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1.
Animals (Basel) ; 13(3)2023 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-36766220

RESUMEN

Probiotic feed additives can support the gut health of shrimp and thereby improve performance, production efficiency and disease resistance. Two experiments in white leg shrimp aimed to investigate the effects of a multi-species probiotic feed supplement (AquaStar®, 3 g/kg feed, Biomin GmbH, Getzersdorf, Austria) in feed formulations with different marine meal levels (32% and 15%) on growth performance and resistance against Vibrio parahaemolyticus. Juvenile shrimp were stocked in a recirculating aquaculture tank system at a density of 20 shrimp/46.8 L and were fed diets with and without the probiotic supplementation for 8 weeks. Afterwards, a bath immersion with V. parahaemolyticus was performed and mortality was observed over a period of 14 days. Independent of the diet formulation, probiotic supplementation significantly improved the survival rate of the shrimp and the specific growth rate while decreasing feed consumption and feed conversion ratio when compared to the control (p ≤ 0.042). After the Vibrio immersion challenge, mortality was significantly decreased by 13.33% with probiotic supplementation in the high marine meal diet experiment (p = 0.042) and numerically decreased by 11.67% in the low marine meal diet experiment (p = 0.133). Overall, the results suggest that the beneficial effects of the probiotic can occur independently of the diet formulation.

2.
Toxins (Basel) ; 15(1)2023 01 06.
Artículo en Inglés | MEDLINE | ID: mdl-36668868

RESUMEN

The estrogenic mycotoxin zearalenone (ZEN) is a common contaminant of animal feed. Effective strategies for the inactivation of ZEN in feed are required. The ZEN-degrading enzyme zearalenone hydrolase ZenA (EC 3.1.1.-, commercial name ZENzyme®, BIOMIN Holding GmbH, Getzersdorf, Austria) converts ZEN to hydrolyzed ZEN (HZEN), thereby enabling a strong reduction in estrogenicity. In this study, we investigated the efficacy of ZenA added to feed to degrade ZEN in the gastrointestinal tract of three monogastric animal species, i.e., pigs, chickens, and rainbow trout. For each species, groups of animals received (i) feed contaminated with ZEN (chickens: 400 µg/kg, pigs: 200 µg/kg, rainbow trout: 2000 µg/kg), (ii) feed contaminated with ZEN and supplemented with ZenA, or (iii) uncontaminated feed. To investigate the fate of dietary ZEN in the gastrointestinal tract in the presence and absence of ZenA, concentrations of ZEN and ZEN metabolites were analyzed in digesta of chickens and rainbow trout and in feces of pigs. Upon ZenA administration, concentrations of ZEN were significantly decreased and concentrations of the degradation product HZEN were significantly increased in digesta/feces of each investigated animal species, indicating degradation of ZEN by ZenA in the gastrointestinal tract. Moreover, upon addition of ZenA to the diet, the concentration of the highly estrogenic ZEN metabolite α-ZEL was significantly reduced in feces of pigs. In conclusion, ZenA was effective in degrading ZEN to HZEN in the gastrointestinal tract of chickens, pigs, and rainbow trout, and counteracted formation of α-ZEL in pigs. Therefore, ZenA could find application as a ZEN-degrading feed additive for these animal species.


Asunto(s)
Micotoxinas , Oncorhynchus mykiss , Zearalenona , Porcinos , Animales , Zearalenona/metabolismo , Oncorhynchus mykiss/metabolismo , Pollos/metabolismo , Tracto Gastrointestinal/metabolismo , Alimentación Animal/análisis
3.
Food Chem Toxicol ; 158: 112719, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34843867

RESUMEN

The impact of the Fusarium-derived metabolites beauvericin, enniatin B and B1 (EB) alone or in combination with deoxynivalenol (DON) was investigated in 28-29 days old weaning piglets over a time period of 14 days. The co-application of EB and DON (EB + DON) led to a significant decrease in the weight gain of the animals. Liver enzyme activities in plasma were significantly decreased at day 14 in piglets receiving the EB + DON-containing diet compared to piglets receiving the control diet. All mycotoxin-contaminated diets led to moderate to severe histological lesions in the jejunum, the liver and lymph nodes. Shotgun metagenomics revealed a significant effect of EB-application on the gut microbiota. Our results provide novel insights into the harmful impact of emerging mycotoxins alone or with DON on the performance, gut health and immunological parameters in pigs.


