RESUMEN
The aim of this study was to evaluate the pharmacological efficacy of persimmon leaves in two glaucoma models, microbeads-induced ocular hypertension (OHT) and DBA/2 mouse. Thus, we demonstrated that Ethanol Extract of Diospyros kaki (EEDK) reduced elevated intraocular pressure (IOP) in both mouse models of glaucoma by measurements with a tonometer. In particular, we revealed that retinal ganglion cell loss and optic nerve damage caused by IOP elevation were markedly diminished as assessed by TUNEL assay, H&E staining, and fluorescent staining, while the expression of soluble guanylate cyclase (sGCα-1) increased, when EEDK was administered, as revealed by western blot. Moreover, the b-wave magnitude indicating functional scotopic vision was significantly improved in EEDK-administered DBA/2 mice during the 10-week follow-up study, as observed with electroretinography. Collectively, our results suggested that EEDK could be an effective therapeutic and IOP-lowering agent for preventing and treating retinal degenerative diseases such as glaucoma.
Asunto(s)
Diospyros/química , Glaucoma/tratamiento farmacológico , Presión Intraocular , Extractos Vegetales/uso terapéutico , Animales , Masculino , Ratones , Ratones Endogámicos C57BL , Nervio Óptico/efectos de los fármacos , Extractos Vegetales/farmacología , Hojas de la Planta/química , Células Ganglionares de la Retina/efectos de los fármacos , Células Ganglionares de la Retina/metabolismo , Guanilil Ciclasa Soluble/metabolismoRESUMEN
The soy isoflavone daidzein is bioconverted to 7,8,4'-trihydroxyisoflavone (7,8,4'-THIF) by microorganisms. Here, we investigated the matrix metalloproteinase (MMP)-1 inhibitory properties of 7,8,4'-THIF that arise through the suppression of UVB-induced MMP-1 expression. 7,8,4'-THIF reduced UVB-induced MMP-1 expression at the transcriptional level in primary human dermal fibroblasts and inhibited UVB-induced transcriptional activity of AP-1, a major activator of MMP-1 expression. Additionally, it was observed that the mitogen-activated protein kinase (MAPK) pathway, a crucial signalling cascade for MMP-1 expression, was suppressed by 7,8,4'-THIF. Protein kinase C iota (PKCι) was suspected to be a direct target of 7,8,4'-THIF. The direct interaction between 7,8,4'-THIF and PKCι was confirmed using pull-down assays and immobilized metal ion affinity-based fluorescence polarization assays. Finally, we observed that 7,8,4'-THIF inhibited UVB-induced MMP-1 expression in a human skin equivalent model. Taken together, these results suggest that 7,8,4'-THIF, a bioconversion product of daidzein, suppresses UVB-induced MMP-1 expression.
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Isoenzimas/antagonistas & inhibidores , Isoflavonas/farmacología , Metaloproteinasa 1 de la Matriz/metabolismo , Proteína Quinasa C/antagonistas & inhibidores , Evaluación Preclínica de Medicamentos , Humanos , Envejecimiento de la Piel/efectos de los fármacos , Rayos UltravioletaRESUMEN
SCOPE: Although ingestion of coffee and its constituent chlorogenic acid (CGA) protects the retina from oxidative stress, the bioaccessibility and bioavailability of coffee metabolites are not well understood. The aim of this study was to determine which coffee metabolites reach the retina and protect against retinal degeneration. METHODS AND RESULTS: UPLC-MS/MS was used to detect CGA and coffee metabolites in the rat eye. The methyl thiazolyl tetrazolium assay and double staining with Hoechst and propidium iodide showed that CGA, caffeic acid (CA), and dihydrocaffeic acid (DHCA) protect retinal ganglion cells from hypoxia-induced damage. Western blots showed that treatment with coffee metabolites up-regulated anti-apoptotic proteins such as Bcl-2 and Bcl-XL and down-regulated pro-apoptotic proteins such as Bad, PARP, and cleaved caspase 3. Adult ICR mice were subjected to optic nerve crush-induced retinal ganglion cell death with intravitreal pre-treatment with coffee metabolites 1 day before and 1 h after the procedure. Retrograde Fluorogold(TM) labeling showed severe retinal ganglion cell loss after optic nerve crushing, and coffee metabolites significantly reduced damage to retinal ganglion cells. CONCLUSION: CGA and coffee metabolites, especially, CA, and DHCA, reach the eye, where they can significantly reduce apoptosis induced by hypoxia and optic nerve crush stress, and thus prevent retinal degeneration.
