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1.
Mol Nutr Food Res ; 67(23): e2300512, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37817369

RESUMEN

SCOPE: Metabolic flexibility is essential for a healthy response to a high fat meal, and is assessed by measuring postprandial changes in blood markers including peripheral blood mononuclear cells (PBMCs; lymphocytes and monocytes). However, there is no clear consensus on postprandial gene expression and protein changes in these cells. METHOD AND RESULTS: The study systematically reviews the literature reporting transcriptional and proteomic changes in PBMCs after consumption of a high fat meal. After re-analysis of the raw data to ensure equivalence between studies, ≈85 genes are significantly changed (defined as in the same direction in ≥3 studies) with about half involved in four processes: inflammation/oxidative stress, GTP metabolism, apoptosis, and lipid localization/transport. For meals consisting predominantly of unsaturated fatty acids (UFA), notable additional processes are phosphorylation and glucocorticoid response. For saturated fatty acids (SFA), genes related to migration/angiogenesis and platelet aggregation are also changed. CONCLUSION: Despite differences in study design, common gene changes are identified in PBMCs following a high fat meal. These common genes and processes will facilitate definition of the postprandial transcriptome as part of the overall postcibalome, linking all molecules and processes that change in the blood after a meal.


Asunto(s)
Grasas de la Dieta , Transcriptoma , Grasas de la Dieta/farmacología , Leucocitos Mononucleares/metabolismo , Consenso , Proteómica , Comidas , Periodo Posprandial , Estudios Cruzados , Triglicéridos
2.
Food Funct ; 14(13): 5962-5976, 2023 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-37306209

RESUMEN

An elevated postprandial glycaemic response is a risk factor for developing type 2 diabetes mellitus (T2DM). Inhibition of digestive enzymes, including membrane-bound brush-border α-glucosidases, leads to slowed carbohydrate digestion and absorption, and reduced postprandial glycaemia. Nuts are eaten widely around the world, and have the potential to inhibit α-glucosidases through their content of polyphenols and other bioactive compounds. We set out to conduct a systematic literature review exploring the inhibitory effect of extracts from edible parts of various nuts on α-glucosidase activity in vitro to ensure, as far as possible, that no papers were missed. After an initial screening, 38 studies were reviewed in full, of which 15 were suitable for the present systematic review. Notably, no studies were found which tested the inhibitory potential of nut extracts against human α-glucosidases. Two studies showed that extracts from almonds and hazelnuts inhibited rat α-glucosidase activity, but the remaining papers reported data on the yeast α-glucosidase enzyme. Where yeast and rat enzymes can be compared, it is clear that nut extracts inhibit yeast α-glucosidase more strongly than mammalian α-glucosidase, which may lead to over-estimation when predicting effects in vivo when using data from the yeast enzyme. In contrast, acarbose is a stronger inhibitor of mammalian α-glucosidase compared to the yeast enzyme. Thus, although the present review indicates that extracts from nuts inhibit yeast α-glucosidase, this cannot be extrapolated to humans in vivo. There is some evidence that extracts from almonds and hazelnuts inhibit rat α-glucosidase, but no information on human enzyme sources. Since most work has been published on the yeast enzyme, future work in vitro must utilise mammalian, and preferably human, α-glucosidases in order to be relevant to human health and disease. This systematic review was registered at INPLASY as INPLASY202280061.


Asunto(s)
Diabetes Mellitus Tipo 2 , Hiperglucemia , Ratas , Humanos , Animales , alfa-Glucosidasas , Inhibidores de Glicósido Hidrolasas/farmacología , Nueces , Saccharomyces cerevisiae , Extractos Vegetales/farmacología , alfa-Amilasas , Hipoglucemiantes/farmacología , Mamíferos
3.
Clin Exp Dermatol ; 47(7): 1314-1323, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35279873

