantly inhibited the cell proliferation of HCT 116 & HT 460 in time and dose dependent manner by inducing apoptosis and cell cycle arrest however, theaflavin exhibited more pronounced effect.  
Keywords: HCT 116; HT 460; Lung cancer; Theaflavins; Thearubigins; synergistic effects

Tentative title: Roles of binding affinity of epigallocatechin-3-O-gallate with proteins in health benefits of green tea
Type: Review
Authors: Kouichi Saeki, Sumio Hayakawa, Shogo Nakano, Sohei Itoh, Yumiko Oishi and Mamoru Isemura
Abstract: Green tea has been shown to have beneficial effects on a variety of diseases such as cancer, obesity, diabetes, cardiovascular disease, and neurodegenerative disease. Green tea component, epigallocatechin-3-O-gallate (EGCG), has been believed to contribute to these effects through antioxidative and prooxidative actions. In addition, several lines of evidence have demonstrated that the binding affinity of EGCG to proteins involves in its action mechanism. There are several methods to demonstrate EGCG-protein bindings. These include dot assays, affinity chromatography, surface plasmon resonance, and computational docking analysis. The present review is aimed to update information from such studies on EGCG-protein interaction and discuss the molecular mechanism by which green tea exerts its health-promoting actions.

 

Back to Top