Asunto(s)
Ácidos Cafeicos/farmacología , Ácido Clorogénico/farmacocinética , Café , Fármacos Neuroprotectores/farmacología , Degeneración Retiniana/tratamiento farmacológico , Animales , Antioxidantes/farmacología , Ácidos Cafeicos/análisis , Hipoxia de la Célula/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Ácido Clorogénico/análisis , Ácido Clorogénico/metabolismo , Café/química , Café/metabolismo , Depuradores de Radicales Libres/farmacología , Masculino , Ratones Endogámicos ICR , Fármacos Neuroprotectores/farmacocinética , Proteínas/metabolismo , Ratas Sprague-Dawley , Degeneración Retiniana/patología , Espectrometría de Masas en TándemRESUMEN
Japanese red pine (Pinus densiflora) is widely present in China, Japan, and Korea. Its green pine leaves have traditionally been used as a food as well as a coloring agent. After being shed, pine leaves change their color from green to brown within two years, and although the brown pine leaves are abundantly available, their value has not been closely assessed. In this study, we investigated the potential anti-photoaging properties of brown pine leaves for skin. Brown pine leaf extract (BPLE) inhibited UVB-induced matrix metalloproteinase-1 (MMP-1) expression to a greater extent than pine leaf extract (PLE) in human keratinocytes and a human skin equivalent model. HPLC analysis revealed that the quantity of trans-communic acid (TCA) and dehydroabietic acid (DAA) significantly increases when the pine leaf color changes from green to brown. BPLE and TCA elicited reductions in UVB-induced MMP-1 mRNA expression and activator protein-1 (AP-1) transactivation by reducing DNA binding activity of phospho-c-Jun, c-fos and Fra-1. BPLE and TCA also inhibited UVB-induced Akt phosphorylation, but not mitogen activated protein kinase (MAPK), known regulators of AP-1 transactivation. We additionally found that BPLE and TCA inhibited phosphoinositide 3-kinase (PI3K), the upstream kinase of Akt, in vitro. In summary, both BPLE and its active component TCA exhibit protective effects against UVB-induced skin aging. Taken together, these findings underline the potential for BPLE and TCA to be utilized as anti-wrinkling agents and cosmetic ingredients, as they suppress UVB-induced MMP-1 expression.
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Diterpenos/farmacología , Metaloproteinasa 1 de la Matriz/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Pinus/química , Extractos Vegetales/farmacología , Activación Transcripcional/efectos de los fármacos , Abietanos/química , Abietanos/aislamiento & purificación , Abietanos/farmacología , Técnicas de Cultivo de Célula , Línea Celular , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Diterpenos/química , Diterpenos/aislamiento & purificación , Fibroblastos/citología , Fibroblastos/metabolismo , Fibroblastos/efectos de la radiación , Humanos , Isomerismo , Modelos Biológicos , Fosfatidilinositol 3-Quinasas/química , Fosforilación/efectos de los fármacos , Fosforilación/efectos de la radiación , Pinus/metabolismo , Extractos Vegetales/química , Hojas de la Planta/química , Hojas de la Planta/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Factor de Transcripción AP-1/genética , Factor de Transcripción AP-1/metabolismo , Rayos UltravioletaRESUMEN
We investigated the effects of an ethanol extract of C. denticulatum (EECD) in a mouse model of glaucoma established by optic nerve crush (ONC), and found that EECD significantly protected against retinal ganglion cell (RGC) death caused by ONC. Furthermore, EECD effectively protected against N-methyl-d-aspartate-induced damage to the rat retinas. In vitro, EECD attenuated transformed retinal ganglion cell (RGC-5) death and significantly blunted the up-regulation of apoptotic proteins and mRNA level induced by 1-buthionine-(S,R)-sulfoximine combined with glutamate, reduced reactive oxygen species production by radical species, and inhibited lipid peroxidation. The major EECD components were found to be chicoric acid and 3,5-dicaffeoylquinic acid (3,5-DCQA) that have shown beneficial effects on retinal degeneration both in vitro and in vivo studies. Thus, EECD could be used as a natural neuroprotective agent for glaucoma, and chicoric acid and 3,5-DCQA as mark compounds for the development of functional food.
