Journal articles: 'Tea polyphenols'

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Yang, Mengmeng, Fang Liang, Defeng Xu, Yue Wang, Huan Zhou, Darcy E Wagner, and Lei Liu. "Tea Polyphenols Selectively Inhibit Proliferation and Migration of Airway Smooth Muscle Cells." Journal of Biology and Life Science 9, no. 2 (April 18, 2018): 39. http://dx.doi.org/10.5296/jbls.v9i2.13018.

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Airway smooth muscle cells (ASMCs) have been recommended as a target for the treatment of inflammation and narrowing of the airways in asthma. New safe and efficient approaches to relieve symptoms caused by ASMCs is highly desired. Inspired by the inhibitory effects of tea polyphenols on vascular smooth muscle cells (VSMCs), tea polyphenols were applied in the current work to evaluate their regulation of ASMCs in vitro. A dose-dependent decrease of ASMCs density was observed after 24 h incubation with tea polyphenols. Additionally, ASMCs were significantly more sensitive to tea polyphenols than human bronchial epithelial cells (HBECs). Tea polyphenol treatment led to a dose dependent inhibition on ASMC migration and reduced the gene expression of nuclear factor-κB (NF-κB). In studies which compared the four main polyphenolic constituents of tea polyphenols—including epicatechin (EC), epicatechingallate (ECG), epigallocatechin (EGC) and epigallocatechingallate (EGCG)—on the proliferation of ASMCs, EGC was identified as being the most potent. These results suggest tea polyphenols are a promising agent for ASMCs targeted asthma control.

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Ranatunge, Imali, Subshini Adikary, Piumi Dasanayake, Chamira Dilanka Fernando, and Preethi Soysa. "Development of a Rapid and Simple Method to Remove Polyphenols from Plant Extracts." International Journal of Analytical Chemistry 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/7230145.

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Polyphenols are secondary metabolites of plants, which are responsible for prevention of many diseases. Polyvinylpolypyrrolidone (PVPP) has a high affinity towards polyphenols. This method involves the use of PVPP column to remove polyphenols under centrifugal force. Standards of gallic acid, epigallocatechin gallate, vanillin, and tea extracts(Camellia sinensis)were used in this study. PVPP powder was packed in a syringe with different quantities. The test samples were layered over the PVPP column and subjected to centrifugation. Supernatant was tested for the total phenol content. The presence of phenolic compounds and caffeine was screened by HPLC and measuring the absorbance at 280. The antioxidant capacity of standards and tea extracts was compared with the polyphenol removed fractions using DPPH scavenging assay. No polyphenols were found in polyphenolic standards or tea extracts after PVPP treatment. The method described in the present study to remove polyphenols is simple, inexpensive, rapid, and efficient and can be employed to investigate the contribution of polyphenols present in natural products to their biological activity.

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Evensen, Nikki A., and Phyllis C. Braun. "The effects of tea polyphenols onCandida albicans: inhibition of biofilm formation and proteasome inactivation." Canadian Journal of Microbiology 55, no. 9 (September 2009): 1033–39. http://dx.doi.org/10.1139/w09-058.

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The adherence of Candida albicans to one another and to various host and biomaterial surfaces is an important prerequisite for the colonization and pathogenesis of this organism. Cells in established biofilms exhibit different phenotypic traits and are inordinately resistant to antimicrobial agents. Recent studies have shown that black and green tea polyphenols exhibit both antimicrobial and strong cancer-preventive properties. Experiments were conducted to determine the effects of these polyphenols on C. albicans. Standard growth curves demonstrated a 40% reduction in the growth rate constant (K) with a 2 mg/mL concentration of Polyphenon 60, a green tea extract containing a mixture of polyphenolic compounds. Cultures treated with 1.0 µmol/L –(–)epigallocatechin-3-gallate (EGCG), the most abundant polyphenol, displayed a 75% reduction of viable cells during biofilm formation. Established biofilms treated with EGCG were also reduced, by 80%, as determined through XTT (2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) colorimetric assays. Identical concentrations of epigallocatechin and epicatechin-3-gallate demonstrated similar biofilm inhibition. Further investigations regarding the possible mechanism of polyphenol action indicate that in vivo proteasome activity was significantly decreased when catechin-treated yeast cells were incubated with a fluorogenic peptide substrate that measured proteasomal chymotrypsin-like and peptidyl-glutamyl peptide-hydrolyzing activities. Impairment of proteasomal activity by tea polyphenols contributes to cellular metabolic and structural disruptions that expedite the inhibition of biofilm formation and maintenance by C. albicans.

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Proctor, G. B., R. Pramanik, G. H. Carpenter, and G. D. Rees. "Salivary Proteins Interact with Dietary Constituents to Modulate Tooth Staining." Journal of Dental Research 84, no. 1 (January 2005): 73–78. http://dx.doi.org/10.1177/154405910508400113.

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Dietary components rich in polyphenols—for example, tea and red wine—are thought to cause tooth staining. In the present study, hydroxyapatite was used as a model of enamel for study of the influence of salivary proteins on the binding of different polyphenols to hydroxyapatite in vitro. Neither salivary protein pellicles nor salivary proteins in solution significantly altered the binding of the small polyphenol epigallocatechin to hydroxyapatite. However, hydroxyapatite binding of anthocyanin, a small grape-skin-derived polyphenol, or the larger polyphenols of black tea was increased by the presence of salivary proteins, either as a pellicle or in solution. Proline-rich proteins were enriched from parotid saliva and found to increase binding of anthocyanin and black tea polyphenols to hydroxyapatite, while enriched histatins did not increase binding. It is concluded that some salivary proteins, including proline-rich protein, can mediate increased staining of enamel by red-wine- and black-tea-derived polyphenols.

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Luo, Qiong, Jia-Rong Zhang, Hua-Bin Li, Ding-Tao Wu, Fang Geng, Harold Corke, Xin-Lin Wei, and Ren-You Gan. "Green Extraction of Antioxidant Polyphenols from Green Tea (Camellia sinensis)." Antioxidants 9, no. 9 (August 25, 2020): 785. http://dx.doi.org/10.3390/antiox9090785.

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In this study, the feasibility of improving the extraction yield of green tea antioxidant polyphenols by the combination of ultrasound-assisted extraction (UAE) and deep eutectic solvents (DESs) was investigated. Choline chloride (ChCl)-glycerol was selected as the best DES among 12 ChCl-based DESs to extract tea antioxidant polyphenols. Subsequently, the influences of extraction parameters on total phenolic content (TPC) values were investigated, and liquid/solid ratio, ultrasonic power, and ultrasonic time were optimized based on the response surface methodology. The optimal extraction conditions were a liquid to solid ratio of 36:1 (mL/g), ultrasonic power of 461.5 W, and ultrasonic time of 21 min, with the highest TPC value of 243 ± 7 mg gallic acid equivalent (mg GAE)/g dry weight (DW), which was 13% higher than that before optimization. In addition, under the optimal extraction conditions, tea polyphenolic extract exhibited higher antioxidant activity compared with conventional extraction methods. Four major catechins in the green tea extracts, including (−)-epicatechin (EC), (−)-epigallocatechin (EGC), (−)-epicatechin gallate (ECG) and (−)-epigallocatechin gallate (EGCG) were identified and quantified by high-performance liquid chromatography. In addition, scanning electron microscopy (SEM) analysis revealed that UAE-DES effectively disrupted the green tea leaf cells, thereby improving tea polyphenol yield. In summary, UAE-DES is an ideal green extraction method for the extraction of tea antioxidant polyphenols.

