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1.
Front Nutr ; 7: 115, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32850936

RESUMEN

Shinkiku (Massa Medicata Fermentata) is a traditional crude drug used to treat anorexia and dyspepsia of elder patients in east Asia. Shinkiku is generally prepared by the microbial fermentation of wheat and herbs. Shinkiku is also used in Japanese Kampo medicine as a component of (Hangebyakujutsutemmato). However, the quality of shinkiku varies by manufacture because there are no reference standards to control the quality of medicinal shinkiku. Thus, we aim to characterize the quality of various commercially available shinkiku by chemical and microbial analysis. We collected 13 shinkiku products manufactured in China and Korea and investigated the microbial structure and chemical constituents. Amplicon sequence analysis revealed that Aspergillus sp. was common microorganism in shinkiku products. Digestive enzymes (α-amylase, protease, and lipase), organic acids (ferulic acid, citric acid, lactic acid, and acetic acid), and 39 volatile compounds were commonly found in shinkiku products. Although there were some commonalities in shinkiku products, microbial and chemical characteristic considerably differed as per the manufacturer. Aspergillus sp. was predominant in Korean products, and Korean products showed higher enzyme activities than Chinese products. Meanwhile, Bacillus sp. was commonly detected in Chinese shinkiku, and ferulic acid was higher in Chinese products. Principal component analysis based on the GC-MS peak area of the volatiles also clearly distinguished shinkiku products manufactured in China from those in Korea. Chinese products contained higher amounts of benzaldehyde and anethole than Korean ones. Korean products were further separated into two groups: one with relatively higher linalool and terpinen-4-ol and another with higher hexanoic acid and 1-octen-3-ol. Thus, our study revealed the commonality and diversity of commercial shinkiku products, in which the commonalities can possibly be the reference standard for quality control of shinkiku, and the diversity suggested the importance of microbial management to stabilize the quality of shinkiku.

2.
Biosci Biotechnol Biochem ; 78(10): 1731-7, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25118018

RESUMEN

Fresh loquat leaves have been used as folk health herb in Asian countries for long time, although the evidence supporting their functions is still minimal. This study aimed to clarify the chemopreventive effect of loquat tea extract (LTE) by investigating the inhibition on proliferation, and underlying mechanisms in human promyelocytic leukemia cells (HL-60). LTE inhibited proliferation of HL-60 in a dose-dependent manner. Molecular data showed that the isolated fraction of LTE induced apoptosis of HL-60 as characterized by DNA fragmentation; activation of caspase-3, -8, and -9; and inactivation of poly(ADP)ribose polymerase. Moreover, LTE fraction increased the ratio of pro-apoptotic Bcl-2-associated X protein (Bax)/anti-apoptotic myeloid cell leukemia 1 (Mcl-1) that caused mitochondrial membrane potential loss and cytochrome c released to cytosol. Thus, our data indicate that LTE might induce apoptosis in HL-60 cells through a mitochondrial dysfunction pathway. These findings enhance our understanding for chemopreventive function of loquat tea.


Asunto(s)
Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Bebidas/análisis , Eriobotrya/química , Depuradores de Radicales Libres/farmacología , Leucemia/patología , Extractos Vegetales/farmacología , Antineoplásicos/química , Compuestos de Bifenilo/química , Proliferación Celular/efectos de los fármacos , Depuradores de Radicales Libres/química , Células HL-60 , Humanos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/metabolismo , Picratos/química , Extractos Vegetales/química , Regulación hacia Arriba/efectos de los fármacos , Proteína X Asociada a bcl-2/metabolismo
3.
Food Funct ; 5(8): 1891-7, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24947273

RESUMEN

Oolong tea theasinensins are a group of tea polyphenols different from green tea catechins and black tea theaflavins, and they are considered as bioactive compounds in Oolong tea. In the present study, based on the properties of theasinensin and information about inflammatory processes, we investigated the anti-inflammatory activity and molecular mechanisms of theasinensin A (TSA) in both cell and animal models. In the cell model, TSA reduced the levels of pro-inflammatory mediators including inducible nitric oxide synthase (iNOS), nitric oxide (NO), interleukin-12 (IL-12) (p70), tumor necrosis factor alpha (TNF-α), and monocyte chemotactic protein-1 (MCP-1) induced by lipopolysaccharide (LPS). Cellular signaling analysis revealed that TSA downregulated MAPK/ERK kinase (MEK)-extracellular signal-regulated kinase (ERK) signaling. Pull-down assay and affinity data revealed that TSA might directly bind to MEK-ERK for the inhibitory action. In the animal model, TSA suppressed the production of IL-12 (p70), TNF-α, and MCP-1 and attenuated mouse paw edema induced by LPS.