RESUMEN

BACKGROUND: Loss and remodelling of the dermal extracellular matrix (ECM) are key features of photodamaged human skin. Green tea catechins (GTCs) have been explored for their anti-inflammatory and chemopreventive properties, but data on the impact of GTCs on ultraviolet radiation (UVR)-induced changes to the dermal ECM are lacking. AIM: To investigate the effect of an inflammatory dose of solar-simulated UVR on human dermal ECM and potential for protection by GTCs in a double-blind randomized controlled trial. METHODS: In total, 50 healthy white (Fitzpatrick skin type I-II) adults aged 18-65 years were randomized to a combination of GTCs 540 mg plus vitamin C 50 mg or to placebo twice daily for 12 weeks. The impact of solar-simulated UVR at 3 × minimal erythema dose on the dermal collagen and elastic fibre networks was assessed by histology and immunohistochemistry in all participants at baseline. The impact of GTC supplementation on UVR-induced effects was compared between the groups post-supplementation. RESULTS: The area of papillary dermis covered by collagen and elastic fibres was significantly lower (P < 0.001) in UVR-exposed skin than in unexposed skin. Significantly lower levels of fibrillin-rich microfibrils (P = 0.02), fibulin-2 (P < 0.001) and fibulin-5 (P < 0.001) were seen in UVR-exposed than unexposed skin, while procollagen-1 deposition was significantly higher in UVR-exposed skin (P = 0.01). Following GTC supplementation, the UVR-induced change in fibulin-5 was abrogated in the active group but not the placebo group, with no difference between the two groups for other components. CONCLUSIONS: Acute UVR induced significant changes in the human dermal collagen and elastic fibre networks, whereas oral GTCs conferred specific UVR protection to fibulin-5. Future studies could explore the impact of GTCs on the effects of repeated suberythemal UVR exposure of human skin.


Asunto(s)
Catequina , Matriz Extracelular , Rayos Ultravioleta , Adulto , Catequina/farmacología , Catequina/uso terapéutico , Colágeno , Matriz Extracelular/efectos de los fármacos , Matriz Extracelular/efectos de la radiación , Humanos , Piel/patología , Té/química , Rayos Ultravioleta/efectos adversos
4.
Free Radic Biol Med ; 162: 191-201, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33091574

RESUMEN

BACKGROUND: Uric acid, a metabolic product of purine degradation in humans, is a risk factor for developing gout and type 2 diabetes, and supplementation with quercetin lowers plasma uric acid in mildly hyperuricemic men. Here we examined the mechanism of inhibition of enzymes involved in uric acid metabolism by quercetin, conjugates and microbial catabolites, and measured the effect of lowered circulating uric acid on endothelial cell gene expression. METHODS: Inhibition of adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP) and xanthine oxidoreductase (XOR) activity by quercetin and metabolites was determined by HPLC. Human umbilical vein endothelial cells (HUVECs) were cultured under conditions mimicking blood flow, treated with uric acid (0, 300 or 500 µmol/L), and changes in gene expression measured using transcriptomics and quantitative droplet digital PCR. RESULTS: In human plasma, no inhibition of PNP activity was observed, and only quercetin weakly inhibited ADA. XOR was not present at sufficient amount in human plasma to use for testing, but quercetin, quercetin-3'-sulfate and the gut microbial metabolite 3',4'-dihydroxyphenylacetic acid inhibited bovine milk XOR. Several changes were observed in gene expression in HUVECs under flow compared to static conditions, but after uric acid treatment, only very few changes were detected. CONCLUSIONS: We propose that the main mechanism by which quercetin, as quercetin-3'-sulfate, lowers uric acid in vivo is through inhibition of XOR, and not ADA nor PNP. The pertinent shift in uric acid concentration was not sufficient to produce significant changes in endothelial gene expression in a cell model.


Asunto(s)
Diabetes Mellitus Tipo 2 , Ácido Úrico , Animales , Bovinos , Células Endoteliales , Endotelio , Expresión Génica , Humanos , Masculino , Quercetina/farmacología
5.
Compr Rev Food Sci Food Saf ; 19(4): 1299-1352, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-33337099

RESUMEN

Acyl-quinic acids (chlorogenic acids) are produced by many plants, including fruits, vegetables, and herbal remedies, with coffee and maté particularly rich dietary sources. Epidemiological and intervention studies suggest that they can reduce the risk of developing type 2 diabetes and cardiovascular disease. This review addresses their metabolic handling after oral consumption to provide a mechanistic basis to explain their possible effects on health. Intact acyl-quinic acids are absorbed only to a small extent in the small intestine, but the cinnamic acids are efficiently absorbed after hydrolysis by either digestive or microbial enzymes in the colon. Metabolism results in phenolic conjugates in the blood and urine, but varying dependent on the acyl-quinic acid, and subject to significant interperson variability. The balance between hydrogenation and complete ß-oxidation of the cinnamic acids, both by liver and gut microbiota, determines the profile of metabolites. Pharmacokinetic data suggest that some metabolites are bound to human serum albumin and/or sequestered in tissues, and some exhibit biological activity in vitro, consistent with proposed protective action in vivo. Significant gaps in the literature include lack of plasma and urinary data for free-living individuals, and pharmacokinetic data for groups who consume coffee or maté at regular short intervals. Data are required for cis isomers. There is a critical need for precise urinary biomarkers of consumption of acyl-quinic acids, accounting for variability in individual metabolism and in beverage composition, thus facilitating better translation of urinary metabolite measurements into accurate coffee consumption data to improve the outcomes of future epidemiological and intervention studies.