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Lorenz, Mario, Stephanie Lehmann, Ilija Djordjevic, Thomas Düsterhöft, Benno F. Zimmermann, Karl Stangl, and Verena Stangl. "Vasodilation of Tea Polyphenols Ex Vivo Is Mediated by Hydrogen Peroxide under Rapid Compound Decay." Antioxidants 9, no. 5 (May 7, 2020): 390. http://dx.doi.org/10.3390/antiox9050390.

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Improvement of endothelial function represents a major health effect of tea in humans. Ex vivo, tea and tea polyphenols stimulate nitric oxide (NO)-dependent vasodilation in isolated blood vessels. However, it was reported that polyphenols can generate reactive oxygen species (ROS) in vitro. We therefore aimed to elucidate the role of ROS production in tea polyphenol-induced vasodilation in explanted aortic rings. Vasorelaxation of rat aortic rings was assessed in an organ chamber model with low concentrations of epigallocatechin-3-gallate (EGCG), theaflavin-3,3’-digallate (TF3), and with green and black tea, with or without pretreatment with catalase or superoxide dismutase (SOD). The stability of EGCG and TF3 was measured by HPLC, and the levels of hydrogen peroxide (H2O2) were determined. EGCG and green tea-induced vasorelaxation was completely prevented by catalase and slightly increased by SOD. TF3 and black tea yielded similar results. Both EGCG and TF3 were rapidly degraded. This was associated with increasing H2O2 levels over time. Hydrogen peroxide concentrations produced in a time range compatible with tea polyphenol decay induced NO-dependent vasodilation in aortic rings. In conclusion, tea polyphenol-induced vasodilation in vitro is mediated by low levels of H2O2 generated during compound decay. The results could explain the apparent lack of vasodilatory effects of isolated tea polyphenols in humans.

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Khan, Naghma, and Hasan Mukhtar. "Tea Polyphenols in Promotion of Human Health." Nutrients 11, no. 1 (December 25, 2018): 39. http://dx.doi.org/10.3390/nu11010039.

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Tea is the most widely used beverage worldwide. Japanese and Chinese people have been drinking tea for centuries and in Asia, it is the most consumed beverage besides water. It is a rich source of pharmacologically active molecules which have been implicated to provide diverse health benefits. The three major forms of tea are green, black and oolong tea based on the degree of fermentation. The composition of tea differs with the species, season, leaves, climate, and horticultural practices. Polyphenols are the major active compounds present in teas. The catechins are the major polyphenolic compounds in green tea, which include epigallocatechin-3-gallate (EGCG), epigallocatechin, epicatechin-3-gallate and epicatechin, gallocatechins and gallocatechin gallate. EGCG is the predominant and most studied catechin in green tea. There are numerous evidences from cell culture and animal studies that tea polyphenols have beneficial effects against several pathological diseases including cancer, diabetes and cardiovascular diseases. The polyphenolic compounds present in black tea include theaflavins and thearubigins. In this review article, we will summarize recent studies documenting the role of tea polyphenols in the prevention of cancer, diabetes, cardiovascular and neurological diseases.

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Annunziata, Giuseppe, Maria Maisto, Connie Schisano, Roberto Ciampaglia, Patricia Daliu, Viviana Narciso, Gian Tenore, and Ettore Novellino. "Colon Bioaccessibility and Antioxidant Activity of White, Green and Black Tea Polyphenols Extract after In Vitro Simulated Gastrointestinal Digestion." Nutrients 10, no. 11 (November 8, 2018): 1711. http://dx.doi.org/10.3390/nu10111711.

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The beneficial effects of the tea beverage are well-known and mainly attributed to polyphenols which, however, have poor bioaccessibility and bioavailability. The purpose of the present study was the evaluation of colon bioaccessibility and antioxidant activity of tea polyphenolic extract. An 80% methanolic extract (v/v) of tea polyphenols was obtained from green (GT), white (WT) and black tea (BT). Simulated gastrointestinal (GI) digestion was performed on acid-resistant capsules containing tea polyphenolic extract. The main tea polyphenols were monitored by HPLC-diode-array detector (DAD) method; in addition, Total Phenol Content (TPC) and antioxidant activity were evaluated. After GI digestion, the bioaccessibility in the colon stage was significantly increased compared to the duodenal stage for both tea polyphenols and TPC. Similarly, the antioxidant activity in the colon stage was significantly higher than that in the duodenal stage. Reasonably, these results could be attributable in vivo to the activity of gut microbiota, which is able to metabolize these compounds, generating metabolites with a greater antioxidant activity. Our results may guide the comprehension of the colon digestion of polyphenols, suggesting that, although poorly absorbed in the duodenum, they can exert their antioxidant and anti-inflammatory activities in the lower gut, resulting in a novel strategy for the management of gut-related inflammatory diseases.

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Li, Zhandong, Yue Liu, Weihao Zhao, Xiuhua Wu, Xiujuan Jiang, Lili Yang, Chaoqun Xing, Lixin You, Jiwei Song, and Hao Li. "Pathogenic Effects and Potential Regulatory Mechanisms of Tea Polyphenols on Obesity." BioMed Research International 2019 (June 11, 2019): 1–11. http://dx.doi.org/10.1155/2019/2579734.

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Overweight and obesity are major threats to human health. Tea polyphenols exert multiple beneficial effects on human health and may play a positive regulatory role in fat assumption. However, how tea polyphenols contribute to the regulation of fat metabolism remains unclear to date. Small RNA expression profile can be regulated by tea polyphenols in adipocytes. Therefore, tea polyphenols may regulate fat metabolism by controlling small RNA-associated biological processes. In this study, we developed a systematic research platform based on mouse models and performed small RNA sequencing to identify the specific role of small RNAs in the regulatory effect of tea polyphenols on fat metabolism. We compared the expression levels of different small RNA subtypes, including piRNAs and miRNAs, and identified a group of differentially expressed small RNAs in the experimental and control groups. Most of these small RNAs participate in lipid metabolism, suggesting that small RNAs play a significant role in tea polyphenol-associated obesity and related pathogenesis. Furthermore, gene ontology and KEGG pathway enrichment indicated that small RNAs influence the regulatory effects of tea polyphenols on obesity, revealing the potential pathogenic mechanisms for such nutritional disease.

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Gao, Lepeng, Tao Zhu, Fuyang He, Zhiqiang Ou, Jian Xu, and Lili Ren. "Preparation and Characterization of Functional Films Based on Chitosan and Corn Starch Incorporated Tea Polyphenols." Coatings 11, no. 7 (July 6, 2021): 817. http://dx.doi.org/10.3390/coatings11070817.

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The functional films based on chitosan and corn starch incorporated tea polyphenols were developed through mixing the chitosan and starch solution and the powder of tea polyphenols by the casting method. The objective of this research was to investigate the effect of different concentrations of tea polyphenols on the functional properties of the films. Attenuated total reflectance Fourier transform infrared spectrometry and X-ray diffraction were used to investigate the potential interactions among chitosan, corn starch and tea polyphenols in the blend films. Physical properties of the blend films, including density, moisture content, opacity, color, water solubility and water swelling, as well as morphological characteristics, were measured. The results demonstrated that the incorporation of tea polyphenols caused the blend films to lead to a darker appearance. The water solubility of the blend film increased with the increase of tea polyphenol concentrations, while moisture content and swelling degree decreased. The hydrogen bonding between chitosan, starch and tea polyphenols restricted the movement of molecular chains and was helpful to the stability of the blend films. The results suggested that these biodegradable blend films could potentially be used as packaging films for the food and drug industries to extend the shelf life to maintain their quality and safety.

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Mudau, Fhatuwani N., Puffy Soundy, and Elsa S. du Toit. "Effects of Nitrogen, Phosphorus, and Potassium Nutrition on Total Polyphenol Content of Bush Tea (Athrixia phylicoides L.) Leaves in Shaded Nursery Environment." HortScience 42, no. 2 (April 2007): 334–38. http://dx.doi.org/10.21273/hortsci.42.2.334.

