Involvement of intracellular oxidative stress-sensitive pathway in phloxine B-induced photocytotoxicity in human T lymphocytic leukemia cells

Hang Qi, Beiwei Zhu, Naomi Abe, Yuko Shin, Yoshiyuki Murata, Yoshimasa Nakamura

Research output: Contribution to journalArticle

9 Citations (Scopus)


We investigated the molecular mechanisms underlying phloxine B (PhB)-induced photocytotoxicity in human T lymphocytic leukemia Jurkat cells. In addition to apoptosis-related biochemical events, photo-irradiated PhB generated intracellular reactive oxygen species (ROS), induced phosphorylation of c-Jun- N-terminal kinase (JNK) in an oxidative stress-dependent manner and up-regulated the gene expression of interferon (IFN)-γ, an inducer of diverse apoptosis-related molecules in activated T cells. PhB-induced apoptosis was significantly inhibited by N-acetyl-l-cysteine, but not by catalase, indicating that ROS generation occurred intracellularly, and by SP600125 and AG490, specific inhibitors of JNK and IFN-γ signaling, respectively, confirming their roles in the apoptotic pathway. IFN-γ up-regulation was also inhibited by SP600125, indicating that it was downstream of JNK activation. These results suggest that PhB-induced apoptosis in Jurkat cells partially involves the intracellular oxidative stress-sensitive and T cell-specific IFN-γ pathway. These data present a novel insight into the mechanisms of photocytotoxicity induced by artificial food colorants in human T lymphocytic leukemia cells.

Original languageEnglish
Pages (from-to)1841-1847
Number of pages7
JournalFood and Chemical Toxicology
Issue number6
Publication statusPublished - Jun 1 2012



  • IFN-γ
  • JNK
  • Jurkat cells
  • Phloxine B
  • Photocytotoxicity

ASJC Scopus subject areas

  • Food Science
  • Toxicology

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