Grape Skin Extract Hydrogel Restores Systemic Redox Balance in Diabetic Rats

Abstract

Chronic diabetic wounds are difficult to heal due to prolonged inflammation and oxidative stress, often leading to severe complications. This study aimed to evaluate the systemic redox status in diabetic rats treated with grape skin extract (GSE)-loaded alginate-gelatin hydrogels. Hydrogels were prepared with 8 mg/mL GSE and applied topically to full-thickness skin wounds in streptozotocin-induced diabetic Wistar rats. Redox biomarkers including TBARS, H₂O₂, O₂⁻, SOD, CAT and GSH were analyzed in blood samples on days 3, 7, and 15 post-treatment. Results showed that untreated diabetic rats exhibited significantly elevated prooxidative markers and reduced antioxidant enzyme activities. In contrast, rats treated with GSE-loaded hydrogels showed progressive normalization of all redox parameters, particularly by day 15, suggesting both early and sustained antioxidant effects. These findings indicate that GSE, which is rich in polyphenols, contributes to systemic redox balance restoration, making these hydrogels a promising therapeutic agents for diabetic wound management.