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Bush tea (Athrixia phylicoides L.) contains high concentrations of polyphenols that are the primary indicator of antioxidant potential in herbal teas. The objective of this study was to determine the seasonal effect of nitrogen (N), phosphorus (P), and potassium (K) nutrition on total polyphenol content in bush tea leaves. Treatments consisted of 0, 100, 200, 300, 400 or 500 kg·ha−1 of N, P, or K in a randomized complete block design under 50% shade nets. Three (N, P, and K) parallel trials were conducted per season (autumn, winter, spring, and summer). Total polyphenols were determined using Folin-Ciocalteau reagents and analyzed in a spectrophotometer. The results of this study demonstrated that, regardless of season, application of nitrogenous, phosphorus, and potassium fertilizers increased quadratically the total polyphenols in bush tea, with most of the increase occurring between 0 and 300 kg·ha−1 N, 300 kg·ha−1 P, and 200 kg·ha−1 K. Linear relationships between percentage leaf tissue N, P, and K with total polyphenols in bush tea were also observed. Therefore, for improved total polyphenol content in bush tea leaves, 300 kg·ha−1 N, 300 kg·ha−1 P, and 200 K kg·ha−1 N is recommended.

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LIU, Yanhong, Jing LI, Kun LI, Xiaoqi YU, and Di WU. "Dicey Tea Industry: Tea Polyphenols." University Chemistry 34, no. 8 (2019): 102–6. http://dx.doi.org/10.3866/pku.dxhx201812015.

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Hurrell, Richard F., Manju Reddy, and James D. Cook. "Inhibition of non-haem iron absorption in man by polyphenolic-containing beverages." British Journal of Nutrition 81, no. 4 (April 1999): 289–95. http://dx.doi.org/10.1017/s0007114599000537.

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The effects of different polyphenol-containing beverages on Fe absorption from a bread meal were estimated in adult human subjects from the erythrocyte incorporation of radio-Fe. The test beverages contained different polyphenol structures and were rich in either phenolic acids (chlorogenic acid in coffee), monomeric flavonoids (herb teas, camomile (Matricaria recutita L.)), vervain (Verbena officinalis L.), lime flower (Tilia cordata Mill.), pennyroyal (Mentha pulegium L.) and peppermint (Mentha piperita L.), or complex polyphenol polymerization products (black tea and cocoa). All beverages were potent inhibitors of Fe absorption and reduced absorption in a dose-dependent fashion depending on the content of total polyphenols. Compared with a water control meal, beverages containing 20–50 mg total polyphenols/serving reduced Fe absorption from the bread meal by 50–70 %, whereas beverages containing 100–400 mg total polyphenols/serving reduced Fe absorption by 60–90 %. Inhibition by black tea was 79–94 %, peppermint tea 84 %, pennyroyal 73 %, cocoa 71 %, vervain 59 %, lime flower 52 % and camomile 47 %. At an identical concentration of total polyphenols, black tea was more inhibitory than cocoa, and more inhibitory than herb teas camomile, vervain, lime flower and pennyroyal, but was of equal inhibition to peppermint tea. Adding milk to coffee and tea had little or no influence on their inhibitory nature. Our findings demonstrate that herb teas, as well as black tea, coffee and cocoa can be potent inhibitors of Fe absorption. This property should be considered when giving dietary advice in relation to Fe nutrition.

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An, Bong-Jeun, Jae-Hoon Kwak, Jun-Ho Son, Jung-Mi Park, Jin-Young Lee, Tae Soon Park, So-Yeun Kim, Yeoung-Sun Kim, Cheorun Jo, and Myung-Woo Byun. "Physiological Activity of Irradiated Green Tea Polyphenol on the Human Skin." American Journal of Chinese Medicine 33, no. 04 (January 2005): 535–46. http://dx.doi.org/10.1142/s0192415x05003144.

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Physiological activity of irradiated green tea polyphenol on the human skin was investigated for further industrial application. The green tea polyphenol was separated and irradiated at 40 kGy by γ-ray. For an anti-wrinkle effect, the collagenase inhibition effect was higher in the irradiated sample (65.3%) than that of the non-irradiated control (56.8%) at 200 ppm of the concentration ( p < 0.05). Collagen biosynthesis rats using a human fibroblast were 19.4% and 16.3% in the irradiated and the non-irradiated polyphenols, respectively. The tyrosinase inhibition effect, which is related to the skin-whitening effect, showed a 45.2% and 42.9% in the irradiated and the non-irradiated polyphenols, respectively, at a 100 ppm level. A higher than 90% growth inhibition on skin cancer cells (SK-MEL-2 and G361) was demonstrated in both the irradiated and the non-irradiated polyphenols. Thus, the irradiation of green tea polyphenol did not change and even increased its anti-wrinkle, skin-whitening and anticancer effects on the human skin. The results indicated that irradiated green tea polyphenol can be used as a natural ingredient with excellent physiological functions for the human skin through cosmetic or food composition.

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Record, Ian R., Jennifer K. McInerney, and Ivor E. Dreosti. "Black tea, green tea, and tea polyphenols." Biological Trace Element Research 53, no. 1-3 (June 1996): 27–43. http://dx.doi.org/10.1007/bf02784542.

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Kumar, Nagi B. "Green Tea Polyphenols." Evidence-Based Integrative Medicine 2, no. 1 (2005): 13–18. http://dx.doi.org/10.2165/01197065-200502010-00004.

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Maulana, Muhammad Fakhri, Lilis Suryaningsih, and Andry Pratama. "PENGARUH PENGGUNAAN EKSTRAK DAUN TEH HIJAU (Camellia sinensis) PADA PROSES PEMBUATAN NAGET DAGING SAPI TERHADAP SIFAT KIMIA." Jurnal Teknologi Hasil Peternakan 1, no. 1 (March 2, 2020): 34. http://dx.doi.org/10.24198/jthp.v1i1.24133.

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Green tea is known as a plant who has many purpose as well as an antioxidant sources. The purpose of this research is to find out the effect of adding green tea (Camellia sinensis) extract in beef nuggets on chemical properties (moisture content, fat content, and polyphenol content). This research is an experimental research using completely randomized design method with 4 treatments and 5 repetition. The treatment that given was P1= beef nugget with no added green tea extract, P2= beef nugget + 0,5% green tea extract, P3= beef nugget + 1% green tea extract, and P4= beef nugget + 1,5% green tea extract with 5 repetition. Chemical analysis that used in this research is moisture content analysis, fat content, and polyphenols content. The obtained results then tested with anova, duncan, and polynomial test. The results showed that the treatment had a significantly real effect on polyphenols content but not on the moisture content and fat content. The addition of 1,5% green tea (Camellia sinensis) extract increase the polyphenol content of 305,96 mg/kg and influence 80,79% of the polyphenol content.

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Nana, Cao, Fan Jiaxin, Yang Zhixin, Hao Limin, Kang Qiaozhen, Liu Xin, and Lu Jike. "Increasing Antioxidant Potentials of Mung Bean Sprouts." Current Topics in Nutraceutical Research 18, no. 1 (July 18, 2018): 75–82. http://dx.doi.org/10.37290/ctnr2641-452x.18:75-82.

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The effects of tea polyphenols and ultraviolet radiation on the growth and antioxidant activity of mung bean sprouts were investigated, followed by the changes in corresponding antioxidant enzyme activities and metabolite composition. The growth of mung bean sprouts was slightly decreased by tea polyphenols and ultraviolet radiation, but the antioxidant activity was increased. The activities of peroxidase and catalase were decreased, and the contents of vitamin C, γ-aminobutyric acid and total phenols were significantly increased by tea polyphenol treatment. While the activities of peroxidase and catalase increased by ultraviolet radiation with concomitant increase in the contents of vitamin C and total phenols. The mung bean sprouts produced following imposition of stressors such as tea polyphenols and ultraviolet radiation from stress conditions could be used as a potential functional food.