Asunto(s)
Depsipéptidos/toxicidad , Microbioma Gastrointestinal/genética , Tricotecenos/toxicidad , Aumento de Peso/efectos de los fármacos , Animales , Ingestión de Alimentos/efectos de los fármacos , Fusarium/metabolismo , Microbioma Gastrointestinal/efectos de los fármacos , Intestinos/efectos de los fármacos , Intestinos/patología , Hígado/efectos de los fármacos , Hígado/enzimología , Hígado/patología , Porcinos , Destete
4.
J Agric Food Chem ; 66(39): 10188-10192, 2018 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-30207714

RESUMEN

The aim of the present study was to investigate the bioavailability of quercetin from onion bulb (OB) and onion skin (OS) extracts in ruminants. Three non-lactating cows equipped with a permanent rumen fistula intraruminally received equimolar amounts of quercetin as either aglycone, rutin, or OB or OS extract, respectively, at a dose of 50 mg of quercetin equivalents/kg of body weight. Blood samples were drawn before and frequently within the 24 h period after application of the respective substance. Quercetin and quercetin metabolites with an intact flavonol structure (kaempferol, isorhamnetin, and tamarixetin) were analyzed in plasma samples by high-performance liquid chromatography with fluorescence detection. All quercetin sources administered resulted in a fast increase of the plasma concentrations of quercetin and total flavonols (sum of quercetin and its metabolites), followed by a rapid decline, whereby significant higher concentrations occurred with OB extract and rutin compared to quercetin aglycone and OS extract, respectively. The results clearly demonstrate a higher systemic availability of quercetin from OB extract and rutin. Taken together, OB extract with a high content of quercetin glucosides is an interesting source for the application of quercetin to ruminants.


Asunto(s)
Bovinos/metabolismo , Cebollas/química , Extractos Vegetales/metabolismo , Quercetina/metabolismo , Rumen/metabolismo , Animales , Disponibilidad Biológica , Bovinos/sangre , Cromatografía Líquida de Alta Presión , Extractos Vegetales/sangre , Quercetina/sangre
5.
PLoS One ; 11(7): e0159428, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27427946

RESUMEN

Green tea catechins have various potential health benefits in humans including anti-inflammatory, anti-oxidative and hepato-protective effects. If present in the circulation, they might have similar effects in ruminants, which are exposed to oxidative stress and fatty liver disease such as dairy cows during the periparturient phase. However, the bioavailability of a substance is a prerequisite for any post absorptive effect in vivo. This study aimed to investigate the appearance of catechins from a green tea extract (GTE) in cattle plasma after intraruminal and intraduodenal administration because absorption is of major importance regarding the bioavailability of catechins. The studies were performed in 5 rumen-fistulated non-lactating heifers and 6 duodenally fistulated lactating dairy cows, respectively, equipped with indwelling catheters placed in a jugular vein. The GTE was applied intraruminally (10 and 50 mg/kg BW, heifers) or duodenally (10, 20 and 30 mg/kg BW, dairy cows) in a cross-over design with a 2 d washout period between different dosages. Blood samples were drawn following the GTE administration at various pre-defined time intervals. The concentration of the major GTE catechins (gallocatechin, epigallocatechin, catechin, epicatechin, epigallocatechin-gallate, epicatechin-gallate) in plasma samples were analysed by HPLC with electrochemical detection. Irrespective of the dose, almost none of the catechins originally contained in the GTE were detected in plasma samples after intraruminal application. In contrast, intraduodenal administration of GTE resulted in increased plasma concentrations of epicatechin, epigallocatechin, epigallocatechin gallate in a dose-dependent manner. Thus, we can conclude that intraruminally or orally administered catechins are intensively metabolized by ruminal microorganisms.