Asunto(s)
Disponibilidad Biológica , Ácido Clorogénico/metabolismo , Ácido Clorogénico/farmacocinética , Cinamatos/metabolismo , Café/química , Humanos , Ilex paraguariensis/química , Ácido Quínico/análogos & derivados , Ácido Quínico/metabolismo
6.
Sci Rep ; 10(1): 19590, 2020 11 11.
Artículo en Inglés | MEDLINE | ID: mdl-33177581

RESUMEN

The origin of inter-individual variability in the action of bioactive small molecules from the diet is poorly understood and poses a substantial obstacle to harnessing their potential for attenuating disease risk. Epidemiological studies show that coffee lowers the risk of developing type 2 diabetes, independently of caffeine, but since coffee is a complex matrix, consumption gives rise to different classes of metabolites in vivo which in turn can affect multiple related pathways in disease development. We quantified key urinary coffee phenolic acid metabolites repeated three times in 36 volunteers, and observed the highest inter- and intra-individual variation for metabolites produced by the colonic microbiome. Notably, a urinary phenolic metabolite not requiring the action of the microbiota was positively correlated with fasting plasma insulin. These data highlight the role of the gut microbiota as the main driver of both intra- and inter-individual variation in metabolism of dietary bioactive small molecules.


Asunto(s)
Biomarcadores/sangre , Café , Microbioma Gastrointestinal/fisiología , Hidroxibenzoatos/orina , Compuestos de Sulfhidrilo/sangre , Ácido Clorogénico/análisis , Ácido Clorogénico/farmacocinética , Café/química , Café/metabolismo , Femenino , Microbioma Gastrointestinal/efectos de los fármacos , Humanos , Hidroxibenzoatos/metabolismo , Grasa Intraabdominal , Masculino
7.
Nutrients ; 12(10)2020 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-33066504

RESUMEN

Insulin resistance (IR) is apparent when tissues responsible for clearing glucose from the blood, such as adipose and muscle, do not respond properly to appropriate signals. IR is estimated based on fasting blood glucose and insulin, but some measures also incorporate an oral glucose challenge. Certain (poly)phenols, as supplements or in foods, can improve insulin resistance by several mechanisms including lowering postprandial glucose, modulating glucose transport, affecting insulin signalling pathways, and by protecting against damage to insulin-secreting pancreatic ß-cells. As shown by intervention studies on volunteers, the most promising candidates for improving insulin resistance are (-)-epicatechin, (-)-epicatechin-containing foods and anthocyanins. It is possible that quercetin and phenolic acids may also be active, but data from intervention studies are mixed. Longer term and especially dose-response studies on mildly insulin resistant participants are required to establish the extent to which (poly)phenols and (poly)phenol-rich foods may improve insulin resistance in compromised groups.


Asunto(s)
Suplementos Dietéticos , Resistencia a la Insulina , Polifenoles/administración & dosificación , Polifenoles/farmacología , Antocianinas/administración & dosificación , Antocianinas/farmacología , Glucemia/metabolismo , Catequina/administración & dosificación , Catequina/farmacología , Transportador de Glucosa de Tipo 4/metabolismo , Humanos , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Periodo Posprandial , Quercetina/administración & dosificación , Quercetina/farmacología , Transducción de Señal/efectos de los fármacos
8.
Food Funct ; 11(6): 4826-4833, 2020 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-32484174

RESUMEN

Epidemiological studies show a convincing long-term and dose-dependent protection of coffee and decaffeinated coffee against developing type 2 diabetes. The mechanisms of this effect are still not understood even though several have been proposed, including a potential effect on blood glucose by chlorogenic acids. However, there is minimal effect of decaffeinated coffee on postprandial blood glucose and insulin when consumed with carbohydrates, although there may be effects on incretin hormones, but these have been measured in only a few studies. Although chlorogenic acids do not affect carbohydrate digestion directly, they may affect glucose absorption and subsequent utilisation, the latter through metabolites derived from endogenous pathways or action of the gut microbiota. To advance understanding of the protective effect of coffee chlorogenic acids, more chronic intervention studies are needed on decaffeinated coffee, coupled with mechanistic studies in vitro using more realistic concentrations of the relevant chlorogenic acid metabolites.


