title: Therapeutic effects of orally administrated antioxidant drugs on acute noise-induced hearing loss.
abstract: OBJECTIVE
  The objective of this study was to investigate the dose-dependent therapeutic effect of the orally administrated antioxidant drugs [4-hydroxy alpha-phenyl-tert-butylnitrone (4-OHPBN) and N-acetyl-L-cysteine (NAC)] on acute noise-induced hearing loss because oral administration is the most commonly used method of drug administration due to its convenience, safety, and economical efficiency.
  
  
  METHODS
  Thirty chinchilla were exposed to a 105 dB octave band noise centered at 4 kHz for 6 h and randomly assigned to a control group (saline only) and three experimental groups [4-OHPBN (10 mg/kg) plus NAC (20 mg/kg), 4-OHPBN (20 mg/kg) plus NAC (50 mg/kg), and 4-OHPBN (50 mg/kg) plus NAC (100 mg/kg)]. The drugs were orally administrated beginning 4 h after noise exposure and then administered twice daily for the next 2 days. Permanent auditory brainstem response threshold shifts, distortion product otoacoustic emission threshold shifts, and the percentage of missing outer hair cell were determined.
  
  
  RESULTS
  The oral administration significantly reduced permanent hearing threshold shift, distortion product otoacoustic emission threshold shift, and the percentage of missing outer hair cell in a dose-dependent manner.
  
  
  CONCLUSIONS
  This result demonstrates that orally administered drugs can treat acute noise-induced hearing loss in a dose-dependent manner. This suggests that oral administration was effective in treating acute noise-induced hearing loss as in intraperitoneal administration.
authors.affiliation: Catholic University of Daegu, Audiology & Speech Language Pathology, Research Institute of Biomimetic Sensory Control, and Catholic Hearing Voice Speech Center , Kyungsansi, Kyungsanbukdo , Republic of Korea.
authors.forename: C-H
authors.initials: CH
authors.lastname: Choi
authors.forename: X
authors.initials: X
authors.lastname: Du
authors.forename: R A
authors.initials: RA
authors.lastname: Floyd
authors.forename: R D
authors.initials: RD
authors.lastname: Kopke
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology*; D000284:Administration, Oral; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002682:Chinchilla; D004305:Dose-Response Relationship, Drug; D005260:Female; D006317:Hearing Loss, Noise-Induced / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D007097:Imines / Q000494:pharmacology*; D010636:Phenols / Q000494:pharmacology*; D011897:Random Allocation
chemical_list: C554675:4-hydroxyphenyl tert-butylnitrone; D000975:Antioxidants; D007097:Imines; D010636:Phenols; D000111:Acetylcysteine