Effect of Melatonin on the Cisplatin Induced Ototoxicity in Rats / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Cisplatin (CP), an antitumor agent widely used in the treatment of head and neck cancers, has side effects such as ototoxicity and nephrotoxicity. These side effects are closely related to oxidative stress. In the present study, we attempted to suppress CP-induced ototoxicity in rats by administering melatonin, an antioxidant. MATERIALS AND METHOD: Male Sprague-Dawley rats were divided into different groups and were treated as follows 1) saline control, 2) CP (16 mg/kg, i.p.), 3) CP plus melatonin (10 mg/kg, i.p.). The rats were sacrificed at the 6th day after CP treatment. RESULTS: CP-treated rats showed increase in cochlear malondialdehyde, hydrogen peroxide, glutathione peroxidase and glutathione reductase levels, and the decrease in cochlear superoxide dismutase (SOD) and catalase levels. CP-treated rats showed markedly decreased in the number of stereocilia on the inner hair cells and mildly decreased in the number of outer hair cells in organ of Corti under the light and scanning electron microscopic examination. Light and electron microscopic findings, and cochlear hydrogen peroxide, malondialdehyde, SOD, catalase, glutathione peroxidase and glutathione reductase levels were restored in the rats injected with CP plus melatonin than those with CP alone. CONCLUSION: These results suggest that melatonin suppresses CP-induced ototoxicity via the suppression of the increased production of reactive oxygen species.