Asunto(s)
Asteraceae/química , Ácidos Cumáricos/administración & dosificación , Ácidos Cumáricos/análisis , Estrés Oxidativo , Enfermedades de la Retina/prevención & control , Animales , Apoptosis/efectos de los fármacos , Ácidos Cafeicos/administración & dosificación , Ácidos Cafeicos/análisis , Ácido Clorogénico/administración & dosificación , Ácido Clorogénico/análogos & derivados , Ácido Clorogénico/análisis , Modelos Animales de Enfermedad , Glaucoma/etiología , Glaucoma/prevención & control , Peroxidación de Lípido/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos ICR , N-Metilaspartato/administración & dosificación , Compresión Nerviosa , Fármacos Neuroprotectores , Nervio Óptico , Extractos Vegetales/administración & dosificación , Ratas , Ratas Sprague-Dawley , Enfermedades de la Retina/etiología , Succinatos/administración & dosificación , Succinatos/análisisRESUMEN
Phenolics of the fresh ripe fruits of Rubus coreanus Miquel were extracted and separated into anthocyanin and the non-anthocyanin fractions, which were used for the evaluation for antioxidant capacity and neuroprotective effects. The anthocyanin fraction accounted for approximately 47-55% of the total antioxidant capacity of the whole extract and had significantly higher free radical-scavenging capacity than the non-anthocyanin fraction. Furthermore, the anthocyanins alleviated intracellular oxidative stress, as assayed by in vitro fluorescent measurements. The anthocyanins showed neuroprotective effects on PC-12 cells in vitro against oxidative stress in a dose-dependent manner. Triple quadrupole LC/MS and Q-TOF LC/MS analyses revealed four major anthocyanins; cyanidin 3-O-sambubioside, cyanidin 3-O-glucoside, cyanidin 3-O-xylosylrutinoside, and cyanidin 3-O-rutinoside in increasing order of amounts. These results demonstrated that anthocyanins are the major components and contributors to the antioxidant capacity of ripe R. coreanus Miquel fruits. Further studies are warranted to determine whether consumption of the fruits reduces oxidative stress in the brain and promotes health.
Asunto(s)
Antocianinas/farmacología , Fármacos Neuroprotectores/farmacología , Extractos Vegetales/farmacología , Rosaceae/química , Animales , Antocianinas/química , Antioxidantes/química , Antioxidantes/farmacología , Cromatografía Líquida de Alta Presión , Frutas/química , Espectrometría de Masas , Neuronas/citología , Fármacos Neuroprotectores/química , Células PC12 , Extractos Vegetales/química , RatasRESUMEN
Phenolics in dry Artemisia princeps Pampanini, an herbal plant traditionally consumed as food ingredients in Korea was extracted, fractionated, and quantified as well as evaluated for its neuroprotection for PC-12 cells. Whole extract had 5,852 mg gallic acid equivalents/100 g of total phenolics and 6,274 mg and 9,698 mg vitamin C equivalents/100 g of antioxidant capacities assayed by DPPH and ABTS radicals, respectively. The fraction extracted with n-butanol had the highest levels of total phenolics and antioxidant capacity than the other fractions (n-hexane, chloroform, ethyl acetate, and water). Using a reversed-phase HPLC system, caffeoylquinic acid (CQA) and its derivatives such as 3-CQA, 4-CQA, 5-CQA, 1,5-diCQA, 3,4-diCQA, 3,5-diCQA, and 4,5-diCQA were isolated and quantified. The whole extract and its n-butanol fraction yielded 3,5-diCQA with the highest amount, which consisted of approximately 36.8% and 33.5%, respectively. The whole extract, the n-butanol fraction, and 3,5-diCQA showed neuroprotective effect on PC-12 cells under the insult of amyloid ß peptide in a dose-dependent manner. Treatments of the whole extract and the n-butanol fraction for PC-12 cells under oxidative stress increased approximately 1.6 and 2.4 times higher cell viability, compared with the control without treatments. For PC-12 cells treated with 3,5-diCQA, intracellular oxidative stress decreased by 51.3% and cell viability increased up to 2.8 times compared to the control with oxidative insult of amyloid ß peptide only. These results indicate that phenolics from A. princeps Pampanini alleviated the oxidative stress and enhanced the viability of PC-12 cells, suggesting that it may be applied as a dietary antineurodegenerative agent in functional foods.
