We fed DBA mice with α-lipoic acid (100 mg/kg body weight/day), beginning 2, 4, or 8 weeks after birth. Hearing thresholds were measured weekly. At 12 weeks after birth, control mice not fed with α-lipoic acid showed significant hearing decreases at all frequencies. In contrast, mice fed with α-lipoic acid beginning at 2 weeks after birth showed significantly better hearing at all frequencies. Mice fed with α-lipoic acid beginning at 4 and 8 weeks after birth also showed significantly better hearing than control mice after they were fed with α-lipoic acid. The stria vascularis of mice fed with α-lipoic acid showed reduced 8-oxoguanine residues in DNA and cytoplasm compared with that of control mice. Western blotting showed that the level of hypoxia-inducible factor-1α was lower in mice fed with α-lipoic acid than in control mice. From these results, we suggest that α-lipoic acid prevented early-onset hearing impairment in DBA mice.
Departments of aOtolaryngology
bInternal Medicine, Asan Medical Center, University of Ulsan College of Medicine
cAsan Institute for Life Sciences
dDepartment of Otolaryngology, Head and Neck Surgery, Konkuk University Hospital, Seoul, Korea
Correspondence to Jong Woo Chung, MD, Department of Otolaryngology, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-Dong Songpa-Gu, Seoul 138-736, Korea
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Received 6 April 2008; accepted 13 May 2008