2002 Volume 90 Issue 4 Pages 328-336
The clinical effectiveness of the Kampo medicine Sho-seiryu-to (SST) has recently been demonstrated in a double-blind randomized study of allergic asthma and rhinitis. We investigated the effect of SST on a type 1 allergic model in mice. Ovalbumin (OVA)-induced sneezing and the total and OVA-specific IgE levels were significantly suppressed with SST at 1.0 g/kg, but that of OVA-specific IgG2a was not. In the splenocytes isolated from SST-administered mice, OVA-induced interleukin (IL)-4 production decreased while interferon (IFN)-γ production was not. The co-culture experiments using purified CD4+T cells and antigen-presenting cells (APCs) suggested that SST influenced both cell types. Flow-cytometric analysis showed that SST suppressed the number of IL-4 producing CD4+T cells but not the number of IFN-γ producing CD4+T cells. The CD86+ major histocompatibility complex class II+ (MHC II)+ cells and CD28+CD4+T cells were decreased by SST treatment, while CD80+MHC II+ cells, CD40+MHC II+ cells and CD154+CD4+T cells showed no change. These data suggested that SST may suppress IL-4 production in CD4+T cells via influencing CD28-CD86 interaction. In addition to the previously reported inhibitory activity on histamine release, suppression of Th2 differentiation at the stage of APC-CD4+T cell interaction may be involved in the anti-allergic effects of SST.