Asunto(s)
Glucemia/efectos de los fármacos , Ácido Clorogénico/farmacología , Café , Diabetes Mellitus Tipo 2/prevención & control , Ácido Clorogénico/metabolismo , Humanos , Periodo Posprandial
9.
Biochem Pharmacol ; 178: 114123, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32593613

RESUMEN

Commonly used drugs for treating many conditions are either natural products or derivatives. In silico modelling has identified several natural products including quercetin as potential highly effective disruptors of the initial infection process involving binding to the interface between the SARS-CoV-2 (Covid-19) Viral Spike Protein and the epithelial cell Angiotensin Converting Enzyme-2 (ACE2) protein. Here we argue that the oral route of administration of quercetin is unlikely to be effective in clinical trials owing to biotransformation during digestion, absorption and metabolism, but suggest that agents could be administered directly by alternative routes such as a nasal or throat spray.


Asunto(s)
Betacoronavirus/efectos de los fármacos , Productos Biológicos/farmacología , Peptidil-Dipeptidasa A/metabolismo , Quercetina/farmacología , Glicoproteína de la Espiga del Coronavirus/metabolismo , Enzima Convertidora de Angiotensina 2 , Betacoronavirus/metabolismo , Betacoronavirus/fisiología , Productos Biológicos/administración & dosificación , Productos Biológicos/química , COVID-19 , Ensayos Clínicos como Asunto/métodos , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/virología , Evaluación Preclínica de Medicamentos/métodos , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Células Epiteliales/virología , Interacciones Huésped-Patógeno/efectos de los fármacos , Humanos , Estructura Molecular , Pandemias/prevención & control , Neumonía Viral/prevención & control , Neumonía Viral/virología , Unión Proteica/efectos de los fármacos , Quercetina/administración & dosificación , Quercetina/química , SARS-CoV-2 , Internalización del Virus/efectos de los fármacos
10.
Nutr Rev ; 78(6): 451-458, 2020 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-31769838

RESUMEN

Many terms for plant-derived food components are commonly used in the literature, but there is a notable lack of standardization and definition of nomenclature. The use of terms is often field-specific, leading to misunderstanding and problems with literature searches and systematic reviews, and results in isolated and divided research; this impacts not only publication quality but also innovation, regulatory compliance, and enforcement. To begin to address this issue, this narrative review describes the current use and definition of terms. The terms are either chemical and/or origin-based, such as phytochemical (chemicals from plants), or function-based, such as phytonutrient, bioactive, or nutraceutical. The ultimate goal is to establish a common harmonized, evidence-based understanding for when to use each term, thereby providing clarity and a specific scientific basis for such nomenclature. Neither the quality nor the quantity of evidence needed to allow the use of functional terms such as phytonutrient or nutraceutical is specifically discussed here; rather, it is simply noted that evidence is needed to apply these terms. The next step would be to define the evidence necessary for a compound to have a functional descriptor. The aim in this article is to establish scientific criteria for definitions that could be applied to clearly define and differentiate commonly used terms and thus ensure their consistent application in the scientific literature.


Asunto(s)
Fitoquímicos , Preparaciones de Plantas , Terminología como Asunto , Investigación Biomédica , Humanos , Ciencias de la Nutrición
11.
Nutrients ; 11(7)2019 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-31266155

