Decreased protein kinase c expression in the cochlear fibroblasts of diabetic rat models induced by curcumin

Abstract

Objectives: Microcirculation and hemodynamic disturbances, including in the cochlea, are commonly found in diabetic patients. A study on diabetic rats discovered histopathological changes in outer hair cells and the spiral ganglion and mitochondrial damage in the ear. Hyperglycemia can increase the activation of protein kinase C (PKC). Curcumin as an antioxidant also affects the regulation of PKC and Ca2+. The aim of this study was to determine the role of curcumin in decreasing PKC expression in the cochlear fibroblasts of diabetic rats. Materials and Methods: An experimental study was performed on 24 Wistar rats divided into the following 6 groups: group 1: control group; group 2: diabetic group without curcumin administration; groups 3 and 4: diabetic groups with curcumin administration (200 mg/kg and 400 mg/kg for 3 days, respectively); groups 5 and 6: diabetic groups with curcumin administration (200 mg/kg and 400 mg/kg for 8 days, respectively). Cochlear tissues were taken from all groups and immunohistochemistry-stained, and the PKC expression scores were analyzed with one-way ANOVA (a significance level of 0.05). Results: Significant differences in PKC expression (p<0.05) were found between group 1 and group 2, and group 2 and groups 3, 4, 5, and 6. There was no significant difference in PKC expression regarding the different doses and the duration of curcumin administration. Conclusion: Curcumin can reduce PKC expression in the cochlear fibroblasts of diabetic rats.