Isolation and characterization of light-dependent hemolytic cytotoxin from harmful red tide phytoplankton Chattonella marina

Aiko Kuroda, Takuji Nakashima, Kenichi Yamaguchi, Tatsuya Oda*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

46 Citations (Scopus)


Chattonella marina (C. marina), a raphidophycean flagellate, is a causative organism of red tide, and highly toxic to fish. In this study, we found that the cell-free methanol extract prepared from this flagellate exhibited potent hemolytic activity against rabbit erythrocytes. Interestingly, the hemolytic activity of the extract was absolutely light-dependent, and no hemolytic activity was detected in the dark even at very high concentration. Gel filtration chromatography of the methanol extract on a column of Sephadex LH-20 revealed that the extract contained hemagglutinin as well as hemolytic agents, and the substances responsible for these activities were separately eluted. These results suggest that the hemagglutinating and hemolytic activities were derived from distinct compounds. The hemolytic fraction obtained after gel filtration (F4) caused marked inhibition of the growth of C. marina itself and other species of phytoplanktons. Furthermore, F4 showed a potent cytotoxicity toward various mammalian cultured cell lines including human tumor cells (HeLa cells) in a dose-dependent manner. The cytotoxicity was also light-dependent, and no cytotoxic effect was exhibited in any cell lines tested in the dark. After further purification procedures via preparative thin-layer chromatography and subsequent HPLC, a major hemolytic agent was obtained as highly purified form. Since the methanol extracts prepared from other raphidophycean flagellates such as Heterosigma akashiwo, Olisthodiscus luteus, and Fibrocapsa japonica showed light-dependent hemolytic activity toward rabbit erythrocytes, it was suggested that the light-dependent hemolytic agents commonly exist at least in these raphidophycean flagellates.

Original languageEnglish
Pages (from-to)297-305
Number of pages9
JournalComparative biochemistry and physiology. C, Comparative pharmacology and toxicology
Issue number3
Publication statusPublished - 2005 Jul
Externally publishedYes


  • Chattonella marina
  • Cytotoxin
  • Hemolysin
  • Pheophorbide a
  • Photodynamic therapy
  • Photosensitizer
  • Phytoplankton
  • Raphidophycean flagellate
  • Red tide

ASJC Scopus subject areas

  • Biochemistry
  • Physiology
  • Toxicology
  • Cell Biology
  • Health, Toxicology and Mutagenesis


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