title: Glossogyne tenuifolia(Hsiang-ju) extract suppresses T cell activation by inhibiting activation of c-Jun N-terminal kinase.
abstract: BACKGROUND
  Glossogyne tenuifolia(GT) (Hsiang-ju) is a Chinese herbal medicine previously exhibited an anti-inflammatory activity. This study aimed to investigate the effect of GT ethanol extract (GTE) on T cell-mediated adaptive immunity.
  
  
  METHODS
  Human peripheral blood mononuclear cells (PBMCs) and Jurkat T cells were activated by phytohemagglutinin in the presence of various doses (3.13-50 μg/mL) of GTE. The effect of GTE on T cell activation was examined by a proliferation assay of activated PBMCs and the level of the activation marker CD69 on the surface of activated Jurkat T cells. Apoptosis was determined by propidium iodide staining in hypotonic solution. Signaling pathway molecules were assessed by western blotting.
  
  
  RESULTS
  Glossogyne tenuifoliaethanol extract was demonstrated to inhibit T cell activation, not only in the proliferation of human PBMCs at the concentrations of 12.5, 25 and 50 μg/mL (P= 0.0118, 0.0030 and 0.0021) but also in the CD69 expression in Jurkat cells, which was not due to the cytotoxicity of GTE. The presence of GTE did not change the activity of nuclear factor kappa-light-chain-enhancer of activated B cells or extracellular signal-regulated kinase upon T cell activation. In addition, GTE significantly reduced activation of c-Jun N-terminal kinase (JNK) (P= 0.0167) and p38 (P= 0.0278). Furthermore, decreased JNK activation mediated the preventive effect of GTE on T cell activation-induced cell death (AICD).
  
  
  CONCLUSIONS
  Glossogyne tenuifoliaethanol extract inhibited T cell activation of Jurkat cells and freshly prepared human PBMCs due to suppression of JNK activity. Furthermore, GTE inhibited AICD by blocking prolonged JNK phosphorylation in activated T cells. Taken together, the anti-inflammatory effects exerted by GTE were mediated via suppression of JNK phosphorylation in T cell activation.
authors.affiliation: Department of Nutrition, I-Shou University, No.8, Yida Rd., Yanchao District, Kaohsiung City, 82445 Taiwan.
authors.forename: Jer-Yiing
authors.initials: JY
authors.lastname: Houng
authors.affiliation: Department of Medical Research, E-Da Hospital, Kaohsiung City, 82445 Taiwan.|School of Medicine for International Students, I-Shou University, Kaohsiung City, 82445 Taiwan.
authors.forename: Tzong-Shyuan
authors.initials: TS
authors.lastname: Tai
authors.affiliation: National Institute of Infectious Diseases and Vaccinology, NHRI, Miaoli County, 35053 Taiwan.|Department of Medical Research, Show-Chwan Memorial Hospital, Changhua County, 50008 Taiwan.
authors.forename: Shu-Ching
authors.initials: SC
authors.lastname: Hsu
authors.affiliation: Department of Nutrition, I-Shou University, No.8, Yida Rd., Yanchao District, Kaohsiung City, 82445 Taiwan.
authors.forename: Hsia-Fen
authors.initials: HF
authors.lastname: Hsu
authors.affiliation: Graduate Institute of Biotechnology, Chinese Culture University, Taipei City, 11114 Taiwan.
authors.forename: Tzann-Shun
authors.initials: TS
authors.lastname: Hwang
authors.affiliation: Department of Leisure and Recreation Management, Da-Yeh University, Changhua County, 51591 Taiwan.
authors.forename: Chih-Jiun
authors.initials: CJ
authors.lastname: Lin
authors.affiliation: Department of Nutrition, I-Shou University, No.8, Yida Rd., Yanchao District, Kaohsiung City, 82445 Taiwan.
authors.forename: Li-Wen
authors.initials: LW
authors.lastname: Fang