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Josep Lluís Torres - One of the best experts on this subject based on the ideXlab platform.
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Hamamelitannin from Witch Hazel (Hamamelis virginiana) Displays Specific Cytotoxic Activity against Colon Cancer Cells
Journal of Natural Products, 2012Co-Authors: Susana Sánchez-tena, Anna Carreras, M. Luisa Mateos-martín, Noelia Costoya, Maria Luisa Fernandez-cachon, Josep Lluís Torres, María J. Núñez, Mary Pat Moyer, Marta CascanteAbstract:Hamamelis virginiana (witch hazel) bark is a rich source of condensed and hydrolyzable tannins reported to exert a protective action against colon cancer. The present study characterizes different witch hazel tannins as selective cytotoxic agents against colon cancer. To cover the structural diversity of the tannins that occur in H. virginiana bark, the hydrolyzable tannins, hamamelitannin and pentagalloylglucose, together with a proanthocyanidin-rich fraction (F800H4) were selected for the study. Treatment with these compounds reduced tumor viability and induced apoptosis, necrosis, and S-phase arrest in the cell cycle of HT29 cells, with hamamelitannin being the most efficient. Owing to polyphenol-mediated H2O2 formation in the incubation media, the antiproliferative effect was determined in the presence and absence of catalase to rule out any such interference. The presence of catalase significantly changed the IC50 only for F800H4. Furthermore, at concentrations that inhibit the growth of HT29 cells b...
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Impact of Thermal Processing on the Activity of Gallotannins and Condensed Tannins from Hamamelis virginiana Used as Functional Ingredients in Seafood
Journal of Agricultural and Food Chemistry, 2010Co-Authors: María Jesús González González, Josep Lluís Torres, Isabel MedinaAbstract:Phenolic extracts from witch hazel, Hamamelis virginiana, are efficient antioxidants against fish lipid peroxidation. The impact of fish thermal processes on the hydrolyzable polyphenols from this source was studied. H. virginiana polyphenols included 80% of hydrolyzable tannins, characterized by a mixture of glucose gallates containing from 5 to 10 units of gallic acid, hamamelitannin, and 20% of proanthocyanidins. Structural modifications of the polyphenols during thermal processes were determined by HPLC-MS. Changes in their reducing and free radical scavenging capacities as a result of high temperatures were also determined. Thermal processes triggered a significant breakdown of hydrolyzable tannins with 6−10 galloyl units to give pentagalloyl glucose (PGG). The release of high concentrations of free gallic acid especially in long-term thermally processed samples leads to an increase of the antioxidant ability of heated H. virginiana extracts. Such an increase was evidenced by an increment in the redu...
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witch hazel Hamamelis virginiana fractions and the importance of gallate moieties electron transfer capacities in their antitumoral properties
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Daneida Lizarraga, Sonia Touriño, Josep Lluís Torres, Jacob J Briede, L.m. Maas, Josep J Centelles, Fernando J Reyeszurita, Theo M De Kok, Joost H M Van Delft, Marta CascanteAbstract:Witch hazel (Hamamelis virginia) extracts are used in traditional medicine. They are particularly rich in gallate esters included in proanthocyanidins, hydrolyzable tannins (galloylated sugars), and methyl gallate. This study examines the response of human colon cancer cells to treatment with fractions obtained from a witch hazel polyphenolic extract. The results are compared with those obtained previously with homologous fractions from grape (less galloylated) and pine (nongalloylated). Witch hazel fractions were the most efficient in inhibiting cell proliferation in HT29 and HCT116 human colon cancer cell lines, which clearly shows that the more galloylated the fractions, the more effective they were at inhibiting proliferation of colon cancer cells. Witch hazel fractions were, in addition, more potent in arresting the cell cycle at the S phase and inducing apoptosis; they also induced a significant percentage of necrosis. Interestingly, the apoptosis and cell cycle arrest effects induced were proportional to their galloylation. Moreover, witch hazel fractions with a high degree of galloylation were also the most effective as scavengers of both hydroxyl and superoxide radicals and in protecting against DNA damage triggered by the hydroxyl radical system. These findings provide a better understanding of the structure-bioactivity relationships of polyphenolics, which should be of assistance in choosing an appropriate source and preparing a rational design for formulations of plant polyphenols in nutritional supplements.
