title: Renexin as a rescue regimen for noise-induced hearing loss.
abstract: Renexin, a compound of cilostazol and ginkgo biloba extract, has been reported to produce neuroprotective effects through antioxidant, antiplatelet, and vasodilatory mechanisms. This study was designed to investigate the protective effects of renexin on hearing, the organ of Corti (OC), and medial olivocochlear efferents against noise-induced damage. C57BL/6 mice were exposed to 110 dB SPL white noise for 60 min and then randomly divided into three groups: high- and low-dose renexin-treated groups and noise only group. Renexin were administered for 7 days: 90 mg/kg to the low-dose, and 180 mg/kg to the high-dose groups. All mice, including the controls underwent hearing tests on postnoise day 8 and were killed for cochlear harvest. We compared the hearing thresholds and morphology of the OC and cochlear efferents across the groups. The renexin-treated groups recovered from the immediate threshold shifts in a dose-dependent manner, while the noise group showed a permanent hearing loss. The renexin-treated ears demonstrated less degeneration of the OC. The diameters of the efferent terminals labeled with α-synuclein were preserved in the high-dose renexin-treated group. In the western blot assay of the cochlear homogenates, the treated groups displayed stronger expressions of α-synuclein than the noise and control groups, which may indicate that noise-induced enhanced activity of the cochlear efferent system was protected by renexin. Our results suggest that pharmacologic treatment with renexin is hopeful to reduce or prevent noise-induced hearing loss as a rescue regimen after noise exposure.
authors.forename: So Young
authors.initials: SY
authors.lastname: Park
authors.forename: Sang A
authors.initials: SA
authors.lastname: Back
authors.forename: Hong Lim
authors.initials: HL
authors.lastname: Kim
authors.forename: Dong Kee
authors.initials: DK
authors.lastname: Kim
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Yeo
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Shi Nae
authors.initials: SN
authors.lastname: Park
mesh_terms: D000818:Animals; D015153:Blotting, Western; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D003051:Cochlea / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D006198:Hair Cells, Auditory / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D006317:Hearing Loss, Noise-Induced / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D009925:Organ of Corti / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D018384:Oxidative Stress / Q000502:physiology; D010936:Plant Extracts / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013777:Tetrazoles / Q000494:pharmacology*; D051844:alpha-Synuclein / Q000032:analysis
chemical_list: D010936:Plant Extracts; D017382:Reactive Oxygen Species; D013777:Tetrazoles; D051844:alpha-Synuclein; C000593066:renexin