The role of riluzole treatment in the prevention of cisplatin- induced ototoxicity

The aim of this study was to analyse the role of riluzole treatment for the prevention of cisplatin induced ototoxicity. Guine pigs were divided into three groups as 8 animals in each group and auditory brainstem response (ABR) thresholds of all animals were detected bilateraly before any drug administration. 5 mg / kg cisplatin was given for all groups for 3 days. In the first group 2 cc of saline was applied and in the second and third group, 2 cc of drug solution that was prepared respectively with 6 mg/ kg and 8 mg/ kg riluzole hydrochloride was given thirty minutes before cisplatin administration. Auditory brainstem response thresholds of groups were reassessed 24 hours after the final drug application. Following intracardiac blood collection under deep anesthesia, bilateral temporal bones were sacrificed. Right temporal bones were spared for transmission electromicroscopic investigation and membranous labirenthyne of left cochleas was stored for biochemical investigation. Statistically significiant lower ABR thresholds were observed in the treatment group with riluzole hydrochloride on the tone burst 8 kHz stimuli for both ear and click stimuli for only left ear. In the grup not-treated by riluzole, significiant ABR threshold changes were detected at 8 kHz. Under transmission electromicroscopic examination (TEM), lower degenerative findings about hair cells and stria vascularis were observed in the groups treated with riluzole than the group not-treated by riluzole. While there was no difference in terms of ABR theresholds between the second and the third group before and after drug administration, hair cells and stria vaskülaris were seemed significiantly closer to normal in the third group than the second group. Contary to expectations, malandialdehid (MDA) levels in the group treated by riluzole was statistically higher than the other groups and this is not meaningful result for this study. In conclusion, the effects of riluzole on protection from cisplatin ototoxicity especially for ABR theresholds at 8 kHz and degeneration of hair cells and stria vascularis was observed. However the effects of riluzole on oxidative mechanisms wasn?t supported with the detected MDA levels. Key words: Riluzole, ototoxicity, cisplatin