Neuroscience

Oxidative stress

Inner ear

Spiral ganglion

Cochlea

Reactive oxygen species

Biology

Hair cell

Antioxidant

Hearing loss

Sensorineural hearing loss

Audiology

Oxidative phosphorylation

Mitochondrion

Cell biology

Biochemistry

Medicine

Antioxidants

Oxygen metabolism in the mitochondria is essential for biological activity, and reactive oxygen species (ROS) are produced simultaneously in the cell. Once an imbalance between ROS production and degradation (oxidative stress) occurs, cells are damaged. Sensory organs, especially those for hearing, are constantly exposed during daily life. Therefore, almost all mammalian species are liable to hearing loss depending on their environment. In the auditory pathway, hair cells, spiral ganglion cells, and the stria vascularis, where mitochondria are abundant, are the main targets of ROS. Excessive generation of ROS in auditory sensory organs is widely known to cause sensorineural hearing loss, and mitochondria-targeted antioxidants are candidates for treatment. This review focuses on the relationship between acquired hearing loss and antioxidant use to provide an overview of novel antioxidants, namely medicines, supplemental nutrients, and natural foods, based on clinical, animal, and cultured-cell studies.

Role of Oxidative Stress and Antioxidants in Acquired Inner Ear Disorders