title: Anti-proliferative effect of methanolic extract of Gracilaria tenuistipitata on oral cancer cells involves apoptosis, DNA damage, and oxidative stress.
abstract: BACKGROUND
  Methanolic extracts of Gracilaria tenuistipitata (MEGT) were obtained from the edible red algae. Previously, we found that water extract of G. tenuistipitata was able to modulate oxidative stress-induced DNA damage and its related cellular responses.
  
  
  METHODS
  In this study, the methanol extraction product MEGT was used to evaluate the cell growth inhibition in oral cancer cells and its possible mechanism was investigated.
  
  
  RESULTS
  The cell viability of MEGT treated Ca9-22 oral cancer cell line was significantly decreased in a dose-response manner (p < 0.05). The sub-G1 population and annexin V intensity of MEGT-treated Ca9-22 cancer cells were significantly increased in a dose-response manner (p < 0.0005 and p < 0.001, respectively). The γH2AX intensities of MEGT-treated Ca9-22 cancer cells were significantly increased in a dose-response manner (p < 0.05). The reactive oxygen species (ROS) and glutathione (GSH)-positive intensities of MEGT-treated Ca9-22 oral cancer cells were significantly increased and decreased, respectively, in a dose-response manner (p < 0.05). The DiOC2(3) intensity for mitochondrial membrane potential (MMP) of MEGT-treated Ca9-22 cancer cells was significantly decreased in a dose-response manner (p < 0.05).
  
  
  CONCLUSIONS
  These results indicated that MEGT had apoptosis-based cytotoxicity against oral cancer cells through the DNA damage, ROS induction, and mitochondrial depolarization. Therefore, MEGT derived from the edible algae may have potential therapeutic effects against oral squamous cell carcinoma (OSCC).
authors.affiliation: Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chi-Chen
authors.initials: CC
authors.lastname: Yeh
authors.forename: Jing-Iong
authors.initials: JI
authors.lastname: Yang
authors.forename: Jin-Ching
authors.initials: JC
authors.lastname: Lee
authors.forename: Chao-Neng
authors.initials: CN
authors.lastname: Tseng
authors.forename: Ya-Ching
authors.initials: YC
authors.lastname: Chan
authors.forename: You-Cheng
authors.initials: YC
authors.lastname: Hseu
authors.forename: Jen-Yang
authors.initials: JY
authors.lastname: Tang
authors.forename: Li-Yeh
authors.initials: LY
authors.lastname: Chuang
authors.forename: Hurng-Wern
authors.initials: HW
authors.lastname: Huang
authors.forename: Fang-Rong
authors.initials: FR
authors.lastname: Chang
authors.forename: Hsueh-Wei
authors.initials: HW
authors.lastname: Chang
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004249:DNA Damage / Q000187:drug effects*; D044724:Gracilaria / Q000737:chemistry*; D006131:Growth Inhibitors / Q000494:pharmacology*; D006801:Humans; D009062:Mouth Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology*; D018384:Oxidative Stress / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology*
chemical_list: D006131:Growth Inhibitors; D010936:Plant Extracts