Asunto(s)
Antiinflamatorios/farmacología , Benzopiranos/farmacología , Fenoles/farmacología , Preparaciones de Plantas/farmacología , Té/química , Animales , Línea Celular Tumoral , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Modelos Animales de Enfermedad , Regulación hacia Abajo , Edema/inducido químicamente , Edema/tratamiento farmacológico , Interleucina-12/metabolismo , Lipopolisacáridos/efectos adversos , MAP Quinasa Quinasa 1/genética , MAP Quinasa Quinasa 1/metabolismo , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Masculino , Ratones , Ratones Endogámicos ICR , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo
4.
Nutr Cancer ; 63(7): 1064-73, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21864060

RESUMEN

Theasinensin A is one of the oolong tea theasinensins, which differ from green tea catechins and black tea theaflavins. In a previous study, we found that theasinesin A had a potential effect on antiinflammation since theasinensin A suppressed LPS-induced COX2 and PGE(2) production. To clarify the molecular mechanisms, we investigated the gene expression profiling in macrophage-like cells treated with theasinensin A through a genome-wide DNA microarray in the present study. Among 22,050 oligonucleotides, the expression levels of 406 genes were increased by ≥3-fold in LPS-activated RAW264 cells, 259 gene signals of which were attenuated by theasinensin A treatment (≥2-fold). Expression levels of 717 genes were decreased by ≥3-fold in LPS-activated cells, of which 471 gene signals were restored by theasinensin A treatment (≥2-fold). These genes were further categorized as "defense, inflammatory response, cytokines activities, and receptor activities," and some of them were confirmed by real-time polymerase chain reaction. Furthermore, pathways analysis revealed that theasinensin A regulated the relevant expression networks of chemokines, interleukins, and interferons to exert its antiinflammatory effects.


Asunto(s)
Benzopiranos/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Macrófagos/efectos de los fármacos , Análisis de Secuencia por Matrices de Oligonucleótidos , Fenoles/farmacología , Té/química , Animales , Antiinflamatorios/farmacología , Línea Celular , Quimiocinas/genética , Quimiocinas/metabolismo , Perfilación de la Expresión Génica , Interferones/genética , Interferones/metabolismo , Interleucinas/genética , Interleucinas/metabolismo , Lipopolisacáridos/efectos adversos , Macrófagos/citología , Macrófagos/metabolismo , Ratones , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal
5.
J Agric Food Chem ; 58(24): 12735-43, 2010 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-21082860

RESUMEN

Oolong tea theasinensins are a group of tea polyphenols different from green tea catechins and black tea theaflavins. The present study reports the inhibitory effects of oolong tea theasinensins on the expression of cyclooxygenase-2 (COX-2) and underlying molecular mechanisms in lipopolysaccharide (LPS)-activated murine macrophage RAW264 cells. The structure-activity data revealed that the galloyl moiety of theasinensins played an important role in the inhibitory actions. Theasinensin A, a more potent inhibitor, caused a dose-dependent inhibition of mRNA, protein, and promoter activity of COX-2. An electrophoretic mobility shift assay (EMSA) revealed that theasinensin A reduced the complex of NF-κB- and AP-1-DNA in the promoter of COX-2. Signaling analysis demonstrated that theasinensin A attenuated IκB-α degradation, nuclear p65 accumulation, and c-Jun phosphorylation. Furthermore, theasinensin A suppressed the phosphorylation of MAPKs, IκB kinase α/ß (IKKα/ß), and TGF-ß activated kinase (TAK1). These data demonstrated that the down-regulation of TAK1-mediated MAPKs and NF-κB signaling pathways might be involved in the inhibition of COX-2 expression by theasinensin A. These findings provide the first molecular basis for the anti-inflammatory properties of oolong tea theasinensins.


