title: Sargassum horneri methanol extract rescues C2C12 murine skeletal muscle cells from oxidative stress-induced cytotoxicity through Nrf2-mediated upregulation of heme oxygenase-1.
abstract: BACKGROUND
  Sargassum horneri, an edible marine brown alga, is typically distributed along the coastal seas of Korea and Japan. Although several studies have demonstrated the anti-oxidative activity of this alga, the regulatory mechanisms have not yet been defined. The aim of the present study was to examine the cytoprotective effects of S. horneri against oxidative stress-induced cell damage in C2C12 myoblasts.
  
  
  METHODS
  We demonstrated the anti-oxidative effects of a methanol extract of S. horneri (SHME) in a hydrogen peroxide (H2O2)-stimulated C2C12 myoblast model. Cytotoxicity was determined using the 3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyl-tetrazolium assay and mode of cell death by cell cycle analysis. DNA damage was measured using a comet assay and expression of phospho-histone γH2A.X (p-γH2A.X). Levels of cellular oxidative stress as reactive oxygen species (ROS) accumulation were measured using 2',7'-dichlorofluorescein diacetate. The involvement of selected genes in the oxidative stress-mediated signaling pathway was explored using Western blot analysis.
  
  
  RESULTS
  SHME attenuated H2O2-induced growth inhibition and exhibited scavenging activity against intracellular ROS that were induced by H2O2. The SHME also inhibited comet tail formation, p-γH2A.X expression, and the number of sub-G1 hypodiploid cells, suggesting that it prevents H2O2-induced cellular DNA damage and apoptotic cell death. Furthermore, the SHME significantly enhanced the expression of heme oxygenase-1 (HO-1) associated with induction of nuclear factor-erythroid 2 related factor 2 (Nrf2) in a time- and concentration-dependent manner. Moreover, the protective effect of the SHME on H2O2-induced C2C12 cell damage was significantly abolished by zinc protoporphyrin IX, a HO-1 competitive inhibitor, in C2C12 cells.
  
  
  CONCLUSIONS
  These findings suggest that the SHME augments cellular antioxidant defense capacity through both intrinsic free radical scavenging activity and activation of the Nrf2/HO-1 pathway, protecting C2C12 cells from H2O2-induced oxidative cytotoxicity.
authors: Blue-Bio Industry RIC, Dongeui University, Busan, 614-714, Republic of Korea. 13839@deu.ac.kr.
authors: Ji Sook
authors: JS
authors: Kang
authors: Department of Microbiology, College of Medicine, Inje University, Busan, 608-737, Republic of Korea. cihima@inje.ac.kr.
authors: Il-Whan
authors: IW
authors: Choi
authors: Anti-Aging Research Center, Dongeui University, Busan, 614-714, Republic of Korea. alsgh0615@lycos.co.kr.
authors: Min Ho
authors: MH
authors: Han
authors: Department of Biochemistry, Dongeui University College of Korean Medicine, Busan, 614-052, Republic of Korea. hongsh@deu.ac.kr.
authors: Su Hyun
authors: SH
authors: Hong
authors: Team for Scientification of Korean Medical Intervention (BK21 Plus) and Department of Herbal Pharmacology, College of Korean Medicine, Daegu Haany University, Daegu, 706-828, Republic of Korea. sokim@dhu.ac.kr.
authors: Sung Ok
authors: SO
authors: Kim
authors: Laboratory of Immunobiology, Department of Marine Life Sciences, Jeju National University, Jeju, 690-756, Republic of Korea. immunkim@cheju.ac.kr.
authors: Gi-Young
authors: GY
authors: Kim
authors: Blue-Bio Industry RIC, Dongeui University, Busan, 614-714, Republic of Korea. hhj2001@deu.ac.kr.|Anti-Aging Research Center, Dongeui University, Busan, 614-714, Republic of Korea. hhj2001@deu.ac.kr.|Department of Food and Nutrition, College of Natural Sciences & Human Ecology, Dongeui University, Busan, 614-714, Republic of Korea. hhj2001@deu.ac.kr.
authors: Hye Jin
authors: HJ
authors: Hwang
authors: Blue-Bio Industry RIC, Dongeui University, Busan, 614-714, Republic of Korea. bwkim@deu.ac.kr.|Anti-Aging Research Center, Dongeui University, Busan, 614-714, Republic of Korea. bwkim@deu.ac.kr.|Department of Life Science and Biotechnology, College of Natural Sciences & Human Ecology, Dongeui University, Busan, 614-714, Republic of Korea. bwkim@deu.ac.kr.
authors: Byung Woo
authors: BW
authors: Kim
authors: Division of Meridian and Structural Medicine, School of Korean Medicine, Pusan National University, Yangsan, 626-870, Republic of Korea. choibt@pusan.ac.kr.
authors: Byung Tae
authors: BT
authors: Choi
authors: Department of Biochemistry, Busan National University College of Medicine, Yangsan, 626-870, Republic of Korea. kimcm@pusan.ac.kr.
authors: Cheol Min
authors: CM
authors: Kim
authors: Blue-Bio Industry RIC, Dongeui University, Busan, 614-714, Republic of Korea. choiyh@deu.ac.kr.|Anti-Aging Research Center, Dongeui University, Busan, 614-714, Republic of Korea. choiyh@deu.ac.kr.|Department of Biochemistry, Dongeui University College of Korean Medicine, Busan, 614-052, Republic of Korea. choiyh@deu.ac.kr.
authors: Yung Hyun
authors: YH
authors: Choi
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001688:Biological Products / Q000494:pharmacology*; D004249:DNA Damage / Q000187:drug effects; D051547:Heme Oxygenase-1 / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D007564:Japan; D051379:Mice; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D032448:Myoblasts, Skeletal / Q000187:drug effects; D051267:NF-E2-Related Factor 2 / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D056910:Republic of Korea; D044647:Sargassum; D015398:Signal Transduction / Q000187:drug effects; D015533:Transcriptional Activation; D015854:Up-Regulation
chemical_list: D000975:Antioxidants; D001688:Biological Products; D051267:NF-E2-Related Factor 2; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D051547:Heme Oxygenase-1
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