To see the other types of publications on this topic, follow the link: Catechines.
Journal articles on the topic 'Catechines'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Catechines.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
He, Hua-Feng, and Yang Ye. "Discrimination Based on Volatile Compounds and Differential Analysis of Chinese Dark Tea." Journal of Agricultural Science 8, no. 9 (2016): 115. http://dx.doi.org/10.5539/jas.v8n9p115.
Full textAbstract:
<p>Simultaneous distillion and extraction (SDE)/gas chromatographymass spectrometry (Gc-Ms) detection coupled with partial least squares-discriminate analysis (PLS-DA) were used to discriminate Chinese dark teas (CDTs). A total of 84 volatile compounds were taken to conduct the cluster analysis. 9 kinds of CDTs could be divided into 3 groups in consistent with the manufacturing processes. Besides, ingredients that were related with the quality of CDT, such as free amino acid, soluble sugar and catechines were analyzed. Differential trends were disclosed between Pu-Er raw tea and Pu-Er ripe tea as well as raw dark green tea (RDGT).</p>
2
Rogovskii, Vladimir S., Sergey V. Popov, Nikolai V. Sturov, and Nikolai L. Shimanovskii. "The Possibility of Preventive and Therapeutic Use of Green Tea Catechins in Prostate Cancer." Anti-Cancer Agents in Medicinal Chemistry 19, no. 10 (2019): 1223–31. http://dx.doi.org/10.2174/1871520619666190404153058.
Full textAbstract:
Background:Prostate cancer is one of the most frequent types of cancer. Despite the existence of various treatment strategies, treatment of prostate cancer still presents serious difficulties (especially in advanced stages). Polyphenols have been extensively assessed in terms of their potential use for prostate cancer treatment and prevention. Catechins are among the most well-known polyphenols in this respect.Objective:In this review, we summarize clinical study results concerning catechin applications with regard to prostate cancer treatment and prevention. We discuss some of the main mechanisms of the anticarcinogenic action of catechins.Conclusion:The main mechanisms of the anticarcinogenic action of catechins are subdivided into two major types: (i) direct action on cancer cells and (ii) indirect effect based on catechins’s impact on the microenvironment of cancer cells, particularly in relation to the immune system. At this level catechins might reduce tumor-associated inflammation and immune tolerance.
3
Markina, O. V., E. V. Maksimenko, N. V. Markin, et al. "STUDY OF COMPOSITION OF PLANT EXTRACTS, POSSESSING ANTIMICROBIAL EFFECT AGAINST VIBRIO CHOLERAE EL TOR, USING HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY." Journal of microbiology epidemiology immunobiology, no. 1 (February 28, 2016): 63–66. http://dx.doi.org/10.36233/0372-9311-2016-1-63-66.
Full textAbstract:
Aim. Study the composition of plant extracts using high-performance liquid chromatography (HPLC) and evaluation of their antimicrobial effect against Vibrio cholerae El Tor. Materials and methods. Qualitative and quantitative composition of plant extracts was studied using HPLC. Determination of sensitivity of microorganisms to plant extracts was carried out by diffusion into agar method and serial dilutions method. Results. Antibacterial effect of water, water-alcohol and acetone extracts of roots of Limonium gmelinii L., Berberis vulgaris L. and Glycyrrhiza glabra L. was studied. The most effective methods of extraction of biologically active substances, possessing antimicrobial effect against various strains of V.cholerae El Tor, were determined. Conclusion. The use of HPLC allowed to establish the presence of catechines, alkaloids protoberberines and glycyrrhizic acid in extracts, possessing antimicrobial effect against V.cholerae El Tor strains.
4
Furushima, Daisuke, Takuma Nishimura, Norikata Takuma, et al. "Prevention of Acute Upper Respiratory Infections by Consumption of Catechins in Healthcare Workers: A Randomized, Placebo-Controlled Trial." Nutrients 12, no. 1 (2019): 4. http://dx.doi.org/10.3390/nu12010004.
Full textAbstract:
Catechins, phytochemicals contained mainly in green tea, exhibit antiviral activity against various acute infectious diseases experimentally. Clinical evidence supporting these effects, however, is not conclusive. We performed a placebo-controlled, single-blind, randomized control trial to evaluate the clinical effectiveness of consumption of catechins-containing beverage for preventing acute upper respiratory tract infections (URTIs). Two hundred and seventy healthcare workers were randomly allocated to high-catechin (three daily doses of 57 mg catechins and 100 mg xanthan gum), low-catechin (one daily dose of 57 mg catechins and 100 mg xanthan gum), or placebo (0 mg catechins and 100 mg xanthan gum) group. Subjects consumed a beverage with or without catechins for 12 weeks from December 2017 through February 2018. The primary endpoint was incidence of URTIs compared among groups using a time-to-event analysis. A total of 255 subjects were analyzed (placebo group n = 86, low-catechin group n = 85, high catechin group n = 84). The URTI incidence rate was 26.7% in the placebo group, 28.2% in the low-catechin group, and 13.1% in the high-catechin group (log rank test, p = 0.042). The hazard ratio (95% confidence interval (CI)) with reference to the placebo group was 1.09 (0.61–1.92) in the low-catechin group and 0.46 (0.23–0.95) in the high-catechin group. These findings suggest that catechins combined with xanthan gum protect against URTIs.
5
Naparlo, Katarzyna, Grzegorz Bartosz, Ireneusz Stefaniuk, Bogumil Cieniek, Miroslaw Soszynski, and Izabela Sadowska-Bartosz. "Interaction of Catechins with Human Erythrocytes." Molecules 25, no. 6 (2020): 1456. http://dx.doi.org/10.3390/molecules25061456.
Full textAbstract:
The aim of this study was to characterize the interaction of chosen catechins ((+)-catechin, (−)-epigallocatechin (EGC), and (−)-epigallocatechin gallate (EGCG)) with human erythrocytes and their protective effects against oxidative damage of erythrocytes. Uptake of the catechins by erythrocytes was studied by fluorimetry, their interaction with erythrocyte membrane was probed by changes in erythrocyte osmotic fragility and in membrane fluidity evaluated with spin labels, while protection against oxidative damage was assessed by protection against hemolysis induced by permanganate and protection of erythrocyte membranes against lipid peroxidation and protein thiol group oxidation. Catechin uptake was similar for all the compounds studied. Accumulation of catechins in the erythrocyte membrane was demonstrated by the catechin-induced increase in osmotic resistance and rigidification of the erythrocyte membrane detected by spin labels 5-doxyl stearic acid and 16-doxyl stearic acid. (−)-Epigallocatechin and EGCG inhibited erythrocyte acetylcholinesterase (mixed-type inhibition). Catechins protected erythrocytes against permanganate-induced hemolysis, oxidation of erythrocyte protein thiol groups, as well as membrane lipid peroxidation. These results contribute to the knowledge of the beneficial effects of catechins present in plant-derived food and beverages.
6
Sasaki, Geoffrey, Yael Vodovotz, Zhongtang Yu, and Richard Bruno. "Catechin Bioavailability Is Reduced in Obese Persons Without Altering Gut Microbial-Derived Valerolactones Following Consumption of a Green Tea Extract Confection." Current Developments in Nutrition 4, Supplement_2 (2020): 468. http://dx.doi.org/10.1093/cdn/nzaa045_101.
Full textAbstract:
Abstract Objectives Green tea extract (GTE) protects against obesity in rodents by reducing gut permeability that otherwise provokes endotoxemia-mediated inflammation. However, whether obesity affects catechin bioavailability and microbial metabolism is unknown. We hypothesized that obesity will reduce catechin bioavailability by increasing microbial biotransformation of catechins. Methods Obese persons (n = 10 M/7F; 33.5 ± 0.7 kg/m2) and age-matched healthy persons (n = 10 M/9F; 21.7 ± 0.4 kg/m2) completed a pharmacokinetics (PK) trial in which a GTE confection [290 mg epigallocatechin gallate (EGCG), 87 mg epigallocatechin (EGC), 39 mg epicatechin (EC), 28 mg epicatechin gallate (ECG)] was ingested prior to collecting plasma at 0, 0.25, 0.5, 1, 2, 3, 5, 8, 10, and 12 h and urine from 0–4, 4–8, 8–12, and 12–24 h. Stool samples were collected and gut permeability was assessed prior to the 12-h PK trial. Plasma and urinary catechin/catechin-derived microbial metabolites were assessed following enzymatic hydrolysis by LC-MS. Results Regardless of health status, relative bioavailability, based on plasma area under the curve (AUC0–12 h), of GTE catechins were: EGCG &gt; EGC &gt; ECG &gt; EC. However, obese persons had 24–27% lower plasma AUC0–12 h for the four catechins compared to lean persons (P &lt; 0.05). They also had 18–36% lower maximum plasma concentrations (Cmax) of GTE catechins but 12 h plasma catechin concentrations were unaffected by obesity status (P &gt; 0.05). 3ʹ,4ʹ-γ-valerolactone (3,4-VL) was detected in the plasma of all participants, while 3ʹ,4ʹ,5ʹ-γ-valerolactone (3,4,5-VL) was detected in 74% and 82% of lean and obese persons, respectively. Plasma AUC0–12 h for these VL metabolites did not differ by obesity status. EGC, EC, 3,4-VL, and 3,4,5-VL, but not EGCG and ECG, were primarily present in urine and urinary total VLs were increased compared with total urinary catechins. However, 24-h urinary excretion of catechins and VLs were unaffected by obesity. Conclusions Obesity reduces GTE catechin bioavailability and Cmax independent of any change in VL metabolite appearance or urinary elimination of catechins, suggesting a gut-level mechanism that limits catechin absorption. Funding Sources Supported by USDA-NIFA and the Foods for Health Discovery Theme at The Ohio State University.