Asunto(s)
Catequina/análogos & derivados , Catequina/farmacocinética , Té/química , Animales , Disponibilidad Biológica , Catéteres de Permanencia , Bovinos , Cromatografía Líquida de Alta Presión , Fístula del Sistema Digestivo , Duodeno/metabolismo , Femenino , Absorción Gastrointestinal/fisiología , Venas Yugulares , Extractos Vegetales/química , Extractos Vegetales/farmacocinética , Rumen/metabolismo
6.
J Nutr Biochem ; 26(12): 1660-3, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26432773

RESUMEN

Exogenous factors such as food components including the flavonoid quercetin are suspected to influence micro RNA (miRNA) concentrations and thus possibly target enzymes involved in xenobiotic metabolism. This study therefore investigates the influence of orally administered quercetin on hepatic miRNA and the identification of enzyme target mRNAs relevant in drug metabolism. Male Wistar rats (n=16) were fed either a diet without (C) or with (Q) the addition of 100-ppm quercetin for 7 weeks and subsequently euthanized at the end of the dark phase. To avoid strong effects of food deprivation on hepatic metabolism, food was not removed until 5 h prior to the procedure. Liver was immediately dissected and snap-frozen in liquid nitrogen. Concentrations of 352 hepatic miRNA were measured in pool samples of each dietary group (n=8) using the RT(2) miRNA PCR Array System. Differential expression of miRNAs was assumed with fold changes ≥3. Target genes of differentially expressed miRNAs were identified using the database TargetScan. Because rno-miR-125b-3p showed the most prominent fold-change (-9) we further analyzed the expression of its top predicted target gene gamma-glutamyl hydrolase (GGH) by quantitative real-time PCR using hypoxanthine phosphoribosyltransferase 1 (hprt1) as endogenous control. Compared to controls, 23 miRNAs were differentially expressed in rats fed quercetin. A ninefold reduction in hepatic miRNA rno-miR-125b-3p was paralleled by significant induction of GGH mRNA in liver of quercetin fed rats. Because increased GGH expressions were repeatedly associated with resistance to methotrexate, concomitant intake with quercetin should be monitored carefully.


Asunto(s)
Dieta , Regulación Enzimológica de la Expresión Génica , Hígado/metabolismo , MicroARNs/metabolismo , Quercetina/química , gamma-Glutamiltransferasa/metabolismo , Animales , Resistencia a Medicamentos , Hipoxantina Fosforribosiltransferasa/metabolismo , Hígado/patología , Masculino , Metotrexato/química , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Xenobióticos/química
7.
Biomed Res Int ; 2014: 748742, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24847478

RESUMEN

Treatment goals of diabetes mellitus type 2 (DMT2) include glycemic control and reduction of nonglycemic risk factors, for example, dyslipidemia. Quercetin, a plant-derived polyphenol, often discussed for possible antidiabetic effects, was investigated for acute postprandial glucose- and lipid-lowering effects in healthy growing pigs. Male pigs (n=16, body weight=BW 25-30 kg) were fed flavonoid-poor grain-based meals without (GBM) or with quercetin (GBMQ). In a first experiment, postprandial plasma concentrations of glucose, nonesterified fatty acids (NEFA), and triacylglycerols were analyzed in 8 pigs receiving 500 g of either GBM or GBMQ (10 mg/kg BW) in a cross-over design. Blood samples were collected before, and up to 5 h every 30 min, as well as 6 and 8 h after the feeding. In the second experiment, 2 h after ingestions of 1000 g of either GBM or GBMQ (50 mg/kg BW) animals were sacrificed; gastric content was collected and analyzed for dry matter content. Quercetin ingestion reduced postprandial glucose, NEFA, and TG concentration, but two hours after ingestion of the meal no effect on gastric emptying was observed. Our results point to inhibitory effects of quercetin on nutrient absorption, which appear not to be attributable to delayed gastric emptying.


Asunto(s)
Alimentación Animal , Glucemia/química , Grano Comestible , Lípidos/química , Quercetina/administración & dosificación , Ciencias de la Nutrición Animal , Animales , Área Bajo la Curva , Peso Corporal , Vaciamiento Gástrico/efectos de los fármacos , Hipoglucemiantes/química , Masculino , Periodo Posprandial , Porcinos
8.
Artículo en Inglés | MEDLINE | ID: mdl-23724859

