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Harold Corke - One of the best experts on this subject based on the ideXlab platform.
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Separation, Identification, and Bioactivities of the Main Gallotannins of Red Sword Bean (Canavalia gladiata) Coats
Frontiers in chemistry, 2018Co-Authors: Kin Weng Kong, Kao Wu, Ying-ying Ge, Hua-bin Li, Chak-lun Chan, Harold CorkeAbstract:The red sword bean (Canavalia gladiata) is an underutilized edible bean cultivated in China. It was previously found to have the highest content of antioxidant polyphenols among 42 edible beans, mainly gallic acid and Gallotannins in its red bean coat, an apparently unique characteristic among edible beans. In this study, the main phenolic compounds in red sword bean coats were further separated by Sephadex LH-20 column chromatography, and identified by LC-MS/MS. Furthermore, the FRAP and ABTS antioxidant activities and antibacterial activity (diameter of inhibition zone, DIZ) of main gallotannin-rich fractions were tested. Our results showed that Gallotannins of red sword bean coats were mainly comprised of nonogalloyl to hexagalloyl hexosides. Interestingly, tetragalloyl, pentagalloyl, and hexagalloyl hexosides were identified as the main candidates responsible for the red color of the coats. On the other hand, gallotannin-rich fractions exhibited diverse antioxidant and antibacterial activities, and tetragalloyl hexoside overall had the highest free radical scavenging and antibacterial activities. The degree of galloylation did not completely explain the structure-function relationship of Gallotannins isolated from red sword bean coats, as there should exist other factors affecting their bioactivities. In conclusion, red sword bean coats are excellent natural sources of Gallotannins, and their gallotannin-rich extracts can be utilized as natural antioxidant and antibacterial agents with potential health benefits as well as application in food industry.
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Separation, Identification, and Bioactivities of the Main Gallotannins of Red Sword Bean (Canavalia gladiata) Coats
Frontiers Media S.A., 2018Co-Authors: Ren-you Gan, Kin Weng Kong, Chak-lun Chan, Xian-ming Shi, Harold CorkeAbstract:The red sword bean (Canavalia gladiata) is an underutilized edible bean cultivated in China. It was previously found to have the highest content of antioxidant polyphenols among 42 edible beans, mainly gallic acid, and Gallotannins in its red bean coat, an apparently unique characteristic among edible beans. In this study, the main phenolic compounds in red sword bean coats were further separated by Sephadex LH-20 column chromatography, and identified by LC-MS/MS. Furthermore, the FRAP and ABTS antioxidant activities and antibacterial activity (diameter of inhibition zone, DIZ) of main gallotannin-rich fractions were tested. Our results showed that Gallotannins of red sword bean coats were mainly comprised of monogalloyl to hexagalloyl hexosides. Interestingly, tetragalloyl, pentagalloyl, and hexagalloyl hexosides were identified as the possible candidates responsible for the red color of the coats. On the other hand, gallotannin-rich fractions exhibited diverse antioxidant and antibacterial activities, and tetragalloyl hexoside overall had the highest free radical scavenging and antibacterial activities. The degree of galloylation did not completely explain the structure-function relationship of Gallotannins isolated from red sword bean coats, as there should exist other factors affecting their bioactivities. In conclusion, red sword bean coats are excellent natural sources of Gallotannins, and their gallotannin-rich extracts can be utilized as natural antioxidant and antibacterial agents with potential health benefits as well as application in food industry
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Rapid identification of Gallotannins from Chinese galls by matrix-assisted laser desorption/ionization time-of-flight quadrupole ion trap mass spectrometry.
Rapid Communications in Mass Spectrometry, 2009Co-Authors: Jie Xing, Jinxia Ke, Zhao-qi Zhan, Harold CorkeAbstract:Chinese gall, a conventional traditional Chinese medicine, contains high levels of Gallotannins. A rapid method for direct analysis of the Gallotannins without using any troublesome sample pretreatments was developed using matrix-assisted laser desorption/ionization time-of-flight quadrupole ion trap mass spectrometry (MALDI-QIT-TOF MS) to successfully identify the gallotannin components in the crude extract of Chinese galls within several minutes. The high quality of the MS and MS2 spectra acquired clearly showed that hydrolysable tannins in Chinese galls were identified as a series of the Gallotannins with degrees of polymerization (DP) of 4–11 galloyl units. The MS2 data indicated that the identified Gallotannins with DP of 4–7 galloyl units had clear fragmentation with loss of 1–5 galloyl units which were further deprived of 1–3 water moieties. This technique may be used for rapid evaluation and screening of hydrolysable tannins in medicinal plants. Copyright © 2009 John Wiley & Sons, Ltd.
