(−)‐Epigallocatechin‐3‐Gallate Ameliorates Photodynamic Therapy Responses in an In Vitro T Lymphocyte Model

• DOI: 10.1002/ptr.5152
• Publication Date: 2014-04-04T03:22:38Z
• Authors: Hang Qi; Naomi Abe; Beiwei Zhu; Yoshiyuki Murata; Yoshimasa Nakamura
• Keywords: Jurkat cells; Gallate

(-)-Epigallocatechin-3-gallate (EGCG), the most abundant polyphenolic constituent in green tea, is known as a powerful antioxidant but concomitantly possesses prooxidant property. We investigated effect of EGCG on phloxine B (PhB)-induced photocytotoxicity human T lymphocytic leukemia Jurkat cells. significantly potentiated PhB-induced photocytotoxic effects, including inhibition cell proliferation, DNA fragmentation, and caspase-3 activity induction Catalase attenuated enhanced cytotoxicity by EGCG, suggesting involvement extracellularly produced hydrogen peroxide. Indeed, extracellular peroxide formation induced photo-irradiated PhB. The also intracellular reactive oxygen species accumulation, c-Jun N-terminal kinase (JNK) phosphorylation, interferon-γ (IFN-γ) gene expression, all which are involved apoptosis. Taken together, our data suggest that capable potentiating photodynamic therapy responses, presumably through oxidative stress-sensitive JNK/IFN-γ pathway exogenous formation.