Asunto(s)
Artemisia/química , Fármacos Neuroprotectores/farmacología , Estrés Oxidativo , Extractos Vegetales/farmacología , Ácido Quínico/análogos & derivados , 1-Butanol/metabolismo , Péptidos beta-Amiloides/metabolismo , Animales , Antioxidantes/farmacología , Supervivencia Celular , Ácido Gálico/farmacología , Células PC12 , Ácido Quínico/farmacología , Ratas , República de CoreaRESUMEN
Cocoa polyphenols have antioxidant and anti-inflammatory effects. TNF-α is a pro-inflammatory cytokine that has a vital role in the pathogenesis of inflammatory diseases such as cancer and psoriasis. Vascular endothelial growth factor (VEGF) expression is associated with tumorigenesis, CVD, rheumatoid arthritis and psoriasis. We tested whether cocoa polyphenol extract (CPE) inhibited TNF-α-induced VEGF expression in promotion-sensitive JB6 mouse epidermal cells. CPE significantly inhibited TNF-α-induced up-regulation of VEGF via reducing TNF-α-induced activation of the nuclear transcription factors activator protein-1 (AP-1) and NF-κB, which are key regulators of VEGF expression. CPE also inhibited TNF-α-induced phosphorylation of protein kinase B (Akt) and extracellular signal-regulated kinase. CPE blocked activation of their downstream kinases, p70 kDa ribosomal protein S6 kinase and p90 kDa ribosomal protein S6 kinase. CPE suppressed phosphoinositide 3-kinase (PI3K) activity via binding PI3K directly. CPE did not affect TNF-α-induced phosphorylation of mitogen-activated protein kinase kinase-1 (MEK1) but suppressed TNF-α-induced MEK1 activity. Collectively, these results indicate that CPE reduced TNF-α-induced up-regulation of VEGF by directly inhibiting PI3K and MEK1 activities, which may contribute to its chemopreventive potential.
Asunto(s)
Antioxidantes/farmacología , Cacao/química , Epidermis/efectos de los fármacos , Flavonoides/farmacología , Fenoles/farmacología , Extractos Vegetales/farmacología , Factor de Necrosis Tumoral alfa/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Animales , Línea Celular , Células Epidérmicas , Epidermis/enzimología , MAP Quinasa Quinasa 1/antagonistas & inhibidores , Ratones , Inhibidores de las Quinasa Fosfoinosítidos-3 , Extractos Vegetales/química , Polifenoles , SemillasRESUMEN
In recent decades, romaine lettuce has been one of the fastest growing vegetables with respect to its consumption and production. An understanding is needed of the effect of major phenolic phytochemicals from romaine lettuce on biological protection for neuron-like PC-12 cells. Phenolics in fresh romaine lettuce were extracted, and then its total phenolics and total antioxidant capacity were measured spectrophotometrically. Neuroprotective effects of phenolic extract of romaine lettuce and its pure caffeic acid derivatives (caffeic, chicoric, chlorogenic, and isochlorogenic acids) in PC-12 cells were evaluated using two different in vitro methods: lactate dehydrogenase release and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assays. Total phenolics and total antioxidant capacity of 100 g of fresh romaine lettuce averaged 22.7 mg of gallic acid equivalents and 31.0 mg of vitamin C equivalents, respectively. The phenolic extract of romaine lettuce protected PC-12 cells against oxidative stress caused by H(2)O(2) in a dose-dependent manner. Isochlorogenic acid, one of the phenolics in romaine lettuce, showed stronger neuroprotection than the other three caffeic acid derivatives also found in the lettuce. Although romaine lettuce had lower levels of phenolics and antioxidant capacity compared to other common vegetables, its contribution to total antioxidant capacity and antineurodegenerative effect in human diets would be higher because of higher amounts of its daily per capita consumption compared to other common vegetables.