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rapid identification of Gallotannins from chinese galls by matrix assisted laser desorption ionization time of flight quadrupole ion trap mass spectrometry
Rapid Communications in Mass Spectrometry, 2009Co-Authors: Fan Zhu, Zhao-qi Zhan, Jie Xing, Yizhong Cai, Harold CorkeAbstract:Chinese gall, a conventional traditional Chinese medicine, contains high levels of Gallotannins. A rapid method for direct analysis of the Gallotannins without using any troublesome sample pretreatments was developed using matrix-assisted laser desorption/ionization time-of-flight quadrupole ion trap mass spectrometry (MALDI-QIT-TOF MS) to successfully identify the gallotannin components in the crude extract of Chinese galls within several minutes. The high quality of the MS and MS2 spectra acquired clearly showed that hydrolysable tannins in Chinese galls were identified as a series of the Gallotannins with degrees of polymerization (DP) of 4–11 galloyl units. The MS2 data indicated that the identified Gallotannins with DP of 4–7 galloyl units had clear fragmentation with loss of 1–5 galloyl units which were further deprived of 1–3 water moieties. This technique may be used for rapid evaluation and screening of hydrolysable tannins in medicinal plants. Copyright © 2009 John Wiley & Sons, Ltd.
Andreas Schieber - One of the best experts on this subject based on the ideXlab platform.
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Effects of gallotannin treatment on attachment, growth, and survival of Escherichia coli O157:H7 and Listeria monocytogenes on spinach and lettuce
European Food Research and Technology, 2012Co-Authors: Christina Engels, Agnes Weiss, Reinhold Carle, Herbert Schmidt, Andreas Schieber, Michael G GanzleAbstract:Food-borne illness outbreaks are increasingly associated with fresh produce. Their high prevalence may reflect the lack of methods to effectively remove pathogenic bacteria from the surface of fruits and vegetables. This study evaluated the effect of antimicrobial Gallotannins on attachment, growth, and survival of food-borne pathogens on green leafy vegetables. Spinach leaves and interior leaves of lettuce harboring high and low cell counts of background microbiota, respectively, were washed with tap water with and without added Gallotannins. To account for the variability among organisms, green leafy vegetables were inoculated with strain cocktails of Escherichia coli O157:H7 and Listeria monocytogenes . Cell counts of L. monocytogenes were significantly reduced by the gallotannin treatment. Lower cell counts after storage for 8 days at 4 °C demonstrated antimicrobial effects of Gallotannins retained on the surface of green leafy vegetables. Gallotannin treatments with 1 g/L did not inhibit E. coli O157:H7 but hindered their attachment to filter paper by up to 94 %. The addition of gallotannin-containing extracts from mango ( Mangifera indica L.) kernels to the washing water did neither alter color nor texture of bagged fresh-cut products. In conclusion, gallotannin treatment significantly reduced surface contamination of green leafy vegetables with L. monocytogenes and reduced the attachment of cells of E. coli O157:H7.
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Fast LC–MS analysis of Gallotannins from mango (Mangifera indica L.) kernels and effects of methanolysis on their antibacterial activity and iron binding capacity
Food Research International, 2012Co-Authors: Christina Engels, Michael G Ganzle, Andreas SchieberAbstract:Abstract Mango ( Mangifera indica L.) kernels were successively extracted with hexane and methanol and the effects of extraction on the profile of Gallotannins as well as on their antimicrobial activity and iron-binding capacity were determined. A new method based on fast liquid chromatography with diode array and mass spectrometric detection was developed which allowed the separation of Gallotannins in less than 7 min. Gallotannins remained stable during Soxhlet extraction with hexane. Methanolysis led to the degradation of highly galloylated tannins to yield penta- O -galloylglucose and methyl gallate. The antimicrobial activity of the extracts was not affected by the compositional change, whereas the iron binding capacity increased with increasing amounts of methyl gallate. The less complex profile of antimicrobial compounds obtained after methanolysis compared to the crude extract will facilitate the standardization of extracts and their application in target products.