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Wang, An Na, Li Gen Wu, Yu Dan Sun, Yuan Yuan Zhang, Xiang Ying Xu, Xiu Ling Li, Jie Wang, Chao Wang, Qin Qin Fu, and Lin Lu Jia. "Texture Profile of Gelatin and Tea Polyphenol Mixed Gels." Advanced Materials Research 201-203 (February 2011): 2862–65. http://dx.doi.org/10.4028/www.scientific.net/amr.201-203.2862.

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The effects of different factors including tea polyphenols concentration, gelatin concentration, pH and temperature on the properties of tea polyphenol/gelatin mixed gels were investigated by using texture profile analysis. The results indicated that the factors all had the influences on mixed gel properties, such as hardness, elasticity, cohesiveness, chewiness, resilience, ets.FTIR spectra verified that tea polyphenols mainly interacted with gelatin by the phenolic hydroxyl binded with reactive group of gelatin peptidyl by hydrogen in the formation of gels. Thermal stability were determined to evaluate the properties of the mixed gels by TGA analysis.

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Guo, Zhiheng, Yi Yang, Yang Shu, Li Qiao, Min Peng, and Zhenpeng Wang. "Stimulus-responsive tea polyphenols as nanocarrier for selective intracellular drug delivery." Journal of Biomaterials Applications 35, no. 2 (May 9, 2020): 149–57. http://dx.doi.org/10.1177/0885328220924539.

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Nanodrug delivery systems have been widely researched to achieve efficient antitumor drug delivery. However, the controlled drug delivery at tumor cells remains the main challenge for antitumor therapy. Herein, a pH and reduction-responsive nanocarrier based on green tea polyphenols was employed as a smart excipient for chemotherapy drug delivery. Paclitaxel, as a chemotherapy drug, was loaded in the nanocarrier, noted as green tea polyphenol/paclitaxel. The green tea polyphenol/paclitaxel kept constant diameter at physiological condition (i.e. pH 7.4), while gradually enlarged at acid environment (pH = 5.5) and the reductive environment. The in vitro paclitaxel release results indicated that the release of paclitaxel from the green tea polyphenol/paclitaxel at pH 7.4 was slow, whereas obviously accelerated at the acid environment (pH = 5.5) and the reductive environment. The in vitro antitumor assay showed more efficient tumor cells inhibition of green tea polyphenol/paclitaxel than free paclitaxel. Meanwhile, due to the proper size (∼100 nm), green tea polyphenol/paclitaxel could effectively accumulate at tumor sites. In the in vivo mice bearing A549 xenograft mouse models, green tea polyphenol/paclitaxel exhibited satisfactory antitumor effect and depressed system toxicity when compared with free paclitaxel, owing to the enhanced paclitaxel accumulation and controlled paclitaxel release in the tumor cells. With simple compositions and satisfactory antitumor effects, this green tea polyphenol-based nanocarrier can be a promising nanodrug delivery system for the therapy of cancers.

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Mhd Jalil, Abbe, Emilie Combet, Christine Edwards, and Ada Garcia. "Effect of β-Glucan and Black Tea in a Functional Bread on Short Chain Fatty Acid Production by the Gut Microbiota in a Gut Digestion/Fermentation Model." International Journal of Environmental Research and Public Health 16, no. 2 (January 15, 2019): 227. http://dx.doi.org/10.3390/ijerph16020227.

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β-Glucan and black tea are fermented by the colonic microbiota producing short chain fatty acids (SCFA) and phenolic acids (PA). We hypothesized that the addition of β-glucan, a dietary fiber, and tea polyphenols to a food matrix like bread will also affect starch digestion in the upper gut and thus further influence colonic fermentation and SCFA production. This study investigated SCFA and PA production from locally developed breads: white bread (WB), black tea bread (BT), β-glucan bread (βG), β-glucan plus black tea bread (βGBT). Each bread was incubated in an in vitro system mimicking human digestion and colonic fermentation. Digestion with α-amylase significantly (p = 0.0001) increased total polyphenol and polyphenolic metabolites from BT bread compared with WB, βG, and βGBT. Total polyphenols in βGBT remained higher (p = 0.016; 1.3-fold) after digestion with pepsin and pancreatin compared with WB. Fermentations containing βG and βGBT produced similar propionate concentrations ranging from 17.5 to 18.6 mmol/L and total SCFA from 46.0 to 48.9 mmol/L compared with control WB (14.0 and 37.4 mmol/L, respectively). This study suggests that combination of black tea with β-glucan in this functional bread did not impact on SCFA production. A higher dose of black tea and β-glucan or in combination with other fibers may be needed to increase SCFA production.

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Yin, Fa-Wen, Xiao-Pei Hu, Da-Yong Zhou, Xiao-Chi Ma, Xiang-Ge Tian, Xiao-Kui Huo, Kanyasiri Rakariyatham, Fereidoon Shahidi, and Bei-Wei Zhu. "Evaluation of the stability of tyrosol esters during in vitro gastrointestinal digestion." Food & Function 9, no. 7 (2018): 3610–16. http://dx.doi.org/10.1039/c8fo00788h.

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Lipophenols such as tea polyphenol palmitate derivatives (palmitoyl esters of tea polyphenols) have been classified as non-toxic food additives due to their better protective effects on lipidic food matrices from oxidation, but their digestion and absorption have remained unexplored.

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Mudau, Nixwell, Puffy Soundy, and Elsa du Toit. "Response of Total Polyphenol Content to Nitrogen, Phosphorus, and Potassium Nutrition of Bush Tea (Athrixia phylicoides)." HortScience 40, no. 4 (July 2005): 1119C—1119. http://dx.doi.org/10.21273/hortsci.40.4.1119c.

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Bush tea (Athrixia phylicoides) belongs to the Asteraceae family. It is a popular beverage, commonly used as an herbal tea and for medicinal purposes. In some parts of South Africa, people consume or drink it as an aphrodisiac. Bush tea was grown under varying nitrogen (N), phosphorus (P) and potassium (K) levels in the four seasons to determine the seasonal nutrient requirements for improved quality. Treatment consisted of 0, 100, 200, 300, 400, or 500 kg·ha–1 N, P, or K in a randomized complete-block design under 50% shade nets. Three N, P, and K parallel trials were conducted per season (autumn, winter, spring, and summer). Total polyphenols were extracted using Folin-Ciaocalteau reagents and analyzed in a spectrophotometer. Results for the N trial suggested that total polyphenols increased quadratically in response to N nutrition during summer, winter, and spring, but not in autumn. The optimum N level was 300 kg·ha–1. The highest total polyphenol was 51.1 mg·g–1 in winter. For the P trial, total polyphenols also increased quadratically in response to P nutrition regardless of season. Again winter had the highest total polyphenols (46.8 mg·g–1). The optimum P level was 300 kg·ha–1. In the K trial, regardless of season, total polyphenols plateaued at 200 kg·ha–1 and the highest polyphenols were in winter (43.3 mg·g–1). Therefore, for improved total polyphenol content, 300 kg·ha–1 N and P and 200 kg·ha–1 K are recommended regardless of season.

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Dew, T. P., A. J. Day, and M. R. A. Morgan. "Bone mineral density, polyphenols and caffeine: a reassessment." Nutrition Research Reviews 20, no. 1 (June 2007): 89–105. http://dx.doi.org/10.1017/s0954422407738805.

