Astragaloside IV inhibits apoptotic cell death in the guinea pig cochlea exposed to impulse noise

Conclusion: The results suggest that the beneficial effect of astragaloside IV on impulse noise-induced hearing loss may be due to its ability to inhibit reactive oxygen species (ROS) and prevent apoptosis. Objective: Astragaloside IV is the major active constituent of Astragalus membranaceus, which has been widely used for the treatment of diseases in China for its antioxidant properties. ROS and apoptosis are involved in damage induced by impulse noise trauma. We aimed to investigate if the beneficial effects of astragaloside IV on cochlea exposed to impulse noise are associated with the inhibition of ROS and the decrease in apoptosis. Methods: 4-Hydroxynonenal (HNE) was used as the marker of ROS. Active-caspase−3 (cas-3) served as a marker for apoptosis. 4HNE and cas-3 were determined immunohistochemically. Guinea pigs in the experimental group were administered astragaloside IV intragastrically. Auditory thresholds were assessed by sound-evoked auditory brainstem response (ABR) 72 h before and after exposure to impulse noise. Results: The results showed that astragaloside IV significantly reduced ABR deficits, and decreased the expression of ROS and cas-3.