title: Plumbagin suppresses tumor cell growth in oral squamous cell carcinoma cell lines.
abstract: OBJECTIVE
  Plumbagin (PL), a naturally occurring quinoid, exerts antitumoral effects in diverse types of cancer cells. However, the effect of PL on tumor cell proliferation in oral squamous cell carcinoma (OSCC) remains poorly understood. In this study, we assessed the efficacy of PL, in human OSCC cells.
  
  
  METHODS
  The effect of PL on the cell growth and apoptosis of OSCC cell lines was evaluated using MTT and Annexin V assays, respectively. The effect of PL on mitochondrial membrane potential loss and reactive oxygen species (ROS) generation was evaluated using flow cytometry analysis.
  
  
  RESULTS
  MTT assay showed that PL dose-dependently suppressed OSCC cell growth, with IC50 values ranging from 3.87 to 14.6 μM. Flow cytometry analysis revealed that PL treatment resulted in a significant decrease in mitochondrial membrane potential and an increase in the number of apoptotic cells. Notably, ROS generation was significantly elevated after PL treatment. Furthermore, a ROS scavenger, N-acetylcysteine (NAC), clearly suppressed the decrease in mitochondrial membrane potential, increase of caspase-3/7 activity, and apoptosis after PL treatment.
  
  
  CONCLUSIONS
  This study provides the considerable evidence of the tumor-suppressive effect of PL, thereby highlighting its therapeutic potential for OSCC treatment.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Aichi Medical University Hospital, Nagakute, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ono
authors.forename: A
authors.initials: A
authors.lastname: Ota
authors.forename: K
authors.initials: K
authors.lastname: Ito
authors.forename: T
authors.initials: T
authors.lastname: Nakaoka
authors.forename: S
authors.initials: S
authors.lastname: Karnan
authors.forename: H
authors.initials: H
authors.lastname: Konishi
authors.forename: A
authors.initials: A
authors.lastname: Furuhashi
authors.forename: T
authors.initials: T
authors.lastname: Hayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Yamada
authors.forename: Y
authors.initials: Y
authors.lastname: Hosokawa
authors.forename: Y
authors.initials: Y
authors.lastname: Kazaoka
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D009062:Mouth Neoplasms / Q000188:drug therapy* / Q000473:pathology; D009285:Naphthoquinones / Q000494:pharmacology*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D009285:Naphthoquinones; C014758:plumbagin
keywords: anti-cancer drug; apoptosis; oral squamous cell carcinoma; plumbagin; reactive oxygen species