Preventive effect of a traditional herbal medicine, Hochu-ekki-to, on immunosuppression induced by surgical stress.

PURPOSE: To examine the effect of preoperative administering of a Japanese traditional herbal medicine, Hochu-ekki-to (TJ-41), on immunosuppression induced by surgical stress in patients with gastrointestinal malignancies. METHODS: To monitor the immune functions, the mitochondrial membrane potential (MMP) and natural killer (NK) cell activity prior to and following operation were measured in peripheral blood lymphocytes (PBL) in patients with (n = 20) or without (n = 27) the preoperative administering of TJ-41 for 7 days. The plasma catecholamine and interleukin (IL)-6 levels were also analyzed prior to and following the operation. RESULTS: The numbers of MMP-high CD56-positive cells (NK cells) and NK cell activities in the TJ-41-treated group were significantly higher than those in the control group (P = 0.026 and P = 0.037, respectively). An elevation of plasma noradrenaline and IL-6 following surgery was also inhibited by the preoperative administering of TJ-41 (P = 0.023 and P = 0.039, respectively). A positive correlation between MMP-high CD56-positive cell numbers and NK cell activity in PBL treated with carbonyl cyanide m-chlorophenyl hydrazone (CCCP) in vitro suggested that MMP measurement in CD56-positive cells can serve as a convenient alternative to evaluate the NK cell activity. CONCLUSION: Our findings suggest that the preoperative administering of TJ-41 prevents surgical stress-induced immunosuppression by maintaining the NK cell activity and inhibiting the elevation of stress mediators.

n-Propyl gallate activates hypoxia-inducible factor 1 by modulating intracellular oxygen-sensing systems.

HIF-1 (hypoxia-inducible factor 1) is a master regulator of cellular adaptive responses to hypoxia. The expression and transcriptional activity of the HIF-1alpha subunit is stringently controlled by intracellular oxygen tension through the action of prolyl and asparaginyl hydroxylases. In the present study we demonstrate that PG (n-propyl gallate) activates HIF-1 and expression of its downstream target genes under normoxic conditions in cultured cells and in mice. The stability and transcriptional activity of HIF-1alpha are increased by PG. PG treatment inhibits the interaction between HIF-1alpha and VHL (von Hippel-Lindau protein) and promotes the interaction between HIF-1alpha and p300, indicating that PG inhibits the activity of both prolyl and asparaginyl HIF-1alpha hydroxylases. We conclude that PG activates HIF-1 and enhances the resultant gene expression by directly affecting the intracellular oxygen sensing system in vitro and in vivo and that PG represents a lead compound for the development of a non-toxic activator of HIF-1.

CD4+CD25+ regulatory T cells in patients with gastrointestinal malignancies: possible involvement of regulatory T cells in disease progression.

BACKGROUND: Active suppression by CD4+CD25+ regulatory T cells plays an important role in the down-regulation of the response of T cells to foreign and self antigens. Experimental tumor models in mice revealed that regulatory T cells inhibit antitumor immune responses. The purpose of the current study was to demonstrate the possible involvement of CD4+CD25+ regulatory T cells in immune system impairment in patients with gastrointestinal malignancies. METHODS: The phenotypes of lymphocytes, particularly those of CD4+CD25+ T cells, were analyzed in peripheral blood in 149 patients with gastrointestinal malignancies and in ascites in 7 patients with peritoneal dissemination. In addition, cytokine production after in vitro stimulation was examined in CD4+CD25+ and CD4+CD25- T cells isolated from patients with malignant disease. RESULTS: Compared with healthy volunteers, patients with gastrointestinal malignancies had a higher proportion of CD4+CD25+ T cells in peripheral blood, due to the presence of a drastically smaller number of CD4+CD25- T cells. Among patients with gastric carcinoma, those with higher percentages of CD4+CD25+ T cells had a poorer prognosis than did those with lower percentages. CD4+CD25+ T cells also were present in greater proportions in ascites from patients who had advanced-stage disease with peritoneal dissemination. Isolated CD4+CD25+ T cells from patients with malignant disease produced interleukin (IL)-4 and IL-10 but not IL-2 or interferon-gamma; these cells also inhibited cytokine production by CD4+CD25- T cells after in vitro stimulation. CONCLUSIONS: The relative increase in CD4+CD25+ regulatory T cells may be related to immunosuppression and tumor progression in patients with gastrointestinal malignancies. This finding suggests that the use of immunomodulatory therapy to treat patients with gastrointestinal malignancies may be an effective strategy.