Asunto(s)
Antiinflamatorios/farmacología , Benzopiranos/farmacología , Ciclooxigenasa 2/genética , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Lipopolisacáridos/inmunología , Macrófagos/enzimología , Fenoles/farmacología , Extractos Vegetales/farmacología , Té/química , Animales , Antiinflamatorios/química , Benzopiranos/química , Línea Celular , Ciclooxigenasa 2/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Ratones , Fenoles/química , Extractos Vegetales/química , Regiones Promotoras Genéticas/efectos de los fármacos , Relación Estructura-Actividad
6.
Phytochemistry ; 71(11-12): 1342-9, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20553697

RESUMEN

This study examined the polyphenols of tea leaves as chemotaxonomic markers to investigate the phenetic relationship between 89 wild (the small-leaved C.sinensis var. sinensis and large-leaved C. sinensis var. assamica), hybrid, and cultivated tea trees from China and Japan. (-)-Epigallocatechin 3-O-gallate, EGCG (1); (-)-epigallocatechin, EGC (2); (-)-epicatechin 3-O-gallate, ECG (3); (-)-epicatechin, EC (4); (+)-catechin, CA (5); strictinin, STR (6); and gallic acid, GA (7) were used as polyphenolic markers. Of the 13 polyphenol patterns observed, Principal Component Analysis (PCA) indicated that the structure-types of the flavonoid B-rings, such as the pyrogallol-(EGCG (1) and EGC (2)) and catechol-(ECG (3) and EC (4)) types, greatly influenced the classification. Ward's minimum-variance cluster analysis was used to produce a dendrogram that consisted of three sub-clusters. One sub-cluster (A) was composed of old tea trees 'Gushu' cha (C. sinensis var. assamica) and cv 'Taidi' cha, suggesting that relatively primitive tea trees contain greater amounts of compounds 3 and 4 and lower amounts of compounds 1 and 2. The other two sub-clusters B and C, made up of Chinese hybrids (sub-cluster B) and Japanese and Taiwanese tea trees (sub-cluster C), had lower contents of 3 and 4 than sub-cluster A. Therefore, PCA and cluster analysis indicated that the greater the amounts of 1 and 2 (and the lower of 3 and 4), the more recent the origin of the tea line. Based on morphological characteristics, geographical information, and the historical information on tea trees, these results show good agreement with the current theory of tea tree origins, and this suggests that the Xishuangbanna district and Puer City are among the original sites of the tea tree species.


Asunto(s)
Camellia sinensis/química , Camellia sinensis/genética , Flavonoides/química , Fenoles/química , Biomarcadores , China , Flavonoides/análisis , Variación Genética , Japón , Estructura Molecular , Fenoles/análisis , Hojas de la Planta/química , Hojas de la Planta/genética , Polifenoles , Estereoisomerismo
7.
Biochem Pharmacol ; 74(5): 742-51, 2007 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-17658484

RESUMEN

Much is known about the bioactive properties of green tea flavan-3-ol. However, very little work has been done to determine the properties of proanthocyanidins, another kind of polyphenols in green tea. In this study, we have investigated the anti-inflammatory effect of tea prodelphinidin B-4 3'-O-gallate (PDG) by demonstrating the inhibitory effects on cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-activated murine macrophage RAW264 cells. PDG caused a dose-dependent inhibition of COX-2 and iNOS at both mRNA and protein levels with the attendant decrease of prostaglandin E2 (PGE2) and nitric oxide (NO) production. Molecular data revealed that PDG downregulated NF-kappaB signaling pathway. Electrophoretic mobility shift assay (EMSA) showed that PDG reduced the binding complex of NF-kappaB-DNA in the promoter of COX-2 and iNOS. Immunochemical analysis revealed that PDG suppressed LPS-induced phosphorylation and degradation of IkappaBalpha, and subsequent nuclear translocation of p65. Consequently, PDG suppressed phosphorylation of IkappaB kinase alpha/beta (IKKalpha/beta) and TGF-beta-activated kinase (TAK1). Taken together, our data indicated that PDG is involved in the inhibition of COX-2 and iNOS via the downregulation of TAK1-NF-kappaB pathway, revealing partial molecular basis for the anti-inflammatory properties of tea PDG.