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Studies on the inhibitory spectrum and mode of antimicrobial action of Gallotannins from mango kernels (Mangifera indica L.)
Applied and Environmental Microbiology, 2011Co-Authors: Christina Engels, Andreas Schieber, Michael G GanzleAbstract:This study investigated the antimicrobial activities and modes of action of penta-, hexa-, hepta-, octa-, nona-, and deca-O-galloylglucose (Gallotannins) isolated from mango kernels. The MICs and minimum bactericidal concentrations (MBCs) against food-borne bacteria and fungi were determined using a critical dilution assay. Gram-positive bacteria were generally more susceptible to Gallotannins than were Gram-negative bacteria. The MICs of Gallotannins against Bacillus subtilis, Bacillus cereus, Clostridium botulinum, Campylobacter jejuni, Listeria monocytogenes, and Staphylococcus aureus were 0.2 g liter 1 or less; enterotoxigenic Escherichia coli and Salmonella enterica were inhibited by 0.5 to 1 g liter 1 , and lactic acid bacteria were resistant. The use of lipopolysaccharide mutants of S. enterica indicated that the outer membrane confers resistance toward Gallotannins. Supplementation of LB medium with iron eliminated the inhibitory activity of Gallotannins against Staphylococcus aureus, and siderophore-deficient mutants of S. enterica were less resistant toward Gallotannins than was the wild-type strain. Hepta-O-galloylglucose sensitized Lactobacillus plantarum TMW1.460 to hop extract, indicating inactivation of hop resistance mechanisms, e.g., the multidrug resistance (MDR) transporter HorA. Carbohydrate metabolism of Lactococcus lactis MG1363, a conditionally respiring organism, was influenced by hepta-O-galloylglucose when grown under aerobic conditions and in the presence of heme but not under anaerobic conditions, indicating that Gallotannins influence the respiratory chain. In conclusion, the inhibitory activities of Gallotannins are attributable to their strong affinity for iron and likely additionally relate to the inactivation of membrane-bound proteins.
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Inhibitory spectra and modes of antimicrobial action of Gallotannins from mango kernels (Mangifera indica L.).
Applied and environmental microbiology, 2011Co-Authors: Christina Engels, Andreas Schieber, Michael G GanzleAbstract:This study investigated the antimicrobial activities and modes of action of penta-, hexa-, hepta-, octa-, nona-, and deca-O-galloylglucose (Gallotannins) isolated from mango kernels. The MICs and minimum bactericidal concentrations (MBCs) against food-borne bacteria and fungi were determined using a critical dilution assay. Gram-positive bacteria were generally more susceptible to Gallotannins than were Gram-negative bacteria. The MICs of Gallotannins against Bacillus subtilis, Bacillus cereus, Clostridium botulinum, Campylobacter jejuni, Listeria monocytogenes, and Staphylococcus aureus were 0.2 g liter 1 or less; enterotoxigenic Escherichia coli and Salmonella enterica were inhibited by 0.5 to 1 g liter 1 , and lactic acid bacteria were resistant. The use of lipopolysaccharide mutants of S. enterica indicated that the outer membrane confers resistance toward Gallotannins. Supplementation of LB medium with iron eliminated the inhibitory activity of Gallotannins against Staphylococcus aureus, and siderophore-deficient mutants of S. enterica were less resistant toward Gallotannins than was the wild-type strain. Hepta-O-galloylglucose sensitized Lactobacillus plantarum TMW1.460 to hop extract, indicating inactivation of hop resistance mechanisms, e.g., the multidrug resistance (MDR) transporter HorA. Carbohydrate metabolism of Lactococcus lactis MG1363, a conditionally respiring organism, was influenced by hepta-O-galloylglucose when grown under aerobic conditions and in the presence of heme but not under anaerobic conditions, indicating that Gallotannins influence the respiratory chain. In conclusion, the inhibitory activities of Gallotannins are attributable to their strong affinity for iron and likely additionally relate to the inactivation of membrane-bound proteins.
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Fractionation of Gallotannins from mango (Mangifera indica L.) kernels by high-speed counter-current chromatography and determination of their antibacterial activity.
