• Title/Summary/Keyword: tea polyphenols

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The Roles of Dietary Polyphenols in Brain Neuromodulation (뇌 신경조절에서의 식이 폴리페놀 화합물의 역할)

  • Lee, Hyeyoung;Lee, Heeseob
    • Journal of Life Science
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    • v.28 no.11
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    • pp.1386-1395
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    • 2018
  • Over recent years, it has become evident that the central nervous system bidirectionally interacts with the gastrointestinal tract along the gut-brain axis. A series of preclinical studies indicate that the gut microbiota can modulate central nervous system function through a multitude of physiological functions. Polyphenols are ubiquitous plant chemicals included in foods such as fruits, vegetables, tea, coffee and wine, and their consumption is directly responsible for beneficial health effects due to antioxidant, anti-inflammatory, antimicrobial, immunomodulatory, anticancer, vasodilating, and prebiotic-like effects. There is increasing evidence that dietary polyphenol can contribute to beneficial effects in neuronal protection acting against oxidative stress and inflammatory injury as well as in cognitive functions. In this paper, we overview the neuroprotective role of dietary polyphenols especially focusing on the neuroinflammation and neurovascular function by interaction with the gut microbiome. Polyphenol metabolites could directly act as neurotransmitters crossing the blood-brain barrier and modulating the cerebrovascular system or indirectly modulating gut microbiota. In addition, evidence suggests that dietary polyphenols are effective in preventing and managing neurological disorders, such as age-related cognitive decline and neurodegeneration, through a multitude of physiological functions. Dietary polyphenols are increasingly envisaged as a potential nutraceuticals in the prevention and treatment of neurological disorders, because they possess the ability to reduce neuroinflammation, to improve memory and cognitive function and to modulate the gut microbiota.

Dietary Effect of Puer Tea Extract on the Body Weight in Rats

  • Kim, Jong-Won;Baek, Sun-Ah;Kim, Hyo-Jeong;Ye, Qing;Kim, Su-Won;Nam, Jin-Sik;Kang, Kyung-Hee;Kang, Myung-Hee;Doh, Seong-Tak;Kwon, Sun-Il;Ahn, Seung-Ju;Kim, Su-Jung;Yoo, Min
    • Biomedical Science Letters
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    • v.16 no.1
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    • pp.68-70
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    • 2010
  • Puer tea is a traditional beverage originating from Yunnam area of China. It supplies basic nutrients such as vitamin C. It has been well reported that daily drinking of Puer tea can help the digestion and ease the stomachache after food intake. Puer tea also contains various polyphenols which may exert antibacterial activity against Staphylococcus aureus and Listeria monocytogenes. Because of these functional effects on digestive system we suspected if Puer tea can display any dietary effect or decrease the obesity after long-term drinking. We employed 6-week old SD rats as experimental animal and treated them with extract of Puer tea in relation to the body weights. Rats were divided into 5 groups (NC, PC, E, E+P, E+P5). NC group was experimental control and rest of them are as follows: water only (PC), water with exercise (E), water with exercise and Puer tea extract (E+P), water with exercise and 5X extract of Puer tea (E+P5). Feeding was carried out every day for 5 weeks by oral administration. Reduction rate of body weights was highest in E group. Relative ratio of losing weight was as follows: PC group (100.78%), E group (95.57%), E+P group (94.53%) and E+P5 group (74.22%), respectively. Exercise was more helpful to control the body weight. The result strongly suggests that Puer tea is highly effective to control the body weight and could be used for pharmaceutical purpose to treat obesity without side effects.

Hypocholesterolemic Effects of Green Tea in Cholesterol-Fed Rats (고 콜레스테롤 식이 투여 흰쥐에 있어서 녹차의 콜레스테롤 저하 효과)

