title: Screening compounds of Chinese medicinal herbs anti-Marek's disease virus.
abstract: BACKGROUND
  Marek's disease (MD) seriously threatens the world poultry industry and has resulted in great economic losses. Chinese medicinal herbs are a rich source for lead compounds and drug candidates for antiviral treatments.
  
  
  OBJECTIVE
  To investigate the anti-MDV activity and mechanism of 20 compounds extracted from Chinese medicinal herbs.
  
  
  METHODS
  Antiviral assay, time of addition experiments, and virucidal assay were performed on chicken embryo fibroblast cells. The 50% cytotoxic concentration and 50% effective concentration were determined and, accordingly, selectivity index and inhibition ratio were calculated.
  
  
  RESULTS
  Antiviral assay showed dipotassium glycyrrhizinate (DG) and sodium tanshinone IIA sulfonate (STS) exhibited significantly inhibitory activity against MDV in a dose-dependent manner. EC50 of DG and STS were 893.5 ± 36.99 µg/mL and 54.82 ± 2.99 µg/mL, and selective index (SI) were >3.36 and >9.12, respectively. Time of addition experiment and virucidal assay demonstrated DG inhibited viral replication in the full replication cycle and inactivated MDV particles in non-time-dependent manner, but STS interfered with the early stage of MDV replication and inactivated MDV particles in a time-dependent manner. Moreover, both DG and STS promoted apoptosis of cells infected by MDV.
  
  
  CONCLUSIONS
  DG and STS have great potential for developing new anti-MDV drugs for clinic application.
authors.affiliation: College of Animal Science and Veterinary Medicine, Shanxi Agricultural University , Taigu, Shanxi , PR China .
authors.forename: Yaogui
authors.initials: Y
authors.lastname: Sun
authors.forename: Li
authors.initials: L
authors.lastname: Niu
authors.forename: Meiqin
authors.initials: M
authors.lastname: Song
authors.forename: Xin
authors.initials: X
authors.lastname: Zhao
authors.forename: Na
authors.initials: N
authors.lastname: Sun
authors.forename: Junping
authors.initials: J
authors.lastname: He
authors.forename: Caihong
authors.initials: C
authors.lastname: Wu
authors.forename: Junbing
authors.initials: J
authors.lastname: Jiang
authors.forename: Yuansheng
authors.initials: Y
authors.lastname: Bai
authors.forename: Jianhua
authors.initials: J
authors.lastname: Guo
authors.forename: Hongquan
authors.initials: H
authors.lastname: Li
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002478:Cells, Cultured; D002642:Chick Embryo; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000737:chemistry* / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000821:virology; D019695:Glycyrrhizic Acid / Q000302:isolation & purification / Q000494:pharmacology*; D008381:Herpesvirus 2, Gallid / Q000187:drug effects* / Q000502:physiology; D010616:Phenanthrenes / Q000302:isolation & purification / Q000494:pharmacology*; D012997:Solvents / Q000737:chemistry; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D004365:Drugs, Chinese Herbal; D010616:Phenanthrenes; D012997:Solvents; C024894:tanshinone II A sodium sulfonate; D019695:Glycyrrhizic Acid
keywords: Antiviral; MDV; apoptosis; dipotassium glycyrrhizinate; sodium tanshinone IIA sulfonate