Journal of Agricultural and Food Chemistry, 2010Co-Authors: Christina Engels, Michael G Ganzle, Andreas SchieberAbstract:High-speed counter-current chromatography was applied to the separation of Gallotannins from mango (Mangifera indica L.) kernels. The kernels were defatted and subsequently extracted with aqueous acetone [80% (v/v)]. The crude extract was purified by being partitioned against ethyl acetate. A hexane/ethyl acetate/methanol/water solvent system [0.5:5:1:5 (v/v/v/v)] was used in the head-to-tail mode to elute tannins according to their degree of galloylation (tetra-O-galloylglucose to deca-O-galloylglucose). The compounds were characterized using liquid chromatography and mass spectrometry in the negative ionization mode. Purities ranged from 72% (tetra-O-galloylglucose) to 100% (octa-O-galloylglucose). The iron binding capacity of Gallotannins was dependent on the number of galloyl groups in the molecule, with a larger capacity at lower degrees of galloylation. The minimum inhibitory concentration against Bacillus subtilis did not change among the different Gallotannins tested and was in the range of 0.05−0...
Navindra P. Seeram - One of the best experts on this subject based on the ideXlab platform.
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structure activity related mechanistic and modeling studies of Gallotannins containing a glucitol core and α glucosidase
RSC Advances, 2015Co-Authors: Daniel B Niesen, Qiong Gu, Jun Xu, Ling Wang, Navindra P. SeeramAbstract:Gallotannins containing a glucitol core, which are only produced by members of the maple (Acer) genus, are more potent α-glucosidase inhibitors than the clinical drug, acarbose. While this activity is influenced by the number of substituents on the glucitol core (e.g. more galloyl groups leads to increased activity), the mechanisms of inhibitory action are not known. Herein, we investigated ligand–enzyme interactions and binding mechanisms of a series of ‘glucitol-core containing Gallotannins (GCGs)’ against the α-glucosidase enzyme. The GCGs included ginnalins A, B and C (containing two, one, and one galloyl/s, respectively), maplexin F (containing 3 galloyls) and maplexin J (containing 4 galloyls). All of the GCGs were noncompetitive inhibitors of α-glucosidase and their interactions with the enzyme were further explored using biophysical and spectroscopic measurements. Thermodynamic parameters (by isothermal titration calorimetry) revealed a 1 : 1 binding ratio between GCGs and α-glucosidase. The binding regions between the GCGs and α-glucosidase, probed by a fluorescent tag, 1,1′-bis(4-anilino-5-naphthalenesulfonic acid), revealed that the GCGs decreased the hydrophobic surface of the enzyme. In addition, circular dichroism analyses showed that the GCGs bind to α-glucosidase and lead to loss of the secondary α-helix structure of the protein. Also, molecular modeling was used to predict the binding site between the GCGs and the α-glucosidase enzyme. This is the first study to evaluate the mechanisms of inhibitory activities of Gallotannins containing a glucitol core on α-glucosidase.
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new gallotannin and other phytochemicals from sycamore maple acer pseudoplatanus leaves
Natural Product Communications, 2015Co-Authors: Daniel B Niesen, Zongcai Tu, Tao Yuan, Lu Zhang, Navindra P. SeeramAbstract:The maple (Acer) genus is a reported source of bioactive (poly)phenols, including Gallotannins, but several of its members, such as the sycamore maple (A. pseudoplatanus). remain uninvestigated. He...