RESUMEN

Previous studies indicate that the intestinal absorption of the nephrotoxic mycotoxin ochratoxin A (OTA) occurs mainly through passive diffusion of the undissociated form. However, several in vitro studies have shown that OTA is partly re-secreted into the intestinal lumen by the multi-drug resistance associated protein (MRP2) and breast cancer resistance protein (BRCP). In vitro studies using Caco-2 cells have shown that some polyphenols (quercetin, genistein, resveratrol) may impair OTA efflux through competitive inhibition of MRP2, possibly resulting in an increased systemic availability of OTA. Among the tested polyphenols, quercetin showed the highest potential as efflux pump inhibitor; therefore, the aim of the present in vivo study was to investigate possible effects of quercetin on the toxicokinetics of OTA in rats. Eighteen growing male F344 Fisher rats (body weight: 200 g) were allocated to two dietary treatments consisting of (1) a commercial, flavonoid-free balanced diet containing 10 mg OTA/kg derived from inoculated wheat and (2) the same diet supplemented with 100 mg quercetin/kg. The animals were fed restrictively (~0.7 of ad libitum intake, 13 g/d) to avoid differences in OTA intake. Animals were kept in metabolism cages to facilitate total urine and faeces collection. After 6 days on trial, rats were euthanised and blood, liver, kidney, muscle and brain samples were taken from each animal. Faeces, urine and tissue samples were analysed for OTA and its main metabolite ochratoxin α by high-performance liquid chromatography using fluorescence detection. Quercetin supplementation had no effect (P > 0.05) on feed consumption, OTA-intake, water intake and body weight gain. Faecal and urinary excretion of OTA and ochratoxin α and concentrations of OTA in all tissues were not affected by quercetin supplementation. Based on the total excretion and tissue concentrations of OTA, it is concluded that the polyphenol quercetin has no impact on the toxicokinetics of OTA in vivo.


Asunto(s)
Micotoxinas/farmacocinética , Micotoxinas/toxicidad , Ocratoxinas/farmacocinética , Ocratoxinas/toxicidad , Quercetina/farmacología , Animales , Masculino , Ratas , Ratas Endogámicas F344 , Distribución Tisular
9.
J Med Food ; 16(4): 312-7, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23514230

RESUMEN

Polyphenols, including green tea catechins, are secondary plant compounds often discussed in the context of health-promoting potential. Evidence for such effects is mainly derived from epidemiological and cell culture studies. The aim of the present study was to investigate antidiabetic, antiadipogenic, and anti-inflammatory effects at nonpharmacological doses in an obese diabetic mouse model that exerts early relevant clinical signs of non-insulin-dependent diabetes mellitus. Female db/db mice received a flavonoid-poor diet either without additive, with rosiglitazone (RSG, 0.02 g/kg diet), or with green tea extract (low-dose green tea extract [LGTE] and high-dose green tea extract [HGTE], 0.1 and 1 g/kg diet). Food and water were freely available. The body weight was monitored weekly. Blood was sampled (12-h fasted) from the tail vein on day 28 and analyzed for glucose, cholesterol, triacylglycerol, nonesterified fatty acids, insulin, adiponectin, and soluble intercellular adhesion molecule-1 (sICAM-1). Blood glucose was also analyzed on day 14. Furthermore, sICAM-1 release was investigated in tumor necrosis factor alpha-stimulated EAhy926 cells. After 14 days, fasting glycemia was improved by RSG or HGTE supplementation compared to controls. However, at the end of the study (day 28), only RSG exhibited glucose-lowering effects and induced plasma adiponectin concentrations, paralleled by higher body weight gain and reduced periuterine fat pads compared to controls. However, only GTE treatment reduced sICAM-1 release in vitro and in vivo. Nonpharmacological HGTE supplementation in db/db mice caused (1) no adiponectin-inducing or antiadipogenic effects, (2) reduced sICAM-1 release, thereby potentially exerting anti-inflammatory effects in the progressive diabetic state, and (3) a transient improvement in glycemia.


Asunto(s)
Glucemia/metabolismo , Camellia sinensis/química , Catequina/uso terapéutico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Inflamación/prevención & control , Obesidad/tratamiento farmacológico , Fitoterapia , Adiponectina/sangre , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/metabolismo , Animales , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Catequina/farmacología , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/patología , Suplementos Dietéticos , Femenino , Flavonoides/administración & dosificación , Hiperglucemia/tratamiento farmacológico , Hiperglucemia/metabolismo , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Inflamación/metabolismo , Molécula 1 de Adhesión Intercelular/sangre , Ratones , Ratones Noqueados , Ratones Obesos , Obesidad/sangre , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Rosiglitazona , Tiazolidinedionas/farmacología , Tiazolidinedionas/uso terapéutico , Factor de Necrosis Tumoral alfa , Aumento de Peso/efectos de los fármacos
10.
Eur J Nutr ; 52(1): 281-8, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22366739