RESUMEN

Consumption of dietary bioactives is an avenue to enhancing the effective healthiness of diets by attenuating the glycaemic response. The intestinal brush border enzyme sucrase-isomaltase (SI) is the sole enzyme hydrolysing consumed sucrose, and we previously showed the acute effects of olive leaf extract (OLE) on sucrase activity when given together with sugars both in vitro and in vivo. Here we tested whether OLE could affect sucrase expression when pre-incubated chronically, a "priming" effect not dependent on competitive interaction with SI, in both a cell model and a human intervention. Using differentiated Caco-2/TC7 cells, long-term pre-treatment with oleuropein-rich olive leaf extract (OLE) lowered SI mRNA, surface protein and activity, and attenuated subsequent sucrose hydrolysis. Based on these results, a randomised, double-blinded, placebo-controlled, crossover pilot study was conducted. OLE (50 mg oleuropein) was consumed in capsule form 3 times a day for 1 week by 11 healthy young women followed by an oral sucrose tolerance test in the absence of OLE. However this treatment, compared to placebo, did not induce a change in post-prandial blood glucose maximum concentration (Glcmax), time to reach Glcmax and incremental area under the curve. These results indicate that changes in SI mRNA, protein and activity in an intestinal cell model by OLE are not sufficient under these conditions to induce a functional effect in vivo in healthy volunteers.


Asunto(s)
Glucemia/metabolismo , Sacarosa en la Dieta/metabolismo , Mucosa Intestinal/efectos de los fármacos , Iridoides/administración & dosificación , Olea , Extractos Vegetales/administración & dosificación , Hojas de la Planta , Complejo Sacarasa-Isomaltasa/metabolismo , Adolescente , Adulto , Anciano , Biomarcadores/sangre , Células CACO-2 , Estudios Cruzados , Método Doble Ciego , Femenino , Regulación de la Expresión Génica , Humanos , Mucosa Intestinal/enzimología , Glucósidos Iridoides , Iridoides/aislamiento & purificación , Persona de Mediana Edad , Olea/química , Extractos Vegetales/aislamiento & purificación , Hojas de la Planta/química , Periodo Posprandial , Complejo Sacarasa-Isomaltasa/genética , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
12.
Food Chem ; 261: 164-168, 2018 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-29739578

RESUMEN

Seasonal variations in crops can alter the profile and amount of constituent compounds and consequentially any biological activity. Differences in phytochemical profile, total phenolic content and inhibitory activity on α-glucosidase (maltase) of Hibiscus sabdariffa calyces grown in South Western Nigeria were determined over wet and dry seasons. The phenolic profile, organic acids and sugars were analysed using HPLC, while inhibition of rat intestinal maltase was measured enzymically. There was a significant increase (1.4-fold; p ≤ 0.05) in total anthocyanin content in the dry compared to wet planting seasons, and maltase inhibition from the dry season was slightly more potent (1.15-fold, p ≤ 0.05). Fructose (1.8-fold), glucose (1.8-fold) and malic acid (3.7-fold) were significantly higher (p ≤ 0.05) but citric acid was lower (62-fold, p ≤ 0.008) in the dry season. Environmental conditions provoke metabolic responses in Hibiscus sabdariffa affecting constituent phytochemicals and nutritional value.


Asunto(s)
Inhibidores de Glicósido Hidrolasas/farmacología , Hibiscus/química , Extractos Vegetales/farmacología , Animales , Antocianinas/análisis , Cromatografía Líquida de Alta Presión , Inhibidores de Glicósido Hidrolasas/análisis , Nigeria , Fenoles/análisis , Extractos Vegetales/análisis , Extractos Vegetales/química , Ratas , Estaciones del Año , alfa-Glucosidasas/análisis , alfa-Glucosidasas/metabolismo
14.
Antioxid Redox Signal ; 29(16): 1633-1659, 2018 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-28826224

RESUMEN

SIGNIFICANCE: Flavonoids can interact with multiple molecular targets to elicit their cellular effects, leading to changes in signal transduction, gene expression, and/or metabolism, which can, subsequently, affect the entire cell and organism. Immortalized cell lines, derived from tumors, are routinely employed as a surrogate for mechanistic studies, with the results extrapolated to tissues in vivo. Recent Advances: We review the activities of selected flavonoids on cultured tumor cells derived from various tissues in comparison to corresponding primary cells or tissues in vivo, mainly using quercetin and flavanols (epicatechin and (-)-epigallocatechin gallate) as exemplars. Several studies have indicated that flavonoids could retard cancer progression in vivo in animal models as well as in tumor cell models. CRITICAL ISSUES: Extrapolation from in vitro and animal models to humans is not straightforward given both the extensive conjugation and complex microbiota-dependent metabolism of flavonoids after consumption, as well as the heterogeneous metabolism of different tumors. FUTURE DIRECTIONS: Comparison of data from studies on primary cells or in vivo are essential not only to validate results obtained from cultured cell models, but also to highlight whether any differences may be further exploited in the clinical setting for chemoprevention. Tumor cell models can provide a useful mechanistic tool to study the effects of flavonoids, provided that the limitations of each model are understood and taken into account in interpretation of the data.


