Si-jun-zi-tang regulate granulocyte macrophage colony-stimulating factor secretion by human peripheral blood mononuclear cells.

Si-Jun-Zi-Tang is one of the widely used Chinese herbal medicines. In this study, human peripheral blood monocytes were treated in vitro with 50% hot ethanol extract of Si-Jun-Zi-Tang and its four major ingredients (Dangshen, Baizhu, Gancao and Fuling). The concentration of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the culture supernatant at 3 hours and 18 hours were measured using an ELISA. Dangshen and Gancao significantly suppressed GM-CSF secretion in a dose-dependent manner. Baizhu showed no statistically significant effect on GM-CSF secretion 18 hours after in vitro drug-treatment. Fuling, by contrast, significantly augmented GM-CSF secretion in a dose-dependent manner after 18 hours of drug treatment. Si-Jun-Zi-Tang showed a suppressive effect on GM-CSF secretion at 3 hours but significantly augmented GM-CSF secretion when the cells were treated with 8 mg/ml of the drug for 18 hours. The data suggested that Si-Jun-Zi-Tang might modulate hematopoiesis and immune response via regulating GM-CSF secretion, and the presence of Fuling in Si-Jun-Zi-Tang could counteract the suppressive effect of Dangshen and Gancao on GM-CSF secretion.