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Highly Galloylated Tannin Fractions from Witch Hazel (Hamamelis virginiana) Bark: Electron Transfer Capacity, In Vitro Antioxidant Activity, and Effects on Skin-Related Cells
Chemical Research in Toxicology, 2008Co-Authors: Sonia Touriño, Daneida Lizarraga, Anna Carreras, Sonia Lorenzo, Vanessa Ugartondo, Luis Julia, María Pilar Vinardell, Montserrat Mitjans, Marta Cascante, Josep Lluís TorresAbstract:Witch hazel (Hammamelis virginiana) bark is a rich source of both condensed and hydrolizable oligomeric tannins. From a polyphenolic extract soluble in both ethyl acetate and water, we have generated fractions rich in pyrogallol-containing polyphenols (proanthocyanidins, gallotannins, and gallates). The mixtures were highly active as free radical scavengers against ABTS, DPPH (hydrogen donation and electron transfer), and HNTTM (electron transfer). They were also able to reduce the newly introduced TNPTM radical, meaning that they included some highly reactive components. Witch hazel phenolics protected red blood cells from free radical-induced hemolysis and were mildly cytotoxic to 3T3 fibroblasts and HaCat keratinocytes. They also inhibited the proliferation of tumoral SK-Mel 28 melanoma cells at lower concentrations than grape and pine procyanidins. The high content in pyrogallol moieties may be behind the effect of witch hazel phenolics on skin cells. Because the most cytotoxic and antiproliferative m...
Marta Cascante - One of the best experts on this subject based on the ideXlab platform.
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Hamamelitannin from Witch Hazel (Hamamelis virginiana) Displays Specific Cytotoxic Activity against Colon Cancer Cells
Journal of Natural Products, 2012Co-Authors: Susana Sánchez-tena, Anna Carreras, M. Luisa Mateos-martín, Noelia Costoya, Maria Luisa Fernandez-cachon, Josep Lluís Torres, María J. Núñez, Mary Pat Moyer, Marta CascanteAbstract:Hamamelis virginiana (witch hazel) bark is a rich source of condensed and hydrolyzable tannins reported to exert a protective action against colon cancer. The present study characterizes different witch hazel tannins as selective cytotoxic agents against colon cancer. To cover the structural diversity of the tannins that occur in H. virginiana bark, the hydrolyzable tannins, hamamelitannin and pentagalloylglucose, together with a proanthocyanidin-rich fraction (F800H4) were selected for the study. Treatment with these compounds reduced tumor viability and induced apoptosis, necrosis, and S-phase arrest in the cell cycle of HT29 cells, with hamamelitannin being the most efficient. Owing to polyphenol-mediated H2O2 formation in the incubation media, the antiproliferative effect was determined in the presence and absence of catalase to rule out any such interference. The presence of catalase significantly changed the IC50 only for F800H4. Furthermore, at concentrations that inhibit the growth of HT29 cells b...
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witch hazel Hamamelis virginiana fractions and the importance of gallate moieties electron transfer capacities in their antitumoral properties
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Daneida Lizarraga, Sonia Touriño, Josep Lluís Torres, Jacob J Briede, L.m. Maas, Josep J Centelles, Fernando J Reyeszurita, Theo M De Kok, Joost H M Van Delft, Marta CascanteAbstract:Witch hazel (Hamamelis virginia) extracts are used in traditional medicine. They are particularly rich in gallate esters included in proanthocyanidins, hydrolyzable tannins (galloylated sugars), and methyl gallate. This study examines the response of human colon cancer cells to treatment with fractions obtained from a witch hazel polyphenolic extract. The results are compared with those obtained previously with homologous fractions from grape (less galloylated) and pine (nongalloylated). Witch hazel fractions were the most efficient in inhibiting cell proliferation in HT29 and HCT116 human colon cancer cell lines, which clearly shows that the more galloylated the fractions, the more effective they were at inhibiting proliferation of colon cancer cells. Witch hazel fractions were, in addition, more potent in arresting the cell cycle at the S phase and inducing apoptosis; they also induced a significant percentage of necrosis. Interestingly, the apoptosis and cell cycle arrest effects induced were proportional to their galloylation. Moreover, witch hazel fractions with a high degree of galloylation were also the most effective as scavengers of both hydroxyl and superoxide radicals and in protecting against DNA damage triggered by the hydroxyl radical system. These findings provide a better understanding of the structure-bioactivity relationships of polyphenolics, which should be of assistance in choosing an appropriate source and preparing a rational design for formulations of plant polyphenols in nutritional supplements.
