title: Protective effects of the seaweed phlorotannin polyphenolic compound dieckol on gentamicin-induced damage in auditory hair cells.
abstract: OBJECTIVE
  Drug-induced ototoxicity from compounds such as aminoglycosides and platinum can damage the inner ear resulting in hearing loss, tinnitus or balance problems and may be caused by the formation of reactive oxygen species (ROS). Dieckol is a phlorotannin polyphenolic compound with strong antioxidant effects found in edible brown algae. This study investigated the protective effects of dieckol on drug-induced ototoxicity in cochlear cultures obtained from neonatal mice.
  
  
  METHODS
  Cochlear explants were pretreated with dieckol and exposed to gentamicin for 48h. The explants were then fixed and stained with fluorescein isothiocyanate-phalloidin and the intact hair cells counted. The free radical scavenging activity of dieckol was assessed using a 1,1-diphenyl-2-picrylhydrazyl assay. E. coli (Escherichia coli) cultures were used to evaluate the effect of dieckol on the antibiotic activity of gentamicin.
  
  
  RESULTS
  Gentamicin treatment resulted in dose-dependent hair cell loss that was partially protected by dieckol. Moreover, at concentrations >67μM dieckol had significant radical scavenging activity. Dieckol did not compromise the antibiotic effect of gentamicin.
  
  
  CONCLUSIONS
  These findings suggest that dieckol can be used as a therapeutic agent that reduces the damage caused by drug-induced ototoxicity.
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 Otolaryngology-Head and Neck Surgery, Soon Chun Hyang University College of Medicine, Seoul, Republic of Korea.
authors.forename: Seon-Hee
authors.initials: SH
authors.lastname: Byon
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: Song Ee
authors.initials: SE
authors.lastname: Han
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Soon Chun Hyang University College of Medicine, Seoul, Republic of Korea.
authors.forename: Ju Yeon
authors.initials: JY
authors.lastname: Kim
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, Soon Chun Hyang University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jong Dae
authors.initials: JD
authors.lastname: Lee
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; D000831:Animals, Newborn; D000900:Anti-Bacterial Agents / Q000633:toxicity*; D017209:Apoptosis / Q000187:drug effects; D001572:Benzofurans / Q000494:pharmacology*; D002470:Cell Survival; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000187:drug effects; D005260:Female; D016166:Free Radical Scavengers / Q000494:pharmacology*; D005839:Gentamicins / Q000633:toxicity*; D006198:Hair Cells, Auditory / Q000166:cytology* / Q000187:drug effects*; D051379:Mice; D008813:Mice, Inbred ICR; D012624:Seaweed / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D001572:Benzofurans; D016166:Free Radical Scavengers; D005839:Gentamicins; C503840:dieckol
keywords: Antioxidant; Brown alga; Dieckol; Hair cell; Ototoxicity