Asunto(s)
Antocianinas/farmacología , Inhibidores de la Ciclooxigenasa 2/farmacología , Ciclooxigenasa 2/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Quinasas Quinasa Quinasa PAM/metabolismo , FN-kappa B/metabolismo , Óxido Nítrico Sintasa de Tipo II/antagonistas & inhibidores , Té/química , Animales , Antocianinas/química , Proteínas Portadoras/metabolismo , Línea Celular , Inhibidores de la Ciclooxigenasa 2/química , Flavonoides/química , Flavonoides/farmacología , Quinasa I-kappa B/metabolismo , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Ratones , Estructura Molecular , Proteínas de Neoplasias/metabolismo , Fenoles/química , Fenoles/farmacología , Polifenoles , Transporte de Proteínas , ARN Mensajero/metabolismo , Factor de Transcripción ReIA
8.
Biosci Biotechnol Biochem ; 70(9): 2178-84, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16960381

RESUMEN

Various extracts of aerial parts of Varthemia (Varthemia iphionoides Boiss) were investigated for radical-scavenging activity, antioxidative activity, and porcine pancreas alpha-amylase inhibitory activity. The ethanol and water extracts showed a pronounced 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, with inhibition of about 90% at a concentration of 100 microg/ml, and alpha-amylase inhibitory activity of about 70% at a concentration of 200 microg/ml by the 2-chloro-4-nitrophenyl alpha-maltotrioside (CNP-G3) degradation method. The ethanol extract was purified by column chromatography to give seven 3-methoxyflavones (1-7) and eudesmane sesquiterpene, selina-4,11(13)-dien-3-on-12-oic acid (8). The structures of these compounds were established by NMR, MS, and UV spectroscopy. Of 3-methoxyflavones, 5,7,4'-trihydroxy-3,6-dimethoxyflavone (1), 5,7,4'-trihydroxy-3,3'-dimethoxyflavone (2), and 5,4'-dihydroxy-3,7,3'-trimethoxyflavone (3,7,3'-tri-O-methyl-quercetin) (7) exhibited pronounced radical-scavenging activity. The antioxidative activity in the linoleic acid system was considerable in compounds 1, 2, and 5,4'-dihydroxy-3,6,7-trimethoxyflavone (4). Compounds 1, 2, 4, 5 (5,7,4'-trihydroxy-3-methoxyflavone), and 6 (5,4'-dihydroxy-3,7-dimethoxyflavone) showed markedly high inhibitory activity against porcine pancreas alpha-amylase. Eudesmane sesquiterpene did not show any activity.


Asunto(s)
Asteraceae/química , Inhibidores Enzimáticos/farmacología , Flavonas/farmacología , Sesquiterpenos de Eudesmano/farmacología , alfa-Amilasas/antagonistas & inhibidores , Compuestos de Bifenilo/química , Cromatografía en Gel , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/aislamiento & purificación , Flavonas/química , Flavonas/aislamiento & purificación , Depuradores de Radicales Libres/química , Depuradores de Radicales Libres/aislamiento & purificación , Depuradores de Radicales Libres/farmacología , Hidrazinas/química , Espectrometría de Masas , Resonancia Magnética Nuclear Biomolecular , Picratos , Extractos Vegetales/química , Extractos Vegetales/farmacología , Sesquiterpenos de Eudesmano/química , Sesquiterpenos de Eudesmano/aislamiento & purificación , Espectrofotometría Ultravioleta , alfa-Amilasas/metabolismo
9.
Chem Pharm Bull (Tokyo) ; 53(9): 1178-9, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16141592

RESUMEN

A novel monoterpene alkaloid, named incarvillateine E, possessing three moles of incarvilline moieties, has been obtained from the aerial parts of Incarvillea sinensis LAM. (Bignoniaceae). On the basis of spectroscopic evidence, the structure of incarvillateine E has been characterized.


