L-Ergothioneine Shows Benefits in Reducing Age-Related Hearing Loss: Improved Signal-in-Noise Detection in Mice

The amino acid, L-ergothioneine (EGT), has gained attention as a potential therapeutic for age-related conditions due to its antioxidant and antiinflammatory properties. EGT is naturally found in various foods and shows promise in protecting against oxidative stress, inflammation, and neurodegeneration. Recent studies have highlighted its role in improving physiological functions in aging models, particularly in mitigating age-related declines in sensory and neurological systems. In this study, we aimed to investigate whether long-term oral administration of EGT via gavage could improve hearing function in aged mice. Hearing sensitivity and signal-in-noise detection were measured to determine the therapeutic potential of EGT for treating age-related hearing loss (ARHL). Over a 4-month period, aged CBA/CaJ mice received weekly EGT treatment, with hearing performance assessed at the end of the period. We used behavioral and neurophysiological measures, including acoustic startle reflex (ASR), signal-in-noise detection tasks (SIN-PPI), and auditory brainstem response (ABR) thresholds. While EGT did not prevent age-related decreases in startle amplitude or influence ABR hearing thresholds, it significantly improved signal-in-noise detection at 16 kHz and 32 kHz but not at 8 kHz. These findings suggest that EGT may improve auditory processing in complex acoustic environments and that these improvements in signal-in-noise detection are mediated in the central auditory nervous system. To our knowledge this is the first study that indicates the therapeutic potential of EGT as an intervention for improving auditory signal detection in aging populations.