Potential protective effect of resveratrol on acoustic trauma: electron microscopy study

Abstract

OBJECTIVE: To investigate the potential preventive effect of resveratrol in rats exposed to acoustic trauma (AT). MATERIALS AND METHODS: In this experimental study, Wistar albino rats were divided into three groups: Group 1 (Control, n = 6), Group 2 (AT, n = 6), and Group 3 (resveratrol + AT). The rats in Group 2 were exposed to AT. The rats in Group 3 received resveratrol (300 mg/kg/day) via gavage for 7 days. On day 7, the rats were exposed to AT 10 min following resveratrol treatment. Histological sections of the cochleae were examined using light microscopy, transmission (TEM), and scanning electron microscopy (SEM). RESULTS: The cochlear hair cells, stereocilia, and Deiters' cells of the control group appeared normal in all microscopic evaluations. In Group 2, light microscopy revealed predominantly inner hair cell loss, although the outer hair cells were affected. TEM and SEM examination showed severe loss of stereocilia and SEM revealed stereocilia arranged in an asymmetric array. The cochlear structure in Group 3 appeared well preserved under the light microscope, and although TEM and SEM revealed stereocilia loss, the hair cells and stereocilia appeared near normal compared with those of Group 2. CONCLUSIONS: Resveratrol may have a protective effect against AT damage in the cochlea, most likely through its antioxidant activity. Our results may be useful for studies in humans exposed to AT and noise-induced hearing loss related to chronic exposure to occupational noise.