7
Ai, Zeyi, Shuyuan Liu, Fengfeng Qu, Haojie Zhang, Yuqiong Chen, and Dejiang Ni. "Effect of Stereochemical Configuration on the Transport and Metabolism of Catechins from Green Tea across Caco-2 Monolayers." Molecules 24, no. 6 (2019): 1185. http://dx.doi.org/10.3390/molecules24061185.
Full textAbstract:
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.
8
Furushima, Daisuke, Yu Otake, Natsumi Koike, et al. "Investigation of the Oral Retention of Tea Catechins in Humans: An Exploratory Interventional Study." Nutrients 13, no. 9 (2021): 3024. http://dx.doi.org/10.3390/nu13093024.
Full textAbstract:
Green tea catechin ingestion or gargling exhibit anti-viral activity against upper respiratory infection. We hypothesized that retention in the oral cavity could improve the anti-viral effects of catechins. The present study investigated the oral retention of catechins in humans and the effect of catechin beverage viscosity on oral retention. Two intervention studies with different test beverages, beverage-C (40 mL, containing 73.4 mg of catechins) and beverage-XT (40 mL, beverage-C containing 100 mg xanthan gum) were conducted in 20 healthy volunteers (mean age 38.7 years). Catechin concentrations were measured in buccal mucosa samples collected at 10 min, 40 min, and 60 min after ingesting test beverages, and the catechin variability of the tissue after intake was compared between test beverages. As a result, the mean (SEM) concentrations of EGCG were 99.9 (27.2), 58.2 (16.6), and 22.3 (5.7) ng/mg-mucosa at 10, 40, and 60 min, respectively, after ingestion of beverage-XT. Similarly, the catechin concentrations were 86.1 (20.3), 32.2 (5.3), and 27.8 (5.9) ng/mg-mucosa after ingestion of beverage-C. The total retention volume over 60 min tended to be slightly higher after ingestion of beverage-XT, though the difference was not statistically significant. Additional studies are needed to confirm the effect of xanthan gum on improving oral retention of catechins.
9
Mohd Zin, Zamzahaila, Nursyafiqah Mohamad, Chong Kah Hui, Nurul Izwanie Majid, and Mohd Khairi Zainol. "Effect of Acidified Ethanol on Antioxidant Properties of Morinda citrifolia Leaf Extract and Its Catechin Derivatives." Current Research in Nutrition and Food Science Journal 9, no. 1 (2021): 172–83. http://dx.doi.org/10.12944/crnfsj.9.1.17.
Full textAbstract:
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.
10
Zheng, Kaiwen, Kai Guo, Jing Xu, et al. "Study on the interaction between catechin and cholesterol by the density functional theory." Open Chemistry 18, no. 1 (2020): 357–68. http://dx.doi.org/10.1515/chem-2020-0038.
Full textAbstract:
AbstractCatechin – a natural polyphenol substance – has excellent antioxidant properties for the treatment of diseases, especially for cholesterol lowering. Catechin can reduce cholesterol content in micelles by forming insoluble precipitation with cholesterol, thereby reducing the absorption of cholesterol in the intestine. In this study, to better understand the molecular mechanism of catechin and cholesterol, we studied the interaction between typical catechins and cholesterol by the density functional theory. Results show that the adsorption energies between the four catechins and cholesterol are obviously stronger than that of cholesterol themselves, indicating that catechin has an advantage in reducing cholesterol micelle formation. Moreover, it is found that the molecular interactions of the complexes are mainly due to charge transfer of the aromatic rings of the catechins as well as the hydrogen bond interactions. Unlike the intuitive understanding of a complex formed by hydrogen bond interaction, which is positively correlated with the number of hydrogen bonds, the most stable complexes (epicatechin–cholesterol or epigallocatechin–cholesterol) have only one but stronger hydrogen bond, due to charge transfer of the aromatic rings of catechins.
11
Nakano, Shogo, Shin-ichi Megro, Tadashi Hase, et al. "Computational Molecular Docking and X-ray Crystallographic Studies of Catechins in New Drug Design Strategies." Molecules 23, no. 8 (2018): 2020. http://dx.doi.org/10.3390/molecules23082020.
Full textAbstract:
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.
12
Mabe, Katsuhiro, Masami Yamada, Itaro Oguni, and Tsuneo Takahashi. "In Vitro and In Vivo Activities of Tea Catechins against Helicobacter pylori." Antimicrobial Agents and Chemotherapy 43, no. 7 (1999): 1788–91. http://dx.doi.org/10.1128/aac.43.7.1788.
Full textAbstract:
ABSTRACT The catechin epigallocatechin gallate showed the strongest activity of the six tea catechins tested against Helicobacter pylori(MIC for 50% of the strains tested, 8 μg/ml). It had bactericidal activity at pH 7 but not at pH ≤5.0. In infected Mongolian gerbils,H. pylori was eradicated in 10 to 36% of the catechin-treated animals, with significant decreases in mucosal hemorrhage and erosion. Tea catechins, therefore, may have therapeutic effects on H. pylori infection.
13
Susanti, Erna, та Febiyanti Suratno. "Catechins Green Tea Clones GMB4 Inhibit Inflammation Process of Atherosclerosis Through Decreasing TNF-Α Levels". Journal of Islamic Pharmacy 1, № 1 (2016): 28. http://dx.doi.org/10.18860/jip.v1i1.3458.
Full textAbstract:
<p>Catechins Green tea clones GMB4 are potential natural subtances to inhibit inflammation process in atherosclerosis. The purpose of this research to determine activity of Catechins Green tea clones GMB4 to decrease TNF-α levels, as well as to determine optimal dose of Catechins. This research was conducted at the Laboratory of Physiology of the University of Brawijaya. The method used in this research is completely randomized design with five treatments: (1) Mice with standard feed (2) mice with high-fat diet (3) mice with high-fat diet + catechins 3mg / day (4) mice with a diet high fat + catechin 6mg / day (5) mice with high-fat diet + catechin 24mg / day. The treatment was done for 60 days and measured levels of TNF-α at the end of the research. The results showed that Catechins green tea clones GMB4 can inhibit the inflammatory process in atherosclerosis through decreasing levels of TNF-α at doses of 3mg / day. The conclusion of this research is catechins at a dose of 3 mg / day can inhibit inflammation in atherosclerosis significantly.</p><p> </p><strong>Keywords</strong> : GMB 4 green tea clones, Catechins, inflammation, TNF-α
14
Wu, Meishan, and Angela C. Brown. "Applications of Catechins in the Treatment of Bacterial Infections." Pathogens 10, no. 5 (2021): 546. http://dx.doi.org/10.3390/pathogens10050546.
Full textAbstract:
Tea is the second most commonly consumed beverage worldwide. Along with its aromatic and delicate flavors that make it an enjoyable beverage, studies report numerous health advantages in tea consumption, including applications in antimicrobial therapy. The antimicrobial properties of tea are related to catechin and its derivatives, which are natural flavonoids that are abundant in tea. Increasing evidence from in vitro studies demonstrated antimicrobial effects of catechins on both gram-positive and gram-negative bacteria, and proposed direct and indirect therapeutic mechanisms. Additionally, catechins were reported to be effective anti-virulence agents. Furthermore, a number of studies presented evidence that catechins display synergistic effects with certain antibiotics, thus potentiating the activity of antibiotics in resistant bacteria. Despite their numerous beneficial properties, catechins face many challenges in their development as therapeutic agents, including poor absorption, low bioavailability, and rapid degradation. The introduction of nanobiotechnology provides target-based and stable delivery, which enhances catechin bioavailability and optimizes drug efficacy. As further research continues to focus on overcoming the unresolved challenges, catechins are likely to see additional promising applications in our continual fight against bacterial infections.