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the hydrolyzable gallotannin penta o galloyl β d glucopyranoside inhibits the formation of advanced glycation endproducts by protecting protein structure
Molecular BioSystems, 2015Co-Authors: Leslie Frost, Liwen Kong, Joel A Dain, Ling Wang, Navindra P. SeeramAbstract:Glycation is a spontaneous process initiated by a condensation reaction between reducing sugars and proteins that leads to the formation of advanced glycation endproducts (AGEs). The in vivo accumulation of AGEs is associated with several chronic human diseases and, thus, the search for AGE inhibitors is of great research interest. Hydrolyzable tannins (Gallotannins and ellagitannins) are bioactive plant polyphenols which show promise as natural inhibitors of glycation and AGE formation. Notably, the gallotannin, 1,2,3,4,6-penta-O-galloyl-β-D-glucose (PGG), is a key intermediate involved in the biosynthesis of hydrolyzable tannins in plants. Herein, we investigated the effects of PGG on the individual stages of protein glycation and on protein structure (using bovine serum albumin; BSA). MALDI-TOF data demonstrated that PGG inhibited early glycation by 75% while the synthetic AGE inhibitor, aminoguanidine (AG), was not active (both at 50 μM). In addition, PGG reduced the formation of middle and late stage AGEs by 90.1 and 60.5%, respectively, which was superior to the positive control, AG. While glycation induced conformational changes in BSA from α-helix to β-sheets (from circular dichroism and congo red binding studies), PGG (at 50 μM) reduced this transition by 50%. Moreover, BSA treated with PGG was more stable in its structure and retained its biophysical properties (based on zeta potential and electrophoretic mobility measurements). The interaction between PGG and BSA was further supported by molecular docking studies. Overall, the current study adds to the growing body of data supporting the anti-AGE effects of hydrolyzable tannins, a ubiquitous class of bioactive plant polyphenols.
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New Gallotannin and other Phytochemicals from Sycamore Maple (Acer pseudoplatanus) Leaves.
Natural product communications, 2015Co-Authors: Lu Zhang, Daniel B Niesen, Tao Yuan, Hui Wang, Navindra P. SeeramAbstract:The maple (Acer) genus is a reported source of bioactive (poly)phenols, including Gallotannins, but several of its members, such as the sycamore maple (A. pseudoplatanus), remain uninvestigated. Herein, thirty-nine compounds, including a new gallotannin, 1,2,3-tri-O-galloyl-6-O-(p-hydroxybenzoyl)-β-D- glucopyranoside (1), and thirty-eight (2-39) known compounds, consisting of four Gallotannins, one ellagitannin, thirteen flavonoids, eight hydroxycinnamic acids, ten benzoic acid derivatives, and two sesquiterpenoids, were isolated from sycamore maple leaves. Their structures were determined based on NMR and mass spectral analyses. The isolates were evaluated for α-glucosidase inhibitory and antioxidant activities. Among the isolates, the Gallotannins were the most potent α-glucosidase inhibitors with thirteen-fold more potent activity compared with the clinical drug, acarbose (IC50 = 16-31 vs. 218 µM). Similarly, the Gallotannins showed the highest antioxidant activities, followed by the other phenolic sub-classes, while the sesquiterpenoids were inactive.
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Anticancer studies of Gallotannins from Maple (Acer) Spp
Planta Medica, 2012Co-Authors: Antonio González-sarrías, Tao Yuan, Navindra P. SeeramAbstract:Gallotannins are hydrolyzable tannins found in higher plants. Here we conducted anticancer and structure activity related studies of twelve Gallotannins isolated from sugar (Acer saccharum) and red (Acer rubrum) maple species. The Gallotannins, ginnalins A-C and maplexins A-I, differ in the number of galloyl groups connected to a 1,5-anhydro-D-glucitol core. The Gallotannins were evaluated for antiproliferative effects against human colon (HCT-116) and breast (MCF-7) cancer cells. While the Gallotannins with one galloyl group were not active, those with two galloyls were more active than those with three galloyls (IC50=28–50 vs. 64–112µg/mL). Also, maplexins C-D, which contained two galloyls, induced apoptosis and arrested cell cycle (in S-phase) of the cancer cell lines. Thus, the anticancer effects of maple Gallotannins are influenced by the number of galloyl groups and are mediated by apoptosis and cell cycle arrest.
Hee-young Kwon - One of the best experts on this subject based on the ideXlab platform.