Asunto(s)
Metabolismo Energético/efectos de los fármacos , Flavonoides/farmacología , Neoplasias/metabolismo , Transducción de Señal/efectos de los fármacos , Animales , Proliferación Celular/efectos de los fármacos , Flavonoides/metabolismo , Humanos , Neoplasias/patología , Oxidación-Reducción/efectos de los fármacos
15.
Am J Clin Nutr ; 106(6): 1384-1393, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29021286

RESUMEN

Background: Low-glycemic index diets have demonstrated health benefits associated with a reduced risk of developing type 2 diabetes.Objectives: We tested whether pomegranate polyphenols could lower the glycemic response of a high-glycemic index food when consumed together and the mechanism by which this might occur.Design: We compared the acute effect of a pomegranate juice and a polyphenol-rich extract from pomegranate (supplement) on the bread-derived postprandial blood glucose concentration in 2 randomized, crossover, controlled studies (double-blinded for the supplements), each on 16 healthy volunteers. An additional randomized, crossover, controlled study on 16 volunteers consuming constituent fruit acids in a pH-balanced solution (same pH as pomegranate) and bread was conducted to determine any contributions to postprandial responses caused by acidic beverages.Results: As primary outcome, the incremental area under the curve for bread-derived blood glucose (-33.1% ± 18.1%, P = 0.000005) and peak blood glucose (25.4% ± 19.3%, P = 0.0004) were attenuated by pomegranate juice, compared with a control solution containing the equivalent amount of sugars. In contrast, the pomegranate supplement, or a solution containing the malic and citric acid components of the juice, was ineffective. The pomegranate polyphenol punicalagin was a very effective inhibitor of human α-amylase in vitro, comparable to the drug acarbose. Neither the pomegranate extract nor the individual component polyphenols inhibited 14C-D-glucose transport across differentiated Caco-2/TC7 cell monolayers, but they inhibited uptake of 14C-glucose into Xenopus oocytes expressing the human glucose transporter type 2. Further, some of the predicted pomegranate gut microbiota metabolites modulated 14C-D-glucose and 14C-deoxy-D-glucose uptake into hepatic HepG2 cells.Conclusions: These data indicate that pomegranate polyphenols, when present in a beverage but not in a supplement, can reduce the postprandial glycemic response of bread, whereas microbial metabolites from pomegranate polyphenols exhibit the potential to further modulate sugar metabolism much later in the postprandial period. This trial was registered at clinicaltrials.gov as NCT02486978, NCT02624609, and NCT03242876.


Asunto(s)
Glucemia/metabolismo , Jugos de Frutas y Vegetales , Índice Glucémico/efectos de los fármacos , Carga Glucémica/efectos de los fármacos , Taninos Hidrolizables/farmacología , Lythraceae/química , Polifenoles/farmacología , Adulto , Animales , Área Bajo la Curva , Pan , Células CACO-2 , Estudios Cruzados , Método Doble Ciego , Frutas , Microbioma Gastrointestinal , Transportador de Glucosa de Tipo 2/metabolismo , Células Hep G2 , Humanos , Hipoglucemiantes/farmacología , Preparaciones de Plantas/farmacología , Periodo Posprandial , Adulto Joven
16.
Mol Nutr Food Res ; 61(12)2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28868668

RESUMEN

SCOPE: High glycaemic sugars result in blood-glucose spikes, while large doses of post-prandial fructose inundate the liver, causing an imbalance in energy metabolism, both leading to increased risk of metabolic malfunction and type 2 diabetes. Acarbose, used for diabetes management, reduces post-prandial hyperglycaemia by delaying carbohydrate digestion. METHODS AND RESULTS: Chamomile and green teas both inhibited digestive enzymes (α-amylase and maltase) related to intestinal sugar release, as already established for acarbose. However, acarbose had no effect on uptake of sugars using both differentiated human Caco-2 cell monolayers and Xenopus oocytes expressing human glucose transporter-2 (GLUT2) and GLUT5. Both teas effectively inhibited transport of fructose and glucose through GLUT2 inhibition, while chamomile tea also inhibited GLUT5. Long term incubation of Caco-2/TC7 cells with chamomile tea for 16 h or 4 days did not enhance the observed effects, indicating that inhibition is acute. Sucrase activity was directly inhibited by green tea and acarbose, but not chamomile. CONCLUSION: These findings show that chamomile and green teas are potential tools to manage absorption and metabolism of sugars with efficacy against high sugar bolus stress inflicted, for example, by high fructose syrups, where the drug acarbose would be ineffective.