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Highly Galloylated Tannin Fractions from Witch Hazel (Hamamelis virginiana) Bark: Electron Transfer Capacity, In Vitro Antioxidant Activity, and Effects on Skin-Related Cells
Chemical Research in Toxicology, 2008Co-Authors: Sonia Touriño, Daneida Lizarraga, Anna Carreras, Sonia Lorenzo, Vanessa Ugartondo, Luis Julia, María Pilar Vinardell, Montserrat Mitjans, Marta Cascante, Josep Lluís TorresAbstract:Witch hazel (Hammamelis virginiana) bark is a rich source of both condensed and hydrolizable oligomeric tannins. From a polyphenolic extract soluble in both ethyl acetate and water, we have generated fractions rich in pyrogallol-containing polyphenols (proanthocyanidins, gallotannins, and gallates). The mixtures were highly active as free radical scavengers against ABTS, DPPH (hydrogen donation and electron transfer), and HNTTM (electron transfer). They were also able to reduce the newly introduced TNPTM radical, meaning that they included some highly reactive components. Witch hazel phenolics protected red blood cells from free radical-induced hemolysis and were mildly cytotoxic to 3T3 fibroblasts and HaCat keratinocytes. They also inhibited the proliferation of tumoral SK-Mel 28 melanoma cells at lower concentrations than grape and pine procyanidins. The high content in pyrogallol moieties may be behind the effect of witch hazel phenolics on skin cells. Because the most cytotoxic and antiproliferative m...
Sonia Touriño - One of the best experts on this subject based on the ideXlab platform.
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witch hazel Hamamelis virginiana fractions and the importance of gallate moieties electron transfer capacities in their antitumoral properties
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Daneida Lizarraga, Sonia Touriño, Josep Lluís Torres, Jacob J Briede, L.m. Maas, Josep J Centelles, Fernando J Reyeszurita, Theo M De Kok, Joost H M Van Delft, Marta CascanteAbstract:Witch hazel (Hamamelis virginia) extracts are used in traditional medicine. They are particularly rich in gallate esters included in proanthocyanidins, hydrolyzable tannins (galloylated sugars), and methyl gallate. This study examines the response of human colon cancer cells to treatment with fractions obtained from a witch hazel polyphenolic extract. The results are compared with those obtained previously with homologous fractions from grape (less galloylated) and pine (nongalloylated). Witch hazel fractions were the most efficient in inhibiting cell proliferation in HT29 and HCT116 human colon cancer cell lines, which clearly shows that the more galloylated the fractions, the more effective they were at inhibiting proliferation of colon cancer cells. Witch hazel fractions were, in addition, more potent in arresting the cell cycle at the S phase and inducing apoptosis; they also induced a significant percentage of necrosis. Interestingly, the apoptosis and cell cycle arrest effects induced were proportional to their galloylation. Moreover, witch hazel fractions with a high degree of galloylation were also the most effective as scavengers of both hydroxyl and superoxide radicals and in protecting against DNA damage triggered by the hydroxyl radical system. These findings provide a better understanding of the structure-bioactivity relationships of polyphenolics, which should be of assistance in choosing an appropriate source and preparing a rational design for formulations of plant polyphenols in nutritional supplements.