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regulation of sirt1 ampk axis is critically involved in gallotannin induced senescence and impaired autophagy leading to cell death in hepatocellular carcinoma cells
Archives of Toxicology, 2018Co-Authors: Hee-young Kwon, Sanjay K SrivastavaAbstract:Hepatocellular carcinoma (HCC) is one of the most fatal malignancies with high mortality worldwide. Here the underlying antitumor mechanism of gallotannin was elucidated in HCC cells. Gallotannin suppressed viability and colony formation, increased subG1 portion and also induced senescence via upregulation of p21, G0/G1 arrest and higher SA-β-gal activity in HepG2 and SK-Hep1 cells. However, pan-caspase inhibitor Z-VAD-FMK reversed the ability of gallotannin to activate caspase 3 at 48 h after treatment in two HCC cells. Of note, gallotannin also induced autophagic features by increasing LC3 punctae, LC3B-II conversion, autophagic vacuoles and decreasing the expression of Beclin1 in two HCC cells. Furthermore, autophagy flux assay using GFP–mRFP–LC3 plasmid revealed increased yellowish color and late autophagy inhibitor CQ or NH4Cl enhanced cytotoxicity, LC3B-II conversion, and LC3 punctae in gallotannin-treated HepG2 and SK-Hep1 cells compared to early autophagy inhibitor 3-MA or wortmannin. Interestingly, gallotannin attenuated the expression of SIRT1 and mTOR and activated phosphorylation of AMPK in two HCC cells. Furthermore, AMPK activator AICAR significantly enhanced SA-β-gal activity and antiproliferation induced by gallotannin, while AMPK inhibitor compound C did not in two HCC cells. Consistently, LC3B-II conversion by gallotannin was not shown in AMPKα1 −/− MEF cells compared to WT AMPK +/+ MEF cells. Consistently, gallotannin reduced in vivo growth of HepG2 cells implanted in NCr nude mice along with decreased expression of PCNA and SIRT1 and increased AMPKα1 and TUNEL. Overall, these findings highlight evidence that regulation of SIRT1/AMPK is critically involved in gallotannin-induced senescence and impaired autophagy leading to cell death in HCC cells.
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Regulation of SIRT1/AMPK axis is critically involved in gallotannin-induced senescence and impaired autophagy leading to cell death in hepatocellular carcinoma cells
Archives of Toxicology, 2017Co-Authors: Hee-young Kwon, Sanjay K SrivastavaAbstract:Hepatocellular carcinoma (HCC) is one of the most fatal malignancies with high mortality worldwide. Here the underlying antitumor mechanism of gallotannin was elucidated in HCC cells. Gallotannin suppressed viability and colony formation, increased subG1 portion and also induced senescence via upregulation of p21, G0/G1 arrest and higher SA-β-gal activity in HepG2 and SK-Hep1 cells. However, pan-caspase inhibitor Z-VAD-FMK reversed the ability of gallotannin to activate caspase 3 at 48 h after treatment in two HCC cells. Of note, gallotannin also induced autophagic features by increasing LC3 punctae, LC3B-II conversion, autophagic vacuoles and decreasing the expression of Beclin1 in two HCC cells. Furthermore, autophagy flux assay using GFP–mRFP–LC3 plasmid revealed increased yellowish color and late autophagy inhibitor CQ or NH4Cl enhanced cytotoxicity, LC3B-II conversion, and LC3 punctae in gallotannin-treated HepG2 and SK-Hep1 cells compared to early autophagy inhibitor 3-MA or wortmannin. Interestingly, gallotannin attenuated the expression of SIRT1 and mTOR and activated phosphorylation of AMPK in two HCC cells. Furthermore, AMPK activator AICAR significantly enhanced SA-β-gal activity and antiproliferation induced by gallotannin, while AMPK inhibitor compound C did not in two HCC cells. Consistently, LC3B-II conversion by gallotannin was not shown in AMPKα1 −/− MEF cells compared to WT AMPK +/+ MEF cells. Consistently, gallotannin reduced in vivo growth of HepG2 cells implanted in NCr nude mice along with decreased expression of PCNA and SIRT1 and increased AMPKα1 and TUNEL. Overall, these findings highlight evidence that regulation of SIRT1/AMPK is critically involved in gallotannin-induced senescence and impaired autophagy leading to cell death in HCC cells.
