Protective Effect of N-Acetylcysteine against Continuous Noise-Induced Hearing Loss

This study aimed to determine the preventive effect of N-Acetylcysteine (NAC) against continuous noise-induced hearing loss.

A total of 24 adult male Wistar rats were randomly assigned into 4 groups of 6 animals: control, noise, noise and NAC, noise and saline. Animals were subjected to 102 dB (102±0.5) of continuous, 8 kHz-centered high pass white noise. For two days before to noise, one hour prior to noise for ten days in a row, and two days after noise, NAC (325 mg/kg) was intraperitoneally administered. Temporary and permanent hearing loss were assessed by pre and post noise (1, 7 and 21 days) recordings of distortion product otoacoustic emissions (DPOAEs).

Amplitudes was temporally reduced significantly first day post noise exposure in all groups, and all frequencies (P<0.05). The initial and subsequent recovery was more pronounced in noise-exposed animal treated with NAC compared to those received noise and saline, especially in higher frequencies (P<0.05). Noise and NAC group experienced less permanent hearing loss than noise and saline group (P<0.05).

NAC could partially improve permanent hearing loss after noise exposure However, temporary hearing loss was not affected by NAC.