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Highly Galloylated Tannin Fractions from Witch Hazel (Hamamelis virginiana) Bark: Electron Transfer Capacity, In Vitro Antioxidant Activity, and Effects on Skin-Related Cells
Chemical Research in Toxicology, 2008Co-Authors: Sonia Touriño, Daneida Lizarraga, Anna Carreras, Sonia Lorenzo, Vanessa Ugartondo, Luis Julia, María Pilar Vinardell, Montserrat Mitjans, Marta Cascante, Josep Lluís TorresAbstract:Witch hazel (Hammamelis virginiana) bark is a rich source of both condensed and hydrolizable oligomeric tannins. From a polyphenolic extract soluble in both ethyl acetate and water, we have generated fractions rich in pyrogallol-containing polyphenols (proanthocyanidins, gallotannins, and gallates). The mixtures were highly active as free radical scavengers against ABTS, DPPH (hydrogen donation and electron transfer), and HNTTM (electron transfer). They were also able to reduce the newly introduced TNPTM radical, meaning that they included some highly reactive components. Witch hazel phenolics protected red blood cells from free radical-induced hemolysis and were mildly cytotoxic to 3T3 fibroblasts and HaCat keratinocytes. They also inhibited the proliferation of tumoral SK-Mel 28 melanoma cells at lower concentrations than grape and pine procyanidins. The high content in pyrogallol moieties may be behind the effect of witch hazel phenolics on skin cells. Because the most cytotoxic and antiproliferative m...
Daneida Lizarraga - One of the best experts on this subject based on the ideXlab platform.
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witch hazel Hamamelis virginiana fractions and the importance of gallate moieties electron transfer capacities in their antitumoral properties
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Daneida Lizarraga, Sonia Touriño, Josep Lluís Torres, Jacob J Briede, L.m. Maas, Josep J Centelles, Fernando J Reyeszurita, Theo M De Kok, Joost H M Van Delft, Marta CascanteAbstract:Witch hazel (Hamamelis virginia) extracts are used in traditional medicine. They are particularly rich in gallate esters included in proanthocyanidins, hydrolyzable tannins (galloylated sugars), and methyl gallate. This study examines the response of human colon cancer cells to treatment with fractions obtained from a witch hazel polyphenolic extract. The results are compared with those obtained previously with homologous fractions from grape (less galloylated) and pine (nongalloylated). Witch hazel fractions were the most efficient in inhibiting cell proliferation in HT29 and HCT116 human colon cancer cell lines, which clearly shows that the more galloylated the fractions, the more effective they were at inhibiting proliferation of colon cancer cells. Witch hazel fractions were, in addition, more potent in arresting the cell cycle at the S phase and inducing apoptosis; they also induced a significant percentage of necrosis. Interestingly, the apoptosis and cell cycle arrest effects induced were proportional to their galloylation. Moreover, witch hazel fractions with a high degree of galloylation were also the most effective as scavengers of both hydroxyl and superoxide radicals and in protecting against DNA damage triggered by the hydroxyl radical system. These findings provide a better understanding of the structure-bioactivity relationships of polyphenolics, which should be of assistance in choosing an appropriate source and preparing a rational design for formulations of plant polyphenols in nutritional supplements.
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Highly Galloylated Tannin Fractions from Witch Hazel (Hamamelis virginiana) Bark: Electron Transfer Capacity, In Vitro Antioxidant Activity, and Effects on Skin-Related Cells
Chemical Research in Toxicology, 2008Co-Authors: Sonia Touriño, Daneida Lizarraga, Anna Carreras, Sonia Lorenzo, Vanessa Ugartondo, Luis Julia, María Pilar Vinardell, Montserrat Mitjans, Marta Cascante, Josep Lluís TorresAbstract:Witch hazel (Hammamelis virginiana) bark is a rich source of both condensed and hydrolizable oligomeric tannins. From a polyphenolic extract soluble in both ethyl acetate and water, we have generated fractions rich in pyrogallol-containing polyphenols (proanthocyanidins, gallotannins, and gallates). The mixtures were highly active as free radical scavengers against ABTS, DPPH (hydrogen donation and electron transfer), and HNTTM (electron transfer). They were also able to reduce the newly introduced TNPTM radical, meaning that they included some highly reactive components. Witch hazel phenolics protected red blood cells from free radical-induced hemolysis and were mildly cytotoxic to 3T3 fibroblasts and HaCat keratinocytes. They also inhibited the proliferation of tumoral SK-Mel 28 melanoma cells at lower concentrations than grape and pine procyanidins. The high content in pyrogallol moieties may be behind the effect of witch hazel phenolics on skin cells. Because the most cytotoxic and antiproliferative m...
