The Antioxidant Effect of Curcumin on Cochlear Fibroblasts in Rat Models of Diabetes Mellitus

INTRODUCTION The aim of this study was to investigate the potential of curcumin as an antioxidant to increase the expression of superoxide dismutase (SOD) in fibroblasts of the cochlear lateral wall in rat models of diabetes mellitus. MATERIALS AND METHODS Twenty-four male Wistar rats Rattus norvegicus were randomly divided into six groups: group 1 as the control group; group 2 as the diabetic group; group 3 and 4 as the diabetic groups that received curcumin therapy of 200 and 400 mg/kg b.w. for 3 days, respectively; and group 5 and 6 as the diabetic groups that received curcumin therapy of 200 and 400 mg/kg b.w. for 8 days, respectively. All rats underwent termination and necropsy procedure on their temporal bones for immunohistochemical assay to determine the expression of SOD. RESULTS The decreased expression of SOD was detected in the diabetic group (without curcumin treatment). The treatment of curcumin at doses of 200 and 400 mg/kg b.w. for 3 and 8 days led to significant differences (P<0.05) in the expression of the SOD compared to diabetic group (without curcumin treatment). No significant differences were found in terms of dose and duration of curcumin administration on the expression of SOD. CONCLUSION Curcumin may act as an antioxidant against oxidative stress due to diabetes mellitus via increased expression of SOD on cochlear fibroblasts in rat models of diabetes mellitus.