Estudios científicos

Comparative studies of the antioxidant effects of a naturally occurring resveratrol analogue — trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene and resveratrol — against oxidation and nitration of biomolecules in blood platelets

Abstract:

The action of two phenolic compounds isolated from the bark of Yucca schidigera: trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene and its analogue — resveratrol (trans-3,4',5-trihydroxystilbene, present also in grapes and wine) on oxidative/nitrative stress induced by peroxynitrite (ONOO(-), which is strong physiological oxidant and inflammatory mediator) in human blood platelets was compared. The trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene, like resveratrol, significantly inhibited protein carbonylation and nitration (measured by enzyme-linked immunosorbent assay method) in the blood platelets treated with peroxynitrite (0.1 mM) and markedly reduced an oxidation of thiol groups of proteins (estimated with 5,5'-dithio-bis(2-nitro-benzoic acid)] or glutathione (measured by high performance liquid chromatography method) in these cells. The trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene, like resveratrol, also caused a distinct reduction of platelet lipid peroxidation induced by peroxynitrite. The obtained results indicate that in vitro trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene and resveratrol have very similar protective effects against peroxynitrite-induced oxidative/nitrative damage to the human platelet proteins and lipids. Moreover, trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene proved to be even more potent than resveratrol in antioxidative tests. We conclude that the novel tested phenolic compound — trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene isolated from Y. schidigera bark possessing Generally Recognized As Safe label given by the Food and Drug Administration and allows their human dietary use — seems to be a promising candidate for future evaluations of its antioxidative activity and may be a good candidate for scavenging peroxynitrite.

Comentarios divulgativos:

La acción de los compuestos fenólicos aislados de la corteza de Yucca schidigera: trans-3, 3 ', 5,5'-tetrahydroxy-4 '-methoxystilbene y su análogo – resveratrol (trans-3, 4' ,5-trihydroxystilbene, también presente en la uva y el vino) se comparó en las plaquetas de la sangre humana. El trans-3, 3 ', 5,5'-tetrahydroxy-4 '-methoxystilbene, como el resveratrol, inhibieron significativamente la carbonilación de proteínas y nitración (medido por el método de ensayo de inmunoabsorción ligado a enzimas) en las plaquetas de la sangre tratada con peroxinitrito (0,1 mM) y se observó una marcada reducción de la oxidación de los grupos tiol de las proteínas en estas células. El trans-3, 3 ', 5,5'-tetrahydroxy-4 '-methoxystilbene y el resveratrol, también causaron una reducción diferenciada de la peroxidación lipídica plaquetaria inducida por el peroxinitrito. Los resultados obtenidos indican que in vitro trans-3, 3', 5,5 '- tetrahydroxy-4'-methoxystilbene y el resveratrol tiene efectos protectores contra el peroxinitrito. Por otra parte, trans-3, 3 ', 5,5'-tetrahydroxy-4 '-methoxystilbene demostraron ser aún más potentes que el resveratrol en las pruebas antioxidantes. Llegamos a la conclusión de que estos compuestos fenólicos – trans-3, 3 ', 5,5'-tetrahydroxy-4 '-methoxystilbene aislados de Y. schidigera permiten su uso dietético en humanos y que parecen ser unos candidatos prometedores para futuras evaluaciones de su actividad antioxidante.