Research article

BMC Complementary and Alternative Medicine

, 12:142

Open Access This content is freely available online to anyone, anywhere at any time.

Anti-proliferative effect of methanolic extract of Gracilaria tenuistipitata on oral cancer cells involves apoptosis, DNA damage, and oxidative stress

  • Chi-Chen YehAffiliated withGraduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University
  • , Jing-Iong YangAffiliated withDepartment of Seafood Science, National Kaohsiung Marine University
  • , Jin-Ching LeeAffiliated withDepartment of Biotechnology, Kaohsiung Medical University
  • , Chao-Neng TsengAffiliated withGraduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical UniversityDepartment of Biomedical Science and Environmental Biology, Kaohsiung Medical University
  • , Ya-Ching ChanAffiliated withDepartment of Biomedical Science and Environmental Biology, Kaohsiung Medical University
  • , You-Cheng HseuAffiliated withDepartment of Cosmeceutics, College of Pharmacy, China Medical University
  • , Jen-Yang TangAffiliated withDepartment of Radiation Oncology, Faculty of Medicine, College of Medicine, Kaohsiung Medical UniversityDepartment of Radiation Oncology, Kaohsiung Medical University Hospital
  • , Li-Yeh ChuangAffiliated withDepartment of Chemical Engineering, I-Shou University
  • , Hurng-Wern HuangAffiliated withInstitute of Biomedical Science, National Sun Yat-Sen University
    • , Fang-Rong ChangAffiliated withGraduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University Email author 
    • , Hsueh-Wei ChangAffiliated withGraduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical UniversityDepartment of Biomedical Science and Environmental Biology, Kaohsiung Medical UniversityCenter of Excellence for Environmental Medicine, Cancer Center, Kaohsiung Medical University Hospital, Kaohsiung Medical University Email author 

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).

Keywords

Red algae Oral cancer Apoptosis γ-H2AX ROS Mitochondrial membrane potential Glutathione