3 research outputs found
Effect of grape-seed polyphenols in endothelial dysfunction and hypertension associated with metabolic syndrome in cafeteria diet-fed rats
Els polifenols presents a la dieta sāhan estudiat extensament pel seus efectes positius sobre diferents components de la siĢndrome metaboĢlica (MetS). En aquesta Tesi, es va proposar avaluar els efecte beneficioĢs dels polifenols de pinyol de raiĢm sobre la disfuncioĢ endotelial i la hipertensioĢ (HTN) associada a la MetS, utilitzant el model de dieta de cafeteria com a model de MetS. Els resultats mostraren que una dosi aguda de 375 mg/Kg dāun extracte de polifenols de baix pes molecular de pinyol de raiĢm (LM-GSPE) 6 hores post- administracioĢ va ser la meĢs efectiva per a baixar la pressioĢ arterial en aquest model de HTN induiĢt per dieta. En questa millora va ser veure la implicacioĢ de la Sirtuina-1 (Sirt-1) aixiĢ com bloqueig del Sistema Renina-Angiotensina-Aldosterona (SRAA), que com a consequĢeĢncia va millorar la funcioĢ endotelial. Per una altra banda, es va veure com alguns dels polifenols meĢs abundants del LM-GSPE, com lā(-)-epicatequina, la (+)-catequina o lāaĢcid gaĢlĀ·lic, actuaren com a moduladors de la funcioĢ endotelial. A meĢs a meĢs, es demostraĢ que a una baixa dosi de 7 mg/Kg, lāaĢcid gaĢlĀ·lic, lāaĢcid fenoĢlic meĢs abundant de lāextracte, baixava la pressioĢ arterial de manera aguda en rates espontaĢniament hipertenses, millorant a meĢs la funcioĢ endotelial a traveĢs del bloqueig el SRAA, com succeiĢ amb LM-GSPE. No obstant aixoĢ, i al contrari que LM-GSPE, es trobaren nivells elevats de bradiquinina i descartaĢ la implicacioĢ de les sirtuiĢnes en aquest efecte antihipertensiu. Finalment, es demostraĢ que la administracioĢ croĢnica de polifenols de pinyol de raiĢm atenuaren el desenvolupament de HTN aixiĢ com dāaltres factors de risc associats amb la MetS. Per tant, es proposen els polifenols de pinyol de raiĢm, incloĢs lāaĢcid gaĢlĀ·lic, com a bons candidats per a ser utilitzats en el tractament de la HTN associada a la MetS.Los polifenoles presentes en la dieta se han estudiado extensivamente por sus efectos positivos sobre diferentes componentes del siĢndrome metaboĢlico (MetS). En esta Tesis, se propuso evaluar el efecto positivo de los polifenoles de pepita de uva sobre la disfuncioĢn endotelial y la hipertensioĢn (HTN) asociada al MetS, utilizando el modelo de dieta de cafeteriĢa como modelo de HTN asociada al MEtS. Los resultados mostraron que la una dosis aguda de 375 mg/Kg de un extracto de polifenoles de bajo peso molecular de pepita de uva (LM-GSPE) 6 horas post-administracioĢn fue la maĢs efectiva para reducir la presioĢn arterial en este modelo de HTN inducido por dieta. La implicacioĢn de la Sirtuina-1 (Sirt-1) y el bloqueo del Sistema Renina-Angiotensina-Aldosterona (SRAA), y por consiguiente, la mejora de la funcioĢn endotelial, fueron demostrados. Por otro lado, se observoĢ como algunos de los polifenoles maĢs abundantes del LM-GSPE, como la (-)- epicatequina, la (+)-catequina o el aĢcido gaĢlico, actuaron como moduladores de la funcioĢn endotelial. AdemaĢs se demostroĢ que el aĢcido gaĢlico, el aĢcido fenoĢlico maĢs abundante del extracto, a una dosis baja de 7 mg/Kg bajaba la presioĢn arterial de manera aguda en ratas espontaĢneamente hipertensas, mejorando ademaĢs la funcioĢn endotelial mediante el bloqueo del SRAA, como sucediĢa con LM-GSPE. No obstante, y al contrario que el extracto, el aĢcido gaĢlico aumentoĢ la concentracioĢn de bradiquinina en plasma y ademaĢs no se vio implicacioĢn de Sirt-1 en el efecto antihipertensivo. Finalmente se demostroĢ que la administracioĢn croĢnica de polifenoles de pepita de uva atenuĢa la elevacioĢn de la presioĢn arterial y el empeoramiento de otros factores de riesgo asociados al MetS. Por tanto, se proponen los polifenoles de pepita de uva, incluido el aĢcido gaĢlico, como buenos agentes para el control de la presioĢn arterial asociada al MetS.Dietary polyphenols have