15
Kapoor, Mahendra P., Masaaki Sugita, Yoshitaka Fukuzawa, Derek Timm, Makoto Ozeki, and Tsutomu Okubo. "Green Tea Catechin Association with Ultraviolet Radiation-Induced Erythema: A Systematic Review and Meta-Analysis." Molecules 26, no. 12 (2021): 3702. http://dx.doi.org/10.3390/molecules26123702.
Full textAbstract:
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.
16
Huang, Shiuh-Tsuen, Yi-An Hung, Meei-Ju Yang, Iou-Zen Chen, Jeu-Ming Yuann, and Ji-Yuan Liang. "Effects of Epigallocatechin Gallate on the Stability of Epicatechin in a Photolytic Process." Molecules 24, no. 4 (2019): 787. http://dx.doi.org/10.3390/molecules24040787.
Full textAbstract:
Catechins belonging to polyhydroxylated polyphenols are the primary compounds found in green tea. They are associated with many physiological properties. Epicatechin (EC) is a non-gallate-type catechin with four phenolic hydroxyl groups attached. The changes in EC treated with color light illumination in an alkaline condition were investigated by chromatographic and mass analyses in this study. In particular, the superoxide anion radical (O2•−) was investigated during the EC photolytic process. EC is unstable under blue light illumination in an alkaline solution. When EC was treated with blue light illumination in an alkaline solution, O2•− was found to occur via a photosensitive redox reaction. In addition, the generation of monomeric, dimeric, and trimeric compounds is investigated. On the other hand, epigallocatechin gallate (EGCG), which is a gallate-type catechin, is stable under blue light illumination in an alkaline solution. Adding EGCG, during the blue light illumination treatment of EC decreased photolytic formation, suggesting that gallate-type catechins can suppress the photosensitive oxidation of EC. Gallate-type catechins are formed via the esterification of non-gallate-type catechins and gallic acid (GA). The carbonyl group on the gallate moiety of gallate-type catechins appears to exhibit its effect on the stability against the photosensitive oxidation caused by blue light illumination.
17
Sabhapondit, Santanu, Tanmoy Karak, Lakshi Prasad Bhuyan, Bhabesh Chandra Goswami, and Mridul Hazarika. "Diversity of Catechin in Northeast Indian Tea Cultivars." Scientific World Journal 2012 (2012): 1–8. http://dx.doi.org/10.1100/2012/485193.
Full textAbstract:
Tea (Camellia sinensisL.) leaf contains a large amount of catechins (a group of very active flavonoids) which contribute to major quality attributes of black tea. Based on morphological characters tea plants were classified as Assam, China, and Cambod varieties. The present study is an attempt for biochemical fingerprinting of the tea varieties based on catechin composition in green leaf of cultivars grown in Northeast India. Assam variety cultivars contained the highest level of catechins followed by Cambod and China. The average catechin contents were 231 ± 7 mg g-1, 202 ± 5 mg g-1, and 157 ± 4 mg g-1of dry weight of green leaf for Assam, Cambod, and China cultivars, respectively. Among the individual catechins the variations in epigallocatechin gallate (EGCG) and epigallocatechin (EGC) were the most prominent among the varieties. High EGC content was found to be a characteristic of Assam variety which was further corroborated through multivariate analysis.
18
Yoo, So-Hee, Yeong-Eun Lee, Jin-Oh Chung, et al. "Addition of flavonols and polysaccharides as excipient ingredients into epicatechin rich green tea extract inhibited free radical formation and glucose uptake." Food & Function 11, no. 4 (2020): 3105–11. http://dx.doi.org/10.1039/c9fo03020d.
Full textAbstract:
Results from the current study suggested that whole green tea components rich in flavonols and polysaccharides could be potential hypoglycemic excipient ingredients into green tea catechins by enhancing catechin absorption.
19
Satoh, Takashi, Haruka Fujisawa, Ami Nakamura, Natsuko Takahashi, and Kazuhiro Watanabe. "Inhibitory Effects of Eight Green Tea Catechins on Cytochrome P450 1A2, 2C9, 2D6, and 3A4 Activities." Journal of Pharmacy & Pharmaceutical Sciences 19, no. 2 (2016): 188. http://dx.doi.org/10.18433/j3ms5c.
Full textAbstract:
PURPOSE: Green tea is a traditional beverage that has been enjoyed by the Japanese to this day. Recently, there has been an increase in the consumption of green tea beverage having high concentrations of catechins, such as (-)-epigallocatechin-3-O-gallate (EGCG). Many people tend to ingest large amounts of catechins through the frequent consumption of green tea beverage, and this dietary habit may lead to unwanted interactions between the catechins in green tea and medicinal drug. METHODS: The inhibitory effects of eight green tea catechins on drug metabolizing enzymes, cytochrome P450 (CYP) 1A2, 2C9, 2D6, and 3A4, were investigated in human liver microsomes. Incubation was initiated by the addition of cocktail probe drugs that served as specific substrates for each CYP, and the resulting metabolites were analyzed by LC-MS. RESULTS: From a comparison of the fifty percent inhibitory concentration (IC50) values of the eight green tea catechins, it was found that non-gallated catechins did not inhibit CYPs, whereas gallated catechins inhibited all CYPs except CYP2D6. Among them, CYP2C9 was most strongly inhibited by (-)-catechin-3-O-gallate (CG) (7.60 µM), and CYP1A2 was most strongly inhibited by EGCG (8.93 µM). Catechin gallate exhibited non-competitive inhibition of CYP2C9, and its Ki value was 9.76 ± 0.47µM. The present study is the first to report the inhibitory effect of CG on CYP2C9. In contrast, EGCG showed competitive inhibition of CYP1A2, and its Ki value was 14.3 ± 0.09 µM. CONCLUSION: Previous reports had predicted that plasma EGCG concentration reached 7.4 µM after ingesting green tea having high concentrations of catechins. That concentration of EGCG is equivalent to one-half to one-third of its Ki value for CYP1A2 and CYP3A4 in this study. The ingestion of beverages containing large amounts of green tea catechins together with drugs that are metabolized by CYP1A2, CYP2C9, and CYP3A4 should be avoided. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.
20
Chen, Jing, W. P. D. Wass Thilakarathna, Tessema Astatkie, and H. P. Vasantha Rupasinghe. "Optimization of Catechin and Proanthocyanidin Recovery from Grape Seeds Using Microwave-Assisted Extraction." Biomolecules 10, no. 2 (2020): 243. http://dx.doi.org/10.3390/biom10020243.
Full textAbstract:
Grape seed extract (GSE) is a rich source of condensed flavonoid tannins, also called proanthocyanidins (PACs). The high molecular weight of polymeric PAC limits their biological activity due to poor bioavailability. The present study was undertaken to explore the potential applicability of microwave-assisted extraction (MAE) to convert GSE-PAC into monomeric catechins. A central composite design (CCD) was used to optimize the processing conditions for the MAE. The maximum total yield of monomeric catechins (catechin, epicatechin, and epicatechin gallate) and PAC were 8.2 mg/g dry weight (DW) and 56.4 mg catechin equivalence (CE)/g DW, respectively. The optimized MAE condition was 94% ethanol, 170 °C temperature, and a duration of 55 min. Compared to the results for PACs extracted via conventional extraction (Con) (94% ethanol; shaking at 25 °C for 55 min), MAE yielded 3.9-fold more monomeric catechins and 5.5-fold more PACs. The MAE showed higher antioxidant capacity and α-glucosidase inhibitory activity than that of the conventional extract, suggesting the potential use of the MAE products of grape seeds as a functional food ingredient and nutraceutical.
21
Zhao, Chunjian, Chunying Li, Shuaihua Liu, and Lei Yang. "The Galloyl Catechins Contributing to Main Antioxidant Capacity of Tea Made fromCamellia sinensisin China." Scientific World Journal 2014 (2014): 1–11. http://dx.doi.org/10.1155/2014/863984.
Full textAbstract:
Total polyphenol content, catechins content, and antioxidant capacities of green, dark, oolong, and black teas made fromCamellia sinensisin China were evaluated. The total polyphenol content of 20 samples of tea was in the range of 7.82–32.36%. Total catechins content was in the range of 4.34–24.27%. The antioxidant capacity of tea extract was determined by the oxygen radical absorbance capacity (ORAC) test and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging test. Total polyphenol content, catechins content, and antioxidant capacity decreased in the following order: green > oolong > black > dark tea. A positive correlation existed between the antioxidant capacity and total polyphenol content or catechins content (R2=0.67–0.87). The antioxidant capacities of five major catechins (epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epicatechin, epigallocatechin, and catechin) were determined by online HPLC DPPH radical-scavenging; the antioxidant activity of tea was mainly attributed to the esterified catechins (EGCG or ECG).
22
Zhou, Juntong, Qingqing Tian, Yuezhu Ma, Yue Wang, and Qing Huo. "Lipase-catalyzed selective esterification of catechin." Materials Express 11, no. 6 (2021): 995–1000. http://dx.doi.org/10.1166/mex.2021.1971.