Asunto(s)
Alcaloides/química , Bignoniaceae/química , Monoterpenos/química , Alcaloides/aislamiento & purificación , Cromatografía en Capa Delgada , Hidrólisis , Espectroscopía de Resonancia Magnética , Monoterpenos/aislamiento & purificación , Extractos Vegetales/química , Espectrometría de Masa Bombardeada por Átomos Veloces
10.
J Agric Food Chem ; 53(11): 4593-8, 2005 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-15913331

RESUMEN

Fifty-four polyphenols isolated from tea leaves were evaluated for their inhibitory activities against pancreatic lipase, the key enzyme of lipid absorption in the gut. (-)-Epigallocatechin 3-O-gallate (EGCG), which is one of major polyphenols in green tea, showed lipase inhibition with an IC50 of 0.349 microM. Moreover, flavan-3-ol digallate esters, such as (-)-epigallocatechin-3,5-digallate, showed higher activities of inhibition on lipase with an IC50 of 0.098 microM. On the other hand, nonesterified flavan-3-ols, such as (+)-catechin, (-)-epicatechin, (+)-gallocatechin, and (-)-epigallocatechin, showed zero and/or the lowest activities against pancreatic lipase (IC50 > 20 microM). These data suggested that the presence of galloyl moieties within the structure was required for enhancement of pancreatic lipase inhibition. It is well-known that flavan-3-ols are polymerized by polyphenol oxidase and/or heating in a manufacturing process of oolong tea. Oolonghomobisflavans A and B and oolongtheanin 3'-O-gallate, which are typical in oolong tea leaves, showed strong inhibitory activities with IC50 values of 0.048, 0.108, and 0.068 microM, respectively, even higher than that of EGCG. The oolong tea polymerized polyphenols (OTPP) were prepared for the assay from oolong tea extract, from which the preparation effectively subtracted the zero and/or less-active monomeric flavan-3-ols by preparative high-performance liquid chromatography. The weight-average molecular weight (Mw) and number-average molecular-weight (Mn) values of OTPP were 2017 and 903, respectively, by using gel permeation choromatography. OTPP showed a 5-fold stronger inhibition against pancreatic lipase (IC50 = 0.28 microg/mL) by comparison with that of the tannase-treated OTPP (IC50 = 1.38 microg/mL). These data suggested that the presence of galloyl moieties within their chemical structures and/or the polymerization of flavan-3-ols were required for enhancement of pancreatic lipase inhibition.


Asunto(s)
Camellia sinensis/química , Inhibidores Enzimáticos/farmacología , Flavonoides/farmacología , Lipasa/antagonistas & inhibidores , Páncreas/enzimología , Fenoles/farmacología , Hojas de la Planta/química , Cromatografía en Gel , Flavonoides/química , Flavonoides/aislamiento & purificación , Flavonoles/química , Flavonoles/farmacología , Fenoles/química , Fenoles/aislamiento & purificación , Polímeros/química , Polímeros/farmacología , Polifenoles , Relación Estructura-Actividad
11.
Int J Mol Med ; 14(4): 627-32, 2004 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15375593

RESUMEN

Baicalein is one component of the dried root of Scutellaria Baicalensis Georgi. (Huang Qin) which is widely used in the traditional Chinese herbal medicine. In this study, we report that baicalein was able to induce apoptosis in human promyelocytic leukemia cells (HL-60), as characterized by poly-(ADP-ribose) polymerase (PARP) cleavage and DNA fragmentation. The efficacious induction of apoptosis was observed at 100 microM for 6 h. Mechanistic analysis demonstrated that baicalein induced the cleavage of Bid protein, cytochrome c release from mitochondria into cytosol, and activation of caspase-3, -8 and -9. Moreover, baicalein caused elevation of intracellular hydrogen peroxide level. Catalase could effectively block baicalein-induced DNA fragmentation. These data indicate that baicalein may trigger an apoptotic death program through reactive oxygen species (ROS)-mediated mitochondrial dysfunction pathway. The findings enhance our understanding of anticancer function of baicalein in herbal medicine.


