title: The inhibitory effect of honokiol, a natural plant product, on vestibular schwannoma cells.
abstract: OBJECTIVE
  As the molecular biology of vestibular schwannoma (VS) is better understood, new means of targeting the pathways involved for intervention in schwannoma cells are being developed. Honokiol, a bioactive constituent of Magnolia officinalis, has attracted attention due to its diverse biological effects. This study was conducted to determine the inhibitory effect of honokiol on schwannoma cell proliferation.
  
  
  METHODS
  HEI 193 cells were used to investigate the growth-inhibitory effects of honokiol. Cell proliferation was assessed by MTT assays. Apoptosis was measured by flow cytometry analysis and immunofluorescence staining including Hoechst 33342 and TUNEL. Western blot analysis was used to assess the potential inhibition of extracellular signal-regulated kinase (ERK) and AKT signaling by honokiol.
  
  
  RESULTS
  Honokiol exhibited significant antiproliferative activity in a dose-dependent manner on HEI 193 cells. Significant apoptosis was detected on schwannoma cells with 7 mg/mL(IC50) honokiol. Western blot analysis showed significant inhibition of ERK phosphorylation.
  
  
  CONCLUSIONS
  Honokiol, a low molecular weight natural product, inhibits cell proliferation and promotes apoptosis in schwannoma cells by targeting the ERK pathway. Our data suggest that honokiol can be evaluated as a chemotherapeutic agent for VS.
authors: Department of Otorhinolaryngology-Head and Neck Surgery, Soonchunhyang University College of Medicine, Bucheon, Korea.
authors: Jong Dae
authors: JD
authors: Lee
authors: Jae Yong
authors: JY
authors: Lee
authors: Byoung Joon
authors: BJ
authors: Baek
authors: Byung Don
authors: BD
authors: Lee
authors: Yoon Woo
authors: YW
authors: Koh
authors: Won-Sang
authors: WS
authors: Lee
authors: Yu-Jin
authors: YJ
authors: Lee
authors: Byoung-Mog
authors: BM
authors: Kwon
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D001713:Biphenyl Compounds / Q000627:therapeutic use*; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D017705:Lignans / Q000627:therapeutic use*; D009464:Neuroma, Acoustic / Q000188:drug therapy* / Q000473:pathology; D014407:Tumor Cells, Cultured; D000498:Allyl Compounds; D010636:Phenols
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D001713:Biphenyl Compounds; D017705:Lignans; C005499:honokiol; D000498:Allyl Compounds; D010636:Phenols