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Several studies have shown beneficial associations between tea consumption and bone mineral density (BMD) and fracture risk. Current investigations into potential mechanisms of benefit are focused upon the F and polyphenol components of tea. However, previous studies have pointed towards caffeine consumption as a potential risk factor for low BMD and high fracture risk. Tea, therefore, represents an interesting paradox as a mildly caffeinated beverage that may enhance bone health. Fruit and vegetable intake has also been associated with BMD, and it is now apparent that several fruit and vegetable components, including polyphenols, may contribute positively to bone health. Evidence surrounding the function(s) of polyphenol-rich foods in bone health is examined, along with more recent studies challenging the relevance of caffeine consumption to in vivo Ca balance. Plant foods rich in polyphenols such as tea, fruit and vegetables, as significant factors in a healthy diet and lifestyle, may have positive roles in bone health, and the negative role of caffeine may have been overestimated. The present review covers evidence of dietary mediation in positive and negative aspects of bone health, in particular the roles of tea, fruit and vegetables, and of caffeine, flavonoids and polyphenols as components of these foods. Since the deleterious effects of caffeine appear to have been overstated, especially in respect of the positive effects of flavonoids, it is concluded that a reassessment of the role of caffeinated beverages may be necessary.

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Rudolphi-Skórska, Elżbieta, Barbara Dyba, Barbara Kreczmer, and Maria Filek. "Impact of polyphenol-rich green tea extracts on the protection of DOPC monolayer against damage caused by ozone induced lipid oxidation." Acta Biochimica Polonica 65, no. 2 (July 8, 2018): 193–97. http://dx.doi.org/10.18388/abp.2018_2612.

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Effectiveness of green tea (compared to two single polyphenols) in removing ozone derived reactive oxygen species acting on dioleoyl phosphatidylcholine monolayers was determined. The lipid oxidation was followed by changes of mechanical properties of the layer spreaded on the aqueous subphase containing various amounts of ozone in presence and absence of polyphenolics. It was shown that tea extract (containing 8.5x10-4 mg/cm3 polyphenols) is capable of inactivating 0.4 ppm ozone.The DPPH radical scavenging test set polyphenols in the order of increasing activity, consistent with their protective effect in relation to lipid oxidation, showing the highest efficacy of EGCG.

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Alqahtani, Shaherah, Kelly Welton, Jeffrey Gius, Suad Elmegerhi, and Takamitsu Kato. "The Effect of Green and Black Tea Polyphenols on BRCA2 Deficient Chinese Hamster Cells by Synthetic Lethality through PARP Inhibition." International Journal of Molecular Sciences 20, no. 6 (March 14, 2019): 1274. http://dx.doi.org/10.3390/ijms20061274.

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Tea polyphenols are known antioxidants presenting health benefits due to their observed cellular activities. In this study, two tea polyphenols, epigallocatechin gallate, which is common in green tea, and theaflavin, which is common in black tea, were investigated for their PARP inhibitory activity and selective cytotoxicity to BRCA2 mutated cells. The observed cytotoxicity of these polyphenols to BRCA2 deficient cells is believed to be a result of PARP inhibition induced synthetic lethality. Chinese hamster V79 cells and their BRCA2 deficient mutant V-C8, and V-C8 with gene complemented cells were tested against epigallocatechin gallate and theaflavin. In addition, Chinese hamster ovary (CHO) wild-type cells and rad51D mutant 51D1 cells were used to further investigate the synthetic lethality of these molecules. The suspected PARP inhibitory activity of epigallocatechin and theaflavin was confirmed through in vitro and in vivo experiments. Epigallocatechin gallate showed a two-fold increase of cytotoxicity to V-C8 cells compared to V79 and gene complimented cells. Compared to CHO wild type cells, 51D1 cells also showed elevated cytotoxicity following treatment with epigallocatechin gallate. Theaflavin, however, showed a similar increase of cytotoxicity to VC8 compared to V79 and gene corrected cells, but did not show elevation of cytotoxicity towards rad51D mutant cells compared to CHO cells. Elevation of sister chromatid exchange formation was observed in both tea polyphenol treatments. Polyphenol treatment induced more micronuclei formation in BRCA2 deficient cells and rad51D deficient cells when compared against the respective wild type cells. In conclusion, tea polyphenols, epigallocatechin gallate, and theaflavin may present selective cytotoxicity to BRCA2 deficient cells through synthetic lethality induced by PARP inhibition.

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Ye, Shan, Zhongjie Zhu, Yanyi Wen, Chen Su, Lei Jiang, Shu He, and Wei Shao. "Facile and Green Preparation of Pectin/Cellulose Composite Films with Enhanced Antibacterial and Antioxidant Behaviors." Polymers 11, no. 1 (January 2, 2019): 57. http://dx.doi.org/10.3390/polym11010057.

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Novel bioactive films based on pectin and cellulose (PC) with different loadings of tea polyphenols and cinnamaldehyde were successfully prepared. A thermal stability was tested, and the results showed that the thermal stability decreased slightly after loading with cinnamaldehyde and tea polyphenols, compared to PC films. The antimicrobial and antioxidant capacities were also investigated. Results showed that PC composite films had good DPPH radical and hydroxyl radical scavenging activities and excellent antibacterial activities against Escherichia coli, Candida albicans and Staphylococcus aureus. Based on the results, the great antioxidant and antibacterial activities of the tea polyphenol and cinnamaldehyde loaded PC films make them suitable for food packaging and preservation.

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Yokozawa, Takako, Jeong Sook Noh, and Chan Hum Park. "Green Tea Polyphenols for the Protection against Renal Damage Caused by Oxidative Stress." Evidence-Based Complementary and Alternative Medicine 2012 (2012): 1–12. http://dx.doi.org/10.1155/2012/845917.

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Green tea, prepared from the leaves ofCamellia sinensisL., is a beverage that is popular worldwide. Polyphenols in green tea have been receiving much attention as potential compounds for the maintenance of human health due to their varied biological activity and low toxicity. In particular, the contribution of antioxidant activity to the prevention of diseases caused by oxidative stress has been focused upon. Therefore, in this study, we investigated the effects of (−)-epigallocatechin 3-O-gallate and (−)-epigallocatechin 3-O-gallate, which account for a large fraction of the components of green tea polyphenol, on oxidative stress-related renal disease. Our observations suggest that green tea polyphenols have a beneficial effect on pathological states related to oxidative stress of the kidney.

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Beecher, G. R., B. A. Warden, and H. Merken. "Analysis of Tea Polyphenols." Experimental Biology and Medicine 220, no. 4 (April 1, 1999): 267–70. http://dx.doi.org/10.3181/00379727-220-44377a.

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Mueen Ahmed, K. K., and Monalisa Baral. "Tea Polyphenols as Antioxidants." Free Radicals and Antioxidants 1, no. 2 (April 2011): 2–3. http://dx.doi.org/10.5530/ax.2011.2.2.

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Sajilata, M. G., Poonam R. Bajaj, and R. S. Singhal. "Tea Polyphenols as Nutraceuticals." Comprehensive Reviews in Food Science and Food Safety 7, no. 3 (June 2008): 229–54. http://dx.doi.org/10.1111/j.1541-4337.2008.00043.x.

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Beecher, Gary R., Beverly A. Warden, and Howard Merken. "Analysis of Tea Polyphenols." Proceedings of the Society for Experimental Biology and Medicine 220, no. 4 (April 1999): 267–70. http://dx.doi.org/10.1046/j.1525-1373.1999.d01-47.x.

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Plundrich, Nathalie, Mary Ann Lila, Edward Foegeding, and Scott Laster. "Protein-bound polyphenols create “ghost” band artifacts during chemiluminescence-based antigen detection." F1000Research 6 (March 13, 2017): 254. http://dx.doi.org/10.12688/f1000research.10622.1.