RESUMEN

PURPOSE: To investigate the influence of dietary proteins (casein, soy protein) and skimmed milk on the plasma kinetics of green tea (GT) catechins. METHODS: In a randomized cross-over design with one-week intervals, 24 healthy normal-weight women consumed a test drink containing 1.75 g GT extract with or without the addition of different proteins. Treatments were GT (control), GT with skimmed milk (GT + M), GT with caseinate (GT + CS), or GT with soy protein (GT + S). Venous blood samples were taken before and several times during a period of 4.5 h after consumption of the test drink. Plasma concentrations of catechins were analyzed by HPLC with electrochemical detection. RESULTS: Compared to control, consumption of GT with milk, caseinate, or soy protein significantly reduced the bioavailability (mean area under the plasma concentration-time curve) of total catechins (means ± SEM; GT + M, 87 ± 5%; GT + CS, 79 ± 5%; GT + S, 88 ± 4%), epigallocatechin gallate (GT + M, 68 ± 4%; GT + CS, 63 ± 5%; GT + S, 76 ± 5%), and epicatechin gallate (GT + M, 68 ± 5%; GT + CS, 66 ± 6%; GT + S, 77 ± 6%), while the bioavailability of non-galloylated catechins such as epigallocatechin (GT + M, 134 ± 9%; GT + CS, 118 ± 9 %; GT + S, 123 ± 8%) and epicatechin (GT + M, 125 ± 10%; GT + CS, 114 ± 11%; GT + S, 110 ± 8%) significantly increased. No significant differences in bioavailability of GT catechins were observed between the treatments GT + M, GT + CS, or GT + S. CONCLUSION: Simultaneous ingestion of dietary proteins reduces the bioavailability of galloylated catechins from GT in humans.


Asunto(s)
Antioxidantes/farmacocinética , Catequina/análogos & derivados , Proteínas en la Dieta/administración & dosificación , Té/química , Adulto , Antioxidantes/administración & dosificación , Disponibilidad Biológica , Índice de Masa Corporal , Catequina/administración & dosificación , Catequina/farmacocinética , Cromatografía Líquida de Alta Presión , Estudios Cruzados , Femenino , Humanos , Encuestas y Cuestionarios , Adulto Joven
11.
Plant Foods Hum Nutr ; 67(4): 377-83, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23135898

RESUMEN

The aim of this study was to investigate possible blood glucose-lowering effects of plant extracts in vivo for which prior to this a peroxisome proliferator-activated receptor-γ activity in vitro was observed. The ability of extracts of winter savory, purple coneflower, buckwheat and black elder to dose-dependently activate peroxisome proliferator-activated receptor-γ was determined in a reporter gene assay in COS-1 cells. For evaluation of glucose-lowering effects in vivo, db/db mice were fed a diet containing either rosiglitazone (0.02 g/kg diet, positive control) or one of the plant extracts (0.1 and 1 g/kg diet) for four weeks. Apart from glucose, insulin, triacylglycerols, non-esterified fatty acids, cholesterol and adiponectin were determined in plasma. All plant extracts showed a dose-dependent peroxisome proliferator-activated receptor-γ-activating effect in vitro. In db/db mice none of the plant extracts exerted glucose-lowering effects at the used dosages compared to rosiglitazone. Non-esterified fatty acids, triacylglycerols, cholesterol, insulin and adiponectin in plasma were not altered by the plant extracts as well. Although dose-dependent peroxisome proliferator-activated receptor-γ activity could be shown in COS-1 cells, the experiments in db/db mice lacked to confirm any anti-diabetic effect of the plant extracts in vivo and emphasizes the importance of verifying cell culture data using an appropriate in vivo model.


Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Echinacea/química , Fagopyrum/química , PPAR gamma/efectos de los fármacos , Sambucus nigra/química , Satureja/química , Adiponectina/sangre , Animales , Glucemia/efectos de los fármacos , Peso Corporal , Células COS , Chlorocebus aethiops , Colesterol/sangre , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Tipo 2/fisiopatología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Femenino , Insulina/sangre , Ratones , Extractos Vegetales/química , Extractos Vegetales/farmacología , Rosiglitazona , Tiazolidinedionas/farmacología , Triglicéridos/sangre
12.
Xenobiotica ; 42(5): 477-82, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22188411

RESUMEN

We investigated acute effects and effects after chronic intake of the orally administered flavonol quercetin on pharmacokinetics of salicylamide metabolites (SAM) after oral administration of salicylamide in pigs. Salicylamide (8 mg/kg body weight) was orally administered to seven pigs either without or with quercetin (10 mg/kg body weight). Additionally, salicylamide was administered to five pigs that had received a diet supplemented with the flavonol for 1 week. Daily quercetin intake was 10 mg/kg in these animals. Co-ingestion of quercetin with the drug did not alter area under the concentration-time curve (AUC(0→∞)), time to achieve maximum plasma concentration (t(max)), mean residence time (MRT) or half-life (t(1/2)) of SAM. However, maximum plasma concentration (c(max)) of SAM was lower when quercetin was administered concomitantly. After quercetin pre-treatment for 1 week AUC(0→∞), t(1/2) and MRT of SAM were decreased, while other parameters investigated were not affected. Co-ingestions and dietary pre-treatment with quercetin influenced SAM metabolism after oral salicylamide intake. But effects seen after acute concomitant intake are rather explained by induced salicylamide excretion from the intestinal mucosa, whereas quercetin pre-treatment seemed to induce hepatic enzymes involved in phase-II metabolism and thereby enhanced elimination of SAM.


Asunto(s)
Fase II de la Desintoxicación Metabólica , Quercetina/administración & dosificación , Quercetina/farmacología , Salicilamidas/sangre , Salicilamidas/metabolismo , Sus scrofa/sangre , Administración Oral , Animales , Dieta , Conducta Alimentaria/efectos de los fármacos , Masculino , Salicilamidas/administración & dosificación , Salicilamidas/farmacocinética
13.
Bioorg Med Chem ; 19(6): 1907-14, 2011 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-21345682

RESUMEN

In general, drugs containing amidines suffer from poor oral bioavailability and are often converted into amidoxime prodrugs to overcome low uptake from the gastrointestinal tract. The esterification of amidoximes with amino acids represents a newly developed double prodrug principle creating derivatives of amidines with both improved oral availability and water solubility. N-valoxybenzamidine (1) is a model compound for this principle, which has been transferred to the antiprotozoic drug pentamidine (8). Prodrug activation depends on esterases and mARC and is thus independent from activation by P450 enzymes. Therefore, drug-drug interactions or side effects will be minimized. The synthesis of these two compounds was established, and their biotransformation was studied in vitro and in vivo. Bioactivation of N-valoxybenzamidine (1) and N,N'-bis(valoxy)pentamidine (7) via hydrolysis and reduction has been demonstrated in vitro with porcine and human subcellular enzyme preparations and the mitochondrial Amidoxime Reducing Component (mARC). Moreover, activation of N-valoxybenzamidine (1) by porcine hepatocytes was studied. In vivo, the bioavailability in rats after oral application of N-valoxybenzamidine (1) was about 88%. Similarly, N,N'-bis(valoxy)pentamidine (7) showed oral bioavailability. Analysis of tissue samples revealed high concentrations of pentamidine (8) in liver and kidney.


Asunto(s)
Amidinas/química , Oximas/química , Profármacos/síntesis química , Valina/química , Animales , Benzamidinas/síntesis química , Benzamidinas/química , Benzamidinas/farmacocinética , Ésteres , Humanos , Microsomas Hepáticos/metabolismo , Oxidorreductasas/antagonistas & inhibidores , Oxidorreductasas/genética , Oxidorreductasas/metabolismo , Pentamidina/síntesis química , Pentamidina/química , Pentamidina/farmacocinética , Profármacos/química , Profármacos/farmacocinética , Ratas , Proteínas Recombinantes/antagonistas & inhibidores , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Porcinos
14.
Eur J Pharm Sci ; 41(1): 16-22, 2010 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-20580672