Full textAbstract:
Catechins show strong antioxidant, antitumoral, antiviral, and anti-inflammatory activities. The uses of catechins in food, cosmetic, and pharmaceutical formulations seem very attractive. Unfortunately, solubility and stability of catechins are poor in apolar media, which limits their efficient uses. In order to improve the solubility of catechins in the oil phase and maintain their oxidation resistance, a regioselective enzymatic acylation was investigated. The effects of reaction medium, water content, carbon chain length of acyl donor and other factors on the acylation reaction were studied, catechins were enzymatically esterified with an aliphatic acid (stearic acid) using an immobilized lipase Novozym 435 in n-butanol. The results show that when the ratio between catechins and stearic acid was 1:5, adding molecular sieves 4A after 11 h of reaction and the temperature of 60 °C led to the maximum conversion yield of 60.36%. Studies have shown that catechin stearate has a higher antioxidant activity than vitamin E and dibutyl hydroxytoluene (BHT).
23
Wangensteen, Helle, Gia M. Duong, Mahiuddin Alamgir, Mokadez Sarder, Anne B. Samuelsen, and Karl E. Malterud. "Biological Activities of Limonoids, Catechins, Procyanidins and Extracts from Xylocarpus granatum." Natural Product Communications 1, no. 11 (2006): 1934578X0600101. http://dx.doi.org/10.1177/1934578x0600101113.
Full textAbstract:
Procyanidins and catechins were found in high amounts in the methanol extract of the bark of the mangrove tree Xylocarpus granatum. The procyanidins showed a consistent structural pattern with catechin as the starter and epicatechin as the extender units. Four limonoids with a tetranortriterpenoid structure, previously identified in X. granatum, were isolated as well. Catechins, procyanidins, limonoids and plant extracts were evaluated for DPPH radical scavenging and 15-lipoxygenase (15-LO) inhibiting effects. Catechins and procyanidins demonstrated high activity, and the procyanidin of the pentamer type was found to be most potent (IC50; DPPH: 3.3 ± 0.3 μM, 15-LO: 9 ± 1 μM). Extracts were also found to have antibacterial activity.
24
Coșarcă, Sanda, Corneliu Tanase, and Daniela Lucia Muntean. "Therapeutic Aspects of Catechin and Its Derivatives – An Update." Acta Biologica Marisiensis 2, no. 1 (2019): 21–29. http://dx.doi.org/10.2478/abmj-2019-0003.
Full textAbstract:
Abstract Catechin and its derivatives are polyphenolic benzopyran compounds. The condensation of catechin units leads to the formation of condensed tannins. It is found in appreciable amount in green tea leaves, cocoa, red wines, beer, chocolate, etc. It possesses important antioxidant, antibacterial, antifungal, antidiabetic, anti-inflammatory, antiproliferative and antitumor properties. The present review outlines recent updates and perspectives of the effects of catechins and the pharmacodynamic mechanisms involved.
25
Suhail, Mohd, Asma parveen, Amjad Husain та Mohd Rehan. "Exploring Inhibitory Mechanisms of Green Tea Catechins as Inhibitors of a Cancer Therapeutic Target, Nuclear Factor-κB (NF-κB)". Biosciences, Biotechnology Research Asia 16, № 04 (2019): 715–23. http://dx.doi.org/10.13005/bbra/2787.
Full textAbstract:
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.
26
Syamsu Nur, Andi Nur Aisyah, Alfat Fadri, Sharfianty, Amriani Sapra, and Fitriyanti Jumaetri Sami. "Comparative study of catechin levels from green tea, oolong tea and black tea product with various treatments." GSC Biological and Pharmaceutical Sciences 14, no. 1 (2021): 001–10. http://dx.doi.org/10.30574/gscbps.2021.14.1.0416.
Full textAbstract:
Background: Tea is a refreshing drink that contains polyphenol compounds, namely catechins that are used for medicine and cosmetics. This study was to assess the content of catechin compounds in green tea, oolong and black tea products from Indonesia, China and Taiwan. Methods: Some tea products are brewed at varying temperatures (75±2; 85±2 and 95±20 C) and times (5; 10 and 15 minutes). Identification of catechin compounds was carried out using chemical reagents and UV spectrophotometry. The level of cathecin in tea products were analyzed by spectrophotometer at 280 nm wavelength. Results: The results obtained indicate that green tea, oolong tea and black tea contain epigallocatechin-3-gallate (EGCG) compounds according to the color change based on chemical reagents and for UV spectrum analysis which has λmax in the range 268-274 nm. The results of quantitative tests using UV-Vis spectrophotometry showed that the green tea samples gave the highest levels of catechins followed by oolong tea and black tea with brewing temperature at 95±20 °C. Conclusion: The catechin content of tea obtained from various products varies according to the type of processing method and the brewing temperature. Therefore, this study is expected to provide information related to catechin content to the public and researchers.
27
Sari, Liza Meutia. "Catechin: Molecular mechanism of Anti-Cancer Effect." Dentika Dental Journal 22, no. 1 (2019): 20–25. http://dx.doi.org/10.32734/dentika.v22i1.683.
Full textAbstract:
Over the recent decade, attention has been focused on the pathologic role of free radicals in a variety of diseases, which are most related to the carcinogenesis process. Carcinogenesis is a multi-step process that is induced primarily by carcinogens leading to the development of cancer. Extensive research in the last few years has revealed that regular consumption of certain fruits and vegetables can reduce the risk of acquiring specific cancers. Catechins are phytochemical compounds found in high concentrations in a variety of plant-based foods and beverages. Studies with cell lines have demonstrated that catechins affect signal transduction pathways, inhibit cell proliferation and induce apoptosis. More mechanistic studies in these areas will help us to understand the inhibitory action of catechin against carcinogenesis and provide background for evaluating the effects of catechin on human carcinogenesis.
28
Zhou, Rui-Qing, Xiao-Li Li, Yong He, and Juan-Juan Jin. "Determination of Catechins and Caffeine Content in Tea (Camellia sinensis L.) Leaves at Different Positions by Fourier-Transform Infrared Spectroscopy." Transactions of the ASABE 61, no. 4 (2018): 1221–30. http://dx.doi.org/10.13031/trans.12515.
Full textAbstract:
Abstract. In new shoots, the contents and distribution of catechins and caffeine, two important bioactive chemicals in tea ( L.), strongly reflect the physiology and nutrition of tea. In this study, four primary catechin monomers and caffeine in tea leaves at different positions on three cultivars were determined by Fourier-transform infrared (FTIR) transmission spectroscopy coupled to chemometrics. A combination of interval partial least squares (iPLS), competitive adaptive reweighted sampling (CARS), and successive projections algorithm (SPA) was used to extract characteristic wavenumbers that reflected the molecular characteristics of the constituents. Furthermore, Gaussian process regression (GPR) determination models were developed for all constituents with good predictability and robustness based on the extracted wavenumbers. The coefficients of determination for the prediction sets were all approximately 0.93, which indicated the high feasibility of FTIR spectroscopy for determination of catechins and caffeine in tea leaves. This analytical method could provide quick and efficient detection of catechin monomers and caffeine in fresh tea leaves, which have great impacts on the cultivation of tea trees and the selection of raw materials for tea processing. Keywords: Caffeine, Catechin, FTIR spectroscopy, Gaussian process regression, Quantification, Tea.
29
Takahashi, Masaki, Masashi Miyashita, Katsuhiko Suzuki, et al. "Acute ingestion of catechin-rich green tea improves postprandial glucose status and increases serum thioredoxin concentrations in postmenopausal women." British Journal of Nutrition 112, no. 9 (2014): 1542–50. http://dx.doi.org/10.1017/s0007114514002530.
Full textAbstract:
Elevated postprandial hyperglycaemia and oxidative stress increase the risks of type 2 diabetes and CVD. Green tea catechin possesses antidiabetic properties and antioxidant capacity. In the present study, we examined the acute and continuous effects of ingestion of catechin-rich green tea on postprandial hyperglycaemia and oxidative stress in healthy postmenopausal women. Participants were randomly assigned into the placebo (P,n11) or green tea (GT,n11) group. The GT group consumed a catechin-rich green tea (catechins 615 mg/350 ml) beverage per d for 4 weeks. The P group consumed a placebo (catechins 92 mg/350 ml) beverage per d for 4 weeks. At baseline and after 4 weeks, participants of each group consumed their designated beverages with breakfast and consumed lunch 3 h after breakfast. Venous blood samples were collected in the fasted state (0 h) and at 2, 4 and 6 h after breakfast. Postprandial glucose concentrations were 3 % lower in the GT group than in the P group (three-factor ANOVA, group × time interaction,P< 0·05). Serum concentrations of the derivatives of reactive oxygen metabolites increased after meals (P< 0·05), but no effect of catechin-rich green tea intake was observed. Conversely, serum postprandial thioredoxin concentrations were 5 % higher in the GT group than in the P group (three-factor ANOVA, group × time interaction,P< 0·05). These findings indicate that an acute ingestion of catechin-rich green tea has beneficial effects on postprandial glucose and redox homeostasis in postmenopausal women.