Andreas Hensel - One of the best experts on this subject based on the ideXlab platform.
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Genotoxic and antigenotoxic effects of catechin and tannins from the bark of Hamamelis virginiana L. in metabolically competent, human hepatoma cells (Hep G2) using single cell gel electrophoresis
Phytochemistry, 2003Co-Authors: Andreas Dauer, Andreas Hensel, Evelyne Lhoste, Siegfried Knasmuller, Volker Mersch-sundermannAbstract:The genotoxic and antigenotoxic activities of catechin, hamamelitannin and two proanthocyanidin fractions prepared from the bark of Hamamelis virginiana L. were investigated in a human derived, metabolically competent hepatoma cell line (Hep G2) using single cell gel electrophoresis (SCGE) for the detection of DNA-damage. DNA-migration was calculated as Olive tail moment (OTM). Catechin and a low-molecular weight proanthocyandin fraction (WM) caused only slight increases of OTM up to concentrations of 166 μg/ml whereas hamamelitannin and the proanthocyandin fraction with higher molecular weight (WA) led to a two-fold enhancement of OTM at the same concentrations. These effects were dose-independent. Treatment of the cells with the test compounds in a dose-range of 2–166 μg/ml prior to the exposure to benzo(a)pyrene (B(a)P, 10 μM, 2.5 μg/ml) led to a significant reduction of induced DNA damage which was dose-dependent for all test compounds, except for hamamelitannin. The inhibitory effects of proanthocyanidins were stronger than those of catechin and hamamelitannin; the lowest effective concentrations were about 2 μg/ml. In order to clarify the mechanisms of protection, possible effects of the test compounds on enzymes involved in toxification and detoxification of B(a)P were investigated. While B(a)P toxification by cytochrome P450 was not inhibited by the test compounds, detoxification by glutathion-S-transferase (GST) was induced by catechin and WM. Combination experiments with the ultimate metabolite of B(a)P, (±)-anti-benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE; 5 μM, 1.5 μg/ml), revealed strong inhibitory effects, indicating that the observed protective effects were caused by scavenging of the ultimate mutagen by the test compounds. Exposure of Hep G2 cells to the test compounds after B(a)P treatment did not influence B(a)P induced DNA damage, demonstrating that repair mechanisms were not affected.
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polymeric proanthocyanidins from the bark of Hamamelis virginiana
Planta Medica, 2003Co-Authors: A Dauer, H Rimpler, Andreas HenselAbstract:Polymeric proanthocyanidins were isolated from the bark of Hamamelis virginiana L. in yields of about 5 %. Fractionation yielded fractions with similar structures but different molecular weights with DP between 17-29 (thiolysis) and 11-20 (GPC). Polymers were composed predominantly of epicatechin and epigallocatechin as chain extension units at ratio of about 1.3:1. Terminal chain units were catechin (approximately 95 %) and gallocatechin (approximately 5 %). All chain extension units were completely galloylated at position O-3, while chain terminating units were not galloylated. Predominant interflavan linkages were 4 --> 8-bonds.
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high molecular compounds polysaccharides and proanthocyanidins from Hamamelis virginiana bark influence on human skin keratinocyte proliferation and differentiation and influence on irritated skin
Phytochemistry, 2001Co-Authors: Alexandra Deters, Andreas Dauer, Esther Schnetz, Manige Fartasch, Andreas HenselAbstract:Although extracts from Hamamelis bark have long been used in therapy of skin diseases and in cosmetic formulas there are only few pharmacological investigations verifying the activity of distinct Hamamelis bark constituents. Therefore two major classes of constituents, namely polymeric proanthocyanidins and polysaccharides were isolated from Hamamelis bark and tested concerning their influence on proliferation and differentiation of cultured human keratinocytes. While the polysaccharide fraction, consisting mainly of arabans and arabinogalactans, did not effect human keratinozytes, the proanthocyanidins strongly increased the proliferation of the cells, while the differentiation was not influenced significantly. Within a preliminary cumulative in vivo study on SLS-irritated skin, proanthocyanidins (ProcyanoPlus) were proven to reduce transepidermal water loss and erythema formation. Furthermore, a clinical scoring indicated that procyanidins can influence irritative processes significantly.
