Protective role of carbon monoxide releasingmolecule-3 (CORM-3) in noise-induced hearing loss

INTRODUCTION: Noise is an important cause of acquired hearing loss that can lead to permanent hearing loss. Noise-induced hearing loss is the most common preventable cause of hearing loss. Although there are methods to reduce noise-induced hearing loss, such as reducing noise at its source or using personal protective equipment; a common treatment protocol with proven success has not yet been defined. The aim of this experimental study is to demonstrate the possible protective effects of Carbon Monoxide Releasing Molecule-3 (CORM-3) on the auditory system after exposure to noise by electrophysiological measurements and histopathological methods. MATERIALS AND METHODS: Twenty-four albino wistar male rats were divided equally into 3 groups. To the group without noise; intraperitoneal saline was applied for 7 days. 16 rats in the other 2 groups were exposed to 120 dB SPL, 4 kHz octave band for 4 hours. Intraperitoneal saline was administered to one group receiving noise, and 10 mg/kg CORM-3 was administered intraperitoneally to the other for 7 days. Hearing levels were measured by distortion product otoacoustic emission and auditory evoked brainstem potentials at 4, 6 and 8 kHz at baseline, days 1 and 7. After the last test, the inner ear structures of all rats were dissected and the cochlea structures were evaluated by light microscopy. RESULTS: Auditory evoked brainstem potential test results showed better hearing thresholds in the CORM-3 group at all frequencies compared to the other group given noise. These findings were also statistically significant (p<0.05). Distortion product otoacoustic emission responses disappeared after noise. In the histopathological evaluation, the cellular damage caused by the noise in the cochlea was shown. CONCLUSION: According to the data obtained, CORM-3 may be a useful molecule that can be used as a preventive and therapeutic agent in noise-induced hearing loss. However, additional studies are needed to prove this protective effect. Keywords: Acoustic trauma, antioxidant, Carbon Monoxide Releasing Molecule-3, noise-induced hearing loss, sensorineural hearing loss