30
Moore, Rosalind J., Kim G. Jackson, and Anne M. Minihane. "Green tea (Camellia sinensis) catechins and vascular function." British Journal of Nutrition 102, no. 12 (2009): 1790–802. http://dx.doi.org/10.1017/s0007114509991218.
Full textAbstract:
The health benefits of green tea (Camellia sinensis) catechins are becoming increasingly recognised. Amongst the proposed benefits are the maintenance of endothelial function and vascular homeostasis and an associated reduction in atherogenesis and CVD risk. The mounting evidence for the influential effect of green tea catechins on vascular function from epidemiological, human intervention and animal studies is subject to review together with exploration of the potential mechanistic pathways involved. Epigallocatechin-3-gallate, one of the most abundant and widely studied catechin found in green tea, will be prominent in the present review. Since there is a substantial inconsistency in the published data with regards to the impact of green tea catechins on vascular function, evaluation and interpretation of the inter- and intra-study variability is included. In conclusion, a positive effect of green tea catechins on vascular function is becoming apparent. Further studies in animal and cell models using physiological concentrations of catechins and their metabolites are warranted in order to gain some insight into the physiology and molecular basis of the observed beneficial effects.
31
Sun, Haiyan, Meichen Yin, Danqing Hao, and Yixiao Shen. "Anti-Cancer Activity of Catechin against A549 Lung Carcinoma Cells by Induction of Cyclin Kinase Inhibitor p21 and Suppression of Cyclin E1 and P–AKT." Applied Sciences 10, no. 6 (2020): 2065. http://dx.doi.org/10.3390/app10062065.
Full textAbstract:
Catechin is one of the major polyphenols in teas, beans, and berry fruits. A number of studies have confirmed that catechins extract possesses health benefits in the prevention of various chronic diseases. In this study, the anti-cancer activity and mechanism of catechin against non-small cell lung cancer A549 cells were investigated. The inhibitory rate of catechin on the proliferation of A549 cells reached 19.76% at a concentration of 600 μmol·L−1 with 24 h incubation. The results demonstrated that catechin inhibits A549 cells by increasing the expressions of p21 and p27 in the cancer cells. Furthermore, the catechin treatment inhibited the expressions of cyclin E1 and phosphorylation of protein kinase (P–AKT) in a dose-dependent manner, which also contributed to the inhibition of cancer cell proliferation. Therefore, the results of this study indicated that catechin can effectively inhibit the proliferation of A549 cells through regulating its cell cycle arrest or indirectly via the p21 signaling pathway. It would provide important information for developing catechin and catechin-rich functional food or co-therapy for antitumor purposes.
32
Ferenczyová, Kristína, Lucia Kindernay, Jana Vlkovičová, Barbora Kaločayová, Tomáš Rajtík, and Monika Barteková. "Pharmacology of Catechins in Ischemia-Reperfusion Injury of the Heart." Antioxidants 10, no. 9 (2021): 1390. http://dx.doi.org/10.3390/antiox10091390.
Full textAbstract:
Catechins represent a group of polyphenols that possesses various beneficial effects in the cardiovascular system, including protective effects in cardiac ischemia-reperfusion (I/R) injury, a major pathophysiology associated with ischemic heart disease, myocardial infarction, as well as with cardioplegic arrest during heart surgery. In particular, catechin, (−)-epicatechin, and epigallocatechin gallate (EGCG) have been reported to prevent cardiac myocytes from I/R-induced cell damage and I/R-associated molecular changes, finally, resulting in improved cell viability, reduced infarct size, and improved recovery of cardiac function after ischemic insult, which has been widely documented in experimental animal studies and cardiac-derived cell lines. Cardioprotective effects of catechins in I/R injury were mediated via multiple molecular mechanisms, including inhibition of apoptosis; activation of cardioprotective pathways, such as PI3K/Akt (RISK) pathway; and inhibition of stress-associated pathways, including JNK/p38-MAPK; preserving mitochondrial function; and/or modulating autophagy. Moreover, regulatory roles of several microRNAs, including miR-145, miR-384-5p, miR-30a, miR-92a, as well as lncRNA MIAT, were documented in effects of catechins in cardiac I/R. On the other hand, the majority of results come from cell-based experiments and healthy small animals, while studies in large animals and studies including comorbidities or co-medications are rare. Human studies are lacking completely. The dosages of compounds also vary in a broad scale, thus, pharmacological aspects of catechins usage in cardiac I/R are inconclusive so far. Therefore, the aim of this focused review is to summarize the most recent knowledge on the effects of catechins in cardiac I/R injury and bring deep insight into the molecular mechanisms involved and dosage-dependency of these effects, as well as to outline potential gaps for translation of catechin-based treatments into clinical practice.
33
Martinez Pomier, Karla, Rashik Ahmed, and Giuseppe Melacini. "Catechins as Tools to Understand the Molecular Basis of Neurodegeneration." Molecules 25, no. 16 (2020): 3571. http://dx.doi.org/10.3390/molecules25163571.
Full textAbstract:
Protein misfolding as well as the subsequent self-association and deposition of amyloid aggregates is implicated in the progression of several neurodegenerative disorders including Alzheimer’s and Parkinson’s diseases. Modulators of amyloidogenic aggregation serve as essential tools to dissect the underlying molecular mechanisms and may offer insight on potential therapeutic solutions. These modulators include green tea catechins, which are potent inhibitors of amyloid aggregation. Although catechins often exhibit poor pharmacokinetic properties and bioavailability, they are still essential tools for identifying the drivers of amyloid aggregation and for developing other aggregation modulators through structural mimicry. As an illustration of such strategies, here we review how catechins have been used to map the toxic surfaces of oligomeric amyloid-like species and develop catechin-based phenolic compounds with enhanced anti-amyloid activity.
34
Koch, Wojciech, Wirginia Kukula-Koch, and Kazimierz Głowniak. "Catechin Composition and Antioxidant Activity of Black Teas in Relation to Brewing Time." Journal of AOAC INTERNATIONAL 100, no. 6 (2017): 1694–99. http://dx.doi.org/10.5740/jaoacint.17-0235.
Full textAbstract:
Abstract Black tea infusions are one of the most popular beverages across the world. Their extract composition depends on several factors, brewing time being one of the most important determinants. The aim of the present study was to determine the catechin composition of different black tea infusions using a validated LC electrospray ionization time-of-flight MS method. Additionally, total phenolic content (TPC) and antioxidant activity of infusions were evaluated using Folin–Ciocalteu reagent and stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). An optimized LC-MS method enabled the precise identification of the studied catechins [epicatechin (EC), EC gallate (ECG), epigallocatechin (EGC), and epigallocatechin-3-gallate (EGCG)] and gallic acid (GA). The major catechin in all investigated teas was EGC (25.6 mg/100 cm3 after 4 min of brewing). EC was present at the lowest concentration in all extracts. TPC and antiradical scavenging activity were in a good agreement with catechins and GA content. In general, the longer the brewing time, the higher the concentration of catechin, TPC, and antioxidant activity values. However, it should be noted that after 2 min brewing, most phenolics had already been extracted, and extract composition did not significantly change at a prolonged extraction time.
35
Haramizu, Satoshi, Noriyasu Ota, Tadashi Hase, and Takatoshi Murase. "Catechins attenuate eccentric exercise-induced inflammation and loss of force production in muscle in senescence-accelerated mice." Journal of Applied Physiology 111, no. 6 (2011): 1654–63. http://dx.doi.org/10.1152/japplphysiol.01434.2010.
Full textAbstract:
Catechins have a great variety of biological actions. We evaluated the potential benefits of catechin ingestion on muscle contractile properties, oxidative stress, and inflammation following downhill running, which is a typical eccentric exercise, in senescence-accelerated prone mice (SAMP). Downhill running (13 m/min for 60 min; 16° decline) induced a greater decrease in the contractile force of soleus muscle and in Ca2+-ATPase activity in SAMP1 compared with the senescence-resistant mice (SAMR1). Moreover, compared with SAMR1, SAMP1 showed greater downhill running-induced increases in plasma CPK and LDH activity, malondialdehyde, and carbonylated protein as markers of oxidative stress; and in protein and mRNA expression levels of the inflammatory mediators such as tumor necrosis factor-α and monocyte chemoattractant protein-1 in muscle. SAMP1 exhibited aging-associated vulnerability to oxidative stress and inflammation in muscle induced by downhill running. Long-term (8 wk) catechin ingestion significantly attenuated the downhill running-induced decrease in muscle force and the increased inflammatory mediators in both plasma and gastrocnemius muscle. Furthermore, catechins significantly inhibited the increase in oxidative stress markers immediately after downhill running, accompanied by an increase in glutathione reductase activity. These findings suggest that long-term catechin ingestion attenuates the aging-associated loss of force production, oxidative stress, and inflammation in muscle after exercise.