Asunto(s)
Acarbosa/farmacología , Manzanilla/química , Glucosa/metabolismo , Té/química , Tés de Hierbas , Animales , Transporte Biológico/efectos de los fármacos , Células CACO-2 , Diferenciación Celular/efectos de los fármacos , Fructosa/metabolismo , Transportador de Glucosa de Tipo 2/antagonistas & inhibidores , Transportador de Glucosa de Tipo 2/genética , Transportador de Glucosa de Tipo 2/metabolismo , Transportador de Glucosa de Tipo 5/antagonistas & inhibidores , Transportador de Glucosa de Tipo 5/genética , Transportador de Glucosa de Tipo 5/metabolismo , Humanos , Oocitos/efectos de los fármacos , Oocitos/metabolismo , Sacarosa/metabolismo , Xenopus , alfa-Amilasas/antagonistas & inhibidores , alfa-Amilasas/metabolismo
17.
J Agric Food Chem ; 65(39): 8643-8651, 2017 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-28914528

RESUMEN

We optimized the assays used to measure inhibition of rat and human α-glucosidases (sucrase and maltase activities), intestinal enzymes which catalyze the final steps of carbohydrate digestion. Cell-free extracts from fully differentiated intestinal Caco-2/TC7 monolayers were shown to be a suitable source of sucrase-isomaltase, with the same sequence as human small intestine, and were compared to a rat intestinal extract. The kinetic conditions of the assay were optimized, including comparison of enzymatic and chromatographic methods to detect the monosaccharide products. Human sucrase activity was more susceptible than the rat enzyme to inhibition by acarbose (IC50 (concentration required for 50% inhibition) = 2.5 ± 0.5 and 12.3 ± 0.6 µM, respectively), by a polyphenol-rich green tea extract, and by pure (-)-epigallocatechin gallate (EGCG) (IC50 = 657 ± 150 and 950 ± 86 µM respectively). In contrast, the reverse was observed when assessing maltase activity (e.g. , EGCG: IC50 = 677 ± 241 and 14.0 ± 2.0 µM for human and rat maltase, respectively). 5-Caffeoylquinic acid did not significantly inhibit maltase and was only a very weak inhibitor of sucrase. The data show that for sucrase and maltase activities, inhibition patterns of rat and human enzymes are generally qualitatively similar but can be quantitatively different.


Asunto(s)
Acarbosa/farmacología , Inhibidores Enzimáticos/farmacología , Hipoglucemiantes , Polifenoles/farmacología , Sacarasa/antagonistas & inhibidores , alfa-Glucosidasas/metabolismo , Animales , Células CACO-2 , Catequina/análogos & derivados , Glucosa/análisis , Inhibidores de Glicósido Hidrolasas/farmacología , Humanos , Intestino Delgado/enzimología , Cinética , Ratas , Sacarasa/metabolismo , Complejo Sacarasa-Isomaltasa/metabolismo , Té/química
18.
J Nutr Biochem ; 44: 44-51, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28391055

RESUMEN

Consumption of foods rich in ferulic acid (FA) such as wholegrain cereals, or FA precursors such as chlorogenic acids in coffee, is inversely correlated with risk of cardiovascular disease and type 2 diabetes. As a result of digestion and phase II metabolism in the gut and liver, FA is converted predominantly into ferulic acid-4-O-sulfate (FA-sul), an abundant plasma metabolite. Although FA-sul is the main metabolite, very little has been reported regarding its bioactivities. We have compared the ex vivo vasorelaxing effect of FA and FA-sul (10-7-3.10-5M) on isolated mouse arteries mounted in tissue myographs. FA-sul, but not FA, elicited a concentration-dependent vasorelaxation of saphenous and femoral arteries and aortae. The FA-sul-mediated vasorelaxation was blunted by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, a soluble guanylate cyclase (sGC) inhibitor. The role of sGC was confirmed in femoral arteries isolated from sGCα1(-/-) knockout mice. Furthermore, 4-aminopyridine, a specific inhibitor of voltage-dependent potassium channels, significantly decreased FA-sul-mediated effects. In anesthetized mice, intravenous injection of FA-sul decreased mean arterial pressure, whereas FA had no effect, confirming the results obtained ex vivo. FA-sul is probably one of the major metabolites accounting for the blood pressure-lowering effects associated with FA consumption.