Asunto(s)
Apoptosis/efectos de los fármacos , Flavanonas/farmacología , Mitocondrias/efectos de los fármacos , Mitocondrias/patología , Especies Reactivas de Oxígeno/metabolismo , Proteína Proapoptótica que Interacciona Mediante Dominios BH3 , Proteínas Portadoras/metabolismo , Caspasa 3 , Caspasa 8 , Caspasa 9 , Caspasas/metabolismo , Supervivencia Celular/efectos de los fármacos , Citocromos c/metabolismo , Activación Enzimática/efectos de los fármacos , Flavanonas/química , Células HL-60 , Humanos , Peróxido de Hidrógeno/metabolismo , Mitocondrias/metabolismo , Estructura Molecular
12.
Biol Pharm Bull ; 26(9): 1235-8, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12951464

RESUMEN

Matrix metalloproteinases (MMPs), especially membrane-type 1 matrix metalloproteinase (MT1-MMP), which generates an active form of MMP-2 from proMMP-2, are deeply involved in angiogenesis as well as in tumor cell migration and metastasis. To obtain a specific inhibitor for MT1-MMP, we screened a number of natural and synthetic compounds using recombinant human MMP-2, MMP-7, and soluble MT1-MMP in a fluorogenic peptide cleavage assay. (-)-Epigallocatechin 3-O-gallate (EGCG) followed by (-)-epigallocatechin 3,5-di-O-gallate and epitheaflagallin 3-O-gallate, was found to have potent and distinct inhibitory activity against MT1-MMP. Therefore, we investigated the effect of EGCG on the suppression of MMP-2 activation as determined by gelatin zymography, and observed that the active form of MMP-2 in the conditioned medium of human umbilical vein endothelial cells was decreased in the presence of EGCG. The results suggest the possibility that tea polyphenols suppress tumor growth through the suppression of angiogenesis.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Benzocicloheptenos/farmacología , Catequina/análogos & derivados , Flavonoides/farmacología , Metaloendopeptidasas/antagonistas & inhibidores , Fenoles/farmacología , Polifenoles/farmacología , Inhibidores de Proteasas/farmacología , Té/química , Inhibidores de la Angiogénesis/farmacología , Anticarcinógenos/farmacología , Benzocicloheptenos/química , Catequina/farmacología , Activación Enzimática/efectos de los fármacos , Flavonoides/química , Gelatina , Humanos , Inhibidores de la Metaloproteinasa de la Matriz , Metaloproteinasas de la Matriz Asociadas a la Membrana , Fenoles/química , Polifenoles/química , Proteínas Recombinantes
13.
Biosci Biotechnol Biochem ; 67(2): 396-401, 2003 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-12729007

RESUMEN

Forty-three polyphenols from tea leaves were evaluated for their anti-oxidative effect against lipid peroxidation by the ferric thiocyanate method in vitro. Among these, 1,4,6-tri-O-galloyl-beta-D-glucose (hydrolyzable tannin) showed the highest anti-oxidative activity against lipid peroxidation, even stronger than that of 3-tert.-butyl-4-hydroxyanisole (BHA). The assay demonstrates that tea polyphenols, except for desgalloylated dimeric proanthocyanidins that possess a catechin structure in the upper unit and desgalloylated flavan-3-ols, and excepting theaflavin 3,3'-di-O-gallate, had more anti-oxidative activity than that of alpha-tocopherol. The chemical structure-activity relationship shows that the anti-oxidative action advanced with the condensation of two molecules of flavan-3-ols as well as with 3-O-acylation in the flavan skeleton such as that by galloyl, (3'-O-methyl)-galloyl, and p-coumaroyl groups.


Asunto(s)
Antioxidantes/farmacología , Flavonoides , Fenoles/farmacología , Polímeros/farmacología , Té/química , Acilación , Antioxidantes/química , Dimerización , Indicadores y Reactivos , Hierro/química , Peroxidación de Lípido/efectos de los fármacos , Fenoles/química , Fenoles/clasificación , Polímeros/química , Polímeros/clasificación , Polifenoles , Relación Estructura-Actividad , Té/clasificación , Tiocianatos/química
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