36
Zenkova, Maria, and Julia Pinchykova. "Chemical composition of sea-buckthorn and highbush blueberry fruits grown in the Republic of Belarus." Food Science and Applied Biotechnology 2, no. 2 (2019): 121. http://dx.doi.org/10.30721/fsab2019.v2.i2.59.
Full textAbstract:
Chemical composition of sea-buckthorn and highbush blueberry fruits determines their value while using them fresh or processed. Berries have distinctive characteristics depending on a variety, soil and climatic conditions and growing techniques. The object of the researches have been Sea-buckthorn (Hippophae L.) of three varieties (Podarok sadu, Trofimovskaya, Botanicheskaya) and Highbush Blueberry (Vaccinium corymbosum L.) of five varieties (Duke, Bluetta, Bluecrop, Northland, Coville) grown in the Republic of Belarus. Sea-buckthorn and Highbush Blueberry fruits chemical composition has been studied during a three-year cycle of monitoring using standard methods and in accordance with technical legal acts of the Republic of Belarus. Solid content (13,0-15,3%), sugar content (4,00-4,80%), organic acids (1,10-2,05%), nitrogen substances content (0,29-0,46%), lipids (3,6-6,2%), pectin content (0,40-0,50%), fiber (3,20-4,90%), minerals, vitamin С (44,7-78,7 мг/100г), β-carotene (4,4-13,2 мг/100г) have been studied in Sea-buckthorn (Hippophae L.). Solid content (12,2-15,1%), sugar content (2,73-3,96%), organic acids (0,59-0,95%), pectin content (0,57-0,97%), fiber (1,20-1,68%), bioflavonoids (276-368 мг/100 г), bioflavonoids complex fractional composition (anthocyanins, leucoanthocyanins, catechines, flavonols), vitamin С (60,5-72,2 мг/100 г) and mineral content have been studied in Highbush Blueberry (Vaccinium corymbosum L.). Exogenous contaminants content (arsenic, heavy metals), hygienical safety indexes, caesium 137 radionuclides content have been investigated in the fruits. Specific varieties characterictics of Sea-buckthorn (Hippophae L.) and Highbush Blueberry (Vaccinium corymbosum L.) fruit chemical composition have been determined. The studied fruit is fully safe and can be recommended to be used both fresh and processed.
37
Rupasova, Zhanna, Vladimir Reshetnikov, Аleksandr Yakovlev, et al. "COMPARATIVE ESTIMATION OF BIOCHEMICAL COMPOSITION OF FRUITS OF ERICACEAE SPECIES UNDER CONDITIONS OF BELARUS." EUREKA: Life Sciences 2 (March 31, 2016): 10–19. http://dx.doi.org/10.21303/2504-5695.2016.00102.
Full textAbstract:
Thus, as a result of biochemical screening of 30 taxons of Ericaceae species taking into account 32 parameters in a long-term cycle of observation it has been established the different degree of dependence of variability level of biochemical structure components of fruits of alien crops on genotype and a hydrothermal mode of the period of their maturing has been revealed. The similarity of parameters of genotypic variability of some traits of all investigated Ericaceae species is also revealed: low one – for the general contents in fruits of soluble sugars, flavonols, of potassium, calcium, magnesium and high one – for the contents of anthocyanins, and also the ratio of fractions of pectinaceous substances and bioflavonoids. Specific features of genetic determinacy of the analyzed traits, testifying the greatest degree of its displays of V. corymbosum for total accumulation of soluble sugars and bioflavonoids, flavonols contents, calcium and magnesium and by the lowest degree – for the contents of titratable acids, vitamin C, anthocyanins and values of a sugar-acid index were established. If to mention V. vitis-idaea L., the parameters of general accumulation in fruits of soluble sugars, dry substances and all major mineral elements were characterized by the greatest degree of genetic determinacy, whereas by the least degree – the contents of anthocyanins, catechines and tannins. If to mention V. macrocarpon, the parameters of accumulation in fruits of dry substances, nitrogen, potassium, calcium, phenol-carboxylic acids have been noted by the most expressed genetic determinacy, and by the least expressed – the contents of anthocyanins, sucrose and pectinaceous substances in fruits.
38
Yang, Chih-Ching, Chang-Jer Wu, Chen-Yen Chien, and Chiang-Ting Chien. "Green Tea Polyphenol Catechins Inhibit Coronavirus Replication and Potentiate the Adaptive Immunity and Autophagy-Dependent Protective Mechanism to Improve Acute Lung Injury in Mice." Antioxidants 10, no. 6 (2021): 928. http://dx.doi.org/10.3390/antiox10060928.
Full textAbstract:
Effective antiviral therapeutics are urgently required to fight severe acute respiratory syndrome (SARS) caused by a SARS coronavirus (SARS-CoV). Because polyphenol catechins could confer antioxidative, anti-inflammatory, antiviral, and antimicrobial activities, we assessed the therapeutic effects of catechins against SARS-CoV replication in Vero E6 cells, the preventive effect of catechins on CD25/CD69/CD94/CD8+ cytotoxic T lymphocytes-mediated adaptive immunity, and the protective effect on lipopolysaccharide-induced acute lung injury (ALI) in mice. We found that catechins containing 32.8% epigallocatechin gallate, 15.2% epicatechin gallate, 13.2 epicatechin, 10.8% epigallocatechin, 10.4% gallocatechin, and 4.4% catechin directly inhibited SARS-CoV replication at sub-micromolecular concentrations. Four-week catechins ingestion increased CD8+ T cell percentage, upregulated CD69+/CD25+/CD94-NKG2A/CD8+ T lymphocytes-mediated adaptive immunity, and increased type I cytokines release responding to ovalbumin/alum. Catechins significantly reduced lipopolysaccharide-induced cytokine storm and oxidative stress and ALI by inhibiting PI3K/AKT/mTOR signaling to upregulate Beclin-1/Atg5-Atg12/LC3-II-mediated autophagy mechanism. Pretreatment of autophagy inhibitor 3-Methyladenine reversed the inhibiting effects of catechins on the cytokines and oxidative stress levels and ALI. In conclusion, our data indicated that catechins directly inhibited SARS-CoV replication, potentiated the CD25/CD69/CD94/CD8+ T lymphocytes-mediated adaptive immunity and attenuated lipopolysaccharide-induced ALI and cytokine storm by PI3K/AKT/mTOR-signaling-mediated autophagy, which may be applied to prevent and/or treat SARS-CoV infection.
39
Kalidass, Sitharanjan, Karuppannau Daiyarvijaya, and Rajagopal Raj Kumar. "Comparative Study on Quantification of Total Catechins Using UV-Vis Spectrophotometric Method and High Performance Liquid Chromatography Techniques." Oriental Journal Of Chemistry 37, no. 1 (2021): 136–42. http://dx.doi.org/10.13005/ojc/370118.
Full textAbstract:
Bioavailability of catechinsin wider range of plants was established earlier and it’s utility as medicine against cardiovascular disease, cancer, etc. were also demonstrated. Recent techniques in relation to quantitative analysis of total catechins seem to be laborious and time consuming process to handle huge number of samples. Established spectrophotometry and HPLC methods developed earlier for quantitative determination of total catechins in tea extracts were compared in the present study.UV-Vis spectrophotometric method was adopted to monitor the absorbance at 500 nm of the reaction mixture (catechins and vanillin-H2SO4reagents). Hewlett Packard automated HPLC was used and equipped with Phenomenex Luna 5 phenyl-hexyl column fitted with a Phenomenex guard column. Binary elution was carried out using Mobile phase A (acetic acid and acetonitrile) and Mobile phase B (acetonitrile). Method adopted showed a good resolution of catechin fractions and was found to be accurate for the quantification of total catechins (sum of individual catechins). Results of the both the methods are comparable and variation amongst the two methods ranged between -3.59 and 2.79% among the clones and varied with seasons.As expected UPASI released tea clones exhibited variations in their bioavailability. Lean season edge over the cropping period sampling in terms of total catechins. Results obtained from both the methods are comparable. Two methods can be used for the routine quantitative analysis of total catechins; however, spectrophotometric method found to be simple, rapid and cost effective than that of HPLC method unless individual catechins composition is warranted.
40
Musial, Claudia, Alicja Kuban-Jankowska, and Magdalena Gorska-Ponikowska. "Beneficial Properties of Green Tea Catechins." International Journal of Molecular Sciences 21, no. 5 (2020): 1744. http://dx.doi.org/10.3390/ijms21051744.
Full textAbstract:
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.