been widely studied for their health effects on different components of metabolic syndrome (MetS). In the present Thesis it was aimed to evaluate the beneficial effect of grape-seed polyphenols on endothelial dysfunction and hypertension (HTN) associated with MetS using cafeteria diet-fed rats as a model of MetS. Results showed that an acute dose of 375 mg/kg of a low-molecular grape seed extract (LM- GSPE) 6h after-administration was the most effective in lowering BP in this diet induced HTN model. This improvement was seen to be mediated by Sirtuin-1 (sirt-1) and blockage of the Renin-Angiotensin-Aldosterone System (RAAS) at reducing Ang I and in turns Ang II plasma levels, and as a consequence, improving the endothelial function. Otherwise, some of the principal polyphenol forms in LM-GSPE, such as (-)-epicatechin and (+)-catechin, also showed to act as modulators of endothelial dysfunction. Furthermore, it was demonstrated that at a low dose of 7mg/Kg of gallic acid, the main phenolic acid present in LM-GSPE, acutely reduced BP in spontaneously hypertensive rats, improving endothelial dysfunction by blockage of the RAAS as LM-GSPE. However, gallic acid in contrast to LM-GSPE increased plasma bradykinin levels and not involved Sirt-1 in its antihypertensive effect. Finally it was demonstrated that a chronic administration of grape-seed polyphenols attenuated the development of HTN and other cardiometabolic risk factors associated with MetS. Therefore, grape-seed polyphenols, including gallic acid, are proposed as good candidates to be used as as BP lowering agents in HTN associated with MetS
Phosphatidylserine positive microparticles improve hemostasis in in-vitro hemophilia A plasma models
Circulating microparticles (MPs) are procoagulant due to the surface containing phosphatidylserine (PS), which facilitates coagulation. We investigated if MPs improve hemostasis in HA plasma models. MPs isolated from pooled normal human plasma were added to severe, moderate and mild HA plasma models (0%, 2.5%, 20% FVIII). The MPs' effect on hemostasis was evaluated by calibrated automated thrombogram (CAT) and overall hemostasis potential (OHP) assays, while fibrin structure was imaged by standard confocal, stimulated emission depletion (STED) microscopy and scanning electron microscopy (SEM). MPs partially restored thrombin generation and fibrin formation in all HA plasma models. The procoagulant effect of MPs requires PS exposure, to a less extent of contact pathway activation, but not tissue factor exposure or in vitro stimulation of MPs. MPs partially normalized the fibrin structure, and using super-resolution STED, MPs attached to fibrin were clearly resolved. In summary, our results demonstrate that PS positive MPs could improve hemostasis in HA plasma models
Phosphatidylserine positive microparticles improve hemostasis in in-vitro hemophilia A plasma models
Circulating microparticles (MPs) are procoagulant due to the surface containing phosphatidylserine (PS), which facilitates coagulation. We investigated if MPs improve hemostasis in HA plasma models. MPs isolated from pooled normal human plasma were added to severe, moderate and mild HA plasma models (0%, 2.5%, 20% FVIII). The MPs' effect on hemostasis was evaluated by calibrated automated thrombogram (CAT) and overall hemostasis potential (OHP) assays, while fibrin structure was imaged by standard confocal, stimulated emission depletion (STED) microscopy and scanning electron microscopy (SEM). MPs partially restored thrombin generation and fibrin formation in all HA plasma models. The procoagulant effect of MPs requires PS exposure, to a less extent of contact pathway activation, but not tissue factor exposure or in vitro stimulation of MPs. MPs partially normalized the fibrin structure, and using super-resolution STED, MPs attached to fibrin were clearly resolved. In summary, our results demonstrate that PS positive MPs could improve hemostasis in HA plasma models