Estudios científicos
Phosphatidylinositol-3-kinase is involved in the antihyperglycemic effect induced by resveratrol in streptozotocin-induced diabetic rats
Abstract:
Resveratrol, a polyphenolic substance found in grape skin, is proposed to account in part for the protective effect of red wine in the cardiovascular system. The aim of the present study is to investigate the action and possible mechanisms of resveratrol-produced regulation of plasma glucose in normal and diabetic rats including the animal model of streptozotocin (STZ)-induced and nicotinamide-STZ-induced (NA-STZ), and insulin-resistant diabetic rats. Resveratrol (p.o.) produced a hypoglycemic effect in a dose-dependent manner in normal and diabetic rats, and the insulin level was increased following resveratrol treatment in normal and NA-STZ diabetic rats. In insulin-deficient STZ-diabetic rats, resveratrol significantly lowered the plasma glucose 90 min after oral treatment, and the hypoglycemic effect was abolished by phosphatidyl-3-kinase (PI3K) inhibitors (LY294002 and wortmannin) which also inhibited resveratrol-induced Akt phosphorylation in soleus muscle of STZ-diabetic rats. The change in the protein expression level of glucose transporter subtype 4 (GLUT4) in the soleus muscle and phosphoenolpyruvate carboxykinase (PEPCK) in the liver of STZ-diabetic rats treated with resveratrol (3 mg/kg, p.o.) for 7 days was examined. Resveratrol normalized hepatic PEPCK expression and increased GLUT4 expression in the soleus muscle of STZ-diabetic rats. The results indicate that the mechanisms contributing to the hypoglycemic effect of resveratrol include insulin-dependent and insulin-independent pathway, and PI3K-Akt-signaling was involved in the latter mechanism to enhance glucose uptake in skeletal muscle.
Comentarios divulgativos:
El resveratrol, una sustancia fenólica que aparece en la piel de la uva, es en parte el responsable del efecto protector del vino tinto en el sistema cardiovascular. El objetivo del presente estudio es investigar la acción y los posibles mecanismos de regulación del resveratrol en la producido de glucosa plasmática en ratas normales y diabéticas, incluyendo el modelo animal de estreptozotocina (STZ)-inducida y la nicotinamida-STZ inducido (NA-STZ), ratas diabéticas y resistentes a la insulina. El resveratrol produjo un efecto hipoglucemiante de manera dosis-dependiente en ratas normales y diabéticas y el nivel de insulina se incrementó después del tratamiento de resveratrol en ratas normales y NA-STZ diabética.También se examinó durante 7 días el cambio en el nivel de expresión de la proteína del subtipo de transportadores de glucosa 4 (GLUT4) en el músculo y la fosfoenolpiruvato carboxiquinasa (PEPCK) en el hígado de las ratas STZ-diabéticas tratadas con resveratrol (3 mg / kg, po). Los resultados indican que los mecanismos que contribuyen al efecto hipoglucemiante de resveratrol son regulados por vias de la insulina-dependiente e independiente a la insulina, y la PI3K-Akt de señalización participó en el último mecanismo para mejorar la captación de glucosa en el músculo esquelético.
