Panax Notoginseng Saponin Controls IL-17 Expression in Helper T Cells.

PURPOSE: Panax Notoginseng, a traditional Chinese medicine, is known as an anti-inflammatory herb. However, the molecular mechanism by which it controls helper T cell mediated immune responses is largely unknown. METHODS: Naive CD4(+) T cells isolated from healthy donors, patients with Behcet's disease, and C57BL/6 mice were polarized into Th1, Th17, and Treg cells. Proliferation and cytokine expression were measured in these cells with the presence or absence of Panax Notoginseng saponins (PNS). Genomewide expression profiles of Th1, Th17, and Treg cells were assessed using Affymetrix microarray analysis. RESULTS: We found that PNS control the proliferation and differentiation of Th17 cells by globally downregulating the expression of inflammatory cytokines and cell cycle genes. CONCLUSIONS: These findings demonstrated that PNS function as an anti-inflammatory agent through directly targeting Th17 cell mediated immune response.