Enhanced production of hematopoietic growth factors through T cell activation in Peyer's patches by oral administration of Kampo (Japanese herbal) medicine, "Juzen-Taiha-To".

The effects of Juzen-Taiho-To (JTT), a Kampo (Japanese herbal) medicine, on Peyer's patch cells mediated hematopoietic response were investigated. When the conditioned medium of Peyer's patch cells obtained from C3H/HeJ mice, which had orally administered JTT for 7 consecutive days, was added to the culture medium for bone marrow cells, the cells significantly proliferated compared with that of mice receiving water alone. Oral administration of JTT for 7 days increased the population of activated T cells in Peyer's patch. The mechanism of Peyer's patch cells mediated proliferation was investigated in vitro. When Peyer's patch cells from untreated C3H/HeJ mice were stimulated with various concentrations of JTT, and the resulting conditioned medium was used for stimulation of bone marrow cells, the cells were proliferated in a dose dependent manner. The contents of granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-6 (IL-6) in the conditioned medium from JTT stimulated Peyer's patch cells were increased compared with those from controls, and the population of Gr-l antigen positive cells in the bone marrow cell cultures also increased. These results demonstrate that orally administered JTT can activate T-cells in Peyer's patch cells and enhance the production of colony stimulating factor(s), in which at least GM-CSF and IL-6 may partly contribute to this activity.