Herbal medicine "sho-saiko-to" induces in vitro granulocyte colony-stimulating factor production on peripheral blood mononuclear cells.

The herbal medicine "Sho-saiko-to (Xiao-Chai-Hu-Tang)" has been used in China for about 3000 years for the treatment of pyretic diseases. This medicine is now available as one of the prescribing drugs approved by the Ministry of Health and Welfare of Japan, and has also been widely used for patients with chronic viral liver disease as one of biological response modifiers in the field of Japan's Western Medicine. However, its mode of action has not been fully described. In the present in vitro study, we added "Sho-saiko-to" (TJ-9, Tsumura, Tokyo) to the culture of peripheral blood mononuclear cells (PBMC) obtained from healthy volunteers, and observed a dose-dependent increase in the production of granulocyte colony-stimulating factor (G-CSF). The same experiment was conducted using other herbal medicines "Dai-saiko-to" (TJ-8) and "Saiko-keishi-to" (TJ-10) which showed similar effects, or "Sho-seiryu-to" (TJ-19) which consists of very different compounds and shows different efficacy. The increases of G-CSF production were similar when "Sho-saiko-to" (TJ-9) or one of the 2 reference drugs (TJ-8 and 10) was added, whereas the increase when the control drug "Sho-seiryu-to" (TJ-19) was added, was quite small. This result shows that G-CSF induction is not a common effect of herbal medicines, but a specific effect of TJ-8, 9, and 10. Among these 3 drugs the increase produced by "Sho-saiko-to" was the largest. Based on this result, we conclude that administration of "Sho-saiko-to" may be useful not only for the treatment of chronic liver disease, but also for malignant diseases and acute infectious diseases where G-CSF is efficacious.