• Journal of Microbiology and Biotechnology
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• v.33 no.10
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• pp.1317-1328
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• 2023

Green tea (GT) polyphenols undergo extensive metabolism within gastrointestinal tract (GIT), where their derivatives compounds potentially modulate the gut microbiome. This biotransformation process involves a cascade of exclusive gut microbial enzymes which chemically modify the GT polyphenols influencing both their bioactivity and bioavailability in host. Herein, we examined the in vitro interactions between 37 different human gut microbiota and the GT polyphenols. UHPLC-LTQ-Orbitrap-MS/MS analysis of the culture broth extracts unravel that genera Adlercreutzia, Eggerthella and Lactiplantibacillus plantarum KACC11451 promoted C-ring opening reaction in GT catechins. In addition, L. plantarum also hydrolyzed catechin galloyl esters to produce gallic acid and pyrogallol, and also converted flavonoid glycosides to their aglycone derivatives. Biotransformation of GT polyphenols into derivative compounds enhanced their antioxidant bioactivities in culture broth extracts. Considering the effects of GT polyphenols on specific growth rates of gut bacteria, we noted that GT polyphenols and their derivate compounds inhibited most species in phylum Actinobacteria, Bacteroides, and Firmicutes except genus Lactobacillus. The present study delineates the likely mechanisms involved in the metabolism and bioavailability of GT polyphenols upon exposure to gut microbiota. Further, widening this workflow to understand the metabolism of various other dietary polyphenols can unravel their biotransformation mechanisms and associated functions in human GIT.

• Archives of Pharmacal Research
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• v.25 no.5
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• pp.561-571
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• 2002

The action mechanisms of several chemopreventive agents derived from herbal medicine and edible plants have become attractive issues in cancer research. Tea is the most widely consumed beverage worldwide. Recently, the cancer chemopreventive actions of tea have been intensively investigated. It have been demonstrated that the active principles of tea were attributed to their tea polyphenols. Recently, tremendous progress has been made in elucidating the molecular mechanisms of cancer chemoprevention by tea and tea polyphenols. The suppression of various tumor biomarkers including growth factor receptor tyrosine kinases, cytokine receptor kinases, P13K, phosphatases, ras, raf, MAPK cascades, NㆍFB, IㆍB kinase, PKA, PKB, PKC, c-jun, c-fos, c-myc, cdks, cyclins, and related transducing proteins by tea polyphenols has been studied in our laboratory and others. The IㆍB kinase (IKK) activity in LPS-activated murine macrophages (RAW 264.7 cells) was found to be inhibited by various tea polyphenols including (-) epigallocatechin-3-gallate (EGCG), theaflavin (TF-1), theaflavin-3-gal-late (TF-2) and theaflavin-3,3'-digallate (TF-3). TF-3 inhibited IKK activity in activated macrophages more strongly than did the other tea polyphenols. TF-3 inhibited both IKK1 and IKK2 activity and prevented the degradation of IㆍBㆍand IㆍBㆍin activated macrophage cells. The results suggested that the inhibition of IKK activity by TF-3 and other tea polyphenols could occur by a direct effect on IKKs or on upstream events in the signal transduction pathway. TF-3 and other tea polyphenols blocked phosphorylation of IB from the cytosolic fraction, inhibited NFB activity and inhibited increases in inducible nitric oxide synthase levels in activated macrophage. TF-3 and other tea polyphenols also inhibited strongly the activities of xanthine oxidase, cyclooxygenase, EGF-receptor tyrosine kinase and protein kinase C. These results suggest that TF-3 and other tea polyphenols may exert their cancer chemoprevention through suppressing tumor promotion and inflammation by blocking signal transduction. The mechanisms of this inhibition may be due to the blockade of the mitogenic and differentiating signals through modulating EGFR function, MAPK cascades, NFkB activation as wll as c-myc, c-jun and c-fos expression.