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Antigen detection during Western blotting commonly utilizes a horseradish peroxidase-coupled secondary antibody and enhanced chemiluminescent substrate. We utilized this technique to examine the impact of green tea-derived polyphenols on the binding of egg white protein-specific IgE antibodies from allergic human plasma to their cognate antigens. Our experiments unexpectedly showed that green tea-derived polyphenols, when stably complexed with egg white proteins, caused hyperactivation of horseradish peroxidase resulting in the appearance of white “ghost” bands. This study suggests that caution should be taken when evaluating polyphenol-bound proteins by enhanced chemiluminescence Western blotting using horseradish peroxidase and demonstrates that protein-bound polyphenols can be a source of “ghost” band artifacts on Western blots.

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Plundrich, Nathalie, Mary Ann Lila, Edward Foegeding, and Scott Laster. "Protein-bound polyphenols create “ghost” band artifacts during chemiluminescence-based antigen detection." F1000Research 6 (May 26, 2017): 254. http://dx.doi.org/10.12688/f1000research.10622.2.

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Antigen detection during Western blotting commonly utilizes a horseradish peroxidase-coupled secondary antibody and enhanced chemiluminescent substrate. We utilized this technique to examine the impact of green tea-derived polyphenols on the binding of egg white protein-specific IgE antibodies from allergic human plasma to their cognate antigens. Our experiments unexpectedly showed that green tea-derived polyphenols, when stably complexed with egg white proteins, caused “ghost” band formation in the presence of horseradish peroxide. This study suggests that caution should be taken when evaluating polyphenol-bound proteins by enhanced chemiluminescence Western blotting using horseradish peroxidase and demonstrates that protein-bound polyphenols can be a source of “ghost” band artifacts on Western blots.

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Mediza Romero, María Laura, Mariana von Staszewski, and María Julia Martínez. "The effect of green tea polyphenols addition on the physicochemical, microbiological and bioactive characteristics of yogurt." British Food Journal 123, no. 7 (February 23, 2021): 2380–97. http://dx.doi.org/10.1108/bfj-07-2020-0648.

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PurposeThe purpose of this paper is to evaluate the effect of green tea polyphenols addition on physicochemical, microbiological and bioactive characteristics of yogurt.Design/methodology/approachTwo incorporation methods of polyphenols were evaluated: direct addition or incorporated within protein particles of whey protein concentrate and gelatin. During yogurt’s shelf life, structure characteristics (water holding capacity, textural and rheological parameters), lactic acid bacteria (LAB) viability and polyphenols antioxidant activity were analyzed. Also, polyphenol bioaccesibility after in vitro digestion was evaluated.FindingsPolyphenols addition (by the two methods used) did not affect the dynamics of the fermentation process, nor the LAB viability during storage. The color parameter a* for the yogurts with the highest polyphenol concentrations showed positive values (tending to red), but not visible to the naked eye. Because of the ability of polyphenols to interact with milk proteins, yogurts with polyphenols presented higher values in firmness and cohesiveness with respect to the control. Additionally, the incorporation of polyphenols in protein particles increased even more these parameters because of the higher protein content of these formulations. After simulated digestion, a high polyphenol bioaccesibility was observed, and the antioxidant activity was retained, which could be explained by the “protector” effect of the milk matrix.Practical implicationsYogurt supplementation with green tea polyphenols is feasible for the development of functional food. However, the use of protein particles would not provide an extra benefit because milk proteins already act as protective molecules of polyphenols.Originality/valueThis study shows not only the physico-chemical implications of including polyphenols in yogurt but also their bioaccesibility after an in vitro digestion, revealing a suitable manner for delivery of antioxidants in a dairy product like yogurt.

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Yang, Chung S., Jee Y. Chung, Guang-yu Yang, Saranjit K. Chhabra, and Mao-Jung Lee. "Tea and Tea Polyphenols in Cancer Prevention." Journal of Nutrition 130, no. 2 (February 1, 2000): 472S—478S. http://dx.doi.org/10.1093/jn/130.2.472s.

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Xu, Jin Ze, Lai Kwok Leung, Yu Huang, and Zhen-Yu Chen. "Epimerisation of tea polyphenols in tea drinks." Journal of the Science of Food and Agriculture 83, no. 15 (2003): 1617–21. http://dx.doi.org/10.1002/jsfa.1597.

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Truong, Van-Long, and Woo-Sik Jeong. "Cellular Defensive Mechanisms of Tea Polyphenols: Structure-Activity Relationship." International Journal of Molecular Sciences 22, no. 17 (August 24, 2021): 9109. http://dx.doi.org/10.3390/ijms22179109.

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Tea is particularly rich in polyphenols, including catechins and theaflavins, thearubigins, flavonols, and phenolic acids, which are believed to contribute to the health benefits of tea. The health-promoting effects of tea polyphenols are believed to be related to their cellular defensive properties. This review is intended to briefly summarize the relationship between the chemical structures of tea polyphenols and their biological activities. Tea polyphenols appear as direct antioxidants by scavenging reactive oxygen/nitrogen species; chelating transition metals; and inhibiting lipid, protein, and DNA oxidations. They also act directly by suppressing “pro-oxidant” enzymes, inducing endogenous antioxidants, and cooperating with vitamins. Moreover, tea polyphenols regulate cellular signaling transduction pathways, importantly contributing to the prevention of chronic diseases and the promotion of physiological functions. Apparently, the features in the chemical structures of tea polyphenols are closely associated with their antioxidant potentials.

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Hodgson, Jonathan M., Shin Yee Chan, Ian B. Puddey, Amanda Devine, Naiyana Wattanapenpaiboon, Mark L. Wahlqvist, Widjaja Lukito, et al. "Phenolic acid metabolites as biomarkers for tea- and coffee-derived polyphenol exposure in human subjects." British Journal of Nutrition 91, no. 2 (February 2004): 301–5. http://dx.doi.org/10.1079/bjn20031046.

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Tea and coffee are rich in polyphenols with a variety of biological activities. Many of the demonstrated activities are consistent with favourable effects on the risk of chronic diseases. 4-O-methylgallic acid (4OMGA) and isoferulic acid are potential biomarkers of exposure to polyphenols derived from tea and coffee respectively. 4OMGA is derived from gallic acid in tea, and isoferulic acid is derived from chlorogenic acid in coffee. Our major objective was to explore the relationships of tea and coffee intake with 24 h urinary excretion of 4OMGA and isoferulic acid in human subjects. The relationships of long-term usual (111 participants) and contemporaneously recorded current (344 participants) tea and coffee intake with 24 h urinary excretion of 4OMGA and isoferulic acid were assessed in two populations. 4OMGA was related to usual (r 0·50, P<0·001) and current (r 0·57, P<0·001) tea intake, and isoferulic acid was related to usual (r 0·26, P=0·008) and current (r 0·18, P<0·001) coffee intake. Overall, our present results are consistent with the proposal that 4OMGA is a good biomarker for black tea-derived polyphenol exposure, but isoferulic acid may be of limited usefulness as a biomarker for coffee-derived polyphenol exposure.

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Chiu, Hui-Fang, Kamesh Venkatakrishnan, Oksana Golovinskaia, and Chin-Kun Wang. "Gastroprotective Effects of Polyphenols against Various Gastro-Intestinal Disorders: A Mini-Review with Special Focus on Clinical Evidence." Molecules 26, no. 7 (April 6, 2021): 2090. http://dx.doi.org/10.3390/molecules26072090.