  • 진현화;양정례;정종화;김양하
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.1
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    • pp.47-51
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    • 2004
  • Green tea, which is high in polyphenols, is thought to have hypocholesterolemic effects. The present study was performed to further elucidate the hypocholesterolemic actions of green tea, specially the catechin and (-)-epigallocatechin gallate (EGCG) for their effects on the diet-induced hypercholesterolemia in rats. Male Sprague-Dawley rats were fed with green tea-free diet (control), diets containing 4% green tea powder (GTP), 1.0% green tea catechin (catechin) or 0.5% epigallocatechin gallate (EGCG) for 7 wks. All diets that were provided green tea contained approximately 0.5% EGCG Hypercholesterolemia was induced by adding 1% cholesterol and 0.5% cholic acid to all diets. There were no differences in food intake among groups. The green tea treatments showed significant improvement in the serum levels of total cholesterol, LDL-cholesterol, triacylglycerides and atherogenic index in the following order; EGCG>Catechin>GTP (p<0.05). The serum HDL-cholesterol level was highest in the EGCG-treated group. The catechin or EGCG diet up-regulated by 5 times the enzyme activity of hepatic cholesterol 7$\alpha$ -hydroxylase (CYP7Al) compared to control diet (p<0.05). Hepatic CYP7Al mRNA level paralleled tile increases in the CYP7Al activity. These results suggest that the EGCG in the green tea may account for the hypocholesterolemic effect by the induction of CYP7Al gene expression.

Free Radical Toxicology and Cancer Chemoprevention

  • Lin, Jen-Kun
    • Toxicological Research
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    • v.17
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    • pp.83-88
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    • 2001
  • Most reactive oxygen species (ROS) are free radicals and implicated in the development of a number of disease processes including artherosclerosis, neurodegenerative disorders, aging and cancer. ROS are byproducts of a number of in vivo metabolic processes and are formed deliberately as part of nor-mal inflammatory response. On the other hand, ROS are generated either as by products of oxygen reduction during xenobiotic metabolism or are liberated as the result of the futile redox cycling of the chemical agents including several chemical carcinogens. A better understanding of the mechanisms of free radical toxicity may yield valuable clue to risks associated with chemical exposures that leading to the development of chronic diseases including cancer. The molecular biology of ROS-mediated alterations in gene expression, signal transduction and carcinognesis is one of the important subjects in free radical toxicology. Epidemiological studies suggest that high intake of vegetables and fruits are associated with the low incidence of human cancer. Many phytopolyphenols such as tea polyphenols, curcumin, resveratrol, apigenin, genistein and other flavonoids have been shown to be cancer chemopreventive agents. Most of these compounds are strong antioxidant and ROS scavengers in vitro and effective inducers of antioxidant enzymes such as superoxide dismutatse, catalase and glutathione peroxidase in vivo. Several cellular transducers namely receptor tyrosine kinase, protein kinase C, MAPK, PI3K, c-jun, c-fos, c-myc, NFkB, IkB kinase, iNOS, COX-2, Bcl-2, Bax, etc have been shown to be actively modulated by phyto-polyphenols. Recent development in free radical toxicology have provided strong basis for understanding the action mechanisms of cancer chemoprevention.

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Enhancement of polyphenols, flavonoids and antioxidant activities in water extract of mulberry (Morus alba L.) root bark by steam treatment

  • Rahul, Kamidi;Kweon, HaeYong;Kim, Hyun-Bok;Lee, Ji Hae;Makwana, Pooja
    • International Journal of Industrial Entomology and Biomaterials
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    • v.44 no.1
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    • pp.21-27
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    • 2022
  • Different parts of the mulberry plant are described to be potential sources of polyphenolics exhibiting strong antioxidant activity. In this study, we prepared various aqueous extracts of mulberry root bark by subjecting to steam at different temperatures and time intervals (45℃, 15 h; 70℃, 15 h; 95℃, 6 h and 95℃, 15 h) followed by extracting at 80℃ for 1 h. The total polyphenolic content ranged from 66.82-101.20 mg gallic acid equivalent (GE)/g of extract whereas the flavonoids were in the range of 13.03-25.23 mg catechin equivalent (CE)/g of extract. The extracts also exhibited strong antioxidant activities (0.99-1.66 mg trolox equivalent (TE)/g of extract in DDPH assay and 10.65-16.26 mg TE/g of extract in ABTS assay). This study clearly showed an improvement in the antioxidant activity of the water extract of mulberry root bark by the steam treatment, which can be used as a tea or health-promoting materials.