• Biomolecules & Therapeutics
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• v.11 no.4
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• pp.238-244
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• 2003

Nicotine is one of the major hazardous components in cigarettc smoke. Nicotine deals a harmful effect to smokers and passive smokers due to its rapid conversion to various carcinogenic metabolites. Nitrosamine-4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is believed to cause lung cancers among the nicotine-derived carcinogens. Recent studies report that NNK synthesis can be inhibited by the metabolism pathway to produce a stable metabolite cotinine from nicotine. Tea polyphenols have been known to contain factors to prevent cancers and to retard progression of cancers. This study aims to correlate tea polyphenol's potential for cancer prevention with an accelerated formation of cotinine. The conversion from nicotine to cotinine in the presence of tea extracts or three polyphenols (Catechin, epicatechin gallate, epigallocatechin gallate) was measured in established cell lines and in Xenopus oocytes. Among three lines of cell used, PLC/PRF5 and HEK293 cells showed a fast turnover from nicotine to cotinine while HepG2 cell line showed a marginal difference between groups treated and non-treated with tea polyphenols. When Xenopus oocytes were microinjected with nicotine, tea polyphenols appear to accelerate the conversion of nicotine to cotinine. Among the polyphenols tested in this study, (＋)－catechin showed the best efficiency overall in accelerating conversion from nicotine to cotinine both in the cell lines and in the oocytes. In summary, the present study indicated that tea polyphenols have a positive effect on conversion of nicotine to cotinine.

• CELLMED
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• v.6 no.2
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• pp.12.1-12.7
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• 2016

Cocos nucifera (C. nucifera) oil is indigenously used to treat cardiovascular diseases. However, coconut husk fibre (which is rich in polyphenols) has not been screened for this property. Based on the ethnomedicinal use of polyphenols in treating cardiovascular diseases, this study was carried out to evaluate the effects of polyphenols of C. nucifera husk fibre on selected cardiovascular disease indices in mice. Fifty adult male Swiss albino mice were assigned randomly into five groups (A-E). Mice in groups B, C, D and E were administered 31.25, 62.5, 125, and 250 mg/kg body weight polyphenols of ethyl acetate extract of C. nucifera husk fibre respectively while the control group (A) mice received 5% DMSO for seven days. The mice were sacrificed twenty four hours after the last administration of polyphenols. Heart and plasma lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities and plasma lipid profile were determined. Results revealed significant reduction (^*p< 0.05) in plasma levels of total cholesterol and LDL-cholesterol with no significant change (^*p> 0.05) in HDL-cholesterol, triglyceride and VLDL levels in the plasma at all doses of polyphenols administered compared to controls. There was significant reduction (^*p< 0.05) in the activities of heart AST and LDH while plasma ALT, AST, and ALP activities were not significantly altered (^*p> 0.05) at all doses of polyphenols administered compared to controls. These results suggest that the polyphenols of C. nucifera husk fibre possess cardio-protective properties and also indicate their possible use in the treatment of cardiovascular diseases.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.563-566
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• 2003

This study was proposed to measure total polyphenols and antioxidant activities from leaves of Stachys sieboldii MIQ. Solvents such as acetone 60%, petroleum ether, ethylacetate, and water were used for this purpose The fraction by ethyl acetate fraction showed the strongest activity by DPPH method and contained much more polyphenols than those by other solvents.

• Molecules and Cells
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• v.39 no.6
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• pp.508-513
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• 2016

To investigate the potential therapeutic effects of polyphenols in treating Pb induced renal dysfunction and intoxication and to explore the detailed underlying mechanisms. Wistar rats were divided into four groups: control groups (CT), Pb exposure groups (Pb), Pb plus Polyphenols groups (Pb+PP) and Polyphenols groups (PP). Animals were kept for 60 days and sacrificed for tests of urea, serum blood urea nitrogen (BUN) and creatinine. Histological evaluations were then performed. In vitro studies were performed using primary kidney mesangial cells to reveal detailed mechanisms. Cell counting kit-8 (CCK-8) was used to evaluate cell viability. Pb induced cell apoptosis was measured by flow cytometry. Reactive oxygen species (ROS) generation and scavenging were tested by DCFH-DA. Expression level of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-1-${\beta}$ (IL-1-${\beta}$) and IL-6 were assayed by ELISA. Western blot and qPCR were used to measure the expression of ERK1/2, JNK1/2 and p38. Polyphenols have obvious protective effects on Pb induced renal dysfunction and intoxication both in vivo and in vitro. Polyphenols reduced Pb concentration and accumulation in kidney. Polyphenols also protected kidney mesangial cells from Pb induced apoptosis. Polyphenols scavenged Pb induced ROS generation and suppressed ROS-mediated ERK/JNK/p38 pathway. Downstream pro-inflammatory cytokines were inhibited in consistency. Polyphenol is protective in Pb induced renal intoxication and inflammatory responses. The underlying mechanisms lie on the antioxidant activity and ROS scavenging activity of polyphenols.