41
Roman, Mark C., Jana Hildreth, and Silvia Bannister. "Determination of Catechins and Caffeine in Camillia sinensis Raw Materials, Extracts, and Dietary Supplements by HPLC-UV: Single-Laboratory Validation." Journal of AOAC INTERNATIONAL 96, no. 5 (2013): 933–41. http://dx.doi.org/10.5740/jaoacint.10-488.
Full textAbstract:
Abstract A rapid method has been developed to quantify seven catechins and caffeine in green tea (Camillia sinensis) raw material and powdered extract, and dietary supplements containing green tea extract. The method utilizes RP HPLC with a phenyl-based stationary phase and gradient elution. Detection is by UV absorbance. The total run time, including column re-equilibration, is 13 min. Single-laboratory validation (SLV) has been performed on the method to determine the repeatability, accuracy, selectivity, LOD, LOQ, ruggedness, and linearity for (+)-catechin, (–)-epicatechin, (–)-epicatechin gallate, (–)-epigallocatechin, (–)-gallocatechin gallate, (–)-epigallocatechin gallate, and (+)-gallocatechin, as well as caffeine. Repeatability precision and recovery results met AOAC guidelines for SLV studies for all catechins and caffeine down to a level of approximately 20 mg/g. Finished products containing high concentrations of minerals require the use of EDTA to prevent decomposition of the catechins.
42
Gregersen, Nikolaj T., Christian Bitz, Inger Krog-Mikkelsen, et al. "Effect of moderate intakes of different tea catechins and caffeine on acute measures of energy metabolism under sedentary conditions." British Journal of Nutrition 102, no. 8 (2009): 1187–94. http://dx.doi.org/10.1017/s0007114509371779.
Full textAbstract:
Green tea may stimulate energy metabolism; however, it is unclear if acute effects are caused by specific catechins, caffeine or their combination. The objective of the present study was to examine the separate and combined effects of different catechins and caffeine on energy expenditure (EE) and fat oxidation over a single day. Fifteen healthy, normal-weight males received capsules containing placebo, caffeine alone (150 mg), or caffeine plus a catechin mixture (600 mg) enriched in either epigallocatechin-3-gallate (EGCG), epigallocatechin or a mix of catechins, in a randomised cross-over double-blinded design. On each test day EE, respiratory quotient (RQ) and substrate oxidation were measured under sedentary conditions in a respiratory chamber for 13·5 h. We found no significant treatment effect on EE (P = 0·20) or RQ (P = 0·68). EGCG with caffeine insignificantly raised EE and fat oxidation v. caffeine-only and placebo (EE 5·71 (se 0·12) v. 5·68 (se 0·14) v. 5·59 (se 0·13) MJ/12·5 h, respectively; fat oxidation 84·8 (se 5·2) v. 80·7 (se 4·7) v. 76·8 (se 4·0) g/12·5 h). Catechin/caffeine combinations at these dosages and mode of application had non-significant acute effects on EE and fat oxidation. The maximum observed effect on EE of about 2 % could still be meaningful for energy balance over much longer period of exposure. However, higher short-term effects reported in the literature may reflect variations in green tea extracts, added caffeine, or synergies with physical activity. The specific mechanisms and conditions that may underpin observed longer-term benefits of catechin-enriched green tea consumption on body composition remain to be confirmed.
43
Paveto, Cristina, María C. Güida, Mónica I. Esteva, et al. "Anti-Trypanosoma cruzi Activity of Green Tea (Camellia sinensis) Catechins." Antimicrobial Agents and Chemotherapy 48, no. 1 (2004): 69–74. http://dx.doi.org/10.1128/aac.48.1.69-74.2004.
Full textAbstract:
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.
44
Krishnamoorthy, Rajapandiyan, Abdulraheem R. Adisa, Vaiyapuri Subbarayan Periasamy, Jegan Athinarayanan, Subash-Babu Pandurangan, and Ali A. Alshatwi. "Colonic Bacteria-Transformed Catechin Metabolite Response to Cytokine Production by Human Peripheral Blood Mononuclear Cells." Biomolecules 9, no. 12 (2019): 830. http://dx.doi.org/10.3390/biom9120830.
Full textAbstract:
Human gut microbes are a profitable tool for the modification of food compounds into biologically active metabolites. The biological properties of catechins have been extensively investigated. However, the bioavailability of catechin in human blood plasma is very low. This study aimed to determine the biotransformed catechin metabolites and their bioactive potentials for modulating the immune response of human peripheral blood mononuclear cells (PBMCs). Biotransformation of catechin was carried out using in-vitro gut microbial biotransformation method, the transformed metabolites were identified and confirmed by gas chromatography-mass spectrometry (GC–MS) and high-performance liquid chromatography-mass spectrometry (HPLC–MS). Present observations confirmed that the catechin was biotransformed into 11 metabolites upon microbial dehydroxylation and C ring cleavage. Further, immunomodulatory potential of catechin metabolites was analyzed in peripheral blood mononuclear cells (PBMCs). We found up-regulation of anti-inflammatory cytokine (IL-4, IL-10) and down-regulation of pro-inflammatory (IL-16, IL-12B) cytokine may be due to Th2 immune response. In conclusion, biotransformed catechin metabolites enhance anti-inflammatory cytokines which is beneficial for overcoming inflammatory disorders.
45
Susanti, Erna, and Endang Susilowati. "The Effect of Green Tea on the Expression of NPC1L1, ABCG5, and ABCG8 in the Intestine of High Fat Diets-induced Rats." Indonesian Biomedical Journal 13, no. 2 (2021): 147–54. http://dx.doi.org/10.18585/inabj.v13i2.1420.
Full textAbstract:
BACKGROUND: Signaling pathways contributing to cholesterol efflux and inhibitory inflammation in atherosclerosis that has not been explored is the liver X receptor (LXR). Catechin as LXR agonist influences the expression of Niemann-pick C1 like 1 (NPC1L1) protein transporter that triggers the inhibition of cholesterol absorption. This study aimed to examine the effect of Catechins on the expression of intestinal transporters: NPC1L1, ATP-binding cassete-proteins G5 (ABCG5) and G8 (ABCG8).METHODS: Twenty-five experimental animals were divided into five treatment groups, with 5 rats in each group. The groups were normal diet rats (group 1), high fat diets-induced rats (group 2), high fat diets-induced rats treated with 30 mg/kg body weight (BW) of Catechins (group 3), high fat diets-induced rats treated with 60 mg/kg BW of Catechins (group 4), and high fat diets-induced rats treated with 120 mg/kg BW of Catechins (group 5). After one-month, all rats were sacrificed, blood and intestine were collected. Lipid profile were determined enzymatically, mRNA levels were determined by reversetranscriptase polymerase chain reaction (RT-PCR), while the expression of protein transporter were determined by immunohistochemistry.RESULTS: Catechins treatment decreased the expression of NPC1L1, but increased the expression of ABCG5 and ABG8.CONCLUSION: Catechins can be developed as a candidate for NPC1L1 inhibitor to mediate the inhibiting absorption of intestinal cholesterol, therefore increasing the inhibitory effect of atherogenesis.KEYWORDS: ABCG5, ABCG8, aterogenesis, Catechins, green tea, NPC1L1
46
Jin, Yan, Jing Zhao, Eun Mi Kim, et al. "Comprehensive Investigation of the Effects of Brewing Conditions in Sample Preparation of Green Tea Infusions." Molecules 24, no. 9 (2019): 1735. http://dx.doi.org/10.3390/molecules24091735.
Full textAbstract:
Chemical and biological investigation of green tea has been generally performed while using different infusions that are prepared without consideration of the effects of sample preparation conditions. In this study, for the first time, the effects of green tea brewing conditions on the antioxidant activity and chemical profiles of metabolome and catechin compounds were examined at 60 °C and 95 °C for a period of 5–300 min. The antioxidant capacities of the tea infusions, which were assessed as per 2,2-diphenyl-1-picryl-hydrazyl hydrate (DPPH) radical scavenging activity, depended more on temperature than time. Metabolomics study that was based on ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UHPLC-QTOF/MS) revealed that the metabolic profiles, including 33 differential metabolites, were significantly changed by temperature and time, with the effects of time being more evident at 95 °C starting after 30 min. Infusions that were brewed at 95 °C for greater than 30 min yielded distinct profiles in the hierarchical clustering analysis. The quantification of eight catechins by UHPLC-QqQ/MS showed that the total catechin level peaked at 95 °C brewing at 10 min, after which the levels of four epi-forms of catechins decreased and those of four non-epi-forms increased, implying the epimerization of catechins over time. These results suggest that the brewing conditions for sample preparation of green tea should be put into careful consideration in studies where green tea extracts are applied as aqueous infusions.
47
Furushima, Daisuke, Kazuki Ide, and Hiroshi Yamada. "Effect of Tea Catechins on Influenza Infection and the Common Cold with a Focus on Epidemiological/Clinical Studies." Molecules 23, no. 7 (2018): 1795. http://dx.doi.org/10.3390/molecules23071795.
