title: Xiao-Qing-Long-Tang (Sho-seiryu-to) inhibited cytopathic effect of human respiratory syncytial virus in cell lines of human respiratory tract.
abstract: BACKGROUND
  Xiao-Qing-Long-Tang (XQLT, TJ-19, Sho-seiryu-to, so-cheong-ryong-tang) has been used against acute airway diseases for thousands of year in ancient China. Most of the acute airway illnesses are caused by virus. However, without activity against influenza virus, XQLT has been questioned to manage respiratory tract viral infection. Nevertheless, XQLT might be active against airway viruses other than influenza. Human respiratory syncytial virus (HRSV) is one of the most common respiratory viral pathogens without effective management. However, it is unknown whether XQLT has anti-HRSV activity.
  
  
  OBJECTIVE
  We tested the hypothesis that XQLT can effectively minimize HRSV-induced plaque formation in respiratory tract mucosal cell lines.
  
  
  METHODS
  Anti-HRSV activity of a hot water extract of XQLT was examined by plaque reduction assay in both human upper (HEp-2) and low (A549) respiratory tract cell lines. Its effects on syncytial formation and viral fusion (F) protein were examined directly by microscopy and by western blot, respectively. Ability of XQLT to stimulate IFN-β was evaluated by enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  Hot water extract of XQLT dose-dependently inhibited HRSV-induced plaque formation in both HEp-2 and A549 cells (P<0.0001), particularly when given before viral inoculation (p<0.0001). XQLT inhibited viral attachment (p<0.0001) and internalization (p<0.0001). 300μg/ml XQLT could decrease both the number and the size of HRSV-induced syncytium without clear effect on the production of viral F protein. XQLT could stimulate epithelial cells to secrete IFN-β before and after viral inoculation to counteract viral infection (p<0.0001).
  
  
  CONCLUSIONS
  XQLT is effective against HRSV infection on airway epithelia by preventing viral attachment, internalization, syncytial formation, and by stimulating interferon secretion.
authors.affiliation: Department of Renal Care, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Jung San
authors.initials: JS
authors.lastname: Chang
authors.forename: Chia Feng
authors.initials: CF
authors.lastname: Yeh
authors.forename: Kuo Chih
authors.initials: KC
authors.lastname: Wang
authors.forename: Den En
authors.initials: DE
authors.lastname: Shieh
authors.forename: Ming Hong
authors.initials: MH
authors.lastname: Yen
authors.forename: Lien Chai
authors.initials: LC
authors.lastname: Chiang
mesh_terms: D000998:Antiviral Agents / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D006801:Humans; D016899:Interferon-beta / Q000378:metabolism; D018357:Respiratory Syncytial Virus Infections / Q000378:metabolism / Q000821:virology; D018113:Respiratory Syncytial Virus, Human / Q000187:drug effects* / Q000502:physiology; D012137:Respiratory System / Q000821:virology; D010948:Viral Plaque Assay; D053585:Virus Attachment / Q000187:drug effects; D053586:Virus Internalization / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D004365:Drugs, Chinese Herbal; C090832:sho-seiryu-to; D016899:Interferon-beta