• CELLMED
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• v.9 no.1
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• pp.2.1-2.6
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• 2019

Decoction of Cocos nucifera husk fibre is used indigenously in Nigeria for malaria treatment. Polyphenols have been identified as the phytochemicals responsible for the antimalarial activity of Cocos nucifera husk fibre, though their toxicity has not been evaluated. The polyphenols of Cocos nucifera husk fibre were therefore evaluated for their effects on selected kidney function indices in mice. Fifty mice were randomly divided into five groups (A-E) of ten mice each. Mice in group A were orally administered 5% DMSO solution while those in groups B, C, D and E were orally administered 31.25, 62.5, 125 and 250 mg/Kg body weight of the polyphenols respectively for seven days. Serum urea, creatinine and uric acid concentrations were determined. Serum levels of sodium, potassium, chloride and calcium ions and kidney alkaline phosphatase (ALP), glutamate dehydrogenase (GDH) and gamma-glutamyltransferase (GGT) activities were also determined. The results showed that the polyphenols significantly reduced (p<0.05) urea concentration at 250 mg/Kg body weight and creatinine concentration at all doses compared to controls. The polyphenols caused no significant alteration (p>0.05) in serum uric acid concentration and kidney ALP, GGT and GDH activities compared to controls. There was significant increase (p<0.05) in serum sodium ion concentration at 31.25, 125 and 250 mg/Kg body weight of polyphenols whereas significant increase (p<0.05) in serum potassium and chloride ions was observed at 62.5 and 250 mg/Kg body weight compared to controls. Thus, polyphenols of Cocos nucifera husk fibre may adversely affect some osmoregulatory functions of the kidney, especially at higher concentrations.

• Journal of the Korean Society of Tobacco Science
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• v.6 no.1
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• pp.13-18
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• 1984

To find out the effect of transplanting time on the autonomic characters, yield of cured leaves and content of polyphenols in burley tobacco, three transplanting time were evaluated. The results obtained are as follows. Low temperature which was caused damage earliest stage of tobacco in early transplanting could escape by vinyl mulching and other treatment. 2. The major polyphenols in leaves were chlorogenic acid and rutin, small amount of scopolin and quercetin were also detected. 3. Chlorogenic acid decreased during curing. 4. Polyphenols content was not influenced by transplanting time.

• Applied Chemistry for Engineering
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• v.29 no.3
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• pp.325-329
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• 2018

In this study, polyphenols were extracted from Angelica, which are known to have a high antioxidant content and the extraction process was optimized using the response surface methodology. The extraction yield and the total polyphenols were set as response values for the methodology. Quantitative factors in the extraction process were the extraction time, volume ratio of alcohol/ultrapure water, and extraction temperature. When considering both the main and interaction effects, the greatest influence factor on the extraction yield and total polyphenols was the extraction time. The optimum extraction time and temperature and alcohol/ultrapure water volume ratio for angelica were 2.8 h, $56.6^{\circ}C$ and 64.0 vol% respectively. The extraction yield and total polyphenols when using the conditions were calculated to be 24.6% and 8.76 mg GAE/g. respectively. Determination coefficients of regression equations for the extraction yield and total polyphenols were 81.4 and 75.4%, respectively. Also the overall satisfaction level was found to be 0.80 and the significance was confirmed within 5%.

• Analytical Science and Technology
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• v.11 no.6
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• pp.478-484
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• 1998

Distribution of polyphenolic compounds in oak tree (Quercus acutissima, three years old) collected from Forest Research Institute located in Kwang Leung, Kyeonggi-do, Korea, was investigated using chromatographic studies. Total 25 polyphenolic fractions were separated from an oak tree, of which 15, 11, 7, 7, and 4 were in leaf, stem, root, bark, and seed, respectively. Catechins are predominant compounds in the polyphenols and some flavonoids were also identified. Distribution of polyphenols was relatively different in each part. Polyphenols in all of the part studied, except leaf where polymer was not detected, were existed as polymeric, oligomeric, and monomeric forms. Relative contents of total polyphenols in Quercus acutissima were the highest in bark, followed by root, leaf, acorn, and stem. Monomeric polyphenols were the predominant compounds present in all of the part of the oak tree.