Optimal HPLC Condition for Simultaneous Determination of Catechins and Caffeine in Green Tea Extracts (녹차 함유 카테친 및 카페인 동시분석을 위한 최적 HPLC 분석 조건)

  • Choung, Myoung-Gun;Lee, Min-Seuk
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.53 no.2
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    • pp.224-232
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    • 2008
  • The health benefits associated with tea consumption have resulted in the wide inclusion of green tea extracts in botanical dietary supplements, which are widely consumed as adjuvants for complementary and alternative medicines. Tea contains polyphenols such as catechins or flavan-3-ols including (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG), as well as the alkaloid, caffeine. The contents of catechins and caffeine in green tea are considered as a standard of quality evaluation of green tea. Therefor, the purpose of this study was to investigate the most suitable HPLC condition for simultaneous determination of catechins and caffeine in green tea extracts. The efficient HPLC analytical condition of catechins and caffeine contained green tea extracts was developed. The gradient elution employed a $250\;mm\;{\times}\;4.6\;mm$ i.d. YMC-pak ODS-AM 303 column. The gradient system was used two mobile phases. A gradient elution was performed with mobile phase A, consisting of 0.1% aqueous phosphoric acid, and mobile phase B, comprising 100% MeOH, and delivered at a flow rate of 1 mL/min as follows: $0{\sim}25\;min$, 80% A; $26{\sim}50\;min$, $80{\sim}70%$ A; 51 min, 80% A. $51{\sim}55\;min$, 80% A. The UV detection wavelength was set at 280 nm. The limit of detection (LOD) for catechins and caffeine standards were under 50 ng/mL.

Comparison of Anti-oxidative Activity in a Single Serving Size of the Commercial Coffees and Teas

  • Kim, Tae-Hun;Lee, Seulgi;Seo, Jin Woo;Bing, Sun Hye;Kim, Jong Im;Kwon, Eui-Ra;Jo, Gune-Hee;Lee, Jae-Myean;Choi, Joon Sig
    • Journal of Food Hygiene and Safety
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    • v.32 no.6
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    • pp.460-469
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    • 2017
  • The aim of this work was to study the comparison of anti-oxidative activity in a single serving size of commercial coffees and teas. Commercial regular coffees and teas, including, brand regular coffees ($BC_A$, $BC_B$, $BC_C$, $BC_D$, and $BC_E$), green tea ($GT_A$, $GT_B$, $GT_C$, and $GT_D$), black tea ($BT_A$, $BT_B$, and $BT_C$), pu-erh tea ($PT_A$, $PT_B$, and $PT_C$), chamomile tea ($CT_A$, $CT_B$, and $CT_C$), peppermint tea ($P_A$, $P_B$, and $P_C$), polygonatum odoratum tea ($POT_A$, $POT_B$, and $POT_C$), and jujube tea ($JT_A$, $JT_B$, and $JT_C$) were assayed for the levels of ascorbic acid, caffeine, total content of polyphenols and flavonoids, and ability to scavenge free radicals, using two in vitro antioxidant assays. The scavenging abilities of $BC_A$ and $BC_C$ were $664.91{\pm}48.87mg$ ascorbic acid equivalent/serving size and $624.36{\pm}16.18mg$ ascorbic acid equivalent/serving size, respectively. The four beverage samples ($BC_A$, $BC_C$, $GT_D$, and $BT_A$) significantly reduced the production of reactive oxygen species (ROS) and intracellular oxidative stress induced by $H_2O_2$. These results suggest that the beverages possess significant radical scavenging ability, which may be due to the presence of antioxidants. Furthermore, the significant reducing level of ROS evidences the potential antioxidant effects of these beverages in human cells.

Isolation of Polyphenol from Green Tea by HPLC and Its Physiological Activities (HPLC에 의한 녹차의 polyphenol 화합물의 분리 및 polyphenol의 생리활성)

