title: Astragaloside IV attenuates impulse noise-induced trauma in guinea pig.
abstract: CONCLUSIONS
  These results suggest that the beneficial effect of astragaloside IV on impulse noise-induced hearing loss may be due to its ability to inhibit inducible nitric oxide synthase (iNOS) and prevent the formation of reactive nitrogen species (RNS).
  
  
  OBJECTIVE
  Astragaloside IV is the major active constituent of Astragalus membranaceus, which has been widely used for the treatment of diseases in China due to its antioxidant properties. iNOS and RNS are involved in damage induced by impulse noise trauma. The purpose of the present study was to investigate if astragaloside IV has the potential to reduce cochlear damage from impulse noise.
  
  
  METHODS
  Guinea pigs in the experimental group were administered astragaloside IV intragastrically. Auditory thresholds were assessed by sound-evoked auditory brainstem response (ABR) at click and tone bursts of 8, 16 and 32 kHz, 72 h before and after exposure to impulse noise. iNOS and nitrotyrosine were determined immunohistochemically. Hair cell damage was analyzed by scanning electron microscopy.
  
  
  RESULTS
  Astragaloside IV significantly reduced ABR deficits, reduced hair cell damage, and decreased the expression of iNOS and RNS formation.
authors.affiliation: Department of Otolaryngology, General Hospital of PLA Guangzhou Command, Liu Hua Road 111, Guangzhou, China. dr_xiong@163.com
authors.forename: Min
authors.initials: M
authors.lastname: Xiong
authors.forename: Huangwen
authors.initials: H
authors.lastname: Lai
authors.forename: Qinglian
authors.initials: Q
authors.lastname: He
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001309:Auditory Threshold / Q000187:drug effects; D004195:Disease Models, Animal; D004365:Drugs, Chinese Herbal; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects*; D006168:Guinea Pigs; D006317:Hearing Loss, Noise-Induced / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism; D012503:Saponins / Q000008:administration & dosage*; D016896:Treatment Outcome; D014315:Triterpenes / Q000008:administration & dosage*
chemical_list: D004365:Drugs, Chinese Herbal; D017382:Reactive Oxygen Species; D012503:Saponins; D014315:Triterpenes; C052064:astragaloside A; D052247:Nitric Oxide Synthase Type II