Quercetine attenuates the gentamicin-induced ototoxicity in a rat model

The aim of this study is to evaluate the protective role of quercetin in gentamicin-induced ototoxicity through an auditory brainstem response (ABR) test and a histopathological evaluation of the cochlea.

In this study, 48 female adult Sprague-Dawley rats aged 20-22 weeks and weighing 200-250g were used. An ABR test was carried out on all rats prior to drug administration, after which, the rats were divided into four groups of 12 animals each. Drug administration was gentamicin 120mg/kg plus ethanol in group one; gentamicin 120mg/kg plus quercetin 15mg/kg in group two; quercetin 15mg/kg in group three; and ethanol in group four. The drugs were administered intraperitoneally once a day for two weeks, and the ABR test was repeated after drug administration. Subsequently, the rats were sacrificed and their cochleae were dissected and examined histopathologically.

There was no significant difference between the pre-treatment ABR measurement values of the groups. However, a significant increase was detected in the ABR values in the group of rats that were administered gentamicin plus ethanol, while no statistically significant increase was found in the ABR values in the groups administered with gentamicin plus quercetin; quercetin alone; and ethanol alone. The number of TUNEL positive cells in the inner and outer hair cells in the Corti organ was found to be fewer, and Caspase 3 and 9 expressions were found to be weaker in the group receiving gentamicin plus quercetin than in the group receiving gentamicin plus ethanol.

Auditory function was detected to be significantly protected and apoptotic cells were found to be decreased when quercetin was administered together with gentamicin. From these results it was concluded that quercetin, a powerful antioxidant, attenuates ABR thresholds and histopathological lesions in the cochlea in gentamicin-induced ototoxicity in rats.