Effect of Moderate Intensity Noise Exposure on the Cochlea of Adult Male Guinea Pig and the Possible Protective Role of Pravastatin: Histological and Immunohistochemical Study

Abstract

Hearing impairment is a rapidly growing healthcare issue worldwide, which has a profound impact on an individual’s quality of life. Excessive exposure to noise causes damage to the auditory system and results in hearing loss, termed noise induced hearing loss (NIHL). Hence, a significant effort has been made to understand the pathophysiological mechanisms of noise-induced cell death in the cochlea as well as to develop interventions in order to reduce or prevent NIHL. Most of these studies extensively documented the damaging effects of high intensity acoustic overexposures on the cochlea, while only few researches were conducted to evaluate the dangers of moderate intensity noise exposure. Moderate intensity noise is a common problem today in the workplace, entertainment areas, and streets. So far, there is no effective treatment for NIHL. Oxidative stress might be one of the mechanisms of NIHL Therefore, antioxidant mechanisms can probably reduce it. Drugs from different families have been used for this purpose. Among antioxidants, statins have also been proposed as efficacious drugs for prevention of NIHL. Different kinds of statins are currently used as cholesterol-lowering agents, though they have other effects on the body independent of this effect. Recently, they have attracted even more attention due to their antioxidant, anti-inflammatory, anti-ischemic, and blood-brain barrier repairing effects which are known as the pleotropic effects of statins.