The free radical scavenger edaravone protects hair cells against aminoglycoside toxicity

Reactive oxygen species are involved in inner ear hair cell death induced by aminoglycosides. Therefore, inhibition of free radicals can prevent hair cell death. The antioxidant, edaravone has been used clinically in Japan. In this study, we evaluated whether edaravone can protect hair cells against aminoglycoside-induced cytotoxicity in cultured mouse utricles. Utricles from CBA/N mice were cultured in medium containing neomycin alone (1 mM), or neomycin plus edaravone. Hair cells cultured with neomycin alone were damaged after 24 hours. Survival of hair cells cultured with neomycin plus edaravone (30 or 100 μM) was significantly greater than that of hair cells cultured with neomycin alone. Immunohistochemistry showed the production of 4-hydroxy-2-nonenal in utricles cultured with neomycin but not in utricles cultured with neomycin plus edaravone (100 μM). These results suggest that the inhibibion of reactive oxygen species production by edaravone protects hair cells. In addition, high concentrations of edaravone did no show cytotoxicity.

hair cell

aminoglycoside

hydroxy radical

Edaravone

ototoxicity