목적: Alpha-lipoic acid (ALA) is well known due to its protective effects in auditory organs. We hypothesized that the antioxidative effect of ALA could protect against gentamicin-induced cytotoxicity, and thus evaluated its effects on gentamicin-induced ototoxicity in HEI-OC1 auditory cells. 방법:HEI-OC1 cells were pretreated with alpha-lipoic acid at a concentration of 10 μM for 24 h, and then exposed to 3 mM gentamicin for 48 h. The cellular viability was measured by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The intracellular ROS level was measured by using a fluorescent dye, 2,7-dichlorofluorescein diacetate (DCFH-DA). Both Annexin V-FITC and propidium iodide (PI) staining were performed to analyze the pattern of apoptosis. 결과:Pretreatment with 10 μM alpha-lipoic acid protected HEI-OC1 auditory cells against gentamicin-induced cytotoxicity. Alpha- lipoic acid significantly reduced the gentamicin-induced increase in ROS. A 14% reduction of ROS and 33% decrease in late apoptosis was observed with alpha-lipoic acid treatment as compared to gentamicin treatment. 결론:This study investigated the protective effects of alpha-lipoic acid on gentamicin-induced ototoxicity in an auditory cell line. Alpha-lipoic acid significantly reduced a gentamicin-induced reactive oxygen species (ROS), thereby inhibiting gentamicin- induced cytotoxicity.