title: Protective effect of a purified polyphenolic extract from Ecklonia cava against noise-induced hearing loss: Prevention of temporary threshold shift.
abstract: OBJECTIVE
  Noise is one of the most common causes of hearing loss. Approximately 16% of American teenagers (12-19 years) have hearing loss caused by loud noise. The implication of noise-induced hearing loss (NIHL) in teenagers has received increasing attention. Although temporary threshold shift (TTS), a type of NIHL, is a transient hearing loss, it can accelerate age-related hearing loss. Reactive oxygen species are a primary cause of TTS. As the polyphenols from Ecklonia cava are known to have potent antioxidant effects, we investigated the protective effects of a purified polyphenolic extract of Ecklonia cava (PPEE) against TTS in mice.
  
  
  METHODS
  The radical-scavenging activity of PPEE was evaluated using the 1,1-diphenyl-2-picrylhydrazyl assay. The PPEE + Noise and Saline + Noise groups were administered intraperitoneal PPEE (100 mg/kg) and saline, respectively, for 5 days before exposure to noise at 100 dB SPL for 60 min. Hearing ability was assessed following noise exposure using auditory brainstem responses and distortion product otoacoustic emissions.
  
  
  RESULTS
  PPEE exhibited significant radical scavenging activity. The ABR threshold shifts 1 day after exposure to noise at 16 kHz and 1, 7, and 14 days after exposure to noise at 32 kHz, were significantly less in the PPEE + Noise than in the Saline + Noise group. One day after noise exposure, mice in the PPEE + Noise group showed a significant degree of protection in relation to their DPOAE level at f2, 17, and 28 kHz.
  
  
  CONCLUSIONS
  These findings suggest that PPEE may be a potential preventive agent against TTS. In addition, as a food ingredient approved by the United States Food and Drug Administration, PPEE may be administered to those who are exposed to noise inevitably with little likelihood of adverse effects, thereby contributing to the prevention of TTS.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Chung-Ang University College of Medicine, Seoul, Republic of Korea.
authors.forename: Mun Young
authors.initials: MY
authors.lastname: Chang
authors.affiliation: Department of Interdisciplinary Program in Biomedical Science, Major Graduate School of Soonchunhyang University, Asan-si, Republic of Korea.
authors.forename: Song Yee
authors.initials: SY
authors.lastname: Han
authors.affiliation: CEWIT Center for Systems Biology, State University of New York, Incheon, Republic of Korea.
authors.forename: Hyeon-Cheol
authors.initials: HC
authors.lastname: Shin
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Soon Chun Hyang University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jang Yul
authors.initials: JY
authors.lastname: Byun
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Korea University Medical Center Ansan Hospital, Ansan-si, Republic of Korea.
authors.forename: Yoon Chan
authors.initials: YC
authors.lastname: Rah
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea. Electronic address: aseptic@snu.ac.kr.
authors.forename: Moo Kyun
authors.initials: MK
authors.lastname: Park
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001309:Auditory Threshold / Q000187:drug effects*; D001713:Biphenyl Compounds; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects*; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006198:Hair Cells, Auditory / Q000187:drug effects*; D006317:Hearing Loss, Noise-Induced / Q000517:prevention & control*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009622:Noise / Q000009:adverse effects*; D017084:Otoacoustic Emissions, Spontaneous / Q000187:drug effects*; D000459:Phaeophyceae; D010851:Picrates
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010851:Picrates; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: Antioxidant; Ecklonia cava; Noise; Noise-induced hearing loss; Temporary threshold shift