Noise induced hearing loss etiology of curcuma longa ( curcumin ) in investigation of the effect

Objective: Noise is the most important reason of acquired hearing loss leading to permanent hearing loss. Although noise-induced hearing loss (NIHL) can be prevented by reduction of noise at the source or by personal protection materials, excessive number of patients with NIHL dispute the effectiveness and efficiency of these methods. Considering the current literature on the subject to understand the mechanism of noise-induced hearing loss and to protect the inner ear from noise and focus on the identification of agents, we encountered in the literature are not yet efficient method. The aim of this study was to evaluate the otoprotection efficacy of Curcumin against noise induced hearing loss in a rat animal model. Material & Method: Fourty-two adult male albino Wistar rats divided into two categories including exposed to noise and not exposed to noise. We created not exposed to noise groups which are saline, dimethyl sulfoxide(DMSO), curcumin groups and also exposed to noise groups including saline, DMSO, curcumin groups. These six groups were administered equal dose (200 mg/kg) by way of intraperitoneally. 21 rats were exposed to 120 dB SPL octave band noise centred at 4 kHz for 4 h. The hearing level of all animals was evaluated with auditory brainstem responses (ABR) at 4, 8, 12, 16 and 32 kHz octave frequencies. ABRs were measured before and after noise exposed at 1st day, 7th, and 10th days. On day 10, after latest ABR measurement, all animals were sacrificed. Results: ABR results at all frequencies demonstrate that the Curcumin group showed more reduced threshold shifts when compared with SS and DMSO group. These shifts were significantly different (p< 0.05). Conclusion: These results indicate that Curcumin may be useful as a potential post-exposure candidate therapy for NIHL as an antioxidant. Key Words: Noise Induced Hearing Loss, Noise Exposure, Curcumin, Antioxidant