Phenotypic and functional maturation of murine dendritic cells (DCs) induced by purified Glycyrrhizin (GL)

The aim of this study is to investigate phenotypic and functional modulation of murine dendritic cells (DCs) with use of purified Glycyrrhizin (GL). These impacts of GL on DCs both from bone marrow derived DCs and established DC cell 2.4 were assessed with conventional scanning electron microscopy (SEM), flow cytometry (FCM), transmission electron microscopy (TEM), cytochemistry assay, FITC-dextran, bio-assay and enzyme linked immunosorbent assay (ELISA). We found that the purified GL induced phenotypic maturation as evidenced by increased expression of CD86, CD40, CD80, CD83 and major histocompatibility complex II (MHC II). The functional tests showed the activity of acidic phosphatase (ACP) inside the DCs2.4 cells were down- regulated after treatment with GL (which occurs when phagocytosis of DCs2.4 cells were decreased). Finally, we proved that GL increased the production of IL-12, IL-10 and decreased the production of tumor necrosis factor alpha (TNF-α). These data indicated that GL could promote maturation of DCs and this adjuvant-like activity may have potential therapeutic value. It is therefore concluded that GL could exert positive modulation on murine DCs.

► GL could markedly induce both morphological and functional maturation of DCs and functions.
► GL could markedly up-regulate expression of key surface molecules, which will trigger a chain of immune responses.
► GL could markedly increase production of cytokine IL-12, which will trigger Th1 response.