Ecabet sodium alleviates neomycin-induced hair cell damage

Abstract

Ecabet sodium (ES) is currently applied to some clinical gastrointestinal disease primarily by the inhibition of the ROS production. In this study, the protective role of ES was evaluated against the neomycin-induced hair cell loss using zebrafish experimental animal model. Zebrafish larvae (5-7 dpf), were treated with each of the following concentrations of ES: 5, 10, 20, 40, and 80 mu g/mL for 1 h, followed by 125 mu M neomycin for 1 h. The positive control group was established by 125 mu M neomycin-only treatment (1 h) and the negative control group with no additional chemicals was also established. Hair cells inside four neuromasts (SO1, SO2, O1, OC1) were assessed using fluorescence microscopy (n=10). Hair cell survival was calculated as the mean number of viable hair cells for each group. Apoptosis and mitochondrial damage were investigated using special staining (TUNEL and DASPEI assay, respectively), and compared among groups. Ultrastructural changes were evaluated using scanning electron microscopy. Pre-treatment group with ES increased the mean number of viable hair cells as a dose-dependent manner achieving almost same number of viable hair cells with 40 mu M/ml ES treatment (12.98 +/- 2.59 cells) comparing to that of the negative control group (14.15 +/- 1.39 cells, p=0.72) and significantly more number of viable hair cells than that of the positive control group (7.45 +/- 0.91 cells, p < 0.01). The production of reactive oxygen species significantly increased by 183% with 125 mu M neomycin treatment than the negative control group and significantly decreased down to 105% with the pre-treatment with 40 mu M/ml ES (n=40, p=0.04). A significantly less number of TUNEL-positive cells (reflecting apoptosis, p < 0.01) and a significantly increased DASPEI reactivity (reflecting viable mitochondria, p<0.01) were observed in 40 mu M/ml ES pre-treatment group. Our data suggest that ES could protect against neomycin-induced hair cell loss possibly by reducing apoptosis, mitochondrial damages, and the ROS generation. (C) 2015 Elsevier Inc. All rights reserved.