  • Woo, Hee-Seob;Choi, Hee-Jin;Han, Ho-Suk;Park, Jung-Hye;Son, Jun-Ho;An, Bong-Jeun;Son, Gyu-Mok;Choi, Cheong
    • Korean Journal of Food Science and Technology
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    • v.35 no.6
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    • pp.1199-1203
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    • 2003
  • Polyphenols were isolated from Korean green tea using Sephadex LH-20 and HPLC. The isolated polyphenols were procyanidin B-4, procyanidin B-2-3,3'-digallate, prodelphinidin C-2-3,3'-di-O-digallate, (+)-catechin-3-O-rhamnose, procyandin B-5, procyanidin B-7-3-0-gallate, gallate, epiafzelechin-$(4{\beta}{\rightarrow}8)$-epiafzelechin, procyanidin B-3-3-O-rhamnose, afzelechin-$(4{\alpha}{\rightarrow}8)$-catechin, prodelphinidin B-5-3,3'-di-O-digallate and (+)-taxifolin-3-O-D-xyloside. The inhibitory effects of prodelphinidin C-2-3,3'-di-O-gallate and procyanidin B-2-3,3'-digallate $(at\;100{\mu}M)$ on angiotensin.converting enzyme were 68.8 and 54.6%, respectively, while the inhibitory effects of prodelphinidin C-2-3,3'-di-O-gallated and procyanidin B-2-3,3'-digallate $(at\;100{\mu}m)$ on xanthine oxidase were 54.5 and 38.2%, respectively. Lastly, the inhibitory activities of prodelphinidin C-2-3,3'-di-O-gallate $(at\;100{\mu}m)$ on tyrosinase was 42.1%.

Quality and Antioxidant Characteristics of Roasted Maize Tea according to Cultivation Period and Variety (파종시기 및 품종별 볶음 옥수수차의 품질 및 항산화 특성)

  • Lee, Ji Hae;Kim, Hyun-Joo;Kim, Mi Jung;Jung, Gun-Ho;Lee, Byong Won;Lee, Byoung Kyu;Woo, Koan Sik
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.11
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    • pp.1316-1326
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    • 2017
  • We evaluated the proximate compositions of raw materials, total polyphenols, total flavonoids, and radical scavenging activities of roasted maize tea according to cultivation period and variety. Proximate compositions of raw materials were significantly different according to cultivation period and variety, and quality characteristics of roasted maize tea extracts were significantly different according to cultivation period. Total polyphenols, total flavonoids, and radical scavenging activities of roasted maize tea were significantly different before and after roasting. The total polyphenol content of Pyeonggangok cultivar sown on April 5th was elevated about 3.60-fold before and after roasting by $3.42{\pm}0.16$ and $12.22{\pm}0.67mg$ gallic acid equivalents/g, respectively. Overall, total polyphenol content was higher in roasted maize tea produced using maize sown on April 5th. 1,1-Diphenyl-2-picrylhydrazyl radical scavenging activity of Gangdaok cultivar sown on April 5th was elevated about 31.6-fold before and after roasting by $7.61{\pm}1.93$ and $240.37{\pm}8.82mg$ Trolox equivalents (TE)/g, respectively. 2,2'-Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging activity of Pyeonggangok cultivar sown on April 5th was elevated about 5.5-fold before and after roasting by $153.84{\pm}1.32$ and $843.54{\pm}3.64mg$ TE/g, respectively. The correlation between proximate compositions of raw materials and quality as well as antioxidant characteristics of roasted maize tea showed overall significance.

Effects of Green Tea Powder Addition on Antioxidant Activities and Texture Properties of Cooked Rice (녹차분말 첨가가 쌀밥의 항산화 활성 및 물성에 미치는 영향)

  • Yang, Jinwoo;Lee, Kyeongmin;Ham, Hyeonmi;Kwak, Jieun;Kim, Younghwa;Jeong, Heon Sang;Lee, Junsoo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.6
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    • pp.765-770
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    • 2017
  • Green tea (Camellia sinensis L.) is consumed as a popular beverage worldwide, particularly in Asia. In this study, the effects of green tea powder addition on the antioxidant activities and texture properties of cooked rice were investigated. Texture analysis was carried out by texture profile analysis. Total polyphenols and total flavonoids were determined using spectrophotometric methods, and antioxidative activities were determined based on DPPH and ABTS radical scavenging activities, reducing power, and lipid peroxidation inhibitory activity. Antioxidant contents and antioxidative activities increased with a higher amount of green tea powder. However, there was no difference in texture properties between cooked rice with green tea powder and the control group. In conclusion, addition of green tea powder to cooked rice would be useful to increase antioxidant contents and antioxidative activities without alteration of texture properties.