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Polyphenols are classified as an organic chemical with phenolic units that display an array of biological functions. However, polyphenols have very low bioavailability and stability, which make polyphenols a less bioactive compound. Many researchers have indicated that several factors might affect the efficiency and the metabolism (biotransformation) of various polyphenols, which include the gut microbiota, structure, and physical properties as well as its interactions with other dietary nutrients (macromolecules). Hence, this mini-review covers the two-way interaction between polyphenols and gut microbiota (interplay) and how polyphenols are metabolized (biotransformation) to produce various polyphenolic metabolites. Moreover, the protective effects of numerous polyphenols and their metabolites against various gastrointestinal disorders/diseases including gastritis, gastric cancer, colorectal cancer, inflammatory bowel disease (IBD) like ulcerative colitis (UC), Crohn’s disease (CD), and irritable bowel syndrome (IBS) like celiac disease (CED) are discussed. For this review, the authors chose only a few popular polyphenols (green tea polyphenol, curcumin, resveratrol, quercetin), and a discussion of their proposed mechanism underpinning the gastroprotection was elaborated with a special focus on clinical evidence. Overall, this contribution would help the general population and science community to identify a potent polyphenol with strong antioxidant, anti-inflammatory, anti-cancer, prebiotic, and immunomodulatory properties to combat various gut-related diseases or disorders (complementary therapy) along with modified lifestyle pattern and standard gastroprotective drugs. However, the data from clinical trials are much limited and hence many large-scale clinical trials should be performed (with different form/metabolites and dose) to confirm the gastroprotective activity of the above-mentioned polyphenols and their metabolites before recommendation.

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Sun, Fei Long, Guo Ni Chen, Bing Wu, Wei Na Zhu, and Yang Yan. "Research on the Extraction and Antibacterial Activity of Tea Polyphenols." Applied Mechanics and Materials 644-650 (September 2014): 5157–60. http://dx.doi.org/10.4028/www.scientific.net/amm.644-650.5157.

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There is an increasing interest in tea polyphenols, as natural plant compounds, in food products and also in pharmaceutical products due to their multiple health care functions. In this paper, a microwave-assisted extraction method was employed for the extraction of tea polyphenols. The effects of microwave power, heating time, and ethanol concentration on extraction of tea polyphenols were investigated by single factor experiments and an orthogonal experiment [L9(3)3]. Results showed that the optimum extraction conditions were that the microwave power was 560W, the heating time was 30s, and the ethanol concentration was 40% (v/v). The antimicrobial properties of tea polyphenols were also discussed. Tea polyphenols had bacteriostatic activity against Escherichia coli and Staphylococcus aureus. This study may be valuable for the extraction and application of tea polyphenols.

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Fu, Jiashun, Hai-Dong Yu, Long Wu, Chenghui Zhang, Yong-Huan Yun, and Weimin Zhang. "Authentication of Geographical Origin in Hainan Partridge Tea (Mallotus obongifolius) by Stable Isotope and Targeted Metabolomics Combined with Chemometrics." Foods 10, no. 9 (September 9, 2021): 2130. http://dx.doi.org/10.3390/foods10092130.

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Partridge tea (Mallotus oblongifolius (Miq.) Müll.Arg.) is a local characteristic tea in Hainan, the southernmost province of China, and the quality of partridge tea may be affected by the producing areas. In this study, stable isotope and targeted metabolomics combined chemometrics were used as potential tools for analyzing and identifying partridge tea from different origins. Elemental analysis—stable isotope ratio mass spectrometer and liquid chromatography-tandem mass spectrometrywas used to analyze the characteristics of C/N/O/H stable isotopes and 54 chemical components, including polyphenols and alkaloids in partridge tea samples from four regions in Hainan (Wanning, Wenchang, Sanya and Baoting). The results showed that there were significant differences in the stable isotope ratios and polyphenol and alkaloid contents of partridge tea from different origins, and both could accurately classify partridge tea from different origins. The correct separation and clustering of the samples were observed by principal component analysis and the cross-validated Q2 values by orthogonal partial least squares discriminant analysis (OPLS-DA) were 0.949 (based on stable isotope) and 0.974 (based on polyphenol and alkaloid), respectively. Potential significance indicators for origin identification were screened out by OPLS-DA and random forest algorithm, including three stable isotopes (δ13C, δ D, and δ18O) and four polyphenols (luteolin, protocatechuic acid, astragalin, and naringenin). This study can provide a preliminary guide for the origin identification of Hainan partridge tea.

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Shen, Xiao Sheng, Bei Lei Qian, Wei Hua Wu, You Qiong Cai, and Cheng Chu Liu. "Elimination of Vibrio parahaemolyticus Contamination in Shucked Oysters (Crassostrea plicatula) to with Natural Antimicrobial Agents TeaPolyphenols." Advanced Materials Research 320 (August 2011): 427–33. http://dx.doi.org/10.4028/www.scientific.net/amr.320.427.

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In this study, the survival of Vibrio parahaemolyticus in suspension in the presence of tea-polyphenols for 6h was first examined. The shucked oysters containing V. parahaemolyticus then were exposed to 2048μg/mL , 1024 μg/mL and 512 μg/mL tea-polyphenols for 4h and the population ofV. parahaemolyticusin shucked oysters was determined every 1h. In addition, shucked oysters containingV. parahaemolyticusexposed into the dose of 1024 μg/mL tea-polyphenols were held at various temperature (0, 5, and 20°C) to examine survival ofV. parahaemolyticusevery 6h till 24h. Populations ofV. parahaemolyticusinoysterwere determined using 3-tube most probable number (MPN) method. The study found that the MIC of tea-polyphenols to Vibrio parahaemolyticus suspension is 1024 μg/mL; when exposed to 2048 μg/mL, 1024 μg/mLand 512μg/mL tea-polyphenols for 4h, the population ofV. parahaemolyticusinshucked oysters decreased by 3.29,2.43 and 1.84 Log10MPN/g respectively; 0, 5 and 20°C,1024μg/mL tea-polyphenols can decrease the population of V. parahaemolyticusinshucked by 4.10, 3.32 and 3.00LogMPN/g at 24thh. Sensory analysis showed that treatments of tea-polyphenols at concentrations 1024μg/mL did not cause negative effects on taste of oyster meat. These results indicated that tea-polyphenols have bactericidal effects againstV. parahaemolyticusand can be applied to shucked oysters to reduce contamination of V. parahaemolyticus.

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Cong, Lin, Chang Cao, Yong Cheng, and Xiao-Yan Qin. "Green Tea Polyphenols Attenuated Glutamate Excitotoxicity via Antioxidative and Antiapoptotic Pathway in the Primary Cultured Cortical Neurons." Oxidative Medicine and Cellular Longevity 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/2050435.

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Green tea polyphenols are a natural product which has antioxidative and antiapoptotic effects. It has been shown that glutamate excitotoxicity induced oxidative stress is linked to neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. In this study we explored the neuroprotective effect of green teen polyphenols against glutamate excitotoxicity in the primary cultured cortical neurons. We found that green tea polyphenols protected against glutamate induced neurotoxicity in the cortical neurons as measured by MTT and TUNEL assays. Green tea polyphenols were then showed to inhibit the glutamate induced ROS release and SOD activity reduction in the neurons. Furthermore, our results demonstrated that green tea polyphenols restored the dysfunction of mitochondrial pro- or antiapoptotic proteins Bax, Bcl-2, and caspase-3 caused by glutamate. Interestingly, the neuroprotective effect of green tea polyphenols was abrogated when the neurons were incubated with siBcl-2. Taken together, these results demonstrated that green tea polyphenols protected against glutamate excitotoxicity through antioxidative and antiapoptotic pathways.

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Dimiņš, Fredijs, Velga Miķelsone, and Miķelis Kaņeps. "Antioxidant Characteristics of Latvian Herbal Tea Types." Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences 67, no. 4-5 (November 1, 2013): 433–36. http://dx.doi.org/10.2478/prolas-2013-0067.