Full textAbstract:
Influenza and the common cold are acute infectious diseases of the respiratory tract. Influenza is a severe disease that is highly infectious and can progress to life-threating diseases such as pneumonia or encephalitis when aggravated. Due to the fact that influenza infections and common colds spread easily via droplets and contact, public prevention measures, such as hand washing and facial masks, are recommended for influenza prophylaxis. Experimental studies have reported that tea catechins inhibited influenza viral adsorption and suppressed replication and neuraminidase activity. They were also effective against some cold viruses. In addition, tea catechins enhance immunity against viral infection. Although the antiviral activity of tea catechins has been demonstrated, the clinical evidence to support their utility remains inconclusive. Since the late 1990s, several epidemiological studies have suggested that the regular consumption of green tea decreases influenza infection rates and some cold symptoms, and that gargling with tea catechin may protect against the development of influenza infection. This review briefly summarizes the effect of tea catechins on influenza infection and the common cold with a focus on epidemiological/clinical studies, and clarifies the need for further studies to confirm their clinical efficacy.
48
Hodges, Joanna, Geoffrey Sasaki, and Richard Bruno. "Epigallocatechin Is Eliminated Faster From Plasma Than Epigallocatechin Gallate: Mathematical Modeling of Green Tea Catechin Metabolism in Healthy Adults." Current Developments in Nutrition 5, Supplement_2 (2021): 323. http://dx.doi.org/10.1093/cdn/nzab037_033.
Full textAbstract:
Abstract Objectives The predominant catechins [epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin (EC), epicatechin gallate (ECG)] in green tea extract (GTE) vary in bioactivity. Our objective was to develop a physiologically relevant mathematical model of catechin metabolism and assess their fractional catabolic rates relative to their structural attributes, which may influence their bioactivities. Methods Pharmacokinetic data were collected from healthy adults (n = 18; 27 ± 7 y; 22 ± 2 kg/m2) after oral intake of 0.5 g GTE (EGCG: 290 mg, EGC: 87 mg, EC: 39 mg, ECG: 28 mg) delivered in 3 gelatin-based confections. Participants maintained a low-polyphenol diet for 3 d prior to the trial. Concentrations of deconjugated catechins were measured by LC-MS in plasma and urine collected at timed intervals over 12 and 24 h, respectively. A multi-compartment model of catechin metabolism was developed using the mean fraction of dose for all catechins. Data were fitted by iterative least squares regression analysis in WinSAAM software. Kinetic parameters for EGCG and EGC were compared using a Student t-test and one-way ANOVA. Results Observed data for each catechin were successfully fit into a 7-compartment model comprised of the gastrointestinal tract (stomach, small and large intestine), liver, plasma, extravascular tissues, and kidneys. Goodness of fit was ascertained by the estimated variability of parameters (FSD &lt; 0.5). Based on plasma response profiles, EGC and EC disappeared from plasma faster compared with EGCG and ECG. The highest fractional uptake was by the extravascular tissues (P &lt; 0.05) with no other between-organ differences. Compared with EGCG, EGC showed a higher fractional transfer from the liver to plasma (2.5 vs. 0.4 pools/h, P &lt; 0.001) and the uptake by kidneys (1.2 vs. 0.01 pools/h, P &lt; 0.001) with no difference in absorption. The fractional catabolic rate was also higher for EGC compared with EGCG (59.4 vs. 42.7 plasma pools/h, P &lt; 0.05), while its plasma transit time was shorter (0.9 vs. 1.3 min, P &lt; 0.05). Conclusions A 7-compartment model, to be validated in a future study, was successfully developed to demonstrate that EGC is eliminated faster compared with EGCG in healthy adults, suggesting that the gallate group may influence relative bioactivity of catechins. Funding Sources The Ohio State University and the National Institute of Food and Agriculture.
49
Kurniatri, Arifayu Addiena, Novi Sulistyaningrum, and Lina Rustanti. "Purifikasi Katekin dari Ekstrak Gambir (Uncaria gambir Roxb.)." Media Penelitian dan Pengembangan Kesehatan 29, no. 2 (2019): 153–60. http://dx.doi.org/10.22435/mpk.v29i2.1108.
Full textAbstract:
Abstract
 Uncaria gambir Roxb., one of native plants of Indonesia contains high levels of catechins. Catechins are very potential to be used for medicinal raw materials because theirs effects are proven to be antibacterial, antiviral, and antidyslipidemic. Derivatization of catechin can be developed to produce drug compounds that are effective as antiviral agents for HIV. Derivatization process needs pure catechin isolate as a starting material in order to obtain maximum result so that the isolation process is one of the important stages. In this study, isolation and purification of catechin isolate from Uncaria gambir Roxb. extract was carried out, which will then be the starting material in the derivatization of catechin. Gambir extract used for catechin isolation was a quality 1 gambir extract obtained from Padang, West Sumatra. Gambier extract is characterized according to the standard method stated in Farmakope Herbal Indonesia. Isolation of catechin from gambir extract was done by percolation method using ethyl acetate solvents. Pure catechin isolate was obtained using a vacuum liquid chromatograpy method with a series of solvent hexane and ethyl acetate gradients. Catechin purification was monitored using Thin Layer Chromatography (TLC) method with eluent chloroform:ethyl acetate:formic acid (5:4:1, then identified using High Performance Liquid Chromatography (HPLC), Nuclear Magnetic Resonance (NMR) Spectroscopy, and Liquid Cromatography- Mass Spectroscopy (LC-MS). The purity of catechin isolate obtained was 99.80%± 0.132.
 Abstrak
 Uncaria gambir Roxb., salah satu tanaman asli Indonesia yang mengandung katekin dengan kadar yang tinggi. Katekin sangat potensial digunakan untuk bahan baku obat karena efeknya terbukti sebagai antibakteri, antivirus, dan antidislipidemia. Derivatisasi katekin dapat dikembangkan untuk menghasilkan senyawa obat yang efektif sebagai antivirus untuk HIV. Untuk derivatisasi ini diperlukan isolat katekin murni sebagai starting material agar diperoleh hasil yang maksimal sehingga proses purifikasi isolat merupakan salah satu tahap yang penting. Dalam penelitian ini dilakukan isolasi dan pemurnian isolat katekin dari ekstrak Uncaria gambir Roxb. yang selanjutnya akan menjadi bahan awal dalam derivatisasi katekin. Ekstrak gambir yang digunakan untuk isolasi katekin adalah ekstrak gambir kualitas 1 yang diperoleh dari Padang, Sumatera Barat. Ekstrak gambir dikarakterisasi sesuai dengan metode standar yang tertera dalam Farmakope Herbal Indonesia. Isolasi katekin dari ekstrak gambir dilakukan dengan metode perkolasi menggunakan pelarut etil asetat. Isolat katekin murni diperoleh menggunakan metode kromatografi cair vakum (KCV) dengan serangkaian gradien pelarut heksana dan etil asetat. Pemurnian katekin dimonitor menggunakan metode kromatografi lapis tipis (KLT) dengan eluen kloroform : etil asetat : asam format (5:4:1), kemudian diidentifikasi menggunakan High Performance Liquid Chromatography (HPLC), spektroskopi Nuclear Magnetic Resonance (NMR), dan Liquid Cromatography-Mass Spectroscopy (LC- MS). Kemurnian isolat katekin yang didapatkan 99,80%± 0,132.
50
Silva, Ana Luísa, Q. G. Da Silva, Lauro Tatsuo Kubota, and A. T. Tanaka. "Determinação de catequinas por eletrodo de carbono impresso modificado com nanotubo de carbono funcionalizado." Eclética Química Journal 40, no. 1 (2015): 52. http://dx.doi.org/10.26850/1678-4618eqj.v40.1.2015.p52-61.
Full textAbstract:
Catechin is a phenolic compound with high oxidizing potential, found in several types of foods, some of the benefits of catechins are capillary strengthening, improvement of blood flow and reduction of cholesterol levels. In this paper, it was used the cyclic voltammetry technique (CV) to optimize the printed carbon electrode modified with carbon nanotube, functionalized to detect and quantify catechin by means of the squarewave voltammetry technique (SWV). For this electrode, the best results were obtained at a catechin concentration of 1x10-3 mol L-1 in means of 0.1 mol L-1 phosphate buffer pH 7.0 at a potential scan rate of 0.05 V s-1. From these conditions, an analytical curve was obtained with a linear behavior in the catechin concentration range of 1,68x10-5 to 2,0x10-7 mol L-1, with limits of detection and quantification of 9,2x10-8 and 3,0x10-7 mol L-1, respectively, by SWV. This electrode showed good repeatability with a standard deviation of 4.05%. Oxidation of catechin showed a peak located around 0,15V vs Ag / AgCl, being close to the peak potentials shown in the literature.