[Abstract Title]. - Society for Neuroscience

Poster
259. Cochlear Mechanoreceptors
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 259.14/BB10
Topic: D.02.a. Mechanoreceptors and cochlea
Support: Fondi di Ateneo 2006/07- UCSC-Italy
Title: Antioxidant property of Ferulic acid in Noise induced hearing loss (NIHL)
Authors: M. RALLI 1 , A. FETONI 1 , G. PALUDETTI 1 , *D. TROIANI 2 ;
1 Otolaryngology, UCSC, Rome, Italy; 2 Inst. Human Physiol, UCSC, Rome 00168, Italy
Abstract: Ferulic Acid (FA) is known for its antioxidant properties and its free-radical
scavenging activity towards peroxynitrite, hydroxyl radicals and oxidized low-density proteins.
FA has been studied as a neuroprotector in neurodegenerative disorders and cerebral ischemia
injury. In this study, we tested the hypothesis that FA might exert, by virtue of its antioxidant
properties, beneficial protective effects against noise-induced hearing loss (NIHL). Loud noise
induces hearing impairment by increasing the production of reactive oxygen species (ROS) and
toxic free radicals which, in turn through a series of reactions, induce lipid peroxidation and cell
damage in the organ of Corti. We evaluated the protective effect of FA against NIHL in guinea
pigs (n=22). Noise-induced hearing loss was induced by exposing animals to a continuous pure
tone of 6kHz, 120dB for 1 h; FA was injected intraperitoneally 1 h before acoustic trauma and
once daily for 3 days. Auditory function was investigated by recording auditory brainstem
responses (ABR) at 2-20 kHz; morphological studies were performed with scanning electron
microscopy (SEM); immunohistochemistry was performed with terminal deoxynucleotidyl
transferase-mediated dUTP nick end labeling assay (TUNEL) for identification of missing and
apoptotic cells, free radical activity was determined via 4-hydroxynonenal (4HNE) and
nitrotyrosine (3NT) as markers of reactive oxygen species and reactive nitrogen species action.
Guinea pigs in the FA group showed significantly smaller auditory threshold shifts than
unprotected control animals, indicative of a lesser extent of both apoptotic activation and hair
cell loss in the organ of Corti. Our preliminary data confirm the antioxidant properties of FA and
show its protective function in NIHL. This might be because FA inhibits the process of lipid
peroxidation as documented by 4HNE immunohistochemistry. Our results suggest a therapeutic
potential of FA in NIHL through its antioxidant property.
Disclosures: M. Ralli, None; A. Fetoni, None; G. Paludetti, None; D. Troiani , None.