Combination photobiomodulation/N-acetyl-L-cysteine treatment appears to mitigate hair cell loss associated with noise-induced hearing loss in rats | JoVE Visualize

Combination photobiomodulation/N-acetyl-L-cysteine treatment appears to mitigate hair cell loss associated with noise-induced hearing loss in rats

Chung-Ku Rhee¹, So-Young Chang²

¹Department of Otolaryngology-Head & Neck Surgery, College of Medicine, Dankook University, 119 Dandae-ro, Cheonan, 31116, Republic of Korea.

Lasers in Medical Science|April 6, 2021

View abstract on PubMed

Summary

Low-level laser therapy combined with N-acetyl-L-cysteine (NAC) shows promise in preventing noise-induced hearing loss (NIHL). This treatment improved hearing thresholds and preserved crucial hair cells in a rat model.

Area of Science:

Oto-rhino-laryngology
Neuroscience
Biomedical Engineering

Background:

Sensorineural hearing loss, often caused by acoustic overstimulation, leads to significant social and emotional challenges.
Current treatments for noise-induced hearing loss (NIHL) are limited, highlighting the need for effective interventions.
Previous research indicated that photobiomodulation (PBM) and antioxidants like N-acetyl-L-cysteine (NAC) can individually mitigate NIHL.

Purpose of the Study:

To investigate the combined efficacy of photobiomodulation (PBM) and N-acetyl-L-cysteine (NAC) in treating noise-induced hearing loss (NIHL).
To evaluate the impact of PBM/NAC treatment on hearing threshold recovery and cochlear hair cell morphology in a rat model of NIHL.

Main Methods:

Rats were exposed to noise to induce hearing loss.
A combination therapy of low-level laser photobiomodulation (PBM) and N-acetyl-L-cysteine (NAC) was administered.
Auditory brainstem response (ABR) thresholds were measured across various frequencies (8, 16, and 32 kHz).
Cochlear hair cell morphology was examined to assess structural integrity and count.

Main Results:

The PBM/NAC combination treatment significantly reduced average auditory brainstem response thresholds across all tested frequencies compared to the noise-only group.
Rats treated with PBM/NAC exhibited intact outer hair cells in all cochlear turns.
A significant increase in hair cell numbers was observed in the middle and basal cochlear turns of the PBM/NAC treated group compared to controls.

Conclusions:

Combined photobiomodulation and N-acetyl-L-cysteine treatment demonstrates a protective effect against noise-induced hearing loss.
This therapeutic approach shows potential for preventing hearing dysfunction and preserving cochlear structures.
PBM/NAC offers a promising strategy for mitigating the detrimental effects of acoustic trauma on hearing.