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Abstract The aim of the study was to characterise antioxidative properties and antiradical activity of the herbal tea collection in Latvia. High-pressure liquid chromatography and spectrophotometry methods were used to characterise antioxidant properties of herbal tea. Antiradical activity was determined spectrophotometrically. The antiradical scavenging activity was measured by the DPPH (2,2-diphenyl-1-picrylhydrazyl) reaction. The herbal tea antiradical scavenging activity was estimated as the broken down quantity of DPPH on 100 grams of the herbal tea. Individual polyphenols in the herbal tea were identified and determined by liquid chromatography. Antiradical scavenging activity of the herbal tea was found to be 104 mol 100 g-1 tea. The following polyphenols were identified chromatographically in herbal tea: gallic, caffeic, chlorogenic, ferulic acids, rutin, catechin, vanillin, and epicatechin. Altogether 12 different varieties of herbal tea samples were analyzed. The results showed that different types of herbal tea substantially differed in composition. Polyphenol content of herbal teas was in the range of 1 mg in 100 g of tea up to 8 g per 100 g of tea. In the case of virus-related disease, infections and weakness of the organism, it is recommended to use tea with high content of rutin, as in Verbascum thapsiforme Schr., Alchemilla vulgaris L., Comarum palustre L. herbal tea.

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Zhou, Yu Jun, Wen Li Wang, Ting Juan Yi, and Guo Hua Chen. "Experimental Verification and Theoretical Analysis of Silk Dyeing and Finishing Functions with Modified Natural Tea Polyphenols Dye." Advanced Materials Research 843 (November 2013): 102–5. http://dx.doi.org/10.4028/www.scientific.net/amr.843.102.

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The modification of natural dyes tea polyphenols is discussed in the silk dyeing. Tea polyphenols and 3-chlorine-2 - hydroxypropyl trimethyl ammonium chloride (CHPTMA) are ionized in alkaline condition, and modified tea polyphenols are prepared. The effect of CHPTMA modifier dosage, pH, temperature and time condition to modification of tea polyphenols are studied systematically. The optimal process of modification is obtained. The dyeing & finishing functional performances on silk were performed experimentally and verified theoretically.

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Sun, Bo, Weijun Wang, Zhibin He, Min Zhang, Fangong Kong, Mohini Sain, and Yonghao Ni. "Improvement of Stability of Tea Polyphenols: A Review." Current Pharmaceutical Design 24, no. 29 (December 8, 2018): 3410–23. http://dx.doi.org/10.2174/1381612824666180810160321.

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Tea polyphenols have received much attention from the pharmaceutical and food industries owing to their extraordinary antioxidant and antibacterial characteristics. However, tea polyphenols are very unstable in processing and storage, since they are sensitive to the environmental factors like temperature, light and pH. Therefore, the effective application of tea polyphenols requires a protective mechanism to maintain its activity. The utilization of compounded tea polyphenols, instead of raw materials, can potentially help to improve their stability. This review focuses on the summarization of the compounding technologies for tea polyphenols, including physical technologies, chemical-interfacial technologies and nano-scale compounding technologies. Of which, the emerging nano cellulose bio-carrier, as a promising technology, is particularly proposed.

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Phung, Lan Huong, Trung Kien Tran, The Cuong Nguyen, Hong Quang Do, Thu Tra Phan, Hong Son Vu, and Tien Huy Nguyen. "Optimization Research into the Ultrasonic-assisted Extraction to Separate Polyphenol from Green Tea Waste." ASEAN Journal of Chemical Engineering 12, no. 2 (February 7, 2013): 52. http://dx.doi.org/10.22146/ajche.49743.

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Today, green tea leaves (Camellia sinensis) have been grown in nearly 30 provinces in Vietnam. Catechins, which are polyphenols, are abundant in green tea. In a freshly picked tea leaf, polyphenols can compose up to 30% of the dry weight. Recently, researchs have focused on tea polyphenols due to its potent anti-oxidant activity, anti-inflammatory and anti-cancer effects. Viet Nam currently ranks the fifth in the world in tea production and export turn-over. However, green tea is made from the top two leaves and buds of a shrub. A large amount of stems, older leaves and tea wastes from tea factories is not produced. For this reason, study to separation polyphenols from these materials plays an important role in science, society and economy. Polyphenols can be extracted from green tea leaves by using hot water and organic solvents. In the method of using hot water, green tea quality deteriorates and catechins are destroyed due to the heat applied. Therefore, we attempted to increase the amount of polyphenols in extracts with using ultrasonic irradiation at low temperature. This work has an aim to investigate the influent process parameters such as extraction time, stirring speed and the rate of raw material/solvent on efficiency of the extraction of polyphenols and antioxidant properties obtained extracts. The ultrasonic-assisted extraction was conducted at room temperature, ultrasound frequency (25 kHz) using water solvent. Extracts were analysed for total phenols content (TPC) by the Lowenthal method. The antioxidant properties have been determined by DPPH free radical scavenging effect, The results of the work are the basis to determine of the optimal technological factors by employing desirability methodology with experimental order of Box-Behnken design and to scale up for designed industrial extraction system that can be applied in tea plants for the production of tea polyphenols from tea wastes.

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Cantele, Carolina, Olga Rojo-Poveda, Marta Bertolino, Daniela Ghirardello, Vladimiro Cardenia, Letricia Barbosa-Pereira, and Giuseppe Zeppa. "In Vitro Bioaccessibility and Functional Properties of Phenolic Compounds from Enriched Beverages Based on Cocoa Bean Shell." Foods 9, no. 6 (June 2, 2020): 715. http://dx.doi.org/10.3390/foods9060715.

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The cocoa bean shell (CBS), a cocoa by-product, contains a significant number of bioactive compounds with functional properties, such as polyphenols and methylxanthines, and is used as an ingredient in beverages and foods. In this work, the bioaccessibility of polyphenols and methylxanthines after In Vitro digestion was evaluated in new flavoured beverages for at-home consumption (capsules and tea bags). In addition, the polyphenolic composition, functional properties (antiradical and α-glucosidase inhibition capacities) and consumer acceptability of these beverages were evaluated. In both capsule and tea bag beverages, the bioaccessibility of methylxanthines was 100% while that of total polyphenols exceeded 50%. The main polyphenols determined using reverse-phase liquid chromatography were type B procyanidins and epicatechin. The antiradical activity in capsule and tea bag beverages was 1.75 and 1.88 mM of Trolox equivalents, respectively, of which 59.50% and 57.09% were recovered after simulated digestion. The percentage of α-glucosidase inhibition before In Vitro digestion (51.64% and 53.82% for capsules and tea bags, respectively) was comparable to that of acarbose at 0.5 mM. All the beverages obtained a high consumer acceptability. Therefore, these results highlight that CBSs can be used as a valid source of bioactive compounds in the preparation of beverages with homemade techniques.

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Tan, He Ping, Huai Ping Li, Hang Song, Wen Ping Xu, Chi Guan, and Li Ping Ran. "A Novel Way of Separation and Preparation Noncaffeine Tea Polyphenols from Green Tea Waste." Advanced Materials Research 550-553 (July 2012): 1875–80. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.1875.

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Abstract:

A simple, clean and economical way of separation and preparation noncaffeine tea polyphenols from green tea waste in one-step by Sephadex LH-20 column chromatography was developed. 20% (v/v) ethanol solution was used for removing caffeine and other components in the first stepwise elution, and tea polyphenols was eluted with 60% (v/v) ethanol solution by using reversed flow in the second stepwise elution. The yield of tea polyphenols above 11% with the purity about 98% and the content of catechins more than 91%, and the content of caffeine in tea polyphenols have not been detected by high-performance liquid chromatography. The recovery of tea polyphenols by column chromatography were about 86%, and the stability of preparative way is very good. Compared with conventional extraction and decaffeination ways, this way has more excellent advantages, such as cheaper raw material, no toxic residues, higher yield, commercially feasible and environment friendly.

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Journal articles on the topic 'Tea polyphenols'

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