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Ácidos Cafeicos/farmacología , Lactuca/química , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Fenoles/farmacología , Extractos Vegetales/farmacología , Animales , Glicina/análogos & derivados , Neuronas/metabolismo , Estrés Oxidativo/efectos de los fármacos , RatasRESUMEN
We evaluated the effects of the two main kiwifruit cultivars (gold kiwifruit (GOK) and green kiwifruit (GRK)) and their active phenolic compound, quercetin, on H2O2-induced inhibition of gap-junction intercellular communication (GJIC) in WB-F344 rat liver epithelial cells. We found that both GOK and GRK protect WB-F344 cells from H2O2-induced inhibition of GJIC. The extracellular signal-regulated protein kinase 1/2 (ERK1/2)-connexin 43 (Cx43) signalling pathway is crucial for the regulation of GJIC, and both GOK and GRK blocked the H2O2-induced phosphorylation of Cx43 and ERK1/2 in WB-F344 cells. Quercetin alone attenuated the H2O2-mediated ERK1/2-Cx43 signalling pathway and consequently reversed H2O2-mediated inhibition of GJIC in WB-F344 cells. A free radical-scavenging assay using 1,1-diphenyl-2-picrylhydrazyl showed that the scavenging activity of quercetin was higher than that of a synthetic antioxidant, butylated hydroxytoluene, per mol, suggesting that the chemopreventive effect of quercetin on H2O2-mediated inhibition of ERK1/2-Cx43 signalling and GJIC may be mediated through its free radical-scavenging activity. Since the carcinogenicity of reactive oxygen species such as H2O2 is attributable to the inhibition of GJIC, GOK, GRK and quercetin may have chemopreventive potential by preventing the inhibition of GJIC.
Asunto(s)
Actinidia/química , Comunicación Celular/efectos de los fármacos , Frutas/química , Uniones Comunicantes/efectos de los fármacos , Peróxido de Hidrógeno/farmacología , Quercetina/farmacología , Actinidia/clasificación , Animales , Línea Celular , Conexina 43/metabolismo , Células Epiteliales/efectos de los fármacos , Células Epiteliales/fisiología , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Hígado/citología , Fosforilación , Extractos Vegetales/química , Extractos Vegetales/farmacología , Quercetina/química , RatasRESUMEN
Free radicals play a crucial role in the pathophysiology of human diseases such as cancer, atherosclerosis, and neurodegenerative diseases, and considerable attention has been focused on functional foods (or nutraceuticals) that are able to decrease the concentrations of free radicals and consequently protect against these diseases. The present study investigated an improved quantitative assay to measure antioxidant activity using the stable and fast-reacting chromogenic indicator [2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)] (ABTS). The ABTS-radical-scavenging activities of various antioxidants and apple extracts were measured in 96-well plates, and plots thereof were linearly interpolated, with the total radical-scavenging capacity quantified as the area under the curve. The first order of linear regression was obtained in a relationship between the absorbance reduction and various concentrations of the tested sample, and the total radical-scavenging capacity was expressed as the vitamin-C-equivalent antioxidant capacity. The advantages of this quantitative assay are that, first, it is fast, sensitive and confers little variation from experimental errors for single or mixed antioxidants; second, a large number of samples in a low quantity at a time can be run using 96-well plates.
Asunto(s)
Antioxidantes/análisis , Análisis de los Alimentos/métodos , Depuradores de Radicales Libres/análisis , Antioxidantes/farmacología , Ácido Ascórbico/análisis , Ácido Ascórbico/farmacología , Benzotiazoles , Hidroxianisol Butilado/análisis , Hidroxianisol Butilado/farmacología , Compuestos Cromogénicos , Colorimetría/métodos , Depuradores de Radicales Libres/farmacología , Humanos , Quempferoles/análisis , Quempferoles/farmacología , Malus/química , Extractos Vegetales/análisis , Extractos Vegetales/farmacología , Quercetina/análogos & derivados , Quercetina/análisis , Quercetina/farmacología , Ácidos SulfónicosRESUMEN
The phenolic compounds isolated from the roots of Lindera fruticosa included four new compounds, 2-methoxy-3,4-methylenedioxybenzophenone (1), (S)-2-methoxy-3,4-methylenedioxybenzhydryl alcohol (2), 3-hydroxy-5-methoxybiphenyl (3), and 1-methoxy-2,5,7-trihydroxyxanthone (4). Three previously identified phenolics were also identified, namely, 3,5-dimethoxybiphenyl (5), benzyl 2-hydroxy-6-methoxybenzoate (6), and 1,7-dihydroxyxanthone (7). These compounds were evaluated for their inhibitory effects on human acyl-CoA:cholesterol acyltransferase activity and on the in vitro oxidation of low-density lipoprotein.