Asunto(s)
Arterias/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Ácidos Cumáricos/farmacología , Ésteres del Ácido Sulfúrico/farmacología , Animales , Arterias/metabolismo , Café/química , Inyecciones Intravenosas , Masculino , Ratones , Ratones Noqueados , Polifenoles/farmacología , Canales de Potasio/efectos de los fármacos , Canales de Potasio/metabolismo , Guanilil Ciclasa Soluble/genética , Guanilil Ciclasa Soluble/metabolismo , Vasodilatación/efectos de los fármacos , Granos Enteros/química
19.
Biochem Pharmacol ; 139: 24-39, 2017 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-28322745

RESUMEN

(Poly)phenols are a large group of compounds, found in food, beverages, dietary supplements and herbal medicines. Owing to interest in their biological activities, absorption and metabolism of the most abundant compounds in humans are well understood. Both the chemical structure of the phenolic moiety and any attached chemical groups define whether the polyphenol is absorbed in the small intestine, or reaches the colon and is subject to extensive catabolism by colonic microbiota. Untransformed substrates may be absorbed, appearing in plasma primarily as methylated, sulfated and glucuronidated derivatives, with in some cases the unchanged substrate. Many of the catabolites are well absorbed from the colon and appear in the plasma either similarly conjugated, or as glycine conjugates, or in some cases unchanged. Although many (poly)phenol catabolites have been identified in human plasma and/or urine, the exact pathways from substrate to final microbial catabolite, and the species of bacteria and enzymes involved, are still scarcely reported. While it is clear that the composition of the human gut microbiota can be modulated in vivo by supplementation with some (poly)phenol-rich commodities, such modulation is definitely not an inevitable consequence of supplementation; it depends on the treatment, length of time and on the individual metabotype, and it is not clear whether the modulation is sustained when supplementation ceases. Some catabolites have been recorded in plasma of volunteers at concentrations similar to those shown to be effective in in vitro studies suggesting that some benefit may be achieved in vivo by diets yielding such catabolites.


Asunto(s)
Colon/metabolismo , Microbioma Gastrointestinal , Absorción Intestinal , Mucosa Intestinal/metabolismo , Intestino Delgado/metabolismo , Polifenoles/metabolismo , Animales , Disponibilidad Biológica , Biotransformación , Colon/microbiología , Dieta Saludable , Suplementos Dietéticos , Digestión , Medicamentos Herbarios Chinos/análisis , Medicamentos Herbarios Chinos/farmacocinética , Glucósidos/metabolismo , Humanos , Hidrólisis , Hidroxilación , Mucosa Intestinal/microbiología , Intestino Delgado/microbiología , Metilación , Especificidad de Órganos , Polifenoles/sangre , Polifenoles/farmacocinética , Prebióticos/administración & dosificación , Prebióticos/efectos adversos
20.
J Agric Food Chem ; 64(24): 4921-31, 2016 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-27226105

RESUMEN

Three varieties of Hibiscus sabdariffa were analyzed for their phytochemical content and inhibitory potential on carbohydrate-digesting enzymes as a basis for selecting a variety for wine production. The dark red variety was chosen as it was highest in phenolic content and an aqueous extract partially inhibited α-glucosidase (maltase), with delphinidin 3-O-sambubioside, cyanidin 3-O-sambubioside, and 3-O-caffeoylquinic acid accounting for 65% of this activity. None of the varieties significantly inhibited α-amylase. Regarding Hibiscus sabdariffa wine, the effect of fermentation temperature (20 and 30 °C) on the physicochemical, phytochemical, and aroma composition was monitored over 40 days. The main change in phytochemical composition observed was the hydrolysis of 3-O-caffeolquinic acid and the concomitant increase of caffeic acid irrespective of fermentation temperature. Wine fermented at 20 °C was slightly more active for α-glucosidase inhibition with more fruity aromas (ethyl octanoate), but there were more flowery notes (2-phenylethanol) at 30 °C.


Asunto(s)
Inhibidores Enzimáticos/química , Glicósido Hidrolasas/antagonistas & inhibidores , Hibiscus/química , Extractos Vegetales/química , Vino/análisis , Flores/química , Glicósido Hidrolasas/química , Humanos
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