title: Melatonin mitigates neomycin-induced hair cell injury in zebrafish.
abstract: BACKGROUND
  Ototoxicity due to medications, such as aminoglycosides, is irreversible, and free radicals in the inner ear are assumed to play a major role. Because melatonin has an antioxidant property, we hypothesize that it might mitigate hair cell injury by aminoglycosides.
  
  
  OBJECTIVE
  The objective of this study was to evaluate whether melatonin has an alleviative effect on neomycin-induced hair cell injury in zebrafish (Danio rerio).
  
  
  METHODS
  Various concentrations of melatonin were administered to 5-day post-fertilization zebrafish treated with 125 μM neomycin for 1 h. Surviving hair cells within four neuromasts were compared with that of a control group. Apoptosis was assessed via terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. The changes of ultrastructure were confirmed using a scanning electron microscope.
  
  
  RESULTS
  Melatonin alleviated neomycin-induced hair cell injury in neuromasts (neomycin + melatonin 100 μM: 13.88 ± 0.91 cells, neomycin only: 7.85 ± 0.90 cells; n = 10, p < 0.05) and reduced neomycin-induced apoptosis in the TUNEL assay. In ultrastructural analysis, hair cells within the neuromasts in zebrafish were preserved exposed to 125 μM neomycin and 100 μM melatonin for 1 h in SEM findings.
  
  
  CONCLUSIONS
  Melatonin is effective in alleviating aminoglycoside-induced hair cell injury in zebrafish. The results of this study demonstrated that melatonin has the potential to reduce apoptosis induced by aminoglycosides in zebrafish.
authors.affiliation: a Department of Otorhinolaryngology-Head and Neck Surgery , Korea University College of Medicine , Seoul , South Korea and.
authors.forename: Kyoung Ho
authors.initials: KH
authors.lastname: Oh
authors.affiliation: a Department of Otorhinolaryngology-Head and Neck Surgery , Korea University College of Medicine , Seoul , South Korea and.
authors.forename: Yoon Chan
authors.initials: YC
authors.lastname: Rah
authors.affiliation: a Department of Otorhinolaryngology-Head and Neck Surgery , Korea University College of Medicine , Seoul , South Korea and.
authors.forename: Kyu Ho
authors.initials: KH
authors.lastname: Hwang
authors.affiliation: a Department of Otorhinolaryngology-Head and Neck Surgery , Korea University College of Medicine , Seoul , South Korea and.
authors.forename: Seung Hoon
authors.initials: SH
authors.lastname: Lee
authors.affiliation: a Department of Otorhinolaryngology-Head and Neck Surgery , Korea University College of Medicine , Seoul , South Korea and.
authors.forename: Soon Young
authors.initials: SY
authors.lastname: Kwon
authors.affiliation: b Medical Science Research Center, Korea University College of Medicine , Ansan , South Korea.
authors.forename: Jae Hyung
authors.initials: JH
authors.lastname: Cha
authors.affiliation: a Department of Otorhinolaryngology-Head and Neck Surgery , Korea University College of Medicine , Seoul , South Korea and.
authors.forename: June
authors.initials: J
authors.lastname: Choi
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D000900:Anti-Bacterial Agents / Q000009:adverse effects* / Q000737:chemistry; D017209:Apoptosis / Q000187:drug effects; D019587:Dietary Supplements; D016166:Free Radical Scavengers / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006199:Hair Cells, Auditory, Inner / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D007814:Larva / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D008550:Melatonin / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D009355:Neomycin / Q000009:adverse effects* / Q000037:antagonists & inhibitors; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009994:Osmolar Concentration; D011500:Protein Synthesis Inhibitors / Q000009:adverse effects* / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D015027:Zebrafish / Q000235:genetics / Q000254:growth & development; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D016166:Free Radical Scavengers; D009419:Nerve Tissue Proteins; D011500:Protein Synthesis Inhibitors; D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; D029961:Zebrafish Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D009355:Neomycin; D008550:Melatonin
keywords: Melatonin; aminoglycoside; ototoxicity; protection; zebrafish