Asunto(s)
Inhibidores Enzimáticos , Lindera/química , Lipoproteínas LDL/efectos de los fármacos , Fenoles , Plantas Medicinales/química , Esterol O-Aciltransferasa/antagonistas & inhibidores , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/aislamiento & purificación , Inhibidores Enzimáticos/farmacología , Etiopía , Humanos , Oxidación-Reducción , Fenoles/química , Fenoles/aislamiento & purificación , Fenoles/farmacología , Raíces de Plantas/químicaRESUMEN
With progressive "Westernization" of the dietary pattern in Asian countries, such as Korea and Japan, unhealthy signs, such as increases in obesity and incidence rate of cancers, are starting to appear in recent statistics. These results support the hypothesis that a dietary pattern of low fats and high antioxidants based on plant foods will reduce the risk of cancer Recently, antioxidative vitamins and phenolic phytochemicals derived from our daily diet have received much attention because of their potential chemopreventive activities. Their chemopreventive mechanisms have been suggested mainly due to their protective effects against oxidative DNA damage. However. several studies have shown that dietary antioxidant supplements, such as vitamins and phenolic phytochemicals, are not beneficial; they may rather, cause DNA damage. These results suggest that a metabolomics approach might demonstrate that antioxidant rich whole diets play a more important role, rather than individual antioxidants in cancer prevention. On the other hand, the chemopreventive mechanisms of dietary vitamins and phenolic phytochemicals may be associated with the inhibition of other carcinogenic processes, particularly tumor promotion, rather than that of tumor initiation. In this article, possible cancer-preventive mechanisms of dietary vitamins and phenolic phytochemicals, are reviewed.
Asunto(s)
Quimioprevención/métodos , Dieta , Neoplasias/prevención & control , Plantas/química , Vitaminas , Antiinflamatorios , Antioxidantes , Apoptosis , Biomarcadores de Tumor , Inhibidores Enzimáticos , Uniones Comunicantes/efectos de los fármacos , Humanos , Inhibidores de la Metaloproteinasa de la Matriz , Neoplasias/etiología , Inhibidores de la Ornitina Descarboxilasa , FenolesRESUMEN
The methanol extract obtained from the aerial parts of Aceriphyllum rossii (Saxifragaceae) was fractionated into ethyl acetate (EtOAc), n-BuOH and H2O layers through solvent fractionation. Repeated silica gel column chromatography of EtOAc and n-BuOH layers afforded six flavonol glycosides. They were identified as kaempferol 3-O-beta-D-glucopyranoside (astragalin, 1), quercetin 3-O-beta-D-glucopyranoside (isoquercitrin, 2), kaempferol 3-O-alpha-L-rhamnopyranosyl (1-->6)-beta-D-glucopyranoside (3), quercetin 3-O-alpha-L-rhamnopyranosyl (1-->6)-beta-D-glucopyranoside (rutin, 4), kaempferol 3-O-[alpha-L-rhamnopyranosyl (1-->4)-alpha-L-rhamnopyranosyl (1-->6)-beta-D-glucopyranoside] (5) and quercetin 3-O-[alpha-L-rhamnopyranosyl (1-->4)-alpha-L-rhamnopyranosyl (1-->6)-beta-D-glucopyranoside] (6) on the basis of several spectral data. The antioxidant activity of the six compounds was investigated using two free radicals such as the ABTS free radical and superoxide anion radical. Compound 1 exhibited the highest antioxidant activity in the ABTS [2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] radical scavenging method. 100 mg/L of compound 1 was equivalent to 72.1+/-1.4 mg/L of vitamin C, and those of compounds 3 and 5 were equivalent to 62.7+/-0.5 mg/L and 54.3+/-1.3 mg/L of vitamin C, respectively. And in the superoxide anion radical scavenging method, compound 5 exhibited the highest activity with an IC50 value of 17.6+/-0.3 microM. In addition, some physical and spectral data of the flavonoids were confirmed.
Asunto(s)
Antioxidantes/aislamiento & purificación , Flavonoles/aislamiento & purificación , Glicósidos/aislamiento & purificación , Saxifragaceae , Antioxidantes/química , Antioxidantes/farmacología , Flavonoles/química , Flavonoles/farmacología , Depuradores de Radicales Libres/antagonistas & inhibidores , Depuradores de Radicales Libres/metabolismo , Glicósidos/química , Glicósidos/farmacología , Concentración 50 Inhibidora , Componentes Aéreos de las Plantas , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Superóxidos/antagonistas & inhibidores , Superóxidos/metabolismoRESUMEN
Several studies have reported that even a moderate daily dose of supplementary vitamin C (200 mg) induces the formation of genotoxins from lipid hydroperoxides, thereby resulting in DNA damage and initiation of carcinogenesis. However, other reports questioned the experimental designs used and suggested that the chemopreventive effects of vitamin C may be linked to the inhibition of tumor promotion as well as to the blocking of tumor initiation. In this article, we discuss issues of contention and some controversies related to the potential chemopreventive effects of vitamin C in carcinogenesis.
