Astragaloside IV inhibits apoptotic cell death in the guinea pig cochlea exposed to impulse noise.
CONCLUSIONS
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.
Department of Otolaryngology, General Hospital of PLA Guangzhou Command, China. dr_xiong@163.com
Min
M
Xiong
Qinglian
Q
He
Huangwen
H
Lai
Jian
J
Wang
D000447:Aldehydes / Q000378:metabolism; D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects*; D003051:Cochlea / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D004195:Disease Models, Animal; D004365:Drugs, Chinese Herbal; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects; D005500:Follow-Up Studies; D006168:Guinea Pigs; D006317:Hearing Loss, Noise-Induced / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D007150:Immunohistochemistry; D009622:Noise / Q000009:adverse effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012503:Saponins / Q000627:therapeutic use*; D016896:Treatment Outcome; D014315:Triterpenes / Q000627:therapeutic use*
D000447:Aldehydes; D004365:Drugs, Chinese Herbal; D017382:Reactive Oxygen Species; D012503:Saponins; D014315:Triterpenes; C052064:astragaloside A; D053148:Caspase 3; C027576:4-hydroxy-2-nonenal