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abstract 3545 gallotannin induces senescence and autophagy leading to cell death via sirt1 inhibition and ampk activation in hepatocellular carcinoma cells
Cancer Research, 2016Co-Authors: Hee-young KwonAbstract:Hepatocellular carcinoma (HCC) is one of the most fatal malignancies with high mortality rate worldwide. In the present study, the underlying antitumor mechanism of gallotannin, a hydrolysable tannic acid, was elucidated in HepG2 and SKHep1 HCC cells. Gallotannin suppressed growth and colony formation and also induced senescence via upregulation of p21, G0 / G1 arrest and higher senescence-associated β-galactosidase (SA-β-gal) activity within 24 h culture in HepG2 and SKHep1 cells. Of note, gallotannin also induced autophagy by increasing the number of protein-cytosol-associated protein light chain 3 (LC3) punctae, LC3B-II conversion and SQSTM1/p62, autophagic vacuoles (AVOs) by transmission electron microscopy (TEM) and decreasing the of Beclin1 in HepG2 and SKHep1 cells. A tandem fluorescent-tagged LC3 reporter plasmid (GFP-mRFP-LC3) transfection revealed that gallotannin increased the number of yellow colored LC3 punctae through the co-localization of GFP and mRFP punctae and yellow colored LC3 punctae were increased by CQ or NH4Cl with accumulation of autophagosomes, LC3B-II and SQSTM1/p62 in HepG2 and SKHep1 cells. Additionally, gallotannin attenuated the of sirtuin1 (SIRT1) and mTOR and activated the phosphorylation of 5′-AMP activated protein kinase (AMPK) in two HCC cells. Furthermore, AMPK activator AICAR significantly enhanced SA-β-gal activity and antiproliferation induced by gallotannin, while AMPK inhibitor compound C did not in two HCC cells. Of note, gallotannin time dependently activated caspase 8 / 3 and time/concentration dependently increased sub G1 portion along with weak cleavages of PARP in two HCC cells. Collectively, gallotannin induces senescence and inhibits late autophagy flux, finally leading to apoptotic cell death in HepG2 and SKHep1 cells via inhibition of SIRT1 and activation of p-AMPK as a potent antitumor agent for HCC treatment. Citation Format: Hee Young Kwon, Sung-hoon Kim. Gallotannin induces senescence and autophagy leading to cell death via SIRT1 inhibition and AMPK activation in hepatocellular carcinoma cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3545.
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inhibition of myeloid cell leukemia 1 and activation of caspases are critically involved in gallotannin induced apoptosis in prostate cancer cells
Phytotherapy Research, 2015Co-Authors: Eunkyung Park, Deokbeom Jung, Arong Jeong, Ji Hoon Jung, Hee-young Kwon, Jinhong CheonAbstract:Although gallotannin contained in several medicinal plants was known to have multi-biological activities, such as antioxidant, antiinflammatory, antimicrobial, immunomodulatory, and antitumor effects, the underlying apoptotic mechanism of gallotannin is not fully understood so far. Thus, in the present study, the apoptotic mechanism of gallotannin was elucidated in DU145, PC-3, and M2182 prostate cancer cells in association with myeloid cell leukemia 1 (Mcl-1) signaling. Gallotannin exerted dose-dependent cytotoxicity in DU145, PC-3, and M2182 prostate cancer cells. Also, gallotannin showed apoptotic morphological features and increased the number of terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells and sub-G1 accumulation in three prostate cancer cell lines. Consistently, gallotannin cleaved poly (ADP-ribose) polymerase (PARP) and attenuated the expression of procaspases 9 and 3 in three prostate cancer cell lines. Furthermore, gallotannin attenuated the expression of survival genes such as Mcl-1, B-cell lymphoma 2, and B-cell lymphoma 2 extra large in three prostate cancer cell lines. Interestingly, overexpression of Mcl-1 reversed the ability of gallotannin to cleave PARP and increase sub-G1 population in three prostate cancer cell lines. Conversely, silencing of Mcl-1 enhanced apoptosis by gallotannin in three prostate cancer cell lines by FACSCalibur (Becton Dickinson, Franklin Lakes, NJ, USA). Taken together, our findings demonstrate that inhibition of Mcl-1 and activation of caspases are critically involved in gallotannin-induced apoptosis in prostate cancer cells. Copyright © 2015 John Wiley & Sons, Ltd.