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Anticarcinógenos/administración & dosificación , Antioxidantes/administración & dosificación , Ácido Ascórbico/administración & dosificación , Neoplasias/prevención & control , Antiinflamatorios/administración & dosificación , Daño del ADN , Suplementos Dietéticos , Frutas , Humanos , Neoplasias/epidemiología , Neoplasias/mortalidad , Oxidación-Reducción , Estados Unidos/epidemiología , VerdurasRESUMEN
To study the effect of polyphenolics on antioxidant capacities of plums, the amounts of total phenolics, total flavonoids and individual phenolic compounds, and vitamin C equivalent antioxidant capacity (VCEAC) of eleven plum cultivars was determined. There was a good linear relationship between the amount of total phenolics and total antioxidant capacity (r2 = 0.9887). The amount of total flavonoids and total antioxidant capacity also showed a good correlation (r2 = 0.9653). Although the summation of individual antioxidant capacity was lower than the total antioxidant capacity of plum samples, there was a positive correlation (r2 = 0.9299) of total antioxidant capacity of plum samples with the sum of the VCEACs calculated from individual phenolics. Chlorogenic acids and glycosides of cyanidin, peonidin, and quercetin were major phenolics among eleven plum cultivars. The antioxidant capacity of chlorogenic acids and anthocyanins showed higher correlation (r2) of 0.7751 and 0.6616 to total VCEAC, respectively, than that of quercetin glycosides (r2 = 0.0279). Chlorogenic acids were a major source of antioxidant activity in plums, and the consumption of one serving (100 g) of plums can provide antioxidants equivalent to 144.4-889.6 mg of vitamin C.
Asunto(s)
Antioxidantes/análisis , Flavonoides/análisis , Frutas/química , Fenoles/análisis , Prunus/química , Cromatografía Líquida de Alta Presión , Extractos Vegetales/química , PolifenolesRESUMEN
Black tea, green tea, red wine, and cocoa are high in phenolic phytochemicals, among which theaflavin, epigallocatechin gallate, resveratrol, and procyanidin, respectively, have been extensively investigated due to their possible role as chemopreventive agents based on their antioxidant capacities. The present study compared the phenolic and flavonoid contents and total antioxidant capacities of cocoa, black tea, green tea, and red wine. Cocoa contained much higher levels of total phenolics (611 mg of gallic acid equivalents, GAE) and flavonoids (564 mg of epicatechin equivalents, ECE) per serving than black tea (124 mg of GAE and 34 mg of ECE, respectively), green tea (165 mg of GAE and 47 mg of ECE), and red wine (340 mg of GAE and 163 mg of ECE). Total antioxidant activities were measured using the 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays and are expressed as vitamin C equivalent antioxidant capacities (VCEACs). Cocoa exhibited the highest antioxidant activity among the samples in ABTS and DPPH assays, with VCEACs of 1128 and 836 mg/serving, respectively. The relative total antioxidant capacities of the samples in both assays were as follows in decreasing order: cocoa > red wine > green tea > black tea. The total antioxidant capacities from ABTS and DPPH assays were highly correlated with phenolic content (r2 = 0.981 and 0.967, respectively) and flavonoid content (r2 = 0.949 and 0.915). These results suggest that cocoa is more beneficial to health than teas and red wine in terms of its higher antioxidant capacity.
