Evaluating the Efficacy of L-N-acetylcysteine and Dexamethasone in Combination to Provide Otoprotection for Electrode Insertion Trauma

• Main Authors: Adrien A. Eshraghi, David Shahal, Camron Davies, Jeenu Mittal, Viraj Shah, Erdogan Bulut, Carolyn Garnham, Priyanka Sinha, Dibyanshi Mishra, Hannah Marwede, Rahul Mittal
• Format: Article
• Language: English
• Published: MDPI AG 2020-03-01
• Series: Journal of Clinical Medicine
• Subjects: electrode insertion trauma; residual hearing; l-n-acetylcysteine; dexamethasone; organ of corti; oxidative stress; proinflammatory cytokines; nitric oxide
• Online Access: https://www.mdpi.com/2077-0383/9/3/716

Background: Electrode insertion trauma (EIT) during cochlear implantation (CI) can cause loss of residual hearing. L-N-acetylcysteine (L-NAC) and dexamethasone (Dex) have been individually shown to provide otoprotection albeit at higher concentrations that may be associated with adverse effects. Objective/Aims: The aim of this study is to determine whether L-NAC and Dex could be combined to decrease their effective dosage. Materials and Methods: The organ of Corti (OC) explants were divided into various groups: 1) control; 2) EIT; 3) EIT treated with different concentrations of Dex; 4) EIT treated with different concentrations of L-NAC; 5) EIT treated with L-NAC and Dex in combination. Hair cell (HC) density, levels of oxidative stress, proinflammatory cytokines and nitric oxide (NO) was determined. Results: There was a significant loss of HCs in explants subjected to EIT compared to the control group. L-NAC and Dex in combination was able to provide significant otoprotection at lower concentrations compared to individual drugs. Conclusions and Significance: A combination containing L-NAC and Dex is effective in protecting sensory cells at lower protective doses than each compound separately. These compounds can be combined allowing a decrease of potential side effects of each compound and providing significant otoprotection for EIT.