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abstract 26 suppression of e cadherin mediates gallotannin induced apoptosis in hep g2 hepatocelluar carcinoma cells
Cancer Research, 2015Co-Authors: Hee-young Kwon, Ji Hoon Jung, Myoung Seok Jeong, Deokbeom JungAbstract:Though gallotannin was known to have anti-oxidant and antitumor activity, the underlying antitumor mechanism of gallotannin still remains unclear. Thus, in the present study, antitumor mechanism of gallotannin was elucidated in hepatocellular carcinoma cells. Gallotannin significantly exerted cytotoxicity against Hep G2 and Chang hepatocellular carcinoma cells with the accumulation of the sub-G1 population and increase of terminal deoxynucleotidyltransferasedUTP nick end labeling (TUNEL) positive cells as an apoptotic feature. Also, gallotannin attenuated the expression of pro-caspase9, pro-caspase3, Bcl2 and integrin β1 and cleaved poly(ADP)-ribose polymerase (PARP) in Hep G2 and Chang cancer cells. Furthermore, gallotannin suppressed cell repair motility by wound healing assay and also inhibited cell adhesion in Hep G2 cells. Of note, gallotannin attenuated the expression of epithelial cadherin (E-cadherin) to form cell-cell adhesion from the early stage, and also beta-catenin at late phase in Hep G2 cells. Consistently, Immunofluorescence assay showed that E-cadherin or β-catenin expression was suppressed in a time dependent manner by gallotannin. Furthermore, silencing of E-cadherin by siRNA transfection method enhanced PAPR cleavage, caspase 3 activation and sub G1 population and attenuated the cell adhesion induced by gallotannin in Hep G2 cells. Overall, our findings demonstrate that the disruption of cell adhesion junction by suppression of E-cadherin mediates gallotannin enhanced apoptosis in Hep G2 liver cancer cells. Citation Format: Hee Young Kwon, Ji Hoon Jung, Hyun Joo Lee, Myoung Seok Jeong, Deok-Beom Jung, Bonglee Kim, Hyemin Lee, Sung-Hoon Kim. Suppression of E-cadherin mediates gallotannin-induced apoptosis in Hep G2 hepatocelluar carcinoma cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 26. doi:10.1158/1538-7445.AM2015-26
Nicolai Berardini - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Gallotannins and benzophenone derivatives from mango (Mangifera indica L. cv. 'Tommy Atkins') peels, pulp and kernels by high-performance liquid chromatography/electrospray ionization mass spectrometry
Rapid Communications in Mass Spectrometry, 2004Co-Authors: Nicolai Berardini, Reinhold Carle, Andreas SchieberAbstract:Polyphenolics were extracted from peels, pulp and kernels of mango fruits (Mangifera indica L. cv. ‘Tommy Atkins’) and characterized by high-performance liquid chromatography/electrospray ionization mass spectrometry. In the peel 18 Gallotannins and five benzophenone derivatives were detected which were tentatively identified as galloylated maclurin and iriflophenone glucosides. Twenty-one and eight Gallotannins were found in the kernels and pulp, respectively, whereas no evidence for the presence of benzophenone derivatives was obtained. Gallotannins quantified by the rhodanine assay amounted to 1.4 mg/g dm in the peels (expressed as gallic acid), while only small amounts (0.2 mg/g dm) were found in the pulp. In contrast, mango kernels contained 15.5 mg/g dm and thus proved to be a rich source of Gallotannins. Copyright © 2004 John Wiley & Sons, Ltd.
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Characterization of Gallotannins and benzophenone derivatives from mango (Mangifera indica L. cv. 'Tommy Atkins') peels, pulp and kernels by high-performance liquid chromatography/electrospray ionization mass spectrometry.
Rapid communications in mass spectrometry : RCM, 2004Co-Authors: Nicolai Berardini, Reinhold Carle, Andreas SchieberAbstract:Polyphenolics were extracted from peels, pulp and kernels of mango fruits (Mangifera indica L. cv. 'Tommy Atkins') and characterized by high-performance liquid chromatography/electrospray ionization mass spectrometry. In the peel 18 Gallotannins and five benzophenone derivatives were detected which were tentatively identified as galloylated maclurin and iriflophenone glucosides. Twenty-one and eight Gallotannins were found in the kernels and pulp, respectively, whereas no evidence for the presence of benzophenone derivatives was obtained. Gallotannins quantified by the rhodanine assay amounted to 1.4 mg/g dm in the peels (expressed as gallic acid), while only small amounts (0.2 mg/g dm) were found in the pulp. In contrast, mango kernels contained 15.5 mg/g dm and thus proved to be a rich source of Gallotannins.