RESUMEN

To study possible insulin sensitizing, anti-inflammatory and anti-oxidative effects of the flavonol quercetin, rats were fed a high-fat diet (19%, w/w) with (HFQ) or without (HF) 0.03% quercetin or a flavonoid-poor low-fat (5%, w/w) maintenance diet (LF) over 4 weeks. Body weight was measured weekly, and plasma concentrations of adiponectin, leptin, insulin, glucose, triacylglycerols, total cholesterol, as well as of markers of inflammation and oxidative stress were measured (12h fasted) at the end of the feeding period. Adiponectin and peroxisome-proliferator-activated-receptor (PPAR)-gamma mRNA were measured in adipose tissue (WAT) by real-time RT-PCR. PPAR-gamma transactivation was investigated by means of a reporter gene assay. HF feeding resulted in elevated fasted plasma glucose concentrations, while HFQ did not differ from LF feeding. In the HFQ group plasma concentrations and WAT mRNA levels of adiponectin were elevated compared with the HF group, however, PPAR-gamma mRNA concentration in WAT was decreased (HFQ vs. HF). Compared to both other groups quercetin feeding significantly reduced oxidative stress, measured by plasma 8-iso-PGF(2alpha), while body weight gain, body composition and plasma leptin levels were not affected. Neither quercetin nor its metabolites induced PPAR-gamma-mediated transactivation in vitro. Adiponectin stimulating effects of quercetin are PPAR-gamma-independent and prevent impairment of insulin sensitivity without affecting body weight and composition.


Asunto(s)
Adiponectina/metabolismo , PPAR gamma/metabolismo , Quercetina/farmacología , Adiponectina/sangre , Animales , Glucemia/análisis , Células Cultivadas , Colesterol/sangre , Cromatografía Líquida de Alta Presión , Insulina/sangre , Leptina/sangre , Masculino , Ratones , Estrés Oxidativo , PPAR gamma/genética , ARN Mensajero/genética , Ratas , Ratas Wistar , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Triglicéridos/sangre
15.
Eur J Pharm Sci ; 38(5): 519-24, 2009 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-19804821

RESUMEN

The influence of the dietary flavonol quercetin on the pharmacokinetics of the HMG-CoA reductase inhibitor simvastatin was investigated in pigs. Simvastatin (0.25mg/kg body weight) was orally administered to six pigs either without or with quercetin (10mg/kg). In addition, simvastatin was administered to three pigs that had received a diet supplemented with the flavonol over a period of 1 week. Daily quercetin intake was 10mg/kg in these animals. Co-ingestion of quercetin with the statin did not alter area under the concentration time curve (AUC(0-->infinity)), time to achieve maximum plasma concentration (t(max)) or half-life (t(1/2)) of simvastatin. However, there was a trend towards a reduction of the maximum plasma concentration (C(max)) of simvastatin when quercetin was administered concomitantly (P=0.06). As compared to controls, AUC(0-->infinity) of simvastatin was significantly decreased after feeding the quercetin-supplemented diet for 1 week. The plasma ratio of simvastatin and its acid metabolite was neither altered by the concomitant quercetin ingestion nor by feeding of the flavonol over a period of 1 week. We conclude that chronic ingestion of high doses of the flavonol quercetin will decrease the bioavailability of simvastatin to a significant extent.


Asunto(s)
Flavonoles/administración & dosificación , Flavonoles/farmacocinética , Interacciones Alimento-Droga/fisiología , Quercetina/administración & dosificación , Quercetina/farmacocinética , Simvastatina/farmacocinética , Animales , Disponibilidad Biológica , Estudios Cruzados , Flavonoles/sangre , Masculino , Quercetina/sangre , Simvastatina/sangre , Porcinos
16.
Bioorg Med Chem Lett ; 19(7): 1960-5, 2009 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-19250826

RESUMEN

A novel series of matriptase inhibitors based on previously identified tribasic 3-amidinophenylalanine derivatives was prepared. The C-terminal basic group was replaced by neutral residues to reduce the hydrophilicity of the inhibitors. The most potent compound 22 inhibits matriptase with a K(i) value of 0.43 nM, but lacks selectivity towards factor Xa. By combination with neutral N-terminal sulfonyl residues several potent thrombin inhibitors were identified, which had reduced matriptase affinity.


