Grape seed extract has superior beneficial effects than vitamin E on oxidative stress and apoptosis in the hippocampus of streptozotocin induced diabetic rats

We aimed to investigate the effects of grape seed extract (GSE) and vitamin E (Vit E) on oxidative stress and apoptosis in the hippocampus of streptozotocin-induced diabetic rats. In Control, Diabetic, and Diabetic treated with GSE (Diabetic + GSE) and vitamin E (Diabetic + Vit E) groups, oxidative stress index (OSI), TUNEL staining and Bcl-2, Bcl-XL, Bax, caspase-3, -9, and -8, Cyt-c, TNF-α, and NF-κB gene expressions were evaluated. OSI was significantly increased in the plasma and hippocampus of the Diabetic compared to Control group and decreased in Diabetic + GSE and Diabetic + Vit E groups compared to Diabetic. TUNEL positive neurons significantly increased in the hippocampus of the Diabetic group compared to Control and decreased in Diabetic + GSE (more prominently) and Diabetic + Vit E groups compared to Diabetic. In the hippocampus of the Diabetic group, Bcl-2 and Bcl-XL gene expressions were significantly decreased; Bax, caspase-3, -9, and -8, Cyt-c, TNF-α, and NF-κB gene expressions were significantly increased compared to Control. In Diabetic + GSE and Diabetic + Vit E groups, Bcl-2 gene expressions were significantly increased; Bcl-XL gene expressions did not differ compared to the Diabetic group. The expression of Bax, caspase-3, -9, and -8, Cyt-c, TNF-α, and NF-κB genes in the Diabetic + GSE group and the expression of caspase-3 and -9, TNF-α, and NF-κB genes in the Diabetic + Vit E group were significantly decreased compared to Diabetic. In conclusion, GSE (more prominently) and vitamin E decreased oxidative stress and neuronal apoptosis occurring in the hippocampus of diabetic rats.