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Antioxidantes/análisis , Bebidas/análisis , Cacao/química , Fenoles/análisis , Té/química , Vino/análisis , Benzotiazoles , Compuestos de Bifenilo , Catequina/análisis , Flavonoides/análisis , Depuradores de Radicales Libres/química , Ácido Gálico/análisis , Picratos/química , Ácidos Sulfónicos/químicaRESUMEN
To express the antioxidant capacity of plant foods in a more familiar and easily understood manner (equivalent to vitamin C mg/100 g), two stable radical species, ABTS(*)(-) and DPPH(*), commonly used for antioxidant activity measurements, were employed independently to evaluate their efficacies using apple polyphenolic extracts and seven polyphenolic standards including synthetic Trolox. Their antioxidant activities were expressed as vitamin C equivalent antioxidant capacity (VCEAC) in mg/100 g apple or mg/100 mL of the reference chemical compounds in 10 and 30 min using the ABTS(*)(-) and DPPH(*) scavenging assays, respectively. The antioxidant capacity of Gala apples and seven phenolic standards, determined by both ABTS(*)(-) and DPPH(*) scavenging assays, showed a dose-response of the first-order. Fresh Gala apples had a VCEAC of 205.4 +/- 5.6 mg/100 g using the ABTS assay, and the relative VCEACs of phenolic standards were as follows: gallic acid > quercetin > epicatechin > catechin > vitamin C > rutin > chlorogenic acid > Trolox. With the DPPH radical assay, the VCEAC of fresh Gala apples was 136.0 +/- 6.6 mg/100 g, and the relative VCEACs of seven phenolic standards were, in decreasing order, as follows: gallic acid > quercetin > epicatechin > catechin > or = vitamin C > Trolox > rutin > chlorogenic acid. Because the ABTS assay can be used in both organic and aqueous solvent systems, employs a specific absorbance at a wavelength remote from the visible region, and requires a short reaction time, it is a more desirable method than the DPPH assay. Therefore, it is recommended that antioxidant capacity be expressed as vitamin C mg/100 g equivalent (VCEAC) using the ABTS assay.
Asunto(s)
Antioxidantes/farmacología , Ácido Ascórbico/farmacología , Fenoles/farmacología , Extractos Vegetales/química , Plantas Comestibles/química , Benzotiazoles , Compuestos de Bifenilo , Catequina/farmacología , Ácido Clorogénico/farmacología , Cromanos/farmacología , Depuradores de Radicales Libres , Radicales Libres , Ácido Gálico/farmacología , Cinética , Malus/química , Oxidación-Reducción , Picratos , Quercetina/farmacología , Rutina/farmacología , Ácidos SulfónicosRESUMEN
Raspberries are rich in phenolic phytochemicals. To study the health benefits of raspberries, four fresh raspberry varieties (Heritage, Kiwigold, Goldie, and Anne) were evaluated for total antioxidant and antiproliferative activities. The total amount of phenolics and flavonoids for each of the four raspberry varieties was determined. The Heritage raspberry variety had the highest total phenolic content (512.7 +/- 4.7 mg/100 g of raspberry) of the varieties measured followed by Kiwigold (451.1 +/- 4.5 mg/100 g of raspberry), Goldie (427.5 +/- 7.5 mg/100 g of raspberry), and Anne (359.2 +/- 3.4 mg/100 g of raspberry). Similarly, the Heritage raspberry variety contained the highest total flavonoids (103.4 +/- 2.0 mg/100 g of raspberry) of the varieties tested, followed by Kiwigold (87.3 +/- 1.8 mg/100 g of raspberry), Goldie (84.2 +/- 1.8 mg/100 g of raspberry), and Anne (63.5 +/- 0.7 mg/100 g of raspberry). The color of the raspberry juice correlated well to the total phenolic, flavonoid, and anthocyanin contents of the raspberry. Heritage had the highest a/b ratio and the darkest colored juice, and the Anne variety showed the lowest phytochemical content and the palest color. Heritage raspberry variety had the highest total antioxidant activity, followed by Kiwigold and Goldie, and the Anne raspberry variety had the lowest antioxidant activity of the varieties tested. The proliferation of HepG(2) human liver cancer cells was significantly inhibited in a dose-dependent manner after exposure to the raspberry extracts. The extract equivalent to 50 mg of Goldie, Heritage, and Kiwigold fruit inhibited the proliferation of those cells by 89.4 +/- 0.1, 88 +/- 0.2, and 87.6 +/- 1.0%, respectively. Anne had the lowest antiproliferative activity of the varieties measured but still exhibited a significant inhibition of 70.3+/- 1.2% with an extract equivalent to 50 mg of fruit. The antioxidant activity of the raspberry was directly related to the total amount of phenolics and flavonoids found in the raspberry (p < 0.01). No relationship was found between antiproliferative activity and the total amount of phenolics/flavonoids found in the same raspberry (p > 0.05).