Asunto(s)
Amidinas/química , Fenilalanina/química , Serina Endopeptidasas/química , Inhibidores de Serina Proteinasa/química , Sulfonamidas/química , Administración Oral , Amidinas/farmacología , Animales , Factor Xa/metabolismo , Inhibidores del Factor Xa , Fenilalanina/análogos & derivados , Fenilalanina/farmacología , Ratas , Serina Endopeptidasas/metabolismo , Inhibidores de Serina Proteinasa/farmacología , Sulfonamidas/farmacología , Trombina/antagonistas & inhibidores , Trombina/metabolismo
17.
Diabetes Metab Res Rev ; 25(2): 185-94, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19219861

RESUMEN

BACKGROUND: High dietary intake of saturated fat impairs insulin sensitivity and lipid metabolism. The influence of fatty acid chain length, however, is not yet fully understood, but evidence exists for different effects of saturated long-chain (LC) versus saturated medium-chain (MC) fatty acids (FA). METHODS: To investigate the effects of the FA chain length, male Wistar rats were fed high-fat diets containing triacylglycerols composed of either MC- or LCFA for 4 weeks; rats fed maintenance diet served as a control. The animals underwent euglycemic hyperinsulinemic clamping or oral metabolic tolerance testing respectively; enzyme activities of mitochondrial (EC2.3.1.21 carnitine palmitoyl transferase) and peroxisomal (EC1.3.3.6 acyl-CoA oxidase) FA oxidation were measured in liver and muscle. RESULTS: LCFA consumption resulted in higher fasted serum insulin and glucose concentrations compared to controls, while MCFA-fed animals did not differ from controls. Insulin sensitivity was reduced by 30% in the LCFA group while the MCFA group did not differ from controls. Feeding MCFA resulted in the controls' lowered fasted and post-prandial triacylglycerol concentration compared to LCFA, while triacylglycerol concentrations in muscle were higher in both high-fat groups compared to controls. No diet-induced changes were found in acyl-CoA oxidase (ACO) activity (liver and muscle), while LCFA feeding significantly raised carnitine palmitoyltransferase activity. CONCLUSIONS: The chain length of saturated fatty acids in isocaloric diets affects insulin sensitivity, lipid metabolism and mitochondrial fatty acid oxidation without influencing body weight. While dietary LCFA clearly impair insulin sensitivity and lipid metabolism, MCFA seem to protect from lipotoxicity and subsequent insulin resistance without caloric restriction.


Asunto(s)
Grasas de la Dieta , Ácidos Grasos no Esterificados/uso terapéutico , Ácidos Grasos/uso terapéutico , Resistencia a la Insulina/fisiología , Síndrome Metabólico/prevención & control , Alimentación Animal , Animales , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Dieta , Metabolismo Energético , Insulina/sangre , Masculino , Ratas , Ratas Wistar
18.
Phytother Res ; 23(9): 1316-25, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19172665

RESUMEN

Thiazolidinediones (TZDs) are insulin sensitizing drugs used to treat type 2 diabetes. The primary target of the TZDs is the peroxisome proliferator-activated receptor (PPAR) gamma, a key regulator of adipogenesis and glucose homeostasis. Currently prescribed TZDs are full PPARgamma agonists, and their use is associated with several side effects. Partial PPARgamma agonists appear to be associated with fewer side effects but may still confer the desired insulin sensitizing action. Extracts from common medicinal/food plants were tested in a screening platform comprising a series of bioassays, including tests for PPARgamma, alpha and delta transactivation, adipocyte differentiation and insulin-stimulated glucose uptake, allowing identification of plants containing potentially interesting PPAR agonists. Twenty-two plant extracts out of 133 were found to increase insulin-stimulated glucose uptake and 18 extracts were found to activate PPARgamma, 3 to activate PPARalpha and gamma, 6 to activate PPARdelta and gamma, and 9 to activate PPARgamma, alpha and delta. Among the 24 different plant species tested in the platform, 50% were shown to contain compounds capable of activating PPARgamma and stimulating insulin-dependent glucose uptake with no or little effect on adipocyte differentiation warranting further studies and characterization.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Glucosa/metabolismo , Hipoglucemiantes/farmacología , Receptores Activados del Proliferador del Peroxisoma/metabolismo , Extractos Vegetales/farmacología , Tiazolidinedionas/farmacología , Células 3T3-L1 , Animales , Humanos , Insulina/farmacología , Ratones , Receptores Activados del Proliferador del Peroxisoma/agonistas , Activación Transcripcional
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