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

Abstract

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.

Functional Hearing Preservation in Cochlear Implantation: The Miami Cocktail Effect

“…The combination of corticosteroids and NAC likely mitigates apoptotic cell death triggered by insertion trauma. Eshraghi et al (6), in organ of Corti explants, showed that this combination decreases EIT at lower protective doses than each compound separately while allowing a decrease of potential side effects of each compound. NAC is a scavenger of free radicals, and it is also a precursor of glutathione, the primary intracellular antioxidant (13).…”

“…Several studies have investigated the effects of various corticosteroid regimens, but the evidence regarding their efficacy is mixed. Furthermore, the potential role of L-N-acetylcysteine (NAC) in preserving residual hearing either alone or in combination with steroids has garnered attention in recent research (6). NAC is believed to counteract the detrimental effects of oxidative stress, which can contribute to cochlear damage and hearing loss.…”

Identification of Target Proteins Involved in Cochlear Hair Cell Progenitor Cytotoxicity following Gentamicin Exposure

“…The size and location of each ROI were consistent for all images. The mean signal intensity was measured and calculated using ImageJ version 1.52 k software (Bethesda, MD, USA) [ 40 , 41 , 42 ].…”

Current Concepts and Future Trends in Increasing the Benefits of Cochlear Implantation: A Narrative Review

“…When studied with noise-induced cochlear damage, N-ACC reduced reactive oxygen species (ROS), protected mitochondria, and inhibited inflammation and necrosis [76]. When studied in vitro on cochlear explants, N-ACC showed no toxicity and a protective role against cochlear implant electrode insertion trauma and TNF-α exposure-induced oxidative stress [77][78][79].…”