Estudios científicos
Some phenolic compounds increase the nitric oxide level in endothelial cells in vitro
Abstract:
The vasorelaxing properties of chocolate and wine might relate to the presence of phenolic compounds. One of the potential mechanisms involved is stimulation of endothelial nitric oxide (NO) production, as NO is a major regulator of vasodilatation. This study aimed to develop an in vitro assay using the hybrid human endothelial cell line EA.hy926 to rapidly screen phenolic compounds for their NO-stimulating potential. The assay was optimized, and a selection of 33 phenolics, namely, procyanidins, monomeric flavan-3-ols, flavonols, a flavone, a flavanone, a chalcone, a stilbene, and phenolic acids, was tested for their ability to enhance endothelial NO level. Resveratrol, a well-known enhancer of NO level, was included as a positive control. Of the 33 phenolics tested, only resveratrol (285% increase in NO level), quercetin (110% increase), epicatechingallate (ECg) (85% increase), and epigallocatechingallate (EGCg) (60% increase) were significant (P <or= 0.05) enhancers. Procyanidins showed a nonsignificant tendency to elevate NO level. Concentration-dependent correlations between enhanced NO level and endothelial nitric oxide synthase (eNOS) expression were demonstrated for the three polyphenols tested (resveratrol, ECg, and EGCg). Thus, an easy screening tool for change in cellular NO level was developed. Use of this assay showed that only a limited number of phenolic compounds might enhance NO level with an increased amount of eNOS enzyme as a possible contributing mechanism.
Comentarios divulgativos:
Las propiedades vasorelajantes del chocolate y del vino están relacionadas con la presencia de compuestos fenólicos. Uno de los potenciales mecanismos involucrados en la estimulación del endotelio es la producción de óxido nítrico ya que este es el mayor regulador en la vasodilatación. En este estudio se diseña un ensayo in vitro usando la línea celular híbrida Eahy926 para hacer un screening rápido de los compuesto febnólicos y su potencial para estimular al NO. Se ha observado que solo un limitado número de compuestos fenólicos aumentan el nivel de NO con un aumento de la enzima NO sintasa.
